WorldWideScience

Sample records for include cassini inputs

  1. Cassini at Saturn Huygens results

    CERN Document Server

    Harland, David M

    2007-01-01

    "Cassini At Saturn - Huygens Results" will bring the story of the Cassini-Huygens mission and their joint exploration of the Saturnian system right up to date. Cassini is due to enter orbit around Saturn on the 1 July 2004 and the author will have 8 months of scientific data available for review, including the most spectacular images of Saturn, its rings and satellites ever obtained by a space mission. As the Cassini spacecraft approached its destination in spring 2004, the quality of the images already being returned by the spacecraft clearly demonstrate the spectacular nature of the close-range views that will be obtained. The book will contain a 16-page colour section, comprising a carefully chosen selection of the most stunning images to be released during the spacecraft's initial period of operation. The Huygens craft will be released by Cassini in December 2004 and is due to parachute through the clouds of Saturn's largest moon, Titan, in January 2005.

  2. NASA 3D Models: Cassini

    Data.gov (United States)

    National Aeronautics and Space Administration — Cassini spacecraft from SPACE rendering package, built by Michael Oberle under NASA contract at JPL. Includes orbiter only, Huygens probe detached. Accurate except...

  3. Cassini's Grand Finale Overview

    Science.gov (United States)

    Spilker, L. J.

    2017-12-01

    After 13 years in orbit, the Cassini-Huygens Mission to Saturn ended in a science-rich blaze of glory. Cassini sent back its final bits of unique science data on September 15, 2017, as it plunged into Saturn's atmosphere, vaporizing and satisfying planetary protection requirements. Cassini's final phase covered roughly ten months and ended with the first time exploration of the region between the rings and planet. In late 2016 Cassini transitioned to a series of 20 Ring Grazing orbits with peripases just outside Saturn's F ring, providing close flybys of tiny ring moons, including Pan, Daphnis and Atlas, and high-resolution views of Saturn's A and F rings. A final Titan flyby in late April 2017 propelled Cassini across Saturn's main rings and into its Grand Finale orbits. Comprised of 22 orbits, Cassini repeatedly dove between Saturn's innermost rings and upper atmosphere to answer fundamental questions unattainable earlier in the mission. The last orbit turned the spacecraft into the first Saturn atmosphere probe. The Grand Finale orbits provided highest resolution observations of both the rings and Saturn, and in-situ sampling of the ring particle composition, Saturn's atmosphere, plasma, and innermost radiation belts. The gravitational field was measured to unprecedented accuracy, providing information on the interior structure of the planet, winds in the deeper atmosphere, and mass of the rings. The magnetic field provided insight into the physical nature of the magnetic dynamo and structure of the internal magnetic field. The ion and neutral mass spectrometer sampled the upper atmosphere for molecules that escape the atmosphere in addition to molecules originating from the rings. The cosmic dust analyzer directly sampled the composition from different parts of the main rings for the first time. Fields and particles instruments directly measured the plasma environment between the rings and planet. Science highlights and new mysteries collected in the Grand

  4. Input-output linearizing tracking control of induction machine with the included magnetic saturation

    DEFF Research Database (Denmark)

    Dolinar, Drago; Ljusev, Petar; Stumberger, Gorazd

    2003-01-01

    The tracking control design of an induction motor, based on input-output linearisation with magnetic saturation included is addressed. The magnetic saturation is represented by a nonlinear magnetising curve for the iron core and is used in the control, the observer of the state variables......, and in the load torque estimator. An input-output linearising control is used to achieve better tracking performances. It is based on the mixed 'stator current - rotor flux linkage' induction motor model with magnetic saturation considered in the stationary reference frame. Experimental results show...... that the proposed input-output linearising tracking control with saturation included behaves considerably better than the one without saturation, and that it introduces smaller position and speed errors, and better motor stiffness on account of the increased computational complexity....

  5. CASSINI V/E/J/S/SS RPWS EDITED WAVEFORM FULL RES V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The Cassini Radio and Plasma Wave Science (RPWS) edited full resolution data set includes all waveform data for the entire Cassini mission. This data set includes...

  6. Environmental impact assessment including indirect effects--a case study using input-output analysis

    International Nuclear Information System (INIS)

    Lenzen, Manfred; Murray, Shauna A.; Korte, Britta; Dey, Christopher J.

    2003-01-01

    Environmental impact assessment (EIA) is a process covered by several international standards, dictating that as many environmental aspects as possible should be identified in a project appraisal. While the ISO 14011 standard stipulates a broad-ranging study, off-site, indirect impacts are not specifically required for an Environmental Impact Statement (EIS). The reasons for this may relate to the perceived difficulty of measuring off-site impacts, or the assumption that these are a relatively insignificant component of the total impact. In this work, we describe a method that uses input-output analysis to calculate the indirect effects of a development proposal in terms of several indicator variables. The results of our case study of a Second Sydney Airport show that the total impacts are considerably higher than the on-site impacts for the indicators land disturbance, greenhouse gas emissions, water use, emissions of NO x and SO 2 , and employment. We conclude that employing input-output analysis enhances conventional EIA, as it allows for national and international effects to be taken into account in the decision-making process

  7. An extended TRANSCAR model including ionospheric convection: simulation of EISCAT observations using inputs from AMIE

    Directory of Open Access Journals (Sweden)

    P.-L. Blelly

    2005-02-01

    Full Text Available The TRANSCAR ionospheric model was extended to account for the convection of the magnetic field lines in the auroral and polar ionosphere. A mixed Eulerian-Lagrangian 13-moment approach was used to describe the dynamics of an ionospheric plasma tube. In the present study, one focuses on large scale transports in the polar ionosphere. The model was used to simulate a 35-h period of EISCAT-UHF observations on 16-17 February 1993. The first day was magnetically quiet, and characterized by elevated electron concentrations: the diurnal F2 layer reached as much as 1012m-3, which is unusual for a winter and moderate solar activity (F10.7=130 period. An intense geomagnetic event occurred on the second day, seen in the data as a strong intensification of the ionosphere convection velocities in the early afternoon (with the northward electric field reaching 150mVm-1 and corresponding frictional heating of the ions up to 2500K. The simulation used time-dependent AMIE outputs to infer flux-tube transports in the polar region, and to provide magnetospheric particle and energy inputs to the ionosphere. The overall very good agreement, obtained between the model and the observations, demonstrates the high ability of the extended TRANSCAR model for quantitative modelling of the high-latitude ionosphere; however, some differences are found which are attributed to the precipitation of electrons with very low energy. All these results are finally discussed in the frame of modelling the auroral ionosphere with space weather applications in mind.

  8. An extended TRANSCAR model including ionospheric convection: simulation of EISCAT observations using inputs from AMIE

    Directory of Open Access Journals (Sweden)

    P.-L. Blelly

    2005-02-01

    Full Text Available The TRANSCAR ionospheric model was extended to account for the convection of the magnetic field lines in the auroral and polar ionosphere. A mixed Eulerian-Lagrangian 13-moment approach was used to describe the dynamics of an ionospheric plasma tube. In the present study, one focuses on large scale transports in the polar ionosphere. The model was used to simulate a 35-h period of EISCAT-UHF observations on 16-17 February 1993. The first day was magnetically quiet, and characterized by elevated electron concentrations: the diurnal F2 layer reached as much as 1012m-3, which is unusual for a winter and moderate solar activity (F10.7=130 period. An intense geomagnetic event occurred on the second day, seen in the data as a strong intensification of the ionosphere convection velocities in the early afternoon (with the northward electric field reaching 150mVm-1 and corresponding frictional heating of the ions up to 2500K. The simulation used time-dependent AMIE outputs to infer flux-tube transports in the polar region, and to provide magnetospheric particle and energy inputs to the ionosphere. The overall very good agreement, obtained between the model and the observations, demonstrates the high ability of the extended TRANSCAR model for quantitative modelling of the high-latitude ionosphere; however, some differences are found which are attributed to the precipitation of electrons with very low energy. All these results are finally discussed in the frame of modelling the auroral ionosphere with space weather applications in mind.

  9. Identifying Cassini's Magnetospheric Location Using Magnetospheric Imaging Instrument (MIMI) Data and Machine Learning

    Science.gov (United States)

    Vandegriff, J. D.; Smith, G. L.; Edenbaum, H.; Peachey, J. M.; Mitchell, D. G.

    2017-12-01

    We analyzed data from Cassini's Magnetospheric Imaging Instrument (MIMI) and Magnetometer (MAG) and attempted to identify the region of Saturn's magnetosphere that Cassini was in at a given time using machine learning. MIMI data are from the Charge-Energy-Mass Spectrometer (CHEMS) instrument and the Low-Energy Magnetospheric Measurement System (LEMMS). We trained on data where the region is known based on a previous analysis of Cassini Plasma Spectrometer (CAPS) plasma data. Three magnetospheric regions are considered: Magnetosphere, Magnetosheath, and Solar Wind. MIMI particle intensities, magnetic field values, and spacecraft position are used as input attributes, and the output is the CAPS-based region, which is available from 2004 to 2012. We then use the trained classifier to identify Cassini's magnetospheric regions for times after 2012, when CAPS data is no longer available. Training accuracy is evaluated by testing the classifier performance on a time range of known regions that the classifier has never seen. Preliminary results indicate a 68% accuracy on such test data. Other techniques are being tested that may increase this performance. We present the data and algorithms used, and will describe the latest results, including the magnetospheric regions post-2012 identified by the algorithm.

  10. Cassini data assessment report

    International Nuclear Information System (INIS)

    1998-08-01

    On October 15, 1997, the Cassini spacecraft was launched from Cape Canaveral Air Station (CCAS) and is now on its way to the planet Saturn. The functional support provided to NASA by DOE included the Advance Launch Support Group (ALSG). If there had been a launch anomaly, the ALSG would have provided a level of radiological emergency response support adequate to transition into a Federal Radiological Monitoring and Assessment Center (FRMAC). Additional functional radiological emergency response support, as part of the ALSG, included the: (1) Aerial Measurement System (AMS); (2) Atmospheric Release Advisory Capability (ARAC); (3) Geographic Information System (GIS); (4) Emergency Response Data System (ERDS); (5) Radiation Emergency Assistance Center and Training Site (REAC/TS); (6) Field monitoring and sampling; (7) Radioanalysis via RASCAL; (8) Source recovery; and (9) Neutron dosimetry and communications support. This functional support provided the capability to rapidly measure and assess radiological impacts from a launch anomaly. The Radiological Control Officer (RCO) on KSC established a Radiological Control Center (RADCC) as the focal point for all on-site and off-site radiological data and information flow. Scientists and radiological response personnel located at the RADCC managed the field monitoring team on the KSC/CCAS federal properties. Off-site radiological emergency response activities for all public lands surrounding the KSC/CCAS complex were coordinated through the Off-site ALSG located at the National Guard Armory in Cocoa, Florida. All of the in situ measurement data of good quality gathered during the dry run, the first launch attempt and the launch day are listed in this document. The RASCAL analysis results of the air filters and impactor planchets are listed

  11. Managing Cassini Safe Mode Attitude at Saturn

    Science.gov (United States)

    Burk, Thomas A.

    2010-01-01

    The Cassini spacecraft was launched on October 15, 1997 and arrived at Saturn on June 30, 2004. It has performed detailed observations and remote sensing of Saturn, its rings, and its satellites since that time. In the event safe mode interrupts normal orbital operations, Cassini has flight software fault protection algorithms to detect, isolate, and recover to a thermally safe and commandable attitude and then wait for further instructions from the ground. But the Saturn environment is complex, and safety hazards change depending on where Cassini is in its orbital trajectory around Saturn. Selecting an appropriate safe mode attitude that insures safe operation in the Saturn environment, including keeping the star tracker field of view clear of bright bodies, while maintaining a quiescent, commandable attitude, is a significant challenge. This paper discusses the Cassini safe table management strategy and the key criteria that must be considered, especially during low altitude flybys of Titan, in deciding what spacecraft attitude should be used in the event of safe mode.

  12. Titan after Cassini Huygens

    Science.gov (United States)

    Beauchamp, P. M.; Lunine, J.; Lebreton, J.; Coustenis, A.; Matson, D.; Reh, K.; Erd, C.

    2008-12-01

    In 2005, the Huygens Probe gave us a snapshot of a world tantalizingly like our own, yet frozen in its evolution on the threshold of life. The descent under parachute, like that of Huygens in 2005, is happening again, but this time in the Saturn-cast twilight of winter in Titan's northern reaches. With a pop, the parachute is released, and then a muffled splash signals the beginning of the first floating exploration of an extraterrestrial sea-this one not of water but of liquid hydrocarbons. Meanwhile, thousands of miles away, a hot air balloon, a "montgolfiere," cruises 6 miles above sunnier terrain, imaging vistas of dunes, river channels, mountains and valleys carved in water ice, and probing the subsurface for vast quantities of "missing" methane and ethane that might be hidden within a porous icy crust. Balloon and floater return their data to a Titan Orbiter equipped to strip away Titan's mysteries with imaging, radar profiling, and atmospheric sampling, much more powerful and more complete than Cassini was capable of. This spacecraft, preparing to enter a circular orbit around Saturn's cloud-shrouded giant moon, has just completed a series of flybys of Enceladus, a tiny but active world with plumes that blow water and organics from the interior into space. Specialized instruments on the orbiter were able to analyze these plumes directly during the flybys. Titan and Enceladus could hardly seem more different, and yet they are linked by their origin in the Saturn system, by a magnetosphere that sweeps up mass and delivers energy, and by the possibility that one or both worlds harbor life. It is the goal of the NASA/ESA Titan Saturn System Mission (TSSM) to explore and investigate these exotic and inviting worlds, to understand their natures and assess the possibilities of habitability in this system so distant from our home world. Orbiting, landing, and ballooning at Titan represent a new and exciting approach to planetary exploration. The TSSM mission

  13. Cassini Mission Sequence Subsystem (MSS)

    Science.gov (United States)

    Alland, Robert

    2011-01-01

    This paper describes my work with the Cassini Mission Sequence Subsystem (MSS) team during the summer of 2011. It gives some background on the motivation for this project and describes the expected benefit to the Cassini program. It then introduces the two tasks that I worked on - an automatic system auditing tool and a series of corrections to the Cassini Sequence Generator (SEQ_GEN) - and the specific objectives these tasks were to accomplish. Next, it details the approach I took to meet these objectives and the results of this approach, followed by a discussion of how the outcome of the project compares with my initial expectations. The paper concludes with a summary of my experience working on this project, lists what the next steps are, and acknowledges the help of my Cassini colleagues.

  14. Titan from Cassini-Huygens

    CERN Document Server

    Brown, Robert H; Waite, J. Hunter

    2010-01-01

    This book reviews our current knowledge of Saturn's largest moon Titan featuring the latest results obtained by the Cassini-Huygens mission. A global author team addresses Titan’s origin and evolution, internal structure, surface geology, the atmosphere and ionosphere as well as magnetospheric interactions. The book closes with an outlook beyond the Cassini-Huygens mission. Colorfully illustrated, this book will serve as a reference to researchers as well as an introduction for students.

  15. Cassini Tour Atlas Automated Generation

    Science.gov (United States)

    Grazier, Kevin R.; Roumeliotis, Chris; Lange, Robert D.

    2011-01-01

    During the Cassini spacecraft s cruise phase and nominal mission, the Cassini Science Planning Team developed and maintained an online database of geometric and timing information called the Cassini Tour Atlas. The Tour Atlas consisted of several hundreds of megabytes of EVENTS mission planning software outputs, tables, plots, and images used by mission scientists for observation planning. Each time the nominal mission trajectory was altered or tweaked, a new Tour Atlas had to be regenerated manually. In the early phases of Cassini s Equinox Mission planning, an a priori estimate suggested that mission tour designers would develop approximately 30 candidate tours within a short period of time. So that Cassini scientists could properly analyze the science opportunities in each candidate tour quickly and thoroughly so that the optimal series of orbits for science return could be selected, a separate Tour Atlas was required for each trajectory. The task of manually generating the number of trajectory analyses in the allotted time would have been impossible, so the entire task was automated using code written in five different programming languages. This software automates the generation of the Cassini Tour Atlas database. It performs with one UNIX command what previously took a day or two of human labor.

  16. Pilot monitoring program: geologic input for the hillslope component (includes a discussion of Caspar Creek geology and geomorphology)

    Science.gov (United States)

    T. E. Spittler

    1995-01-01

    The California Department of Conservation, Division of Mines and Geology (DMG) is submitting this report and accompanying maps to the California Department of Forestry and Fire Protection (CDF) to fulfill Interagency Agreement number 8CA38400, Pilot Monitoring Program -- Geologic Input for the Hillslope Component. Under this agreement, DMG has assisted CDF in the...

  17. The Cassini-Huygens mission

    CERN Document Server

    The joint NASA-ESA Cassini-Huygens mission promises to return four (and possibly more) years of unparalleled scientific data from the solar system’s most exotic planet, the ringed, gas giant, Saturn. Larger than Galileo with a much greater communication bandwidth, Cassini can accomplish in a single flyby what Galileo returned in a series of passes. Cassini explores the Saturn environment in three dimensions, using gravity assists to climb out of the equatorial plane to look down on the rings from above, to image the aurora and to study polar magnetospheric processes such as field-aligned currents. Since the radiation belt particle fluxes are much more benign than those at Jupiter, Cassini can more safely explore the inner regions of the magnetosphere. The spacecraft approaches the planet closer than Galileo could, and explores the inner moons and the rings much more thoroughly than was possible at Jupiter. This book is the second volume, in a three volume set, that describes the Cassini/Huygens mission. Thi...

  18. Input parameters and scenarios, including economic inputs

    DEFF Research Database (Denmark)

    Boklund, Anette; Hisham Beshara Halasa, Tariq

    2012-01-01

    scenarios, we excluded hobby-type farms1 In the vaccination scenarios, herds within the vaccination zone were simulated to be vaccinated 14 days after detection of the first herd or when 10, 20, 30 or 50 herds were infected. All herds within the zones were simulated to be vaccinated. We used vaccination...... zones of either a 1, 2, 3 or 5 km. In some scenarios, hobby herds were not vaccinated. In one scenario, no sheep were vaccinated, and in another scenario no swine were vaccinated. from depopulation in zones. The resources for depopulation were estimated to 4,800 swine and 2,000 ruminants a day...

  19. Cassini-Huygens Science Highlights: Surprises in the Saturn System

    Science.gov (United States)

    Spilker, Linda; Altobelli, Nicolas; Edgington, Scott

    2014-05-01

    The Cassini-Huygens mission has greatly enhanced our understanding of the Saturn system. Fundamental discoveries have altered our views of Saturn, its retinue of icy moons including Titan, the dynamic rings, and the system's complex magnetosphere. Launched in 1997, the Cassini-Huygens spacecraft spent seven years traveling to Saturn, arriving in July 2004, roughly two years after the northern winter solstice. Cassini has orbited Saturn for 9.5 years, delivering the Huygens probe to its Titan landing in 2005, crossing northern equinox in August 2009, and completing its Prime and Equinox Missions. It is now three years into its 7-year Solstice mission, returning science in a previously unobserved seasonal phase between equinox and solstice. As it watches the approach of northern summer, long-dark regions throughout the system become sunlit, allowing Cassini's science instruments to probe as-yet unsolved mysteries. Key Cassini-Huygens discoveries include icy jets of material streaming from tiny Enceladus' south pole, lakes of liquid hydrocarbons and methane rain on giant Titan, three-dimensional structures in Saturn's rings, and curtain-like aurorae flickering over Saturn's poles. The Huygens probe sent back amazing images of Titan's surface, and made detailed measurements of the atmospheric composition, structure and winds. Key Cassini-Huygens science highlights will be presented. The Solstice Mission continues to provide new science. First, the Cassini spacecraft observes seasonally and temporally dependent processes on Saturn, Titan, Enceladus and other icy satellites, and within the rings and magnetosphere. Second, it addresses new questions that have arisen during the mission thus far, for example providing qualitatively new measurements of Enceladus and Titan that could not be accommodated in the earlier mission phases. Third, it will conduct a close-in mission at Saturn yielding fundamental knowledge about the interior of Saturn. This grand finale of the

  20. Cassini Solstice Mission Maneuver Experience: Year Two

    Science.gov (United States)

    Arrieta, Juan; Ballard, Christopher G.; Hahn, Yungsun

    2012-01-01

    The Cassini Spacecraft was launched in October 1997 on a mission to observe Saturn and its moons; it entered orbit around Saturn in July 2004 for a nominal four-year Prime Mission, later augmented by two extensions: the Equinox Mission, from July 2008 through September 2010, and the Solstice Mission, from October 2010 through September 2017. This paper provides an overview of the maneuver activities from August 2011 through June 2012 which include the design of 38 Orbit Trim Maneuvers--OTM-288 through OTM-326-- for attaining 14 natural satellite encounters: seven with Titan, six with Enceladus, and one with Dione.

  1. Cassini's Grand Finale Science Highlights

    Science.gov (United States)

    Spilker, Linda

    2017-10-01

    After 13 years in orbit, the Cassini-Huygens Mission to Saturn ended in a science-rich blaze of glory. Cassini returned its final bits of unique science data on September 15, 2017, as it plunged into Saturn's atmosphere satisfying planetary protection requirements. Cassini's Grand Finale covered a period of roughly five months and ended with the first time exploration of the region between the rings and planet.The final close flyby of Titan in late April 2017 propelled Cassini across Saturn’s main rings and into its Grand Finale orbits; 22 orbits that repeatedly dove between Saturn’s innermost rings and upper atmosphere making Cassini the first spacecraft to explore this region. The last orbit turned the spacecraft into the first Saturn upper atmospheric probe.The Grand Finale orbits provided highest resolution observations of both the rings and Saturn, and in-situ sampling of the ring particle composition, Saturn's atmosphere, plasma, and innermost radiation belts. The gravitational field was measured to unprecedented accuracy, providing information on the interior structure of the planet, winds in the deeper atmosphere, and mass of the rings. The magnetic field provided insight into the physical nature of the magnetic dynamo and structure of the internal magnetic field. The ion and neutral mass spectrometer sampled the upper atmosphere for molecules that escape the atmosphere in addition to molecules originating from the rings. The cosmic dust analyzer directly sampled the composition from different parts of the main rings for the first time. Fields and particles instruments directly measured the plasma environment between the rings and planet.Science highlights and new mysteries gleaned to date from the Grand Finale orbits will be discussed.The research described in this paper was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. Copyright 2017

  2. Enhancing Cassini Operations & Science Planning Tools

    Science.gov (United States)

    Castello, Jonathan

    2012-01-01

    The Cassini team uses a variety of software utilities as they manage and coordinate their mission to Saturn. Most of these tools have been unchanged for many years, and although stability is a virtue for long-lived space missions, there are some less-fragile tools that could greatly benefit from modern improvements. This report shall describe three such upgrades, including their architectural differences and their overall impact. Emphasis is placed on the motivation and rationale behind architectural choices rather than the final product, so as to illuminate the lessons learned and discoveries made.These three enhancements included developing a strategy for migrating Science Planning utilities to a new execution model, rewriting the team's internal portal for ease of use and maintenance, and developing a web-based agenda application for tracking the sequence of files being transmitted to the Cassini spacecraft. Of this set, the first two have been fully completed, while the agenda application is currently in the early prototype stage.

  3. Cassini at Saturn: The Final Two Years

    Science.gov (United States)

    Spilker, L.; Edgington, S.; Altobelli, N.

    2015-10-01

    After 11 years in orbit, the Cassini-Huygens Mission to Saturn, a collaboration of NASA, ESA, and ASI, continues to wow the imagination and reveal unprecedented findings. Every year Cassini produces answers to questions raised by the Voyager flybys, while at the same time posing new questions that can only be answered with a long duration mission using a flagship-class spacecraft. Here we sample a few of Cassini's discoveries from the past year and give an overview of Cassini's final two years.

  4. Titan's Topography and Shape at the End of the Cassini Mission

    Science.gov (United States)

    Corlies, P.; Hayes, A. G.; Birch, S. P. D.; Lorenz, R.; Stiles, B. W.; Kirk, R.; Poggiali, V.; Zebker, H.; Iess, L.

    2017-12-01

    With the conclusion of the Cassini mission, we present an updated topographic map of Titan, including all the available altimetry, SARtopo, and stereophotogrammetry topographic data sets available from the mission. We use radial basis functions to interpolate the sparse data set, which covers only ˜9% of Titan's global area. The most notable updates to the topography include higher coverage of the poles of Titan, improved fits to the global shape, and a finer resolution of the global interpolation. We also present a statistical analysis of the error in the derived products and perform a global minimization on a profile-by-profile basis to account for observed biases in the input data set. We find a greater flattening of Titan than measured, additional topographic rises in Titan's southern hemisphere and better constrain the possible locations of past and present liquids on Titan's surface.

  5. CASSINI E/J/S/SW MIMI INCA SENSOR UNCALIBRATED DATA V1.1

    Data.gov (United States)

    National Aeronautics and Space Administration — The Cassini Magnetospheric Imaging Instrument(MIMI) Imaging Neutral Camera (INCA) uncalibrated data set includes all data collected from the MIMI Data Processing...

  6. CASSINI E/J/S/SW MIMI INCA SENSOR UNCALIBRATED DATA V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The Cassini Magnetospheric Imaging Instrument(MIMI) Imaging Neutral Camera (INCA) uncalibrated data set includes all data collected from the MIMI Data Processing...

  7. Cassini-Huygens maneuver automation for navigation

    Science.gov (United States)

    Goodson, Troy; Attiyah, Amy; Buffington, Brent; Hahn, Yungsun; Pojman, Joan; Stavert, Bob; Strange, Nathan; Stumpf, Paul; Wagner, Sean; Wolff, Peter; hide

    2006-01-01

    Many times during the Cassini-Huygens mission to Saturn, propulsive maneuvers must be spaced so closely together that there isn't enough time or workforce to execute the maneuver-related software manually, one subsystem at a time. Automation is required. Automating the maneuver design process has involved close cooperation between teams. We present the contribution from the Navigation system. In scope, this includes trajectory propagation and search, generation of ephemerides, general tasks such as email notification and file transfer, and presentation materials. The software has been used to help understand maneuver optimization results, Huygens probe delivery statistics, and Saturn ring-plane crossing geometry. The Maneuver Automation Software (MAS), developed for the Cassini-Huygens program enables frequent maneuvers by handling mundane tasks such as creation of deliverable files, file delivery, generation and transmission of email announcements, generation of presentation material and other supporting documentation. By hand, these tasks took up hours, if not days, of work for each maneuver. Automated, these tasks may be completed in under an hour. During the cruise trajectory the spacing of maneuvers was such that development of a maneuver design could span about a month, involving several other processes in addition to that described, above. Often, about the last five days of this process covered the generation of a final design using an updated orbit-determination estimate. To support the tour trajectory, the orbit determination data cut-off of five days before the maneuver needed to be reduced to approximately one day and the whole maneuver development process needed to be reduced to less than a week..

  8. Health Physics Innovations Developed During Cassini for Future Space Applications

    Science.gov (United States)

    Nickell, Rodney E.; Rutherford, Theresa M.; Marmaro, George M.

    1999-01-01

    The long history of space flight includes missions that used Space Nuclear Auxiliary Power devices, starting with the Transit 4A Spacecraft (1961), continuing through the Apollo, Pioneer, Viking, Voyager, Galileo, Ulysses, Mars Pathfinder, and most recently, Cassini (1997). All Major Radiological Source (MRS) missions were processed at Kennedy Space Center/Cape Canaveral Air Station (KSC/CCAS) Launch Site in full compliance with program and regulatory requirements. The cumulative experience gained supporting these past missions has led to significant innovations which will be useful for benchmarking future MRS mission ground processing. Innovations developed during ground support for the Cassini mission include official declaration of sealed-source classifications, utilization of a mobile analytical laboratory, employment of a computerized dosimetry record management system, and cross-utilization of personnel from related disciplines.

  9. Cassini: The Journey and the Legacy

    KAUST Repository

    Porco, Carolyn

    2018-01-01

    An international mission to explore, in depth, the Saturnian system ヨthe planet Saturn and its magnetosphere, glorious rings, and many moons- begun over 27 years ago. After seven years of development, the Cassini spacecraft was launched in 1997

  10. Cassini radar: Instrument description and performance status

    Science.gov (United States)

    Johnson, W. T. K.; Im, E.; Borgarelli, L.; ZampoliniFaustini, E.

    1995-01-01

    The spacecraft of the Cassini mission is planned to be launched towards Saturn in October 1997. The mission is designed to study the physical structure and chemical composition of Titan. The results of the tests performed on the Cassini radar engineering qualification model (EQM) are summarized. The approach followed in the verification and evaluation of the performance of the radio frequency subsystem EQM is presented. The results show that the instrument satisfies the most relevant mission requirements.

  11. SAR Ambiguity Study for the Cassini Radar

    Science.gov (United States)

    Hensley, Scott; Im, Eastwood; Johnson, William T. K.

    1993-01-01

    The Cassini Radar's synthetic aperture radar (SAR) ambiguity analysis is unique with respect to other spaceborne SAR ambiguity analyses owing to the non-orbiting spacecraft trajectory, asymmetric antenna pattern, and burst mode of data collection. By properly varying the pointing, burst mode timing, and radar parameters along the trajectory this study shows that the signal-to-ambiguity ratio of better than 15 dB can be achieved for all images obtained by the Cassini Radar.

  12. Saturn's Magnetic Field from the Cassini Grand Finale orbits

    Science.gov (United States)

    Dougherty, M. K.; Cao, H.; Khurana, K. K.; Hunt, G. J.; Provan, G.; Kellock, S.; Burton, M. E.; Burk, T. A.

    2017-12-01

    The fundamental aims of the Cassini magnetometer investigation during the Cassini Grand Finale orbits were determination of Saturn's internal planetary magnetic field and the rotation rate of the deep interior. The unique geometry of the orbits provided an unprecedented opportunity to measure the intrinsic magnetic field at close distances never before encountered. The surprising close alignment of Saturn's magnetic axis with its spin axis, known about since the days of Pioneer 11, has been a focus of the team's analysis since Cassini Saturn Orbit Insertion. However, the varying northern and southern magnetospheric planetary period oscillations, which fill the magnetosphere, has been a factor in masking the field signals from the interior. Here we describe an overview of the magnetometer results from the Grand Finale orbits, including confirmation of the extreme axisymmetric nature of the planetary magnetic field, implications for knowledge of the rotation rate and the behaviour of external magnetic fields (arising from the ring current, field aligned currents both at high and low latitudes and the modulating effect of the planetary period oscillations).

  13. Cassini: The Journey and the Legacy

    KAUST Repository

    Porco, Carolyn

    2018-01-15

    An international mission to explore, in depth, the Saturnian system ヨthe planet Saturn and its magnetosphere, glorious rings, and many moons- begun over 27 years ago. After seven years of development, the Cassini spacecraft was launched in 1997, spent seven years trekking to Saturn, and finally entered Saturn orbit in the summer of 2004. In the course of its 13 years orbiting this ring world, Cassini returned over 450 thousand images, 635GB of data, and invaluable insights on the solar systemメs most splendid and scientifically rich planetary system. In this lecture, Carolyn Porco, the leader of the imaging science team on NASA\\'s Cassini mission, will delight her audience with a retrospective look at what has been learned from this profoundly successful mission and what its final legacy is likely to be.

  14. Cassini-Huygens Nears Saturn Orbit Insertion

    Science.gov (United States)

    Showstack, Randy

    2004-06-01

    After nearly 7 years and a 3.5-billion-km, circuitous journey from Earth, the $3-billion Cassini-Huygens mission to Saturn and Titan-an international effort by NASA, the European Space Agency, and the Italian Space Agency-now is just days away from its critical Saturn orbit insertion. Scheduled for 30 June, this will begin the 4-years part of the mission to study the Saturnian system. At a 3 June briefing at NASA headquarters in Washington, D.C., Robert Mitchell, the Cassini program manager with the Jet Propulsion Laboratory in Pasadena, California, said that scientists involved with the program are feeling excited, relieved, and also a bit anxious as the Cassini-Huygens spacecraft draws near to the ringed planet and its system.

  15. Flight Path Control Design for the Cassini Solstice Mission

    Science.gov (United States)

    Ballard, Christopher G.; Ionasescu, Rodica

    2011-01-01

    The Cassini spacecraft has been in orbit around Saturn for just over 7 years, with a planned 7-year extension, called the Solstice Mission, which started on September 27, 2010. The Solstice Mission includes 205 maneuvers and 70 flybys which consist of the moons Titan, Enceladus, Dione, and Rhea. This mission is designed to use all available propellant with a statistical margin averaging 0.6 m/s per encounter, and the work done to prove and ensure the viability of this margin is highlighted in this paper.

  16. Modernization of the Cassini Ground System

    Science.gov (United States)

    Razo, Gus; Fujii, Tammy

    2014-01-01

    The Cassini Spacecraft and its ground system have been operational for over 16 years. Modernization presents several challenges due to the personnel, processes, and tools already invested and embedded into the current ground system structure. Every mission's ground system has its own unique complexities and challenges, involving various organizational units. As any mission from its inception to its execution, schedules are always tight. This forces GDS engineers to implement a working ground system that is not necessarily fully optimized. Ground system challenges increase as technology evolves and cyber threats become more sophisticated. Cassini's main challenges were due to its ground system existing before many security requirements were levied on the multi-mission tools and networks. This caused a domino effect on Cassini GDS tools that relied on outdated technological features. In the aerospace industry reliable and established technology is preferred over innovative yet less proven technology. Loss of data for a spacecraft mission can be catastrophic; therefore, there is a reluctance to make changes and updates to the ground system. Nevertheless, all missions and associated teams face the need to modernize their processes and tools. Systems development methods from well-known system analysis and design principles can be applied to many missions' ground systems. Modernization should always be considered, but should be done in such a way that it does not affect flexibility nor interfere with established practices. Cassini has accomplished a secure and efficient ground data system through periodic updates. The obstacles faced while performing the modernization of the Cassini ground system will be outlined, as well as the advantages and challenges that were encountered.

  17. TURTLE with MAD input (Trace Unlimited Rays Through Lumped Elements) -- A computer program for simulating charged particle beam transport systems and DECAY TURTLE including decay calculations

    Energy Technology Data Exchange (ETDEWEB)

    Carey, D.C.

    1999-12-09

    TURTLE is a computer program useful for determining many characteristics of a particle beam once an initial design has been achieved, Charged particle beams are usually designed by adjusting various beam line parameters to obtain desired values of certain elements of a transfer or beam matrix. Such beam line parameters may describe certain magnetic fields and their gradients, lengths and shapes of magnets, spacings between magnetic elements, or the initial beam accepted into the system. For such purposes one typically employs a matrix multiplication and fitting program such as TRANSPORT. TURTLE is designed to be used after TRANSPORT. For convenience of the user, the input formats of the two programs have been made compatible. The use of TURTLE should be restricted to beams with small phase space. The lumped element approximation, described below, precludes the inclusion of the effect of conventional local geometric aberrations (due to large phase space) or fourth and higher order. A reading of the discussion below will indicate clearly the exact uses and limitations of the approach taken in TURTLE.

  18. TURTLE with MAD input (Trace Unlimited Rays Through Lumped Elements) -- A computer program for simulating charged particle beam transport systems and DECAY TURTLE including decay calculations

    International Nuclear Information System (INIS)

    Carey, D.C.

    1999-01-01

    TURTLE is a computer program useful for determining many characteristics of a particle beam once an initial design has been achieved, Charged particle beams are usually designed by adjusting various beam line parameters to obtain desired values of certain elements of a transfer or beam matrix. Such beam line parameters may describe certain magnetic fields and their gradients, lengths and shapes of magnets, spacings between magnetic elements, or the initial beam accepted into the system. For such purposes one typically employs a matrix multiplication and fitting program such as TRANSPORT. TURTLE is designed to be used after TRANSPORT. For convenience of the user, the input formats of the two programs have been made compatible. The use of TURTLE should be restricted to beams with small phase space. The lumped element approximation, described below, precludes the inclusion of the effect of conventional local geometric aberrations (due to large phase space) or fourth and higher order. A reading of the discussion below will indicate clearly the exact uses and limitations of the approach taken in TURTLE

  19. Cassini-VIMS at Jupiter: Solar occultation measurements using Io

    Science.gov (United States)

    Formisano, V.; D'Aversa, E.; Bellucci, G.; Baines, K.H.; Bibring, J.-P.; Brown, R.H.; Buratti, B.J.; Capaccioni, F.; Cerroni, P.; Clark, R.N.; Coradini, A.; Cruikshank, D.P.; Drossart, P.; Jaumann, R.; Langevin, Y.; Matson, D.L.; McCord, T.B.; Mennella, V.; Nelson, R.M.; Nicholson, P.D.; Sicardy, B.; Sotin, Christophe; Chamberlain, M.C.; Hansen, G.; Hibbits, K.; Showalter, M.; Filacchione, G.

    2003-01-01

    We report unusual and somewhat unexpected observations of the jovian satellite Io, showing strong methane absorption bands. These observations were made by the Cassini VIMS experiment during the Jupiter flyby of December/January 2000/2001. The explanation is straightforward: Entering or exiting from Jupiter's shadow during an eclipse, Io is illuminated by solar light which has transited the atmosphere of Jupiter. This light, therefore becomes imprinted with the spectral signature of Jupiter's upper atmosphere, which includes strong atmospheric methane absorption bands. Intercepting solar light refracted by the jovian atmosphere, Io essentially becomes a "miffor" for solar occultation events of Jupiter. The thickness of the layer where refracted solar light is observed is so large (more than 3000 km at Io's orbit), that we can foresee a nearly continuous multi-year period of similar events at Saturn, utilizing the large and bright ring system. During Cassini's 4-year nominal mission, this probing tecnique should reveal information of Saturn's atmosphere over a large range of southern latitudes and times. ?? 2003 Elsevier Inc. All rights reserved.

  20. Jovian atmospheric dynamics: an update after Galileo and Cassini

    International Nuclear Information System (INIS)

    Vasavada, Ashwin R; Showman, Adam P

    2005-01-01

    The Galileo and Cassini spacecrafts have greatly enhanced the observational record of Jupiter's tropospheric dynamics, particularly through returning high spatial resolution, multi-spectral and global imaging data with episodic coverage over periods of months to years. These data, along with those from Earth-based telescopes, have revealed the stability of Jupiter's zonal jets, captured the evolution of vortices and equatorial waves, and mapped the distributions of lightning and moist convection. Because no observations of Jupiter's interior exist, a forward modelling approach has been used to relate observations at cloud level to models of shallow or deep jet structure, shallow or deep jet forcing and energy transfer between turbulence, vortices and jets. A range of observed phenomena can be reproduced in shallow models, though the Galileo probe winds and jet stability arguments hint at the presence of deep jets. Many deep models, however, fail to reproduce Jupiter-like non-zonal features (e.g. vortices). Jupiter's dynamics likely include both deep and shallow processes, requiring an integrated approach to future modelling-an important goal for the post-Galileo and Cassini era

  1. Characterization of Cassini GPHS fueled clad production girth welds

    International Nuclear Information System (INIS)

    Franco-Ferreira, E.A.; Moyer, M.W.; Reimus, M.A.H.; Placr, A.; Howard, B.D.

    2000-01-01

    Fueled clads for radioisotope power systems are produced by encapsulating 238 PuO 2 in iridium alloy cups, which are joined at their equators by gas tungsten arc welding. Cracking problems at the girth weld tie-in area during production of the Galileo/Ulysses GPHS capsules led to the development of a first-generation ultrasonic test for girth weld inspection at the Savannah River Plant. A second-generation test and equipment with significantly improved sensitivity and accuracy were jointly developed by the Oak Ridge Y-12 Plant and Westinghouse Savannah River Company for use during the production of Cassini GPHS capsules by the Los Alamos National Laboratory. The test consisted of Lamb wave ultrasonic scanning of the entire girth weld from each end of the capsule combined with a time-of-flight evaluation to aid in characterizing nonrelevant indications. Tangential radiography was also used as a supplementary test for further evaluation of reflector geometry. Each of the 317 fueled GP HS capsules, which were girth welded for the Cassini Program, was subjected to a series of nondestructive tests that included visual, dimensional, helium leak rate, and ultrasonic testing. Thirty-three capsules were rejected prior to ultrasonic testing. Of the 44 capsules rejected by the standard ultrasonic test, 22 were upgraded to flight quality through supplementary testing for an overall process acceptance rate of 82.6%. No confirmed instances of weld cracking were found

  2. Cassini Information Management System in Distributed Operations Collaboration and Cassini Science Planning

    Science.gov (United States)

    Equils, Douglas J.

    2008-01-01

    Launched on October 15, 1997, the Cassini-Huygens spacecraft began its ambitious journey to the Saturnian system with a complex suite of 12 scientific instruments, and another 6 instruments aboard the European Space Agencies Huygens Probe. Over the next 6 1/2 years, Cassini would continue its relatively simplistic cruise phase operations, flying past Venus, Earth, and Jupiter. However, following Saturn Orbit Insertion (SOI), Cassini would become involved in a complex series of tasks that required detailed resource management, distributed operations collaboration, and a data base for capturing science objectives. Collectively, these needs were met through a web-based software tool designed to help with the Cassini uplink process and ultimately used to generate more robust sequences for spacecraft operations. In 2001, in conjunction with the Southwest Research Institute (SwRI) and later Venustar Software and Engineering Inc., the Cassini Information Management System (CIMS) was released which enabled the Cassini spacecraft and science planning teams to perform complex information management and team collaboration between scientists and engineers in 17 countries. Originally tailored to help manage the science planning uplink process, CIMS has been actively evolving since its inception to meet the changing and growing needs of the Cassini uplink team and effectively reduce mission risk through a series of resource management validation algorithms. These algorithms have been implemented in the web-based software tool to identify potential sequence conflicts early in the science planning process. CIMS mitigates these sequence conflicts through identification of timing incongruities, pointing inconsistencies, flight rule violations, data volume issues, and by assisting in Deep Space Network (DSN) coverage analysis. In preparation for extended mission operations, CIMS has also evolved further to assist in the planning and coordination of the dual playback redundancy of

  3. The architecture of the Cassini division

    Science.gov (United States)

    Hedman, M.M.; Nicholson, P.D.; Baines, K.H.; Buratti, B.J.; Sotin, Christophe; Clark, R.N.; Brown, R.H.; French, R.G.; Marouf, E.A.

    2010-01-01

    The Cassini Division in Saturn's rings contains a series of eight named gaps, three of which contain dense ringlets. Observations of stellar occultations by the Visual and Infrared Mapping Spectrometer onboard the Cassini spacecraft have yielded 40 accurate and precise measurements of the radial position of the edges of all of these gaps and ringlets. These data reveal suggestive patterns in the shapes of many of the gap edges: the outer edges of the five gaps without ringlets are circular to within 1 km, while the inner edges of six of the gaps are eccentric, with apsidal precession rates consistent with those expected for eccentric orbits near each edge. Intriguingly, the pattern speeds of these eccentric inner gap edges, together with that of the eccentric Huygens Ringlet, form a series with a characteristic spacing of 006 day-1. The two gaps with non-eccentric inner edges lie near first-order inner Lindblad resonances (ILRs) with moons. One such edge is close to the 5:4 ILR with Prometheus, and the radial excursions of this edge do appear to have an m = 5 component aligned with that moon. The other resonantly confined edge is the outer edge of the B ring, which lies near the 2:1 Mimas ILR. Detailed investigation of the B-ring-edge data confirm the presence of an m = 2 perturbation on the B-ring edge, but also show that during the course of the Cassini Mission, this pattern has drifted backward relative to Mimas. Comparisons with earlier occultation measurements going back to Voyager suggest the possibility that the m = 2 pattern is actually librating relative to Mimas with a libration frequency L 006 day-1 (or possibly 012 day -1). In addition to the m = 2 pattern, the B-ring edge also has an m = 1 component that rotates around the planet at a rate close to the expected apsidal precession rate (?? ?? ?? B ??? 5.??06 day -1). Thus, the pattern speeds of the eccentric edges in the Cassini Division can be generated from various combinations of the pattern speeds

  4. Cassini Scientist for a Day: an international contest in Greece

    Science.gov (United States)

    Solomonidou, Anezina; Moussas, Xenophon; Xystouris, Georgios; Coustenis, Athena; Lebreton, Jean-Pierre; Katsavrias, Christos; Bampasidis, Georgios; Kyriakopoulos, Konstantinos; Kouloumvakos, Athanasios; Patsou, Ioanna

    2013-04-01

    The Cassini Outreach Team of NASA's Jet Propulsion Laboratory is being organizing a brilliant school contest in Astronomy focusing in the Saturnian system. This essay contest provides school students all around the worlds with the opportunity to get involved in astronomy and astrophysics and planetary sciences in particular. From 2010 the 'Cassini Scientist for a Day' contest has being one of the most successful as well as important outreach activities of ESA and NASA in Greece with hundreds of participants all over Greece. The number of participants is growing rapidly every year. This type of school competition in Greece is particularly important since Astronomy and Astrophysics and Space Sciences, although very popular, are not included in the school curricula and thus students rarely have the opportunity to experience and participate actively in these subjects. For the years 2010 and 2011, the Space Physics Group of the Astronomy, Astrophysics and Mechanics section of the University of Athens in association with external colleagues has been selected as the co-ordinator of NASA for the competition in Greece. Under the guidance of Cassini Outreach team, the members of the Space Physics Group have informed, explained and spread the rules of the competition at primary, secondary and high schools all over Greece. In general, the students have the option to choose Cassini monitoring between three targets of the Saturnian system, which the participants show that will bring the best scientific result. Their arguments should be summarized in an essay of 500 words more or less. They also have the option to do team work through groups of maximum three students. The participation in the contest for 2010 was unexpectedly high and thoroughly satisfied. The winners awarded through a ceremony which was held in the largest amphitheater at the central building of the University of Athens, that was fully packed. The following year 2011 the participation increased up to 300% while

  5. Titan's interior from Cassini-Huygens

    Science.gov (United States)

    Tobie, G.; Baland, R.-M.; Lefevre, A.; Monteux, J.; Cadek, O.; Choblet, G.; Mitri, G.

    2013-09-01

    The Cassini-Huygens mission has brought many informations about Titan that can be used to infer its interior structure: the gravity field coefficients (up to degree 3, [1]), the surface shape (up to degree 6, [2]), the tidal Love number [1], the electric field [3], and the orientation of its rotation axis [4]. The measured obliquity and gravity perturbation due to tides, as well as the electric field, are lines of evidence for the presence of an internal global ocean beneath the ice surface of Titan [5,1,3]. The observed surface shape and gravity can be used to further constrain the structure of the ice shell above the internal ocean. The presence of a significant topography associated with weak gravity anomalies indicates that deflections of internal interface or lateral density variations may exist to compensate the topography. To assess the sources of compensation, we consider interior models including interface deflections and/or density variations, which reproduces simultaneously the surface gravity and long-wavelength topography data [6]. Furthermore, in order to test the long-term mechanical stability of the internal mass anomalies, we compute the relaxation rate of each internal interface in response to surface mass load. We show that the topography can be explained either by defections of the ocean/ice interface or by density variations in an upper crust [6]. For non-perfectly compensated models of the outer ice shell, the present-day structure is stable only for a conductive layer above a relatively cold ocean (for bottom viscosity > 1016 Pa.s, T residual gravity anomalies. The existence of mass anomalies in the rocky core is a most likely explanation. However, as the observed geoid and topography are mostly sensitive to the lateral structure of the outer ice shell, no information can be retrieved on the ice shell thickness, ocean density and/or size of the rocky core. Constraints on these internal parameters can be obtained from the tidal Love number and

  6. Cassini's Test Methodology for Flight Software Verification and Operations

    Science.gov (United States)

    Wang, Eric; Brown, Jay

    2007-01-01

    The Cassini spacecraft was launched on 15 October 1997 on a Titan IV-B launch vehicle. The spacecraft is comprised of various subsystems, including the Attitude and Articulation Control Subsystem (AACS). The AACS Flight Software (FSW) and its development has been an ongoing effort, from the design, development and finally operations. As planned, major modifications to certain FSW functions were designed, tested, verified and uploaded during the cruise phase of the mission. Each flight software upload involved extensive verification testing. A standardized FSW testing methodology was used to verify the integrity of the flight software. This paper summarizes the flight software testing methodology used for verifying FSW from pre-launch through the prime mission, with an emphasis on flight experience testing during the first 2.5 years of the prime mission (July 2004 through January 2007).

  7. Modeling Saturn's Inner Plasmasphere: Cassini's Closest Approach

    Science.gov (United States)

    Moore, L.; Mendillo, M.

    2005-05-01

    Ion densities from the three-dimensional Saturn-Thermosphere-Ionosphere-Model (STIM, Moore et al., 2004) are extended above the plasma exobase using the formalism of Pierrard and Lemaire (1996, 1998), which evaluates the balance of gravitational, centrifugal and electric forces on the plasma. The parameter space of low-energy ionospheric contributions to Saturn's plasmasphere is explored by comparing results that span the observed extremes of plasma temperature, 650 K to 1700 K, and a range of velocity distributions, Lorentzian (or Kappa) to Maxwellian. Calculations are made for plasma densities along the path of the Cassini spacecraft's orbital insertion on 1 July 2004. These calculations neglect any ring or satellite sources of plasma, which are most likely minor contributors at 1.3 Saturn radii. Modeled densities will be compared with Cassini measurements as they become available. Moore, L.E., M. Mendillo, I.C.F. Mueller-Wodarg, and D.L. Murr, Icarus, 172, 503-520, 2004. Pierrard, V. and J. Lemaire, J. Geophys. Res., 101, 7923-7934, 1996. Pierrard, V. and J. Lemaire, J. Geophys. Res., 103, 4117, 1998.

  8. Cassini ISS Observation of Saturn from Grand Finale Orbits

    Science.gov (United States)

    Blalock, J. J.; Sayanagi, K. M.; Ingersoll, A. P.; Dyudina, U.; Ewald, S. P.; McCabe, R. M.; Garland, J.; Gunnarson, J.; Gallego, A.

    2017-12-01

    We present images captured during Cassini's Grand Finale orbits, and their preliminary analyses. During the final 22 orbits of the mission, the spacecraft is in orbits that have 6.5 day period at an inclination of 62 degrees, apoapsis altitude of about 1,272,000 km, and periapsis altitudes of about 2,500 km. Images captured during periapsis passes show Saturn's atmosphere at unprecedented spatial resolution. We present preliminary analyses of these images, including the final images captured before the end of the mission when the spacecraft enters Saturn's atmosphere on September 15th, 2017. Prominent features captured during the final orbits include the north polar vortex and other vortices as well as very detailed views of the "popcorn clouds" that reside between the Hexagon and the north pole. In the cloud field between zonal jets, clouds either resemble linear streaks suggestive of cirrus-like clouds or round shapes suggestive of vortices or cumulus anvil. The presence of linear streaks that follow lines of constant latitudes suggests that meridional mixing is inhibited at those latitudes. The size of vortices may reflect latitudinal variation in the atmospheric deformation radius. We also compare the new images to those captured earlier in the Cassini mission to characterize the temporal evolution such as changes in the zonal jet speeds, and prevalence and colors of vortices. A particular focus of our interest is the long-term change in the color of the hexagon, the evolution of the wind speeds in the jetstream that blows eastward at the boundary of the hexagon, and the morphology of the north polar vortex. Our work has been supported by NASA PATM NNX14AK07G, NSF AAG 1212216, and NASA NESSF NNX15AQ70H.

  9. Titan's cold case files - Outstanding questions after Cassini-Huygens

    Science.gov (United States)

    Nixon, C. A.; Lorenz, R. D.; Achterberg, R. K.; Buch, A.; Coll, P.; Clark, R. N.; Courtin, R.; Hayes, A.; Iess, L.; Johnson, R. E.; Lopes, R. M. C.; Mastrogiuseppe, M.; Mandt, K.; Mitchell, D. G.; Raulin, F.; Rymer, A. M.; Todd Smith, H.; Solomonidou, A.; Sotin, C.; Strobel, D.; Turtle, E. P.; Vuitton, V.; West, R. A.; Yelle, R. V.

    2018-06-01

    The entry of the Cassini-Huygens spacecraft into orbit around Saturn in July 2004 marked the start of a golden era in the exploration of Titan, Saturn's giant moon. During the Prime Mission (2004-2008), ground-breaking discoveries were made by the Cassini orbiter including the equatorial dune fields (flyby T3, 2005), northern lakes and seas (T16, 2006), and the large positive and negative ions (T16 & T18, 2006), to name a few. In 2005 the Huygens probe descended through Titan's atmosphere, taking the first close-up pictures of the surface, including large networks of dendritic channels leading to a dried-up seabed, and also obtaining detailed profiles of temperature and gas composition during the atmospheric descent. The discoveries continued through the Equinox Mission (2008-2010) and Solstice Mission (2010-2017) totaling 127 targeted flybys of Titan in all. Now at the end of the mission, we are able to look back on the high-level scientific questions from the start of the mission, and assess the progress that has been made towards answering these. At the same time, new scientific questions regarding Titan have emerged from the discoveries that have been made. In this paper we review a cross-section of important scientific questions that remain partially or completely unanswered, ranging from Titan's deep interior to the exosphere. Our intention is to help formulate the science goals for the next generation of planetary missions to Titan, and to stimulate new experimental, observational and theoretical investigations in the interim.

  10. Titan's Surface Temperatures Maps from Cassini - CIRS Observations

    Science.gov (United States)

    Cottini, Valeria; Nixon, C. A.; Jennings, D. E.; Anderson, C. M.; Samuelson, R. E.; Irwin, P. G. J.; Flasar, F. M.

    2009-09-01

    The Cassini Composite Infrared Spectrometer (CIRS) observations of Saturn's largest moon, Titan, are providing us with the ability to detect the surface temperature of the planet by studying its outgoing radiance through a spectral window in the thermal infrared at 19 μm (530 cm-1) characterized by low opacity. Since the first acquisitions of CIRS Titan data the instrument has gathered a large amount of spectra covering a wide range of latitudes, longitudes and local times. We retrieve the surface temperature and the atmospheric temperature profile by modeling proper zonally averaged spectra of nadir observations with radiative transfer computations. Our forward model uses the correlated-k approximation for spectral opacity to calculate the emitted radiance, including contributions from collision induced pairs of CH4, N2 and H2, haze, and gaseous emission lines (Irwin et al. 2008). The retrieval method uses a non-linear least-squares optimal estimation technique to iteratively adjust the model parameters to achieve a spectral fit (Rodgers 2000). We show an accurate selection of the wide amount of data available in terms of footprint diameter on the planet and observational conditions, together with the retrieved results. Our results represent formal retrievals of surface brightness temperatures from the Cassini CIRS dataset using a full radiative transfer treatment, and we compare to the earlier findings of Jennings et al. (2009). In future, application of our methodology over wide areas should greatly increase the planet coverage and accuracy of our knowledge of Titan's surface brightness temperature. References: Irwin, P.G.J., et al.: "The NEMESIS planetary atmosphere radiative transfer and retrieval tool" (2008). JQSRT, Vol. 109, pp. 1136-1150, 2008. Rodgers, C. D.: "Inverse Methods For Atmospheric Sounding: Theory and Practice". World Scientific, Singapore, 2000. Jennings, D.E., et al.: "Titan's Surface Brightness Temperatures." Ap. J. L., Vol. 691, pp. L103-L

  11. Cassini RTG's -- Small scale module tests

    International Nuclear Information System (INIS)

    Kelly, C.E.; Klee, P.M.

    1994-01-01

    The Cassini spacecraft, scheduled for a 1997 launch to Saturn, will be powered by three GPHS RTGs (General Purpose Heat Source Radioisotope thermoelectric Generators). The RTGs are the same type as those powering the Galileo and Ulysses spacecraft. Three new converters (F-6, F-7, and F-8) are to be built and one converter (F-2) remaining from the GPHS program will be used. F-6 and F-7 are to be fueled and F-8 serves as a spare converter. In addition, the back-up RTG (F-5) from the Ulysses launch, which is still fueled, will serve as the Cassini back-up RTG. The new RTGs will have a lower fuel loading than in the past and will provide a minimum of 276 watts each at B.O.M. (beginning of mission). The mission length is 10.75 years, at which time these RTGs will provide a minimum of 216 watts and a possible extension to 16 years when the power will be 199 watts. This paper discusses tests performed to date to confirm the successful re-establishment of the unicouple production at Martin Marietta. This production line, shut down 10 years ago, has been restarted and over 1,500 unicouples have been produced to date. Confirmation will be primarily obtained by the performance of three small scale converters in comparison with previously tested modules from the Multi Hundred Watt (MHW) (Voyager) and GPHS (Galileo, Ulysses) programs. Test results to date have shown excellent agreement with the data base

  12. CASSINI SCALAR MAGNETOMETER CALIB DATA V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains magnetic-field data acquired during the cruise and tour phases of the Cassini mission to Saturn. Data collection began on 16 August (day 228),...

  13. CASSINI MAGNETOMETER RAW DATA V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains magnetic-field data acquired during the cruise and tour phases of the Cassini mission to Saturn. The data set begins with data collected on 16...

  14. Distributed Operations for the Cassini/Huygens Mission

    Science.gov (United States)

    Lock, P.; Sarrel, M.

    1998-01-01

    The cassini project employs a concept known as distributed operations which allows independent instrument operations from diverse locations, provides full empowerment of all participants and maximizes use of limited resources.

  15. Cassini’s Discoveries at Saturn and the Proposed Cassini Solstice Mission

    Science.gov (United States)

    Pappalardo, R. T.; Spilker, L. J.; Mitchell, R. T.; Cuzzi, J.; Gombosi, T. I.; Ingersoll, A. P.; Lunine, J. I.

    2009-12-01

    Understanding of the Saturn system has been greatly enhanced by the Cassini-Huygens mission. Fundamental discoveries have altered our views of Saturn, Titan and the other icy satellites, the rings, and magnetosphere of the system. Key discoveries include: water-rich plumes emanating from the south pole of Enceladus; hints of possible activity on Dione and of rings around Rhea; a methane hydrological cycle on Titan complete with fluvial erosion, lakes, and seas of liquid methane and ethane; non-axisymmetric ring microstructure in all moderate optical depth rings; south polar vortices on Saturn; and a unique magnetosphere that shares characteristics with both Earth’s and Jupiter’s magnetospheres. These new discoveries are directly relevant to current Solar System science goals including: planet and satellite formation processes, formation of gas giants, the nature of organic material, the history of volatiles, habitable zones and processes for life, processes that shape planetary bodies, and evolution of exoplanets. The proposed 7-year Cassini Solstice Mission would address new questions that have arisen during the Cassini Prime and Equinox Missions, and would observe seasonal and temporal change in the Saturn system to prepare for future missions to Saturn, Titan, and Enceladus. The proposed Cassini Solstice Mission would provide new science in three ways. First, it would observe seasonally and temporally dependent processes on Saturn, Titan and other icy satellites, and within the rings and magnetosphere, in a hitherto unobserved seasonal phase from equinox to solstice. Second, it would address new questions that have arisen during the mission thus far, providing qualitatively new measurements (e.g. of Enceladus and Titan) which could not be accommodated in the earlier mission phases. Tthird, it would conduct a close-in mission phase at Saturn that would provide unique science including comparison to the Juno observations at Jupiter.

  16. Cassini Radar EQM Model: Instrument Description and Performance Status

    Science.gov (United States)

    Borgarelli, L.; Faustini, E. Zampolini; Im, E.; Johnson, W. T. K.

    1996-01-01

    The spaeccraft of the Cassini Mission is planned to be launched towards Saturn in October 1997. The mission is designed to study the physical structure and chemical composition of Titan. The results of the tests performed on the Cassini radar engineering qualification model (EQM) are summarized. The approach followed in the verification and evaluation of the performance of the radio frequency subsystem EQM is presented. The results show that the instrument satisfies the relevant mission requirements.

  17. Exploring inner structure of Titan's dunes from Cassini Radar observations

    Science.gov (United States)

    Sharma, P.; Heggy, E.; Farr, T. G.

    2013-12-01

    Linear dunes discovered in the equatorial regions of Titan by the Cassini-Huygens mission are morphologically very similar to many terrestrial linear dune fields. These features have been compared with terrestrial longitudinal dune fields like the ones in Namib desert in western Africa. This comparison is based on the overall parallel orientation of Titan's dunes to the predominant wind direction on Titan, their superposition on other geomorphological features and the way they wrap around topographic obstacles. Studying the internal layering of dunes has strong implications in understanding the hypothesis for their origin and evolution. In Titan's case, although the morphology of the dunes has been studied from Cassini Synthetic Aperture Radar (SAR) images, it has not been possible to investigate their internal structure in detail as of yet. Since no radar sounding data is available for studying Titan's subsurface yet, we have developed another technique to examine the inner layering of the dunes. In this study, we utilize multiple complementary radar datasets, including radar imaging data for Titan's and Earth's dunes and Ground Penetrating Radar (GPR)/radar sounding data for terrestrial dunes. Based on dielectric mixing models, we suggest that the Cassini Ku-band microwaves should be able to penetrate up to ~ 3 m through Titan's dunes, indicating that the returned radar backscatter signal would include contributions from both surface and shallow subsurface echoes. This implies that the shallow subsurface properties can be retrieved from the observed radar backscatter (σ0). In our analysis, the variation of the radar backscatter as a function of dune height is used to provide an insight into the layering in Titan's dunes. We compare the variation of radar backscatter with elevation over individual dunes on Titan and analogous terrestrial dunes in three sites (Great Sand Sea, Siwa dunes and Qattaniya dunes) in the Egyptian Sahara. We observe a strong, positive

  18. Diurnal Variations of Titan's Surface Temperatures From Cassini -CIRS Observations

    Science.gov (United States)

    Cottini, Valeria; Nixon, Conor; Jennings, Don; Anderson, Carrie; Samuelson, Robert; Irwin, Patrick; Flasar, F. Michael

    The Cassini Composite Infrared Spectrometer (CIRS) observations of Saturn's largest moon, Titan, are providing us with the ability to detect the surface temperature of the planet by studying its outgoing radiance through a spectral window in the thermal infrared at 19 m (530 cm-1) characterized by low opacity. Since the first acquisitions of CIRS Titan data the in-strument has gathered a large amount of spectra covering a wide range of latitudes, longitudes and local times. We retrieve the surface temperature and the atmospheric temperature pro-file by modeling proper zonally averaged spectra of nadir observations with radiative transfer computations. Our forward model uses the correlated-k approximation for spectral opacity to calculate the emitted radiance, including contributions from collision induced pairs of CH4, N2 and H2, haze, and gaseous emission lines (Irwin et al. 2008). The retrieval method uses a non-linear least-squares optimal estimation technique to iteratively adjust the model parameters to achieve a spectral fit (Rodgers 2000). We show an accurate selection of the wide amount of data available in terms of footprint diameter on the planet and observational conditions, together with the retrieved results. Our results represent formal retrievals of surface brightness temperatures from the Cassini CIRS dataset using a full radiative transfer treatment, and we compare to the earlier findings of Jennings et al. (2009). The application of our methodology over wide areas has increased the planet coverage and accuracy of our knowledge of Titan's surface brightness temperature. In particular we had the chance to look for diurnal variations in surface temperature around the equator: a trend with slowly increasing temperature toward the late afternoon reveals that diurnal temperature changes are present on Titan surface. References: Irwin, P.G.J., et al.: "The NEMESIS planetary atmosphere radiative transfer and retrieval tool" (2008). JQSRT, Vol. 109, pp

  19. Cassini UVIS Auroral Observations in 2016 and 2017

    Science.gov (United States)

    Pryor, Wayne R.; Esposito, Larry W.; Jouchoux, Alain; Radioti, Aikaterini; Grodent, Denis; Gustin, Jacques; Gerard, Jean-Claude; Lamy, Laurent; Badman, Sarah; Dyudina, Ulyana A.; Cassini UVIS Team, Cassini VIMS Team, Cassini ISS Team, HST Saturn Auroral Team

    2017-10-01

    In 2016 and 2017, the Cassini Saturn orbiter executed a final series of high-inclination, low-periapsis orbits ideal for studies of Saturn's polar regions. The Cassini Ultraviolet Imaging Spectrograph (UVIS) obtained an extensive set of auroral images, some at the highest spatial resolution obtained during Cassini's long orbital mission (2004-2017). In some cases, two or three spacecraft slews at right angles to the long slit of the spectrograph were required to cover the entire auroral region to form auroral images. We will present selected images from this set showing narrow arcs of emission, more diffuse auroral emissions, multiple auroral arcs in a single image, discrete spots of emission, small scale vortices, large-scale spiral forms, and parallel linear features that appear to cross in places like twisted wires. Some shorter features are transverse to the main auroral arcs, like barbs on a wire. UVIS observations were in some cases simultaneous with auroral observations from the Cassini Imaging Science Subsystem (ISS) the Cassini Visual and Infrared Mapping Spectrometer (VIMS), and the Hubble Space Telescope Space Telescope Imaging Spectrograph (STIS) that will also be presented.

  20. RTG performance on Galileo and Ulysses and Cassini test results

    International Nuclear Information System (INIS)

    Kelly, C. Edward; Klee, Paul M.

    1997-01-01

    Power output from telemetry for the two Galileo RTGs are shown from the 1989 launch to the recent Jupiter encounter. Comparisons of predicted, measured and required performance are shown. Similar comparisons are made for the RTG on the Ulysses spacecraft which completed its planned mission in 1995. Also presented are test results from small scale thermoelectric modules and full scale converters performed for the Cassini program. The Cassini mission to Saturn is scheduled for an October 1997 launch. Small scale module test results on thermoelectric couples from the qualification and flight production runs are shown. These tests have exceeded 19,000 hours are continuing to provide increased confidence in the predicted long term performance of the Cassini RTGs. Test results are presented for full scale units both ETGs (E-6, E-7) and RTGs (F-2, F-5) along with mission power predictions. F-5, fueled in 1985, served as a spare for the Galileo and Ulysses missions and plays the same role in the Cassini program. It has successfully completed all acceptance testing. The ten years storage between thermal vacuum tests is the longest ever experienced by an RTG. The data from this test are unique in providing the effects of long term low temperature storage on power output. All ETG and RTG test results to date indicate that the power requirements of the Cassini spacecraft will be met. BOM and EOM power margins of at least five percent are predicted

  1. RTG performance on Galileo and Ulysses and Cassini test results

    International Nuclear Information System (INIS)

    Kelly, C.E.; Klee, P.M.

    1997-01-01

    Power output from telemetry for the two Galileo RTGs are shown from the 1989 launch to the recent Jupiter encounter. Comparisons of predicted, measured and required performance are shown. Similar comparisons are made for the RTG on the Ulysses spacecraft which completed its planned mission in 1995. Also presented are test results from small scale thermoelectric modules and full scale converters performed for the Cassini program. The Cassini mission to Saturn is scheduled for an October 1997 launch. Small scale module test results on thermoelectric couples from the qualification and flight production runs are shown. These tests have exceeded 19,000 hours are continuing to provide increased confidence in the predicted long term performance of the Cassini RTGs. Test results are presented for full scale units both ETGs (E-6, E-7) and RTGs (F-2, F-5) along with mission power predictions. F-5, fueled in 1985, served as a spare for the Galileo and Ulysses missions and plays the same role in the Cassini program. It has successfully completed all acceptance testing. The ten years storage between thermal vacuum tests is the longest ever experienced by an RTG. The data from this test are unique in providing the effects of long term low temperature storage on power output. All ETG and RTG test results to date indicate that the power requirements of the Cassini spacecraft will be met. BOM and EOM power margins of at least five percent are predicted. copyright 1997 American Institute of Physics

  2. Man with a Mission: Jean-Dominique Cassini

    Science.gov (United States)

    Belkora, Leila

    2004-03-01

    Jean-Dominique Cassini, for whom the Cassini mission to Saturn is named, is best known for his early understanding of that planet's rings. This article is an overview of his influential career in astronomy and other scientific fields.= Born in Italy in1625 and formally educated at an early age, he was a professor of astronomy at the University of Bologna, a leading center of learning in Europe of the time. He was an early observer of Jupiter, Mars, and Venus. He is best known for constructing a giant pinhole camera in a cathedral that he used with a meridian line on the floor to track the Sun's image through the year, thus providing the Catholic Church with a reliable calendar. Cassini also used the pinhole camera observations to calculate the variation in the distance between the Sun and Earth, thus lending support to the Copernican (Sun-centered) view of the solar system. Cassini moved to Paris at the request of King Louis XIV, originally to oversee the surveying needed for a new map system of France, but ultimately he took over as the director of the Paris Observatory. Cassini's descendants ran the observatory there for the following century.

  3. IMF dependence of Saturn's auroras: modelling study of HST and Cassini data from 12–15 February 2008

    Directory of Open Access Journals (Sweden)

    E. S. Belenkaya

    2010-08-01

    Full Text Available To gain better understanding of auroral processes in Saturn's magnetosphere, we compare ultraviolet (UV auroral images obtained by the Hubble Space Telescope (HST with the position of the open-closed field line boundary in the ionosphere calculated using a magnetic field model that employs Cassini measurements of the interplanetary magnetic field (IMF as input. Following earlier related studies of pre-orbit insertion data from January 2004 when Cassini was located ~ 1300 Saturn radii away from the planet, here we investigate the interval 12–15 February 2008, when UV images of Saturn's southern dayside aurora were obtained by the HST while the Cassini spacecraft measured the IMF in the solar wind just upstream of the dayside bow shock. This configuration thus provides an opportunity, unique to date, to determine the IMF impinging on Saturn's magnetosphere during imaging observations, without the need to take account of extended and uncertain interplanetary propagation delays. The paraboloid model of Saturn's magnetosphere is then employed to calculate the magnetospheric magnetic field structure and ionospheric open-closed field line boundary for averaged IMF vectors that correspond, with appropriate response delays, to four HST images. We show that the IMF-dependent open field region calculated from the model agrees reasonably well with the area lying poleward of the UV emissions, thus supporting the view that the poleward boundary of Saturn's auroral oval in the dayside ionosphere lies adjacent to the open-closed field line boundary.

  4. Automation of Cassini Support Imaging Uplink Command Development

    Science.gov (United States)

    Ly-Hollins, Lisa; Breneman, Herbert H.; Brooks, Robert

    2010-01-01

    "Support imaging" is imagery requested by other Cassini science teams to aid in the interpretation of their data. The generation of the spacecraft command sequences for these images is performed by the Cassini Instrument Operations Team. The process initially established for doing this was very labor-intensive, tedious and prone to human error. Team management recognized this process as one that could easily benefit from automation. Team members were tasked to document the existing manual process, develop a plan and strategy to automate the process, implement the plan and strategy, test and validate the new automated process, and deliver the new software tools and documentation to Flight Operations for use during the Cassini extended mission. In addition to the goals of higher efficiency and lower risk in the processing of support imaging requests, an effort was made to maximize adaptability of the process to accommodate uplink procedure changes and the potential addition of new capabilities outside the scope of the initial effort.

  5. PLEXOS Input Data Generator

    Energy Technology Data Exchange (ETDEWEB)

    2017-02-01

    The PLEXOS Input Data Generator (PIDG) is a tool that enables PLEXOS users to better version their data, automate data processing, collaborate in developing inputs, and transfer data between different production cost modeling and other power systems analysis software. PIDG can process data that is in a generalized format from multiple input sources, including CSV files, PostgreSQL databases, and PSS/E .raw files and write it to an Excel file that can be imported into PLEXOS with only limited manual intervention.

  6. Cassini RADAR Observations at Titan : Results at the End of the Nominal Mission

    Science.gov (United States)

    Lorenz, Ralph

    This talk will review some recent results of the Cassini RADAR investigations at Titan. In particular, the first half of 2008 includes three low-latitude flybys with SAR observations of Xanadu, the Huygens Landing site, and in particular three areas that may be associated with cryovolcanic features - Tortola Facula, Hotei Arcus, and Tui Regio. In addition to providing SAR coverage (which will include further mapping of dunes in the Shangri-La dark areas as well as the features above), these new flybys will permit refinement of the apparently dynamic Titan rotational state, as well as expanding our topographic knowledge.

  7. Titan Density Reconstruction Using Radiometric and Cassini Attitude Control Flight Data

    Science.gov (United States)

    Andrade, Luis G., Jr.; Burk, Thomas A.

    2015-01-01

    This paper compares three different methods of Titan atmospheric density reconstruction for the Titan 87 Cassini flyby. T87 was a unique flyby that provided independent Doppler radiometric measurements on the ground throughout the flyby including at Titan closest approach. At the same time, the onboard accelerometer provided an independent estimate of atmospheric drag force and density during the flyby. These results are compared with the normal method of reconstructing atmospheric density using thruster on-time and angular momentum accumulation. Differences between the estimates are analyzed and a possible explanation for the differences is evaluated.

  8. Saturn's Ring: Pre-Cassini Status and Mission Goals

    Science.gov (United States)

    Cuzzi, Jeff N.; DeVincenzi, Donald L. (Technical Monitor)

    1999-01-01

    In November 1980, and again in August 1981, identical Voyager spacecraft flew through the Saturn system, changing forever the way we think about planetary rings. Although Saturn's rings had been the only known ring system for three centuries, a ring system around Uranus had been discovered by stellar occultations from Earth in 1977, and the nearly transparent ring of Jupiter was imaged by Voyager in 1979 (the presence of material there had been inferred from charged particle experiments on Pioneer 10 and 11 several years earlier). While Saturn had thus temporarily lost its uniqueness as having the only ring system, with Voyager it handily recaptured the role of having the most fascinating one. The Voyager breakthroughs included spiral density and bending waves such as cause galactic structure; ubiquitous fine-scale radial 'irregular' structure, with the appearance of record-grooves; regional and local variations in particle color; complex, azimuthally variable ring structure; empty gaps in the rings, some containing very regular, sharp-edged, elliptical rings and one containing both a small moonlet and incomplete arcs of dusty material; and shadowy 'spokes' that flicker across the main rings. One of the paradigm shifts of this period was the realization that many aspects of planetary rings, and even the ring systems themselves, could be 'recent' on geological timescales. These early results are reviewed and summarized in the Arizona Space Science series volumes 'Saturn'. (An excellent review of ring dynamics at a formative stage is by Goldreich and Tremaine.) From the mid 1980's to the time of this writing, progress has been steady, while at a less heady pace, and some of the novel ring properties revealed by Voyager 1 and 2 are beginning to be better understood. It is clearly impossible to cite, much less review, every advance over the last decade; however, below we summarize the main advances in understanding of Saturn's rings since the mid 1980's, in the context

  9. Cassini RADAR at Titan : Results in 2013/2014

    Science.gov (United States)

    Lorenz, Ralph D.; Cassini RadarTeam

    2014-05-01

    Since the last EGU meeting, several Cassini flybys of Titan have featured significant RADAR observations. These include T91 and T92 (May/July 2013) with SAR and altimetry observations of Ligeia Mare. The latter have placed tight constraints on surface roughness (Zebker et al., in press), showing that wind-driven waves were not present. A remarkable altimetry analysis by Mastrogiuseppe et al. (submitted) detects a bottom echo from the bed of Ligeia, only possible if the liquid is exceptionally radar-transparent. This opens the way to wider radar bathymetry analyses of the northern seas. SAR coverage, augmented by some distant HiSAR observations, has now allowed construction of a more-or-less complete map of the northern polar region. This map now defines the extent of the northern lakes and seas, permitting oceanographic studies. T95 (October 2013) made SAR observations of the impact crater Selk (previously observed by VIMS and RADAR). As well as a closer view of this rather polygonal crater, the observation shows dramatic change in the dune orientation around the crater and its ejecta blanket. The T98 encounter is due to occur in February 2014, and will feature the last prime SAR observation of Ontario Lacus, giving a good baseline for change detection against prior observations. Additionally, close-approach observations (mandated to avoid solar heating constraints on other instruments) will give high-resolution altimetry data on the Shangri-La dunes. Preliminary results may be available in time for the meeting, at which this solicted talk will review analyses of these and other observations.

  10. Cassini ISS Observations of Jupiter: An Exoplanet Perspective

    Science.gov (United States)

    West, Robert A.; Knowles, Benjamin

    2017-10-01

    Understanding the optical and physical properties of planets in our solar system can guide our approach to the interpretation of observations of exoplanets. Although some work has already been done along these lines, there remain low-hanging fruit. During the Cassini Jupiter encounter, the Imaging Science Subsystem (ISS) obtained an extensive set of images over a large range of phase angles (near-zero to 140 degrees) and in filters from near-UV to near-IR, including three methane bands and nearby continuum. The ISS also obtained images using polarizers. Much later in the mission we also obtained distant images while in orbit around Saturn. Some of these data have already been studied to reveal phase behavior (Dyudina et al., Astrophys. J.822, DOI: 10.3847/0004-637X/822/2/76; Mayorga et al., 2016, Astron. J. 152, DOI: 10.3847/0004-6256/152/6/209). Here we examine rotational modulation to determine wavelength and phase angle dependence, and how these may depend on cloud and haze vertical structure and optical properties. The existence of an optically thin forward-scattering and longitudinally-homogeneous haze overlying photometrically-variable cloud fields tends to suppress rotational modulation as phase angle increases, although in the strong 890-nm methane band cloud vertical structure is important. Cloud particles (non-spherical ammonia ice, mostly) have very small polarization signatures at intermediate phase angles and rotational modulation is not apparent above the noise level of our instrument. Part of this work was performed by the Jet Propulsion Lab, Cal. Inst. Of Technology.

  11. Cassini RTG acceptance test results and RTG performance on Galileo and Ulysses

    International Nuclear Information System (INIS)

    Kelly, C.E.; Klee, P.M.

    1997-01-01

    Flight acceptance testing has been completed for the RTGs to be used on the Cassini spacecraft which is scheduled for an October 6, 1997 launch to Saturn. The acceptance test program includes vibration tests, magnetic field measurements, mass properties (weight and c.g.) and thermal vacuum test. This paper presents the thermal vacuum test results. Three RTGs are to be used, F-2, F-6, and F-7. F-5 is the backup RTG, as it was for the Galileo and Ulysses missions launched in 1989 and 1990, respectively. RTG performance measured during the thermal vacuum tests carried out at the Mound Laboratory facility met all specification requirements. Beginning of mission (BOM) and end of mission (EOM) power predictions have been made based on these tests results. BOM power is predicted to be 888 watts compared to the minimum requirement of 826 watts. Degradation models predict the EOM power after 16 years is to be 640 watts compared to a minimum requirement of 596 watts. Results of small scale module tests are also shown. The modules contain couples from the qualification and flight production runs. The tests have exceeded 28,000 hours (3.2 years) and are continuing to provide increased confidence in the predicted long term performance of the Cassini RTGs. All test results indicate that the power requirements of the Cassini spacecraft will be met. BOM and EOM power margins of over 5% are predicted. Power output from telemetry for the two Galileo RTGs are shown from the 1989 launch to the recent Jupiter encounter. Comparisons of predicted, measured and required performance are shown. Telemetry data are also shown for the RTG on the Ulysses spacecraft which completed its planned mission in 1995 and is now in the extended mission

  12. Cassini RTG acceptance test results and RTG performance on Galileo and Ulysses

    International Nuclear Information System (INIS)

    Kelly, C.E.; Klee, P.M.

    1997-01-01

    Flight acceptance testing has been completed for the RTGs to be used on the Cassini spacecraft which is scheduled for an October 6, 1997 launch to Saturn. The acceptance test program includes vibration tests, magnetic field measurements, properties (weight and c.g.) and thermal vacuum test. This paper presents The thermal vacuum test results. Three RTGs are to be used, F-2, F-6, and F-7. F-5 is tile back-up RTG, as it was for the Galileo and Ulysses missions launched in 1989 and 1990, respectively. RTG performance measured during the thermal vacuum tests carried out at die Mound Laboratory facility met all specification requirements. Beginning of mission (BOM) and end of mission (EOM) power predictions have been made based on than tests results. BOM power is predicted to be 888 watts compared to the minimum requirement of 826 watts. Degradation models predict the EOM power after 16 years is to be 640 watts compared to a minimum requirement of 596 watts. Results of small scale module tests are also showing. The modules contain couples from the qualification and flight production runs. The tests have exceeded 28,000 hours (3.2 years) and are continuing to provide increased confidence in the predicted long term performance of the Cassini RTGs. All test results indicate that the power requirements of the Cassini spacecraft will be met. BOM and EOM power margins of over five percent are predicted. Power output from telemetry for the two Galileo RTGs are shown from the 1989 launch to the recent Jupiter encounter. Comparisons of predicted, measured and required performance are shown. Telemetry data are also shown for the RTG on the Ulysses spacecraft which completed its planned mission in 1995 and is now in the extended mission

  13. Cassini Scientist for a Day: a tactile experience

    Science.gov (United States)

    Canas, L.; Altobelli, N.

    2012-09-01

    In September 2011, the Cassini spacecraft took images of three targets and a challenge was launched to all students: to choose the one target they thought would provide the best science and to write an essay explaining their reasons (more information on the "Cassini Scientist for a Day" essay contest official webpage in: http://saturn.jpl.nasa.gov/education/scientistforaday10thedition/, run by NASA/JPL) The three targets presented were: Hyperion, Rhea and Titan, and Saturn. The idea behind "Cassini Scientist for a Day: a tactile experience" was to transform each of these images into schematic tactile images, highlighting relevant features apprehended through a tactile key, accompanied by a small text in Braille with some additional information. This initial approach would allow reach a broader community of students, more specifically those with visual impairment disabilities. Through proper implementation and careful study cases the adapted images associated with an explanatory key provide more resources in tactile astronomy. As the 2012 edition approaches a new set of targeted objet images will be once again transformed and adapted to visually impaired students and will aim to reach more students into participate in this international competition and to engage them in a quest to expand their knowledge in the amazing Cassini discoveries and the wonders of Saturn and its moons. As the winning essays will be published on the Cassini website and contest winners invited to participate in a dedicated teleconference with Cassini scientists from NASA's Jet Propulsion Laboratory, this initiative presents a great chance to all visually impaired students and teachers to participate in an exciting experience. These initiatives must be complemented with further information to strengthen the learning experience. However they stand as a good starting point to tackle further astronomical concepts in the classroom, especially this field that sometimes lacks the resources. Although

  14. AN ATLAS OF BRIGHT STAR SPECTRA IN THE NEAR-INFRARED FROM CASSINI-VIMS

    International Nuclear Information System (INIS)

    Stewart, Paul N.; Tuthill, Peter G.; Nicholson, Philip D.; Sloan, G. C.; Hedman, Matthew M.

    2015-01-01

    We present the Cassini Atlas Of Stellar Spectra (CAOSS), comprised of near-infrared, low-resolution spectra of bright stars recovered from space-based observations by the Cassini spacecraft. The 65 stellar targets in the atlas are predominately M, K, and S giants. However, it also contains spectra of other bright nearby stars including carbon stars and main-sequence stars from A to F. The spectra presented are free of all spectral contamination caused by the Earth's atmosphere, including the detrimental telluric molecular bands which put parts of the near-infrared spectrum out of reach of terrestrial observations. With a single instrument, a spectro-photometric data set is recovered that spans the near-infrared from 0.8 to 5.1 μm with spectral resolution ranging from R = 53.5 to R = 325. Spectra have been calibrated into absolute flux units after careful characterization of the instrumental spectral efficiency. Spectral energy distributions for most stars match closely with literature values. All final data products have been made available online

  15. AN ATLAS OF BRIGHT STAR SPECTRA IN THE NEAR-INFRARED FROM CASSINI-VIMS

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, Paul N.; Tuthill, Peter G. [Sydney Institute for Astronomy, School of Physics, The University of Sydney, NSW 2006 (Australia); Nicholson, Philip D. [Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States); Sloan, G. C. [Cornell Center for Astrophyics and Planetary Science, Cornell University, Ithaca, NY 14853 (United States); Hedman, Matthew M., E-mail: p.stewart@physics.usyd.edu.au [Department of Physics, University of Idaho, Moscow, ID 83844 (United States)

    2015-12-15

    We present the Cassini Atlas Of Stellar Spectra (CAOSS), comprised of near-infrared, low-resolution spectra of bright stars recovered from space-based observations by the Cassini spacecraft. The 65 stellar targets in the atlas are predominately M, K, and S giants. However, it also contains spectra of other bright nearby stars including carbon stars and main-sequence stars from A to F. The spectra presented are free of all spectral contamination caused by the Earth's atmosphere, including the detrimental telluric molecular bands which put parts of the near-infrared spectrum out of reach of terrestrial observations. With a single instrument, a spectro-photometric data set is recovered that spans the near-infrared from 0.8 to 5.1 μm with spectral resolution ranging from R = 53.5 to R = 325. Spectra have been calibrated into absolute flux units after careful characterization of the instrumental spectral efficiency. Spectral energy distributions for most stars match closely with literature values. All final data products have been made available online.

  16. GPHS-RTGs in support of the Cassini RTG Program. Final technical report, January 11, 1991 - April 30, 1998

    International Nuclear Information System (INIS)

    1998-08-01

    As noted in the historical summary, this program encountered a number of changes in direction, schedule, and scope over the period 11 January 1991 to 31 December 1998. The report provides a comprehensive summary of all the varied aspects of the program over its seven and a quarter years, and highlights those aspects that provide information beneficial to future radioisotope programs. In addition to summarizing the scope of the Cassini GPHS-RTG Program provided as background, the introduction includes a discussion of the scope of the final report and offers reference sources for information on those topics not covered. Much of the design heritage of the GPHS-RTG comes from the Multi-Hundred Watt (MHW) RTGs used on the Lincoln Experimental Satellites (LES) 8/9 and Voyager spacecraft. The design utilized for the Cassini program was developed, in large part, under the GPHS-RTG program which produced the Galileo and Ulysses RTGs. Reports from those programs included detailed documentation of the design, development, and testing of converter components and full converters that were identical to, or similar to, components used in the Cassini program. Where such information is available in previous reports, it is not repeated here

  17. GPHS-RTGs in support of the Cassini RTG Program. Final technical report, January 11, 1991--April 30, 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-08-01

    As noted in the historical summary, this program encountered a number of changes in direction, schedule, and scope over the period 11 January 1991 to 31 December 1998. The report provides a comprehensive summary of all the varied aspects of the program over its seven and a quarter years, and highlights those aspects that provide information beneficial to future radioisotope programs. In addition to summarizing the scope of the Cassini GPHS-RTG Program provided as background, the introduction includes a discussion of the scope of the final report and offers reference sources for information on those topics not covered. Much of the design heritage of the GPHS-RTG comes from the Multi-Hundred Watt (MHW) RTGs used on the Lincoln Experimental Satellites (LES) 8/9 and Voyager spacecraft. The design utilized for the Cassini program was developed, in large part, under the GPHS-RTG program which produced the Galileo and Ulysses RTGs. Reports from those programs included detailed documentation of the design, development, and testing of converter components and full converters that were identical to, or similar to, components used in the Cassini program. Where such information is available in previous reports, it is not repeated here.

  18. Ongoing Analysis of Jupiter's Equatorial Hotspots and Plumes from Cassini

    Science.gov (United States)

    Choi, D. S.; Showmwn, A. P.; Vasavada, A. R.; Simon-Miller, A. A.

    2012-01-01

    We present updated results from our ongoing analysis of Cassini observations of Jupiter's equatorial meteorology. For two months preceding the spacecraft's closest approach of the planet, the ISS instrument onboard Cassini regularly imaged the atmosphere of Jupiter. We created time-lapse movies from this period that show the complex activity and interactions of the equatorial atmosphere. During this period, hot spots exhibited significant variations in size and shape over timescales of days and weeks. Some of these changes appear to be a result of interactions with passing vortex systems in adjacent latitudes. Strong anticyclonic gyres to the southeast of the dark areas converge with flow from the west and appear to circulate into a hot spot at its southwestern corner.

  19. Fast forward modeling of Titan’s infrared spectra to invert VIMS/CASSINI hyperspectral images

    Science.gov (United States)

    Rodriguez, S.; Le Mouélic, S.; Rannou, P.; Combe, J.; Le Corre, L.; Griffith, C. A.; Tobie, G.; Barnes, J. W.; Sotin, C.; Brown, R. H.; Baines, K. H.; Buratti, B. J.; Clark, R. N.

    2009-12-01

    The surface of Titan, the largest icy moon of Saturn, is veiled by a very thick and hazy atmosphere. The Visual and Infrared Mapping Spectrometer onboard the Cassini spacecraft, in orbit around Saturn since July 2004, has been conducting an intensive survey of Titan with the objective of understanding the complex nature and interaction of the atmosphere and surface of this mysterious moon. Retrieving and separating contributions from the surface and the atmosphere in Titan’s infrared spectra requires accurate radiative transfer modeling, which is often very demanding of computer resources. As Cassini has gathered hitherto millions of spectra of Titan and will continue to observe it until at least 2010, we report here on the development of a new rapid, simple and versatile radiative transfer model specially designed to process VIMS datacubes. Currently, our model accounts for gas absorption, haze scattering and surface reflectance and can be implemented in an inversion scheme. First results of forward modeling provide spectral shapes that are consistent with VIMS measurements, as well as surface and aerosol properties in the range of validity for Titan. Further inversion tests will be carried on VIMS hyperspectral images for the estimate of spatial coherence of the results, accuracy of the surface reflectance within the atmospheric windows, and potential needs for improved input data and modeling. This work was partly performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract to the National Aeronautics and Space Administration. Calibrated VIMS data appear courtesy of the VIMS team. We thank the CNES French agency for its financial support.

  20. Design and analysis of RTGs for CRAF and Cassini missions

    International Nuclear Information System (INIS)

    Schock, A.; Noravian, H.; Or, C.; Sankarankandath, K.

    1991-01-01

    The paper describes the design and analysis of Radioisotope Thermoelectric Generators (RTGs) integrated with the Jet Proplusion Laboratory's CRAF (Comet Rendezvous and Asteroid Flyby) and Cassini Spacecraft. The principal purpose of the CRAF mission is the study of Asteroids and comets, and the principal purpose of the Cassini mission is the study of asteroids, Saturn, and its moons (particularly Titan). Both misions will employ the Mariner/Mark-2 spacecraft, and each will be powered by two GPHS-RTGs (General Purpose Heat Source-RTGs). JPL's spacecraft designers wish to locate the two RTGs in close proximity to each other, resulting in mutual and unsymmetrical obstruction of their heat rejection paths. To support JPL's design studies, the U.S. Department of Energy asked Fairchild to determine the effect of the RTGs' proximity on their power output. As described in the paper, this required the development of novel analysis methods and computer codes for the coupled thermal and electrical analysis of obstructed RTGs with axial and circumferential temperature, voltage, and current variations. The code was validated against measured data of unobstructed RTG tests, and was used for the detailed analysis of the obstructed CRAF and Cassini RTGs. Also described is a new method for predicting the combined effect of fuel decay and thermoelectric degradation on the output of obstructed RTGs, which amounts for the effect of diminishing temperatures on degradation rates. For the 24-degree separation angle of JPL's original baseline design, and for the 35-degree RTG separation of JPL's revised design, the computed results indicate that the mutually obstructed GPHS/RTGs with standard fuel loading and operating temperatures can comfortably meet the JPL-specified power requirements for the CRAF mission and almost meet the specified requirements for the Cassini mission

  1. Saturn's Internal Magnetic Field Revealed by Cassini Grand Finale

    Science.gov (United States)

    Cao, H.; Dougherty, M. K.; Khurana, K. K.; Hunt, G. J.; Provan, G.; Kellock, S.; Burton, M. E.; Burk, T. A.

    2017-12-01

    Saturn's internal magnetic field has been puzzling since the first in-situ measurements during the Pioneer 11 Saturn flyby. Cassini magnetometer measurements prior to the Grand Finale phase established 1) the highly axisymmetric nature of Saturn's internal magnetic field with a dipole tilt smaller than 0.06 degrees, 2) at least an order of magnitude slower secular variation rate compared to that of the current geomagnetic field, and 3) expulsion of magnetic fluxes from the equatorial region towards high latitude. The highly axisymmetric nature of Saturn's intrinsic magnetic field not only challenges dynamo theory but also makes an accurate determination of the interior rotation rate of Saturn extremely difficult. The Cassini spacecraft entered the Grand Finale phase in April 2017, during which time the spacecraft dived through the gap between Saturn's atmosphere and the inner edge of the D-ring 22 times before descending into the deep atmosphere of Saturn. The unprecedented proximity to Saturn (reaching 2500 km above the cloud deck) and the highly inclined nature of the Grand Finale orbits provided an ideal opportunity to decode Saturn's internal magnetic field. The fluxgate magnetometer onboard Cassini made precise vector measurements during the Grand Finale phase. Magnetic signals from the interior of the planet, the magnetospheric ring current, the high-latitude field-aligned current (FAC) modulated by the 10.7 hour planetary period oscillation, and low-latitude FACs were observed during the Grand Finale phase. Here we report the magnetometer measurements during the Cassini Grand Finale phase, new features of Saturn's internal magnetic field revealed by these measurements (e.g., the high degree magnetic moments of Saturn, the level of axisymmetry beyond dipole), and implications for the deep interior of Saturn.

  2. Cassini UVIS Observations of Saturn during the Grand Finale Orbits

    Science.gov (United States)

    Pryor, W. R.; Esposito, L. W.; West, R. A.; Jouchoux, A.; Radioti, A.; Grodent, D. C.; Gerard, J. C. M. C.; Gustin, J.; Lamy, L.; Badman, S. V.

    2017-12-01

    In 2016 and 2017, the Cassini Saturn orbiter executed a final series of high inclination, low-periapsis orbits ideal for studies of Saturn's polar regions. The Cassini Ultraviolet Imaging Spectrograph (UVIS) obtained an extensive set of auroral images, some at the highest spatial resolution obtained during Cassini's long orbital mission (2004-2017). In some cases, two or three spacecraft slews at right angles to the long slit of the spectrograph were required to cover the entire auroral region to form auroral images. We will present selected images from this set showing narrow arcs of emission, more diffuse auroral emissions, multiple auroral arcs in a single image, discrete spots of emission, small scale vortices, large-scale spiral forms, and parallel linear features that appear to cross in places like twisted wires. Some shorter features are transverse to the main auroral arcs, like barbs on a wire. UVIS observations were in some cases simultaneous with auroral observations from the Hubble Space Telescope Space Telescope Imaging Spectrograph (STIS) that will also be presented. UVIS polar images also contain spectral information suitable for studies of the auroral electron energy distribution. The long wavelength part of the UVIS polar images contains a signal from reflected sunlight containing absorption signatures of acetylene and other Saturn hydrocarbons. The hydrocarbon spatial distribution will also be examined.

  3. Probing Small Lakes on Titan Using the Cassini RADAR Altimeter

    Science.gov (United States)

    Mastrogiuseppe, M.; Poggiali, V.; Hayes, A.; Lunine, J. I.; Seu, R.; Lorenz, R. D.; Mitri, G.; Mitchell, K. L.; Janssen, M. A.; Casarano, D.; Notarnicola, C.; Le Gall, A. A.

    2017-12-01

    The T126 Cassini's final flyby of Titan has offered a unique opportunity to observe an area in the Northern Polar terrain, where several small - medium size (10 - 50 km) hydrocarbon lakes are present and have been previously imaged by Cassini. The successful observation allowed the radar to operate at the closest approach over several small lakes, using its altimetry mode for the investigation of depth and liquid composition. Herein we present the result of a dedicate processing previously applied to altimetric data acquired over Ligeia Mare where the radar revealed the bathymetry and composition of the sea [1,2]. We show that, the optimal geometry condition met during the T126 fly-by allowed the radar to probe Titan's lakes revealing that such small liquid bodies can exceed one-hundred meters of depth. [1] M. Mastrogiuseppe et al. (2014, Mar.). The bathymetry of a Titan Sea. Geophysical Research Letters. [Online]. 41 (5), pp. 1432-1437. Available: http://dx.doi.org/10.1002/2013GL058618 [2] M.Mastrogiuseppe et al. (2016, Oct). Radar Sounding Using the Cassini Altimeter: Waveform Modeling and Monte Carlo Approach for Data Inversion of Observations of Titan's Seas, IEEE Transactions On Geoscience And Remote Sensing, Vol. 54, No. 10, doi: 10.1109/TGRS.2016.2563426.

  4. Cassini at Saturn Proximal Orbits - Attitude Control Challenges

    Science.gov (United States)

    Burk, Thomas A.

    2013-01-01

    The Cassini mission at Saturn will come to an end in the spring and summer of 2017 with a series of 22 orbits that will dip inside the rings of Saturn. These are called proximal orbits and will conclude with spacecraft disposal into the atmosphere of the ringed world on September 15, 2017. These unique orbits that cross the ring plane only a few thousand kilometers above the cloud tops of the planet present new attitude control challenges for the Cassini operations team. Crossing the ring plane so close to the inner edge of the rings means that the Cassini orientation during the crossing will be tailored to protect the sensitive electronics bus of the spacecraft. This orientation will put the sun sensors at some extra risk so this paper discusses how the team prepares for dust hazards. Periapsis is so close to the planet that spacecraft controllability with RCS thrusters needs to be evaluated because of the predicted atmospheric torque near closest approach to Saturn. Radiation during the ring plane crossings will likely trigger single event transients in some attitude control sensors. This paper discusses how the attitude control team deals with radiation hazards. The angular size and unique geometry of the rings and Saturn near periapsis means that star identification will be interrupted and this paper discusses how the safe mode attitude is selected to best deal with these large bright bodies during the proximal orbits.

  5. THERMAL AND CHEMICAL STRUCTURE VARIATIONS IN TITAN'S STRATOSPHERE DURING THE CASSINI MISSION

    Energy Technology Data Exchange (ETDEWEB)

    Bampasidis, Georgios; Coustenis, A.; Vinatier, S. [Laboratoire d' Etudes Spatiales et d' Instrumentation en Astrophysique (LESIA), Observatoire de Paris, CNRS, UPMC Univ. Paris 06, Univ. Paris-Diderot, 5, place Jules Janssen, F-92195 Meudon Cedex (France); Achterberg, R. K. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Lavvas, P. [GSMA, Universite Reims Champagne-Ardenne, F-51687 Reims Cedex 2 (France); Nixon, C. A.; Jennings, D. E.; Flasar, F. M.; Carlson, R. C.; Romani, P. N.; Guandique, E. A. [Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Teanby, N. A. [School of Earth Sciences, University of Bristol, Bristol BS8 1RJ (United Kingdom); Moussas, X.; Preka-Papadema, P.; Stamogiorgos, S., E-mail: gbabasid@phys.uoa.gr [Faculty of Physics, National and Kapodistrian University of Athens, Panepistimioupolis, GR 15783 Zographos, Athens (Greece)

    2012-12-01

    We have developed a line-by-line Atmospheric Radiative Transfer for Titan code that includes the most recent laboratory spectroscopic data and haze descriptions relative to Titan's stratosphere. We use this code to model Cassini Composite Infrared Spectrometer data taken during the numerous Titan flybys from 2006 to 2012 at surface-intercepting geometry in the 600-1500 cm{sup -1} range for latitudes from 50 Degree-Sign S to 50 Degree-Sign N. We report variations in temperature and chemical composition in the stratosphere during the Cassini mission, before and after the Northern Spring Equinox (NSE). We find indication for a weakening of the temperature gradient with warming of the stratosphere and cooling of the lower mesosphere. In addition, we infer precise concentrations for the trace gases and their main isotopologues and find that the chemical composition in Titan's stratosphere varies significantly with latitude during the 6 years investigated here, with increased mixing ratios toward the northern latitudes. In particular, we monitor and quantify the amplitude of a maximum enhancement of several gases observed at northern latitudes up to 50 Degree-Sign N around mid-2009, at the time of the NSE. We find that this rise is followed by a rapid decrease in chemical inventory in 2010 probably due to a weakening north polar vortex with reduced lateral mixing across the vortex boundary.

  6. Production of iridium-alloy clad vent sets for the Cassini mission to Saturn

    International Nuclear Information System (INIS)

    Helle, K.J.; Moore, J.P.

    1995-01-01

    Martin Marietta Energy Systems, Inc., has successfully produced the iridium-alloy clad vent sets required for encapsulation of plutonia for the National Aeronautics and Space Administration Cassini mission to Saturn. Numerous improvements were made to the manufacturing process in various areas including dye-penetrant examination of cups, foil part stamping, chemical analysis, tungsten fixturing for laser welding, and enhanced inspections at high magnification. In addition, systems were initiated to ensure process control, and a detailed quality and technical surveillance program was prepared and followed to detect any incipient production problem early in the process so that corrective action could be taken immediately. The quality of the resulting iridium components has been high, and production yields have been above 90%. During the course of the production campaign for the Cassini mission, worker efficiencies lowered production costs, and further cost reductions are possible if operations are consolidated into a single area and bare-forming of the iridium alloys cups can be qualified for flight-quality clad vent sets

  7. A post-Cassini view of Titan's methane-based hydrologic cycle

    Science.gov (United States)

    Hayes, Alexander G.; Lorenz, Ralph D.; Lunine, Jonathan I.

    2018-05-01

    The methane-based hydrologic cycle on Saturn's largest moon, Titan, is an extreme analogue to Earth's water cycle. Titan is the only planetary body in the Solar System, other than Earth, that is known to have an active hydrologic cycle. With a surface pressure of 1.5 bar and temperatures of 90 to 95 K, methane and ethane condense out of a nitrogen-based atmosphere and flow as liquids on the moon's surface. Exchange processes between atmospheric, surface and subsurface reservoirs produce methane and ethane cloud systems, as well as erosional and depositional landscapes that have strikingly similar forms to their terrestrial counterparts. Over its 13-year exploration of the Saturn system, the Cassini-Huygens mission revealed that Titan's hydrocarbon-based hydrology is driven by nested methane cycles that operate over a range of timescales, including geologic, orbital (for example, Croll-Milankovitch cycles), seasonal and that of a single convective storm. In this Review Article, we describe the dominant exchange processes that operate over these timescales and present a post-Cassini view of Titan's methane-based hydrologic system.

  8. Constraints on the Mass and Location of Planet 9 set by Range and VLBI Observations of Cassini

    Science.gov (United States)

    Jacobson, Robert Arthur; Folkner, William; Park, Ryan; Williams, James

    2018-04-01

    Batygin and Brown, 2016 AJ, found that Kuiper belt objects (KBOs) with well determined orbits having periods greater than 4000 years are apsidally aligned. They attribute this orbital clustering to the existence of a distant planet, Planet 9, well beyond Neptune, with a mass roughly ten times that of Earth. If such a planet exists, it would affect the motion of the known solar system planets, in particular Saturn, which is well observed with radiometric ranging from the Cassini spacecraft and VLBI observations of Cassini. The current planetary ephemerides do not account for the postulated Planet 9, yet their fit to the observational data shows no obvious effect that could be attributed to neglecting that planet. However, it is possible that the effect could be absorbed by the estimated parameters used to determine the ephemerides. Those parameters include the planetary orbital elements, mass of the Sun, and the masses of the asteroids that perturb the Martian orbit. We recently updated the Cassini data set and extended it through the end of the mssion in 2017 September. We analyze the sensitivity of these data to the tidal perturbations caused by the postulated Planet 9 for a range of positions on the sky and tidal parameters (the ratio of the mass of Planet 9 to the cube of its distance from Saturn). We determine an upper bound on the tidal parameter and the most probable directions consistent with the observational data.

  9. Irregular Saturnian Moon Lightcurves from Cassini-ISS Observations: Update

    Science.gov (United States)

    Denk, Tilmann; Mottola, S.

    2013-10-01

    Cassini ISS-NAC observations of the irregular moons of Saturn revealed various physical information on these objects. 16 synodic rotational periods: Hati (S43): 5.45 h; Mundilfari (S25): 6.74 h; Suttungr (S23): ~7.4 h; Kari (S45): 7.70 h; Siarnaq (S29): 10.14 h; Tarvos (S21): 10.66 h; Ymir (S19, sidereal period): 11.92220 h ± 0.1 s; Skathi (S27): ~12 h; Hyrrokkin (S44): 12.76 h; Ijiraq (S22): 13.03 h; Albiorix (S26): 13.32 h; Bestla (S39): 14.64 h; Bebhionn (S37): ~15.8 h; Kiviuq (S24): 21.82 h; Thrymr (S30): ~27 h; Erriapus (S28): ~28 h. The average period for the prograde-orbiting moons is ~16 h, for the retrograde moons ~11½ h (includes Phoebe's 9.2735 h from Bauer et al., AJ, 2004). Phase-angle dependent behavior of lightcurves: The phase angles of the observations range from 2° to 105°. The lightcurves which were obtained at low phase (<40°) show the 2-maxima/ 2-minima pattern expected for this kind of objects. At higher phases, more complicated lightcurves emerge, giving rough indications on shapes. Ymir pole and shape: For satellite Ymir, a convex-hull shape model and the pole-axis orientation have been derived. Ymir's north pole points toward λ = 230°±180°, β = -85°±10°, or RA = 100°±20°, Dec = -70°±10°. This is anti-parallel to the rotation axes of the major planets, indicating that Ymir not just orbits, but also rotates in a retrograde sense. The shape of Ymir resembles a triangular prism with edge lengths of ~20, ~24, and ~25 km. The ratio between the longest 25 km) and shortest axis (pole axis, ~15 km) is ~1.7. Erriapus seasons: The pole direction of object Erriapus has probably a low ecliptic latitude. This gives this moon seasons similar to the Uranian regular moons with periods where the sun stands very high in the sky over many years, and with years-long periods of permanent night. Hati density: The rotational frequency of the fastest rotator (Hati) is close to the frequency where the object would lose material from the surface if

  10. Vorticity and energy diagnostics from the 2000 Cassini Jupiter flyby

    Science.gov (United States)

    Young, R. M. B.; Read, P. L.; Armstrong, D.; Lancaster, A.

    2011-10-01

    The Cassini spacecraft flew by Jupiter in December 2000, returning hundreds of images near closest approach [1]. We have been analysing the images spanning four Jupiter rotation periods at closest approach using automated cloud tracking software to obtain horizontal velocity fields. Our method has some advantages over other methods used for this purpose in that it accounts for both cloud deformation and rotation in addition to the standard translation. We shall present detailed horizontal velocity vectors and related vorticity and energy fields over four Jupiter rotation periods. We also intend to produce derived energy and turbulence diagnostics that will help us to understand the interplay between processes acting on different length scales. It may also be possible to relate these diagnostics to 'zonostrophic' jets and small-scale turbulence studied in the laboratory using the Coriolis rotating tank, work itself motivated by jets in giant planet atmospheres [2]. In the future we intend to combine velocity fields with temperature data to produce fully-3D velocity and potential vorticity fields for Jupiter's troposphere and stratosphere. The cloud tracking method is based on correlation image velocimetry (CIV) and was originally developed by the Coriolis facility team at LEGI, Université de Grenoble [3], where it is used to extract velocity fields from data obtained in their 13m diameter rotating tank experiment. The method has two stages. First, velocity vectors are calculated using translation only, where the velocity is defined by the highest correlation between two images taken 63 minutes apart of a small pixel patch moving within a larger search box. In the second stage the correlation analysis is repeated, but instead of just translation of the pixel patch, rotation and deformation (shearing, stretching) are taken into account. We use the first stage velocity field as an estimate of the velocity vector and search within a small window around this, including

  11. Cassini-Huygens makes first close approach to Titan

    Science.gov (United States)

    2004-10-01

    Purple zaze hi-res Size hi-res: 88 kb Credits: NASA/JPL/Space Science Institute Purple haze around Titan This NASA/ESA/ASI Cassini-Huygens image of Titan was taken with the narrow-angle camera on 3 July 2004, from a distance of about 789 000 kilometres from Titan. The image scale is 4.7 kilometres per pixel. This image shows two thin haze layers. The outer haze layer is detached and appears to float high in the atmosphere. Because of its thinness, the high haze layer is best seen at the moon's limb. The image was taken using a spectral filter sensitive to wavelengths of ultraviolet light centred at 338 nanometres. The image has been falsely coloured, the globe of Titan retains the pale orange hue our eyes would usually see, but both the main atmospheric haze and the thin detached layer have been brightened and given a purple colour to enhance their visibility. At the time of the closest approach, which is scheduled for 18:44 CEST, the spacecraft will be travelling only 1200 kilometres above the surface of the moon, almost grazing the outer atmosphere, at a speed of six kilometres per second (21 800 kilometres per hour)! Confirmation that the fly-by was successful and that all the data were received will not take place until 03:30 CEST on 27 October. This fly-by not only allows important surface science to be performed, such as radar analysis at close quarters, but also it significantly changes the orbit of the spacecraft around Saturn. Currently Cassini-Huygens has an orbital period of four months, which will change to 48 days, thus setting the course for the next close Titan fly-by on 13 December 2004 and the Huygens probe release on 25 December. Several of the observations performed during this fly-by will provide important information for ESA’s Huygens team, who will be using the data gathered to double-check atmospheric models for entry and descent on 14 January 2005. The Huygens probe will need to perform reliably in some of the most challenging and remote

  12. Pulling it all together: the self-consistent distribution of neutral tori in Saturn's Magnetosphere based on all Cassini observations

    Science.gov (United States)

    Smith, H. T.; Richardson, J. D.

    2017-12-01

    Saturn's magnetosphere is unique in that the plumes from the small icy moon, Enceladus, serve at the primary source for heavy particles in Saturn's magnetosphere. The resulting co-orbiting neutral particles interact with ions, electrons, photons and other neutral particles to generate separate H2O, OH and O tori. Characterization of these toroidal distributions is essential for understanding Saturn magnetospheric sources, composition and dynamics. Unfortunately, limited direct observations of these features are available so modeling is required. A significant modeling challenge involves ensuring that either the plasma and neutral particle populations are not simply input conditions but can provide feedback to each population (i.e. are self-consistent). Jurac and Richardson (2005) executed such a self-consistent model however this research was performed prior to the return of Cassini data. In a similar fashion, we have coupled a 3-D neutral particle model (Smith et al. 2004, 2005, 2006, 2007, 2009, 2010) with a plasma transport model (Richardson 1998; Richardson & Jurac 2004) to develop a self-consistent model which is constrained by all available Cassini observations and current findings on Saturn's magnetosphere and the Enceladus plume source resulting in much more accurate neutral particle distributions. We present a new self-consistent model of the distribution of the Enceladus-generated neutral tori that is validated by all available observations. We also discuss the implications for source rate and variability.

  13. The Saturnian satellite Rhea as seen by Cassini VIMS

    Science.gov (United States)

    Stephan, K.; Jaumann, R.; Wagner, R.; Clark, R.N.; Cruikshank, D.P.; Giese, B.; Hibbitts, C.A.; Roatsch, T.; Matz, K.-D.; Brown, R.H.; Filacchione, G.; Cappacioni, F.; Scholten, F.; Buratti, B.J.; Hansen, G.B.; Nicholson, P.D.; Baines, K.H.; Nelson, R.M.; Matson, D.L.

    2012-01-01

    Since the arrival of the Cassini spacecraft at Saturn in June 2004, the Visual and Infrared Mapping Spectrometer has obtained new spectral data of the icy satellites of Saturn in the spectral range from 0.35 to 5.2 ??m. Numerous flybys were performed at Saturn's second largest satellite Rhea, providing a nearly complete coverage with pixel-ground resolutions sufficient to analyze variations of spectral properties across Rhea's surface in detail. We present an overview of the VIMS observations obtained so far, as well as the analysis of the spectral properties identified in the VIMS spectra and their variations across its surface compared with spatially highly resolved Cassini ISS images and digital elevation models. Spectral variations measured across Rhea's surface are similar to the variations observed in the VIMS observations of its neighbor Dione, implying similar processes causing or at least inducing their occurrence. Thus, magnetospheric particles and dust impacting onto the trailing hemisphere appear to be responsible for the concentration of dark rocky/organic material and minor amounts of CO 2 in the cratered terrain on the trailing hemisphere. Despite the prominent spectral signatures of Rhea's fresh impact crater Inktomi, radiation effects were identified that also affect the H 2O ice-rich cratered terrain of the leading hemisphere. The concentration of H 2O ice in the vicinity of steep tectonic scarps near 270??W and geologically fresh impact craters implies that Rhea exhibits an icy crust at least in the upper few kilometers. Despite the evidence for past tectonic events, no indications of recent endogenically powered processes could be identified in the Cassini data. ?? 2011 Elsevier Ltd. All rights reserved.

  14. Cassini revisited by the Cassini-Huygens probe: dynamical and photometric study of the rings with the ISS images

    International Nuclear Information System (INIS)

    Deau, Estelle

    2007-12-01

    In the Solar system, the planetary rings represent a fantastic opportunity of studying a majority of phenomena taking place in the thin discs. One can find discs at all redshifts and on all scales of the Universe. Planetary discs are very different: among the Jovian rings, one finds a halo of fine and diffuse dust; the rings of Uranus are very compact, like radially confined strings and the system of rings of Neptune consists of azimuthally stable arcs. However our interest goes on Saturn which has the most complex and widest system of rings known to date: 484 000 km and a vertical extension which increases with the distance to Saturn (typically less than 1 km to 10 000 km). The interest of such a matter organization around Saturn plus its many moons (more than one forty including 8 of a size of several hundreds kilometers) gave birth to the exploration mission CASSINI, supposed to allow the development and the refinement of models set up at the flybies of the two interplanetary probes VOYAGER. The CASSINI Mission began its nominal tour on January, 15 2005 after the orbital insertion the 1 July 2004 and the dropping of HUYGENS probe on january, 14 2005 on Titan's surface. The purpose of this thesis consists to revisit two subjects unsolved of long date in the photometric and dynamic behaviours of the Saturn's rings. In a first part, we try to solve the problem of accretion of matter within the Roche limit by studying the F ring. This ring, since its discovery in 1979 by Pioneer 11, is involved in a most various dynamic theories to explain its complex multi-radial structure and its variable azimuthal structure. We showed that the multi-radial structure of this ring can be understood by the existence of a spiral which is rolled up around a central area, bright, eccentric and inclined: the core. The lifespan of this spiral is not the same one as the core, suggesting that the processes which create the spiral are periodic. Moreover, we showed that the structure of the

  15. Cassini CAPS Identification of Pickup Ion Compositions at Rhea

    Science.gov (United States)

    Desai, R. T.; Taylor, S. A.; Regoli, L. H.; Coates, A. J.; Nordheim, T. A.; Cordiner, M. A.; Teolis, B. D.; Thomsen, M. F.; Johnson, R. E.; Jones, G. H.; Cowee, M. M.; Waite, J. H.

    2018-02-01

    Saturn's largest icy moon, Rhea, hosts a tenuous surface-sputtered exosphere composed primarily of molecular oxygen and carbon dioxide. In this Letter, we examine Cassini Plasma Spectrometer velocity space distributions near Rhea and confirm that Cassini detected nongyrotropic fluxes of outflowing CO2+ during both the R1 and R1.5 encounters. Accounting for this nongyrotropy, we show that these possess comparable along-track densities of ˜2 × 10-3 cm-3. Negatively charged pickup ions, also detected during R1, are surprisingly shown as consistent with mass 26 ± 3 u which we suggest are carbon-based compounds, such as CN-, C2H-, C2-, or HCO-, sputtered from carbonaceous material on the moon's surface. The negative ions are calculated to possess along-track densities of ˜5 × 10-4 cm-3 and are suggested to derive from exogenic compounds, a finding consistent with the existence of Rhea's dynamic CO2 exosphere and surprisingly low O2 sputtering yields. These pickup ions provide important context for understanding the exospheric and surface ice composition of Rhea and of other icy moons which exhibit similar characteristics.

  16. Enhanced Input in LCTL Pedagogy

    Directory of Open Access Journals (Sweden)

    Marilyn S. Manley

    2009-08-01

    Full Text Available Language materials for the more-commonly-taught languages (MCTLs often include visual input enhancement (Sharwood Smith 1991, 1993 which makes use of typographical cues like bolding and underlining to enhance the saliency of targeted forms. For a variety of reasons, this paper argues that the use of enhanced input, both visual and oral, is especially important as a tool for the lesscommonly-taught languages (LCTLs. As there continues to be a scarcity of teaching resources for the LCTLs, individual teachers must take it upon themselves to incorporate enhanced input into their own self-made materials. Specific examples of how to incorporate both visual and oral enhanced input into language teaching are drawn from the author’s own experiences teaching Cuzco Quechua. Additionally, survey results are presented from the author’s Fall 2010 semester Cuzco Quechua language students, supporting the use of both visual and oral enhanced input.

  17. Enhanced Input in LCTL Pedagogy

    Directory of Open Access Journals (Sweden)

    Marilyn S. Manley

    2010-08-01

    Full Text Available Language materials for the more-commonly-taught languages (MCTLs often include visual input enhancement (Sharwood Smith 1991, 1993 which makes use of typographical cues like bolding and underlining to enhance the saliency of targeted forms. For a variety of reasons, this paper argues that the use of enhanced input, both visual and oral, is especially important as a tool for the lesscommonly-taught languages (LCTLs. As there continues to be a scarcity of teaching resources for the LCTLs, individual teachers must take it upon themselves to incorporate enhanced input into their own self-made materials. Specific examples of how to incorporate both visual and oral enhanced input into language teaching are drawn from the author’s own experiences teaching Cuzco Quechua. Additionally, survey results are presented from the author’s Fall 2010 semester Cuzco Quechua language students, supporting the use of both visual and oral enhanced input.

  18. Cassini RADAR Observations of Phoebe, Iapetus, Enceladus, and Rhea

    Science.gov (United States)

    Ostro, S. J.; West, R. D.; Janssen, M. A.; Zebker, H. A.; Wye, L. C.; Lunine, J. I.; Lopes, R. M.; Kelleher, K.; Hamilton, G. A.; Gim, Y.; Anderson, Y. Z.; Boehmer, R. A.; Lorenz, R. D.

    2005-12-01

    Operating in its scatterometry mode, the Cassini radar has obtained 2.2-cm-wavelength echo power spectra from Phoebe on the inbound and outbound legs of its flyby (subradar points at W. Long, Lat. = 245,-22 deg and 328,+27 deg), from Iapetus' leading side (66,+39 deg) and trailing side (296,+44 deg) on the inbound and outbound legs of orbit BC, from Enceladus during orbits 3 (0,0 deg) and 4 (70,-13 deg), and from Rhea during orbit 11 (64,-77 deg). Our echo spectra, obtained in the same linear (SL) polarization as transmitted, are broad, nearly featureless, and much stronger than expected if the echoes were due just to single backreflections. Rather, volume scattering from the subsurface probably is primarily responsible for the echoes. This conclusion is supported by the strong anticorrelation between our targets' radar albedos (radar cross section divided by target projected area) and disc brightness temperatures estimated from passive radiometric measurements obtained during each radar flyby. Taking advantage of the available information about the radar properties of the icy satellites of Saturn and Jupiter, especially the linear- and circular-polarization characteristics of groundbased echoes from the icy Galilean satellites (Ostro et al. 1992, J. Geophys. Res. 97, 18227-18244), we estimate our targets' 2.2-cm total-power (TP) albedos and compare them to Arecibo and Goldstone values for icy satellites at 3.5, 13, and 70 cm. Our four targets' albedos span an order of magnitude and decrease in the same order as their optical albedos: Enceladus/Rhea/Iapetus/Phoebe. This sequence most likely corresponds to increasing contamination of near-surface water ice, whose extremely low electrical loss at radio wavelengths permits the multiple scattering responsible for high radar albedos. Plausible candidates for contaminants causing variations in radar albedo include ammonia, silicates, and polar organics. Modeling of icy Galilean satellite echoes indicates that penetration

  19. GPHS-RTGs in support of the Cassini RTG Program. Addendum to the final technical report, May 1--December 31, 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    This Addendum to the Cassini GPHS-RTG Program Final Technical Progress Report describes activities performed during the period 1 May 1998 through 31 December 1998, including effort reflecting contract modification M058. These activities include Earth Gravity Assist (EGA) reentry and related analyses which are detailed in Part A, and effort related to the installation of CAGO equipment within Lockheed Martin`s Building 100 facility in Valley Forge, PA, which is detailed in Part B.

  20. GPHS-RTGs in support of the Cassini RTG Program. Addendum to the final technical report, May 1-December 31, 1998

    International Nuclear Information System (INIS)

    1998-12-01

    This Addendum to the Cassini GPHS-RTG Program Final Technical Progress Report describes activities performed during the period 1 May 1998 through 31 December 1998, including effort reflecting contract modification M058. These activities include Earth Gravity Assist (EGA) reentry and related analyses which are detailed in Part A, and effort related to the installation of CAGO equipment within Lockheed Martin's Building 100 facility in Valley Forge, PA, which is detailed in Part B

  1. Tiger Stripes and Cassini ISS High-Resolution Imaging of Enceladus

    Science.gov (United States)

    Helfenstein, Paul; Denk, T.; Giese, B.; McEwen, A. S.; Neukum, G.; Perry, J.; Porco, C. C.; Thomas, P. C.; Turtle, E.; Verbiscer, A.; Veverka, J.

    2008-09-01

    Deciphering the mechanisms of Enceladus’ plumes is one of the most important and challenging tasks for planetary science. Cassini has provided a wealth of data by remote and in-situ data collection, but fundamental details of the vents and their context remain elusive. Three flybys of Enceladus by Cassini in 2008, on August 11 (altitude: 50km), October 9 (30km), and October 31 (200 km) are designed to further our knowledge of Enceladus’ geology and geophysics. Anticipated data include images as good as 7 m/pixel of parts of the geologically active South Polar Terrain (SPT). We targeted six different known eruption sites (Spitale and Porco 2007, Nature 449, 695-697) along Cairo Sulcus, Baghdad Suclus, and Damascus Sulcus, as well as non-active portions of the the "tiger stripes" and bright grooved terrain in between. On each of the three flybys we also plan contiguous ISS broadband multi-spectral mosaics of the entire SPT region so that we can search for volcanically and tectonically driven temporal changes and construct detailed digital terrain maps. Previous images of the tiger stripes and other rift systems on Enceladus resolve geomorphic structures on hundred meter scales or larger. Within those resolution limits, tiger stripes are morphologically distinguished most strongly from comparably sized young looking rifts elsewhere on Enceladus by their prominent upturned flanks, the muted appearance of their surface relief, and their relative absence of distinct cliff faces, probably of solid ice along scarps. The anticipated new high-resolution images will provide critical structural details needed to identify the extent to which unique attributes of tiger stripes are caused by mantling by plume fallout, tectonic deformation, seismic disruption, or perhaps thermal processes. Here, we present a first analysis of the August 11 close flyby images.

  2. Scientific and synergistic lessons learned from the Cassini-Huygens mission

    Science.gov (United States)

    Coustenis, Athena

    The Cassini-Huygens mission to the Saturnian system has been an extraordinary success for the planetary community since the Saturn-Orbit-Insertion (SOI) in July 2004 and again the very successful probe descent and landing of Huygens on January 14, 2005. One of its main targets was Titan. Titan, Saturn's largest satellite, is the only other object in our Solar system to possess an extensive nitrogen atmosphere, host to an active organic chemistry, based on the interaction of N2 with methane (CH4). Titan was revealed to be a complex world more like the Earth than any other: it has a dense mostly nitrogen atmosphere and active climate and meteorological cycles where the working fluid, methane, behaves under Titan conditions the way that water does on Earth. Its geology, from lakes and seas to broad river valleys and mountains, while carved in ice is, in its balance of processes, again most like Earth. Beneath this panoply of Earth-like processes an ice crust floats atop what appears to be a liquid water ocean. Titan is also rich in organic molecules—more so in its surface and atmosphere than anyplace in the solar system, including Earth [2-4]. These molecules were formed in the atmosphere, deposited on the surface and, in coming into contact with liquid water may undergo an aqueous chemistry that could replicate aspects of life's origins. I will discuss our current understanding of Titan's complex environment in view of the Cassini-Huygens mission results [1-8], which demonstrated the power of synergistic remote and in situ exploration. I will focus on the atmospheric structure (temperature and composition), and the surface nature. I will show how these and other elements can give us clues as to the origin and evolution of the satellite, and how they connect to the observations of the other satellites, Enceladus in particular. Future space missions to Titan can help us understand the kronian and also our Solar System as a whole. Finally, I will describe the future

  3. Iapetus: First data from the Cassini Visual Infrared Mapping Spectrometer

    Science.gov (United States)

    Buratti, B. J.; Cruikshank, D. P.; Clark, R.; Brown, R. H.; Bauer, J. M.; Simonelli, D. P.; Jaumann, R.; Hibbitts, K.; McCord, T. B.; Soderlund, K.; Baines, K. H.; Bellucci, G.; Bibring, J. P.; Capaccioni, F.; Cerroni, P.; Coradini, A.; Drossart, P.; Formisano, V.; Langevin, Y.; Matson, D. L.; Mennella, V.; Nelson, R.; Nicholson, P. D.; Sicardy, B.; Sotin, C.

    2004-11-01

    Iapetus is perhaps the most enigmatic body in the solar system: One hemisphere is as dark as lampblack, and the other is almost as bright as snow. The models that have been offered to explain this dichotomy range from endogenously placed material (Smith et al., 1982, Science 215, 504), to material exogenously placed from Phoebe (Soter, 1974, IAU Colloq. 28), or other bodies (Owen et al., 2001, Icarus 149, 160; Buratti et al., 2002, Icarus 155, 375; Buratti et al., 2003, B.A.A.S, 915). No mechanism for the darkening process or purported source for the exogenic particles is entirely satisfactory. One key question is whether the process that led to the formation of the low-albedo hemisphere of Iapetus is unique, or whether the satellite has been subjected to a satellite alteration process in a more extreme form. Both Callisto and the outer satellites of Uranus show evidence for exogenic accretion of particles onto their leading sides. A targeted flyby of Iapetus by Cassini, during which the spacecraft will approach the satellite to within 1000 km, is scheduled to occur in September 2007. An untargeted approach of 65,000 km to the satellite will occur on New Year's day 2005, and observations are planned for the period around closest approach. However, a "sneak peak" of the satellite was afforded by Cassini on July 19, 2004, during which the spacecraft approached to less than three million miles (the Voyager closest approach was 909,070 km). The first disk resolved spectra of Iapetus in the 0.4 to 5 micron region were obtained by the Cassini Visual Infrared Mapping Spectrometer (VIMS). We report the tentative identification of carbon dioxide on the low-albedo portion of the surface. A comparison of the spectrum of Iapetus to that obtained by VIMS during its flyby of Phoebe on June 11, 2004 will be made. Mixing models incorporating water ice, minerals, and organics can replicate the spectrum of the dark hemisphere. Work performed at the Jet Propulsion Laboratory

  4. Tidal Control of Jet Eruptions Observed by Cassini ISS

    Science.gov (United States)

    Hurford, T. A.; Helfenstein, P.; Spitale, J. N.

    2012-01-01

    Observations by Cassini's Imaging Science Subsystem (ISS) of Enceladus' south polar region at high phase angles has revealed jets of material venting into space. Observations by Cassini's Composite Infrared Spectrometer (CIRS) have also shown that the south polar region is anomalously warm with hotspots associated with geological features called the Tiger Stripes. The Tiger Stripes are large rifts near the south pole of Enceladus, which are typically about 130 km in length, 2 km wide, with a trough 500 m deep, and are l1anked on each side by 100m tall ridges. Preliminary triangulation of jets as viewed at different times and with different viewing geometries in Cassini ISS images taken between 2005 and 2007 have constrained the locations of eight major eruptions of material and found all of them associated with the south polar fractures unofficially the 'Tiger Stripes', and found four of them coincident with the hotspots reported in 2006 by CIRS. While published ISS observations of jet activity suggest that individual eruption sites stay active on the timescale of years, any shorter temporal variability (on timescales of an orbital period, or 1.3 Earth days, for example) is more difficult to establish because of the spotty temporal coverage and the difficulty of visually isolating one jet from the forest of many seen in a typical image. Consequently, it is not known whether individual jets are continuously active, randomly active, or if they erupt on a predictable, periodic schedule. One mechanism that may control the timing of eruptions is diurnal tidal stress, which oscillates between compression/tension as well as right and left lateral shear at any given location throughout Enceladus' orbit and may allow the cracks to open and close regularly. We examine the stresses on the Tiger Stripe regions to see how well diurnal tidal stress caused by Enceladus' orbital eccentricity may possibly correlate with and thus control the observed eruptions. We then identify

  5. An overview of the risk uncertainty assessment process for the Cassini space mission

    International Nuclear Information System (INIS)

    Wyss, G.D.

    1996-01-01

    The Cassini spacecraft is a deep space probe whose mission is to explore the planet Saturn and its moons. Since the spacecraft's electrical requirements will be supplied by radioisotope thermoelectric generators (RTGs), the spacecraft designers and mission planners must assure that potential accidents involving the spacecraft do not pose significant human risk. The Cassini risk analysis team is seeking to perform a quantitative uncertainty analysis as a part of the overall mission risk assessment program. This paper describes the uncertainty analysis methodology to be used for the Cassini mission and compares it to the methods that were originally developed for evaluation of commercial nuclear power reactors

  6. TART input manual

    International Nuclear Information System (INIS)

    Kimlinger, J.R.; Plechaty, E.F.

    1982-01-01

    The TART code is a Monte Carlo neutron/photon transport code that is only on the CRAY computer. All the input cards for the TART code are listed, and definitions for all input parameters are given. The execution and limitations of the code are described, and input for two sample problems are given

  7. FLUTAN input specifications

    International Nuclear Information System (INIS)

    Borgwaldt, H.; Baumann, W.; Willerding, G.

    1991-05-01

    FLUTAN is a highly vectorized computer code for 3-D fluiddynamic and thermal-hydraulic analyses in cartesian and cylinder coordinates. It is related to the family of COMMIX codes originally developed at Argonne National Laboratory, USA. To a large extent, FLUTAN relies on basic concepts and structures imported from COMMIX-1B and COMMIX-2 which were made available to KfK in the frame of cooperation contracts in the fast reactor safety field. While on the one hand not all features of the original COMMIX versions have been implemented in FLUTAN, the code on the other hand includes some essential innovative options like CRESOR solution algorithm, general 3-dimensional rebalacing scheme for solving the pressure equation, and LECUSSO-QUICK-FRAM techniques suitable for reducing 'numerical diffusion' in both the enthalphy and momentum equations. This report provides users with detailed input instructions, presents formulations of the various model options, and explains by means of comprehensive sample input, how to use the code. (orig.) [de

  8. GARFEM input deck description

    Energy Technology Data Exchange (ETDEWEB)

    Zdunek, A.; Soederberg, M. (Aeronautical Research Inst. of Sweden, Bromma (Sweden))

    1989-01-01

    The input card deck for the finite element program GARFEM version 3.2 is described in this manual. The program includes, but is not limited to, capabilities to handle the following problems: * Linear bar and beam element structures, * Geometrically non-linear problems (bar and beam), both static and transient dynamic analysis, * Transient response dynamics from a catalog of time varying external forcing function types or input function tables, * Eigenvalue solution (modes and frequencies), * Multi point constraints (MPC) for the modelling of mechanisms and e.g. rigid links. The MPC definition is used only in the geometrically linearized sense, * Beams with disjunct shear axis and neutral axis, * Beams with rigid offset. An interface exist that connects GARFEM with the program GAROS. GAROS is a program for aeroelastic analysis of rotating structures. Since this interface was developed GARFEM now serves as a preprocessor program in place of NASTRAN which was formerly used. Documentation of the methods applied in GARFEM exists but is so far limited to the capacities in existence before the GAROS interface was developed.

  9. Electrical interferences observed in the Cassini CIRS spectrometer

    Science.gov (United States)

    Chan, Cheong; Albright, Shane; Gorius, Nicolas; Brasunas, John; Jennings, Don; Flasar, F. Michael; Carlson, Ronald; Guandique, Ever; Nixon, Conor

    2015-06-01

    The Composite Infrared Spectrometer (CIRS) carried onboard the Cassini spacecraft has now operated successfully for 17 years, following launch in 1997. Following insertion into Saturnian orbit in July 2004, the instrument has taken data nearly continuously, returning over 100 million interferograms (spectra) to date. Although of generally high quality, and resulting in more than 100 peer-reviewed scientific articles, the spectra are afflicted with several types of instrumental electrical (non-random) noise artifacts. These noise artifacts require either mitigation strategies (prevention), removal from the observed data, or else awareness of the affected spectral areas which must be excluded from scientific analysis. The sources and nature of these varied noise types were not readily identified until after launch. The purpose of this article is to inform users of the noise in the CIRS dataset and to serve as a `lesson-learned' guide for designers of future instruments.

  10. Saturn's equatorial jet structure from Cassini/ISS

    Science.gov (United States)

    García-Melendo, Enrique; Legarreta, Jon; Sánchez-Lavega, Agustín.; Pérez-Hoyos, Santiago; Hueso, Ricardo

    2010-05-01

    Detailed wind observations of the equatorial regions of the gaseous giant planets, Jupiter and Saturn, are crucial for understanding the basic problem of the global circulation and obtaining new detailed information on atmospheric phenomena. In this work we present high resolution data of Saturn's equatorial region wind profile from Cassini/ISS images. To retrieve wind measurements we applied an automatic cross correlator to image pairs taken by Cassini/ISS with the MT1, MT2, MT3 filters centred at the respective three methane absorbing bands of 619nm, 727nm, and 889nm, and with the adjacent continuum CB1, CB2, and CB3 filters. We obtained a complete high resolution coverage of Saturn's wind profile in the equatorial region. The equatorial jet displays an overall symmetric structure similar to that shown the by same region in Jupiter. This result suggests that, in accordance to some of the latest compressible atmosphere computer models, probably global winds in gaseous giants are deeply rooted in the molecular hydrogen layer. Wind profiles in the methane absorbing bands show the effect of strong vertical shear, ~40m/s per scale height, confirming previous results and an important decay in the wind intensity since the Voyager era (~100 m/s in the continuum and ~200 m/s in the methane absorbing band). We also report the discovery of a new feature, a very strong and narrow jet on the equator, about only 5 degrees wide, that despite the vertical shear maintains its intensity (~420 m/s) in both, the continuum and methane absorbing band filters. Acknowledgements: Work supported by the Spanish MICIIN AYA2009-10701 with FEDER and Grupos Gobierno Vasco IT-464-07.

  11. Cassini/CIRS Observations of Water Vapor in Titan's Stratosphere

    Science.gov (United States)

    Bjoraker, Gordon L.; Achterberg, R. K.; Anderson, C. M.; Samuelson, R. E.; Carlson, R. C.; Jennings, D. E.

    2008-01-01

    The Composite Infrared Spectrometer (CIRS) on the Cassini spacecraft has obtained spectra of Titan during most of the 44 flybys of the Cassini prime mission. Water vapor on Titan was first detected using whole-disk observations from the Infrared Space Observatory (Coustenis et al 1998, Astron. Astrophys. 336, L85-L89). CIRS data permlt the retrieval of the latitudinal variation of water on Titan and some limited information on its vertical profile. Emission lines of H2O on Titan are very weak in the CIRS data. Thus, large spectral averages as well as improvements in calibration are necessary to detect water vapor. Water abundances were retrieved in nadir spectra at 55 South, the Equator, and at 19 North. Limb spectra of the Equator were also modeled to constrain the vertical distribution of water. Stratospheric temperatures in the 0.5 - 4.0 mbar range were obtained by inverting spectra of CH4 in the v4 band centered at 1304/cm. The temperature in the lower stratosphere (4 - 20 mbar) was derived from fitting pure rotation lines of CH4 between 80 and 160/cm. The origin of H2O and CO2 is believed to be from the ablation of micrometeorites containing water ice, followed by photochemistry. This external source of water originates either within the Saturn system or from the interplanetary medium. Recently, Horst et al (J. Geophys. Res. 2008, in press) developed a photochemical model of Titan in which there are two external sources of oxygen. Oxygen ions (probably from Enceladus) precipitate into Titan's atmosphere to form CO at very high altitudes (1100 km). Water ice ablation at lower altitudes (700 km) forms H2O and subsequent chemistry produces CO2. CIRS measurements of CO, CO2, and now of H2O will provide valuable constraints to these photochemical models and - improve our understanding of oxygen chemistry on Titan.

  12. Tidally modulated eruptions on Enceladus: Cassini ISS observations and models

    International Nuclear Information System (INIS)

    Nimmo, Francis; Porco, Carolyn; Mitchell, Colin

    2014-01-01

    We use images acquired by the Cassini Imaging Science Subsystem (ISS) to investigate the temporal variation of the brightness and height of the south polar plume of Enceladus. The plume's brightness peaks around the moon's apoapse, but with no systematic variation in scale height with either plume brightness or Enceladus' orbital position. We compare our results, both alone and supplemented with Cassini near-infrared observations, with predictions obtained from models in which tidal stresses are the principal control of the eruptive behavior. There are three main ways of explaining the observations: (1) the activity is controlled by right-lateral strike slip motion; (2) the activity is driven by eccentricity tides with an apparent time delay of about 5 hr; (3) the activity is driven by eccentricity tides plus a 1:1 physical libration with an amplitude of about 0.°8 (3.5 km). The second hypothesis might imply either a delayed eruptive response, or a dissipative, viscoelastic interior. The third hypothesis requires a libration amplitude an order of magnitude larger than predicted for a solid Enceladus. While we cannot currently exclude any of these hypotheses, the third, which is plausible for an Enceladus with a subsurface ocean, is testable by using repeat imaging of the moon's surface. A dissipative interior suggests that a regional background heat source should be detectable. The lack of a systematic variation in plume scale height, despite the large variations in plume brightness, is plausibly the result of supersonic flow; the details of the eruption process are yet to be understood.

  13. Discovery Of B Ring Propellers In Cassini UVIS, And ISS

    Science.gov (United States)

    Sremcevic, Miodrag; Stewart, G. R.; Albers, N.; Esposito, L. W.

    2012-10-01

    We present evidence for the existence of propellers in Saturn's B ring by combining data from Cassini Ultraviolet Imaging Spectrograph (UVIS) and Imaging Science Subsystem (ISS) experiments. We identify two propeller populations: (1) tens of degrees wide propellers in the dense B ring core, and (2) smaller, more A ring like, propellers populating the inner B ring. The prototype of the first population is an object observed at 18 different epochs between 2005 and 2010. The ubiquitous propeller "S" shape is seen both in UVIS occultations as an optical depth depletion and in ISS as a 40 degrees wide bright stripe in unlit geometries and dark in lit geometries. Combining the available Cassini data we infer that the object is a partial gap embedded in the high optical depth region of the B ring. The gap moves at orbital speed consistent with its radial location. From the radial separation of the propeller wings we estimate that the embedded body, which causes the propeller structure, is about 1.5km in size located at a=112,921km. The UVIS occultations indicate an asymmetric propeller "S" shape. Since the object is located at an edge between high and relatively low optical depth, this asymmetry is most likely a consequence of the strong surface mass density gradient. We estimate that there are possibly dozen up to 100 other propeller objects in Saturn's B ring. The location of the discovered body, at an edge of a dense ringlet within the B ring, suggests a novel mechanism for the up to now illusive B ring irregular large-scale structure of alternating high and low optical depth ringlets. We propose that this B ring irregular structure may have its cause in the presence of many embedded bodies that shepherd the individual B ring ringlets.

  14. Riddles of the Sphinx: Titan Science Questions at the End of Cassini-Huygens

    Science.gov (United States)

    Nixon, C. A.; Achterberg, R. K.; Buch, A.; Clark, R. N.; Coll, P.; Flasar, F. M.; Hayes, A. G.; Iess, L.; Lorenz, R. D.; Lopes, R.; Mastroguiseppe, M.; Raulin, F.; Smith, T.; Solomidou, A.; Sotin, C.; Strobel, D. F.; Turtle, E. P.; Vuitton, V.; West, R. A.; Yelle, R.

    2017-02-01

    The paper will describe the outstanding high-level questions for Titan science that are remaining at the end of the Cassini-Huygens mission, compiled by a cross-section of scientists from multiple instrument teams.

  15. CASSINI S MIMI CHEMS SENSOR CALIBRATED DATA V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The Cassini Magnetospheric Imaging Instrument(MIMI) Charge Energy Mass Spectrometer (CHEMS) contains a deflection system and an overall field of view of 159 x 4 deg....

  16. CASSINI RSS RAW DATA SET - SROC20 V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The Cassini Radio Science Saturn Ring and Atmospheric Occultation experiments (SROC20) Raw Data Archive is a time-ordered collection of radio science raw data...

  17. Input-output supervisor

    International Nuclear Information System (INIS)

    Dupuy, R.

    1970-01-01

    The input-output supervisor is the program which monitors the flow of informations between core storage and peripheral equipments of a computer. This work is composed of three parts: 1 - Study of a generalized input-output supervisor. With sample modifications it looks like most of input-output supervisors which are running now on computers. 2 - Application of this theory on a magnetic drum. 3 - Hardware requirement for time-sharing. (author) [fr

  18. Cassini MIMI Close-Up of Saturn Energetic Particles: Low Altitude Trapped Radiation, Auroral Ion Acceleration, and Interchange Flow Channels

    Science.gov (United States)

    Mitchell, D. G.; Krimigis, S. M.; Krupp, N.; Paranicas, C.; Roussos, E.; Kollmann, P.

    2017-12-01

    We present observations from the final orbits of the Cassini Mission at Saturn by the Magnetospheric Imaging Instrument (MIMI). Crossing inside the D-Ring at the equator and just above Saturn's atmosphere, these orbits covered regions never visited previously in the mission. Highlights include the confirmation of an inner radiation belt analogous to the inner radiation belt at Earth by the Low Energy Magnetospheric Measurement System (LEMMS), with surprising twists—Saturn's D-ring material appears to be a source for these particles. Details will be presented in another session. The Grand Finale orbits also afforded a close-up view of the auroral ion acceleration regions by the Ion and Neutral Camera (INCA). Ionospheric ions at the base of auroral field lines are accelerated perpendicular to the magnetic field to 10's and 100's of keV, and charge exchange with exospheric neutrals to be emitted as energetic neutral atoms and images by INCA. We show that this acceleration region lies at about 0.1 Rs. Another feature seen previously in the mission but imaged with greater resolution is a flow channel associated with interchange motion in the middle magnetosphere. We show this feature to extend over several Saturn radii in the radial direction, and over about 2 Saturn radii azimuthally. Additional data have been received since the writing of this abstract and before Cassini's plunge into the atmosphere on September 15, so additional features may be presented.

  19. Storm clouds on Saturn: Lightning-induced chemistry and associated materials consistent with Cassini/VIMS spectra

    Science.gov (United States)

    Baines, K.H.; Delitsky, M.L.; Momary, T.W.; Brown, R.H.; Buratti, B.J.; Clark, R.N.; Nicholson, P.D.

    2009-01-01

    Thunderstorm activity on Saturn is associated with optically detectable clouds that are atypically dark throughout the near-infrared. As observed by Cassini/VIMS, these clouds are ~20% less reflective than typical neighboring clouds throughout the spectral range from 0.8 ??m to at least 4.1 ??m. We propose that active thunderstorms originating in the 10-20 bar water-condensation region vertically transport dark materials at depth to the ~1 bar level where they can be observed. These materials in part may be produced by chemical processes associated with lightning, likely within the water clouds near the ~10 bar freezing level of water, as detected by the electrostatic discharge of lightning flashes observed by Cassini/RPWS (e.g., Fischer et al. 2008, Space Sci. Rev., 137, 271-285). We review lightning-induced pyrolytic chemistry involving a variety of Saturnian constituents, including hydrogen, methane, ammonia, hydrogen sulfide, phosphine, and water. We find that the lack of absorption in the 1-2 ??m spectral region by lightning-generated sulfuric and phosphorous condensates renders these constituents as minor players in determining the color of the dark storm clouds. Relatively small particulates of elemental carbon, formed by lightning-induced dissociation of methane and subsequently upwelled from depth - perhaps embedded within and on the surface of spectrally bright condensates such as ammonium hydrosulfide or ammonia - may be a dominant optical material within the dark thunderstorm-related clouds of Saturn. ?? 2009 Elsevier Ltd. All rights reserved.

  20. SSYST-3. Input description

    International Nuclear Information System (INIS)

    Meyder, R.

    1983-12-01

    The code system SSYST-3 is designed to analyse the thermal and mechanical behaviour of a fuel rod during a LOCA. The report contains a complete input-list for all modules and several tested inputs for a LOCA analysis. (orig.)

  1. MDS MIC Catalog Inputs

    Science.gov (United States)

    Johnson-Throop, Kathy A.; Vowell, C. W.; Smith, Byron; Darcy, Jeannette

    2006-01-01

    This viewgraph presentation reviews the inputs to the MDS Medical Information Communique (MIC) catalog. The purpose of the group is to provide input for updating the MDS MIC Catalog and to request that MMOP assign Action Item to other working groups and FSs to support the MITWG Process for developing MIC-DDs.

  2. Gravity Field and Interior Structure of Saturn from Cassini Observations

    Science.gov (United States)

    Anderson, J. D.; Schubert, G.

    2007-05-01

    We discuss the sources for a determination of Saturn's external gravitational potential, beginning with a Pioneer 11 flyby in September 1979, two Voyager flybys in November 1980 for Voyager 1 and August 1981 for Voyager 2, four useful close approaches by the Cassini orbiter in May and June 2005, and culminating in an extraordinary close approach for Radio Science in September 2006. Results from the 2006 data are not yet available, but even without them, Cassini offers improvements in accuracy over Pioneer and Voyager by a factor of 37 in the zonal coefficient J2, a factor of 14 in J4, and a factor of 5 in J6. These improvements are important to our understanding of the internal structure of Saturn in particular, and to solar and extrasolar giant planets in general. Basically, Saturn can be modeled as a rapidly rotating planet in hydrostatic equilibrium. Consistent with the limited data available, we express the density distribution as a polynomial of fifth degree in the normalized mean radius β = r/R over the real interval zero to one, where R is the radius of a sphere with density equal to the mean density of Saturn. Then the six coefficients of the polynomial are adjusted by nonlinear least squares until they match the measured even zonal gravity coefficients J2,J4,J6 within a fraction of a standard deviation. The gravity coefficients are computed from the density distribution by the method of level surfaces to the third order in the rotational smallness parameter. Two degrees of freedom are removed by applying the constraints that (1)~the derivative of the density distribution is zero at the center, and (2)~the density is zero at the surface. Further, a unique density distribution is obtained by the method of singular value decomposition truncated at rank three. Given this unique density distribution, the internal pressure can be obtained by numerical integration of the equation of hydrostatic equilibrium, expressed in terms of the single independent parameter

  3. Photochemistry, mixing and transport in Jupiter's stratosphere constrained by Cassini

    Science.gov (United States)

    Hue, V.; Hersant, F.; Cavalié, T.; Dobrijevic, M.; Sinclair, J. A.

    2018-06-01

    In this work, we aim at constraining the diffusive and advective transport processes in Jupiter's stratosphere, using Cassini/CIRS observations published by Nixon et al. (2007,2010). The Cassini-Huygens flyby of Jupiter on December 2000 provided the highest spatially resolved IR observations of Jupiter so far, with the CIRS instrument. The IR spectrum contains the fingerprints of several atmospheric constituents and allows probing the tropospheric and stratospheric composition. In particular, the abundances of C2H2 and C2H6, the main compounds produced by methane photochemistry, can be retrieved as a function of latitude in the pressure range at which CIRS is sensitive to. CIRS observations suggest a very different meridional distribution for these two species. This is difficult to reconcile with their photochemical histories, which are thought to be tightly coupled to the methane photolysis. While the overall abundance of C2H2 decreases with latitude, C2H6 becomes more abundant at high latitudes. In this work, a new 2D (latitude-altitude) seasonal photochemical model of Jupiter is developed. The model is used to investigate whether the addition of stratospheric transport processes, such as meridional diffusion and advection, are able to explain the latitudinal behavior of C2H2 and C2H6. We find that the C2H2 observations are fairly well reproduced without meridional diffusion. Adding meridional diffusion to the model provides an improved agreement with the C2H6 observations by flattening its meridional distribution, at the cost of a degradation of the fit to the C2H2 distribution. However, meridional diffusion alone cannot produce the observed increase with latitude of the C2H6 abundance. When adding 2D advective transport between roughly 30 mbar and 0.01 mbar, with upwelling winds at the equator and downwelling winds at high latitudes, we can, for the first time, reproduce the C2H6 abundance increase with latitude. In parallel, the fit to the C2H2 distribution is

  4. Gravimagnetic effect of the barycentric motion of the Sun and determination of the post-Newtonian parameter γ in the Cassini experiment

    Science.gov (United States)

    Kopeikin, S. M.; Polnarev, A. G.; Schäfer, G.; Vlasov, I. Yu.

    2007-07-01

    The most precise test of the post-Newtonian γ parameter in the solar system has been achieved in measurement of the frequency shift of radio waves to and from the Cassini spacecraft as they passed near the Sun. The test relies upon the JPL model of radiowave propagation that includes, but does not explicitly parametrize, the impact of the non-stationary component of the gravitational field of the Sun, generated by its barycentric orbital motion, on the Shapiro delay. This non-stationary gravitational field of the Sun is associated with the Lorentz transformation of the metric tensor and the affine connection from the heliocentric to the barycentric frame of the solar system and can be treated as gravimagnetic field. The gravimagnetic field perturbs the propagation of a radio wave and contributes to its frequency shift at the level up to 4×10-13 that may affect the precise measurement of the parameter γ in the Cassini experiment to about one part in 10 000. Our analysis suggests that the translational gravimagnetic field of the Sun can be extracted from the Cassini data, and its effect is separable from the space curvature characterized by the parameter γ.

  5. Charged Particle In-Situ Measurements in the Inner Saturnian Magnetosphere during the "grand Finale" of Cassini in 2016/2017

    Science.gov (United States)

    Krupp, N.; Roussos, E.; Mitchell, D. G.; Kollmann, P.; Paranicas, C.; Krimigis, S. M.; Hedman, M. M.; Dougherty, M. K.

    2017-12-01

    After 13 years in orbit around Saturn Cassini came to an end on 15 September 2017. The last phase of the mission was called the "Grand Finale" and consisted of high latitude orbits crossing the F-Ring 22 times between Nov 2016 and April 2017 followed by the so called proximal orbits passing the ring plane inside the D-ring. The roughly 7-day long F-ring orbits with periapsis at nearly the same local time allowed to study temporal variations of the particle distributions in the inner part of Saturn's magnetosphere while during the proximal orbits Cassini measured for the first time the charged particle environment in-situ inside the D-ring up to 2500 km above the 1-bar cloud level of the planet. In this presentation first results of the Low Energy Magnetospheric Measurement System LEMMS, part of the Magnetosphere Imaging Instrument MIMI during the "Grand Finale" will be summarized in detail, including the discovery of MeV particles close to Saturn, higher intensities of charged particles when Cassini was magnetically connected to the D-Ring, sharp dropouts at the inner edge of the D-ring as well as unexpected features and asymmetries in the particle measurements related to newly discovered ring arcs in the inner magnetosphere.

  6. Constituency Input into Budget Management.

    Science.gov (United States)

    Miller, Norman E.

    1995-01-01

    Presents techniques for ensuring constituency involvement in district- and site-level budget management. Outlines four models for securing constituent input and focuses on strategies to orchestrate the more complex model for staff and community participation. Two figures are included. (LMI)

  7. Analytical thermal model validation for Cassini radioisotope thermoelectric generator

    International Nuclear Information System (INIS)

    Lin, E.I.

    1997-01-01

    The Saturn-bound Cassini spacecraft is designed to rely, without precedent, on the waste heat from its three radioisotope thermoelectric generators (RTGs) to warm the propulsion module subsystem, and the RTG end dome temperature is a key determining factor of the amount of waste heat delivered. A previously validated SINDA thermal model of the RTG was the sole guide to understanding its complex thermal behavior, but displayed large discrepancies against some initial thermal development test data. A careful revalidation effort led to significant modifications and adjustments of the model, which result in a doubling of the radiative heat transfer from the heat source support assemblies to the end domes and bring up the end dome and flange temperature predictions to within 2 C of the pertinent test data. The increased inboard end dome temperature has a considerable impact on thermal control of the spacecraft central body. The validation process offers an example of physically-driven analytical model calibration with test data from not only an electrical simulator but also a nuclear-fueled flight unit, and has established the end dome temperatures of a flight RTG where no in-flight or ground-test data existed before

  8. SOLAR OCCULTATION BY TITAN MEASURED BY CASSINI/UVIS

    Energy Technology Data Exchange (ETDEWEB)

    Capalbo, Fernando J.; Benilan, Yves [Laboratoire Interuniversitaire des Systemes Atmospheriques (LISA), UMR 7583 du CNRS, Universites Paris Est Creteil (UPEC) and Paris Diderot - UPD, 61 avenue du General de Gaulle, 94010 Creteil Cedex (France); Yelle, Roger V.; Koskinen, Tommi T.; Sandel, Bill R. [Lunar and Planetary Laboratory, University of Arizona, 1629 E. University Blvd., Tucson, AZ 85721 (United States); Holsclaw, Gregory M.; McClintock, William E., E-mail: fernando.capalbo@lisa.u-pec.fr [Laboratory for Atmospheric and Space Physics, University of Colorado, 3665 Discovery Drive, Boulder, CO 80303 (United States)

    2013-04-01

    We present the first published analysis of a solar occultation by Titan's atmosphere measured by the Ultraviolet Imaging Spectrograph on board Cassini. The data were measured during flyby T53 in 2009 April and correspond to latitudes between 21 Degree-Sign and 28 Degree-Sign south. The analysis utilizes the absorption of two solar emission lines (584 A and 630 A) in the ionization continuum of the N{sub 2} absorption cross section and solar emission lines around 1085 A where absorption is due to CH{sub 4}. The measured transmission at these wavelengths provides a direct estimate of the N{sub 2} and CH{sub 4} column densities along the line of sight from the spacecraft to the Sun, which we inverted to obtain the number densities. The high signal-to-noise ratio of the data allowed us to retrieve density profiles in the altitude range 1120-1400 km for nitrogen and 850-1300 km for methane. We find an N{sub 2} scale height of {approx}76 km and a temperature of {approx}153 K. Our results are in general agreement with those from previous work, although there are some differences. Particularly, our profiles agree, considering uncertainties, with the density profiles derived from the Voyager 1 Ultraviolet Spectrograph data, and with in situ measurements by the Ion Neutral Mass Spectrometer with revised calibration.

  9. ColloInputGenerator

    DEFF Research Database (Denmark)

    2013-01-01

    This is a very simple program to help you put together input files for use in Gries' (2007) R-based collostruction analysis program. It basically puts together a text file with a frequency list of lexemes in the construction and inserts a column where you can add the corpus frequencies. It requires...... it as input for basic collexeme collostructional analysis (Stefanowitsch & Gries 2003) in Gries' (2007) program. ColloInputGenerator is, in its current state, based on programming commands introduced in Gries (2009). Projected updates: Generation of complete work-ready frequency lists....

  10. Titan’s mid-latitude surface regions with Cassini VIMS and RADAR

    Science.gov (United States)

    Solomonidou, Anezina; Lopes, Rosaly M. C.; Coustenis, Athena; Malaska, Michael; Rodriguez, Sebastien; Maltagliati, Luca; Drossart, Pierre; Janssen, Michael; Lawrence, Kenneth; Jaumann, Ralf; Sohl, Frank; Stephan, Katrin; Brown, Robert H.; Bratsolis, Emmanuel; Matsoukas, Christos

    2015-11-01

    The Cassini-Huygens mission instruments have revealed Titan to have a complex and dynamic atmosphere and surface. Data from the remote sensing instruments have shown the presence of diverse surface terrains in terms of morphology and composition, suggesting both exogenic and endogenic processes [1]. We define both the surface and atmospheric contributions in the VIMS spectro-imaging data by use of a radiative transfer code in the near-IR range [2]. To complement this dataset, the Cassini RADAR instrument provides additional information on the surface morphology, from which valuable geological interpretations can be obtained [3]. We examine the origin of key Titan terrains, covering the mid-latitude zones extending from 50ºN to 50ºS. The different geological terrains we investigate include: mountains, plains, labyrinths, craters, dune fields, and possible cryovolcanic and/or evaporite features. We have found that the labyrinth terrains and the undifferentiated plains seem to consist of a very similar if not the same material, while the different types of plains show compositional variations [3]. The processes most likely linked to their formation are aeolian, fluvial, sedimentary, lacustrine, in addition to the deposition of atmospheric products though the process of photolysis and sedimentation of organics. We show that temporal variations of surface albedo exist for two of the candidate cryovolcanic regions. The surface albedo variations together with the presence of volcanic-like morphological features suggest that the active regions are possibly related to the deep interior, possibly via cryovolcanism processes (with important implications for the satellite’s astrobiological potential) as also indicated by new interior structure models of Titan and corresponding calculations of the spatial pattern of maximum tidal stresses [4]. However, an explanation attributed to exogenic processes is also possible [5]. We will report on results from our most recent

  11. Confirmation of a traveling feature in Saturn's rings in Cassini Imaging Science Subsystem data

    Science.gov (United States)

    Aye, K. M.; Rehnberg, M.; Esposito, L. W.

    2017-12-01

    Introduction: Using Cassini UVIS occultation data, a traveling wave feature has been identified in the Saturn rings that is most likely caused by the radial positions swap of the moons Janus and Epimetheus [1]. The hypothesis is that non-linear interferences between the density waves when being relocated by the moon swap create a solitary wave that is traveling outward through the rings. The observations in [1] further lead to the derivation of values for the radial travel speeds of the identified traveling features, from 39.6 km/yr for the Janus 5:4 resonance up to 45.8 for the Janus 4:3 resonance. Previous confirmations in ISS data: Work in [1] also identified the feature in Cassini Imaging Science Subsystem (ISS) data that was taken around the time of the UVIS occultations where the phenomenon was first discovered, so far one ISS image for each Janus resonances 2:1, 4:3, 5:4, and 6:5. Searches performed in ISS data: Filtering all existing ISS data down to the best resolutions that include both a clearly identifiable minimum and maximum ring radius, we have visually inspected approx. 200 images, both with and without known resonances within the image, but unbeknownst to the inspector. Identification of a feature of interest happens when train waves are being interrupted by anomalies. Comparing the radial locations of identified ISS features with those in UV data of [1], we have identified several at the same radii. Considering the vast differences in radial resolution, we conclude that the traveling feature causes observable anomalies at both small scales of meters, up to large scales of hundreds of meters to kilometers.References: [1] Rehnberg, M.E., Esposito, L.W., Brown, Z.L., Albers, N., Sremčević, M., Stewart, G.R., 2016. A Traveling Feature in Saturn's Rings. Icarus, accepted in June 2016. [2] K.-Michael Aye (2016, November 11). michaelaye/pyciss: . v0.6.0 Zenodo. https://doi.org/10.5281/zenodo.596802

  12. Input description for BIOPATH

    International Nuclear Information System (INIS)

    Marklund, J.E.; Bergstroem, U.; Edlund, O.

    1980-01-01

    The computer program BIOPATH describes the flow of radioactivity within a given ecosystem after a postulated release of radioactive material and the resulting dose for specified population groups. The present report accounts for the input data necessary to run BIOPATH. The report also contains descriptions of possible control cards and an input example as well as a short summary of the basic theory.(author)

  13. Input and execution

    International Nuclear Information System (INIS)

    Carr, S.; Lane, G.; Rowling, G.

    1986-11-01

    This document describes the input procedures, input data files and operating instructions for the SYVAC A/C 1.03 computer program. SYVAC A/C 1.03 simulates the groundwater mediated movement of radionuclides from underground facilities for the disposal of low and intermediate level wastes to the accessible environment, and provides an estimate of the subsequent radiological risk to man. (author)

  14. Gestures and multimodal input

    OpenAIRE

    Keates, Simeon; Robinson, Peter

    1999-01-01

    For users with motion impairments, the standard keyboard and mouse arrangement for computer access often presents problems. Other approaches have to be adopted to overcome this. In this paper, we will describe the development of a prototype multimodal input system based on two gestural input channels. Results from extensive user trials of this system are presented. These trials showed that the physical and cognitive loads on the user can quickly become excessive and detrimental to the interac...

  15. Atmospheric structure and helium abundance on Saturn from Cassini/UVIS and CIRS observations

    Science.gov (United States)

    Koskinen, T. T.; Guerlet, S.

    2018-06-01

    We combine measurements from stellar occultations observed by the Cassini Ultraviolet Imaging Spectrograph (UVIS) and limb scans observed by the Composite Infrared Spectrometer (CIRS) to create empirical atmospheric structure models for Saturn corresponding to the locations probed by the occultations. The results cover multiple locations at low to mid-latitudes between the spring of 2005 and the fall of 2015. We connect the temperature-pressure (T-P) profiles retrieved from the CIRS limb scans in the stratosphere to the T-P profiles in the thermosphere retrieved from the UVIS occultations. We calculate the altitudes corresponding to the pressure levels in each case based on our best fit composition model that includes H2, He, CH4 and upper limits on H. We match the altitude structure to the density profile in the thermosphere that is retrieved from the occultations. Our models depend on the abundance of helium and we derive a volume mixing ratio of 11 ± 2% for helium in the lower atmosphere based on a statistical analysis of the values derived for 32 different occultation locations. We also derive the mean temperature and methane profiles in the upper atmosphere and constrain their variability. Our results are consistent with enhanced heating at the polar auroral region and a dynamically active upper atmosphere.

  16. Haze and cloud structure of Saturn's North Pole and Hexagon Wave from Cassini/ISS imaging

    Science.gov (United States)

    Sanz-Requena, J. F.; Pérez-Hoyos, S.; Sánchez-Lavega, A.; Antuñano, A.; Irwin, Patrick G. J.

    2018-05-01

    In this paper we present a study of the vertical haze and cloud structure in the upper two bars of Saturn's Northern Polar atmosphere using the Imaging Science Subsystem (ISS) instrument onboard the Cassini spacecraft. We focus on the characterization of latitudes from 53° to 90° N. The observations were taken during June 2013 with five different filters (VIO, BL1, MT2, CB2 and MT3) covering spectral range from the 420 nm to 890 nm (in a deep methane absorption band). Absolute reflectivity measurements of seven selected regions at all wavelengths and several illumination and observation geometries are compared with the values produced by a radiative transfer model. The changes in reflectivity at these latitudes are mostly attributed to changes in the tropospheric haze. This includes the haze base height (from 600 ± 200 mbar at the lowest latitudes to 1000 ± 300 mbar in the pole), its particle number density (from 20 ± 2 particles/cm3 to 2 ± 0.5 particles/cm3 at the haze base) and its scale height (from 18 ± 0.1 km to 50 ± 0.1 km). We also report variability in the retrieved particle size distribution and refractive indices. We find that the Hexagonal Wave dichotomizes the studied stratospheric and tropospheric hazes between the outer, equatorward regions and the inner, Polar Regions. This suggests that the wave or the jet isolates the particle distribution at least at tropospheric levels.

  17. Meteorology of Jupiter's Equatorial Hot Spots and Plumes from Cassini

    Science.gov (United States)

    Choi, David Sanghun; Showman, Adam P.; Vasavada, Ashwin R.; Simon-Miller, Amy A.

    2013-01-01

    We present an updated analysis of Jupiter's equatorial meteorology from Cassini observations. For two months preceding the spacecraft's closest approach, the Imaging Science Subsystem (ISS) onboard regularly imaged the atmosphere. We created time-lapse movies from this period in order to analyze the dynamics of equatorial hot spots and their interactions with adjacent latitudes. Hot spots are relatively cloud-free regions that emit strongly at 5 lm; improved knowledge of these features is crucial for fully understanding Galileo probe measurements taken during its descent through one. Hot spots are quasistable, rectangular dark areas on visible-wavelength images, with defined eastern edges that sharply contrast with surrounding clouds, but diffuse western edges serving as nebulous boundaries with adjacent equatorial plumes. Hot spots exhibit significant variations in size and shape over timescales of days and weeks. Some of these changes correspond with passing vortex systems from adjacent latitudes interacting with hot spots. Strong anticyclonic gyres present to the south and southeast of the dark areas appear to circulate into hot spots. Impressive, bright white plumes occupy spaces in between hot spots. Compact cirrus-like 'scooter' clouds flow rapidly through the plumes before disappearing within the dark areas. These clouds travel at 150-200 m/s, much faster than the 100 m/s hot spot and plume drift speed. This raises the possibility that the scooter clouds may be more illustrative of the actual jet stream speed at these latitudes. Most previously published zonal wind profiles represent the drift speed of the hot spots at their latitude from pattern matching of the entire longitudinal image strip. If a downward branch of an equatorially-trapped Rossby wave controls the overall appearance of hot spots, however, the westward phase velocity of the wave leads to underestimates of the true jet stream speed.

  18. Mapping Ring Particle Cooling across Saturn's Rings with Cassini CIRS

    Science.gov (United States)

    Brooks, Shawn M.; Spilker, L. J.; Edgington, S. G.; Pilorz, S. H.; Deau, E.

    2010-10-01

    Previous studies have shown that the rings' thermal inertia, a measure of their response to changes in the thermal environment, varies from ring to ring. Thermal inertia can provide insight into the physical structure of Saturn's ring particles and their regoliths. Low thermal inertia and quick temperature responses are suggestive of ring particles that have more porous or fluffy regoliths or that are riddled with cracks. Solid, coherent particles can be expected to have higher thermal inertias (Ferrari et al. 2005). Cassini's Composite Infrared Spectrometer has recorded millions of spectra of Saturn's rings since its arrival at Saturn in 2004 (personal communication, M. Segura). CIRS records far infrared radiation between 10 and 600 cm-1 (16.7 and 1000 µm) at focal plane 1 (FP1), which has a field of view of 3.9 mrad. Thermal emission from Saturn's rings peaks in this wavelength range. FP1 spectra can be used to infer ring temperatures. By tracking how ring temperatures vary, we can determine the thermal inertia of the rings. In this work we focus on CIRS observations of the shadowed portion of Saturn's rings. The thermal budget of the rings is dominated by the solar radiation absorbed by its constituent particles. When ring particles enter Saturn's shadow this source of energy is abruptly cut off. As a result, ring particles cool as they traverse Saturn's shadow. From these shadow observations we can create cooling curves at specific locations across the rings. We will show that the rings' cooling curves and thus their thermal inertia vary not only from ring to ring, but by location within the individual rings. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Copyright 2010 California Institute of Technology. Government sponsorship acknowledged.

  19. Transient surface liquid in Titan's south polar region from Cassini

    Science.gov (United States)

    Hayes, A.G.; Aharonson, O.; Lunine, J.I.; Kirk, R.L.; Zebker, H.A.; Wye, L.C.; Lorenz, R.D.; Turtle, E.P.; Paillou, P.; Mitri, Giuseppe; Wall, S.D.; Stofan, E.R.; Mitchell, K.L.; Elachi, C.

    2011-01-01

    Cassini RADAR images of Titan's south polar region acquired during southern summer contain lake features which disappear between observations. These features show a tenfold increases in backscatter cross-section between images acquired one year apart, which is inconsistent with common scattering models without invoking temporal variability. The morphologic boundaries are transient, further supporting changes in lake level. These observations are consistent with the exposure of diffusely scattering lakebeds that were previously hidden by an attenuating liquid medium. We use a two-layer model to explain backscatter variations and estimate a drop in liquid depth of approximately 1-m-per-year. On larger scales, we observe shoreline recession between ISS and RADAR images of Ontario Lacus, the largest lake in Titan's south polar region. The recession, occurring between June 2005 and July 2009, is inversely proportional to slopes estimated from altimetric profiles and the exponential decay of near-shore backscatter, consistent with a uniform reduction of 4 ± 1.3 m in lake depth. Of the potential explanations for observed surface changes, we favor evaporation and infiltration. The disappearance of dark features and the recession of Ontario's shoreline represents volatile transport in an active methane-based hydrologic cycle. Observed loss rates are compared and shown to be consistent with available global circulation models. To date, no unambiguous changes in lake level have been observed between repeat images in the north polar region, although further investigation is warranted. These observations constrain volatile flux rates in Titan's hydrologic system and demonstrate that the surface plays an active role in its evolution. Constraining these seasonal changes represents the first step toward our understanding of longer climate cycles that may determine liquid distribution on Titan over orbital time periods.

  20. Detecting dust hits at Enceladus, Saturn and beyond using CAPS / ELS data from Cassini

    Science.gov (United States)

    Vandegriff, J. D.; Stoneberger, P. J.; Jones, G.; Waite, J. H., Jr.

    2016-12-01

    It has recently been shown (1) that the impact of hypervelocity dust grains on the Cassini spacecraft can be detected by the Cassini Plasma Spectrometer (CAPS) Electron Spectrometer (ELS) instrument. For multiple Enceladus flybys, fine scale features in the lower energy regime of ELS energy spectra can be explained as short-duration, isotropic plasma clouds due to dust impacts. We have developed an algorithm for detecting these hypervelocity dust impacts, and the list of such impacts during Enceladus flybys will be presented. We also present preliminary results obtained when using the algorithm to search for dust impacts in other regions of Saturn's magnetosphere as well as in the solar wind. (1) Jones, Geraint, Hypervelocity dust impact signatures detected by Cassini CAPS-ELS in the Enceladus plume, MOP Meeting, June 1-5, 2015, Atlanta, GA

  1. Cassini Operational Sun Sensor Risk Management During Proximal Orbit Saturn Ring Plane Crossings

    Science.gov (United States)

    Bates, David M.

    2016-01-01

    NASA's Cassini Spacecraft, launched on October 15th, 1997 which arrived at Saturn on June 30th, 2004, is the largest and most ambitious interplanetary spacecraft in history. As the first spacecraft to achieve orbit at Saturn, Cassini has collected science data throughout its four-year prime mission (2004–08), and has since been approved for a first and second extended mission through 2017. As part of the final extended missions, Cassini will begin an aggressive and exciting campaign of high inclination, low altitude flybys within the inner most rings of Saturn, skimming Saturn’s outer atmosphere, until the spacecraft is finally disposed of via planned impact with the planet. This final campaign, known as the proximal orbits, requires a strategy for managing the Sun Sensor Assembly (SSA) health, the details of which are presented in this paper.

  2. Cassini Attitude and Articulation Control Subsystem Fault Protection Challenges During Saturn Proximal Orbits

    Science.gov (United States)

    Bates, David M.

    2015-01-01

    NASA's Cassini Spacecraft, launched on October 15th, 1997 arrived at Saturn on June 30th, 2004, is the largest and most ambitious interplanetary spacecraft in history. As the first spacecraft to achieve orbit at Saturn, Cassini has collected science data throughout its four-year prime mission (2004-08), and has since been approved for a first and second extended mission through 2017. As part of the final extended mission, Cassini will begin an aggressive and exciting campaign of high inclination low altitude flybys within the inner most rings of Saturn, skimming Saturn's outer atmosphere, until the spacecraft is finally disposed of via planned impact with the planet. This final campaign, known as the proximal orbits, presents unique fault protection related challenges, the details of which are discussed in this paper.

  3. Cost Comparison in 2015 Dollars for Radioisotope Power Systems -- Cassini and Mars Science Laboratory

    International Nuclear Information System (INIS)

    Werner, James Elmer; Johnson, Stephen Guy; Dwight, Carla Chelan; Lively, Kelly Lynn

    2016-01-01

    Radioisotope power systems (RPSs) have enabled missions requiring reliable, long-lasting power in remote, harsh environments such as space since the early 1960s. Costs for RPSs are high, but are often misrepresented due to the complexity of space missions and inconsistent charging practices among the many and changing participant organizations over the years. This paper examines historical documentation associated with two past successful flight missions, each with a different RPS design, to provide a realistic cost basis for RPS production and deployment. The missions and their respective RPSs are Cassini, launched in 1997, that uses the general purpose heat source (GPHS) radioisotope thermoelectric generator (RTG), and Mars Science Laboratory (MSL), launched in 2011, that uses the multi-mission RTG (MMRTG). Actual costs in their respective years are discussed for each of the two RTG designs and the missions they enabled, and then present day values to 2015 are computed to compare the costs. Costs for this analysis were categorized into two areas: development of the specific RTG technology, and production and deployment of an RTG. This latter category includes material costs for the flight components (including Pu-238 and fine weave pierced fabric (FWPF)); manufacturing of flight components; assembly, testing, and transport of the flight RTG(s); ground operations involving the RTG(s) through launch; nuclear safety analyses for the launch and for the facilities housing the RTG(s) during all phases of ground operations; DOE's support for NEPA analyses; and radiological contingency planning. This analysis results in a fairly similar 2015 normalized cost for the production and deployment of an RTG-approximately $118M for the GPHS-RTG and $109M for the MMRTG. In addition to these two successful flight missions, the costs for development of the MMRTG are included to serve as a future reference. Note that development costs included herein for the MMRTG do not include

  4. Cost Comparison in 2015 Dollars for Radioisotope Power Systems -- Cassini and Mars Science Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Werner, James Elmer [Idaho National Lab. (INL), Idaho Falls, ID (United States); Johnson, Stephen Guy [Idaho National Lab. (INL), Idaho Falls, ID (United States); Dwight, Carla Chelan [Idaho National Lab. (INL), Idaho Falls, ID (United States); Lively, Kelly Lynn [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-07-01

    Radioisotope power systems (RPSs) have enabled missions requiring reliable, long-lasting power in remote, harsh environments such as space since the early 1960s. Costs for RPSs are high, but are often misrepresented due to the complexity of space missions and inconsistent charging practices among the many and changing participant organizations over the years. This paper examines historical documentation associated with two past successful flight missions, each with a different RPS design, to provide a realistic cost basis for RPS production and deployment. The missions and their respective RPSs are Cassini, launched in 1997, that uses the general purpose heat source (GPHS) radioisotope thermoelectric generator (RTG), and Mars Science Laboratory (MSL), launched in 2011, that uses the multi-mission RTG (MMRTG). Actual costs in their respective years are discussed for each of the two RTG designs and the missions they enabled, and then present day values to 2015 are computed to compare the costs. Costs for this analysis were categorized into two areas: development of the specific RTG technology, and production and deployment of an RTG. This latter category includes material costs for the flight components (including Pu-238 and fine weave pierced fabric (FWPF)); manufacturing of flight components; assembly, testing, and transport of the flight RTG(s); ground operations involving the RTG(s) through launch; nuclear safety analyses for the launch and for the facilities housing the RTG(s) during all phases of ground operations; DOE’s support for NEPA analyses; and radiological contingency planning. This analysis results in a fairly similar 2015 normalized cost for the production and deployment of an RTG—approximately $118M for the GPHS-RTG and $109M for the MMRTG. In addition to these two successful flight missions, the costs for development of the MMRTG are included to serve as a future reference. Note that development costs included herein for the MMRTG do not include

  5. Titan's Surface Composition from Cassini VIMS Solar Occultation Observations

    Science.gov (United States)

    McCord, Thomas; Hayne, Paul; Sotin, Christophe

    2013-04-01

    Titan's surface is obscured by a thick absorbing and scattering atmosphere, allowing direct observation of the surface within only a few spectral win-dows in the near-infrared, complicating efforts to identify and map geologi-cally important materials using remote sensing IR spectroscopy. We there-fore investigate the atmosphere's infrared transmission with direct measure-ments using Titan's occultation of the Sun as well as Titan's reflectance measured at differing illumination and observation angles observed by Cas-sini's Visual and Infrared Mapping Spectrometer (VIMS). We use two im-portant spectral windows: the 2.7-2.8-mm "double window" and the broad 5-mm window. By estimating atmospheric attenuation within these windows, we seek an empirical correction factor that can be applied to VIMS meas-urements to estimate the true surface reflectance and map inferred composi-tional variations. Applying the empirical corrections, we correct the VIMS data for the viewing geometry-dependent atmospheric effects to derive the 5-µm reflectance and 2.8/2.7-µm reflectance ratio. We then compare the cor-rected reflectances to compounds proposed to exist on Titan's surface. We propose a simple correction to VIMS Titan data to account for atmospheric attenuation and diffuse scattering in the 5-mm and 2.7-2.8 mm windows, generally applicable for airmass water ice for the majority of the low-to-mid latitude area covered by VIMS measurements. Four compositional units are defined and mapped on Titan's surface based on the positions of data clusters in 5-mm vs. 2.8/2.7-mm scatter plots; a simple ternary mixture of H2O, hydrocarbons and CO2 might explain the reflectance properties of these surface units. The vast equatorial "dune seas" are compositionally very homogeneous, perhaps suggesting transport and mixing of particles over very large distances and/or and very consistent formation process and source material. The composi-tional branch characterizing Tui Regio and Hotei Regio is

  6. Input measurements in reprocessing plants

    International Nuclear Information System (INIS)

    Trincherini, P.R.; Facchetti, S.

    1980-01-01

    The aim of this work is to give a review of the methods and the problems encountered in measurements in 'input accountability tanks' of irradiated fuel treatment plants. This study was prompted by the conviction that more and more precise techniques and methods should be at the service of safeguards organizations and that ever greater efforts should be directed towards promoting knowledge of them among operators and all those general area of interest includes the nuclear fuel cycle. The overall intent is to show the necessity of selecting methods which produce measurements which are not only more precise but are absolutely reliable both for routine plant operation and for safety checks in the input area. A description and a critical evaluation of the most common physical and chemical methods are provided, together with an estimate of the precision and accuracy obtained in real operating conditions

  7. FMT (Flight Software Memory Tracker) For Cassini Spacecraft-Software Engineering Using JAVA

    Science.gov (United States)

    Kan, Edwin P.; Uffelman, Hal; Wax, Allan H.

    1997-01-01

    The software engineering design of the Flight Software Memory Tracker (FMT) Tool is discussed in this paper. FMT is a ground analysis software set, consisting of utilities and procedures, designed to track the flight software, i.e., images of memory load and updatable parameters of the computers on-board Cassini spacecraft. FMT is implemented in Java.

  8. Galileo SSI and Cassini ISS Observations of Io's Pele Hotspot: Temperatures, Areas, and Variation with Time

    Science.gov (United States)

    Radebaugh, J.; McEwen, A. S.; Milazzo, M.; Davies, A. G.; Keszthelyi, L. P.; Geissler, P.

    2002-01-01

    Temperatures of Io's Pele hotspot were found using dual-filter observations from Galileo and Cassini. Temperatures average 1375 K, but vary widely over tens of minutes. Dropoff in emission with rotation consistent with lava fountaining at a lava lake. Additional information is contained in the original extended abstract.

  9. SSRPT (SSR Pointer Trackeer) for Cassini Mission Operations - A Ground Data Analysis Tool

    Science.gov (United States)

    Kan, E.

    1998-01-01

    Tracking the resources of the two redundant Solid State Recorders (SSR) is a necessary routine for Cassini spacecraft mission operations. Instead of relying on a full-fledged spacecraft hardware/software simulator to track and predict the SSR recording and playback pointer positions, a stand-alone SSR Pointer Tracker tool was developed as part of JPL's Multimission Spacecraft Analysis system.

  10. Voyager in-situ and Cassini Remote Measurements Suggest a Bubble-like Shape for the Global Heliosphere

    Science.gov (United States)

    Dialynas, K.; Krimigis, S. M.; Mitchell, D. G.; Decker, R. B.; Roelof, E. C.

    2017-12-01

    The Low Energy Charged Particle (LECP) in situ measurements from Voyager 1 and Voyager 2 (V1, V2) have revealed the reservoir of ions and electrons that constitute the heliosheath after crossing the termination shock 35 deg north and 32 deg south of the ecliptic plane at 94 and 84 astronomical units (1 AU=1.5x108 km), respectively. In August 2012, at 121.6 AU, V1 crossed the heliopause to enter the interstellar space, while V2 remains in the heliosheath since 2007. The advent of Energetic Neutral Atom (ENA, produced through charge exchange between ions and neutral particles flowing through the heliosphere) imaging, has revealed the global nature of the heliosheath at both high (5.2-55 keV, Cassini/Ion and Neutral Camera-INCA, from 10 AU) and low (INCA global imaging through ENA in overlapping energy bands provides a powerful tool for examining the spatial, temporal, and spectral evolution of the source hot plasma ions. Here we report 5.2-55 keV ENA global images of the heliosphere from Cassini/INCA and compare them with V1,2/LECP 28-53 keV ions measured within the heliosheath over a 13-year period (2003-2016). The similarity between the time profiles of ENA and ions establish that the heliosheath ions are the source of ENA. These measurements also demonstrate that the heliosphere responds promptly, within 2-3 years, to outward propagating solar wind changes (manifested in solar sunspot numbers and solar wind energy input) in both the upstream (nose) and downstream (tail) hemispheres. These results, taken together with the V1 measurement of a 0.5 nT interstellar magnetic field and the enhanced ratio between particle pressure and magnetic pressure in the heliosheath, constrain the shape of the global heliosphere: by contrast to the magnetosphere-like heliotail (that past modeling broadly assumed for more than 55 years), a more symmetric, diamagnetic bubble-like heliosphere, with few substantial tail-like features is revealed.

  11. Bathymetry and composition of Titan's Ontario Lacus derived from Monte Carlo-based waveform inversion of Cassini RADAR altimetry data

    Science.gov (United States)

    Mastrogiuseppe, M.; Hayes, A. G.; Poggiali, V.; Lunine, J. I.; Lorenz, R. D.; Seu, R.; Le Gall, A.; Notarnicola, C.; Mitchell, K. L.; Malaska, M.; Birch, S. P. D.

    2018-01-01

    Recently, the Cassini RADAR was used to sound hydrocarbon lakes and seas on Saturn's moon Titan. Since the initial discovery of echoes from the seabed of Ligeia Mare, the second largest liquid body on Titan, a dedicated radar processing chain has been developed to retrieve liquid depth and microwave absorptivity information from RADAR altimetry of Titan's lakes and seas. Herein, we apply this processing chain to altimetry data acquired over southern Ontario Lacus during Titan fly-by T49 in December 2008. The new signal processing chain adopts super resolution techniques and dedicated taper functions to reveal the presence of reflection from Ontario's lakebed. Unfortunately, the extracted waveforms from T49 are often distorted due to signal saturation, owing to the extraordinarily strong specular reflections from the smooth lake surface. This distortion is a function of the saturation level and can introduce artifacts, such as signal precursors, which complicate data interpretation. We use a radar altimetry simulator to retrieve information from the saturated bursts and determine the liquid depth and loss tangent of Ontario Lacus. Received waveforms are represented using a two-layer model, where Cassini raw radar data are simulated in order to reproduce the effects of receiver saturation. A Monte Carlo based approach along with a simulated waveform look-up table is used to retrieve parameters that are given as inputs to a parametric model which constrains radio absorption of Ontario Lacus and retrieves information about the dielectric properties of the liquid. We retrieve a maximum depth of 50 m along the radar transect and a best-fit specific attenuation of the liquid equal to 0.2 ± 0.09 dB m-1 that, when converted into loss tangent, gives tanδ = 7 ± 3 × 10-5. When combined with laboratory measured cryogenic liquid alkane dielectric properties and the variable solubility of nitrogen in ethane-methane mixtures, the best-fit loss tangent is consistent with a

  12. Continuing Improvement in the Planetary Ephemeris with VLBA Observations of Cassini

    Science.gov (United States)

    Jones, Dayton L.; Folkner, William M.; Jacobson, Robert A.; Jacobs, Christopher S.; Romney, Jonathan D.; Dhawan, Vivek; Fomalont, Edward B.

    2016-06-01

    During the past decade a continuing series of measurements of the barycentric position of the Saturn system in the inertial International Celestial Reference Frame (ICRF) has led to a significant improvement in our knowledge of Saturn's orbit. This in turn has improved the current accuracy and time range of the solar system ephemeris produced and maintained by the Jet Propulsion Laboratory. Our observing technique involves high-precision astrometry of the radio signal from Cassini with the NRAO Very Long Baseline Array, combined with solutions for the orbital motion of Cassini about the Saturn barycenter from Doppler tracking by the Deep Space Network. Our VLBA astrometry is done in a phase-referencing mode, providing nrad-level relative positions between Cassini and angularly nearby extragalactic radio sources. The positions of those reference radio sources are tied to the ICRF through dedicated VLBI observations by several groups around the world. We will present recent results from our astrometric observations of Cassini through early 2016. This program will continue until the end of the Cassini mission in 2017, although future improvement in Saturn's orbit will be more incremental because we have already covered more that a quarter of Saturn's orbital period. The Juno mission to Jupiter, which will orbit Jupiter for about 1.5 years starting in July 2016, will provide an excellent opportunity for us to apply the same VLBA astrometry technique to improve the orbit of Jupiter by a factor of several. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. This work made use of the Swinburne University of Technology software correlator, developed as part of the Australian Major National Research Facilities Program and operated under license. Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract

  13. Electrical properties of Titan's surface from Cassini RADAR scatterometer measurements

    Science.gov (United States)

    Wye, Lauren C.; Zebker, Howard A.; Ostro, Steven J.; West, Richard D.; Gim, Yonggyu; Lorenz, Ralph D.; The Cassini Radar Team

    2007-06-01

    We report regional-scale low-resolution backscatter images of Titan's surface acquired by the Cassini RADAR scatterometer at a wavelength of 2.18-cm. We find that the average angular dependence of the backscatter from large regions and from specific surface features is consistent with a model composed of a quasi-specular Hagfors term plus a diffuse cosine component. A Gaussian quasi-specular term also fits the data, but less well than the Hagfors term. We derive values for the mean dielectric constant and root-mean-square (rms) slope of the surface from the quasi-specular term, which we ascribe to scattering from the surface interface only. The diffuse term accommodates contributions from volume scattering, multiple scattering, or wavelength-scale near-surface structure. The Hagfors model results imply a surface with regional mean dielectric constants between 1.9 and 3.6 and regional surface roughness that varies between 5.3° and 13.4° in rms-slope. Dielectric constants between 2 and 3 are expected for a surface composed of solid simple hydrocarbons, water ice, or a mixture of both. Smaller dielectric constants, between 1.6 and 1.9, are consistent with liquid hydrocarbons, while larger dielectric constants, near 4.5, may indicate the presence of water-ammonia ice [Lorenz, R.D., 1998. Icarus 136, 344-348] or organic heteropolymers [Thompson, W.R., Squyres, S.W., 1990. Icarus 86, 336-354]. We present backscatter images corrected for angular effects using the model residuals, which show strong features that correspond roughly to those in 0.94-μm ISS images. We model the localized backscatter from specific features to estimate dielectric constant and rms slope when the angular coverage is within the quasi-specular part of the backscatter curve. Only two apparent surface features are scanned with angular coverage sufficient for accurate modeling. Data from the bright albedo feature Quivira suggests a dielectric constant near 2.8 and rms slope near 10.1°. The dark

  14. What does Cassini ENA observations tell us about gas around Europa?

    Science.gov (United States)

    Brandt, Pontus; Mauk, Barry; Westlake, Joseph; Smith, Todd; Mitchell, Donald

    2015-04-01

    From about December 2000 to January 2001 the Ion and Neutral Camera (INCA) imaged Jupiter in Energetic Neutral Atoms (ENA) from a distance of about 137-250 Jovian planetary radii (RJ) over an energy range from about 10 to 300 keV. A forward model is employed to derive column densities and assumes a neutral gas-plasma model and an energetic ion distribution based on Galileo in-situ measurements. We demonstrate that Jupiter observations by INCA are consistent with a column density peaking around Europa's orbit in the range from 2x1012 cm-2 to 7x1012 cm-2, assuming H2, and are consistent with the upper limits reported from the Cassini/UVIS observations. Most of the INCA observations are consistent with a roughly azimuthally symmetric gas distribution, but some appear consistent with an asymmetric gas distribution centred on Europa, which would directly imply that Europa is the source of the gas. Although our neutral gas model assumes a Europa source, we explore other explanations of the INCA observations including: (1) ENAs are produced by charge exchange between energetic ions and neutral hydrogen originating from charge-exchanged protons in the Io plasma torus. However, estimated densities by Cheng (1986) are about one order of magnitude too low to explain the INCA observations; (2) ENAs are produced by charge exchange between energetic ions and plasma ions such as O+ and S+ originating from Io. However, that would require O+ plasma densities higher than expected to compensate for the low charge-exchange cross section between protons and O+; (3) We re-examine the INCA Point-Spread Function (PSF) to determine if the ENA emissions in the vicinity of Europa's orbit could be explained by internal scattering of ENAs originating from Jupiter's high-latitude upper atmosphere. However, the PSF was well constrained by using Jupiter from distances where it could be considered a point source.

  15. Ultra High Resolution Imaging of Enceladus Tiger Stripe Thermal Emission with Cassini CIRS

    Science.gov (United States)

    Spencer, John R.; Gorius, Nicolas; Howett, Carly; Verbiscer, Anne J.; Cassini CIRS Team

    2017-10-01

    In October 2015, Cassini flew within 48 km of Enceladus’ south pole. The spacecraft attitude was fixed during the flyby, but the roll angle of the spacecraft was chosen so that the remote sensing instrument fields of view passed over Damascus, Baghdad, and Cairo Sulci. The Composite Infrared Spectrometer (CIRS) instrument obtained a single interferometer scan during the flyby, using a special mode, enabled by a flight software update, which bypassed numerical filters to improve the fidelity of the interferograms. This generated a total of 11 interferograms, at 5 contiguous spatial locations for each of the 7 - 9 micron (FP4) and 9 - 17 micron (FP3) focal planes, and a single larger field of view for the 17 - 500 micron focal plane (FP1). Strong spikes were seen in the interferograms when crossing each of the sulci, due to the rapid passage of warm material through the field of view. For FP3 and FP4, the temporal variations of the signals from the 5 contiguous detectors can be used to generated 5-pixel-wide images of the thermal emission, which show excellent agreement between the two focal planes. FP3 and FP4 spatial resolution, limited along track by the 5 msec time sampling of the interferogram, and across track by the CIRS field of view, is a remarkable 40 x 40 meters. At this resolution, the tiger stripe thermal emission shows a large amount of structure, including both continuous emission along the fractures, discrete hot spots less than 100 meters across, and extended emission with complex structure.

  16. A Strong High Altitude Narrow Jet At Saturn'S Equator From Cassini/ISS Images

    Science.gov (United States)

    Garcia-Melendo, Enrique; Sánchez-Lavega, A.; Legarreta, J.; Pérez-Hoyos, S.; Hueso, R.

    2010-10-01

    The intense equatorial eastward jets observed at cloud level in Jupiter and Saturn, represent a major challenge for geophysical fluid dynamics. Saturn's equatorial jet is of particular interest in view of its three dimensional structure, suspected large temporal variability, and related stratospheric semiannual oscillation. Here we report the discovery at the upper cloud level of an extremely narrow and strong jet centered in the middle of the broad equatorial jet. Previously published works on Saturn's equatorial winds at cloud level provided only a partial coverage. Automatic correlation of brightness scans and manually tracked cloud features, retrieved from images obtained by the Cassini Imaging Science Subsystem (ISS), show that the jet reaches 430 ms-1 with a peak speed difference of 180 ms-1 relative to nearby latitudes at 60 mbar and 390 ms-1 at depths > 500 mbar. Images were obtained in two filters: MT3, centred at the 889nm strong methane absorption band, and CB3 centred at the near infrared 939nm continuum, which are sensitive to different altitude levels at the upper clouds and hazes. Contrarily to what is observed in other latitudes, its velocity increases with altitude. Our findings helps to extend the view we have of the equatorial stratospheric dynamics of fast rotating planets beyond the best known terrestrial environment, and extract more general consequences of the interaction between waves and mean flow. It remains to be known if this equatorial jet structure, now determined in detail in three dimensions, is permanent or variable with the seasonal solar insolation cycle, including the variable shadow cast by the rings. EGM, ASL, JL, SPH, and RH have been funded by the Spanish MICIIN AYA2009-10701 with FEDER support and ASL, JL, SPH, and RH by Grupos Gobierno Vasco IT-464-07

  17. Five Fabulous Flybys of the Small Inner Moons of Saturn by the Cassini Spacecraft

    Science.gov (United States)

    Buratti, B. J.; Momary, T.; Clark, R. N.; Brown, R. H.; Filacchione, G.; Mosher, J. A.; Baines, K. H.; Nicholson, P. D.

    2017-12-01

    The Saturn system possesses a number of small unique moons, including the coorbitals Janus and Epimetheus; the ring moons Pan and Daphnis; and Prometheus, Pandora, and Atlas, which orbit near the edge of the main ring system. During the last phases of the Cassini mission, when the spacecraft executed close passes to the F-ring of Saturn, five "best-ever" flybys of these moons occurred. Pan, Daphnis, Atlas, Pandora, and Epimetheus were approached at distances ranging from 6000-40,000 km. The Visual Infrared Mapping Spectrometer (VIMS) captured data from the spectral range spanning 0.35-5.1 microns, as well as capturing solar phase angles not observed before. When combined with spectra from different regions of the moons obtained throughout the mission, the VIMS observations reveal substantial changes in the depth of water-ice absorption bands and color over the moons' surfaces. These measurements show the accretion of main-ring material onto the moons, with leading sides exhibiting stronger water-ice signatures in general. Atlas and Pandora have red visible spectra similar to the A-ring and unlike other icy moons, which are blue, further revealing accretion of main ring material onto the small inner moons. In general the visible spectra of the moons gets bluer with distance from Saturn until the surface of the moons is dominated by contamination from the E-ring, which is composed of fresh ice. There is a weak correlation between color and albedo, with lower-albedo moons being redder, suggesting the existence of a dark reddish contaminant from the main ring system. The solar phase curves of the moons are similar to those of larger icy moons (unfortunately no opposition surge data was gathered). 2017 California Institute of Technology. Government sponsorship acknowledged.

  18. Input or intimacy

    Directory of Open Access Journals (Sweden)

    Judit Navracsics

    2014-01-01

    Full Text Available According to the critical period hypothesis, the earlier the acquisition of a second language starts, the better. Owing to the plasticity of the brain, up until a certain age a second language can be acquired successfully according to this view. Early second language learners are commonly said to have an advantage over later ones especially in phonetic/phonological acquisition. Native-like pronunciation is said to be most likely to be achieved by young learners. However, there is evidence of accentfree speech in second languages learnt after puberty as well. Occasionally, on the other hand, a nonnative accent may appear even in early second (or third language acquisition. Cross-linguistic influences are natural in multilingual development, and we would expect the dominant language to have an impact on the weaker one(s. The dominant language is usually the one that provides the largest amount of input for the child. But is it always the amount that counts? Perhaps sometimes other factors, such as emotions, ome into play? In this paper, data obtained from an EnglishPersian-Hungarian trilingual pair of siblings (under age 4 and 3 respectively is analyzed, with a special focus on cross-linguistic influences at the phonetic/phonological levels. It will be shown that beyond the amount of input there are more important factors that trigger interference in multilingual development.

  19. GAROS input deck description

    Energy Technology Data Exchange (ETDEWEB)

    Vollan, A.; Soederberg, M. (Aeronautical Research Inst. of Sweden, Bromma (Sweden))

    1989-01-01

    This report describes the input for the programs GAROS1 and GAROS2, version 5.8 and later, February 1988. The GAROS system, developed by Arne Vollan, Omega GmbH, is used for the analysis of the mechanical and aeroelastic properties for general rotating systems. It has been specially designed to meet the requirements of aeroelastic stability and dynamic response of horizontal axis wind energy converters. Some of the special characteristics are: * The rotor may have one or more blades. * The blades may be rigidly attached to the hub, or they may be fully articulated. * The full elastic properties of the blades, the hub, the machine house and the tower are taken into account. * With the same basic model, a number of different analyses can be performed: Snap-shot analysis, Floquet method, transient response analysis, frequency response analysis etc.

  20. Access to Research Inputs

    DEFF Research Database (Denmark)

    Czarnitzki, Dirk; Grimpe, Christoph; Pellens, Maikel

    2015-01-01

    The viability of modern open science norms and practices depends on public disclosure of new knowledge, methods, and materials. However, increasing industry funding of research can restrict the dissemination of results and materials. We show, through a survey sample of 837 German scientists in life...... sciences, natural sciences, engineering, and social sciences, that scientists who receive industry funding are twice as likely to deny requests for research inputs as those who do not. Receiving external funding in general does not affect denying others access. Scientists who receive external funding...... of any kind are, however, 50 % more likely to be denied access to research materials by others, but this is not affected by being funded specifically by industry...

  1. Access to Research Inputs

    DEFF Research Database (Denmark)

    Czarnitzki, Dirk; Grimpe, Christoph; Pellens, Maikel

    The viability of modern open science norms and practices depend on public disclosure of new knowledge, methods, and materials. However, increasing industry funding of research can restrict the dissemination of results and materials. We show, through a survey sample of 837 German scientists in life...... sciences, natural sciences, engineering, and social sciences, that scientists who receive industry funding are twice as likely to deny requests for research inputs as those who do not. Receiving external funding in general does not affect denying others access. Scientists who receive external funding...... of any kind are, however, 50% more likely to be denied access to research materials by others, but this is not affected by being funded specifically by industry....

  2. Cassini results on Titan's atmospheric and surface properties changes since the northern equinox

    Science.gov (United States)

    Coustenis, Athena; Drossart, Pierre; Flasar, F. Michael; Achterberg, Richard K.; Rodriguez, Sebastien; Nixon, Conor; Bampasidis, Georgios; Solomonidou, Anezina; Jennings, Donald; Lavvas, Panayiotis

    2016-07-01

    Since 2010, we observe the set in and enhancement at Titan's south pole of several trace species, such as HC3N and C6H6, observed only at high northern latitudes before equinox. We will present an analysis of spectra acquired by Cassini/CIRS at high resolution from 2012 in nadir mode. We investigated here several latitudes of 70°S to 70°N since 2010 (after the Southern Autumnal Equinox) until end of 2014 [1]. For some of the most abundant and longest-lived hydrocarbons (C2H2, C2H6 and C3H8) and CO2, the evolution in the past 4 years at a given latitude is not very significant within error bars especially until mid-2013 [1]. In more recent dates, these molecules show a dramatic trend for increase in the south. The 70°S and 50°S or mid-latitudes show different behavior demonstrating that they are subject to different dynamical processes in and out of the polar vortex region. For most species, we find higher abundances at 50°N compared to 50°S, with the exception of C3H8, CO2, C6H6 and HC3N, which arrive at similar mixing ratios after mid-2013 [1]. While the 70°N data show generally no change with a trend rather to a small decrease for most species within 2014, the 70°S results indicate a strong enhancement in trace stratospheric gases after 2012. In particular, HC3N, HCN and C6H6 have increased by 3 orders of magnitude over the past 3-4 years while other molecules, including C2H4, C3H4 and C4H2, have increased less sharply (by 1-2 orders of magnitude). This is a strong indication of the rapid and sudden buildup of the gaseous inventory in the southern stratosphere during 2013-2014, as expected as the pole moves deeper into winter shadow. Subsidence gases that accumulate in the absence of ultraviolet sunlight, evidently increased quickly since 2012 and some of them may be responsible also for the reported haze decrease in the north and its appearance in the south at the same time [2]. Clearly Titan is a dynamic system with indications of short and long

  3. Modeling and generating input processes

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, M.E.

    1987-01-01

    This tutorial paper provides information relevant to the selection and generation of stochastic inputs to simulation studies. The primary area considered is multivariate but much of the philosophy at least is relevant to univariate inputs as well. 14 refs.

  4. METER-SIZED MOONLET POPULATION IN SATURN'S C RING AND CASSINI DIVISION

    International Nuclear Information System (INIS)

    Baillié, Kévin; Colwell, Joshua E.; Esposito, Larry W.; Lewis, Mark C.

    2013-01-01

    Stellar occultations observed by the Cassini Ultraviolet Imaging Spectrograph reveal the presence of transparent holes a few meters to a few tens of meters in radial extent in otherwise optically thick regions of the C ring and the Cassini Division. We attribute the holes to gravitational disturbances generated by a population of ∼10 m boulders in the rings that is intermediate in size between the background ring particle size distribution and the previously observed ∼100 m propeller moonlets in the A ring. The size distribution of these boulders is described by a shallower power-law than the one that describes the ring particle size distribution. The number and size distribution of these boulders could be explained by limited accretion processes deep within Saturn's Roche zone.

  5. Cassini Spacecraft In-Flight Swap to Backup Attitude Control Thrusters

    Science.gov (United States)

    Bates, David M.

    2010-01-01

    NASA's Cassini Spacecraft, launched on October 15th, 1997 and arrived at Saturn on June 30th, 2004, is the largest and most ambitious interplanetary spacecraft in history. In order to meet the challenging attitude control and navigation requirements of the orbit profile at Saturn, Cassini is equipped with a monopropellant thruster based Reaction Control System (RCS), a bipropellant Main Engine Assembly (MEA) and a Reaction Wheel Assembly (RWA). In 2008, after 11 years of reliable service, several RCS thrusters began to show signs of end of life degradation, which led the operations team to successfully perform the swap to the backup RCS system, the details and challenges of which are described in this paper. With some modifications, it is hoped that similar techniques and design strategies could be used to benefit other spacecraft.

  6. Reprocessing input data validation

    International Nuclear Information System (INIS)

    Persiani, P.J.; Bucher, R.G.; Pond, R.B.; Cornella, R.J.

    1990-01-01

    The Isotope Correlation Technique (ICT), in conjunction with the gravimetric (Pu/U ratio) method for mass determination, provides an independent verification of the input accountancy at the dissolver or accountancy stage of the reprocessing plant. The Isotope Correlation Technique has been applied to many classes of domestic and international reactor systems (light-water, heavy-water, graphite, and liquid-metal) operating in a variety of modes (power, research, production, and breeder), and for a variety of reprocessing fuel cycle management strategies. Analysis of reprocessing operations data based on isotopic correlations derived for assemblies in a PWR environment and fuel management scheme, yielded differences between the measurement-derived and ICT-derived plutonium mass determinations of (-0.02 ± 0.23)% for the measured U-235 and (+0.50 ± 0.31)% for the measured Pu-239, for a core campaign. The ICT analyses has been implemented for the plutonium isotopics in a depleted uranium assembly in a heavy-water, enriched uranium system and for the uranium isotopes in the fuel assemblies in light-water, highly-enriched systems. 7 refs., 5 figs., 4 tabs

  7. Spatial distribution of Langmuir waves observed upstream of Saturn's bow shock by Cassini

    Czech Academy of Sciences Publication Activity Database

    Píša, David; Santolík, Ondřej; Hospodarsky, G. B.; Kurth, W. S.; Gurnett, D. A.; Souček, Jan

    2016-01-01

    Roč. 121, č. 8 (2016), s. 7771-7784 ISSN 2169-9380 R&D Projects: GA ČR GJ16-16050Y; GA ČR(CZ) GAP209/12/2394 Institutional support: RVO:68378289 Keywords : Langmuir waves * Cassini * foreshock * Saturn Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.733, year: 2016 http://onlinelibrary.wiley.com/doi/10.1002/2016JA022912/abstract

  8. Cassini RTG program. Monthly technical progress report, September 29, 1997--October 26, 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-11-24

    This report describes work on the contract to provide Radioisotope Thermoelectric Generators (RTG) and Ancillary Activities in support of the Cassini Spacecraft launch. The craft was successfully launched on October 15, 1997. Early telemetry results show excellent performance from the three launched RTG modules. A major share of this report describes safety analyses for contamination radii in the event of launch failures and generator destruction, as well as launch related activities.

  9. Statistics of Langmuir wave amplitudes observed inside Saturn's foreshock by the Cassini spacecraft

    Czech Academy of Sciences Publication Activity Database

    Píša, David; Hospodarsky, G. B.; Kurth, W. S.; Santolík, Ondřej; Souček, Jan; Gurnett, D. A.; Masters, A.; Hill, M. E.

    2015-01-01

    Roč. 120, č. 4 (2015), s. 2531-2542 ISSN 2169-9380 R&D Projects: GA ČR GAP205/10/2279; GA ČR(CZ) GAP209/12/2394 Institutional support: RVO:68378289 Keywords : Langmuir waves * foreshock * Saturn * Cassini Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.318, year: 2015 http://onlinelibrary.wiley.com/doi/10.1002/2014JA020560/abstract

  10. Improved Atlases of Mimas and Enceladus derived from Cassini-ISS images

    Science.gov (United States)

    Roatsch, T.; Kersten, E.; Matz, K. D.; Bland, M. T.; Becker, T. L.; Patterson, G. W.

    2017-12-01

    The Cassini Imaging Science Subsystem (ISS) took a couple of high-resolution images of the Icy satellites Mimas and Enceladus during the last few years of the Cassini mission. Both satellites were captured over a period of non-targeted flybys: Mimas in 2016 and 2017 in orbits 230, 249, and 259 and Enceladus in 2015 and 2016 in orbits 224, 228, and 250. We used the new Mimas images to improve the existing semi-controlled mosaic of Mimas. A new controlled Enceladus mosaic was published recently [1] and was now updated using the latest Enceladus images. Both new mosaics are the baseline for improved atlases of Mimas in 3 tiles with a scale of 1:1,000,000 and Enceladus in 15 tiles with a scale of 1:500,000. The nomenclature for both satellites was proposed by the Cassini-ISS team and approved by the IAU and was not changed here. Examples of the improved atlases will be shown in this presentation. Reference: [1] Bland, M.T. et. al., A new Enceladus base map and global control network in support of geological mapping, 46th Lunar and Planetary Science Conference (2015) , abstract 2303.

  11. Energy deposition and ion production from thermal oxygen ion precipitation during Cassini's T57 flyby

    Science.gov (United States)

    Snowden, Darci; Smith, Michael; Jimson, Theodore; Higgins, Alex

    2018-05-01

    Cassini's Radio Science Investigation (RSS) and Langmuir Probe observed abnormally high electron densities in Titan's ionosphere during Cassini's T57 flyby. We have developed a three-dimensional model to investigate how the precipitation of thermal magnetospheric O+ may have contributed to enhanced ion production in Titan's ionosphere. The three-dimensional model builds on previous work because it calculates both the flux of oxygen through Titan's exobase and the energy deposition and ion production rates in Titan's atmosphere. We find that energy deposition rates and ion production rates due to thermal O+ precipitation have a similar magnitude to the rates from magnetospheric electron precipitation and that the simulated ionization rates are sufficient to explain the abnormally high electron densities observed by RSS and Cassini's Langmuir Probe. Globally, thermal O+ deposits less energy in Titan's atmosphere than solar EUV, suggesting it has a smaller impact on the thermal structure of Titan's neutral atmosphere. However, our results indicate that thermal O+ precipitation can have a significant impact on Titan's ionosphere.

  12. Estimation of Gravitation Parameters of Saturnian Moons Using Cassini Attitude Control Flight Data

    Science.gov (United States)

    Krening, Samantha C.

    2013-01-01

    A major science objective of the Cassini mission is to study Saturnian satellites. The gravitational properties of each Saturnian moon is of interest not only to scientists but also to attitude control engineers. When the Cassini spacecraft flies close to a moon, a gravity gradient torque is exerted on the spacecraft due to the mass of the moon. The gravity gradient torque will alter the spin rates of the reaction wheels (RWA). The change of each reaction wheel's spin rate might lead to overspeed issues or operating the wheel bearings in an undesirable boundary lubrication condition. Hence, it is imperative to understand how the gravity gradient torque caused by a moon will affect the reaction wheels in order to protect the health of the hardware. The attitude control telemetry from low-altitude flybys of Saturn's moons can be used to estimate the gravitational parameter of the moon or the distance between the centers of mass of Cassini and the moon. Flight data from several low altitude flybys of three Saturnian moons, Dione, Rhea, and Enceladus, were used to estimate the gravitational parameters of these moons. Results are compared with values given in the literature.

  13. Measuring Input Thresholds on an Existing Board

    Science.gov (United States)

    Kuperman, Igor; Gutrich, Daniel G.; Berkun, Andrew C.

    2011-01-01

    A critical PECL (positive emitter-coupled logic) interface to Xilinx interface needed to be changed on an existing flight board. The new Xilinx input interface used a CMOS (complementary metal-oxide semiconductor) type of input, and the driver could meet its thresholds typically, but not in worst-case, according to the data sheet. The previous interface had been based on comparison with an external reference, but the CMOS input is based on comparison with an internal divider from the power supply. A way to measure what the exact input threshold was for this device for 64 inputs on a flight board was needed. The measurement technique allowed an accurate measurement of the voltage required to switch a Xilinx input from high to low for each of the 64 lines, while only probing two of them. Directly driving an external voltage was considered too risky, and tests done on any other unit could not be used to qualify the flight board. The two lines directly probed gave an absolute voltage threshold calibration, while data collected on the remaining 62 lines without probing gave relative measurements that could be used to identify any outliers. The PECL interface was forced to a long-period square wave by driving a saturated square wave into the ADC (analog to digital converter). The active pull-down circuit was turned off, causing each line to rise rapidly and fall slowly according to the input s weak pull-down circuitry. The fall time shows up as a change in the pulse width of the signal ready by the Xilinx. This change in pulse width is a function of capacitance, pulldown current, and input threshold. Capacitance was known from the different trace lengths, plus a gate input capacitance, which is the same for all inputs. The pull-down current is the same for all inputs including the two that are probed directly. The data was combined, and the Excel solver tool was used to find input thresholds for the 62 lines. This was repeated over different supply voltages and

  14. The Caviar software package for the astrometric reduction of Cassini ISS images: description and examples

    Science.gov (United States)

    Cooper, N. J.; Lainey, V.; Meunier, L.-E.; Murray, C. D.; Zhang, Q.-F.; Baillie, K.; Evans, M. W.; Thuillot, W.; Vienne, A.

    2018-02-01

    Aims: Caviar is a software package designed for the astrometric measurement of natural satellite positions in images taken using the Imaging Science Subsystem (ISS) of the Cassini spacecraft. Aspects of the structure, functionality, and use of the software are described, and examples are provided. The integrity of the software is demonstrated by generating new measurements of the positions of selected major satellites of Saturn, 2013-2016, along with their observed minus computed (O-C) residuals relative to published ephemerides. Methods: Satellite positions were estimated by fitting a model to the imaged limbs of the target satellites. Corrections to the nominal spacecraft pointing were computed using background star positions based on the UCAC5 and Tycho2 star catalogues. UCAC5 is currently used in preference to Gaia-DR1 because of the availability of proper motion information in UCAC5. Results: The Caviar package is available for free download. A total of 256 new astrometric observations of the Saturnian moons Mimas (44), Tethys (58), Dione (55), Rhea (33), Iapetus (63), and Hyperion (3) have been made, in addition to opportunistic detections of Pandora (20), Enceladus (4), Janus (2), and Helene (5), giving an overall total of 287 new detections. Mean observed-minus-computed residuals for the main moons relative to the JPL SAT375 ephemeris were - 0.66 ± 1.30 pixels in the line direction and 0.05 ± 1.47 pixels in the sample direction. Mean residuals relative to the IMCCE NOE-6-2015-MAIN-coorb2 ephemeris were -0.34 ± 0.91 pixels in the line direction and 0.15 ± 1.65 pixels in the sample direction. The reduced astrometric data are provided in the form of satellite positions for each image. The reference star positions are included in order to allow reprocessing at some later date using improved star catalogues, such as later releases of Gaia, without the need to re-estimate the imaged star positions. The Caviar software is available for free download from: ftp

  15. Studying Titan's surface photometry in the 5 microns atmospheric window with the Cassini/VIMS instrument

    Science.gov (United States)

    Cornet, T.; Altobelli, N.; Sotin, C.; Le Mouelic, S.; Rodriguez, S.; Philippe, S.; Brown, R. H.; Barnes, J. W.; Buratti, B. J.; Baines, K. H.; Clark, R. N.; Nicholson, P. D.

    2014-12-01

    Due to the influence of methane gas and a thick aerosols haze in the atmosphere, Titan's surface is only visible in 7 spectral atmospheric windows centered at 0.93, 1.08, 1.27, 1.59, 2.01, 2.7-2.8 and 5 microns with the Cassini Visual and Infrared Mapping Spectrometer (VIMS). The 5 microns atmospheric window constitutes the only one being almost insensitive to the haze scattering and which presents only a reduced atmospheric absorption contribution to the signal recorded by the instrument. Despite these advantages leading to the almost direct view of the surface, the 5 microns window is also the noisiest spectral window of the entire VIMS spectrum (an effect highly dependent on the time exposure used for the observations), and it is not totally free from atmospheric contributions, enough to keep "artefacts" in mosaics of several thousands of cubes due to atmospheric and surface photometric effects amplified by the very heterogeneous viewing conditions between each Titan flyby. At first order, a lambertian surface photometry at 5 microns has been used as an initial parameter in order to estimate atmospheric opacity and surface photometry in all VIMS atmospheric windows and to determine the albedo of the surface, yet unknown, both using radiative transfer codes on single cubes or empirical techniques on global hyperspectral mosaics. Other studies suggested that Titan's surface photometry would not be uniquely lambertian but would also contain anisotropic lunar-like contributions. In the present work, we aim at constraining accurately the surface photometry of Titan and residual atmospheric absorption effects in this 5 microns window using a comprehensive study of relevant sites located at various latitudes. Those include bright and dark (dunes) terrains, 5-microns bright terrains (Hotei Regio and Tui Regio), the Huygens Landing Site and high latitudes polar lakes and seas. The VIMS 2004 to 2014 database, composed of more than 40,000 hyperspectral cubes acquired on

  16. The Effect of Input-Based Instruction Type on the Acquisition of Spanish Accusative Clitics

    Science.gov (United States)

    White, Justin

    2015-01-01

    The purpose of this paper is to compare structured input (SI) with other input-based instructional treatments. The input-based instructional types include: input flood (IF), text enhancement (TE), SI activities, and focused input (FI; SI without implicit negative feedback). Participants included 145 adult learners enrolled in an intermediate…

  17. Outreach for Cassini Huyghens mission and future Saturn and Titan exploration: From the Antikythera Mechanism to the TSSM mission

    Science.gov (United States)

    Moussas, Xenophon; Bampasidis, Georgios; Coustenis, Athena; Solomonidou, Anezina

    2010-05-01

    These days Outreach is an activity tightly related to success in science. The public with its great interest to space and astronomy in general, the solar system exploration and Saturn and Titan in particular, loves the scientific outcome of Cassini and Huygens. This love of the public gives a lot, as its known interest to space, persuades politicians and policy makers to support space and future Saturn and Titan explorations. We use the scientific results from Cassini and Huyghens together with a mosaic from ancient science concerning the history of solar system exploration, such as the oldest known complex astronomical device, the Antikyhtera Mechanism, in outreach activities to ensure future missions and continuous support to present ones. A future mission to the Saturnian System focusing on exotic Titan will broaden people's interest not only to Physics and Astronomy, but to Mechanics, Technology and even Philosophy as well, since, obviously, the roots of the vast contribution of Space Science and Astronomy to the contemporary society can be traced back to the first astronomers of Antiquity. As an example we use the Antikythera Mechanism, a favourite astronomical device for the public, which is the first geared astronomical device ever, constructed that combines the spirit of the ancient Astronomy and scientific accuracy. It is common belief that Astronomy and Astrophysics is a perfect tool to easily involve people in Science, as the public is always interested in space subjects, captivated by the beauty and the mystery of the Universe. Years after the successful entry, descent and landing of the Huygens probe on Titan's surface, the outstanding achievements of the Cassini-Huygens mission enhance the outreach potential of Space Science. Titan is an earth-like world, embedded in a dense nitrogen atmospheric envelop and a surface carved by rivers, mountains, dunes and lakes, its exploration will certainly empower the perspective of the society for space activities

  18. Input Manipulation, Enhancement and Processing: Theoretical Views and Empirical Research

    Science.gov (United States)

    Benati, Alessandro

    2016-01-01

    Researchers in the field of instructed second language acquisition have been examining the issue of how learners interact with input by conducting research measuring particular kinds of instructional interventions (input-oriented and meaning-based). These interventions include such things as input flood, textual enhancement and processing…

  19. Input from Evian 2011

    International Nuclear Information System (INIS)

    Lamont, M.

    2012-01-01

    The LHC Beam Operation workshop 2011 took place in Evian (France) from 12. to 14. December. The principle aims of the workshop were to review 2011 LHC beam commissioning and beam operations experience, and to look forward to the operation of the LHC in 2012. Issues covered include: availability; injection; operational performance; beam loss and machine protection; system performance; limitations; and the outlook for 2012. (author)

  20. Probing the Boundaries of the Heliosphere Using Observations of the Polar ENA Flux from IBEX and Cassini/INCA

    Science.gov (United States)

    Reisenfeld, D. B.; Janzen, P. H.; Bzowski, M.; Dialynas, K.; Funsten, H. O.; Fuselier, S. A.; Galli, A.; Kubiak, M. A.; McComas, D. J.; Schwadron, N.; Sokol, J. M.

    2016-12-01

    The IBEX Mission has been collecting ENAs from the outer heliosphere for nearly eight years, or three-quarters of a solar cycle. In that time, we have observed clear evidence of the imprint of the solar cycle in the time variation in the ENA flux. The most detailed of such studies has focused on the polar ENA flux observed by IBEX-Hi, as the IBEX spacecraft attitude allows for continuous coverage of the ENA flux incident from the ecliptic poles (Reisenfeld et al. 2012, 2016). By time correlating the ENA-derived heliosheath pressure to the observed 1 AU dynamic pressure, we can estimate the distance to the ENA source region. We can further derive the thickness of the ENA-producing region (presumably the inner heliosheath) by assuming pressure balance at the termination shock (TS). This requires using the 1 AU observations to derive the dynamic pressure at the TS shock by use of a mass-loaded solar wind propagation model (Schwadron et al. 2011), and by integrating ENA observations across all energies that significantly contribute to the heliosheath pressure. This means including polar ENA observations from not only IBEX-Hi, but from IBEX-Lo and Cassini/INCA, spanning an energy range of 15 eV to 40 keV. We will present our latest polar ENA observations and estimates for the distance to the TS and the thickness of the heliosheath.

  1. Congressional interest and input

    International Nuclear Information System (INIS)

    Donnelly, W.H.

    1985-01-01

    While congressional interest in nonproliferation policy has been evident since the 1940s, the 1970s were propitious for efforts by Congress to exert influence in this sphere. Its suspicions of the executive branch had been stirred by controversies over Vietnam and Watergate at the beginning of the decade; by the end of the decade, Congress was able to curtail the unrestrained freedom of the executive branch to carry out the vaguely stated policies of the Atomic Energy Act of 1954. Congressional nonproliferation interests were further amplified during the decade by pressures from the expanding environmental movement, which included a strong antinuclear plank. This was to bring down the powerful Atomic Energy Commission (AEC). The Energy Reorganization Act of 1974 abolished the AEC and divided its responsibilities between the new Energy Research and Development Administration (ERDA), later to become the Department of Energy (DOE), and the new Nuclear Regulatory Commission

  2. Inputs and spatial distribution patterns of Cr in Jiaozhou Bay

    Science.gov (United States)

    Yang, Dongfang; Miao, Zhenqing; Huang, Xinmin; Wei, Linzhen; Feng, Ming

    2018-03-01

    Cr pollution in marine bays has been one of the critical environmental issues, and understanding the input and spatial distribution patterns is essential to pollution control. In according to the source strengths of the major pollution sources, the input patterns of pollutants to marine bay include slight, moderate and heavy, and the spatial distribution are corresponding to three block models respectively. This paper analyzed input patterns and distributions of Cr in Jiaozhou Bay, eastern China based on investigation on Cr in surface waters during 1979-1983. Results showed that the input strengths of Cr in Jiaozhou Bay could be classified as moderate input and slight input, and the input strengths were 32.32-112.30 μg L-1 and 4.17-19.76 μg L-1, respectively. The input patterns of Cr included two patterns of moderate input and slight input, and the horizontal distributions could be defined by means of Block Model 2 and Block Model 3, respectively. In case of moderate input pattern via overland runoff, Cr contents were decreasing from the estuaries to the bay mouth, and the distribution pattern was parallel. In case of moderate input pattern via marine current, Cr contents were decreasing from the bay mouth to the bay, and the distribution pattern was parallel to circular. The Block Models were able to reveal the transferring process of various pollutants, and were helpful to understand the distributions of pollutants in marine bay.

  3. Temperature variations in Titan's upper atmosphere: Impact on Cassini/Huygens

    Directory of Open Access Journals (Sweden)

    B. Kazeminejad

    2005-06-01

    Full Text Available Temperature variations of Titan's upper atmosphere due to the plasma interaction of the satellite with Saturn's magnetosphere and Titan's high altitude monomer haze particles can imply an offset of up to ±30K from currently estimated model profiles. We incorporated these temperature uncertainties as an offset into the recently published Vervack et al. (2004 (Icarus, Vol. 170, 91-112 engineering model and derive extreme case (i.e. minimum and maximum profiles temperature, pressure, and density profiles. We simulated the Huygens probe hypersonic entry trajectory and obtain, as expected, deviations of the probe trajectory for the extreme atmosphere models compared to the simulation based on the nominal one. These deviations are very similar to the ones obtained with the standard Yelle et al. (1997 (ESA SP-1177 profiles. We could confirm that the difference in aerodynamic drag is of an order of magnitude that can be measured by the probe science accelerometer. They represent an important means for the reconstruction of Titan's upper atmospheric properties. Furthermore, we simulated a Cassini low Titan flyby trajectory. No major trajectory deviations were found. The atmospheric torques due to aerodynamic drag, however, are twice as high for our high temperature profile as the ones obtained with the Yelle maximum profile and more than 5 times higher than the worst case estimations from the Cassini project. We propose to use the Cassini atmospheric torque measurements during its low flybys to derive the atmospheric drag and to reconstruct Titan's upper atmosphere density, pressure, and temperature. The results could then be compared to the reconstructed profiles obtained from Huygens probe measurements. This would help to validate the probe measurements and decrease the error bars.

  4. Cassini Radio Occultations of Saturn's Ionosphere: Modeling a Variable Influx of Water into Saturn's Atmosphere

    Science.gov (United States)

    Moore, L.; Mendillo, M.

    2006-12-01

    The Saturn-Thermosphere-Ionosphere-Model (STIM), a global circulation model (GCM) of Saturn's upper atmosphere, is used to investigate a range of possible parameters that could lead to the profiles measured recently by the Radio Science Subsystem (RSS) aboard Cassini. Specifically, electron density observations of Saturn's equatorial ionosphere demonstrate a dawn/dusk asymmetry, a possible double peak, and a high degree of vertical structure and variability. On average, peak electron densities are larger at dusk than dawn (5400 cm-3 vs. 1700 cm-3) and the peak altitudes are lower at dusk than dawn (1880 km vs. 2360 km). Self-consistent, time-dependent 1D water diffusion calculations have been combined with the GCM in order to examine the possibility that a topside flux of neutral water into Saturn's atmosphere may provide a loss mechanism -- via charge exchange with protons -- that is sufficient to reproduce the observed ionosphere. Our previous modeling results indicated that a constant background influx of (0.5 -- 1.0) x 107 H2O cm-2 sec-1 was adequate in reproducing Cassini measurements on average [Moore et al., 2006], however the large observed variations in the vertical electron density profiles require additional complexities in the modeling. In this study we show that one possible source of the structuring observed in the electron density profiles could be from brief surges and/or reductions in the background water flux, which ultimately may be linked to geysers near Enceladus' southern pole. Moore, L., A.F. Nagy, A.J. Kliore, I. Mueller-Wodarg, J.D. Richardson, M. Mendillo (2006), Cassini radio occultations of Saturn's ionopshere: I. model comparisons using a constant water flux, submitted to GRL.

  5. Temperature variations in Titan's upper atmosphere: Impact on Cassini/Huygens

    Directory of Open Access Journals (Sweden)

    B. Kazeminejad

    2005-06-01

    Full Text Available Temperature variations of Titan's upper atmosphere due to the plasma interaction of the satellite with Saturn's magnetosphere and Titan's high altitude monomer haze particles can imply an offset of up to ±30K from currently estimated model profiles. We incorporated these temperature uncertainties as an offset into the recently published Vervack et al. (2004 (Icarus, Vol. 170, 91-112 engineering model and derive extreme case (i.e. minimum and maximum profiles temperature, pressure, and density profiles. We simulated the Huygens probe hypersonic entry trajectory and obtain, as expected, deviations of the probe trajectory for the extreme atmosphere models compared to the simulation based on the nominal one. These deviations are very similar to the ones obtained with the standard Yelle et al. (1997 (ESA SP-1177 profiles. We could confirm that the difference in aerodynamic drag is of an order of magnitude that can be measured by the probe science accelerometer. They represent an important means for the reconstruction of Titan's upper atmospheric properties. Furthermore, we simulated a Cassini low Titan flyby trajectory. No major trajectory deviations were found. The atmospheric torques due to aerodynamic drag, however, are twice as high for our high temperature profile as the ones obtained with the Yelle maximum profile and more than 5 times higher than the worst case estimations from the Cassini project. We propose to use the Cassini atmospheric torque measurements during its low flybys to derive the atmospheric drag and to reconstruct Titan's upper atmosphere density, pressure, and temperature. The results could then be compared to the reconstructed profiles obtained from Huygens probe measurements. This would help to validate the probe measurements and decrease the error bars.

  6. Cassini/VIMS hyperspectral observations of the HUYGENS landing site on Titan

    Science.gov (United States)

    Rodriguez, S.; Le, Mouelic S.; Sotin, Christophe; Clenet, H.; Clark, R.N.; Buratti, B.; Brown, R.H.; McCord, T.B.; Nicholson, P.D.; Baines, K.H.

    2006-01-01

    Titan is one of the primary scientific objectives of the NASA-ESA-ASI Cassini-Huygens mission. Scattering by haze particles in Titan's atmosphere and numerous methane absorptions dramatically veil Titan's surface in the visible range, though it can be studied more easily in some narrow infrared windows. The Visual and Infrared Mapping Spectrometer (VIMS) instrument onboard the Cassini spacecraft successfully imaged its surface in the atmospheric windows, taking hyperspectral images in the range 0.4-5.2 ??m. On 26 October (TA flyby) and 13 December 2004 (TB flyby), the Cassini-Huygens mission flew over Titan at an altitude lower than 1200 km at closest approach. We report here on the analysis of VIMS images of the Huygens landing site acquired at TA and TB, with a spatial resolution ranging from 16 to14.4 km/pixel. The pure atmospheric backscattering component is corrected by using both an empirical method and a first-order theoretical model. Both approaches provide consistent results. After the removal of scattering, ratio images reveal subtle surface heterogeneities. A particularly contrasted structure appears in ratio images involving the 1.59 and 2.03 ??m images north of the Huygens landing site. Although pure water ice cannot be the only component exposed at Titan's surface, this area is consistent with a local enrichment in exposed water ice and seems to be consistent with DISR/Huygens images and spectra interpretations. The images show also a morphological structure that can be interpreted as a 150 km diameter impact crater with a central peak. ?? 2006 Elsevier Ltd. All rights reserved.

  7. Cassini Ion Mass Spectrometer Peak Calibrations from Statistical Analysis of Flight Data

    Science.gov (United States)

    Woodson, A. K.; Johnson, R. E.

    2017-12-01

    The Cassini Ion Mass Spectrometer (IMS) is an actuating time-of-flight (TOF) instrument capable of resolving ion mass, energy, and trajectory over a field of view that captures nearly the entire sky. One of three instruments composing the Cassini Plasma Spectrometer, IMS sampled plasma throughout the Kronian magnetosphere from 2004 through 2012 when it was permanently disabled due to an electrical malfunction. Initial calibration of the flight instrument at Southwest Research Institute (SwRI) was limited to a handful of ions and energies due to time constraints, with only about 30% of planned measurements carried out prior to launch. Further calibration measurements were subsequently carried out after launch at SwRI and Goddard Space Flight Center using the instrument prototype and engineering model, respectively. However, logistical differences among the three calibration efforts raise doubts as to how accurately the post-launch calibrations describe the behavior of the flight instrument. Indeed, derived peak parameters for some ion species differ significantly from one calibration to the next. In this study we instead perform a statistical analysis on 8 years of flight data in order to extract ion peak parameters that depend only on the response of the flight instrument itself. This is accomplished by first sorting the TOF spectra based on their apparent compositional similarities (e.g. primarily water group ions, primarily hydrocarbon ions, etc.) and normalizing each spectrum. The sorted, normalized data are then binned according to TOF, energy, and counts in order to generate energy-dependent probability density maps of each ion peak contour. Finally, by using these density maps to constrain a stochastic peak fitting algorithm we extract confidence intervals for the model parameters associated with various measured ion peaks, establishing a logistics-independent calibration of the body of IMS data gathered over the course of the Cassini mission.

  8. Risk Assessment of Cassini Sun Sensor Integrity Due to Hypervelocity Impact of Saturn Dust Particles

    Science.gov (United States)

    Lee, Allan Y.

    2016-01-01

    A sophisticated interplanetary spacecraft, Cassini is one of the heaviest and most sophisticated interplanetary spacecraft humans have ever built and launched. Since achieving orbit at Saturn in 2004, Cassini has collected science data throughout its four-year prime mission (2004-08), and has since been approved for first and second extended missions through September 2017. In late 2016, the Cassini spacecraft will begin a daring set of ballistic orbits that will hop the rings and dive between the upper atmosphere of Saturn and its innermost D-ring twenty-two times. The "dusty" environment of the inner D-ring region the spacecraft must fly through is hazardous because of the possible damage that dust particles, travelling at speeds as high as 31.4 km/s, can do to spacecraft hardware. During hazardous proximal ring-plane crossings, the Cassini mission operation team plans to point the high-gain antenna to the RAM vector in order to protect most of spacecraft instruments from the incoming energetic ring dust particles. However, this particular spacecraft attitude will expose two Sun sensors (that are mounted on the antenna dish) to the incoming dust particles. High-velocity impacts on the Sun sensor cover glass might penetrate the 2.54-mm glass cover of the Sun sensor. Even without penetration damage, craters created by these impacts on the surface of the cover glass will degrade the transmissibility of light through it. Apart from being directly impacted by the dust particles, the Sun sensors are also threatened by some fraction of ricochet ejecta that are produced by dust particle impacts on the large antenna dish (made of graphite fiber epoxy composite material). Finally, the spacecraft attitude control system must cope with disturbances due to both the translational and angular impulses imparted on the large antenna dish and the long magnetometer boom by the incoming high-velocity projectiles. Analyses performed to quantify the risks the Sun sensors must contend

  9. Jovian decametric radiation seen from Juno, Cassini, STEREO A, WIND, and Earth-based radio observatories

    Science.gov (United States)

    Imai, M.; Kurth, W. S.; Hospodarsky, G. B.; Bolton, S. J.; Connerney, J. E. P.; Levin, S. M.; Lecacheux, A.; Lamy, L.; Zarka, P.; Clarke, T. E.; Higgins, C. A.

    2017-09-01

    Jupiter's decametric (DAM) radiation is generated very close to the local gyrofrequency by the electron cyclotron maser instability (CMI). The first two-point common detections of Jovian DAM radiation were made using the Voyager spacecraft and ground-based radio observatories in early 1979, but, due to geometrical constraints and limited flyby duration, a full understanding of the latitudinal beaming of Jovian DAM radiation remains elusive. The stereoscopic DAM radiation viewed from Juno, Cassini, STEREO A, WIND, and Earth-based radio observatories provides a unique opportunity to analyze the CMI emission mechanism and beaming properties.

  10. Light weight radioisotope heater unit (LWRHU) production for the Cassini mission

    International Nuclear Information System (INIS)

    Rinehart, G.H.

    1997-01-01

    The Light-Weight Radioisotope Heater Unit (LWRHU) is a [sup 238]PuO[sub 2] fueled heat source designed to provide one thermal watt in each of various locations on a spacecraft. The heat sources are required to maintain the temperature of specific components within normal operating ranges. The heat source consists of a hot- pressed [sup 238]PuO[sub 2] fuel pellet, a Pt-3ORh vented capsule, a pyrolytic graphite insulator, and a woven graphite aeroshell assembly. Los Alamos National Laboratory has fabricated 180 heat sources, 157 of which will be used on the Cassini mission

  11. A parallel input composite transimpedance amplifier

    Science.gov (United States)

    Kim, D. J.; Kim, C.

    2018-01-01

    A new approach to high performance current to voltage preamplifier design is presented. The design using multiple operational amplifiers (op-amps) has a parasitic capacitance compensation network and a composite amplifier topology for fast, precision, and low noise performance. The input stage consisting of a parallel linked JFET op-amps and a high-speed bipolar junction transistor (BJT) gain stage driving the output in the composite amplifier topology, cooperating with the capacitance compensation feedback network, ensures wide bandwidth stability in the presence of input capacitance above 40 nF. The design is ideal for any two-probe measurement, including high impedance transport and scanning tunneling microscopy measurements.

  12. Six axis force feedback input device

    Science.gov (United States)

    Ohm, Timothy (Inventor)

    1998-01-01

    The present invention is a low friction, low inertia, six-axis force feedback input device comprising an arm with double-jointed, tendon-driven revolute joints, a decoupled tendon-driven wrist, and a base with encoders and motors. The input device functions as a master robot manipulator of a microsurgical teleoperated robot system including a slave robot manipulator coupled to an amplifier chassis, which is coupled to a control chassis, which is coupled to a workstation with a graphical user interface. The amplifier chassis is coupled to the motors of the master robot manipulator and the control chassis is coupled to the encoders of the master robot manipulator. A force feedback can be applied to the input device and can be generated from the slave robot to enable a user to operate the slave robot via the input device without physically viewing the slave robot. Also, the force feedback can be generated from the workstation to represent fictitious forces to constrain the input device's control of the slave robot to be within imaginary predetermined boundaries.

  13. Material input of nuclear fuel

    International Nuclear Information System (INIS)

    Rissanen, S.; Tarjanne, R.

    2001-01-01

    The Material Input (MI) of nuclear fuel, expressed in terms of the total amount of natural material needed for manufacturing a product, is examined. The suitability of the MI method for assessing the environmental impacts of fuels is also discussed. Material input is expressed as a Material Input Coefficient (MIC), equalling to the total mass of natural material divided by the mass of the completed product. The material input coefficient is, however, only an intermediate result, which should not be used as such for the comparison of different fuels, because the energy contents of nuclear fuel is about 100 000-fold compared to the energy contents of fossil fuels. As a final result, the material input is expressed in proportion to the amount of generated electricity, which is called MIPS (Material Input Per Service unit). Material input is a simplified and commensurable indicator for the use of natural material, but because it does not take into account the harmfulness of materials or the way how the residual material is processed, it does not alone express the amount of environmental impacts. The examination of the mere amount does not differentiate between for example coal, natural gas or waste rock containing usually just sand. Natural gas is, however, substantially more harmful for the ecosystem than sand. Therefore, other methods should also be used to consider the environmental load of a product. The material input coefficient of nuclear fuel is calculated using data from different types of mines. The calculations are made among other things by using the data of an open pit mine (Key Lake, Canada), an underground mine (McArthur River, Canada) and a by-product mine (Olympic Dam, Australia). Furthermore, the coefficient is calculated for nuclear fuel corresponding to the nuclear fuel supply of Teollisuuden Voima (TVO) company in 2001. Because there is some uncertainty in the initial data, the inaccuracy of the final results can be even 20-50 per cent. The value

  14. Phasing Out a Polluting Input

    OpenAIRE

    Eriksson, Clas

    2015-01-01

    This paper explores economic policies related to the potential conflict between economic growth and the environment. It applies a model with directed technological change and focuses on the case with low elasticity of substitution between clean and dirty inputs in production. New technology is substituted for the polluting input, which results in a gradual decline in pollution along the optimal long-run growth path. In contrast to some recent work, the era of pollution and environmental polic...

  15. Giovanni Domenico Cassini a modern astronomer in the 17th century

    CERN Document Server

    Bernardi, Gabriella

    2017-01-01

    This book offers a fascinating account of the life and scientific achievements of Giovanni Domenico Cassini, or Cassini I, the most famous astronomer of his time, who is remembered today especially for his observations of the rings and satellites of Saturn and his earlier construction of the great meridian line in the Basilica of San Petronio in Bologna. The various stages of his life are recounted in an engaging style, from his early childhood in Perinaldo and his time at the famous Jesuit College in Genoa, to his later experiences in Bologna and Paris. The emphasis, however, is on the scientific side of his life. The book explores his impressive body of work in diverse fields while also drawing attention to the international character of his endeavors, the rigor of his research, and his outstanding management skills, which combined to make him an early embodiment of the “European scientist.” It was also these abilities that gained him the attention of the most powerfu l king in Europe, Louis XIV of Fran...

  16. Observations and temperatures of Io's Pele Patera from Cassini and Galileo spacecraft images

    Science.gov (United States)

    Radebaugh, J.; McEwen, A.S.; Milazzo, M.P.; Keszthelyi, L.P.; Davies, A.G.; Turtle, E.P.; Dawson, D.D.

    2004-01-01

    Pele has been the most intense high-temperature hotspot on Io to be continuously active during the Galileo monitoring from 1996-2001. A suite of characteristics suggests that Pele is an active lava lake inside a volcanic depression. In 2000-2001, Pele was observed by two spacecraft, Cassini and Galileo. The Cassini observations revealed that Pele is variable in activity over timescales of minutes, typical of active lava lakes in Hawaii and Ethiopia. These observations also revealed that the short-wavelength thermal emission from Pele decreases with rotation of Io by a factor significantly greater than the cosine of the emission angle, and that the color temperature becomes more variable and hotter at high emission angles. This behavior suggests that a significant portion of the visible thermal emission from Pele comes from lava fountains within a topographically confined lava body. High spatial resolution, nightside images from a Galileo flyby in October 2001 revealed a large, relatively cool (Pele has lavas with ultramafic compositions. The long-lived, vigorous activity of what is most likely an actively overturning lava lake in Pele Patera indicates that there is a strong connection to a large, stable magma source region. ?? 2003 Elsevier Inc. All rights reserved.

  17. Dynamics Of Saturn'S Mid-scale Storms In The Cassini Era.

    Science.gov (United States)

    Del Rio Gaztelurrutia, Teresa; Hueso, R.; Sánchez-Lavega, A.

    2010-10-01

    Convective storms, similar to those in Earth, but of much larger scale, develop often in Saturn's atmosphere. During the Voyagers’ flybys of Saturn in 1981 mid-scale storms, with an horizontal extension of the order of 1000-3000 km were observed to occur mainly in a narrow tropical-latitude band in the Northern hemisphere at latitudes 38-40 deg North. Contrasting with the Voyagers’ era, since the starting of the Cassini mission in 2004, a similar mid-scale convective activity has concentrated in the so-called "storm alley", a narrow band at a symmetric Southern latitude of 38 deg.. In this work, we characterize this storm activity using available visual information provided by Cassini ISS cameras and the continuous survey from the Earth by the International Outer Planets Watch (IOPW) and its online database PVOL (Hueso et al., Planetary and Space Science, 2010). We study the frequency of appearance of storms with sizes above 2000 km, their characteristic size and life-time, as well as their interaction with surrounding dynamical features. In particular we examine the possibility that storms might provide a mechanism of injection of energy into Saturn's jets, the influence of storms in the generation of atmospheric vortices, and the analogies and differences of Voyagers’ and present day jet structure at the relevant latitudes. Acknowledgments: This work has been funded by the Spanish MICIIN AYA2009-10701 with FEDER support and Grupos Gobierno Vasco IT-464

  18. JUPITER’S PHASE VARIATIONS FROM CASSINI : A TESTBED FOR FUTURE DIRECT-IMAGING MISSIONS

    International Nuclear Information System (INIS)

    Mayorga, L. C.; Jackiewicz, J.; Rages, K.; West, R. A.; Knowles, B.; Lewis, N.; Marley, M. S.

    2016-01-01

    We present empirical phase curves of Jupiter from ∼0° to 140° as measured in multiple optical bandpasses by Cassini /Imaging Science Subsystem (ISS) during the Millennium flyby of Jupiter in late 2000 to early 2001. Phase curves are of interest for studying the energy balance of Jupiter and understanding the scattering behavior of the planet as an exoplanet analog. We find that Jupiter is significantly darker at partial phases than an idealized Lambertian planet by roughly 25% and is not well fit by Jupiter-like exoplanet atmospheric models across all wavelengths. We provide analytic fits to Jupiter’s phase function in several Cassini /ISS imaging filter bandpasses. In addition, these observations show that Jupiter’s color is more variable with phase angle than predicted by models. Therefore, the color of even a near Jupiter-twin planet observed at a partial phase cannot be assumed to be comparable to that of Jupiter at full phase. We discuss how the Wide-Field Infrared Survey Telescope and other future direct-imaging missions can enhance the study of cool giants.

  19. The Cassini-Huygens visit to Saturn an historic mission to the ringed planet

    CERN Document Server

    Meltzer, Michael

    2015-01-01

    Cassini-Huygens was the most ambitious and successful space journey ever launched to the outer Solar System. This book examines all aspects of the journey: its conception and planning; the lengthy political processes needed to make it a reality; the engineering and development required to build the spacecraft; its 2.2-billion mile journey from Earth to the Ringed Planet; and the amazing discoveries from the mission. The author traces how the visions of a few brilliant scientists matured, gained popularity, and eventually became a reality. Innovative technical leaps were necessary to assemble such a multifaceted spacecraft and reliably operate it while it orbited a planet so far from our own. The Cassini-Huygens spacecraft design evolved from other deep space efforts, most notably the Galileo mission to Jupiter, enabling the voluminous, paradigm-shifting scientific data collected by the spacecraft.  Some of these discoveries are absolute gems. A small satellite that scientists once thought of as a dead pi...

  20. Emitted Power of Jupiter Based on Cassini CIRS and VIMS Observations

    Science.gov (United States)

    Li, Liming; Baines, Kevin H.; Smith, Mark A.; West, Robert A.; Perez-Hoyos, Santiago; Trammel, Harold J.; Simon-Miller, Amy A.; Conrath, Barney J.; Gierasch, Peter J.; Orton, Glenn S.; hide

    2012-01-01

    The emitted power of Jupiter and its meridional distribution are determined from observations by the Composite Infrared Spectrometer (CIRS) and Visual and Infrared Spectrometer (VIMS) onboard Cassini during its flyby en route to Saturn in late 2000 and early 2001. Jupiter's global- average emitted power and effective temperature are measured to be 14.10+/-0.03 W/sq m and 125.57+/-0.07 K, respectively. On a global scale, Jupiter's 5-micron thermal emission contributes approx. 0.7+/-0.1 % to the total emitted power at the global scale, but it can reach approx. 1.9+/-0.6% at 15degN. The meridional distribution of emitted power shows a significant asymmetry between the two hemispheres with the emitted power in the northern hemisphere 3.0+/-0.3% larger than that in the southern hemisphere. Such an asymmetry shown in the Cassini epoch (2000-01) is not present during the Voyager epoch (1979). In addition, the global-average emitted power increased approx. 3.8+/-1.0% between the two epochs. The temporal variation of Jupiter's total emitted power is mainly due to the warming of atmospheric layers around the pressure level of 200 mbar. The temporal variation of emitted power was also discovered on Saturn (Li et al., 2010). Therefore, we suggest that the varying emitted power is a common phenomenon on the giant planets.

  1. Cassini CAPS-ELS observations of carbon-based anions and aerosol growth in Titan's ionosphere

    Science.gov (United States)

    Desai, Ravindra; Coates, Andrew; Wellbrock, Anne; Kataria, Dhiren; Jones, Geraint; Lewis, Gethyn; Waite, J.

    2016-06-01

    Cassini observations of Titans ionosphere revealed an atmosphere rich in positively charged ions with masses up to > 350 amu and negatively charged ions and aerosols with mass over charge ratios as high as 13,800 amu/q. The detection of negatively charged molecules by the Cassini CAPS Electron Spectrometer (CAPS-ELS) was particularly surprising and showed how the synthesis of large aerosol-size particles takes place at altitudes much greater than previously thought. Here, we present further analysis into this CAPS-ELS dataset, through an enhanced understanding of the instrument's response function. In previous studies the intrinsic E/E energy resolution of the instrument did not allow specific species to be identified and the detections were classified into broad mass ranges. In this study we use an updated fitting procedure to show how the ELS mass spectrum can be resolved into specific peaks at multiples of carbon-based anions up to > 100 amu/q. The negatively charged ions and aerosols in Titans ionosphere increase in mass with decreasing altitude, the lightest species being observed close to Titan's exobase of ˜1,450km and heaviest species observed at altitudes < 950km. We identify key stages in this apparent growth process and report on key intermediaries which appear to trigger the rapid growth of the larger aerosol-size particles.

  2. The atmospheres of Saturn and Titan in the near-infrared: First results of Cassini/Vims

    Science.gov (United States)

    Baines, K.H.; Momary, T.W.; Buratti, B.J.; Matson, D.L.; Nelson, R.M.; Drossart, P.; Sicardy, B.; Formisano, V.; Bellucci, G.; Coradini, A.; Griffith, C.; Brown, R.H.; Bibring, J.-P.; Langevin, Y.; Capaccioni, F.; Cerroni, P.; Clark, R.N.; Combes, M.; Cruikshank, D.P.; Jaumann, R.; McCordt, T.B.; Mennella, V.; Nicholson, P.D.; Sotin, Christophe

    2006-01-01

    The wide spectral coverage and extensive spatial, temporal, and phase-angle mapping capabilities of the Visual Infrared Mapping Spectrometer (VIMS) onboard the Cassini-Huygens Orbiter are producing fundamental new insights into the nature of the atmospheres of Saturn and Titan. For both bodies, VIMS maps over time and solar phase angles provide information for a multitude of atmospheric constituents and aerosol layers, providing new insights into atmospheric structure and dynamical and chemical processes. For Saturn, salient early results include evidence for phosphine depletion in relatively dark and less cloudy belts at temperate and mid-latitudes compared to the relatively bright and cloudier Equatorial Region, consistent with traditional theories of belts being regions of relative downwelling. Additional Saturn results include (1) the mapping of enhanced trace gas absorptions at the south pole, and (2) the first high phase-angle, high-spatial-resolution imagery of CH4 fluorescence. An additional fundamental new result is the first nighttime near-infrared mapping of Saturn, clearly showing discrete meteorological features relatively deep in the atmosphere beneath the planet's sunlit haze and cloud layers, thus revealing a new dynamical regime at depth where vertical dynamics is relatively more important than zonal dynamics in determining cloud morphology. Zonal wind measurements at deeper levels than previously available are achieved by tracking these features over multiple days, thereby providing measurements of zonal wind shears within Saturn's troposphere when compared to cloudtop movements measured in reflected sunlight. For Titan, initial results include (1) the first detection and mapping of thermal emission spectra of CO, CO2, and CH3D on Titan's nightside limb, (2) the mapping of CH4 fluorescence over the dayside bright limb, extending to ??? 750 km altitude, (3) wind measurements of ???0.5 ms-1, favoring prograde, from the movement of a persistent

  3. Organic chemistry in Titan's upper atmosphere and its astrobiological consequences: I. Views towards Cassini plasma spectrometer (CAPS) and ion neutral mass spectrometer (INMS) experiments in space

    Science.gov (United States)

    Ali, A.; Sittler, E. C.; Chornay, D.; Rowe, B. R.; Puzzarini, C.

    2015-05-01

    The discovery of carbocations and carbanions by Ion Neutral Mass Spectrometer (INMS) and the Cassini Plasma Spectrometer (CAPS) instruments onboard the Cassini spacecraft in Titan's upper atmosphere is truly amazing for astrochemists and astrobiologists. In this paper we identify the reaction mechanisms for the growth of the complex macromolecules observed by the CAPS Ion Beam Spectrometer (IBS) and Electron Spectrometer (ELS). This identification is based on a recently published paper (Ali et al., 2013. Planet. Space Sci. 87, 96) which emphasizes the role of Olah's nonclassical carbonium ion chemistry in the synthesis of the organic molecules observed in Titan's thermosphere and ionosphere by INMS. The main conclusion of that work was the demonstration of the presence of the cyclopropenyl cation - the simplest Huckel's aromatic molecule - and its cyclic methyl derivatives in Titan's atmosphere at high altitudes. In this study, we present the transition from simple aromatic molecules to the complex ortho-bridged bi- and tri-cyclic hydrocarbons, e.g., CH2+ mono-substituted naphthalene and phenanthrene, as well as the ortho- and peri-bridged tri-cyclic aromatic ring, e.g., perinaphthenyl cation. These rings could further grow into tetra-cyclic and the higher order ring polymers in Titan's upper atmosphere. Contrary to the pre-Cassini observations, the nitrogen chemistry of Titan's upper atmosphere is found to be extremely rich. A variety of N-containing hydrocarbons including the N-heterocycles where a CH group in the polycyclic rings mentioned above is replaced by an N atom, e.g., CH2+ substituted derivative of quinoline (benzopyridine), are found to be dominant in Titan's upper atmosphere. The mechanisms for the formation of complex molecular anions are discussed as well. It is proposed that many closed-shell complex carbocations after their formation first, in Titan's upper atmosphere, undergo the kinetics of electron recombination to form open-shell neutral

  4. Harmonize input selection for sediment transport prediction

    Science.gov (United States)

    Afan, Haitham Abdulmohsin; Keshtegar, Behrooz; Mohtar, Wan Hanna Melini Wan; El-Shafie, Ahmed

    2017-09-01

    In this paper, three modeling approaches using a Neural Network (NN), Response Surface Method (RSM) and response surface method basis Global Harmony Search (GHS) are applied to predict the daily time series suspended sediment load. Generally, the input variables for forecasting the suspended sediment load are manually selected based on the maximum correlations of input variables in the modeling approaches based on NN and RSM. The RSM is improved to select the input variables by using the errors terms of training data based on the GHS, namely as response surface method and global harmony search (RSM-GHS) modeling method. The second-order polynomial function with cross terms is applied to calibrate the time series suspended sediment load with three, four and five input variables in the proposed RSM-GHS. The linear, square and cross corrections of twenty input variables of antecedent values of suspended sediment load and water discharge are investigated to achieve the best predictions of the RSM based on the GHS method. The performances of the NN, RSM and proposed RSM-GHS including both accuracy and simplicity are compared through several comparative predicted and error statistics. The results illustrated that the proposed RSM-GHS is as uncomplicated as the RSM but performed better, where fewer errors and better correlation was observed (R = 0.95, MAE = 18.09 (ton/day), RMSE = 25.16 (ton/day)) compared to the ANN (R = 0.91, MAE = 20.17 (ton/day), RMSE = 33.09 (ton/day)) and RSM (R = 0.91, MAE = 20.06 (ton/day), RMSE = 31.92 (ton/day)) for all types of input variables.

  5. High-Resolution Mid-IR Imaging of Jupiter's Great Red Spot: Comparing Cassini, VLT and Subaru Observations

    Science.gov (United States)

    Fletcher, Leigh N.; Orton, G. S.; Yanamandra-Fisher, P.; Irwin, P. G. J.; Baines, K. H.; Edkins, E.; Line, M. R.; Mousis, O.; Parrish, P. D.; Vanzi, L.; Fuse, T.; Fujoyoshi, T.

    2008-09-01

    In the eight years since the Cassini fly-by of Jupiter, the spatial resolution of ground-based observations of Jupiter's giant anticyclonic storm systems (the Great Red Spot, Oval BA and others) using 8m-class telescopes has surpassed the resolution of the Cassini/CIRS maps. We present a time-series of mid-IR imaging of the Great Red Spot (GRS) and its environs from the VISIR instrument on the Very Large Telescope (UT3/Melipal) and the COMICS instrument on the Subaru telescope (Hawaii). The NEMESIS optimal-estimation retrieval algorithm (Irwin et al., 2008) is used to analyse both the 7-25 micron filtered imaging from 2005-2008 and Cassini/CIRS 7-16 micron data from 2000. We demonstrate the ability to map temperatures in the 100-400 mbar range, NH3, aerosol opacity and the para-H2 fraction from the filtered imaging. Furthermore, the Cassini/CIRS spectra are used to map the PH3 mole fraction around the GRS. The thermal field, gaseous composition and aerosol distribution are used as diagnostics for the atmospheric motion associated with the GRS. Changes in the atmospheric state in response to close encounters with Oval BA and other vortices will be assessed. These results will be discussed in light of their implications for the planning of the Europa-Jupiter System Mission.

  6. Equinoctial Activity Over Titan Dune Fields Revealed by Cassini/vims

    Science.gov (United States)

    Rodriguez, S.; Le Mouelic, S.; Barnes, J. W.; Hirtzig, M.; Rannou, P.; Sotin, C.; Brown, R. H.; Bow, J.; Vixie, G.; Cornet, T.; Bourgeois, O.; Narteau, C.; Courrech Du Pont, S.; Le Gall, A.; Reffet, E.; Griffith, C. A.; Jaumann, R.; Stephan, K.; Buratti, B. J.; Clark, R. N.; Baines, K. H.; Nicholson, P. D.; Coustenis, A.

    2012-12-01

    Titan, the largest satellite of Saturn, is the only satellite in the solar system with a dense atmosphere. The close and continuous observations of Titan by the Cassini spacecraft, in orbit around Saturn since July 2004, bring us evidences that Titan troposphere and low stratosphere experience an exotic, but complete meteorological cycle similar to the Earth hydrological cycle, with hydrocarbons evaporation, condensation in clouds, and rainfall. Cassini monitoring campaigns also demonstrate that Titan's cloud coverage and climate vary with latitude. Titan's tropics, with globally weak meteorological activity and widespread dune fields, seem to be slightly more arid than the poles, where extensive and numerous liquid reservoirs and sustained cloud activity have been discovered. Only a few tropo-spheric clouds have been observed at Titan's tropics during the southern summer. As equinox was approaching (in August 2009), they occurred more frequently and appeared to grow in strength and size. We present here the observation of intense brightening at Titan's tropics, very close to the equinox. These detections were conducted with the Visual and Infrared Mapping Spectrometer (VIMS) onboard Cassini. We will discuss the VIMS images of the three individual events detected so far, observed during the Titan's flybys T56 (22 May 2009), T65 (13 January 2010) and T70 (21 June 2010). T56, T65 and T70 observations show an intense and transient brighten-ing of large regions very close to the equator, right over the extensive dune fields of Senkyo, Belet and Shangri-La. They all appear spectrally and morphologically different from all transient surface features or atmospheric phenomena previously reported. Indeed, these events share in particular a strong brightening at wavelengths greater than 2 μm (especially at 5 μm), making them spectrally distinct from the small tropical clouds observed before the equinox and the large storms observed near the equator in September and October

  7. The Plasma Proton Environment within Saturn's inner magnetosphere as Observed by the Cassini Plasma Spectrometer (CAPS) during Saturn Orbit Insertion

    Science.gov (United States)

    Sittler, E. C., Jr.; Elrod, M. K.; Johnson, R. E.; Cooper, J. F.; Tseng, W. L.; Smith, H. T.; Chornay, D. J.; Shappirio, M.; Simpson, D. G.

    2017-12-01

    In analyzing the Cassini data between Saturn's A-ring outer edge and Mimas' L shell numerous inconsistencies have been reported in estimates of total ionic charge and electron density. The primary focus of our work is to understand these inconsistencies. We present our recent discovery of plasma protons during Saturn Orbit Insertion (SOI) outbound pass of the magnetospheric region between the F and G rings. We also searched for H2+ ions but no such events were found. The discovery of protons was made possible by a recent analysis of the CAPS Ion Mass Spectrometer's (IMS's) time-of-flight (TOF) composition data in a mode of reduced post-acceleration voltage at 6 kV instead of the usual 14.6 kV. All previous work for this region had not considered the TOF data. The new proton analysis was enabled by minimum scattering of 6 kV protons in the instrument's ultrathin carbon foils (CF), in comparison to larger scattering for the heavier ions such as for O+ and O2+. We use a SIMION model of the CAPS IMS including the effects of energy straggling and scattering by the instrument's CFs in an attempt to understand the TOF composition data for the heavier ions. This analysis within the uncertainties of the instrument allows us to estimate the relative abundances of the heavier ions and thus run our 2D velocity ion moments code to get ion densities, temperatures and velocities during the SOI outbound pass through the F-ring and G-ring gap. Comparisons with other data sets will be made.

  8. World Input-Output Network.

    Directory of Open Access Journals (Sweden)

    Federica Cerina

    Full Text Available Production systems, traditionally analyzed as almost independent national systems, are increasingly connected on a global scale. Only recently becoming available, the World Input-Output Database (WIOD is one of the first efforts to construct the global multi-regional input-output (GMRIO tables. By viewing the world input-output system as an interdependent network where the nodes are the individual industries in different economies and the edges are the monetary goods flows between industries, we analyze respectively the global, regional, and local network properties of the so-called world input-output network (WION and document its evolution over time. At global level, we find that the industries are highly but asymmetrically connected, which implies that micro shocks can lead to macro fluctuations. At regional level, we find that the world production is still operated nationally or at most regionally as the communities detected are either individual economies or geographically well defined regions. Finally, at local level, for each industry we compare the network-based measures with the traditional methods of backward linkages. We find that the network-based measures such as PageRank centrality and community coreness measure can give valuable insights into identifying the key industries.

  9. Parameter setting and input reduction

    NARCIS (Netherlands)

    Evers, A.; van Kampen, N.J.|info:eu-repo/dai/nl/126439737

    2008-01-01

    The language acquisition procedure identifies certain properties of the target grammar before others. The evidence from the input is processed in a stepwise order. Section 1 equates that order and its typical effects with an order of parameter setting. The question is how the acquisition procedure

  10. Remote input/output station

    CERN Multimedia

    1972-01-01

    A general view of the remote input/output station installed in building 112 (ISR) and used for submitting jobs to the CDC 6500 and 6600. The card reader on the left and the line printer on the right are operated by programmers on a self-service basis.

  11. Lithium inputs to subduction zones

    NARCIS (Netherlands)

    Bouman, C.; Elliott, T.R.; Vroon, P.Z.

    2004-01-01

    We have studied the sedimentary and basaltic inputs of lithium to subduction zones. Various sediments from DSDP and ODP drill cores in front of the Mariana, South Sandwich, Banda, East Sunda and Lesser Antilles island arcs have been analysed and show highly variable Li contents and δ

  12. The Changing Surface of Saturn's Titan: Cassini Observations Suggest Active Cryovolcanism

    Science.gov (United States)

    Nelson, R. M.

    2008-12-01

    R. M. Nelson(1), L. Kamp(1), R. M. C. Lopes(1), D. L. Matson(1), S. D. Wall(1), R. L. Kirk(2), K. L Mitchell(1), G. Mitri(1), B. W. Hapke(3), M. D. Boryta(4), F. E. Leader(1) , W. D. Smythe(1), K. H. Baines(1), R. Jauman(5), C. Sotin(1), R. N. Clark(6), D. P. Cruikshank(7) , P. Drossart(9), B. J. Buratti(1) , J.Lunine(8), M. Combes(9), G. Bellucci(10), J.-P. Bibring(11), F. Capaccioni(10), P. Cerroni(10), A. Coradini(10), V. Formisano(10), G Filacchione(10), R. Y. Langevin(11), T. B. McCord(12), V. Mennella(13), P. D. Nicholson(14) , B. Sicardy(8) 1-JPL, 4800 Oak Grove Drive, Pasadena CA 91109, 2-USGS, Flagstaff, 3-U Pittsburgh, 4-Mt. Sac Col, 5- DLR, Berlin, 6-USGS Denver, 7-NASA AMES, 8-U Paris-Meudon, 9-Obs de Paris, 10-ISFI-CNR Rome, 11-U Paris -Sud. Orsay, 12-Bear Flt Cntr Winthrop WA, 13-Obs Capodimonte Naples, 14-Cornell U. Several Instruments on the Cassini Saturn Orbiter have been observing the surface of Saturn's moon Titan since mid 2004. The Visual and Infrared Mapping Spectrometer (VIMS) reports that regions near 26oS, 78oW (region 1) and 7oS, 138oW (region 2) exhibit photometric changes consistent with on-going surface activity. These regions are photometrically variable with time(1). Cassini Synthetic Aperture Rader (SAR) has investigated these regions and reports that both of these regions exhibit morphologies consistent with cryovolcanism (2). VIMS observed region 1 eight times and reported that on two occasions the region brightened two-fold and then decreased again on timescales of several weeks. Region 2 was observed on four occasions (Tb-Dec13/2004 ,T8-Oct27/2005, T10-Jan15/2006, T12-Mar18/2006) and exhibited a pronounced change in I/F betweenT8 and T10. Our photometric analysis finds that both regions do not exhibit photometric properties consistent with atmospheric phenomena such as tropospheric clouds. These changes must be at or very near the surface. Radar images of these regions reveal morphology that is consistent with cryovolcanoes. We

  13. Laser Mode Behavior of the Cassini CIRS Fourier Transform Spectrometer at Saturn

    Science.gov (United States)

    Brasunas, John C.

    2012-01-01

    The CIRS Fourier transform spectrometer aboard the NASA/ESA/ASI Cassini orbiter has been acquiring spectra of the Saturnian system since 2004. The CIRS reference interferometer employs a laser diode to trigger the interferogram sampling. Although the control of laser diode drive current and operating temperature are stringent enough to restrict laser wavelength variation to a small fraction of CIRS finest resolution element, the CIRS instrument does need to be restarted every year or two, at which time it may start in a new laser mode. By monitoring the Mylar absorption features in uncalibrated spectra due to the beam splitter Mylar substrate, it can be shown that these jumps are to adjacent modes and that most of the eight-year operation so far is restricted to three adjacent modes. For a given mode, the wavelength stability appears consistent with the stability of the laser diode drive curren.t and operating temperature.

  14. Flyby Error Analysis Based on Contour Plots for the Cassini Tour

    Science.gov (United States)

    Stumpf, P. W.; Gist, E. M.; Goodson, T. D.; Hahn, Y.; Wagner, S. V.; Williams, P. N.

    2008-01-01

    The maneuver cancellation analysis consists of cost contour plots employed by the Cassini maneuver team. The plots are two-dimensional linear representations of a larger six-dimensional solution to a multi-maneuver, multi-encounter mission at Saturn. By using contours plotted with the dot product of vectors B and R and the dot product of vectors B and T components, it is possible to view the effects delta V on for various encounter positions in the B-plane. The plot is used in operations to help determine if the Approach Maneuver (ensuing encounter minus three days) and/or the Cleanup Maneuver (ensuing encounter plus three days) can be cancelled and also is a linear check of an integrated solution.

  15. Tidal Control of Jet Eruptions on Enceladus as Observed by Cassini ISS between 2005 and 2007

    Science.gov (United States)

    Hurford, T. A.; Helfenstein, P.; Spitale, J. N.

    2012-01-01

    Observations of Enceladus have revealed active jets of material erupting from cracks on its south polar surface. It has previously been proposed that diurnal tidal stress, driven by Enceladus' orbital eccentricity, may actively produce surface movement along these cracks daily and thus may regulate when eruptions occur. Our analysis of the stress on jet source regions identified in Cassini ISS images reveals tidal stress as a plausible controlling mechanism of jet activity. However, the evidence available in the published and preliminary observations of jet activity between 2005 and 2007 may not be able to solidify the link between tidal stress and eruptions from fissures. Ongoing, far more comprehensive analyses based on recent, much higher resolution jetting observations have the potential to prove otherwise.

  16. Effective stability around the Cassini state in the spin-orbit problem

    Science.gov (United States)

    Sansottera, Marco; Lhotka, Christoph; Lemaître, Anne

    2014-05-01

    We investigate the long-time stability in the neighborhood of the Cassini state in the conservative spin-orbit problem. Starting with an expansion of the Hamiltonian in the canonical Andoyer-Delaunay variables, we construct a high-order Birkhoff normal form and give an estimate of the effective stability time in the Nekhoroshev sense. By extensively using algebraic manipulations on a computer, we explicitly apply our method to the rotation of Titan. We obtain physical bounds of Titan's latitudinal and longitudinal librations, finding a stability time greatly exceeding the estimated age of the Universe. In addition, we study the dependence of the effective stability time on three relevant physical parameters: the orbital inclination, , the mean precession of the ascending node of Titan orbit, , and the polar moment of inertia,.

  17. Examining the Combined Saturn and Ring Exosphere/Ionosphere using Cassini's Proximal orbits

    Science.gov (United States)

    Tucker, O. J.; Tseng, W. L.; Johnson, R. E.; Perry, M. E.

    2017-12-01

    Neutral molecules that are emitted from Saturn's exobase (i.e., H2) and the main rings (i.e., H2, O2, H) are a source of material for both the Saturn and ring ionospheres as well as Saturn's magnetosphere (Tseng et al., 2013 [PSS 85 164 - 167]). However, the density gradient of H2 produced from the main rings is very different than that produced by Saturn's exospheric flux due to its emission from the ring plane and distance from Saturn. Cassini measurements obtained during the proximal orbits can likely be used to identify contributions from Saturn and the rings. Here we present results obtained from Monte Carlo models of the Saturn and ring exosphere used to analyze INMS data of neutrals and ions measured along the trajectories of the Proximal orbits. Understanding the sources of neutrals and the concomitant ions can help provide insight about the dynamics occurring in the Saturn system.

  18. On Radiative Factors in Planetary Rings: New Insight Derived from Cassini CIRS Observations at Saturn Equinox

    Science.gov (United States)

    Brooks, S. M.; Spilker, L. J.; Pilorz, S.; Edgington, S. G.; Deau, E.; Morishima, R.

    2012-12-01

    Since arriving at Saturn in 2004, Cassini's Composite Infrared Spectrometer has recorded tens of millions of spectra of Saturn's rings (personal communication, M. Segura). CIRS records far infrared radiation (16.7-1000 microns) at focal plane 1 (FP1). Thermal emission from Saturn's rings peaks at FP1 wavelengths. CIRS spectra are well characterized as blackbody emission at an effective temperature Te, multiplied by a scalar factor related to ring emissivity (Spilker et al. [2005, 2006]). CIRS can therefore characterize the rings' temperature and study the thermal environment to which the ring particles are subject. We focus on CIRS data from the 2009 Saturnian equinox. As the Sun's disk crossed the ring plane, CIRS obtained several radial scans of the rings at a variety of phase angles, local hour angles and distances. With the Sun's rays striking the rings at an incidence angle of zero, solar heating is virtually absent, and thermal radiation from Saturn and sunlight reflected by Saturn dominate the thermal environment. These observations appear to present a paradox. Equinox data show that the flux of thermal energy radiated by the rings can even exceed the energy incident upon them as prescribed by thermal models, particularly in the C ring and Cassini Division (Ferrari and Leyrat [2006], Morishima et al. [2009, 2010]). Conservation principles suggest that such models underestimate heating of the rings in these cases, as it is clearly unphysical for the rings to radiate significantly more energy than is incident upon them. In this presentation, we will describe our efforts to resolve this paradox and determine what doing so can teach us about Saturn's rings. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Copyright 2012 California Institute of Technology. Government sponsorship acknowledged.

  19. What Does Titan's Atmosphere Look Like Near The Poles At The End Of The Cassini Mission ?

    Science.gov (United States)

    Nixon, C. A.; Coustenis, A.; Jennings, D. E.; Achterberg, R. K.; Bampasidis, G.; Cottini, V.; Flasar, F. M.; Lavvas, P.

    2017-12-01

    The Cassini mission ends on Sept. 15, 2017, after - among other - 127 targeted Titan flybys. We have monitored the seasonal evolution near Titan's poles during the mission. Titan's North pole had been enhanced in chemical species since the beginning of the observations, but since 2010, we observe at Titan's south pole a strong temperature decrease and the onset of a dramatic enhancement of several trace species such as complex hydrocarbons and nitriles (HC3N and C6H6 in particular) previously observed only at high northern latitudes (Coustenis et al. 2016 and references therein). This is due to the transition of Titan's seasons from northern winter in 2002 to northern summer in 2017 and, at the same time, the advent of winter in the south pole, during which time species with longer chemical lifetimes remain in the north for a little longer undergoing slow photochemical destruction, while those with shorter lifetimes disappear, reappearing in the south. An opposite effect has been expected in the North, but not observed with any significant certainty until 2016. We present here an analysis of nadir spectra acquired by Cassini/CIRS (Jennings et al., 2017) at high resolution in the past years and describe the newly observed decrease in chemical abundances of the components in the North. From 2013 until 2016, the Northern polar region has shown a temperature increase of 10 K, while the South had shown a more significant decrease in a similar period of time. The chemical content in the North is finally showing a clear depletion for most molecules since 2015 (Coustenis et al., 2017). References: Coustenis et al., 2016, Icarus 270, 409-420 ; Coustenis et al., 2017, submitted; Jennings et al., 2017, Applied Optics 56, no 18, 5274-5294.

  20. Dione and Rhea seasonal exospheres revealed by Cassini CAPS and INMS

    Science.gov (United States)

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

    2016-07-01

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

  1. Statistical Analysis of Interchange Injection Events from Over a Decade of Cassini Data

    Science.gov (United States)

    Azari, A.; Jia, X.; Liemohn, M. W.; Sergis, N.; Thomsen, M. F.; Mitchell, D. G.; Rymer, A. M.; Paranicas, C.; Provan, G.; Ye, S.; Cowley, S. W. H.; Hospodarsky, G. B.; Vandegriff, J. D.; Kurth, W. S.

    2017-12-01

    The Cassini spacecraft has routinely observed interchange injection events with multiple instruments since arriving at Saturn in 2004. Interchange injection events are thought to initiate from a Rayleigh-Taylor like plasma instability sourced from Saturn's rapid rotation (period 10.8 hours) and dense plasma population outgassing primarily from Enceladus, and are the primary source of mass transport in the inner/middle magnetosphere. This dense plasma must be transported outward, and to conserve magnetic flux, inward moving flux tubes of low density, energetic (> keV) plasma from the outer reaches of the Saturnian system also occur. These inward-bound flux tubes are referred to as interchange injections. We will present a statistical evaluation of the occurrence rates of interchange injections at Saturn demonstrating seasonal dependence of interchange over the entirety of the Cassini mission's equatorial orbits between 2005 and 2016. We identify interchange events from CHarge Energy Mass Spectrometer (CHEMS) H+ data using a trained and tested automated algorithm. Our event identification compares well with manual identification and previous surveys of injections by L-shell and local time (Chen and Hill, 2008, Lai et al., 2016, Kennelly et al., 2013). We find that peak rates of interchange events occur between 7 - 9 Saturn radii, in agreement with previous surveys. We also evaluate interchange by preferred local time sector and season, splitting our events into pre-equinox, equinox, and post - equinox time periods. We determine that over all seasons, nightside occurrence dominated as compared to dayside, but the preferred dayside sector shifts from pre-noon during equinox, to post-noon during post-equinox. We will further investigate seasonal dependence by presenting occurrence organized by the phase systems derived based on Saturn kilometric radiation (SKR) and magnetic field perturbations (PPO).

  2. Iapetus Surface Temperatures, and the Influence of Sublimation on the Albedo Dichotomy: Cassini CIRS Constraints

    Science.gov (United States)

    Spencer, J. R.; Pearl, J. C.; Segura, M.; Cassini CIRS Team

    2005-08-01

    The Composite Infrared Spectrometer (CIRS) on the Cassini orbiter obtained extensive observations of Iapetus' thermal emission during the New Year 2005 flyby, with best 8 - 16 μ m spatial resolution of 35 km per pixel. Observed subsolar temperatures on the dark terrain reach nearly 130 K, much warmer than any other satellite surface in the Saturn system, due to the combination of low albedo and slow rotation. These high temperatures mean that, uniquely in the Saturn system, water ice sublimation rates are significant at low latitudes on Iapetus' dark side, and surface water ice is probably not stable there on geological timescales. This result is consistent with the lack of water ice at low latitudes on the dark terrain inferred from Cassini UVIS UV spectra (Hendrix et al., 2005 LPSC). Thermally-controlled migration of water ice may thus contribute to the curious shape of the light/dark boundary on Iapetus, with bright poles and dark terrain extending round the equator onto the trailing side. Impacts of Saturn-centric or prograde heliocentric material cannot alone explain this shape, as their impact flux depends only on distance from the apex of motion (though the impact distribution of Oort cloud comet dust may be consistent with the observed albedo pattern (Cook and Franklin 1970)). We model the ballistic migration of water ice across the surface of Iapetus, determining temperatures and sublimation rates assuming CIRS-constrained thermal inertia and a simple dependence of albedo on distance from the apex of motion. Water ice is lost rapidly from low latitudes on the dark leading side and accumulates near the poles, and is also lost, though more slowly, in equatorial regions near the sub-Saturn and anti-Saturn points. The resulting water ice distribution pattern matches the distribution of Iapetus' bright terrain remarkably well. Albedo modification by thermal migration can thus help to reconcile Iapetus' albedo patterns with albedo control by Saturn-centric or

  3. Analyses of the Behavior of Spokes in Saturn's B Ring as Observed in Cassini ISS Images

    Science.gov (United States)

    Mitchell, Colin; Porco, C.; Dones, L.; Spitale, J.

    2008-09-01

    We report on analyses of the spokes in Saturn's B ring as observed by the Cassini spacecraft, from the first sighting in September 2005 to the present. Following Porco and Danielson (1982), we calculate as a function of time the spoke activity level, defined as the area-integrated optical depth of the spokes. We convert the spoke I/F into optical depth, using a radiative transfer "doubling code" and assuming that the presence of microscopic particles in the spokes is the only change in the optical properties of the ring region within a spoke. We search for periodicities in the variation of spoke activity and also correlations with magnetic longitude using a magnetic longitude system derived from the emission of the Saturn Kilometric Radiation (SKR), the rotation of which varies slightly from a constant rate (Kurth et al. 2008). Additionally, we track the activity over a period of years in order to characterize the seasonal nature of this phenomenon. We also report on the photometric profiles of spokes during different phases of their evolution. We present an analysis of spoke kinematics, measuring the motion on timescales of tens of minutes of the leading and trailing edges of spokes that appear in multiple consecutive images. Assuming that the small ice particles which comprise the spokes are in circular orbits, the azimuthal motion is a measure of their charge-to-mass ratio. While most spoke edges have exhibited normal Keplerian orbital motion and shear, some spokes were observed during their active phase in which the spoke's optical depth increases and its edges move at different rates, broadening the spoke. We acknowledge the financial support of the Cassini Project.

  4. Revisit the modeling of the Saturnian ring atmosphere and ionosphere from the "Cassini Grand Finale" results

    Science.gov (United States)

    Tseng, W. L.; Johnson, R. E.; Tucker, O. J.; Perry, M. E.; Ip, W. H.

    2017-12-01

    During the Cassini Grand Finale mission, this spacecraft, for the first time, has done the in-situ measurements of Saturn's upper atmosphere and its rings and provides critical information for understanding the coupling dynamics between the main rings and the Saturnian system. The ring atmosphere is the source of neutrals (i.e., O2, H2, H; Tseng et al., 2010; 2013a), which is primarily generated by photolytic decomposition of water ice (Johnson et al., 2006), and plasma (i.e., O2+ and H2+; Tseng et al., 2011) in the Saturnian magnetosphere. In addition, the main rings have strong interaction with Saturn's atmosphere and ionosphere (i.e., a source of oxygen into Saturn's upper atmosphere and/or the "ring rain" in O'Donoghue et al., 2013). Furthermore, the near-ring plasma environment is complicated by the neutrals from both the seasonally dependent ring atmosphere and Enceladus torus (Tseng et al., 2013b), and, possibly, from small grains from the main and tenuous F and G rings (Johnson et al.2017). The data now coming from Cassini Grand Finale mission already shed light on the dominant physics and chemistry in this region of Saturn's magnetosphere, for example, the presence of carbonaceous material from meteorite impacts in the main rings and each gas species have similar distribution in the ring atmosphere. We will revisit the details in our ring atmosphere/ionosphere model to study, such as the source mechanism for the organic material and the neutral-grain-plasma interaction processes.

  5. Reconciling Electrical Properties of Titan's Surface Derived from Cassini RADAR Scatterometer and Radiometer Measurements

    Science.gov (United States)

    Zebker, H. A.; Wye, L. C.; Janssen, M.; Paganelli, F.; Cassini RADAR Team

    2006-12-01

    We observe Titan, Saturn's largest moon, using active and passive microwave instruments carried on board the Cassini spacecraft. The 2.2-cm wavelength penetrates the thick atmosphere and provides surface measurements at resolutions from 10-200 km over much of the satellite's surface. The emissivity and reflectivity of surface features are generally anticorrelated, and both values are fairly high. Inversion of either set of data alone yields dielectric constants ranging from 1.5 to 3 or 4, consistent with an icy hydrocarbon or water ice composition. However, the dielectric constants retrieved from radiometric data alone are usually less than those inferred from backscatter measurements, a discrepancy consistent with similar analyses dating back to lunar observations in the 1960's. Here we seek to reconcile Titan's reflectivity and emissivity observations using a single physical model of the surface. Our approach is to calculate the energy scattered by Titan's surface and near subsurface, with the remainder absorbed. In equilibrium the absorption equals the emission, so that both the reflectivity and emissivity are described by the model. We use a form of the Kirchhoff model for modeling surface scatter, and a model based on weak localization of light for the volume scatter. With this model we present dielectric constant and surface roughness parameters that match both sets of Cassini RADAR observations over limited regions on Titan's surface, helping to constrain the composition and roughness of the surface. Most regions display electrical properties consistent with solid surfaces, however some of the darker "lake-like" features at higher latitudes can be modeled as either solid or liquid materials. The ambiguity arises from the limited set of observational angles available.

  6. OPUS: A Comprehensive Search Tool for Remote Sensing Observations of the Outer Planets. Now with Enhanced Geometric Metadata for Cassini and New Horizons Optical Remote Sensing Instruments.

    Science.gov (United States)

    Gordon, M. K.; Showalter, M. R.; Ballard, L.; Tiscareno, M.; French, R. S.; Olson, D.

    2017-06-01

    The PDS RMS Node hosts OPUS - an accurate, comprehensive search tool for spacecraft remote sensing observations. OPUS supports Cassini: CIRS, ISS, UVIS, VIMS; New Horizons: LORRI, MVIC; Galileo SSI; Voyager ISS; and Hubble: ACS, STIS, WFC3, WFPC2.

  7. Last Looks at the Eye of Saturn by Cassini/VIMS During the Grand Finale

    Science.gov (United States)

    Momary, Thomas W.; Baines, Kevin H.; Badman, Sarah; Brown, Robert H.; Buratti, Bonnie J.; Clark, Roger Nelson; Nicholson, Philip D.; Sotin, Christophe

    2017-10-01

    A lasting remnant of the Great Storm that erupted on Saturn in late 2010 has been a massive lone anticyclone persisting to the present time in a NH3-dry 5-µm-bright “desert” zone that spans the entire Saturnian globe at 34o N. We have been observing this oval storm with Cassini/VIMS since 2011 and, in 2017, as Cassini performs its Grand Finale orbits close to the planet, have captured it at our highest resolution since January 2012 at 260 km/pixel - enough to resolve spiral structure inside the oval at 5 µm. The spot drifts latitudinally in Saturn’s zonal currents: it was at 35.9o planetocentric latitude in May 2011, wandered northward to 37.8o in 2012, hovered near 37o through 2013, meandered as far south as 36.5o in 2014, drifted northward to 37o in 2015, and then returned back to about 36.3o in 2016, where it remains presently. It has also periodically bumped up against the dark band above it, spinning off material in 2013, 2015, and 2017. We measured a prograde zonal drift speed of 22 m/s in 2012, increasing as much as 60% through 2013, then relaxing to a more moderate 15 m/s in 2014 and 2015. It slowed considerably in 2016 to 4.7 m/s and is currently drifting slightly faster at 8.5 m/s. The spot has varied in size over time as it spins, spanning 4.9o x 3.2o in 2011, elongating to 7.3o x 2.9o by 2013, contracting to 5.5o x 2.9o in 2014, enlarging again to 9o x 4o in 2015, and contracting currently to 7.0o x 3.2o (6100 x 3200 km) in 2017, symmetrically oval in shape. It has varied in terms of cloudiness, being 90% 5-µm dark (obscured) in 2011, whereas by 2013 it was mostly bright (clear) with a thin dark edge. It was 90% dark in 2015, and in 2017 is about 65% obscured, with a bright central eye. Utilizing night observations to isolate thermal flux, we have found that the mean 5-µm flux coming from the anticyclone has diminished steadily by about 75% since 2013. The entire storm latitude of ~34o N itself has remained persistently 5-µm bright since 2011

  8. Searching for a traveling feature in Saturn's rings in Cassini Imaging Science Subsystem data

    Science.gov (United States)

    Aye, Klaus-Michael; Rehnberg, Morgan; Brown, Zarah; Esposito, Larry W.

    2016-10-01

    Introduction: Using Cassini UVIS occultation data, a traveling wave feature has been identified in the Saturn rings that is most likely caused by the radial positions swap of the moons Janus and Epimetheus [1]. The hypothesis is that non-linear interferences between the linear density waves when being relocated by the moon swap create a solitary wave that is traveling outward through the rings. The observations in [1] further lead to the derivation of values for the radial travel speeds of the identified traveling features, from 39.6 km/yr for the Janus 5:4 resonance up to 45.8 for the Janus 4:3 resonance.Previous confirmations in ISS data: Work in [1] also identified the feature in Cassini Imaging Science Subsystem (ISS) data that was taken around the time of the UVIS occultations where the phenomenon was first discovered, so far one ISS image for each Janus resonances 2:1, 4:3, 5:4, and 6:5.Search guided by predicted locations: Using the observation-fitted radial velocities from [1], we can extrapolate these to identify Saturn radii at which the traveling feature should be found at later times. Using this and new image analysis and plotting tools available in [2], we have identified a potential candidate feature in an ISS image that was taken 2.5 years after the feature causing moon swap in January 2006. We intend to expand our search by identifying candidate ISS data by a meta-database search constraining the radius at future times corresponding to the predicted future locations of the hypothesized solitary wave and present our findings at this conference.References: [1] Rehnberg, M.E., Esposito, L.W., Brown, Z.L., Albers, N., Sremčević, M., Stewart, G.R., 2016. A Traveling Feature in Saturn's Rings. Icarus, accepted in June 2016. [2] K.-Michael Aye. (2016). pyciss: v0.5.0. Zenodo. 10.5281/zenodo.53092

  9. Mobile gaze input system for pervasive interaction

    DEFF Research Database (Denmark)

    2017-01-01

    feedback to the user in response to the received command input. The unit provides feedback to the user on how to position the mobile unit in front of his eyes. The gaze tracking unit interacts with one or more controlled devices via wireless or wired communications. Example devices include a lock......, a thermostat, a light or a TV. The connection between the gaze tracking unit may be temporary or longer-lasting. The gaze tracking unit may detect features of the eye that provide information about the identity of the user....

  10. Spatially resolved near infrared observations of Enceladus' tiger stripe eruptions from Cassini VIMS

    Science.gov (United States)

    Dhingra, Deepak; Hedman, Matthew M.; Clark, Roger N.; Nicholson, Philip D.

    2017-08-01

    Particle properties of individual fissure eruptions within Enceladus' plume have been analyzed using high spatial resolution Visible and Infrared Mapping Spectrometer (VIMS) observations from the Cassini mission. To first order, the spectra of the materials emerging from Cairo, Baghdad and Damascus sulci are very similar, with a strong absorption band around 3 μm due to water-ice. The band minimum position indicates that the ice grains emerging from all the fissures are predominantly crystalline, which implies that the water-ice particles' formation temperatures are likely above 130 K. However, there is also evidence for subtle variations in the material emerging from the different source fissures. Variations in the spectral slope between 1-2.5 μm are observed and probably reflect differences in the size distributions of particles between 0.5 and 5 μm in radius. We also note variations in the shape of the 3 μm water-ice absorption band, which are consistent with differences in the relative abundance of > 5 μm particles. These differences in the particle size distribution likely reflect variations in the particle formation conditions and/or their transport within the fissures. These observations therefore provide strong motivation for detailed modeling to help place important constraints on the diversity of the sub-surface environmental conditions at the geologically active south-pole of Enceladus.

  11. An Analysis of Cassini Observations Regarding the Structure of Jupiter's Equatorial Atmosphere

    Science.gov (United States)

    Choi, David S.; Simon-Miller, Amy A.

    2012-01-01

    A variety of intriguing atmospheric phenomena reside on both sides of Jupiter's equator. 5-micron bright hot spots and opaque plumes prominently exhibit dynamic behavior to the north, whereas compact, dark chevron-shaped features and isolated anticyclonic disturbances periodically occupy the southern equatorial latitudes. All of these phenomena are associated with the vertical and meridional perturbations of Rossby waves disturbing the mean atmospheric state. As previous observational analysis and numerical simulations have investigated the dynamics of the region, an examination of the atmosphere's vertical structure though radiative transfer analysis is necessary for improved understanding of this unique environment. Here we present preliminary analysis of a multispectral Cassini imaging data set acquired during the spacecraft's flyby of Jupiter in 2000. We evaluated multiple methane and continuum spectral channels at available viewing angles to improve constraints on the vertical structure of the haze and cloud layers comprising these interesting features. Our preliminary results indicate distinct differences in the structure for both hemispheres. Upper troposphere hazes and cloud layers are prevalent in the northern equatorial latitudes, but are not present in corresponding southern latitudes. Continued analysis will further constrain the precise structure present in these phenomena and the differences between them.

  12. A Survey of Cassini CAPS Ion Observations During Titan Flybys TA-T83

    Science.gov (United States)

    Woodson, A. K.; Johnson, R. E.; Smith, H. T.; Crary, F. J.

    2015-12-01

    The Cassini Plasma Spectrometer (CAPS) sampled Titan's plasma environment during each of 83 encounters with the moon between orbit insertion on June 30, 2004 and June 1, 2012. The CAPS Ion Mass Spectrometer (IMS) acquired energy- and mass-per-charge-discriminated time-of-flight (TOF) spectra associated with ionospheric H+, H2+, H3+, CHx+, and C2Hx+ during at least 68 of those encounters. Herein we discuss ion energy distributions extracted from these spectra, each accumulated over an ~4 minute interval along the spacecraft trajectory. This is accomplished by fitting calibration peak models to TOF spectra in order to determine the TOF range associated with each aforementioned ion group, and then summing counts over each TOF range to obtain well-resolved energy peaks for each group. Energy distributions are determined by fitting the logistic power peak function to each of the resulting energy spectra. We then plot the resulting distribution parameters (peak energy, peak amplitude, and peak width or temperature) for each species and each encounter against Titan latitude, longitude, and altitude to generate a map of ion parameters. In addition, the encounters are grouped according to ambient plasma and magnetic field measurements in order to characterize the ion distribution parameters in different regions of Saturn's magnetosphere.

  13. High-resolution CASSINI-VIMS mosaics of Titan and the icy Saturnian satellites

    Science.gov (United States)

    Jaumann, R.; Stephan, K.; Brown, R.H.; Buratti, B.J.; Clark, R.N.; McCord, T.B.; Coradini, A.; Capaccioni, F.; Filacchione, G.; Cerroni, P.; Baines, K.H.; Bellucci, G.; Bibring, J.-P.; Combes, M.; Cruikshank, D.P.; Drossart, P.; Formisano, V.; Langevin, Y.; Matson, D.L.; Nelson, R.M.; Nicholson, P.D.; Sicardy, B.; Sotin, Christophe; Soderbloom, L.A.; Griffith, C.; Matz, K.-D.; Roatsch, Th.; Scholten, F.; Porco, C.C.

    2006-01-01

    The Visual Infrared Mapping Spectrometer (VIMS) onboard the CASSINI spacecraft obtained new spectral data of the icy satellites of Saturn after its arrival at Saturn in June 2004. VIMS operates in a spectral range from 0.35 to 5.2 ??m, generating image cubes in which each pixel represents a spectrum consisting of 352 contiguous wavebands. As an imaging spectrometer VIMS combines the characteristics of both a spectrometer and an imaging instrument. This makes it possible to analyze the spectrum of each pixel separately and to map the spectral characteristics spatially, which is important to study the relationships between spectral information and geological and geomorphologic surface features. The spatial analysis of the spectral data requires the determination of the exact geographic position of each pixel on the specific surface and that all 352 spectral elements of each pixel show the same region of the target. We developed a method to reproject each pixel geometrically and to convert the spectral data into map projected image cubes. This method can also be applied to mosaic different VIMS observations. Based on these mosaics, maps of the spectral properties for each Saturnian satellite can be derived and attributed to geographic positions as well as to geological and geomorphologic surface features. These map-projected mosaics are the basis for all further investigations. ?? 2006 Elsevier Ltd. All rights reserved.

  14. Mapping and interpretation of Sinlap crater on Titan using Cassini VIMS and RADAR data

    Science.gov (United States)

    Le, Mouelic S.; Paillou, P.; Janssen, M.A.; Barnes, J.W.; Rodriguez, S.; Sotin, Christophe; Brown, R.H.; Baines, K.H.; Buratti, B.J.; Clark, R.N.; Crapeau, M.; Encrenaz, P.J.; Jaumann, R.; Geudtner, D.; Paganelli, F.; Soderblom, L.; Tobie, G.; Wall, S.

    2008-01-01

    Only a few impact craters have been unambiguously detected on Titan by the Cassini-Huygens mission. Among these, Sinlap is the only one that has been observed both by the RADAR and VIMS instruments. This paper describes observations at centimeter and infrared wavelengths which provide complementary information about the composition, topography, and surface roughness. Several units appear in VIMS false color composites of band ratios in the Sinlap area, suggesting compositional heterogeneities. A bright pixel possibly related to a central peak does not show significant spectral variations, indicating either that the impact site was vertically homogeneous, or that this area has been recovered by homogeneous deposits. Both VIMS ratio images and dielectric constant measurements suggest the presence of an area enriched in water ice around the main ejecta blanket. Since the Ku-band SAR may see subsurface structures at the meter scale, the difference between infrared and SAR observations can be explained by the presence of a thin layer transparent to the radar. An analogy with terrestrial craters in Libya supports this interpretation. Finally, a tentative model describes the geological history of this area prior, during, and after the impact. It involves mainly the creation of ballistic ejecta and an expanding plume of vapor triggered by the impact, followed by the redeposition of icy spherules recondensed from this vapor plume blown downwind. Subsequent evolution is then driven by erosional processes and aeolian deposition. Copyright 2008 by the American Geophysical Union.

  15. High-angular-resolution stellar imaging with occultations from the Cassini spacecraft - III. Mira

    Science.gov (United States)

    Stewart, Paul N.; Tuthill, Peter G.; Nicholson, Philip D.; Hedman, Matthew M.

    2016-04-01

    We present an analysis of spectral and spatial data of Mira obtained by the Cassini spacecraft, which not only observed the star's spectra over a broad range of near-infrared wavelengths, but was also able to obtain high-resolution spatial information by watching the star pass behind Saturn's rings. The observed spectral range of 1-5 microns reveals the stellar atmosphere in the crucial water-bands which are unavailable to terrestrial observers, and the simultaneous spatial sampling allows the origin of spectral features to be located in the stellar environment. Models are fitted to the data, revealing the spectral and spatial structure of molecular layers surrounding the star. High-resolution imagery is recovered revealing the layered and asymmetric nature of the stellar atmosphere. The observational data set is also used to confront the state-of-the-art cool opacity-sampling dynamic extended atmosphere models of Mira variables through a detailed spectral and spatial comparison, revealing in general a good agreement with some specific departures corresponding to particular spectral features.

  16. A Model of Titan-like Chemistry to Connect Experiments and Cassini Observations

    Science.gov (United States)

    Raymond, Alexander W.; Sciamma-O’Brien, Ella; Salama, Farid; Mazur, Eric

    2018-02-01

    A numerical model is presented for interpreting the chemical pathways that lead to the experimental mass spectra acquired in the Titan Haze Simulation (THS) laboratory experiments and for comparing the electron density and temperature of the THS plasma to observations made at Titan by the Cassini spacecraft. The THS plasma is a pulsed glow-discharge experiment designed to simulate the reaction of N2/CH4-dominated gas in Titan's upper atmosphere. The transient, one-dimensional model of THS chemistry tracks the evolution of more than 120 species in the direction of the plasma flow. As the minor species C2H2 and C2H4 are added to the N2/CH4-based mixture, the model correctly predicts the emergence of reaction products with up to five carbon atoms in relative abundances that agree well with measured mass spectra. Chemical growth in Titan's upper atmosphere transpires through ion–neutral and neutral–neutral chemistry, and the main reactions involving a series of known atmospheric species are retrieved from the calculation. The model indicates that the electron density and chemistry are steady during more than 99% of the 300 μs long discharge pulse. The model also suggests that the THS ionization fraction and electron temperature are comparable to those measured in Titan's upper atmosphere. These findings reaffirm that the THS plasma is a controlled analog environment for studying the first and intermediate steps of chemistry in Titan's upper atmosphere.

  17. Water Vapor on Titan: The Stratospheric Vertical Profile from Cassini/CIRS Infrared Spectra

    Science.gov (United States)

    Cottini, V.; Jennings, D. E.; Nixon, C. A.; Anderson, C. M.; Gorius, N.; Bjoraker, G. L.; Coustenis, A.; Achterberg, R. K.; Teanby, N. A.; deKok, R.; hide

    2012-01-01

    Water vapor in Titan's middle atmosphere has previously been detected only by disk-average observations from the Infrared Space Observatory (Coustenis et al., 1998). We report here the successful detection of stratospheric water vapor using the Cassini Composite Infrared Spectrometer (CIRS, Flasar et al., 2004) following an earlier null result (de Kok et al., 2007a). CIRS senses water emissions in the far-infrared spectral region near 50 microns, which we have modeled using two independent radiative transfer and inversion codes (NEMESIS, Irwin et al 2008 and ART, Coustenis et al., 2010). From the analysis of nadir spectra we have derived a mixing ratio of (0.14 plus or minus 0.05) ppb at 100 km, corresponding to a column abundance of approximately (3.7 plus or minus 1.3) x 10(exp 14) moles per square centimeter. Using limb observations, we obtained mixing ratios of (0.13 plus or minus 0.04) ppb at 125 km and (0.45 plus or minus 0.15) ppb at 225 km of altitude, confirming that the water abundance has a positive vertical gradient as predicted by photochemical models. In the latitude range (80 deg. S - 30 deg. N) we see no evidence for latitudinal variations in these abundances within the error bars.

  18. Water Vapor in Titan's Stratosphere from Cassini CIRS Far-Infrared Spectra

    Science.gov (United States)

    Cottini, V.; Nixon, C. A.; Jennings, D. E.; Anderson, C. M.; Gorius, N.; Bjoraker, G. L.; Coustenis, A.; Teanby, N. A.; Achterberg, R. K.; Bezard, B.; hide

    2012-01-01

    Here we report the measurement of water vapor in Titan's stratosphere using the Cassini Composite Infrared Spectrometer (CIRS). CIRS senses water emissions in the far infrared spectral region near 50 micron, which we have modeled using two independent radiative transfer codes. From the analysis of nadir spectra we have derived a mixing ratio of 0.14 +/- 0.05 ppb at an altitude of 97 km, which corresponds to an integrated (from 0 to 600 km) surface normalized column abundance of 3.7 +/- 1.3 1014 molecules/cm2. In the latitude range 80S to 30N we see no evidence for latitudinal variations in these abundances within the error bars. Using limb observations, we obtained mixing ratios of 0.13 +/- 0.04 ppb at an altitude of 115 km and 0.45 +/- 0.15 ppb at an altitude of 230 km, confirming that the water abundance has a positive vertical gradient as predicted by photochemical models. We have also fitted our data using scaling factors of 0.1-0.6 to these photochemical model profiles, indicating that the models over-predict the water abundance in Titan's lower stratosphere.

  19. TITAN’S UPPER ATMOSPHERE FROM CASSINI/UVIS SOLAR OCCULTATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Capalbo, Fernando J.; Bénilan, Yves [Laboratoire Inter-Universitaire des Systèmes Atmosphériques (LISA), UMR 7583 du CNRS, Universités Paris Est Créteil (UPEC) and Paris Diderot - UPD, 61 avenue du Général de Gaulle, F-94010, Créteil Cédex (France); Yelle, Roger V.; Koskinen, Tommi T., E-mail: fernando.capalbo@lisa.u-pec.fr [Lunar and Planetary Laboratory, University of Arizona, 1629 E. University Blvd., Tucson, AZ 85721 (United States)

    2015-12-01

    Titan’s atmosphere is composed mainly of molecular nitrogen, methane being the principal trace gas. From the analysis of 8 solar occultations measured by the Extreme Ultraviolet channel of the Ultraviolet Imaging Spectrograph (UVIS) on board Cassini, we derived vertical profiles of N{sub 2} in the range 1100–1600 km and vertical profiles of CH{sub 4} in the range 850–1300 km. The correction of instrument effects and observational effects applied to the data are described. We present CH{sub 4} mole fractions, and average temperatures for the upper atmosphere obtained from the N{sub 2} profiles. The occultations correspond to different times and locations, and an analysis of variability of density and temperature is presented. The temperatures were analyzed as a function of geographical and temporal variables, without finding a clear correlation with any of them, although a trend of decreasing temperature toward the north pole was observed. The globally averaged temperature obtained is (150 ± 1) K. We compared our results from solar occultations with those derived from other UVIS observations, as well as studies performed with other instruments. The observational data we present confirm the atmospheric variability previously observed, add new information to the global picture of Titan’s upper atmosphere composition, variability, and dynamics, and provide new constraints to photochemical models.

  20. A Three-Dimensional View of Titan's Surface Features from Cassini RADAR Stereogrammetry

    Science.gov (United States)

    Kirk, R. L.; Howington-Kraus, E.; Redding, B. L.; Becker, T. L.; Lee, E. M.; Stiles, B. W.; Hensley, S.; Hayes, A.; Lopes, R. M.; Lorenz, R. D.; Mitchell, K. L.; Radebaugh, J.; Paganelli, F.; Soderblom, L. A.; Stofan, E. R.; Wood, C. A.; Wall, S. D.; Cassini RADAR Team

    2008-12-01

    As of the end of its four-year Prime Mission, Cassini has obtained 300-1500 m resolution synthetic aperture radar images of the surface of Titan during 19 flybys. The elongated image swaths overlap extensively, and ~2% of the surface has now been imaged two or more times. The majority of image pairs have different viewing directions, and thus contain stereo parallax that encodes information about Titan's surface relief over distances of ~1 km and greater. As we have previously reported, the first step toward extracting quantitative topographic information was the development of rigorous "sensor models" that allowed the stereo systems previously used at the USGS and JPL to map Venus with Magellan images to be used for Titan mapping. The second major step toward extensive topomapping of Titan has been the reprocessing of the RADAR images based on an improved model of the satellite's rotation. Whereas the original images (except for a few pairs obtained at similar orbital phase, some of which we have mapped previously) were offset by as much as 30 km, the new versions align much better. The remaining misalignments, typically carbono)logic" cycle of precipitation, evaporation, and surface and subsurface fluid flow?

  1. Chemical sensors are hybrid-input memristors

    Science.gov (United States)

    Sysoev, V. I.; Arkhipov, V. E.; Okotrub, A. V.; Pershin, Y. V.

    2018-04-01

    Memristors are two-terminal electronic devices whose resistance depends on the history of input signal (voltage or current). Here we demonstrate that the chemical gas sensors can be considered as memristors with a generalized (hybrid) input, namely, with the input consisting of the voltage, analyte concentrations and applied temperature. The concept of hybrid-input memristors is demonstrated experimentally using a single-walled carbon nanotubes chemical sensor. It is shown that with respect to the hybrid input, the sensor exhibits some features common with memristors such as the hysteretic input-output characteristics. This different perspective on chemical gas sensors may open new possibilities for smart sensor applications.

  2. Analysis of Input and Output Ripples of PWM AC Choppers

    Directory of Open Access Journals (Sweden)

    Pekik Argo Dahono

    2008-11-01

    Full Text Available This paper presents an analysis of input and output ripples of PWM AC choppers. Expressions of input and output current and voltage ripples of single-phase PWM AC choppers are first derived. The derived expressions are then extended to three-phase PWM AC choppers. As input current and output voltage ripples specification alone cannot be used to determine the unique values of inductance and capacitance of the LC filters, an additional criterion based on the minimum reactive power is proposed. Experimental results are included in this paper to show the validity of the proposed analysis method.

  3. Input/Output linearizing control of a nuclear reactor

    International Nuclear Information System (INIS)

    Perez C, V.

    1994-01-01

    The feedback linearization technique is an approach to nonlinear control design. The basic idea is to transform, by means of algebraic methods, the dynamics of a nonlinear control system into a full or partial linear system. As a result of this linearization process, the well known basic linear control techniques can be used to obtain some desired dynamic characteristics. When full linearization is achieved, the method is referred to as input-state linearization, whereas when partial linearization is achieved, the method is referred to as input-output linearization. We will deal with the latter. By means of input-output linearization, the dynamics of a nonlinear system can be decomposed into an external part (input-output), and an internal part (unobservable). Since the external part consists of a linear relationship among the output of the plant and the auxiliary control input mentioned above, it is easy to design such an auxiliary control input so that we get the output to behave in a predetermined way. Since the internal dynamics of the system is known, we can check its dynamics behavior on order of to ensure that the internal states are bounded. The linearization method described here can be applied to systems with one-input/one-output, as well as to systems with multiple-inputs/multiple-outputs. Typical control problems such as stabilization and reference path tracking can be solved using this technique. In this work, the input/output linearization theory is presented, as well as the problem of getting the output variable to track some desired trayectories. Further, the design of an input/output control system applied to the nonlinear model of a research nuclear reactor is included, along with the results obtained by computer simulation. (Author)

  4. Repositioning Recitation Input in College English Teaching

    Science.gov (United States)

    Xu, Qing

    2009-01-01

    This paper tries to discuss how recitation input helps overcome the negative influences on the basis of second language acquisition theory and confirms the important role that recitation input plays in improving college students' oral and written English.

  5. Investigating gaze-controlled input in a cognitive selection test

    OpenAIRE

    Gayraud, Katja; Hasse, Catrin; Eißfeldt, Hinnerk; Pannasch, Sebastian

    2017-01-01

    In the field of aviation, there is a growing interest in developing more natural forms of interaction between operators and systems to enhance safety and efficiency. These efforts also include eye gaze as an input channel for human-machine interaction. The present study investigates the application of gaze-controlled input in a cognitive selection test called Eye Movement Conflict Detection Test. The test enables eye movements to be studied as an indicator for psychological test performance a...

  6. IFF, Full-Screen Input Menu Generator for FORTRAN Program

    International Nuclear Information System (INIS)

    Seidl, Albert

    1991-01-01

    1 - Description of program or function: The IFF-package contains input modules for use within FORTRAN programs. This package enables the programmer to easily include interactive menu-directed data input (module VTMEN1) and command-word processing (module INPCOM) into a FORTRAN program. 2 - Method of solution: No mathematical operations are performed. 3 - Restrictions on the complexity of the problem: Certain restrictions of use may arise from the dimensioning of arrays. Field lengths are defined via PARAMETER-statements

  7. Textual Enhancement of Input: Issues and Possibilities

    Science.gov (United States)

    Han, ZhaoHong; Park, Eun Sung; Combs, Charles

    2008-01-01

    The input enhancement hypothesis proposed by Sharwood Smith (1991, 1993) has stimulated considerable research over the last 15 years. This article reviews the research on textual enhancement of input (TE), an area where the majority of input enhancement studies have aggregated. Methodological idiosyncrasies are the norm of this body of research.…

  8. 7 CFR 3430.607 - Stakeholder input.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Stakeholder input. 3430.607 Section 3430.607 Agriculture Regulations of the Department of Agriculture (Continued) COOPERATIVE STATE RESEARCH, EDUCATION... § 3430.607 Stakeholder input. CSREES shall seek and obtain stakeholder input through a variety of forums...

  9. 7 CFR 3430.15 - Stakeholder input.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Stakeholder input. 3430.15 Section 3430.15... Stakeholder input. Section 103(c)(2) of the Agricultural Research, Extension, and Education Reform Act of 1998... RFAs for competitive programs. CSREES will provide instructions for submission of stakeholder input in...

  10. FLUTAN 2.0. Input specifications

    International Nuclear Information System (INIS)

    Willerding, G.; Baumann, W.

    1996-05-01

    FLUTAN is a highly vectorized computer code for 3D fluiddynamic and thermal-hydraulic analyses in Cartesian or cylinder coordinates. It is related to the family of COMMIX codes originally developed at Argonne National Laboratory, USA, and particularly to COMMIX-1A and COMMIX-1B, which were made available to FZK in the frame of cooperation contracts within the fast reactor safety field. FLUTAN 2.0 is an improved version of the FLUTAN code released in 1992. It offers some additional innovations, e.g. the QUICK-LECUSSO-FRAM techniques for reducing numerical diffusion in the k-ε turbulence model equations; a higher sophisticated wall model for specifying a mass flow outside the surface walls together with its flow path and its associated inlet and outlet flow temperatures; and a revised and upgraded pressure boundary condition to fully include the outlet cells in the solution process of the conservation equations. Last but not least, a so-called visualization option based on VISART standards has been provided. This report contains detailed input instructions, presents formulations of the various model options, and explains how to use the code by means of comprehensive sample input. (orig.) [de

  11. The Outer Planets and their Moons Comparative Studies of the Outer Planets prior to the Exploration of the Saturn System by Cassini-Huygens

    CERN Document Server

    Encrenaz, T; Owen, T. C; Sotin, C

    2005-01-01

    This volume gives an integrated summary of the science related to the four giant planets in our solar system. It is the result of an ISSI workshop on «A comparative study of the outer planets before the exploration of Saturn by Cassini-Huygens» which was held at ISSI in Bern on January 12-16, 2004. Representatives of several scientific communities, such as planetary scientists, astronomers, space physicists, chemists and astrobiologists have met with the aim to review the knowledge on four major themes: (1) the study of the formation and evolution processes of the outer planets and their satellites, beginning with the formation of compounds and planetesimals in the solar nebula, and the subsequent evolution of the interiors of the outer planets, (2) a comparative study of the atmospheres of the outer planets and Titan, (3) the study of the planetary magnetospheres and their interactions with the solar wind, and (4) the formation and properties of satellites and rings, including their interiors, surfaces, an...

  12. Turn customer input into innovation.

    Science.gov (United States)

    Ulwick, Anthony W

    2002-01-01

    It's difficult to find a company these days that doesn't strive to be customer-driven. Too bad, then, that most companies go about the process of listening to customers all wrong--so wrong, in fact, that they undermine innovation and, ultimately, the bottom line. What usually happens is this: Companies ask their customers what they want. Customers offer solutions in the form of products or services. Companies then deliver these tangibles, and customers just don't buy. The reason is simple--customers aren't expert or informed enough to come up with solutions. That's what your R&D team is for. Rather, customers should be asked only for outcomes--what they want a new product or service to do for them. The form the solutions take should be up to you, and you alone. Using Cordis Corporation as an example, this article describes, in fine detail, a series of effective steps for capturing, analyzing, and utilizing customer input. First come indepth interviews, in which a moderator works with customers to deconstruct a process or activity in order to unearth "desired outcomes." Addressing participants' comments one at a time, the moderator rephrases them to be both unambiguous and measurable. Once the interviews are complete, researchers then compile a comprehensive list of outcomes that participants rank in order of importance and degree to which they are satisfied by existing products. Finally, using a simple mathematical formula called the "opportunity calculation," researchers can learn the relative attractiveness of key opportunity areas. These data can be used to uncover opportunities for product development, to properly segment markets, and to conduct competitive analysis.

  13. PREVIMER : Meteorological inputs and outputs

    Science.gov (United States)

    Ravenel, H.; Lecornu, F.; Kerléguer, L.

    2009-09-01

    PREVIMER is a pre-operational system aiming to provide a wide range of users, from private individuals to professionals, with short-term forecasts about the coastal environment along the French coastlines bordering the English Channel, the Atlantic Ocean, and the Mediterranean Sea. Observation data and digital modelling tools first provide 48-hour (probably 96-hour by summer 2009) forecasts of sea states, currents, sea water levels and temperatures. The follow-up of an increasing number of biological parameters will, in time, complete this overview of coastal environment. Working in partnership with the French Naval Hydrographic and Oceanographic Service (Service Hydrographique et Océanographique de la Marine, SHOM), the French National Weather Service (Météo-France), the French public science and technology research institute (Institut de Recherche pour le Développement, IRD), the European Institute of Marine Studies (Institut Universitaire Européen de la Mer, IUEM) and many others, IFREMER (the French public institute fo marine research) is supplying the technologies needed to ensure this pertinent information, available daily on Internet at http://www.previmer.org, and stored at the Operational Coastal Oceanographic Data Centre. Since 2006, PREVIMER publishes the results of demonstrators assigned to limited geographic areas and to specific applications. This system remains experimental. The following topics are covered : Hydrodynamic circulation, sea states, follow-up of passive tracers, conservative or non-conservative (specifically of microbiological origin), biogeochemical state, primary production. Lastly, PREVIMER provides researchers and R&D departments with modelling tools and access to the database, in which the observation data and the modelling results are stored, to undertake environmental studies on new sites. The communication will focus on meteorological inputs to and outputs from PREVIMER. It will draw the lessons from almost 3 years during

  14. The Evolution and Fate of Saturn's Stratospheric Vortex: Infrared Spectroscopy from Cassini

    Science.gov (United States)

    Fletcher, Leigh N.; Hesman, B. E.; Arhterberg, R. K.; Bjoraker, G.; Irwin, P. G. J.; Hurley, J.; Sinclair, J.; Gorius, N.; Orton, G. S.; Read, P. L.; hide

    2012-01-01

    The planet-encircling springtime storm in Saturn's troposphere (December 2010-July 2011) produced dramatic perturbations to stratospheric temperatures, winds and composition at mbar pressures that persisted long after the tropospheric disturbance had abated. Observations from the Cassini Composite Infrared Spectrometer (CIRS), supported by ground-based imaging from the VISIR instrument on the Very Large Telescope,is used to track the evolution of a large, hot stratospheric anticyclone between January 2011 and the present day. The evolutionary sequence can be divided into three phases: (I) the formation and intensification of two distinct warm airmasses near 0.5 mbar between 25 and 35N (one residing directly above the convective storm head) between January-April 2011, moving westward with different zonal velocities; (II) the merging of the warm airmasses to form the large single 'stratospheric beacon' near 40N between April and June 2011, dissociated from the storm head and at a higher pressure (2 mbar) than the original beacons; and (III) the mature phase characterized by slow cooling and longitudinal shrinkage of the anticyclone since July 2011, moving west with a near-constant velocity of 2.70+/-0.04 deg/day (-24.5+/-0.4 m/s at 40N). Peak temperatures of 220 K at 2 mbar were measured on May 5th 2011 immediately after the merger, some 80 K warmer than the quiescent surroundings. Thermal winds hear calculations in August 2011 suggest clockwise peripheral velocities of 200400 mls at 2 mbar, defining a peripheral collar with a width of 65 degrees longitude (50,000 km in diameter) and 25 degrees latitude. Stratospheric acetylene (C2H2) was uniformly enhanced by a factor of three within the vortex, whereas ethane (C2H6) remained unaffected. We will discuss the thermal and chemical characteristics of Saturn's beacon in its mature phase, and implications for stratospheric vortices on other giant planets.

  15. Dynamics of Saturn’s 2010 Great White Spot from high-resolution Cassini ISS observations

    Science.gov (United States)

    Hueso, Ricardo; Sánchez-Lavega, A.; del Río-Gaztelurrutia, T.

    2012-10-01

    On December 5th 2010 a storm erupted in Saturn’s North Temperate latitudes which were experiencing early spring season. The storm quickly developed to a planet-wide disturbance of the Great White Spot type. The ISS instrument onboard Cassini acquired its first images of the storm on 23th December 2010 and performed repeated observations with a variety of spatial resolutions over the nearly 10 months period the storm continued active. Here we present an analysis of two of the image sequences with better spatial resolution of the mature storm when it was fully developed and very active. We used an image correlation algorithm to measure the cloud motions obtained from images separated 20 minutes and obtained 16,000 wind tracers in a domain of 60 degrees longitude per 20 degrees in latitude. Intense zonal and meridional motions accompanied the storm and reached values of 120 m/s in particular regions of the active storm. The storm released a chain of anticyclonic and cyclonic vortices at planetocentric latitudes of 36° and 32° respectively. The short time difference between the images results in estimated wind uncertainties of 15 m/s that did not allow to perform a complete analysis of the turbulence and kinetic spectrum of the motions. We identify locations of the updrafts and link those with the morphology in different observing filters. The global behaviour of the storm was examined in images separated by 10 hours confirming the intensity of the winds and the global behaviour of the vortices. Acknowledgments: This work was supported by the Spanish MICIIN project AYA2009-10701 with FEDER funds, by Grupos Gobierno Vasco IT-464-07 and by Universidad País Vasco UPV/EHU through program UFI11/55.

  16. Investigation of Jupiter's Equatorial Hotspots and Plumes Using Cassini ISS Observations

    Science.gov (United States)

    Choi, David S.; Showman, A. P.; Vasavada, A. R.; Simon-Miller, A. A.

    2012-01-01

    We present updated analysis of Jupiter's equatorial meteorology from Cassini observations. For two months preceding the spacecraft's closest approach, the ISS onboard regularly imaged the atmosphere. We created time-lapse movies from this period in order to analyze the dynamics of equatorial 5-micron hot spots and their interactions with adjacent latitudes. Hot spots are quasi-stable, rectangular dark areas on visible-wavelength images, with defined eastern edges that sharply contrast with surrounding clouds, but a diffuse western edge serving as a nebulous boundary with adjacent equatorial plumes. Hot spots exhibit significant variations in size and shape over timescales of days and weeks. Some of these changes correspond with passing vortex systems from adjacent latitudes interacting with hot spots. Strong anticyclonic gyres present to the south and southeast of the dark areas appear to circulate into hot spots. Impressive, bright white plumes occupy spaces in between hot spots. Compact cirrus-iike 'scooter' clouds flow rapidly through the plumes before disappearing within the dark areas. This raises the possibility that the plumes and fast-moving clouds are at higher altitudes, because their speed does not match previously published zonal wind profiles. Most profiles represent the drift speed of the hot spots at their latitude from pattern matching of the entire longitudinal image strip. If a downward branch of an equatorially-trapped Rossby waves controls the overall appearance of hot spots, however, the westward phase velocity of the wave leads to underestimates of the true jet stream speed. Instead, our expanded data set demonstrating the rapid flow of these scooter clouds may be more illustrative of the actual jet stream speed at these latitudes. This research was supported by a NASA JDAP grant and the NASA Postdoctoral Program.

  17. Seasonal evolution of Titan’s stratosphere near the poles from Cassini/CIRS data

    Science.gov (United States)

    Coustenis, Athena; Jennings, Donald E.; Achterberg, Richard K.; Bampasidis, Georgios; Cottini, Valeria; Nixon, Conor A.; Flasar, F. Michael

    2017-10-01

    We report on the monitoring of the seasonal evolution near Titan’s poles. Since 2010, we observe at Titan’s south pole a strong temperature decrease and the onset of a dramatic enhancement of several trace species such as complex hydrocarbons and nitriles (HC3N and C6H6 in particular) previously observed only at high northern latitudes (Coustenis et al. 2016 and references therein). This is due to the transition of Titan’s seasons from northern winter in 2002 to northern summer in 2017 and, at the same time, the advent of winter in the south pole, during which time species with longer chemical lifetimes remain in the north for a little longer undergoing slow photochemical destruction, while those with shorter lifetimes disappear, reappearing in the south. An opposite effect has been expected in the North, but not observed with any significant certainty until 2016. We present here an analysis of nadir spectra acquired by Cassini/CIRS (Jennings et al., 2017) at high resolution in the past years and describe the newly observed decrease in chemical abundances of the components in the North. From 2013 until 2016, the Northern polar region has shown a temperature increase of 10 K, while the South had shown a more significant decrease in a similar period of time. The chemical content in the North is finally showing a clear depletion for most molecules since 2015 (Coustenis et al., 2017).References: Coustenis et al., 2016, Icarus 270, 409-420 ; Coustenis et al., 2017, in preparation; Jennings et al., 2017, Applied Optics 56, no 18, 5274-5294.

  18. Photometric Modeling and VIS-IR Albedo Maps of Dione From Cassini-VIMS

    Science.gov (United States)

    Filacchione, G.; Ciarniello, M.; D'Aversa, E.; Capaccioni, F.; Cerroni, P.; Buratti, B. J.; Clark, R. N.; Stephan, K.; Plainaki, C.

    2018-03-01

    We report about visible and infrared albedo maps and spectral indicators of Dione's surface derived from the complete Visual and Infrared Mapping Spectrometer (VIMS) data set acquired between 2004 and 2017 during the Cassini tour in Saturn's system. Maps are derived by applying a photometric correction necessary to disentangle the intrinsic albedo of the surface from illumination and viewing geometry occurring at the time of the observation. The photometric correction is based on the Shkuratov et al. (2011, https://doi.org/10.1016/j.pss.2011.06.011) method which yields values of the surface equigonal albedo. Dione's surface albedo maps are rendered at five visible (VIS: 0.35, 0.44, 0.55, 0.7, and 0.95 μm) and five infrared (IR: 1.046, 1.540, 1.822, 2.050, and 2.200 μm) wavelengths in cylindrical projection with a 0.5° × 0.5° angular resolution in latitude and longitude, corresponding to a spatial resolution of 4.5 km/bin. Apart from visible and infrared albedo maps, we report about the distribution of the two visible spectral slopes (0.35-0.55 and 0.55-0.95 μm) and water ice 2.050 μm band depth computed after having applied the photometric correction. The derived spectral indicators are employed to trace Dione's composition variability on both global and local scales allowing to study the dichotomy between the bright‐leading and dark‐trailing hemispheres, the distribution of fresh material on the impact craters and surrounding ejecta, and the resurfacing of the bright material within the chasmata caused by tectonism.

  19. Variations in Ring Particle Cooling across Saturn's Rings with Cassini CIRS

    Science.gov (United States)

    Brooks, S. M.; Spilker, L. J.; Pilorz, S.; Edgington, S. G.; Déau, E.; Altobelli, N.

    2010-12-01

    Cassini's Composite Infrared Spectrometer has recorded over two million of spectra of Saturn's rings in the far infrared since arriving at Saturn in 2004. CIRS records far infrared radiation between 10 and 600 cm-1 ( 16.7 and 1000 μ {m} ) at focal plane 1 (FP1), which has a field of view of 3.9 mrad. Thermal emission from Saturn’s rings peaks in this wavelength range. Ring temperatures can be inferred from FP1 data. By tracking how ring temperatures vary, we can determine the thermal inertia of the rings. Previous studies have shown that the rings' thermal inertia, a measure of their response to changes in the thermal environment, varies from ring to ring. Thermal inertia can provide insight into the physical structure of Saturn's ring particles and their regoliths. Low thermal inertia and rapidly changing temperatures are suggestive of ring particles that have more porous or fluffy regoliths or that are riddled with cracks. Solid particles can be expected to have higher thermal inertias. Ferrari et al. (2005) fit thermal inertia values of 5218 {Jm)-2 {K}-1 {s}-1/2 to their B ring data and 6412 {Jm)-2 {K}-1 {s}-1/2 to their C ring data. In this work we focus on CIRS observations of the shadowed portion of Saturn's rings. The rings’ thermal budget is dominated by its absorption of solar radiation. As a result, ring particles abruptly cool as they traverse Saturn's shadow. From these shadow observations we can create cooling curves at specific locations across the rings. We will show that the rings' cooling curves and thus their thermal inertia vary not only from ring to ring, but by location within the individual rings. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Copyright 2010 California Institute of Technology. Government sponsorship acknowledged.

  20. Spectroscopy, morphometry, and photoclinometry of Titan's dunefields from Cassini/VIMS

    Science.gov (United States)

    Barnes, J.W.; Brown, R.H.; Soderblom, L.; Sotin, Christophe; Le, Mouelic S.; Rodriguez, S.; Jaumann, R.; Beyer, R.A.; Buratti, B.J.; Pitman, K.; Baines, K.H.; Clark, R.; Nicholson, P.

    2008-01-01

    Fine-resolution (500 m/pixel) Cassini Visual and Infrared Mapping Spectrometer (VIMS) T20 observations of Titan resolve that moon's sand dunes. The spectral variability in some dune regions shows that there are sand-free interdune areas, wherein VIMS spectra reveal the exposed dune substrate. The interdunes from T20 are, variously, materials that correspond to the equatorial bright, 5-??m-bright, and dark blue spectral units. Our observations show that an enigmatic "dark red" spectral unit seen in T5 in fact represents a macroscopic mixture with 5-??m-bright material and dunes as its spectral endmembers. Looking more broadly, similar mixtures of varying amounts of dune and interdune units of varying composition can explain the spectral and albedo variability within the dark brown dune global spectral unit that is associated with dunes. The presence of interdunes indicates that Titan's dunefields are both mature and recently active. The spectrum of the dune endmember reveals the sand to be composed of less water ice than the rest of Titan; various organics are consistent with the dunes' measured reflectivity. We measure a mean dune spacing of 2.1 km, and find that the dunes are oriented on the average in an east-west direction, but angling up to 10?? from parallel to the equator in specific cases. Where no interdunes are present, we determine the height of one set of dunes photoclinometrically to be between 30 and 70 m. These results pave the way for future exploration and interpretation of Titan's sand dunes. ?? 2007 Elsevier Inc. All rights reserved.

  1. Characterizing Observed Limit Cycles in the Cassini Main Engine Guidance Control System

    Science.gov (United States)

    Rizvi, Farheen; Weitl, Raquel M.

    2011-01-01

    The Cassini spacecraft dynamics-related telemetry during long Main Engine (ME) burns has indicated the presence of stable limit cycles between 0.03-0.04 Hz frequencies. These stable limit cycles cause the spacecraft to possess non-zero oscillating rates for extended periods of time. This indicates that the linear ME guidance control system does not model the complete dynamics of the spacecraft. In this study, we propose that the observed limit cycles in the spacecraft dynamics telemetry appear from a stable interaction between the unmodeled nonlinear elements in the ME guidance control system. Many nonlinearities in the control system emerge from translating the linear engine gimbal actuator (EGA) motion into a spacecraft rotation. One such nonlinearity comes from the gear backlash in the EGA system, which is the focus of this paper. The limit cycle characteristics and behavior can be predicted by modeling this gear backlash nonlinear element via a describing function and studying the interaction of this describing function with the overall dynamics of the spacecraft. The linear ME guidance controller and gear backlash nonlinearity are modeled analytically. The frequency, magnitude, and nature of the limit cycle are obtained from the frequency response of the ME guidance controller and nonlinear element. In addition, the ME guidance controller along with the nonlinearity is simulated. The simulation response contains a limit cycle with similar characterstics as predicted analytically: 0.03-0.04 Hz frequency and stable, sustained oscillations. The analytical and simulated limit cycle responses are compared to the flight telemetry for long burns such as the Saturn Orbit Insertion and Main Engine Orbit Trim Maneuvers. The analytical and simulated limit cycle characteristics compare well with the actual observed limit cycles in the flight telemetry. Both have frequencies between 0.03-0.04 Hz and stable oscillations. This work shows that the stable limit cycles occur

  2. Disribution and interplay of geologic processes on Titan from Cassini radar data

    Science.gov (United States)

    Lopes, R.M.C.; Stofan, E.R.; Peckyno, R.; Radebaugh, J.; Mitchell, K.L.; Mitri, Giuseppe; Wood, C.A.; Kirk, R.L.; Wall, S.D.; Lunine, J.I.; Hayes, A.; Lorenz, R.; Farr, Tom; Wye, L.; Craig, J.; Ollerenshaw, R.J.; Janssen, M.; LeGall, A.; Paganelli, F.; West, R.; Stiles, B.; Callahan, P.; Anderson, Y.; Valora, P.; Soderblom, L.

    2010-01-01

    The Cassini Titan Radar Mapper is providing an unprecedented view of Titan's surface geology. Here we use Synthetic Aperture Radar (SAR) image swaths (Ta-T30) obtained from October 2004 to December 2007 to infer the geologic processes that have shaped Titan's surface. These SAR swaths cover about 20% of the surface, at a spatial resolution ranging from ~350 m to ~2 km. The SAR data are distributed over a wide latitudinal and longitudinal range, enabling some conclusions to be drawn about the global distribution of processes. They reveal a geologically complex surface that has been modified by all the major geologic processes seen on Earth - volcanism, tectonism, impact cratering, and erosion and deposition by fluvial and aeolian activity. In this paper, we map geomorphological units from SAR data and analyze their areal distribution and relative ages of modification in order to infer the geologic evolution of Titan's surface. We find that dunes and hummocky and mountainous terrains are more widespread than lakes, putative cryovolcanic features, mottled plains, and craters and crateriform structures that may be due to impact. Undifferentiated plains are the largest areal unit; their origin is uncertain. In terms of latitudinal distribution, dunes and hummocky and mountainous terrains are located mostly at low latitudes (less than 30 degrees), with no dunes being present above 60 degrees. Channels formed by fluvial activity are present at all latitudes, but lakes are at high latitudes only. Crateriform structures that may have been formed by impact appear to be uniformly distributed with latitude, but the well-preserved impact craters are all located at low latitudes, possibly indicating that more resurfacing has occurred at higher latitudes. Cryovolcanic features are not ubiquitous, and are mostly located between 30 degrees and 60 degrees north. We examine temporal relationships between units wherever possible, and conclude that aeolian and fluvial

  3. Distribution and interplay of geologic processes on Titan from Cassini radar data

    Science.gov (United States)

    Lopes, R.M.C.; Stofan, E.R.; Peckyno, R.; Radebaugh, J.; Mitchell, K.L.; Mitri, Giuseppe; Wood, C.A.; Kirk, R.L.; Wall, S.D.; Lunine, J.I.; Hayes, A.; Lorenz, R.; Farr, Tom; Wye, L.; Craig, J.; Ollerenshaw, R.J.; Janssen, M.; LeGall, A.; Paganelli, F.; West, R.; Stiles, B.; Callahan, P.; Anderson, Y.; Valora, P.; Soderblom, L.

    2010-01-01

    The Cassini Titan Radar Mapper is providing an unprecedented view of Titan's surface geology. Here we use Synthetic Aperture Radar (SAR) image swaths (Ta-T30) obtained from October 2004 to December 2007 to infer the geologic processes that have shaped Titan's surface. These SAR swaths cover about 20% of the surface, at a spatial resolution ranging from ???350 m to ???2 km. The SAR data are distributed over a wide latitudinal and longitudinal range, enabling some conclusions to be drawn about the global distribution of processes. They reveal a geologically complex surface that has been modified by all the major geologic processes seen on Earth - volcanism, tectonism, impact cratering, and erosion and deposition by fluvial and aeolian activity. In this paper, we map geomorphological units from SAR data and analyze their areal distribution and relative ages of modification in order to infer the geologic evolution of Titan's surface. We find that dunes and hummocky and mountainous terrains are more widespread than lakes, putative cryovolcanic features, mottled plains, and craters and crateriform structures that may be due to impact. Undifferentiated plains are the largest areal unit; their origin is uncertain. In terms of latitudinal distribution, dunes and hummocky and mountainous terrains are located mostly at low latitudes (less than 30??), with no dunes being present above 60??. Channels formed by fluvial activity are present at all latitudes, but lakes are at high latitudes only. Crateriform structures that may have been formed by impact appear to be uniformly distributed with latitude, but the well-preserved impact craters are all located at low latitudes, possibly indicating that more resurfacing has occurred at higher latitudes. Cryovolcanic features are not ubiquitous, and are mostly located between 30?? and 60?? north. We examine temporal relationships between units wherever possible, and conclude that aeolian and fluvial/pluvial/lacustrine processes are the

  4. Equatorial Oscillation and Planetary Wave Activity in Saturn's Stratosphere Through the Cassini Epoch

    Science.gov (United States)

    Guerlet, S.; Fouchet, T.; Spiga, A.; Flasar, F. M.; Fletcher, L. N.; Hesman, B. E.; Gorius, N.

    2018-01-01

    Thermal infrared spectra acquired by Cassini/Composite InfraRed Spectrometer (CIRS) in limb-viewing geometry in 2015 are used to derive 2-D latitude-pressure temperature and thermal wind maps. These maps are used to study the vertical structure and evolution of Saturn's equatorial oscillation (SEO), a dynamical phenomenon presenting similarities with the Earth's quasi-biennal oscillation (QBO) and semi-annual oscillation (SAO). We report that a new local wind maximum has appeared in 2015 in the upper stratosphere and derive the descent rates of other wind extrema through time. The phase of the oscillation observed in 2015, as compared to 2005 and 2010, remains consistent with a ˜15 year period. The SEO does not propagate downward at a regular rate but exhibits faster descent rate in the upper stratosphere, combined with a greater vertical wind shear, compared to the lower stratosphere. Within the framework of a QBO-type oscillation, we estimate the absorbed wave momentum flux in the stratosphere to be on the order of ˜7 × 10-6 N m-2. On Earth, interactions between vertically propagating waves (both planetary and mesoscale) and the mean zonal flow drive the QBO and SAO. To broaden our knowledge on waves potentially driving Saturn's equatorial oscillation, we searched for thermal signatures of planetary waves in the tropical stratosphere using CIRS nadir spectra. Temperature anomalies of amplitude 1-4 K and zonal wave numbers 1 to 9 are frequently observed, and an equatorial Rossby (n = 1) wave of zonal wave number 3 is tentatively identified in November 2009.

  5. The Ring System of Saturn as Seen by Cassini-VIMS (Invited)

    Science.gov (United States)

    Filacchione, G.; Ciarniello, M.; Capaccioni, F.

    2015-08-01

    Since 2004 the Visual and Infrared Mapping Spectrometer (VIMS) aboard Cassini has acquired numerous hyperspectral mosaics in the 0.35-5.1 μm spectral range of Saturn's main rings in very different illumination and viewing geometries. These observations have allowed us to infer the ring particles physical properties and composition: water ice abundance is estimated through the 1.25-1.5-2.0 μm band depths, chromophores distribution is derived from visible spectral slopes while organic material is traced by the aliphatic compounds signature at 3.42 μm which appears stronger on CD and C ring than on A-B rings (Filacchione et al., 2014). Observed reflectance spectra are fitted with a spectrophotometric model based on Montecarlo ray-tracing with the scope to infer particles composition while disentangling photometric effects (caused by multiple scattering, opposition surge and forward scattering) which depend on illumination/viewing geometries. Spectral bond albedo for different regions of the rings has been best-fitted using Hapke's radiative transfer modeling (Ciarniello et al, 2011) by choosing different mixtures of water ice, tholin, and amorphous carbon particles populations. While tholin distribution seems to be fairly constant across the rings, the amorphous carbon appears anti-correlated with optical depth. Moreover, dark material contamination is less effective on densest regions, where the more intense rejuvenation processes occur, in agreement with the ballistic transport theory (Cuzzi and Estrada,1998). Finally, the 3.6 μm continuum peak wavelength is used to infer particles temperature, which is anti-correlated with the albedo and the optical depth (tau): low-albedo/low-tau C ring and CD have higher temperatures than A-B rings where albedo and tau are high. This trend matches direct temperature measurements by CIRS (Spilker et al., 2013).

  6. Looking For Thermal IR Polarization In Saturn's Rings With Cassini/CIRS

    Science.gov (United States)

    Edgington, Scott G.; Spilker, L. J.; Jennings, D. E.; Altobelli, N.; Pilorz, S. H.; Pearl, J. C.; Leyrat, C.; CIRS Team

    2007-10-01

    The Cassini Composite Infrared Spectrometer (CIRS) FP1 channel is a polarizing interferometer covering the spectral range from 10 to 600 cm-1. By rotating the instrument about its optical axis, it is possible to measure the IR polarization of target objects over that spectral range. This requires the FP1 footprint on the rings, the emission angle, and the phase angle to be fairly constant for the duration of the observation. With these constraints, we turned two composition observations, both allocated long periods of time for sitting-and-staring, into polarization observations. The time was divided equally amongst observations of the A, B, and C rings, with one observation taking place on the lit side and the other on the unlit side. We chose relative rotations of 0, 30, and 60 degrees (future observations will use 0, 45, 90, and 135 degree rotations). For each ring, we will determine the Stokes Vector (I, Q, U, V) and the degree of polarization, (Q+U+V)/I. We will also examine the degree to which the temperature and emissivity varies with the orientation of the field of view. One of the observation takes place at low phase angles. At low phase angles, the filling factor of the C-Ring has been shown to increase steeply with decreasing spacecraft elevation (Altobelli, et al., 2007). We will determine the limitations of this physical effect on the determination of the polarization of the C-ring. Successful measurements should provide information on the microscopic roughness of ring particles. We will report on results of these observations. For a similar analysis pertaining to Iapetus' surface, see J. C. Pearl, et al. (this meeting). The research described in this paper was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

  7. NANODUST DETECTION BETWEEN 1 AND 5 AU USING CASSINI WAVE MEASUREMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Schippers, P.; Vernet, N. Meyer-; Lecacheux, A.; Belheouane, S.; Moncuquet, M. [LESIA—CNRS—Observatoire de Paris, 5 place Jules Janssen, F-92195 Meudon (France); Kurth, W. S. [Department of Physics and Astronomy, University of Iowa, Iowa City, IA (United States); Mann, I. [EISCAT Scientific Association, Kiruna, Sweden and Department of Physics Umeå University (Sweden); Mitchell, D. G. [Applied Physics Laboratory, John Hopkins University, Laurel, MD (United States); André, N. [IRAP, 9 Avenue du Colonel Roche, F-31028 Toulouse (France)

    2015-06-10

    The solar system contains solids of all sizes, ranging from kilometer-sized bodies to nano-sized particles. Nanograins have been detected in situ in the Earth's atmosphere, near cometary and giant planet environments, and more recently in the solar wind at 1 AU. The latter nanograins are thought to be formed in the inner solar system dust cloud, mainly through the collisional break-up of larger grains, and are then picked up and accelerated by the magnetized solar wind because of their large charge-to-mass ratio. In the present paper, we analyze the low frequency bursty noise identified in the Cassini radio and plasma wave data during the spacecraft cruise phase inside Jupiter's orbit. The magnitude, spectral shape, and waveform of this broadband noise are consistent with the signatures of the nano particles that traveled at solar wind speed and impinged on the spacecraft surface. Nanoparticles were observed whenever the radio instrument was turned on and able to detect them at different heliocentric distances between Earth and Jupiter, suggesting their ubiquitous presence in the heliosphere. We analyzed the radial dependence of the nanodust flux with heliospheric distance and found that it is consistent with the dynamics of nanodust originating from the inner heliosphere and picked up by the solar wind. The contribution of the nanodust produced in the asteroid belt appears to be negligible compared to the trapping region in the inner heliosphere. In contrast, further out, nanodust is mainly produced by the volcanism of active moons such as Io and Enceladus.

  8. Stochastic weather inputs for improved urban water demand forecasting: application of nonlinear input variable selection and machine learning methods

    Science.gov (United States)

    Quilty, J.; Adamowski, J. F.

    2015-12-01

    Urban water supply systems are often stressed during seasonal outdoor water use as water demands related to the climate are variable in nature making it difficult to optimize the operation of the water supply system. Urban water demand forecasts (UWD) failing to include meteorological conditions as inputs to the forecast model may produce poor forecasts as they cannot account for the increase/decrease in demand related to meteorological conditions. Meteorological records stochastically simulated into the future can be used as inputs to data-driven UWD forecasts generally resulting in improved forecast accuracy. This study aims to produce data-driven UWD forecasts for two different Canadian water utilities (Montreal and Victoria) using machine learning methods by first selecting historical UWD and meteorological records derived from a stochastic weather generator using nonlinear input variable selection. The nonlinear input variable selection methods considered in this work are derived from the concept of conditional mutual information, a nonlinear dependency measure based on (multivariate) probability density functions and accounts for relevancy, conditional relevancy, and redundancy from a potential set of input variables. The results of our study indicate that stochastic weather inputs can improve UWD forecast accuracy for the two sites considered in this work. Nonlinear input variable selection is suggested as a means to identify which meteorological conditions should be utilized in the forecast.

  9. On magnetospheric electron impact ionisation and dynamics in Titan's ram-side and polar ionosphere – a Cassini case study

    Directory of Open Access Journals (Sweden)

    G. R. Lewis

    2007-11-01

    Full Text Available We present data from the sixth Cassini flyby of Titan (T5, showing that the magnetosphere of Saturn strongly interacts with the moon's ionosphere and exo-ionosphere. A simple electron ionisation model provides a reasonable agreement with the altitude structure of the ionosphere. Furthermore, we suggest that the dense and cold exo-ionosphere (from the exobase at 1430 km and outward to several Titan radii from the surface can be explained by magnetospheric forcing and other transport processes whereas exospheric ionisation by impacting low energy electrons seems to play a minor role.

  10. Ballistic Transport: After the Cassini Grand Finale, is there a Final Consensus on Ring Origin and Age?

    Science.gov (United States)

    Estrada, P. R.; Durisen, R. H.; Cuzzi, J. N.

    2017-12-01

    As the Cassini mission comes to its much anticipated end, somewhat befittingly to be immortalized and enshrined for all time within the gaseous confines of a planet named for the Greek god of time (Kronos), we find the time appropriate to return to the subject of ring age and origin. During Cassini's remarkable tenure, important measurements have been obtained that can help to elucidate and perhaps settle the debate once and for all on whether the rings are young or old. At the forefront lie the results of the Cassini Dust Analyzer (CDA) experiment which indicate that the range of the micrometeoroid flux at infinity for Saturn are comparable to the nominal value of the meteoroid flux value currently adopted for use in ballistic transport (BT) applications and models (Estrada et al., 2015, 2017). Moreover, the source of the micrometeoroid flux has been localized to the Edgeworth-Kuiper Belt (EKB) and is not cometary in origin as previously assumed (Altobelli et al., 2015). A major consequence of these measurements is that the EKB flux is much more gravitationally focused increasing the impact flux on the rings by a factor of ˜25 relative to cometary. This implies that the process of micrometeoroid bombardment and BT is likely even more influential in the rings' structural and compositional evolution over time. This measurement taken together with recent analysis of the bulk mass fraction of non-icy constituents (Zhang et al., 2017a,b) using Cassini radiometry data argue strongly for young rings. Another observation that will help to provide a constraint (though not absolute) is the pending measurement of the (B) ring mass. A high mass estimate as argued by some does not necessarily mean old rings, whereas a low mass ring would certainly imply as much. There are several factors that can offer insight on to the age of the rings from BT modeling, such as saturation of the ramp(s), color differences across the B-C (A-CD) boundaries, color differences across plateaus

  11. Metacognitive Instruction: Global and Local Shifts in Considering Listening Input

    Directory of Open Access Journals (Sweden)

    Hossein Bozorgian

    2013-01-01

    Full Text Available A key shift of thinking for effective learning and teaching of listening input has been seen and organized in education locally and globally. This study has probed whether metacognitive instruction through a pedagogical cycle shifts high-intermediate students' English language learning and English as a second language (ESL teacher's teaching focus on listening input. Twenty male Iranian students with an age range of 18 to 24 received a guided methodology including metacognitive strategies (planning, monitoring, and evaluation for a period of three months. This study has used the strategies and probed the importance of metacognitive instruction through interviewing both the teacher and the students. The results have shown that metacognitive instruction helped both the ESL teacher's and the students' shift of thinking about teaching and learning listening input. This key shift of thinking has implications globally and locally for classroom practices of listening input.

  12. GPHS-RTGs in support of the Cassini Mission. Semi annual technical progress report, 1 April 1996--29 September 1996

    International Nuclear Information System (INIS)

    1996-01-01

    This technical progress report discusses work on the Radioisotope Generators and Ancillary Activities for the Cassini spacecraft. The Cassini spacecraft is expected to launch in October 1997, and will explore Saturn and its moons. This progress report discusses issues in: spacecraft integration and liason, engineering support, safety, qualified unicouple fabrication, ETG fabrication and testing, ground support equipment, RTG shipping and launch support, designs, reviews and mission application. Safety analysis of the RTGs during reentry and launch accidents are covered. This report covers the period of April 1 to September 29, 1996

  13. Input filter compensation for switching regulators

    Science.gov (United States)

    Lee, F. C.; Kelkar, S. S.

    1982-01-01

    The problems caused by the interaction between the input filter, output filter, and the control loop are discussed. The input filter design is made more complicated because of the need to avoid performance degradation and also stay within the weight and loss limitations. Conventional input filter design techniques are then dicussed. The concept of pole zero cancellation is reviewed; this concept is the basis for an approach to control the peaking of the output impedance of the input filter and thus mitigate some of the problems caused by the input filter. The proposed approach for control of the peaking of the output impedance of the input filter is to use a feedforward loop working in conjunction with feedback loops, thus forming a total state control scheme. The design of the feedforward loop for a buck regulator is described. A possible implementation of the feedforward loop design is suggested.

  14. Asymmetric Temporal Integration of Layer 4 and Layer 2/3 Inputs in Visual Cortex

    OpenAIRE

    Hang, Giao B.; Dan, Yang

    2010-01-01

    Neocortical neurons in vivo receive concurrent synaptic inputs from multiple sources, including feedforward, horizontal, and feedback pathways. Layer 2/3 of the visual cortex receives feedforward input from layer 4 and horizontal input from layer 2/3. Firing of the pyramidal neurons, which carries the output to higher cortical areas, depends critically on the interaction of these pathways. Here we examined synaptic integration of inputs from layer 4 and layer 2/3 in rat visual cortical slices...

  15. Comparison of the Cloud Morphology Spatial Structure Between Jupiter and Saturn Using JunoCam and Cassini ISS

    Science.gov (United States)

    Garland, Justin; Sayanagi, Kunio M.; Blalock, John J.; Gunnarson, Jacob; McCabe, Ryan M.; Gallego, Angelina; Hansen, Candice; Orton, Glenn S.

    2017-10-01

    We present an analysis of the spatial-scales contained in the cloud morphology of Jupiter’s southern high latitudes using images captured by JunoCam in 2016 and 2017, and compare them to those on Saturn using images captured using the Imaging Science Subsystem (ISS) on board the Cassini orbiter. For Jupiter, the characteristic spatial scale of cloud morphology as a function of latitude is calculated from images taken in three visual (600-800, 500-600, 420-520 nm) bands and a near-infrared (880- 900 nm) band. In particular, we analyze the transition from the banded structure characteristic of Jupiter’s mid-latitudes to the chaotic structure of the polar region. We apply similar analysis to Saturn using images captured using Cassini ISS. In contrast to Jupiter, Saturn maintains its zonally organized cloud morphology from low latitudes up to the poles, culminating in the cyclonic polar vortices centered at each of the poles. By quantifying the differences in the spatial scales contained in the cloud morphology, our analysis will shed light on the processes that control the banded structures on Jupiter and Saturn. Our work has been supported by the following grants: NASA PATM NNX14AK07G, NASA MUREP NNX15AQ03A, and NSF AAG 1212216.

  16. Vomeronasal inputs to the rodent ventral striatum.

    Science.gov (United States)

    Ubeda-Bañon, I; Novejarque, A; Mohedano-Moriano, A; Pro-Sistiaga, P; Insausti, R; Martinez-Garcia, F; Lanuza, E; Martinez-Marcos, A

    2008-03-18

    Vertebrates sense chemical signals through the olfactory and vomeronasal systems. In squamate reptiles, which possess the largest vomeronasal system of all vertebrates, the accessory olfactory bulb projects to the nucleus sphericus, which in turn projects to a portion of the ventral striatum known as olfactostriatum. Characteristically, the olfactostriatum is innervated by neuropeptide Y, tyrosine hydroxylase and serotonin immunoreactive fibers. In this study, the possibility that a structure similar to the reptilian olfactostriatum might be present in the mammalian brain has been investigated. Injections of dextran-amines have been aimed at the posteromedial cortical amygdaloid nucleus (the putative mammalian homologue of the reptilian nucleus sphericus) of rats and mice. The resulting anterograde labeling includes the olfactory tubercle, the islands of Calleja and sparse terminal fields in the shell of the nucleus accumbens and ventral pallidum. This projection has been confirmed by injections of retrograde tracers into the ventral striato-pallidum that render retrograde labeling in the posteromedial cortical amygdaloid nucleus. The analysis of the distribution of neuropeptide Y, tyrosine hydroxylase, serotonin and substance P in the ventral striato-pallidum of rats, and the anterograde tracing of the vomeronasal amygdaloid input in the same material confirm that, similar to reptiles, the ventral striatum of mammals includes a specialized vomeronasal structure (olfactory tubercle and islands of Calleja) displaying dense neuropeptide Y-, tyrosine hydroxylase- and serotonin-immunoreactive innervations. The possibility that parts of the accumbens shell and/or ventral pallidum could be included in the mammalian olfactostriatum cannot be discarded.

  17. Optimization of Saturn paraboloid magnetospheric field model parameters using Cassini equatorial magnetic field data

    Directory of Open Access Journals (Sweden)

    E. S. Belenkaya

    2016-07-01

    Full Text Available The paraboloid model of Saturn's magnetosphere describes the magnetic field as being due to the sum of contributions from the internal field of the planet, the ring current, and the tail current, all contained by surface currents inside a magnetopause boundary which is taken to be a paraboloid of revolution about the planet-Sun line. The parameters of the model have previously been determined by comparison with data from a few passes through Saturn's magnetosphere in compressed and expanded states, depending on the prevailing dynamic pressure of the solar wind. Here we significantly expand such comparisons through examination of Cassini magnetic field data from 18 near-equatorial passes that span wide ranges of local time, focusing on modelling the co-latitudinal field component that defines the magnetic flux passing through the equatorial plane. For 12 of these passes, spanning pre-dawn, via noon, to post-midnight, the spacecraft crossed the magnetopause during the pass, thus allowing an estimate of the concurrent subsolar radial distance of the magnetopause R1 to be made, considered to be the primary parameter defining the scale size of the system. The best-fit model parameters from these passes are then employed to determine how the parameters vary with R1, using least-squares linear fits, thus providing predictive model parameters for any value of R1 within the range. We show that the fits obtained using the linear approximation parameters are of the same order as those for the individually selected parameters. We also show that the magnetic flux mapping to the tail lobes in these models is generally in good accord with observations of the location of the open-closed field line boundary in Saturn's ionosphere, and the related position of the auroral oval. We then investigate the field data on six passes through the nightside magnetosphere, for which the spacecraft did not cross the magnetopause, such that in this case we compare the

  18. Saturn's north polar cyclone and hexagon at depth revealed by Cassini/VIMS

    Science.gov (United States)

    Baines, K.H.; Momary, T.W.; Fletcher, L.N.; Showman, A.P.; Roos-Serote, M.; Brown, R.H.; Buratti, B.J.; Clark, R.N.; Nicholson, P.D.

    2009-01-01

    A high-speed cyclonic vortex centered on the north pole of Saturn has been revealed by the visual-infrared mapping spectrometer (VIMS) onboard the Cassini-Huygens Orbiter, thus showing that the tropospheres of both poles of Saturn are occupied by cyclonic vortices with winds exceeding 135 m/s. High-spatial-resolution (~200 km per pixel) images acquired predominantly under night-time conditions during Saturn's polar winter-using a thermal wavelength of 5.1 ??m to obtain time-lapsed imagery of discrete, deep-seated (>2.1-bar) cloud features viewed in silhouette against Saturn's internally generated thermal glow-show a classic cyclonic structure, with prograde winds exceeding 135 m/s at its maximum near 88.3?? (planetocentric) latitude, and decreasing to conditions as the polar winter wanes shows the hexagon is still visible in reflected sunlight nearly 28 years since its discovery, that a similar 3-lane structure is observed in reflected and thermal light, and that the cloudtops may be typically lower in the hexagon than in nearby discrete cloud features outside of it. Clouds are well-correlated in visible and 5.1 ??m images, indicating little windshear above the ~2-bar level. The polar cyclone is similar in size and shape to its counterpart at the south pole; a primary difference is the presence of a small (<600 km in diameter) nearly pole-centered cloud, perhaps indicative of localized upwelling. Many dozens of discrete, circular cloud features dot the polar region, with typical diameters of 300-700 km. Equatorward of 87.8??N, their compact nature in the high-wind polar environment suggests that vertical shear in horizontal winds may be modest on 1000 km scales. These circular clouds may be anticyclonic vortices produced by baroclinic instabilities, barotropic instabilities, moist convection or other processes. The existence of cyclones at both poles of Saturn indicates that cyclonic circulation may be an important dynamical style in planets with significant

  19. The geology of Hotei Regio, Titan: Correlation of Cassini VIMS and RADAR

    Science.gov (United States)

    Soderblom, L.A.; Brown, R.H.; Soderblom, J.M.; Barnes, J.W.; Kirk, R.L.; Sotin, Christophe; Jaumann, R.; MacKinnon, D.J.; Mackowski, D.W.; Baines, K.H.; Buratti, B.J.; Clark, R.N.; Nicholson, P.D.

    2009-01-01

    Joint Cassini VIMS and RADAR SAR data of ???700-km-wide Hotei Regio reveal a rich collection of geological features that correlate between the two sets of images. The degree of correlation is greater than anywhere else seen on Titan. Central to Hotei Regio is a basin filled with cryovolcanic flows that are anomalously bright in VIMS data (in particular at 5 ??m) and quite variable in roughness in SAR. The edges of the flows are dark in SAR data and appear to overrun a VIMS-bright substrate. SAR-stereo topography shows the flows to be viscous, 100-200 m thick. On its southern edge the basin is ringed by higher (???1 km) mountainous terrain. The mountains show mixed texture in SAR data: some regions are extremely rough, exhibit low and spectrally neutral albedo in VIMS data and may be partly coated with darker hydrocarbons. Around the southern margin of Hotei Regio, the SAR image shows several large, dendritic, radar-bright channels that flow down from the mountainous terrain and terminate in dark blue patches, seen in VIMS images, whose infrared color is consistent with enrichment in water ice. The patches are in depressions that we interpret to be filled with fluvial deposits eroded and transported by liquid methane in the channels. In the VIMS images the dark blue patches are encased in a latticework of lighter bands that we suggest to demark a set of circumferential and radial fault systems bounding structural depressions. Conceivably the circular features are tectonic structures that are remnant from an ancient impact structure. We suggest that impact-generated structures may have simply served as zones of weakness; no direct causal connection, such as impact-induced volcanism, is implied. We also speculate that two large dark features lying on the northern margin of Hotei Regio could be calderas. In summary the preservation of such a broad suite of VIMS infrared color variations and the detailed correlation with features in the SAR image and SAR topography

  20. The 12C/ 13C isotopic ratio in Titan hydrocarbons from Cassini/CIRS infrared spectra

    Science.gov (United States)

    Nixon, C. A.; Achterberg, R. K.; Vinatier, S.; Bézard, B.; Coustenis, A.; Irwin, P. G. J.; Teanby, N. A.; de Kok, R.; Romani, P. N.; Jennings, D. E.; Bjoraker, G. L.; Flasar, F. M.

    2008-06-01

    We have analyzed infrared spectra of Titan recorded by the Cassini Composite Infrared Spectrometer (CIRS) to measure the isotopic ratio 12C/ 13C in each of three chemical species in Titan's stratosphere: CH 4, C 2H 2 and C 2H 6. This is the first measurement of 12C/ 13C in any C 2 molecule on Titan, and the first measurement of 12CH 4/ 13CH 4 (non-deuterated) on Titan by remote sensing. Our spectra cover five widely-spaced latitudes, 65° S to 71° N and we have searched for both latitude variability of 12C/ 13C within a given species, and also for differences between the 12C/ 13C in the three gases. For CH 4 alone, we find C12/C13=76.6±2.7 (1- σ), essentially in agreement with the 12CH 4/ 13CH 4 measured by the Huygens Gas Chromatograph/Mass Spectrometer instrument (GCMS) [Niemann, H.B., and 17 colleagues, 2005. Nature 438, 779-784]: 82.3±1.0, and also with measured values in H 13CN and 13CH 3D by CIRS at lower precision [Bézard, B., Nixon, C., Kleiner, I., Jennings, D., 2007. Icarus 191, 397-400; Vinatier, S., Bézard, B., Nixon, C., 2007. Icarus 191, 712-721]. For the C 2 species, we find C12/C13=84.8±3.2 in C 2H 2 and 89.8±7.3 in C 2H 6, a possible trend of increasingly value with molecular mass, although these values are both compatible with the Huygens GCMS value to within error bars. There are no convincing trends in latitude. Combining all fifteen measurements, we obtain a value of C12/C13=80.8±2.0, also compatible with GCMS. Therefore, the evidence is mounting that 12C/ 13C is some 8% lower on Titan than on the Earth (88.9, inorganic standard), and lower than typical for the outer planets ( 88±7 [Sada, P.V., McCabe, G.H., Bjoraker, G.L., Jennings, D.E., Reuter, D.C., 1996. Astrophys. J. 472, 903-907]). There is no current model for this enrichment, and we discuss several mechanisms that may be at work.

  1. Mapping the Thermal Inertia of Saturn’s Rings with Cassini CIRS

    Science.gov (United States)

    Brooks, Shawn M.; Spilker, L. J.; PIlorz, S. H.; Showalter, M. R.

    2013-10-01

    We use data from Cassini's Composite Infrared Spectrometer to map out the thermal response of Saturn's ring particles passing through Saturn's shadow and to determine variations in ring thermal inertia. CIRS records far infrared radiation in three separate detectors, each of which covers a distinct wavelength range. In this work, we analyze rings spectra recorded at focal plane 1 (FP1), as its wavelength response (16.7-1000 microns) is well suited to detecting direct thermal emission from Saturn's rings. The thermal budget of the rings is typically dominated by solar radiation. When ring particles enter Saturn’s shadow this source of energy is abruptly cut off with a consequential drop in ring temperature. Likewise, temperatures rebound when particles exit the shadow. To characterize these heating and cooling events, FP1 was repeatedly scanned across the main rings. Each scan was offset from either the ingress or egress shadow boundary by an amount corresponding to a fraction of a Keplerian orbit. By resampling these scans onto a common radial grid, we can map out the rings’ response to the abrupt changes in insolation at shadow ingress and egress. Periods near equinox represent a unique situation. During this time the Sun's disk crosses the ring plane and its rays strike the rings at zero incidence. Solar heating is virtually absent, and thermal radiation from Saturn and sunlight reflected by Saturn dominate the thermal environment. While ring temperature variations at equinox are much more subtle, they represent temperature contrasts that vary at the unique timescale corresponding to variations in Saturn contributions to the rings’ thermal budget. By analyzing CIRS data at a variety of locations and epochs, we will map out thermal inertia across the rings and attempt to tease out structural information about the particles which comprise Saturn’s rings. This presentation will report upon our progress towards these ends. This research was carried out at the

  2. Investigation of Titan's surface and atmosphere photometric functions using the Cassini/VIMS instrument

    Science.gov (United States)

    Cornet, Thomas; Altobelli, Nicolas; Rodriguez, Sébastien; Maltagliati, Luca; Le Mouélic, Stéphane; Sotin, Christophe; Brown, Robert; Barnes, Jason; Buratti, Bonnie; Baines, Kevin; Clark, Roger; Nicholson, Phillip

    2015-04-01

    After 106 flybys spread over 10 years, the Cassini Visual and Infrared Mapping Spectrometer (VIMS) instrument acquired 33151 hyperspectral cubes pointing at the surface of Titan on the dayside. Despite this huge amount of data available for surface studies, and due to the strong influence of the atmosphere (methane absorption and haze scattering), Titan's surface is only visible with VIMS in 7 spectral atmospheric windows centred at 0.93, 1.08, 1.27, 1.59, 2.01, 2.7-2.8 and 5 microns. Atmospheric scattering and absorption effects dominate Titan's spectrum at wavelengths shorter than 3 microns, while the 5 micron window, almost insensitive to the haze scattering, only presents a reduced atmospheric absorption contribution to the signal recorded by VIMS. In all cases, the recorded I/F represents an apparent albedo, which depends on the atmospheric contributions and the surface photometry at each wavelength. We therefore aim to determine real albedo values for Titan's surface by finding photometric functions for the surface and the atmosphere that could be used as a basis for empirical corrections or Radiative Transfer calculations. After updating the navigation of the VIMS archive, we decomposed the entire VIMS data set into a MySQL relational database gathering the viewing geometry, location, time (season) and I/F (for pure atmosphere and surface-atmosphere images) for each pixel of the 33151 individual VIMS cubes. We then isolated all the VIMS pixels where Titan's surface has been repeatedly imaged at low phase angles (< 20 degrees) in order to characterize phase curves for the surface at 5 microns and for the atmosphere. Among these, the T88 flyby appears noteworthy, with a "Emergence-Phase Function (EPF)"-type observation: 25 cubes acquired during the same flyby, over the same area (close to Tortola Facula, in relatively dark terrains), at a constant incidence and with varying emergence and phase (from 0 to 60 degrees) angles. The data clearly exhibit an increase

  3. Pre-processing of input files for the AZTRAN code

    International Nuclear Information System (INIS)

    Vargas E, S.; Ibarra, G.

    2017-09-01

    The AZTRAN code began to be developed in the Nuclear Engineering Department of the Escuela Superior de Fisica y Matematicas (ESFM) of the Instituto Politecnico Nacional (IPN) with the purpose of numerically solving various models arising from the physics and engineering of nuclear reactors. The code is still under development and is part of the AZTLAN platform: Development of a Mexican platform for the analysis and design of nuclear reactors. Due to the complexity to generate an input file for the code, a script based on D language is developed, with the purpose of making its elaboration easier, based on a new input file format which includes specific cards, which have been divided into two blocks, mandatory cards and optional cards, including a pre-processing of the input file to identify possible errors within it, as well as an image generator for the specific problem based on the python interpreter. (Author)

  4. READDATA: a FORTRAN 77 codeword input package

    International Nuclear Information System (INIS)

    Lander, P.A.

    1983-07-01

    A new codeword input package has been produced as a result of the incompatibility between different dialects of FORTRAN, especially when character variables are passed as parameters. This report is for those who wish to use a codeword input package with FORTRAN 77. The package, called ''Readdata'', attempts to combine the best features of its predecessors such as BINPUT and pseudo-BINPUT. (author)

  5. CREATING INPUT TABLES FROM WAPDEG FOR RIP

    International Nuclear Information System (INIS)

    K.G. Mon

    1998-01-01

    The purpose of this calculation is to create tables for input into RIP ver. 5.18 (Integrated Probabilistic Simulator for Environmental Systems) from WAPDEG ver. 3.06 (Waste Package Degradation) output. This calculation details the creation of the RIP input tables for TSPA-VA REV.00

  6. Wave energy input into the Ekman layer

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This paper is concerned with the wave energy input into the Ekman layer, based on 3 observational facts that surface waves could significantly affect the profile of the Ekman layer. Under the assumption of constant vertical diffusivity, the analytical form of wave energy input into the Ekman layer is derived. Analysis of the energy balance shows that the energy input to the Ekman layer through the wind stress and the interaction of the Stokes-drift with planetary vorticity can be divided into two kinds. One is the wind energy input, and the other is the wave energy input which is dependent on wind speed, wave characteristics and the wind direction relative to the wave direction. Estimates of wave energy input show that wave energy input can be up to 10% in high-latitude and high-wind speed areas and higher than 20% in the Antarctic Circumpolar Current, compared with the wind energy input into the classical Ekman layer. Results of this paper are of significance to the study of wave-induced large scale effects.

  7. Input Enhancement and L2 Question Formation.

    Science.gov (United States)

    White, Lydia; And Others

    1991-01-01

    Investigated the extent to which form-focused instruction and corrective feedback (i.e., "input enhancement"), provided within a primarily communicative program, contribute to learners' accuracy in question formation. Study results are interpreted as evidence that input enhancement can bring about genuine changes in learners' interlanguage…

  8. GPHS-RTGs in support of the Cassini Mission. Semi-annual technical progress report, April 3, 1995--October 1, 1995

    International Nuclear Information System (INIS)

    1995-01-01

    This document is the April-October 1995 Progress Report on the Cassini RTG Program. Nine tasks are summarized; (1) Spacecraft integration and liason, (2) Engineering support, (3) Safety, (4) Unicouple fabrication, (5) ETG fabrication, assembly, and test, (6) Ground support equipment, (7) RTG shipping and launch support, (8) Design, reviews, and mission applications, and (9) Project management, QA, contract changes, and material acquisitions

  9. Statistical identification of effective input variables

    International Nuclear Information System (INIS)

    Vaurio, J.K.

    1982-09-01

    A statistical sensitivity analysis procedure has been developed for ranking the input data of large computer codes in the order of sensitivity-importance. The method is economical for large codes with many input variables, since it uses a relatively small number of computer runs. No prior judgemental elimination of input variables is needed. The sceening method is based on stagewise correlation and extensive regression analysis of output values calculated with selected input value combinations. The regression process deals with multivariate nonlinear functions, and statistical tests are also available for identifying input variables that contribute to threshold effects, i.e., discontinuities in the output variables. A computer code SCREEN has been developed for implementing the screening techniques. The efficiency has been demonstrated by several examples and applied to a fast reactor safety analysis code (Venus-II). However, the methods and the coding are general and not limited to such applications

  10. Energy Inputs Uncertainty: Total Amount, Distribution and Correlation Between Different Forms of Energy

    Science.gov (United States)

    Deng, Yue

    2014-01-01

    Describes solar energy inputs contributing to ionospheric and thermospheric weather processes, including total energy amounts, distributions and the correlation between particle precipitation and Poynting flux.

  11. New seismograph includes filters

    Energy Technology Data Exchange (ETDEWEB)

    1979-11-02

    The new Nimbus ES-1210 multichannel signal enhancement seismograph from EG and G geometrics has recently been redesigned to include multimode signal fillers on each amplifier. The ES-1210F is a shallow exploration seismograph for near subsurface exploration such as in depth-to-bedrock, geological hazard location, mineral exploration, and landslide investigations.

  12. Residual N effects from livestock manure inputs to soils

    NARCIS (Netherlands)

    Schroder, J.J.; Bechini, L.; Bittman, S.; Brito, M.P.; Delin, S.; Lalor, S.T.J.; Morvan, T.; Chambers, B.J.; Sakrabani, R.; Sørensen, P.B.

    2013-01-01

    Organic inputs including livestock manures provide nitrogen (N) to crops beyond the year of their application. This so-called residual N effect should be taken into account when making decisions on N rates for individual fields, but also when interpreting N response trials in preparation of

  13. On Babies and Bathwater: Input in Foreign Language Learning.

    Science.gov (United States)

    VanPatten, Bill

    1987-01-01

    A discussion of Krashen's monitor theory and its applications to foreign language teaching includes consideration of the very important role input plays in language development and examination of the relationship between the development of grammatical competence and traditional instruction in grammar. (CB)

  14. Residual N effects from livestock manure inputs to soils

    DEFF Research Database (Denmark)

    Schröder, Jaap; Bechini, Luca; Bittman, Shabtai

    Organic inputs including livestock manures provide nitrogen (N) to crops beyond the year of their application. This so-called residual N effect should be taken into account when making decisions on N rates for individual fields, but also when interpreting N response trials in preparation...

  15. Analytic device including nanostructures

    KAUST Repository

    Di Fabrizio, Enzo M.; Fratalocchi, Andrea; Totero Gongora, Juan Sebastian; Coluccio, Maria Laura; Candeloro, Patrizio; Cuda, Gianni

    2015-01-01

    A device for detecting an analyte in a sample comprising: an array including a plurality of pixels, each pixel including a nanochain comprising: a first nanostructure, a second nanostructure, and a third nanostructure, wherein size of the first nanostructure is larger than that of the second nanostructure, and size of the second nanostructure is larger than that of the third nanostructure, and wherein the first nanostructure, the second nanostructure, and the third nanostructure are positioned on a substrate such that when the nanochain is excited by an energy, an optical field between the second nanostructure and the third nanostructure is stronger than an optical field between the first nanostructure and the second nanostructure, wherein the array is configured to receive a sample; and a detector arranged to collect spectral data from a plurality of pixels of the array.

  16. Saskatchewan resources. [including uranium

    Energy Technology Data Exchange (ETDEWEB)

    1979-09-01

    The production of chemicals and minerals for the chemical industry in Saskatchewan are featured, with some discussion of resource taxation. The commodities mentioned include potash, fatty amines, uranium, heavy oil, sodium sulfate, chlorine, sodium hydroxide, sodium chlorate and bentonite. Following the successful outcome of the Cluff Lake inquiry, the uranium industry is booming. Some developments and production figures for Gulf Minerals, Amok, Cenex and Eldorado are mentioned.

  17. MARS code manual volume II: input requirements

    International Nuclear Information System (INIS)

    Chung, Bub Dong; Kim, Kyung Doo; Bae, Sung Won; Jeong, Jae Jun; Lee, Seung Wook; Hwang, Moon Kyu

    2010-02-01

    Korea Advanced Energy Research Institute (KAERI) conceived and started the development of MARS code with the main objective of producing a state-of-the-art realistic thermal hydraulic systems analysis code with multi-dimensional analysis capability. MARS achieves this objective by very tightly integrating the one dimensional RELAP5/MOD3 with the multi-dimensional COBRA-TF codes. The method of integration of the two codes is based on the dynamic link library techniques, and the system pressure equation matrices of both codes are implicitly integrated and solved simultaneously. In addition, the Equation-Of-State (EOS) for the light water was unified by replacing the EOS of COBRA-TF by that of the RELAP5. This input manual provides a complete list of input required to run MARS. The manual is divided largely into two parts, namely, the one-dimensional part and the multi-dimensional part. The inputs for auxiliary parts such as minor edit requests and graph formatting inputs are shared by the two parts and as such mixed input is possible. The overall structure of the input is modeled on the structure of the RELAP5 and as such the layout of the manual is very similar to that of the RELAP. This similitude to RELAP5 input is intentional as this input scheme will allow minimum modification between the inputs of RELAP5 and MARS3.1. MARS3.1 development team would like to express its appreciation to the RELAP5 Development Team and the USNRC for making this manual possible

  18. Optimal Input Design for Aircraft Parameter Estimation using Dynamic Programming Principles

    Science.gov (United States)

    Morelli, Eugene A.; Klein, Vladislav

    1990-01-01

    A new technique was developed for designing optimal flight test inputs for aircraft parameter estimation experiments. The principles of dynamic programming were used for the design in the time domain. This approach made it possible to include realistic practical constraints on the input and output variables. A description of the new approach is presented, followed by an example for a multiple input linear model describing the lateral dynamics of a fighter aircraft. The optimal input designs produced by the new technique demonstrated improved quality and expanded capability relative to the conventional multiple input design method.

  19. Total dose induced increase in input offset voltage in JFET input operational amplifiers

    International Nuclear Information System (INIS)

    Pease, R.L.; Krieg, J.; Gehlhausen, M.; Black, J.

    1999-01-01

    Four different types of commercial JFET input operational amplifiers were irradiated with ionizing radiation under a variety of test conditions. All experienced significant increases in input offset voltage (Vos). Microprobe measurement of the electrical characteristics of the de-coupled input JFETs demonstrates that the increase in Vos is a result of the mismatch of the degraded JFETs. (authors)

  20. Discrete Input Signaling for MISO Visible Light Communication Channels

    KAUST Repository

    Arfaoui, Mohamed Amine

    2017-05-12

    In this paper, we study the achievable secrecy rate of visible light communication (VLC) links for discrete input distributions. We consider single user single eavesdropper multiple-input single-output (MISO) links. In addition, both beamforming and robust beamforming are considered. In the former case, the location of the eavesdropper is assumed to be known, whereas in the latter case, the location of the eavesdropper is unknown. We compare the obtained results with those achieved by some continuous distributions including the truncated generalized normal (TGN) distribution and the uniform distribution. We numerically show that the secrecy rate achieved by the discrete input distribution with a finite support is significantly improved as compared to those achieved by the TGN and the uniform distributions.

  1. CBM first-level event selector input interface

    Energy Technology Data Exchange (ETDEWEB)

    Hutter, Dirk [Frankfurt Institute for Advanced Studies, Goethe University, Frankfurt (Germany); Collaboration: CBM-Collaboration

    2016-07-01

    The CBM First-level Event Selector (FLES) is the central event selection system of the upcoming CBM experiment at FAIR. Designed as a high-performance computing cluster, its task is an online analysis of the physics data at a total data rate exceeding 1 TByte/s. To allow efficient event selection, the FLES performs timeslice building, which combines the data from all given input links to self-contained, overlapping processing intervals and distributes them to compute nodes. Partitioning the input data streams into specialized containers allows to perform this task very efficiently. The FLES Input Interface defines the linkage between FEE and FLES data transport framework. Utilizing a custom FPGA board, it receives data via optical links, prepares them for subsequent timeslice building, and transfers the data via DMA to the PC's memory. An accompanying HDL module implements the front-end logic interface and FLES link protocol in the front-end FPGAs. Prototypes of all Input Interface components have been implemented and integrated into the FLES framework. In contrast to earlier prototypes, which included components to work without a FPGA layer between FLES and FEE, the structure matches the foreseen final setup. This allows the implementation and evaluation of the final CBM read-out chain. An overview of the FLES Input Interface as well as studies on system integration and system start-up are presented.

  2. Reentry response of the lightweight radioisotope heater unit resulting from a Cassini Venus-Venus-Earth-Jupiter gravity assist maneuver accident

    International Nuclear Information System (INIS)

    1996-12-01

    Reentry analyses consisting of ablation response, thermal response and thermal stress response have been conducted on the Lightweight Radioisotope Heater Unit (LWRHU) for Cassini/Venus-Venus-Earth-Jupiter-Gravity-Assist (VVEJGA) reentry conditions. Sequential ablation analyses of the LWRHU aeroshell, and the fuel pellet have been conducted in reentry regimes where the aeroshell has been deemed to fail. The failure criterion for ablation is generally assumed to be recession corresponding to 75% and 100% of the wall thickness. The 75% recession failure criteria allows for uncertainties that result mainly because of the high energies involved in the VVEJGA reentries compared to orbital decay reentries. Risk evaluations should consider the fact that for shallow flight paths the unit may disassemble at high-altitude as a result of ablation or may remain intact with a clad that had been molten. Within the limitations of the methodologies and assumptions of the analyses, the results indicate that: (1) For a side-on stable LWRHU reentry, aeroshell ablation failures occur for all reentry angles. (2)For a side-on spinning LWRHU reentry, aeroshell ablation failures are minimal. (3) For the tumbling LWRHU reentry, the aeroshell survives for most angles. (4) For the thermostructural analyses, using both a 1% and 5% allowable strain, all reentry angles and orientations examined resulted in small localized failures, but aeroshell breach is not predicted for any case. The analyses included in this report concentrate on VVEJGA reentry scenarios. Analyses reported previously have demonstrated that the LWRHU has adequate design margin to survive reentry from orbital decay scenarios and most injection scenarios at speeds up to escape speeds. The exception is a narrow range of flight path angles that produce multiple skip trajectories which may have excessive ablation

  3. A new interpretation and validation of variance based importance measures for models with correlated inputs

    Science.gov (United States)

    Hao, Wenrui; Lu, Zhenzhou; Li, Luyi

    2013-05-01

    In order to explore the contributions by correlated input variables to the variance of the output, a novel interpretation framework of importance measure indices is proposed for a model with correlated inputs, which includes the indices of the total correlated contribution and the total uncorrelated contribution. The proposed indices accurately describe the connotations of the contributions by the correlated input to the variance of output, and they can be viewed as the complement and correction of the interpretation about the contributions by the correlated inputs presented in "Estimation of global sensitivity indices for models with dependent variables, Computer Physics Communications, 183 (2012) 937-946". Both of them contain the independent contribution by an individual input. Taking the general form of quadratic polynomial as an illustration, the total correlated contribution and the independent contribution by an individual input are derived analytically, from which the components and their origins of both contributions of correlated input can be clarified without any ambiguity. In the special case that no square term is included in the quadratic polynomial model, the total correlated contribution by the input can be further decomposed into the variance contribution related to the correlation of the input with other inputs and the independent contribution by the input itself, and the total uncorrelated contribution can be further decomposed into the independent part by interaction between the input and others and the independent part by the input itself. Numerical examples are employed and their results demonstrate that the derived analytical expressions of the variance-based importance measure are correct, and the clarification of the correlated input contribution to model output by the analytical derivation is very important for expanding the theory and solutions of uncorrelated input to those of the correlated one.

  4. Being Included and Excluded

    DEFF Research Database (Denmark)

    Korzenevica, Marina

    2016-01-01

    Following the civil war of 1996–2006, there was a dramatic increase in the labor mobility of young men and the inclusion of young women in formal education, which led to the transformation of the political landscape of rural Nepal. Mobility and schooling represent a level of prestige that rural...... politics. It analyzes how formal education and mobility either challenge or reinforce traditional gendered norms which dictate a lowly position for young married women in the household and their absence from community politics. The article concludes that women are simultaneously excluded and included from...... community politics. On the one hand, their mobility and decision-making powers decrease with the increase in the labor mobility of men and their newly gained education is politically devalued when compared to the informal education that men gain through mobility, but on the other hand, schooling strengthens...

  5. CONSTRAINING SATURN'S CORE PROPERTIES BY A MEASUREMENT OF ITS MOMENT OF INERTIA-IMPLICATIONS TO THE CASSINI SOLSTICE MISSION

    International Nuclear Information System (INIS)

    Helled, R.

    2011-01-01

    Knowledge of Saturn's axial moment of inertia can provide valuable information on its internal structure. We suggest that Saturn's angular momentum may be determined by the Solstice Mission (Cassini XXM) by measuring Saturn's pole precession rate and the Lense-Thirring acceleration on the spacecraft, and therefore put constraints on Saturn's moment of inertia. It is shown that Saturn's moment of inertia can change up to ∼2% due to different core properties. However, a determination of Saturn's rotation rate is required to constrain its axial moment of inertia. A change of about seven minutes in rotation period leads to a similar uncertainty in the moment of inertia value as different core properties (mass, radius). A determination of Saturn's angular momentum and rotation period by the Solstice Mission could reveal important information on Saturn's internal structure, in particular, its core properties.

  6. Input-output rearrangement of isolated converters

    DEFF Research Database (Denmark)

    Madsen, Mickey Pierre; Kovacevic, Milovan; Mønster, Jakob Døllner

    2015-01-01

    This paper presents a new way of rearranging the input and output of isolated converters. The new arrangement posses several advantages, as increased voltage range, higher power handling capabilities, reduced voltage stress and improved efficiency, for applications where galvanic isolation...

  7. Multiple Input - Multiple Output (MIMO) SAR

    Data.gov (United States)

    National Aeronautics and Space Administration — This effort will research and implement advanced Multiple-Input Multiple-Output (MIMO) Synthetic Aperture Radar (SAR) techniques which have the potential to improve...

  8. Outsourcing, public Input provision and policy cooperation

    OpenAIRE

    Aronsson, Thomas; Koskela, Erkki

    2009-01-01

    This paper concerns public input provision as an instrument for redistribution under international outsourcing by using a model-economy comprising two countries, North and South, where firms in the North may outsource part of their low-skilled labor intensive production to the South. We consider two interrelated issues: (i) the incentives for each country to modify the provision of public input goods in response to international outsourcing, and (ii) whether international outsourcing justifie...

  9. Towards an Understanding of Radiative Factors on Planetary Rings: a Perspective from Cassini CIRS Observations at Saturn Equinox

    Science.gov (United States)

    Brooks, Shawn M.; Spilker, L.; Edgington, S. G.; Déau, E.; Pilorz, S. H.

    2012-10-01

    Since arriving at Saturn in 2004, Cassini's Composite Infrared Spectrometer has recorded tens of millions of spectra of Saturn’s rings (personal communication, M. Segura). CIRS records far infrared radiation (16.7-1000 microns) at focal plane 1 (FP1). Thermal emission from Saturn’s rings peaks at FP1 wavelengths. CIRS spectra are well characterized as blackbody emission at an effective temperature Te, multiplied by a scalar factor related to ring emissivity (Spilker et al. [2005, 2006]). CIRS can therefore characterize the rings' temperature and study the thermal environment to which the ring particles are subject. We focus on CIRS data from the 2009 Saturnian equinox. As the Sun's disk crossed the ring plane, CIRS obtained several radial scans of the rings at a variety of phase angles, local hour angles and distances. With the Sun's rays striking the rings at an incidence angle of zero, solar heating is virtually absent, and thermal radiation from Saturn and sunlight reflected by Saturn dominate the thermal environment. These observations present an apparent paradox. Equinox data show that the flux of thermal energy radiated by the rings is roughly equivalent to or even exceeds the energy incident upon them as prescribed by thermal models (Froidevaux [1981], Ferrari and Leyrat [2006], Morishima et al. [2009, 2010]). This apparent energy excess is largest in the C ring and Cassini Division. Conservation principles suggest that models underestimate heating of the rings, as it is clearly unphysical for the rings to radiate significantly more energy than is incident upon them. In this presentation, we will attempt to resolve this paradox and determine what this can teach us about Saturn's rings. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Copyright 2012 California Institute of Technology. Government sponsorship acknowledged.

  10. Is the Recently Proposed Mars-Sized Perturber at 65–80 AU Ruled Out by the Cassini Ranging Data?

    Energy Technology Data Exchange (ETDEWEB)

    Iorio, Lorenzo, E-mail: lorenzo.iorio@libero.it [Ministero dell' Istruzione, dell' Università e della Ricerca, Rome (Italy)

    2017-10-26

    Recently, the existence of a pointlike pertuber PX with 1 m{sub ♂} ≲ m{sub X} ≲ 2.4 m{sub ⊕} (the symbol “♂” denotes Mars) supposedly moving at 65–80 AU along a moderately inclined orbit has been hypothesized in order to explain certain features of the midplane of the Kuiper Belt Objects (KBOs). We preliminarily selected two possible scenarios for such a PX, and numerically simulated its effect on the Earth-Saturn range ρ(t) by varying some of its orbital parameters over a certain time span; then, we compared our results with some existing actual range residuals. By assuming m{sub X} = 1 m{sub ♂} and a circular orbit, such a putative new member of our Solar System would nominally perturb ρ(t) by a few km over Δt = 12 year (2004 − 2016). However, the Cassini spacecraft accurately measured ρ(t) to the level of σ{sub ρ} ≃ 100 m. Nonetheless, such a scenario should not be considered as necessarily ruled out since the Cassini data were reduced so far without explicitly modeling any PX. Indeed, a NASA JPL team recently demonstrated that an extra-signature as large as 4 km affecting the Kronian range would be almost completely absorbed in fitting incomplete dynamical models, i.e., without PX itself, to such simulated data, thus not showing up in the standard post-fit range residuals. Larger anomalous signatures would instead occur for m{sub X} > 1 m{sub ♂}. Their nominal amplitude could be as large as 50 − 150 km for m{sub X} = 2.4 m{sub ⊕}, thus making less plausible their existence.

  11. Is the Recently Proposed Mars-Sized Perturber at 65–80 AU Ruled Out by the Cassini Ranging Data?

    Directory of Open Access Journals (Sweden)

    Lorenzo Iorio

    2017-10-01

    Full Text Available Recently, the existence of a pointlike pertuber PX with 1 m♂ ≲ mX ≲ 2.4 m⊕ (the symbol “♂” denotes Mars supposedly moving at 65–80 AU along a moderately inclined orbit has been hypothesized in order to explain certain features of the midplane of the Kuiper Belt Objects (KBOs. We preliminarily selected two possible scenarios for such a PX, and numerically simulated its effect on the Earth-Saturn range ρ(t by varying some of its orbital parameters over a certain time span; then, we compared our results with some existing actual range residuals. By assuming mX = 1 m♂ and a circular orbit, such a putative new member of our Solar System would nominally perturb ρ(t by a few km over Δt = 12 year (2004 − 2016. However, the Cassini spacecraft accurately measured ρ(t to the level of σρ ≃ 100 m. Nonetheless, such a scenario should not be considered as necessarily ruled out since the Cassini data were reduced so far without explicitly modeling any PX. Indeed, a NASA JPL team recently demonstrated that an extra-signature as large as 4 km affecting the Kronian range would be almost completely absorbed in fitting incomplete dynamical models, i.e., without PX itself, to such simulated data, thus not showing up in the standard post-fit range residuals. Larger anomalous signatures would instead occur for mX > 1 m♂. Their nominal amplitude could be as large as 50 − 150 km for mX = 2.4 m⊕, thus making less plausible their existence.

  12. Nitrogen input inventory in the Nooksack-Abbotsford-Sumas ...

    Science.gov (United States)

    Nitrogen (N) is an essential biological element, so optimizing N use for food production while minimizing the release of N and co-pollutants to the environment is an important challenge. The Nooksack-Abbotsford-Sumas Transboundary (NAS) Region, spanning a portion of the western interface of British Columbia, Washington state, and the Lummi Nation and the Nooksack Tribe, supports agriculture, fisheries, diverse wildlife, and vibrant urban areas. Groundwater nitrate contamination affects thousands of households in this region. Fisheries and air quality are also affected including periodic closures of shellfish harvest. To reduce the release of N to the environment, successful approaches are needed that partner all stakeholders with appropriate institutions to integrate science, outreach and management efforts. Our goal is to determine the distribution and quantities of N inventories of the watershed. This work synthesizes publicly available data on N sources including deposition, sewage and septic inputs, fertilizer and manure applications, marine-derived N from salmon, and more. The information on cross-boundary N inputs to the landscape will be coupled with stream monitoring data and existing knowledge about N inputs and exports from the watershed to estimate the N residual and inform N management in the search for the environmentally and economically viable and effective solutions. We will estimate the N inputs into the NAS region and transfers within

  13. A guidance on MELCOR input preparation : An input deck for Ul-Chin 3 and 4 Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Song Won

    1997-02-01

    The objective of this study is to enhance the capability of assessing the severe accident sequence analyses and the containment behavior using MELCOR computer code and to provide the guideline of its efficient use. This report shows the method of the input deck preparation as well as the assessment strategy for the MELCOR code. MELCOR code is a fully integrated, engineering-level computer code that models the progression of severe accidents in light water reactor nuclear power plants. The code is being developed at Sandia National Laboratories for the U.S. NRC as a second generation plant risk assessment tool and the successor to the source term code package. The accident sequence of the reference input deck prepared in this study for Ulchin unit 3 and 4 nuclear power plants, is the total loss of feedwater (TLOFW) without any success of safety systems, which is similar to station blackout (TLMB). It is very useful to simulate a well-known sequence through the best estimated code or experiment, because the results of the simulation before core melt can be compared with the FSAR, but no data is available after core melt. The precalculation for the TLOFW using the reference input deck is performed successfully as expected. The other sequences will be carried out with minor changes in the reference input. This input deck will be improved continually by the adding of the safety systems not included in this input deck, and also through the sensitivity and uncertainty analyses. (author). 19 refs., 10 tabs., 55 figs.

  14. A guidance on MELCOR input preparation : An input deck for Ul-Chin 3 and 4 Nuclear Power Plant

    International Nuclear Information System (INIS)

    Cho, Song Won.

    1997-02-01

    The objective of this study is to enhance the capability of assessing the severe accident sequence analyses and the containment behavior using MELCOR computer code and to provide the guideline of its efficient use. This report shows the method of the input deck preparation as well as the assessment strategy for the MELCOR code. MELCOR code is a fully integrated, engineering-level computer code that models the progression of severe accidents in light water reactor nuclear power plants. The code is being developed at Sandia National Laboratories for the U.S. NRC as a second generation plant risk assessment tool and the successor to the source term code package. The accident sequence of the reference input deck prepared in this study for Ulchin unit 3 and 4 nuclear power plants, is the total loss of feedwater (TLOFW) without any success of safety systems, which is similar to station blackout (TLMB). It is very useful to simulate a well-known sequence through the best estimated code or experiment, because the results of the simulation before core melt can be compared with the FSAR, but no data is available after core melt. The precalculation for the TLOFW using the reference input deck is performed successfully as expected. The other sequences will be carried out with minor changes in the reference input. This input deck will be improved continually by the adding of the safety systems not included in this input deck, and also through the sensitivity and uncertainty analyses. (author). 19 refs., 10 tabs., 55 figs

  15. Computer Generated Inputs for NMIS Processor Verification

    International Nuclear Information System (INIS)

    J. A. Mullens; J. E. Breeding; J. A. McEvers; R. W. Wysor; L. G. Chiang; J. R. Lenarduzzi; J. T. Mihalczo; J. K. Mattingly

    2001-01-01

    Proper operation of the Nuclear Identification Materials System (NMIS) processor can be verified using computer-generated inputs [BIST (Built-In-Self-Test)] at the digital inputs. Preselected sequences of input pulses to all channels with known correlation functions are compared to the output of the processor. These types of verifications have been utilized in NMIS type correlation processors at the Oak Ridge National Laboratory since 1984. The use of this test confirmed a malfunction in a NMIS processor at the All-Russian Scientific Research Institute of Experimental Physics (VNIIEF) in 1998. The NMIS processor boards were returned to the U.S. for repair and subsequently used in NMIS passive and active measurements with Pu at VNIIEF in 1999

  16. Shaped input distributions for structural damage localization

    DEFF Research Database (Denmark)

    Ulriksen, Martin Dalgaard; Bernal, Dionisio; Damkilde, Lars

    2018-01-01

    localization method is cast that operates on the premise of shaping inputs—whose spatial distribution is fixed—by use of a model, such that these inputs, in one structural subdomain at a time, suppress certain steady-state vibration quantities (depending on the type of damage one seeks to interrogate for......). Accordingly, damage is localized when the vibration signature induced by the shaped inputs in the damaged state corresponds to that in the reference state, hereby implying that the approach does not point directly to damage. Instead, it operates with interrogation based on postulated damage patterns...

  17. Nuclear reaction inputs based on effective interactions

    Energy Technology Data Exchange (ETDEWEB)

    Hilaire, S.; Peru, S.; Dubray, N.; Dupuis, M.; Bauge, E. [CEA, DAM, DIF, Arpajon (France); Goriely, S. [Universite Libre de Bruxelles, Institut d' Astronomie et d' Astrophysique, CP-226, Brussels (Belgium)

    2016-11-15

    Extensive nuclear structure studies have been performed for decades using effective interactions as sole input. They have shown a remarkable ability to describe rather accurately many types of nuclear properties. In the early 2000 s, a major effort has been engaged to produce nuclear reaction input data out of the Gogny interaction, in order to challenge its quality also with respect to nuclear reaction observables. The status of this project, well advanced today thanks to the use of modern computers as well as modern nuclear reaction codes, is reviewed and future developments are discussed. (orig.)

  18. Simulation of a Multidimensional Input Quantum Perceptron

    Science.gov (United States)

    Yamamoto, Alexandre Y.; Sundqvist, Kyle M.; Li, Peng; Harris, H. Rusty

    2018-06-01

    In this work, we demonstrate the improved data separation capabilities of the Multidimensional Input Quantum Perceptron (MDIQP), a fundamental cell for the construction of more complex Quantum Artificial Neural Networks (QANNs). This is done by using input controlled alterations of ancillary qubits in combination with phase estimation and learning algorithms. The MDIQP is capable of processing quantum information and classifying multidimensional data that may not be linearly separable, extending the capabilities of the classical perceptron. With this powerful component, we get much closer to the achievement of a feedforward multilayer QANN, which would be able to represent and classify arbitrary sets of data (both quantum and classical).

  19. Load Estimation from Natural input Modal Analysis

    DEFF Research Database (Denmark)

    Aenlle, Manuel López; Brincker, Rune; Canteli, Alfonso Fernández

    2005-01-01

    One application of Natural Input Modal Analysis consists in estimating the unknown load acting on structures such as wind loads, wave loads, traffic loads, etc. In this paper, a procedure to determine loading from a truncated modal model, as well as the results of an experimental testing programme...... estimation. In the experimental program a small structure subjected to vibration was used to estimate the loading from the measurements and the experimental modal space. The modal parameters were estimated by Natural Input Modal Analysis and the scaling factors of the mode shapes obtained by the mass change...

  20. High Input Voltage, Silicon Carbide Power Processing Unit Performance Demonstration

    Science.gov (United States)

    Bozak, Karin E.; Pinero, Luis R.; Scheidegger, Robert J.; Aulisio, Michael V.; Gonzalez, Marcelo C.; Birchenough, Arthur G.

    2015-01-01

    A silicon carbide brassboard power processing unit has been developed by the NASA Glenn Research Center in Cleveland, Ohio. The power processing unit operates from two sources: a nominal 300 Volt high voltage input bus and a nominal 28 Volt low voltage input bus. The design of the power processing unit includes four low voltage, low power auxiliary supplies, and two parallel 7.5 kilowatt (kW) discharge power supplies that are capable of providing up to 15 kilowatts of total power at 300 to 500 Volts (V) to the thruster. Additionally, the unit contains a housekeeping supply, high voltage input filter, low voltage input filter, and master control board, such that the complete brassboard unit is capable of operating a 12.5 kilowatt Hall effect thruster. The performance of the unit was characterized under both ambient and thermal vacuum test conditions, and the results demonstrate exceptional performance with full power efficiencies exceeding 97%. The unit was also tested with a 12.5kW Hall effect thruster to verify compatibility and output filter specifications. With space-qualified silicon carbide or similar high voltage, high efficiency power devices, this would provide a design solution to address the need for high power electric propulsion systems.

  1. The effect of cutting conditions on power inputs when machining

    Science.gov (United States)

    Petrushin, S. I.; Gruby, S. V.; Nosirsoda, Sh C.

    2016-08-01

    Any technological process involving modification of material properties or product form necessitates consumption of a certain power amount. When developing new technologies one should take into account the benefits of their implementation vs. arising power inputs. It is revealed that procedures of edge cutting machining are the most energy-efficient amongst the present day forming procedures such as physical and technical methods including electrochemical, electroerosion, ultrasound, and laser processing, rapid prototyping technologies etc, such as physical and technical methods including electrochemical, electroerosion, ultrasound, and laser processing, rapid prototyping technologies etc. An expanded formula for calculation of power inputs is deduced, which takes into consideration the mode of cutting together with the tip radius, the form of the replaceable multifaceted insert and its wear. Having taken as an example cutting of graphite iron by the assembled cutting tools with replaceable multifaceted inserts the authors point at better power efficiency of high feeding cutting in comparison with high-speed cutting.

  2. Cassini Spacecraft Uncertainty Analysis Data and Methodology Review and Update/Volume 1: Updated Parameter Uncertainty Models for the Consequence Analysis

    Energy Technology Data Exchange (ETDEWEB)

    WHEELER, TIMOTHY A.; WYSS, GREGORY D.; HARPER, FREDERICK T.

    2000-11-01

    Uncertainty distributions for specific parameters of the Cassini General Purpose Heat Source Radioisotope Thermoelectric Generator (GPHS-RTG) Final Safety Analysis Report consequence risk analysis were revised and updated. The revisions and updates were done for all consequence parameters for which relevant information exists from the joint project on Probabilistic Accident Consequence Uncertainty Analysis by the United States Nuclear Regulatory Commission and the Commission of European Communities.

  3. Analysis of Titan's neutral upper atmosphere from Cassini Ion Neutral Mass Spectrometer measurements in the Closed Source Neutral mode

    Science.gov (United States)

    Cui, Jun

    In this thesis I present an in-depth study of the distribution of various neutral species in Titan's upper atmosphere, at altitudes between 950 and 1,500 km for abundant species (N 2 , CH 4 as well as their isotopes) and between 950 and 1,200 km for most minor species. However, the study of the H 2 distribution on Titan is extended to an altitude as high as 6,000 km in the exosphere. The analysis is based on a large sample of Cassini/INMS (Ion Neutral Mass Spectrometer) measurements in the CSN (Closed Source Neutral) mode, obtained during 15 close flybys of Titan. The densities of abundant species including N 2 , CH 4 and H 2 are determined directly from their main channels. However, to untangle the overlapping cracking patterns of minor species, the technique of Singular Value Decomposition (SVD) is used to determine simultaneously the densities of various hydrocarbons, nitriles and oxygen compounds. All minor species except for 40 Ar present density enhancements measured during the outbound legs. This can be interpreted as a result of wall effects, which could be either adsorption/desorption or heterogeneous surface chemistry on the chamber walls. In the thesis, I use a simple model to describe the observed time behavior of minor species. Results on their atmospheric abundances are provided both in terms of direct inbound measurements assuming ram pressure enhancement and values corrected for wall adsorption/desorption. Among all minor species of photochemical interest, the INMS data provide direct observational evidences for C 2 H 2 , C 2 H 4 , C 2 H 6 , CH 3 C 2 H, C 4 H 2 , C 6 H 6 , HC 3 N and C 2 N 2 in Titan's upper atmosphere. Upper limits are put for other minor species. The globally averaged distribution of N 2 , CH 4 and H 2 are each modeled with the diffusion approximation. The N 2 profile suggests an average thermospheric temperature of 154 K. The CH 4 and H 2 distribution constrains their fluxes to be 3.0 × 10 9 cm -2 s -1 and 1.3 × 10 10 cm -2 s

  4. Controlling uncertain neutral dynamic systems with delay in control input

    International Nuclear Information System (INIS)

    Park, Ju H.; Kwon, O.

    2005-01-01

    This article gives a novel criterion for the asymptotic stabilization of the zero solutions of a class of neutral systems with delays in control input. By constructing Lyapunov functionals, we have obtained the criterion which is expressed in terms of matrix inequalities. The solutions of the inequalities can be easily solved by efficient convex optimization algorithms. A numerical example is included to illustrate the design procedure of the proposed method

  5. The use of synthetic input sequences in time series modeling

    International Nuclear Information System (INIS)

    Oliveira, Dair Jose de; Letellier, Christophe; Gomes, Murilo E.D.; Aguirre, Luis A.

    2008-01-01

    In many situations time series models obtained from noise-like data settle to trivial solutions under iteration. This Letter proposes a way of producing a synthetic (dummy) input, that is included to prevent the model from settling down to a trivial solution, while maintaining features of the original signal. Simulated benchmark models and a real time series of RR intervals from an ECG are used to illustrate the procedure

  6. 7 CFR 3430.907 - Stakeholder input.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Stakeholder input. 3430.907 Section 3430.907 Agriculture Regulations of the Department of Agriculture (Continued) COOPERATIVE STATE RESEARCH, EDUCATION, AND EXTENSION SERVICE, DEPARTMENT OF AGRICULTURE COMPETITIVE AND NONCOMPETITIVE NON-FORMULA FEDERAL...

  7. Input and Intake in Language Acquisition

    Science.gov (United States)

    Gagliardi, Ann C.

    2012-01-01

    This dissertation presents an approach for a productive way forward in the study of language acquisition, sealing the rift between claims of an innate linguistic hypothesis space and powerful domain general statistical inference. This approach breaks language acquisition into its component parts, distinguishing the input in the environment from…

  8. A summary of WIMSD4 input option

    International Nuclear Information System (INIS)

    Halsall, M.J.

    1980-07-01

    A description is given of all the available input data options in the ICL 4/70 and IBM 370 versions of WIMSD4, with little more than a reference where there is already adequate documentation but with rather more detail where no such documentation exists. (author)

  9. Representations of space based on haptic input

    NARCIS (Netherlands)

    Zuidhoek, S.

    2005-01-01

    The present thesis focused on the representations of grasping space based on haptic input. We aimed at identifying their characteristics, and the underlying neurocognitive processes and mechanisms. To this end, we studied the systematic distortions in performance on several orientation perception

  10. Hydrogen Generation Rate Model Calculation Input Data

    International Nuclear Information System (INIS)

    KUFAHL, M.A.

    2000-01-01

    This report documents the procedures and techniques utilized in the collection and analysis of analyte input data values in support of the flammable gas hazard safety analyses. This document represents the analyses of data current at the time of its writing and does not account for data available since then

  11. Leaders’ receptivity to subordinates’ creative input: the role of achievement goals and composition of creative input

    NARCIS (Netherlands)

    Sijbom, R.B.L.; Janssen, O.; van Yperen, N.W.

    2015-01-01

    We identified leaders’ achievement goals and composition of creative input as important factors that can clarify when and why leaders are receptive to, and supportive of, subordinates’ creative input. As hypothesized, in two experimental studies, we found that relative to mastery goal leaders,

  12. Integrate-and-fire vs Poisson models of LGN input to V1 cortex: noisier inputs reduce orientation selectivity.

    Science.gov (United States)

    Lin, I-Chun; Xing, Dajun; Shapley, Robert

    2012-12-01

    One of the reasons the visual cortex has attracted the interest of computational neuroscience is that it has well-defined inputs. The lateral geniculate nucleus (LGN) of the thalamus is the source of visual signals to the primary visual cortex (V1). Most large-scale cortical network models approximate the spike trains of LGN neurons as simple Poisson point processes. However, many studies have shown that neurons in the early visual pathway are capable of spiking with high temporal precision and their discharges are not Poisson-like. To gain an understanding of how response variability in the LGN influences the behavior of V1, we study response properties of model V1 neurons that receive purely feedforward inputs from LGN cells modeled either as noisy leaky integrate-and-fire (NLIF) neurons or as inhomogeneous Poisson processes. We first demonstrate that the NLIF model is capable of reproducing many experimentally observed statistical properties of LGN neurons. Then we show that a V1 model in which the LGN input to a V1 neuron is modeled as a group of NLIF neurons produces higher orientation selectivity than the one with Poisson LGN input. The second result implies that statistical characteristics of LGN spike trains are important for V1's function. We conclude that physiologically motivated models of V1 need to include more realistic LGN spike trains that are less noisy than inhomogeneous Poisson processes.

  13. Cassini UVIS solar occultations by Saturn's F ring and the detection of collision-produced micron-sized dust

    Science.gov (United States)

    Becker, Tracy M.; Colwell, Joshua E.; Esposito, Larry W.; Attree, Nicholas O.; Murray, Carl D.

    2018-05-01

    We present an analysis of eleven solar occultations by Saturn's F ring observed by the Ultraviolet Imaging Spectrograph (UVIS) on the Cassini spacecraft. In four of the solar occultations we detect an unambiguous signal from diffracted sunlight that adds to the direct solar signal just before or after the occultations occur. The strongest detection was a 10% increase over the direct signal that was enabled by the accidental misalignment of the instrument's pointing. We compare the UVIS data with images of the F ring obtained by the Cassini Imaging Science Subsystem (ISS) and find that in each instance of an unambiguous diffraction signature in the UVIS data, the ISS data shows that there was a recent disturbance in that region of the F ring. Similarly, the ISS images show a quiescent region of the F ring for all solar occultations in which no diffraction signature was detected. We therefore conclude that collisions in the F ring produce a population of small ring particles that can produce a detectable diffraction signal immediately interior or exterior to the F ring. The clearest example of this connection comes from the strong detection of diffracted light in the 2007 solar occultation, when the portion of the F ring that occulted the Sun had suffered a large collisional event, likely with S/2004 S 6, several months prior. This collision was observed in a series of ISS images (Murray et al., 2008). Our spectral analysis of the data shows no significant spectral features in the F ring, indicating that the particles must be at least 0.2 μm in radius. We apply a forward model of the solar occultations, accounting for the effects of diffracted light and the attenuated direct solar signal, to model the observed solar occultation light curves. These models constrain the optical depth, radial width, and particle size distribution of the F ring. We find that when the diffraction signature is present, we can best reproduce the occultation data using a particle population

  14. IM-135-562-00 IDIM instruction manual for the isolated digital input module for SLC

    International Nuclear Information System (INIS)

    Kieffer, J.

    1983-01-01

    This unit is designed as a general purpose digital input module. Each input is opto-isolated, and is designed to operate over a wide range of positive input voltages. The unit is nonlatching, each CAMAC Read of the unit presenting the data as seen at the inputs at the time of the Read command. The manual includes the following sections: specifications; front panel, lights and connectors; reference list; functional description; 82S100 logic equations; test and checkout procedures; appendix A, SLAC 82S100 programming data; and appendix B, JXK-FORTH 135-562 program listing

  15. An improved robust model predictive control for linear parameter-varying input-output models

    NARCIS (Netherlands)

    Abbas, H.S.; Hanema, J.; Tóth, R.; Mohammadpour, J.; Meskin, N.

    2018-01-01

    This paper describes a new robust model predictive control (MPC) scheme to control the discrete-time linear parameter-varying input-output models subject to input and output constraints. Closed-loop asymptotic stability is guaranteed by including a quadratic terminal cost and an ellipsoidal terminal

  16. Effects of Textual Enhancement and Input Enrichment on L2 Development

    Science.gov (United States)

    Rassaei, Ehsan

    2015-01-01

    Research on second language (L2) acquisition has recently sought to include formal instruction into second and foreign language classrooms in a more unobtrusive and implicit manner. Textual enhancement and input enrichment are two techniques which are aimed at drawing learners' attention to specific linguistic features in input and at the same…

  17. Opening the "Black Box" of efficiency measurement : Input allocation in multi-output settings

    NARCIS (Netherlands)

    Dierynck, B.; Cherchye, L.J.H.; Sabbe, J.; Roodhooft, F.; de Rock, B.

    2013-01-01

    We develop a new data envelopment analysis (DEA)-based methodology for measuring the efficiency of decision-making units (DMUs) characterized by multiple inputs and multiple outputs. The distinguishing feature of our method is that it explicitly includes information about output-specific inputs and

  18. An input shaping controller enabling cranes to move without sway

    International Nuclear Information System (INIS)

    Singer, N.; Singhose, W.; Kriikku, E.

    1997-01-01

    A gantry crane at the Savannah River Technology Center was retrofitted with an Input Shaping controller. The controller intercepts the operator's pendant commands and modifies them in real time so that the crane is moved without residual sway in the suspended load. Mechanical components on the crane were modified to make the crane suitable for the anti-sway algorithm. This paper will describe the required mechanical modifications to the crane, as well as, a new form of Input Shaping that was developed for use on the crane. Experimental results are presented which demonstrate the effectiveness of the new process. Several practical considerations will be discussed including a novel (patent pending) approach for making small, accurate moves without residual oscillations

  19. Development and operation of K-URT data input system

    International Nuclear Information System (INIS)

    Kim, Yun Jae; Myoung, Noh Hoon; Kim, Jong Hyun; Han, Jae Jun

    2010-05-01

    Activities for TSPA(Total System Performance Assessment) on the permanent disposal of high level radioactive waste includes production of input data, safety assessment using input data, license procedure and others. These activities are performed in 5 steps as follows; (1) Adequate planning, (2) Controlled execution, (3) Complete documentation, (4) Thorough review, (5) Independent oversight. For the confidence building, it is very important to record and manage the materials obtained from research works in transparency. For the documentation of disposal research work from planning stage to data management stage, KAERI developed CYPRUS named CYBER R and D Platform for Radwaste Disposal in Underground System with a QA(Quality Assurance) System. In CYPRUS, QA system makes effects on other functions such as data management, project management and others. This report analyzes the structure of CYPRUS and proposes to accumulate qualified data, to provide a convenient application and to promote access and use of CYPRUS for a future-oriented system

  20. Volume measurement study for large scale input accountancy tank

    International Nuclear Information System (INIS)

    Uchikoshi, Seiji; Watanabe, Yuichi; Tsujino, Takeshi

    1999-01-01

    Large Scale Tank Calibration (LASTAC) facility, including an experimental tank which has the same volume and structure as the input accountancy tank of Rokkasho Reprocessing Plant (RRP) was constructed in Nuclear Material Control Center of Japan. Demonstration experiments have been carried out to evaluate a precision of solution volume measurement and to establish the procedure of highly accurate pressure measurement for a large scale tank with dip-tube bubbler probe system to be applied to the input accountancy tank of RRP. Solution volume in a tank is determined from substitution the solution level for the calibration function obtained in advance, which express a relation between the solution level and its volume in the tank. Therefore, precise solution volume measurement needs a precise calibration function that is determined carefully. The LASTAC calibration experiments using pure water showed good result in reproducibility. (J.P.N.)

  1. Generic MIDI devices as new input for specialized software

    Directory of Open Access Journals (Sweden)

    Marcin Badurowicz

    2016-12-01

    Full Text Available There are plenty of sublime devices, including input devices, for all kinds of specialists working with computers available on the market. Furthermore, the more specific solutions are needed, the more expensive and complicated they are. At the time when many people prefer to try as many things as possible before selecting the specific learning paths, both high price and high entry threshold, can appear as blockers. In the paper, there are selected some hardware and software solutions for facilitating the work of the professionals , who expect more analog-like interfaces and more natural ways to control computers presented. Additionally, the authors describe original software and hardware solution that allows the use of wide range MIDI devices as custom input devices. The concept of the software made is being presented, as well as some results of initial interaction of different kind of professionals and the proposed solution software and hardware.

  2. Do efficiency scores depend on input mix?

    DEFF Research Database (Denmark)

    Asmild, Mette; Hougaard, Jens Leth; Kronborg, Dorte

    2013-01-01

    In this paper we examine the possibility of using the standard Kruskal-Wallis (KW) rank test in order to evaluate whether the distribution of efficiency scores resulting from Data Envelopment Analysis (DEA) is independent of the input (or output) mix of the observations. Since the DEA frontier...... is estimated, many standard assumptions for evaluating the KW test statistic are violated. Therefore, we propose to explore its statistical properties by the use of simulation studies. The simulations are performed conditional on the observed input mixes. The method, unlike existing approaches...... the assumption of mix independence is rejected the implication is that it, for example, is impossible to determine whether machine intensive project are more or less efficient than labor intensive projects....

  3. Application of computer voice input/output

    International Nuclear Information System (INIS)

    Ford, W.; Shirk, D.G.

    1981-01-01

    The advent of microprocessors and other large-scale integration (LSI) circuits is making voice input and output for computers and instruments practical; specialized LSI chips for speech processing are appearing on the market. Voice can be used to input data or to issue instrument commands; this allows the operator to engage in other tasks, move about, and to use standard data entry systems. Voice synthesizers can generate audible, easily understood instructions. Using voice characteristics, a control system can verify speaker identity for security purposes. Two simple voice-controlled systems have been designed at Los Alamos for nuclear safeguards applicaations. Each can easily be expanded as time allows. The first system is for instrument control that accepts voice commands and issues audible operator prompts. The second system is for access control. The speaker's voice is used to verify his identity and to actuate external devices

  4. Energetic Neutral Atom (ENA) intensity gradients in the heliotail during year 2003, using Cassini/INCA measurements

    International Nuclear Information System (INIS)

    Dialynas, K; Krimigis, S M; Mitchell, D G; Roelof, E C

    2015-01-01

    In the present study we use all-sky energy-resolved (5-55 keV) energetic neutral atom (ENA) maps obtained by the Ion and Neutral CAmera (INCA) on board Cassini during the time period DOY 265/2003 to 268/2003, to investigate the properties of the peak-to-basin ENA emissions in the direction of the heliotail. Our conclusions can be summarized as follows: (1) a relatively smooth boundary (called t ransition region ) between the very low (basin) and high (tail) ENA emissions from the heliosheath, with a spatial width of ∼30° deg in ecl. longitude, that no theory had predicted to date, is identified in the energy range of 5-55 keV; (2) the ENA intensity gradient in this transition region is almost invariant as a function of both ecl. Latitude and energy, with an average value of ∼2.4% per degree; (3) the deduced partial plasma pressure distributions in the 5-55 keV energy range are consistent with the ENA intensity distributions in the same energy range, while the ENA intensity gradient translates to a corresponding partial pressure gradient that occurs in the transition region; and (4) this partial pressure gradient is possibly not consistent with a tail magnetic field configuration that is similar to the measured magnetic fields by the Voyagers in the nose hemisphere

  5. The Dunes of Shangri-La : New Cassini RADAR results on patterns of aeolian features and the influence of topography

    Science.gov (United States)

    Lorenz, R. D.; Radebaugh, J.; Wall, S. D.; Kirk, R.; Le Gall, A.; Janssen, M. A.; Zebker, H.; Paganelli, F.; Wye, L.; Lunine, J.

    2008-12-01

    Recent flybys (T43, T44 - and just prior to this meeting, T48) provide SAR imagery of northern Shangri-La, the large dark region just to the WNW of Xanadu. Previous imaging of SE Shangri-La (T13) showed that dunes there take a pronounced southward dip compared with the E-W direction seen elsewhere. The new data show rather different directions for dunes in northern Shangri-La, and confirm a blocking or divergent influence of Xanadu. Application of monopulse radar methods to retrieve elevations from Cassini SAR images ('SARTopo') now allows us to explore the influence of topography on the local dune (and by implication, wind) patterns, and the relationship between elevation and sediment accumulation. The lack of large positive relief at Xanadu makes its influence on the dunes somewhat surprising. We consider the possible mechanisms of Xanadu's effect on the winds, using terrestrial analogs as a guide. We review the global pattern of dune orientations and their implications for atmospheric circulation: this orientation map presents a challenging constraint for modelers. We note preliminary indications that scatterometry of Titan's dunefields yields azimuth-dependent radar cross-sections (as is the case for terrestrial sand seas) and note future plans for dune studies on Titan with multi-angle observations that will provide constraints on dune-scale slopes and duneforms too small to resolve.

  6. A dusty road connecting Saturn and its rings - preliminary results from Cassini Cosmic Dust Analyser during the Grand Finale Mission

    Science.gov (United States)

    Hsu, S.; Burton, M. E.; Horanyi, M.; Kempf, S.; Khawaja, N.; Moragas-Klostermeyer, G.; Postberg, F.; Schirdenwahn, D.; Seiss, M.; Schmidt, J.; Spahn, F.; Srama, R.

    2017-12-01

    The Cosmic Dust Analyzer observations during the Cassini Grand Finale Orbits were designed for the in situ characterization of Saturn's ring composition and to study their interaction with the host planet. It is found that the gap between the inner most D ring and Saturn is almost free of larger, micron-sized dust grains but rich in nanodust particles (radius smaller than 100 nm) that only become detectable by CDA because of the high spacecraft speed of 30 km/s through this region. Regarding the grain composition, while the majority of CDA mass spectra recorded during this phase are too faint to be individually calibrated, two types of mass spectra have been identified - water ice and silicates. These two types of grains were detected at different locations with respect to the ring plane, indicating that there are compositional differences across the rings. As for the dynamics, the observations confirm the transport of charged nanodust from the main rings along magnetic field lines to the planet, as previously proposed. The agreement between the simulated density profile and the observation strongly suggests nanodust as a pathway of ring-planet interaction associated with both exogenous (e.g., impactor ejecta) and endogenous (ionospheric plasma charging) processes. CDA measurements do not indicate significant temporal variation during the the Grand Finale orbits. The measured flux corresponds to a mass transport of < 0.1 kg/sec from the main rings to Saturn in the form of nanodust, with most of the deposition occurring near the equator.

  7. Constraining the physical properties of Titan's empty lake basins using nadir and off-nadir Cassini RADAR backscatter

    Science.gov (United States)

    Michaelides, R. J.; Hayes, A. G.; Mastrogiuseppe, M.; Zebker, H. A.; Farr, T. G.; Malaska, M. J.; Poggiali, V.; Mullen, J. P.

    2016-05-01

    We use repeat synthetic aperture radar (SAR) observations and complementary altimetry passes acquired by the Cassini spacecraft to study the scattering properties of Titan's empty lake basins. The best-fit coefficients from fitting SAR data to a quasi-specular plus diffuse backscatter model suggest that the bright basin floors have a higher dielectric constant, but similar facet-scale rms surface facet slopes, to surrounding terrain. Waveform analysis of altimetry returns reveals that nadir backscatter returns from basin floors are greater than nadir backscatter returns from basin surroundings and have narrower pulse widths. This suggests that floor deposits are structurally distinct from their surroundings, consistent with the interpretation that some of these basins may be filled with evaporitic and/or sedimentary deposits. Basin floor deposits also express a larger diffuse component to their backscatter, which is likely due to variations in subsurface structure or an increase in roughness at the wavelength scale (Hayes, A.G. et al. [2008]. Geophys. Res. Lett. 35, 9). We generate a high-resolution altimetry radargram of the T30 altimetry pass over an empty lake basin, with which we place geometric constraints on the basin's slopes, rim heights, and depth. Finally, the importance of these backscatter observations and geometric measurements for basin formation mechanisms is briefly discussed.

  8. Sensory Synergy as Environmental Input Integration

    Directory of Open Access Journals (Sweden)

    Fady eAlnajjar

    2015-01-01

    Full Text Available The development of a method to feed proper environmental inputs back to the central nervous system (CNS remains one of the challenges in achieving natural movement when part of the body is replaced with an artificial device. Muscle synergies are widely accepted as a biologically plausible interpretation of the neural dynamics between the CNS and the muscular system. Yet the sensorineural dynamics of environmental feedback to the CNS has not been investigated in detail. In this study, we address this issue by exploring the concept of sensory synergy. In contrast to muscle synergy, we hypothesize that sensory synergy plays an essential role in integrating the overall environmental inputs to provide low-dimensional information to the CNS. We assume that sensor synergy and muscle synergy communicate using these low-dimensional signals. To examine our hypothesis, we conducted posture control experiments involving lateral disturbance with 9 healthy participants. Proprioceptive information represented by the changes on muscle lengths were estimated by using the musculoskeletal model analysis software SIMM. Changes on muscles lengths were then used to compute sensory synergies. The experimental results indicate that the environmental inputs were translated into the two dimensional signals and used to move the upper limb to the desired position immediately after the lateral disturbance. Participants who showed high skill in posture control were found to be likely to have a strong correlation between sensory and muscle signaling as well as high coordination between the utilized sensory synergies. These results suggest the importance of integrating environmental inputs into suitable low-dimensional signals before providing them to the CNS. This mechanism should be essential when designing the prosthesis’ sensory system to make the controller simpler

  9. Sensory synergy as environmental input integration.

    Science.gov (United States)

    Alnajjar, Fady; Itkonen, Matti; Berenz, Vincent; Tournier, Maxime; Nagai, Chikara; Shimoda, Shingo

    2014-01-01

    The development of a method to feed proper environmental inputs back to the central nervous system (CNS) remains one of the challenges in achieving natural movement when part of the body is replaced with an artificial device. Muscle synergies are widely accepted as a biologically plausible interpretation of the neural dynamics between the CNS and the muscular system. Yet the sensorineural dynamics of environmental feedback to the CNS has not been investigated in detail. In this study, we address this issue by exploring the concept of sensory synergy. In contrast to muscle synergy, we hypothesize that sensory synergy plays an essential role in integrating the overall environmental inputs to provide low-dimensional information to the CNS. We assume that sensor synergy and muscle synergy communicate using these low-dimensional signals. To examine our hypothesis, we conducted posture control experiments involving lateral disturbance with nine healthy participants. Proprioceptive information represented by the changes on muscle lengths were estimated by using the musculoskeletal model analysis software SIMM. Changes on muscles lengths were then used to compute sensory synergies. The experimental results indicate that the environmental inputs were translated into the two dimensional signals and used to move the upper limb to the desired position immediately after the lateral disturbance. Participants who showed high skill in posture control were found to be likely to have a strong correlation between sensory and muscle signaling as well as high coordination between the utilized sensory synergies. These results suggest the importance of integrating environmental inputs into suitable low-dimensional signals before providing them to the CNS. This mechanism should be essential when designing the prosthesis' sensory system to make the controller simpler.

  10. PREP-45, Input Preparation for CITATION-2

    International Nuclear Information System (INIS)

    Ramalho Carlos, C.A.

    1995-01-01

    1 - Description of program or function: A Fortran program has been created, which saves much effort in preparing sections 004 (intervals in the coordinates) and 005 (zone numbers) of the input data file for the multigroup theory code CITATION (version CITATION-2, NESC0387/09), particularly when a thin complicated mesh is used. 2 - Method of solution: A domain is defined for CITATION calculations through specifying its sub-domains (e.g. graphite, lead, beryllium, water and fuel sub-domains) in a compact and simple way. An independent and previous geometrical specification is made of the various types of elements which are envisaged to constitute the contents of the reactor core grid positions. Then the load table for the configuration is input and scanned throughout, thus enabling the geometric mesh description to be produced (section 004). Also the zone placement (section 005) is achieved by means of element description subroutines for the different types of element (which may require appropriate but simple changes in the actual cases). The output of PREP45 is directly obtained in a format which is compatible with CITATION-2 input. 3 - Restrictions on the complexity of the problem: Only rectangular two-dimensional Cartesian coordinates are considered. A maximum of 12 sub-domains in the x direction (18 in the y direction) and up to 8 distinct element types are considered in this version. Other limitations exist which can nevertheless be overcome with simple changes in the source program

  11. Molecular structure input on the web

    Directory of Open Access Journals (Sweden)

    Ertl Peter

    2010-02-01

    Full Text Available Abstract A molecule editor, that is program for input and editing of molecules, is an indispensable part of every cheminformatics or molecular processing system. This review focuses on a special type of molecule editors, namely those that are used for molecule structure input on the web. Scientific computing is now moving more and more in the direction of web services and cloud computing, with servers scattered all around the Internet. Thus a web browser has become the universal scientific user interface, and a tool to edit molecules directly within the web browser is essential. The review covers a history of web-based structure input, starting with simple text entry boxes and early molecule editors based on clickable maps, before moving to the current situation dominated by Java applets. One typical example - the popular JME Molecule Editor - will be described in more detail. Modern Ajax server-side molecule editors are also presented. And finally, the possible future direction of web-based molecule editing, based on technologies like JavaScript and Flash, is discussed.

  12. Effect of different input management on weed composition, diversity and density of corn field

    Directory of Open Access Journals (Sweden)

    Surur Khoramdel

    2016-04-01

    Full Text Available In order to investigate the effects of input intensity on species diversity, composition and density of weeds in corn (Zea mays L., an experiment was conducted based on a randomized complete block design with three replications at the Agricultural Research Station, Ferdowsi University of Mashhad, Iran during the year 2009. Treatments included low input, medium input and high input systems. Low input received 30 tonha-1or 30 tonha-1 compost, zero tillage and hand weeding (twice. Medium input was based on 15 tonha-1 manure, 150 kgha-1 urea as chemical fertilizer, twice tillage operations and 2, 4-D (1.5 Lha-1, at five leaves emergence as an herbicide and hand weeding (once. High input received 300 kgha-1 urea, four tillage operations and Paraquat (2 Lha-1, after planting and 2, 4-D (1.5 Lha-1, at five leaves emergence. Manure and compost were applied in the planting time. Weed samplings were done in three stages (early, mid and late growing season. Results indicated that the highest and the lowest weed species diversity and density were observed in low input based on manure and high input systems, respectively. The highest range of weed relative density was obtained for black nightshade (Solanum nigrum with 9.09-75.00%. The highest number of species was observed in low input based on manure. Also, management practices affected weed dry matter and diversity indices. The highest and the lowest amounts of weed dry matter were observed in low input based on manure and high input systems, respectively. In the first, second and the third stages of sampling, the maximum and the minimum amounts of Margalef index were observed in low input based on manure (with 5.3, 5.4 and 3.3, respectively and high input systems (with 0.8, 2.3 and 2.6, respectively. In the first, second and the third stages of sampling, the highest and the lowest values of Shannon index were observed in low input based on manure (with 0.6, 0.7 and 0.5 respectively and high input (with 0

  13. Canonical multi-valued input Reed-Muller trees and forms

    Science.gov (United States)

    Perkowski, M. A.; Johnson, P. D.

    1991-01-01

    There is recently an increased interest in logic synthesis using EXOR gates. The paper introduces the fundamental concept of Orthogonal Expansion, which generalizes the ring form of the Shannon expansion to the logic with multiple-valued (mv) inputs. Based on this concept we are able to define a family of canonical tree circuits. Such circuits can be considered for binary and multiple-valued input cases. They can be multi-level (trees and DAG's) or flattened to two-level AND-EXOR circuits. Input decoders similar to those used in Sum of Products (SOP) PLA's are used in realizations of multiple-valued input functions. In the case of the binary logic the family of flattened AND-EXOR circuits includes several forms discussed by Davio and Green. For the case of the logic with multiple-valued inputs, the family of the flattened mv AND-EXOR circuits includes three expansions known from literature and two new expansions.

  14. Joint analysis of input and parametric uncertainties in watershed water quality modeling: A formal Bayesian approach

    Science.gov (United States)

    Han, Feng; Zheng, Yi

    2018-06-01

    Significant Input uncertainty is a major source of error in watershed water quality (WWQ) modeling. It remains challenging to address the input uncertainty in a rigorous Bayesian framework. This study develops the Bayesian Analysis of Input and Parametric Uncertainties (BAIPU), an approach for the joint analysis of input and parametric uncertainties through a tight coupling of Markov Chain Monte Carlo (MCMC) analysis and Bayesian Model Averaging (BMA). The formal likelihood function for this approach is derived considering a lag-1 autocorrelated, heteroscedastic, and Skew Exponential Power (SEP) distributed error model. A series of numerical experiments were performed based on a synthetic nitrate pollution case and on a real study case in the Newport Bay Watershed, California. The Soil and Water Assessment Tool (SWAT) and Differential Evolution Adaptive Metropolis (DREAM(ZS)) were used as the representative WWQ model and MCMC algorithm, respectively. The major findings include the following: (1) the BAIPU can be implemented and used to appropriately identify the uncertain parameters and characterize the predictive uncertainty; (2) the compensation effect between the input and parametric uncertainties can seriously mislead the modeling based management decisions, if the input uncertainty is not explicitly accounted for; (3) the BAIPU accounts for the interaction between the input and parametric uncertainties and therefore provides more accurate calibration and uncertainty results than a sequential analysis of the uncertainties; and (4) the BAIPU quantifies the credibility of different input assumptions on a statistical basis and can be implemented as an effective inverse modeling approach to the joint inference of parameters and inputs.

  15. PERSPECTIVES ON A DOE CONSEQUENCE INPUTS FOR ACCIDENT ANALYSIS APPLICATIONS

    International Nuclear Information System (INIS)

    O'Kula, K.R.; Thoman, D.C.; Lowrie, J.; Keller, A.

    2008-01-01

    Department of Energy (DOE) accident analysis for establishing the required control sets for nuclear facility safety applies a series of simplifying, reasonably conservative assumptions regarding inputs and methodologies for quantifying dose consequences. Most of the analytical practices are conservative, have a technical basis, and are based on regulatory precedent. However, others are judgmental and based on older understanding of phenomenology. The latter type of practices can be found in modeling hypothetical releases into the atmosphere and the subsequent exposure. Often the judgments applied are not based on current technical understanding but on work that has been superseded. The objective of this paper is to review the technical basis for the major inputs and assumptions in the quantification of consequence estimates supporting DOE accident analysis, and to identify those that could be reassessed in light of current understanding of atmospheric dispersion and radiological exposure. Inputs and assumptions of interest include: Meteorological data basis; Breathing rate; and Inhalation dose conversion factor. A simple dose calculation is provided to show the relative difference achieved by improving the technical bases

  16. Response of spiking neurons to correlated inputs

    International Nuclear Information System (INIS)

    Moreno, Ruben; Rocha, Jaime de la; Renart, Alfonso; Parga, Nestor

    2002-01-01

    The effect of a temporally correlated afferent current on the firing rate of a leaky integrate-and-fire neuron is studied. This current is characterized in terms of rates, autocorrelations, and cross correlations, and correlation time scale τ c of excitatory and inhibitory inputs. The output rate ν out is calculated in the Fokker-Planck formalism in the limit of both small and large τ c compared to the membrane time constant τ of the neuron. By simulations we check the analytical results, provide an interpolation valid for all τ c , and study the neuron's response to rapid changes in the correlation magnitude

  17. Culture Input in Foreign Language Teaching

    Institute of Scientific and Technical Information of China (English)

    胡晶

    2009-01-01

    Language and culture are highly interrelated, that is to say, language is not only the carrier of culture but it is also restricted by culture. Therefore, foreign language teaching aiming at cultivate students' intercultural communication should take culture differences into consideration. In this paper, the relationship between language and culture will be discussed. Then I will illustrate the importance of intercultural communication. Finally, according to the present situation of foreign language teaching in China, several strategies for cultural input in and out of class will be suggested.

  18. Flexible input, dazzling output with IBM i

    CERN Document Server

    Victória-Pereira, Rafael

    2014-01-01

    Link your IBM i system to the modern business server world! This book presents easier and more flexible ways to get data into your IBM i system, along with rather surprising methods to export and present the vital business data it contains. You'll learn how to automate file transfers, seamlessly connect PC applications with your RPG programs, and much more. Input operations will become more flexible and user-proof, with self-correcting import processes and direct file transfers that require a minimum of user intervention. Also learn novel ways to present information: your DB2 data will look gr

  19. The Importance of Input and Interaction in SLA

    Institute of Scientific and Technical Information of China (English)

    党春花

    2009-01-01

    As is known to us, input and interaction play the crucial roles in second language acquisition (SLA). Different linguistic schools have different explanations to input and interaction Behaviorist theories hold a view that input is composed of stimuli and response, putting more emphasis on the importance of input, while mentalist theories find input is a necessary condition to SLA, not a sufficient condition. At present, social interaction theories, which is one type of cognitive linguistics, suggests that besides input, interaction is also essential to language acquisition. Then, this essay will discuss how input and interaction result in SLA.

  20. Computer code ANISN multiplying media and shielding calculation 2. Code description (input/output)

    International Nuclear Information System (INIS)

    Maiorino, J.R.

    1991-01-01

    The new code CCC-0514-ANISN/PC is described, as well as a ''GENERAL DESCRIPTION OF ANISN/PC code''. In addition to the ANISN/PC code, the transmittal package includes an interactive input generation programme called APE (ANISN Processor and Evaluator), which facilitates the work of the user in giving input. Also, a 21 group photon cross section master library FLUNGP.LIB in ISOTX format, which can be edited by an executable file LMOD.EXE, is included in the package. The input and output subroutines are reviewed. 6 refs, 1 fig., 1 tab

  1. Modality of Input and Vocabulary Acquisition

    Directory of Open Access Journals (Sweden)

    Tetyana Sydorenko

    2010-06-01

    Full Text Available This study examines the effect of input modality (video, audio, and captions, i.e., on-screen text in the same language as audio on (a the learning of written and aural word forms, (b overall vocabulary gains, (c attention to input, and (d vocabulary learning strategies of beginning L2 learners. Twenty-six second-semester learners of Russian participated in this study. Group one (N = 8 saw video with audio and captions (VAC; group two (N = 9 saw video with audio (VA; group three (N = 9 saw video with captions (VC. All participants completed written and aural vocabulary tests and a final questionnaire.The results indicate that groups with captions (VAC and VC scored higher on written than on aural recognition of word forms, while the reverse applied to the VA group. The VAC group learned more word meanings than the VA group. Results from the questionnaire suggest that learners paid most attention to captions, followed by video and audio, and acquired most words by associating them with visual images. Pedagogical implications of this study are that captioned video tends to aid recognition of written word forms and the learning of word meaning, while non-captioned video tends to improve listening comprehension as it facilitates recognition of aural word forms.

  2. [Prosody, speech input and language acquisition].

    Science.gov (United States)

    Jungheim, M; Miller, S; Kühn, D; Ptok, M

    2014-04-01

    In order to acquire language, children require speech input. The prosody of the speech input plays an important role. In most cultures adults modify their code when communicating with children. Compared to normal speech this code differs especially with regard to prosody. For this review a selective literature search in PubMed and Scopus was performed. Prosodic characteristics are a key feature of spoken language. By analysing prosodic features, children gain knowledge about underlying grammatical structures. Child-directed speech (CDS) is modified in a way that meaningful sequences are highlighted acoustically so that important information can be extracted from the continuous speech flow more easily. CDS is said to enhance the representation of linguistic signs. Taking into consideration what has previously been described in the literature regarding the perception of suprasegmentals, CDS seems to be able to support language acquisition due to the correspondence of prosodic and syntactic units. However, no findings have been reported, stating that the linguistically reduced CDS could hinder first language acquisition.

  3. Radionuclides in the oceans inputs and inventories

    International Nuclear Information System (INIS)

    Guegueniat, P.; Germain, P.; Metivier, H.

    1996-01-01

    Ten years after Chernobyl, following the decision by France to end nuclear weapon testing in the Pacific ocean, after the end of the OECD-NEA Coordinated Research and Environmental Surveillance programme related to low-level waste dumping in the deep ocean, and one hundred years after the discovery of radioactivity, the IPSN wanted to compile and review the available information on artificial radioactivity levels in seas and oceans. International experts have been invited to present data on inputs and inventories of radionuclides in the marine environment, and to describe the evolution of radioactivity levels in water, sediments and living organisms. Different sources of radionuclides present in the aquatic environment are described: atmospheric fallout before and after Chernobyl, industrial wastes, dumped wastes and ships, nuclear ship accidents, river inputs, earth-sea atmospheric transfers and experimental sites for nuclear testing. Radioactivity levels due to these sources are dealt with at ocean (Atlantic, Pacific and Indian) and sea level (Channel, North Sea, Irish Sea, Mediterranean, Baltic, Black Sea and Arctic seas). These data collected in the present book give an up-to-date assessment of radionuclide distributions which will be very useful to address scientific and wider public concerns about radionuclides found in the aquatic environment. It gives many references useful to those who want to deepen their understanding of particular aspects of marine radioecology. (authors)

  4. Ground motion input in seismic evaluation studies

    International Nuclear Information System (INIS)

    Sewell, R.T.; Wu, S.C.

    1996-07-01

    This report documents research pertaining to conservatism and variability in seismic risk estimates. Specifically, it examines whether or not artificial motions produce unrealistic evaluation demands, i.e., demands significantly inconsistent with those expected from real earthquake motions. To study these issues, two types of artificial motions are considered: (a) motions with smooth response spectra, and (b) motions with realistic variations in spectral amplitude across vibration frequency. For both types of artificial motion, time histories are generated to match target spectral shapes. For comparison, empirical motions representative of those that might result from strong earthquakes in the Eastern U.S. are also considered. The study findings suggest that artificial motions resulting from typical simulation approaches (aimed at matching a given target spectrum) are generally adequate and appropriate in representing the peak-response demands that may be induced in linear structures and equipment responding to real earthquake motions. Also, given similar input Fourier energies at high-frequencies, levels of input Fourier energy at low frequencies observed for artificial motions are substantially similar to those levels noted in real earthquake motions. In addition, the study reveals specific problems resulting from the application of Western U.S. type motions for seismic evaluation of Eastern U.S. nuclear power plants

  5. FED, Geometry Input Generator for Program TRUMP

    International Nuclear Information System (INIS)

    Schauer, D.A.; Elrod, D.C.

    1996-01-01

    1 - Description of program or function: FED reduces the effort required to obtain the necessary geometric input for problems which are to be solved using the heat-transfer code, TRUMP (NESC 771). TRUMP calculates transient and steady-state temperature distributions in multidimensional systems. FED can properly zone any body of revolution in one, or three dimensions. 2 - Method of solution: The region of interest must first be divided into areas which may consist of a common material. The boundaries of these areas are the required FED input. Each area is subdivided into volume nodes, and the geometrical properties are calculated. Finally, FED connects the adjacent nodes to one another, using the proper surface area, interface distance, and, if specified, radiation form factor and interface conductance. 3 - Restrictions on the complexity of the problem: Rectangular bodies can only be approximated by using a very large radius of revolution compared to the total radial thickness and by considering only a small angular segment in the circumferential direction

  6. On the Discovery of CO Nighttime Emissions on Titan by Cassini/VIMS: Derived Stratospheric Abundances and Geological Implications

    Science.gov (United States)

    Bainesa, Kevin H.; Drossart, Pierre; Lopez-Valverde, Miguel A.; Atreya, Sushil K.; Sotin, Christophe; Momary, Thomas W.; Brown, Robert H.; Buratti, Bonnie J.; Clark, Roger N.; Nicholson, Philip D.

    2006-01-01

    We present a quantitative analysis of CO thermal emissions discovered on the nightside of Titan by Baines et al. [2005. The atmospheres of Saturn and Titan in the near-infrared: First results of Cassini/VIMS. Earth, Moon, and Planets, 96, 119-147] in Cassini/VIMS spectral imagery. We identify these emission features as the P and R branches of the 1-0 vibrational band of carbon monoxide (CO) near 4.65 microns. For CH3D, the prominent Q branch of the nu(2) fundamental band of CH3D near 4.55 microns is apparent. CO2 emissions from the strong nu(3) vibrational band are virtually absent, indicating a CO2 abundance several orders of magnitude less than CO, in agreement with previous investigations. Analysis of CO emission spectra obtained over a variety of altitudes on Titan's nightside limb indicates that the stratospheric abundance of CO is 32 +/- 15 ppm, and together with other recent determinations, suggests a vertical distribution of CO nearly constant at this value from the surface throughout the troposphere to at least the stratopause near 300 km altitude. The corresponding total atmospheric content of CO in Titan is similar to 2.9 +/- 1.5 x 10(exp 14) kg. Given the long lifetime of CO in the oxygen-poor Titan atmosphere (similar to 0.5-1.0 Gyr), we find a mean CO atmospheric production rate of 6 +/- 3 x 10(exp 5) kg yr(exp -1). Given the lack of primordial heavy noble gases observed by Huygens [Niemann et al., 2005. The abundances of constituents of Titan's atmosphere from the GCMS on the Huygens probe. Nature, 438, 779-784], the primary source of atmospheric CO is likely surface emissions. The implied CO/CH4 mixing ratio of near-surface material is 1.8 +/- 0.9 x 10(exp -4), based on an average methane surface emission rate over the past 0.5 Gyr of 1.3 x 10(exp -13) gm cm(exp -2) s(exp -1) as required to balance hydrocarbon haze production via methane photolysis [Wilson and Atreya, 2004. Current state of modeling the photochemistry of Titan's mutually dependent

  7. Carbon dioxide on the satellites of Saturn: Results from the Cassini VIMS investigation and revisions to the VIMS wavelength scale

    Science.gov (United States)

    Cruikshank, D.P.; Meyer, A.W.; Brown, R.H.; Clark, R.N.; Jaumann, R.; Stephan, K.; Hibbitts, C.A.; Sandford, S.A.; Mastrapa, R.M.E.; Filacchione, G.; Ore, C.M.D.; Nicholson, P.D.; Buratti, B.J.; McCord, T.B.; Nelson, R.M.; Dalton, J.B.; Baines, K.H.; Matson, D.L.

    2010-01-01

    Several of the icy satellites of Saturn show the spectroscopic signature of the asymmetric stretching mode of C-O in carbon dioxide (CO2) at or near the nominal solid-phase laboratory wavelength of 4.2675 ??m (2343.3 cm-1), discovered with the Visible-Infrared Mapping Spectrometer (VIMS) on the Cassini spacecraft. We report here on an analysis of the variation in wavelength and width of the CO2 absorption band in the spectra of Phoebe, Iapetus, Hyperion, and Dione. Comparisons are made to laboratory spectra of pure CO2, CO2 clathrates, ternary mixtures of CO2 with other volatiles, implanted and adsorbed CO2 in non-volatile materials, and ab initio theoretical calculations of CO2 * nH2O. At the wavelength resolution of VIMS, the CO2 on Phoebe is indistinguishable from pure CO2 ice (each molecule's nearby neighbors are also CO2) or type II clathrate of CO2 in H2O. In contrast, the CO2 band on Iapetus, Hyperion, and Dione is shifted to shorter wavelengths (typically ???4.255 ??m (???2350.2 cm-1)) and broadened. These wavelengths are characteristic of complexes of CO2 with different near-neighbor molecules that are encountered in other volatile mixtures such as with H2O and CH3OH, and non-volatile host materials like silicates, some clays, and zeolites. We suggest that Phoebe's CO2 is native to the body as part of the initial inventory of condensates and now exposed on the surface, while CO2 on the other three satellites results at least in part from particle or UV irradiation of native H2O plus a source of C, implantation or accretion from external sources, or redistribution of native CO2 from the interior. The analysis presented here depends on an accurate VIMS wavelength scale. In preparation for this work, the baseline wavelength calibration for the Cassini VIMS was found to be distorted around 4.3 ??m, apparently as a consequence of telluric CO2 gas absorption in the pre-launch calibration. The effect can be reproduced by convolving a sequence of model detector

  8. Seasonal Variability of Saturn's Tropospheric Temperatures, Winds and Para-H2 from Cassini Far-IR Spectroscopy

    Science.gov (United States)

    Fletcher, Leigh N.; Irwin, P. G. J; Achterberg, R. K.; Orton, G. S.; Flasar, F. M.

    2015-01-01

    Far-IR 16-1000 micrometer spectra of Saturn's hydrogen-helium continuum measured by Cassini's Composite Infrared Spectrometer (CIRS) are inverted to construct a near-continuous record of upper tropospheric (70-700 mbar) temperatures and para-H2 fraction as a function of latitude, pressure and time for a third of a saturnian year (2004-2014, from northern winter to northern spring). The thermal field reveals evidence of reversing summertime asymmetries superimposed onto the belt/zone structure. The temperature structure is almost symmetric about the equator by 2014, with seasonal lag times that increase with depth and are qualitatively consistent with radiative climate models. Localised heating of the tropospheric hazes (100-250 mbar) create a distinct perturbation to the temperature profile that shifts in magnitude and location, declining in the autumn hemisphere and growing in the spring. Changes in the para-H2 (f(sub p)) distribution are subtle, with a 0.02-0.03 rise over the spring hemisphere (200-500 mbar) perturbed by (i) low-f(sub p) air advected by both the springtime storm of 2010 and equatorial upwelling; and (ii) subsidence of high-f(sub p) air at northern high latitudes, responsible for a developing north-south asymmetry in f(sub p). Conversely, the shifting asymmetry in the para-H2 disequilibrium primarily reflects the changing temperature structure (and hence the equilibrium distribution of f(sub p)), rather than actual changes in f(sub p) induced by chemical conversion or transport. CIRS results interpolated to the same point in the seasonal cycle as re-analysed Voyager-1 observations (early northern spring) show qualitative consistency from year to year (i.e., the same tropospheric asymmetries in temperature and f(sub p)), with the exception of the tropical tropopause near the equatorial zones and belts, where downward propagation of a cool temperature anomaly associated with Saturn's stratospheric oscillation could potentially perturb tropopause

  9. Heliosheath ENA images by Cassini/INCA and in-situ hot plasma ion measurements by Voyagers

    Science.gov (United States)

    Krimigis, Stamatios; Roelof, Edmond; Mitchell, Donald; Decker, Robert; Dialynas, Konstantinos

    2016-07-01

    The advent of Energetic Neutral Atom (ENA) imaging, (the result of charge-exchange with energetic ions), has revealed the global nature of the heliosheath (HS) at both high ( > 5 keV, Cassini from 10 AU) and low (INCA (Ion and Neutral CAmera) since 2003 with a full image available since 2009, when IBEX global imaging observations also became available. The presence of the two Voyagers measuring ions locally in the HS contemporaneously with INCA global imaging through ENA in overlapping energy bands provides a powerful tool for examining the spatial, temporal, and spectral evolution of the source hot plasma ions and the global variability of the neutral component. Some of the key findings from the Voyagers and INCA measurements are as follows: (a) The HS contains a hot plasma population that carries a substantial part (30-50%) of the total pressure at E > 5 keV, the rest residing below that range, resulting in a beta (particle/magnetic pressure) always > 1, typically > 10. (b) The width of the HS in the direction of V1 is ˜~ 30 AU, but is thought to be larger (40-70 AU) in the southern ecliptic where V2 currently travels. (c) The ENA intensities at E > 5 keV exhibit a correlation with the solar cycle (SC) over the period 2003 to 2014, with minimum intensities in the anti-nose direction observed ˜~ 1.5 yrs after solar minimum followed by a recovery thereafter, and (d) The in situ ion measurements at V2 within the HS also show a similar SC dependence. The totality of the observations, together with the near-contemporaneous variability in intensities of ions in situ in the HS and ENA in the inner heliosphere suggests that the source of such emissions at E > 5 keV must reside in the HS. These observations constrain the shape of the HS and suggest configurations that are at some variance with current models.

  10. Simulations of the response function of a plasma ion beam spectrometer for the Cassini mission to Saturn

    International Nuclear Information System (INIS)

    Vilppola, J.H.; Tanskanen, P.J.; Huomo, H.; Barraclough, B.L.

    1996-01-01

    To obtain very high (∼1%) energy resolution with spherical-section electrostatic analyzers requires high precision in both fabrication and in the alignment process. In order to aid in the calibration of the instrument and to help minimize fabrication costs, we have applied simulation models to the ion beam spectrometer for the NASA/ESA Cassini mission to Saturn. Previously we studied the effects of misalignment and simple irregularities of the hemispherical surfaces on the performance of an electrostatic analyzer. We have considered a hemispherical electrostatic analyzer equipped with an aperture plate to collimate the stray electric field at the entrance apertures. The influence of a curved entrance aperture has also been added to the simulation model, and its effects have been studied in detail. A cylindrical three-dimensional simultaneous overrelaxation algorithm has been introduced to solve for the stray electric field. The maximum loss of transmitted particles with respect to the transmission of an ideal instrument has been set at 10%. We demonstrate that the deviation in the distributions of the energies is less than 0.2% and that the deviation in the distributions of entrance angles of transmitted particles is less than 0.1 degree. It has been found that the energy resolution of an electrostatic analyzer can be improved from ΔE/E=(1.6±0.2)% to ΔE/E=(1.3±0.2)% by the introduction of front aperture plates. Through the introduction of curved entrance slits, the azimuthal angle resolution has changed from β=(1.4±0.1)degree for the simplified geometry simulation results of our previous article to β=(2.3±0.1)degree. We have confirmed that an accuracy of 25 μm in the alignment of the two hemispherical surfaces is sufficient to give the instrument the desired resolutions. copyright 1996 American Institute of Physics

  11. Cassini ISS Observations Of The Early Stages Of The Formation Of Titan's South Polar Hood And Vortex In 2012

    Science.gov (United States)

    West, Robert A.; Del Genio, A.; Perry, J.; Ingersoll, A. P.; Turtle, E. P.; Porco, C.; Ovanessian, A.

    2012-10-01

    Northern spring equinox on Titan occurred on August 11, 2009. In March of 2012 the Imaging Science Subsystem (ISS) on the Cassini spacecraft saw the first evidence for the formation of a polar hood in the atmosphere above Titan’s south pole. Views of the limb showed an optical thickening primarily at about 360 km altitude across a few degrees of latitude centered on the pole. Images of Titan in front of Saturn provide a nearly direct measure of the line-of-sight optical depth as a function of latitude and altitude from about 250 km and higher. Two or more distinct layers are seen, both near the pole and at other latitudes. The highest of these, near 360 km altitude, hosts the embryonic polar hood. On June 27, 2012 ISS observed the pole from high latitude. These images show a distinct and unusual cloudy patch, elongated and not centered on the pole and with an elevated perimeter. The morphology and color indicate an unfamiliar (for Titan) composition and dynamical regime. The interior of the feature consists of concentrations of cloud/haze organized on spatial scales of tens of kilometers. Its morphology is reminiscent of the open cellular convection sometimes seen in the atmospheric boundary layer over Earth’s oceans under conditions of large-scale subsidence. Unlike Earth, where such convection is forced by large surface heat fluxes or the onset of drizzle, convection at 360 km on Titan is more likely to be driven from above by radiative cooling. During the 9 hours we observed Titan, this feature completed a little over one rotation around the pole, providing direct evidence for a polar vortex rotating at a rate roughly consistent with angular-momentum-conserving flow for air displaced from the equator. Part of this work was performed by the Jet Propulsion Laboratory, California Institute of Technology.

  12. Manual input device for controlling a robot arm

    International Nuclear Information System (INIS)

    Fischer, P.J.; Siva, K.V.

    1990-01-01

    A six-axis input device, eg joystick, is supported by a mechanism which enables the joystick to be aligned with any desired orientation, eg parallel to the tool. The mechanism can then be locked to provide a rigid support of the joystick. The mechanism may include three pivotal joints whose axes are perpendicular, each incorporating a clutch. The clutches may be electromagnetic or mechanical and may be operable jointly or independently. The robot arm comprises a base rotatable about a vertical axis, an upper arm, a forearm and a tool or grip rotatable about three perpendicular axes relative to the forearm. (author)

  13. Control rod drive WWER 1000 – tuning of input parameters

    Directory of Open Access Journals (Sweden)

    Markov P.

    2007-10-01

    Full Text Available The article picks up on the contributions presented at the conferences Computational Mechanics 2005 and 2006, in which a calculational model of an upgraded control rod linear stepping drive for the reactors WWER 1000 (LKP-M/3 was described and results of analysis of dynamical response of its individual parts when moving up- and downwards were included. The contribution deals with the tuning of input parameters of the 3rd generation drive with the objective of reaching its running as smooth as possible so as to get a minimum wear of its parts as a result and hence to achieve maximum life-time.

  14. Two coupled Lévy queues with independent input

    OpenAIRE

    Jevgenijs Ivanovs; Onno Boxma

    2014-01-01

    We consider a pair of coupled queues driven by independent spectrally-positive Lévy processes. With respect to the bi-variate workload process this framework includes both the coupled processor model and the two-server fluid network with independent Lévy inputs. We identify the joint transform of the stationary workload distribution in terms of Wiener-Hopf factors corresponding to two auxiliary Lévy processes with explicit Laplace exponents. We reinterpret and extend the ideas of Cohen and Bo...

  15. Seasonal Evolution of the North and South Polar Vortex on Titan From 2004 to 2017 as Seen by Cassini/VIMS

    Science.gov (United States)

    Le Mouelic, S.; Robidel, R.; Rousseau, B.; Rodriguez, S.; Cornet, T.; Sotin, C.; Barnes, J. W.; Brown, R. H.; Buratti, B. J.; Baines, K. H.; Clark, R. N.; Nicholson, P. D.

    2017-12-01

    Cassini entered in Saturn's orbit in July 2004. In thirteen years, 127 targeted flybys of Titan have been performed. We focus our study on the analysis of the complete Visual and Infrared Mapping Spectrometer data set, with a particular emphasis on the evolving features on both poles. We have computed individual global maps of the north and south poles for each of the 127 targeted flybys, using VIMS wavelengths sensitive both to clouds and surface features. First evidences for a vast ethane cloud covering the North Pole is seen as soon as the first and second targeted flyby in October 2004 and December 2005 [1]. The first detailed imaging of this north polar feature with VIMS was obtained in December 2006, thanks to a change in inclination of the spacecraft orbit [2]. At this time, the northern lakes and seas of Titan were totally masked to the optical instruments by the haze and clouds, whereas the southern pole was well illuminated and mostly clear of haze and vast clouds. The vast north polar feature progressively vanished around the equinox in 2009 [2,3,4], in agreement with the predictions of Global Circulation Models [5]. It revealed progressively the underlying lakes to the ISS and VIMS instruments, which show up very nicely in VIMS in a series of flybys between T90 and T100. First evidences of an atmospheric vortex growing over the south pole occurred in May 2012 (T82), with a high altitude feature being detected consistently at each flyby up to the last T126 targeted flyby, and also appearing in more distant observations up to the end of the Cassini mission. Cassini has covered almost half a titanian year, corresponding to two seasons. The situation observed at the South Pole in the last images may correspond to what was observed in the north as Cassini just arrived. [1] Griffith et al., Science, 2006. [2] Le Mouélic et al., PSS, 2012. [3] Rodriguez et al., Nature, 2009. [4] Rodriguez et al., Icarus 2011. [4] Hirtzig et al., Icarus, 2013. [5] Rannou et al

  16. First Principles Based Reactive Atomistic Simulations to Understand the Effects of Molecular Hypervelocity Impact on Cassini's Ion and Neutral Mass Spectrometer

    Science.gov (United States)

    Jaramillo-Botero, A.; Cheng, M-J; Cvicek, V.; Beegle, Luther W.; Hodyss, R.; Goddard, W. A., III

    2011-01-01

    We report here on the predicted impact of species such as ice-water, CO2, CH4, and NH3, on oxidized titanium, as well as HC species on diamond surfaces. These simulations provide the dynamics of product distributions during and after a hypervelocity impact event, ionization fractions, and dissociation probabilities for the various species of interest as a function of impact velocity (energy). We are using these results to determine the relevance of the fragmentation process to Cassini INMS results, and to quantify its effects on the observed spectra.

  17. An Envelope Correlation Formula for (N,N MIMO Antenna Arrays Using Input Scattering Parameters, and Including Power Losses

    Directory of Open Access Journals (Sweden)

    Y. A. S. Dama

    2011-01-01

    Full Text Available The scattering parameter formulation for the envelope correlation in an (N,N MIMO antenna array has been modified to take the intrinsic antenna power losses into account. This method of calculation provides a major simplification over the use of antenna radiation field patterns. Its accuracy is illustrated in three examples, which also show that the locations of the correlation minima are sensitive to the intrinsic losses.

  18. Do dyslexics have auditory input processing difficulties?

    DEFF Research Database (Denmark)

    Poulsen, Mads

    2011-01-01

    Word production difficulties are well documented in dyslexia, whereas the results are mixed for receptive phonological processing. This asymmetry raises the possibility that the core phonological deficit of dyslexia is restricted to output processing stages. The present study investigated whether....... The finding suggests that input processing difficulties are associated with the phonological deficit, but that these difficulties may be stronger above the level of phoneme perception.......Word production difficulties are well documented in dyslexia, whereas the results are mixed for receptive phonological processing. This asymmetry raises the possibility that the core phonological deficit of dyslexia is restricted to output processing stages. The present study investigated whether...... a group of dyslexics had word level receptive difficulties using an auditory lexical decision task with long words and nonsense words. The dyslexics were slower and less accurate than chronological age controls in an auditory lexical decision task, with disproportionate low performance on nonsense words...

  19. Auto Draw from Excel Input Files

    Science.gov (United States)

    Strauss, Karl F.; Goullioud, Renaud; Cox, Brian; Grimes, James M.

    2011-01-01

    The design process often involves the use of Excel files during project development. To facilitate communications of the information in the Excel files, drawings are often generated. During the design process, the Excel files are updated often to reflect new input. The problem is that the drawings often lag the updates, often leading to confusion of the current state of the design. The use of this program allows visualization of complex data in a format that is more easily understandable than pages of numbers. Because the graphical output can be updated automatically, the manual labor of diagram drawing can be eliminated. The more frequent update of system diagrams can reduce confusion and reduce errors and is likely to uncover symmetric problems earlier in the design cycle, thus reducing rework and redesign.

  20. Optimizing microwave photodetection: input-output theory

    Science.gov (United States)

    Schöndorf, M.; Govia, L. C. G.; Vavilov, M. G.; McDermott, R.; Wilhelm, F. K.

    2018-04-01

    High fidelity microwave photon counting is an important tool for various areas from background radiation analysis in astronomy to the implementation of circuit quantum electrodynamic architectures for the realization of a scalable quantum information processor. In this work we describe a microwave photon counter coupled to a semi-infinite transmission line. We employ input-output theory to examine a continuously driven transmission line as well as traveling photon wave packets. Using analytic and numerical methods, we calculate the conditions on the system parameters necessary to optimize measurement and achieve high detection efficiency. With this we can derive a general matching condition depending on the different system rates, under which the measurement process is optimal.

  1. Input and output constraints affecting irrigation development

    Science.gov (United States)

    Schramm, G.

    1981-05-01

    In many of the developing countries the expansion of irrigated agriculture is used as a major development tool for bringing about increases in agricultural output, rural economic growth and income distribution. Apart from constraints imposed by water availability, the major limitations considered to any acceleration of such programs are usually thought to be those of costs and financial resources. However, as is shown on the basis of empirical data drawn from Mexico, in reality the feasibility and effectiveness of such development programs is even more constrained by the lack of specialized physical and human factors on the input and market limitations on the output side. On the input side, the limited availability of complementary factors such as, for example, truly functioning credit systems for small-scale farmers or effective agricultural extension services impose long-term constraints on development. On the output side the limited availability, high risk, and relatively slow growth of markets for high-value crops sharply reduce the usually hoped-for and projected profitable crop mix that would warrant the frequently high costs of irrigation investments. Three conclusions are drawn: (1) Factors in limited supply have to be shadow-priced to reflect their high opportunity costs in alternative uses. (2) Re-allocation of financial resources from immediate construction of projects to longer-term increase in the supply of scarce, highly-trained manpower resources are necessary in order to optimize development over time. (3) Inclusion of high-value, high-income producing crops in the benefit-cost analysis of new projects is inappropriate if these crops could potentially be grown in already existing projects.

  2. Distribution Development for STORM Ingestion Input Parameters

    Energy Technology Data Exchange (ETDEWEB)

    Fulton, John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-07-01

    The Sandia-developed Transport of Radioactive Materials (STORM) code suite is used as part of the Radioisotope Power System Launch Safety (RPSLS) program to perform statistical modeling of the consequences due to release of radioactive material given a launch accident. As part of this modeling, STORM samples input parameters from probability distributions with some parameters treated as constants. This report described the work done to convert four of these constant inputs (Consumption Rate, Average Crop Yield, Cropland to Landuse Database Ratio, and Crop Uptake Factor) to sampled values. Consumption rate changed from a constant value of 557.68 kg / yr to a normal distribution with a mean of 102.96 kg / yr and a standard deviation of 2.65 kg / yr. Meanwhile, Average Crop Yield changed from a constant value of 3.783 kg edible / m 2 to a normal distribution with a mean of 3.23 kg edible / m 2 and a standard deviation of 0.442 kg edible / m 2 . The Cropland to Landuse Database ratio changed from a constant value of 0.0996 (9.96%) to a normal distribution with a mean value of 0.0312 (3.12%) and a standard deviation of 0.00292 (0.29%). Finally the crop uptake factor changed from a constant value of 6.37e-4 (Bq crop /kg)/(Bq soil /kg) to a lognormal distribution with a geometric mean value of 3.38e-4 (Bq crop /kg)/(Bq soil /kg) and a standard deviation value of 3.33 (Bq crop /kg)/(Bq soil /kg)

  3. Analysis on relation between safety input and accidents

    Institute of Scientific and Technical Information of China (English)

    YAO Qing-guo; ZHANG Xue-mu; LI Chun-hui

    2007-01-01

    The number of safety input directly determines the level of safety, and there exists dialectical and unified relations between safety input and accidents. Based on the field investigation and reliable data, this paper deeply studied the dialectical relationship between safety input and accidents, and acquired the conclusions. The security situation of the coal enterprises was related to the security input rate, being effected little by the security input scale, and build the relationship model between safety input and accidents on this basis, that is the accident model.

  4. Modal Parameter Identification from Responses of General Unknown Random Inputs

    DEFF Research Database (Denmark)

    Ibrahim, S. R.; Asmussen, J. C.; Brincker, Rune

    1996-01-01

    Modal parameter identification from ambient responses due to a general unknown random inputs is investigated. Existing identification techniques which are based on assumptions of white noise and or stationary random inputs are utilized even though the inputs conditions are not satisfied....... This is accomplished via adding. In cascade. A force cascade conversion to the structures system under consideration. The input to the force conversion system is white noise and the output of which is the actual force(s) applied to the structure. The white noise input(s) and the structures responses are then used...

  5. History of nutrient inputs to the northeastern United States, 1930-2000

    Science.gov (United States)

    Hale, Rebecca L.; Hoover, Joseph H.; Wollheim, Wilfred M.; Vörösmarty, Charles J.

    2013-04-01

    Humans have dramatically altered nutrient cycles at local to global scales. We examined changes in anthropogenic nutrient inputs to the northeastern United States (NE) from 1930 to 2000. We created a comprehensive time series of anthropogenic N and P inputs to 437 counties in the NE at 5 year intervals. Inputs included atmospheric N deposition, biological N2 fixation, fertilizer, detergent P, livestock feed, and human food. Exports included exports of feed and food and volatilization of ammonia. N inputs to the NE increased throughout the study period, primarily due to increases in atmospheric deposition and fertilizer. P inputs increased until 1970 and then declined due to decreased fertilizer and detergent inputs. Livestock consistently consumed the majority of nutrient inputs over time and space. The area of crop agriculture declined during the study period but consumed more nutrients as fertilizer. We found that stoichiometry (N:P) of inputs and absolute amounts of N matched nutritional needs (livestock, humans, crops) when atmospheric components (N deposition, N2 fixation) were not included. Differences between N and P led to major changes in N:P stoichiometry over time, consistent with global trends. N:P decreased from 1930 to 1970 due to increased inputs of P, and increased from 1970 to 2000 due to increased N deposition and fertilizer and decreases in P fertilizer and detergent use. We found that nutrient use is a dynamic product of social, economic, political, and environmental interactions. Therefore, future nutrient management must take into account these factors to design successful and effective nutrient reduction measures.

  6. Effect of input compression and input frequency response on music perception in cochlear implant users.

    Science.gov (United States)

    Halliwell, Emily R; Jones, Linor L; Fraser, Matthew; Lockley, Morag; Hill-Feltham, Penelope; McKay, Colette M

    2015-06-01

    A study was conducted to determine whether modifications to input compression and input frequency response characteristics can improve music-listening satisfaction in cochlear implant users. Experiment 1 compared three pre-processed versions of music and speech stimuli in a laboratory setting: original, compressed, and flattened frequency response. Music excerpts comprised three music genres (classical, country, and jazz), and a running speech excerpt was compared. Experiment 2 implemented a flattened input frequency response in the speech processor program. In a take-home trial, participants compared unaltered and flattened frequency responses. Ten and twelve adult Nucleus Freedom cochlear implant users participated in Experiments 1 and 2, respectively. Experiment 1 revealed a significant preference for music stimuli with a flattened frequency response compared to both original and compressed stimuli, whereas there was a significant preference for the original (rising) frequency response for speech stimuli. Experiment 2 revealed no significant mean preference for the flattened frequency response, with 9 of 11 subjects preferring the rising frequency response. Input compression did not alter music enjoyment. Comparison of the two experiments indicated that individual frequency response preferences may depend on the genre or familiarity, and particularly whether the music contained lyrics.

  7. Robust input design for nonlinear dynamic modeling of AUV.

    Science.gov (United States)

    Nouri, Nowrouz Mohammad; Valadi, Mehrdad

    2017-09-01

    Input design has a dominant role in developing the dynamic model of autonomous underwater vehicles (AUVs) through system identification. Optimal input design is the process of generating informative inputs that can be used to generate the good quality dynamic model of AUVs. In a problem with optimal input design, the desired input signal depends on the unknown system which is intended to be identified. In this paper, the input design approach which is robust to uncertainties in model parameters is used. The Bayesian robust design strategy is applied to design input signals for dynamic modeling of AUVs. The employed approach can design multiple inputs and apply constraints on an AUV system's inputs and outputs. Particle swarm optimization (PSO) is employed to solve the constraint robust optimization problem. The presented algorithm is used for designing the input signals for an AUV, and the estimate obtained by robust input design is compared with that of the optimal input design. According to the results, proposed input design can satisfy both robustness of constraints and optimality. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  8. Description of the CONTAIN input model for the Dodewaard nuclear power plant

    International Nuclear Information System (INIS)

    Velema, E.J.

    1992-02-01

    This report describes the ECN standard CONTAIN input model for the Dodewaard Nuclear Power Plant (NPP) that has been developed by ECN. This standard input model will serve as a basis for analyses of the phenomena which may occur inside the Dodewaard containment in the event of a postulated severe accident. Boundary conditions for specific containment analyses can easily be implemented in the input model. as a result ECN will be able to respond quickly on requests for analyses from the utilities of the authorities. The report also includes brief descriptions of the Dodewaard NPP and the CONTAIN computer program. (author). 7 refs.; 5 figs.; 3 tabs

  9. Water resources and environmental input-output analysis and its key study issues: a review

    Science.gov (United States)

    YANG, Z.; Xu, X.

    2013-12-01

    inland water resources IOA. Recent internal study references related to environmental input-output table, pollution discharge analysis and environmental impact assessment had taken the leading position. Pollution discharge analysis mainly aiming at CO2 discharge had been regard as a new hotspot of environmental IOA. Environmental impact assessment was an important direction of inland environmental IOA in recent years. Key study issues including Domestic Technology Assumption(DTA) and Sectoral Aggregation(SA) had been mentioned remarkably. It was pointed out that multiply multi-region input-output analysis(MIOA) may be helpful to solve DTA. Because there was little study using effective analysis tools to quantify the bias of SA and the exploration of the appropriate sectoral aggregation degree was scarce, research dedicating to explore and solve these two key issues was deemed to be urgently needed. According to the study status, several points of outlook were proposed in the end.

  10. Responses of tree and insect herbivores to elevated nitrogen inputs: A meta-analysis

    Science.gov (United States)

    Li, Furong; Dudley, Tom L.; Chen, Baoming; Chang, Xiaoyu; Liang, Liyin; Peng, Shaolin

    2016-11-01

    Increasing atmospheric nitrogen (N) inputs have the potential to alter terrestrial ecosystem function through impacts on plant-herbivore interactions. The goal of our study is to search for a general pattern in responses of tree characteristics important for herbivores and insect herbivorous performance to elevated N inputs. We conducted a meta-analysis based on 109 papers describing impacts of nitrogen inputs on tree characteristics and 16 papers on insect performance. The differences in plant characteristics and insect performance between broadleaves and conifers were also explored. Tree aboveground biomass, leaf biomass and leaf N concentration significantly increased under elevated N inputs. Elevated N inputs had no significantly overall effect on concentrations of phenolic compounds and lignin but adversely affected tannin, as defensive chemicals for insect herbivores. Additionally, the overall effect of insect herbivore performance (including development time, insect biomass, relative growth rate, and so on) was significantly increased by elevated N inputs. According to the inconsistent responses between broadleaves and conifers, broadleaves would be more likely to increase growth by light interception and photosynthesis rather than producing more defensive chemicals to elevated N inputs by comparison with conifers. Moreover, the overall carbohydrate concentration was significantly reduced by 13.12% in broadleaves while increased slightly in conifers. The overall tannin concentration decreased significantly by 39.21% in broadleaves but a 5.8% decrease in conifers was not significant. The results of the analysis indicated that elevated N inputs would provide more food sources and ameliorate tree palatability for insects, while the resistance of trees against their insect herbivores was weakened, especially for broadleaves. Thus, global forest insect pest problems would be aggravated by elevated N inputs. As N inputs continue to rise in the future, forest

  11. Discrete Input Signaling for MISO Visible Light Communication Channels

    KAUST Repository

    Arfaoui, Mohamed Amine; Rezki, Zouheir; Ghrayeb, Ali; Alouini, Mohamed-Slim

    2017-01-01

    In this paper, we study the achievable secrecy rate of visible light communication (VLC) links for discrete input distributions. We consider single user single eavesdropper multiple-input single-output (MISO) links. In addition, both beamforming

  12. Radioactive inputs to the North Sea and the Channel

    International Nuclear Information System (INIS)

    1984-01-01

    The subject is covered in sections: introduction (radioactivity; radioisotopes; discharges from nuclear establishments); data sources (statutory requirements); sources of liquid radioactive waste (figure showing location of principal sources of radioactive discharges; tables listing principal discharges by activity and by nature of radioisotope); Central Electricity Generating Board nuclear power stations; research and industrial establishments; Ministy of Defence establishments; other UK inputs of radioactive waste; total inputs to the North Sea and the Channel (direct inputs; river inputs; adjacent sea areas); conclusions. (U.K.)

  13. On the source of the 5-55 keV Heliosphere ENAs measured with Cassini/INCA

    Science.gov (United States)

    Dialynas, Konstantinos; Roelof, Edmond; Mitchell, Donald; Krimigis, Stamatios; Decker, Robert

    2016-07-01

    The Low Energy Charged Particle (LECP) in situ measurements from V1 and V2 have revealed a reservoir of ions and electrons that constitute the heliosheath (HS) after crossing the termination shock (TS) 35deg north and 32deg south of the ecliptic plane at 94 and 84 astronomical units (1 AU= 1.5 x10 ^{8} km), respectively. The outer Heliosphere boundary, the Heliopause (HP), has now been determined in the direction of V1 to be at ˜122 AU. The in situ measurements by each Voyager were placed in a global context by remote sensing images using ENA obtained with the Ion and Neutral Camera (INCA) onboard Cassini orbiting Saturn. The ENA images have revealed a 5.2-55 keV hydrogen (H) ENA region (Belt) that loops through the celestial sphere and contributes to balancing the pressure of the interstellar magnetic field (ISMF). Here we address one of the remaining and most important questions: Where do the 5-55 keV ENAs that INCA measures come from? We analyzed INCA all-sky maps from 2003 to 2015 and compare the solar cycle (SC) variation of the ENAs in both the nose (upstream) and anti-nose (downstream) directions with the intensities of > 30 keV ions (source of ENA through charge exchange-CE with H) measured in-situ by V1 and V2, in overlapping energy bands ˜30-55 keV. ENA intensities decrease during the declining phase of SC23 by ˜x3 from 2003 to 2011 but recover through 2014 (SC24); similarly, V1 and V2 ion intensities also decrease and then recover through 2014. The similarity of time profiles of remotely sensed ENA and locally measured ions are consistent with (a) ENA originating in the HS, and (b) the global HS responding promptly (within ˜1-1.5 years) to outward-propagating solar wind changes throughout the SC. Further, recovery of the Belt during SC24 precedes asymmetrically from south to north in the general direction of the nose. This may be related to the non-symmetric evolution of solar coronal holes during SC recovery.

  14. A three-coordinate system (ecliptic, galactic, ISMF) spectral analysis of heliospheric ENA emissions using CASSINI/INCA measurements

    International Nuclear Information System (INIS)

    Dialynas, K.; Krimigis, S. M.; Mitchell, D. G.; Roelof, E. C.; Decker, R. B

    2013-01-01

    In the present study, we use all-sky energy-resolved energetic neutral atom (ENA) maps obtained by the Ion and Neutral CAmera (INCA) instrument on board Cassini that correspond to the time period from 2003 to 2009, in four discrete energy passbands (∼5.4 to ∼55 keV), to investigate the geometrical characteristics of the belt (a broad band of emission in the sky). The heliospheric ENA emissions are mapped in three different coordinate systems (ecliptic, Galactic, and interstellar magnetic field (ISMF)), and spectral analyses are performed to further examine the belt's possible energy dependence. Our conclusions are summarized as follows: (1) the high flux ENA belt identified in the energy range of 8-42 keV is moderately well organized in Galactic coordinates, as the ENA minima appear in the vicinity of the north and south Galactic poles; (2) using minimization criteria ( B · R ∼ 0), the deviation of the ENA emissions from the equator is effectively minimized in a rotated frame, which we interpret as ISMF, where its north pole points toward 190° ecliptic longitude and 15° ecliptic latitude; (3) ENA spectra show a power-law form in energy that can be fitted with a single function presenting higher spectral slopes in the belt region and lower outside (3.4 < γ < 4.4); (4) the spectra are almost indistinguishable between the tail and the nose regions, i.e., no noticeable asymmetry is observed; (5) the consistency of the ENA distributions as a function of latitude among the different INCA channels indicates that the morphology of the belt (peak, width, and structure) is nearly energy independent from 8 keV to 30 keV (minor deviations start to appear at >35 keV); and (6) in the low count rate regions, the long-term ENA count rate profiles do not match the measured cosmic ray profiles, indicating that even the minimum ENA emissions detected by INCA are foreground ENAs.

  15. Calibrating the input accountancy tanks on THORP

    International Nuclear Information System (INIS)

    Whyte, C.G.; Hillier, A.P.; Temple, A.

    1995-01-01

    BNFL's Thermal Oxide Reprocessing Plant (THORP), at Sellafield in the UK, processes oxide fuels from customers around the world. The fuel moves through the plant from shearing and dissolution in the Head End and subsequently to solvent extraction in the Chemical Plant. Clarified dissolver liquor is accumulated in three large buffer storage tanks (each of approximately 75 m 3 capacity), in the Head End prior to feeding to the Chemical Plant. The amount of dissolver liquor being passed to these tanks is accurately measured in one of two Input Accountancy Tanks, which are each of 23 m 3 working capacity, and are equipped with high accuracy weight and level measurement systems. Several papers have been published which describe the principles applied to achieve the Safeguarding of THORP. This paper describes the setting to work of a key measurement point in the THORP process and details the complex trials that were begun during the early commissioning phases, to ensure that these accountancy systems would eventually be fully characterized

  16. Information Fusion of Conflicting Input Data

    Directory of Open Access Journals (Sweden)

    Uwe Mönks

    2016-10-01

    Full Text Available Sensors, and also actuators or external sources such as databases, serve as data sources in order to realise condition monitoring of industrial applications or the acquisition of characteristic parameters like production speed or reject rate. Modern facilities create such a large amount of complex data that a machine operator is unable to comprehend and process the information contained in the data. Thus, information fusion mechanisms gain increasing importance. Besides the management of large amounts of data, further challenges towards the fusion algorithms arise from epistemic uncertainties (incomplete knowledge in the input signals as well as conflicts between them. These aspects must be considered during information processing to obtain reliable results, which are in accordance with the real world. The analysis of the scientific state of the art shows that current solutions fulfil said requirements at most only partly. This article proposes the multilayered information fusion system MACRO (multilayer attribute-based conflict-reducing observation employing the μBalTLCS (fuzzified balanced two-layer conflict solving fusion algorithm to reduce the impact of conflicts on the fusion result. The performance of the contribution is shown by its evaluation in the scope of a machine condition monitoring application under laboratory conditions. Here, the MACRO system yields the best results compared to state-of-the-art fusion mechanisms. The utilised data is published and freely accessible.

  17. Information Fusion of Conflicting Input Data.

    Science.gov (United States)

    Mönks, Uwe; Dörksen, Helene; Lohweg, Volker; Hübner, Michael

    2016-10-29

    Sensors, and also actuators or external sources such as databases, serve as data sources in order to realise condition monitoring of industrial applications or the acquisition of characteristic parameters like production speed or reject rate. Modern facilities create such a large amount of complex data that a machine operator is unable to comprehend and process the information contained in the data. Thus, information fusion mechanisms gain increasing importance. Besides the management of large amounts of data, further challenges towards the fusion algorithms arise from epistemic uncertainties (incomplete knowledge) in the input signals as well as conflicts between them. These aspects must be considered during information processing to obtain reliable results, which are in accordance with the real world. The analysis of the scientific state of the art shows that current solutions fulfil said requirements at most only partly. This article proposes the multilayered information fusion system MACRO (multilayer attribute-based conflict-reducing observation) employing the μ BalTLCS (fuzzified balanced two-layer conflict solving) fusion algorithm to reduce the impact of conflicts on the fusion result. The performance of the contribution is shown by its evaluation in the scope of a machine condition monitoring application under laboratory conditions. Here, the MACRO system yields the best results compared to state-of-the-art fusion mechanisms. The utilised data is published and freely accessible.

  18. Grammar in Context using Comprehended Input

    Directory of Open Access Journals (Sweden)

    Mariam Mohamed Nor

    2014-03-01

    Full Text Available There have been so many ongoing disputes on different approaches to teaching grammar. This study aims to evaluate the effectiveness of teaching grammar using Gass comprehended Input technique (GCI (1997 (implicit and to explore the undergraduates’ perception on the GCI technique. The respondents consisted of 30 undergraduates’ who are currently pursuing their Bachelor of English. Using the qualitative method, the research instrument was a set of 23- item interview and content analysis of the students’ written work. Results showed that the teaching of grammar using explicit instructions was more preferred than implicit instruction for complex components in grammatical rules. However, implicit instruction is equally effective regardless of the proficiency levels to enable pedagogy to be executed. It is also noted that there is lots of room for improvement, since the undergraduates have a weak grasp of the basic tense aspect of English grammar. Therefore, the Malaysian Ministry of Education should consider having grammar formally taught in isolation as what was practised previously.

  19. Remote sensing inputs to water demand modeling

    Science.gov (United States)

    Estes, J. E.; Jensen, J. R.; Tinney, L. R.; Rector, M.

    1975-01-01

    In an attempt to determine the ability of remote sensing techniques to economically generate data required by water demand models, the Geography Remote Sensing Unit, in conjunction with the Kern County Water Agency of California, developed an analysis model. As a result it was determined that agricultural cropland inventories utilizing both high altitude photography and LANDSAT imagery can be conducted cost effectively. In addition, by using average irrigation application rates in conjunction with cropland data, estimates of agricultural water demand can be generated. However, more accurate estimates are possible if crop type, acreage, and crop specific application rates are employed. An analysis of the effect of saline-alkali soils on water demand in the study area is also examined. Finally, reference is made to the detection and delineation of water tables that are perched near the surface by semi-permeable clay layers. Soil salinity prediction, automated crop identification on a by-field basis, and a potential input to the determination of zones of equal benefit taxation are briefly touched upon.

  20. Keyboards for inputting Japanese language -A study based on US patents

    OpenAIRE

    Mishra, Umakant

    2013-01-01

    The most commonly used Japanese alphabets are Kanji, Hiragana and Katakana. The Kanji alphabet includes pictographs or ideographic characters that were adopted from the Chinese alphabet. Hiragana is used to spell words of Japanese origin, while Katakana is used to spell words of western or other foreign origin. Two methods are commonly used to input Japanese to the computer. One, the 'kana input method' that uses a keyboard having 46 Japanese iroha (or kana) letter keys. The other method is '...

  1. Comparison of Linear Microinstability Calculations of Varying Input Realism

    International Nuclear Information System (INIS)

    Rewoldt, G.

    2003-01-01

    The effect of varying ''input realism'' or varying completeness of the input data for linear microinstability calculations, in particular on the critical value of the ion temperature gradient for the ion temperature gradient mode, is investigated using gyrokinetic and gyrofluid approaches. The calculations show that varying input realism can have a substantial quantitative effect on the results

  2. Distinctiveness and Bidirectional Effects in Input Enhancement for Vocabulary Learning

    Science.gov (United States)

    Barcroft, Joe

    2003-01-01

    This study examined input enhancement and second language (L2) vocabulary learning while exploring the role of "distinctiveness," the degree to which an item in the input diverges from the form in which other items in the input are presented, with regard to the nature and direction of the effects of enhancement. In this study,…

  3. 7 CFR 3431.4 - Solicitation of stakeholder input.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Solicitation of stakeholder input. 3431.4 Section... Designation of Veterinarian Shortage Situations § 3431.4 Solicitation of stakeholder input. The Secretary will solicit stakeholder input on the process and procedures used to designate veterinarian shortage situations...

  4. Comparison of linear microinstability calculations of varying input realism

    International Nuclear Information System (INIS)

    Rewoldt, G.; Kinsey, J.E.

    2004-01-01

    The effect of varying 'input realism' or varying completeness of the input data for linear microinstability calculations, in particular on the critical value of the ion temperature gradient for the ion temperature gradient mode, is investigated using gyrokinetic and gyrofluid approaches. The calculations show that varying input realism can have a substantial quantitative effect on the results

  5. Evaluating the uncertainty of input quantities in measurement models

    Science.gov (United States)

    Possolo, Antonio; Elster, Clemens

    2014-06-01

    The Guide to the Expression of Uncertainty in Measurement (GUM) gives guidance about how values and uncertainties should be assigned to the input quantities that appear in measurement models. This contribution offers a concrete proposal for how that guidance may be updated in light of the advances in the evaluation and expression of measurement uncertainty that were made in the course of the twenty years that have elapsed since the publication of the GUM, and also considering situations that the GUM does not yet contemplate. Our motivation is the ongoing conversation about a new edition of the GUM. While generally we favour a Bayesian approach to uncertainty evaluation, we also recognize the value that other approaches may bring to the problems considered here, and focus on methods for uncertainty evaluation and propagation that are widely applicable, including to cases that the GUM has not yet addressed. In addition to Bayesian methods, we discuss maximum-likelihood estimation, robust statistical methods, and measurement models where values of nominal properties play the same role that input quantities play in traditional models. We illustrate these general-purpose techniques in concrete examples, employing data sets that are realistic but that also are of conveniently small sizes. The supplementary material available online lists the R computer code that we have used to produce these examples (stacks.iop.org/Met/51/3/339/mmedia). Although we strive to stay close to clause 4 of the GUM, which addresses the evaluation of uncertainty for input quantities, we depart from it as we review the classes of measurement models that we believe are generally useful in contemporary measurement science. We also considerably expand and update the treatment that the GUM gives to Type B evaluations of uncertainty: reviewing the state-of-the-art, disciplined approach to the elicitation of expert knowledge, and its encapsulation in probability distributions that are usable in

  6. Inhalation Exposure Input Parameters for the Biosphere Model

    Energy Technology Data Exchange (ETDEWEB)

    M. A. Wasiolek

    2003-09-24

    This analysis is one of the nine reports that support the Environmental Radiation Model for Yucca Mountain Nevada (ERMYN) biosphere model. The ''Biosphere Model Report'' (BSC 2003a) describes in detail the conceptual model as well as the mathematical model and its input parameters. This report documents a set of input parameters for the biosphere model, and supports the use of the model to develop biosphere dose conversion factors (BDCFs). The biosphere model is one of a series of process models supporting the Total System Performance Assessment (TSPA) for a Yucca Mountain repository. This report, ''Inhalation Exposure Input Parameters for the Biosphere Model'', is one of the five reports that develop input parameters for the biosphere model. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling, and the plan for development of the biosphere abstraction products for TSPA, as identified in the ''Technical Work Plan: for Biosphere Modeling and Expert Support'' (BSC 2003b). It should be noted that some documents identified in Figure 1-1 may be under development at the time this report is issued and therefore not available at that time. This figure is included to provide an understanding of how this analysis report contributes to biosphere modeling in support of the license application, and is not intended to imply that access to the listed documents is required to understand the contents of this analysis report. This analysis report defines and justifies values of mass loading, which is the total mass concentration of resuspended particles (e.g., dust, ash) in a volume of air. Measurements of mass loading are used in the air submodel of ERMYN to calculate concentrations of radionuclides in air surrounding crops and concentrations in air

  7. Inhalation Exposure Input Parameters for the Biosphere Model

    International Nuclear Information System (INIS)

    M. A. Wasiolek

    2003-01-01

    This analysis is one of the nine reports that support the Environmental Radiation Model for Yucca Mountain Nevada (ERMYN) biosphere model. The ''Biosphere Model Report'' (BSC 2003a) describes in detail the conceptual model as well as the mathematical model and its input parameters. This report documents a set of input parameters for the biosphere model, and supports the use of the model to develop biosphere dose conversion factors (BDCFs). The biosphere model is one of a series of process models supporting the Total System Performance Assessment (TSPA) for a Yucca Mountain repository. This report, ''Inhalation Exposure Input Parameters for the Biosphere Model'', is one of the five reports that develop input parameters for the biosphere model. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling, and the plan for development of the biosphere abstraction products for TSPA, as identified in the ''Technical Work Plan: for Biosphere Modeling and Expert Support'' (BSC 2003b). It should be noted that some documents identified in Figure 1-1 may be under development at the time this report is issued and therefore not available at that time. This figure is included to provide an understanding of how this analysis report contributes to biosphere modeling in support of the license application, and is not intended to imply that access to the listed documents is required to understand the contents of this analysis report. This analysis report defines and justifies values of mass loading, which is the total mass concentration of resuspended particles (e.g., dust, ash) in a volume of air. Measurements of mass loading are used in the air submodel of ERMYN to calculate concentrations of radionuclides in air surrounding crops and concentrations in air inhaled by a receptor. Concentrations in air to which the

  8. Appreciate the Appreciation: Imported Inputs and Concern Over Dutch Disease

    Directory of Open Access Journals (Sweden)

    Wardah Naim

    2013-03-01

    Full Text Available If anything is to blame for a higher dollar having negative effects on the Central Canadian manufacturing sector, you are not likely to find it in any “Dutch Disease” supposedly caused by Alberta’s oil sands. Contrary to popular belief, the higher value of the Canadian dollar may even help Central Canadian manufacturers grow stronger, cut costs, and create jobs. The idea that a booming, commodity-driven dollar is hurting Canadian goods exports, afflicting the country with so-called Dutch Disease, may be popular among certain politicians, including federal Opposition leader Thomas Mulcair and former Premier of Ontario Dalton McGuinty, but is not supported by the facts. It turns out that the simple economic theory these politicians have in mind is incomplete. A more thorough, data-driven look at the nation’s manufacturing sector reveals that Canadian businesses rely very heavily on imported materials and equipment as inputs in the manufacturing process. Canadian industry overall has one of the highest import ratios for such intermediate goods in the OECD, roughly twice as high as that of the U.S., the European Union and Japan. Compared to all other sectors, manufacturers are the heaviest users of imported materials and equipment, with more than 40 per cent of their inputs coming from other countries. A higher dollar may make it more expensive for foreign buyers to purchase Canadian manufactured goods, but that effect appears to be more than offset by the savings that Canadian producers enjoy with a higher dollar that makes possible cheaper imported-inputs and lower cost of production, which have a lowering effect on prices. The net result is that Canadian manufacturers actually get more benefit from a higher dollar, and the regions that get the biggest boost from it are the Central Canadian provinces of Ontario and Quebec. Policy-makers looking to aid the Canadian economy as a whole, and the manufacturing sector in particular, should stop

  9. Seaweed community response to a massive CO2 input

    Science.gov (United States)

    Sangil, Carlos; Clemente, Sabrina; Brito, Alberto; Rodríguez, Adriana; Balsalobre, Marc; Mendoza, José Carlos; Martínez, David; Hernández, José Carlos

    2016-09-01

    Changes in the structure of seaweed communities were examined following a massive CO2 input caused by a submarine eruption near the coast of El Hierro island (Canary Islands, Spain). The event lasted almost five months (October 2011-March 2012) and created a significant pH gradient. Specifically, we compared three different zones: highly affected with extreme low pH (6.7-7.3), affected with low pH (7.6-7.8), and unaffected ambient pH zone (∼8.1) according to the pH gradient generated by the predominate currents and waves in the south of the island. Studies were carried out before, during and after the CO2 input event in each zone. We found community-wide effects on seaweed communities during the eruption; these included changes in species abundance and changes in the diversity. However, changes in all these community traits were only evident in the highly affected zone, where there were major shifts in the seaweed community, with a replacement of Lobophora variegata by ephemeral seaweeds. Lobophora variegata dropped in cover from 87-94 to 27% while ephemeral seaweeds increased 6-10 to 29%. When the impact ended Lobophora variegata began to recover reaching a cover higher than 60%. In the moderate affected area the Lobophora variegata canopies maintained their integrity avoiding phase shifts to turfs. Here the only significant changes were the reduction of the cover of the crustose and geniculate coralline algae.

  10. Ankylosing Spondylitis and Posture Control: The Role of Visual Input

    Directory of Open Access Journals (Sweden)

    Alessandro Marco De Nunzio

    2015-01-01

    Full Text Available Objectives. To assess the motor control during quiet stance in patients with established ankylosing spondylitis (AS and to evaluate the effect of visual input on the maintenance of a quiet posture. Methods. 12 male AS patients (mean age 50.1 ± 13.2 years and 12 matched healthy subjects performed 2 sessions of 3 trials in quiet stance, with eyes open (EO and with eyes closed (EC on a baropodometric platform. The oscillation of the centre of feet pressure (CoP was acquired. Indices of stability and balance control were assessed by the sway path (SP of the CoP, the frequency bandwidth (FB1 that includes the 80% of the area under the amplitude spectrum, the mean amplitude of the peaks (MP of the sway density curve (SDC, and the mean distance (MD between 2 peaks of the SDC. Results. In severe AS patients, the MD between two peaks of the SDC and the SP of the center of feet pressure were significantly higher than controls during both EO and EC conditions. The MP was significantly reduced just on EC. Conclusions. Ankylosing spondylitis exerts negative effect on postural stability, not compensable by visual inputs. Our findings may be useful in the rehabilitative management of the increased risk of falling in AS.

  11. Ankylosing Spondylitis and Posture Control: The Role of Visual Input

    Science.gov (United States)

    De Nunzio, Alessandro Marco; Iervolino, Salvatore; Zincarelli, Carmela; Di Gioia, Luisa; Rengo, Giuseppe; Multari, Vincenzo; Peluso, Rosario; Di Minno, Matteo Nicola Dario; Pappone, Nicola

    2015-01-01

    Objectives. To assess the motor control during quiet stance in patients with established ankylosing spondylitis (AS) and to evaluate the effect of visual input on the maintenance of a quiet posture. Methods. 12 male AS patients (mean age 50.1 ± 13.2 years) and 12 matched healthy subjects performed 2 sessions of 3 trials in quiet stance, with eyes open (EO) and with eyes closed (EC) on a baropodometric platform. The oscillation of the centre of feet pressure (CoP) was acquired. Indices of stability and balance control were assessed by the sway path (SP) of the CoP, the frequency bandwidth (FB1) that includes the 80% of the area under the amplitude spectrum, the mean amplitude of the peaks (MP) of the sway density curve (SDC), and the mean distance (MD) between 2 peaks of the SDC. Results. In severe AS patients, the MD between two peaks of the SDC and the SP of the center of feet pressure were significantly higher than controls during both EO and EC conditions. The MP was significantly reduced just on EC. Conclusions. Ankylosing spondylitis exerts negative effect on postural stability, not compensable by visual inputs. Our findings may be useful in the rehabilitative management of the increased risk of falling in AS. PMID:25821831

  12. Lattice QCD inputs to the CKM unitarity triangle analysis

    International Nuclear Information System (INIS)

    Laiho, Jack; Lunghi, E.; Van de Water, Ruth S.

    2010-01-01

    We perform a global fit to the Cabibbo-Kobayashi-Maskawa unitarity triangle using the latest experimental and theoretical constraints. Our emphasis is on the hadronic weak matrix elements that enter the analysis, which must be computed using lattice QCD or other nonperturbative methods. Realistic lattice QCD calculations which include the effects of the dynamical up, down, and strange quarks are now available for all of the standard inputs to the global fit. We therefore present lattice averages for all of the necessary hadronic weak matrix elements. We attempt to account for correlations between lattice QCD results in a reasonable but conservative manner: whenever there are reasons to believe that an error is correlated between two lattice calculations, we take the degree of correlation to be 100%. These averages are suitable for use as inputs both in the global Cabibbo-Kobayashi-Maskawa unitarity triangle fit and other phenomenological analyses. In order to illustrate the impact of the lattice averages, we make standard model predictions for the parameters B-circumflex K , |V cb |, and |V ub |/|V cb |. We find a (2-3)σ tension in the unitarity triangle, depending upon whether we use the inclusive or exclusive determination of |V cb |. If we interpret the tension as a sign of new physics in either neutral kaon or B mixing, we find that the scenario with new physics in kaon mixing is preferred by present data.

  13. Tritium Records to Trace Stratospheric Moisture Inputs in Antarctica

    Science.gov (United States)

    Fourré, E.; Landais, A.; Cauquoin, A.; Jean-Baptiste, P.; Lipenkov, V.; Petit, J.-R.

    2018-03-01

    Better assessing the dynamic of stratosphere-troposphere exchange is a key point to improve our understanding of the climate dynamic in the East Antarctica Plateau, a region where stratospheric inputs are expected to be important. Although tritium (3H or T), a nuclide naturally produced mainly in the stratosphere and rapidly entering the water cycle as HTO, seems a first-rate tracer to study these processes, tritium data are very sparse in this region. We present the first high-resolution measurements of tritium concentration over the last 50 years in three snow pits drilled at the Vostok station. Natural variability of the tritium records reveals two prominent frequencies, one at about 10 years (to be related to the solar Schwabe cycles) and the other one at a shorter periodicity: despite dating uncertainty at this short scale, a good correlation is observed between 3H and Na+ and an anticorrelation between 3H and δ18O measured on an individual pit. The outputs from the LMDZ Atmospheric General Circulation Model including stable water isotopes and tritium show the same 3H-δ18O anticorrelation and allow further investigation on the associated mechanism. At the interannual scale, the modeled 3H variability matches well with the Southern Annular Mode index. At the seasonal scale, we show that modeled stratospheric tritium inputs in the troposphere are favored in winter cold and dry conditions.

  14. LTRACK: Beam-transport calculation including wakefield effects

    International Nuclear Information System (INIS)

    Chan, K.C.D.; Cooper, R.K.

    1988-01-01

    LTRACK is a first-order beam-transport code that includes wakefield effects up to quadrupole modes. This paper will introduce the readers to this computer code by describing the history, the method of calculations, and a brief summary of the input/output information. Future plans for the code will also be described

  15. Asymmetric temporal integration of layer 4 and layer 2/3 inputs in visual cortex.

    Science.gov (United States)

    Hang, Giao B; Dan, Yang

    2011-01-01

    Neocortical neurons in vivo receive concurrent synaptic inputs from multiple sources, including feedforward, horizontal, and feedback pathways. Layer 2/3 of the visual cortex receives feedforward input from layer 4 and horizontal input from layer 2/3. Firing of the pyramidal neurons, which carries the output to higher cortical areas, depends critically on the interaction of these pathways. Here we examined synaptic integration of inputs from layer 4 and layer 2/3 in rat visual cortical slices. We found that the integration is sublinear and temporally asymmetric, with larger responses if layer 2/3 input preceded layer 4 input. The sublinearity depended on inhibition, and the asymmetry was largely attributable to the difference between the two inhibitory inputs. Interestingly, the asymmetric integration was specific to pyramidal neurons, and it strongly affected their spiking output. Thus via cortical inhibition, the temporal order of activation of layer 2/3 and layer 4 pathways can exert powerful control of cortical output during visual processing.

  16. Development of an Input Model to MELCOR 1.8.5 for the Ringhals 3 PWR

    International Nuclear Information System (INIS)

    Nilsson, Lars

    2004-12-01

    An input file to the severe accident code MELCOR 1.8.5 has been developed for the Swedish pressurized water reactor Ringhals 3. The aim was to produce a file that can be used for calculations of various postulated severe accident scenarios, although the first application is specifically on cases involving large hydrogen production. The input file is rather detailed with individual modelling of all three cooling loops. The report describes the basis for the Ringhals 3 model and the input preparation step by step and is illustrated by nodalization schemes of the different plant systems. Present version of the report is restricted to the fundamental MELCOR input preparation, and therefore most of the figures of Ringhals 3 measurements and operating parameters are excluded here. These are given in another, complete version of the report, for limited distribution, which includes tables for pertinent data of all components. That version contains appendices with a complete listing of the input files as well as tables of data compiled from a RELAP5 file, that was a major basis for the MELCOR input for the cooling loops. The input was tested in steady-state calculations in order to simulate the initial conditions at current nominal operating conditions in Ringhals 3 for 2775 MW thermal power. The results of the steady-state calculations are presented in the report. Calculations with the MELCOR model will then be carried out of certain accident sequences for comparison with results from earlier MAAP4 calculations. That work will be reported separately

  17. Development of the RETRAN input model for Ulchin 3/4 visual system analyzer

    International Nuclear Information System (INIS)

    Lee, S. W.; Kim, K. D.; Lee, Y. J.; Lee, W. J.; Chung, B. D.; Jeong, J. J.; Hwang, M. K.

    2004-01-01

    As a part of the Long-Term Nuclear R and D program, KAERI has developed the so-called Visual System Analyzer (ViSA) based on best-estimate codes. The MARS and RETRAN codes are used as the best-estimate codes for ViSA. Between these two codes, the RETRAN code is used for realistic analysis of Non-LOCA transients and small-break loss-of-coolant accidents, of which break size is less than 3 inch diameter. So it is necessary to develop the RETRAN input model for Ulchin 3/4 plants (KSNP). In recognition of this, the RETRAN input model for Ulchin 3/4 plants has been developed. This report includes the input model requirements and the calculation note for the input data generation (see the Appendix). In order to confirm the validity of the input data, the calculations are performed for a steady state at 100 % power operation condition, inadvertent reactor trip and RCP trip. The results of the steady-state calculation agree well with the design data. The results of the other transient calculations seem to be reasonable and consistent with those of other best-estimate calculations. Therefore, the RETRAN input data can be used as a base input deck for the RETRAN transient analyzer for Ulchin 3/4. Moreover, it is found that Core Protection Calculator (CPC) module, which is modified by Korea Electric Power Research Institute (KEPRI), is well adapted to ViSA

  18. Input/output plugin architecture for MDSplus

    International Nuclear Information System (INIS)

    Stillerman, Joshua; Fredian, Thomas; Manduchi, Gabriele

    2014-01-01

    The first version of MDSplus was released in 1991 for VAX/VMS. Since that time the underlying file formats have remained constant. The software however has evolved, it was ported to unix, linux, Windows, and Macintosh. In 1997 a TCP based protocol, mdsip, was added to provide network access to MDSplus data. In 2011 a mechanism was added to allow protocol plugins to permit the use of other transport mechanisms such as ssh to access data users. This paper describes a similar design which permits the insertion of plugins to handle the reading and writing of MDSplus data at the data storage level. Tree paths become URIs which specify the protocol, host, and protocol specific information. The protocol is provided by a dynamically activated shared library that can provide any consistent subset of the data store access API, treeshr. The existing low level network protocol called mdsip, is activated by defining tree paths like “host::/directory”. Using the new plugin mechanism this is re-implemented as an instance of the general plugin that replaces the low level treeshr input/output routines. It is specified by using a path like “mdsip://host/directory”. This architecture will make it possible to adapt the MDSplus data organization and analysis tools to other underlying data storage. The first new application of this, after the existing network protocol is implemented, will be a plugin based on a key value store. Key value stores, can provide inexpensive scalable, redundant data storage. An example of this might be an Amazon G3 plugin which would let you specify a tree path such as “AG3://container” to access MDSplus data stored in the cloud

  19. Input/output plugin architecture for MDSplus

    Energy Technology Data Exchange (ETDEWEB)

    Stillerman, Joshua, E-mail: jas@psfc.mit.edu [Massachusetts Institute of Technology, 175 Albany Street, Cambridge, MA 02139 (United States); Fredian, Thomas, E-mail: twf@psfc.mit.edu [Massachusetts Institute of Technology, 175 Albany Street, Cambridge, MA 02139 (United States); Manduchi, Gabriele, E-mail: gabriele.manduchi@igi.cnr.it [Consorzio RFX, Euratom-ENEA Association, Corso Stati Uniti 4, Padova 35127 (Italy)

    2014-05-15

    The first version of MDSplus was released in 1991 for VAX/VMS. Since that time the underlying file formats have remained constant. The software however has evolved, it was ported to unix, linux, Windows, and Macintosh. In 1997 a TCP based protocol, mdsip, was added to provide network access to MDSplus data. In 2011 a mechanism was added to allow protocol plugins to permit the use of other transport mechanisms such as ssh to access data users. This paper describes a similar design which permits the insertion of plugins to handle the reading and writing of MDSplus data at the data storage level. Tree paths become URIs which specify the protocol, host, and protocol specific information. The protocol is provided by a dynamically activated shared library that can provide any consistent subset of the data store access API, treeshr. The existing low level network protocol called mdsip, is activated by defining tree paths like “host::/directory”. Using the new plugin mechanism this is re-implemented as an instance of the general plugin that replaces the low level treeshr input/output routines. It is specified by using a path like “mdsip://host/directory”. This architecture will make it possible to adapt the MDSplus data organization and analysis tools to other underlying data storage. The first new application of this, after the existing network protocol is implemented, will be a plugin based on a key value store. Key value stores, can provide inexpensive scalable, redundant data storage. An example of this might be an Amazon G3 plugin which would let you specify a tree path such as “AG3://container” to access MDSplus data stored in the cloud.

  20. The Effects of Type and Quantity of Input on Iranian EFL Learners’ Oral Language Proficiency

    Directory of Open Access Journals (Sweden)

    Zahra Hassanzadeh

    2014-05-01

    Full Text Available In the written texts on foreign language learning, a group of studies has stressed the function of learning context and learning chances for learners’ language input. The present thesis had two main goals: on the one hand, different types of input to which Iranian grade four high school EFL learners’ are exposed were looked at; on the other hand, the possible relationship between types and quantity of input and Iranian EFL learners’ oral proficiency was investigated. It was supposed that EFL learners who have access to more input will show better oral proficiency than those who do not have. Instruments used in the present study for the purpose of data collation included  PET test, researcher- made questionnaire, oral language proficiency test and face- to -face interview. Data were gathered from 50 Iranian female grade four high school foreign language learners who were selected from among 120 students whose score on PET test were +1SD from the mean score. The results of the Spearman rank –order correlation test for the types of input and oral language proficiency scores, showed that the participants’ oral proficiency score significantly correlated with the intended four sources of input including spoken (rho= 0.416, sig=0.003, written (rho= 0.364, sig=0.009, aural (rho= 0.343, sig=0.015 and visual or audio-visual types of input (rho= 0.47, sig=0.00. The findings of Spearman rank –order correlation test for the quantity of input and oral language proficiency scores also showed a significant relationship between quantity of input and oral language proficiency (rho= 0.543, sig= 0.00. The findings showed that EFL learners’ oral proficiency is significantly correlated with efficient and effective input. The findings may also suggest  answers to the question why most Iranian English learners fail to speak English fluently, which might be due to  lack of effective input. This may emphasize the importance of the types and quantity of

  1. On the Nature of the Input in Optimality Theory

    DEFF Research Database (Denmark)

    Heck, Fabian; Müller, Gereon; Vogel, Ralf

    2002-01-01

    The input has two main functions in optimality theory (Prince and Smolensky 1993). First, the input defines the candidate set, in other words it determines which output candidates compete for optimality, and which do not. Second, the input is referred to by faithfulness constraints that prohibit...... output candidates from deviating from specifications in the input. Whereas there is general agreement concerning the relevance of the input in phonology, the nature of the input in syntax is notoriously unclear. In this article, we show that the input should not be taken to define syntactic candidate...... and syntax is due to a basic, irreducible difference between these two components of grammar: Syntax is an information preserving system, phonology is not....

  2. High-frequency matrix converter with square wave input

    Science.gov (United States)

    Carr, Joseph Alexander; Balda, Juan Carlos

    2015-03-31

    A device for producing an alternating current output voltage from a high-frequency, square-wave input voltage comprising, high-frequency, square-wave input a matrix converter and a control system. The matrix converter comprises a plurality of electrical switches. The high-frequency input and the matrix converter are electrically connected to each other. The control system is connected to each switch of the matrix converter. The control system is electrically connected to the input of the matrix converter. The control system is configured to operate each electrical switch of the matrix converter converting a high-frequency, square-wave input voltage across the first input port of the matrix converter and the second input port of the matrix converter to an alternating current output voltage at the output of the matrix converter.

  3. Analysis of Hot Ions Detected during Equatorial Orbits of the Cassini Spacecraft at Saturn using the Convected Kappa Distribution Function and a Comparison to Voyager and Galileo Measurements at Jupiter

    Science.gov (United States)

    Kane, M.; Mitchell, D. G.; Carbary, J. F.; Hill, M. E.; Dialynas, K.; Mauk, B.; Krimigis, S. M.

    2017-12-01

    An extensive analysis of Cassini INCA and CHEMS measurements of 5-149 keV ions acquired during all equatorial orbits has been completed using a 3-D convected kappa distribution model. The computed plasma azimuthal speed, expressed as a fraction of the local corotation speed, decreases sharply with increasing distance from Saturn. The oxygen ion profile follows the hydrogen ion trend. For both species, the polar convection speed is the smallest of the 3 velocity components, and is centered about zero, but the radial speed has a significant radially outward component. Further, the radial component is enhanced in the pre-dawn sector. The hydrogen and oxygen temperatures increase with decreasing distance to Saturn. The calculated pattern of convection is consistent with an empirical model of plasma convection that includes outward radial transport and escape of plasma in a dawnside boundary layer of plasma entrained by the dawn magnetosheath flow. When the model convection pattern is scaled to the sub-solar magnetopause distance and to the sizes of Jupiter and Saturn, the pattern agrees with that derived from analysis of hot ions detected by the LECP detector on Voyager and the EPD instrument on Galileo. This and previous analysis of hot ion distributions has shown that the convected kappa distribution, with isotropy assumed in the plasma rest frame, has well described hot ion observed fluxes within a limited range of ion energies and has produced meaningful and ordered physical plasma parameters including plasma bulk velocity vectors, kappa distribution temperature profiles, and the general magnetospheric convection pattern at Jupiter and Saturn.

  4. A new quantum flux parametron logic gate with large input margin

    International Nuclear Information System (INIS)

    Hioe, W.; Hosoya, M.; Goto, E.

    1991-01-01

    This paper reports on the Quantum Flux Parametron (QFP) which is a flux transfer, flux activated Josephson logic device which realizes much lower power dissipation than other Josephson logic devices. Being a two-terminal device its correct operation may be affected by coupling to other QFPs. The problems include backcoupling from active QFPs through inactive QFPs (relay noise), coupling between QFPs activated at different times because of clock skew (homophase noise), and interaction between active QFPs (reaction hazard). Previous QFP circuits worked by wired-majority, which being a linear input logic, has low input margin. A new logic gate (D-gate) using a QFP to perform logic operations has been analyzed and tested by computer simulation. Relay noise, homophase noise and reaction hazard are substantially reduced. Moreover, the input have little interaction hence input margin is greatly improved

  5. Fertilizing growth: Agricultural inputs and their effects in economic development.

    Science.gov (United States)

    McArthur, John W; McCord, Gordon C

    2017-07-01

    This paper estimates the role of agronomic inputs in cereal yield improvements and the consequences for countries' processes of structural change. The results suggest a clear role for fertilizer, modern seeds and water in boosting yields. We then test for respective empirical links between agricultural yields and economic growth, labor share in agriculture and non-agricultural value added per worker. The identification strategy includes a novel instrumental variable that exploits the unique economic geography of fertilizer production and transport costs to countries' agricultural heartlands. We estimate that a half ton increase in staple yields generates a 14 to 19 percent higher GDP per capita and a 4.6 to 5.6 percentage point lower labor share in agriculture five years later. The results suggest a strong role for agricultural productivity as a driver of structural change.

  6. Lysimeter data as input to performance assessment models

    International Nuclear Information System (INIS)

    McConnell, J.W. Jr.

    1998-01-01

    The Field Lysimeter Investigations: Low-Level Waste Data Base Development Program is obtaining information on the performance of radioactive waste forms in a disposal environment. Waste forms fabricated using ion-exchange resins from EPICOR-117 prefilters employed in the cleanup of the Three Mile Island (TMI) Nuclear Power Station are being tested to develop a low-level waste data base and to obtain information on survivability of waste forms in a disposal environment. The program includes reviewing radionuclide releases from those waste forms in the first 7 years of sampling and examining the relationship between code input parameters and lysimeter data. Also, lysimeter data are applied to performance assessment source term models, and initial results from use of data in two models are presented

  7. Producing a unified progress report with inputs from several contractors

    International Nuclear Information System (INIS)

    Nelson, O.A.

    1981-01-01

    The project management organization in which the author works produces an annual technical progress report for the Clinch River Breeder Reactor Plant Project. The report has to be integrated and edited from the inputs of six major Project participants scattered from coast to coast. The integrated report manuscript then has to be submitted for two formal reviews, and the report must be published in a readable and attractive form. Accomplishing those steps in a reasonable length of time, with a high degree of accuracy, and at minimum expense requires careful planning and close supervision. Planning includes scheduling in such a way as to perform operations in parallel, where possible, instead of in series. Exploiting the capabilities of word processing saves much keyboarding and proofreading time. Art from previous reports is reused when possible. Many of these methods can be applied to other reports that require integration and editing of material from several sources

  8. Comparing apples and oranges: fold-change detection of multiple simultaneous inputs.

    Directory of Open Access Journals (Sweden)

    Yuval Hart

    Full Text Available Sensory systems often detect multiple types of inputs. For example, a receptor in a cell-signaling system often binds multiple kinds of ligands, and sensory neurons can respond to different types of stimuli. How do sensory systems compare these different kinds of signals? Here, we consider this question in a class of sensory systems - including bacterial chemotaxis- which have a property known as fold-change detection: their output dynamics, including amplitude and response time, depends only on the relative changes in signal, rather than absolute changes, over a range of several decades of signal. We analyze how fold-change detection systems respond to multiple signals, using mathematical models. Suppose that a step of fold F1 is made in input 1, together with a step of F2 in input 2. What total response does the system provide? We show that when both input signals impact the same receptor with equal number of binding sites, the integrated response is multiplicative: the response dynamics depend only on the product of the two fold changes, F1F2. When the inputs bind the same receptor with different number of sites n1 and n2, the dynamics depend on a product of power laws, [Formula: see text]. Thus, two input signals which vary over time in an inverse way can lead to no response. When the two inputs affect two different receptors, other types of integration may be found and generally the system is not constrained to respond according to the product of the fold-change of each signal. These predictions can be readily tested experimentally, by providing cells with two simultaneously varying input signals. The present study suggests how cells can compare apples and oranges, namely by comparing each to its own background level, and then multiplying these two fold-changes.

  9. Subsidy or subtraction: how do terrestrial inputs influence consumer production in lakes?

    Science.gov (United States)

    Jones, Stuart E.; Solomon, Christopher T.; Weidel, Brian C.

    2012-01-01

    Cross-ecosystem fluxes are ubiquitous in food webs and are generally thought of as subsidies to consumer populations. Yet external or allochthonous inputs may in fact have complex and habitat-specific effects on recipient ecosystems. In lakes, terrestrial inputs of organic carbon contribute to basal resource availability, but can also reduce resource availability via shading effects on phytoplankton and periphyton. Terrestrial inputs might therefore either subsidise or subtract from consumer production. We developed and parameterised a simple model to explore this idea. The model estimates basal resource supply and consumer production given lake-level characteristics including total phosphorus (TP) and dissolved organic carbon (DOC) concentration, and consumer-level characteristics including resource preferences and growth efficiencies. Terrestrial inputs diminished primary production and total basal resource supply at the whole-lake level, except in ultra-oligotrophic systems. However, this system-level generalisation masked complex habitat-specific effects. In the pelagic zone, dissolved and particulate terrestrial carbon inputs were available to zooplankton via several food web pathways. Consequently, zooplankton production usually increased with terrestrial inputs, even as total whole-lake resource availability decreased. In contrast, in the benthic zone the dominant, dissolved portion of the terrestrial carbon load had predominantly negative effects on resource availability via shading of periphyton. Consequently, terrestrial inputs always decreased zoobenthic production except under extreme and unrealistic parameterisations of the model. Appreciating the complex and habitat-specific effects of allochthonous inputs may be essential for resolving the effects of cross-habitat fluxes on consumers in lakes and other food webs.

  10. A Ring-‘Rain’ influence for Saturn’s Cloud Albedo and Temperatures? Evidence Pro or Con from Voyager, HST, and Cassini

    Science.gov (United States)

    West, Robert A.; Li, Liming

    2015-11-01

    J. E. P. Connerney [Geophys. Res. Lett, 13, 773-776, 1986] pointed out that ‘latitudinal variations in images of Saturn’s disk, upper atmospheric temperatures, and ionospheric electron densities are found in magnetic conjugacy with features in Saturn’s ring plane’, and proposed ‘that these latitudinal variations are the result of a variable influx of water, transported along magnetic field lines from sources in Saturn’s ring plane’. Observations of H3+ support a ring-ionosphere connection [O'Donoghue et al., Nature 496, 7444, 2013]. What about cloud albedo and temperature? Connerney attributed a hemispheric asymmetry in haze and temperature to an asymmetry in water flux and predicted that ‘the presently-observed north-south asymmetry (upper tropospheric temperatures, aerosols) will persist throughout the Saturn year’. We can now test these ideas with data from the Cassini mission, from the Hubble Space Telescope, and from ground-based observations. Analyses of ground-based images and especially Hubble data established that the hemispheric asymmetry of the aerosol population does change, and seasonal effects are dominant, although non-seasonal variations are also observed [Karkoschka and Tomasko, Icarus 179, 195-221, 2005]. Upper tropospheric temperatures also vary as expected in response to seasonal forcing [Fletcher et al., Icarus 208, 337-352, 2009]. Connerney also identified dark bands in Voyager Green-filter images on magnetic conjugacy with the E ring and edges of the A and B rings. In Cassini Green-filter images there is some correspondence between dark bands and ring features in magnetic conjugacy, but collectively the correlation is not strong. Cassini 727-nm methane band images do not suggest depletion of aerosols in the upper troposphere at ring edge magnetic conjugacy latitudes as proposed by Connerney. We conclude that ring rain does not have a significant influence on upper tropospheric aerosols and temperatures on Saturn. Part of

  11. Response sensitivity of barrel neuron subpopulations to simulated thalamic input.

    Science.gov (United States)

    Pesavento, Michael J; Rittenhouse, Cynthia D; Pinto, David J

    2010-06-01

    Our goal is to examine the relationship between neuron- and network-level processing in the context of a well-studied cortical function, the processing of thalamic input by whisker-barrel circuits in rodent neocortex. Here we focus on neuron-level processing and investigate the responses of excitatory and inhibitory barrel neurons to simulated thalamic inputs applied using the dynamic clamp method in brain slices. Simulated inputs are modeled after real thalamic inputs recorded in vivo in response to brief whisker deflections. Our results suggest that inhibitory neurons require more input to reach firing threshold, but then fire earlier, with less variability, and respond to a broader range of inputs than do excitatory neurons. Differences in the responses of barrel neuron subtypes depend on their intrinsic membrane properties. Neurons with a low input resistance require more input to reach threshold but then fire earlier than neurons with a higher input resistance, regardless of the neuron's classification. Our results also suggest that the response properties of excitatory versus inhibitory barrel neurons are consistent with the response sensitivities of the ensemble barrel network. The short response latency of inhibitory neurons may serve to suppress ensemble barrel responses to asynchronous thalamic input. Correspondingly, whereas neurons acting as part of the barrel circuit in vivo are highly selective for temporally correlated thalamic input, excitatory barrel neurons acting alone in vitro are less so. These data suggest that network-level processing of thalamic input in barrel cortex depends on neuron-level processing of the same input by excitatory and inhibitory barrel neurons.

  12. Method and System for Physiologically Modulating Videogames and Simulations which Use Gesture and Body Image Sensing Control Input Devices

    Science.gov (United States)

    Pope, Alan T. (Inventor); Stephens, Chad L. (Inventor); Habowski, Tyler (Inventor)

    2017-01-01

    Method for physiologically modulating videogames and simulations includes utilizing input from a motion-sensing video game system and input from a physiological signal acquisition device. The inputs from the physiological signal sensors are utilized to change the response of a user's avatar to inputs from the motion-sensing sensors. The motion-sensing system comprises a 3D sensor system having full-body 3D motion capture of a user's body. This arrangement encourages health-enhancing physiological self-regulation skills or therapeutic amplification of healthful physiological characteristics. The system provides increased motivation for users to utilize biofeedback as may be desired for treatment of various conditions.

  13. (including travel dates) Proposed itinerary

    Indian Academy of Sciences (India)

    Ashok

    31 July to 22 August 2012 (including travel dates). Proposed itinerary: Arrival in Bangalore on 1 August. 1-5 August: Bangalore, Karnataka. Suggested institutions: Indian Institute of Science, Bangalore. St Johns Medical College & Hospital, Bangalore. Jawaharlal Nehru Centre, Bangalore. 6-8 August: Chennai, TN.

  14. THE VARIABILITY OF HCN IN TITAN’S UPPER ATMOSPHERE AS IMPLIED BY THE CASSINI ION-NEUTRAL MASS SPECTROMETER MEASUREMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Cui, J.; Cao, Y.-T. [National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Lavvas, P. P. [Groupe de Spectroscopie Moleculaire et Atmospherique, Universite de Reims, Champagne-Ardenne, CNRS UMR F-7331 (France); Koskinen, T. T. [Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721 (United States)

    2016-07-20

    HCN is an important constituent in Titan’s upper atmosphere, serving as the main coolant in the local energy budget. In this study, we derive the HCN abundance at the altitude range of 960–1400 km, combining the Ion-Neutral Mass Spectrometer data acquired during a large number of Cassini flybys with Titan. Typically, the HCN abundance declines modestly with increasing altitude and flattens to a near constant level above 1200 km. The data reveal a tendency for dayside depletion of HCN, which is clearly visible below 1000 km but weakens with increasing altitude. Despite the absence of convincing anti-correlation between HCN volume mixing ratio and neutral temperature, we argue that the variability in HCN abundance makes an important contribution to the large temperature variability observed in Titan’s upper atmosphere.

  15. Automated input data management in manufacturing process simulation

    OpenAIRE

    Ettefaghian, Alireza

    2015-01-01

    Input Data Management (IDM) is a time consuming and costly process for Discrete Event Simulation (DES) projects. Input Data Management is considered as the basis of real-time process simulation (Bergmann, Stelzer and Strassburger, 2011). According to Bengtsson et al. (2009), data input phase constitutes on the average about 31% of the time of an entire simulation project. Moreover, the lack of interoperability between manufacturing applications and simulation software leads to a high cost to ...

  16. The Economic Impact of Tourism. An Input-Output Analysis

    OpenAIRE

    Camelia SURUGIU

    2009-01-01

    The paper presents an Input-Output Analysis for Romania, an important source of information for the investigation of the inter-relations existing among different industries. The Input-Output Analysis is used to determine the role and importance of different economic value added, incomes and employment and it analyses the existing connection in an economy. This paper is focused on tourism and the input-output analysis is finished for the Hotels and Restaurants Sector.

  17. Soil-related Input Parameters for the Biosphere Model

    International Nuclear Information System (INIS)

    A. J. Smith

    2003-01-01

    This analysis is one of the technical reports containing documentation of the Environmental Radiation Model for Yucca Mountain Nevada (ERMYN), a biosphere model supporting the Total System Performance Assessment (TSPA) for the geologic repository at Yucca Mountain. The biosphere model is one of a series of process models supporting the Total System Performance Assessment (TSPA) for the Yucca Mountain repository. A graphical representation of the documentation hierarchy for the ERMYN biosphere model is presented in Figure 1-1. This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling, and the plan for development of the biosphere abstraction products for TSPA, as identified in the ''Technical Work Plan: for Biosphere Modeling and Expert Support'' (BSC 2003 [163602]). It should be noted that some documents identified in Figure 1-1 may be under development at the time this report is issued and therefore not available. This figure is included to provide an understanding of how this analysis report contributes to biosphere modeling in support of the license application, and is not intended to imply that access to the listed documents is required to understand the contents of this report. This report, ''Soil Related Input Parameters for the Biosphere Model'', is one of the five analysis reports that develop input parameters for use in the ERMYN model. This report is the source documentation for the six biosphere parameters identified in Table 1-1. ''The Biosphere Model Report'' (BSC 2003 [160699]) describes in detail the conceptual model as well as the mathematical model and its input parameters. The purpose of this analysis was to develop the biosphere model parameters needed to evaluate doses from pathways associated with the accumulation and depletion of radionuclides in the soil. These parameters support the calculation of radionuclide concentrations in soil from on-going irrigation and ash

  18. Soil organic carbon dynamics jointly controlled by climate, carbon inputs, soil properties and soil carbon fractions.

    Science.gov (United States)

    Luo, Zhongkui; Feng, Wenting; Luo, Yiqi; Baldock, Jeff; Wang, Enli

    2017-10-01

    Soil organic carbon (SOC) dynamics are regulated by the complex interplay of climatic, edaphic and biotic conditions. However, the interrelation of SOC and these drivers and their potential connection networks are rarely assessed quantitatively. Using observations of SOC dynamics with detailed soil properties from 90 field trials at 28 sites under different agroecosystems across the Australian cropping regions, we investigated the direct and indirect effects of climate, soil properties, carbon (C) inputs and soil C pools (a total of 17 variables) on SOC change rate (r C , Mg C ha -1  yr -1 ). Among these variables, we found that the most influential variables on r C were the average C input amount and annual precipitation, and the total SOC stock at the beginning of the trials. Overall, C inputs (including C input amount and pasture frequency in the crop rotation system) accounted for 27% of the relative influence on r C , followed by climate 25% (including precipitation and temperature), soil C pools 24% (including pool size and composition) and soil properties (such as cation exchange capacity, clay content, bulk density) 24%. Path analysis identified a network of intercorrelations of climate, soil properties, C inputs and soil C pools in determining r C . The direct correlation of r C with climate was significantly weakened if removing the effects of soil properties and C pools, and vice versa. These results reveal the relative importance of climate, soil properties, C inputs and C pools and their complex interconnections in regulating SOC dynamics. Ignorance of the impact of changes in soil properties, C pool composition and C input (quantity and quality) on SOC dynamics is likely one of the main sources of uncertainty in SOC predictions from the process-based SOC models. © 2017 John Wiley & Sons Ltd.

  19. Theory including future not excluded

    DEFF Research Database (Denmark)

    Nagao, K.; Nielsen, H.B.

    2013-01-01

    We study a complex action theory (CAT) whose path runs over not only past but also future. We show that, if we regard a matrix element defined in terms of the future state at time T and the past state at time TA as an expectation value in the CAT, then we are allowed to have the Heisenberg equation......, Ehrenfest's theorem, and the conserved probability current density. In addition,we showthat the expectation value at the present time t of a future-included theory for large T - t and large t - T corresponds to that of a future-not-included theory with a proper inner product for large t - T. Hence, the CAT...

  20. Comparative analysis of environmental impacts of agricultural production systems, agricultural input efficiency, and food choice

    Science.gov (United States)

    Clark, Michael; Tilman, David

    2017-06-01

    Global agricultural feeds over 7 billion people, but is also a leading cause of environmental degradation. Understanding how alternative agricultural production systems, agricultural input efficiency, and food choice drive environmental degradation is necessary for reducing agriculture’s environmental impacts. A meta-analysis of life cycle assessments that includes 742 agricultural systems and over 90 unique foods produced primarily in high-input systems shows that, per unit of food, organic systems require more land, cause more eutrophication, use less energy, but emit similar greenhouse gas emissions (GHGs) as conventional systems; that grass-fed beef requires more land and emits similar GHG emissions as grain-feed beef; and that low-input aquaculture and non-trawling fisheries have much lower GHG emissions than trawling fisheries. In addition, our analyses show that increasing agricultural input efficiency (the amount of food produced per input of fertilizer or feed) would have environmental benefits for both crop and livestock systems. Further, for all environmental indicators and nutritional units examined, plant-based foods have the lowest environmental impacts; eggs, dairy, pork, poultry, non-trawling fisheries, and non-recirculating aquaculture have intermediate impacts; and ruminant meat has impacts ∼100 times those of plant-based foods. Our analyses show that dietary shifts towards low-impact foods and increases in agricultural input use efficiency would offer larger environmental benefits than would switches from conventional agricultural systems to alternatives such as organic agriculture or grass-fed beef.

  1. Development of the MARS input model for Kori nuclear units 1 transient analyzer

    International Nuclear Information System (INIS)

    Hwang, M.; Kim, K. D.; Lee, S. W.; Lee, Y. J.; Lee, W. J.; Chung, B. D.; Jeong, J. J.

    2004-11-01

    KAERI has been developing the 'NSSS transient analyzer' based on best-estimate codes for Kori Nuclear Units 1 plants. The MARS and RETRAN codes have been used as the best-estimate codes for the NSSS transient analyzer. Among these codes, the MARS code is adopted for realistic analysis of small- and large-break loss-of-coolant accidents, of which break size is greater than 2 inch diameter. So it is necessary to develop the MARS input model for Kori Nuclear Units 1 plants. This report includes the input model (hydrodynamic component and heat structure models) requirements and the calculation note for the MARS input data generation for Kori Nuclear Units 1 plant analyzer (see the Appendix). In order to confirm the validity of the input data, we performed the calculations for a steady state at 100 % power operation condition and a double-ended cold leg break LOCA. The results of the steady-state calculation agree well with the design data. The results of the LOCA calculation seem to be reasonable and consistent with those of other best-estimate calculations. Therefore, the MARS input data can be used as a base input deck for the MARS transient analyzer for Kori Nuclear Units 1

  2. Influence of Road Excitation and Steering Wheel Input on Vehicle System Dynamic Responses

    Directory of Open Access Journals (Sweden)

    Zhen-Feng Wang

    2017-06-01

    Full Text Available Considering the importance of increasing driving safety, the study of safety is a popular and critical topic of research in the vehicle industry. Vehicle roll behavior with sudden steering input is a main source of untripped rollover. However, previous research has seldom considered road excitation and its coupled effect on vehicle lateral response when focusing on lateral and vertical dynamics. To address this issue, a novel method was used to evaluate effects of varying road level and steering wheel input on vehicle roll behavior. Then, a 9 degree of freedom (9-DOF full-car roll nonlinear model including vertical and lateral dynamics was developed to study vehicle roll dynamics with or without of road excitation. Based on a 6-DOF half-car roll model and 9-DOF full-car nonlinear model, relationship between three-dimensional (3-D road excitation and various steering wheel inputs on vehicle roll performance was studied. Finally, an E-Class (SUV level car model in CARSIM® was used, as a benchmark, with and without road input conditions. Both half-car and full-car models were analyzed under steering wheel inputs of 5°, 10° and 15°. Simulation results showed that the half-car model considering road input was found to have a maximum accuracy of 65%. Whereas, the full-car model had a minimum accuracy of 85%, which was significantly higher compared to the half-car model under the same scenario.

  3. Assigning probability distributions to input parameters of performance assessment models

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Srikanta [INTERA Inc., Austin, TX (United States)

    2002-02-01

    This study presents an overview of various approaches for assigning probability distributions to input parameters and/or future states of performance assessment models. Specifically,three broad approaches are discussed for developing input distributions: (a) fitting continuous distributions to data, (b) subjective assessment of probabilities, and (c) Bayesian updating of prior knowledge based on new information. The report begins with a summary of the nature of data and distributions, followed by a discussion of several common theoretical parametric models for characterizing distributions. Next, various techniques are presented for fitting continuous distributions to data. These include probability plotting, method of moments, maximum likelihood estimation and nonlinear least squares analysis. The techniques are demonstrated using data from a recent performance assessment study for the Yucca Mountain project. Goodness of fit techniques are also discussed, followed by an overview of how distribution fitting is accomplished in commercial software packages. The issue of subjective assessment of probabilities is dealt with in terms of the maximum entropy distribution selection approach, as well as some common rules for codifying informal expert judgment. Formal expert elicitation protocols are discussed next, and are based primarily on the guidance provided by the US NRC. The Bayesian framework for updating prior distributions (beliefs) when new information becomes available is discussed. A simple numerical approach is presented for facilitating practical applications of the Bayes theorem. Finally, a systematic framework for assigning distributions is presented: (a) for the situation where enough data are available to define an empirical CDF or fit a parametric model to the data, and (b) to deal with the situation where only a limited amount of information is available.

  4. Assigning probability distributions to input parameters of performance assessment models

    International Nuclear Information System (INIS)

    Mishra, Srikanta

    2002-02-01

    This study presents an overview of various approaches for assigning probability distributions to input parameters and/or future states of performance assessment models. Specifically,three broad approaches are discussed for developing input distributions: (a) fitting continuous distributions to data, (b) subjective assessment of probabilities, and (c) Bayesian updating of prior knowledge based on new information. The report begins with a summary of the nature of data and distributions, followed by a discussion of several common theoretical parametric models for characterizing distributions. Next, various techniques are presented for fitting continuous distributions to data. These include probability plotting, method of moments, maximum likelihood estimation and nonlinear least squares analysis. The techniques are demonstrated using data from a recent performance assessment study for the Yucca Mountain project. Goodness of fit techniques are also discussed, followed by an overview of how distribution fitting is accomplished in commercial software packages. The issue of subjective assessment of probabilities is dealt with in terms of the maximum entropy distribution selection approach, as well as some common rules for codifying informal expert judgment. Formal expert elicitation protocols are discussed next, and are based primarily on the guidance provided by the US NRC. The Bayesian framework for updating prior distributions (beliefs) when new information becomes available is discussed. A simple numerical approach is presented for facilitating practical applications of the Bayes theorem. Finally, a systematic framework for assigning distributions is presented: (a) for the situation where enough data are available to define an empirical CDF or fit a parametric model to the data, and (b) to deal with the situation where only a limited amount of information is available

  5. Consumer input into research: the Australian Cancer Trials website.

    Science.gov (United States)

    Dear, Rachel F; Barratt, Alexandra L; Crossing, Sally; Butow, Phyllis N; Hanson, Susan; Tattersall, Martin Hn

    2011-06-26

    The Australian Cancer Trials website (ACTO) was publicly launched in 2010 to help people search for cancer clinical trials recruiting in Australia, provide information about clinical trials and assist with doctor-patient communication about trials. We describe consumer involvement in the design and development of ACTO and report our preliminary patient evaluation of the website. Consumers, led by Cancer Voices NSW, provided the impetus to develop the website. Consumer representative groups were consulted by the research team during the design and development of ACTO which combines a search engine, trial details, general information about trial participation and question prompt lists. Website use was analysed. A patient evaluation questionnaire was completed at one hospital, one week after exposure to the website. ACTO's main features and content reflect consumer input. In February 2011, it covered 1, 042 cancer trials. Since ACTO's public launch in November 2010, until the end of February 2011, the website has had 2, 549 new visits and generated 17, 833 page views. In a sub-study of 47 patient users, 89% found the website helpful for learning about clinical trials and all respondents thought patients should have access to ACTO. The development of ACTO is an example of consumers working with doctors, researchers and policy makers to improve the information available to people whose lives are affected by cancer and to help them participate in their treatment decisions, including consideration of clinical trial enrolment. Consumer input has ensured that the website is informative, targets consumer priorities and is user-friendly. ACTO serves as a model for other health conditions.

  6. Consumer input into research: the Australian Cancer Trials website

    Directory of Open Access Journals (Sweden)

    Butow Phyllis N

    2011-06-01

    Full Text Available Abstract Background The Australian Cancer Trials website (ACTO was publicly launched in 2010 to help people search for cancer clinical trials recruiting in Australia, provide information about clinical trials and assist with doctor-patient communication about trials. We describe consumer involvement in the design and development of ACTO and report our preliminary patient evaluation of the website. Methods Consumers, led by Cancer Voices NSW, provided the impetus to develop the website. Consumer representative groups were consulted by the research team during the design and development of ACTO which combines a search engine, trial details, general information about trial participation and question prompt lists. Website use was analysed. A patient evaluation questionnaire was completed at one hospital, one week after exposure to the website. Results ACTO's main features and content reflect consumer input. In February 2011, it covered 1, 042 cancer trials. Since ACTO's public launch in November 2010, until the end of February 2011, the website has had 2, 549 new visits and generated 17, 833 page views. In a sub-study of 47 patient users, 89% found the website helpful for learning about clinical trials and all respondents thought patients should have access to ACTO. Conclusions The development of ACTO is an example of consumers working with doctors, researchers and policy makers to improve the information available to people whose lives are affected by cancer and to help them participate in their treatment decisions, including consideration of clinical trial enrolment. Consumer input has ensured that the website is informative, targets consumer priorities and is user-friendly. ACTO serves as a model for other health conditions.

  7. Comfort constraints. Input for simulation of residents' behavior; Comforthinder. Input bij simulatie van bewonersgedrag

    Energy Technology Data Exchange (ETDEWEB)

    Phaff, H. [TNO Bouw en Ondergrond, Delft (Netherlands)

    2010-04-15

    Buildings in reality, use more energy than predicted. Among many causes, occupant behaviour plays an important role. Better simulation of occupant behaviour, with respect to thermal comfort and energy use of buildings, opens the possibility to design better, comfortable buildings that have lower energy consumption in reality. Thermal discomfort, a dynamical version of Fanger's PPD, is proposed to be used as input to simulate occupant behaviour via a 'flexible task list' and two Markov processes. [Dutch] Simulatie van bewonersgedrag m.b.t. energiegebruik in gebouwen biedt de mogelijkheid om gebouwen en bijbehorende energie installaties zo te ontwerpen dat ze prettiger zijn om in te wonen en te werken. Thermisch discomfort, een dynamische versie van PPD (percentage of dissatisfied persons) wordt hier voorgesteld om via een Markov-proces en een takenlijst bewonersgedrag mee te simuleren.

  8. Impact of magnetic saturation on the input-output linearising tracking control of an induction motor

    DEFF Research Database (Denmark)

    Dolinar, Drago; Ljusev, Petar; Stumberger, Gorazd

    2004-01-01

    This paper deals with the tracking control design of an induction motor, based on input-output linearization with magnetic saturation included. Magnetic saturation is represented by the nonlinear magnetizing curve of the iron core and is used in the control design, the observer of state variables......, and in the load torque estimator. An input-output linearising control is used to achieve better tracking performances of the drive. It is based on the mixed ”stator current - rotor flux linkage” induction motor model with magnetic saturation considered in the stationary reference frame. Experimental results show...... that the proposed input-output linearising tracking control with the included saturation behaves considerably better than the one without saturation, and that it introduces smaller position and speed errors, and better motor stiffness on account of the increased computational complexity....

  9. How to Manage Inputs from Co-production Processes in Emergy Accounting

    DEFF Research Database (Denmark)

    Kamp, Andreas; Østergård, Hanne

    2012-01-01

    In life cycle assessments it is a challenge to allocate resource use and environmental impact in processes with multiple outputs. This is especially the case when systems include agricultural products that in their production cannot be separated from each other. For emergy accounting, Bastianoni...... with systems that do not depend on joint production processes is still lacking. As a consequence, a product relying on inputs from joint production processes appears to compete poorly with a similar product that does not have to account for co-products appearing upstream. This is counter to perceived benefits...... and Marchettini (2000) suggested how to calculate transformities and other indices for joint production systems. Their proposals however, do not include how to manage inputs from joint production systems. Thus a practical method for making systems with inputs from joint production processes comparable...

  10. How to manage inputs from joint production processes in emergy accounting

    DEFF Research Database (Denmark)

    Kamp, Andreas; Østergård, Hanne

    In life-cycle assessments it is a challenge to allocate resource use and environmental impact in processes with multiple outputs. This is especially the case when systems include agricultural products that in their production cannot be separated from each other. For emergy accounting, Bastianoni...... with systems that do not depend on joint production processes is still lacking. As a consequence, a product relying on inputs from joint production processes appears to compete poorly with a similar product that does not have to account for by-products appearing upstream. This is counter to perceived benefits...... and Marchettini (2000) suggested how to calculate transformities and other indices for joint production systems. Their proposals however, do not include how to manage inputs from joint production systems. Thus a practical method for making systems with inputs from joint production processes comparable...

  11. Device including a contact detector

    DEFF Research Database (Denmark)

    2011-01-01

    arms (12) may extend from the supporting body in co-planar relationship with the first surface. The plurality of cantilever arms (12) may extend substantially parallel to each other and each of the plurality of cantilever arms (12) may include an electrical conductive tip for contacting the area......The present invention relates to a probe for determining an electrical property of an area of a surface of a test sample, the probe is intended to be in a specific orientation relative to the test sample. The probe may comprise a supporting body defining a first surface. A plurality of cantilever...... of the test sample by movement of the probe relative to the surface of the test sample into the specific orientation.; The probe may further comprise a contact detector (14) extending from the supporting body arranged so as to contact the surface of the test sample prior to any one of the plurality...

  12. Neoclassical transport including collisional nonlinearity.

    Science.gov (United States)

    Candy, J; Belli, E A

    2011-06-10

    In the standard δf theory of neoclassical transport, the zeroth-order (Maxwellian) solution is obtained analytically via the solution of a nonlinear equation. The first-order correction δf is subsequently computed as the solution of a linear, inhomogeneous equation that includes the linearized Fokker-Planck collision operator. This equation admits analytic solutions only in extreme asymptotic limits (banana, plateau, Pfirsch-Schlüter), and so must be solved numerically for realistic plasma parameters. Recently, numerical codes have appeared which attempt to compute the total distribution f more accurately than in the standard ordering by retaining some nonlinear terms related to finite-orbit width, while simultaneously reusing some form of the linearized collision operator. In this work we show that higher-order corrections to the distribution function may be unphysical if collisional nonlinearities are ignored.

  13. Soil-Related Input Parameters for the Biosphere Model

    International Nuclear Information System (INIS)

    Smith, A. J.

    2004-01-01

    This report presents one of the analyses that support the Environmental Radiation Model for Yucca Mountain Nevada (ERMYN). The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes the details of the conceptual model as well as the mathematical model and the required input parameters. The biosphere model is one of a series of process models supporting the postclosure Total System Performance Assessment (TSPA) for the Yucca Mountain repository. A schematic representation of the documentation flow for the Biosphere input to TSPA is presented in Figure 1-1. This figure shows the evolutionary relationships among the products (i.e., analysis and model reports) developed for biosphere modeling, and the biosphere abstraction products for TSPA, as identified in the ''Technical Work Plan for Biosphere Modeling and Expert Support'' (TWP) (BSC 2004 [DIRS 169573]). This figure is included to provide an understanding of how this analysis report contributes to biosphere modeling in support of the license application, and is not intended to imply that access to the listed documents is required to understand the contents of this report. This report, ''Soil-Related Input Parameters for the Biosphere Model'', is one of the five analysis reports that develop input parameters for use in the ERMYN model. This report is the source documentation for the six biosphere parameters identified in Table 1-1. The purpose of this analysis was to develop the biosphere model parameters associated with the accumulation and depletion of radionuclides in the soil. These parameters support the calculation of radionuclide concentrations in soil from on-going irrigation or ash deposition and, as a direct consequence, radionuclide concentration in other environmental media that are affected by radionuclide concentrations in soil. The analysis was performed in accordance with the TWP (BSC 2004 [DIRS 169573]) where the governing procedure was defined as AP-SIII.9Q, ''Scientific Analyses''. This

  14. Soil-Related Input Parameters for the Biosphere Model

    Energy Technology Data Exchange (ETDEWEB)

    A. J. Smith

    2004-09-09

    This report presents one of the analyses that support the Environmental Radiation Model for Yucca Mountain Nevada (ERMYN). The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes the details of the conceptual model as well as the mathematical model and the required input parameters. The biosphere model is one of a series of process models supporting the postclosure Total System Performance Assessment (TSPA) for the Yucca Mountain repository. A schematic representation of the documentation flow for the Biosphere input to TSPA is presented in Figure 1-1. This figure shows the evolutionary relationships among the products (i.e., analysis and model reports) developed for biosphere modeling, and the biosphere abstraction products for TSPA, as identified in the ''Technical Work Plan for Biosphere Modeling and Expert Support'' (TWP) (BSC 2004 [DIRS 169573]). This figure is included to provide an understanding of how this analysis report contributes to biosphere modeling in support of the license application, and is not intended to imply that access to the listed documents is required to understand the contents of this report. This report, ''Soil-Related Input Parameters for the Biosphere Model'', is one of the five analysis reports that develop input parameters for use in the ERMYN model. This report is the source documentation for the six biosphere parameters identified in Table 1-1. The purpose of this analysis was to develop the biosphere model parameters associated with the accumulation and depletion of radionuclides in the soil. These parameters support the calculation of radionuclide concentrations in soil from on-going irrigation or ash deposition and, as a direct consequence, radionuclide concentration in other environmental media that are affected by radionuclide concentrations in soil. The analysis was performed in accordance with the TWP (BSC 2004 [DIRS 169573]) where the governing procedure

  15. Input variable selection for data-driven models of Coriolis flowmeters for two-phase flow measurement

    International Nuclear Information System (INIS)

    Wang, Lijuan; Yan, Yong; Wang, Xue; Wang, Tao

    2017-01-01

    Input variable selection is an essential step in the development of data-driven models for environmental, biological and industrial applications. Through input variable selection to eliminate the irrelevant or redundant variables, a suitable subset of variables is identified as the input of a model. Meanwhile, through input variable selection the complexity of the model structure is simplified and the computational efficiency is improved. This paper describes the procedures of the input variable selection for the data-driven models for the measurement of liquid mass flowrate and gas volume fraction under two-phase flow conditions using Coriolis flowmeters. Three advanced input variable selection methods, including partial mutual information (PMI), genetic algorithm-artificial neural network (GA-ANN) and tree-based iterative input selection (IIS) are applied in this study. Typical data-driven models incorporating support vector machine (SVM) are established individually based on the input candidates resulting from the selection methods. The validity of the selection outcomes is assessed through an output performance comparison of the SVM based data-driven models and sensitivity analysis. The validation and analysis results suggest that the input variables selected from the PMI algorithm provide more effective information for the models to measure liquid mass flowrate while the IIS algorithm provides a fewer but more effective variables for the models to predict gas volume fraction. (paper)

  16. Direct energy inputs to the middle atmosphere

    Science.gov (United States)

    Rosenberg, T. J.; Lanzerotti, L. J.

    1979-01-01

    As a working definition of the extent of the middle atmosphere (MA), the height range from 30 to 100 km was adopted. The neutral and ionic composition and the dynamics within this height range are, for the most part, poorly understood. From available information, the importance of various particle and photon energy sources, including their variability, for ionization of the neutral atmosphere in this height range is assessed. The following topics are discussed: (1) penetration of the MA by particle and electromagnetic energy; (2) ionization sources for the MA; (3) galactic cosmic rays; (4) solar H Ly alpha, other EUV, and X-rays; (5) magnetospheric electrons and bremsstrahlung X-rays; and (6) solar cosmic rays.

  17. 40 CFR 1065.210 - Work input and output sensors.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Work input and output sensors. 1065... Ambient Conditions § 1065.210 Work input and output sensors. (a) Application. Use instruments as specified... sensors, transducers, and meters that meet the specifications in Table 1 of § 1065.205. Note that your...

  18. Input reduction for long-term morphodynamic simulations

    NARCIS (Netherlands)

    Walstra, D.J.R.; Ruessink, G.; Hoekstra, R.; Tonnon, P.K.

    2013-01-01

    Input reduction is imperative to long-term (> years) morphodynamic simulations to avoid excessive computation times. Here, we discuss the input-reduction framework for wave-dominated coastal settings introduced by Walstra et al. (2013). The framework comprised 4 steps, viz. (1) the selection of the

  19. Identifying Inputs to Leadership Development within an Interdisciplinary Leadership Minor

    Science.gov (United States)

    McKim, Aaron J.; Sorensen, Tyson J.; Velez, Jonathan J.

    2015-01-01

    Researchers conducted a qualitative analysis of students' experiences while enrolled in an interdisciplinary leadership minor with the intent to determine programmatic inputs that spur leadership development. Based on students' reflections, three domains of programmatic inputs for leadership development within the minor were identified. These…

  20. Off-line learning from clustered input examples

    NARCIS (Netherlands)

    Marangi, Carmela; Solla, Sara A.; Biehl, Michael; Riegler, Peter; Marinaro, Maria; Tagliaferri, Roberto

    1996-01-01

    We analyze the generalization ability of a simple perceptron acting on a structured input distribution for the simple case of two clusters of input data and a linearly separable rule. The generalization ability computed for three learning scenarios: maximal stability, Gibbs, and optimal learning, is

  1. Phonology: An Emergent Consequence of Memory Constraints and Sensory Input.

    Science.gov (United States)

    Lacerda, Francisco

    2003-01-01

    Presents a theoretical model that attempts to account for the early stages of language acquisition in terms of interaction between biological constraints and input characteristics. Notes that the model uses the implications of stochastic representations of the sensory input in a volatile and limited memory. Argues that phonological structure is a…

  2. History of the special committee on INIS input preparation

    International Nuclear Information System (INIS)

    Itabashi, Keizo

    2011-06-01

    The special committee on INIS input techniques was held 8 times from December 1970 to March 1973. The special committee on INIS input preparation was held 39 times from February 1974 to December 2004. The history of these two committees is described. (author)

  3. Modeling recognition memory using the similarity structure of natural input

    NARCIS (Netherlands)

    Lacroix, J.P.W.; Murre, J.M.J.; Postma, E.O.; van den Herik, H.J.

    2006-01-01

    The natural input memory (NIM) model is a new model for recognition memory that operates on natural visual input. A biologically informed perceptual preprocessing method takes local samples (eye fixations) from a natural image and translates these into a feature-vector representation. During

  4. Modeling Recognition Memory Using the Similarity Structure of Natural Input

    Science.gov (United States)

    Lacroix, Joyca P. W.; Murre, Jaap M. J.; Postma, Eric O.; van den Herik, H. Jaap

    2006-01-01

    The natural input memory (NAM) model is a new model for recognition memory that operates on natural visual input. A biologically informed perceptual preprocessing method takes local samples (eye fixations) from a natural image and translates these into a feature-vector representation. During recognition, the model compares incoming preprocessed…

  5. INPUT-OUTPUT ANALYSIS : THE NEXT 25 YEARS

    NARCIS (Netherlands)

    Dietzenbacher, Erik; Lenzen, Manfred; Los, Bart; Guan, Dabo; Lahr, Michael L.; Sancho, Ferran; Suh, Sangwon; Yang, Cuihong; Sancho, S.

    2013-01-01

    This year marks the 25th anniversary of the International Input-Output Association and the 25th volume of Economic Systems Research. To celebrate this anniversary, a group of eight experts provide their views on the future of input-output. Looking forward, they foresee progress in terms of data

  6. A Brief Talk on Cultural Input in English Teaching

    Institute of Scientific and Technical Information of China (English)

    王敏

    2007-01-01

    Different countries have different languages and cultures. My paper starts from the differentiation between western culture and Chinese culture to point out the importance and necessity of cultural input in English teaching and puts forward some approaches to enforce the cultural input in language teaching.

  7. Determinants of Agro-inputs redemption under the electronic wallet ...

    African Journals Online (AJOL)

    The study assessed the spread of farmers and participation in terms of input redemption and the determinants of farmers redeemed with agro-inputs under the electronic-wallet initiative of the Growth Enhancement Support Scheme of the On-going Agricultural Transformation Agenda. Secondary data covering the Nigerian ...

  8. Does Input Enhancement Work for Learning Politeness Strategies?

    Science.gov (United States)

    Khatib, Mohammad; Safari, Mahmood

    2013-01-01

    The present study investigated the effect of input enhancement on the acquisition of English politeness strategies by intermediate EFL learners. Two groups of freshman English majors were randomly assigned to the experimental (enhanced input) group and the control (mere exposure) group. Initially, a TOEFL test and a discourse completion test (DCT)…

  9. Exact Repetition as Input Enhancement in Second Language Acquisition.

    Science.gov (United States)

    Jensen, Eva Dam; Vinther, Thora

    2003-01-01

    Reports on two studies on input enhancement used to support learners' selection of focus of attention in Spanish second language listening material. Input consisted of video recordings of dialogues between native speakers. Exact repetition and speech rate reduction were examined for effect on comprehension, acquisition of decoding strategies, and…

  10. Variance-based sensitivity indices for models with dependent inputs

    International Nuclear Information System (INIS)

    Mara, Thierry A.; Tarantola, Stefano

    2012-01-01

    Computational models are intensively used in engineering for risk analysis or prediction of future outcomes. Uncertainty and sensitivity analyses are of great help in these purposes. Although several methods exist to perform variance-based sensitivity analysis of model output with independent inputs only a few are proposed in the literature in the case of dependent inputs. This is explained by the fact that the theoretical framework for the independent case is set and a univocal set of variance-based sensitivity indices is defined. In the present work, we propose a set of variance-based sensitivity indices to perform sensitivity analysis of models with dependent inputs. These measures allow us to distinguish between the mutual dependent contribution and the independent contribution of an input to the model response variance. Their definition relies on a specific orthogonalisation of the inputs and ANOVA-representations of the model output. In the applications, we show the interest of the new sensitivity indices for model simplification setting. - Highlights: ► Uncertainty and sensitivity analyses are of great help in engineering. ► Several methods exist to perform variance-based sensitivity analysis of model output with independent inputs. ► We define a set of variance-based sensitivity indices for models with dependent inputs. ► Inputs mutual contributions are distinguished from their independent contributions. ► Analytical and computational tests are performed and discussed.

  11. Adaptive projective synchronization of different chaotic systems with nonlinearity inputs

    International Nuclear Information System (INIS)

    Niu Yu-Jun; Pei Bing-Nan; Wang Xing-Yuan

    2012-01-01

    We investigate the projective synchronization of different chaotic systems with nonlinearity inputs. Based on the adaptive technique, sliding mode control method and pole assignment technique, a novel adaptive projective synchronization scheme is proposed to ensure the drive system and the response system with nonlinearity inputs can be rapidly synchronized up to the given scaling factor. (general)

  12. Achievable Information Rates on Linear Interference Channels with Discrete Input

    DEFF Research Database (Denmark)

    Yankov, Metodi Plamenov; Forchhammer, Søren

    2015-01-01

    In this paper lower bound on the capacity of multi-dimensional linear interference channels is derived, when the input is taken from a finite size alphabet. The bounds are based on the QR decomposition of the channel matrix, and hold for any input distribution that is independent across dimensions...

  13. A strategy for integrated low-input potato production

    NARCIS (Netherlands)

    Vereijken, P.H.; Loon, van C.D.

    1991-01-01

    Current systems of potato growing use large amounts of pesticides and fertilizers; these inputs are costly and cause environmental problems. In this paper a strategy for integrated low-input potato production is developed with the aim of reducing costs, improving product quality and reducing

  14. Smart-Guard: Defending User Input from Malware

    DEFF Research Database (Denmark)

    Denzel, Michael; Bruni, Alessandro; Ryan, Mark

    2016-01-01

    Trusted input techniques can profoundly enhance a variety of scenarios like online banking, electronic voting, Virtual Private Networks, and even commands to a server or Industrial Control System. To protect the system from malware of the sender’s computer, input needs to be reliably authenticated...

  15. Sound effects: Multimodal input helps infants find displaced objects.

    Science.gov (United States)

    Shinskey, Jeanne L

    2017-09-01

    Before 9 months, infants use sound to retrieve a stationary object hidden by darkness but not one hidden by occlusion, suggesting auditory input is more salient in the absence of visual input. This article addresses how audiovisual input affects 10-month-olds' search for displaced objects. In AB tasks, infants who previously retrieved an object at A subsequently fail to find it after it is displaced to B, especially following a delay between hiding and retrieval. Experiment 1 manipulated auditory input by keeping the hidden object audible versus silent, and visual input by presenting the delay in the light versus dark. Infants succeeded more at B with audible than silent objects and, unexpectedly, more after delays in the light than dark. Experiment 2 presented both the delay and search phases in darkness. The unexpected light-dark difference disappeared. Across experiments, the presence of auditory input helped infants find displaced objects, whereas the absence of visual input did not. Sound might help by strengthening object representation, reducing memory load, or focusing attention. This work provides new evidence on when bimodal input aids object processing, corroborates claims that audiovisual processing improves over the first year of life, and contributes to multisensory approaches to studying cognition. Statement of contribution What is already known on this subject Before 9 months, infants use sound to retrieve a stationary object hidden by darkness but not one hidden by occlusion. This suggests they find auditory input more salient in the absence of visual input in simple search tasks. After 9 months, infants' object processing appears more sensitive to multimodal (e.g., audiovisual) input. What does this study add? This study tested how audiovisual input affects 10-month-olds' search for an object displaced in an AB task. Sound helped infants find displaced objects in both the presence and absence of visual input. Object processing becomes more

  16. Uncertainty of input data for room acoustic simulations

    DEFF Research Database (Denmark)

    Jeong, Cheol-Ho; Marbjerg, Gerd; Brunskog, Jonas

    2016-01-01

    Although many room acoustic simulation models have been well established, simulation results will never be accurate with inaccurate and uncertain input data. This study addresses inappropriateness and uncertainty of input data for room acoustic simulations. Firstly, the random incidence absorption...... and scattering coefficients are insufficient when simulating highly non-diffuse rooms. More detailed information, such as the phase and angle dependence, can greatly improve the simulation results of pressure-based geometrical and wave-based models at frequencies well below the Schroeder frequency. Phase...... summarizes potential advanced absorption measurement techniques that can improve the quality of input data for room acoustic simulations. Lastly, plenty of uncertain input data are copied from unreliable sources. Software developers and users should be careful when spreading such uncertain input data. More...

  17. On Optimal Input Design and Model Selection for Communication Channels

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yanyan [ORNL; Djouadi, Seddik M [ORNL; Olama, Mohammed M [ORNL

    2013-01-01

    In this paper, the optimal model (structure) selection and input design which minimize the worst case identification error for communication systems are provided. The problem is formulated using metric complexity theory in a Hilbert space setting. It is pointed out that model selection and input design can be handled independently. Kolmogorov n-width is used to characterize the representation error introduced by model selection, while Gel fand and Time n-widths are used to represent the inherent error introduced by input design. After the model is selected, an optimal input which minimizes the worst case identification error is shown to exist. In particular, it is proven that the optimal model for reducing the representation error is a Finite Impulse Response (FIR) model, and the optimal input is an impulse at the start of the observation interval. FIR models are widely popular in communication systems, such as, in Orthogonal Frequency Division Multiplexing (OFDM) systems.

  18. Analytic uncertainty and sensitivity analysis of models with input correlations

    Science.gov (United States)

    Zhu, Yueying; Wang, Qiuping A.; Li, Wei; Cai, Xu

    2018-03-01

    Probabilistic uncertainty analysis is a common means of evaluating mathematical models. In mathematical modeling, the uncertainty in input variables is specified through distribution laws. Its contribution to the uncertainty in model response is usually analyzed by assuming that input variables are independent of each other. However, correlated parameters are often happened in practical applications. In the present paper, an analytic method is built for the uncertainty and sensitivity analysis of models in the presence of input correlations. With the method, it is straightforward to identify the importance of the independence and correlations of input variables in determining the model response. This allows one to decide whether or not the input correlations should be considered in practice. Numerical examples suggest the effectiveness and validation of our analytic method in the analysis of general models. A practical application of the method is also proposed to the uncertainty and sensitivity analysis of a deterministic HIV model.

  19. Modeling inputs to computer models used in risk assessment

    International Nuclear Information System (INIS)

    Iman, R.L.

    1987-01-01

    Computer models for various risk assessment applications are closely scrutinized both from the standpoint of questioning the correctness of the underlying mathematical model with respect to the process it is attempting to model and from the standpoint of verifying that the computer model correctly implements the underlying mathematical model. A process that receives less scrutiny, but is nonetheless of equal importance, concerns the individual and joint modeling of the inputs. This modeling effort clearly has a great impact on the credibility of results. Model characteristics are reviewed in this paper that have a direct bearing on the model input process and reasons are given for using probabilities-based modeling with the inputs. The authors also present ways to model distributions for individual inputs and multivariate input structures when dependence and other constraints may be present

  20. Double input converters for different voltage sources with isolated charger

    Directory of Open Access Journals (Sweden)

    Chalash Sattayarak

    2014-09-01

    Full Text Available This paper presents the double input converters for different voltage input sources with isolated charger coils. This research aims to increase the performance of the battery charger circuit. In the circuit, there are the different voltage levels of input source. The operating modes of the switch in the circuit use the microcontroller to control the battery charge and to control discharge mode automatically when the input voltage sources are lost from the system. The experimental result of this research shows better performance for charging at any time period of the switch, while the voltage input sources work together. Therefore, this research can use and develop to battery charger for present or future.

  1. Anthropogenic inputs of dissolved organic matter in New York Harbor

    Science.gov (United States)

    Gardner, G. B.; Chen, R. F.; Olavasen, J.; Peri, F.

    2016-02-01

    The Hudson River flows into the Atlantic Ocean through a highly urbanized region which includes New York City to the east and Newark, New Jersey to the west. As a result, the export of Dissolved Organic Carbon (DOC) from the Hudson to the Atlantic Ocean includes a significant anthropogenic component. A series of high resolution studies of the DOC dynamics of this system were conducted between 2003 and 2010. These included both the Hudson and adjacent large waterways (East River, Newark Bay, Kill Van Kull and Arthur Kill) using coastal research vessels and smaller tributaries (Hackensack, Pasaic and Raritan rivers) using a 25' boat. In both cases measurements were made using towed instrument packages which could be cycled from near surface to near bottom depths with horizontal resolution of approximately 20 to 200 meters depending on depth and deployment strategy. Sensors on the instrument packages included a CTD to provide depth and salinity information and a chromophoric dissolved organic matter(CDOM) fluorometer to measure the fluorescent fraction of the DOC. Discrete samples allowed calibration of the fluorometer and the CDOM data to be related to DOC. The combined data set from these cruises identified multiple scales of source and transport processes for DOC within the Hudson River/New York Harbor region. The Hudson carries a substantial amount of natural DOC from its 230 km inland stretch. Additional sources exist in fringing salt marshes adjacent to the Hackensack and Raritan rivers. However the lower Hudson/New Harbor region receives a large input of DOC from multiple publically owned treatment works (POTW) discharges. The high resolution surveys allowed us to elucidate the distribution of these sources and the manner in which they are rapidly mixed to create the total export. We estimate that anthropogenic sources account for up to 2.5 times the DOC flux contributed by natural processes.

  2. Quantifying input uncertainty in an assemble-to-order system simulation with correlated input variables of mixed types

    NARCIS (Netherlands)

    Akçay, A.E.; Biller, B.

    2014-01-01

    We consider an assemble-to-order production system where the product demands and the time since the last customer arrival are not independent. The simulation of this system requires a multivariate input model that generates random input vectors with correlated discrete and continuous components. In

  3. Development of an Input Model to MELCOR 1.8.5 for the Oskarshamn 3 BWR

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Lars [Lentek, Nykoeping (Sweden)

    2006-05-15

    .8.6 code, but its models are incorporated in the COR package. Two demonstration runs with the NONBH version were carried out, a total loss of power case and a case simulating a large steam line LOCA. The results are briefly presented and discussed in the report. Complete lists of the input files can be found in the appendices. However, the appendices are not included in the report for disclosure reasons.

  4. The neutron transport code DTF-Traca users manual and input data

    Energy Technology Data Exchange (ETDEWEB)

    Ahnert, C

    1979-07-01

    This is a users manual of the neutron transport code DTF-TRACA, which is a version of the original DTF-IV with some modifications made at JEN. A detailed input data descriptions is given. The new options developed at JEN are included too. (Author) 18 refs.

  5. 75 FR 46909 - Solicitation of Input From Stakeholders Regarding Assessments Focused on Improving Food Aid and...

    Science.gov (United States)

    2010-08-04

    ... implemented in the field to benefit highly vulnerable populations, including recommendations on the most cost... Institute of Food and Agriculture, USDA. ACTION: Notice; request for public comment. SUMMARY: The National... Extension Service (CSREES) requests input from the public regarding (1) the assessment of methods and tools...

  6. Central Cross-Talk in Task Switching : Evidence from Manipulating Input-Output Modality Compatibility

    Science.gov (United States)

    Stephan, Denise Nadine; Koch, Iring

    2010-01-01

    Two experiments examined the role of compatibility of input and output (I-O) modality mappings in task switching. We define I-O modality compatibility in terms of similarity of stimulus modality and modality of response-related sensory consequences. Experiment 1 included switching between 2 compatible tasks (auditory-vocal vs. visual-manual) and…

  7. Economic and environmental impacts of dietary changes in Iran : an input-output analysis

    NARCIS (Netherlands)

    Rahmani, R.; Bakhshoodeh, M.; Zibaei, M.; Heijman, W.J.M.; Eftekhari, M.H.

    2012-01-01

    Iran's simple and environmentally extended commodity by commodity input-output (IO) model was used to determine the impacts of dietary changes on the Iranian economy and on the environmental load. The original model is based on the status-quo diet and was modified to include the World Health

  8. The neutron transport code DTF-Traca users manual and input data

    International Nuclear Information System (INIS)

    Ahnert, C.

    1979-01-01

    This is a users manual of the neutron transport code DTF-TRACA, which is a version of the original DTF-IV with some modifications made at JEN. A detailed input data descriptions is given. The new options developed at JEN are included too. (Author) 18 refs

  9. The Effects of Input Enhancement and Recasts on the Development of Second Language Pragmatic Competence

    Science.gov (United States)

    Nguyen, Minh Thi Thuy; Pham, Hanh Thi; Pham, Tam Minh

    2017-01-01

    This study investigates the combined effects of input enhancement and recasts on a group of Vietnamese EFL learners' performance of constructive criticism during peer review activities. Particularly, the study attempts to find out whether the instruction works for different aspects of pragmatic learning, including the learners' sociopragmatic and…

  10. Explicit Input Enhancement: Effects on Target and Non-Target Aspects of Second Language Acquisition

    Science.gov (United States)

    Gascoigne, Carolyn

    2006-01-01

    Many recent studies have examined the effectiveness of various types of input enhancement. The following study expands this line of inquiry to include technological applications of language learning by comparing the effectiveness of the computer application of diacritics to a traditional pen-and-paper process among beginning students of French and…

  11. The neutron transport code DTF-TRACA. User's manual and input data

    International Nuclear Information System (INIS)

    Anhert, C.

    1979-01-01

    A user's manual of the neutron transport code DTF-TRACA, which is a version of the original DTF-IV with some modifications made at JEN. A detailed input data description is given. The new options developped at JEN are included too. (author)

  12. Economic Input-Output Life Cycle Assessment of Water Reuse Strategies in Residential Buildings

    Science.gov (United States)

    This paper evaluates the environmental sustainability and economic feasibility of four water reuse designs through economic input-output life cycle assessments (EIO-LCA) and benefit/cost analyses. The water reuse designs include: 1. Simple Greywater Reuse System for Landscape Ir...

  13. Design, Fabrication, and Modeling of a Novel Dual-Axis Control Input PZT Gyroscope.

    Science.gov (United States)

    Chang, Cheng-Yang; Chen, Tsung-Lin

    2017-10-31

    Conventional gyroscopes are equipped with a single-axis control input, limiting their performance. Although researchers have proposed control algorithms with dual-axis control inputs to improve gyroscope performance, most have verified the control algorithms through numerical simulations because they lacked practical devices with dual-axis control inputs. The aim of this study was to design a piezoelectric gyroscope equipped with a dual-axis control input so that researchers may experimentally verify those control algorithms in future. Designing a piezoelectric gyroscope with a dual-axis control input is more difficult than designing a conventional gyroscope because the control input must be effective over a broad frequency range to compensate for imperfections, and the multiple mode shapes in flexural deformations complicate the relation between flexural deformation and the proof mass position. This study solved these problems by using a lead zirconate titanate (PZT) material, introducing additional electrodes for shielding, developing an optimal electrode pattern, and performing calibrations of undesired couplings. The results indicated that the fabricated device could be operated at 5.5±1 kHz to perform dual-axis actuations and position measurements. The calibration of the fabricated device was completed by system identifications of a new dynamic model including gyroscopic motions, electromechanical coupling, mechanical coupling, electrostatic coupling, and capacitive output impedance. Finally, without the assistance of control algorithms, the "open loop sensitivity" of the fabricated gyroscope was 1.82 μV/deg/s with a nonlinearity of 9.5% full-scale output. This sensitivity is comparable with those of other PZT gyroscopes with single-axis control inputs.

  14. Life cycle assessment of small-scale high-input Jatropha biodiesel production in India

    International Nuclear Information System (INIS)

    Pandey, Krishan K.; Pragya, Namita; Sahoo, P.K.

    2011-01-01

    Highlights: → NEB and NER of high input Jatropha biodiesel system was higher than those of low input. → These values further increase on including the energy content of the co-products, and in the further years. → Maximum energy use was during oil extraction, followed by oil processing and fertilizer use. → Allocation of resources at right time and with proper care increase the overall system productivity. -- Abstract: In the current scenario of depleting energy resources, increasing food insecurity and global warming, Jatropha has emerged as a promising energy crop for India. The aim of this study is to examine the life cycle energy balance for Jatropha biodiesel production and greenhouse gas emissions from post-energy use and end combustion of biodiesel, over a period of 5 years. It's a case specific study for a small scale, high input Jatropha biodiesel system. Most of the existing studies have considered low input Jatropha biodiesel system and have used NEB (Net energy balance i.e. difference of energy output and energy input) and NER (Net energy ratio i.e. ratio of energy output to energy input) as indicators for estimating the viability of the systems. Although, many of them have shown these indicators to be positive, yet the values are very less. The results of this study, when compared with two previous studies of Jatropha, show that the values for these indicators can be increased to a much greater extent, if we use a high input Jatropha biodiesel system. Further, when compared to a study done on palm oil and Coconut oil, it was found even if the NEB and NER of biodiesel from Jatropha were lesser in comparison to those of Palm oil and Coconut oil, yet, when energy content of the co-products were also considered, Jatropha had the highest value for both the indicators in comparison to the rest two.

  15. Design, Fabrication, and Modeling of a Novel Dual-Axis Control Input PZT Gyroscope

    Directory of Open Access Journals (Sweden)

    Cheng-Yang Chang

    2017-10-01

    Full Text Available Conventional gyroscopes are equipped with a single-axis control input, limiting their performance. Although researchers have proposed control algorithms with dual-axis control inputs to improve gyroscope performance, most have verified the control algorithms through numerical simulations because they lacked practical devices with dual-axis control inputs. The aim of this study was to design a piezoelectric gyroscope equipped with a dual-axis control input so that researchers may experimentally verify those control algorithms in future. Designing a piezoelectric gyroscope with a dual-axis control input is more difficult than designing a conventional gyroscope because the control input must be effective over a broad frequency range to compensate for imperfections, and the multiple mode shapes in flexural deformations complicate the relation between flexural deformation and the proof mass position. This study solved these problems by using a lead zirconate titanate (PZT material, introducing additional electrodes for shielding, developing an optimal electrode pattern, and performing calibrations of undesired couplings. The results indicated that the fabricated device could be operated at 5.5±1 kHz to perform dual-axis actuations and position measurements. The calibration of the fabricated device was completed by system identifications of a new dynamic model including gyroscopic motions, electromechanical coupling, mechanical coupling, electrostatic coupling, and capacitive output impedance. Finally, without the assistance of control algorithms, the “open loop sensitivity” of the fabricated gyroscope was 1.82 μV/deg/s with a nonlinearity of 9.5% full-scale output. This sensitivity is comparable with those of other PZT gyroscopes with single-axis control inputs.

  16. Learning Structure of Sensory Inputs with Synaptic Plasticity Leads to Interference

    Directory of Open Access Journals (Sweden)

    Joseph eChrol-Cannon

    2015-08-01

    Full Text Available Synaptic plasticity is often explored as a form of unsupervised adaptationin cortical microcircuits to learn the structure of complex sensoryinputs and thereby improve performance of classification and prediction. The question of whether the specific structure of the input patterns is encoded in the structure of neural networks has been largely neglected. Existing studies that have analyzed input-specific structural adaptation have used simplified, synthetic inputs in contrast to complex and noisy patterns found in real-world sensory data.In this work, input-specific structural changes are analyzed forthree empirically derived models of plasticity applied to three temporal sensory classification tasks that include complex, real-world visual and auditory data. Two forms of spike-timing dependent plasticity (STDP and the Bienenstock-Cooper-Munro (BCM plasticity rule are used to adapt the recurrent network structure during the training process before performance is tested on the pattern recognition tasks.It is shown that synaptic adaptation is highly sensitive to specific classes of input pattern. However, plasticity does not improve the performance on sensory pattern recognition tasks, partly due to synaptic interference between consecutively presented input samples. The changes in synaptic strength produced by one stimulus are reversed by thepresentation of another, thus largely preventing input-specific synaptic changes from being retained in the structure of the network.To solve the problem of interference, we suggest that models of plasticitybe extended to restrict neural activity and synaptic modification to a subset of the neural circuit, which is increasingly found to be the casein experimental neuroscience.

  17. Numerical simulation of waveguide input/output couplers for a planar mm-wave linac cavity

    International Nuclear Information System (INIS)

    Kang, Y.W.

    1994-01-01

    A double-sided planar mm-wave linear accelerating cavity structure has been studied. The input/output couplers for the accelerating cavity structure have been designed using the Hewlett-Packard High Frequency Structure Simulator (HFSS). The program is a frequency domain finite element 3-D field solver and can include matched port boundary conditions. The power transmission property of the structure is calculated in the frequency domain. The dimensions of the, coupling cavities and the irises at the input/output ports are adjusted to have the structure matched to rectangular waveguides. The field distributions in the accelerating structure for the 2π/3-mode traveling wave are shown

  18. WORM: A general-purpose input deck specification language

    International Nuclear Information System (INIS)

    Jones, T.

    1999-01-01

    Using computer codes to perform criticality safety calculations has become common practice in the industry. The vast majority of these codes use simple text-based input decks to represent the geometry, materials, and other parameters that describe the problem. However, the data specified in input files are usually processed results themselves. For example, input decks tend to require the geometry specification in linear dimensions and materials in atom or weight fractions, while the parameter of interest might be mass or concentration. The calculations needed to convert from the item of interest to the required parameter in the input deck are usually performed separately and then incorporated into the input deck. This process of calculating, editing, and renaming files to perform a simple parameter study is tedious at best. In addition, most computer codes require dimensions to be specified in centimeters, while drawings or other materials used to create the input decks might be in other units. This also requires additional calculation or conversion prior to composition of the input deck. These additional calculations, while extremely simple, introduce a source for error in both the calculations and transcriptions. To overcome these difficulties, WORM (Write One, Run Many) was created. It is an easy-to-use programming language to describe input decks and can be used with any computer code that uses standard text files for input. WORM is available, via the Internet, at worm.lanl.gov. A user's guide, tutorials, example models, and other WORM-related materials are also available at this Web site. Questions regarding WORM should be directed to wormatlanl.gov

  19. Mars 2.2 code manual: input requirements

    International Nuclear Information System (INIS)

    Chung, Bub Dong; Lee, Won Jae; Jeong, Jae Jun; Lee, Young Jin; Hwang, Moon Kyu; Kim, Kyung Doo; Lee, Seung Wook; Bae, Sung Won

    2003-07-01

    Korea Advanced Energy Research Institute (KAERI) conceived and started the development of MARS code with the main objective of producing a state-of-the-art realistic thermal hydraulic systems analysis code with multi-dimensional analysis capability. MARS achieves this objective by very tightly integrating the one dimensional RELAP5/MOD3 with the multi-dimensional COBRA-TF codes. The method of integration of the two codes is based on the dynamic link library techniques, and the system pressure equation matrices of both codes are implicitly integrated and solved simultaneously. In addition, the Equation-of-State (EOS) for the light water was unified by replacing the EOS of COBRA-TF by that of the RELAP5. This input manual provides a complete list of input required to run MARS. The manual is divided largely into two parts, namely, the one-dimensional part and the multi-dimensional part. The inputs for auxiliary parts such as minor edit requests and graph formatting inputs are shared by the two parts and as such mixed input is possible. The overall structure of the input is modeled on the structure of the RELAP5 and as such the layout of the manual is very similar to that of the RELAP. This similitude to RELAP5 input is intentional as this input scheme will allow minimum modification between the inputs of RELAP5 and MARS. MARS development team would like to express its appreciation to the RELAP5 Development Team and the USNRC for making this manual possible

  20. Input data required for specific performance assessment codes

    International Nuclear Information System (INIS)

    Seitz, R.R.; Garcia, R.S.; Starmer, R.J.; Dicke, C.A.; Leonard, P.R.; Maheras, S.J.; Rood, A.S.; Smith, R.W.

    1992-02-01

    The Department of Energy's National Low-Level Waste Management Program at the Idaho National Engineering Laboratory generated this report on input data requirements for computer codes to assist States and compacts in their performance assessments. This report gives generators, developers, operators, and users some guidelines on what input data is required to satisfy 22 common performance assessment codes. Each of the codes is summarized and a matrix table is provided to allow comparison of the various input required by the codes. This report does not determine or recommend which codes are preferable