A missional perspective on funerals and bereavement counselling

Directory of Open Access Journals (Sweden)

Peter Kotze

2015-08-01

Full Text Available This article deals with the importance of a missional approach to the funeral and bereavement counselling process in congregational praxis in the midst of a context of secularisation. The creation of a missional perspective on the funeral and bereavement counselling could support the nature and praxis of a congregation in a secular society, especially if the congregation finds its relevance in the expression of the missio Dei. The basic theoretical research for missional ecclesiology, which is the systematic study directed toward greater knowledge of the fundamental aspects of missional ecclesiology (National Science Foundation 1953:38, is based on the premise that God is the source of all missions. The expression missio Dei means to join God in the mission he is already busy with in the world. As the one who sends, God the Father sends the Son, the Son sends the Holy Spirit, and the Holy Spirit sends the church. The church only participates in the mission God is already busy with. It is a mission that uses both words and deeds and brings hope in the midst of tragedy. It is the hope of the kingdom of God and the incarnation of Christ that can already be experienced and expressed in the present. It is also the hope of the transformation of everything to form a new heaven and earth. Hope and mission can therefore not be separated. The concretisation of the expression of the kingdom of Christ in the world is hope, and a strong emphasis is therefore placed on mission as action in hope. Hope must be present where tragedy reigns, and the funeral and bereavement counselling can be used as a vehicle for this hope. Hope can then become an instrument of healing. The church can thus participate in God’s mission in the midst of tragedy and make an impact on society by taking on a missional character of hope.

Tunable Superconducting Gravity Gradiometer for Mars Climate, Atmosphere, and Gravity Field Investigation

Science.gov (United States)

Griggs, C. E.; Paik, H. J.; Moody, M. V.; Han, S.-C.; Rowlands, D. D.; Lemoine, F. G.; Shirron, P. J.

2015-01-01

We are developing a compact tensor superconducting gravity gradiometer (SGG) for obtaining gravimetric measurements from planetary orbits. A new and innovative design gives a potential sensitivity of approximately 10(sup -4) E Hz(sup - 1/2)( 1 E = 10(sup -9 S(sup -2) in the measurement band up to 0.1 Hz (suitale for short wavelength static gravity) and of approximately 10(sup -4) E Hz(sup - 1/2) in the frequency band less than 1 mHz (for long wavelength time-variable gravity) from the same device with a baseline just over 10 cm. The measurement band and sensitiy can be optimally tuned in-flight during the mission by changing resonance frequencies, which allows meaurements of both static and time-variable gravity fields from the same mission. Significant advances in the technologies needed for space-based cryogenic instruments have been made in the last decade. In particular, the use of cryocoolers will alleviate the previously severe constraint on mission lifetime imposed by the use of liquid helium, enabling mission durations in the 5 - 10 year range.

The Bragg Reflection Polarimeter On the Gravity and Extreme Magnetism Small Explorer Mission

Science.gov (United States)

Allured, Ryan; Griffiths, S.; Daly, R.; Prieskorn, Z.; Marlowe, H.; Kaaret, P.; GEMS Team

2011-09-01

The strong gravity associated with black holes warps the spacetime outside of the event horizon, and it is predicted that this will leave characteristic signatures on the polarization of X-ray emission originating in the accretion disk. The Gravity and Extreme Magnetism Small Explorer (GEMS) mission will be the first observatory with the capability to make polarization measurements with enough sensitivity to quantitatively test this prediction. Students at the University of Iowa are currently working on the development of the Bragg Reflection Polarimeter (BRP), a soft X-ray polarimeter sensitive at 500 eV, that is the student experiment on GEMS. The BRP will complement the main experiment by making a polarization measurement from accreting black holes below the main energy band (2-10 keV). This measurement will constrain the inclination of the accretion disk and tighten measurements of black hole spin.

High-resolution Local Gravity Model of the South Pole of the Moon from GRAIL Extended Mission Data

Science.gov (United States)

Goossens, Sander Johannes; Sabaka, Terence J.; Nicholas, Joseph B.; Lemoine, Frank G.; Rowlands, David D.; Mazarico, Erwan; Neumann, Gregory A.; Smith, David E.; Zuber, Maria T.

2014-01-01

We estimated a high-resolution local gravity field model over the south pole of the Moon using data from the Gravity Recovery and Interior Laboratory's extended mission. Our solution consists of adjustments with respect to a global model expressed in spherical harmonics. The adjustments are expressed as gridded gravity anomalies with a resolution of 1/6deg by 1/6deg (equivalent to that of a degree and order 1080 model in spherical harmonics), covering a cap over the south pole with a radius of 40deg. The gravity anomalies have been estimated from a short-arc analysis using only Ka-band range-rate (KBRR) data over the area of interest. We apply a neighbor-smoothing constraint to our solution. Our local model removes striping present in the global model; it reduces the misfit to the KBRR data and improves correlations with topography to higher degrees than current global models.

The impact of using jason-1 and cryosat-2 geodetic mission altimetry for gravity field modeling

DEFF Research Database (Denmark)

Andersen, Ole Baltazar; Jain, Maulik; Knudsen, Per

2016-01-01

Since the release of the Danish Technical University DTU10 global marine gravity field in 2010, the amount of geodetic mission altimetry data has nearly tripled. The Cryosat-2 satellite have provided data along its 369 day near repeat since 2010 and as of May 2012 the Jason-1 satellite has been o...

New dimensions new hopes

International Nuclear Information System (INIS)

Sarkar, Utpal

2001-05-01

We live in a four dimensional world. But the idea of unification of fundamental interactions lead us to higher dimensional theories. Recently a new theory with extra dimensions has emerged where only gravity propagates in the extra dimension and all other interactions are confined to only four dimensions. This theory gives us many new hopes. In earlier theories unification of strong, weak and the electromagnetic forces was possible at around 10 16 GeV in a grand unified theory (GUT) and it could get unified with gravity at around the Planck scale of 10 19 GeV. With this new idea it is possible to bring down all unification scales within the reach of the new generation accelerators, i.e., around 10 4 GeV. (author)

Tests Results of the Electrostatic Accelerometer Flight Models for Gravity Recovery and Climate Experiment Follow-On Mission (GRACE FO)

Science.gov (United States)

Perrot, E.; Boulanger, D.; Christophe, B.; Foulon, B.; Lebat, V.; Huynh, P. A.; Liorzou, F.

2015-12-01

The GRACE FO mission, led by the JPL (Jet Propulsion Laboratory), is an Earth-orbiting gravity mission, continuation of the GRACE mission, which will produce an accurate model of the Earth's gravity field variation providing global climatic data during five years at least. The mission involves two satellites in a loosely controlled tandem formation, with a micro-wave link measuring the inter-satellites distance variation. Earth's mass distribution non-uniformities cause variations of the inter-satellite distance. This variation is measured to recover gravity, after subtracting the non-gravitational contributors, as the residual drag. ONERA (the French Aerospace Lab) is developing, manufacturing and testing electrostatic accelerometers measuring this residual drag applied on the satellites. The accelerometer is composed of two main parts: the Sensor Unit (including the Sensor Unit Mechanics - SUM - and the Front-End Electronic Unit - FEEU) and the Interface Control Unit - ICU. In the Accelerometer Core, located in the Sensor Unit Mechanics, the proof mass is levitated and maintained at the center of an electrode cage by electrostatic forces. Thus, any drag acceleration applied on the satellite involves a variation on the servo-controlled electrostatic suspension of the mass. The voltage on the electrodes providing this electrostatic force is the output measurement of the accelerometer. The impact of the accelerometer defaults (geometry, electronic and parasitic forces) leads to bias, misalignment and scale factor error, non-linearity and noise. Some of these accelerometer defaults are characterized by tests with micro-gravity pendulum bench on ground and with drops in ZARM catapult. The Critical Design Review was achieved successfully on September 2014. The Engineering Model (EM) was integrated and tested successfully, with ground levitation, drops, Electromagnetic Compatibility and thermal vacuum. The integration of the two Flight Models was done on July 2015. The

First champ mission results for gravity, magnetic and atmospheric studies

CERN Document Server

Lühr, Hermann; Schwintzer, Peter

2003-01-01

In the summer of 2000 the German geo-research satellite CHAMP was launched into orbit. Its innovative payload arrangement and the low intial orbit allow CHAMP to simultaneously collect and almost continuously analyse precise data relating to gravity and magnetic fields at low altitude. In addition to this CHAMP also measures the neutral atmosphere and ionosphere using GPS techniques. Eighteen months after the launch, CHAMP research groups from all over the world met at the Geo-Forschungs-Zentrum in Potsdam for an initial exchange of experiences and results. The main outcome of this user meeting is summarized in this volume. Apart from technical information about the mission, the book offers a comprehensive insight into the present status of CHAMP data exploitation for Earth system research and practical applications in geodesy, geophysics and meteorology.

Gravity Probe-B (GP-B) Mission and Tracking, Telemetry and Control Subsystem Overview

Science.gov (United States)

Kennedy, Paul; Bell, Joseph L. (Technical Monitor)

2001-01-01

The National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) in Huntsville, Alabama will launch the Gravity Probe B (GP-B) space experiment in the Fall of 2002. The GP-B spacecraft was developed to prove Einstein's theory of General Relativity. This paper will provide an overview of the GPB mission and will discuss the design, and test of the spacecraft Tracking, Telemetry and Control (TT&C) subsystem which incorporates NASA's latest generation standard transponder for use with the NASA Tracking and Data Relay Satellite System (TDRSS).

Quantum Gravity

International Nuclear Information System (INIS)

Giribet, G E

2005-01-01

Claus Kiefer presents his book, Quantum Gravity, with his hope that '[the] book will convince readers of [the] outstanding problem [of unification and quantum gravity] and encourage them to work on its solution'. With this aim, the author presents a clear exposition of the fundamental concepts of gravity and the steps towards the understanding of its quantum aspects. The main part of the text is dedicated to the analysis of standard topics in the formulation of general relativity. An analysis of the Hamiltonian formulation of general relativity and the canonical quantization of gravity is performed in detail. Chapters four, five and eight provide a pedagogical introduction to the basic concepts of gravitational physics. In particular, aspects such as the quantization of constrained systems, the role played by the quadratic constraint, the ADM decomposition, the Wheeler-de Witt equation and the problem of time are treated in an expert and concise way. Moreover, other specific topics, such as the minisuperspace approach and the feasibility of defining extrinsic times for certain models, are discussed as well. The ninth chapter of the book is dedicated to the quantum gravitational aspects of string theory. Here, a minimalistic but clear introduction to string theory is presented, and this is actually done with emphasis on gravity. It is worth mentioning that no hard (nor explicit) computations are presented, even though the exposition covers the main features of the topic. For instance, black hole statistical physics (within the framework of string theory) is developed in a pedagogical and concise way by means of heuristical arguments. As the author asserts in the epilogue, the hope of the book is to give 'some impressions from progress' made in the study of quantum gravity since its beginning, i.e., since the end of 1920s. In my opinion, Kiefer's book does actually achieve this goal and gives an extensive review of the subject. (book review)

Solar Probe Plus: Mission design challenges and trades

Science.gov (United States)

Guo, Yanping

2010-11-01

NASA plans to launch the first mission to the Sun, named Solar Probe Plus, as early as 2015, after a comprehensive feasibility study that significantly changed the original Solar Probe mission concept. The original Solar Probe mission concept, based on a Jupiter gravity assist trajectory, was no longer feasible under the new guidelines given to the mission. A complete redesign of the mission was required, which called for developing alternative trajectories that excluded a flyby of Jupiter. Without the very powerful gravity assist from Jupiter it was extremely difficult to get to the Sun, so designing a trajectory to reach the Sun that is technically feasible under the new mission guidelines became a key enabler to this highly challenging mission. Mission design requirements and challenges unique to this mission are reviewed and discussed, including various mission scenarios and six different trajectory designs utilizing various planetary gravity assists that were considered. The V 5GA trajectory design using five Venus gravity assists achieves a perihelion of 11.8 solar radii ( RS) in 3.3 years without any deep space maneuver (DSM). The V 7GA trajectory design reaches a perihelion of 9.5 RS using seven Venus gravity assists in 6.39 years without any DSM. With nine Venus gravity assists, the V 9GA trajectory design shows a solar orbit at inclination as high as 37.9° from the ecliptic plane can be achieved with the time of flight of 5.8 years. Using combined Earth and Venus gravity assists, as close as 9 RS from the Sun can be achieved in less than 10 years of flight time at moderate launch C3. Ultimately the V 7GA trajectory was chosen as the new baseline mission trajectory. Its design allowing for science investigation right after launch and continuing for nearly 7 years is unprecedented for interplanetary missions. The redesigned Solar Probe Plus mission is not only feasible under the new guidelines but also significantly outperforms the original mission concept

Low-degree gravity change from GPS data of COSMIC and GRACE satellite missions

Science.gov (United States)

Lin, Tingjung; Hwang, Cheinway; Tseng, Tzu-Pang; Chao, B. F.

2012-01-01

This paper demonstrates estimation of time-varying gravity harmonic coefficients from GPS data of COSMIC and GRACE satellite missions. The kinematic orbits of COSMIC and GRACE are determined to the cm-level accuracy. The NASA Goddard's GEODYN II software is used to model the orbit dynamics of COSMIC and GRACE, including the effect of a static gravity field. The surface forces are estimated per one orbital period. Residual orbits generated from kinematic and reference orbits serve as observables to determine the harmonic coefficients in the weighted-constraint least-squares. The monthly COSMIC and GRACE GPS data from September 2006 to December 2007 (16 months) are processed to estimate harmonic coefficients to degree 5. The geoid variations from the GPS and CSR RL04 (GRACE) solutions show consistent patterns over space and time, especially in regions of active hydrological changes. The monthly GPS-derived second zonal coefficient closely resembles the SLR-derived and CSR RL04 values, and third and fourth zonal coefficients resemble the CSR RL04 values.

Global gravity field from recent satellites (DTU15) - Arctic improvements

DEFF Research Database (Denmark)

Andersen, O. B.; Knudsen, P.; Kenyon, S.

2017-01-01

Global marine gravity field modelling using satellite altimetry is currently undergoing huge improvement with the completion of the Jason-1 end-of-life geodetic mission, but particularly with the continuing Cryosat-2 mission. These new satellites provide three times as many geodetic mission...... altimetric sea surface height observations as ever before. The impact of these new geodetic mission data is a dramatic improvement of particularly the shorter wavelength of the gravity field (10-20 km) which is now being mapped at significantly higher accuracy. The quality of the altimetric gravity field...... is in many places surpassing the quality of gravity fields derived using non-commercial marine gravity observations. Cryosat-2 provides for the first time altimetry throughout the Arctic Ocean up to 88°N. Here, the huge improvement in marine gravity mapping is shown through comparison with high quality...

Loop-quantum-gravity vertex amplitude.

Science.gov (United States)

Engle, Jonathan; Pereira, Roberto; Rovelli, Carlo

2007-10-19

Spin foam models are hoped to provide the dynamics of loop-quantum gravity. However, the most popular of these, the Barrett-Crane model, does not have the good boundary state space and there are indications that it fails to yield good low-energy n-point functions. We present an alternative dynamics that can be derived as a quantization of a Regge discretization of Euclidean general relativity, where second class constraints are imposed weakly. Its state space matches the SO(3) loop gravity one and it yields an SO(4)-covariant vertex amplitude for Euclidean loop gravity.

A new method for optimization of low-thrust gravity-assist sequences

Science.gov (United States)

Maiwald, V.

2017-09-01

Recently missions like Hayabusa and Dawn have shown the relevance and benefits of low-thrust spacecraft concerning the exploration of our solar system. In general, the efficiency of low-thrust propulsion is one means of improving mission payload mass. At the same time, gravity-assist maneuvers can serve as mission enablers, as they have the capability to provide "free energy." A combination of both, gravity-assist and low-thrust propulsion, has the potential to generally improve mission performance, i.e. planning and optimization of gravity-assist sequences for low-thrust missions is a desirable asset. Currently no established methods exist to include the gravity-assist partners as optimization variable for low-thrust missions. The present paper explains how gravity-assists are planned and optimized, including the gravity-assist partners, for high-thrust missions and discusses the possibility to transfer the established method, based on the Tisserand Criterion, to low-thrust missions. It is shown how the Tisserand Criterion needs to be adapted using a correction term for the low-thrust situation. It is explained why this necessary correction term excludes an a priori evaluation of sequences and therefore their planning and an alternate approach is proposed. Preliminary results of this method, by application of a Differential Evolution optimization algorithm, are presented and discussed, showing that the method is valid but can be improved. Two constraints on the search space are briefly presented for that aim.

The Near Side : Regional Lunar Gravity Field Determination

NARCIS (Netherlands)

Goossens, S.

2005-01-01

In the past ten years the Moon has come fully back into focus, resulting in missions such as Clementine and Lunar Prospector. Data from these missions resulted in a boost in lunar gravity field modelling. Until this date, the lunar gravity field has mainly been expressed in a global representation,

Europe's Preparation For GOCE Gravity Field Recovery

Science.gov (United States)

Suenkel, H.; Suenkel, H.

2001-12-01

The European Space Agency ESA is preparing for its first dedicated gravity field mission GOCE (Gravity Field and Steady-state Ocean Circulation Explorer) with a proposed launch in fall 2005. The mission's goal is the mapping of the Earth's static gravity field with very high resolution and utmost accuracy on a global scale. GOCE is a drag-free mission, flown in a circular and sun-synchronous orbit at an altitude between 240 and 250 km. Each of the two operational phases will last for 6 months. GOCE is based on a sensor fusion concept combining high-low satellite-to-satellite tracking (SST) and satellite gravity gradiometry (SGG). The transformation of the GOCE sensor data into a scientific product of utmost quality and reliability requires a well-coordinated effort of experts in satellite geodesy, applied mathematics and computer science. Several research groups in Europe do have this expertise and decided to form the "European GOCE Gravity Consortium (EGG-C)". The EGG-C activities are subdivided into tasks such as standard and product definition, data base and data dissemination, precise orbit determination, global gravity field model solutions and regional solutions, solution validation, communication and documentation, and the interfacing to level 3 product scientific users. The central issue of GOCE data processing is, of course, the determination of the global gravity field model using three independent mathematical-numerical techniques which had been designed and pre-developed in the course of several scientific preparatory studies of ESA: 1. The direct solution which is a least squares adjustment technique based on a pre-conditioned conjugated gradient method (PCGM). The method is capable of efficiently transforming the calibrated and validated SST and SGG observations directly or via lumped coefficients into harmonic coefficients of the gravitational potential. 2. The time-wise approach considers both SST and SGG data as a time series. For an idealized

Shallow-earth rheology from glacial isostasy and satellite gravity : A sensitivity analysis for GOCE

NARCIS (Netherlands)

Schotman, H.H.A.

2008-01-01

In recent years, satellite gravity missions have been launched that probe the earth's long- to mediumwavelength (1000 - 500 km) gravity field. The upcoming ESA satellite gravity mission GOCE is predicted to measure the gravity field with an accuracy of a few centimeters at spatial scales of 100 km.

Topspin networks in loop quantum gravity

International Nuclear Information System (INIS)

Duston, Christopher L

2012-01-01

We discuss the extension of loop quantum gravity to topspin networks, a proposal which allows topological information to be encoded in spin networks. We will show that this requires minimal changes to the phase space, C*-algebra and Hilbert space of cylindrical functions. We will also discuss the area and Hamiltonian operators, and show how they depend on the topology. This extends the idea of ‘background independence’ in loop quantum gravity to include topology as well as geometry. It is hoped this work will confirm the usefulness of the topspin network formalism and open up several new avenues for research into quantum gravity. (paper)

Crustal and Upper Mantle Structure from Joint Inversion of Body Wave and Gravity Data

Science.gov (United States)

2012-09-01

We use both free-air and Bouguer gravity anomalies derived from the global gravity model of the GRACE satellite mission. The gravity data provide...relocation analysis. We use both free-air and Bouguer gravity anomalies derived from the global gravity model of the GRACE satellite mission. The gravity...topographic relief this effect needs to be removed; thus, we converted free-air anomalies into Bouguer anomalies assuming a standard density for crustal rocks

Surface mass redistribution inversion from global GPS deformation and Gravity Recovery and Climate Experiment (GRACE) gravity data

NARCIS (Netherlands)

Kusche, J.; Schrama, E.J.O.

2005-01-01

Monitoring hydrological redistributions through their integrated gravitational effect is the primary aim of the Gravity Recovery and Climate Experiment (GRACE) mission. Time?variable gravity data from GRACE can be uniquely inverted to hydrology, since mass transfers located at or near the Earth's

The gravity field and GGOS

DEFF Research Database (Denmark)

Forsberg, René; Sideris, M.G.; Shum, C.K.

2005-01-01

The gravity field of the earth is a natural element of the Global Geodetic Observing System (GGOS). Gravity field quantities are like spatial geodetic observations of potential very high accuracy, with measurements, currently at part-per-billion (ppb) accuracy, but gravity field quantities are also...... unique as they can be globally represented by harmonic functions (long-wavelength geopotential model primarily from satellite gravity field missions), or based on point sampling (airborne and in situ absolute and superconducting gravimetry). From a GGOS global perspective, one of the main challenges...... is to ensure the consistency of the global and regional geopotential and geoid models, and the temporal changes of the gravity field at large spatial scales. The International Gravity Field Service, an umbrella "level-2" IAG service (incorporating the International Gravity Bureau, International Geoid Service...

Towards the map of quantum gravity

Science.gov (United States)

Mielczarek, Jakub; Trześniewski, Tomasz

2018-06-01

In this paper we point out some possible links between different approaches to quantum gravity and theories of the Planck scale physics. In particular, connections between loop quantum gravity, causal dynamical triangulations, Hořava-Lifshitz gravity, asymptotic safety scenario, Quantum Graphity, deformations of relativistic symmetries and nonlinear phase space models are discussed. The main focus is on quantum deformations of the Hypersurface Deformations Algebra and Poincaré algebra, nonlinear structure of phase space, the running dimension of spacetime and nontrivial phase diagram of quantum gravity. We present an attempt to arrange the observed relations in the form of a graph, highlighting different aspects of quantum gravity. The analysis is performed in the spirit of a mind map, which represents the architectural approach to the studied theory, being a natural way to describe the properties of a complex system. We hope that the constructed graphs (maps) will turn out to be helpful in uncovering the global picture of quantum gravity as a particular complex system and serve as a useful guide for the researchers.

Assessing GOCE Gravity Models using Altimetry and In-situ Ocean Current Observation

DEFF Research Database (Denmark)

Knudsen, Per; Andersen, Ole Baltazar; Honecker, Johanna

gravity models provided by the GOCE mission have enhanced the resolution and sharpened the boundaries of those features and the associated geostrophic surface currents reveal improvements for all of the ocean's current systems. In this study, a series of 23 newer gravity models including observations from...... as quantified quality measures associated with the 23 GOCE gravity models.......The Gravity and steady state Ocean Circulation Explorer (GOCE) satellite mission measures Earth's gravity field with an unprecedented accuracy at short spatial scales. Previous results have demonstrated a significant advance in our ability to determine the ocean's general circulation. The improved...

India's mission to Mars cost less than the movie Gravity: Multidimensional View in Engineering Education

Science.gov (United States)

Rani, Meenu; Kumar, Pawan; Vandana, Vandana

2016-07-01

Over the years, Mars has been the centre of attraction for science fiction writers, Hollywood movie makers, astrologers, astronomers and the scientific community. For scientists and technologists, Mars continues to be an enigma. This is essentially because even tough humans have dreamt for long about human colonisation of Mars. Indian space programme had a very humble beginning during the early 1960s. India launched its first satellite in 1975 with assistance from the erstwhile USSR. India achieved the status of space-faring nation2 by 1980, and by the end of 2014 has launched around 75 satellites. India has become the first nation to reach Mars on its maiden attempt after its Mars Orbiter Mission completed its 10-month journey and successfully entered the Red Planet's orbit. The Mars Orbiter Mission, a low-cost 74 million project, blasted off from Earth on November 5, 2013, aboard an Indian Polar Satellite Launch Vehicle. At its initial stage, the rocket booster placed the probe into Earth's orbit before the craft fired the engines to break free of Earth's gravity en route to Mars. This is India's first mission into such deep space to search for evidence of life on the Red Planet. But the mission's primary objective is technological-if successful, the country will be joining an elite club of nations: the United States, Russia and Europe. India is becoming known for low-cost innovation in diverse fields such as healthcare and education. The technological capability being demonstrated and the knowledge gained from the operations of the mission will be invaluable in future developments and also in the training of the flight operations and mission control staff. All of this capability can be carried forward to future launches and operations. The sustained presence of methane observed by previous missions suggests that an active production mechanism is at work, most likely tectonic in nature, although there are some suggestions that it may point to a biological origin

Ground Reaction Forces During Reduced Gravity Running in Parabolic Flight.

Science.gov (United States)

Cavanagh, Peter; Rice, Andrea; Glauberman, Molly; Sudduth, Amanda; Cherones, Arien; Davis, Shane; Lewis, Michael; Hanson, Andrea; Wilt, Grier

2017-08-01

Treadmills have been employed as both a form of exercise and a countermeasure to prevent changes in the musculoskeletal system on almost all NASA missions and many Russian missions since the early Space Shuttle flights. It is possible that treadmills may also be part of exercise programs on future Mars missions and that they may be a component of exercise facilities in lunar or Martian habitats. In order to determine if the ambient gravity on these destinations will provide osteogenic effects while performing exercise on a treadmill, ground reactions forces (GRFs) were measured on eight subjects (six women and two men) running at 6 mph during parabolic flight in Martian and lunar gravity conditions. On average, stride length increased as gravity decreased. The first and second peaks of the GRFs decreased by 0.156 and 0.196 bodyweights, respectively, per 1/10 g change in ambient gravity. Based on comparisons with previously measured GRF during loaded treadmill running on the International Space Station, we conclude that unloaded treadmill running under lunar and Martian conditions during exploration missions is not likely to be an osteo-protective exercise.Cavanagh P, Rice A, Glauberman M, Sudduth A, Cherones A, Davis S, Lewis M, Hanson A, Wilt G. Ground reaction forces during reduced gravity running in parabolic flight. Aerosp Med Hum Perform. 2017; 88(8):730-736.

Human Biomechanical and Cardiopulmonary Responses to Partial Gravity – A Systematic Review

Directory of Open Access Journals (Sweden)

Charlotte Richter

2017-08-01

Full Text Available The European Space Agency has recently announced to progress from low Earth orbit missions on the International Space Station to other mission scenarios such as exploration of the Moon or Mars. Therefore, the Moon is considered to be the next likely target for European human space explorations. Compared to microgravity (μg, only very little is known about the physiological effects of exposure to partial gravity (μg < partial gravity <1 g. However, previous research studies and experiences made during the Apollo missions comprise a valuable source of information that should be taken into account when planning human space explorations to reduced gravity environments. This systematic review summarizes the different effects of partial gravity (0.1–0.4 g on the human musculoskeletal, cardiovascular and respiratory systems using data collected during the Apollo missions as well as outcomes from terrestrial models of reduced gravity with either 1 g or microgravity as a control. The evidence-based findings seek to facilitate decision making concerning the best medical and exercise support to maintain astronauts' health during future missions in partial gravity. The initial search generated 1,323 publication hits. Out of these 1,323 publications, 43 studies were included into the present analysis and relevant data were extracted. None of the 43 included studies investigated long-term effects. Studies investigating the immediate effects of partial gravity exposure reveal that cardiopulmonary parameters such as heart rate, oxygen consumption, metabolic rate, and cost of transport are reduced compared to 1 g, whereas stroke volume seems to increase with decreasing gravity levels. Biomechanical studies reveal that ground reaction forces, mechanical work, stance phase duration, stride frequency, duty factor and preferred walk-to-run transition speed are reduced compared to 1 g. Partial gravity exposure below 0.4 g seems to be insufficient to maintain

Lunar Prospector Orbit Determination Uncertainties Using the High Resolution Lunar Gravity Models

Science.gov (United States)

Carranza, Eric; Konopliv, Alex; Ryne, Mark

1999-01-01

The Lunar Prospector (LP) mission began on January 6, 1998, when the LP spacecraft was launched from Cape Canaveral, Florida. The objectives of the mission were to determine whether water ice exists at the lunar poles, generate a global compositional map of the lunar surface, detect lunar outgassing, and improve knowledge of the lunar magnetic and gravity fields. Orbit determination of LP performed at the Jet Propulsion Laboratory (JPL) is conducted as part of the principal science investigation of the lunar gravity field. This paper will describe the JPL effort in support of the LP Gravity Investigation. This support includes high precision orbit determination, gravity model validation, and data editing. A description of the mission and its trajectory will be provided first, followed by a discussion of the orbit determination estimation procedure and models. Accuracies will be examined in terms of orbit-to-orbit solution differences, as a function of oblateness model truncation, and inclination in the plane-of-sky. Long term predictions for several gravity fields will be compared to the reconstructed orbits to demonstrate the accuracy of the orbit determination and oblateness fields developed by the Principal Gravity Investigator.

Overload control of artificial gravity facility using spinning tether system for high eccentricity transfer orbits

Science.gov (United States)

Gou, Xing-wang; Li, Ai-jun; Tian, Hao-chang; Wang, Chang-qing; Lu, Hong-shi

2018-06-01

As the major part of space life supporting systems, artificial gravity requires further study before it becomes mature. Spinning tether system is a good alternative solution to provide artificial gravity for the whole spacecraft other than additional devices, and its longer tether length could significantly reduce spinning velocity and thus enhance comfortability. An approximated overload-based feedback method is proposed to provide estimated spinning velocity signals for controller, so that gravity level could be accurately controlled without complicated GPS modules. System behavior in high eccentricity transfer orbits is also studied to give a complete knowledge of the spinning stabilities. The application range of the proposed method is studied in various orbit cases and spinning velocities, indicating that it is accurate and reliable for most of the mission phases especially for the final constant gravity level phase. In order to provide stable gravity level for transfer orbit missions, a sliding mode controller based on estimated angular signals is designed for closed-loop control. Numerical results indicate that the combination of overload-based feedback and sliding mode controller could satisfy most of the long-term artificial gravity missions. It is capable of forming flexible gravity environment in relatively good accuracy even in the lowest possible orbital radiuses and high eccentricity orbits of crewed space missions. The proposed scheme provides an effective tether solution for the artificial gravity construction in interstellar travel.

A Tale of 2 Missions (And Hopefully 2 Different Landings)

International Nuclear Information System (INIS)

Wiens, Roger C.

2012-01-01

This talk, to be given at the LANL IGPP Annual Review dinner in Santa Fe, NM on July 17, 2012, highlights two important NASA missions LANL played a key role in: The Genesis mission was the first to return to Earth from beyond the Moon, bearing solar particles to help understand the composition of the Sun; and Curiosity, a 1-ton Mars rover launched to the red planet in 2011 with a suite of instruments from LANL called ChemCam.

Gravity Field of the Orientale Basin from the Gravity Recovery and Interior Laboratory Mission

Science.gov (United States)

Zuber, Maria T.; Smith, David E.; Neumann, Gregory A.; Goossens, Sander; Andrews-Hanna, Jeffrey C.; Head, James W.; Kiefer, Walter S.; Asmar, Sami W.; Konopliv, Alexander S.; Lemoine, Frank G.;

GRACE Status at Mission End

Science.gov (United States)

Tapley, B. D.; Flechtner, F. M.; Watkins, M. M.; Bettadpur, S. V.

2017-12-01

The twin satellites of the Gravity Recovery and Climate Experiment (GRACE) were launched on March 17, 2002 and have operated for nearly 16 years. The mission objectives are to observe the spatial and temporal variations of the Earth's mass through its effects on the gravity field at the GRACE satellite altitude. The mass changes observed are related to both the changes within the solid earth and the change within and between the Erath system components. A significant cause of the time varying mass is water motion and the GRACE mission has provided a continuous decade long measurement sequence which characterizes the seasonal cycle of mass transport between the oceans, land, cryosphere and atmosphere; its inter-annual variability; and the climate driven secular, or long period, mass transport signals. The fifth reanalysis on the mission data set, the RL05 data, were released in mid-2013. With the planned launch of GRACE Follow-On in early 2018, plans are underway for a reanalysis that will be consistent with the GRACE FO processing standards. The mission is entering the final phases of its operation life with mission end expected to occur in early 2018. The current mission operations strategy emphasizes extending the mission lifetime to obtain an overlap with the GRACE FO. This presentation will review the mission status and the projections for mission lifetime, describe the current operations philosophy and its impact on the science data, discuss the issues related to achieving the GRACE and GRACE FO connection and discuss issues related to science data products during this phase of the mission period.

Hope

NARCIS (Netherlands)

Blöser, Claudia; Stahl, Titus; Zalta, Edward

2017-01-01

Discussions of hope can be found throughout the history of philosophy and across all Western philosophical traditions, even though philosophy has traditionally not paid the same attention to hope as it has to attitudes like belief and desire. However, even though hope has historically only rarely

Valuing hope.

Science.gov (United States)

McMillan, John; Walker, Simon; Hope, Tony

2014-01-01

This article argues that hope is of value in clinical ethics and that it can be important for clinicians to be sensitive to both the risks of false hope and the importance of retaining hope. However, this sensitivity requires an understanding of the complexity of hope and how it bears on different aspects of a well-functioning doctor-patient relationship. We discuss hopefulness and distinguish it, from three different kinds of hope, or 'hopes for', and then relate these distinctions back to differing accounts of autonomy. This analysis matters because it shows how an overly narrow view of the ethical obligations of a clinician to their patient, and autonomy, might lead to scenarios where patients regret the choices they make.

An application of GOCE satellite gravity to resolve mantle heterogeneity in Europe

DEFF Research Database (Denmark)

Herceg, Matija; Artemieva, Irina; Thybo, Hans

2015-01-01

The aim of this study is to obtain new information on the density structure of the European upper mantle by incorporating the state-of-the-art global gravity data derived from the GOCE satellite gravity mission and recently released seismic model for the crustal structure, EUNAseis. The residual ...... by seismic tomography. Furthermore, we compare our regional upper mantle density model with petrological studies of mantle-derived xenoliths from the Baltic shield and the Arkhangelsk region.......The aim of this study is to obtain new information on the density structure of the European upper mantle by incorporating the state-of-the-art global gravity data derived from the GOCE satellite gravity mission and recently released seismic model for the crustal structure, EUNAseis. The residual...

Growing fresh food on future space missions

NARCIS (Netherlands)

Meinen, Esther; Dueck, Tom; Kempkes, Frank; Stanghellini, Cecilia

2018-01-01

This paper deals with vegetable cultivation that could be faced in a space mission. This paper focusses on optimization, light, temperature and the harvesting process, while other factors concerning cultivation in space missions, i.e. gravity, radiation, were not addressed. It describes the work

Gravity and Extreme Magnetism SMEX

Science.gov (United States)

2012-01-01

The Gravity and Extreme Magnetism SMEX mission will be the first mission to catalogue the X-ray polarisation of many astrophysical objects including black-holes and pulsars. This first of its kind mission is enabled by the novel use of a time projection chamber as an X-ray polarimeter. The detector has been developed over the last 5 years, with the current effort charged toward a demonstration of it's technical readiness to be at level 6 prior to the preliminary design review. This talk will describe the design GEMS polarimeter and the results to date from the engineering test unit.

Bringing Gravity to Space

Science.gov (United States)

Norsk, P.; Shelhamer, M.

2016-01-01

This panel will present NASA's plans for ongoing and future research to define the requirements for Artificial Gravity (AG) as a countermeasure against the negative health effects of long-duration weightlessness. AG could mitigate the gravity-sensitive effects of spaceflight across a host of physiological systems. Bringing gravity to space could mitigate the sensorimotor and neuro-vestibular disturbances induced by G-transitions upon reaching a planetary body, and the cardiovascular deconditioning and musculoskeletal weakness induced by weightlessness. Of particular interest for AG during deep-space missions is mitigation of the Visual Impairment Intracranial Pressure (VIIP) syndrome that the majority of astronauts exhibit in space to varying degrees, and which presumably is associated with weightlessness-induced fluid shift from lower to upper body segments. AG could be very effective for reversing the fluid shift and thus help prevent VIIP. The first presentation by Dr. Charles will summarize some of the ground-based and (very little) space-based research that has been conducted on AG by the various space programs. Dr. Paloski will address the use of AG during deep-space exploration-class missions and describe the different AG scenarios such as intra-vehicular, part-of-vehicle, or whole-vehicle centrifugations. Dr. Clement will discuss currently planned NASA research as well as how to coordinate future activities among NASA's international partners. Dr. Barr will describe some possible future plans for using space- and ground-based partial-G analogs to define the relationship between physiological responses and G levels between 0 and 1. Finally, Dr. Stenger will summarize how the human cardiovascular system could benefit from intermittent short-radius centrifugations during long-duration missions.

Hope against hope: exploring the hopes and challenges of rural female caregivers of persons with advanced cancer

Science.gov (United States)

2013-01-01

Background This paper focuses on the qualitative component of a study evaluating a hope intervention, entitled Living with Hope Program (LWHP), designed to foster hope in female caregivers of family members living with advanced cancer. The purpose of this research is to share, in the form of a story, the experiences of rural female caregivers caring for family members with advanced cancer, focusing on what fosters their hope. Hope is a psychosocial and spiritual resource that has been found to help family caregivers live through difficult transitions and challenges. Methods Twenty-three participants from rural Western Canada completed daily journal entries documenting their hopes and challenges. Cortazzi’s (2001) method of narrative analysis was used to analyze the data, which was then transcribed into a narrative entitled ‘hope against hope.’ Results The journal entries highlighted: the caregivers’ hopes and what fostered their hope; the various challenges of caregiving; self-care strategies, and; their emotional journey. Hope was integrated throughout their entire experience, and ‘hope against hope’ describes how hope persists even when there is no hope for a cure. Conclusions This research contributes to the assessment of caregiver interventions that impact hope and quality of life, while illustrating the value of a narrative approach to both research and practice. Journaling may be particularly valuable for rural caregivers who are isolated, and may lack direct professional and peer support. There is an opportunity for health professionals and other providers to foster a relationship of trust with family caregivers, in which their story can be told openly and where practitioners pay closer attention to the psychosocial needs of caregivers. PMID:24341372

Constraining the loop quantum gravity parameter space from phenomenology

Science.gov (United States)

Brahma, Suddhasattwa; Ronco, Michele

2018-03-01

Development of quantum gravity theories rarely takes inputs from experimental physics. In this letter, we take a small step towards correcting this by establishing a paradigm for incorporating putative quantum corrections, arising from canonical quantum gravity (QG) theories, in deriving falsifiable modified dispersion relations (MDRs) for particles on a deformed Minkowski space-time. This allows us to differentiate and, hopefully, pick between several quantization choices via testable, state-of-the-art phenomenological predictions. Although a few explicit examples from loop quantum gravity (LQG) (such as the regularization scheme used or the representation of the gauge group) are shown here to establish the claim, our framework is more general and is capable of addressing other quantization ambiguities within LQG and also those arising from other similar QG approaches.

Gravity Field Constraints on the Upper Mantle of Northwestern Europe

NARCIS (Netherlands)

Root, B.C.

2017-01-01

In the last decade, the gravity field of the Earth has been observed with increased coverage due to dedicated satellite missions, which resulted in higher resolution and more accurate global gravity field models than were previously available. These models make it possible to study large scale

Beyond breaking bad news: the roles of hope and hopefulness.

Science.gov (United States)

Whitney, Simon N; McCullough, Laurence B; Frugé, Ernest; McGuire, Amy L; Volk, Robert J

2008-07-15

Hope is important to patients, yet physicians are sometimes unsure how to promote hope in the face of life-threatening illness. Hope in medicine is of two kinds: specific (hope for specific outcomes) and generalized (a nonspecific sense of hopefulness). At the time of diagnosis of a life-ending condition, the specific goal of a long life is dashed, and there may be no medically plausible specific outcome that the patient feels is worth wishing for. Yet the physician may nonetheless maintain an open-ended hopefulness that is compatible with the physician's obligation to be truthful; this hopefulness can help sustain patient and family through the turbulent period of adaptation to the unwelcome reality of major illness. As this adaptation evolves, the physician can help patients and families adapt to suffering and loss of control by selecting and achieving specific goals such as improvement of the patient's environment in hospital or hospice, pain control, and relief of sleeplessness. Thus hope for specific (but far more modest) future events can again become a positive part of the patient s emotional landscape. The authors do not propose that physicians remain upbeat no matter the circumstance, for they must respect the constraints of reality and the patients' mortality. However, physicians can provide both cognitive and affective support as patients learn how to adapt. Hope and hopefulness are both important in this process. Hope is always important to patients. Physicians can and should promote hopefulness without endorsing unrealistic hope. (c) 2008 American Cancer Society.

The Juno Gravity Science Instrument

Science.gov (United States)

Asmar, Sami W.; Bolton, Scott J.; Buccino, Dustin R.; Cornish, Timothy P.; Folkner, William M.; Formaro, Roberto; Iess, Luciano; Jongeling, Andre P.; Lewis, Dorothy K.; Mittskus, Anthony P.; Mukai, Ryan; Simone, Lorenzo

2017-11-01

The Juno mission's primary science objectives include the investigation of Jupiter interior structure via the determination of its gravitational field. Juno will provide more accurate determination of Jupiter's gravity harmonics that will provide new constraints on interior structure models. Juno will also measure the gravitational response from tides raised on Jupiter by Galilean satellites. This is accomplished by utilizing Gravity Science instrumentation to support measurements of the Doppler shift of the Juno radio signal by NASA's Deep Space Network at two radio frequencies. The Doppler data measure the changes in the spacecraft velocity in the direction to Earth caused by the Jupiter gravity field. Doppler measurements at X-band (˜ 8 GHz) are supported by the spacecraft telecommunications subsystem for command and telemetry and are used for spacecraft navigation as well as Gravity Science. The spacecraft also includes a Ka-band (˜ 32 GHz) translator and amplifier specifically for the Gravity Science investigation contributed by the Italian Space Agency. The use of two radio frequencies allows for improved accuracy by removal of noise due to charged particles along the radio signal path.

Moving base Gravity Gradiometer Survey System (GGSS) program

Science.gov (United States)

Pfohl, Louis; Rusnak, Walter; Jircitano, Albert; Grierson, Andrew

1988-04-01

The GGSS program began in early 1983 with the objective of delivering a landmobile and airborne system capable of fast, accurate, and economical gravity gradient surveys of large areas anywhere in the world. The objective included the development and use of post-mission data reduction software to process the survey data into solutions for the gravity disturbance vector components (north, east and vertical). This document describes the GGSS equipment hardware and software, integration and lab test procedures and results, and airborne and land survey procedures and results. Included are discussions on test strategies, post-mission data reduction algorithms, and the data reduction processing experience. Perspectives and conclusions are drawn from the results.

Potential fields & satellite missions: what they tell us about the Earth's core?

Science.gov (United States)

Mandea, M.; Panet, I.; Lesur, V.; de Viron, O.; Diament, M.; Le Mouël, J.

2012-12-01

Since the advent of satellite potential field missions, the search to find information they can carry about the Earth's core has been motivated both by an interest in understanding the structure of dynamics of the Earth's interior and by the possibility of applying new space data analysis. While it is agreed upon that the magnetic field measurements from space bring interesting information on the rapid variations of the core magnetic field and flows associated with, the question turns to whether the core process can have a signature in the space gravity data. Here, we tackle this question, in the light of the recent data from the GRACE mission, that reach an unprecedented precision. Our study is based on eight years of high-resolution, high-accuracy gravity and magnetic satellite data, provided by the GRACE and CHAMP satellite missions. From the GRACE CNES/GRGS geoid solutions, we have emphasized the long-term variability by using a specific post-processing technique. From the CHAMP magnetic data we have computed models for the core magnetic field and its temporal variations, and the flow at the top of the core. A correlation analysis between the gravity and magnetic gridded series indicates that the inter-annual changes in the core magnetic field - under a region from the Atlantic to Indian Oceans - coincide with similar changes in the gravity field. These results should be considered as a constituent when planning new Earth's observation space missions and future innovations relevant to both gravity (after GRACE Follow-On) and magnetic (after Swarm) missions.

Constraining the loop quantum gravity parameter space from phenomenology

Directory of Open Access Journals (Sweden)

Suddhasattwa Brahma

2018-03-01

Full Text Available Development of quantum gravity theories rarely takes inputs from experimental physics. In this letter, we take a small step towards correcting this by establishing a paradigm for incorporating putative quantum corrections, arising from canonical quantum gravity (QG theories, in deriving falsifiable modified dispersion relations (MDRs for particles on a deformed Minkowski space–time. This allows us to differentiate and, hopefully, pick between several quantization choices via testable, state-of-the-art phenomenological predictions. Although a few explicit examples from loop quantum gravity (LQG (such as the regularization scheme used or the representation of the gauge group are shown here to establish the claim, our framework is more general and is capable of addressing other quantization ambiguities within LQG and also those arising from other similar QG approaches.

Lectures on Quantum Gravity

CERN Document Server

Gomberoff, Andres

2006-01-01

The 2002 Pan-American Advanced Studies Institute School on Quantum Gravity was held at the Centro de Estudios Cientificos (CECS),Valdivia, Chile, January 4-14, 2002. The school featured lectures by ten speakers, and was attended by nearly 70 students from over 14 countries. A primary goal was to foster interaction and communication between participants from different cultures, both in the layman’s sense of the term and in terms of approaches to quantum gravity. We hope that the links formed by students and the school will persist throughout their professional lives, continuing to promote interaction and the essential exchange of ideas that drives research forward. This volume contains improved and updated versions of the lectures given at the School. It has been prepared both as a reminder for the participants, and so that these pedagogical introductions can be made available to others who were unable to attend. We expect them to serve students of all ages well.

a Search for New Physics with the Beacon Mission

Science.gov (United States)

Turyshev, Slava G.; Shao, Michael; Girerd, André; Lane, Benjamin

The primary objective of the Beyond Einstein Advanced Coherent Optical Network (BEACON) mission is a search for new physics beyond general relativity by measuring the curvature of relativistic space-time around the Earth. This curvature is characterized by the Eddington parameter γ — the most fundamental relativistic gravity parameter and a direct measure for the presence of new physical interactions. BEACON will achieve an accuracy of 1 × 10-9 in measuring the parameter γ, thereby going a factor of 30,000 beyond the present best result involving the Cassini spacecraft. Secondary mission objectives include: (i) a direct measurement of the "frame-dragging" and geodetic precessions in the Earth's rotational gravitomagnetic field, to 0.05% and 0.03% accuracy respectively, (ii) the first measurement of gravity's nonlinear effects on light and the corresponding second order spatial metric's effects to 0.01% accuracy. BEACON will lead to robust advances in tests of fundamental physics — this mission could discover a violation or extension of general relativity and/or reveal the presence of an additional long range interaction in physics. It will provide crucial information to separate modern scalar-tensor theories of gravity from general relativity, probe possible ways for gravity quantization, and test modern theories of cosmological evolution.

Grand unification and gravity - selected topics

International Nuclear Information System (INIS)

Zee, A.

1981-09-01

The material given here was presented in lectures delivered at the 4th Kyoto Summer Institute on Grand Unification and Related Topics. It consists of six sections. The sections are: the family problem, fermion mass hierarchy, maximal local symmetry, operator analysis of new physics, dynamically generated gravity, and Kaluza theory and grand unification. The last section contains a (hopefully) pedagogical introduction to Kaluza theory. For pedagogical completeness, several appendices reviewing some elementary notions of differential geometry have been added

Toward a theory of persuasive hope: effects of cognitive appraisals, hope appeals, and hope in the context of climate change.

Science.gov (United States)

Chadwick, Amy E

2015-01-01

Hope has the potential to be a powerful motivator for influencing behavior. However, hope and messages that evoke hope (hope appeals) have rarely been the focus of theoretical development or empirical research. As a step toward the effective development and use of hope appeals in persuasive communication, this study conceptualized and operationalized hope appeals in the context of climate change prevention. Then, the study manipulated components of the hope evocation part of a hope appeal. Specifically, the components were designed to address appraisals of the importance, goal congruence, future expectation, and possibility of climate protection, resulting in a 2 (strong/weak importance) × 2 (strong/weak goal congruence) × 2 (strong/weak future expectation) × 2 (strong/weak possibility) between-subjects pretest-posttest factorial design. Two hundred forty-five undergraduate students were randomly assigned to one of the 16 message conditions and completed the study online. The study tested whether the four appraisals predict feelings of hope. It determined whether message components that address importance, goal congruence, future expectation, and possibility affect appraisals, feelings of hope, and persuasion outcomes. Finally, this study tested the effects of feelings of hope on persuasion outcomes. This study takes an important step toward enabling the effective use of hope appeals in persuasive communication.

Gravity gradiometer system for Earth Exploration

NARCIS (Netherlands)

Cuperus, R.; Flokstra, F.F.; Droogendijk, H.; Wiegerink, Remco J.; Flokstra, Jakob; Flokstra, Jan

2009-01-01

We develop a gravity gradiometer (GG) for use on planetary missions to planets like Mars and Jupiter. With some modifications this development is extended to include (airborne) applications for the Dutch exploratory industry. We adapt key technology of the space based GG for the use in an

Recovery of the Earth's Gravity Field Based on Spaceborne Atom-interferometry and Its Accuracy Estimation

Directory of Open Access Journals (Sweden)

ZHU Zhu

2017-09-01

Full Text Available The electrostatic gravity gradiometer has been successfully applied as a core sensor in satellite gravity gradiometric mission GOCE, and its observations are used to recover the Earth's static gravity field with a degree and order above 200. The lifetime of GOCE has been over, and the next generation satellite gravity gradiometry with higher resolution is urgently required in order to recover the global steady-state gravity field with a degree and order of 200~360. High potential precision can be obtained in space by atom-interferometry gravity gradiometer due to its long interference time, and thus the atom-interferometry-based satellite gravity gradiometry has been proposed as one of the candidate techniques for the next satellite gravity gradiometric mission. In order to achieve the science goal for high resolution gravity field measurement in the future, a feasible scheme of atom-interferometry gravity gradiometry in micro-gravity environment is given in this paper, and the gravity gradient measurement can be achieved with a noise of 0.85mE/Hz1/2. Comparison and estimation of the Earth's gravity field recovery precision for different types of satellite gravity gradiometry is discussed, and the results show that the satellite gravity gradiometry based on atom-interferometry is expected to provide the global gravity field model with an improved accuracy of 7~8cm in terms of geoid height and 3×10-5 m/s2 in terms of gravity anomaly respectively at a degree and order of 252~290.

Hope as fantasy

DEFF Research Database (Denmark)

Winther-Lindqvist, Ditte Alexandra

2017-01-01

, for a miracle to occur, for more time, or in some cases hoping for death to come sooner than later. I recognize hope as a form of imaginative activity and practice, because hope is formed in light of an uncertain future, and rests upon imagined scenarios of what could be. Hope, like imagination, remembering...

Trajectory design for a rendezvous mission to Earth's Trojan asteroid 2010 TK7

Science.gov (United States)

Lei, Hanlun; Xu, Bo; Zhang, Lei

2017-12-01

In this paper a rendezvous mission to the Earth's Trojan asteroid 2010 TK7 is proposed, and preliminary transfer trajectories are designed. Due to the high inclination (∼ 20.9°) of the target asteroid relative to the ecliptic plane, direct transfers usually require large amounts of fuel consumption, which is beyond the capacity of current technology. As gravity assist technique could effectively change the inclination of spacecraft's trajectory, it is adopted to reduce the launch energy and rendezvous velocity maneuver. In practical computation, impulsive and low-thrust, gravity-assisted trajectories are considered. Among all the trajectories computed, the low-thrust gravity-assisted trajectory with Venus-Earth-Venus (V-E-V) swingby sequence performs the best in terms of propellant mass. For a spacecraft with initial mass of 800 kg , propellant mass of the best trajectory is 36.74 kg . Numerical results indicate that both the impulsive and low-thrust, gravity-assisted trajectories corresponding to V-E-V sequence could satisfy mission constraints, and can be applied to practical rendezvous mission.

Centrifuge in Free Fall: Combustion at Partial Gravity

Science.gov (United States)

Ferkul, Paul

2017-01-01

A centrifuge apparatus is developed to study the effect of variable acceleration levels in a drop tower environment. It consists of a large rotating chamber, within which the experiment is conducted. NASA Glenn Research Center 5.18-second Zero-Gravity Facility drop tests were successfully conducted at rotation rates up to 1 RPS with no measurable effect on the overall Zero-Gravity drop bus. Arbitrary simulated gravity levels from zero to 1-g (at a radius of rotation 30 cm) were produced. A simple combustion experiment was used to exercise the capabilities of the centrifuge. A total of 23 drops burning a simulated candle with heptane and ethanol fuel were performed. The effect of gravity level (rotation rate) and Coriolis force on the flames was observed. Flames became longer, narrower, and brighter as gravity increased. The Coriolis force tended to tilt the flames to one side, as expected, especially as the rotation rate was increased. The Zero-Gravity Centrifuge can be a useful tool for other researchers interested in the effects of arbitrary partial gravity on experiments, especially as NASA embarks on future missions which may be conducted in non-Earth gravity.

A Transportable Gravity Gradiometer Based on Atom Interferometry

Science.gov (United States)

Yu, Nan; Thompson, Robert J.; Kellogg, James R.; Aveline, David C.; Maleki, Lute; Kohel, James M.

2010-01-01

A transportable atom interferometer-based gravity gradiometer has been developed at JPL to carry out measurements of Earth's gravity field at ever finer spatial resolutions, and to facilitate high-resolution monitoring of temporal variations in the gravity field from ground- and flight-based platforms. Existing satellite-based gravity missions such as CHAMP and GRACE measure the gravity field via precise monitoring of the motion of the satellites; i.e. the satellites themselves function as test masses. JPL's quantum gravity gradiometer employs a quantum phase measurement technique, similar to that employed in atomic clocks, made possible by recent advances in laser cooling and manipulation of atoms. This measurement technique is based on atomwave interferometry, and individual laser-cooled atoms are used as drag-free test masses. The quantum gravity gradiometer employs two identical atom interferometers as precision accelerometers to measure the difference in gravitational acceleration between two points (Figure 1). By using the same lasers for the manipulation of atoms in both interferometers, the accelerometers have a common reference frame and non-inertial accelerations are effectively rejected as common mode noise in the differential measurement of the gravity gradient. As a result, the dual atom interferometer-based gravity gradiometer allows gravity measurements on a moving platform, while achieving the same long-term stability of the best atomic clocks. In the laboratory-based prototype (Figure 2), the cesium atoms used in each atom interferometer are initially collected and cooled in two separate magneto-optic traps (MOTs). Each MOT, consisting of three orthogonal pairs of counter-propagating laser beams centered on a quadrupole magnetic field, collects up to 10(exp 9) atoms. These atoms are then launched vertically as in an atom fountain by switching off the magnetic field and introducing a slight frequency shift between pairs of lasers to create a moving

Timing system design and tests for the Gravity Probe B relativity mission

International Nuclear Information System (INIS)

Li, J; Keiser, G M; Ohshima, Y; Shestople, P; Lockhart, J M

2015-01-01

In this paper, we discuss the timing system design and tests for the NASA/Stanford Gravity Probe B (GP-B) relativity mission. The primary clock of GP-B, called the 16f o clock, was an oven-controlled crystal oscillator that produced a 16.368 MHz master frequency 3 . The 16f o clock and the 10 Hz data strobe, which was divided down from the 16f o clock, provided clock signals to all GP-B components and synchronized the data collection, transmission, and processing. The sampled data of science signals were stamped with the vehicle time, a counter of the 10 Hz data strobe. The time latency between the time of data sampling and the stamped vehicle time was compensated in the ground data processing. Two redundant global positioning system receivers onboard the GP-B satellite supplied an external reference for time transfer between the vehicle time and coordinated universal time (UTC), and the time conversion was established in the ground preprocessing of the telemetry timing data. The space flight operation showed that the error of time conversion between the vehicle time and UTC was less than 2 μs. Considering that the constant timing offsets were compensated in the ground processing of the GP-B science data, the time latency between the effective sampling time of GP-B science signals and the stamped vehicle time was verified to within 1 ms in the ground tests. (paper)

GRACE, time-varying gravity, Earth system dynamics and climate change

Science.gov (United States)

Wouters, B.; Bonin, J. A.; Chambers, D. P.; Riva, R. E. M.; Sasgen, I.; Wahr, J.

2014-11-01

Continuous observations of temporal variations in the Earth's gravity field have recently become available at an unprecedented resolution of a few hundreds of kilometers. The gravity field is a product of the Earth's mass distribution, and these data—provided by the satellites of the Gravity Recovery And Climate Experiment (GRACE)—can be used to study the exchange of mass both within the Earth and at its surface. Since the launch of the mission in 2002, GRACE data has evolved from being an experimental measurement needing validation from ground truth, to a respected tool for Earth scientists representing a fixed bound on the total change and is now an important tool to help unravel the complex dynamics of the Earth system and climate change. In this review, we present the mission concept and its theoretical background, discuss the data and give an overview of the major advances GRACE has provided in Earth science, with a focus on hydrology, solid Earth sciences, glaciology and oceanography.

Hope dies last: two aspects of hope in contemporary Moscow

NARCIS (Netherlands)

Zigon, J.

2009-01-01

The concept of hope has, for the most part, been neglected by anthropologists. Recently, however, hope has been analyzed by two prominent anthropologists who view it either as a passive attitude or a future-oriented stance toward a good. My research in Moscow, Russia, suggests that hope is not so

Global Lunar Gravity Field Determination Using Historical and Recent Tracking Data in Preparation for SELENE

Science.gov (United States)

Goossens, S.; Matsumoto, K.; Namiki, N.; Hanada, H.; Iwata, T.; Tsuruta, S.; Kawano, N.; Sasaki, S.

2006-12-01

In the near future, a number of satellite missions are planned to be launched to the Moon. These missions include initiatives by China, India, the USA, as well as the Japanese SELENE mission. These missions will gather a wealth of lunar data which will improve the knowledge of the Moon. One of the main topics to be addressed will be the lunar gravity field. Especially SELENE will contribute to improving the knowledge of the gravity field, by applying 4-way Doppler tracking between the main satellite and a relay satellite, and by applying a separate differential VLBI experiment. These will improve the determination of the global gravity field, especially over the far side and at the lower degrees (mostly for degrees lower than 30), as is shown by extensive simulations of the SELENE mission. This work focuses on the determination of the global lunar gravity field from all available tracking data to this date. In preparation for the SELENE mission, analysis using Lunar Prospector tracking data, as well as Clementine data and historical data from the Apollo and Lunar Orbiter projects is being conducted at NAOJ. Some SMART-1 tracking data are also included. The goal is to combine the good-quality data from the existing lunar missions up to this date with the tracking data from SELENE in order to derive a new lunar gravity field model. The focus therefore currently lies on processing the available data and extracting lunar gravity field information from them. It is shown that the historical tracking data contribute especially to the lower degrees of the global lunar gravity field model. Due to the large gap in tracking data coverage over the far side for the historical data, the higher degrees are almost fully determined by the a priori information in the form of a Kaula rule. The combination with SELENE data is thus expected to improve the estimate for the lower degrees even further, including coverage of the far side. Since historical tracking data are from orbits with

Prospects for Probing Strong Gravity with a Pulsar-Black Hole System

Science.gov (United States)

Wex, N.; Liu, K.; Eatough, R. P.; Kramer, M.; Cordes, J. M.; Lazio, T. J. W.

2012-01-01

The discovery of a pulsar (PSR) in orbit around a black hole (BH) is expected to provide a superb new probe of relativistic gravity and BH properties. Apart from a precise mass measurement for the BH, one could expect a clean verification of the dragging of space-time caused by the BH spin. In order to measure the quadrupole moment of the BH for testing the no-hair theorem of general relativity (GR), one has to hope for a sufficiently massive BH. In this respect, a PSR orbiting the super-massive BH in the center of our Galaxy would be the ultimate laboratory for gravity tests with PSRs. But even for gravity theories that predict the same properties for BHs as GR, a PSR-BH system would constitute an excellent test system, due to the high grade of asymmetry in the strong field properties of these two components. Here we highlight some of the potential gravity tests that one could expect from different PSR-BH systems.

Constraint propagation equations of the 3+1 decomposition of f(R) gravity

International Nuclear Information System (INIS)

Paschalidis, Vasileios; Shapiro, Stuart L; Halataei, Seyyed M H; Sawicki, Ignacy

2011-01-01

Theories of gravity other than general relativity (GR) can explain the observed cosmic acceleration without a cosmological constant. One such class of theories of gravity is f(R). Metric f(R) theories have been proven to be equivalent to Brans-Dicke (BD) scalar-tensor gravity without a kinetic term (ω = 0). Using this equivalence and a 3+1 decomposition of the theory, it has been shown that metric f(R) gravity admits a well-posed initial value problem. However, it has not been proven that the 3+1 evolution equations of metric f(R) gravity preserve the (Hamiltonian and momentum) constraints. In this paper, we show that this is indeed the case. In addition, we show that the mathematical form of the constraint propagation equations in BD-equilavent f(R) gravity and in f(R) gravity in both the Jordan and Einstein frames is exactly the same as in the standard ADM 3+1 decomposition of GR. Finally, we point out that current numerical relativity codes can incorporate the 3+1 evolution equations of metric f(R) gravity by modifying the stress-energy tensor and adding an additional scalar field evolution equation. We hope that this work will serve as a starting point for relativists to develop fully dynamical codes for valid f(R) models.

Gradiometry coexperiments to the gravity probe B and step missions

International Nuclear Information System (INIS)

Tapley, M.; Breakwell, J.; Everitt, C.W.F.; Vanpatten, R.; Worden, P.

1990-01-01

The Gravity Probe-B (GP-B) spacecraft, designed to test predictions of general relativity, will fly in the mid 1990s. It will carry four electrostatically suspended gyroscopes in a cryogenic environment and will have a drag-free control system to minimize disturbances on the gyroscopes. The Stanford Test of Equivalence Principle (STEP) spacecraft, to fly later, will carry a set of test masses under very similar conditions. The possibility of using differential measurements of the GP-B gyroscopes suspension forces and the STEP tests mass displacement readout to form single-axis gravity gradiometers is explored. It is shown that the noise in the suspension systems is sufficiently small in the relevant frequency range, and that enough information is collected to compensate for the spacecrafts' attitude motion. Finally, using Breakwell's flat-earth approximation, these experiments are compared to other geodesy experiments and predict the contribution they can make to the knowledge of the Earth's geopotential

Incorporation of omics analyses into artificial gravity research for space exploration countermeasure development.

Science.gov (United States)

Schmidt, Michael A; Goodwin, Thomas J; Pelligra, Ralph

The next major steps in human spaceflight include flyby, orbital, and landing missions to the Moon, Mars, and near earth asteroids. The first crewed deep space mission is expected to launch in 2022, which affords less than 7 years to address the complex question of whether and how to apply artificial gravity to counter the effects of prolonged weightlessness. Various phenotypic changes are demonstrated during artificial gravity experiments. However, the molecular dynamics (genotype and molecular phenotypes) that underlie these morphological, physiological, and behavioral phenotypes are far more complex than previously understood. Thus, targeted molecular assessment of subjects under various G conditions can be expected to miss important patterns of molecular variance that inform the more general phenotypes typically being measured. Use of omics methods can help detect changes across broad molecular networks, as various G-loading paradigms are applied. This will be useful in detecting off-target, or unanticipated effects of the different gravity paradigms applied to humans or animals. Insights gained from these approaches may eventually be used to inform countermeasure development or refine the deployment of existing countermeasures. This convergence of the omics and artificial gravity research communities may be critical if we are to develop the proper artificial gravity solutions under the severely compressed timelines currently established. Thus, the omics community may offer a unique ability to accelerate discovery, provide new insights, and benefit deep space missions in ways that have not been previously considered.

Evaluation of gravity field model EIGEN-6C4 by means of various functions of gravity potential, and by GNSS/levelling

Directory of Open Access Journals (Sweden)

Jan Kostelecký

2015-06-01

Full Text Available The combined gravity field model EIGEN-6C4 (Förste et al., 2014 is the latest combined global gravity field model of GFZ Potsdam and GRGS Toulouse. EIGEN-6C4 has been generated including the satellite gravity gradiometry data of the entire GOCE mission (November 2009 till October 2013 and is of maximum spherical degree and order 2190. In this study EIGEN-6C4 has been compared with EGM2008 to its maximum degree and order via gravity disturbances and Tzz part of the Marussi tensor of the second derivatives of the disturbing potential. The emphasis is put on such areas where GOCE data (complete set of gradiometry measurements after reductions in EIGEN-6C4 obviously contributes to an improvement of the gravity field description. GNSS/levelling geoid heights are independent data source for the evaluation of gravity field models. Therefore, we use the GNSS/levelling data sets over the territories of Europe, Czech Republic and Slovakia for the evaluation of EIGEN-6C4 w.r.t. EGM2008.

Two-phase alkali-metal experiments in reduced gravity

International Nuclear Information System (INIS)

Antoniak, Z.I.

1986-06-01

Future space missions envision the use of large nuclear reactors utilizing either a single or a two-phase alkali-metal working fluid. The design and analysis of such reactors require state-of-the-art computer codes that can properly treat alkali-metal flow and heat transfer in a reduced-gravity environment. A literature search of relevant experiments in reduced gravity is reported on here, and reveals a paucity of data for such correlations. The few ongoing experiments in reduced gravity are noted. General plans are put forth for the reduced-gravity experiments which will have to be performed, at NASA facilities, with benign fluids. A similar situation exists regarding two-phase alkali-metal flow and heat transfer, even in normal gravity. Existing data are conflicting and indequate for the task of modeling a space reactor using a two-phase alkali-metal coolant. The major features of past experiments are described here. Data from the reduced-gravity experiments with innocuous fluids are to be combined with normal gravity data from the two-phase alkali-metal experiments. Analyses undertaken here give every expectation that the correlations developed from this data base will provide a valid representation of alkali-metal heat transfer and pressure drop in reduced gravity

Focus on quantum Einstein gravity Focus on quantum Einstein gravity

Science.gov (United States)

Ambjorn, Jan; Reuter, Martin; Saueressig, Frank

2012-09-01

time cosmology and the big bang, as well as TeV-scale gravity models testable at the Large Hadron Collider. On different grounds, Monte-Carlo studies of the gravitational partition function based on the discrete causal dynamical triangulations approach provide an a priori independent avenue towards unveiling the non-perturbative features of gravity. As a highlight, detailed simulations established that the phase diagram underlying causal dynamical triangulations contains a phase where the triangulations naturally give rise to four-dimensional, macroscopic universes. Moreover, there are indications for a second-order phase transition that naturally forms the discrete analog of the non-Gaussian fixed point seen in the continuum computations. Thus there is a good chance that the discrete and continuum computations will converge to the same fundamental physics. This focus issue collects a series of papers that outline the current frontiers of the gravitational asymptotic safety program. We hope that readers get an impression of the depth and variety of this research area as well as our excitement about the new and ongoing developments. References [1] Weinberg S 1979 General Relativity, an Einstein Centenary Survey ed S W Hawking and W Israel (Cambridge: Cambridge University Press)

Biomedical Aspects of Lunar and Mars Exploration Missions

Science.gov (United States)

Charles, John B.

2006-01-01

Recent long-range planning for exploration-class missions has emphasized the need for anticipating the medical and human factors aspects of such expeditions. Missions returning Americans to the moon for stays of up to 6 months at a time will provide the opportunity to demonstrate the means to function safely and efficiently on another planet. Details of mission architectures are still under study, but a typical Mars design reference mission comprises a six-month transit from Earth to Mars, eighteen months in residence on Mars, and a six-month transit back to Earth. Physiological stresses will come from environmental factors such as prolonged exposure to radiation, weightlessness en route to Mars and then back to Earth, and low gravity and a toxic atmosphere while on Mars. Psychological stressors will include remoteness from Earth, confinement, and potential interpersonal conflicts, all complicated by circadian alterations. Medical risks including trauma must be considered. The role of such risk-modifying influences as artificial gravity and improved propulsion technologies to shorten round-trip time will also be discussed. Results of planning for assuring human health and performance will be presented.

Retrograde and Direct Powered Aero-Gravity-Assist Trajectories around Mars

Science.gov (United States)

Murcia, J. O.; Prado, A. F. B. A.; Gomes, V. M.

2018-04-01

A Gravity-Assist maneuver is used to reduce fuel consumption and/or trip times in interplanetary missions. It is based in a close approach of a spacecraft to a celestial body. Missions like Voyager and Ulysses used this concept. The present paper performs a study of a maneuver that combines three effects: the gravity of the planet, the application of an impulsive maneuver when the spacecraft is passing by the periapsis and the effects of the atmosphere of the planet. Direct and retrograde trajectories are considered, with particular attention to the differences due to the higher relative velocity between the spacecraft and the atmosphere, which increases the effects of the atmosphere. The planet Mars is used for the numerical examples.

Seasonal gravity change at Yellowstone caldera

Science.gov (United States)

Poland, M. P.; de Zeeuw-van Dalfsen, E.

2017-12-01

The driving forces behind Yellowstone's dynamic deformation, vigorous hydrothermal system, and abundant seismicity are usually ascribed to "magmatic fluids," which could refer to magma, water, volatiles, or some combination. Deformation data alone cannot distinguish the relative importance of these fluids. Gravity measurements, however, provide an indication of mass change over time and, when combined with surface displacements, can constrain the density of subsurface fluids. Unfortunately, several decades of gravity surveys at Yellowstone have yielded ambiguous results. We suspect that the difficulty in interpreting Yellowstone gravity data is due to seasonal variations in environmental conditions—especially surface and ground water. Yellowstone gravity surveys are usually carried out at the same time of year (generally late summer) to minimize the impact of seasonality. Nevertheless, surface and subsurface water levels are not likely to be constant from year to year, given annual differences in precipitation. To assess the overall magnitude of seasonal gravity changes, we conducted gravity surveys of benchmarks in and around Yellowstone caldera in May, July, August, and October 2017. Our goal was to characterize seasonal variations due to snow melt/accumulation, changes in river and lake levels, changes in groundwater levels, and changes in hydrothermal activity. We also hope to identify sites that show little variation in gravity over the course of the 2017 surveys, as these locations may be less prone to seasonal changes and more likely to detect small variations due to magmatic processes. Preliminary examination of data collected in May and July 2017 emphasizes the importance of site location relative to sources of water. For example, a site on the banks of the Yellowstone River showed a gravity increase of several hundred microgals associated with a 50 cm increase in the river level. A high-altitude site far from rivers and lakes, in contrast, showed a

Simulation and preparation of surface EVA in reduced gravity at the Marseilles Bay subsea analogue sites

Science.gov (United States)

Weiss, P.; Gardette, B.; Chirié, B.; Collina-Girard, J.; Delauze, H. G.

2012-12-01

Extravehicular activity (EVA) of astronauts during space missions is simulated nowadays underwater in neutral buoyancy facilities. Certain aspects of weightlessness can be reproduced underwater by adding buoyancy to a diver-astronaut, therefore exposing the subject to the difficulties of working without gravity. Such tests were done at the COMEX' test pool in Marseilles in the 1980s to train for a French-Russian mission to the MIR station, for the development of the European HERMES shuttle and the COLUMBUS laboratory. However, space agencies are currently studying missions to other destinations than the International Space Station in orbit, such as the return to the Moon, NEO (near-Earth objects) or Mars. All these objects expose different gravities: Moon has one sixth of Earth's gravity, Mars has a third of Earth's gravity and asteroids have virtually no surface gravity; the astronaut "floats" above the ground. The preparation of such missions calls for a new concept in neutral buoyancy training, not on man-made structures, but on natural terrain, underwater, to simulate EVA operations such as sampling, locomotion or even anchoring in low gravity. Underwater sites can be used not only to simulate the reduced gravity that astronauts will experience during their field trips, also human factors like stress are more realistically reproduced in such environment. The Bay of Marseille hosts several underwater sites that can be used to simulate various geologic morphologies, such as sink-holes which can be used to simulate astronaut descends into craters, caves where explorations of lava tubes can be trained or monolithic rock structures that can be used to test anchoring devices (e.g., near Earth objects). Marseilles with its aerospace and maritime/offshore heritage hosts the necessary logistics and expertise that is needed to perform such simulations underwater in a safe manner (training of astronaut-divers in local test pools, research vessels, subsea robots and

The laser astrometric test of relativity mission

International Nuclear Information System (INIS)

Turyshev, Slava G.; Shao, Michael; Nordtvedt, Kenneth L.

2004-01-01

This paper discusses new fundamental physics experiment to test relativistic gravity at the accuracy better than the effects of the 2nd order in the gravitational field strength, ∝ G 2 . The Laser Astrometric Test Of Relativity (LATOR) mission uses laser interferometry between two micro-spacecraft whose lines of sight pass close by the Sun to accurately measure deflection of light in the solar gravity. The key element of the experimental design is a redundant geometry optical truss provided by a long-baseline (100 m) multi-channel stellar optical interferometer placed on the International Space Station (ISS). The interferometer is used for measuring the angles between the two spacecraft. In Euclidean geometry, determination of a triangle's three sides determines any angle therein; with gravity changing the optical lengths of sides passing close by the Sun and deflecting the light, the Euclidean relationships are overthrown. The geometric redundancy enables LATOR to measure the departure from Euclidean geometry caused by the solar gravity field to a very high accuracy. LATOR will not only improve the value of the parameterized post-Newtonian (PPN) parameter γ to unprecedented levels of accuracy of 10 -8 , it will also reach ability to measure effects of the next post-Newtonian order (c -4 ) of light deflection resulting from gravity's intrinsic non-linearity. The solar quadrupole moment parameter, J2, will be measured with high precision, as well as a variety of other relativistic effects including Lense-Thirring precession. LATOR will lead to very robust advances in the tests of fundamental physics: this mission could discover a violation or extension of general relativity, or reveal the presence of an additional long range interaction in the physical law. There are no analogs to the LATOR experiment; it is unique and is a natural culmination of solar system gravity experiments

D-1 report: The first German spacelab mission

Science.gov (United States)

1985-01-01

Introduction of a new popular magazine on the DI mission, the first West German Space mission. The DI project office publishes the magazine. The German sponsored astronauts are to study the gravitational effects of reduced gravity on the human generated processes of the environment. Other areas of concern are boundary surface and transport phenomena, physical chemisty and process engineering, metals and composite materials, and single crystals.

Hope in Motion

Science.gov (United States)

Yeasting, Kevin; Jung, Sandy

2010-01-01

Hope has been described by many as a basic, fundamental, and essential part of life. This article introduces a new approach to incorporate hope with clients experiencing a range of difficulties in the general counseling setting. In this framework, three stages are proposed to enable clients to strengthen and solidify their hope. In the first…

A global mean ocean circulation estimation using goce gravity models - the DTU12MDT mean dynamic topography model

DEFF Research Database (Denmark)

Knudsen, Per; Andersen, Ole Baltazar

2012-01-01

The Gravity and Ocean Circulation Experiment - GOCE satellite mission measure the Earth gravity field with unprecedented accuracy leading to substantial improvements in the modelling of the ocean circulation and transport. In this study of the performance of GOCE, a newer gravity model have been...... combined with the DTU10MSS mean sea surface model to construct a global mean dynamic topography model named DTU10MDT. The results of preliminary analyses using preliminary GOCE gravity models clearly demonstrated the potential of GOCE mission. Both the resolution and the estimation of the surface currents...... have been improved significantly compared to results obtained using pre-GOCE gravity field models. The results of this study show that geostrophic surface currents associated with the mean circulation have been further improved and that currents having speeds down to 5 cm/s have been recovered....

Ocean tides in GRACE monthly averaged gravity fields

DEFF Research Database (Denmark)

Knudsen, Per

2003-01-01

The GRACE mission will map the Earth's gravity fields and its variations with unprecedented accuracy during its 5-year lifetime. Unless ocean tide signals and their load upon the solid earth are removed from the GRACE data, their long period aliases obscure more subtle climate signals which GRACE...... aims at. In this analysis the results of Knudsen and Andersen (2002) have been verified using actual post-launch orbit parameter of the GRACE mission. The current ocean tide models are not accurate enough to correct GRACE data at harmonic degrees lower than 47. The accumulated tidal errors may affect...... the GRACE data up to harmonic degree 60. A study of the revised alias frequencies confirm that the ocean tide errors will not cancel in the GRACE monthly averaged temporal gravity fields. The S-2 and the K-2 terms have alias frequencies much longer than 30 days, so they remain almost unreduced...

Pedagogies of Hope

Science.gov (United States)

Webb, Darren

2013-01-01

Hoping is an integral part of what it is to be human, and its significance for education has been widely noted. Hope is, however, a contested category of human experience and getting to grips with its characteristics and dynamics is a difficult task. The paper argues that hope is not a singular undifferentiated experience and is best understood as…

Ways of Hoping: Navigating the Paradox of Hope and Despair in Chronic Pain.

Science.gov (United States)

Eaves, Emery R; Nichter, Mark; Ritenbaugh, Cheryl

2016-03-01

In this paper, we explore hope in the context of living with chronic pain. Individuals with chronic pain from temporomandibular disorder(s) were interviewed four to five times over the course of their 18-month participation in a clinical trial investigating the effectiveness of Traditional Chinese Medicine. We sought to understand shifts in participants' descriptions of expectations and hopefulness, particularly with regard to the work involved in counterbalancing positive thinking with buffers against disappointment. We found hope to be a dynamic and multifaceted mindset as distinct from being a single entity to be measured. Drawing upon Polanyi's concept of tacit knowing, we explore how different ways of hoping emerge and index one another in participant narratives. We offer a working typology of hope and raise as an issue the manner in which the paradox of hope--hoping enough to carry on while keeping hopes in check to avoid the ever-present possibility of despair--complicates simplistic notions of the relationship between positive thinking and the placebo response.

GRACE, time-varying gravity, Earth system dynamics and climate change

International Nuclear Information System (INIS)

Wouters, B; Bonin, J A; Chambers, D P; Riva, R E M; Sasgen, I; Wahr, J

2014-01-01

Continuous observations of temporal variations in the Earth's gravity field have recently become available at an unprecedented resolution of a few hundreds of kilometers. The gravity field is a product of the Earth's mass distribution, and these data—provided by the satellites of the Gravity Recovery And Climate Experiment (GRACE)—can be used to study the exchange of mass both within the Earth and at its surface. Since the launch of the mission in 2002, GRACE data has evolved from being an experimental measurement needing validation from ground truth, to a respected tool for Earth scientists representing a fixed bound on the total change and is now an important tool to help unravel the complex dynamics of the Earth system and climate change. In this review, we present the mission concept and its theoretical background, discuss the data and give an overview of the major advances GRACE has provided in Earth science, with a focus on hydrology, solid Earth sciences, glaciology and oceanography. (review article)

Progress towards CSR RL06 GRACE gravity solutions

Science.gov (United States)

Save, Himanshu

2017-04-01

The GRACE project plans to re-processes the GRACE mission data in order to be consistent with the first gravity products released by the GRACE-FO project. The next generation Release-06 (RL06) gravity products from GRACE will include the improvements in GRACE Level-1 data products, background gravity models and the processing methodology. This paper will outline the planned improvements for CSR - RL06 and discuss the preliminary results. This paper will discuss the evolution of the quality of the GRACE solutions, especially over the past few years. We will also discuss the possible challenges we may face in connecting/extending the measurements of mass fluxes from the GRACE era to the GRACE-FO era due quality of the GRACE solutions from recent years.

Two-phase reduced gravity experiments for a space reactor design

International Nuclear Information System (INIS)

Antoniak, Z.I.

1986-08-01

Future space missions envision the use of large nuclear reactors utilizing either a single or a two-phase alkali-metal working fluid. The design and analysis of such reactors require state-of-the-art computer codes that can properly treat alkali-metal flow and heat transfer in a reduced-gravity environment. New flow regime maps, models, and correlations are required if the codes are to be successfully applied to reduced-gravity flow and heat transfer. General plans are put forth for the reduced-gravity experiments which will have to be performed, at NASA facilities, with benign fluids. Data from the reduced-gravity experiments with innocuous fluids are to be combined with normal gravity data from two-phase alkali-metal experiments. Because these reduced-gravity experiments will be very basic, and will employ small test loops of simple geometry, a large measure of commonality exists between them and experiments planned by other organizations. It is recommended that a committee be formed, to coordinate all ongoing and planned reduced gravity flow experiments

Investigating gravity waves evidences in the Venus upper atmosphere

Science.gov (United States)

Migliorini, Alessandra; Altieri, Francesca; Shakun, Alexey; Zasova, Ludmila; Piccioni, Giuseppe; Bellucci, Giancarlo; Grassi, Davide

2014-05-01

We present a method to investigate gravity waves properties in the upper mesosphere of Venus, through the O2 nightglow observations acquired with the imaging spectrometer VIRTIS on board Venus Express. Gravity waves are important dynamical features that transport energy and momentum. They are related to the buoyancy force, which lifts air particles. Then, the vertical displacement of air particles produces density changes that cause gravity to act as restoring force. Gravity waves can manifest through fluctuations on temperature and density fields, and hence on airglow intensities. We use the O2 nightglow profiles showing double peaked structures to study the influence of gravity waves in shaping the O2 vertical profiles and infer the waves properties. In analogy to the Earth's and Mars cases, we use a well-known theory to model the O2 nightglow emissions affected by gravity waves propagation. Here we propose a statistical discussion of the gravity waves characteristics, namely vertical wavelength and wave amplitude, with respect to local time and latitude. The method is applied to about 30 profiles showing double peaked structures, and acquired with the VIRTIS/Venus Express spectrometer, during the mission period from 2006-07-05 to 2008-08-15.

Making Ripples of Hope

Science.gov (United States)

Lopez, Shane J.

2011-01-01

Hope, the ideas and energy for the future, is one of the most potent predictors of the success of the youth. Based on the Gallup Student Poll, an online school-based measure of student hope (and engagement and well-being), half of American students are hopeful. Hopeful students are energetic, full of life. They're able to develop many strategies…

Measuring the Change in Water Table with Gravity Methods - a Controlled Experiment

DEFF Research Database (Denmark)

Lund, S; Christiansen, Lars; Andersen, O. B.

2009-01-01

Gravity changes linearly with the change in soil water content. With the GRACE satellite mission the interest for ground-based gravity methods in hydrology has gained new attention. Time-lapse gravity data have the potential to constrain hydrological model parameters in a calibration scheme....... The greatest potential is seen for specific yield. The gravity signal from hydrology is small (10^-8 m/s^2 level) and the application of ground-based methods is mainly limited by the sensitivity of available instruments. In order to demonstrate the ability of the Scintrex CG-5 gravity meter to detect a change...... in water content, a controlled experiment was set up in 30 m by 20 m basin. The water table was lowered 0.69 m within 1½ hours and the corresponding gravity signal measured using two different approaches: a time series measurements at one location and a gravity network measurement including four points...

A global mean dynamic topography and ocean circulation estimation using a preliminary GOCE gravity model

DEFF Research Database (Denmark)

Knudsen, Per; Bingham, R.; Andersen, Ole Baltazar

2011-01-01

The Gravity and steady-state Ocean Circulation Explorer (GOCE) satellite mission measures Earth’s gravity field with an unprecedented accuracy at short spatial scales. In doing so, it promises to significantly advance our ability to determine the ocean’s general circulation. In this study, an ini...

Sisters Hope

DEFF Research Database (Denmark)

Lawaetz, Anna; Worre Hallberg, Gry

2011-01-01

Sisters Hope invites young scholars to visit our elite-school for run-away youngsters. Maybe you will be the next one to be collected and accepted?......Sisters Hope invites young scholars to visit our elite-school for run-away youngsters. Maybe you will be the next one to be collected and accepted?...

Road to Io

International Nuclear Information System (INIS)

Chang, T.

1989-01-01

The potential study of Io by the Galileo mission is discussed. The mission, which is scheduled for launch from the Space Shuttle in 1989, is expected to fly 20 to 100 times closer to the Galilean moons of Jupiter than the Voyager missions. Topics which the mission hopes to address include volcanism, tidal forces and continental drift on Io, and the torus of charged particles that accompanies Io on its orbit of Jupiter. The Venus-earth-earth gravity assist route of the mission and the NIR mapping spectrometer aboard Galileo are considered

Hope and the uncertain future

OpenAIRE

PIETARINEN JUHANI

2014-01-01

Benedict Spinoza defined hope as an inconstant joy inconstant, because hope involves uncertainty and doubt. Hope means optimism mixed with pessimistic feelings. For Spinoza, hope amounts to an increase in our inherent active power, in our vitality or love of life, but because of being associated with fear, hope also involves something which is apt to reduce this power. Our beliefs concerning future outcomes are crucial here. They form the ultimate basis of our hope.

A Breakthrough Propulsion Architecture for Interstellar Precursor Missions

Data.gov (United States)

National Aeronautics and Space Administration — We propose a new power/propulsion architecture to enable missions such as a 12-yr flight time to 500 AU—the distance at which solar gravity lensing can be used to...

From hope to hope: the experience of older Chinese people with advanced cancer.

Science.gov (United States)

Chen, Hong; Komaromy, Carol; Valentine, Christine

2015-03-01

In our study that explored the current end-of-life care provision for Chinese older people with advanced/terminal cancer, hope emerged as a significant aspect of coping with their condition. Drawing on data from in-depth interviews with a group of older people, their family carers and health professionals, this article explores participants' constructions of hope in terms of what they were hoping for, how their hopes helped them cope with their illness and what sociocultural resources they drew on to build and sustain these hopes. While acknowledging similarities to Western studies of hope in terminal illness, this article identifies significant divergences in terms of the impact of different sociocultural values and their implications for clinical practice in light of an unfavourable health care environment for patients with advanced cancer and a social support system sustained mainly by Chinese families. It argues that hope represents an important resource for coping with terminal illness among these patients. © The Author(s) 2014.

Post-Flight Back Pain Following International Space Station Missions: Evaluation of Spaceflight Risk Factors

Science.gov (United States)

Laughlin, Mitzi S.; Murray, Jocelyn D.; Wear, Mary L.; Van Baalen, Mary

2016-01-01

Back pain during spaceflight has often been attributed to the lengthening of the spinal column due to the absence of gravity during both short and long-duration missions. Upon landing and re-adaptation to gravity, the spinal column reverts back to its original length thereby causing some individuals to experience pain and muscular spasms, while others experience no ill effects. With International Space Station (ISS) missions, cases of back pain and injury are more common post-flight, but little is known about the potential risk factors.

Preliminary Assessment of Artificial Gravity Impacts to Deep-Space Vehicle Design

Science.gov (United States)

Joosten, B. Kent

2007-01-01

Even after more than thirty years of scientific investigation, serious concerns regarding human physiological effects of long-duration microgravity exposure remain. These include loss of bone mineral density, skeletal muscle atrophy, and orthostatic hypertension, among others. In particular, "Safe Passage: Astronaut Care for Exploration Missions," states "loss of bone density, which apparently occurs at a rate of 1% per month in microgravity, is relatively manageable on the short-duration missions of the space shuttle, but it becomes problematic on the ISS [International Space Station]. ...If this loss is not mitigated, interplanetary missions will be impossible." While extensive investigations into potential countermeasures are planned on the ISS, the delay in attaining full crew complement and onboard facilities, and the potential for extending crews tours of duty threaten the timely (definitive design requirements, especially acceptable artificial gravity levels and rotation rates, the perception of high vehicle mass and performance penalties, the incompatibility of resulting vehicle configurations with space propulsion options (i.e., aerocapture), the perception of complications associated with de-spun components such as antennae and photovoltaic arrays, and the expectation of effective crew micro-gravity countermeasures. These perception and concerns may have been overstated, or may be acceptable alternatives to countermeasures of limited efficacy. This study was undertaken as an initial step to try to understand the implications of and potential solutions to incorporating artificial gravity in the design of human deep-space exploration vehicles. Of prime interest will be the mass penalties incurred by incorporating AG, along with any mission performance degradation.

Radial and tangential gravity rates from GRACE in areas of glacial isostatic adjustment

Science.gov (United States)

van der Wal, Wouter; Kurtenbach, Enrico; Kusche, Jürgen; Vermeersen, Bert

2011-11-01

In areas dominated by Glacial Isostatic Adjustment (GIA), the free-air gravity anomaly rate can be converted to uplift rate to good approximation by using a simple spectral relation. We provide quantitative comparisons between gravity rates derived from monthly gravity field solutions (GFZ Potsdam, CSR Texas, IGG Bonn) from the Gravity Recovery and Climate Experiment (GRACE) satellite mission with uplift rates measured by GPS in these areas. The band-limited gravity data from the GRACE satellite mission can be brought to very good agreement with the point data from GPS by using scaling factors derived from a GIA model (the root-mean-square of differences is 0.55 mm yr-1 for a maximum uplift rate signal of 10 mm yr-1). The root-mean-square of the differences between GRACE derived uplift rates and GPS derived uplift rates decreases with increasing GRACE time period to a level below the uncertainty that is expected from GRACE observations, GPS measurements and the conversion from gravity rate to uplift rate. With the current length of time-series (more than 8 yr) applying filters and a hydrology correction to the GRACE data does not reduce the root-mean-square of differences significantly. The smallest root-mean-square was obtained with the GFZ solution in Fennoscandia and with the CSR solution in North America. With radial gravity rates in excellent agreement with GPS uplift rates, more information on the GIA process can be extracted from GRACE gravity field solutions in the form of tangential gravity rates, which are equivalent to a rate of change in the deflection of the vertical scaled by the magnitude of gravity rate vector. Tangential gravity rates derived from GRACE point towards the centre of the previously glaciated area, and are largest in a location close to the centre of the former ice sheet. Forward modelling showed that present day tangential gravity rates have maximum sensitivity between the centre and edge of the former ice sheet, while radial gravity

The simulation of lunar gravity field recovery from D-VLBI of Chang’E-1 and SELENE lunar orbiters

Science.gov (United States)

Yan, Jianguo; Ping, Jingsong; Matsumoto, K.; Li, Fei

2008-07-01

The lunar gravity field is a foundation to study the lunar interior structure, and to recover the evolution history of the Moon. It is still an open and key topic for lunar science. For above mentioned reasons, it becomes one of the important scientific objectives of recent lunar missions, such as KAGUYA (SELENE) the Japanese lunar mission and Chang’E-1, the Chinese lunar mission. The Chang’E-1 and the SELENE were successfully launched in 2007. It is estimated that these two missions can fly around the Moon longer than 6 months simultaneously. In these two missions, the Chinese new VLBI (Very Long Baseline Interferometry) network will be applied for precise orbit determination (POD) by using a differential VLBI (D-VLBI) method during the mission period. The same-beam D-VLBI technique will contribute to recover the lunar gravity field together with other conventional observables, i.e. R&RR (Range and Range Rate) and multi-way Doppler. Taking VLBI tracking conditions into consideration and using the GEODYNII/SOVLE software of GSFC/NASA/USA [Rowlands, D.D., Marshall, J.A., Mccarthy, J., et al. GEODYN II System Description, vols. 1 5. Contractor Report, Hughes STX Corp. Greenbelt, MD, 1997; Ullman, R.E. SOLVE program: mathematical formulation and guide to user input, Hughes/STX Contractor Report, Contract NAS5-31760. NASA Goddard Space Flight Center, Greenbelt, Maryland, 1994], we simulated the lunar gravity field recovering ability with and without D-VLBI between the Chang’E-1 and SELENE main satellite. The cases of overlapped flying and tracking period of 30 days, 60 days and 90 days have been analyzed, respectively. The results show that D-VLBI tracking between two lunar satellites can improve the gravity field recovery remarkably. The results and methods introduced in this paper will benefit the actual missions.

Dynamic gene expression response to altered gravity in human T cells.

Science.gov (United States)

Thiel, Cora S; Hauschild, Swantje; Huge, Andreas; Tauber, Svantje; Lauber, Beatrice A; Polzer, Jennifer; Paulsen, Katrin; Lier, Hartwin; Engelmann, Frank; Schmitz, Burkhard; Schütte, Andreas; Layer, Liliana E; Ullrich, Oliver

2017-07-12

We investigated the dynamics of immediate and initial gene expression response to different gravitational environments in human Jurkat T lymphocytic cells and compared expression profiles to identify potential gravity-regulated genes and adaptation processes. We used the Affymetrix GeneChip® Human Transcriptome Array 2.0 containing 44,699 protein coding genes and 22,829 non-protein coding genes and performed the experiments during a parabolic flight and a suborbital ballistic rocket mission to cross-validate gravity-regulated gene expression through independent research platforms and different sets of control experiments to exclude other factors than alteration of gravity. We found that gene expression in human T cells rapidly responded to altered gravity in the time frame of 20 s and 5 min. The initial response to microgravity involved mostly regulatory RNAs. We identified three gravity-regulated genes which could be cross-validated in both completely independent experiment missions: ATP6V1A/D, a vacuolar H + -ATPase (V-ATPase) responsible for acidification during bone resorption, IGHD3-3/IGHD3-10, diversity genes of the immunoglobulin heavy-chain locus participating in V(D)J recombination, and LINC00837, a long intergenic non-protein coding RNA. Due to the extensive and rapid alteration of gene expression associated with regulatory RNAs, we conclude that human cells are equipped with a robust and efficient adaptation potential when challenged with altered gravitational environments.

Hope and Hopelessness: The Role of Hope in Buffering the Impact of Hopelessness on Suicidal Ideation.

Science.gov (United States)

Huen, Jenny M Y; Ip, Brian Y T; Ho, Samuel M Y; Yip, Paul S F

2015-01-01

The present study investigated whether hope and hopelessness are better conceptualized as a single construct of bipolar spectrum or two distinct constructs and whether hope can moderate the relationship between hopelessness and suicidal ideation. Hope, hopelessness, and suicidal ideation were measured in a community sample of 2106 participants through a population-based household survey. Confirmatory factor analyses showed that a measurement model with separate, correlated second-order factors of hope and hopelessness provided a good fit to the data and was significantly better than that of the model collapsing hope and hopelessness into a single second-order factor. Negative binomial regression showed that hope and hopelessness interacted such that the effect of hopelessness on suicidal ideation was lower in individuals with higher hope than individuals with lower hope. Hope and hopelessness are two distinct but correlated constructs. Hope can act as a resilience factor that buffers the impact of hopelessness on suicidal ideation. Inducing hope in people may be a promising avenue for suicide prevention.

BOOK REVIEW: Quantum Gravity: third edition Quantum Gravity: third edition

Science.gov (United States)

Rovelli, Carlo

2012-09-01

to the wide-angle attention of Claus Kiefer to the recent evolution of the field. It is also because of this attention that the neglect of a thriving research direction on which a large number of research groups are currently engaged jumps to the eye. The book provides a nice introduction to loop quantum gravity. The main kinematical results of the loop approach are carefully explained. At the point of discussing dynamics, however, it focuses only on the canonical formulation, mentioning the covariant loop theory only en passant. Given Kiefer's open-mindness, I imagine that the shortfall is due to the novelty of the major results of the covariant theory (or spinfoam formalism). The theorem proving the finiteness of the transition amplitudes to all orders, due to Han, Fairbairn and Meusburger, for instance, dates only from 2010. But the various theorems on the asymptotic of the vertex amplitude, by Barrett-Pereira-Dowdall-Fairbairn-Hellmann, Friedel-Conrady and others, which have sparked interest in the spinfoam approach by indicating that the theory may have the correct classical limit, are from 2009. The fact that they are not even mentioned in Kiefer's book is strident for me. The covariant loop amplitudes may not be the final solution to the problem of quantum gravity, but the existence of a family of Lorentz covariant amplitudes with indications of the correct classical limit, which are finite at each order of the expansion, is a result that cannot be ignored in a broad book that aims at being comprehensive in quantum gravity. There are other pages of the book where I was not very happy. For instance, the discussion of the so-called 'problem of time'. But surely a broad book in a recalcitrant field like quantum gravity will never make everybody entirely happy: at least as long as the problem is not solved. Which, we all hope, might not be too far into the future. Few fundamental problems have resisted the investigation of theoretical physics for so long, and

Recent developments in high-resolution global altimetric gravity field modeling

DEFF Research Database (Denmark)

Andersen, Ole Baltazar; Knudsen, Per; Berry, P. A .M.

2010-01-01

older gravity fields show accuracy improvement of the order of 20-40% due to a combination of retracking, enhanced processing, and the use of the new EGM2008 geoid model. In coastal and polar regions, accuracy improved in many places by 40-50% (or more) compared with older global marine gravity fields.......In recent years, dedicated effort has been made to improve high-resolution global marine gravity fields. One new global field is the Danish National Space Center (DNSC) 1-minute grid called DNSC08GRA, released in 2008. DNSC08GRA was derived from double-retracked satellite altimetry, mainly from...... the ERS-1 geodetic mission data, augmented with new retracked GEOSAT data which have significantly enhanced the range and hence the gravity field accuracy. DNSC08GRA is the first high-resolution global gravity field to cover the entire Arctic Ocean all the way to the North Pole. Comparisons with other...

Belief, hope and faith.

Science.gov (United States)

Figueiredo, Luis Claudio

2004-12-01

A case of hysteria is presented in order to create a frame of reference for the author's approach to the concepts of hope, belief and faith. A difference between hope as a 'sad passion' (which is here called regressive hope) and hope as a principle of mental functioning is established. The concept of hope will at first always be based on beliefs--either beliefs organised in the paranoid-schizoid position (called here fragmented and delusional beliefs)--or those organised from the depressive position (complex systems of beliefs, which end up being dogmatic); the latter typically occur in neurotics. It is suggested here that there is another possibility for hope, which is based on faith. The meaning of faith is considered here externally to the religious sense. The solid establishment of hope as a principle--based on faith--can be viewed as responsible for the opening up of creative potentials and as one of the main aims of analysis. Such an aim, however requires the establishment of a deep relationship, both in theory and in clinical practice, between the Kleinian question of the depressive position and the Freudian question of the Oedipus complex.

Survivability and Hope

Science.gov (United States)

... Current Issue Past Issues Special Section Survivability and Hope Past Issues / Spring 2007 Table of Contents For ... cure or long-term survivorship." This message of hope is a hallmark of the latest advances in ...

Induced gravity II: grand unification

Energy Technology Data Exchange (ETDEWEB)

Einhorn, Martin B. [Kavli Institute for Theoretical Physics, Kohn Hall,University of California,Santa Barbara, CA 93106-4030 (United States); Jones, D.R. Timothy [Kavli Institute for Theoretical Physics, Kohn Hall,University of California,Santa Barbara, CA 93106-4030 (United States); Dept. of Mathematical Sciences, University of Liverpool,Peach Street, Liverpool L69 3BX (United Kingdom)

2016-05-31

As an illustration of a renormalizable, asymptotically-free model of induced gravity, we consider an SO(10) gauge theory interacting with a real scalar multiplet in the adjoint representation. We show that dimensional transmutation can occur, spontaneously breaking SO(10) to SU(5)⊗U(1), while inducing the Planck mass and a positive cosmological constant, all proportional to the same scale v. All mass ratios are functions of the values of coupling constants at that scale. Below this scale (at which the Big Bang may occur), the model takes the usual form of Einstein-Hilbert gravity in de Sitter space plus calculable corrections. We show that there exist regions of parameter space in which the breaking results in a local minimum of the effective action giving a positive dilaton (mass){sup 2} from two-loop corrections associated with the conformal anomaly. Furthermore, unlike the singlet case we considered previously, some minima lie within the basin of attraction of the ultraviolet fixed point. Moreover, the asymptotic behavior of the coupling constants also lie within the range of convergence of the Euclidean path integral, so there is hope that there will be candidates for sensible vacua. Although open questions remain concerning unitarity of all such renormalizable models of gravity, it is not obvious that, in curved backgrounds such as those considered here, unitarity is violated. In any case, any violation that may remain will be suppressed by inverse powers of the reduced Planck mass.

Lunar Exploration Missions Since 2006

Science.gov (United States)

Lawrence, S. J. (Editor); Gaddis, L. R.; Joy, K. H.; Petro, N. E.

2017-01-01

The announcement of the Vision for Space Exploration in 2004 sparked a resurgence in lunar missions worldwide. Since the publication of the first "New Views of the Moon" volume, as of 2017 there have been 11 science-focused missions to the Moon. Each of these missions explored different aspects of the Moon's geology, environment, and resource potential. The results from this flotilla of missions have revolutionized lunar science, and resulted in a profoundly new emerging understanding of the Moon. The New Views of the Moon II initiative itself, which is designed to engage the large and vibrant lunar science community to integrate the results of these missions into new consensus viewpoints, is a direct outcome of this impressive array of missions. The "Lunar Exploration Missions Since 2006" chapter will "set the stage" for the rest of the volume, introducing the planetary community at large to the diverse array of missions that have explored the Moon in the last decade. Content: This chapter will encompass the following missions: Kaguya; ARTEMIS (Acceleration, Reconnection, Turbulence, and Electrodynamics of the Moon’s Interaction with the Sun); Chang’e-1; Chandrayaan-1; Moon Impact Probe; Lunar Reconnaissance Orbiter (LRO); Lunar Crater Observation Sensing Satellite (LCROSS); Chang’e-2; Gravity Recovery and Interior Laboratory (GRAIL); Lunar Atmosphere and Dust Environment Explorer (LADEE); Chang’e-3.

Hope and Hopelessness: The Role of Hope in Buffering the Impact of Hopelessness on Suicidal Ideation

Science.gov (United States)

Huen, Jenny M. Y.; Ip, Brian Y. T.; Ho, Samuel M. Y.; Yip, Paul S. F.

2015-01-01

Objectives The present study investigated whether hope and hopelessness are better conceptualized as a single construct of bipolar spectrum or two distinct constructs and whether hope can moderate the relationship between hopelessness and suicidal ideation. Methods Hope, hopelessness, and suicidal ideation were measured in a community sample of 2106 participants through a population-based household survey. Results Confirmatory factor analyses showed that a measurement model with separate, correlated second-order factors of hope and hopelessness provided a good fit to the data and was significantly better than that of the model collapsing hope and hopelessness into a single second-order factor. Negative binomial regression showed that hope and hopelessness interacted such that the effect of hopelessness on suicidal ideation was lower in individuals with higher hope than individuals with lower hope. Conclusions Hope and hopelessness are two distinct but correlated constructs. Hope can act as a resilience factor that buffers the impact of hopelessness on suicidal ideation. Inducing hope in people may be a promising avenue for suicide prevention. PMID:26107687

Fundamental Hope and Practical Identity

NARCIS (Netherlands)

Bloeser, Claudia; Stahl, Titus

2017-01-01

This article considers the question 'What makes hope rational?' We take Adrienne Martin's recent incorporation analysis of hope as representative of a tradition that views the rationality of hope as a matter of instrumental reasons. Against this tradition, we argue that an important subset of hope,

Superconducting gravity gradiometer and a test of inverse square law

International Nuclear Information System (INIS)

Moody, M.V.; Paik, H.J.

1989-01-01

The equivalence principle prohibits the distinction of gravity from acceleration by a local measurement. However, by making a differential measurement of acceleration over a baseline, platform accelerations can be cancelled and gravity gradients detected. In an in-line superconducting gravity gradiometer, this differencing is accomplished with two spring-mass accelerometers in which the proof masses are confined to motion in a single degree of freedom and are coupled together by superconducting circuits. Platform motions appear as common mode accelerations and are cancelled by adjusting the ratio of two persistent currents in the sensing circuit. The sensing circuit is connected to a commercial SQUID amplifier to sense changes in the persistent currents generated by differential accelerations, i.e., gravity gradients. A three-axis gravity gradiometer is formed by mounting six accelerometers on the faces of a precision cube, with the accelerometers on opposite faces of the cube forming one of three in-line gradiometers. A dedicated satellite mission for mapping the earth's gravity field is an important one. Additional scientific goals are a test of the inverse square law to a part in 10(exp 10) at 100 km, and a test of the Lense-Thirring effect by detecting the relativistic gravity magnetic terms in the gravity gradient tensor for the earth

Hope for health and health care.

Science.gov (United States)

Stempsey, William E

2015-02-01

Virtually all activities of health care are motivated at some level by hope. Patients hope for a cure; for relief from pain; for a return home. Physicians hope to prevent illness in their patients; to make the correct diagnosis when illness presents itself; that their prescribed treatments will be effective. Researchers hope to learn more about the causes of illness; to discover new and more effective treatments; to understand how treatments work. Ultimately, all who work in health care hope to offer their patients hope. In this paper, I offer a brief analysis of hope, considering the definitions of Hobbes, Locke, Hume and Thomas Aquinas. I then differentiate shallow and deep hope and show how hope in health care can remain shallow. Next, I explore what a philosophy of deep hope in health care might look like, drawing important points from Ernst Bloch and Gabriel Marcel. Finally, I suggest some implications of this philosophy of hope for patients, physicians, and researchers.

Some considerations about the quest for quantum gravity and a conjecture

International Nuclear Information System (INIS)

Matsas, George

2009-01-01

Full text. There are two main possible routes for the quest for quantum gravity; the top-down and the bottom-up ones. The first option is built on the hope that human endeavor and some luck will be enough to bring us over our goal, while the later one relies on our well tested physical theories to unveil reliable low-energy quantum gravity effects, which would eventually bridge us to the full theory. In this talk I shall argue in favor of the latter one and illustrate how this strategy can bring us new insights about some full quantum gravity problems. In particular, we will revisit in this context the problem of the existence of naked singularities and endorse the view that 'the cosmic censor' would be oblivious to processes involving quantum effects. Finally, inspired by our results, we raise a thought provoking conjecture connecting naked singularities to elementary particles, namely, that 'naked singularities and elementary particles would be low-energy manifestations of a same quantum gravity structure a nd argue that, if this is the case, the Higgs (scalar) boson expected to be found in the LHC would be a composite rather than an elementary particle. (author)

Count Nicolaus Ludwig Von Zinzendorf’s Theory for Missions Portrayed at Herrnhut and by Selected 18th-20th Century Moravian Missions.

Science.gov (United States)

1986-01-01

the progressive methods in advanced missions with churches, schools, gardens, vineyards and orchards, sheep herding, gristmill, cutlery, printing press...pear tree soon became gardens, orchards and vineyards . His success led to Dutch Church and Boer farmer insistence that he leave. Hoping to return, he

Hope, Symptoms, and Palliative Care.

Science.gov (United States)

Davis, Mellar P; Lagman, Ruth; Parala, Armida; Patel, Chirag; Sanford, Tanya; Fielding, Flannery; Brumbaugh, Anita; Gross, James; Rao, Archana; Majeed, Sumreen; Shinde, Shivani; Rybicki, Lisa A

2017-04-01

Hope is important to patients with cancer. Identifying factors that influence hope is important. Anxiety, depression, fatigue, and pain are reported to impair hope. The objective of this study was to determine whether age, gender, marital status, duration of cancer, symptoms, or symptom burden measured by the sum of severity scores on the Edmonton Symptom Assessment Scale (ESAS) correlated with hope measured by the Herth Hope Index (HHI). Patients with advanced cancer in a palliative care unit participated. Demographics including age, gender, marital status, cancer site, and duration of cancer were collected. Individuals completed the ESAS and HHI. Spearman correlation and linear regression were used to assess associations adjusting for gender (male vs female), age ( 12 months). One hundred and ninety-seven were participated in the study, of which 55% were female with a mean age of 61 years (standard deviation 11). Hope was not associated with gender, age, marital status, or duration of cancer. In univariable analysis, hope inversely correlated with ESAS score (-0.28), lack of appetite (-0.22), shortness of breath (-0.17), depression (-0.39), anxiety (-0.32), and lack of well-being (-0.33); only depression was clinically relevant. In multivariable analysis, total symptom burden weakly correlated with hope; only depression remained clinically significant. This study found correlation between symptom burden and hope was not clinically relevant but was so for depression. Among 9 ESAS symptoms, only depression had a clinically relevant correlation with hope.

IMP - INTEGRATED MISSION PROGRAM

Science.gov (United States)

Dauro, V. A.

1994-01-01

IMP is a simulation language that is used to model missions around the Earth, Moon, Mars, or other planets. It has been used to model missions for the Saturn Program, Apollo Program, Space Transportation System, Space Exploration Initiative, and Space Station Freedom. IMP allows a user to control the mission being simulated through a large event/maneuver menu. Up to three spacecraft may be used: a main, a target and an observer. The simulation may begin at liftoff, suborbital, or orbital. IMP incorporates a Fehlberg seventh order, thirteen evaluation Runge-Kutta integrator with error and step-size control to numerically integrate the equations of motion. The user may choose oblate or spherical gravity for the central body (Earth, Mars, Moon or other) while a spherical model is used for the gravity of an additional perturbing body. Sun gravity and pressure and Moon gravity effects are user-selectable. Earth/Mars atmospheric effects can be included. The optimum thrust guidance parameters are calculated automatically. Events/maneuvers may involve many velocity changes, and these velocity changes may be impulsive or of finite duration. Aerobraking to orbit is also an option. Other simulation options include line-of-sight communication guidelines, a choice of propulsion systems, a soft landing on the Earth or Mars, and rendezvous with a target vehicle. The input/output is in metric units, with the exception of thrust and weight which are in English units. Input is read from the user's input file to minimize real-time keyboard input. Output includes vehicle state, orbital and guide parameters, event and total velocity changes, and propellant usage. The main output is to the user defined print file, but during execution, part of the input/output is also displayed on the screen. An included FORTRAN program, TEKPLOT, will display plots on the VDT as well as generating a graphic file suitable for output on most laser printers. The code is double precision. IMP is written in

The Gravity Probe B experiment and early results

Energy Technology Data Exchange (ETDEWEB)

Conklin, John W [Stanford University (United States)], E-mail: johnwc@stanford.edu

2008-11-01

The NASA Gravity Probe B orbiting gyroscope test of General Relativity, launched from Vandenberg Air Force Base on 20 April, 2004 tests two consequences of Einstein's theory: 1) the predicted 6.6 arcs/yr geodetic effect due to the motion of the gyroscope through the curved space-time around the Earth; 2) the predicted 0.039 arcs/yr frame-dragging effect due to the rotating Earth. The mission required the development of many technologies that did not exist when experiment was conceived in 1960. Cryogenic gyroscopes with drift-rates 7 orders of magnitude better than the best inertial navigation gyroscopes, a < 1 marcs star tracking telescope, and other essential technologies were developed as a result of an intensive collaboration between Stanford physicists and engineers, NASA and industry. Gravity Probe B collected science data from August 27, 2004 through September 29, 2005. Analysis of the data began during the mission and is on-going. This paper describes the main features and challenges of the experiment and presents the preliminary results to date.

The Gravity Probe B experiment and early results

International Nuclear Information System (INIS)

Conklin, John W

2008-01-01

The NASA Gravity Probe B orbiting gyroscope test of General Relativity, launched from Vandenberg Air Force Base on 20 April, 2004 tests two consequences of Einstein's theory: 1) the predicted 6.6 arcs/yr geodetic effect due to the motion of the gyroscope through the curved space-time around the Earth; 2) the predicted 0.039 arcs/yr frame-dragging effect due to the rotating Earth. The mission required the development of many technologies that did not exist when experiment was conceived in 1960. Cryogenic gyroscopes with drift-rates 7 orders of magnitude better than the best inertial navigation gyroscopes, a < 1 marcs star tracking telescope, and other essential technologies were developed as a result of an intensive collaboration between Stanford physicists and engineers, NASA and industry. Gravity Probe B collected science data from August 27, 2004 through September 29, 2005. Analysis of the data began during the mission and is on-going. This paper describes the main features and challenges of the experiment and presents the preliminary results to date.

Understanding hope and factors that enhance hope in women with breast cancer.

Science.gov (United States)

Ebright, Patricia R; Lyon, Brenda

2002-04-01

To examine the extent to which antecedent variables and appraisals differentiate levels of hope in women during treatment for breast cancer. Descriptive, correlational. Two large midwestern urban areas. 73 Caucasian women between the ages of 20-73 with first-time diagnosis of breast cancer; recruited through five physician offices; within three months after surgical intervention with planned chemotherapy, radiation therapy, or tamoxifen; and able to read English. Identical surveys mailed to participants 3 and 12 months after surgery. Instruments included Lazarus' Appraisal Components and Themes Scales, Herth Hope Index, Rosenberg's Self-Esteem Scale, Personal Resource Questionnaire 85-Part 2, Helpfulness of Religious Beliefs Scale, and demographics questionnaire. Appraisal, hope, self-esteem, social support, and helpfulness of religious beliefs. Variables influencing appraisals during breast cancer treatment on both surveys were self-esteem and helpfulness of religious beliefs. Potential for coping appraisals and self-esteem contributed to variation in hope at both time points. Social support was a significant contributor to hope in the 12-month survey. Appraisal themes reflected challenge but not fear. Self-esteem and helpfulness of religious beliefs influence women's appraisals regarding the potential for coping; appraisals and antecedent variables relevant for differentiating hope are beliefs about the potential for coping, self-esteem, and social support. Care of women with breast cancer during the first year of treatment should include assessment of beliefs regarding the potential for coping. Results suggest that support for interventions related to self-esteem, social support, and helpfulness of religious beliefs increase confidence in coping abilities and hope.

Multigenerational Independent Colony for Extraterrestrial Habitation, Autonomy, and Behavior Health (MICEHAB): An Investigation of a Long Duration, Partial Gravity, Autonomous Rodent Colony

Science.gov (United States)

Rodgers, Erica M.; Simon, Matthew A.; Antol, Jeffrey; Chai, Patrick R.; Jones, Christopher A.; Klovstad, Jordan J.; Neilan, James H.; Stillwagen, Frederic H.; Williams, Phillip A.; Bednara, Michael;

How much gravity is needed to establish the perceptual upright?

Science.gov (United States)

Harris, Laurence R; Herpers, Rainer; Hofhammer, Thomas; Jenkin, Michael

2014-01-01

Might the gravity levels found on other planets and on the moon be sufficient to provide an adequate perception of upright for astronauts? Can the amount of gravity required be predicted from the physiological threshold for linear acceleration? The perception of upright is determined not only by gravity but also visual information when available and assumptions about the orientation of the body. Here, we used a human centrifuge to simulate gravity levels from zero to earth gravity along the long-axis of the body and measured observers' perception of upright using the Oriented Character Recognition Test (OCHART) with and without visual cues arranged to indicate a direction of gravity that differed from the body's long axis. This procedure allowed us to assess the relative contribution of the added gravity in determining the perceptual upright. Control experiments off the centrifuge allowed us to measure the relative contributions of normal gravity, vision, and body orientation for each participant. We found that the influence of 1 g in determining the perceptual upright did not depend on whether the acceleration was created by lying on the centrifuge or by normal gravity. The 50% threshold for centrifuge-simulated gravity's ability to influence the perceptual upright was at around 0.15 g, close to the level of moon gravity but much higher than the threshold for detecting linear acceleration along the long axis of the body. This observation may partially explain the instability of moonwalkers but is good news for future missions to Mars.

Slab Geometry and Segmentation on Seismogenic Subduction Zone; Insight from gravity gradients

Science.gov (United States)

Saraswati, A. T.; Mazzotti, S.; Cattin, R.; Cadio, C.

2017-12-01

Slab geometry is a key parameter to improve seismic hazard assessment in subduction zones. In many cases, information about structures beneath subduction are obtained from geophysical dedicated studies, including geodetic and seismic measurements. However, due to the lack of global information, both geometry and segmentation in seismogenic zone of many subductions remain badly-constrained. Here we propose an alternative approach based on satellite gravity observations. The GOCE (Gravity field and steady-state Ocean Circulation Explorer) mission enables to probe Earth deep mass structures from gravity gradients, which are more sensitive to spatial structure geometry and directional properties than classical gravitational data. Gravity gradients forward modeling of modeled slab is performed by using horizontal and vertical gravity gradient components to better determine slab geophysical model rather than vertical gradient only. Using polyhedron method, topography correction on gravity gradient signal is undertaken to enhance the anomaly signal of lithospheric structures. Afterward, we compare residual gravity gradients with the calculated signals associated with slab geometry. In this preliminary study, straightforward models are used to better understand the characteristic of gravity gradient signals due to deep mass sources. We pay a special attention to the delineation of slab borders and dip angle variations.

Global Earth Structure Recovery from State-of-the-art Models of the Earth's Gravity Field and Additional Geophysical Information

NARCIS (Netherlands)

Hamayun, H.

2014-01-01

Currently, a tremendous improvement is observed in the accuracy and spatial resolution of global Earth’s gravity field models. This improvement is achieved due to using various new data, including those from satellite gravimetry missions (CHAMP, GRACE, and GOCE); terrestrial and airborne gravity

Massive gravity from bimetric gravity

International Nuclear Information System (INIS)

Baccetti, Valentina; Martín-Moruno, Prado; Visser, Matt

2013-01-01

We discuss the subtle relationship between massive gravity and bimetric gravity, focusing particularly on the manner in which massive gravity may be viewed as a suitable limit of bimetric gravity. The limiting procedure is more delicate than currently appreciated. Specifically, this limiting procedure should not unnecessarily constrain the background metric, which must be externally specified by the theory of massive gravity itself. The fact that in bimetric theories one always has two sets of metric equations of motion continues to have an effect even in the massive gravity limit, leading to additional constraints besides the one set of equations of motion naively expected. Thus, since solutions of bimetric gravity in the limit of vanishing kinetic term are also solutions of massive gravity, but the contrary statement is not necessarily true, there is no complete continuity in the parameter space of the theory. In particular, we study the massive cosmological solutions which are continuous in the parameter space, showing that many interesting cosmologies belong to this class. (paper)

Influence of the Choice of Lunar Gravity Model on Orbit Determination for Lunar Orbiters

Directory of Open Access Journals (Sweden)

Young-Rok Kim

2018-01-01

Full Text Available We examine the influence of the lunar gravity model on the orbit determination (OD of a lunar orbiter operating in a 100 km high, lunar polar orbit. Doppler and sequential range measurements by three Deep Space Network antennas and one Korea Deep Space Antenna were used. For measurement simulation and OD analysis, STK11 and ODTK6 were utilized. GLGM2, LP100K, LP150Q, GRAIL420A, and GRAIL660B were used for investigation of lunar gravity model selection effect. OD results were assessed by position and velocity uncertainties with error covariance and an external orbit comparison using simulated true orbit. The effect of the lunar gravity models on the long-term OD, degree and order level, measurement-acquisition condition, and lunar altitude was investigated. For efficiency verification, computational times for the five lunar gravity models were compared. Results showed that significant improvements to OD accuracy are observed by applying a GRAIL-based model; however, applying a full order and degree gravity modeling is not always the best strategy, owing to the computational burden. Consequently, we consider that OD using GRAIL660B with 70 × 70 degree and order is the most efficient strategy for mission preanalysis. This study provides useful guideline for KPLO OD analysis during nominal mission operation.

Hope grounded in belief: Influences of reward for application and social cynicism on dispositional hope.

Science.gov (United States)

Bernardo, Allan B I

2013-12-01

Two studies explore whether general beliefs about the social world or social axioms may be antecedents of dispositional hope. Social axioms are generalized cognitive representations that provide frames for constructing individuals' hope-related cognitions. Considering social axioms' instrumental and ego-defensive functions, two social axioms, social cynicism and reward for application are hypothesized to be negative and positive predictors of hope, respectively. Study 1 used multiple regression analysis to test the hypothesis. Study 2 used structural equation modeling to test the model with a pathway linking reward for application with hope, and another pathway linking social cynicism and hope that is mediated by self-esteem. The results are discussed in terms of extending the range of psychological constructs and processes that foster the development of hope. © 2013 The Scandinavian Psychological Associations.

How Much Hope Is Enough? Levels of Hope and Students' Psychological and School Functioning

Science.gov (United States)

Marques, Susana C.; Lopez, Shane J.; Fontaine, Anne Marie; Coimbra, Susana; Mitchell, Joanna

2015-01-01

This study investigated the characteristics of students who report extremely high levels of hope. A sample of 682 students (ages 11-17) completed measures of hope, school engagement, life satisfaction, self-worth, and mental health. Academic achievement was obtained from students' school records. Based on their hope scores, students were divided…

Pulmonary function evaluation during the Skylab and Apollo-Soyuz missions

Science.gov (United States)

Sawin, C. F.; Nicogossian, A. E.; Rummel, J. A.; Michel, E. L.

1976-01-01

Previous experience during Apollo postflight exercise testing indicated no major changes in pulmonary function. Pulmonary function has been studied in detail following exposure to hypoxic and hyperoxic normal gravity environments, but no previous study has reported on men exposed to an environment that was both normoxic at 258 torr total pressure and at null gravity as encountered in Skylab. Forced vital capacity (FVC) was measured during the preflight and postflight periods of the Skylab 2 mission. Inflight measurements of vital capacity (VC) were obtained during the last 2 weeks of the second manned mission (Skylab 3). More detailed pulmonary function screening was accomplished during the Skylab 4 mission. The primary measurements made during Skylab 4 testing included residual volume determination (RV), closing volume (CV), VC, FVC and its derivatives. In addition, VC was measured in flight at regular intervals during the Skylab 4 mission. Vital capacity was decreased slightly (-10%) in flight in all Skylab 4 crewmen. No major preflight-to-postflight changes were observed. The Apollo-Soyuz Test Project (ASTP) crewmen were studied using equipment and procedures similar to those employed during Skylab 4. Postflight evaluation of the ASTP crewmen was complicated by their inadvertent exposure to nitrogen tetroxide gas fumes upon reentry.

Ultra-Sensitive Electrostatic Accelerometers and Future Fundamental Physics Missions

Science.gov (United States)

Touboul, Pierre; Christophe, Bruno; Rodrigues, M.; Marque, Jean-Pierre; Foulon, Bernard

Ultra-sensitive electrostatic accelerometers have in the last decade demonstrated their unique performance and reliability in orbit leading to the success of the three Earth geodesy missions presently in operation. In the near future, space fundamental physics missions are in preparation and highlight the importance of this instrument for achieving new scientific objectives. Corner stone of General Relativity, the Equivalence Principle may be violated as predicted by attempts of Grand Unification. Verification experiment at a level of at least 10-15 is the objective of the CNES-ESA mission MICROSCOPE, thanks to a differential accelerometer configuration with concentric cylindrical test masses. To achieve the numerous severe requirements of the mission, the instrument is also used to control the attitude and the orbital motion of the space laboratory leading to a pure geodesic motion of the drag-free satellite. The performance of the accelerometer is a few tenth of femto-g, at the selected frequency of the test about 10-3 Hz, i.e several orbit frequencies. Another important experimental research in Gravity is the verification of the Einstein metric, in particular its dependence with the distance to the attractive body. The Gravity Advanced Package (GAP) is proposed for the future EJSM planetary mission, with the objective to verify this scale dependence of the gravitation law from Earth to Jupiter. This verification is performed, during the interplanetary cruise, by following precisely the satellite trajectory in the planet and Sun fields with an accurate measurement of the non-gravitational accelerations in order to evaluate the deviations to the geodesic motion. Accelerations at DC and very low frequency domain are concerned and the natural bias of the electrostatic accelerometer is thus compensated down to 5 10-11 m/s2 thanks to a specific bias calibration device. More ambitious, the dedicated mission Odyssey, proposed for Cosmic Vision, will fly in the Solar

The meaning of hope in nursing research

DEFF Research Database (Denmark)

Hammer, Kristianna; Mogensen, Ole; Hall, Elisabeth O C

2009-01-01

regardless of whether the human being was healthy, chronically or terminally ill. They comprise the complexity of hope and were: living in hope, hoping for something, hope as a light on the horizon, hope as a human-to-human relationship, hope vs. hopelessness and fear: two sides of the same coin, and hope......Scand J Caring Sci; 2009 The meaning of hope in nursing research: a meta-synthesisThe aim of this study was to develop a meta-synthesis of nursing research about hope as perceived by people during sickness and by healthy people. A meta-synthesis does not intend to cover all studies about hope....... Data were 15 qualitative studies published in nursing or allied health journals and conducted in USA, Great Britain, Canada, Australia, Norway, Sweden and Finland. The meta-synthesis resulted in six metaphors that illustrate dimensions of hope. These metaphors permeated the experiences of hope...

The Earth Gravitational Observatory (EGO): Nanosat Constellations For Advanced Gravity Mapping

Science.gov (United States)

Yunck, T.; Saltman, A.; Bettadpur, S. V.; Nerem, R. S.; Abel, J.

2017-12-01

The trend to nanosats for space-based remote sensing is transforming system architectures: fleets of "cellular" craft scanning Earth with exceptional precision and economy. GeoOptics Inc has been selected by NASA to develop a vision for that transition with an initial focus on advanced gravity field mapping. Building on our spaceborne GNSS technology we introduce innovations that will improve gravity mapping roughly tenfold over previous missions at a fraction of the cost. The power of EGO is realized in its N-satellite form where all satellites in a cluster receive dual-frequency crosslinks from all other satellites, yielding N(N-1)/2 independent measurements. Twelve "cells" thus yield 66 independent links. Because the cells form a 2D arc with spacings ranging from 200 km to 3,000 km, EGO senses a wider range of gravity wavelengths and offers greater geometrical observing strength. The benefits are two-fold: Improved time resolution enables observation of sub-seasonal processes, as from hydro-meteorological phenomena; improved measurement quality enhances all gravity solutions. For the GRACE mission, key limitations arise from such spacecraft factors as long-term accelerometer error, attitude knowledge and thermal stability, which are largely independent from cell to cell. Data from a dozen cells reduces their impact by 3x, by the "root-n" averaging effect. Multi-cell closures improve on this further. The many closure paths among 12 cells provide strong constraints to correct for observed range changes not compatible with a gravity source, including accelerometer errors in measuring non-conservative forces. Perhaps more significantly from a science standpoint, system-level estimates with data from diverse orbits can attack the many scientifically limiting sources of temporal aliasing.

Hope as fantasy in action

DEFF Research Database (Denmark)

Winther-Lindqvist, Ditte Alexandra

’s attempts for upholding a conduct of everyday life. I argue that hoping serves as a meaning horizon, a gegenstand for adjusting to the ongoing challenges that living with illness impose on the families. Hoping is an imaginary backdrop, against which events and tasks, moods and impressions are experienced......Drawing on Vygotsky’s theory of imagination (Vygotsky 2004) I am proposing a phenomenology of hoping as fantasy in action. Based on analysis of 35 interviews with teenagers who are living in households with a somatically ill parent, I suggest that hoping plays a central role in the teenager...... and evaluated, and thus the fantasies involved in hoping becomes constitutive for experiencing. I apply Vygotsky’s experiential view of imaginary activities and explore the experiential status of the “imagined” and the relation between imagining and the real, through the empirical material on hope. This work...

Gravity Plant Physiology Facility (GPPF) Team in the Spacelab Payload Operations Control Center (SL

Science.gov (United States)

1992-01-01

The primary payload for Space Shuttle Mission STS-42, launched January 22, 1992, was the International Microgravity Laboratory-1 (IML-1), a pressurized manned Spacelab module. The goal of IML-1 was to explore in depth the complex effects of weightlessness of living organisms and materials processing. Around-the-clock research was performed on the human nervous system's adaptation to low gravity and effects of microgravity on other life forms such as shrimp eggs, lentil seedlings, fruit fly eggs, and bacteria. Materials processing experiments were also conducted, including crystal growth from a variety of substances such as enzymes, mercury iodide, and a virus. The Huntsville Operations Support Center (HOSC) Spacelab Payload Operations Control Center (SL POCC) at the Marshall Space Flight Center (MSFC) was the air/ground communication channel used between the astronauts and ground control teams during the Spacelab missions. Featured is the Gravity Plant Physiology Facility (GPPF) team in the SL POCC during the IML-1 mission.

Abort Options for Human Missions to Earth-Moon Halo Orbits

Science.gov (United States)

Jesick, Mark C.

2013-01-01

Abort trajectories are optimized for human halo orbit missions about the translunar libration point (L2), with an emphasis on the use of free return trajectories. Optimal transfers from outbound free returns to L2 halo orbits are numerically optimized in the four-body ephemeris model. Circumlunar free returns are used for direct transfers, and cislunar free returns are used in combination with lunar gravity assists to reduce propulsive requirements. Trends in orbit insertion cost and flight time are documented across the southern L2 halo family as a function of halo orbit position and free return flight time. It is determined that the maximum amplitude southern halo incurs the lowest orbit insertion cost for direct transfers but the maximum cost for lunar gravity assist transfers. The minimum amplitude halo is the most expensive destination for direct transfers but the least expensive for lunar gravity assist transfers. The on-orbit abort costs for three halos are computed as a function of abort time and return time. Finally, an architecture analysis is performed to determine launch and on-orbit vehicle requirements for halo orbit missions.

Mars gravity field error analysis from simulated radio tracking of Mars Observer

International Nuclear Information System (INIS)

Smith, D.E.; Lerch, F.J.; Chan, J.C.; Chinn, D.S.; Iz, H.B.; Mallama, A.; Patel, G.B.

1990-01-01

The Mars Observer (MO) Mission, in a near-polar orbit at 360-410 km altitude for nearly a 2-year observing period, will greatly improve our understanding of the geophysics of Mars, including its gravity field. To assess the expected improvement of the gravity field, the authors have conducted an error analysis based upon the mission plan for the Mars Observer radio tracking data from the Deep Space Network. Their results indicate that it should be possible to obtain a high-resolution model (spherical harmonics complete to degree and order 50 corresponding to a 200-km horizontal resolution) for the gravitational field of the planet. This model, in combination with topography from MO altimetry, should provide for an improved determination of the broad scale density structure and stress state of the Martian crust and upper mantle. The mathematical model for the error analysis is based on the representation of doppler tracking data as a function of the Martian gravity field in spherical harmonics, solar radiation pressure, atmospheric drag, angular momentum desaturation residual acceleration (AMDRA) effects, tracking station biases, and the MO orbit parameters. Two approaches are employed. In the first case, the error covariance matrix of the gravity model is estimated including the effects from all the nongravitational parameters (noise-only case). In the second case, the gravity recovery error is computed as above but includes unmodelled systematic effects from atmospheric drag, AMDRA, and solar radiation pressure (biased case). The error spectrum of gravity shows an order of magnitude of improvement over current knowledge based on doppler data precision from a single station of 0.3 mm s -1 noise for 1-min integration intervals during three 60-day periods

Design strategies for the International Space University's variable gravity research facility

Science.gov (United States)

Bailey, Sheila G.; Chiaramonte, Francis P.; Davidian, Kenneth J.

1990-01-01

A variable gravity research facility named 'Newton' was designed by 58 students from 13 countries at the International Space University's 1989 summer session at the Universite Louis Pasteur, Strasbourge, France. The project was comprehensive in scope, including a political and legal foundation for international cooperation, development and financing; technical, science and engineering issues; architectural design; plausible schedules; and operations, crew issues and maintenance. Since log-term exposure to zero gravity is known to be harmful to the human body, the main goal was to design a unique variable gravity research facility which would find a practical solution to this problem, permitting a manned mission to Mars. The facility would not duplicate other space-based facilities and would provide the flexibility for examining a number of gravity levels, including lunar and Martian gravities. Major design alternatives included a truss versus a tether based system which also involved the question of docking while spinning or despinning to dock. These design issues are described. The relative advantages or disadvantages are discussed, including comments on the necessary research and technology development required for each.

Approaches to quantum gravity. Loop quantum gravity, spinfoams and topos approach

International Nuclear Information System (INIS)

Flori, Cecilia

2010-01-01

One of the main challenges in theoretical physics over the last five decades has been to reconcile quantum mechanics with general relativity into a theory of quantum gravity. However, such a theory has been proved to be hard to attain due to i) conceptual difficulties present in both the component theories (General Relativity (GR) and Quantum Theory); ii) lack of experimental evidence, since the regimes at which quantum gravity is expected to be applicable are far beyond the range of conceivable experiments. Despite these difficulties, various approaches for a theory of Quantum Gravity have been developed. In this thesis we focus on two such approaches: Loop Quantum Gravity and the Topos theoretic approach. The choice fell on these approaches because, although they both reject the Copenhagen interpretation of quantum theory, their underpinning philosophical approach to formulating a quantum theory of gravity are radically different. In particular LQG is a rather conservative scheme, inheriting all the formalism of both GR and Quantum Theory, as it tries to bring to its logical extreme consequences the possibility of combining the two. On the other hand, the Topos approach involves the idea that a radical change of perspective is needed in order to solve the problem of quantum gravity, especially in regard to the fundamental concepts of 'space' and 'time'. Given the partial successes of both approaches, the hope is that it might be possible to find a common ground in which each approach can enrich the other. This thesis is divided in two parts: in the first part we analyse LQG, paying particular attention to the semiclassical properties of the volume operator. Such an operator plays a pivotal role in defining the dynamics of the theory, thus testing its semiclassical limit is of uttermost importance. We then proceed to analyse spin foam models (SFM), which are an attempt at a covariant or path integral formulation of canonical Loop Quantum Gravity (LQG). In

Approaches to quantum gravity. Loop quantum gravity, spinfoams and topos approach

Energy Technology Data Exchange (ETDEWEB)

Flori, Cecilia

2010-07-23

One of the main challenges in theoretical physics over the last five decades has been to reconcile quantum mechanics with general relativity into a theory of quantum gravity. However, such a theory has been proved to be hard to attain due to i) conceptual difficulties present in both the component theories (General Relativity (GR) and Quantum Theory); ii) lack of experimental evidence, since the regimes at which quantum gravity is expected to be applicable are far beyond the range of conceivable experiments. Despite these difficulties, various approaches for a theory of Quantum Gravity have been developed. In this thesis we focus on two such approaches: Loop Quantum Gravity and the Topos theoretic approach. The choice fell on these approaches because, although they both reject the Copenhagen interpretation of quantum theory, their underpinning philosophical approach to formulating a quantum theory of gravity are radically different. In particular LQG is a rather conservative scheme, inheriting all the formalism of both GR and Quantum Theory, as it tries to bring to its logical extreme consequences the possibility of combining the two. On the other hand, the Topos approach involves the idea that a radical change of perspective is needed in order to solve the problem of quantum gravity, especially in regard to the fundamental concepts of 'space' and 'time'. Given the partial successes of both approaches, the hope is that it might be possible to find a common ground in which each approach can enrich the other. This thesis is divided in two parts: in the first part we analyse LQG, paying particular attention to the semiclassical properties of the volume operator. Such an operator plays a pivotal role in defining the dynamics of the theory, thus testing its semiclassical limit is of uttermost importance. We then proceed to analyse spin foam models (SFM), which are an attempt at a covariant or path integral formulation of canonical Loop Quantum

"Hope is that fiery feeling": Using Poetry as Data to Explore the Meanings of Hope for Young People

Directory of Open Access Journals (Sweden)

Emily Bishop

2014-01-01

Full Text Available Poetic inquiry is a contentious area of qualitative research. In this article, we discuss some of the issues plaguing this field of inquiry. We then analyse a collection of poems about hope written by a sample of young people from Tasmania, Australia. The poems were written as part of the 2011 Tree of Hope project, which utilised multiple, arts-based methods to provide insights into what young people hope for in the future and the role of hope in their lives. Participants utilised one of three poetic structures. While each structure produced distinct themes, a connection between "hope and happiness" overlapped the two structured types of poetry—the acrostic and sense poetry. However, when writing free verse poetry, the expression of additional dimensions of hope, including the flipside of both having hope and losing hope was evident. We conclude that hope is particularly important to young people and that inviting participant-voiced poetry is an effective technique for investigating conceptual topics such as young people and hope. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs140194

Parental hope for children with advanced cancer.

Science.gov (United States)

Kamihara, Junne; Nyborn, Justin A; Olcese, Maura E; Nickerson, Taylor; Mack, Jennifer W

2015-05-01

Previous work suggests that parents of children with cancer can remain hopeful despite receiving prognostic information, but we know little about what hope means to such parents, or the extent to which parents can feel hopeful even while facing the child's impending death. We audiotaped conversations between clinicians and parents of 32 children with relapsed or refractory cancer, and then interviewed parents about their hopes and expectations for their child. Parent statements about prognosis in interviews mirrored those made by clinicians during discussions about the child's diagnosis with refractory or relapsed cancer. Clinicians used language referring to hope during these conversations but did not ask parents directly about their hopes. Parents expressed a range of hopes for their children, from hopes related to cure or treatment response, to quality of life, normalcy, and love and relationships for the child. For most parents, expectations about prognosis were not aligned with their hopes for the child; for example, many parents hoped for a cure and also reported that they did not believe cure was possible. Many parents were able to acknowledge this incongruence. Parents accurately conveyed the reality of their child's serious condition in the setting of advanced cancer, and yet maintained hope. Hopes were not limited to hope for cure/treatment response. Clinicians should be encouraged to engage in direct conversations about hope with parents as a means to elicit realistic hopes that can help to focus the most meaningful plans for the child and family. Copyright © 2015 by the American Academy of Pediatrics.

On the track of gravity modes: study of the dynamics of the solar core

International Nuclear Information System (INIS)

Mathur, Savita

2007-01-01

This thesis is dedicated to the study of the dynamics of the solar radiative zone through gravity modes. Though the core represents more than 50% of the solar mass, we still do not have an accurate vision of the rotation profile in the very inner part of the Sun. To understand the evolution of stars, we try to put constraints on dynamic processes. Several paths have been followed in this thesis to tackle this issue: solar modeling, the study of a new instrument, observations and inversions of the rotation. The necessity of the detection of gravity modes is driven by the will for a better comprehension of the solar dynamics. With a technological prototype built at the CEA (GOLF-NG), we want to validate a few technical points and prepare the scientific mission which aim will be to detect these gravity modes. We studied first the photodetector and then the whole instrument response. We show the feasibility of the instrument. The observation of the resonance in all the channels proves that it works the way we expected. However, before this mission takes place, the analysis of GOLF data enabled us to detect one gravity-mode candidate as well as the signature of dipole gravity modes. This work benefited from a more theoretical approach on the prediction of gravity-mode frequencies. We show the influence of several physical processes and quantities. Finally, as the dynamical processes in the Sun are not well constrained, we tried to understand the impact of the introduction of one and several gravity modes on the inferred rotation profiles. We also tried to give constraints on the observations so that we could obtain some information on the rotation profile in the core. (author) [fr

What can be learned about the lunar mantle from the Gravity Recovery and Interior Laboratory (GRAIL)?

Science.gov (United States)

Zuber, M. T.; Smith, D. E.; Asmar, S. W.; Konopliv, A. S.; Lemoine, F. G.; Melosh, J.; Neumann, G. A.; Phillips, R. J.; Solomon, S. C.; Watkins, M. M.; Wieczorek, M. A.; Williams, J. G.; Andrews-Hanna, J. C.; Garrick-Bethell, I.; Head, J. W.; Kiefer, W. S.; Matsuyama, I.; McGovern, P. J.; Nimmo, F.; Soderblom, J. M.; Taylor, J.; Weber, R. C.; Goossens, S. J.; Kruizinga, G. L.; Mazarico, E.; Park, R. S.; Yuan, D.

2013-12-01

The Gravity Recovery and Interior Laboratory (GRAIL), a dual-spacecraft, gravity-mapping mission that is a component of NASA's Discovery Program, has successfully concluded its Primary and Extended Missions, and is currently in the science analysis phase. In order to safely navigate the dual spacecraft at an average altitude of 22.5 km above the lunar surface during the Extended Mission phase in the fall of 2012, and to derive the greatest information from the full mission data set, the focus had been on the production of gravitational fields with the highest-possible resolution. Spherical harmonic models of the Moon's gravitational field, produced by separate software systems at the Goddard Space Flight Center and the Jet Propulsion Laboratory, now include observations from both the Primary and Extended Missions. The highest-resolution models to date are to degree and order 900, corresponding to a spatial block size of 6 km, and are ideally suited to study the structure of the Moon's crust in extraordinary detail. GRAIL has achieved all measurement objectives for the Primary Mission, enabling all science investigations to be addressed. One of these investigations is to study the lunar hemispherical asymmetry, i.e., the difference between the nearside and farside. In this study we explore the nearside and farside mantle by isolating the long-wavelength gravity field. We accomplish this objective by removing plausible short-wavelength contributions from the crust that were based on the full resolution of high-degree and -order models, and by considering constraints from crustal compositions and volumes of mare basalt deposits. We localize the power spectral contributions of the nearside and farside to constrain lateral density variations, such as those associated with melting from the source regions of the mare basalts.

Hope in newly diagnosed cancer patients.

Science.gov (United States)

Duggleby, Wendy; Ghosh, Sunita; Cooper, Dan; Dwernychuk, Lynne

2013-11-01

Hope is important to cancer patients as it helps them deal with their diagnosis. Little is known about hope in newly diagnosed cancer patients. Based on the Transcending Possibilities conceptual model of hope, the purpose of this study was to examine the relationship of hope with pain, energy, and psychological and demographic characteristics in newly diagnosed adult oncology outpatients. Data from 310 New Patient Assessment Forms from cancer outpatients' health records were collected. Health records from the first six months of 2009 were reviewed and data were collected on hope, energy, pain, depression, anxiety, feeling overwhelmed, and demographic variables. A generalized linear modeling approach was used to study the relationship of hope scores with these variables. Hypothesized variables and variables that were significant at the P = 0.01 level from the univariate analysis were entered into the multivariate model, with hope scores as the dependent variable. Hope scores were significantly negatively related to age (P = 0.02). More specifically, oncology patients who were 65 years of age or older had significantly less hope than those under the age of 65 years (P = 0.01). Gender (P = 0.009) also was a significant factor, with men having higher hope scores than women. No other variables were significant. Older adults comprise the majority of persons in Canada with cancer. The lower hope scores found in this age group compared with their younger counterparts underscore the importance of further research. This study provides a foundation for future research in this important area for oncology patients. Copyright © 2013 U.S. Cancer Pain Relief Committee. Published by Elsevier Inc. All rights reserved.

24 CFR 971.11 - HOPE VI developments.

Science.gov (United States)

2010-04-01

... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false HOPE VI developments. 971.11... § 971.11 HOPE VI developments. Developments with HOPE VI implementation grants that have approved HOPE... with reasonable revitalization plans. Future HUD actions to approve or deny proposed HOPE VI...

Hope dies last … A qualitative study into the meaning of hope for people with cancer in the palliative phase.

Science.gov (United States)

Nierop-van Baalen, C; Grypdonck, M; van Hecke, A; Verhaeghe, S

2016-07-01

Palliative patients may have strong hope, even hope for a cure, despite knowing their prognosis. Health professionals do not always understand patients who have this kind of hope. The aim of this article was to explore the meaning of hope among patients with cancer in the palliative phase. A secondary analysis was conducted including a constant comparative analysis to uncover the processes underlying the maintenance of hope, of previously collected interview data (n = 76). The meaning of hope is related to the importance of the object it is attached to, rather than to a real chance of achieving this object. Hope has a dual function: patients hope because they cannot forsake it and because they benefit so much from it. Hope can spring from many sources and is influenced by various factors. If there are fewer potent sources to tap into, people create hope themselves and this type of self-created hope takes more effort to maintain. Patients use different strategies to increase their hope, described as the 'the work of hope'. A better understanding of the work of hope can lead to better psychosocial support by health professionals. Health professionals convey many messages that affect the work of hope. © 2016 John Wiley & Sons Ltd.

Gravity Probe B spacecraft description

International Nuclear Information System (INIS)

Bennett, Norman R; Burns, Kevin; Katz, Russell; Kirschenbaum, Jon; Mason, Gary; Shehata, Shawky

2015-01-01

The Gravity Probe B spacecraft, developed, integrated, and tested by Lockheed Missiles and Space Company and later Lockheed Martin Corporation, consisted of structures, mechanisms, command and data handling, attitude and translation control, electrical power, thermal control, flight software, and communications. When integrated with the payload elements, the integrated system became the space vehicle. Key requirements shaping the design of the spacecraft were: (1) the tight mission timeline (17 months, 9 days of on-orbit operation), (2) precise attitude and translational control, (3) thermal protection of science hardware, (4) minimizing aerodynamic, magnetic, and eddy current effects, and (5) the need to provide a robust, low risk spacecraft. The spacecraft met all mission requirements, as demonstrated by dewar lifetime meeting specification, positive power and thermal margins, precision attitude control and drag-free performance, reliable communications, and the collection of more than 97% of the available science data. (paper)

Playing Around in the Solar System: Mini-games for Many Missions

Science.gov (United States)

Fisher, D. K.; Leon, N.; Fitzpatrick, A. J.; Wessen, A.

2010-12-01

Several NASA solar system missions will have major milestones during 2011, the Year of the Solar System. These events include launches, encounters, and orbit insertions. Other missions will continue the explorations already underway. The “Year of the Solar System Game” on The Space Place website (http://spaceplace.nasa.gov/en/kids/solar-system) brings all these efforts together in the context of the whole solar system. The game helps to build awareness of the characteristics of our solar system and some of the missions that are continuing to advance our knowledge and understanding. It is one of many educational tools being developed and deployed for the Year of the Solar System. The game is a “super-game” that encompasses a number of mission-related “mini-games.” The mini-games can be played individually, and they all contribute toward achievements in the super-game. The enveloping interface for all the games is an animated solar system. The player clicks on a planet or a moon, sees a close-up image, and reads a short paragraph about the object. If the object has been endowed with a mission mini-game, player can click on the tiny spacecraft, read about the mission, then play the game—or, if impatient, just immediately play the game (and read about the mission later, we hope). A score “page” keeps track of the player’s achievements and scores. Players earn achievements by reading about the planets, moons, asteroids, comets, and missions and by playing the mission mini-games. The game targets upper elementary age children, as does the entire Space Place website. Each mini-game, although simple, incorporates elements of the spacecrafts’ missions and their target objects. For example, in Cassini Commander, the player must navigate the Cassini spacecraft through gaps in Saturn’s rings and around Saturn’s moons. The super-game is designed to accommodate any number of mission mini-games, so we are hoping to continue to add missions and increase

Cold Atom Interferometers Used In Space (CAIUS) for Measuring the Earth's Gravity Field

Science.gov (United States)

Carraz, O.; Luca, M.; Siemes, C.; Haagmans, R.; Silvestrin, P.

2016-12-01

In the past decades, it has been shown that atomic quantum sensors are a newly emerging technology that can be used for measuring the Earth's gravity field. There are two ways of making use of that technology: One is a gravity gradiometer concept and the other is in a low-low satellite-to-satellite ranging concept. Whereas classical accelerometers typically suffer from high noise at low frequencies, Cold Atom Interferometers are highly accurate over the entire frequency range. We recently proposed a concept using cold atom interferometers for measuring all diagonal elements of the gravity gradient tensor and the full spacecraft angular velocity in order to achieve better performance than the GOCE gradiometer over a larger part of the spectrum, with the ultimate goals of determining the fine structures in the gravity field better than today. This concept relies on a high common mode rejection, which relaxes the drag free control compare to GOCE mission, and benefits from a long interaction time with the free falling clouds of atoms due to the micro gravity environment in space as opposed to the 1-g environment on-ground. Other concept is also being studied in the frame of NGGM, which relies on the hybridization between quantum and classical techniques to improve the performance of accelerometers. This could be achieved as it is realized in frequency measurements where quartz oscillators are phase locked on atomic or optical clocks. This technique could correct the spectrally colored noise of the electrostatic accelerometers in the lower frequencies. In both cases, estimation of the Earth gravity field model from the instruments has to be evaluated taking into account different system parameters such as attitude control, altitude of the satellite, time duration of the mission, etc. Miniaturization, lower consumptions and upgrading Technical Readiness Level are the key engineering challenges that have to be faced for these space quantum technologie.

A high resolution gravity model for Venus - GVM-1

Science.gov (United States)

Nerem, R. S.; Bills, B. G.; Mcnamee, J. B.

1993-01-01

A spherical harmonic model of the gravitational field of Venus complete to degree and order 50 has been developed using the S-band Doppler tracking data of the Pioneer Venus Orbiter (PVO) collected between 1979 and 1982. The short wavelengths of this model could only be resolved near the PVO periapse location (about 14 deg N latitude), therefore a priori constraints were applied to the model to bias poorly observed coefficients towards zero. The resulting model has a half-wavelength resolution of 400 km near the PVO periapse location, but the resolution degrades to greater than 1000 km near the poles. This gravity model correlates well with a degree 50 spherical harmonic expansion of the Venus topography derived from a combination of Magellan and PVO data. New tracking data from Magellan's gravity mission should provide some improvement to this model, although a complete model of the Venusian gravity field will depend on tracking of Magellan after the circularization of its orbit using aerobraking.

Human and Robotic Mission to Small Bodies: Mapping, Planning and Exploration

Science.gov (United States)

Neffian, Ara V.; Bellerose, Julie; Beyer, Ross A.; Archinal, Brent; Edwards, Laurence; Lee, Pascal; Colaprete, Anthony; Fong, Terry

2013-01-01

This study investigates the requirements, performs a gap analysis and makes a set of recommendations for mapping products and exploration tools required to support operations and scientific discovery for near- term and future NASA missions to small bodies. The mapping products and their requirements are based on the analysis of current mission scenarios (rendezvous, docking, and sample return) and recommendations made by the NEA Users Team (NUT) in the framework of human exploration. The mapping products that sat- isfy operational, scienti c, and public outreach goals include topography, images, albedo, gravity, mass, density, subsurface radar, mineralogical and thermal maps. The gap analysis points to a need for incremental generation of mapping products from low (flyby) to high-resolution data needed for anchoring and docking, real-time spatial data processing for hazard avoidance and astronaut or robot localization in low gravity, high dynamic environments, and motivates a standard for coordinate reference systems capable of describing irregular body shapes. Another aspect investigated in this study is the set of requirements and the gap analysis for exploration tools that support visualization and simulation of operational conditions including soil interactions, environment dynamics, and communications coverage. Building robust, usable data sets and visualisation/simulation tools is the best way for mission designers and simulators to make correct decisions for future missions. In the near term, it is the most useful way to begin building capabilities for small body exploration without needing to commit to specific mission architectures.

Solar maximum mission

International Nuclear Information System (INIS)

Ryan, J.

1981-01-01

By understanding the sun, astrophysicists hope to expand this knowledge to understanding other stars. To study the sun, NASA launched a satellite on February 14, 1980. The project is named the Solar Maximum Mission (SMM). The satellite conducted detailed observations of the sun in collaboration with other satellites and ground-based optical and radio observations until its failure 10 months into the mission. The main objective of the SMM was to investigate one aspect of solar activity: solar flares. A brief description of the flare mechanism is given. The SMM satellite was valuable in providing information on where and how a solar flare occurs. A sequence of photographs of a solar flare taken from SMM satellite shows how a solar flare develops in a particular layer of the solar atmosphere. Two flares especially suitable for detailed observations by a joint effort occurred on April 30 and May 21 of 1980. These flares and observations of the flares are discussed. Also discussed are significant discoveries made by individual experiments

A Saturn Ring Observer Mission Using Multi-Mission Radioisotope Power Systems

International Nuclear Information System (INIS)

Abelson, Robert D.; Spilker, Thomas R.; Shirley, James H.

2006-01-01

Saturn remains one of the most fascinating planets within the solar system. To better understand the complex ring structure of this planet, a conceptual Saturn Ring Observer (SRO) mission is presented that would spend one year in close proximity to Saturn's A and B rings, and perform detailed observations and measurements of the ring particles and electric and magnetic fields. The primary objective of the mission would be to understand ring dynamics, including the microphysics of individual particles and small scale (meters to a few kilometers) phenomena such as particle agglomeration behavior. This would be accomplished by multispectral imaging of the rings at multiple key locations within the A and B rings, and by ring-particle imaging at an unprecedented resolution of 0.5 cm/pixel. The SRO spacecraft would use a Venus-Earth-Earth-Jupiter Gravity Assist (VEEJGA) and be aerocaptured into Saturn orbit using an advanced aeroshell design to minimize propellant mass. Once in orbit, the SRO would stand off from the ring plane 1 to 1.4 km using chemical thrusters to provide short propulsive maneuvers four times per revolution, effectively causing the SRO vehicle to 'hop' above the ring plane. The conceptual SRO spacecraft would be enabled by the use of a new generation of multi-mission Radioisotope Power Systems (RPSs) currently being developed by NASA and DOE. These RPSs include the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) and Stirling Radioisotope Generator (SRG). The RPSs would generate all necessary electrical power (≥330 We at beginning of life) during the 10-year cruise and 1-year science mission (∼11 years total). The RPS heat would be used to maintain the vehicle's operating and survival temperatures, minimizing the need for electrical heaters. Such a mission could potentially launch in the 2015-2020 timeframe, with operations at Saturn commencing in approximately 2030

Features of the Gravity Probe B Space Vehicle

Science.gov (United States)

Reeve, William; Green, Gaylord

2007-04-01

Space vehicle performance enabled successful relativity data collection throughout the Gravity Probe B mission. Precision pointing and drag-free translation control was maintained using proportional helium micro-thrusters. Electrical power was provided by rigid, double sided solar arrays. The 1.8 kelvin science instrument temperature was maintained using the largest cryogenic liquid helium dewar ever flown in space. The flight software successfully performed autonomous operations and safemode protection. Features of the Gravity Probe B Space Vehicle mechanisms include: 1) sixteen helium micro-thrusters, the first proportional thrusters flown in space, and large-orifice thruster isolation valves, 2) seven precision and high-authority mass trim mechanisms, 3) four non-pyrotechnic, highly reliable solar array deployment and release mechanism sets. Early incremental prototyping was used extensively to reduce spacecraft development risk. All spacecraft systems were redundant and provided multiple failure tolerance in critical systems. Lockheed Martin performed the spacecraft design, systems engineering, hardware and software integration, environmental testing and launch base operations, as well as on-orbit operations support for the Gravity Probe B space science experiment.

The potential of ground gravity measurements to validate GRACE data

Directory of Open Access Journals (Sweden)

D. Crossley

2003-01-01

Full Text Available New satellite missions are returning high precision, time-varying, satellite measurements of the Earth’s gravity field. The GRACE mission is now in its calibration/- validation phase and first results of the gravity field solutions are imminent. We consider here the possibility of external validation using data from the superconducting gravimeters in the European sub-array of the Global Geodynamics Project (GGP as ‘ground truth’ for comparison with GRACE. This is a pilot study in which we use 14 months of 1-hour data from the beginning of GGP (1 July 1997 to 30 August 1998, when the Potsdam instrument was relocated to South Africa. There are 7 stations clustered in west central Europe, and one station, Metsahovi in Finland. We remove local tides, polar motion, local and global air pressure, and instrument drift and then decimate to 6-hour samples. We see large variations in the time series of 5–10µgal between even some neighboring stations, but there are also common features that correlate well over the 427-day period. The 8 stations are used to interpolate a minimum curvature (gridded surface that extends over the geographical region. This surface shows time and spatial coherency at the level of 2– 4µgal over the first half of the data and 1–2µgal over the latter half. The mean value of the surface clearly shows a rise in European gravity of about 3µgal over the first 150 days and a fairly constant value for the rest of the data. The accuracy of this mean is estimated at 1µgal, which compares favorably with GRACE predictions for wavelengths of 500 km or less. Preliminary studies of hydrology loading over Western Europe shows the difficulty of correlating the local hydrology, which can be highly variable, with large-scale gravity variations.Key words. GRACE, satellite gravity, superconducting gravimeter, GGP, ground truth

Galaxy Mission Completes Four Star-Studded Years in Space

Science.gov (United States)

2007-01-01

NASA's Galaxy Evolution Explorer is celebrating its fourth year in space with some of M81's 'hottest' stars. In a new ultraviolet image, the magnificent M81 spiral galaxy is shown at the center. The orbiting observatory spies the galaxy's 'sizzling young starlets' as wisps of bluish-white swirling around a central golden glow. The tints of gold at M81's center come from a 'senior citizen' population of smoldering stars. 'This is a spectacular view of M81,' says Dr. John Huchra, of the Harvard Smithsonian Center for Astrophysics, Cambridge, Mass. 'When we proposed to observe this galaxy with GALEX we hoped to see globular clusters, open clusters, and young stars...this view is everything that we were hoping for.' The image is one of thousands gathered so far by GALEX, which launched April 28, 2003. This mission uses ultraviolet wavelengths to measure the history of star formation 80 percent of the way back to the Big Bang. The large fluffy bluish-white material to the left of M81 is a neighboring galaxy called Holmberg IX. This galaxy is practically invisible to the naked human eye. However, it is illuminated brilliantly in GALEX's wide ultraviolet eyes. Its ultraviolet colors show that it is actively forming young stars. The bluish-white fuzz in the space surrounding M81 and Holmberg IX is new star formation triggered by gravitational interactions between the two galaxies. Huchra notes that the active star formation in Holmberg IX is a surprise, and says that more research needs to be done in light of the new findings from GALEX. 'Some astronomers suspect that the galaxy Holmberg IX is the result of a galactic interaction between M81 and another neighboring galaxy M82,' says Huchra. 'This particular galaxy is especially important because there are a lot of galaxies like Holmberg IX around our Milky Way galaxy. By understanding how Holmberg IX came to be, we hope to understand how all the little galaxies surrounding the Milky Way developed.' 'Four years after GALEX

Monte Carlo Analysis as a Trajectory Design Driver for the TESS Mission

Science.gov (United States)

Nickel, Craig; Lebois, Ryan; Lutz, Stephen; Dichmann, Donald; Parker, Joel

2016-01-01

The Transiting Exoplanet Survey Satellite (TESS) will be injected into a highly eccentric Earth orbit and fly 3.5 phasing loops followed by a lunar flyby to enter a mission orbit with lunar 2:1 resonance. Through the phasing loops and mission orbit, the trajectory is significantly affected by lunar and solar gravity. We have developed a trajectory design to achieve the mission orbit and meet mission constraints, including eclipse avoidance and a 30-year geostationary orbit avoidance requirement. A parallelized Monte Carlo simulation was performed to validate the trajectory after injecting common perturbations, including launch dispersions, orbit determination errors, and maneuver execution errors. The Monte Carlo analysis helped identify mission risks and is used in the trajectory selection process.

24 CFR 572.1 - Overview of HOPE 3.

Science.gov (United States)

2010-04-01

... 24 Housing and Urban Development 3 2010-04-01 2010-04-01 false Overview of HOPE 3. 572.1 Section... DEVELOPMENT COMMUNITY FACILITIES HOPE FOR HOMEOWNERSHIP OF SINGLE FAMILY HOMES PROGRAM (HOPE 3) General § 572.1 Overview of HOPE 3. The purpose of the HOPE for Homeownership of Single Family Homes program (HOPE...

Deconstructing the shallow internal structure of the Moon using GRAIL gravity and LOLA topography

Science.gov (United States)

Zuber, M. T.

2015-12-01

Globally-distributed, high-resolution gravity and topography observations of the Moon from the Gravity Recovery and Interior Laboratory (GRAIL) mission and Lunar Orbiter Laser Altimeter (LOLA) instrument aboard the Lunar Reconnaissance Orbiter (LRO) spacecraft afford the unprecedented opportunity to explore the shallow internal structure of the Moon. Gravity and topography can be combined to produce Bouguer gravity that reveals the distribution of mass in the subsurface, with high degrees in the spherical harmonic expansion of the Bouguer anomalies sensitive to shallowest structure. For isolated regions of the lunar highlands and several basins we have deconstructed the gravity field and mapped the subsurface distribution of density anomalies. While specified spherical harmonic degree ranges can be used to estimate contributions at different depths, such analyses require considerable caution in interpretation. A comparison of filtered Bouguer gravity with forward models of disk masses with plausible densities illustrates the interdependencies of the gravitational power of density anomalies with depth and spatial scale. The results have implications regarding the limits of interpretation of lunar subsurface structure.

A Combined Gravity Compensation Method for INS Using the Simplified Gravity Model and Gravity Database.

Science.gov (United States)

Zhou, Xiao; Yang, Gongliu; Wang, Jing; Wen, Zeyang

2018-05-14

In recent decades, gravity compensation has become an important way to reduce the position error of an inertial navigation system (INS), especially for a high-precision INS, because of the extensive application of high precision inertial sensors (accelerometers and gyros). This paper first deducts the INS's solution error considering gravity disturbance and simulates the results. Meanwhile, this paper proposes a combined gravity compensation method using a simplified gravity model and gravity database. This new combined method consists of two steps all together. Step 1 subtracts the normal gravity using a simplified gravity model. Step 2 first obtains the gravity disturbance on the trajectory of the carrier with the help of ELM training based on the measured gravity data (provided by Institute of Geodesy and Geophysics; Chinese Academy of sciences), and then compensates it into the error equations of the INS, considering the gravity disturbance, to further improve the navigation accuracy. The effectiveness and feasibility of this new gravity compensation method for the INS are verified through vehicle tests in two different regions; one is in flat terrain with mild gravity variation and the other is in complex terrain with fierce gravity variation. During 2 h vehicle tests, the positioning accuracy of two tests can improve by 20% and 38% respectively, after the gravity is compensated by the proposed method.

Role of hope in academic and sport achievement.

Science.gov (United States)

Curry, L A; Snyder, C R; Cook, D L; Ruby, B C; Rehm, M

1997-12-01

Hope is the sum of goal thoughts as tapped by pathways and agency. Pathways reflect the perceived capability to produce goal routes; agency reflects the perception that one can initiate action along these pathways. Using trait and state hope scales, studies explored hope in college student athletes. In Study 1, male and female athletes were higher in trait hope than nonathletes; moreover, hope significantly predicted semester grade averages beyond cumulative grade point average and overall self-worth. In Study 2, with female cross-country athletes, trait hope predicted athletic outcomes; further, weekly state hope tended to predict athletic outcomes beyond dispositional hope, training, and self-esteem, confidence, and mood. In Study 3, with female track athletes, dispositional hope significantly predicted athletic outcomes beyond variance related to athletic abilities and affectivity; moreover, athletes had higher hope than nonathletes.

Holding on to hope: A review of the literature exploring missing persons, hope and ambiguous loss.

Science.gov (United States)

Wayland, Sarah; Maple, Myfanwy; McKay, Kathy; Glassock, Geoffrey

2016-01-01

When a person goes missing, those left behind mourn an ambiguous loss where grief can be disenfranchised. Different to bereavement following death, hope figures into this experience as a missing person has the potential to return. This review explores hope for families of missing people. Lived experience of ambiguous loss was deconstructed to reveal responses punctuated by hope, which had practical and psychological implications for those learning to live with an unresolved absence. Future lines of enquiry must address the dearth of research exploring the role of hope, unresolved grief, and its clinical implications when a person is missing.

Genetic analysis of gravity signal transduction in roots

Science.gov (United States)

Masson, Patrick; Strohm, Allison; Baldwin, Katherine

gravitropism, we sought genetic enhancers of arg1 as a way to identify new gravity signal transducers. Two of these modifiers, named mar1 and mar2, were found to affect genes that encode two subunits of the plastidic outer-membrane protein import complex, TOC75 and TOC132, respectively. mar2 did not affect the ultrastructure of amyloplasts in the statocytes nor did it alter their ability to sediment in response to gravistimulation, suggesting a role for the outer membrane of the amyloplasts in gravity signal transduction (reviewed in Stanga et al., 2009, Plant Signal Behavior 4(10): 1-9). The contribution of TOC132 in gravity signal transduction is being investigated by analyzing the regions of this protein that are needed for the pathway, and investigating the contribution of a putative TOC132-interacting protein in gravity signal transduction. We have also isolated additional putative enhancers of arg1-2 in the hope of identifying new plastid-associated gravity signal transducers, and have initiated a screen for genetic enhancers of mar2 to seek new transducers in the ARG1 branch of the pathway.

Space Mission Human Reliability Analysis (HRA) Project

Science.gov (United States)

Boyer, Roger

2014-01-01

The purpose of the Space Mission Human Reliability Analysis (HRA) Project is to extend current ground-based HRA risk prediction techniques to a long-duration, space-based tool. Ground-based HRA methodology has been shown to be a reasonable tool for short-duration space missions, such as Space Shuttle and lunar fly-bys. However, longer-duration deep-space missions, such as asteroid and Mars missions, will require the crew to be in space for as long as 400 to 900 day missions with periods of extended autonomy and self-sufficiency. Current indications show higher risk due to fatigue, physiological effects due to extended low gravity environments, and others, may impact HRA predictions. For this project, Safety & Mission Assurance (S&MA) will work with Human Health & Performance (HH&P) to establish what is currently used to assess human reliabiilty for human space programs, identify human performance factors that may be sensitive to long duration space flight, collect available historical data, and update current tools to account for performance shaping factors believed to be important to such missions. This effort will also contribute data to the Human Performance Data Repository and influence the Space Human Factors Engineering research risks and gaps (part of the HRP Program). An accurate risk predictor mitigates Loss of Crew (LOC) and Loss of Mission (LOM).The end result will be an updated HRA model that can effectively predict risk on long-duration missions.

Plant biology in reduced gravity on the Moon and Mars.

Science.gov (United States)

Kiss, J Z

2014-01-01

While there have been numerous studies on the effects of microgravity on plant biology since the beginning of the Space Age, our knowledge of the effects of reduced gravity (less than the Earth nominal 1 g) on plant physiology and development is very limited. Since international space agencies have cited manned exploration of Moon/Mars as long-term goals, it is important to understand plant biology at the lunar (0.17 g) and Martian levels of gravity (0.38 g), as plants are likely to be part of bioregenerative life-support systems on these missions. First, the methods to obtain microgravity and reduced gravity such as drop towers, parabolic flights, sounding rockets and orbiting spacecraft are reviewed. Studies on gravitaxis and gravitropism in algae have suggested that the threshold level of gravity sensing is around 0.3 g or less. Recent experiments on the International Space Station (ISS) showed attenuation of phototropism in higher plants occurs at levels ranging from 0.l g to 0.3 g. Taken together, these studies suggest that the reduced gravity level on Mars of 0.38 g may be enough so that the gravity level per se would not be a major problem for plant development. Studies that have directly considered the impact of reduced gravity and microgravity on bioregenerative life-support systems have identified important biophysical changes in the reduced gravity environments that impact the design of these systems. The author suggests that the current ISS laboratory facilities with on-board centrifuges should be used as a test bed in which to explore the effects of reduced gravity on plant biology, including those factors that are directly related to developing life-support systems necessary for Moon and Mars exploration. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

The nature of hope among Iranian cancer patients.

Science.gov (United States)

Afrooz, Rashed; Rahmani, Azad; Zamanzadeh, Vahid; Abdullahzadeh, Farahnaz; Azadi, Arman; Faghany, Safieh; Pirzadeh, Asgar

2014-01-01

Hope is an important coping resource for cancer patients. Types and sources of hope and hope- inspiring strategies are not well investigated among Iranian cancer patients. The aims of present study were therefore to investigate the nature of hope and some demographic predictors of hope among Iranian cancer patients. This descriptive-correlational study was undertaken among 200 cancer patients admitted to an educational center affiliated to Ardabil University of Medical Sciences, Iran. Participants were selected using a convenience sampling method. The Herth Hope Index and other validated questionnaires were used to investigate level of hope and types and sources of hope, as well as hope-inspiring strategies. Data were analyzed using SPSS statistical software. The overall score for hope was 31 from total scores ranging between 12 and 48. Some 94% of patients mentioned 'return to normal life' and 'complete healing of disease by drugs and physicians' as their main hopes. The most important sources of hope reported by patients include spiritual resources, family members, healthcare workers, and medicines and treatments available for the disease. Relationship with God, praying/blessing, controlling the signs and symptoms of the disease, and family/health care workers' support were the main hope-inspiring strategies. Patients who had a history of metastasis, or who were older, illiterate, divorced/widowed and lived with their children reported lower levels of hope. On the other hand, employed patients and those with good support from their families had higher levels of hope. The study findings showed moderate to high levels of hope among Iranian cancer patients. Accordingly, the role of spiritual/religion, family members and health care workers should be considered in developing care plans for these patients.

Human Performance in Simulated Reduced Gravity Environments

Science.gov (United States)

Cowley, Matthew; Harvill, Lauren; Rajulu, Sudhakar

2014-01-01

the ARGOS, but only 0.2 +/- 0.1 on the C-9. Discussion: Gait analysis showed differences in joint kinematics and temporal-spatial parameters between the reduced gravity simulators and with respect to earth gravity. Although most of the subjects chose a somewhat unique ambulation style as a result of learning to ambulate in a new environment, all but two were consistent with keeping an Earth-like gait. Learning how reduced gravity affects ambulation will help NASA to determine optimal suit designs, influence mission planning, help train crew, and may shed light on the underlying methods the body uses to optimize gait for energetic efficiency. Conclusion: Kinematic and kinetic analysis demonstrated noteworthy differences between an offloaded environment and 1-g, as would be expected. The analysis showed a trend to change the ambulation style in an offloaded environment to a rolling-loping walk (resembling crosscountry skiing) with increased swing time. This ambulation modification, particularly in the ARGOS, indicated that the relative kinetic energy of the subject was increased, on average, per the static body weight compared to the 1-g condition. How much of this was influenced by the active offloading of the ARGOS system is unknown.

The tenacity and tenuousness of hope: parental experiences of hope when their child has a poor cancer prognosis.

Science.gov (United States)

Barrera, Maru; Granek, Leeat; Shaheed, Jenny; Nicholas, David; Beaune, Laura; D'Agostino, Norma M; Bouffet, Eric; Antle, Beverly

2013-01-01

The meaning and role of hope in parents of children with life-threatening illnesses remain relatively unstudied. The objectives of this study were to explore parental hope when a child is being treated for a malignancy resistant to treatment and to identify facilitators and barriers to maintaining hope in this context. Thirty-five parents of children with difficult-to-treat cancer were interviewed 3 months after diagnosis. Line-by-line coding of transcripts was used to establish categories and themes. Constant comparison was used to examine relationships within and across codes and categories. Parental hope was related to the child's cure and future. The concept, however, oscillated between being tenacious and robust, and tenuous and elusive, depending on how the child was responding to treatment and the psychosocial context. Focusing on positive outcomes and experiences, spirituality, and social support facilitated being hopeful. Awareness of negative outcomes, information overload, physical and emotional depletion, and fear and uncertainty challenged parental hope. Developing a model that identifies the nature of parental hope as well as barriers and facilitators to maintaining hope shortly after childhood cancer diagnosis may assist healthcare professionals in supporting parents. Understanding parental hope may assist healthcare professionals to avoid overloading parents with too much information at once. Healthcare professionals can also ensure that social support from family, community, and the medical center is available for parents and that their physical and emotional needs are being met to ensure that they maintain hope to best care for their child with cancer.

Fostering hope in the patient with cancer.

Science.gov (United States)

Lichwala, Rebecca

2014-06-01

When a patient is diagnosed with cancer, feelings such as fear, anxiety, and hopelessness can negatively affect a person's frame of mind. Hope can help a patient decrease anxiety and increase quality of life. Nurses should assess hope, provide interventions, be empathetic, listen, and treat patients with dignity to help improve hope and quality of life. This article features how hope can have a positive impact and provides specific information about how nurses can promote and foster hope in patients with cancer.

Three-Gorge Reservoir: A 'Controlled Experiment' for Calibration/Validation of Time-Variable Gravity Signals Detected from Space

Science.gov (United States)

Chao, Benjamin F.; Boy, J. P.

2003-01-01

With the advances of measurements, modern space geodesy has become a new type of remote sensing for the Earth dynamics, especially for mass transports in the geophysical fluids on large spatial scales. A case in point is the space gravity mission GRACE (Gravity Recovery And Climate Experiment) which has been in orbit collecting gravity data since early 2002. The data promise to be able to detect changes of water mass equivalent to sub-cm thickness on spatial scale of several hundred km every month or so. China s Three-Gorge Reservoir has already started the process of water impoundment in phases. By 2009,40 km3 of water will be stored behind one of the world s highest dams and spanning a section of middle Yangtze River about 600 km in length. For the GRACE observations, the Three-Gorge Reservoir would represent a geophysical controlled experiment , one that offers a unique opportunity to do detailed geophysical studies. -- Assuming a complete documentation of the water level and history of the water impoundment process and aided with a continual monitoring of the lithospheric loading response (such as in area gravity and deformation), one has at hand basically a classical forwardinverse modeling problem of surface loading, where the input and certain output are known. The invisible portion of the impounded water, i.e. underground storage, poses either added values as an observable or a complication as an unknown to be modeled. Wang (2000) has studied the possible loading effects on a local scale; we here aim for larger spatial scales upwards from several hundred km, with emphasis on the time-variable gravity signals that can be detected by GRACE and follow-on missions. Results using the Green s function approach on the PREM elastic Earth model indicate the geoid height variations reaching several millimeters on wavelengths of about a thousand kilometers. The corresponding vertical deformations have amplitude of a few centimeters. In terms of long

Development of an Atom Interferometer Gravity Gradiometer for Earth Sciences

Science.gov (United States)

Rakholia, A.; Sugarbaker, A.; Black, A.; Kasecivh, M.; Saif, B.; Luthcke, S.; Callahan, L.; Seery, B.; Feinberg, L.; Mather, J.;

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...

Between hope and hopelessness

DEFF Research Database (Denmark)

Andersen, Ingrid Charlotte; Thomsen, Thora Grothe; Bruun, Poul

2018-01-01

and seven family members during follow-up visits at hospital and at the participants' homes between 2014 and 2016. A phenomenological-hermeneutical approach was used to interpret the data. RESULTS: 'Between hope and hopelessness' involved frustrations, concerns and doubts, all of which could relate...... to the interaction with healthcare providers. 'Seeking support from healthcare services', 'navigating between healthcare providers' and 'collaborating with healthcare providers at home' could entail opportunities to strengthen self-management and hope; however, it could also entail reduced faith in getting the right...... help and hopelessness. CONCLUSION: During a period of transition after hospitalisation, available and well-coordinated healthcare services, and alliances with healthcare professionals are crucial to COPD patients and their family members in terms of their self-management, hope and well-being....

Newtonian gravity in loop quantum gravity

OpenAIRE

Smolin, Lee

2010-01-01

We apply a recent argument of Verlinde to loop quantum gravity, to conclude that Newton's law of gravity emerges in an appropriate limit and setting. This is possible because the relationship between area and entropy is realized in loop quantum gravity when boundaries are imposed on a quantum spacetime.

Thermosyphon Flooding Limits in Reduced Gravity Environments

Science.gov (United States)

Gibson, Marc A.; Jaworske, Donald A.; Sanzi, James L.; Ljubanovic, Damir

2012-01-01

Fission Power Systems have long been recognized as potential multi-kilowatt power solutions for lunar, Martian, and extended planetary surface missions. Current heat rejection technology associated with fission surface power systems has focused on titanium water thermosyphons embedded in carbon composite radiator panels. The thermosyphons, or wickless heat pipes, are used as a redundant and efficient way to spread the waste heat from the power conversion unit(s) over the radiator surface area where it can be rejected to space. It is well known that thermosyphon performance is reliant on gravitational forces to keep the evaporator wetted with the working fluid. One of the performance limits that can be encountered, if not understood, is the phenomenon of condenser flooding, otherwise known as evaporator dry out. This occurs when the gravity forces acting on the condensed fluid cannot overcome the shear forces created by the vapor escaping the evaporator throat. When this occurs, the heat transfer process is stalled and may not re-stabilize to effective levels without corrective control actions. The flooding limit in earth's gravity environment is well understood as experimentation is readily accessible, but when the environment and gravity change relative to other planetary bodies, experimentation becomes difficult. An innovative experiment was designed and flown on a parabolic flight campaign to achieve the Reduced Gravity Environments (RGE) needed to obtain empirical data for analysis. The test data is compared to current correlation models for validation and accuracy.

Chiral gravity, log gravity, and extremal CFT

International Nuclear Information System (INIS)

Maloney, Alexander; Song Wei; Strominger, Andrew

2010-01-01

We show that the linearization of all exact solutions of classical chiral gravity around the AdS 3 vacuum have positive energy. Nonchiral and negative-energy solutions of the linearized equations are infrared divergent at second order, and so are removed from the spectrum. In other words, chirality is confined and the equations of motion have linearization instabilities. We prove that the only stationary, axially symmetric solutions of chiral gravity are BTZ black holes, which have positive energy. It is further shown that classical log gravity--the theory with logarithmically relaxed boundary conditions--has finite asymptotic symmetry generators but is not chiral and hence may be dual at the quantum level to a logarithmic conformal field theories (CFT). Moreover we show that log gravity contains chiral gravity within it as a decoupled charge superselection sector. We formally evaluate the Euclidean sum over geometries of chiral gravity and show that it gives precisely the holomorphic extremal CFT partition function. The modular invariance and integrality of the expansion coefficients of this partition function are consistent with the existence of an exact quantum theory of chiral gravity. We argue that the problem of quantizing chiral gravity is the holographic dual of the problem of constructing an extremal CFT, while quantizing log gravity is dual to the problem of constructing a logarithmic extremal CFT.

The DNSC08GRA global marine gravity field from double retracked satellite altimetry

DEFF Research Database (Denmark)

Andersen, Ole Baltazar; Knudsen, Per; Berry, P.A.M.

2010-01-01

Satellite radar altimetry has been monitoring the earth's oceans from space for several decades. However, only the GEOSAT and ERS-1 geodetic mission data recorded more than a decade ago provide altimetry with adequate spatial coverage to derive a high-resolution marine gravity field. The original...

Sisters Hope - the exposed self

DEFF Research Database (Denmark)

Lawaetz, Anna; Hallberg, Gry Worre

Sisters Hope is an art-educational method and a practice-led research tool, rooted in the construction of a fictional parallel universe revolving around the twin sisters Coco and Coca Pebber. Our work is rooted in the ambition to democratize the aesthetic dimension through ‘affective engineering......’ and the establishment of fictional spaces outside the institutional art context. In the Unfolding Academia-context Sisters Hope investigates new forms of research and (re)presentation through the creation of interactive and affective learning-spaces. At Collective Futures Sisters Hope explored questions such as: How...

Speeding up N-body simulations of modified gravity: chameleon screening models

Science.gov (United States)

Bose, Sownak; Li, Baojiu; Barreira, Alexandre; He, Jian-hua; Hellwing, Wojciech A.; Koyama, Kazuya; Llinares, Claudio; Zhao, Gong-Bo

2017-02-01

We describe and demonstrate the potential of a new and very efficient method for simulating certain classes of modified gravity theories, such as the widely studied f(R) gravity models. High resolution simulations for such models are currently very slow due to the highly nonlinear partial differential equation that needs to be solved exactly to predict the modified gravitational force. This nonlinearity is partly inherent, but is also exacerbated by the specific numerical algorithm used, which employs a variable redefinition to prevent numerical instabilities. The standard Newton-Gauss-Seidel iterative method used to tackle this problem has a poor convergence rate. Our new method not only avoids this, but also allows the discretised equation to be written in a form that is analytically solvable. We show that this new method greatly improves the performance and efficiency of f(R) simulations. For example, a test simulation with 5123 particles in a box of size 512 Mpc/h is now 5 times faster than before, while a Millennium-resolution simulation for f(R) gravity is estimated to be more than 20 times faster than with the old method. Our new implementation will be particularly useful for running very high resolution, large-sized simulations which, to date, are only possible for the standard model, and also makes it feasible to run large numbers of lower resolution simulations for covariance analyses. We hope that the method will bring us to a new era for precision cosmological tests of gravity.

Speeding up N -body simulations of modified gravity: chameleon screening models

International Nuclear Information System (INIS)

Bose, Sownak; Li, Baojiu; He, Jian-hua; Llinares, Claudio; Barreira, Alexandre; Hellwing, Wojciech A.; Koyama, Kazuya; Zhao, Gong-Bo

2017-01-01

We describe and demonstrate the potential of a new and very efficient method for simulating certain classes of modified gravity theories, such as the widely studied f ( R ) gravity models. High resolution simulations for such models are currently very slow due to the highly nonlinear partial differential equation that needs to be solved exactly to predict the modified gravitational force. This nonlinearity is partly inherent, but is also exacerbated by the specific numerical algorithm used, which employs a variable redefinition to prevent numerical instabilities. The standard Newton-Gauss-Seidel iterative method used to tackle this problem has a poor convergence rate. Our new method not only avoids this, but also allows the discretised equation to be written in a form that is analytically solvable. We show that this new method greatly improves the performance and efficiency of f ( R ) simulations. For example, a test simulation with 512 3 particles in a box of size 512 Mpc/ h is now 5 times faster than before, while a Millennium-resolution simulation for f ( R ) gravity is estimated to be more than 20 times faster than with the old method. Our new implementation will be particularly useful for running very high resolution, large-sized simulations which, to date, are only possible for the standard model, and also makes it feasible to run large numbers of lower resolution simulations for covariance analyses. We hope that the method will bring us to a new era for precision cosmological tests of gravity.

Speeding up N -body simulations of modified gravity: chameleon screening models

Energy Technology Data Exchange (ETDEWEB)

Bose, Sownak; Li, Baojiu; He, Jian-hua; Llinares, Claudio [Institute for Computational Cosmology, Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Barreira, Alexandre [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching (Germany); Hellwing, Wojciech A.; Koyama, Kazuya [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth PO1 3FX (United Kingdom); Zhao, Gong-Bo, E-mail: sownak.bose@durham.ac.uk, E-mail: baojiu.li@durham.ac.uk, E-mail: barreira@mpa-garching.mpg.de, E-mail: jianhua.he@durham.ac.uk, E-mail: wojciech.hellwing@port.ac.uk, E-mail: kazuya.koyama@port.ac.uk, E-mail: claudio.llinares@durham.ac.uk, E-mail: gbzhao@nao.cas.cn [National Astronomy Observatories, Chinese Academy of Science, Beijing, 100012 (China)

2017-02-01

We describe and demonstrate the potential of a new and very efficient method for simulating certain classes of modified gravity theories, such as the widely studied f ( R ) gravity models. High resolution simulations for such models are currently very slow due to the highly nonlinear partial differential equation that needs to be solved exactly to predict the modified gravitational force. This nonlinearity is partly inherent, but is also exacerbated by the specific numerical algorithm used, which employs a variable redefinition to prevent numerical instabilities. The standard Newton-Gauss-Seidel iterative method used to tackle this problem has a poor convergence rate. Our new method not only avoids this, but also allows the discretised equation to be written in a form that is analytically solvable. We show that this new method greatly improves the performance and efficiency of f ( R ) simulations. For example, a test simulation with 512{sup 3} particles in a box of size 512 Mpc/ h is now 5 times faster than before, while a Millennium-resolution simulation for f ( R ) gravity is estimated to be more than 20 times faster than with the old method. Our new implementation will be particularly useful for running very high resolution, large-sized simulations which, to date, are only possible for the standard model, and also makes it feasible to run large numbers of lower resolution simulations for covariance analyses. We hope that the method will bring us to a new era for precision cosmological tests of gravity.

Assessing GOCE Gravity Models using Altimetry and Drifters

DEFF Research Database (Denmark)

Knudsen, Per; Andersen, Ole Baltazar

The improved gravity models provided by the GOCE mission have enhanced the resolution and sharpened the boundaries of those features and the associated geostrophic surface currents reveal improvements for all of the ocean’s current systems. There are still important signals to be recovered...... and issues related to errors in the models have been identified.In this study, a series of newer gravity models including observations from GRACE and GOCE are compared with the DTU15MSS mean sea surface to analyse resolution capacities and to identify issues caused by errors in the models. The comparisons...... are carried out in regional analyses using Fourier techniques to derive the spectral characteristics as well as anisotropic patterns to identify differences and to quantify quality measures associated with the models. In addition, regional analyses are carried out using in-situ observations of the geostrophic...

Signature of Europa's Ocean Density on Gravity Data

Science.gov (United States)

Castillo, J. C.; Rambaux, N.

2015-12-01

Observations by the Galileo mission at Europa and Cassini-Huygens mission at Europa, Ganymede, Callisto, Enceladus, and Titan have found deep oceans at these objects with evidence for the presence of salts. Salt compounds are the products of aqueous alteration of the rock phase under hydrothermal conditions and have been predicted theoretically for these objects per analogy with carbonaceous chondrite parent bodies. Evidence for salt enrichment comes from magnetometer measurements (Galilean satellites), direct detection in the case of Enceladus, and inversion of the gravity data obtained at Titan. While there is direct detection for the presence of chlorides in icy grains ejected from Enceladus, the chemistry of the oceans detected so far, or even their densities, remain mostly unconstrained. However the increased ocean density impacts the interpretation of the tidal Love number k2and this may introduce confusion in the inference of the icy shell thickness from that parameter. We will present estimates of k2for a range of assumptions on Europa's hydrospheric structure that build on geophysical observations obtained by the Galileo mission combined with new models of Europa's interior. These models keep track of the compositions of the hydrated core and oceanic composition in a self-consistent manner. We will also estimate the electrical conductivity corresponding to the modeled oceanic composition. Finally we will explore how combining electromagnetic, topographic, and gravity data can decouple the signatures of the shell thickness and ocean composition on these geophysical observations. Acknowledgement: This work is being carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract to NASA. Government sponsorship acknowledged.

Low-gravity homogenization and solidification of aluminum antimonide. [Apollo-Soyuz test project

Science.gov (United States)

Ang, C.-Y.; Lacy, L. L.

1976-01-01

The III-V semiconducting compound AlSb shows promise as a highly efficient solar cell material, but it has not been commercially exploited because of difficulties in compound synthesis. Liquid state homogenization and solidification of AlSb were carried out in the Apollo-Soyuz Test Project Experiment MA-044 in the hope that compositional homogeneity would be improved by negating the large density difference between the two constituents. Post-flight analysis and comparative characterization of the space-processed and ground-processed samples indicate that there are major homogeneity improvements in the low-gravity solidified material.

Time-Variable Gravity from Space: Quarter Century of Observations, Mysteries, and Prospects

Science.gov (United States)

Chao, Benjamin F.; Boy, John-Paul

2003-01-01

Any large mass transport in the Earth system produces changes in the gravity field. Via the space geodetic technique of satellite-laser ranging in the last quarter century, the Earth's dynamic oblateness J2 (the lowest-degree harmonic component of the gravity field) has been observed to undergo a slight decrease -- until around 1998, when it switched quite suddenly to an increase trend which has continued to 2001 before sharply turning back to the value which it is "supposed to be"!. The secular decrease in J2 has long been attributed primarily to the post-glacial rebound in the mantle; the present increase signifies an even larger change in global mass distribution whose J2 effect overshadows that of the post-glacial rebound, at least over interannual timescales. Intriguing evidences have been found in the ocean water distribution, especially in the extratropical Pacific basins, that may be responsible for this J2 change. New techniques based on satellite-to-satellite tracking will yield greatly improved observations for time-variable gravity, with much higher precision and spatial resolution (i.e., much higher harmonic degrees). The most important example is the GRACE mission launched in March 2002, following the success of the CHAMP mission. Such observations are becoming a new and powerful tool for remote sensing of geophysical fluid processes that involve larger-scale mass transports.

Development of new experimental platform 'MARS'-Multiple Artificial-gravity Research System-to elucidate the impacts of micro/partial gravity on mice.

Science.gov (United States)

Shiba, Dai; Mizuno, Hiroyasu; Yumoto, Akane; Shimomura, Michihiko; Kobayashi, Hiroe; Morita, Hironobu; Shimbo, Miki; Hamada, Michito; Kudo, Takashi; Shinohara, Masahiro; Asahara, Hiroshi; Shirakawa, Masaki; Takahashi, Satoru

2017-09-07

This Japan Aerospace Exploration Agency project focused on elucidating the impacts of partial gravity (partial g) and microgravity (μg) on mice using newly developed mouse habitat cage units (HCU) that can be installed in the Centrifuge-equipped Biological Experiment Facility in the International Space Station. In the first mission, 12 C57BL/6 J male mice were housed under μg or artificial earth-gravity (1 g). Mouse activity was monitored daily via downlinked videos; μg mice floated inside the HCU, whereas artificial 1 g mice were on their feet on the floor. After 35 days of habitation, all mice were returned to the Earth and processed. Significant decreases were evident in femur bone density and the soleus/gastrocnemius muscle weights of μg mice, whereas artificial 1 g mice maintained the same bone density and muscle weight as mice in the ground control experiment, in which housing conditions in the flight experiment were replicated. These data indicate that these changes were particularly because of gravity. They also present the first evidence that the addition of gravity can prevent decreases in bone density and muscle mass, and that the new platform 'MARS' may provide novel insights on the molecular-mechanisms regulating biological processes controlled by partial g/μg.

NASA Laboratory Analysis for Manned Exploration Missions

Science.gov (United States)

Krihak, Michael K.; Shaw, Tianna E.

2014-01-01

The Exploration Laboratory Analysis (ELA) project supports the Exploration Medical Capability Element under the NASA Human Research Program. ELA instrumentation is identified as an essential capability for future exploration missions to diagnose and treat evidence-based medical conditions. However, mission architecture limits the medical equipment, consumables, and procedures that will be available to treat medical conditions during human exploration missions. Allocated resources such as mass, power, volume, and crew time must be used efficiently to optimize the delivery of in-flight medical care. Although commercial instruments can provide the blood and urine based measurements required for exploration missions, these commercial-off-the-shelf devices are prohibitive for deployment in the space environment. The objective of the ELA project is to close the technology gap of current minimally invasive laboratory capabilities and analytical measurements in a manner that the mission architecture constraints impose on exploration missions. Besides micro gravity and radiation tolerances, other principal issues that generally fail to meet NASA requirements include excessive mass, volume, power and consumables, and nominal reagent shelf-life. Though manned exploration missions will not occur for nearly a decade, NASA has already taken strides towards meeting the development of ELA medical diagnostics by developing mission requirements and concepts of operations that are coupled with strategic investments and partnerships towards meeting these challenges. This paper focuses on the remote environment, its challenges, biomedical diagnostics requirements and candidate technologies that may lead to successful blood-urine chemistry and biomolecular measurements in future space exploration missions.

A Least Squares Collocation Approach with GOCE gravity gradients for regional Moho-estimation

Science.gov (United States)

Rieser, Daniel; Mayer-Guerr, Torsten

2014-05-01

The depth of the Moho discontinuity is commonly derived by either seismic observations, gravity measurements or combinations of both. In this study, we aim to use the gravity gradient measurements of the GOCE satellite mission in a Least Squares Collocation (LSC) approach for the estimation of the Moho depth on regional scale. Due to its mission configuration and measurement setup, GOCE is able to contribute valuable information in particular in the medium wavelengths of the gravity field spectrum, which is also of special interest for the crust-mantle boundary. In contrast to other studies we use the full information of the gradient tensor in all three dimensions. The problem outline is formulated as isostatically compensated topography according to the Airy-Heiskanen model. By using a topography model in spherical harmonics representation the topographic influences can be reduced from the gradient observations. Under the assumption of constant mantle and crustal densities, surface densities are directly derived by LSC on regional scale, which in turn are converted in Moho depths. First investigations proofed the ability of this method to resolve the gravity inversion problem already with a small amount of GOCE data and comparisons with other seismic and gravitmetric Moho models for the European region show promising results. With the recently reprocessed GOCE gradients, an improved data set shall be used for the derivation of the Moho depth. In this contribution the processing strategy will be introduced and the most recent developments and results using the currently available GOCE data shall be presented.

Development and preliminary testing of the Schizophrenia Hope Scale, a brief scale to measure hope in people with schizophrenia.

Science.gov (United States)

Choe, Kwisoon

2014-06-01

Hope has received attention as a central component of recovery from mental illness; however, most instruments measuring hope were developed outside the mental health field. To measure the effects of mental health programs on hope in people with schizophrenia, a specialized scale is needed. This study examined the psychometric properties of the newly developed 9-item Schizophrenia Hope Scale (SHS-9) designed to measure hope in individuals with schizophrenia. A descriptive survey design. Participants were recruited from three psychiatric hospitals and two community mental health centers in South Korea. A total of 347 individuals over age 18 with a DSM-IV diagnosis of schizophrenia, schizoaffective, or schizophrenia spectrum disorders (competent to provide written informed consent) participated in this study; 149 (94 men, 55 women) completed a preliminary scale consisting of 40 revised items, and 198 (110 men, 88 women) completed the second scale of 17 items. Scale items were first selected from extensive literature reviews and a qualitative study on hope in people with schizophrenia; the validity and reliability of a preliminary scale was then evaluated by an expert panel and exploratory factor analysis. The remaining 9 items forming the Schizophrenia Hope Scale (SHS-9) were evaluated through confirmatory factor analysis. The SHS-9 demonstrates promising psychometric integrity. The internal consistency alpha coefficient was 0.92 with a score range of 0-18 and a mean total score of 12.06 (SD=4.96), with higher scores indicating higher levels of hope. Convergent validity was established by correlating the SHS-9 to the State-Trait Hope Inventory, r=0.61 (phope accounting for 61.77% of the total item variance. As hope has been shown to facilitate recovery from mental illness, the accurate assessment of hope provided by the short, easy-to-use Schizophrenia Hope Scale (SHS-9) may aid clinicians in improving the quality of life of individuals with schizophrenia. Copyright �

Ocular Blood Flow Measured Noninvasively in Zero Gravity

Science.gov (United States)

Ansari, Rafat R.; Manuel, Francis K.; Geiser, Martial; Moret, Fabrice; Messer, Russell K.; King, James F.; Suh, Kwang I.

2003-01-01

In spaceflight or a reduced-gravity environment, bodily fluids shift to the upper extremities of the body. The pressure inside the eye, or intraocular pressure, changes significantly. A significant number of astronauts report changes in visual acuity during orbital flight. To date this remains of unknown etiology. Could choroidal engorgement be the primary mechanism and a change in the curvature or shape of the cornea or lens be the secondary mechanism for this change in visual acuity? Perfused blood flow in the dense meshwork of capillaries of the choroidal tissue (see the preceding illustration) provides necessary nutrients to the outer layers of the retina (photoreceptors) to keep it healthy and maintain good vision. Unlike the vascular system, the choroid has no baroreceptors to autoregulate fluid shifts, so it can remain engorged, pushing the macula forward and causing a hyperopic (farsighted) shift of the eye. Experiments by researchers at the NASA Glenn Research Center could help answer this question and facilitate planning for long-duration missions. We are investigating the effects of zero gravity on the choroidal blood flow of volunteer subjects. This pilot project plans to determine if choroidal blood flow is autoregulated in a reduced-gravity environment.

Improving communication on hope in palliative care. A qualitative study of palliative care professionals' metaphors of hope: grip, source, tune, and vision

NARCIS (Netherlands)

Olsman, Erik; Duggleby, Wendy; Nekolaichuk, Cheryl; Willems, Dick; Gagnon, Judith; Kruizinga, Renske; Leget, Carlo

2014-01-01

Hope is important in palliative care. However, palliative care professionals' perspectives on hope are not well understood. Metaphors of hope are a way of better understanding these perspectives. To describe palliative care professionals' perspectives on hope by examining the hope metaphors they

Preliminary trajectory design for a solar polar observatory using SEP and multiple gravity assists

NARCIS (Netherlands)

Corpaccioli, L.; Noomen, R.; De Smet, S.; Parker, J.S.; Herman, J.F.C.

2015-01-01

Satellite solar observatories have always been of central importance to heliophysics; while there have been numerous such missions, the solar poles have been extremely under-observed. This paper proposes to use low-thrust as well as multiple gravity assists to reach the enormous energies required

HOPEFULNESS IN HOPELESSNESS: A HERMENEUTICAL ...

African Journals Online (AJOL)

Dean SPGS NAU

time at Auschwitz that people who lost all hope were the first to die. He writes: ... The future was to be one of happiness to which all men are ... The OT's hope falls short with death. .... Going back in our memory lane, one remembers when.

Change and Hope in Physics

Science.gov (United States)

Goradia, Shantilal

2009-05-01

Physics = Ideas + Analyses. Newton reconciled Kepler's laws, Einstein's GR reconciled action at a distance. Our Planck Scale Statistics (see v3 and v4 of [1]) is a change that reconciles gravity with quantum physics simply. It does what a change should do and I will answer your questions again. It completes TOE, so what? There should not be any fear about disappearance of challenges. It will create other challenges to occupy creative physicists meaningfully. Physicists score highest on GRE score with the exception of mechanical engineers. They will come up with ideas applicable to other sectors like energy and economy. Newton, also a gold mine executive, introduced annuity for life, an insurance feature of social security. Here, I try one bold suggestion to illustrate the point. Putting 10% tax on new housing permits would raise the price of each house in the USA by an average of 2 x 10^4 dollars generating a wealth of 2x10^12 dollars for existing 10^8 houses, encouraging people to stick to their houses, inviting investors to grab existing houses, discouraging new construction which goes against the sale of existing houses, and injecting two trillion dollars in the economy without creating a deficit budget. The hope is that this change would challenge other high GRE scorers to come up with additional ideas. It is imaginative minds that solve problems, not subjective knowledge. [1] http://www.arXiv.org/pdf/physics/0210040.

A Strategic Approach to Medical Care for Exploration Missions

Science.gov (United States)

Canga, Michael A.; Shah, Ronak V.; Mindock, Jennifer A.; Antonsen, Erik L.

2016-01-01

Exploration missions will present significant new challenges to crew health, including effects of variable gravity environments, limited communication with Earth-based personnel for diagnosis and consultation for medical events, limited resupply, and limited ability for crew return. Providing health care capabilities for exploration class missions will require system trades be performed to identify a minimum set of requirements and crosscutting capabilities, which can be used in design of exploration medical systems. Medical data, information, and knowledge collected during current space missions must be catalogued and put in formats that facilitate querying and analysis. These data are used to inform the medical research and development program through analysis of risk trade studies between medical care capabilities and system constraints such as mass, power, volume, and training. Medical capability as a quantifiable variable is proposed as a surrogate risk metric and explored for trade space analysis that can improve communication between the medical and engineering approaches to mission design. The resulting medical system design approach selected will inform NASA mission architecture, vehicle, and subsystem design for the next generation of spacecraft.

Modes of hoping: understanding hope and expectation in the context of a clinical trial of complementary and alternative medicine for chronic pain.

Science.gov (United States)

Eaves, Emery R; Ritenbaugh, Cheryl; Nichter, Mark; Hopkins, Allison L; Sherman, Karen J

2014-01-01

This article explores the role of hope in participants' assessments of their expectations, experiences and treatment outcomes. Data analysis focused on semi-structured, open-ended interviews with 44 participants, interviewed 3-5 times each over the course of a study evaluating Traditional Chinese Medicine (TCM) for temporomandibular disorders (TMD), a form of chronic orofacial pain. Transcripts were coded and analyzed using qualitative and ethnographic methods. A "Modes of Hoping" (Webb, 2007)(1) framework informed our analysis. Five modes of hoping emerged from participant narratives: Realistic Hope, Wishful Hope, Utopian Hope, Technoscience Hope, and Transcendent Hope. Using this framework, hope is demonstrated as exerting a profound influence over how participants assess and report their expectations. This suggests that researchers interested in measuring expectations and understanding their role in treatment outcomes should consider hope as exercising a multi-faceted and dynamic influence on participants' reporting of expectations and their experience and evaluation of treatment. Copyright © 2014 Elsevier Inc. All rights reserved.

Determining the 3D Subsurface Density Structure of Taurus Littrow Valley Using Apollo 17 Gravity Data

Science.gov (United States)

Urbancic, N.; Ghent, R.; Stanley, S,; Johnson, C. L.; Carroll, K. A.; Hatch, D.; Williamson, M. C.; Garry, W. B.; Talwani, M.

2016-01-01

Surface gravity surveys can detect subsurface density variations that can reveal subsurface geologic features. In 1972, the Apollo 17 (A17) mission conducted the Traverse Gravimeter Experiment (TGE) using a gravimeter that measured the local gravity field near Taurus Littrow Valley (TLV), located on the south-eastern rim of the Serenitatis basin. TLV is hypothesized to be a basaltfilled radial graben resulting from the impact that formed Mare Serenitatis. It is bounded by both the North and South Massifs (NM and SM) as well as other smaller mountains to the East that are thought to be mainly composed of brecciated highland material. The TGE is the first and only successful gravity survey on the surface of the Moon. Other more recent satellite surveys, such as NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission (2011- 2012), have produced the best global gravity field to date (approx. 13km resolution). However, these satellite surveys are not sensitive enough to detect fine-scale (<1km) lunar subsurface structures. This underscores the value of the data collected at the surface by A17. In the original analysis of the data a 2D forward-modelling approach was used to derive a thickness of the subsurface basalt layer of 1.0 km by assuming a simple flat-faced rectangular geometry and using densities derived from Apollo lunar samples. We are investigating whether modern 3D modelling techniques in combination with high-resolution topographical and image datasets can reveal additional fine-scale subsurface structure in TLV.

Emblem for the second manned Skylab mission, Skylab 3

Science.gov (United States)

1973-01-01

This is the emblem for the second manned Skylab mission. It will be a mission of up to 56 days. The patch symbolizes the main objectives of the flight. The central figure, adapted from one by Leonardo da Vinci, illustrates the proportions of the human form and suggests the many studies of man himself to be conducted in the zero-gravity environment of space. This drawing is superimposed on two hemispheres representing the two additional main areas of research - studies of the Sun and the development of techniques for survey of the Earth's resources. The left hemisphere show the Sun as it will be seen in the red light radiated by hydrogen atoms in the solar atmosphere. The right hemisphere is intended to suggest the studies of Earth resources to be conducted on Skylab. Although the patch denotes this mission as Skylab II, it is actually consided to be the Skylab III mission.

Phobos Environment Model and Regolith Simulant for MMX Mission

Science.gov (United States)

Miyamoto, H.; Niihara, T.; Wada, K.; Ogawa, K.; Baresi, N.; Abell, Paul A.; Asphaug, E.; Britt, D.; Dodbiba, G.; Fujita, T.;

Gravity Probe B data system description

International Nuclear Information System (INIS)

Bennett, Norman R

2015-01-01

The Gravity Probe B data system, developed, integrated, and tested by Lockheed Missiles and Space Company, and later Lockheed Martin Corporation, included flight and ground command, control, and communications software. The development was greatly facilitated, conceptually and by the transfer of key personnel, through Lockheed’s earlier flight and ground test software development for the Hubble Space Telescope (HST). Key design challenges included the tight mission timeline (17 months, 9 days of on-orbit operation), the need to tune the system once on-orbit, and limited 2 Kbps real-time data rates and ground asset availability. The result was a completely integrated space vehicle and Stanford mission operations center, which successfully collected and archived 97% of the ‘guide star valid’ data to support the science analysis. Lessons learned and incorporated from the HST flight software development and on-orbit support experience, and Lockheed’s independent research and development effort, will be discussed. (paper)

Gravity Field Parameter Estimation Using QR Factorization

Science.gov (United States)

Klokocnik, J.; Wagner, C. A.; McAdoo, D.; Kostelecky, J.; Bezdek, A.; Novak, P.; Gruber, C.; Marty, J.; Bruinsma, S. L.; Gratton, S.; Balmino, G.; Baboulin, M.

2007-12-01

This study compares the accuracy of the estimated geopotential coefficients when QR factorization is used instead of the classical method applied at our institute, namely the generation of normal equations that are solved by means of Cholesky decomposition. The objective is to evaluate the gain in numerical precision, which is obtained at considerable extra cost in terms of computer resources. Therefore, a significant increase in precision must be realized in order to justify the additional cost. Numerical simulations were done in order to examine the performance of both solution methods. Reference gravity gradients were simulated, using the EIGEN-GL04C gravity field model to degree and order 300, every 3 seconds along a near-circular, polar orbit at 250 km altitude. The simulation spanned a total of 60 days. A polar orbit was selected in this simulation in order to avoid the 'polar gap' problem, which causes inaccurate estimation of the low-order spherical harmonic coefficients. Regularization is required in that case (e.g., the GOCE mission), which is not the subject of the present study. The simulated gravity gradients, to which white noise was added, were then processed with the GINS software package, applying EIGEN-CG03 as the background gravity field model, followed either by the usual normal equation computation or using the QR approach for incremental linear least squares. The accuracy assessment of the gravity field recovery consists in computing the median error degree-variance spectra, accumulated geoid errors, geoid errors due to individual coefficients, and geoid errors calculated on a global grid. The performance, in terms of memory usage, required disk space, and CPU time, of the QR versus the normal equation approach is also evaluated.

Cura animarum as hope care: Towards a theology of the resurrection within the human quest for meaning and hope

Directory of Open Access Journals (Sweden)

Daniel J. Louw

2014-04-01

Full Text Available The following critical questions are posed: is hope the antidote of dread and despair or a kind of escapism from the harsh realities of anguish and suffering? What is meant by hope in Christian spirituality and how is hope connected to a theology of the resurrection? Is resurrection hope merely a kind of cheap triumphantalism and variant of a theologia gloriae? The basic assumption is that the notion of the resurrection can contribute to ‘the thickening of alternative stories of faith’. A theologia resurrectionis is about the reframing of life by means of a radical paradox: ‘Where, O death is your victory? Where, O death is your sting?’ If pastoral caregiving is indeed about change and hope, the resurrection describes an ontology of hope by which human beings are transformed into a total new being. Beyond the discriminating and stigmatising categories of many social and cultural discourses on our being human, resurrection theology defines hope as a new state of mind and being. The identity of human beings is therefore not determined by descent, gender, race or social status, but by eschatology (new creation. Hope care is primarily about a new courage to be. It opens up different frameworks for meaningful living within the realm of human suffering.

Exploring the martian moons a human mission to Deimos and Phobos

CERN Document Server

von Ehrenfried, Manfred “Dutch”

2017-01-01

This book explores the once popular idea of 'Flexible Path' in terms of Mars, a strategy that would focus on a manned orbital mission to Mars's moons rather than the more risky, expensive and time-consuming trip to land humans on the Martian surface. While currently still not the most popular idea, this mission would take advantage of the operational, scientific and engineering lessons to be learned from going to Mars's moons first. Unlike a trip to the planet's surface, an orbital mission avoids the dangers of the deep gravity well of Mars and a very long stay on the surface. This is analogous to Apollo 8 and 10, which preceded the landing on the Moon of Apollo 11. Furthermore, a Mars orbital mission could be achieved at least five years, possibly 10 before a landing mission. Nor would an orbital mission require all of the extra vehicles, equipment and supplies needed for a landing and a stay on the planet for over a year. The cost difference between the two types of missions is in the order of tens of billi...

Hope, Life, and Death: A Qualitative Analysis of Dying Cancer Patients' Talk about Hope

Science.gov (United States)

Eliott, Jaklin A.; Olver, Ian N.

2009-01-01

Although deemed vital to patient well-being, hope in persons who are terminally ill is often thought to be problematic, particularly when centered on cure. As part of a study on end-of-life decision-making, we asked 28 patients with cancer, believed to be within weeks of their death, to talk about hope. Responses were transcribed and discursively…

Medical and technology requirements for human solar system exploration missions

Science.gov (United States)

Nicogossian, Arnauld; Harris, Leonard; Couch, Lana; Sulzman, Frank; Gaiser, Karen

1989-01-01

Measures that need to be taken to cope with the health problems posed by zero gravity and radiation in manned solar system exploration missions are discussed. The particular systems that will be used aboard Space Station Freedom are addressed, and relevant human factors problems are examined. The development of a controlled ecological life support system is addressed.

Measuring hope among families impacted by cognitive impairment.

Science.gov (United States)

Hunsaker, Amanda E; Terhorst, Lauren; Gentry, Amanda; Lingler, Jennifer H

2016-07-01

The current exploratory investigation aims to establish the reliability and validity of a hope measure, the Herth Hope Index, among families impacted by early cognitive impairment (N = 96). Exploratory factor analysis was used to examine the dimensionality of the measure. Bivariate analyses were used to examine construct validity. The sample had moderately high hope scores. A two-factor structure emerged from the factor analysis, explaining 51.44% of the variance. Both factors exhibited strong internal consistency (Cronbach's alphas ranged from .83 to .86). Satisfaction with social support was positively associated with hope, supporting convergent validity. Neurocognitive status, illness insight, and depression were not associated with hope, indicating discriminant validity. Families impacted by cognitive impairment may maintain hope in the face of a potentially progressive illness, regardless of cognitive status. The Herth Hope Index can be utilized as a reliable and valid measure of hope by practitioners providing support to families impacted by cognitive impairment. © The Author(s) 2014.

On the Inversion for Mass (Re)Distribution from Global (Time-Variable) Gravity Field

Science.gov (United States)

Chao, Benjamin F.

2004-01-01

The well-known non-uniqueness of the gravitational inverse problem states the following: The external gravity field, even if completely and exactly known, cannot Uniquely determine the density distribution of the body that produces the gravity field. This is an intrinsic property of a field that obeys the Laplace equation, as already treated in mathematical as well as geophysical literature. In this paper we provide conceptual insight by examining the problem in terms of spherical harmonic expansion of the global gravity field. By comparing the multipoles and the moments of the density function, we show that in 3-S the degree of knowledge deficiency in trying to inversely recover the density distribution from external gravity field is (n+l)(n+2)/2 - (2n+l) = n(n-1)/2 for each harmonic degree n. On the other hand, on a 2-D spherical shell we show via a simple relationship that the inverse solution of the surface density distribution is unique. The latter applies quite readily in the inversion of time-variable gravity signals (such as those observed by the GRACE space mission) where the sources over a wide range of the scales largely come from the Earth's Surface.

The Armour of Hope and other works

Directory of Open Access Journals (Sweden)

Kate Just

2013-01-01

Full Text Available The series of work entitled 'The Skin of Hope' was produced during a 2012 Australia Council for the Arts studio residency in Barcelona, where I was accompanied by my partner Paula and our adopted daughter, Hope. Blurring the usual divide between familial life and art practice, the residency inspired a series of hand knitted sculptures and photographs weaving an account of the ways that Hope and I acknowledge, bond and imprint each other at skin level. Materialising our past wounds and present, tactile connections, the works include a hanging, child-sized, knitted suit of armour for Hope and a reversible pair of knitted arm-length gloves for me, scar-embroidered with surgical stitches and the words HOPE and MOTHER. Through the slow crafting of the works, and the photographs of us wearing the garments, I reflected on Hope's and my own resilience, repair and capacity to love. In a photographic work featuring Hope's text and drawing of herself on my naked back, I further framed skin as both a receptive and transmissive space, bearing witness to our most intimate moments.

New vision solar system exploration missions study: Analysis of the use of biomodal space nuclear power systems to support outer solar system exploration missions. Final report

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-12-08

This report presents the results of an analysis of the capability of nuclear bimodal systems to perform outer solar system exploration missions. Missions of interest include orbiter mission s to Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. An initial technology baseline consisting of a NEBA 10 kWe, 1000 N thrust, 850 s, 1500 kg bimodal system was selected, and its performance examined against a data base for trajectories to outer solar system planetary destinations to select optimal direct and gravity assisted trajectories for study. A conceptual design for a common bimodal spacecraft capable of performing missions to all the planetary destinations was developed and made the basis of end to end mission designs for orbiter missions to Jupiter, Saturn, and Neptune. Concepts for microspacecraft capable of probing Jupiter`s atmosphere and exploring Titan were also developed. All mission designs considered use the Atlas 2AS for launch. It is shown that the bimodal nuclear power and propulsion system offers many attractive option for planetary missions, including both conventional planetary missions in which all instruments are carried by a single primary orbiting spacecraft, and unconventional missions in which the primary spacecraft acts as a carrier, relay, and mother ship for a fleet of micro spacecraft deployed at the planetary destination.

Expected Recovery of Europa's Geophysical Attributes with Clipper Gravity Science Investigation

Science.gov (United States)

Verma, Ashok Kumar; Margot, Jean-Luc

2017-10-01

The primary gravity science objective of NASA’s Clipper mission to Europa is to confirm the presence or absence of a global subsurface ocean beneath Europa's icy crust. Gravity field measurements obtained with a radio science investigation can reveal much about Europa's interior structure. Here, we conduct extensive simulations of the radio science measurements with the anticipated spacecraft trajectory and attitude (17F12V2) and assets on the spacecraft and the ground, including antenna orientations and beam patterns, transmitter characteristics, and receiver noise figures. In addition to two-way Doppler measurements, we also include radar altimeter crossover range measurements. We concentrate on +/-2 hour intervals centered on the closest approach of each one of the 46 flybys. Our covariance analyses reveal the precision with which the tidal Love number k2, second-degree gravity coefficients C20 and C22, and higher-order gravity coefficients can be determined. The results depend strongly on the Deep Space Network (DSN) assets that are deployed to track the spacecraft. We find that some DSN allocations are sufficient to conclusively confirm the presence or absence of a global ocean and to evaluate whether the ice shell is hydrostatic.

Feeling hopeful inspires support for social change

NARCIS (Netherlands)

Greenaway, Katharine H.; Cichocka, Aleksandra; van Veelen, Ruth; Likki, Tiina; Branscombe, Nyla R.

2014-01-01

Hope is an emotion that has been implicated in social change efforts, yet little research has examined whether feeling hopeful actually motivates support for social change. Study 1 (N = 274) confirmed that hope is associated with greater support for social change in two countries with different

Ancient igneous intrusions and early expansion of the Moon revealed by GRAIL gravity gradiometry.

Science.gov (United States)

Andrews-Hanna, Jeffrey C; Asmar, Sami W; Head, James W; Kiefer, Walter S; Konopliv, Alexander S; Lemoine, Frank G; Matsuyama, Isamu; Mazarico, Erwan; McGovern, Patrick J; Melosh, H Jay; Neumann, Gregory A; Nimmo, Francis; Phillips, Roger J; Smith, David E; Solomon, Sean C; Taylor, G Jeffrey; Wieczorek, Mark A; Williams, James G; Zuber, Maria T

2013-02-08

The earliest history of the Moon is poorly preserved in the surface geologic record due to the high flux of impactors, but aspects of that history may be preserved in subsurface structures. Application of gravity gradiometry to observations by the Gravity Recovery and Interior Laboratory (GRAIL) mission results in the identification of a population of linear gravity anomalies with lengths of hundreds of kilometers. Inversion of the gravity anomalies indicates elongated positive-density anomalies that are interpreted to be ancient vertical tabular intrusions or dikes formed by magmatism in combination with extension of the lithosphere. Crosscutting relationships support a pre-Nectarian to Nectarian age, preceding the end of the heavy bombardment of the Moon. The distribution, orientation, and dimensions of the intrusions indicate a globally isotropic extensional stress state arising from an increase in the Moon's radius by 0.6 to 4.9 kilometers early in lunar history, consistent with predictions of thermal models.

HOPE udveksling i Europa

DEFF Research Database (Denmark)

Pedersen, Ulla

1996-01-01

En artikel om deltagelse i HOPE (Hospital Professional Exchange) - 6 ugers studiebesøg på et hospital i udlandet. Ulla Pedersen fortæller om 6 uger med fokus på rehabilitering i det hollandske sundhedsvæsen.......En artikel om deltagelse i HOPE (Hospital Professional Exchange) - 6 ugers studiebesøg på et hospital i udlandet. Ulla Pedersen fortæller om 6 uger med fokus på rehabilitering i det hollandske sundhedsvæsen....

Gravity Maps of Antarctic Lithospheric Structure from Remote-Sensing and Seismic Data

Science.gov (United States)

Tenzer, Robert; Chen, Wenjin; Baranov, Alexey; Bagherbandi, Mohammad

2018-02-01

Remote-sensing data from altimetry and gravity satellite missions combined with seismic information have been used to investigate the Earth's interior, particularly focusing on the lithospheric structure. In this study, we use the subglacial bedrock relief BEDMAP2, the global gravitational model GOCO05S, and the ETOPO1 topographic/bathymetric data, together with a newly developed (continental-scale) seismic crustal model for Antarctica to compile the free-air, Bouguer, and mantle gravity maps over this continent and surrounding oceanic areas. We then use these gravity maps to interpret the Antarctic crustal and uppermost mantle structure. We demonstrate that most of the gravity features seen in gravity maps could be explained by known lithospheric structures. The Bouguer gravity map reveals a contrast between the oceanic and continental crust which marks the extension of the Antarctic continental margins. The isostatic signature in this gravity map confirms deep and compact orogenic roots under the Gamburtsev Subglacial Mountains and more complex orogenic structures under Dronning Maud Land in East Antarctica. Whereas the Bouguer gravity map exhibits features which are closely spatially correlated with the crustal thickness, the mantle gravity map reveals mainly the gravitational signature of the uppermost mantle, which is superposed over a weaker (long-wavelength) signature of density heterogeneities distributed deeper in the mantle. In contrast to a relatively complex and segmented uppermost mantle structure of West Antarctica, the mantle gravity map confirmed a more uniform structure of the East Antarctic Craton. The most pronounced features in this gravity map are divergent tectonic margins along mid-oceanic ridges and continental rifts. Gravity lows at these locations indicate that a broad region of the West Antarctic Rift System continuously extends between the Atlantic-Indian and Pacific-Antarctic mid-oceanic ridges and it is possibly formed by two major

Even-dimensional topological gravity from Chern-Simons gravity

International Nuclear Information System (INIS)

Merino, N.; Perez, A.; Salgado, P.

2009-01-01

It is shown that the topological action for gravity in 2n-dimensions can be obtained from the (2n+1)-dimensional Chern-Simons gravity genuinely invariant under the Poincare group. The 2n-dimensional topological gravity is described by the dynamics of the boundary of a (2n+1)-dimensional Chern-Simons gravity theory with suitable boundary conditions. The field φ a , which is necessary to construct this type of topological gravity in even dimensions, is identified with the coset field associated with the non-linear realizations of the Poincare group ISO(d-1,1).

Time-variable gravity fields and ocean mass change from 37 months of kinematic Swarm orbits

Science.gov (United States)

Lück, Christina; Kusche, Jürgen; Rietbroek, Roelof; Löcher, Anno

2018-03-01

Measuring the spatiotemporal variation of ocean mass allows for partitioning of volumetric sea level change, sampled by radar altimeters, into mass-driven and steric parts. The latter is related to ocean heat change and the current Earth's energy imbalance. Since 2002, the Gravity Recovery and Climate Experiment (GRACE) mission has provided monthly snapshots of the Earth's time-variable gravity field, from which one can derive ocean mass variability. However, GRACE has reached the end of its lifetime with data degradation and several gaps occurred during the last years, and there will be a prolonged gap until the launch of the follow-on mission GRACE-FO. Therefore, efforts focus on generating a long and consistent ocean mass time series by analyzing kinematic orbits from other low-flying satellites, i.e. extending the GRACE time series. Here we utilize data from the European Space Agency's (ESA) Swarm Earth Explorer satellites to derive and investigate ocean mass variations. For this aim, we use the integral equation approach with short arcs (Mayer-Gürr, 2006) to compute more than 500 time-variable gravity fields with different parameterizations from kinematic orbits. We investigate the potential to bridge the gap between the GRACE and the GRACE-FO mission and to substitute missing monthly solutions with Swarm results of significantly lower resolution. Our monthly Swarm solutions have a root mean square error (RMSE) of 4.0 mm with respect to GRACE, whereas directly estimating constant, trend, annual, and semiannual (CTAS) signal terms leads to an RMSE of only 1.7 mm. Concerning monthly gaps, our CTAS Swarm solution appears better than interpolating existing GRACE data in 13.5 % of all cases, when artificially removing one solution. In the case of an 18-month artificial gap, 80.0 % of all CTAS Swarm solutions were found closer to the observed GRACE data compared to interpolated GRACE data. Furthermore, we show that precise modeling of non-gravitational forces

The Gravity Field of Mercury After the Messenger Low-Altitude Campaign

Science.gov (United States)

Mazarico, Erwan; Genova, Antonio; Goossens, Sander; Lemoine, Frank G.; Smith, David E.; Zuber, Maria T.; Neumann, Gary A.; Solomon, Sean C.

2015-01-01

The final year of the MESSENGER mission was designed to take advantage of the remaining propellant onboard to provide a series of lowaltitude observation campaigns and acquire novel scientific data about the innermost planet. The lower periapsis altitude greatly enhances the sensitivity to the short-wavelength gravity field, but only when the spacecraft is in view of Earth. After more than 3 years in orbit around Mercury, the MESSENGER spacecraft was tracked for the first time below 200-km altitude on 5 May 2014 by the NASA Deep Space Network (DSN). Between August and October, periapsis passages down to 25-km altitude were routinely tracked. These periods considerably improved the quality of the data coverage. Before the end of its mission, MESSENGER will fly at very low altitudes for extended periods of time. Given the orbital geometry, however the periapses will not be visible from Earth and so no new tracking data will be available for altitudes lower than 75 km. Nevertheless, the continuous tracking of MESSENGER in the northern hemisphere will help improve the uniformity of the spatial coverage at altitudes lower than 150 km, which will further improve the overall quality of the Mercury gravity field.

OMV mission simulator

Science.gov (United States)

Cok, Keith E.

1989-01-01

The Orbital Maneuvering Vehicle (OMV) will be remotely piloted during rendezvous, docking, or proximity operations with target spacecraft from a ground control console (GCC). The real-time mission simulator and graphics being used to design a console pilot-machine interface are discussed. A real-time orbital dynamics simulator drives the visual displays. The dynamics simulator includes a J2 oblate earth gravity model and a generalized 1962 rotating atmospheric and drag model. The simulator also provides a variable-length communication delay to represent use of the Tracking and Data Relay Satellite System (TDRSS) and NASA Communications (NASCOM). Input parameter files determine the graphics display. This feature allows rapid prototyping since displays can be easily modified from pilot recommendations. A series of pilot reviews are being held to determine an effective pilot-machine interface. Pilots fly missions with nominal to 3-sigma dispersions in translational or rotational axes. Console dimensions, switch type and layout, hand controllers, and graphic interfaces are evaluated by the pilots and the GCC simulator is modified for subsequent runs. Initial results indicate a pilot preference for analog versus digital displays and for two 3-degree-of-freedom hand controllers.

Polar gravity fields from GOCE and airborne gravity

DEFF Research Database (Denmark)

Forsberg, René; Olesen, Arne Vestergaard; Yidiz, Hasan

2011-01-01

Airborne gravity, together with high-quality surface data and ocean satellite altimetric gravity, may supplement GOCE to make consistent, accurate high resolution global gravity field models. In the polar regions, the special challenge of the GOCE polar gap make the error characteristics...... of combination models especially sensitive to the correct merging of satellite and surface data. We outline comparisons of GOCE to recent airborne gravity surveys in both the Arctic and the Antarctic. The comparison is done to new 8-month GOCE solutions, as well as to a collocation prediction from GOCE gradients...... in Antarctica. It is shown how the enhanced gravity field solutions improve the determination of ocean dynamic topography in both the Arctic and in across the Drake Passage. For the interior of Antarctica, major airborne gravity programs are currently being carried out, and there is an urgent need...

The gravity fields of Ganymede, Callisto and Europa: how well can JUICE do?

Science.gov (United States)

Parisi, Marzia; Iess, Luciano; Finocchiaro, Stefano

2014-05-01

With 20 flybys of Callisto, 2 of Europa and an extended orbital phase around Ganymede, ESA's JUICE mission offers an excellent opportunity to investigate the interiors of the three Galilean satellites. All of these moons can host an internal ocean, but the evidence is compelling only for Europa, where Galileo's measurements of the induced magnetic field are not marred by an intrinsic field as for Ganymede. However, both Europa's and Ganymede's appear to be differentiated (Showman and Malhotra, 1999), and probably hosting a subsurface liquid water ocean underneath the icy surface (Khurana et al., 1998; Kivelson et al., 2002). But even for Callisto, which appears as an undifferentiated body of ice and rock (Showman and Malhotra, 1999), a global or partial subsurface ocean cannot be ruled out (Khurana et al., 1998). The determination of the interior structure of the Galilean satellites, one of the main goal of the JUICE mission, can be accomplished by a combination of gravity, altimetric and magnetic measurements. Gravity measurements are addressed by the 3GM (Geodesy and Geophysics of Jupiter and the Galilean Moons) by means of highly accurate Doppler tracking of the spacecraft from ground antennas. Precise range rate measurements are enabled by a dedicated Ka-band (32-34 GHz) transponder, heritage from the Juno and BepiColombo missions. The expected range rate accuracies are around 0.01 mm/s at 60 s integration time, at nearly all solar elongation angles. A complete cancellation of the interplanetary plasma noise is indeed possible by operating simultaneously the links at X and Ka band. The current mission profile envisages two, low altitude, orbital phases around Ganymede: a circular polar, orbit at an altitude of 500 km for the first 102 days, and circular polar orbit at an altitude of 200 km for the last 30 days. The low altitude will permit the determination of Ganymede's gravity field with a relative accuracy of about 10^-5 for both J2 and C22. The 18 tidal

Global Characteristics of Porosity and Density Stratification Within the Lunar Crust from GRAIL Gravity and Lunar Orbiter Laser Altimeter Topography Data

Science.gov (United States)

Han, Shin-Chan; Schmerr, Nicholas; Neumann, Gregory; Holmes, Simon

2014-01-01

The Gravity Recovery and Interior Laboratory (GRAIL) mission is providing unprecedentedly high-resolution gravity data. The gravity signal in relation to topography decreases from 100 km to 30 km wavelength, equivalent to a uniform crustal density of 2450 kg/cu m that is 100 kg/cu m smaller than the density required at 100 km. To explain such frequency-dependent behavior, we introduce rock compaction models under lithostatic pressure that yield radially stratified porosity (and thus density) and examine the depth extent of porosity. Our modeling and analysis support the assertion that the crustal density must vary from surface to deep crust by up to 500 kg/cu m. We found that the surface density of mega regolith is around 2400 kg/cu m with an initial porosity of 10-20%, and this porosity is eliminated at 10-20 km depth due to lithostatic overburden pressure. Our stratified density models provide improved fits to both GRAIL primary and extended mission data.

A Robust, Gravity-Insensitive, High-Temperature Condenser for Water Recovery

Science.gov (United States)

Chen, Weibo; Conboy, Thomas; Ewert, Michael

2016-01-01

Regenerative life support systems are vital for NASA's future long-duration human space exploration missions. A Heat Melt Compactor (HMC) system is being developed by NASA to dry and compress trash generated during space missions. The resulting water vapor is recovered and separated from the process gas flow by a gravity-insensitive condenser. Creare is developing a high-temperature condenser for this application. The entire condenser is constructed from metals that have excellent resistance to chemical attack from contaminants and is suitable for high-temperature operation. The metal construction and design configuration also offer greatest flexibility for potential coating and regeneration processes to reduce biofilm growth and thus enhancing the reliability of the condenser. The proposed condenser builds on the gravity-insensitive phase separator technology Creare developed for aircraft and spacecraft applications. This paper will first discuss the design requirements for the condenser in an HMC system that will be demonstrated on the International Space Station (ISS). Then, it will present the overall design of the condenser and the preliminary thermal test results of a subscale condenser. Finally, this paper will discuss the predicted performance of the full-size condenser and the development plan to mature the technology and enhance its long-term reliability for a flight system.

Improving communication on hope in palliative care. A qualitative study of palliative care professionals' metaphors of hope: grip, source, tune, and vision.

Science.gov (United States)

Olsman, Erik; Duggleby, Wendy; Nekolaichuk, Cheryl; Willems, Dick; Gagnon, Judith; Kruizinga, Renske; Leget, Carlo

2014-11-01

Hope is important in palliative care. However, palliative care professionals' perspectives on hope are not well understood. Metaphors of hope are a way of better understanding these perspectives. To describe palliative care professionals' perspectives on hope by examining the hope metaphors they spontaneously used to describe their own hope and their perspectives on the hope of patients and their families. Semistructured interviews with palliative care professionals were recorded, transcribed, and analyzed using a narrative approach. Results were discussed until the researchers reached consensus and reinforced by other health-care professionals and by observing several palliative care settings. The 64 participants (mean (SD) age, 48.42 (9.27) years and 72% female) were physicians (41%), nurses (34%), chaplains (20%), or other professionals (5%), working in Canada (19%) or The Netherlands (81%). Participants described the hope of patients, their families, or themselves as a 1) grip, which implied safety; 2) source, which implied strength; 3) tune, which implied harmony; and 4) vision, which implied a positive perspective. Compared with Dutch participants, Canadian participants generally put more emphasis on spirituality and letting go of their own hope as a grip (safety). Compared with other included professionals, physicians used hope as a grip (safety) most often, whereas chaplains used hope as a tune (harmony) most often. Our findings help to increase the understanding of hope and contribute to improving communication skills in palliative care professionals. Copyright © 2014 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

Meta-Analyses of Predictors of Hope in Adolescents.

Science.gov (United States)

Yarcheski, Adela; Mahon, Noreen E

2016-03-01

The purposes of this study were to identify predictors of hope in the literature reviewed, to use meta-analysis to determine the mean effect size (ES) across studies between each predictor and hope, and to examine four moderators on each predictor-hope relationship. Using preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines for the literature reviewed, 77 published studies or doctoral dissertations completed between 1990 and 2012 met the inclusion criteria. Eleven predictors of hope were identified and each predictor in relation to hope was subjected to meta-analysis. Five predictors (positive affect, life satisfaction, optimism, self-esteem, and social support) of hope had large mean ESs, 1 predictor (depression) had a medium ES, 4 predictors (negative affect, stress, academic achievement, and violence) had small ESs, and 1 predictor (gender) had a trivial ES. Findings are interpreted for the 11 predictors in relation to hope. Limitations and conclusions are addressed; future studies are recommended. © The Author(s) 2014.

Going Beyond Einstein with the Constellation-X Mission

Science.gov (United States)

White, Nicholas

2007-01-01

The Constellation-X mission will address the questions: "What happens to matter close to a black hole?" and "What is Dark Energy?" These questions are central to the NASA Beyond Einstein Program, where Constellation-X plays a central role. The mission will address these questions by using high throughput X-ray spectroscopy to observe the effects of strong gravity close to the event horizon of black holes, and to observe the formation and evolution of clusters of galaxies in order to precisely determine Cosmological parameters. To achieve these primary science goals requires a factor of 25-100 increase in sensitivity for high resolution X-ray spectroscopy.'The mission will also perform routine high-resolution X-ray spectroscopy of faint 2nd extended X-ray source populations. This will provide diagnostic information such as density, elemental abundances, velocity; and ionization state for a wide range of astrophysical problems, including new constraints on the Neutron Star equation of state.

Hope, self-efficacy, spiritual well-being and job satisfaction.

Science.gov (United States)

Duggleby, Wendy; Cooper, Dan; Penz, Kelly

2009-11-01

Hope, self-efficacy, spiritual well-being and job satisfaction. This paper is a report of a study of the relations of spiritual well-being, global job satisfaction, and general self-efficacy to hope in Continuing Care Assistants. Healthcare providers have described their hope as an important part of their work and a form of work motivation. Hope may be an important factor in preventing burnout and improving job satisfaction. A concurrent triangulation mixed method design was used. Sixty-four Continuing Care Assistants (personal care aides) who registered for a 'Living with Hope' Conference completed a demographic form, Herth Hope Index, Global Job Satisfaction Questionnaire, Spiritual Well-Being Scale, General Self-Efficacy Scale, and a hope questionnaire. Data were collected in 2007. The response rate was 58%. Using linear regression, 29.9% of the variance in Herth Hope Index score was accounted for by scores from the General Self-Efficacy Scale and Spiritual Well-Being Scale. General Self-efficacy scores (positive relationship) and Spiritual Well-Being scores (negative relationship) accounted for a significant part of the variance. Qualitative data supported all findings, with the exception of the negative relationship between hope and spiritual well-being; participants wrote that faith, relationships, helping others and positive thinking helped them to have hope. They also wrote that hope had a positive influence on their job satisfaction and performance. Hope is an important concept in the work life of Continuing Care Assistants. Supportive relationships, adequate resources, encouragement by others, and improving perceptions of self-efficacy (ability to achieve goals in their workplace) may foster their hope.

Non-planetary Science from Planetary Missions

Science.gov (United States)

Elvis, M.; Rabe, K.; Daniels, K.

2015-12-01

Planetary science is naturally focussed on the issues of the origin and history of solar systems, especially our own. The implications of an early turbulent history of our solar system reach into many areas including the origin of Earth's oceans, of ores in the Earth's crust and possibly the seeding of life. There are however other areas of science that stand to be developed greatly by planetary missions, primarily to small solar system bodies. The physics of granular materials has been well-studied in Earth's gravity, but lacks a general theory. Because of the compacting effects of gravity, some experiments desired for testing these theories remain impossible on Earth. Studying the behavior of a micro-gravity rubble pile -- such as many asteroids are believed to be -- could provide a new route towards exploring general principles of granular physics. These same studies would also prove valuable for planning missions to sample these same bodies, as techniques for anchoring and deep sampling are difficult to plan in the absence of such knowledge. In materials physics, first-principles total-energy calculations for compounds of a given stoichiometry have identified metastable, or even stable, structures distinct from known structures obtained by synthesis under laboratory conditions. The conditions in the proto-planetary nebula, in the slowly cooling cores of planetesimals, and in the high speed collisions of planetesimals and their derivatives, are all conditions that cannot be achieved in the laboratory. Large samples from comets and asteroids offer the chance to find crystals with these as-yet unobserved structures as well as more exotic materials. Some of these could have unusual properties important for materials science. Meteorites give us a glimpse of these exotic materials, several dozen of which are known that are unique to meteorites. But samples retrieved directly from small bodies in space will not have been affected by atmospheric entry, warmth or

Absolute Gravity Datum in the Age of Cold Atom Gravimeters

Science.gov (United States)

Childers, V. A.; Eckl, M. C.

2014-12-01

The international gravity datum is defined today by the International Gravity Standardization Net of 1971 (IGSN-71). The data supporting this network was measured in the 1950s and 60s using pendulum and spring-based gravimeter ties (plus some new ballistic absolute meters) to replace the prior protocol of referencing all gravity values to the earlier Potsdam value. Since this time, gravimeter technology has advanced significantly with the development and refinement of the FG-5 (the current standard of the industry) and again with the soon-to-be-available cold atom interferometric absolute gravimeters. This latest development is anticipated to provide improvement in the range of two orders of magnitude as compared to the measurement accuracy of technology utilized to develop ISGN-71. In this presentation, we will explore how the IGSN-71 might best be "modernized" given today's requirements and available instruments and resources. The National Geodetic Survey (NGS), along with other relevant US Government agencies, is concerned about establishing gravity control to establish and maintain high order geodetic networks as part of the nation's essential infrastructure. The need to modernize the nation's geodetic infrastructure was highlighted in "Precise Geodetic Infrastructure, National Requirements for a Shared Resource" National Academy of Science, 2010. The NGS mission, as dictated by Congress, is to establish and maintain the National Spatial Reference System, which includes gravity measurements. Absolute gravimeters measure the total gravity field directly and do not involve ties to other measurements. Periodic "intercomparisons" of multiple absolute gravimeters at reference gravity sites are used to constrain the behavior of the instruments to ensure that each would yield reasonably similar measurements of the same location (i.e. yield a sufficiently consistent datum when measured in disparate locales). New atomic interferometric gravimeters promise a significant

The content of hope in ambulatory patients with colon cancer.

Science.gov (United States)

Beckman, Emily S; Helft, Paul R; Torke, Alexia M

2013-01-01

Although hope is a pervasive concept in cancer treatment, we know little about how ambulatory patients with cancer define or experience hope. We explored hope through semistructured interviews with ten patients with advanced (some curable, some incurable) colon cancer at one Midwestern, university-based cancer center. We conducted a thematic analysis to identify key concepts related to patient perceptions of hope. Although we did ask specifically about hope, patients also often revealed their hopes in response to indirect questions or by telling stories about their cancer experience. We identified four major themes related to hope: 1) hope is essential, 2) a change in perspective, 3) the content of hope, and 4) communicating about hope. The third theme, the content of hope, included three subthemes: a) the desire for normalcy, b) future plans, and c) hope for a cure. We conclude that hope is an essential concept for patients undergoing treatment for cancer as it pertains to their psychological well-being and quality of life, and hope for a cure is not and should not be the only consideration. In a clinical context, the exploration of patients' hopes and aspirations in light of their cancer diagnosis is important because it provides a frame for understanding their goals for treatment. Exploration of the content of patients' hope can not only help to illuminate misunderstandings but also clarify how potential treatments may or may not contribute to achieving patients' goals.

Keeping hope possible: a grounded theory study of the hope experience of parental caregivers who have children in treatment for cancer.

Science.gov (United States)

Bally, Jill M G; Duggleby, Wendy; Holtslander, Lorraine; Mpofu, Christopher; Spurr, Shelley; Thomas, Roanne; Wright, Karen

2014-01-01

Hope has been found to support parents as they care for their child with a life-limiting or life-threatening illness. However, very little research focuses on the nursing care of parents of pediatric oncology patients, and therefore, nurses may have difficulty in understanding and supporting parental well-being. The purpose of this qualitative study was to gain an understanding of the experience of hope for parents who care for their child in treatment for cancer. Using purposive theoretical sampling, 16 parents participated in this study. Thirty-three open-ended, face-to-face interviews were conducted, and 14 parent journals were collected. Analysis of the data was conducted using Charmaz's constructivist grounded theory approach. A developing, substantive grounded theory was constructed. Parental hope was described as an essential, powerful, deliberate, life-sustaining, dynamic, cyclical process that was anchored in time; was calming and strengthening; and provided inner guidance through the challenging experience of preparing for the worst and hoping for the best. Parents' main concern was "fearing the loss of hope," which was ameliorated by the basic social process of "keeping hope possible" through accepting reality, establishing control, restructuring hope, and purposive positive thinking. Parents journeyed through numerous transitions related to the treatment of cancer that caused feelings of uncertainty, anxiety, stress, and loss of control. Hope was identified as vital to parents. To minimize these adverse experiences, nurses can support parents' ability to keep hope possible and thus to optimize their well-being by understanding, assessing, and supporting parental hope.

Asteroid Redirect Robotic Mission: Robotic Boulder Capture Option Overview

Science.gov (United States)

Mazanek, Daniel D.; Merrill, Raymond G.; Belbin, Scott P.; Reeves, David M.; Earle, Kevin D.; Naasz, Bo J.; Abell, Paul A.

2014-01-01

The National Aeronautics and Space Administration (NASA) is currently studying an option for the Asteroid Redirect Robotic Mission (ARRM) that would capture a multi-ton boulder (typically 2-4 meters in size) from the surface of a large (is approximately 100+ meter) Near-Earth Asteroid (NEA) and return it to cislunar space for subsequent human and robotic exploration. This alternative mission approach, designated the Robotic Boulder Capture Option (Option B), has been investigated to determine the mission feasibility and identify potential differences from the initial ARRM concept of capturing an entire small NEA (4-10 meters in size), which has been designated the Small Asteroid Capture Option (Option A). Compared to the initial ARRM concept, Option B allows for centimeter-level characterization over an entire large NEA, the certainty of target NEA composition type, the ability to select the boulder that is captured, numerous opportunities for mission enhancements to support science objectives, additional experience operating at a low-gravity planetary body including extended surface contact, and the ability to demonstrate future planetary defense strategies on a hazardous-size NEA. Option B can leverage precursor missions and existing Agency capabilities to help ensure mission success by targeting wellcharacterized asteroids and can accommodate uncertain programmatic schedules by tailoring the return mass.

The scientific objectives of the International Solar Polar Mission

International Nuclear Information System (INIS)

Wenzel, K.-P.

1980-01-01

The International Solar Polar Mission (I.S.P.M.), originally known as the Out-of-Ecliptic Mission, will be the first spacecraft mission to explore the third dimension of the heliosphere within a few astronomical units of the Sun and to view the Sun over the full range of heliographic latitudes. Its main objectives are to investigate, as a function of solar latitude, the properties of the interplanetary medium and the solar corona. The I.S.P.M. is a two spacecraft venture jointly conducted by E.S.A. and N.A.S.A. The two spacecraft will be injected into elliptical heliocentric orbits approximately at right angles to the ecliptic plane, by using the Jupiter gravity assist method, one northwards and the other southwards. After passing nearly above the poles of the Sun, each spacecraft crosses the ecliptic plane and passes over the other solar pole. The complete mission time from launch, foreseen for February 1983, to the second polar passage is approximately 42/3 years. This paper summarizes the main scientific objectives of the instruments to be carried on this exploratory mission. It concludes with an outline of the payload, the spacecraft, the trajectory and the mission schedule. (author)

Time-variable gravity fields and ocean mass change from 37 months of kinematic Swarm orbits

Directory of Open Access Journals (Sweden)

C. Lück

2018-03-01

Full Text Available Measuring the spatiotemporal variation of ocean mass allows for partitioning of volumetric sea level change, sampled by radar altimeters, into mass-driven and steric parts. The latter is related to ocean heat change and the current Earth's energy imbalance. Since 2002, the Gravity Recovery and Climate Experiment (GRACE mission has provided monthly snapshots of the Earth's time-variable gravity field, from which one can derive ocean mass variability. However, GRACE has reached the end of its lifetime with data degradation and several gaps occurred during the last years, and there will be a prolonged gap until the launch of the follow-on mission GRACE-FO. Therefore, efforts focus on generating a long and consistent ocean mass time series by analyzing kinematic orbits from other low-flying satellites, i.e. extending the GRACE time series. Here we utilize data from the European Space Agency's (ESA Swarm Earth Explorer satellites to derive and investigate ocean mass variations. For this aim, we use the integral equation approach with short arcs (Mayer-Gürr, 2006 to compute more than 500 time-variable gravity fields with different parameterizations from kinematic orbits. We investigate the potential to bridge the gap between the GRACE and the GRACE-FO mission and to substitute missing monthly solutions with Swarm results of significantly lower resolution. Our monthly Swarm solutions have a root mean square error (RMSE of 4.0 mm with respect to GRACE, whereas directly estimating constant, trend, annual, and semiannual (CTAS signal terms leads to an RMSE of only 1.7 mm. Concerning monthly gaps, our CTAS Swarm solution appears better than interpolating existing GRACE data in 13.5 % of all cases, when artificially removing one solution. In the case of an 18-month artificial gap, 80.0 % of all CTAS Swarm solutions were found closer to the observed GRACE data compared to interpolated GRACE data. Furthermore, we show that precise modeling of non

Types of hope and action styles of adolescents

Directory of Open Access Journals (Sweden)

Aleksandra Myślińska

2016-04-01

Full Text Available The problem discussed in this article concerns the relationship between hope and action styles in adolescents. An action style is a way in which man perceives and responds to the outside world, and it may be aimed at securing oneself or interacting with the surroundings. The main aim of this analysis was to find out if, and to what degree, the level of hope is connected with action styles. The following hypotheses are proposed: H – 1. There is a relationship between hope and an action style. H- 2. Persons with different types of hope are characterised by different styles of action. H – 3. Persons with a high level of hope have a cooperation -oriented style. H – 4. Persons with a low level of hope are often characterised by a style aimed at protecting themselves. 149 persons aged 17 – 18 participated in the study. The following methods were used: the Basic Hope Inventory (BHI-12 – compiled by Trzebiński and M. Zięba, the Hope for Success Questionnaire (KNS – adaptation of C. R. Snyder’s questionnaire made by M. Łaguna, J. Trzebiński and M. Zięba, as well as the Action Styles Questionnaire by Z. Uchnast . The results obtained have allowed the researchers to form the opinion that hope helps individuals function better in the world. The way in which a person perceives the world and their own capabilities translates into the style of action which they choose. A person who is full of hope seeks self -actualisation as well as cooperation with others.

Understanding NEOs: The Role of Characterization Missions

Science.gov (United States)

Morrison, David

2007-10-01

NEOs are important from multiple perspectives, including science, hazard mitigation, space resources, and as targets for human missions. Much can be learned from ground-based studies, especially with radar, but the unique value of in situ investigation has been shown by missions such as NEAR-Shoemaker and Hayabusa to asteroids Eros and Itokawa, and Deep Impact and Stardust to comets. The next mission targets are likely to be NEAs in the subkilometer size range. Because these smaller objects are much more numerous, they are the objects we most need to understand from a defense perspective, and they are also the most likely targets for early human missions. However, there are unique challenges in sending spacecraft to investigate sub-km asteroids. Reconnaissance flybys are of little use, orbiting requires active control, and landing on such a low-gravity surface is perhaps better described as docking. Yet we need to operate close to the target, and probably to land, to obtain crucial information about interior structure. This paper deals primarily with small landers like the Near Earth Asteroid Trailblazer Mission (NEAT) studied at Ames Research Center. The NEAT objectives are to provide global reconnaissance (shape, mass, density, dynamical state), in situ surface characterization, and long-term precision tracking. Alternative approaches use deep-penetrating radar and electromagnetic sounding to probe interior structure. A third class of missions is ballistic impactors such as the ESA Don Quijote, which test one of the technologies for deflecting small asteroids. If the targets are selected for their accessibility, such missions could be implemented with low-cost launchers such as Pegasus, Falcon, or Minotaur. Such missions will have high science return. But from the perspective of defense, we have not yet developed a consensus strategy for the role of such characterization missions.

Correcting GRACE gravity fields for ocean tide effects

DEFF Research Database (Denmark)

Knudsen, Per; Andersen, Ole Baltazar

2002-01-01

[1] The GRACE mission will be launch in early 2002 and will map the Earth's gravity fields and its variations with unprecedented accuracy during its 5-year lifetime. Unless ocean tide signals and their load upon the solid earth are removed from the GRACE data, their long period aliases obscure more...... tide model if altimetry corrected for inverted barometer effects was used in its derivation. To study the temporal characteristics of the ocean tidal constituents when sampled by GRACE, approximate alias frequencies were derived assuming a sampling of half a sidereal day. Those results show...

Faith, hope and love in sport

Directory of Open Access Journals (Sweden)

Jernej Pisk

2017-11-01

Full Text Available In the Christian religious tradition, theological virtues of faith, hope and love have a central role. Along with the cardinal virtues of prudence, justice, fortitude and temperance they present the whole of the good human life. While cardinal virtues can be cultivated by human will, faith, hope and love are given by God and therefore open ‘natural’ human life on Earth toward transcendent spiritual realities. Human beings as bio-psycho-social and spiritual beings incorporate theological virtues in all the activities of their life. In sport, faith, hope and love have an important, though often neglected, role. On a practical level faith can be recognized in any relation between athlete and coach. To trust one’s coach, without any guarantee that the outcome of prescribed workouts will lead to the desired results, needs strong faith, trust and confidence. Moreover, faith is the virtue that makes sport so attractive also for spectators even to the point of being a ‘secular’ religion for the masses. Hope is the virtue of ‘not yet’ or of something ‘being on its way’. For most athletes, daily workouts are not a goal, but just the means to that end. Any reason for doing sports needs a hope behind it in order to move or will oneself to action. Along with hope, understood as a golden mean, we find despair on the one hand and ‘false hope’ on the other. Both are corruptions of hope seen daily in the world of sport. To manage hope in sport practices correctly offers a path to success in sport at all levels. Love is at the apex of the theological virtues. There are many formulations of love both in ancient Greek and Roman times: eros, agape, caritas, amor. Each has its special characteristic meaning also in sport. In sport we can see laughter and tears because any love is connected with highest human joy and deepest depression. Yet, in summation, it is argued that love in sport must be understood as the binding force and source of

New space vehicle archetypes for human planetary missions

Science.gov (United States)

Sherwood, Brent

1991-01-01

Contemporary, archetypal, crew-carrying spacecraft concepts developed for NASA are presented for: a lunar transportation system, two kinds of Mars landers, and five kinds of Mars transfer vehicles. These cover the range of propulsion technologies and mission modes of interest for the Space Exploration Initiative, and include both aerobraking and artificial gravity as appropriate. They comprise both upgrades of extant archetypes and completely new ones. Computer solid models, configurations and mass statements are presented for each.

Impact of combining GRACE and GOCE gravity data on ocean circulation estimates

Directory of Open Access Journals (Sweden)

T. Janjić

2012-02-01

Full Text Available With the focus on the Southern Ocean circulation, results of assimilation of multi-mission-altimeter data and the GRACE/GOCE gravity data into the finite element ocean model (FEOM are investigated. We use the geodetic method to obtain the dynamical ocean topography (DOT. This method combines the multi-mission-altimeter sea surface height and the GRACE/GOCE gravity field. Using the profile approach, the spectral consistency of both fields is achieved by filtering the sea surface height and the geoid. By combining the GRACE and GOCE data, a considerably shorter filter length can be used, which results in more DOT details. We show that this increase in resolution of measured DOT carries onto the results of data assimilation for the surface data. By assimilating only absolute dynamical topography data using the ensemble Kalman filter, we were able to improve modeled fields. Results are closer to observations which were not used for assimilation and lie outside the area covered by altimetry in the Southern Ocean (e.g. temperature of surface drifters or deep temperatures in the Weddell Sea area at 800 m depth derived from Argo composite.

On the feasibility of using satellite gravity observations for detecting large-scale solid mass transfer events

Science.gov (United States)

Peidou, Athina C.; Fotopoulos, Georgia; Pagiatakis, Spiros

2017-10-01

The main focus of this paper is to assess the feasibility of utilizing dedicated satellite gravity missions in order to detect large-scale solid mass transfer events (e.g. landslides). Specifically, a sensitivity analysis of Gravity Recovery and Climate Experiment (GRACE) gravity field solutions in conjunction with simulated case studies is employed to predict gravity changes due to past subaerial and submarine mass transfer events, namely the Agulhas slump in southeastern Africa and the Heart Mountain Landslide in northwestern Wyoming. The detectability of these events is evaluated by taking into account the expected noise level in the GRACE gravity field solutions and simulating their impact on the gravity field through forward modelling of the mass transfer. The spectral content of the estimated gravity changes induced by a simulated large-scale landslide event is estimated for the known spatial resolution of the GRACE observations using wavelet multiresolution analysis. The results indicate that both the Agulhas slump and the Heart Mountain Landslide could have been detected by GRACE, resulting in {\\vert }0.4{\\vert } and {\\vert }0.18{\\vert } mGal change on GRACE solutions, respectively. The suggested methodology is further extended to the case studies of the submarine landslide in Tohoku, Japan, and the Grand Banks landslide in Newfoundland, Canada. The detectability of these events using GRACE solutions is assessed through their impact on the gravity field.

Massive Gravity

OpenAIRE

de Rham, Claudia

2014-01-01

We review recent progress in massive gravity. We start by showing how different theories of massive gravity emerge from a higher-dimensional theory of general relativity, leading to the Dvali–Gabadadze–Porrati model (DGP), cascading gravity, and ghost-free massive gravity. We then explore their theoretical and phenomenological consistency, proving the absence of Boulware–Deser ghosts and reviewing the Vainshtein mechanism and the cosmological solutions in these models. Finally, we present alt...

Scales of gravity

International Nuclear Information System (INIS)

Dvali, Gia; Kolanovic, Marko; Nitti, Francesco; Gabadadze, Gregory

2002-01-01

We propose a framework in which the quantum gravity scale can be as low as 10 -3 eV. The key assumption is that the standard model ultraviolet cutoff is much higher than the quantum gravity scale. This ensures that we observe conventional weak gravity. We construct an explicit brane-world model in which the brane-localized standard model is coupled to strong 5D gravity of infinite-volume flat extra space. Because of the high ultraviolet scale, the standard model fields generate a large graviton kinetic term on the brane. This kinetic term 'shields' the standard model from the strong bulk gravity. As a result, an observer on the brane sees weak 4D gravity up to astronomically large distances beyond which gravity becomes five dimensional. Modeling quantum gravity above its scale by the closed string spectrum we show that the shielding phenomenon protects the standard model from an apparent phenomenological catastrophe due to the exponentially large number of light string states. The collider experiments, astrophysics, cosmology and gravity measurements independently point to the same lower bound on the quantum gravity scale, 10 -3 eV. For this value the model has experimental signatures both for colliders and for submillimeter gravity measurements. Black holes reveal certain interesting properties in this framework

Monte Carlo Analysis as a Trajectory Design Driver for the Transiting Exoplanet Survey Satellite (TESS) Mission

Science.gov (United States)

Nickel, Craig; Parker, Joel; Dichmann, Don; Lebois, Ryan; Lutz, Stephen

2016-01-01

The Transiting Exoplanet Survey Satellite (TESS) will be injected into a highly eccentric Earth orbit and fly 3.5 phasing loops followed by a lunar flyby to enter a mission orbit with lunar 2:1 resonance. Through the phasing loops and mission orbit, the trajectory is significantly affected by lunar and solar gravity. We have developed a trajectory design to achieve the mission orbit and meet mission constraints, including eclipse avoidance and a 30-year geostationary orbit avoidance requirement. A parallelized Monte Carlo simulation was performed to validate the trajectory after injecting common perturbations, including launch dispersions, orbit determination errors, and maneuver execution errors. The Monte Carlo analysis helped identify mission risks and is used in the trajectory selection process.

Seasonal and Static Gravity Field of Mars from MGS, Mars Odyssey and MRO Radio Science

Science.gov (United States)

Genova, Antonio; Goossens, Sander; Lemoine, Frank G.; Mazarico, Erwan; Neumann, Gregory A.; Smith, David E.; Zuber, Maria T.

2016-01-01

We present a spherical harmonic solution of the static gravity field of Mars to degree and order 120, GMM-3, that has been calculated using the Deep Space Network tracking data of the NASA Mars missions, Mars Global Surveyor (MGS), Mars Odyssey (ODY), and the Mars Reconnaissance Orbiter (MRO). We have also jointly determined spherical harmonic solutions for the static and time-variable gravity field of Mars, and the Mars k 2 Love numbers, exclusive of the gravity contribution of the atmosphere. Consequently, the retrieved time-varying gravity coefficients and the Love number k 2 solely yield seasonal variations in the mass of the polar caps and the solid tides of Mars, respectively. We obtain a Mars Love number k 2 of 0.1697 +/-0.0027 (3- sigma). The inclusion of MRO tracking data results in improved seasonal gravity field coefficients C 30 and, for the first time, C 50 . Refinements of the atmospheric model in our orbit determination program have allowed us to monitor the odd zonal harmonic C 30 for approx.1.5 solar cycles (16 years). This gravity model shows improved correlations with MOLA topography up to 15% larger at higher harmonics ( l = 60–80) than previous solutions.

Maintaining hope at the 11th hour: authenticity buffers the effect of limited time perspective on hope.

Science.gov (United States)

Davis, William E; Hicks, Joshua A

2013-12-01

Four studies tested the hypothesis that limited time perceptions are associated with lower levels of hope, and that this effect is buffered by high levels of authenticity. Study 1 (n = 256) utilized a cross-sectional design in which participants completed dispositional measures of time perspective, hope, and authenticity. Three subsequent studies tested our hypothesis experimentally. In a pilot study (n = 124), participants reported their perceived authenticity, future time perspective (FTP) was manipulated (limited vs. open-ended), and state hope was assessed. Study 2 (n = 156) introduced a new manipulation of FTP, and Study 3 (n = 242) replicated Study 2 with the addition of a neutral control condition. Across all studies, individuals who perceived time as limited reported lower levels of hope relative to those who perceived time as open-ended (or those in a neutral control condition), but, importantly, this effect was attenuated for highly authentic individuals.

Gravity-Dependent Combustion and Fluids Research - From Drop Towers to Aircraft to the ISS

Science.gov (United States)

Urban, David L.; Singh, Bhim S.; Kohl, Fred J.

2007-01-01

Driven by the need for knowledge related to the low-gravity environment behavior of fluids in liquid fuels management, thermal control systems and fire safety for spacecraft, NASA embarked on a decades long research program to understand, accommodate and utilize the relevant phenomena. Beginning in the 1950s, and continuing through to today, drop towers and aircraft were used to conduct an ever broadening and increasingly sophisticated suite of experiments designed to elucidate the underlying gravity-dependent physics that drive these processes. But the drop towers and aircraft afford only short time periods of continuous low gravity. Some of the earliest rocket test flights and manned space missions hosted longer duration experiments. The relatively longer duration low-g times available on the space shuttle during the 1980s and 1990s enabled many specialized experiments that provided unique data for a wide range of science and engineering disciplines. Indeed, a number of STS-based Spacelab missions were dedicated solely to basic and applied microgravity research in the biological, life and physical sciences. Between 1980 and 2000, NASA implemented a vigorous Microgravity Science Program wherein combustion science and fluid physics were major components. The current era of space stations from the MIR to the International Space Station have opened up a broad range of opportunities and facilities that are now available to support both applied research for technologies that will help to enable the future exploration missions and for a continuation of the non-exploration basic research that began over fifty years ago. The ISS-based facilities of particular value to the fluid physics and combustion/fire safety communities are the Fluids and Combustion Facility Combustion Integrated Rack and the Fluids Integrated Rack.

PPN-limit of Fourth Order Gravity inspired by Scalar-Tensor Gravity

OpenAIRE

Capozziello, S.; Troisi, A.

2005-01-01

Based on the {\\it dynamical} equivalence between higher order gravity and scalar-tensor gravity the PPN-limit of fourth order gravity is discussed. We exploit this analogy developing a fourth order gravity version of the Eddington PPN-parameters. As a result, Solar System experiments can be reconciled with higher order gravity, if physical constraints descending from experiments are fulfilled.

Hope as a Predictor of Interpersonal Suicide Risk

Science.gov (United States)

Davidson, Collin L.; Wingate, LaRicka R.; Rasmussen, Kathy A.; Slish, Meredith L.

2009-01-01

The current study hypothesized that (1) hope would negatively predict burdensomeness, thwarted belongingness, and acquired capability to enact lethal injury; (2) hope would negatively predict suicidal ideation; and (3) the interpersonal suicide risk factors would predict suicidal ideation. Results indicated that hope negatively predicted…

Terrestrial gravity data analysis for interim gravity model improvement

Science.gov (United States)

1987-01-01

This is the first status report for the Interim Gravity Model research effort that was started on June 30, 1986. The basic theme of this study is to develop appropriate models and adjustment procedures for estimating potential coefficients from terrestrial gravity data. The plan is to use the latest gravity data sets to produce coefficient estimates as well as to provide normal equations to NASA for use in the TOPEX/POSEIDON gravity field modeling program.

Ground track density considerations on the resolvability of gravity field harmonics in a repeat orbit

Czech Academy of Sciences Publication Activity Database

Klokočník, Jaroslav; Wagner, C. A.; Kostelecký, J.; Bezděk, Aleš

2015-01-01

Roč. 56, č. 6 (2015), 1146-1160 ISSN 0273-1177 R&D Projects: GA ČR GA13-36843S Institutional support: RVO:67985815 Keywords : gravity field of the Earth * resonant/repeat orbit missions * ground track density Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 1.409, year: 2015

Constraints on Covariant Horava-Lifshitz Gravity from frame-dragging experiment

Energy Technology Data Exchange (ETDEWEB)

Radicella, Ninfa; Lambiase, Gaetano; Parisi, Luca; Vilasi, Gaetano, E-mail: ninfa.radicella@sa.infn.it, E-mail: lambiase@sa.infn.it, E-mail: parisi@sa.infn.it, E-mail: vilasi@sa.infn.it [Dipartimento di Fisica ' ' E.R. Caianiello" , Università di Salerno, Via Giovanni Paolo II 132, 84081 Fisciano (Italy)

2014-12-01

The effects of Horava-Lifshitz corrections to the gravito-magnetic field are analyzed. Solutions in the weak field, slow motion limit, referring to the motion of a satellite around the Earth are considered. The post-newtonian paradigm is used to evaluate constraints on the Horava-Lifshitz parameter space from current satellite and terrestrial experiments data. In particular, we focus on GRAVITY PROBE B, LAGEOS and the more recent LARES mission, as well as a forthcoming terrestrial project, GINGER.

Science, technology and mission design for LATOR experiment

Science.gov (United States)

Turyshev, Slava G.; Shao, Michael; Nordtvedt, Kenneth L.

2017-11-01

The Laser Astrometric Test of Relativity (LATOR) is a Michelson-Morley-type experiment designed to test the Einstein's general theory of relativity in the most intense gravitational environment available in the solar system - the close proximity to the Sun. By using independent time-series of highly accurate measurements of the Shapiro time-delay (laser ranging accurate to 1 cm) and interferometric astrometry (accurate to 0.1 picoradian), LATOR will measure gravitational deflection of light by the solar gravity with accuracy of 1 part in a billion, a factor {30,000 better than currently available. LATOR will perform series of highly-accurate tests of gravitation and cosmology in its search for cosmological remnants of scalar field in the solar system. We present science, technology and mission design for the LATOR mission.

Advancing Venus Geophysics with the NF4 VOX Gravity Investigation.

Science.gov (United States)

Iess, L.; Mazarico, E.; Andrews-Hanna, J. C.; De Marchi, F.; Di Achille, G.; Di Benedetto, M.; Smrekar, S. E.

2017-12-01

The Venus Origins Explorer is a JPL-led New Frontiers 4 mission proposal to Venus to answer critical questions about the origin and evolution of Venus. Venus stands out among other planets as Earth's twin planet, and is a natural target to better understand our own planet's place, in our own Solar System but also among the ever-increasing number of exoplanetary systems. The VOX radio science investigation will make use of an innovative Ka-band transponder provided by the Italian Space Agency (ASI) to map the global gravity field of Venus to much finer resolution and accuracy than the current knowledge, based on the NASA Magellan mission. We will present the results of comprehensive simulations performed with the NASA GSFC orbit determination and geodetic parameter estimation software `GEODYN', based on a realistic mission scenario, tracking schedule, and high-fidelity Doppler tracking noise model. We will show how the achieved resolution and accuracy help fulfill the geophysical goals of the VOX mission, in particular through the mapping of subsurface crustal density or thickness variations that will inform the composition and origin of the tesserae and help ascertain the heat loss and importance of tectonism and subduction.

Overview of the LARES Mission: orbit, error analysis and technological aspects

International Nuclear Information System (INIS)

Ciufolini, Ignazio; Paolozzi, Antonio; Paris, Claudio

2012-01-01

LARES (LAser RElativity Satellite), is an Italian Space Agency (ASI) mission to be launched beginning of 2012 with the new European launch vehicle, VEGA; the launch opportunity was provided by the European Space Agency (ESA). LARES is a laser ranged satellite; it will be launched into a nearly circular orbit, with an altitude of 1450 km and an inclination of 69.5 degrees. The goal of the mission is the measurement of the Lense-Thirring effect with an uncertainty of few percent; such a small uncertainty will be achieved using LARES data together with data from the LAGEOS I (NASA) and LAGEOS II (NASA and ASI) satellites, and because GRACE mission (NASA-CSR and DLR-GFZ) is improving Earth's gravity field models. This paper describes LARES experiment along with the principal error sources affecting the measurement. Furthermore, some engineering aspects of the mission, in particular the structure and materials of the satellite (designed in order to minimize the non-gravitational perturbations), are described.

Cryosphere campaigns in support of ESA's Earth Explorers Missions

Science.gov (United States)

Casal, Tânia; Davidson, Malcolm; Plank, Gernot; Floberghagen, Rune; Parrinello, Tommaso; Mecklenburg, Susanne; Drusch, Matthias; Fernandez, Diego

2014-05-01

In the framework of its Earth Observation Programmes the European Space Agency (ESA) carries out ground based and airborne campaigns to support geophysical algorithm development, calibration/validation, simulation of future spaceborne Earth observation missions, and applications development related to land, oceans, atmosphere and solid Earth. ESA has conducted over 110 airborne and ground measurements campaigns since 1981 and this presentation will describe three campaigns in Antarctica and the Arctic. They were undertaken during the calibration/validation phase of Earth Explorer (EE) missions, such as SMOS (Soil Moisture and Ocean Salinity), GOCE (Gravity field and steady-state Ocean Circulation Explorer) and CryoSat-2. In support of SMOS and GOCE, the DOMECair airborne campaign took place in Antarctica, in the Dome C region in the middle of January 2013. The two main objectives were a) to quantify and document the spatial variability in the DOME C area (SMOS) and b) to fill a gap in the high-quality gravity anomaly maps in Antarctica where airborne gravity measurements are sparse (GOCE). Results from the campaign for the SMOS component, showed that the DOME C area is not as spatially homogenous as previously assumed, therefore comparisons of different missions (e.g. SMOS and NASA's Aquarius) with different footprints must be done with care, highlighting once again the importance of field work to test given assumptions. One extremely surprising outcome of this campaign was the pattern similarity between the gravity measurements and brightness temperature fields. To date, there has never been an indication that L-Band brightness temperatures could be correlated to gravity, but preliminary analysis showed coincident high brightness temperature with high gravity values, suggesting that topography may influence microwave emissions. Also in support of SMOS, the SMOSice airborne campaign has been planned in the Arctic. It was motived by a previous ESA SMOSice study that

Establishing a Near Term Lunar Farside Gravity Model via Inexpensive Add-on Navigation Payload

Science.gov (United States)

Folta, David; Mesarch, Michael; Miller, Ronald; Bell, David; Jedrey, Tom; Butman, Stanley; Asmar, Sami

2007-01-01

The Space Communications and Navigation, Constellation Integration Project (SCIP) is tasked with defining, developing, deploying and operating an evolving multi-decade communications and navigation (C/N) infrastructure including services and subsystems that will support both robotic and human exploration activities at the Moon. This paper discusses an early far side gravitational mapping service and related telecom subsystem that uses an existing spacecraft (WIND) and the Lunar Reconnaissance Orbiter (LRO) to collect data that would address several needs of the SCIP. An important aspect of such an endeavor is to vastly improve the current lunar gravity model while demonstrating the navigation and stationkeeping of a relay spacecraft. We describe a gravity data acquisition activity and the trajectory design of the relay orbit in an Earth-Moon L2 co-linear libration orbit. Several phases of the transfer from an Earth-Sun to the Earth-Moon region are discussed along with transfers within the Earth-Moon system. We describe a proposed, but not integrated, add-on to LRO scheduled to be launched in October of 2008. LRO provided a real host spacecraft against which we designed the science payload and mission activities. From a strategic standpoint, LRO was a very exciting first flight opportunity for gravity science data collection. Gravity Science data collection requires the use of one or more low altitude lunar polar orbiters. Variations in the lunar gravity field will cause measurable variations in the orbit of a low altitude lunar orbiter. The primary means to capture these induced motions is to monitor the Doppler shift of a radio signal to or from the low altitude spacecraft, given that the signal is referenced to a stable frequency reference. For the lunar far side, a secondary orbiting radio signal platform is required. We provide an in-depth look at link margins, trajectory design, and hardware implications. Our approach posed minimum risk to a host mission while

Superconducting gravity gradiometer for sensitive gravity measurements. I. Theory

International Nuclear Information System (INIS)

Chan, H.A.; Paik, H.J.

1987-01-01

Because of the equivalence principle, a global measurement is necessary to distinguish gravity from acceleration of the reference frame. A gravity gradiometer is therefore an essential instrument needed for precision tests of gravity laws and for applications in gravity survey and inertial navigation. Superconductivity and SQUID (superconducting quantum interference device) technology can be used to obtain a gravity gradiometer with very high sensitivity and stability. A superconducting gravity gradiometer has been developed for a null test of the gravitational inverse-square law and space-borne geodesy. Here we present a complete theoretical model of this instrument. Starting from dynamical equations for the device, we derive transfer functions, a common mode rejection characteristic, and an error model of the superconducting instrument. Since a gradiometer must detect a very weak differential gravity signal in the midst of large platform accelerations and other environmental disturbances, the scale factor and common mode rejection stability of the instrument are extremely important in addition to its immunity to temperature and electromagnetic fluctuations. We show how flux quantization, the Meissner effect, and properties of liquid helium can be utilized to meet these challenges

Dualities and emergent gravity: Gauge/gravity duality

Science.gov (United States)

de Haro, Sebastian

2017-08-01

In this paper I develop a framework for relating dualities and emergence: two notions that are close to each other but also exclude one another. I adopt the conception of duality as 'isomorphism', from the physics literature, cashing it out in terms of three conditions. These three conditions prompt two conceptually different ways in which a duality can be modified to make room for emergence; and I argue that this exhausts the possibilities for combining dualities and emergence (via coarse-graining). I apply this framework to gauge/gravity dualities, considering in detail three examples: AdS/CFT, Verlinde's scheme, and black holes. My main point about gauge/gravity dualities is that the theories involved, qua theories of gravity, must be background-independent. I distinguish two senses of background-independence: (i) minimalistic and (ii) extended. I argue that the former is sufficiently strong to allow for a consistent theory of quantum gravity; and that AdS/CFT is background-independent on this account; while Verlinde's scheme best fits the extended sense of background-independence. I argue that this extended sense should be applied with some caution: on pain of throwing the baby (general relativity) out with the bath-water (extended background-independence). Nevertheless, it is an interesting and potentially fruitful heuristic principle for quantum gravity theory construction. It suggests some directions for possible generalisations of gauge/gravity dualities. The interpretation of dualities is discussed; and the so-called 'internal' vs. 'external' viewpoints are articulated in terms of: (i) epistemic and metaphysical commitments; (ii) parts vs. wholes. I then analyse the emergence of gravity in gauge/gravity dualities in terms of the two available conceptualisations of emergence; and I show how emergence in AdS/CFT and in Verlinde's scenario differ from each other. Finally, I give a novel derivation of the Bekenstein-Hawking black hole entropy formula based on

Hope as experienced in women newly diagnosed with gynaecological cancer

DEFF Research Database (Denmark)

Hammer, Kristianna; Mogensen, Ole; Hall, Elisabeth O C

2009-01-01

cancer diagnosis made the women oscillate between hope and hopelessness, between positive expectations of getting cured and frightening feelings of the disease taking over. Five major interrelated themes of hope were identified: hope of being cured, cared for and getting back to normal, hope as being...... at a gynaecological department of a Danish university hospital. The women, aged 24-87 (median 52yrs), were diagnosed with ovarian, endometrial, cervical and vulvar cancer. RESULTS: Hope was found to be connected to both diagnosis, cure, family life and life itself and closely tied to hopelessness. The newly received...... active and feeling well, hope as an internal power to maintain integration, hope as significant relationships and hope as fighting against hopelessness. Thus, hope was woven together with hopelessness in a mysterious way; it took command through inner strength and courage based on a trust in being cured...

Contravariant gravity on Poisson manifolds and Einstein gravity

International Nuclear Information System (INIS)

Kaneko, Yukio; Watamura, Satoshi; Muraki, Hisayoshi

2017-01-01

A relation between gravity on Poisson manifolds proposed in Asakawa et al (2015 Fortschr. Phys . 63 683–704) and Einstein gravity is investigated. The compatibility of the Poisson and Riemann structures defines a unique connection, the contravariant Levi-Civita connection, and leads to the idea of the contravariant gravity. The Einstein–Hilbert-type action yields an equation of motion which is written in terms of the analog of the Einstein tensor, and it includes couplings between the metric and the Poisson tensor. The study of the Weyl transformation reveals properties of those interactions. It is argued that this theory can have an equivalent description as a system of Einstein gravity coupled to matter. As an example, it is shown that the contravariant gravity on a two-dimensional Poisson manifold can be described by a real scalar field coupled to the metric in a specific manner. (paper)

The color and texture of hope: some preliminary findings and implications for hope theory and counseling among diverse racial/ethnic groups.

Science.gov (United States)

Chang, Edward C; Banks, Kira Hudson

2007-04-01

To clarify and extend Snyder's (1994, 2002) hope theory to a more diverse population, this study examined variations in agentic and pathways thinking, and their relations with social problem solving, affect, and with life satisfaction across a college student sample of 46 European Americans, 30 African Americans, 33 Latinos, and 46 Asian Americans. Although comparative results indicated variations in levels of hope components across the 4 racial/ethnic groups, correlational results indicated that the manner in which hope components related to measures of behavior and adjustment were similar across groups. Regression results indicated similarities and differences in predictors of hope components across the different racial/ethnic groups. Potential implications for promoting hope in working with diverse college students are discussed. (c) 2007 APA, all rights reserved.

Hope, Perceived Financial Risk and Propensity for Indebtedness

Directory of Open Access Journals (Sweden)

Lucia Barros

2012-10-01

Full Text Available Hope is an important construct in marketing, since it is an antecedent of important marketing variables, such as trust, expectation and satisfaction (MacInnis & Mello, 2005. Specifically, literature suggests that hope plays an important influence in risk perception (MacInnis & Mello, 2005 and propensity for indebtedness (Fleming, 2008. Thus, we aim to investigate the relationships among hope, risk perception related to purchasing and consumption and propensity for indebtedness by conducting two empirical studies. The first is a laboratory experiment, which accessed hope and risk perception of getting a mortgage loan. The second is a survey, investigating university students’ propensity to get indebted to pay for their university tuition, analyzed through the Structural Equations Modeling method. These studies found that higher levels of hope predicted an increase in the propensity to accept the mortgage loan, independent of actual risks, and an increase in the propensity of college students to get indebted to pay for their studies. In addition, the first study suggests that hope may lead to a decrease in risk perception, which, however, wasn’t confirmed by the second study. Finally, this research offers some methodological contributions, using an experimental approach to understand hope and its relationship with perceived financial risk and propensity for indebtedness.

The Exo-S probe class starshade mission

Science.gov (United States)

Seager, Sara; Turnbull, Margaret; Sparks, William; Thomson, Mark; Shaklan, Stuart B.; Roberge, Aki; Kuchner, Marc; Kasdin, N. Jeremy; Domagal-Goldman, Shawn; Cash, Webster; Warfield, Keith; Lisman, Doug; Scharf, Dan; Webb, David; Trabert, Rachel; Martin, Stefan; Cady, Eric; Heneghan, Cate

2015-09-01

Exo-S is a direct imaging space-based mission to discover and characterize exoplanets. With its modest size, Exo-S bridges the gap between census missions like Kepler and a future space-based flagship direct imaging exoplanet mission. With the ability to reach down to Earth-size planets in the habitable zones of nearly two dozen nearby stars, Exo-S is a powerful first step in the search for and identification of Earth-like planets. Compelling science can be returned at the same time as the technological and scientific framework is developed for a larger flagship mission. The Exo-S Science and Technology Definition Team studied two viable starshade-telescope missions for exoplanet direct imaging, targeted to the $1B cost guideline. The first Exo-S mission concept is a starshade and telescope system dedicated to each other for the sole purpose of direct imaging for exoplanets (The "Starshade Dedicated Mission"). The starshade and commercial, 1.1-m diameter telescope co-launch, sharing the same low-cost launch vehicle, conserving cost. The Dedicated mission orbits in a heliocentric, Earth leading, Earth-drift away orbit. The telescope has a conventional instrument package that includes the planet camera, a basic spectrometer, and a guide camera. The second Exo-S mission concept is a starshade that launches separately to rendezvous with an existing on-orbit space telescope (the "Starshade Rendezvous Mission"). The existing telescope adopted for the study is the WFIRST-AFTA (Wide-Field Infrared Survey Telescope Astrophysics Focused Telescope Asset). The WFIRST-AFTA 2.4-m telescope is assumed to have previously launched to a Halo orbit about the Earth-Sun L2 point, away from the gravity gradient of Earth orbit which is unsuitable for formation flying of the starshade and telescope. The impact on WFIRST-AFTA for starshade readiness is minimized; the existing coronagraph instrument performs as the starshade science instrument, while formation guidance is handled by the

Globally covering a-priori regional gravity covariance models

Directory of Open Access Journals (Sweden)

D. Arabelos

2003-01-01

Full Text Available Gravity anomaly data generated using Wenzel’s GPM98A model complete to degree 1800, from which OSU91A has been subtracted, have been used to estimate covariance functions for a set of globally covering equal-area blocks of size 22.5° × 22.5° at Equator, having a 2.5° overlap. For each block an analytic covariance function model was determined. The models are based on 4 parameters: the depth to the Bjerhammar sphere (determines correlation, the free-air gravity anomaly variance, a scale factor of the OSU91A error degree-variances and a maximal summation index, N, of the error degree-variances. The depth of Bjerhammar-sphere varies from -134km to nearly zero, N varies from 360 to 40, the scale factor from 0.03 to 38.0 and the gravity variance from 1081 to 24(10µms-22. The parameters are interpreted in terms of the quality of the data used to construct OSU91A and GPM98A and general conditions such as the occurrence of mountain chains. The variation of the parameters show that it is necessary to use regional covariance models in order to obtain a realistic signal to noise ratio in global applications.Key words. GOCE mission, Covariance function, Spacewise approach`

An Atmospheric Variability Model for Venus Aerobraking Missions

Science.gov (United States)

Tolson, Robert T.; Prince, Jill L. H.; Konopliv, Alexander A.

2013-01-01

Aerobraking has proven to be an enabling technology for planetary missions to Mars and has been proposed to enable low cost missions to Venus. Aerobraking saves a significant amount of propulsion fuel mass by exploiting atmospheric drag to reduce the eccentricity of the initial orbit. The solar arrays have been used as the primary drag surface and only minor modifications have been made in the vehicle design to accommodate the relatively modest aerothermal loads. However, if atmospheric density is highly variable from orbit to orbit, the mission must either accept higher aerothermal risk, a slower pace for aerobraking, or a tighter corridor likely with increased propulsive cost. Hence, knowledge of atmospheric variability is of great interest for the design of aerobraking missions. The first planetary aerobraking was at Venus during the Magellan mission. After the primary Magellan science mission was completed, aerobraking was used to provide a more circular orbit to enhance gravity field recovery. Magellan aerobraking took place between local solar times of 1100 and 1800 hrs, and it was found that the Venusian atmospheric density during the aerobraking phase had less than 10% 1 sigma orbit to orbit variability. On the other hand, at some latitudes and seasons, Martian variability can be as high as 40% 1 sigmaFrom both the MGN and PVO mission it was known that the atmosphere, above aerobraking altitudes, showed greater variability at night, but this variability was never quantified in a systematic manner. This paper proposes a model for atmospheric variability that can be used for aerobraking mission design until more complete data sets become available.

Is nonrelativistic gravity possible?

International Nuclear Information System (INIS)

Kocharyan, A. A.

2009-01-01

We study nonrelativistic gravity using the Hamiltonian formalism. For the dynamics of general relativity (relativistic gravity) the formalism is well known and called the Arnowitt-Deser-Misner (ADM) formalism. We show that if the lapse function is constrained correctly, then nonrelativistic gravity is described by a consistent Hamiltonian system. Surprisingly, nonrelativistic gravity can have solutions identical to relativistic gravity ones. In particular, (anti-)de Sitter black holes of Einstein gravity and IR limit of Horava gravity are locally identical.

On the estimation of physical height changes using GRACE satellite mission data – A case study of Central Europe

Directory of Open Access Journals (Sweden)

Godah Walyeldeen

2017-12-01

Full Text Available The dedicated gravity satellite missions, in particular the GRACE (Gravity Recovery and Climate Experiment mission launched in 2002, provide unique data for studying temporal variations of mass distribution in the Earth’s system, and thereby, the geometry and the gravity fi eld changes of the Earth. The main objective of this contribution is to estimate physical height (e.g. the orthometric/normal height changes over Central Europe using GRACE satellite mission data as well as to analyse them and model over the selected study area. Physical height changes were estimated from temporal variations of height anomalies and vertical displacements of the Earth surface being determined over the investigated area. The release 5 (RL05 GRACE-based global geopotential models as well as load Love numbers from the Preliminary Reference Earth Model (PREM were used as input data. Analysis of the estimated physical height changes and their modelling were performed using two methods: the seasonal decomposition method and the PCA/ EOF (Principal Component Analysis/Empirical Orthogonal Function method and the differences obtained were discussed. The main fi ndings reveal that physical height changes over the selected study area reach up to 22.8 mm. The obtained physical height changes can be modelled with an accuracy of 1.4 mm using the seasonal decomposition method.

Materials processing in zero gravity. [space manufacturing

Science.gov (United States)

Wuenscher, H. F.

1973-01-01

Manufacturing processes which are expected to show drastic changes in a space environment due to the absence of earth gravity are classified according to (1) buoyancy and thermal convection sensitive processes and (2) processes where molecular forces like cohesion and adhesion remain as the relatively strongest and hence controlling factors. Some specific process demonstration experiments carried out during the Apollo 14 mission and in the Skylab program are described. These include chemical separation by electrophoresis, the M551 metals melting experiment, the M552 exothermic brazing experiment, the M553 sphere forming experiment, the M554 composite casting experiment, and the M555 gallium arsenide crystal growth experiment.

Education for Peace and a Pedagogy of Hope

Science.gov (United States)

Carl, A. E.

2011-01-01

There are many approaches and arguments on how hope could be given to children in a society characterised by violence and conflict, hope that may contribute towards optimising their potential. This article focuses on the notion and meaning of Peace Education, what the possible link between Peace Education and a Pedagogy of Hope might be and…

Gravity control of growth form in brassica rapa and arabidopsis thaliana (brassicaceae): consequences for secondary metabolism

NARCIS (Netherlands)

Allen, J.; Bisbee, P.A.; Darnell, R.L.; Kuang, A.; Levine, L.H.; Musgrave, M.E.; van Loon, J.J.W.A.

2009-01-01

How gravity influences the growth form and flavor components of plants is of interest to the space program because plants could be used for food and life support during prolonged missions away from the planet, where that constant feature of Earth’s environment does not prevail. We used plant growth

Gravity-matter entanglement in Regge quantum gravity

International Nuclear Information System (INIS)

Paunković, Nikola; Vojinović, Marko

2016-01-01

We argue that Hartle-Hawking states in the Regge quantum gravity model generically contain non-trivial entanglement between gravity and matter fields. Generic impossibility to talk about “matter in a point of space” is in line with the idea of an emergent spacetime, and as such could be taken as a possible candidate for a criterion for a plausible theory of quantum gravity. Finally, this new entanglement could be seen as an additional “effective interaction”, which could possibly bring corrections to the weak equivalence principle. (paper)

The Laughter as Hope Principle

Directory of Open Access Journals (Sweden)

Mateus Domingues da Silva

2015-04-01

Full Text Available The work aims to establish a parallel between the concept of laughter and the Hope Principle of Ernst Bloch, differentiating their relationship between the pursuit of individual happiness, said to be ideological, deceptive and precarious, and the pursuit of collective happiness, altruistic, that despite utopian it is also true and real, just for being selfless and real because, as a collective expression, indicating concretely and politically, is a real possibility.Keywords: Laughter, Hope Principle, Ernest Bloch, altruism.

The Armour of Hope and other works

OpenAIRE

Just, Kate

2013-01-01

The series of work entitled 'The Skin of Hope' was produced during a 2012 Australia Council for the Arts studio residency in Barcelona, where I was accompanied by my partner Paula and our adopted daughter, Hope. Blurring the usual divide between familial life and art practice, the residency inspired a series of hand knitted sculptures and photographs weaving an account of the ways that Hope and I acknowledge, bond and imprint each other at skin level. Materialising our past wounds and present...

Lovelock gravities from Born-Infeld gravity theory

Science.gov (United States)

Concha, P. K.; Merino, N.; Rodríguez, E. K.

2017-02-01

We present a Born-Infeld gravity theory based on generalizations of Maxwell symmetries denoted as Cm. We analyze different configuration limits allowing to recover diverse Lovelock gravity actions in six dimensions. Further, the generalization to higher even dimensions is also considered.

Euler–Chern–Simons gravity from Lovelock–Born–Infeld gravity

OpenAIRE

Izaurieta, F.; Rodriguez, E.; Salgado, P.

2004-01-01

In the context of a gauge theoretical formulation, higher dimensional gravity invariant under the AdS group is dimensionally reduced to Euler-Chern-Simons gravity. The dimensional reduction procedure of Grignani-Nardelli [Phys. Lett. B 300, 38 (1993)] is generalized so as to permit reducing D-dimensional Lanczos Lovelock gravity to d=D-1 dimensions.

Hope in severe disease: a review of the literature on the construct and the tools for assessing hope in the psycho-oncologic setting.

Science.gov (United States)

Piccinelli, Claudia; Clerici, Carlo Alfredo; Veneroni, Laura; Ferrari, Andrea; Proserpio, Tullio

2015-01-01

Research on the topic of hope began a long time ago but, more recently, interest in this construct has focused mainly on the development of psychometric tools for its assessment. The 2 steps of the present article are defining the construct of hope by completing a preliminary review of the literature and analyzing the tools used to assess hope in the setting of oncologic medicine, conducting a systematic review of the existing scientific literature. Our study was conducted in 2 stages. The first stage involved a nonsystematic preliminary review of the literature, the second a systematic search in all the medical journals contained in the Medline database as of 2012. The literature identified at the first stage was divided according to several topical categories, i.e., theoretical, empirical, and clinical works on the construct of hope. In the second systematic search, we identified the main psychometric tools used to measure hope in the field of clinical oncology and assessed their validity. A total of 22 articles were identified. What emerged when we pooled the findings of our 2 lines of research was that, despite its broad theoretical definitions, the construct of hope can be broken down to a few constituent elements when hope is studied using currently available psychometric tools. In particular, these identified constituent elements were coping, spiritual well-being, quality of life, distress, and depression. The factors contained in the construct of hope include temporality, future, expectancy, motivation, and interconnectedness. The review of the scientific literature does not reveal a clear definition of hope. Multidisciplinary studies are needed to communicate different perspectives (medical, psychological, spiritual, theological) among each other for better definition of the constituent elements of hope in order to support the hope with specific interventions.

eXTP: Enhanced X-Ray Timing and Polarimetry Mission

Science.gov (United States)

Zhang, S. N.; Feroci, M.; Santangelo, A.; Dong, Y. W.; Feng, H.; Lu, F. J.; Nandra, K.; Wang, Z. S.; Zhang, S.; Bozzo, E.;

Renegotiating hope while living with lymphoedema after cancer: a qualitative study.

Science.gov (United States)

Hamilton, R; Thomas, R

2016-09-01

Hope is defined as a multi-dimensional life force, a coping resource and a necessity for coping with illness. Concepts of normalcy, hope and loss are explored in this qualitative study and positioned within recent scholarship on hope in cancer survivors. The experiences of 13 participants (11 women, 2 men) in two Canadian provinces who were living with lymphoedema secondary to cancer were analysed. For these participants, hope assumed various meanings. For some, hope was seen as passive inaction, whereas hope for others was positive and action-oriented, even when faced with the uncertainty of chronic illness. Hope for the individual with lymphoedema is also juxtaposed with hope associated with cancer treatment where a desired return to normal is the object of hope and paramount to coping. However, when met with the chronic nature of lymphoedema, the hope of a return to normalcy is lost and the meaning, direction and actions of hope must be renegotiated. © 2015 John Wiley & Sons Ltd.

A modeling study of the effect of gravity on airflow distribution and particle deposition in the lung.

Science.gov (United States)

Asgharian, Bahman; Price, Owen; Oberdörster, Gunter

2006-06-01

Inhalation of particles generated as a result of thermal degradation from fire or smoke, as may occur on spacecraft, is of major health concern to space-faring countries. Knowledge of lung airflow and particle transport under different gravity environments is required to addresses this concern by providing information on particle deposition. Gravity affects deposition of particles in the lung in two ways. First, the airflow distribution among airways is changed in different gravity environments. Second, particle losses by sedimentation are enhanced with increasing gravity. In this study, a model of airflow distribution in the lung that accounts for the influence of gravity was used for a mathematical description of particle deposition in the human lung to calculate lobar, regional, and local deposition of particles in different gravity environments. The lung geometry used in the mathematical model contained five lobes that allowed the assessment of lobar ventilation distribution and variation of particle deposition. At zero gravity, it was predicted that all lobes of the lung expanded and contracted uniformly, independent of body position. Increased gravity in the upright position increased the expansion of the upper lobes and decreased expansion of the lower lobes. Despite a slight increase in predicted deposition of ultrafine particles in the upper lobes with decreasing gravity, deposition of ultrafine particles was generally predicted to be unaffected by gravity. Increased gravity increased predicted deposition of fine and coarse particles in the tracheobronchial region, but that led to a reduction or even elimination of deposition in the alveolar region for coarse particles. The results from this study show that existing mathematical models of particle deposition at 1 G can be extended to different gravity environments by simply correcting for a gravity constant. Controlled studies in astronauts on future space missions are needed to validate these predictions.

Management Through Hope

DEFF Research Database (Denmark)

Papazu, Irina

2016-01-01

fieldwork conducted on Samsø in 2013 and 2014, the paper takes as its starting point a citizens’ meeting in which a new renewable energy project is proposed by a municipal coordinator. This meeting, in which the municipal coordinator exhibits a “change management” attitude, fails to win the citizens......’ support and becomes an entry point into an investigation of how the REI project developers managed to get the island community to actively support the project. A gateway to the past, the meeting allows the author to ethnographically describe the unobserved events of 1997-2007. Findings – The argument...... is that the REI project developers practised management through hope or “hope management”, in contrast to “change management”, creating a project that succeeded in accomplishing its goals of changing the island due to its openness, its rootedness in the island community’s past, and the project developers’ ability...

Exploring the relationship between hope and burnout in competitive sport.

Science.gov (United States)

Gustafsson, Henrik; Hassmén, Peter; Podlog, Leslie

2010-12-01

Researchers have postulated that hope may be an important factor associated with burnout. Consistent with hope theory contentions, low-hope individuals may be susceptible to burnout because they are prone to experience goal blockage, frustration, and negative affect, all of which likely increase the risk of burnout. We examined the relationship between hope and athlete burnout among 178 competitive athletes (63 females and 115 males) aged 15-20 years. Hope was significantly and negatively correlated with all three burnout subscales: emotional/physical exhaustion, a reduced sense of accomplishment, and sport devaluation. Moreover, results of a multivariate analysis of variance showed that low-hope athletes scored significantly higher than medium- and high-hope athletes on all three burnout dimensions. Finally, results revealed that agency thinking was a significant predictor of all burnout dimensions. Frustration over unmet goals and a perceived lack of agency, a characteristic of low-hope athletes, might pose a risk factor in athlete burnout, whereas being able to maintain hope appears to be associated with health and well-being.

Gravity

CERN Document Server

Gamow, George

2003-01-01

A distinguished physicist and teacher, George Gamow also possessed a special gift for making the intricacies of science accessible to a wide audience. In Gravity, he takes an enlightening look at three of the towering figures of science who unlocked many of the mysteries behind the laws of physics: Galileo, the first to take a close look at the process of free and restricted fall; Newton, originator of the concept of gravity as a universal force; and Einstein, who proposed that gravity is no more than the curvature of the four-dimensional space-time continuum.Graced with the author's own draw

The ethics of providing hope in psychotherapy.

Science.gov (United States)

Dembo, Justine Sarah; Clemens, Norman A

2013-07-01

The instillation of hope is a common factor in most psychotherapies. A considerable literature exists on the ethics of providing false or positively biased hope in non-psychiatric medical settings, and ethicists have generally concluded that this practice is unethical. However, the literature on the ethics of encouraging hope in psychotherapy, especially in the case of treatment-resistant mental illness, is sparse. The author explores two clinical cases with the intention of examining the nature of hope, false hope, positive illusions, and denial, as they relate to our definitions of mental health and psychotherapy. The cases highlight the ethics of balancing an acknowledgment of likely treatment futility with a desire to hope. Clinical psychological studies on depressive realism and optimistic bias indicate that some degree of positive bias, referred to by some authors as "the optimal margin of illusion," is in fact necessary to promote what we define as "good mental health;" conversely, stark realism is correlated with mild to moderate depression. An examination of the existential literature, including Ernest Becker's work, The Denial of Death, indicates that without the defense mechanism of denial, human beings tend to experience paralytic despair as a result of being fallible, mortal creatures in a frightening world. The combination of these diverse bodies of literature, along with the surprising outcomes of our case examples, leads to an unexpected conclusion: it may occasionally be ethical to encourage some degree of optimistic bias, and perhaps even positive illusion, when treating patients in psychotherapy.

Metrics of hope: disciplining affect in oncology.

Science.gov (United States)

Brown, Nik

2015-03-01

This article explores the emergence of a 'regime of hope' in the context of oncology care, practice and research. More specifically, my focus is the emergence, since the 1970s or so, of hope scales and indexes used to metricise the emotional states of cancer patients. These usually take the form of psychometric tests designed and deployed in order to subject affective life to calculative and rational scrutiny. This article locates this within the tensions of a 'turn' towards the emotions in critical social science literature. Scholarship has, for instance, been anxious not to deny the embodied reality of affectivity and the emotions. But it has been equally important to recognise the extent to which emotions are discursively ordered and structured as objects and effects of power. This article charts the emergence of hope scales historically alongside wider historical forces in the metrification of life and health and more specifically the emotions. It locates hope scales in a post-war climate of individual resilience and perseverant enterprise and the significance of hope as a naturalised vitalistic attribute of biopolitical life. © The Author(s) 2014.

Dynamics of Superfluid Helium in Low-Gravity

Science.gov (United States)

Frank, David J.

1997-01-01

This report summarizes the work performed under a contract entitled 'Dynamics of Superfluid Helium in Low Gravity'. This project performed verification tests, over a wide range of accelerations of two Computational Fluid Dynamics (CFD) codes of which one incorporates the two-fluid model of superfluid helium (SFHe). Helium was first liquefied in 1908 and not until the 1930s were the properties of helium below 2.2 K observed sufficiently to realize that it did not obey the ordinary physical laws of physics as applied to ordinary liquids. The term superfluidity became associated with these unique observations. The low temperature of SFHe and it's temperature unifonrmity have made it a significant cryogenic coolant for use in space applications in astronomical observations with infrared sensors and in low temperature physics. Superfluid helium has been used in instruments such as the Shuttle Infrared Astronomy Telescope (IRT), the Infrared Astronomy Satellite (IRAS), the Cosmic Background Observatory (COBE), and the Infrared Satellite Observatory (ISO). It is also used in the Space Infrared Telescope (SIRTF), Relativity Mission Satellite formally called Gravity Probe-B (GP-B), and the Test of the Equivalence Principle (STEP) presently under development. For GP-B and STEP, the use of SFHE is used to cool Superconducting Quantum Interference Detectors (SQUIDS) among other parts of the instruments. The Superfluid Helium On-Orbit Transfer (SHOOT) experiment flown in the Shuttle studied the behavior of SFHE. This experiment attempted to get low-gravity slosh data, however, the main emphasis was to study the low-gravity transfer of SFHE from tank to tank. These instruments carried tanks of SFHE of a few hundred liters to 2500 liters. The capability of modeling the behavior of SFHE is important to spacecraft control engineers who must design systems that can overcome disturbances created by the movement of the fluid. In addition instruments such as GP-B and STEP are very

Analysis of Weyl-affine theories of gravity in terms of the gravitational frequency shift effect

International Nuclear Information System (INIS)

Coley, A.A.; Sarmiento, G.A.

1986-01-01

A subclass of nonmetric theories of gravity, called Weyl-affine theories of gravity (WATGs), is analyzed by calculating their predictions for the gravitational frequency shift undergone by a wave signal in a planned solar probe. The analysis is carried out using a formalism in a spherically symmetric and static gravitational field. One of the advantages of the formalism is that any possible ''nonmetricity'' is contained in an arbitrary function, λ, of the Newtonian gravitational potential, U. The numerical results are calculated for a situation modeling a future experiment in the solar system. In the calculations, the metric components and the function, λ, are expanded up to third order in U. Within the limits of the gravitational redshift experiments performed to date, it is found that WATGs must coincide with their metric counterparts (i.e., λ is unity). It is hoped that the planned solar probe will test the nature of the theories under investigation to a higher degree of accuracy

Lower dimensional gravity

International Nuclear Information System (INIS)

Brown, J.D.

1988-01-01

This book addresses the subject of gravity theories in two and three spacetime dimensions. The prevailing philosophy is that lower dimensional models of gravity provide a useful arena for developing new ideas and insights, which are applicable to four dimensional gravity. The first chapter consists of a comprehensive introduction to both two and three dimensional gravity, including a discussion of their basic structures. In the second chapter, the asymptotic structure of three dimensional Einstein gravity with a negative cosmological constant is analyzed. The third chapter contains a treatment of the effects of matter sources in classical two dimensional gravity. The fourth chapter gives a complete analysis of particle pair creation by electric and gravitational fields in two dimensions, and the resulting effect on the cosmological constant

Proposed gravity-gradient dynamics experiments in lunar orbit using the RAE-B spacecraft

Science.gov (United States)

Blanchard, D. L.; Walden, H.

1973-01-01

A series of seven gravity-gradient dynamics experiments is proposed utilizing the Radio Astronomy Explorer (RAE-B) spacecraft in lunar orbit. It is believed that none of the experiments will impair the spacecraft structure or adversely affect the continuation of the scientific mission of the satellite. The first experiment is designed to investigate the spacecraft dynamical behavior in the absence of libration damper action and inertia. It requires stable gravity-gradient capture of the spacecraft in lunar orbit with small amplitude attitude librations as a prerequisite. Four subsequent experiments involve partial retraction, ultimately followed by full redeployment, of one or two of the 230-meter booms forming the lunar-directed Vee-antenna. These boom length change operations will induce moderate amplitude angular librations of the spacecraft.

Lovelock gravities from Born–Infeld gravity theory

Directory of Open Access Journals (Sweden)

P.K. Concha

2017-02-01

Full Text Available We present a Born–Infeld gravity theory based on generalizations of Maxwell symmetries denoted as Cm. We analyze different configuration limits allowing to recover diverse Lovelock gravity actions in six dimensions. Further, the generalization to higher even dimensions is also considered.

Spirituality, hope, and self-sufficiency among low-income job seekers.

Science.gov (United States)

2015-04-01

Self-sufficiency (SS) is an important social welfare policy goal in the United States, yet little is known about the process that leads to SS. To address this gap in the literature, this study examined the relationship between spirituality, hope, and SS among a sample of low-income job seekers (N = 116). It was hypothesized that spirituality would be related to hope, and that hope, in turn, would be related to SS. Using survey data from two workforce development agencies, this hypothesis was confirmed-hope fully mediated the relationship between spirituality and SS. Of the two factors through which hope is commonly operationalized-agency and pathways-supplemental analysis suggested that spirituality only affects SS through the agency channel. To help foster hope in direct practice settings, it is suggested that social workers might employ spiritually modified cognitive-behavioral therapy protocols. Macrostructural interventions that block the pathway component of hope are also suggested to help reverse exclusion from labor market entry. As such, hope needs to be addressed comprehensively-intrapsychically and macrostructurally-to effect bottom-up change for SS. Engendering hope may assist clients overcome some of the many challenges they encounter on the journey to SS.

Posttraumatic growth and hope in parents of children with cancer.

Science.gov (United States)

Hullmann, Stephanie E; Fedele, David A; Molzon, Elizabeth S; Mayes, Sunnye; Mullins, Larry L

2014-01-01

Posttraumatic growth (PTG), a positive change in values and major life goals experienced as a result of the struggle with a highly challenging life circumstance, has been shown to be related to the construct of hope, the belief that goals can be met. To date, no studies have examined the relationship between PTG and hope in parents of children with cancer. Participants were parents (N = 85) of children and adolescents (ages 2-18 years, M = 7.72 years) receiving treatment for cancer. Parents completed a demographic questionnaire, the Posttraumatic Growth Inventory (PTGI), and Hope Scale (HS). Hope was found to be related to PTG in parents of children with cancer, with higher levels of hope associated with greater PTG. Exploratory analyses on the subscales of the PTGI revealed that hope was also related to higher scores on the Relating to Others, New Possibilities, Personal Strength, and Appreciation of Life subscales. Spiritual change was not related to hope in parents. Findings suggest that experiencing hope during the pediatric cancer experience may facilitate posttraumatic growth in parents. The construct of hope may be an important target of intervention for promoting positive adjustment in this population.

Self-esteem and hopefulness in adolescents with cancer.

Science.gov (United States)

Ritchie, M A

2001-02-01

Increased survivorship in childhood cancer has raised questions about adolescents' psychosocial functioning during the treatment experience and long-term adaptation as cancer survivors. This descriptive correlation study examines the relationships among the stages of adolescence, gender, self-esteem, and hopefulness in a sample of 45 adolescents with cancer. The perceived level of self-esteem was measured by using the Coopersmith Self-Esteem Inventory; the amount of hopefulness was measured by using the Hopefulness Scale for Adolescents. Mean scores for self-esteem and hopefulness were comparable to normative data reported for healthy adolescents on each scale. Perceived level of self-esteem and hopefulness did not significantly differ between boys and girls overall; early, middle, and late adolescents; or between boys and girls within each stage of adolescence. A stepwise multiple regression analysis showed self-esteem and the early stage of adolescence accounted for 27.3% (R2 = .306) of the variance in hopefulness scores. Self-esteem was the most significant predictor (F = 12.456, p = .001), explaining 20.7% of the variance (R2 = .225, p = .001). This study contributes to nursing the knowledge of the psychosocial response and the treatment experience in adolescents with cancer. These results can be used in future research to develop and test nursing actions that can influence a perceived sense of self-esteem and hopefulness and potentially allow for continued psychosocial development and effective coping among these adolescents during treatment and into survivorship.

Development of an Indexing Media Filtration System for Long Duration Space Missions

Science.gov (United States)

Agui, Juan H.; Vijayakumar, R.

2013-01-01

The effective maintenance of air quality aboard spacecraft cabins will be vital to future human exploration missions. A key component will be the air cleaning filtration system which will need to remove a broad size range of particles derived from multiple biological and material sources. In addition, during surface missions any extraterrestrial planetary dust, including dust generated by near-by ISRU equipment, which is tracked into the habitat will also need to be managed by the filtration system inside the pressurized habitat compartments. An indexing media filter system is being developed to meet the demand for long-duration missions that will result in dramatic increases in filter service life and loading capacity, and will require minimal crew involvement. The filtration system consists of three stages: an inertial impactor stage, an indexing media stage, and a high-efficiency filter stage, packaged in a stacked modular cartridge configuration. Each stage will target a specific range of particle sizes that optimize the filtration and regeneration performance of the system. An 1/8th scale and full-scale prototype of the filter system have been fabricated and have been tested in the laboratory and reduced gravity environments that simulate conditions on spacecrafts, landers and habitats. Results from recent laboratory and reduce-gravity flight tests data will be presented. The features of the new filter system may also benefit other closed systems, such as submarines, and remote location terrestrial installations where servicing and replacement of filter units is not practical.

Nonlocal gravity

CERN Document Server

Mashhoon, Bahram

2017-01-01

Relativity theory is based on a postulate of locality, which means that the past history of the observer is not directly taken into account. This book argues that the past history should be taken into account. In this way, nonlocality---in the sense of history dependence---is introduced into relativity theory. The deep connection between inertia and gravitation suggests that gravity could be nonlocal, and in nonlocal gravity the fading gravitational memory of past events must then be taken into account. Along this line of thought, a classical nonlocal generalization of Einstein's theory of gravitation has recently been developed. A significant consequence of this theory is that the nonlocal aspect of gravity appears to simulate dark matter. According to nonlocal gravity theory, what astronomers attribute to dark matter should instead be due to the nonlocality of gravitation. Nonlocality dominates on the scale of galaxies and beyond. Memory fades with time; therefore, the nonlocal aspect of gravity becomes wea...

A high-energy (35-500 MeV) proton monitor for the Gravity Probe-B Mission

Energy Technology Data Exchange (ETDEWEB)

McKenna-Lawlor, S. E-mail: stil@may.ie; Rusznyak, Peter; Buchman, Sasha; Shestople, Paul; Thatcher, John

2003-02-11

An innovative fault tolerant, high-energy particle monitor designed to record protons in the range 35-500 MeV when in polar orbit aboard NASA's Gravity Probe B spacecraft, is described. This device, which is configured to provide continuous, reliable operation in the hostile particle environment traversed by the spacecraft, can potentially be used either as an onboard monitor or as a scientific experiment.

Hope for recovery - how clinicians may facilitate this in their work.

Science.gov (United States)

Hobbs, Mia; Baker, Martyn

2012-04-01

The importance of having hope for recovery has been highlighted in numerous qualitative studies of recovery. It is identified as a vital part of this process, and guidelines suggest that service providers should therefore facilitate hope in their clinical work; however, they do not indicate how this guidance can be operationalised. To identify the sources of hope for recovery based on the accounts of people with experience of recovery; to ascertain how these accounts show service providers can facilitate such hope in their therapeutic work. Semi-structured interviews were conducted with eight people with experience of recovering from mental health problems. A grounded theory analysis was undertaken. A model conceptualising the role of hope in recovery was developed with three categories: "influence of others on hope", "personal hope" and "doing recovery". The model indicates a complex interaction between hope and recovery with an important role for social context and interpersonal relationships, including those with clinicians. Mental health service providers occupy a powerful position in relation to service users' hope, and must carefully consider how they communicate their own hopefulness about clients' recovery. Suggestions are made about facilitating hope for recovery.

Enhanced Gravity Tractor Technique for Planetary Defense

Science.gov (United States)

Mazanek, Daniel D.; Reeves, David M.; Hopkins, Joshua B.; Wade, Darren W.; Tantardini, Marco; Shen, Haijun

2015-01-01

Given sufficient warning time, Earth-impacting asteroids and comets can be deflected with a variety of different "slow push/pull" techniques. The gravity tractor is one technique that uses the gravitational attraction of a rendezvous spacecraft to the impactor and a low-thrust, high-efficiency propulsion system to provide a gradual velocity change and alter its trajectory. An innovation to this technique, known as the Enhanced Gravity Tractor (EGT), uses mass collected in-situ to augment the mass of the spacecraft, thereby greatly increasing the gravitational force between the objects. The collected material can be a single boulder, multiple boulders, regolith or a combination of different sources. The collected mass would likely range from tens to hundreds of metric tons depending on the size of the impactor and warning time available. Depending on the propulsion system's capability and the mass collected, the EGT approach can reduce the deflection times by a factor of 10 to 50 or more, thus reducing the deflection times of several decades to years or less and overcoming the main criticism of the traditional gravity tractor approach. Additionally, multiple spacecraft can orbit the target in formation to provide the necessary velocity change and further reduce the time needed by the EGT technique to divert hazardous asteroids and comets. The robotic segment of NASA's Asteroid Redirect Mission (ARM) will collect a multi-ton boulder from the surface of a large Near-Earth Asteroid (NEA) and will provide the first ever demonstration of the EGT technique and validate one method of collecting in-situ mass on an asteroid of hazardous size.

Risk of Orthostatic Intolerance During Re-Exposure to Gravity

Science.gov (United States)

Platts, Steven; Stenger, Michael B.; Lee, Stuart M. C.; Westby, Christian M.; Phillips, Tiffany R.; Arzeno, Natalia M.; Johnston, Smith; Mulugeta, Lealem

2015-01-01

Post-spaceflight orthostatic intolerance remains a significant concern to NASA. In Space Shuttle missions, astronauts wore anti-gravity suits and liquid cooling garments to protect against orthostatic intolerance during re-entry and landing, but in-flight exercise and the end-of-mission fluid loading failed to protect approximately 30% of Shuttle astronauts when these garments were not worn. The severity of the problem appears to be increased after long-duration space flight. Five of six US astronauts could not complete a 10-minutes upright-posture tilt testing on landing day following 4-5 month stays aboard the Mir space station. The majority of these astronauts had experienced no problems of orthostatic intolerance following their shorter Shuttle flights. More recently, four of six US astronauts could not complete a tilt test on landing day following approximately 6 month stays on the International Space Station. Similar observations were made in the Soviet and Russian space programs, such that some cosmonauts wear the Russian compression garments (Kentavr) up to 4 days after landing. Future exploration missions, such as those to Mars or Near Earth Objects, will be long duration, and astronauts will be landing on planetary bodies with no ground-support teams. The occurrence of severe orthostatic hypotension could threaten the astronauts' health and safety and success of the mission.

Testing general relativity and alternative theories of gravity with space-based atomic clocks and atom interferometers

Directory of Open Access Journals (Sweden)

Bondarescu Ruxandra

2015-01-01

Full Text Available The successful miniaturisation of extremely accurate atomic clocks and atom interferometers invites prospects for satellite missions to perform precision experiments. We discuss the effects predicted by general relativity and alternative theories of gravity that can be detected by a clock, which orbits the Earth. Our experiment relies on the precise tracking of the spacecraft using its observed tick-rate. The spacecraft’s reconstructed four-dimensional trajectory will reveal the nature of gravitational perturbations in Earth’s gravitational field, potentially differentiating between different theories of gravity. This mission can measure multiple relativistic effects all during the course of a single experiment, and constrain the Parametrized Post-Newtonian Parameters around the Earth. A satellite carrying a clock of fractional timing inaccuracy of Δ f / f ∼ 10−16 in an elliptic orbit around the Earth would constrain the PPN parameters |β − 1|, |γ − 1| ≲ 10−6. We also briefly review potential constraints by atom interferometers on scalar tensor theories and in particular on Chameleon and dilaton models.

Geometric Liouville gravity

International Nuclear Information System (INIS)

La, H.

1992-01-01

A new geometric formulation of Liouville gravity based on the area preserving diffeo-morphism is given and a possible alternative to reinterpret Liouville gravity is suggested, namely, a scalar field coupled to two-dimensional gravity with a curvature constraint

Modeling and estimation of a low degree geopotential model from terrestrial gravity data

Science.gov (United States)

Pavlis, Nikolaos K.

1988-01-01

The development of appropriate modeling and adjustment procedures for the estimation of harmonic coefficients of the geopotential, from surface gravity data was studied, in order to provide an optimum way of utilizing the terrestrial gravity information in combination solutions currently developed at NASA/Goddard Space Flight Center, for use in the TOPEX/POSEIDON mission. The mathematical modeling was based on the fundamental boundary condition of the linearized Molodensky boundary value problem. Atmospheric and ellipsoidal corrections were applied to the surface anomalies. Terrestrial gravity solutions were found to be in good agreement with the satellite ones over areas which are well surveyed (gravimetrically), such as North America or Australia. However, systematic differences between the terrestrial only models and GEMT1, over extended regions in Africa, the Soviet Union, and China were found. In Africa, gravity anomaly differences on the order of 20 mgals and undulation differences on the order of 15 meters, over regions extending 2000 km in diameter, occur. Comparisons of the GEMT1 implied undulations with 32 well distributed Doppler derived undulations gave an RMS difference of 2.6 m, while corresponding comparison with undulations implied by the terrestrial solution gave RMS difference on the order of 15 m, which implies that the terrestrial data in that region are substantially in error.

Correlation of Normal Gravity Mixed Convection Blowoff Limits with Microgravity Forced Flow Blowoff Limits

Science.gov (United States)

Marcum, Jeremy W.; Olson, Sandra L.; Ferkul, Paul V.

2016-01-01

The axisymmetric rod geometry in upward axial stagnation flow provides a simple way to measure normal gravity blowoff limits to compare with microgravity Burning and Suppression of Solids - II (BASS-II) results recently obtained aboard the International Space Station. This testing utilized the same BASS-II concurrent rod geometry, but with the addition of normal gravity buoyant flow. Cast polymethylmethacrylate (PMMA) rods of diameters ranging from 0.635 cm to 3.81 cm were burned at oxygen concentrations ranging from 14 to 18% by volume. The forced flow velocity where blowoff occurred was determined for each rod size and oxygen concentration. These blowoff limits compare favorably with the BASS-II results when the buoyant stretch is included and the flow is corrected by considering the blockage factor of the fuel. From these results, the normal gravity blowoff boundary for this axisymmetric rod geometry is determined to be linear, with oxygen concentration directly proportional to flow speed. We describe a new normal gravity 'upward flame spread test' method which extrapolates the linear blowoff boundary to the zero stretch limit in order to resolve microgravity flammability limits-something current methods cannot do. This new test method can improve spacecraft fire safety for future exploration missions by providing a tractable way to obtain good estimates of material flammability in low gravity.

Gravity resistance, another graviresponse in plants - role of microtubule-membrane-cell wall continuum

Science.gov (United States)

Hoson, T.; Saito, Y.; Usui, S.; Soga, K.; Wakabayashi, K.

Resistance to the gravitational force has been a serious problem for plants to survive on land, after they first went ashore more than 400 million years ago. Thus, gravity resistance is the principal graviresponse in plants comparable to gravitropism. Nevertheless, only limited information has been obtained for this second gravity response. We have examined the mechanism of gravity resistance using hypergravity conditions produced by centrifugation. The results led a hypothesis on the mechanism of plant resistance to the gravitational force that the plant constructs a tough body by increasing the cell wall rigidity, which are brought about by modification of the cell wall metabolism and cell wall environment, especially pH. The hypothesis was further supported by space experiments during the Space Shuttle STS-95 mission. On the other hand, we have shown that gravity signal may be perceived by mechanoreceptors (mechanosensitive ion channels) on the plasma membrane and amyloplast sedimentation in statocytes is not involved in gravity resistance. Moreover, hypergravity treatment increased the expression levels of genes encoding alpha-tubulin, a component of microtubules and 3-hydroxy-3-methylglutaryl-Coenzyme A reductase (HMGR), which catalyzes a reaction producing mevalonic acid, a key precursor of terpenoids such as membrane sterols. The expression of HMGR and alpha- and beta-tubulin genes increased within several hours after hypergravity treatment, depending on the magnitude of gravity. The determination of levels of gene products as well as the analysis with knockout mutants of these genes by T-DNA insertions in Arabidopsis supports the involvement of both membrane sterols and microtubules in gravity resistance. These results suggest that structural or physiological continuum of microtubule-cell membrane-cell wall is responsible for plant resistance to the gravitational force.

A pragmatist approach to the hope discourse in health care research.

Science.gov (United States)

Herrestad, Henning; Biong, Stian; McCormack, Brendan; Borg, Marit; Karlsson, Bengt

2014-07-01

Hope is a central concept in nursing and other fields of health care. However, there is no consensus about the concept of hope. We argue that seeking consensus is futile given the multifaceted and multidimensional nature of the concept, but instead we encourage in-depth studies of the assumptions behind talk about hope in specific contexts. Our approach to the 'science of hope' is inspired by philosophical pragmatism. We argue that hope is a concept that opens different rooms for action in different contexts and that accordingly, all hope interventions are contextually sensitive. Careful attention to how the relative positions and power of nurses and patients influence what can be inferred from their different ways of talking about hope may make hopeful conversations more meaningful in health care relationships. © 2014 John Wiley & Sons Ltd.

Covariant w∞ gravity

NARCIS (Netherlands)

Bergshoeff, E.; Pope, C.N.; Stelle, K.S.

1990-01-01

We discuss the notion of higher-spin covariance in w∞ gravity. We show how a recently proposed covariant w∞ gravity action can be obtained from non-chiral w∞ gravity by making field redefinitions that introduce new gauge-field components with corresponding new gauge transformations.

Near Earth Asteroid redirect missions based on gravity assist maneuver

Science.gov (United States)

Ledkov, Anton; Shustov, Boris M.; Eismont, Natan; Boyarsky, Michael; Nazirov, Ravil; Fedyaev, Konstantin

During last years several events attracted world community attention to the hazards of hitting the Earth by sky objects. One of these objects is Apophis asteroid what was expected with nonzero probability to hit the Earth in 2036. Luckily after more precise measurements this event is considered as practically improbable. But the other object has really reached the Earth, entered the atmosphere in the Chelyabinsk area and caused vast damages. After this the hazardous near Earth objects problem received practical confirmation of the necessity to find the methods of its resolution. The methods to prevent collision of the dangerous sky object with the Earth proposed up to now look not practical enough if one mentions such as gravitational tractor or changing the reflectivity of the asteroid surface. Even the method supposing the targeting of the spacecraft to the hazardous object in order to deflect it from initial trajectory by impact does not work because its low mass as compared with the mass of asteroid to be deflected. For example the mass of the Apophis is estimated to be about 40 million tons but the spacecraft which can be launched to intercept the asteroid using contemporary launchers has the mass not more than 5 tons. So the question arises where to find the heavier projectile which is possible to direct to the dangerous object? The answer proposed in our paper is very simple: to search it among small near Earth asteroids. As small ones we suppose those which have the cross section size not more than 12-15 meters and mass not exceeding 1500 -1700 tons. According to contemporary estimates the number of such asteroids is not less than 100000. The other question is how to redirect such asteroid to the dangerous one. In the paper the possibilities are studied to use for that purpose gravity assist maneuvers near Earth. It is shown that even among asteroids included in contemporary catalogue there are the ones which could be directed to the trajectory of the

The feeling of hope in cancer patients: an existential analysis

Directory of Open Access Journals (Sweden)

Catarina Aparecida Sales

2014-10-01

Full Text Available This study aimed at unveiling the feeling of hope in people who experience cancer in their existence. Qualitative study based on Heidegger’s phenomenology, performed with eight cancer patients assisted in a philanthropic organization, between December 2013 and February 2014, in a northwestern city in Paraná, Brazil, using the following guiding question: “How do you perceive the feeling of hope at this time in your life?” The analysis resulted in the ontological themes: searching for hope in dealing with cancer, and experiencing feelings of hope and despair in being with others. Patients revealed mixed feelings, going from the lack of hope at the time of diagnosis to a rekindling of hope, as well as those who never lost the will to live. We conclude that living with cancer causes extreme feelings; and hope emerges as a feeling capable of influencing and causes an expressive impact in coping with that.

Development of the Two Phase Flow Separator Experiment for a Reduced Gravity Aircraft Flight

Science.gov (United States)

Golliher, Eric; Gotti, Daniel; Owens, Jay; Gilkey, Kelly; Pham, Nang; Stehno, Philip

2016-01-01

The recent hardware development and testing of a reduced gravity aircraft flight experiment has provided valuable insights for the future design of the Two Phase Flow Separator Experiment (TPFSE). The TPFSE is scheduled to fly within the Fluids Integration Rack (FIR) aboard the International Space Station (ISS) in 2020. The TPFSE studies the operational limits of gas and liquid separation of passive cyclonic separators. A passive cyclonic separator utilizes only the inertia of the incoming flow to accomplish the liquid-gas separation. Efficient phase separation is critical for environmental control and life support systems, such as recovery of clean water from bioreactors, for long duration human spaceflight missions. The final low gravity aircraft flight took place in December 2015 aboard NASA's C9 airplane.

First Results of the aerogravity measurements during the geoscientific flight mission GEOHALO over Italy and the adjacent Mediterranean

Science.gov (United States)

Heyde, Ingo; Barthelmes, Franz; Scheinert, Mirko

2013-04-01

In June 2012 the first scientific flight mission was realized with the new German research aircraft HALO (High Altitude and Long Range Research Aircraft). For this geoscientific flight mission GEOHALO was equipped with geophysical-geodetic instrumentation to acquire data over the tectonically active region of Italy and the adjacent Medtiterranean. The Federal Institute for Geosciences and Resources (BGR) as a member of the "HALO geoscience group" operated the recently modernized KSS32-M aerogravity system. The instrumentation of the group partners consists of an additional gravimeter, vector and scalar magnetometers, a laser altimeter and GNSS equipment with zenith, sideward and nadir antennas. During four flights with duration of up to 10 hours, data along a total track length of 16150 kilometers were obtained. The mission flights started and ended at the special airfield Oberpfaffenhofen, near the compound of the German Aerospace Center (DLR). Eight parallel profiles running from north-west to south-east were flown in an altitude of about 3500 m. The length of each profile was about 1000 km with a line spacing of 40 km. The flight velocity on the survey lines amounted to approximately 450 km/h. Four crossing lines of about 300 km length and a profile at an altitude of about 10500 m along the same track as a line in the lower altitude completed the survey. The first results of the BGR aerogravity will be presented. To determine the free-air gravity anomalies from the measured gravimeter data a number of corrections have to be applied. For their calculation mainly high-precision position and velocity data are mandatory. The kinematic GPS data were combined with INS data. In addition to own GPS base station data from Oberpfaffenhofen, data of Italian GNSS stations were considered to improve the determination of the flight trajectory by differential GPS. The corrected gravity data are compared with the corresponding data from global gravity models. The free

Analogue Gravity

Directory of Open Access Journals (Sweden)

Carlos Barceló

2011-05-01

Full Text Available Analogue gravity is a research programme which investigates analogues of general relativistic gravitational fields within other physical systems, typically but not exclusively condensed matter systems, with the aim of gaining new insights into their corresponding problems. Analogue models of (and for gravity have a long and distinguished history dating back to the earliest years of general relativity. In this review article we will discuss the history, aims, results, and future prospects for the various analogue models. We start the discussion by presenting a particularly simple example of an analogue model, before exploring the rich history and complex tapestry of models discussed in the literature. The last decade in particular has seen a remarkable and sustained development of analogue gravity ideas, leading to some hundreds of published articles, a workshop, two books, and this review article. Future prospects for the analogue gravity programme also look promising, both on the experimental front (where technology is rapidly advancing and on the theoretical front (where variants of analogue models can be used as a springboard for radical attacks on the problem of quantum gravity.

Beauty and Hope: A Moral Beauty Intervention

Science.gov (United States)

Diessner, Rhett; Rust, Teri; Solom, Rebecca C.; Frost, Nellie; Parsons, Lucas

2006-01-01

Pedagogical intervention regarding engagement with natural, artistic and moral beauty can lead to an increase in trait hope. In a quasi-experimental design with college students the intervention group showed significantly higher gain scores on trait hope than did the comparison group; the effect size was moderate. The experimental group also…

Hope for Animals

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 20; Issue 8. Hope for Animals. Prasanna Venkhatesh V. Book Review Volume 20 Issue 8 August 2015 pp 753-754. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/020/08/0753-0754. Author Affiliations.

LISA Pathfinder E2E performance simulation: optical and self-gravity stability analysis

Science.gov (United States)

Brandt, N.; Fichter, W.; Kersten, M.; Lucarelli, S.; Montemurro, F.

2005-05-01

End-to-end (E2E) modelling and simulation, i.e. verifying the science performance of LISA Pathfinder (spacecraft and payload), is mandatory in order to minimize mission risks. In this paper, focus is on two particular applications of the E2E performance simulator currently being developed at EADS Astrium GmbH: the opto-dynamical stability and the self-gravity disturbance stability analysis. The E2E models applied here comprise the opto-dynamical modelling of the optical metrology systems (OMS) laser interferometry, the thermo-elastic distortion modelling of the OMS optical elements and the self-gravity disturbance model accounting for structural distortions. Preliminary analysis results are presented in detail, identifying shortcomings of the current LISA technology package (LTP) mounting baseline. As a consequence, the design is now being revised.

LISA Pathfinder E2E performance simulation: optical and self-gravity stability analysis

International Nuclear Information System (INIS)

Brandt, N; Fichter, W; Kersten, M; Lucarelli, S; Montemurro, F

2005-01-01

End-to-end (E2E) modelling and simulation, i.e. verifying the science performance of LISA Pathfinder (spacecraft and payload), is mandatory in order to minimize mission risks. In this paper, focus is on two particular applications of the E2E performance simulator currently being developed at EADS Astrium GmbH: the opto-dynamical stability and the self-gravity disturbance stability analysis. The E2E models applied here comprise the opto-dynamical modelling of the optical metrology systems (OMS) laser interferometry, the thermo-elastic distortion modelling of the OMS optical elements and the self-gravity disturbance model accounting for structural distortions. Preliminary analysis results are presented in detail, identifying shortcomings of the current LISA technology package (LTP) mounting baseline. As a consequence, the design is now being revised

Quantum Gravity Phenomenology

OpenAIRE

Amelino-Camelia, Giovanni

2003-01-01

Comment: 9 pages, LaTex. These notes were prepared while working on an invited contribution to the November 2003 issue of Physics World, which focused on quantum gravity. They intend to give a non-technical introduction (accessible to readers from outside quantum gravity) to "Quantum Gravity Phenomenology"

Effect of storytelling on hopefulness in girl students.

Science.gov (United States)

Shafieyan, Shima; Soleymani, Mohammad Reza; Samouei, Raheleh; Afshar, Mina

2017-01-01

One of the methods that help students in learning critical thinking and decision-making skills is storytelling. Story helps the students to place themselves in the same situation as the main protagonist and try different ways and finally select and implement the best possible method. The goal of this study is to investigate the effect of storytelling on hopefulness of students, age 8-11 in Isfahan's 2 nd educational district. This is an applied, quasi-experimental study. The study population comprised of 34 randomly selected students attending one of the schools in Isfahan's 2 nd educational district. The data gathering tool was the standard Kazdin hopefulness scale (α = 0.72) and data were gathered before and after 8 storytelling sessions for the intervention group. The gathered data were analyzed using descriptive and analytical (paired and independent t -test) with the help of SPSS Version 18 software. The study's findings showed a significant difference in the average hopefulness score of students in study group in pre- and posttest ( P = 0.04). Furthermore, independent t -test results showed a significant difference in hopefulness score of intervention and control ( P = 0.001). The average hopefulness score of the control group after storytelling sessions was higher than that of the intervention and control. The results show the effectiveness of storytelling as a method for improving hopefulness in students.

Marine Geoid Undulation Assessment Over South China Sea Using Global Geopotential Models and Airborne Gravity Data

Science.gov (United States)

Yazid, N. M.; Din, A. H. M.; Omar, K. M.; Som, Z. A. M.; Omar, A. H.; Yahaya, N. A. Z.; Tugi, A.

2016-09-01

Global geopotential models (GGMs) are vital in computing global geoid undulations heights. Based on the ellipsoidal height by Global Navigation Satellite System (GNSS) observations, the accurate orthometric height can be calculated by adding precise and accurate geoid undulations model information. However, GGMs also provide data from the satellite gravity missions such as GRACE, GOCE and CHAMP. Thus, this will assist to enhance the global geoid undulations data. A statistical assessment has been made between geoid undulations derived from 4 GGMs and the airborne gravity data provided by Department of Survey and Mapping Malaysia (DSMM). The goal of this study is the selection of the best possible GGM that best matches statistically with the geoid undulations of airborne gravity data under the Marine Geodetic Infrastructures in Malaysian Waters (MAGIC) Project over marine areas in Sabah. The correlation coefficients and the RMS value for the geoid undulations of GGM and airborne gravity data were computed. The correlation coefficients between EGM 2008 and airborne gravity data is 1 while RMS value is 0.1499.In this study, the RMS value of EGM 2008 is the lowest among the others. Regarding to the statistical analysis, it clearly represents that EGM 2008 is the best fit for marine geoid undulations throughout South China Sea.

Automated borehole gravity meter system

International Nuclear Information System (INIS)

Lautzenhiser, Th.V.; Wirtz, J.D.

1984-01-01

An automated borehole gravity meter system for measuring gravity within a wellbore. The gravity meter includes leveling devices for leveling the borehole gravity meter, displacement devices for applying forces to a gravity sensing device within the gravity meter to bring the gravity sensing device to a predetermined or null position. Electronic sensing and control devices are provided for (i) activating the displacement devices, (ii) sensing the forces applied to the gravity sensing device, (iii) electronically converting the values of the forces into a representation of the gravity at the location in the wellbore, and (iv) outputting such representation. The system further includes electronic control devices with the capability of correcting the representation of gravity for tidal effects, as well as, calculating and outputting the formation bulk density and/or porosity

The Port Hope area initiative from municipal perspective

International Nuclear Information System (INIS)

Austin, R.

2006-01-01

'Full text:' This paper explores the Municipal perspective of the Port Hope Area Initiative (PHAI). The PHAI is unique in that it emerged from proposals to the Federal Government and subsequently a tri-partite agreement between the Federal Government and the Municipalities of Port Hope and Clarington for the cleanup and management of historic low-level radioactive wastes in long-term waste management facilities in their Municipalities. A key feature of the Port Hope Project is the remediation of many major and small scale sites in the urban area. As part of this Legal Agreement, each Municipality is required to give consent at key milestones for the project to proceed to the next stage. In addition, the Municipality also has veto authority if the preferred option is changed by the federal government during its final review. The Agreement also ensures that the Municipalities have the resources to conduct an independent assessment of the work completed by the federal proponent and to advise the Municipality on related matters. While this Legal Agreement provides the Municipalities with influence over the outcome of the EA and the project description, especially when compared with the typical role of municipalities in other Federal EAs, there are many challenges that Port Hope faces as partner in this process. These include: Balancing Port Hope's interests with those of the Federal Government; Reaching agreement on how clean the remediation sites should be; Considering the interests of future generations while meeting the needs of existing residents; Ensuring that the Project will have a positive legacy for Port Hope; Ensuring that institutional controls are in place and that Port Hope has a partnership role in monitoring the Project performance during the Construction Phase and the long term Maintenance and Monitoring Phase. In this context, this paper presents the unique aspects of the Municipal involvement in the process to finally achieve a safe, environmentally

Gravity is Geometry.

Science.gov (United States)

MacKeown, P. K.

1984-01-01

Clarifies two concepts of gravity--those of a fictitious force and those of how space and time may have geometry. Reviews the position of Newton's theory of gravity in the context of special relativity and considers why gravity (as distinct from electromagnetics) lends itself to Einstein's revolutionary interpretation. (JN)

Gravity inversion code

International Nuclear Information System (INIS)

Burkhard, N.R.

1979-01-01

The gravity inversion code applies stabilized linear inverse theory to determine the topography of a subsurface density anomaly from Bouguer gravity data. The gravity inversion program consists of four source codes: SEARCH, TREND, INVERT, and AVERAGE. TREND and INVERT are used iteratively to converge on a solution. SEARCH forms the input gravity data files for Nevada Test Site data. AVERAGE performs a covariance analysis on the solution. This document describes the necessary input files and the proper operation of the code. 2 figures, 2 tables

CDC Vital Signs: New Hope for Stopping HIV

Science.gov (United States)

... 27 MB] Read the MMWR Science Clips New Hope for Stopping HIV Testing and Medical Care Save ... acquired immunodeficiency syndrome) and early death. There's new hope today for stopping HIV in the US. Medicines ( ...

Gravity brake

Science.gov (United States)

Lujan, Richard E.

2001-01-01

A mechanical gravity brake that prevents hoisted loads within a shaft from free-falling when a loss of hoisting force occurs. A loss of hoist lifting force may occur in a number of situations, for example if a hoist cable were to break, the brakes were to fail on a winch, or the hoist mechanism itself were to fail. Under normal hoisting conditions, the gravity brake of the invention is subject to an upward lifting force from the hoist and a downward pulling force from a suspended load. If the lifting force should suddenly cease, the loss of differential forces on the gravity brake in free-fall is translated to extend a set of brakes against the walls of the shaft to stop the free fall descent of the gravity brake and attached load.

The Cause of Gravity

OpenAIRE

Byrne, Michael

1999-01-01

Einstein said that gravity is an acceleration like any other acceleration. But gravity causes relativistic effects at non-relativistic speeds; so gravity could have relativistic origins. And since the strong force is thought to cause most of mass, and mass is proportional to gravity; the strong force is therefore also proportional to gravity. The strong force could thus cause relativistic increases of mass through the creation of virtual gluons; along with a comparable contraction of space ar...

Ultimate journey of the terminally ill: Ways and pathways of hope.

Science.gov (United States)

Daneault, Serge; Lussier, Véronique; Mongeau, Suzanne; Yelle, Louise; Côté, Andréanne; Sicotte, Claude; Paillé, Pierre; Dion, Dominique; Coulombe, Manon

2016-08-01

To better understand the role of hope among terminally ill cancer patients. Qualitative analysis. A tertiary specialized cancer centre in Canada. Cancer patients in palliative care with an estimated remaining life expectancy of 12 months or less (N = 12) and their loved ones (N = 12) and treating physicians (N = 12). Each patient underwent up to 3 interviews and identified a loved one who participated in 1 interview. Treating physicians were also interviewed. All interviews were fully transcribed and analyzed by at least 2 investigators. Interviews were collected until saturation occurred. Seven attributes describe the experiences of palliative cancer patients and their caregivers: hope as an irrational phenomenon that is a deeply rooted, affect-based response to adversity; initial hope for miraculous healing; hope as a phenomenon that changes over time, evolving in different ways depending on circumstances; hope for prolonged life when there is no further hope for cure; hope for a good quality of life when the possibility of prolonging life becomes limited; a lack of hope for some when treatments are no longer effective in curbing illness progression; and for others hope as enjoying the present moment and preparing for the end of life. Approaches aimed at sustaining hope need to reflect that patients' reactions might fluctuate between despair and a form of acceptance that leads to a certain serenity. Clinicians need to maintain some degree of hope while remaining as realistic as possible. The findings also raise questions about how hope influences patients' perceptions and acceptance of their treatments. Copyright© the College of Family Physicians of Canada.

Cutoff for extensions of massive gravity and bi-gravity

International Nuclear Information System (INIS)

Matas, Andrew

2016-01-01

Recently there has been interest in extending ghost-free massive gravity, bi-gravity, and multi-gravity by including non-standard kinetic terms and matter couplings. We first review recent proposals for this class of extensions, emphasizing how modifications of the kinetic and potential structure of the graviton and modifications of the coupling to matter are related. We then generalize existing no-go arguments in the metric language to the vielbein language in second-order form. We give an ADM argument to show that the most promising extensions to the kinetic term and matter coupling contain a Boulware–Deser ghost. However, as recently emphasized, we may still be able to view these extensions as effective field theories below some cutoff scale. To address this possibility, we show that there is a decoupling limit where a ghost appears for a wide class of matter couplings and kinetic terms. In particular, we show that there is a decoupling limit where the linear effective vielbein matter coupling contains a ghost. Using the insight we gain from this decoupling limit analysis, we place an upper bound on the cutoff for the linear effective vielbein coupling. This result can be generalized to new kinetic interactions in the vielbein language in second-order form. Combined with recent results, this provides a strong uniqueness argument on the form of ghost-free massive gravity, bi-gravity, and multi-gravity. (paper)

Impact landing ends SMART-1 mission to the Moon

Science.gov (United States)

2006-09-01

SMART-1 scientists, engineers and space operations experts witnessed the final moments of the spacecraft’s life in the night between Saturday 2 and Sunday 3 September at ESA’s European Space Operations Centre (ESOC), in Darmstadt, Germany. The confirmation of the impact reached ESOC at 07:42:22 CEST (05:42:22 UT) when ESA’s New Norcia ground station in Australia suddenly lost radio contact with the spacecraft. SMART-1 ended its journey in the Lake of Excellence, in the point situated at 34.4º South latitude and 46.2º West longitude. The SMART-1 impact took place on the near side of the Moon, in a dark area just near the terminator (the line separating the day side from the night side), at a “grazing” angle of about one degree and a speed of about 2 kilometres per second. The impact time and location was planned to favour observations of the impact event from telescopes on Earth, and was achieved by a series of orbit manoeuvres and corrections performed during the course of summer 2006, the last of which was on 1 September. Professional and amateur ground observers all around the world - from South Africa to the Canary Islands, South America, the continental United States, Hawaii, and many other locations - were watching before and during the small SMART-1 impact, hoping to spot the faint impact flash and to obtain information about the impact dynamics and about the lunar surface excavated by the spacecraft. The quality of the data and images gathered from the ground observatories - a tribute to the end of the SMART-1 mission and a possible additional contribution to lunar science - will be assessed in the days to come. For the last 16 months and until its final orbits, SMART-1 has been studying the Moon, gathering data about the morphology and mineralogical composition of the surface in visible, infrared and X-ray light. “The legacy left by the huge wealth of SMART-1 data, to be analysed in the months and years to come, is a precious contribution to

The Call to Teach and Teacher Hopefulness

Science.gov (United States)

Bullough, Robert V., Jr.; Hall-Kenyon, Kendra M.

2011-01-01

The purpose of this paper is to explore teacher motivation and well-being. Our analysis focuses on two central concepts, the notion of a "calling to teach" and of teacher "hopefulness." Data from 205 preservice and inservice teachers were collected to determine teachers' sense of calling and level of hope. Results indicate that overwhelmingly,…

Monthly gravity field recovery from GRACE orbits and K-band measurements using variational equations approach

Directory of Open Access Journals (Sweden)

Changqing Wang

2015-07-01

Full Text Available The Gravity Recovery and Climate Experiment (GRACE mission can significantly improve our knowledge of the temporal variability of the Earth's gravity field. We obtained monthly gravity field solutions based on variational equations approach from GPS-derived positions of GRACE satellites and K-band range-rate measurements. The impact of different fixed data weighting ratios in temporal gravity field recovery while combining the two types of data was investigated for the purpose of deriving the best combined solution. The monthly gravity field solution obtained through above procedures was named as the Institute of Geodesy and Geophysics (IGG temporal gravity field models. IGG temporal gravity field models were compared with GRACE Release05 (RL05 products in following aspects: (i the trend of the mass anomaly in China and its nearby regions within 2005–2010; (ii the root mean squares of the global mass anomaly during 2005–2010; (iii time-series changes in the mean water storage in the region of the Amazon Basin and the Sahara Desert between 2005 and 2010. The results showed that IGG solutions were almost consistent with GRACE RL05 products in above aspects (i–(iii. Changes in the annual amplitude of mean water storage in the Amazon Basin were 14.7 ± 1.2 cm for IGG, 17.1 ± 1.3 cm for the Centre for Space Research (CSR, 16.4 ± 0.9 cm for the GeoForschungsZentrum (GFZ and 16.9 ± 1.2 cm for the Jet Propulsion Laboratory (JPL in terms of equivalent water height (EWH, respectively. The root mean squares of the mean mass anomaly in Sahara were 1.2 cm, 0.9 cm, 0.9 cm and 1.2 cm for temporal gravity field models of IGG, CSR, GFZ and JPL, respectively. Comparison suggested that IGG temporal gravity field solutions were at the same accuracy level with the latest temporal gravity field solutions published by CSR, GFZ and JPL.

The Value of Biomedical Simulation Environments to Future Human Space Flight Missions

Science.gov (United States)

Mulugeta,Lealem; Myers, Jerry G.; Lewandowski, Beth; Platts, Steven H.

2011-01-01

Mars and NEO missions will expose astronaut to extended durations of reduced reduced gravity, isolation and higher radiation. These new operation conditions pose health risks that are not well understood and perhaps unanticipated. Advanced computational simulation environments can beneficially augment research to predict, assess and mitigate potential hazards to astronaut health. The NASA Digital Astronaut Project (DAP), within the NASA Human Research Program, strives to achieve this goal.

Predictors of hope among women with breast cancer during chemotherapy

Directory of Open Access Journals (Sweden)

Alessandra Cristina Sartore Balsanelli

Full Text Available Abstract OBJECTIVE Identifying the predictors of hope in patients with breast cancer during chemotherapy treatment. METHOD A prospective longitudinal study. The sample was composed of 122 women who responded to the instruments of hope, anxiety and depression, coping, fatigue, religiosity and self-esteem in the first and last cycle of chemotherapy. These variables were used in adjusting the logistic regression model that characterized multivariate statistics, allowing identification of predictor variables. RESULT The increase of hope at the end of chemotherapy treatment was statistically significant (p = 0.012. The delay in undergoing treatment from the onset of breast cancer symptoms, Karnofsky Performance Status, depression, self-esteem and pain were characterized as factors being associated to hope by univariate analysis. Among the variables analyzed, pain was the only predicting factor of hope. CONCLUSION Pain was the predicting factor in this sample. Hope increased during treatment and revealed the following associated factors: Karnofsky Performance Status, delay in starting the treatment, depression, self-esteem and pain. This study brought forth a multidisciplinary contribution, allowing for understanding the factors that can influence hope and presenting support to nursing care. The data evidenced conditions of improvement or worsening of hope, which requires interdisciplinary attention in Oncology.

Gravity, Magnetism, and "Down": Non-Physics College Students' Conceptions of Gravity

Science.gov (United States)

Asghar, Anila; Libarkin, Julie C.

2010-01-01

This study investigates how students enrolled in entry-level geology, most of whom would graduate from college without university-level physics courses, thought about and applied the concept of gravity while solving problems concerning gravity. The repercussions of students' gravity concepts are then considered in the context of non-physics…

Gsolve, a Python computer program with a graphical user interface to transform relative gravity survey measurements to absolute gravity values and gravity anomalies

Science.gov (United States)

McCubbine, Jack; Tontini, Fabio Caratori; Stagpoole, Vaughan; Smith, Euan; O'Brien, Grant

2018-01-01

A Python program (Gsolve) with a graphical user interface has been developed to assist with routine data processing of relative gravity measurements. Gsolve calculates the gravity at each measurement site of a relative gravity survey, which is referenced to at least one known gravity value. The tidal effects of the sun and moon, gravimeter drift and tares in the data are all accounted for during the processing of the survey measurements. The calculation is based on a least squares formulation where the difference between the absolute gravity at each surveyed location and parameters relating to the dynamics of the gravimeter are minimized with respect to the relative gravity observations, and some supplied gravity reference site values. The program additionally allows the user to compute free air gravity anomalies, with respect to the GRS80 and GRS67 reference ellipsoids, from the determined gravity values and calculate terrain corrections at each of the surveyed sites using a prism formula and a user supplied digital elevation model. This paper reviews the mathematical framework used to reduce relative gravimeter survey observations to gravity values. It then goes on to detail how the processing steps can be implemented using the software.

Simultaneous measurement of gravity acceleration and gravity gradient with an atom interferometer

International Nuclear Information System (INIS)

Sorrentino, F.; Lien, Y.-H.; Rosi, G.; Tino, G. M.; Bertoldi, A.; Bodart, Q.; Cacciapuoti, L.; Angelis, M. de; Prevedelli, M.

2012-01-01

We demonstrate a method to measure the gravitational acceleration with a dual cloud atom interferometer; the use of simultaneous atom interferometers reduces the effect of seismic noise on the gravity measurement. At the same time, the apparatus is capable of accurate measurements of the vertical gravity gradient. The ability to determine the gravity acceleration and gravity gradient simultaneously and with the same instrument opens interesting perspectives in geophysical applications.

Comfort and hope in the preanesthesia stage in patients undergoing surgery.

Science.gov (United States)

Seyedfatemi, Naima; Rafii, Forough; Rezaei, Mahboubeh; Kolcaba, Katharine

2014-06-01

Comfort and hope have been identified as important components in the care of perianesthesia patients. The purpose of this study was to explore the relationship between comfort and hope in the preanesthesia stage in patients undergoing surgery. A descriptive cross-sectional survey was conducted with 191 surgical patients. Data were collected using the Perianesthesia Comfort Questionnaire and Herth Hope Index. Direct and significant relationships were observed between comfort and hope (P≤.001, r=0.65). Also, significant relationships were observed between educational level and marital status with comfort (P≤.01). The relationship between educational level and hope was significant (P≤.001). Significant relationships were also observed between gender and marital status with hope (P≤.01). Overall, this study showed that a significant relationship exists between comfort and hope. Additionally, some demographic characteristics influenced comfort and hope in these patients. Health care providers should arrange the environment in a way that allows the surgical patients to experience comfort and hope and recognize the impact of personal characteristics when caring for surgical patients, particularly in the preanesthesia stage. Copyright © 2014 American Society of PeriAnesthesia Nurses. Published by Elsevier Inc. All rights reserved.

Airborne Gravity: NGS' Gravity Data for EN08 (2013)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for New York, Vermont, New Hampshire, Massachusettes, Maine, and Canada collected in 2013 over 1 survey. This data set is part of the Gravity...

The earth's shape and gravity

CERN Document Server

Garland, G D; Wilson, J T

2013-01-01

The Earth's Shape and Gravity focuses on the progress of the use of geophysical methods in investigating the interior of the earth and its shape. The publication first offers information on gravity, geophysics, geodesy, and geology and gravity measurements. Discussions focus on gravity measurements and reductions, potential and equipotential surfaces, absolute and relative measurements, and gravity networks. The text then elaborates on the shape of the sea-level surface and reduction of gravity observations. The text takes a look at gravity anomalies and structures in the earth's crust; interp

Game Changing: NASA's Space Launch System and Science Mission Design

Science.gov (United States)

Creech, Stephen D.

2013-01-01

NASA s Marshall Space Flight Center (MSFC) is directing efforts to build the Space Launch System (SLS), a heavy-lift rocket that will carry the Orion Multi-Purpose Crew Vehicle (MPCV) and other important payloads far beyond Earth orbit (BEO). Its evolvable architecture will allow NASA to begin with Moon fly-bys and then go on to transport humans or robots to distant places such as asteroids and Mars. Designed to simplify spacecraft complexity, the SLS rocket will provide improved mass margins and radiation mitigation, and reduced mission durations. These capabilities offer attractive advantages for ambitious missions such as a Mars sample return, by reducing infrastructure requirements, cost, and schedule. For example, if an evolved expendable launch vehicle (EELV) were used for a proposed mission to investigate the Saturn system, a complicated trajectory would be required - with several gravity-assist planetary fly-bys - to achieve the necessary outbound velocity. The SLS rocket, using significantly higher C3 energies, can more quickly and effectively take the mission directly to its destination, reducing trip time and cost. As this paper will report, the SLS rocket will launch payloads of unprecedented mass and volume, such as "monolithic" telescopes and in-space infrastructure. Thanks to its ability to co-manifest large payloads, it also can accomplish complex missions in fewer launches. Future analyses will include reviews of alternate mission concepts and detailed evaluations of SLS figures of merit, helping the new rocket revolutionize science mission planning and design for years to come.

Airborne Gravity: NGS' Gravity Data for AN08 (2016)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Alaska collected in 2016 over one survey. This data set is part of the Gravity for the Re-definition of the American Vertical Datum...

A simulation of the Four-way lunar Lander-Orbiter tracking mode for the Chang'E-5 mission

Science.gov (United States)

Li, Fei; Ye, Mao; Yan, Jianguo; Hao, Weifeng; Barriot, Jean-Pierre

2016-06-01

The Chang'E-5 mission is the third phase of the Chinese Lunar Exploration Program and will collect and return lunar samples. After sampling, the Orbiter and the ascent vehicle will rendezvous and dock, and both spacecraft will require high precision orbit navigation. In this paper, we present a novel tracking mode-Four-way lunar Lander-Orbiter tracking that possibly can be employed during the Chang'E-5 mission. The mathematical formulas for the Four-way lunar Lander-Orbiter tracking mode are given and implemented in our newly-designed lunar spacecraft orbit determination and gravity field recovery software, the LUnar Gravity REcovery and Analysis Software/System (LUGREAS). The simulated observables permit analysis of the potential contribution Four-way lunar Lander-Orbiter tracking could make to precision orbit determination for the Orbiter. Our results show that the Four-way lunar Lander-Orbiter Range Rate has better geometric constraint on the orbit, and is more sensitive than the traditional two-way range rate that only tracks data between the Earth station and lunar Orbiter. After combining the Four-way lunar Lander-Orbiter Range Rate data with the traditional two-way range rate data and considering the Lander position error and lunar gravity field error, the accuracy of precision orbit determination for the Orbiter in the simulation was improved significantly, with the biggest improvement being one order of magnitude, and the Lander position could be constrained to sub-meter level. This new tracking mode could provide a reference for the Chang'E-5 mission and have enormous potential for the positioning of future lunar farside Lander due to its relay characteristic.

Artificial gravity - The evolution of variable gravity research

Science.gov (United States)

Fuller, Charles A.; Sulzman, Frank M.; Keefe, J. Richard

1987-01-01

The development of a space life science research program based on the use of rotational facilities is described. In-flight and ground centrifuges can be used as artificial gravity environments to study the following: nongravitational biological factors; the effects of 0, 1, and hyper G on man; counter measures for deconditioning astronauts in weightlessness; and the development of suitable artificial gravity for long-term residence in space. The use of inertial fields as a substitute for gravity, and the relations between the radius of the centrifuge and rotation rate and specimen height and rotation radius are examined. An example of a centrifuge study involving squirrel monkeys is presented.

Inspiring hope-A physician's responsibility, translating the science into clinical practice.

Science.gov (United States)

Temple, Walley J

2018-03-01

Giving hope to patients is our responsibility. It is the essence of a meaningful practice in medicine. Science now allows us to understand this complex and multidimensional human dynamic, and translate it into clinical practice. Quantitative research has shown hope is strong even in terminal illness. Through qualitative methodology hope fostering strategies and hope hindering behaviors have been identified. This exciting new knowledge facilitates the challenging task of disclosure of bad news while enabling hope. © 2017 Wiley Periodicals, Inc.

Hope pictured in drawings by women newly diagnosed with gynecological cancer

DEFF Research Database (Denmark)

Hammer, Kristianna; Hall, Elisabeth; Mogensen, Ole

2013-01-01

BACKGROUND:: In mysterious ways, hope makes life meaningful even in chaotic and uncontrolled situations. When a woman is newly diagnosed with gynecologic cancer, hope is ineffable and needs exploring. Drawings help express ineffable phenomena. OBJECTIVE:: The aim of the study was to explore how...... women newly diagnosed with gynecologic cancer express the meaning of hope in drawings. METHOD:: Participants were 15 women who on the same day had received the diagnosis of gynecologic cancer. They were between 24 and 87 years (median, 52 years) with a variety of gynecologic cancer diagnoses. Data from...... 15 drawings and postdrawing interviews with the women were analyzed using visual and hermeneutic phenomenology. RESULTS:: Three themes emerged: hope as a spirit to move on, hope as energy through nature, and hope as a communion with families. CONCLUSION:: Hope as pictured in drawings often appears...

Combustion of Metals in Reduced-Gravity and Extraterrestrial Environment

Science.gov (United States)

Abbud-Madrid, A.; Omaly, P.; Branch, M. C.; Daily, J. W.

1999-01-01

As a result of the ongoing exploration of Mars and the several unmanned and manned missions planned for the future, increased attention has been given to the use of the natural resources of the planet for rocket propellant production and energy generation. Since the atmosphere of Mars consists of approximately 95% carbon dioxide (CO2), this gas is the resource of choice to be employed for these purposes. Unfortunately, CO2 is also a final product in most combustion reactions, requiring further processing to extract useful reactants such as carbon monoxide (CO), oxygen (O2), and hydrocarbons. An exception is the use Of CO2 as an oxidizer reacting directly with metal fuel. Since many metals burn vigorously with CO2, these may be used as an energy source and as propellants for an ascent/descent vehicle in sample-collection missions on Mars. In response to NASA's Human Exploration and Development of Space (HEDS) Enterprise to search for appropriate in-situ resource utilization techniques, this investigation will study the burning characteristics of promising metal/CO2 combinations. The use of reduced gravity is essential to eliminate the intrusive buoyant flows that plague the high-temperature metal reactions, to remove the destructive effect of gravity on the shape of molten metal samples, and to study the influence of radiative heat transfer from solid oxides undisturbed by natural convection. In studies with large metal specimens, the burning process is invariably influenced by strong convective currents that accelerate the reaction and shorten the burning times. Although these currents are nearly absent from small burning particles, the high emissivity of the flames, rapid reaction, small length scales, and intermittent explosions make the gathering of any useful information on burning rates and flame structure very difficult. This investigation has the ultimate goal of providing a careful probing of flame structure and dynamics by taking advantage of large, free

Airborne Gravity: NGS' Gravity Data for AS01 (2008)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Alaska collected in 2008 over 1 survey. This data set is part of the Gravity for the Re-definition of the American Vertical Datum (GRAV-D)...

Airborne Gravity: NGS' Gravity Data for CS04 (2009)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Texas collected in 2009 over 1 survey. This data set is part of the Gravity for the Re-definition of the American Vertical Datum (GRAV-D)...

Airborne Gravity: NGS' Gravity Data for AN05 (2011)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Alaska collected in 2011 over 1 survey. This data set is part of the Gravity for the Re-definition of the American Vertical Datum (GRAV-D)...

Airborne Gravity: NGS' Gravity Data for TS01 (2014)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Puerto Rico and the Virgin Islands collected in 2009 over 1 survey. This data set is part of the Gravity for the Re-definition of the...

Airborne Gravity: NGS' Gravity Data for AN06 (2011)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Alaska collected in 2011 over 1 survey. This data set is part of the Gravity for the Re-definition of the American Vertical Datum (GRAV-D)...

Airborne Gravity: NGS' Gravity Data for AS02 (2010)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Alaska collected in 2010 over 2 surveys. This data set is part of the Gravity for the Re-definition of the American Vertical Datum (GRAV-D)...

Airborne Gravity: NGS' Gravity Data for EN01 (2011)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for New York, Canada, and Lake Ontario collected in 2011 over 1 survey. This data set is part of the Gravity for the Re-definition of the...

Airborne Gravity: NGS' Gravity Data for AN03 (2010)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Alaska collected in 2010 and 2012 over 2 surveys. This data set is part of the Gravity for the Re-definition of the American Vertical Datum...

Airborne Gravity: NGS' Gravity Data for AN04 (2010)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Alaska collected in 2010 over 1 survey. This data set is part of the Gravity for the Re-definition of the American Vertical Datum (GRAV-D)...

Airborne Gravity: NGS' Gravity Data for CS05 (2014)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Texas collected in 2014 over 2 surveys. This data set is part of the Gravity for the Re-definition of the American Vertical Datum (GRAV-D)...

Airborne Gravity: NGS' Gravity Data for EN06 (2016)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Maine, Canada, and the Atlantic Ocean collected in 2012 over 2 surveys. This data set is part of the Gravity for the Re-definition of the...

Airborne Gravity: NGS' Gravity Data for AN02 (2010)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Alaska collected in 2010 over 1 survey. This data set is part of the Gravity for the Re-definition of the American Vertical Datum (GRAV-D)...

Airborne Gravity: NGS' Gravity Data for ES01 (2013)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Florida, the Bahamas, and the Atlantic Ocean collected in 2013 over 1 survey. This data set is part of the Gravity for the Re-definition of...

Analogue Gravity

Directory of Open Access Journals (Sweden)

Barceló Carlos

2005-12-01

Full Text Available Analogue models of (and for gravity have a long and distinguished history dating back to the earliest years of general relativity. In this review article we will discuss the history, aims, results, and future prospects for the various analogue models. We start the discussion by presenting a particularly simple example of an analogue model, before exploring the rich history and complex tapestry of models discussed in the literature. The last decade in particular has seen a remarkable and sustained development of analogue gravity ideas, leading to some hundreds of published articles, a workshop, two books, and this review article. Future prospects for the analogue gravity programme also look promising, both on the experimental front (where technology is rapidly advancing and on the theoretical front (where variants of analogue models can be used as a springboard for radical attacks on the problem of quantum gravity.

Gravity field recovery in the framework of a Geodesy and Time Reference in Space (GETRIS)

Science.gov (United States)

Hauk, Markus; Schlicht, Anja; Pail, Roland; Murböck, Michael

2017-04-01

The study ;Geodesy and Time Reference in Space; (GETRIS), funded by European Space Agency (ESA), evaluates the potential and opportunities coming along with a global space-borne infrastructure for data transfer, clock synchronization and ranging. Gravity field recovery could be one of the first beneficiary applications of such an infrastructure. This paper analyzes and evaluates the two-way high-low satellite-to-satellite-tracking as a novel method and as a long-term perspective for the determination of the Earth's gravitational field, using it as a synergy of one-way high-low combined with low-low satellite-to-satellite-tracking, in order to generate adequate de-aliasing products. First planned as a constellation of geostationary satellites, it turned out, that an integration of European Union Global Navigation Satellite System (Galileo) satellites (equipped with inter-Galileo links) into a Geostationary Earth Orbit (GEO) constellation would extend the capability of such a mission constellation remarkably. We report about simulations of different Galileo and Low Earth Orbiter (LEO) satellite constellations, computed using time variable geophysical background models, to determine temporal changes in the Earth's gravitational field. Our work aims at an error analysis of this new satellite/instrument scenario by investigating the impact of different error sources. Compared to a low-low satellite-to-satellite-tracking mission, results show reduced temporal aliasing errors due to a more isotropic error behavior caused by an improved observation geometry, predominantly in near-radial direction within the inter-satellite-links, as well as the potential of an improved gravity recovery with higher spatial and temporal resolution. The major error contributors of temporal gravity retrieval are aliasing errors due to undersampling of high frequency signals (mainly atmosphere, ocean and ocean tides). In this context, we investigate adequate methods to reduce these errors. We

Modeling gravity effects on water retention and gas transport characteristics in plant growth substrates

DEFF Research Database (Denmark)

Deepagoda Thuduwe Kankanamge Kelum, Chamindu; Jones, Scott B.; Tuller, Markus

2014-01-01

utilization to conserve energy and to limit transport costs, native materials mined on Moon or Mars are of primary interest for plant growth media in a future outpost, while terrestrial porous substrates with optimal growth media characteristics will be useful for onboard plant growth during space missions....... Due to limited experimental opportunities and prohibitive costs, liquid and gas behavior in porous substrates under reduced gravity conditions has been less studied and hence remains poorly understood. Based on ground-based measurements, this study examined water retention, oxygen diffusivity and air...... that estimates the gas percolation threshold based on the pore size distribution. The model successfully captured measured data for all investigated media and demonstrated the implications of the poorly-understood shift in gas percolation threshold with improved gas percolation in reduced gravity. Finally, using...

Adaptation and validation of The Hope Index for Brazilian adolescents Adaptação e validação da The Hope Index para adolescentes Brasileiros

Directory of Open Access Journals (Sweden)

Juliana Cerentini Pacico

2011-01-01

Full Text Available This study aimed at adapting and validating the Staats Hope Index for Brazilian adolescents. Participants were 450 high school students aged from 14 to 18 years old being 56% females. They responded to the Staats Hope Index, Adult Dispositional Hope Scale, Revised Life Orientation Test (LOT-R and Rosenberg Self-Esteem Scale. A factor analysis extracted two factors, replicating the structure of the original scale. Coefficients alphas were .83 and .81, for each factor, respectively. The correlations of the Hope Index factors with dispositional hope, optimism and self-esteem were similar to the findings reported in the literature and indicated convergent validity. The results indicate that the Hope Index is valid to be used in Brazil and that hope is perceived similarly by Brazilians and Americans despite of some cultural differences.O objetivo deste estudo foi adaptar e validar a escala The Hope Index para adolescentes brasileiros. Participaram 450 estudantes do ensino médio, sendo 56% do sexo feminino. As idades variaram entre 14 e 18 anos. Os instrumentos utilizados foram the Hope Index, Adult Dispositional Hope Scale, Revised Life Orientation Test (LOT-R e Rosenberg Self-esteem Scale. A análise fatorial revelou duas dimensões, conforme a estrutura original da escala com valores do coeficiente alfa de 0,83 e 0,81. As correlações dos fatores da escala The Hope Index com esperança disposicional, otimismo e autoestima foram similares aos achados da literatura e indicam validade convergente. Esses resultados indicam que a escala é válida para uso no Brasil e que Brasileiros e Americanos percebem a esperança de modo similar, apesar de algumas diferenças culturais.

NGS Absolute Gravity Data

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NGS Absolute Gravity data (78 stations) was received in July 1993. Principal gravity parameters include Gravity Value, Uncertainty, and Vertical Gradient. The...

Airborne Gravity: NGS' Gravity Data for CS08 (2015)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for CS08 collected in 2006 over 1 survey. This data set is part of the Gravity for the Re-definition of the American Vertical Datum (GRAV-D)...

Airborne Gravity: NGS' Gravity Data for ES02 (2013)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Florida and the Gulf of Mexico collected in 2013 over 1 survey. This data set is part of the Gravity for the Re-definition of the American...

The stress-buffering effects of hope on adjustment to multiple sclerosis.

Science.gov (United States)

Madan, Sindia; Pakenham, Kenneth I

2014-12-01

Hope is an important resource for coping with chronic illness; however, the role of hope in adjusting to multiple sclerosis (MS) has been neglected, and the mechanisms by which hope exerts beneficial impacts are not well understood. This study aims to examine the direct and stress-moderating effects of dispositional hope and its components (agency and pathways) on adjustment to MS. A total of 296 people with MS completed questionnaires at time 1 at 12 months later and time 2. Focal predictors were stress, hope, agency and pathways, and the adjustment outcomes were anxiety, depression, positive affect, positive states of mind and life satisfaction. Results of regression analyses showed that as predicted, greater hope was associated with better adjustment after controlling for the effects of time 1 adjustment and relevant demographics and illness variables. However, these direct effects of hope were subsumed by stress-buffering effects. Regarding the hope components, the beneficial impacts of agency emerged via a direct effects mechanism, whereas the effects of pathways were evidenced via a moderating mechanism. Findings highlight hope as an important protective coping resource for coping with MS and accentuate the roles of both agency and pathways thinking and their different modes of influence in this process.

In psoriasis, levels of hope and quality of life are linked.

Science.gov (United States)

Hawro, Tomasz; Maurer, Marcus; Hawro, Marlena; Kaszuba, Andrzej; Cierpiałkowska, Lidia; Królikowska, Monika; Zalewska, Anna

2014-09-01

Psychological resources such as hope have been suggested to positively influence quality of life (QoL) in chronic disorders. Here, we determined hope levels of psoriasis vulgaris in-patients and analyzed their relation to QoL. A total of 60 (29 male) patients were assessed for their QoL with a generic tool (WHOQOL-BREF) and a skin disease-specific instrument, the Dermatology Life Quality Index (DLQI). Hope levels were determined by use of the Basic Hope Inventory. We found a positive correlation between hope and all domains of WHOQOL-BREF (physical: r = 0.446, p = 0.000; psychological r = 0.464, p = 0.000; social r = 0.302, p = 0.019; environmental r = 0.480, p = 0000; and global r = 0.501, p = 0.000) and a negative correlation with DLQI (r = -0.281, p = 0.030) indicating higher QoL in patients with high hope. Hope was not correlated with disease severity or duration. Hope may play a substantial role in preventing QoL impairment in psoriasis. Psychotherapeutic interventions aimed at strengthening hope could improve QoL in this condition.

Classical Weyl transverse gravity

Energy Technology Data Exchange (ETDEWEB)

Oda, Ichiro [University of the Ryukyus, Department of Physics, Faculty of Science, Nishihara, Okinawa (Japan)

2017-05-15

We study various classical aspects of the Weyl transverse (WTDiff) gravity in a general space-time dimension. First of all, we clarify a classical equivalence among three kinds of gravitational theories, those are, the conformally invariant scalar tensor gravity, Einstein's general relativity and the WTDiff gravity via the gauge-fixing procedure. Secondly, we show that in the WTDiff gravity the cosmological constant is a mere integration constant as in unimodular gravity, but it does not receive any radiative corrections unlike the unimodular gravity. A key point in this proof is to construct a covariantly conserved energy-momentum tensor, which is achieved on the basis of this equivalence relation. Thirdly, we demonstrate that the Noether current for the Weyl transformation is identically vanishing, thereby implying that the Weyl symmetry existing in both the conformally invariant scalar tensor gravity and the WTDiff gravity is a ''fake'' symmetry. We find it possible to extend this proof to all matter fields, i.e. the Weyl-invariant scalar, vector and spinor fields. Fourthly, it is explicitly shown that in the WTDiff gravity the Schwarzschild black hole metric and a charged black hole one are classical solutions to the equations of motion only when they are expressed in the Cartesian coordinate system. Finally, we consider the Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmology and provide some exact solutions. (orig.)

High resolution time-lapse gravity field from GRACE for hydrological modelling

DEFF Research Database (Denmark)

Krogh, Pernille Engelbredt

Calibration of large scale hydrological models have traditionally been performed using point observations, which are often sparsely distributed. The Gravity Recovery And Climate Experiment (GRACE) mission provides global remote sensing information about mass fluxes with unprecedented accuracy...... than for the mascon only solution, but later than the GLDAS/Noah TWS and the CNES/GRGS SH solutions. The deviations are 10–20 days. From this point of view, the tuning of hydrological models with KBRR data is certainly feasible, though highly time consuming and complicated at the moment. The method...

Southern Africa Gravity Data

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data base (14,559 records) was received in January 1986. Principal gravity parameters include elevation and observed gravity. The observed gravity values are...

Gravity and Nonconservative Force Model Tuning for the GEOSAT Follow-On Spacecraft

Science.gov (United States)

Lemoine, Frank G.; Zelensky, Nikita P.; Rowlands, David D.; Luthcke, Scott B.; Chinn, Douglas S.; Marr, Gregory C.; Smith, David E. (Technical Monitor)

2000-01-01

The US Navy's GEOSAT Follow-On spacecraft was launched on February 10, 1998 and the primary objective of the mission was to map the oceans using a radar altimeter. Three radar altimeter calibration campaigns have been conducted in 1999 and 2000. The spacecraft is tracked by satellite laser ranging (SLR) and Doppler beacons and a limited amount of data have been obtained from the Global Positioning Receiver (GPS) on board the satellite. Even with EGM96, the predicted radial orbit error due to gravity field mismodelling (to 70x70) remains high at 2.61 cm (compared to 0.88 cm for TOPEX). We report on the preliminary gravity model tuning for GFO using SLR, and altimeter crossover data. Preliminary solutions using SLR and GFO/GFO crossover data from CalVal campaigns I and II in June-August 1999, and January-February 2000 have reduced the predicted radial orbit error to 1.9 cm and further reduction will be possible when additional data are added to the solutions. The gravity model tuning has improved principally the low order m-daily terms and has reduced significantly the geographically correlated error present in this satellite orbit. In addition to gravity field mismodelling, the largest contributor to the orbit error is the non-conservative force mismodelling. We report on further nonconservative force model tuning results using available data from over one cycle in beta prime.

Einstein gravity emerging from quantum weyl gravity

International Nuclear Information System (INIS)

Zee, A.

1983-01-01

We advocate a conformal invariant world described by the sum of the Weyl, Dirac, and Yang-Mills action. Quantum fluctuations bring back Einstein gravity so that the long-distance phenomenology is as observed. Formulas for the induced Newton's constant and Eddington's constant are derived in quantized Weyl gravity. We show that the analogue of the trace anomaly for the Weyl action is structurally similar to that for the Yang-Mills action

Autism, "recovery (to normalcy)", and the politics of hope.

Science.gov (United States)

Broderick, Alicia A

2009-08-01

This article draws on the traditions of critical discourse analysis (N. Fairclough, 1995, 2001; M. Foucault, 1972, 1980; J. P. Gee, 1999) in critically examining the discursive formation of "recovery" from autism in applied behavioral analysis (ABA) discourse and its relationship to constructs of hope. Constituted principally in the work of O. I. Lovaas (1987) and C. Maurice (1993), and central to ABA discourse on recovery, has been the construction of a particular vision of hope that has at least 2 integral conceptual elements: (a) Hope for recovery within ABA discourse is constructed in binary opposition to hopelessness, and (b) recovery within ABA discourse is discursively constructed as "recovery (to normalcy)." The author analyzes these 2 pivotal ABA texts within the context of an analysis of other uses of the term recovery in broader bodies of literature: (a) within prior autism-related literature, particularly autobiography, and (b) within literature emanating from the psychiatric survivors' movement. If, indeed, visions of hope inform educational policy and decision making, this analysis addresses S. Danforth's (1997) cogent query, "On what basis hope?", and asserts that moral and political commitments should be central sources of visions of hope and, therefore, inform educational policy and decision making for young children with labels of autism.

Herth hope index: psychometric testing of the Chinese version.

Science.gov (United States)

Chan, Keung Sum; Li, Ho Cheung William; Chan, Sally Wai-Chi; Lopez, Violeta

2012-09-01

This article is a report on psychometric testing of the Chinese version of the herth hope index. The availability of a valid and reliable instrument that accurately measures the level of hope in patients with heart failure is crucial before any hope-enhancing interventions can be appropriately planned and evaluated. There is no such instrument for Chinese people. A test-retest, within-subjects design was used. A purposive sample of 120 Hong Kong Chinese patients with heart failure between the ages of 60 and 80 years admitted to two medical wards was recruited during an 8-month period in 2009. Participants were asked to respond to the Chinese version of the herth hope index, Hamilton depression rating scale and Rosenberg's self-esteem scale. The internal consistency, content validity and construct validity and test-retest reliability of the Chinese version of the herth hope index were assessed. The newly translated scale demonstrated adequate internal consistency, good content validity and appropriate convergent and discriminant validity. Confirmatory factor analysis added further evidence of the construct validity of the scale. Results suggest that the newly translated scale can be used as a self-report assessment tool in assessing the level of hope in Hong Kong Chinese patients with heart failure. © 2011 Blackwell Publishing Ltd.

influence of gravity

Directory of Open Access Journals (Sweden)

Animesh Mukherjee

1991-01-01

Full Text Available Based upon Biot's [1965] theory of initial stresses of hydrostatic nature produced by the effect of gravity, a study is made of surface waves in higher order visco-elastic media under the influence of gravity. The equation for the wave velocity of Stonely waves in the presence of viscous and gravitational effects is obtained. This is followed by particular cases of surface waves including Rayleigh waves and Love waves in the presence of viscous and gravity effects. In all cases the wave-velocity equations are found to be in perfect agreement with the corresponding classical results when the effects of gravity and viscosity are neglected.

Preemptive strikes: Fear, hope, and defensive aggression.

Science.gov (United States)

Halevy, Nir

2017-02-01

Preemptive strikes are costly and harmful. Existing models of defensive aggression focus narrowly on the role fear plays in motivating preemptive strikes. Theoretically integrating the literatures on conflict, decision making, and emotion, the current research investigated how specific emotions associated with certainty or uncertainty, including fear, anger, disgust, hope, and happiness, influence preemptive strikes. Study 1 demonstrated that hope negatively predicts defensive exits from relationships in choice dilemmas. Studies 2 and 3 experimentally manipulated risk of being attacked in an incentivized, interactive decision making task-the Preemptive Strike Game. Risk of being attacked fueled preemptive strikes; reduced feelings of hope partially mediated this effect in Study 3. Studies 4 and 5 investigated preemptive strikes under uncertainty (rather than risk). In Study 4, reasoning about the factors that make one trustful of others curbed preemptive strikes; cogitating about the factors that underlie discrete emotions, however, did not influence defensive aggression. Study 5 demonstrated that the valence and uncertainty appraisals of incidental emotions interact in shaping preemptive strikes. Specifically, recalling an autobiographical emotional experience that produced hope significantly decreased attack rates relative to fear, happiness, and a control condition. Fear, anger, disgust, and happiness were either unrelated to preemptive strikes or showed inconsistent relationships with preemptive strikes across the 5 studies. These findings shed light on how emotions shape defensive aggression, advance knowledge on strategic choice under risk and uncertainty, and demonstrate hope's positive effects on social interactions and relationships. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Comparing scalar-tensor gravity and f(R)-gravity in the Newtonian limit

International Nuclear Information System (INIS)

Capozziello, S.; Stabile, A.; Troisi, A.

2010-01-01

Recently, a strong debate has been pursued about the Newtonian limit (i.e. small velocity and weak field) of fourth order gravity models. According to some authors, the Newtonian limit of f(R)-gravity is equivalent to the one of Brans-Dicke gravity with ω BD =0, so that the PPN parameters of these models turn out to be ill-defined. In this Letter, we carefully discuss this point considering that fourth order gravity models are dynamically equivalent to the O'Hanlon Lagrangian. This is a special case of scalar-tensor gravity characterized only by self-interaction potential and that, in the Newtonian limit, this implies a non-standard behavior that cannot be compared with the usual PPN limit of General Relativity. The result turns out to be completely different from the one of Brans-Dicke theory and in particular suggests that it is misleading to consider the PPN parameters of this theory with ω BD =0 in order to characterize the homologous quantities of f(R)-gravity. Finally the solutions at Newtonian level, obtained in the Jordan frame for an f(R)-gravity, reinterpreted as a scalar-tensor theory, are linked to those in the Einstein frame.

AVIATR - Aerial Vehicle for In-situ and Airborne Titan Reconnaissance A Titan Airplane Mission Concept

Science.gov (United States)

Barnes, Jason W.; Lemke, Lawrence; Foch, Rick; McKay, Christopher P.; Beyer, Ross A.; Radebaugh, Jani; Atkinson, David H.; Lorenz, Ralph D.; LeMouelic, Stephane; Rodriguez, Sebastien;

The Port Hope area initiative municipal involvement

International Nuclear Information System (INIS)

Austin, Rick; Stevenson, Mark

2006-01-01

Port Hope (Canada) contains one of the world's oldest nuclear facility sites. From the 1930's through to the 1970's, processing residues from radium refining facilities located at the Port Hope Harbour were being stored and/or deposited on numerous sites throughout the municipality. For a variety of reasons, including spillage of material during transportation and un-monitored or unauthorized diversion of materials, many private and public properties in the municipality were contaminated with low level radioactive waste. Over the past 30 years, the community has demanded that the nuclear industry and the federal government clean up the mess left in Port Hope. In the 1980's and 1990's, the federal government sought to fulfill its commitment to clean up over one million cubic metres of contaminated material remaining in Port Hope but was unable to find a solution. The Low Level Radioactive Waste Management Siting Task Force worked in trying to find a home for historic LLRW in the 1980's and 1990's. It is only within the past 6 years that Port Hope's community began to see the 'light at the end of the tunnel'. And, the light began to shine when the communities took the issue of long term management of the waste into their own hands and proposed possible solutions to the federal government. So the Port Hope Area Initiative is a community-based initiative. In this paper the author presents some of the reasons for success (so far) and some opportunities and challenges that his municipality, and specifically municipal Council, faces as a partner in this Environmental Assessment and project development process. He addresses some of the key elements of the Project that he believes have led to the success of the Project to this point, including: the Legal Agreement and Agreement Monitoring process; the Property Value Protection Program; the Hosting Fee; the Municipal veto on some decisions; the end Use as an asset to the Community; the Value of Peer Review. He also touches

77 FR 31841 - Hope Gas, Inc.; Notice of Baseline Filing

Science.gov (United States)

2012-05-30

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PR12-23-001] Hope Gas, Inc.; Notice of Baseline Filing Take notice that on May 16, 2012, Hope Gas, Inc. (Hope Gas) submitted a revised baseline filing of their Statement of Operating Conditions for services provided under Section 311 of the...

77 FR 26535 - Hope Gas, Inc.; Notice of Baseline Filing

Science.gov (United States)

2012-05-04

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PR12-23-000] Hope Gas, Inc.; Notice of Baseline Filing Take notice that on April 26, 2012, Hope Gas, Inc. (Hope Gas) submitted a baseline filing of their Statement of Operating Conditions for services provided under Section 311 of the...

Development and analysis of a twelfth degree and order gravity model for Mars

Science.gov (United States)

Christensen, E. J.; Balmino, G.

1979-01-01

Satellite geodesy techniques previously applied to artificial earth satellites have been extended to obtain a high-resolution gravity field for Mars. Two-way Doppler data collected by 10 Deep Space Network (DSN) stations during Mariner 9 and Viking 1 and 2 missions have been processed to obtain a twelfth degree and order spherical harmonic model for the martian gravitational potential. The quality of this model was evaluated by examining the rms residuals within the fit and the ability of the model to predict the spacecraft state beyond the fit. Both indicators show that more data and higher degree and order harmonics will be required to further refine our knowledge of the martian gravity field. The model presented shows much promise, since it resolves local gravity features which correlate highly with the martian topography. An isostatic analysis based on this model, as well as an error analysis, shows rather complete compensation on a global (long wavelength) scale. Though further model refinements are necessary to be certain, local (short wavelength) features such as the shield volcanos in Tharsis appear to be uncompensated. These are interpreted to place some bounds on the internal structure of Mars.

Transferring hope

DEFF Research Database (Denmark)

Høyen, Marianne

in yet another educational intitiative. As educated fast-track teachers they enter settings where they face social and cultural challenges, as they are not educated the way the local teachers and the teacher's union prefers. These teachers therefore have to build their hope for the future from three...... their academic and vocational qualifications were viewed adversely. I explore how the informants construct their new working life under these conditions through narratives about past and future. Drawing on Bruner’s Life as Narrative (2004), I study their use of language, comparing the discourse around...

Organizing Hope

DEFF Research Database (Denmark)

Jensen, Boris Brorman; Hjemdal, Tor Inge

2012-01-01

Greenland has four municipalities and four Mayors. All four Mayors were invited to Ilulissat in February 2012 to meet with the Possible Greenland team. On the second day of the seminar the Mayor of Qaasuitsup Municipality Jess Svane had to fly up north to Nutaarmiut and assist the small community...... after a young man killed three family members and wounded four others. Tor Inge Hjemdal and Boris Brorman Jensen met with the other three mayors: Simon Simonsen, Asii Chemnitz Narup and Hermann Berthelsen to discuss their hopes and concerns for Greenland....

Excitation of Earth Rotation Variations "Observed" by Time-Variable Gravity

Science.gov (United States)

Chao, Ben F.; Cox, C. M.

2005-01-01

Time variable gravity measurements have been made over the past two decades using the space geodetic technique of satellite laser ranging, and more recently by the GRACE satellite mission with improved spatial resolutions. The degree-2 harmonic components of the time-variable gravity contain important information about the Earth s length-of-day and polar motion excitation functions, in a way independent to the traditional "direct" Earth rotation measurements made by, for example, the very-long-baseline interferometry and GPS. In particular, the (degree=2, order= 1) components give the mass term of the polar motion excitation; the (2,O) component, under certain mass conservation conditions, gives the mass term of the length-of-day excitation. Combining these with yet another independent source of angular momentum estimation calculated from global geophysical fluid models (for example the atmospheric angular momentum, in both mass and motion terms), in principle can lead to new insights into the dynamics, particularly the role or the lack thereof of the cores, in the excitation processes of the Earth rotation variations.

The determination of the orbit of the Japanese satellite Ajisai and the GEM-T1 and GEM-T2 gravity field models

Science.gov (United States)

Sanchez, Braulio V.

1990-01-01

The Japanese Experimental Geodetic Satellite Ajisai was launched on August 12, 1986. In response to the TOPEX-POSEIDON mission requirements, the GSFC Space Geodesy Branch and its associates are producing improved models of the Earth's gravitational field. With the launch of Ajisai, precise laser data is now available which can be used to test many current gravity models. The testing of the various gravity field models show improvements of more than 70 percent in the orbital fits when using GEM-T1 and GEM-T2 relative to results obtained with the earlier GEM-10B model. The GEM-T2 orbital fits are at the 13-cm level (RMS). The results of the tests with the various versions of the GEM-T1 model indicate that the addition of satellite altimetry and surface gravity anomalies as additional data types should improve future gravity field models.

The motivational properties of hope in goal striving

NARCIS (Netherlands)

Nelissen, R.M.A.

2017-01-01

We argue that hope is not an expectancy based on beliefs about pathways to desired goals and personal capacities to act on them, but an experience of the mere possibility of a desired outcome. We propose that in the latter sense, hope has unique motivational consequences for goal striving.

Deposition of CdTe films under microgravity: Foton M3 mission

Energy Technology Data Exchange (ETDEWEB)

Benz, K.W.; Croell, A. [Freiburger Materialforschungszentrum FMF, Albert-Ludwigs-Universitaet Freiburg (Germany); Zappettini, A.; Calestani, D. [CNR Parma, Instituto Materiali Speciali per Elettronica e Magnetismo IMEM, Fontani Parma (Italy); Dieguez, E. [Universidad Autonoma de Madrid (Spain). Departamento de Fisica de Materiales; Carotenuto, L.; Bassano, E. [Telespazio Napoli, Via Gianturco 31, 80146 Napoli (Italy); Fiederle, M.

2009-10-15

Experiments of deposition of CdTe films have been carried out under microgravity in the Russian Foton M3 mission. The influence of gravity has been studied with these experiments and compared to the results of simulations. The measured deposition rate could be confirmed by the theoretical results for lower temperatures. For higher temperatures the measured thickness of the deposited films was larger compared to the theoretical data. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

MarsSedEx I and II: Experimental investigation of gravity effects on sedimentation on Mars

Science.gov (United States)

Kuhn, N. J.; Kuhn, B.; Gartmann, A.

2014-12-01

Sorting of sedimentary rocks is a proxy for the environmental conditions at the time of deposition, in particular the runoff that moved and deposited the material forming the rocks. Settling of sediment is strongly influenced by the gravity of a planetary body. As a consequence, sorting of a sedimentary rock varies with gravity for a given depth and velocity of surface runoff. Theoretical considerations for spheres indicate that sorting is less uniform on Mars than on Earth for runoff of identical depth. The effects of gravity on flow hydraulics limit the use of common, semi-empirical models developed to simulate particle settling in terrestrial environments, on Mars. Assessing sedimentation patterns on Mars, aimed at identifying strata potentially hosting traces of life, is potentially affected by such uncertainties. Using first-principle approaches, e.g. through Computational Fluid Dynamics, for calculating settling velocities on other planetary bodies requires a large effort and is limited by the values of boundary conditions, e.g. the shape of the particle. The degree of uncertainty resulting from the differences in gravity on Earth and Mars was therefore tested during three reduced-gravity flights, the MarsSedEx I and II missions, conducted in November 2012 and 2013. Nine types of sediment, ranging in size, shape and density were tested in custom-designed settling tubes during parabolas of Martian gravity lasting 20 to 25 seconds. Based on the observed settling velocities, the uncertainties of empirical relationships developed on Earth to assess particle settling on Mars are discussed. In addition, the potential effects of reduced gravity on patterns of erosion, transport and sorting of sediment, including the implications for identifying strata bearing traces of past life on are examined.

Hope voor het MKB : goede resultaten na toepassing Human Oriented Production Engineering (HOPE)

NARCIS (Netherlands)

Verweij, M.J.

1997-01-01

De doorlooptijd werd 40% korter, de kwaliteitsproblemen namen af en de voorraden slonken met een kwart. Het Belgische bedrijf Verhaegen was zeer tevreden over de resultaten van de methode HOPE (Human Oriented Production Engineering). Dit Europeese project richt zich op het midden- en kleinbedrijf.

Is Gravity an Entropic Force?

Directory of Open Access Journals (Sweden)

Shan Gao

2011-04-01

Full Text Available The remarkable connections between gravity and thermodynamics seem to imply that gravity is not fundamental but emergent, and in particular, as Verlinde suggested, gravity is probably an entropic force. In this paper, we will argue that the idea of gravity as an entropic force is debatable. It is shown that there is no convincing analogy between gravity and entropic force in Verlinde’s example. Neither holographic screen nor test particle satisfies all requirements for the existence of entropic force in a thermodynamics system. Furthermore, we show that the entropy increase of the screen is not caused by its statistical tendency to increase entropy as required by the existence of entropic force, but in fact caused by gravity. Therefore, Verlinde’s argument for the entropic origin of gravity is problematic. In addition, we argue that the existence of a minimum size of spacetime, together with the Heisenberg uncertainty principle in quantum theory, may imply the fundamental existence of gravity as a geometric property of spacetime. This may provide a further support for the conclusion that gravity is not an entropic force.

Rasch Analysis of the Locus-of-Hope Scale. Brief Report

Science.gov (United States)

Gadiana, Leny G.; David, Adonis P.

2015-01-01

The Locus-of-Hope Scale (LHS) was developed as a measure of the locus-of-hope dimensions (Bernardo, 2010). The present study adds to the emerging literature on locus-of-hope by assessing the psychometric properties of the LHS using Rasch analysis. The results from the Rasch analyses of the four subscales of LHS provided evidence on the…

Gravity Probe B data analysis: II. Science data and their handling prior to the final analysis

International Nuclear Information System (INIS)

Silbergleit, A S; Conklin, J W; Heifetz, M I; Holmes, T; Li, J; Mandel, I; Solomonik, V G; Stahl, K; P W Worden Jr; Everitt, C W F; Adams, M; Berberian, J E; Bencze, W; Clarke, B; Al-Jadaan, A; Keiser, G M; Kozaczuk, J A; Al-Meshari, M; Muhlfelder, B; Salomon, M

2015-01-01

The results of the Gravity Probe B relativity science mission published in Everitt et al (2011 Phys. Rev. Lett. 106 221101) required a rather sophisticated analysis of experimental data due to several unexpected complications discovered on-orbit. We give a detailed description of the Gravity Probe B data reduction. In the first paper (Silbergleit et al Class. Quantum Grav. 22 224018) we derived the measurement models, i.e., mathematical expressions for all the signals to analyze. In the third paper (Conklin et al Class. Quantum Grav. 22 224020) we explain the estimation algorithms and their program implementation, and discuss the experiment results obtained through data reduction. This paper deals with the science data preparation for the main analysis yielding the relativistic drift estimates. (paper)

Strings and quantum gravity

International Nuclear Information System (INIS)

Vega, H.J. de

1990-01-01

One of the main challenges in theoretical physics today is the unification of all interactions including gravity. At present, string theories appear as the most promising candidates to achieve such a unification. However, gravity has not completely been incorporated in string theory, many technical and conceptual problems remain and a full quantum theory of gravity is still non-existent. Our aim is to properly understand strings in the context of quantum gravity. Attempts towards this are reviewed. (author)

Gravity interpretation via EULDPH

International Nuclear Information System (INIS)

Ebrahimzadeh Ardestani, V.

2003-01-01

Euler's homogeneity equation for determining the coordinates of the source body especially to estimate the depth (EULDPH) is discussed at this paper. This method is applied to synthetic and high-resolution real data such as gradiometric or microgravity data. Low-quality gravity data especially in the areas with a complex geology structure has rarely been used. The Bouguer gravity anomalies are computed from absolute gravity data after the required corrections. Bouguer anomaly is transferred to residual gravity anomaly. The gravity gradients are estimated from residual anomaly values. Bouguer anomaly is the gravity gradients, using EULDPH. The coordinates of the perturbing body will be determined. Two field examples one in the east of Tehran (Mard Abad) where we would like to determine the location of the anomaly (hydrocarbon) and another in the south-east of Iran close to the border with Afghanistan (Nosrat Abad) where we are exploring chromite are presented

Anomalies and gravity

International Nuclear Information System (INIS)

Mielke, Eckehard W.

2006-01-01

Anomalies in Yang-Mills type gauge theories of gravity are reviewed. Particular attention is paid to the relation between the Dirac spin, the axial current j5 and the non-covariant gauge spin C. Using diagrammatic techniques, we show that only generalizations of the U(1)- Pontrjagin four-form F and F = dC arise in the chiral anomaly, even when coupled to gravity. Implications for Ashtekar's canonical approach to quantum gravity are discussed

Spacelab Life Science-1 Mission Onboard Photograph

Science.gov (United States)

1995-01-01

Spacelab Life Science -1 (SLS-1) was the first Spacelab mission dedicated solely to life sciences. The main purpose of the SLS-1 mission was to study the mechanisms, magnitudes, and time courses of certain physiological changes that occur during space flight, to investigate the consequences of the body's adaptation to microgravity and readjustment to Earth's gravity, and bring the benefits back home to Earth. The mission was designed to explore the responses of the heart, lungs, blood vessels, kidneys, and hormone-secreting glands to microgravity and related body fluid shifts; examine the causes of space motion sickness; and study changes in the muscles, bones, and cells. This photograph shows astronaut Rhea Seddon conducting an inflight study of the Cardiovascular Deconditioning experiment by breathing into the cardiovascular rebreathing unit. This experiment focused on the deconditioning of the heart and lungs and changes in cardiopulmonary function that occur upon return to Earth. By using noninvasive techniques of prolonged expiration and rebreathing, investigators can determine the amount of blood pumped out of the heart (cardiac output), the ease with which blood flows through all the vessels (total peripheral resistance), oxygen used and carbon dioxide released by the body, and lung function and volume changes. SLS-1 was launched aboard the Space Shuttle Orbiter Columbia (STS-40) on June 5, 1995.

Space-Wise approach for airborne gravity data modelling

Science.gov (United States)

Sampietro, D.; Capponi, M.; Mansi, A. H.; Gatti, A.; Marchetti, P.; Sansò, F.

2017-05-01

Regional gravity field modelling by means of remove-compute-restore procedure is nowadays widely applied in different contexts: it is the most used technique for regional gravimetric geoid determination, and it is also used in exploration geophysics to predict grids of gravity anomalies (Bouguer, free-air, isostatic, etc.), which are useful to understand and map geological structures in a specific region. Considering this last application, due to the required accuracy and resolution, airborne gravity observations are usually adopted. However, due to the relatively high acquisition velocity, presence of atmospheric turbulence, aircraft vibration, instrumental drift, etc., airborne data are usually contaminated by a very high observation error. For this reason, a proper procedure to filter the raw observations in both the low and high frequencies should be applied to recover valuable information. In this work, a software to filter and grid raw airborne observations is presented: the proposed solution consists in a combination of an along-track Wiener filter and a classical Least Squares Collocation technique. Basically, the proposed procedure is an adaptation to airborne gravimetry of the Space-Wise approach, developed by Politecnico di Milano to process data coming from the ESA satellite mission GOCE. Among the main differences with respect to the satellite application of this approach, there is the fact that, while in processing GOCE data the stochastic characteristics of the observation error can be considered a-priori well known, in airborne gravimetry, due to the complex environment in which the observations are acquired, these characteristics are unknown and should be retrieved from the dataset itself. The presented solution is suited for airborne data analysis in order to be able to quickly filter and grid gravity observations in an easy way. Some innovative theoretical aspects focusing in particular on the theoretical covariance modelling are presented too

HOPE: Just-in-time Python compiler for astrophysical computations

Science.gov (United States)

Akeret, Joel; Gamper, Lukas; Amara, Adam; Refregier, Alexandre

2014-11-01

HOPE is a specialized Python just-in-time (JIT) compiler designed for numerical astrophysical applications. HOPE focuses on a subset of the language and is able to translate Python code into C++ while performing numerical optimization on mathematical expressions at runtime. To enable the JIT compilation, the user only needs to add a decorator to the function definition. By using HOPE, the user benefits from being able to write common numerical code in Python while getting the performance of compiled implementation.

Airborne Gravity: NGS' Gravity Data for CN02 (2013 & 2014)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Nebraska collected in 2013 & 2014 over 3 surveys. This data set is part of the Gravity for the Re-definition of the American Vertical...

Translating Music into Hope | NIH MedlinePlus the Magazine

Science.gov (United States)

... contents Translating Music into Hope Follow us Translating Music into Hope Black Eyed Peas’ Taboo talks about ... for years as a member of the hit music group Black Eyed Peas. He shares his recent ...

Gravity loop corrections to the standard model Higgs in Einstein gravity

International Nuclear Information System (INIS)

Yugo Abe; Masaatsu Horikoshi; Takeo Inami

2016-01-01

We study one-loop quantum gravity corrections to the standard model Higgs potential V(φ) à la Coleman-Weinberg and examine the stability question of V(φ) in the energy region of Planck mass scale, μ ≃ M_P_l (M_P_l = 1.22x10"1"9 GeV). We calculate the gravity one-loop corrections to V(φ) in Einstein gravity by using the momentum cut-off Λ. We have found that even small gravity corrections compete with the standard model term of V(φ) and affect the stability argument of the latter part alone. This is because the latter part is nearly zero in the energy region of M_P_l. (author)

Data reduction and tying in regional gravity surveys—results from a new gravity base station network and the Bouguer gravity anomaly map for northeastern Mexico

Science.gov (United States)

Hurtado-Cardador, Manuel; Urrutia-Fucugauchi, Jaime

2006-12-01

Since 1947 Petroleos Mexicanos (Pemex) has conducted oil exploration projects using potential field methods. Geophysical exploration companies under contracts with Pemex carried out gravity anomaly surveys that were referred to different floating data. Each survey comprises observations of gravity stations along highways, roads and trails at intervals of about 500 m. At present, 265 separate gravimeter surveys that cover 60% of the Mexican territory (mainly in the oil producing regions of Mexico) are available. This gravity database represents the largest, highest spatial resolution information, and consequently has been used in the geophysical data compilations for the Mexico and North America gravity anomaly maps. Regional integration of gravimeter surveys generates gradients and spurious anomalies in the Bouguer anomaly maps at the boundaries of the connected surveys due to the different gravity base stations utilized. The main objective of this study is to refer all gravimeter surveys from Pemex to a single new first-order gravity base station network, in order to eliminate problems of gradients and spurious anomalies. A second objective is to establish a network of permanent gravity base stations (BGP), referred to a single base from the World Gravity System. Four regional loops of BGP covering eight States of Mexico were established to support the tie of local gravity base stations from each of the gravimeter surveys located in the vicinity of these loops. The third objective is to add the gravity constants, measured and calculated, for each of the 265 gravimeter surveys to their corresponding files in the Pemex and Instituto Mexicano del Petroleo database. The gravity base used as the common datum is the station SILAG 9135-49 (Latin American System of Gravity) located in the National Observatory of Tacubaya in Mexico City. We present the results of the installation of a new gravity base network in northeastern Mexico, reference of the 43 gravimeter surveys

The Relationship between Hope and Self-Esteem in Patients with Leukemia

Science.gov (United States)

Parvan, Kobra; Jabbarzadeh Tabrizi, Faranak; Rahmani, Azad; Ghojazadeh, Morteza; Azadi, Arman; Golchin, Mehri

2015-01-01

Introduction: Patients with hematologic malignancies often experience many emotional reactions which are different based on patient’s culture. Indeed culture determines the different ways that patients understand cancer. Accordingly, the aim of this study was to determine the relationship of self-esteem and hope among Iranian cancer patients. Methods: This descriptive-correlational study was undertaken among 85 leukemic patients admitted to Shahid Ghazi hospital in East-Azerbaijan province, Iran. They were selected using consecutive sampling method. Persian form of Hearth Hope Index and Coppersmith Self-Esteem Inventory were used to identify patients’ hope and self-esteem. The data were analyzed using SPSS version 13.0. Results: The overall scores of hope and self-esteem were 33.05 (5.24) and 94.61 (11.51), respectively. There was a positive correlation between hope and self-esteem (rs = 0.73, n = 85, P self-esteem and hope relationship could be similar in different cultures. The findings of this study indicate that nurses could be helpful through designing and implementing appropriate educational programs in order to enhance hope and self-esteem of leukemia patients. PMID:26464838

A preliminary study of level 1A data processing of a low–low satellite to satellite tracking mission

Directory of Open Access Journals (Sweden)

Peng Xu

2015-09-01

Full Text Available With the Gravity Recovery and Climate Experiment (GRACE mission as the prime example, an overview is given on the management and processing of Level 1A data of a low–low satellite to satellite tracking mission. To illustrate the underlying principle and algorithm, a detailed study is made on the K-band ranging (KBR assembly, which includes the measurement principles, modeling of noises, the generation of Level 1A data from that of Level 0 as well as Level 1A to Level 1B data processing.

Hope and fatigue in chronic illness: The role of perceived stress.

Science.gov (United States)

Hirsch, Jameson K; Sirois, Fuschia M

2016-04-01

Fatigue is a debilitating symptom of chronic illness that is deleteriously affected by perceived stress, a process particularly relevant to inflammatory disease. Hopefulness, a goal-based motivational construct, may beneficially influence stress and fatigue, yet little research has examined these associations. We assessed the relation between hope and fatigue, and the mediating effect of stress, in individuals with fibromyalgia, arthritis, and inflammatory bowel disease. Covarying age, sex, and pain, stress partially mediated the association between hope and fatigue; those with greater hope reported less stress and consequent fatigue. Therapeutically, bolstering hope may allow proactive management of stressors, resulting in less fatigue. © The Author(s) 2014.

Reaping a Harvest of Hope - Continuum Magazine | NREL

Science.gov (United States)

Reaping a Harvest of Hope On May 4, 2007, an EF-5 tornado-the highest rating of tornados-tore Reaping a Harvest of Hope Five years after a devastating tornado, Greensburg, Kansas, has new energy and a city also relied on NREL's life-cycle cost analysis and its extensive energy project development and

Airborne Gravity: NGS' Gravity Data for CS02 (2008-2009)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Louisana and Mississippi collected in 2008-2009 over 2 surveys. This data set is part of the Gravity for the Re-definition of the American...

Quantum gravity from noncommutative spacetime

Energy Technology Data Exchange (ETDEWEB)

Lee, Jungjai [Daejin University, Pocheon (Korea, Republic of); Yang, Hyunseok [Korea Institute for Advanced Study, Seoul (Korea, Republic of)

2014-12-15

We review a novel and authentic way to quantize gravity. This novel approach is based on the fact that Einstein gravity can be formulated in terms of a symplectic geometry rather than a Riemannian geometry in the context of emergent gravity. An essential step for emergent gravity is to realize the equivalence principle, the most important property in the theory of gravity (general relativity), from U(1) gauge theory on a symplectic or Poisson manifold. Through the realization of the equivalence principle, which is an intrinsic property in symplectic geometry known as the Darboux theorem or the Moser lemma, one can understand how diffeomorphism symmetry arises from noncommutative U(1) gauge theory; thus, gravity can emerge from the noncommutative electromagnetism, which is also an interacting theory. As a consequence, a background-independent quantum gravity in which the prior existence of any spacetime structure is not a priori assumed but is defined by using the fundamental ingredients in quantum gravity theory can be formulated. This scheme for quantum gravity can be used to resolve many notorious problems in theoretical physics, such as the cosmological constant problem, to understand the nature of dark energy, and to explain why gravity is so weak compared to other forces. In particular, it leads to a remarkable picture of what matter is. A matter field, such as leptons and quarks, simply arises as a stable localized geometry, which is a topological object in the defining algebra (noncommutative *-algebra) of quantum gravity.

Quantum gravity from noncommutative spacetime

International Nuclear Information System (INIS)

Lee, Jungjai; Yang, Hyunseok

2014-01-01

We review a novel and authentic way to quantize gravity. This novel approach is based on the fact that Einstein gravity can be formulated in terms of a symplectic geometry rather than a Riemannian geometry in the context of emergent gravity. An essential step for emergent gravity is to realize the equivalence principle, the most important property in the theory of gravity (general relativity), from U(1) gauge theory on a symplectic or Poisson manifold. Through the realization of the equivalence principle, which is an intrinsic property in symplectic geometry known as the Darboux theorem or the Moser lemma, one can understand how diffeomorphism symmetry arises from noncommutative U(1) gauge theory; thus, gravity can emerge from the noncommutative electromagnetism, which is also an interacting theory. As a consequence, a background-independent quantum gravity in which the prior existence of any spacetime structure is not a priori assumed but is defined by using the fundamental ingredients in quantum gravity theory can be formulated. This scheme for quantum gravity can be used to resolve many notorious problems in theoretical physics, such as the cosmological constant problem, to understand the nature of dark energy, and to explain why gravity is so weak compared to other forces. In particular, it leads to a remarkable picture of what matter is. A matter field, such as leptons and quarks, simply arises as a stable localized geometry, which is a topological object in the defining algebra (noncommutative *-algebra) of quantum gravity.

Superconducting gravity gradiometer for sensitive gravity measurements. II. Experiment

International Nuclear Information System (INIS)

Chan, H.A.; Moody, M.V.; Paik, H.J.

1987-01-01

A sensitive superconducting gravity gradiometer has been constructed and tested. Coupling to gravity signals is obtained by having two superconducting proof masses modulate magnetic fields produced by persistent currents. The induced electrical currents are differenced by a passive superconducting circuit coupled to a superconducting quantum interference device. The experimental behavior of this device has been shown to follow the theoretical model closely in both signal transfer and noise characteristics. While its intrinsic noise level is shown to be 0.07 E Hz/sup -1/2/ (1 Eequivalent10/sup -9/ sec/sup -2/), the actual performance of the gravity gradiometer on a passive platform has been limited to 0.3--0.7 E Hz/sup -1/2/ due to its coupling to the environmental noise. The detailed structure of this excess noise is understood in terms of an analytical error model of the instrument. The calibration of the gradiometer has been obtained by two independent methods: by applying a linear acceleration and a gravity signal in two different operational modes of the instrument. This device has been successfully operated as a detector in a new null experiment for the gravitational inverse-square law. In this paper we report the design, fabrication, and detailed test results of the superconducting gravity gradiometer. We also present additional theoretical analyses which predict the specific dynamic behavior of the gradiometer and of the test

Airborne Gravity: NGS' Gravity Data for EN07 (2012-2013)

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National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Maine and Canada collected in 2012 and 2013 over 2 surveys. This data set is part of the Gravity for the Re-definition of the American...

Airborne Gravity: NGS' Gravity Data for AS03 (2010-2012)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Alaska collected in 2010 and 2012 over 2 surveys. This data set is part of the Gravity for the Re-definition of the American Vertical Datum...

Gravity wave astronomy

International Nuclear Information System (INIS)

Pinheiro, R.

1979-01-01

The properties and production of gravitational radiation are described. The prospects for their detection are considered including the Weber apparatus and gravity-wave telescopes. Possibilities of gravity-wave astronomy are noted

Radioisotope electric propulsion for robotic science missions to near-interstellar space

International Nuclear Information System (INIS)

Noble, R.J.

1994-10-01

The use of radioisotope electric propulsion for sending small robotic probes on fast science missions several hundred astronomical units (AU) from the Sun is investigated. Such missions would address a large variety of solar, interstellar, galactic and cosmological science themes from unique vantage points at 100 to 600 AU, including parallax distance measurements for the entire Milky Way Galaxy, sampling of the interstellar medium and imaging of cosmological objects at the gravitational lens foci of the Sun (≥ 550 AU). Radioisotope electric propulsion (REP) systems are low-thrust, ion propulsion units based on multi-hundred watt, radioisotope electric generators and ion thrusters. In a previous work, the flight times for rendezvous missions to the outer planets (< 30 AU) using REP were found to be less than fifteen years. However fast prestellar missions to several hundred AU are not possible unless the probe's energy can be substantially increased in the inner Solar System so as to boost the final hyperbolic excess velocity. In this paper an economical hybrid propulsion scheme combining chemical propulsion and gravity assist in the inner Solar System and radioisotope electric propulsion in the outer Solar System is studied which enables fast prestellar missions. Total hyperbolic excess velocities of 15 AU/year and flight times to 550 AU of about 40 years are possible using REP technology that may be available in the next decade

Cineradiographic Analysis of Mouse Postural Response to Alteration of Gravity and Jerk (Gravity Deceleration Rate

Directory of Open Access Journals (Sweden)

Katsuya Hasegawa

2014-04-01

Full Text Available The ability to maintain the body relative to the external environment is important for adaptation to altered gravity. However, the physiological limits for adaptation or the disruption of body orientation are not known. In this study, we analyzed postural changes in mice upon exposure to various low gravities. Male C57BL6/J mice (n = 6 were exposed to various gravity-deceleration conditions by customized parabolic flight-maneuvers targeting the partial-gravity levels of 0.60, 0.30, 0.15 and μ g (<0.001 g. Video recordings of postural responses were analyzed frame-by-frame by high-definition cineradiography and with exact instantaneous values of gravity and jerk. As a result, the coordinated extension of the neck, spine and hindlimbs was observed during the initial phase of gravity deceleration. Joint angles widened to 120%–200% of the reference g level, and the magnitude of the thoracic-curvature stretching was correlated with gravity and jerk, i.e., the gravity deceleration rate. A certain range of jerk facilitated mouse skeletal stretching efficiently, and a jerk of −0.3~−0.4 j (g/s induced the maximum extension of the thoracic-curvature. The postural response of animals to low gravity may undergo differential regulation by gravity and jerk.

Zero Temperature Hope Calculations

International Nuclear Information System (INIS)

Rozsnyai, B. F.

2002-01-01

The primary purpose of the HOPE code is to calculate opacities over a wide temperature and density range. It can also produce equation of state (EOS) data. Since the experimental data at the high temperature region are scarce, comparisons of predictions with the ample zero temperature data provide a valuable physics check of the code. In this report we show a selected few examples across the periodic table. Below we give a brief general information about the physics of the HOPE code. The HOPE code is an ''average atom'' (AA) Dirac-Slater self-consistent code. The AA label in the case of finite temperature means that the one-electron levels are populated according to the Fermi statistics, at zero temperature it means that the ''aufbau'' principle works, i.e. no a priory electronic configuration is set, although it can be done. As such, it is a one-particle model (any Hartree-Fock model is a one particle model). The code is an ''ion-sphere'' model, meaning that the atom under investigation is neutral within the ion-sphere radius. Furthermore, the boundary conditions for the bound states are also set at the ion-sphere radius, which distinguishes the code from the INFERNO, OPAL and STA codes. Once the self-consistent AA state is obtained, the code proceeds to generate many-electron configurations and proceeds to calculate photoabsorption in the ''detailed configuration accounting'' (DCA) scheme. However, this last feature is meaningless at zero temperature. There is one important feature in the HOPE code which should be noted; any self-consistent model is self-consistent in the space of the occupied orbitals. The unoccupied orbitals, where electrons are lifted via photoexcitation, are unphysical. The rigorous way to deal with that problem is to carry out complete self-consistent calculations both in the initial and final states connecting photoexcitations, an enormous computational task. The Amaldi correction is an attempt to address this problem by distorting the

Navigating the MESSENGER Spacecraft through End of Mission

Science.gov (United States)

Bryan, C. G.; Williams, B. G.; Williams, K. E.; Taylor, A. H.; Carranza, E.; Page, B. R.; Stanbridge, D. R.; Mazarico, E.; Neumann, G. A.; O'Shaughnessy, D. J.; McAdams, J. V.; Calloway, A. B.

2015-12-01

The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft orbited the planet Mercury from March 2011 until the end of April 2015, when it impacted the planetary surface after propellant reserves used to maintain the orbit were depleted. This highly successful mission was led by the principal investigator, Sean C. Solomon, of Columbia University. The Johns Hopkins University Applied Physics Laboratory (JHU/APL) designed and assembled the spacecraft and served as the home for spacecraft operations. Spacecraft navigation for the entirety of the mission was provided by the Space Navigation and Flight Dynamics Practice (SNAFD) of KinetX Aerospace. Orbit determination (OD) solutions were generated through processing of radiometric tracking data provided by NASA's Deep Space Network (DSN) using the MIRAGE suite of orbital analysis tools. The MESSENGER orbit was highly eccentric, with periapsis at a high northern latitude and periapsis altitude in the range 200-500 km for most of the orbital mission phase. In a low-altitude "hover campaign" during the final two months of the mission, periapsis altitudes were maintained within a narrow range between about 35 km and 5 km. Navigating a spacecraft so near a planetary surface presented special challenges. Tasks required to meet those challenges included the modeling and estimation of Mercury's gravity field and of solar and planetary radiation pressure, and the design of frequent orbit-correction maneuvers. Superior solar conjunction also presented observational modeling issues. One key to the overall success of the low-altitude hover campaign was a strategy to utilize data from an onboard laser altimeter as a cross-check on the navigation team's reconstructed and predicted estimates of periapsis altitude. Data obtained from the Mercury Laser Altimeter (MLA) on a daily basis provided near-real-time feedback that proved invaluable in evaluating alternative orbit estimation strategies, and

Hope, Coping, and Quality of Life in Adults with Myasthenia Gravis.

Science.gov (United States)

Koopman, Wilma J; LeBlanc, Nicole; Fowler, Sue; Nicolle, Michael W; Hulley, Denise

2016-01-01

Myasthenia gravis significantly impacts quality of life. However, the relationship between hope, coping, and quality of life (QOL)in myasthenia patients has not been studied (Kulkantrakorn & Jarungkiatkul, 2009; Raggi et al., 2010). The aim of this study was to explore the relationship between hope, coping, and quality of life in adults with myasthenia gravis. Subjects with MG (n = 100) completed six questionnaires, including a demographic profile, the Myasthenia Gravis Activities of Daily Living Scale (MG-ADL), Herth Hope Index (HHI), Jalowiec Coping Scale (JCS), Myasthenia Gravis Quality-of-Life Scale (MG-QOL15), and Short Form Health Survey (SF-36v2). Mean hope scores indicated a high level of hope. An optimistic coping style was the most common and effective coping strategy identified by subjects. Positive thinking and humour were also frequently used strategies. Participants identified quality of life as good tolerability, above general population mental well-being, and below general populationphysical well-being. Participants who identified good quality of life had low scores on the MG-QOL15 scale and high scores on the SF36v2. Hope and independence for activities of daily living were found to correlate with improved quality of life and mental well-being(p life in the relationship between hope and coping. Hope and coping were not important factors for well-being or quality of life. Nurses caring for adults with myasthenia gravis should use interventions that continue to support hope, quality of life, and coping throughout the unpredictable and chronic course of MG.

Restoring Hope: You Can Help Save A Life

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Department of Defense Submit Search Restoring Hope Sep. 1, 2010 You Can Help Save A Life More Focus Needed to of Staff Videos Pentagon Channel Restoring Hope: 90 min. Special - Part 1 | Part 2 More Pentagon Prevention Month: Marine Corps Team Helps Save Lives. I Will Never Quit on Life Sept.8, 2010 - Mrs. Mullen on

Hope as a Political Virtue | Moellendorf | Philosophical Papers

African Journals Online (AJOL)

... understand why it is a political virtue of persons. I also argue that securing the institutional bases of hope is a virtue of state institutions, particularly in states in transition from severe injustice. And, finally, when the bases are secure, a person who fails to hope for the political future is in that regard prima facie blameworthy.

Airborne Gravity: NGS' Gravity Data for ES05 (2015-2016)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Florida and the Atlantic Ocean collected in two surveys, FL15-1 and FL15-2. This data set is part of the Gravity for the Re-definition of...

Airborne Gravity: NGS' Gravity Data for AS04 (2015-2016)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Alaska collected in 2015 and 2016 over 2 surveys, AK15 and AK16. This data set is part of the Gravity for the Re-definition of the American...

Development of a new generation gravity map of Antarctica: ADGRAV Antarctic Digital Gravity Synthesis

Directory of Open Access Journals (Sweden)

R. A. Arko

1999-06-01

Full Text Available The U.S. National Science Foundation (NSF has agreed to support the development of a new generation gravity map of Antarctica (ADGRAV - Antarctic Digital Gravity Synthesis, funding the development of a web based access tool. The goal of this project is the creation of an on-line Antarctic gravity database which will facilitate access to improved high resolution satellite gravity models, in conjunction with shipboard, airborne, and land based gravity measurements for the continental regions. This database will complement parallel projects underway to develop new continental bedrock (BEDMAP and magnetic (ADMAP maps of Antarctica.

[Hope as psychological resource for nurturant professionals (medicine case study)].

Science.gov (United States)

Водопьянова, Наталия Е; Чикер, Вера А; Потявина, Валерия В

In the article, the issues concerning hope, which is one of the most important resources for specialists of many nurturant professions, are observed. The theoretical analysis of hope and its categorization from the perspective of subjective and resource-based view is given. The special scientific and practical interest to human subjective and personal resources is determined by their unique role not only in human life support, but also in overcoming hard situations and extreme obstacles, including crisis situations in professional activity, with the example of the profession of a doctor. The aim of the empirical research is studying the correlation between hope and such manifestations of subjective regulations medical practice as inner subjective control and failure avoidance motivation. 120 doctors (60 men and 60 women) working in St. Petersburg hospitals took part in the research. Several research methods were used, such as 'Resource map' application form, R. Snyder's hope scale adapted by K. Muzdybayev, 'Subjective control level' method by E. Bazhin, E. Golynkina and L. Etkind, 'Failure avoidance motivation' method by T. Ehlers. Doctors think that Hope and Optimism are among important components of their professional practice, together with willing features helping them to reach their goals (such as persistence, patience, eagerness, insistence and endurance) and such personal qualities as self-assuredness, motion control in different situations, ability to solve hard problems. According the data of correlation and regression analyses, the anticipation that hope is determined by high level of inner control locus and low failure avoidance motivation (responsibility for patients' lives) within medical practice. Most doctors have average or high level of hope, which lets determine this personal disposition quality as one of the important ones for this profession. Being the positive result of professional practice and not depending on the doctors' sex and

The Gravity and Extreme Magnetism Small Explorer (GEMS)

Science.gov (United States)

Kallman, T. R.

2011-01-01

The Gravity and Extreme Magnetism Small Explorer (GEMS) was selected by NASA for flight in 2014 to make a sensitive search for X-ray polarization from a wide set of source classes, including stellar black holes, Seyfert galaxies and quasars, blazars, rotation and accretion-powered pulsars, magnetars, shell supernova remnants and pulsar wind nebulae. Among the primary scientific objectives are determining the effects of the spin of black holes and the geometry of supermassive black hole accretion, determining the configurations of the magnetic fields and the X-ray emission of magnetars, and determining the magnetic structure of the supernova shocks in which cosmic rays are accelerated. GEMS will observe 23 targets during a 16 month prime mission, in observations that will be able to reach predicted levels of polarization. The mission can be extended to provide a guest observer phase. The GEMS instrument has time projection chamber polarimeters with high 2-10 keV efficiency at the focus of thin foil mirrors. The 4.5 m focal length mirrors will be deployed on an extended boom. The spacecraft with the instrument is rotated with a period of about 10 minutes to enable measurement and correction of systematic errors. A small Bragg reflection soft X-ray experiment takes advantage of this rotation to obtain a measurement at 0.5 keV. The design of the GEMS instrument and the mission, the expected performance and the planned science program will be discussed.

Cosmological tests of modified gravity.

Science.gov (United States)