A Topology Control Strategy with Reliability Assurance for Satellite Cluster Networks in Earth Observation.

Science.gov (United States)

Chen, Qing; Zhang, Jinxiu; Hu, Ze

2017-02-23

This article investigates the dynamic topology control problemof satellite cluster networks (SCNs) in Earth observation (EO) missions by applying a novel metric of stability for inter-satellite links (ISLs). The properties of the periodicity and predictability of satellites' relative position are involved in the link cost metric which is to give a selection criterion for choosing the most reliable data routing paths. Also, a cooperative work model with reliability is proposed for the situation of emergency EO missions. Based on the link cost metric and the proposed reliability model, a reliability assurance topology control algorithm and its corresponding dynamic topology control (RAT) strategy are established to maximize the stability of data transmission in the SCNs. The SCNs scenario is tested through some numeric simulations of the topology stability of average topology lifetime and average packet loss rate. Simulation results show that the proposed reliable strategy applied in SCNs significantly improves the data transmission performance and prolongs the average topology lifetime.

A Topology Control Strategy with Reliability Assurance for Satellite Cluster Networks in Earth Observation

Directory of Open Access Journals (Sweden)

Qing Chen

2017-02-01

Full Text Available This article investigates the dynamic topology control problemof satellite cluster networks (SCNs in Earth observation (EO missions by applying a novel metric of stability for inter-satellite links (ISLs. The properties of the periodicity and predictability of satellites’ relative position are involved in the link cost metric which is to give a selection criterion for choosing the most reliable data routing paths. Also, a cooperative work model with reliability is proposed for the situation of emergency EO missions. Based on the link cost metric and the proposed reliability model, a reliability assurance topology control algorithm and its corresponding dynamic topology control (RAT strategy are established to maximize the stability of data transmission in the SCNs. The SCNs scenario is tested through some numeric simulations of the topology stability of average topology lifetime and average packet loss rate. Simulation results show that the proposed reliable strategy applied in SCNs significantly improves the data transmission performance and prolongs the average topology lifetime.

Levee reliability analyses for various flood return periods - a case study in southern Taiwan

Science.gov (United States)

Huang, W.-C.; Yu, H.-W.; Weng, M.-C.

2015-04-01

In recent years, heavy rainfall conditions have caused disasters around the world. To prevent losses by floods, levees have often been constructed in inundation-prone areas. This study performed reliability analyses for the Chiuliao First Levee in southern Taiwan. The failure-related parameters were the water level, the scouring depth, and the in situ friction angle. Three major failure mechanisms were considered: the slope sliding failure of the levee and the sliding and overturning failures of the retaining wall. When the variability of the in situ friction angle and the scouring depth are considered for various flood return periods, the variations of the factor of safety for the different failure mechanisms show that the retaining wall sliding and overturning failures are more sensitive to the change of the friction angle. When the flood return period is greater than 2 years, the levee could fail with slope sliding for all values of the water level difference. The results of levee stability analysis considering the variability of different parameters could aid engineers in designing the levee cross sections, especially with potential failure mechanisms in mind.

A Comprehensive Structural Dynamic Analysis Approach for Multi Mission Earth Entry Vehicle (MMEEV) Development

Science.gov (United States)

Perino, Scott; Bayandor, Javid; Siddens, Aaron

2012-01-01

The anticipated NASA Mars Sample Return Mission (MSR) requires a simple and reliable method in which to return collected Martian samples back to earth for scientific analysis. The Multi-Mission Earth Entry Vehicle (MMEEV) is NASA's proposed solution to this MSR requirement. Key aspects of the MMEEV are its reliable and passive operation, energy absorbing foam-composite structure, and modular impact sphere (IS) design. To aid in the development of an EEV design that can be modified for various missions requirements, two fully parametric finite element models were developed. The first model was developed in an explicit finite element code and was designed to evaluate the impact response of the vehicle and payload during the final stage of the vehicle's return to earth. The second model was developed in an explicit code and was designed to evaluate the static and dynamic structural response of the vehicle during launch and reentry. In contrast to most other FE models, built through a Graphical User Interface (GUI) pre-processor, the current model was developed using a coding technique that allows the analyst to quickly change nearly all aspects of the model including: geometric dimensions, material properties, load and boundary conditions, mesh properties, and analysis controls. Using the developed design tool, a full range of proposed designs can quickly be analyzed numerically and thus the design trade space for the EEV can be fully understood. An engineer can then quickly reach the best design for a specific mission and also adapt and optimize the general design for different missions.

Low Cost Mars Sample Return Utilizing Dragon Lander Project

Science.gov (United States)

Stoker, Carol R.

2014-01-01

We studied a Mars sample return (MSR) mission that lands a SpaceX Dragon Capsule on Mars carrying sample collection hardware (an arm, drill, or small rover) and a spacecraft stack consisting of a Mars Ascent Vehicle (MAV) and Earth Return Vehicle (ERV) that collectively carry the sample container from Mars back to Earth orbit.

Earth reencounter probabilities for aborted space disposal of hazardous nuclear waste

Science.gov (United States)

Friedlander, A. L.; Feingold, H.

1977-01-01

A quantitative assessment is made of the long-term risk of earth reencounter and reentry associated with aborted disposal of hazardous material in the space environment. Numerical results are presented for 10 candidate disposal options covering a broad spectrum of disposal destinations and deployment propulsion systems. Based on representative models of system failure, the probability that a single payload will return and collide with earth within a period of 250,000 years is found to lie in the range .0002-.006. Proportionately smaller risk attaches to shorter time intervals. Risk-critical factors related to trajectory geometry and system reliability are identified as possible mechanisms of hazard reduction.

Mars Sample Return Using Solar Sail Propulsion

Science.gov (United States)

Johnson, Les; Macdonald, Malcolm; Mcinnes, Colin; Percy, Tom

2012-01-01

Many Mars Sample Return (MSR) architecture studies have been conducted over the years. A key element of them is the Earth Return Stage (ERS) whose objective is to obtain the sample from the Mars Ascent Vehicle (MAV) and return it safely to the surface of the Earth. ERS designs predominantly use chemical propulsion [1], incurring a significant launch mass penalty due to the low specific impulse of such systems coupled with the launch mass sensitivity to returned mass. It is proposed to use solar sail propulsion for the ERS, providing a high (effective) specific impulse propulsion system in the final stage of the multi-stage system. By doing so to the launch mass of the orbiter mission can be significantly reduced and hence potentially decreasing mission cost. Further, solar sailing offers a unique set of non-Keplerian low thrust trajectories that may enable modifications to the current approach to designing the Earth Entry Vehicle by potentially reducing the Earth arrival velocity. This modification will further decrease the mass of the orbiter system. Solar sail propulsion uses sunlight to propel vehicles through space by reflecting solar photons from a large, mirror-like surface made of a lightweight, reflective material. The continuous photonic pressure provides propellantless thrust to conduct orbital maneuvering and plane changes more efficiently than conventional chemical propulsion. Because the Sun supplies the necessary propulsive energy, solar sails require no onboard propellant, thus reducing system mass. This technology is currently at TRL 7/8 as demonstrated by the 2010 flight of the Japanese Aerospace Exploration Agency, JAXA, IKAROS mission. [2

A Recursive Formula for the Evaluation of Earth Return Impedance on Buried Cables

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Reynaldo Iracheta

2015-09-01

Full Text Available This paper presents an alternative solution based on infinite series for the accurate and efficient evaluation of cable earth return impedances. This method uses Wedepohl and Wilcox’s transformation to decompose Pollaczek’s integral in a set of Bessel functions and a definite integral. The main feature of Bessel functions is that they are easy to compute in modern mathematical software tools such as Matlab. The main contributions of this paper are the approximation of the definite integral by an infinite series, since it does not have analytical solution; and its numerical solution by means of a recursive formula. The accuracy and efficiency of this recursive formula is compared against the numerical integration method for a broad range of frequencies and cable  configurations. Finally, the proposed method is used as a subroutine for cable parameter calculation in the inverse Numerical Laplace Transform (NLT to obtain accurate transient responses in the time domain.

Computing return times or return periods with rare event algorithms

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Lestang, Thibault; Ragone, Francesco; Bréhier, Charles-Edouard; Herbert, Corentin; Bouchet, Freddy

2018-04-01

The average time between two occurrences of the same event, referred to as its return time (or return period), is a useful statistical concept for practical applications. For instance insurances or public agencies may be interested by the return time of a 10 m flood of the Seine river in Paris. However, due to their scarcity, reliably estimating return times for rare events is very difficult using either observational data or direct numerical simulations. For rare events, an estimator for return times can be built from the extrema of the observable on trajectory blocks. Here, we show that this estimator can be improved to remain accurate for return times of the order of the block size. More importantly, we show that this approach can be generalised to estimate return times from numerical algorithms specifically designed to sample rare events. So far those algorithms often compute probabilities, rather than return times. The approach we propose provides a computationally extremely efficient way to estimate numerically the return times of rare events for a dynamical system, gaining several orders of magnitude of computational costs. We illustrate the method on two kinds of observables, instantaneous and time-averaged, using two different rare event algorithms, for a simple stochastic process, the Ornstein–Uhlenbeck process. As an example of realistic applications to complex systems, we finally discuss extreme values of the drag on an object in a turbulent flow.

Spearman's "law of diminishing returns" and the role of test reliability investigated in a large sample of Danish military draftees

DEFF Research Database (Denmark)

Teasdale, Thomas William; Hartmann, P.

2005-01-01

The present article investigates Spearman's "Law of Diminishing Returns" (SLODR), which hypothesizes that the g saturation for cognitive tests is lower for high ability subjects than for low ability subjects. This hypothesis was tested in a large sample of Danish military draftees (N = 6757) who...... were representative of the young adult male population, aged 18-19, and tested with a group-administered intelligence test comprised of four subtests. The aim of the study was twofold. The first was to reproduce previous SLODR findings by the present authors. This was done by replicating...... in reliability could account for the difference in g saturation across ability groups. The results showed that the reliability was larger for the High ability group, thereby not explaining the present findings....

Ground Return Current Behaviour in High Voltage Alternating Current Insulated Cables

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Roberto Benato

2014-12-01

Full Text Available The knowledge of ground return current in fault occurrence plays a key role in the dimensioning of the earthing grid of substations and of cable sealing end compounds, in the computation of rise of earth potential at substation sites and in electromagnetic interference (EMI on neighbouring parallel metallic conductors (pipes, handrails, etc.. Moreover, the ground return current evaluation is also important in steady-state regime since this stray current can be responsible for EMI and also for alternating current (AC corrosion. In fault situations and under some assumptions, the ground return current value at a substation site can be computed by means of k-factors. The paper shows that these simplified and approximated approaches have a lot of limitations and only multiconductor analysis can show the ground return current behaviour along the cable (not only the two end values both in steady-state regime and in short circuit occurrence (e.g., phase-to-ground and phase-to-phase-to-ground. Multiconductor cell analysis (MCA considers the cable system in its real asymmetry without simplified and approximated hypotheses. The sensitivity of ground return current on circuit parameters (cross-bonding box resistances, substation earthing resistances, soil resistivity is presented in the paper.

Phobos Sample Return: Next Approach

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Zelenyi, Lev; Martynov, Maxim; Zakharov, Alexander; Korablev, Oleg; Ivanov, Alexey; Karabadzak, George

The Martian moons still remain a mystery after numerous studies by Mars orbiting spacecraft. Their study cover three major topics related to (1) Solar system in general (formation and evolution, origin of planetary satellites, origin and evolution of life); (2) small bodies (captured asteroid, or remnants of Mars formation, or reaccreted Mars ejecta); (3) Mars (formation and evolution of Mars; Mars ejecta at the satellites). As reviewed by Galimov [2010] most of the above questions require the sample return from the Martian moon, while some (e.g. the characterization of the organic matter) could be also answered by in situ experiments. There is the possibility to obtain the sample of Mars material by sampling Phobos: following to Chappaz et al. [2012] a 200-g sample could contain 10-7 g of Mars surface material launched during the past 1 mln years, or 5*10-5 g of Mars material launched during the past 10 mln years, or 5*1010 individual particles from Mars, quantities suitable for accurate laboratory analyses. The studies of Phobos have been of high priority in the Russian program on planetary research for many years. Phobos-88 mission consisted of two spacecraft (Phobos-1, Phobos-2) and aimed the approach to Phobos at 50 m and remote studies, and also the release of small landers (long-living stations DAS). This mission implemented the program incompletely. It was returned information about the Martian environment and atmosphere. The next profect Phobos Sample Return (Phobos-Grunt) initially planned in early 2000 has been delayed several times owing to budget difficulties; the spacecraft failed to leave NEO in 2011. The recovery of the science goals of this mission and the delivery of the samples of Phobos to Earth remain of highest priority for Russian scientific community. The next Phobos SR mission named Boomerang was postponed following the ExoMars cooperation, but is considered the next in the line of planetary exploration, suitable for launch around 2022. A

Self-impedances of finite and infinite wires with earth-return

International Nuclear Information System (INIS)

Koglin, H.J.; Meyer, E.P.

1981-01-01

The electromagnetic field for a thin wire of finite length, embedded in a homogeneous earth of infinite extent in all directions, is given. The distribution of the electric field intensity close to the wire is examined. The mathematical model for the finite wire is expanded by substituting a spheroidal earth-electrode at each end. The external self-impedance of the wire between the earth-electrodes is calculated by integrating the electric field intensity along a presupposed radius. Especially in the case of short wires the results show considerable deviations to the known depth of current penetration as compared to that of an infinitely long wire. By considering the approximations used for short wires in this model, one can draw conclusions on the external self-impedance for short wires above, on and under the earth's surface. (orig.) [de

Strategies for Building a Reliable, Diverse Pipeline of Earth Data Scientists

Science.gov (United States)

Fowler, R.; Robinson, E.

2015-12-01

The grand challenges facing the geosciences are increasingly data-driven and require large-scale collaboration. Today's geoscience community is primarily self-taught or peer-taught as neither data science nor collaborative skills are traditionally part of the geoscience curriculum. This is not a sustainable model. By increasing understanding of the role of data science and collaboration in the geosciences, and Earth and space science informatics, an increased number of students pursuing STEM degrees may choose careers in these fields. Efforts to build a reliable pipeline of future Earth data scientists must incorporate the following: (1) improved communication: covering not only what data science is, but what a data scientist working in the geosciences does and the impact their work has; (2) effective identification and promotion of the skills and knowledge needed, including possible academic and career paths, the availability and types of jobs in the geosciences, and how to develop the necessary skills for these careers; (3) the employment of recruitment and engagement strategies that result in a diverse data science workforce, especially the recruitment and inclusion of underrepresented minority students; and (4) changing organizational cultures to better retain and advance women and other minority groups in data science. In this presentation we'll discuss strategies to increase the number of women and underrepresented minority students pursuing careers in data science, with an emphasis on effective strategies for recruiting and mentoring these groups, as well as challenges faced and lessons learned.

Comet coma sample return instrument

Science.gov (United States)

Albee, A. L.; Brownlee, Don E.; Burnett, Donald S.; Tsou, Peter; Uesugi, K. T.

1994-01-01

The sample collection technology and instrument concept for the Sample of Comet Coma Earth Return Mission (SOCCER) are described. The scientific goals of this Flyby Sample Return are to return to coma dust and volatile samples from a known comet source, which will permit accurate elemental and isotopic measurements for thousands of individual solid particles and volatiles, detailed analysis of the dust structure, morphology, and mineralogy of the intact samples, and identification of the biogenic elements or compounds in the solid and volatile samples. Having these intact samples, morphologic, petrographic, and phase structural features can be determined. Information on dust particle size, shape, and density can be ascertained by analyzing penetration holes and tracks in the capture medium. Time and spatial data of dust capture will provide understanding of the flux dynamics of the coma and the jets. Additional information will include the identification of cosmic ray tracks in the cometary grains, which can provide a particle's process history and perhaps even the age of the comet. The measurements will be made with the same equipment used for studying micrometeorites for decades past; hence, the results can be directly compared without extrapolation or modification. The data will provide a powerful and direct technique for comparing the cometary samples with all known types of meteorites and interplanetary dust. This sample collection system will provide the first sample return from a specifically identified primitive body and will allow, for the first time, a direct method of matching meteoritic materials captured on Earth with known parent bodies.

System for Packaging Planetary Samples for Return to Earth

Science.gov (United States)

Badescu, Mircea; Bar-Cohen, Yoseph; Backes, paul G.; Sherrit, Stewart; Bao, Xiaoqi; Scott, James S.

2010-01-01

A system is proposed for packaging material samples on a remote planet (especially Mars) in sealed sample tubes in preparation for later return to Earth. The sample tubes (Figure 1) would comprise (1) tubes initially having open tops and closed bottoms; (2) small, bellows-like collapsible bodies inside the tubes at their bottoms; and (3) plugs to be eventually used to close the tops of the tubes. The top inner surface of each tube would be coated with solder. The side of each plug, which would fit snugly into a tube, would feature a solder-filled ring groove. The system would include equipment for storing, manipulating, filling, and sealing the tubes. The containerization system (see Figure 2) will be organized in stations and will include: the storage station, the loading station, and the heating station. These stations can be structured in circular or linear pattern to minimize the manipulator complexity, allowing for compact design and mass efficiency. The manipulation of the sample tube between stations is done by a simple manipulator arm. The storage station contains the unloaded sample tubes and the plugs before sealing as well as the sealed sample tubes with samples after loading and sealing. The chambers at the storage station also allow for plug insertion into the sample tube. At the loading station the sample is poured or inserted into the sample tube and then the tube is topped off. At the heating station the plug is heated so the solder ring melts and seals the plug to the sample tube. The process is performed as follows: Each tube is filled or slightly overfilled with sample material and the excess sample material is wiped off the top. Then, the plug is inserted into the top section of the tube packing the sample material against the collapsible bellowslike body allowing the accommodation of the sample volume. The plug and the top of the tube are heated momentarily to melt the solder in order to seal the tube.

Proposals for Protection of Return Cables on SwePol Link

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Tadeusz Szczepański

2013-03-01

Full Text Available The return cable on the SwePol Link has been introduced as an alternative forced by environmentalists due to lack of social acceptance of other solutions. This is why in the proposed solution water and earth have been replaced by two return cables, although from a technical point of view such a solution is less effective. The last, eleventh fault of the return cable took place on 15 October 2012. In eight earlier cases the faults were caused by electrical failures in the cable in the sea and were located between ten and twenty kilometers from the Polish shore and triggered by disturbances in the northern part of the Polish power grid. In this situation it has been suggested to analyze and introduce one or two solutions shown below which may significantly limit the effects and lower the costs caused by return cable faults: a assembly of additional surge arresters b return to electrodes – lack of return cables c ”partial” electrodes working with one return cable d operation of the link only with earthings on converter stations. To sum up it needs to be stated that: • a relatively cheap way of protecting return cables against electrical failures is installing surge arresters in the cabinet located next to the cable container on the Polish shore • from the suggested preventive measures it seems reasonable to introduce the above mentioned solutions a and d simultaneously, as both of them are simple solutions which require neither considerable financial expenditure nor authorizations and may quickly show the expected results.

Expected commodity returns and pricing models

International Nuclear Information System (INIS)

Cortazar, Gonzalo; Kovacevic, Ivo; Schwartz, Eduardo S.

2015-01-01

Stochastic models of commodity prices have evolved considerably in terms of their structure and the number and interpretation of the state variables that model the underlying risk. Using multiple factors, different specifications and modern estimation techniques, these models have gained wide acceptance because of their success in accurately fitting the observed commodity futures' term structures and their dynamics. It is not well emphasized however that these models, in addition to providing the risk neutral distribution of future spot prices, also provide their true distribution. While the parameters of the risk neutral distribution are estimated more precisely and are usually statistically significant, some of the parameters of the true distribution are typically measured with large errors and are statistically insignificant. In this paper we argue that to increase the reliability of commodity pricing models, and therefore their use by practitioners, some of their parameters — in particular the risk premium parameters — should be obtained from other sources and we show that this can be done without losing any precision in the pricing of futures contracts. We show how the risk premium parameters can be obtained from estimations of expected futures returns and provide alternative procedures for estimating these expected futures returns. - Highlights: • Simple methodology to improve the performance of commodity pricing models • New information about commodity futures expected return is added to the estimation. • No significant effect in pricing futures contracts is observed. • More reliable commodity pricing model's expected returns are obtained. • Methodology is open to any expected futures return model preferred by practitioner

Mars Sample Return Landed with Red Dragon

Science.gov (United States)

Stoker, Carol R.; Lemke, Lawrence G.

2013-01-01

A Mars Sample Return (MSR) mission is the highest priority science mission for the next decade as recommended by the recent Decadal Survey of Planetary Science. However, an affordable program to carry this out has not been defined. This paper describes a study that examined use of emerging commercial capabilities to land the sample return elements, with the goal of reducing mission cost. A team at NASA Ames examined the feasibility of the following scenario for MSR: A Falcon Heavy launcher injects a SpaceX Dragon crew capsule and trunk onto a Trans Mars Injection trajectory. The capsule is modified to carry all the hardware needed to return samples collected on Mars including a Mars Ascent Vehicle (MAV), an Earth Return Vehicle (ERV) and Sample Collection and Storage hardware. The Dragon descends to land on the surface of Mars using SuperSonic Retro Propulsion (SSRP) as described by Braun and Manning [IEEEAC paper 0076, 2005]. Samples are acquired and deliverd to the MAV by a prelanded asset, possibly the proposed 2020 rover. After samples are obtained and stored in the ERV, the MAV launches the sample-containing ERV from the surface of Mars. We examined cases where the ERV is delivered to either low Mars orbit (LMO), C3 = 0 (Mars escape), or an intermediate energy state. The ERV then provides the rest of the energy (delta V) required to perform trans-Earth injection (TEI), cruise, and insertion into a Moon-trailing Earth Orbit (MTEO). A later mission, possibly a crewed Dragon launched by a Falcon Heavy (not part of the current study) retrieves the sample container, packages the sample, and performs a controlled Earth re-entry to prevent Mars materials from accidentally contaminating Earth. The key analysis methods used in the study employed a set of parametric mass estimating relationships (MERs) and standard aerospace analysis software codes modified for the MAV class of launch vehicle to determine the range of performance parameters that produced converged

Uniform Foam Crush Testing for Multi-Mission Earth Entry Vehicle Impact Attenuation

Science.gov (United States)

Patterson, Byron W.; Glaab, Louis J.

2012-01-01

Multi-Mission Earth Entry Vehicles (MMEEVs) are blunt-body vehicles designed with the purpose of transporting payloads from outer space to the surface of the Earth. To achieve high-reliability and minimum weight, MMEEVs avoid use of limited-reliability systems, such as parachutes and retro-rockets, instead using built-in impact attenuators to absorb energy remaining at impact to meet landing loads requirements. The Multi-Mission Systems Analysis for Planetary Entry (M-SAPE) parametric design tool is used to facilitate the design of MMEEVs and develop the trade space. Testing was conducted to characterize the material properties of several candidate impact foam attenuators to enhance M-SAPE analysis. In the current effort, four different Rohacell foams are tested at three different, uniform, strain rates (approximately 0.17, approximately 100, approximately 13,600%/s). The primary data analysis method uses a global data smoothing technique in the frequency domain to remove noise and system natural frequencies. The results from the data indicate that the filter and smoothing technique are successful in identifying the foam crush event and removing aberrations. The effect of strain rate increases with increasing foam density. The 71-WF-HT foam may support Mars Sample Return requirements. Several recommendations to improve the drop tower test technique are identified.

Performance of single wire earth return transformers with amorphous alloy core in a rural electric energy distribution system

Directory of Open Access Journals (Sweden)

Benedito Antonio Luciano

2012-10-01

Full Text Available In this paper are presented some considerations about the performance of single wire earth return amorphous alloy core transformers in comparison with conventional silicon steel sheets cores transformers used in rural electric energy distribution network. It has been recognized that amorphous metal core transformers improve electrical power distribution efficiency by reducing transformer core losses. This reduction is due to some electromagnetic properties of the amorphous alloys such as: high magnetic permeability, high resistivity, and low coercivity. Experimental results obtained with some single-phase, 60 Hz, 5 kVA amorphous core transformers installed in a rural area electric distribution system in Northern Brazil have been confirming their superior performance in comparison to identical nominal rated transformers built with conventional silicon steel cores, particularly with regard to the excitation power and to the no-load losses.

The earth and the moon

CERN Document Server

Elkins-Tanton, Linda T

2010-01-01

The moon is the only body in the solar system outside of the Earth that has been visited by humans. More than 440 pounds of lunar material are brought by NASA and Soviet space missions to Earth for study. The information gleaned about the moon from this relatively small pile of rocks is mind-boggling and stands as the greatest proof that Martian planetary science would be greatly enhanced by returning samples to Earth. Compositional studies of lunar rocks show that the moon and the Earth are made of similar material, and because lunar material has not been reworked through erosion and plate te

Planetary Protection for LIFE-Sample Return from Enceladus

Science.gov (United States)

Tsou, Peter; Yano, Hajime; Takano, Yoshinori; McKay, David; Takai, Ken; Anbar, Ariel; Baross, J.

Introduction: We are seeking a balanced approach to returning Enceladus plume samples to state-of-the-art terrestrial laboratories to search for signs of life. NASA, ESA, JAXA and other space agencies are seeking habitable worlds and life beyond Earth. Enceladus, an icy moon of Saturn, is the first known body in the Solar System besides Earth to emit liquid water from its interior. Enceladus is the most accessible body in our Solar System for a low cost flyby sample return mission to capture aqueous based samples, to determine its state of life development, and shed light on how life can originate on wet planets/moons. LIFE combines the unique capabilities of teams of international exploration expertise. These returned Enceladus plume samples will determine if this habitable body is in fact inhabited [McKay et al, 2014]. This paper describes an approach for the LIFE mission to capture and return samples from Enceladus while meeting NASA and COSPAR planetary protection requirements. Forward planetary protection requirements for spacecraft missions to icy solar system bodies have been defined, however planetary protection requirements specific to an Earth return of samples collected from Enceladus or other Outer Planet Icy Moons, have yet to be defined. Background: From the first half century of space exploration, we have returned samples only from the Moon, comet Wild 2, the Solar Wind and the asteroid Itokawa. The in-depth analyses of these samples in terrestrial laboratories have yielded detailed chemical information that could not have been obtained otherwise. While obtaining samples from Solar System bodies is trans-formative science, it is rarely performed due to cost and complexity. The discovery by Cassini of geysers on Enceladus and organic materials in the ejected plume indicates that there is an exceptional opportunity and strong scientific rationale for LIFE. The earliest low-cost possible flight opportunity is the next Discovery Mission [Tsou et al 2012

ECLSS Reliability for Long Duration Missions Beyond Lower Earth Orbit

Science.gov (United States)

Sargusingh, Miriam J.; Nelson, Jason

2014-01-01

Reliability has been highlighted by NASA as critical to future human space exploration particularly in the area of environmental controls and life support systems. The Advanced Exploration Systems (AES) projects have been encouraged to pursue higher reliability components and systems as part of technology development plans. However, there is no consensus on what is meant by improving on reliability; nor on how to assess reliability within the AES projects. This became apparent when trying to assess reliability as one of several figures of merit for a regenerable water architecture trade study. In the Spring of 2013, the AES Water Recovery Project (WRP) hosted a series of events at the NASA Johnson Space Center (JSC) with the intended goal of establishing a common language and understanding of our reliability goals and equipping the projects with acceptable means of assessing our respective systems. This campaign included an educational series in which experts from across the agency and academia provided information on terminology, tools and techniques associated with evaluating and designing for system reliability. The campaign culminated in a workshop at JSC with members of the ECLSS and AES communities with the goal of developing a consensus on what reliability means to AES and identifying methods for assessing our low to mid-technology readiness level (TRL) technologies for reliability. This paper details the results of the workshop.

The Extinction and Return of Fear of Public Speaking.

Science.gov (United States)

Laborda, Mario A; Schofield, Casey A; Johnson, Emily M; Schubert, Jessica R; George-Denn, Daniel; Coles, Meredith E; Miller, Ralph R

2016-11-01

Prior studies indicate extinguished fear often partially returns when participants are later tested outside the extinction context. Cues carried from the extinction context to the test context sometimes reduce return of fear, but it is unclear whether such extinction cues (ECs) reduce return of fear of public speaking. Here we assessed return of fear of public speaking, and whether either of two types of ECs can attenuate it. Participants gave speeches of increasing difficulty during an exposure practice session and were tested 2 days later in a different context. Testing occurred in the presence of physical ECs, after mentally rehearsing the exposure session, or without either reminder. Practice reduced fear of public speaking, but fear partially returned at test. Neither physical nor mental ECs reduced partial return of fear of public speaking. The return of extinguished fear of public speaking, although small, was reliable, but not appreciably sensitive to presence of ECs. © The Author(s) 2016.

Return and profitability of space programs. Information - the main product of flights in space

Science.gov (United States)

Nikolova, Irena

The basic branch providing global information, as a product on the market, is astronautics and in particular aero and space flights. Nowadays economic categories like profitability, return, and self-financing are added to space information. The activity in the space information service market niche is an opportunity for realization of high economic efficiency and profitability. The present report aims at examining the possibilities for return and profitability of space programs. Specialists in economics from different countries strive for defining the economic effect of implementing space technologies in the technical branches on earth. Still the priorities here belong to government and insufficient market organization and orientation is apparent. Attracting private investors and searching for new mechanisms of financing are the factors for increasing economic efficiency and return of capital invested in the mentioned sphere. Return of utilized means is an economically justified goal, a motive for a bigger enlargement of efforts and directions for implementing the achievements of astronautics in the branches of economy on earth.

Phobos/Deimos sample return via solar sail.

Science.gov (United States)

Matloff, Gregory L; Taylor, Travis; Powell, Conley; Moton, Tryshanda

2005-12-01

A sample-return mission to the Martian satellites using a con-temporary solar sail for all post-Earth-escape propulsion is proposed. The 0.015 kg/m(2) areal mass-thickness sail unfurls after launch and injection onto a Mars-bound Hohmann-transfer ellipse. Structure and payload increase spacecraft areal mass thickness to 0.028 kg/m(2). During the Mars encounter, the sail functions as a parachute in the outer atmosphere of Mars to accomplish aerocapture. On-board thrusters or the sail maneuver the spacecraft into an orbit with periapsis near Mars and apoapsis near Phobos. The orbit is circularized for Phobos-rendezvous; surface samples are collected. The sail then raises the orbit for Deimos-rendezvous and sample collection. The sail next places the spacecraft on an Earth-bound Hohmann-transfer ellipse. During Earth encounter, the sail accomplishes Earth-aerocapture or partially decelerates the sample container for entry into the Earth's atmosphere. Mission mass budget is about 218 grams and mission duration is less than five years.

Crew emergency return vehicle - Electrical power system design study

Science.gov (United States)

Darcy, E. C.; Barrera, T. P.

1989-01-01

A crew emergency return vehicle (CERV) is proposed to perform the lifeboat function for the manned Space Station Freedom. This escape module will be permanently docked to Freedom and, on demand, will be capable of safely returning the crew to earth. The unique requirements that the CERV imposes on its power source are presented, power source options are examined, and a baseline system is selected. It consists of an active Li-BCX DD-cell modular battery system and was chosen for the maturity of its man-rated design and its low development costs.

Mars Sample Return: Mars Ascent Vehicle Mission and Technology Requirements

Science.gov (United States)

Bowles, Jeffrey V.; Huynh, Loc C.; Hawke, Veronica M.; Jiang, Xun J.

2013-01-01

A Mars Sample Return mission is the highest priority science mission for the next decade recommended by the recent Decadal Survey of Planetary Science, the key community input process that guides NASAs science missions. A feasibility study was conducted of a potentially simple and low cost approach to Mars Sample Return mission enabled by the use of developing commercial capabilities. Previous studies of MSR have shown that landing an all up sample return mission with a high mass capacity lander is a cost effective approach. The approach proposed is the use of an emerging commercially available capsule to land the launch vehicle system that would return samples to Earth. This paper describes the mission and technology requirements impact on the launch vehicle system design, referred to as the Mars Ascent Vehicle (MAV).

A Review of New and Developing Technology to Significantly Improve Mars Sample-Return Missions

Science.gov (United States)

Carsey, F.; Brophy, J.; Gilmore, M.; Rodgers, D.; Wilcox, B.

2000-07-01

A JPL development activity was initiated in FY 1999 for the purpose of examining and evaluating technologies that could materially improve future (i.e., beyond the 2005 launch) Mars sample return missions. The scope of the technology review was comprehensive and end-to-end; the goal was to improve mass, cost, risk, and scientific return. A specific objective was to assess approaches to sample return with only one Earth launch. While the objective of the study was specifically for sample-return, in-situ missions can also benefit from using many of the technologies examined.

Neutron logging reliability techniques and apparatus

International Nuclear Information System (INIS)

Johnstone, C.W.

1978-01-01

This invention relates in general to neutron logging of earth formations, and in particular, to novel apparatus and procedures for determining the validity, or reliability, of data derived at least in part by logging neutron characteristics of earth formations and, if desired, for affording verifiably accurate indications of such data

Neutron logging reliability techniques and apparatus

International Nuclear Information System (INIS)

Johnstone, C.W.

1974-01-01

This invention relates in general to neutron logging of earth formations, and in particular, to novel apparatus and procedures for determining the validity, or reliability, of data derived at least in part by logging neutron characteristics of earth formations and, if desired, for affording verifiably accurate indications of such data. (author)

Triple F - A Comet Nucleus Sample Return Mission

Science.gov (United States)

Kueppers, Michael; Keller, Horst Uwe; Kuhrt, Ekkehard; A'Hearn, Michael; Altwegg, Kathrin; Betrand, Regis; Busemann, Henner; Capria, Maria Teresa; Colangeli, Luigi

2008-01-01

The Triple F (Fresh From the Fridge) mission, a Comet Nucleus Sample Return, has been proposed to ESA s Cosmic Vision program. A sample return from a comet enables us to reach the ultimate goal of cometary research. Since comets are the least processed bodies in the solar system, the proposal goes far beyond cometary science topics (like the explanation of cometary activity) and delivers invaluable information about the formation of the solar system and the interstellar molecular cloud from which it formed. The proposed mission would extract three samples of the upper 50 cm from three locations on a cometary nucleus and return them cooled to Earth for analysis in the laboratory. The simple mission concept with a touch-and-go sampling by a single spacecraft was proposed as an M-class mission in collaboration with the Russian space agency ROSCOSMOS.

Capturing near-Earth asteroids around Earth

Science.gov (United States)

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

2012-12-01

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

Carbon Isotopic Ratios of Amino Acids in Stardust-Returned Samples

Science.gov (United States)

Elsila, Jamie E.; Glavin, Daniel P.; Dworkin, Jason P.

2009-01-01

NASA's Stardust spacecraft returned to Earth samples from comet 81P/Wild 2 in January 2006. Preliminary examinations revealed the presence of a suite of organic compounds including several amines and amino acids, but the origin of these compounds could not be identified. Here. we present the carbon isotopic ratios of glycine and E-aminocaproic acid (EACH), the two most abundant amino acids observed, in Stardust-returned foil samples measured by gas chromatography-combustion-isotope ratio crass spectrometry coupled with quadrupole mass spectrometry (GC-QMS/IRMS).

Predictions of asteroid hazard to the Earth for the 21st century

Science.gov (United States)

Petrov, Nikita; Sokolov, Leonid; Polyakhova, Elena; Oskina, Kristina

2018-05-01

Early detection and investigation of possible collisions and close approaches of asteroids with the Earth are necessary to exept the asteroid-comet hazard. The difficulty of prediction of close approaches and collisions associated with resonant returns after encounters with the Earth due to loss of precision in these encounters. The main research object is asteroid Apophis (99942), for which we found many possible orbits of impacts associated with resonant returns. It is shown that the early orbit change of Apophis allows to avoid main impacts, associated with resonant returns. Such a change of the orbit, in principle, is feasible. We also study the possible impacts with the Ground asteroid 2015 RN35. We present 21 possible collisions in this century, including 7 collisions with large gaps presented in NASA website. The results of observations by the telescope ZA-320M at Pulkovo Obser-vatory of the three near-Earth asteroids, namely, 7822, 20826, 68216, two of which 7822 and 68216 are potentially hazardous, are presented.

Adaptive Changes in the Vestibular System of Land Snail to a 30-Day Spaceflight and Readaptation on Return to Earth

Directory of Open Access Journals (Sweden)

Nikolay Aseyev

2017-11-01

Full Text Available The vestibular system receives a permanent influence from gravity and reflexively controls equilibrium. If we assume gravity has remained constant during the species' evolution, will its sensory system adapt to abrupt loss of that force? We address this question in the land snail Helix lucorum exposed to 30 days of near weightlessness aboard the Bion-M1 satellite, and studied geotactic behavior of postflight snails, differential gene expressions in statocyst transcriptome, and electrophysiological responses of mechanoreceptors to applied tilts. Each approach revealed plastic changes in the snail's vestibular system assumed in response to spaceflight. Absence of light during the mission also affected statocyst physiology, as revealed by comparison to dark-conditioned control groups. Readaptation to normal tilt responses occurred at ~20 h following return to Earth. Despite the permanence of gravity, the snail responded in a compensatory manner to its loss and readapted once gravity was restored.

Reliable Portfolio Selection Problem in Fuzzy Environment: An mλ Measure Based Approach

Directory of Open Access Journals (Sweden)

Yuan Feng

2017-04-01

Full Text Available This paper investigates a fuzzy portfolio selection problem with guaranteed reliability, in which the fuzzy variables are used to capture the uncertain returns of different securities. To effectively handle the fuzziness in a mathematical way, a new expected value operator and variance of fuzzy variables are defined based on the m λ measure that is a linear combination of the possibility measure and necessity measure to balance the pessimism and optimism in the decision-making process. To formulate the reliable portfolio selection problem, we particularly adopt the expected total return and standard variance of the total return to evaluate the reliability of the investment strategies, producing three risk-guaranteed reliable portfolio selection models. To solve the proposed models, an effective genetic algorithm is designed to generate the approximate optimal solution to the considered problem. Finally, the numerical examples are given to show the performance of the proposed models and algorithm.

Quantitative Planetary Protection for Sample Return from Ocean Worlds

Science.gov (United States)

Neveu, Marc; Takano, Yoshinori; Porco, Carolyn; McKay, Christopher P.; Glavin, Daniel; Anbar, Ariel; Sherwood, Brent; Yano, Hajime

2016-07-01

Volcanism on ocean worlds [1,2] facilitates ocean sample return missions, enabling uniquely flexible, sensitive, and specific laboratory analyses on Earth to study how far chemistry has evolved in presumably habitable oceans [3,4]. Such mission concepts have yet to quantitatively address planetary protection (PP) for ocean worlds [3,4]. These harbor liquid water [5,6], metabolically useful energy [7], and organic matter to support life [8]. Ocean temperatures may not exceed the limit for life as we know it [9,10], they are shielded from exogenic radiation by kilometers of ice, and their material has likely not been naturally exchanged with Earth [11]. The above factors would place sample return missions in Cat. V - Restricted Earth Return [12,13]. Forward PP requirements for Europa [13] and other ocean worlds [14] require that the probability of "introduction of a single viable terrestrial microorganism into a liquid-water environment" be lower than 10 ^{-4}. This probability should be estimated from (F1) "bioburden at launch," (F2) "cruise survival for contaminating organisms," (F3) "organism survival in the radiation environment adjacent to the target," (F4) "the probability of encountering […] the target," (F5) "the probability of surviving landing/impact on the target," (F6) "mechanisms and timescales of transport to the subsurface," and (F7) "survival […] after subsurface transfer" [13,14]. The compliance of specific designs of known cost could be evaluated from measurements of molecular contaminants as robust and universal proxies for microbial particulates [15] (F1); known microbial radiation tolerance [16] and planetary radiation budgets [17] (F2-F3); trajectory design (F4); projected impact velocities [18] (F5); ice transport timescales [19] (F6), and biomass growth rates in ice [20] (F7). In contrast, current backward PP requirements are only qualitative. Current policy [13,15] prohibits "destructive impact upon return," and requires that (B1) "unless

Mars Sample Return - Launch and Detection Strategies for Orbital Rendezvous

Science.gov (United States)

Woolley, Ryan C.; Mattingly, Richard L.; Riedel, Joseph E.; Sturm, Erick J.

2011-01-01

This study sets forth conceptual mission design strategies for the ascent and rendezvous phase of the proposed NASA/ESA joint Mars Sample Return Campaign. The current notional mission architecture calls for the launch of an acquisition/cache rover in 2018, an orbiter with an Earth return vehicle in 2022, and a fetch rover and ascent vehicle in 2024. Strategies are presented to launch the sample into a coplanar orbit with the Orbiter which facilitate robust optical detection, orbit determination, and rendezvous. Repeating ground track orbits exist at 457 and 572 km which provide multiple launch opportunities with similar geometries for detection and rendezvous.

Mars Sample Return: Launch and Detection Strategies for Orbital Rendezvous

Science.gov (United States)

Woolley, Ryan C.; Mattingly, Richard L.; Riedel, Joseph E.; Sturm, Erick J.

2011-01-01

This study sets forth conceptual mission design strategies for the ascent and rendezvous phase of the proposed NASA/ESA joint Mars Sample Return Campaign. The current notional mission architecture calls for the launch of an acquisition/ caching rover in 2018, an Earth return orbiter in 2022, and a fetch rover with ascent vehicle in 2024. Strategies are presented to launch the sample into a nearly coplanar orbit with the Orbiter which would facilitate robust optical detection, orbit determination, and rendezvous. Repeating ground track orbits existat 457 and 572 km which would provide multiple launch opportunities with similar geometries for detection and rendezvous.

OSIRIS-REx: Sample Return from Asteroid (101955) Bennu

Science.gov (United States)

Lauretta, D. S.; Balram-Knutson, S. S.; Beshore, E.; Boynton, W. V.; Drouet d'Aubigny, C.; DellaGiustina, D. N.; Enos, H. L.; Golish, D. R.; Hergenrother, C. W.; Howell, E. S.; Bennett, C. A.; Morton, E. T.; Nolan, M. C.; Rizk, B.; Roper, H. L.; Bartels, A. E.; Bos, B. J.; Dworkin, J. P.; Highsmith, D. E.; Lorenz, D. A.; Lim, L. F.; Mink, R.; Moreau, M. C.; Nuth, J. A.; Reuter, D. C.; Simon, A. A.; Bierhaus, E. B.; Bryan, B. H.; Ballouz, R.; Barnouin, O. S.; Binzel, R. P.; Bottke, W. F.; Hamilton, V. E.; Walsh, K. J.; Chesley, S. R.; Christensen, P. R.; Clark, B. E.; Connolly, H. C.; Crombie, M. K.; Daly, M. G.; Emery, J. P.; McCoy, T. J.; McMahon, J. W.; Scheeres, D. J.; Messenger, S.; Nakamura-Messenger, K.; Righter, K.; Sandford, S. A.

2017-10-01

In May of 2011, NASA selected the Origins, Spectral Interpretation, Resource Identification, and Security- Regolith Explorer (OSIRIS-REx) asteroid sample return mission as the third mission in the New Frontiers program. The other two New Frontiers missions are New Horizons, which explored Pluto during a flyby in July 2015 and is on its way for a flyby of Kuiper Belt object 2014 MU69 on January 1, 2019, and Juno, an orbiting mission that is studying the origin, evolution, and internal structure of Jupiter. The spacecraft departed for near-Earth asteroid (101955) Bennu aboard an United Launch Alliance Atlas V 411 evolved expendable launch vehicle at 7:05 p.m. EDT on September 8, 2016, on a seven-year journey to return samples from Bennu. The spacecraft is on an outbound-cruise trajectory that will result in a rendezvous with Bennu in November 2018. The science instruments on the spacecraft will survey Bennu to measure its physical, geological, and chemical properties, and the team will use these data to select a site on the surface to collect at least 60 g of asteroid regolith. The team will also analyze the remote-sensing data to perform a detailed study of the sample site for context, assess Bennu's resource potential, refine estimates of its impact probability with Earth, and provide ground-truth data for the extensive astronomical data set collected on this asteroid. The spacecraft will leave Bennu in 2021 and return the sample to the Utah Test and Training Range (UTTR) on September 24, 2023.

Apollo 11 Earth Training Exercises

Science.gov (United States)

1969-01-01

In preparation of the nation's first lunar landing mission, Apollo 11 crew members underwent training to practice activities they would be performing during the mission. In this photograph, taken at the Manned Spacecraft Center in Houston, Texas, an engineer, Bob Mason, donned in a space suit, goes through some of those training exercises on the mock lunar surface. He performed activites similar to those planned for astronauts Neil Armstrong and Edwin Aldrin during their moon walk. The Apollo 11 mission launched from the Kennedy Space Center (KSC) in Florida via the Marshall Space Flight Center (MSFC) developed Saturn V launch vehicle on July 16, 1969 and safely returned to Earth on July 24, 1969. Aboard the space craft were astronauts Neil A. Armstrong, commander; Michael Collins, Command Module (CM) pilot; and Edwin E. (Buzz) Aldrin Jr., Lunar Module (LM) pilot. The CM, 'Columbia', piloted by Collins, remained in a parking orbit around the Moon while the LM, 'Eagle'', carrying astronauts Armstrong and Aldrin, landed on the Moon. On July 20, 1969, Armstrong was the first human to ever stand on the lunar surface, followed by Aldrin. During 2½ hours of surface exploration, the crew collected 47 pounds of lunar surface material for analysis back on Earth. With the success of Apollo 11, the national objective to land men on the Moon and return them safely to Earth had been accomplished.

78 FR 30747 - Reliability Standards for Geomagnetic Disturbances

Science.gov (United States)

2013-05-23

... that the scientific understanding of GMDs is still evolving, we recognize that Reliability Standards... by solar events, results in distortions to the earth's magnetic field, can be of varying intensity... systems.\\4\\ The interaction of the earth's magnetic field and solar events can cause low frequency GICs to...

JSC Advanced Curation: Research and Development for Current Collections and Future Sample Return Mission Demands

Science.gov (United States)

Fries, M. D.; Allen, C. C.; Calaway, M. J.; Evans, C. A.; Stansbery, E. K.

2015-01-01

Curation of NASA's astromaterials sample collections is a demanding and evolving activity that supports valuable science from NASA missions for generations, long after the samples are returned to Earth. For example, NASA continues to loan hundreds of Apollo program samples to investigators every year and those samples are often analyzed using instruments that did not exist at the time of the Apollo missions themselves. The samples are curated in a manner that minimizes overall contamination, enabling clean, new high-sensitivity measurements and new science results over 40 years after their return to Earth. As our exploration of the Solar System progresses, upcoming and future NASA sample return missions will return new samples with stringent contamination control, sample environmental control, and Planetary Protection requirements. Therefore, an essential element of a healthy astromaterials curation program is a research and development (R&D) effort that characterizes and employs new technologies to maintain current collections and enable new missions - an Advanced Curation effort. JSC's Astromaterials Acquisition & Curation Office is continually performing Advanced Curation research, identifying and defining knowledge gaps about research, development, and validation/verification topics that are critical to support current and future NASA astromaterials sample collections. The following are highlighted knowledge gaps and research opportunities.

Lunar lander and return propulsion system trade study

Science.gov (United States)

Hurlbert, Eric A.; Moreland, Robert; Sanders, Gerald B.; Robertson, Edward A.; Amidei, David; Mulholland, John

1993-01-01

This trade study was initiated at NASA/JSC in May 1992 to develop and evaluate main propulsion system alternatives to the reference First Lunar Outpost (FLO) lander and return-stage transportation system concept. Thirteen alternative configurations were developed to explore the impacts of various combinations of return stage propellants, using either pressure or pump-fed propulsion systems and various staging options. Besides two-stage vehicle concepts, the merits of single-stage and stage-and-a-half options were also assessed in combination with high-performance liquid oxygen and liquid hydrogen propellants. Configurations using an integrated modular cryogenic engine were developed to assess potential improvements in packaging efficiency, mass performance, and system reliability compared to non-modular cryogenic designs. The selection process to evaluate the various designs was the analytic hierarchy process. The trade study showed that a pressure-fed MMH/N2O4 return stage and RL10-based lander stage is the best option for a 1999 launch. While results of this study are tailored to FLO needs, the design date, criteria, and selection methodology are applicable to the design of other crewed lunar landing and return vehicles.

Capturing asteroids into bound orbits around the earth: Massive early return on an asteroid terminal defense system

International Nuclear Information System (INIS)

Hills, J.G.

1992-01-01

Nuclear explosives may be used to capture small asteroids (e.g., 20--50 meters in diameter) into bound orbits around the earth. The captured objects could be used for construction material for manned and unmanned activity in Earth orbit. Asteroids with small approach velocities, which are the ones most likely to have close approaches to the Earth, require the least energy for capture. They are particularly easy to capture if they pass within one Earth radius of the surface of the Earth. They could be intercepted with intercontinental missiles if the latter were retrofit with a more flexible guiding and homing capability. This asteroid capture-defense system could be implemented in a few years at low cost by using decommissioned ICMs. The economic value of even one captured asteroid is many times the initial investment. The asteroid capture system would be an essential part of the learning curve for dealing with larger asteroids that can hit the earth

EURO-CARES: European Roadmap for a Sample Return Curation Facility and Planetary Protection Implications.

Science.gov (United States)

Brucato, John Robert

2016-07-01

A mature European planetary exploration program and evolving sample return mission plans gathers the interest of a wider scientific community. The interest is generated from studying extraterrestrial samples in the laborato-ry providing new opportunities to address fundamental issues on the origin and evolution of the Solar System, on the primordial cosmochemistry, and on the nature of the building blocks of terrestrial planets and on the origin of life. Major space agencies are currently planning for missions that will collect samples from a variety of Solar Sys-tem environments, from primitive (carbonaceous) small bodies, from the Moon, Mars and its moons and, final-ly, from icy moons of the outer planets. A dedicated sample return curation facility is seen as an essential re-quirement for the receiving, assessment, characterization and secure preservation of the collected extraterrestrial samples and potentially their safe distribution to the scientific community. EURO-CARES is a European Commission study funded under the Horizon-2020 program. The strategic objec-tive of EURO-CARES is to create a roadmap for the implementation of a European Extraterrestrial Sample Cu-ration Facility. The facility has to provide safe storage and handling of extraterrestrial samples and has to enable the preliminary characterization in order to achieve the required effectiveness and collaborative outcomes for the whole international scientific community. For example, samples returned from Mars could pose a threat on the Earth's biosphere if any living extraterrestrial organism are present in the samples. Thus planetary protection is an essential aspect of all Mars sample return missions that will affect the retrival and transport from the point of return, sample handling, infrastructure methodology and management of a future curation facility. Analysis of the state of the art of Planetary Protection technology shows there are considerable possibilities to define and develop

The bottom of the universe: Flat earth science in the Age of Encounter.

Science.gov (United States)

Allegro, James J

2017-03-01

This essay challenges the dominance of the spherical earth model in fifteenth- and early-sixteenth-century Western European thought. It examines parallel strains of Latin and vernacular writing that cast doubt on the existence of the southern hemisphere. Three factors shaped the alternate accounts of the earth as a plane and disk put forward by these sources: (1) the unsettling effects of maritime expansion on scientific thought; (2) the revival of interest in early Christian criticism of the spherical earth; and (3) a rigid empirical stance toward entities too large to observe in their entirety, including the earth. Criticism of the spherical earth model faded in the decades after Magellan's crew returned from circuiting the earth in 1522.

International cooperation for Mars exploration and sample return

Science.gov (United States)

Levy, Eugene H.; Boynton, William V.; Cameron, A. G. W.; Carr, Michael H.; Kitchell, Jennifer H.; Mazur, Peter; Pace, Norman R.; Prinn, Ronald G.; Solomon, Sean C.; Wasserburg, Gerald J.

1990-01-01

The National Research Council's Space Studies Board has previously recommended that the next major phase of Mars exploration for the United States involve detailed in situ investigations of the surface of Mars and the return to earth for laboratory analysis of selected Martian surface samples. More recently, the European space science community has expressed general interest in the concept of cooperative Mars exploration and sample return. The USSR has now announced plans for a program of Mars exploration incorporating international cooperation. If the opportunity becomes available to participate in Mars exploration, interest is likely to emerge on the part of a number of other countries, such as Japan and Canada. The Space Studies Board's Committee on Cooperative Mars Exploration and Sample Return was asked by the National Aeronautics and Space Administration (NASA) to examine and report on the question of how Mars sample return missions might best be structured for effective implementation by NASA along with international partners. The committee examined alternatives ranging from scientific missions in which the United States would take a substantial lead, with international participation playing only an ancillary role, to missions in which international cooperation would be a basic part of the approach, with the international partners taking on comparably large mission responsibilities. On the basis of scientific strategies developed earlier by the Space Studies Board, the committee considered the scientific and technical basis of such collaboration and the most mutually beneficial arrangements for constructing successful cooperative missions, particularly with the USSR.

Development of a Mars Environmental Control and Life Support System (ECLSS).

Science.gov (United States)

Henninger, Donald L.

2016-01-01

ECLS systems for very long-duration human missions to Mars will be designed to operate reliably for many years and will never be returned to Earth. The need for high reliability is driven by unsympathetic abort scenarios. Abort from a Mars mission could be as long as 450 days to return to Earth. Simply put, the goal of an ECLSS is to duplicate the functions the Earth provides in terms of human living and working on our home planet but without the benefit of the Earth's large buffers - the atmospheres, the oceans and land masses. With small buffers a space-based ECLSS must operate as a true dynamic system rather than independent processors taking things from tanks, processing them, and then returning them to product tanks. Key is a development process that allows for a logical sequence of validating successful development (maturation) in a stepwise manner with key performance parameters (KPPs) at each step; especially KPPs for technologies evaluated in a full systems context with human crews on Earth and on space platforms such as the ISS. This paper will explore the implications of such an approach to ECLSS development and the roles of ground and space-based testing necessary to develop a highly reliable life support system for long duration human exploration missions. Historical development and testing of ECLS systems from Mercury to the International Space Station (ISS) will be reviewed. Current work as well as recommendations for future work will be described.

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

Science.gov (United States)

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

2015-10-01

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

Backward Planetary Protection Issues and Possible Solutions for Icy Plume Sample Return Missions from Astrobiological Targets

Science.gov (United States)

Yano, Hajime; McKay, Christopher P.; Anbar, Ariel; Tsou, Peter

). While this is an ideal specification, it far exceeds the current PPP requirements for Category-V “restricted Earth return”, which typically center on a probability of escape of a biologically active particle (e.g., 50 nm diameter). Particles of this size (orders of magnitude larger than a helium atom) are not volatile and generally “sticky” toward surfaces; the mobility of viruses and biomolecules requires aerosolization. Thus, meeting the planetary protection challenge does not require hermetic seal. So far, only a handful of robotic missions accomplished deep space sample returns, i.e., Genesis, Stardust and Hayabusa. This year, Hayabusa-2 will be launched and OSIRIS-REx will follow in a few years. All of these missions are classified as “unrestricted Earth return” by the COSPAR PPP recommendation. Nevertheless, scientific requirements of organic contamination control have been implemented to all WBS regarding sampling mechanism and Earth return capsule of Hayabusa-2. While Genesis, Stardust and OSIRIS-REx capsules “breathe” terrestrial air as they re-enter Earth’s atmosphere, temporal “air-tight” design was already achieved by the Hayabusa-1 sample container using a double O-ring seal, and that for the Hayabusa-2 will retain noble gas and other released gas from returned solid samples using metal seal technology. After return, these gases can be collected through a filtered needle interface without opening the entire container lid. This expertise can be extended to meeting planetary protection requirements from “restricted return” targets. There are still some areas requiring new innovations, especially to assure contingency robustness in every phase of a return mission. These must be achieved by meeting both PPP and scientific requirements during initial design and WBS of the integrated sampling system including the Earth return capsule. It is also important to note that international communities in planetary protection, sample return

Reliability analysis of HVDC grid combined with power flow simulations

Energy Technology Data Exchange (ETDEWEB)

Yang, Yongtao; Langeland, Tore; Solvik, Johan [DNV AS, Hoevik (Norway); Stewart, Emma [DNV KEMA, Camino Ramon, CA (United States)

2012-07-01

Based on a DC grid power flow solver and the proposed GEIR, we carried out reliability analysis for a HVDC grid test system proposed by CIGRE working group B4-58, where the failure statistics are collected from literature survey. The proposed methodology is used to evaluate the impact of converter configuration on the overall reliability performance of the HVDC grid, where the symmetrical monopole configuration is compared with the bipole with metallic return wire configuration. The results quantify the improvement on reliability by using the later alternative. (orig.)

Omega-optimized portfolios: applying stochastic dominance criterion for the selection of the threshold return

Directory of Open Access Journals (Sweden)

Renaldas Vilkancas

2016-05-01

Full Text Available Purpose of the article: While using asymmetric risk-return measures an important role is played by selection of the investor‘s required or threshold rate of return. The scientific literature usually states that every investor should define this rate according to their degree of risk aversion. In this paper, it is attempted to look at the problem from a different perspective – empirical research is aimed at determining the influence of the threshold rate of return on the portfolio characteristics. Methodology/methods: In order to determine the threshold rate of return a stochastic dominance criterion was used. The results are verified using the commonly applied method of backtesting. Scientific aim: The aim of this paper is to propose a method allowing selecting the threshold rate of return reliably and objectively. Findings: Empirical research confirms that stochastic dominance criteria can be successfully applied to determine the rate of return preferred by the investor. Conclusions: A risk-free investment rate or simply a zero rate of return commonly used in practice is often justified neither by theoretical nor empirical studies. This work suggests determining the threshold rate of return by applying the stochastic dominance criterion

Idleness, returns to education and child labor

Directory of Open Access Journals (Sweden)

José Raimundo Carvalho

2012-12-01

Full Text Available Although recent trends about child labor are positive, see ILO (2006, there still are important shortcomings which require further investigation. Among them, the exclusion of the category "idle children" (those who neither work nor study from past studies, as well as the lack of reliable information on returns to education are two significant omissions. By using a data base that contains details on idle children and a proxy for the returns to education, we find evidence that confirms traditional findings both with regard to the strong positive effect of parental background and to the positive relationship between the number of children in the household and child labor. On the other hand, our estimates point out new insights, such as the great regional variation of estimates and the fact that the Body Mass Index effect is positive. Finally, we suggest a new perspective on the issue of "street children" through the analysis of the category of "idle children".

Analysis advanced methods of data bases of industrial experience return

International Nuclear Information System (INIS)

Lannoy, A.; Procaccia, H.

1994-05-01

This is a presentation, through different conceptions of data bases on industrial experience return, of the principal methods for treatments and analyses of the collected data, going from the frequency statistic and factorial analysis, to the the Bayesian statistical decision theory, which is a real decision assistance tool for responsibles, conceivers and operators. Examples in various fields are given (OREDA: Offshore REliability DAta bank for marine drilling platforms, CEDB: Component Event Data Bank for european electric power industry, RDF 93: reliability of electronic components of ''France Telecom'', EVT: failure EVenTs data bank in the french nuclear power plants by ''EDF''). (A.B.). refs., figs., tabs

OSIRIS-REx Asteroid Sample Return Mission Image Analysis

Science.gov (United States)

Chevres Fernandez, Lee Roger; Bos, Brent

2018-01-01

NASA’s Origins Spectral Interpretation Resource Identification Security-Regolith Explorer (OSIRIS-REx) mission constitutes the “first-of-its-kind” project to thoroughly characterize a near-Earth asteroid. The selected asteroid is (101955) 1999 RQ36 (a.k.a. Bennu). The mission launched in September 2016, and the spacecraft will reach its asteroid target in 2018 and return a sample to Earth in 2023. The spacecraft that will travel to, and collect a sample from, Bennu has five integrated instruments from national and international partners. NASA's OSIRIS-REx asteroid sample return mission spacecraft includes the Touch-And-Go Camera System (TAGCAMS) three camera-head instrument. The purpose of TAGCAMS is to provide imagery during the mission to facilitate navigation to the target asteroid, confirm acquisition of the asteroid sample and document asteroid sample stowage. Two of the TAGCAMS cameras, NavCam 1 and NavCam 2, serve as fully redundant navigation cameras to support optical navigation and natural feature tracking. The third TAGCAMS camera, StowCam, provides imagery to assist with and confirm proper stowage of the asteroid sample. Analysis of spacecraft imagery acquired by the TAGCAMS during cruise to the target asteroid Bennu was performed using custom codes developed in MATLAB. Assessment of the TAGCAMS in-flight performance using flight imagery was done to characterize camera performance. One specific area of investigation that was targeted was bad pixel mapping. A recent phase of the mission, known as the Earth Gravity Assist (EGA) maneuver, provided images that were used for the detection and confirmation of “questionable” pixels, possibly under responsive, using image segmentation analysis. Ongoing work on point spread function morphology and camera linearity and responsivity will also be used for calibration purposes and further analysis in preparation for proximity operations around Bennu. Said analyses will provide a broader understanding

Reliability improvements on Thales RM2 rotary Stirling coolers: analysis and methodology

Science.gov (United States)

Cauquil, J. M.; Seguineau, C.; Martin, J.-Y.; Benschop, T.

2016-05-01

The cooled IR detectors are used in a wide range of applications. Most of the time, the cryocoolers are one of the components dimensioning the lifetime of the system. The cooler reliability is thus one of its most important parameters. This parameter has to increase to answer market needs. To do this, the data for identifying the weakest element determining cooler reliability has to be collected. Yet, data collection based on field are hardly usable due to lack of informations. A method for identifying the improvement in reliability has then to be set up which can be used even without field return. This paper will describe the method followed by Thales Cryogénie SAS to reach such a result. First, a database was built from extensive expertizes of RM2 failures occurring in accelerate ageing. Failure modes have then been identified and corrective actions achieved. Besides this, a hierarchical organization of the functions of the cooler has been done with regard to the potential increase of its efficiency. Specific changes have been introduced on the functions most likely to impact efficiency. The link between efficiency and reliability will be described in this paper. The work on the two axes - weak spots for cooler reliability and efficiency - permitted us to increase in a drastic way the MTTF of the RM2 cooler. Huge improvements in RM2 reliability are actually proven by both field return and reliability monitoring. These figures will be discussed in the paper.

Integrated science and engineering for the OSIRIS-REx asteroid sample return mission

Science.gov (United States)

Lauretta, D.

2014-07-01

Introduction: The Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) asteroid sample return mission will survey near-Earth asteroid (101955) Bennu to understand its physical, mineralogical, and chemical properties, assess its resource potential, refine the impact hazard, and return a sample of this body to the Earth [1]. This mission is scheduled for launch in 2016 and will rendezvous with the asteroid in 2018. Sample return to the Earth follows in 2023. The OSIRIS-REx mission has the challenge of visiting asteroid Bennu, characterizing it at global and local scales, then selecting the best site on the asteroid surface to acquire a sample for return to the Earth. Minimizing the risk of exploring an unknown world requires a tight integration of science and engineering to inform flight system and mission design. Defining the Asteroid Environment: We have performed an extensive astronomical campaign in support of OSIRIS-REx. Lightcurve and phase function observations were obtained with UA Observatories telescopes located in southeastern Arizona during the 2005--2006 and 2011--2012 apparitions [2]. We observed Bennu using the 12.6-cm radar at the Arecibo Observatory in 1999, 2005, and 2011 and the 3.5-cm radar at the Goldstone tracking station in 1999 and 2005 [3]. We conducted near-infrared measurements using the NASA Infrared Telescope Facility at the Mauna Kea Observatory in Hawaii in September 2005 [4]. Additional spectral observations were obtained in July 2011 and May 2012 with the Magellan 6.5-m telescope [5]. We used the Spitzer space telescope to observe Bennu in May 2007 [6]. The extensive knowledge gained as a result of our telescopic characterization of Bennu was critical in the selection of this object as the OSIRIS-REx mission target. In addition, we use these data, combined with models of the asteroid, to constrain over 100 different asteroid parameters covering orbital, bulk, rotational, radar

Volumetric visualization of multiple-return LIDAR data: Using voxels

Science.gov (United States)

Stoker, Jason M.

2009-01-01

Elevation data are an important component in the visualization and analysis of geographic information. The creation and display of 3D models representing bare earth, vegetation, and surface structures have become a major focus of light detection and ranging (lidar) remote sensing research in the past few years. Lidar is an active sensor that records the distance, or range, of a laser usually fi red from an airplane, helicopter, or satellite. By converting the millions of 3D lidar returns from a system into bare ground, vegetation, or structural elevation information, extremely accurate, high-resolution elevation models can be derived and produced to visualize and quantify scenes in three dimensions. These data can be used to produce high-resolution bare-earth digital elevation models; quantitative estimates of vegetative features such as canopy height, canopy closure, and biomass; and models of urban areas such as building footprints and 3D city models.

Is Mars Sample Return Required Prior to Sending Humans to Mars?

Science.gov (United States)

Carr, Michael; Abell, Paul; Allwood, Abigail; Baker, John; Barnes, Jeff; Bass, Deborah; Beaty, David; Boston, Penny; Brinkerhoff, Will; Budney, Charles;

A High Reliability Frequency Stabilized Semiconductor Laser Source, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Ultrastable, narrow linewidth, high reliability MOPA sources are needed for high performance LIDARs in NASA for, wind speed measurement, surface topography and earth...

Building on the Cornerstone: Destinations for Nearside Sample Return

Science.gov (United States)

Lawrence, S. J.; Jolliff, B. L.; Draper, D.; Stopar, J. D.; Petro, N. E.; Cohen, B. A.; Speyerer, E. J.; Gruener, J. E.

2016-01-01

Discoveries from LRO (Lunar Reconnaissance Orbiter) have transformed our knowledge of the Moon, but LRO's instruments were originally designed to collect the measurements required to enable future lunar surface exploration. Compelling science questions and critical resources make the Moon a key destination for future human and robotic exploration. Lunar surface exploration, including rovers and other landed missions, must be part of a balanced planetary science and exploration portfolio. Among the highest planetary exploration priorities is the collection of new samples and their return to Earth for more comprehensive analysis than can be done in-situ. The Moon is the closest and most accessible location to address key science questions through targeted sample return. The Moon is the only other planet from which we have contextualized samples, yet critical issues need to be addressed: we lack important details of the Moon's early and recent geologic history, the full compositional and age ranges of its crust, and its bulk composition.

In Situ Pre-Selection of Return Samples with Bio-Signatures by Combined Laser Mass Spectrometry and Optical Microscopy

Science.gov (United States)

Wiesendanger, R.; Wurz, P.; Tulej, M.; Wacey, D.; Neubeck, A.; Grimaudo, V.; Riedo, A.; Moreno, P.; Cedeño-López, A.; Ivarsson, M.

2018-04-01

The University of Bern developed instrument prototypes that allow analysis of samples on Mars prior to bringing them back to Earth, allowing to maximize the scientific outcome of the returned samples. We will present the systems and first results.

Large micro-mirror arrays: key components in future space instruments for Universe and Earth Observation

Directory of Open Access Journals (Sweden)

Zamkotsian Frederic

2015-01-01

Full Text Available In future space missions for Universe and Earth Observation, scientific return could be optimized using MOEMS devices. Micro-mirror arrays are used for designing new generation of instruments, multi-object spectrographs in Universe Observation and programmable wide field spectrographs in Earth Observation. Mock-ups have been designed and built for both applications and they show very promising results.

Martian Chemical and Isotopic Reference Standards in Earth-based Laboratories — An Invitation for Geochemical, Astrobiological, and Engineering Dialog on Considering a Weathered Chondrite for Mars Sample Return.

Science.gov (United States)

Ashley, J. W.; Tait, A. W.; Velbel, M. A.; Boston, P. J.; Carrier, B. L.; Cohen, B. A.; Schröder, C.; Bland, P.

2017-12-01

Exogenic rocks (meteorites) found on Mars 1) have unweathered counterparts on Earth; 2) weather differently than indigenous rocks; and 3) may be ideal habitats for putative microorganisms and subsequent biosignature preservation. These attributes show the potential of meteorites for addressing hypothesis-driven science. They raise the question of whether chondritic meteorites, of sufficient weathering intensity, might be considered as candidates for sample return in a potential future mission. Pursuant to this discussion are the following questions. A) Is there anything to be learned from the laboratory study of a martian chondrite that cannot be learned from indigenous materials; and if so, B) is the science value high enough to justify recovery? If both A and B answer affirmatively, then C) what are the engineering constraints for sample collection for Mars 2020 and potential follow-on missions; and finally D) what is the likelihood of finding a favorable sample? Observations relevant to these questions include: i) Since 2005, 24 candidate and confirmed meteorites have been identified on Mars at three rover landing sites, demonstrating their ubiquity and setting expectations for future finds. All have been heavily altered by a variety of physical and chemical processes. While the majority of these are irons (not suitable for recovery), several are weathered stony meteorites. ii) Exogenic reference materials provide the only chemical/isotope standards on Mars, permitting quantification of alteration rates if residence ages can be attained; and possibly enabling the removal of Late Amazonian weathering overprints from other returned samples. iii) Recent studies have established the habitability of chondritic meteorites with terrestrial microorganisms, recommending their consideration when exploring astrobiological questions. High reactivity, organic content, and permeability show stony meteorites to be more attractive for colonization and subsequent biosignature

Comparison of different reliability improving investment strategies of Finnish medium-voltage distribution systems

Energy Technology Data Exchange (ETDEWEB)

Laagland, H.

2012-07-01

The electricity distribution sector in Finland is highly regulated and the return on investments in distribution networks is low. Low profits don't make the electricity distribution sector attractive to outside investors. During the second regulatory period of 2008-2011 incentives are included into the Finnish regulation model which allows higher profits for the network owners for right allocated network investments leading to lower operation and interruption costs. The goal of the thesis is to find cost-effective medium-voltage distribution system investment strategies for the Finnish power distribution companies with respect to the incentives of the second regulatory period. In this work the sectionalisation concept is further developed by deriving equations for a homogeneous electricity distribution system for the economical and reliability indices as a function of the number of sectionalisation zones. The cost-effective medium-voltage distribution system investment strategies are found by studying the technical and economic interaction of feeder automation on different network structures. Ten feeder automation schemes have been applied to six urban/rural area generic feeders and two real rural area feeders of a distribution company in western Finland. The analytical approach includes modelling of the feeders and feeder functions and calculation of the economical and reliability indices. The following investment areas are included: different electricity distribution systems, new substation, new switching station, central earth-fault current compensation, cabling and feeder automation. The value of the results of this work is that they reveal the influence that feeder automation has on the reliability and economy of different distribution structures. This created transparency enables a national and/or distribution company network investment strategy to optimise the economic benefits of investments. (orig.)

Mineral remains of early life on Earth? On Mars?

Science.gov (United States)

Iberall, Robbins E.; Iberall, A.S.

1991-01-01

The oldest sedimentary rocks on Earth, the 3.8-Ga Isua Iron-Formation in southwestern Greenland, are metamorphosed past the point where organic-walled fossils would remain. Acid residues and thin sections of these rocks reveal ferric microstructures that have filamentous, hollow rod, and spherical shapes not characteristic of crystalline minerals. Instead, they resemble ferric-coated remains of bacteria. Because there are no earlier sedimentary rocks to study on Earth, it may be necessary to expand the search elsewhere in the solar system for clues to any biotic precursors or other types of early life. A study of morphologies of iron oxide minerals collected in the southern highlands during a Mars sample return mission may therefore help to fill in important gaps in the history of Earth's earliest biosphere. -from Authors

Options for human ``return to the moon'' using tomorrow's SSTO, ISRU, and LOX-augmented NTR technologies

Science.gov (United States)

Borowski, Stanley K.

1996-03-01

The feasibility of conducting human missions to the Moon is examined assuming the use of three ``high leverage'' technologies: (1) a single-stage-to-orbit (SSTO) launch vehicle, (2) ``in-situ'' resource utilization (ISRU)—specifically ``lunar-derived'' liquid oxygen (LUNOX), and (3) LOX-augmented nuclear thermal rocket (LANTR) propulsion. Lunar transportation system elements consisting of a LANTR-powered lunar transfer vehicle (LTV) and a chemical propulsion lunar landing/Earth return vehicle (LERV) are configured to fit within the ``compact'' dimensions of the SSTO cargo bay (diameter: 4.6 m/length: 9.0 m) while satisfying an initial mass in low Earth orbit (IMLEO) limit of ˜60 t (3 SSTO launches). Using ˜8 t of LUNOX to ``reoxidize'' the LERV for a ``direct return'' flight to Earth reduces its size and mass allowing delivery to LEO on a single 20 t SSTO launch. Similarly, the LANTR engine's ability to operate at any oxygen/hydrogen mixture ratio from 0 to 7 with high specific impulse (˜940 to 515 s) is exploited to reduce hydrogen tank volume, thereby improving packaging of the LANTR LTV's ``propulsion'' and ``propellant modules''. Expendable and reusable, piloted and cargo missions and vehicle designs are presented along with estimates of LUNOX production required to support the different mission modes.

Transonic Stability Test of Variable Drag Ballute, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Low cost, reliable atmospheric entry technology is needed to support NASA cargo recovery from the ISS, earth return of small payloads, planetary aerocapture, and...

Strategic Map for Enceladus Plume Biosignature Sample Return

Science.gov (United States)

Sherwood, B.

2014-12-01

The discovery of jets emitting salty water from the interior of Saturn's small moon Enceladus is one of the most astounding results of the Cassini mission to date. The measured presence of organic species in the resulting plume, the finding that the jet activity is valved by tidal stretching at apocrone, the modeled lifetime of E-ring particles, and gravitational inference of a long-lived, deep, large water reservoir all indicate that the textbook conditions for habitability are met at Enceladus today: liquid water, biologically available elements, source of energy, and longevity of conducive conditions. Enceladus may be the best place in our solar system to search for direct evidence of biomarkers, and the plume provides a way to sample, analyze, and even return them to Earth for detailed analysis. For example, it is straightforward to define a Stardust-like, fly-through, plume ice-particle, dust, and gas collection mission. Concept engineering and evaluation indicate that the associated technical, programmatic, regulatory, and cost issues are quite unlike the Stardust precedent however, not least because of such a mission's Category-V, Restricted Earth Return, classification. The poster presents a strategic framework for systematic integration of the enabling issues: cultivation of science advocacy, resolution of diverse stakeholder concerns, development of verifiable and affordable technical solutions, validation of cost estimation methods, alignment with other candidate astrobiology missions, complementarity of international agency goals, and finally the identification of appropriate research and flight-mission opportunities. A strategic approach is essential if we are to know the astrobiological state of Enceladus in our lifetime, and two international teams are already dedicated to implementing key steps on this roadmap.

Sample Return Mission to the South Pole Aitken Basin

Science.gov (United States)

Duke, M. B.; Clark, B. C.; Gamber, T.; Lucey, P. G.; Ryder, G.; Taylor, G. J.

1999-01-01

affected all of the planets of the inner solar system, and in particular, could have been critical to the history of life on Earth. If the SPA is significantly older, a more orderly cratering history may be inferred. Secondly, melt-rock compositions and clasts in melt rocks or breccias may yield evidence of the composition of the lunar mantle, which could have been penetrated by the impact or exposed by the rebound process that occurred after the impact. Thirdly, study of mare and cryptomare basalts could yield further constraints on the age of SPA and the thermal history of the crust and mantle in that region. The integration of these data may allow inferences to be made on the nature of the impacting body. Secondary science objectives in samples from the SPA could include analysis of the regolith for the latitudinal effects of solar wind irradiation, which should be reduced from its equatorial values; possible remnant magnetization of very old basalts; and evidence for Imbrium Basin ejecta and KREEP materials. If a sampling site is chosen close enough to the poles, it is possible that indirect evidence of polar-ice deposits may be found in the form of oxidized or hydrated regolith constituents. A sample return mission to the Moon may be possible within the constraints of NASA's Discovery Program. Recent progress in the development of sample return canisters for Genesis, Stardust, and Mars Sample Return missions suggests that a small capsule can be returned directly to the ground without a parachute, thus reducing its mass and complexity. Return of a 1-kg sample from the lunar surface would appear to be compatible with a Delta 11 class launch from Earth, or possibly with a piggyback opportunity on a commercial launch to GEO. A total mission price tag on the order of 100 million would be a goal. Target date would be late 2002. Samples would be returned to the curatorial facility at the Johnson Space Center for description and allocation for investigations. Concentration of

A new framework for estimating return levels using regional frequency analysis

Science.gov (United States)

Winter, Hugo; Bernardara, Pietro; Clegg, Georgina

2017-04-01

We propose a new framework for incorporating more spatial and temporal information into the estimation of extreme return levels. Currently, most studies use extreme value models applied to data from a single site; an approach which is inefficient statistically and leads to return level estimates that are less physically realistic. We aim to highlight the benefits that could be obtained by using methodology based upon regional frequency analysis as opposed to classic single site extreme value analysis. This motivates a shift in thinking, which permits the evaluation of local and regional effects and makes use of the wide variety of data that are now available on high temporal and spatial resolutions. The recent winter storms over the UK during the winters of 2013-14 and 2015-16, which have caused wide-ranging disruption and damaged important infrastructure, provide the main motivation for the current work. One of the most impactful natural hazards is flooding, which is often initiated by extreme precipitation. In this presentation, we focus on extreme rainfall, but shall discuss other meteorological variables alongside potentially damaging hazard combinations. To understand the risks posed by extreme precipitation, we need reliable statistical models which can be used to estimate quantities such as the T-year return level, i.e. the level which is expected to be exceeded once every T-years. Extreme value theory provides the main collection of statistical models that can be used to estimate the risks posed by extreme precipitation events. Broadly, at a single site, a statistical model is fitted to exceedances of a high threshold and the model is used to extrapolate to levels beyond the range of the observed data. However, when we have data at many sites over a spatial domain, fitting a separate model for each separate site makes little sense and it would be better if we could incorporate all this information to improve the reliability of return level estimates. Here

The Exploration of Near-Earth Objects

Science.gov (United States)

1998-01-01

small fraction of NEOs are particularly accessible for exploration by spacecraft. To identify the exploration targets of highest scientific interest, the orbits and classification of a large number of NEOs should be determined by telescopic observations. Desired characterization would also include measurements of size, mass, shape, surface composition and heterogeneity, gas and dust emission, and rotation. Laboratory studies of meteorites can focus NEO exploration objectives and quantify the information obtained from telescopes. Once high-priority targets have been identified, various kinds of spacecraft missions (flyby, rendezvous, and sample return) can be designed. Some currently operational (Near-Earth Asteroid Rendezvous [NEAR]) or planned (Deep Space 1) U.S. missions are of the first two types, and other planned U.S. and Japanese spacecraft missions will return samples. Rendezvous missions with sample return are particularly desirable from a scientific perspective because of the very great differences in the analytical capabilities that can be brought to bear in orbit and in the laboratory setting. Although it would be difficult to justify human exploration of NEOs on the basis of cost-benefit analysis of scientific results alone, a strong case can be made for starting with NEOs if the decision to carry out human exploration beyond low Earth orbit is made for other reasons. Some NEOs are especially attractive targets for astronaut missions because of their orbital accessibility and short flight duration. Because they represent deep space exploration at an intermediate level of technical challenge, these missions would also serve as stepping stones for human missions to Mars. Human exploration of NEOs would provide significant advances in observational and sampling capabilities. With respect to ground based telescopic studies, the recommended baseline is that NASA and other appropriate agencies suupport research programs for interpreting the spectra of near-Earth

The computational challenges of Earth-system science.

Science.gov (United States)

O'Neill, Alan; Steenman-Clark, Lois

2002-06-15

The Earth system--comprising atmosphere, ocean, land, cryosphere and biosphere--is an immensely complex system, involving processes and interactions on a wide range of space- and time-scales. To understand and predict the evolution of the Earth system is one of the greatest challenges of modern science, with success likely to bring enormous societal benefits. High-performance computing, along with the wealth of new observational data, is revolutionizing our ability to simulate the Earth system with computer models that link the different components of the system together. There are, however, considerable scientific and technical challenges to be overcome. This paper will consider four of them: complexity, spatial resolution, inherent uncertainty and time-scales. Meeting these challenges requires a significant increase in the power of high-performance computers. The benefits of being able to make reliable predictions about the evolution of the Earth system should, on their own, amply repay this investment.

Mir Environmental Effects Payload and Returned Mir Solar Panel Cleanliness

Science.gov (United States)

Harvey, Gale A.; Humes, Donald H.; Kinard, William H.

2000-01-01

The MIR Environmental Effects Payload (MEEP) was attached to the Docking Module of the MIR space station for 18 months during calendar years 1996 and 1997 (March 1996, STS 76 to October 1997, STS 86). A solar panel array with more than 10 years space exposure was removed from the MIR core module in November 1997, and returned to Earth in January, 1998, STS 89. MEEP and the returned solar array are part of the International Space Station (ISS) Risk Mitigation Program. This space flight hardware has been inspected and studied by teams of space environmental effects (SEE) investigators for micrometeoroid and space debris effects, space exposure effects on materials, and electrical performance. This paper reports changes in cleanliness of parts of MEEP and the solar array due to the space exposures. Special attention is given to the extensive water soluble residues deposited on some of the flight hardware surfaces. Directionality of deposition and chemistry of these residues are discussed.

Propagation of ELF Radiation from RS-LC System and Red Sprites in Earth-Ionosphere Waveguide

Directory of Open Access Journals (Sweden)

M. K. Paras

2012-10-01

Full Text Available In this paper, two different mechanisms return stroke-lateral corona (RS-LC system and red sprites which excite Earth-ionosphere waveguide have been discussed. The electric and magnetic fields from RS-LC system and red spites in the Earth-ionosphere waveguide have been calculated. It has been found that red sprites contribute to the Schumann resonances (SR greatly as compared to the RS-LC system.

Translation, cultural adaptation and validation of simplified Chinese version of the anterior cruciate ligament return to sport after injury (ACL-RSI scale.

Directory of Open Access Journals (Sweden)

Tianwu Chen

Full Text Available To translate and cross-culturally adapt the anterior cruciate ligament-return to sport after injury (ACL-RSI into simplified Chinese [ACL-RSI (Cn].In this diagnostic study, the translation, cross-culturally adaptation, and validation of the ACL-RSI was performed according to international guidelines. A total of 112 patients with ACL reconstruction participated in this study. All were capable of competitive sports before the injury and completed the Knee Injury and Osteoarthritis Outcome (KOOS, the International Knee Documentation Committee (IKDC, the Tampa Scale of Kinesiophobia (TSK, and the Tegner activity score. Forty-eight patients completed the ACL-RSI (Cn twice within two weeks. The validity was tested using seven premade hypotheses. Internal consistency, reliability, and measurement error was assessed.At meanly 15.6 months postoperative, 81 (72.3% patients returned to sport, with 57 (50.9% to competitive sport and 24 (21.4% to recreational sport. Thirty-one (27.7% patients didn't return to any sport, with 19 (17.0% still had planned to return, and 12 (10.7% gave up sport. The ACL-RSI (Cn demonstrated excellent validity with all hypotheses confirmed. The outcome of ACL-RSI (Cn was strongly correlated the KOOS subscale quality of life (r = 0.66, p<0.001, the TSK (r = -0.678, p<0.001, the Tegner score (r = 0.695, p<0.001. There was statistic difference between cases returned (68.6 ± 10.1 and didn't return to sport (41.3 ± 17.7, p<0.001; between cases returned to competitive (71.1 ± 8.9 and recreational sport (62.9 ± 10.5, (P = 0.002; between cases who planned to return (50.7 ± 14.1 and gave up sport (26.5 ± 11.7, (P<0.001. The internal consistency (Cronbach's α = 0.96 and test-retest reliability [intra-class correlation coefficient (ICC = 0.90] was excellent. The measurement error, floor and ceiling effect was satisfactory. Administration time was 3.2 minutes, and no item was missed.The ACL-RSI (Cn scale was confirmed as a valid

Reliability Analysis on NPP's Safety-Related Control Module with Field Data

International Nuclear Information System (INIS)

Lee, Sang Yong; Jung, Jae Hyun; Kim, Seong Hun

2006-01-01

The automatic control systems used in nuclear power plant (NPP) consists of numerous control modules that can be considered to be a network of components various complex ways. The control modules require relatively high reliability than industrial electronic products. Reliability prediction provides the rational basis of system designs and also provides the safety significance of system operations. The aim of this paper is to minimize the deficiencies of the traditional reliability prediction method calculation using the available field return data. This way is possible to do more realistic reliability assessment. SAMCHANG Enterprise Company (SEC) has established database containing high quality data at the module and component level from module maintenance in NPP. On the basis of these, this paper compares results that add failure record (field data) to Telcordia-SR-332 reliability prediction model with MIL-HDBK-217F prediction results

26 CFR 301.6103(h)(2)-1 - Disclosure of returns and return information (including taxpayer return information) to and by...

Science.gov (United States)

2010-04-01

... administration. 301.6103(h)(2)-1 Section 301.6103(h)(2)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT... Returns Returns and Records § 301.6103(h)(2)-1 Disclosure of returns and return information (including..., shall, to the extent provided by section 6103(h)(2) (A), (B), and (C) and subject to the requirements of...

Rare earth elements behavior in Peruibe black mud

International Nuclear Information System (INIS)

Torrecilha, Jefferson K.; Carvalho, Leandro P.; Gouvea, Paulo F.M.; Silva, Paulo S.C. da

2015-01-01

Rare earth elements in sediments have been used as powerful tools for environmental studies because of their behavior during geochemical processes and are also widely accepted as reliable provenance tracers because they are largely water-immobile and thus behave conservatively during sedimentary processes. The Peruibe Black Mud (PBM) is a sedimentary deposit originated from the interactions of marine sediments and organic matter in an estuarine environment that originates a peloid currently used for medicinal purposes. The objective of this study was to examine rare earth elements pattern distribution in the Peruibe black mud sedimentary deposit as a proxy for its geochemical development. Elemental ratios such as LaN/YbN, Th/U and La/Th were determined and a normalization of the mean rare earth elements concentrations in the samples related to NASC indicates that the light (La to Eu) rare earth elements present values close to the unity while the heavy (Tb to Lu) rare earth elements are depleted related to NASC. It can be observed that the light rare earth elements present enrichment values slightly enriched over the unity while the heavy rare earth elements present values generally below the unity reflecting the enrichment of the light rare earth elements over the heavy rare earth. Rare earth elements concentrations determined in Peruibe black mud samples showed a distribution similar to that found in the NASC for the light rare earth elements and depleted for the heavy rare earth elements. (author)

Rare earth elements behavior in Peruibe black mud

Energy Technology Data Exchange (ETDEWEB)

Torrecilha, Jefferson K.; Carvalho, Leandro P.; Gouvea, Paulo F.M.; Silva, Paulo S.C. da, E-mail: jeffkoy@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

Rare earth elements in sediments have been used as powerful tools for environmental studies because of their behavior during geochemical processes and are also widely accepted as reliable provenance tracers because they are largely water-immobile and thus behave conservatively during sedimentary processes. The Peruibe Black Mud (PBM) is a sedimentary deposit originated from the interactions of marine sediments and organic matter in an estuarine environment that originates a peloid currently used for medicinal purposes. The objective of this study was to examine rare earth elements pattern distribution in the Peruibe black mud sedimentary deposit as a proxy for its geochemical development. Elemental ratios such as LaN/YbN, Th/U and La/Th were determined and a normalization of the mean rare earth elements concentrations in the samples related to NASC indicates that the light (La to Eu) rare earth elements present values close to the unity while the heavy (Tb to Lu) rare earth elements are depleted related to NASC. It can be observed that the light rare earth elements present enrichment values slightly enriched over the unity while the heavy rare earth elements present values generally below the unity reflecting the enrichment of the light rare earth elements over the heavy rare earth. Rare earth elements concentrations determined in Peruibe black mud samples showed a distribution similar to that found in the NASC for the light rare earth elements and depleted for the heavy rare earth elements. (author)

Predictable return distributions

DEFF Research Database (Denmark)

Pedersen, Thomas Quistgaard

trace out the entire distribution. A univariate quantile regression model is used to examine stock and bond return distributions individually, while a multivariate model is used to capture their joint distribution. An empirical analysis on US data shows that certain parts of the return distributions......-of-sample analyses show that the relative accuracy of the state variables in predicting future returns varies across the distribution. A portfolio study shows that an investor with power utility can obtain economic gains by applying the empirical return distribution in portfolio decisions instead of imposing...

Developing Reliable Life Support for Mars

Science.gov (United States)

Jones, Harry W.

2017-01-01

A human mission to Mars will require highly reliable life support systems. Mars life support systems may recycle water and oxygen using systems similar to those on the International Space Station (ISS). However, achieving sufficient reliability is less difficult for ISS than it will be for Mars. If an ISS system has a serious failure, it is possible to provide spare parts, or directly supply water or oxygen, or if necessary bring the crew back to Earth. Life support for Mars must be designed, tested, and improved as needed to achieve high demonstrated reliability. A quantitative reliability goal should be established and used to guide development t. The designers should select reliable components and minimize interface and integration problems. In theory a system can achieve the component-limited reliability, but testing often reveal unexpected failures due to design mistakes or flawed components. Testing should extend long enough to detect any unexpected failure modes and to verify the expected reliability. Iterated redesign and retest may be required to achieve the reliability goal. If the reliability is less than required, it may be improved by providing spare components or redundant systems. The number of spares required to achieve a given reliability goal depends on the component failure rate. If the failure rate is under estimated, the number of spares will be insufficient and the system may fail. If the design is likely to have undiscovered design or component problems, it is advisable to use dissimilar redundancy, even though this multiplies the design and development cost. In the ideal case, a human tended closed system operational test should be conducted to gain confidence in operations, maintenance, and repair. The difficulty in achieving high reliability in unproven complex systems may require the use of simpler, more mature, intrinsically higher reliability systems. The limitations of budget, schedule, and technology may suggest accepting lower and

Social-Emotional Inhibition of Return in Children with Autism Spectrum Disorder versus Typical Development

Science.gov (United States)

Antezana, Ligia; Mosner, Maya G.; Troiani, Vanessa; Yerys, Benjamin E.

2016-01-01

In typical development there is a bias to orient visual attention to social information. Children with ASD do not reliably demonstrate this bias, and the role of attention orienting has not been well studied. We examined attention orienting via the inhibition of return (IOR) mechanism in a spatial cueing task using social-emotional cues; we…

Return-to-Work Program for Injured Workers: Factors of Successful Return to Employment.

Science.gov (United States)

Awang, Halimah; Shahabudin, Sharifah Muhairah; Mansor, Norma

2016-11-01

This study examined the factors of successful return to employment among participants in the return to work program (RTW) following work-related injury. Data were obtained from the Social Security Organization database containing 9850 injured workers who underwent RTW in 2010 to 2013. About 65% had successfully returned to employment. Significant factors of successful return include gender, employer interest, motivation, age, intervention duration, and type of injury. Male and motivated employees were more likely to return to employment compared with female and unmotivated employees, respectively. Participants from interested employers were 23.22 times more likely to return to work than those from uninterested employers, whereas participants whose intervention period exceeded 5 months were 41% less likely to return to work compared with those whose intervention period was within 3 months. Appropriate strategy and enhanced collaboration between the stakeholders would improve the proportion of successful return to employment. © 2016 APJPH.

26 CFR 1.6013-2 - Joint return after filing separate return.

Science.gov (United States)

2010-04-01

... the case of a joint return made under section 6013(b), the period of limitations provided in sections... (c)(1) of this section, relating to the application of sections 6501 and 6651 with respect to a joint... 26 Internal Revenue 13 2010-04-01 2010-04-01 false Joint return after filing separate return. 1...

Navigation: bat orientation using Earth's magnetic field.

Science.gov (United States)

Holland, Richard A; Thorup, Kasper; Vonhof, Maarten J; Cochran, William W; Wikelski, Martin

2006-12-07

Bats famously orientate at night by echolocation, but this works over only a short range, and little is known about how they navigate over longer distances. Here we show that the homing behaviour of Eptesicus fuscus, known as the big brown bat, can be altered by artificially shifting the Earth's magnetic field, indicating that these bats rely on a magnetic compass to return to their home roost. This finding adds to the impressive array of sensory abilities possessed by this animal for navigation in the dark.

A core handling device for the Mars Sample Return Mission

Science.gov (United States)

Gwynne, Owen

1989-01-01

A core handling device for use on Mars is being designed. To provide a context for the design study, it was assumed that a Mars Rover/Sample Return (MRSR) Mission would have the following characteristics: a year or more in length; visits by the rover to 50 or more sites; 100 or more meter-long cores being drilled by the rover; and the capability of returning about 5 kg of Mars regolith to Earth. These characteristics lead to the belief that in order to bring back a variegated set of samples that can address the range of scientific objetives for a MRSR mission to Mars there needs to be considerable analysis done on board the rover. Furthermore, the discrepancy between the amount of sample gathered and the amount to be returned suggests that there needs to be some method of choosing the optimal set of samples. This type of analysis will require pristine material-unaltered by the drilling process. Since the core drill thermally and mechanically alters the outer diameter (about 10 pct) of the core sample, this outer area cannot be used. The primary function of the core handling device is to extract subsamples from the core and to position these subsamples, and the core itself if needed, with respect to the various analytical instruments that can be used to perform these analyses.

Lunar Science from and for Planet Earth

Science.gov (United States)

Pieters, M. C.; Hiesinger, H.; Head, J. W., III

2008-09-01

anniversary in 2007 over the launch of Sputnik (from the former Soviet Union). The ensuing Apollo (US) and Luna (USSR) programs initiated serious exploration of the Moon. The samples returned from those (now historic!) early missions changed our understanding of our place in the universe forever. They were the first well documented samples from an extraterrestrial body and attracted some of the top scientists in the world to extract the first remarkable pieces of information about Earth's nearest neighbour. And so they did - filling bookcases with profound new discoveries about this airless, waterless, and beautifully mysterious ancient world. The Moon was found to represent pure geology for a silicate planetary body - without all the complicating factors of plate tectonics, climate, and weather that recycle or transform Earth materials repeatedly. And then nothing happened. After the flush of reconnaissance, there was no further exploration of the Moon. For several decades scientists had nothing except the returned samples and a few telescopes with which to further study Earth's neighbour. Lack of new information breeds ignorance and can be stifling. Even though the space age was expanding its horizons to the furthest reaches of the solar system and the universe, lunar science moved slowly if at all and was kept in the doldrums. The drought ended with two small missions to the Moon in the 1990's, Clementine and Lunar Prospector. As summarized in the SSB/NRC report (and more completely in Jolliff et al. Eds. 2006, New Views of the Moon, Rev. Min. & Geochem.), the limited data returned from these small spacecraft set in motion several fundamental paradigm shifts in our understanding of the Moon and re-invigorated an aging science community. We learned that the largest basin in the solar system and oldest on the Moon dominates the southern half of the lunar farside (only seen by spacecraft). The age of this huge basin, if known, would constrain the period of heavy bombardment

Variation of Time Domain Failure Probabilities of Jack-up with Wave Return Periods

Science.gov (United States)

Idris, Ahmad; Harahap, Indra S. H.; Ali, Montassir Osman Ahmed

2018-04-01

This study evaluated failure probabilities of jack up units on the framework of time dependent reliability analysis using uncertainty from different sea states representing different return period of the design wave. Surface elevation for each sea state was represented by Karhunen-Loeve expansion method using the eigenfunctions of prolate spheroidal wave functions in order to obtain the wave load. The stochastic wave load was propagated on a simplified jack up model developed in commercial software to obtain the structural response due to the wave loading. Analysis of the stochastic response to determine the failure probability in excessive deck displacement in the framework of time dependent reliability analysis was performed by developing Matlab codes in a personal computer. Results from the study indicated that the failure probability increases with increase in the severity of the sea state representing a longer return period. Although the results obtained are in agreement with the results of a study of similar jack up model using time independent method at higher values of maximum allowable deck displacement, it is in contrast at lower values of the criteria where the study reported that failure probability decreases with increase in the severity of the sea state.

The Risk Return Relationship: Evidence from Index Return and Realised Variance Series

OpenAIRE

Minxian Yang

2014-01-01

The risk return relationship is analysed in bivariate models for return and realised variance(RV) series. Based on daily time series from 21 international market indices for more than 13 years (January 2000 to February 2013), the empirical findings support the arguments of risk return tradeoff, volatility feedback and statistical balance. It is reasoned that the empirical risk return relationship is primarily shaped by two important data features: the negative contemporaneous correlation betw...

Closed model of the earth's magnetosphere

International Nuclear Information System (INIS)

Piddington, J.H.

1979-01-01

The existence of large-scale motions within the earth's magnetosphere and that of a long magnetotail were predicted in 1960 as results of a hypothetical frictional interaction between the solar wind and the geomagnetic field. The boundary layer model of this interaction involves the flow of magnetosheath plasma in a magnetospheric boundary layer. The flow is across magnetic field lines, and so the layer must be polarized, with a space charge field nearly balancing the induction field V x B. The space charge tends to discharge through the ionosphere, thus providing some magnetic and related activity as well as the Lorentz frictional force. This closed magnetosphere model has been largely neglected in favor of the reconnection model but is now strongly supported by observational results and their interpretation as follows. (1) The evidence for the reconnection model, increasing activity with a southward interplanetary field and invasion of the polar caps by flare particles, is shown to be equally compatible with the closed field model. (2) The magnetotail grows by the motions of closed flux tubes through the dawn and dusk meridians, a process which depends on the nature of the boundary between magnetosphere and magnetosheath plasmas and perhaps also on the solar wind dynamo. Both of these features depend, in turn, on the direction of the interplanetary magnetic field. (3) Closed field lines entering the tail may be stretched to a few tens of earth radii and then contract back to the corotating magnetosphere. Others enter the long tail and are stretched to hundreds of earth radii and so are pervious to fast solar particles. (4) A new model of the magnetospheric substorm involves the entry of closed field lines into the tail and their rapid return to the corotating magnetosphere. The return is due, first, to the release of their trapped plasma as it becomes electrically polarized and, second, to mounting magnetic and plasma stresses in the inflated magnetotail

NASA'S Earth Science Data Stewardship Activities

Science.gov (United States)

Lowe, Dawn R.; Murphy, Kevin J.; Ramapriyan, Hampapuram

2015-01-01

NASA has been collecting Earth observation data for over 50 years using instruments on board satellites, aircraft and ground-based systems. With the inception of the Earth Observing System (EOS) Program in 1990, NASA established the Earth Science Data and Information System (ESDIS) Project and initiated development of the Earth Observing System Data and Information System (EOSDIS). A set of Distributed Active Archive Centers (DAACs) was established at locations based on science discipline expertise. Today, EOSDIS consists of 12 DAACs and 12 Science Investigator-led Processing Systems (SIPS), processing data from the EOS missions, as well as the Suomi National Polar Orbiting Partnership mission, and other satellite and airborne missions. The DAACs archive and distribute the vast majority of data from NASA’s Earth science missions, with data holdings exceeding 12 petabytes The data held by EOSDIS are available to all users consistent with NASA’s free and open data policy, which has been in effect since 1990. The EOSDIS archives consist of raw instrument data counts (level 0 data), as well as higher level standard products (e.g., geophysical parameters, products mapped to standard spatio-temporal grids, results of Earth system models using multi-instrument observations, and long time series of Earth System Data Records resulting from multiple satellite observations of a given type of phenomenon). EOSDIS data stewardship responsibilities include ensuring that the data and information content are reliable, of high quality, easily accessible, and usable for as long as they are considered to be of value.

Spaceship Earth: A partnership in curriculum writing

Science.gov (United States)

Lindstrom, Marilyn M.

1993-01-01

As the Apollo astronauts left Earth to venture onto the surface of another planetary body, they saw their home planet in a new global perspective. Unmanned NASA missions have given us a closer look at all the other planets in our solar system and emphasized the uniqueness of Earth as the only place in our solar system that can sustain life as we know it. Spaceship Earth is a new science curriculum which was developed to help students and teachers to explore the Earth, to see it in the global perspective, and to understand the relationships among life, the planet, and the sun. Astronaut photographs, especially shuttle pictures, are used as groundbased studies to help students to understand global Earth Science and integrate various aspects of physical, life, and social science. The Spaceship Earth curriculum was developed at by a team of JSC scientists working in collaboration with teachers from local school districts. This project was done under the auspices of Partner-In-Space, a local non-profit organization dedicated to improving science education and our general knowledge of space. The team met once a month for a year then assembled the curriculum during the summer. The project is now in the testing stage as the teachers try it out in their classrooms. It was supported by the Texas Education Agency and will be offered by the State of Texas as a supplemental curriculum for statewide use. Because the curriculum was developed by teachers, it is self contained and the lessons are easy to implement and give students concrete experiences. The three sub-units follow in a logical order, but may be used independently. If they are used separately, they may be tied together by the teacher returning to the basic theme of the global Earth as each unit is completed.

Thermal performance envelopes for MHTGRs - Reliability by design

International Nuclear Information System (INIS)

Etzel, K.T.; Howard, W.W.; Zgliczynski, J.

1992-01-01

Thermal performance envelopes are used to specify steady-state design requirements for the systems of the modular high-temperature gas-cooled reactor (MHTGR) to maximize plant performance reliability with optimized design. The thermal performance envelopes are constructed around the expected operating point to account for uncertainties in actual plant as-built parameters and plant operation. The components are then designed to perform successfully at all points within the envelope. As a result, plant reliability is maximized by accounting for component thermal performance variation in the design. The design is optimized by providing a means to determine required margins in a disciplined and visible fashion. This is accomplished by coordinating these requirements with the various system and component designers in the early stages of the design, applying the principles of total quality management. The design is challenged by the more complex requirements associated with a range of operating conditions, but in return, high probability of delivering reliable performance throughout the plant life is ensured

Multi-objective optimization of GENIE Earth system models.

Science.gov (United States)

Price, Andrew R; Myerscough, Richard J; Voutchkov, Ivan I; Marsh, Robert; Cox, Simon J

2009-07-13

The tuning of parameters in climate models is essential to provide reliable long-term forecasts of Earth system behaviour. We apply a multi-objective optimization algorithm to the problem of parameter estimation in climate models. This optimization process involves the iterative evaluation of response surface models (RSMs), followed by the execution of multiple Earth system simulations. These computations require an infrastructure that provides high-performance computing for building and searching the RSMs and high-throughput computing for the concurrent evaluation of a large number of models. Grid computing technology is therefore essential to make this algorithm practical for members of the GENIE project.

Navigation: Bat orientation using Earth's magnetic field

DEFF Research Database (Denmark)

Holland, Richard A.; Thorup, Kasper; Vonhof, Maarten J.

2006-01-01

Bats famously orientate at night by echolocation 1 , but this works over only a short range, and little is known about how they navigate over longer distances 2 . Here we show that the homing behaviour of Eptesicus fuscus, known as the big brown bat, can be altered by artificially shifting the Ea...... the Earth's magnetic field, indicating that these bats rely on a magnetic compass to return to their home roost. This finding adds to the impressive array of sensory abilities possessed by this animal for navigation in the dark....

Priorities to Advance Monitoring of Ecosystem Services Using Earth Observation.

Science.gov (United States)

Cord, Anna F; Brauman, Kate A; Chaplin-Kramer, Rebecca; Huth, Andreas; Ziv, Guy; Seppelt, Ralf

2017-06-01

Managing ecosystem services in the context of global sustainability policies requires reliable monitoring mechanisms. While satellite Earth observation offers great promise to support this need, significant challenges remain in quantifying connections between ecosystem functions, ecosystem services, and human well-being benefits. Here, we provide a framework showing how Earth observation together with socioeconomic information and model-based analysis can support assessments of ecosystem service supply, demand, and benefit, and illustrate this for three services. We argue that the full potential of Earth observation is not yet realized in ecosystem service studies. To provide guidance for priority setting and to spur research in this area, we propose five priorities to advance the capabilities of Earth observation-based monitoring of ecosystem services. Copyright © 2017 Elsevier Ltd. All rights reserved.

Forward Capacity Markets: Maintaining Grid Reliability in Europe

OpenAIRE

Chaigneau, Matthieu

2012-01-01

The liberalization process of the electricity industry in many countries leads to new rules and new challenges for the grid management. System reliability is a major concern, mainly because of (a) the high level penetration of renewable energy sources and (b) the growing peak load and environmental regulations In most electricity markets, peak resources operate only during a short period, and at a high operating cost, jeopardizing their return on investment, while low-cost base resources make...

The Proposed Mars Astrobiology Explorer - Cacher [MAX-C] Rover: First Step in a Potential Sample Return Campaign

Science.gov (United States)

Allen, Carlton C.; Beaty, David W.

2010-01-01

Sample return from Mars has been advocated by numerous scientific advisory panels for over 30 years, most prominently beginning with the National Research Council s [1] strategy for the exploration of the inner solar system, and most recently by the Mars Exploration Program Analysis Group (MEPAG s) Next Decade Science Analysis Group [2]. Analysis of samples here on Earth would have enormous advantages over in situ analyses in producing the data quality needed to address many of the complex scientific questions the community has posed about Mars. Instead of a small, predetermined set of analytical techniques, state of the art preparative and instrumental resources of the entire scientific community could be applied to the samples. The analytical emphasis could shift as the meaning of each result becomes better appreciated. These arguments apply both to igneous rocks and to layered sedimentary materials, either of which could contain water and other volatile constituents. In 2009 MEPAG formed the Mid-Range Rover Science Analysis Group (MRR-SAG) to formulate a mission concept that would address two general objectives: (1) conduct high-priority in situ science and (2) make concrete steps towards the potential return of samples to Earth. This analysis resulted in a mission concept named the Mars Astrobiology Explorer-Cacher (MAX-C), which was envisioned for launch in the 2018 opportunity. After extensive discussion, this group concluded that by far the most definitive contribution to sample return by this mission would be to collect and cache, in an accessible location, a suite of compelling samples that could potentially be recovered and returned by a subsequent mission. This would have the effect of separating two of the essential functions of MSR, the acquisition of the sample collection and its delivery to martian orbit, into two missions.

Reliability-based design methods to determine the extreme response distribution of offshore wind turbines

NARCIS (Netherlands)

Cheng, P.W.; Bussel, van G.J.W.; Kuik, van G.A.M.; Vugts, J.H.

2003-01-01

In this article a reliability-based approach to determine the extreme response distribution of offshore wind turbines is presented. Based on hindcast data, the statistical description of the offshore environment is formulated. The contour lines of different return periods can be determined.

Forecasting return products in an integrated forward/reverse supply chain utilizing an ANFIS

Directory of Open Access Journals (Sweden)

Kumar D. Thresh

2014-09-01

Full Text Available Interests in Closed-Loop Supply Chain (CLSC issues are growing day by day within the academia, companies, and customers. Many papers discuss profitability or cost reduction impacts of remanufacturing, but a very important point is almost missing. Indeed, there is no guarantee about the amounts of return products even if we know a lot about demands of first products. This uncertainty is due to reasons such as companies’ capabilities in collecting End-of-Life (EOL products, customers’ interests in returning (and current incentives, and other independent collectors. The aim of this paper is to deal with the important gap of the uncertainties of return products. Therefore, we discuss the forecasting method of return products which have their own open-loop supply chain. We develop an integrated two-phase methodology to cope with the closed-loop supply chain design and planning problem. In the first phase, an Adaptive Network Based Fuzzy Inference System (ANFIS is presented to handle the uncertainties of the amounts of return product and to determine the forecasted return rates. In the second phase, and based on the results of the first one, the proposed multi-echelon, multi-product, multi-period, closed-loop supply chain network is optimized. The second-phase optimization is undertaken based on using general exact solvers in order to achieve the global optimum. Finally, the performance of the proposed forecasting method is evaluated in 25 periods using a numerical example, which contains a pattern in the returning of products. The results reveal acceptable performance of the proposed two-phase optimization method. Based on them, such forecasting approaches can be applied to real-case CLSC problems in order to achieve more reliable design and planning of the network

Integrated Human-in-the-Loop Ground Testing - Value, History, and the Future

Science.gov (United States)

Henninger, Donald L.

2016-01-01

Systems for very long-duration human missions to Mars will be designed to operate reliably for many years and many of these systems will never be returned to Earth. The need for high reliability is driven by the requirement for safe functioning of remote, long-duration crewed systems and also by unsympathetic abort scenarios. Abort from a Mars mission could be as long as 450 days to return to Earth. The key to developing a human-in-the-loop architecture is a development process that allows for a logical sequence of validating successful development in a stepwise manner, with assessment of key performance parameters (KPPs) at each step; especially important are KPPs for technologies evaluated in a full systems context with human crews on Earth and on space platforms such as the ISS. This presentation will explore the implications of such an approach to technology development and validation including the roles of ground and space-based testing necessary to develop a highly reliable system for long duration human exploration missions. Historical development and systems testing from Mercury to the International Space Station (ISS) to ground testing will be reviewed. Current work as well as recommendations for future work will be described.

Examination of returned solar-max surfaces for impacting orbital debris and meteoroids

Science.gov (United States)

Kessler, D. J.; Zook, H. A.; Potter, A. E.; Mckay, D. S.; Clanton, U. S.; Warren, J. L.; Watts, L. A.; Schultz, R. A.; Schramm, L. S.; Wentworth, S. J.

1985-01-01

Previous theoretical studies predicted that in certain regions of earth orbit, the man-made earth orbiting debris environment will soon exceed the interplanetary meteoroid environment for sizes smaller than 1 cm. The surfaces returned from the repaired Solar Max Mission (SMM) by STS 41-C on April 12, 1984, offered an excellent opportunity to examine both the debris and meteoroid environments. To date, approximately 0.7 sq. met. of the thermal insulation and 0.05 sq. met of the aluminum louvers have been mapped by optical microscope for crater diameters larger than 40 microns. Craters larger in diameter than about 100 microns found on the initial 75 micron thick Kapton first sheet on the MEB (Main Electronics Box) blanket are actually holes and constitute perforations through that blanket. The following populations have been found to date in impact sites on these blankets: (1) meteoritic material; (2) thermal paint particles; (3) aluminum droplets; and (4) waste particles.

Increasing reliability of Gauss-Kronrod quadrature by Eratosthenes' sieve method

Science.gov (United States)

Adam, Gh.; Adam, S.

2001-04-01

The reliability of the local error estimates returned by the Gauss-Kronrod quadrature rules can be raised up to the theoretical 100% rate of success, under error estimate sharpening, provided a number of natural validating conditions are required. The self-validating scheme of the local error estimates, which is easy to implement and adds little supplementary computing effort, strengthens considerably the correctness of the decisions within the automatic adaptive quadrature.

Journal of Earth System Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Global Shuttle Radar Topography Mission (SRTM) data products have been widely used in EarthSciences without an estimation of their accuracy and reliability even though large outliers exist in them.The global 1 arc-sec, 30 m resolution, SRTM C-Band (C-30) data collected in February 2000 has beenrecently released ...

Use of EDTA for potentiometric back titration of rare earths and analysis of their mixtures

International Nuclear Information System (INIS)

Zayed, M.A.; Rizk, M.S.; Khalifa, H.; Omer, W.F.

1987-01-01

Advantage was taken of the stoichiometric reaction between mercury(II), rare earths, alkaline earths, heavy metal ions and EDTA in urotropine buffered media to determine rare earths by back-titration of excess EDTA in the course of estimating a variety of lanthanides or analysing their binary mixture with one of the alkaline earth metals by selective control of pH; or analysing their binary mixtures with heavy metals using fluoride as a good masking agent for rare earths; or analysing their ternary mixtures with both heavy and alkaline earth metals in two steps, one by selective control of pH and the other by masking of rare earths with fluoride at lower pH to estimate the heavy metal. The procedures given are simple, rapid and extremely reliable. 19 refs. (author)

China’s Rare Earths Production Forecasting and Sustainable Development Policy Implications

Directory of Open Access Journals (Sweden)

Xibo Wang

2017-06-01

Full Text Available Because of their unique physical and chemical properties, Rare earth elements (REEs perform important functions in our everyday lives, with use in a range of products. Recently, the study of China’s rare earth elements production has become a hot topic of worldwide interest, because of its dominant position in global rare earth elements supply, and an increasing demand for rare earth elements due to the constant use of rare earth elements in high-tech manufacturing industries. At the same time, as an exhaustible resource, the sustainable development of rare earth elements has received extensive attention. However, most of the study results are based on a qualitative analysis of rare earth elements distribution and production capacity, with few studies using quantitative modeling. To achieve reliable results with more factors being taken into consideration, this paper applies the generic multivariant system dynamics model to forecast China’s rare earth elements production trend and Hubbert peak, using Vensim software based on the Hubbert model. The results show that the peak of China’s rare earth elements production will appear by 2040, and that production will slowly decline afterwards. Based on the results, the paper proposes some policy recommendations for the sustainable development of China’s—and the world’s—rare earth elements market and rare earth-related industries.

Predictability of Stock Returns

Directory of Open Access Journals (Sweden)

Ahmet Sekreter

2017-06-01

Full Text Available Predictability of stock returns has been shown by empirical studies over time. This article collects the most important theories on forecasting stock returns and investigates the factors that affecting behavior of the stocks’ prices and the market as a whole. Estimation of the factors and the way of estimation are the key issues of predictability of stock returns.

Investigating the Geological History of Asteroid 101955 Bennu Through Remote Sensing and Returned Sample Analyses

Science.gov (United States)

Messenger, S.; Connolly, H. C., Jr.; Lauretta, D. S.; Bottke, W. F.

2014-01-01

The NASA New Frontiers Mission OSRIS-REx will return surface regolith samples from near-Earth asteroid 101955 Bennu in September 2023. This target is classified as a B-type asteroid and is spectrally similar to CI and CM chondrite meteorites [1]. The returned samples are thus expected to contain primitive ancient Solar System materials that formed in planetary, nebular, interstellar, and circumstellar environments. Laboratory studies of primitive astromaterials have yielded detailed constraints on the origins, properties, and evolutionary histories of a wide range of Solar System bodies. Yet, the parent bodies of meteorites and cosmic dust are generally unknown, genetic and evolutionary relationships among asteroids and comets are unsettled, and links between laboratory and remote observations remain tenuous. The OSIRIS-REx mission will offer the opportunity to coordinate detailed laboratory analyses of asteroidal materials with known and well characterized geological context from which the samples originated. A primary goal of the OSIRIS-REx mission will be to provide detailed constraints on the origin and geological and dynamical history of Bennu through coordinated analytical studies of the returned samples. These microanalytical studies will be placed in geological context through an extensive orbital remote sensing campaign that will characterize the global geological features and chemical diversity of Bennu. The first views of the asteroid surface and of the returned samples will undoubtedly bring remarkable surprises. However, a wealth of laboratory studies of meteorites and spacecraft encounters with primitive bodies provides a useful framework to formulate priority scientific questions and effective analytical approaches well before the samples are returned. Here we summarize our approach to unraveling the geological history of Bennu through returned sample analyses.

Single versus mixture Weibull distributions for nonparametric satellite reliability

International Nuclear Information System (INIS)

Castet, Jean-Francois; Saleh, Joseph H.

2010-01-01

Long recognized as a critical design attribute for space systems, satellite reliability has not yet received the proper attention as limited on-orbit failure data and statistical analyses can be found in the technical literature. To fill this gap, we recently conducted a nonparametric analysis of satellite reliability for 1584 Earth-orbiting satellites launched between January 1990 and October 2008. In this paper, we provide an advanced parametric fit, based on mixture of Weibull distributions, and compare it with the single Weibull distribution model obtained with the Maximum Likelihood Estimation (MLE) method. We demonstrate that both parametric fits are good approximations of the nonparametric satellite reliability, but that the mixture Weibull distribution provides significant accuracy in capturing all the failure trends in the failure data, as evidenced by the analysis of the residuals and their quasi-normal dispersion.

Cross-cultural adaptation and validation of the Injury-Psychological Readiness to Return to Sport scale to Persian language.

Science.gov (United States)

Naghdi, Soofia; Nakhostin Ansari, Noureddin; Farhadi, Yasaman; Ebadi, Safoora; Entezary, Ebrahim; Glazer, Douglas

2016-10-01

The aim of the present study was to develop and provide validation statistics for the Persian Injury-Psychological Readiness to Return to Sport scale (I-PRRS) following a cross-sectional and prospective cohort study design. The I-PRRS was forward/back-translated and culturally adapted into Persian language. The Persian I-PRRS was administered to 100 injured athletes (93 male; age 26.0 ± 5.6 years; time since injury 4.84 ± 6.4 months) and 50 healthy athletes (36 male; mean age 25.7 ± 6.0 years). The Persian I-PRRS was re-administered to 50 injured athletes at 1 week to examine test-retest reliability. There were no floor or ceiling effects confirming the content validity of Persian I-PRRS. The internal consistency reliability was good. Excellent test-retest reliability and agreement were demonstrated. The statistically significant difference in Persian I-PRRS total scores between the injured athletes and healthy athletes provides an evidence of discriminative validity. The Persian I-PRRS total scores were positively correlated with the Farsi Mood Scale (FARMS) total scores, showing construct validity. The principal component analysis indicated a two-factor solution consisting of "Confidence to play" and "Confidence in the injured body part and skill level". The Persian I-PRRS showed excellent reliability and validity and can be used to assess injured athletes' psychological readiness to return to sport among Persian-speaking populations.

The Return to Foreign Aid

DEFF Research Database (Denmark)

Dalgaard, Carl-Johan Lars; Hansen, Henrik

2017-01-01

We estimate the average rate of return on investments financed by aid and by domestic resource mobilisation, using aggregate data. Both returns are expected to vary across countries and time. Consequently we develop a correlated random coefficients model to estimate the average returns. Across...... different estimators and two different data sources for GDP and investment our findings are remarkably robust; the average gross return on ‘aid investments’ is about 20 per cent. This is in accord with micro estimates of the economic rate of return on aid projects and with aggregate estimates of the rate...

Strategies for Distinguishing Abiotic Chemistry from Martian Biochemistry in Samples Returned from Mars

Science.gov (United States)

Glavin, D. P.; Burton, A. S.; Callahan, M. P.; Elsila, J. E.; Stern, J. C.; Dworkin, J. P.

2012-01-01

A key goal in the search for evidence of extinct or extant life on Mars will be the identification of chemical biosignatures including complex organic molecules common to all life on Earth. These include amino acids, the monomer building blocks of proteins and enzymes, and nucleobases, which serve as the structural basis of information storage in DNA and RNA. However, many of these organic compounds can also be formed abiotically as demonstrated by their prevalence in carbonaceous meteorites [1]. Therefore, an important challenge in the search for evidence of life on Mars will be distinguishing between abiotic chemistry of either meteoritic or martian origin from any chemical biosignatures from an extinct or extant martian biota. Although current robotic missions to Mars, including the 2011 Mars Science Laboratory (MSL) and the planned 2018 ExoMars rovers, will have the analytical capability needed to identify these key classes of organic molecules if present [2,3], return of a diverse suite of martian samples to Earth would allow for much more intensive laboratory studies using a broad array of extraction protocols and state-of-theart analytical techniques for bulk and spatially resolved characterization, molecular detection, and isotopic and enantiomeric compositions that may be required for unambiguous confirmation of martian life. Here we will describe current state-of-the-art laboratory analytical techniques that have been used to characterize the abundance and distribution of amino acids and nucleobases in meteorites, Apollo samples, and comet- exposed materials returned by the Stardust mission with an emphasis on their molecular characteristics that can be used to distinguish abiotic chemistry from biochemistry as we know it. The study of organic compounds in carbonaceous meteorites is highly relevant to Mars sample return analysis, since exogenous organic matter should have accumulated in the martian regolith over the last several billion years and the

Anthropogenic Cycles of Rare Earth Elements

Science.gov (United States)

Du, X.; Graedel, T. E.

2009-12-01

This research will develop quantitatively resolved anthropogenic cycles and in-use stocks for the rare earth metals specifically cerium, lanthanum and dysprosium in Japan, China, and the U.S. for the year of 2007. Rare earth elements (REE) is a group of 17 scare metals widely used in a growing number of emerging technologies and have been in high demand for emerging technologies as raw materials during past the three decades. New market participants from newly industrializing countries, primarily China, have had strong impacts on the demand of share. Consequently, the importance to sustain a reliable, steady, uninterrupted supply on global market triggered comprehensive research to recognize and understand the life cycles of rare earths. Moreover, because China plays a dominant role in mining production since 1990, it requires the assessment for the countries, which are almost completely dependent on imports from China with respect to rare earth resources. The study aims to analyze the flows and stocks of rare earth elements individually as elemental form in spite of their natural geological co-occurrence and mixed composition in applications. By applying the method of Material Flow Analysis (MFA) work has been done on evaluating current and historical flows of specific technologically significant materials, for example, copper, zinc, nickel, etc., determining the stocks available in different types of reservoirs (e.g., lithosphere, in-use) and the flows among the reservoirs, developing scenarios of possible futures of metal use, and assessing the environmental and policy implications of the results. Therefore, REE as a new target deserves inclusion because of its potential demand-supply conflict and importance to secure the competitive advantage of technical innovation in future. This work will generate a quantitatively resolved anthropogenic life cycle and in-use stocks for REE for the main target countries for a chosen year, 2007, providing flows and stocks from

On the safeness of examinees and the reliability of system

International Nuclear Information System (INIS)

Kudo, Kazumi; Kanda, Kosuke; Saito, Kazuhiko; Maesawa, Tsuneharu; Idekami, Tomio

1979-01-01

The control technique of the reliability of examination system was investigated from the viewpoint of patient safety and image information, based on the prevention of microshock owing to circulatory organ checking system. As for the equipments in hospitals, the size of rooms, air conditioning system, power source installation, earth and piping arrangements should be fully discussed at the planning stage. EPR system must be introduced for the prevention for microshock. Intensive education and training are required for operators to secure safeness in operation. Thorough care should be taken to prevent bacilli infection. Further examinations were made on the control technique of the reliability of photographing system from viewpoint of image information, and it is necessary to study the factors for obtaining the reliability of compound machinery components and the devices of generating radiation. (Kobatake, H.)

Geomatic Methods for the Analysis of Data in the Earth Sciences: Lecture Notes in Earth Sciences, Vol. 95

Science.gov (United States)

Pavlis, Nikolaos K.

Geomatics is a trendy term that has been used in recent years to describe academic departments that teach and research theories, methods, algorithms, and practices used in processing and analyzing data related to the Earth and other planets. Naming trends aside, geomatics could be considered as the mathematical and statistical “toolbox” that allows Earth scientists to extract information about physically relevant parameters from the available data and accompany such information with some measure of its reliability. This book is an attempt to present the mathematical-statistical methods used in data analysis within various disciplines—geodesy, geophysics, photogrammetry and remote sensing—from a unifying perspective that inverse problem formalism permits. At the same time, it allows us to stretch the relevance of statistical methods in achieving an optimal solution.

MIDAS and HIT-6 French translation: reliability and correlation between tests.

Science.gov (United States)

Magnoux, E; Freeman, M A; Zlotnik, G

2008-01-01

The aim was to evaluate the test-retest reliability of the French translation of the Migraine Disability Assessment (MIDAS) and Headache Impact Test (HIT)-6 questionnaires as applied to episodic and chronic headaches and to assess the correlation between these two questionnaires. The MIDAS and HIT-6 questionnaires, which assess the degree of migraine-related functional disability, are widely used in headache treatment clinics. The French translation has not been checked for test-retest reliability. MIDAS involves recall, over the previous 3 months, of the number of days with functional disability with regard to work and to home and social life. HIT-6 involves a more subjective and general assessment of headache-related disability over the previous 4 weeks. We expect that there may be greater impact recall bias for chronic headaches than for episodic headaches and considered it important to be able to determine if the reliability of these questionnaires is equally good for these two patient populations. Given that both questionnaires have the same objective, that of assessing headache impact, it was thought useful to determine if their results might show a correlation and if they could thus be used interchangeably. The study was approved by an external ethics committee. The subjects were patients who regularly visit the Clinique de la Migraine de Montréal, which specializes in the treatment of headaches. The MIDAS and HIT-6 questionnaires were completed by the patients during their regular visit. Twelve days later, the same questionnaires were mailed with a prepaid return envelope. Sixty-five patients were required in both the episodic and chronic headache groups, assuming an 80% questionnaire return rate. One hundred and eighty-five patients were enrolled, and 143 completed the study, 75 with episodic headaches and 68 with chronic headaches. The questionnaire return rate was 78.9%. On average, questionnaires were completed a second time 21 days after the first

Risk assessment and reliability for low level radioactive waste disposal

International Nuclear Information System (INIS)

Gregory, P.O.; Jones, G.A.

1986-01-01

The reliability of critical design features at low-level radioactive waste disposal facilities is a major concern in the licensing of these structures. To date, no systematic methodology has been adopted to evaluate the geotechnical reliability of Uranium Mill Tailings Remedial Action (UMTRA) disposal facilities currently being designed and/or constructed. This paper discusses and critiques the deterministic methods currently used to evaluate UMTRA reliability. Because deterministic methods may not be applicable in some cases because of the unusually long design life of UMTRA facilities, it is proposed that a probabilistic risk assessment-based methodology be used as a secondary method to aid in the evaluating of geotechnical reliability of critical items. Similar methodologies have proven successful in evaluating the reliability of a variety of conventional earth structures. In this paper, an ''acceptable'' level of risk for UMTRA facilities is developed, an evaluation method is presented, and two example applications of the proposed methodology are provided for a generic UMTRA disposal facility. The proposed technique is shown to be a simple method which might be used to aid in reliability evaluations on a selective basis. Finally, other possible applications and the limitations of the proposed methodology are discussed

Using wind plant data to increase reliability.

Energy Technology Data Exchange (ETDEWEB)

Peters, Valerie A. (Sandia National Laboratories, Livermore, CA); Ogilvie, Alistair B.; McKenney, Bridget L.

2011-01-01

Operators interested in improving reliability should begin with a focus on the performance of the wind plant as a whole. To then understand the factors which drive individual turbine performance, which together comprise the plant performance, it is necessary to track a number of key indicators. Analysis of these key indicators can reveal the type, frequency, and cause of failures and will also identify their contributions to overall plant performance. The ideal approach to using data to drive good decisions includes first determining which critical decisions can be based on data. When those required decisions are understood, then the analysis required to inform those decisions can be identified, and finally the data to be collected in support of those analyses can be determined. Once equipped with high-quality data and analysis capabilities, the key steps to data-based decision making for reliability improvements are to isolate possible improvements, select the improvements with largest return on investment (ROI), implement the selected improvements, and finally to track their impact.

76 FR 22611 - Specified Tax Return Preparers Required To File Individual Income Tax Returns Using Magnetic...

Science.gov (United States)

2011-04-22

... Specified Tax Return Preparers Required To File Individual Income Tax Returns Using Magnetic Media... Register on Wednesday, March 30, 2011 (76 FR 17521) providing guidance to specified tax return preparers who prepare and file individual income tax returns using magnetic media pursuant to section 6011(e)(3...

Temporal Oculomotor Inhibition of Return and Spatial Facilitation of Return in a Visual Encoding Task

Directory of Open Access Journals (Sweden)

Steven G Luke

2013-07-01

Full Text Available Oculomotor inhibition of return (O-IOR is an increase in saccade latency prior to an eye movement to a recently fixated location compared to other locations. It has been proposed that this temporal O-IOR may have spatial consequences, facilitating foraging by inhibiting return to previously attended regions. In order to test this possibility, participants viewed arrays of objects and of words while their eye movements were recorded. Temporal O-IOR was observed, with equivalent effects for object and word arrays, indicating that temporal O-IOR is an oculomotor phenomenon independent of array content. There was no evidence for spatial inhibition of return. Instead, spatial facilitation of return was observed: Participants were significantly more likely than chance to make return saccades and to refixate just-visited locations. Further, the likelihood of making a return saccade to an object or word was contingent on the amount of time spent viewing that object or word before leaving it. This suggests that, unlike temporal O-IOR, return probability is influenced by cognitive processing. Taken together, these results are inconsistent with the hypothesis that inhibition of return functions as a foraging facilitator. The results also provide strong evidence for a different oculomotor bias that could serve as a foraging facilitator: saccadic momentum, a tendency to repeat the most recently executed saccade program. We suggest that models of visual attention could incorporate saccadic momentum in place of inhibition of return.

Heavy rare earths, permanent magnets, and renewable energies: An imminent crisis

International Nuclear Information System (INIS)

Smith Stegen, Karen

2015-01-01

This article sounds the alarm that a significant build-out of efficient lighting and renewable energy technologies may be endangered by shortages of rare earths and rare earth permanent magnets. At the moment, China is the predominant supplier of both and its recent rare earth industrial policies combined with its own growing demand for rare earths have caused widespread concern. To diversify supplies, new mining—outside of China—is needed. But what many observers of the “rare earth problem” overlook is that China also dominates in (1) the processing of rare earths, particularly the less abundant heavy rare earths, and (2) the supply chains for permanent magnets. Heavy rare earths and permanent magnets are critical for many renewable energy technologies, and it will require decades to develop new non-Chinese deposits, processing capacity, and supply chains. This article clarifies several misconceptions, evaluates frequently proposed solutions, and urges policy makers outside of China to undertake measures to avert a crisis, such as greater support for research and development and for the cultivation of intellectual capital. - Highlights: • Rare earths are needed for many efficient lighting and renewable energy technologies. • The industries for rare earths and permanent magnets are dominated by China. • China's reliability is compromised, necessitating non-Chinese mining and processing. • Recycling, substitution and reducing rare earth content are long-term solutions only. • Policy makers should support development of supply chains and intellectual capital

An integrated and accessible sample data library for Mars sample return science

Science.gov (United States)

Tuite, M. L., Jr.; Williford, K. H.

2015-12-01

Over the course of the next decade or more, many thousands of geological samples will be collected and analyzed in a variety of ways by researchers at the Jet Propulsion Laboratory (California Institute of Technology) in order to facilitate discovery and contextualize observations made of Mars rocks both in situ and here on Earth if samples are eventually returned. Integration of data from multiple analyses of samples including petrography, thin section and SEM imaging, isotope and organic geochemistry, XRF, XRD, and Raman spectrometry is a challenge and a potential obstacle to discoveries that require supporting lines of evidence. We report the development of a web-accessible repository, the Sample Data Library (SDL) for the sample-based data that are generated by the laboratories and instruments that comprise JPL's Center for Analysis of Returned Samples (CARS) in order to facilitate collaborative interpretation of potential biosignatures in Mars-analog geological samples. The SDL is constructed using low-cost, open-standards-based Amazon Web Services (AWS), including web-accessible storage, relational data base services, and a virtual web server. The data structure is sample-centered with a shared registry for assigning unique identifiers to all samples including International Geo-Sample Numbers. Both raw and derived data produced by instruments and post-processing workflows are automatically uploaded to online storage and linked via the unique identifiers. Through the web interface, users are able to find all the analyses associated with a single sample or search across features shared by multiple samples, sample localities, and analysis types. Planned features include more sophisticated search and analytical interfaces as well as data discoverability through NSF's EarthCube program.

Potential benefits of maximal exercise just prior to return from weightlessness

Science.gov (United States)

Convertino, Victor A.

1987-01-01

The purpose of this study was to determine whether performance of a single maximal bout of exercise during weightlessness within hours of return to earth would enhance recovery of aerobic fitness and physical work capacities under a 1G environment. Ten healthy men were subjected to a 10-d bedrest period in the 6-deg headdown position. A graded maximal supine cycle ergometer test was performed before and at the end of bedrest to simulate exercise during weightlessness. Following 3 h of resumption of the upright posture, a second maximal exercise test was performed on a treadmill to measure work capacity under conditions of 1G. Compared to before bedrest, peak oxygen consumption, V(O2), decreased by 8.7 percent and peak heart rate (HR) increased by 5.6 percent in the supine cycle test at the end of bedrest. However, there were no significant changes in peak V(O2) and peak HR in the upright treadmill test following bedrest. These data suggest that one bout of maximal leg exercise prior to return from 10 d of weightlessness may be adequate to restore preflight aerobic fitness and physical work capacity.

Programmable wide field spectrograph for earth observation

Science.gov (United States)

Zamkotsian, Frédéric; Lanzoni, Patrick; Liotard, Arnaud; Viard, Thierry; Costes, Vincent; Hébert, Philippe-Jean

2017-11-01

In Earth Observation, Universe Observation and Planet Exploration, scientific return of the instruments must be optimized in future missions. Micro-Opto-Electro-Mechanical Systems (MOEMS) could be key components in future generation of space instruments. These devices are based on the mature micro-electronics technology and in addition to their compactness, scalability, and specific task customization, they could generate new functions not available with current technologies. French and European space agencies, the Centre National d'Etudes Spatiales (CNES) and the European Space Agency (ESA) have initiated several studies with LAM and TAS for listing the new functions associated with several types of MEMS, and developing new ideas of instruments.

26 CFR 20.6018-2 - Returns; person required to file return.

Science.gov (United States)

2010-04-01

... executor or administrator shall file the return. If there is more than one executor or administrator, the return must be made jointly by all. If there is no executor or administrator appointed, qualified and... decedent situated in the United States is constituted an executor for purposes of the tax (see § 20.2203-1...

Solution thermodynamics of rare-earth metal ions - physicochemical study-

Energy Technology Data Exchange (ETDEWEB)

Amerkhanova, Sh K; Shlyapov, R M; Uali, A S [Buketov Karaganda state university, University str., 28, Karaganda, 100028 (Kazakhstan)], E-mail: amerkhanova_sh@mail.ru

2009-02-01

The results of the studying of interactions in multicomponent systems 'polyvinyl alcohol (PVA) - rare-earth element ion - nitrate of sodium - water' are represented. It is established that for rubidium (I) ions temperature and ionic strength is render destroying action, and for yttrium (III) ions the influence of these factors has return character which is connected with features of an electronic structure of metal ion. It is revealed that a dominating role of non-electrostatic formation composed, hence, the formation of donor-acceptor connection of 'metal - ligand' occurs through atom of oxygen.

Reliability of short form-36 in an Internet- and a pen-and-paper version

DEFF Research Database (Denmark)

Basnov, Maja; Kongsved, Sissel Marie; Bech, Per

2009-01-01

Use of Internet versions of questionnaires may have several advantages in clinical and epidemiological research, but we know little about if Internet versions differ with respect to validity and reliability. We aimed to compare Internet- and pen-and-paper versions of short form-36 (SF-36......) with respect to test-retest reliability and internal consistency. Women referred to mammography (n = 782) were randomised to receive either a paper version with a prepaid return envelope or a guideline on how to fill in the Internet version. A subgroup was asked to answer the questionnaire once again...... in the alternative version. Test-retest reliability was assessed by the intra-class correlation coefficient. Internal consistency was calculated as Cronbach's alpha. The between-version test-retest reliability for the eight subscales were between 0.63 and 0.92. Cronbach's alpha for the two versions were all between...

Physics at the edge of the earth

International Nuclear Information System (INIS)

Allen, J.P.

1988-01-01

The author recounts experiences he had as an astronaut, and the ways this allowed him to practice physics in a very applied manner. He describes some of the phenomena observed in the zero gravity of space flight which are very different, and hard to imagine, by minds immersed in the images and experiences of normal gravity. Most of the paper is devoted to a description of the task of recovering lost communication satellites and returning them to earth for repair and potential redeployment. From his perspective as a physicist and astronaut he explains briefly the orbital mechanics experienced in earth orbit, and the problems in compensating for these effects which maneuvering in space untethered to the shuttle. This presents hard practical problems to be met and solved in order to accomplish the task. Using a manned maneuvering unit his mission was able to successfully couple to the satellite and bring it to the shuttle. This involved a lot of practice of the classical physics principles of orbital dynamics, and the influence that perception in a space environment has upon these laws

The Consortium for the Valuation of Applications Benefits Linked with Earth Science (VALUABLES)

Science.gov (United States)

Kuwayama, Y.; Mabee, B.; Wulf Tregar, S.

2017-12-01

National and international organizations are placing greater emphasis on the societal and economic benefits that can be derived from applications of Earth observations, yet improvements are needed to connect to the decision processes that produce actions with direct societal benefits. There is a need to substantiate the benefits of Earth science applications in socially and economically meaningful terms in order to demonstrate return on investment and to prioritize investments across data products, modeling capabilities, and information systems. However, methods and techniques for quantifying the value proposition of Earth observations are currently not fully established. Furthermore, it has been challenging to communicate the value of these investments to audiences beyond the Earth science community. The Consortium for the Valuation of Applications Benefits Linked with Earth Science (VALUABLES), a cooperative agreement between Resources for the Future (RFF) and the National Aeronautics and Space Administration (NASA), has the goal of advancing methods for the valuation and communication of the applied benefits linked with Earth observations. The VALUABLES Consortium will focus on three pillars: (a) a research pillar that will apply existing and innovative methods to quantify the socioeconomic benefits of information from Earth observations; (b) a capacity building pillar to catalyze interdisciplinary linkages between Earth scientists and social scientists; and (c) a communications pillar that will convey the value of Earth observations to stakeholders in government, universities, the NGO community, and the interested public. In this presentation, we will describe ongoing and future activities of the VALUABLES Consortium, provide a brief overview of frameworks to quantify the socioeconomic value of Earth observations, and describe how Earth scientists and social scientist can get involved in the Consortium's activities.

High pressure, high current, low inductance, high reliability sealed terminals

Science.gov (United States)

Hsu, John S [Oak Ridge, TN; McKeever, John W [Oak Ridge, TN

2010-03-23

The invention is a terminal assembly having a casing with at least one delivery tapered-cone conductor and at least one return tapered-cone conductor routed there-through. The delivery and return tapered-cone conductors are electrically isolated from each other and positioned in the annuluses of ordered concentric cones at an off-normal angle. The tapered cone conductor service can be AC phase conductors and DC link conductors. The center core has at least one service conduit of gate signal leads, diagnostic signal wires, and refrigerant tubing routed there-through. A seal material is in direct contact with the casing inner surface, the tapered-cone conductors, and the service conduits thereby hermetically filling the interstitial space in the casing interior core and center core. The assembly provides simultaneous high-current, high-pressure, low-inductance, and high-reliability service.

Clay catalyzed RNA synthesis under Martian conditions: Application for Mars return samples.

Science.gov (United States)

Joshi, Prakash C; Dubey, Krishna; Aldersley, Michael F; Sausville, Meaghen

2015-06-26

Catalysis by montmorillonites clay minerals is regarded as a feasible mechanism for the abiotic production and polymerization of key biomolecules on early Earth. We have investigated a montmorillonite-catalyzed reaction of the 5'-phosphorimidazolide of nucleosides as a model to probe prebiotic synthesis of RNA-type oligomers. Here we show that this model is specific for the generation of RNA oligomers despite deoxy-mononucleotides adsorbing equally well onto the montmorillonite catalytic surfaces. Optimum catalytic activity was observed over a range of pH (6-9) and salinity (1 ± 0.2 M NaCl). When the weathering steps of early Earth that generated catalytic montmorillonite were modified to meet Martian soil conditions, the catalytic activity remained intact without altering the surface layer charge. Additionally, the formation of oligomers up to tetramer was detected using as little as 0.1 mg of Na⁺-montmorillonite, suggesting that the catalytic activity of a Martian clay return sample can be investigated with sub-milligram scale samples. Copyright © 2015 Elsevier Inc. All rights reserved.

PUC fast track nips returns

International Nuclear Information System (INIS)

Anon.

1990-01-01

In the first of what it says will be annual cost-of-capital proceedings to set returns on equity and rates of return on rate base for electric utilities, the California Public Utilities Commission (PUC) lowered from 1989 levels the 1990 returns on common equity (ROE) and rates of return (ROR) for the state's four major investor-owned electric utilities. Under this fast-track procedure, by May 8 of every year, utilities will have to file an application for rate adjustments that reflect their projected costs of capital for the following year

The return to foreign aid

DEFF Research Database (Denmark)

Dalgaard, Carl-Johan Lars; Hansen, Henrik

We investigate the marginal productivity of investment across countries. The aim is to estimate the return on investments financed by foreign aid and by domestic resource mobilization, using aggregate data. Both returns are expected to vary across countries and time. Consequently we develop...... a correlated random coefficients model, to estimate the average aggregate return on ‘aid investments’ and ‘domestic investments’. Across different estimators and two different sources for GDP and investment data our findings are remarkably robust; the average gross return on ‘aid investments’ is about 20 per...

Natural background radioactivity of the earth's surface -- essential information for environmental impact studies

International Nuclear Information System (INIS)

Tauchid, M.; Grasty, R.L.

2002-01-01

An environmental impact study is basically a study of change. This change is compared to the preexisting conditions that are usually perceived to be the original one or the 'pristine' stage. Unfortunately reliable information on the 'so called' pristine stage is far from adequate. One of the essential parts of this information is a good knowledge of the earth's chemical make up, or its geochemistry. Presently available data on the geochemistry of the earth's surface, including those related to radioactive elements, are incomplete and inconsistent. The main reason why a number of regulations are judged to be too strict and disproportional to the risks that might be caused by some human activities, is the lack of reliable information on the natural global geochemical background on which environmental regulations should be based. The main objective of this paper is to present a view on the need for complete baseline information on the earth's surface environment and in particular its geochemical character. It is only through the availability of complete information, including reliable baseline information on the natural radioactivity, that an appropriate study on the potential effect of the various naturally occurring elements on human health be carried out. Presented here are a number of examples where the natural radioactivity of an entire country has been mapped, or is in progress. Also described are the ways these undertakings were accomplished. There is a general misconception that elevated radioactivity can be found only around uranium mines, nuclear power reactors and similar nuclear installations. As can be seen from some of these maps, the natural background radioactivity of the earth's surface closely reflects the underlying geological formations and their alteration products. In reality, properly regulated and managed facilities, the levels of radioactivity associated with many of these facilities are generally quite low relative to those associated with

Projeto de aterramento para sistema monofilar com retorno pelo terra Grounding project for single wire earth return system

Directory of Open Access Journals (Sweden)

Humberto C Bertolo

2011-02-01

Full Text Available Este trabalho apresenta o projeto de aterramento elétrico para Sistema Monofilar com Retorno pela Terra (MRT, em solicitações de baixas frequências, utilizando-se o método das imagens e considerando a simplificação do método dos potenciais constantes. Simulou-se o comportamento de três diferentes configurações de aterramento: hastes em triângulo, em quadrado vazio e para nove hastes, formando uma malha com quatro quadrados. A partir da simulação obtiveram-se o valor da resistência de aterramento para cada configuração e os potenciais gerados na superfície do solo. Com base nesses resultados foi possível comparar os valores tabelados para resistências mínimas, em função da potência do transformador, aplicados para diferentes concessionárias de energia que utilizam o Sistema MRT, com os valores calculados que mantêm os potenciais no solo em níveis seguros para seres humanos e animais. Os resultados mostraram que é possível utilizar aterramentos mais simples e mais baratos, pois os gradientes de tensões no solo se mantiveram em níveis seguros.This work presents a grounding project for a Single Wire Earth Return (SWER system in low frequency applications, through the use of the image method, a simplification of the constant potential method. The responses of three different grounding configurations were simulated: electrodes in triangular format, electrodes placed in the corners of a square and nine electrodes placed in the corners of a grid with four squares. With the mentioned simulation it was possible to calculate the ground resistance and the surface voltage of each configuration. Based on these results, it was possible to compare the values for minimal resistance, depending on the power of the transformer, applied to various power utilities that use the SWER system with the values that hold the potential in the soil at safe levels for human beings and animals. Results showed that it is possible to use simpler and

Test-retest and interrater reliability of the functional lower extremity evaluation.

Science.gov (United States)

Haitz, Karyn; Shultz, Rebecca; Hodgins, Melissa; Matheson, Gordon O

2014-12-01

Repeated-measures clinical measurement reliability study. To establish the reliability and face validity of the Functional Lower Extremity Evaluation (FLEE). The FLEE is a 45-minute battery of 8 standardized functional performance tests that measures 3 components of lower extremity function: control, power, and endurance. The reliability and normative values for the FLEE in healthy athletes are unknown. A face validity survey for the FLEE was sent to sports medicine personnel to evaluate the level of importance and frequency of clinical usage of each test included in the FLEE. The FLEE was then administered and rated for 40 uninjured athletes. To assess test-retest reliability, each athlete was tested twice, 1 week apart, by the same rater. To assess interrater reliability, 3 raters scored each athlete during 1 of the testing sessions. Intraclass correlation coefficients were used to assess the test-retest and interrater reliability of each of the FLEE tests. In the face validity survey, the FLEE tests were rated as highly important by 58% to 71% of respondents but frequently used by only 26% to 45% of respondents. Interrater reliability intraclass correlation coefficients ranged from 0.83 to 1.00, and test-retest reliability ranged from 0.71 to 0.95. The FLEE tests are considered clinically important for assessing lower extremity function by sports medicine personnel but are underused. The FLEE also is a reliable assessment tool. Future studies are required to determine if use of the FLEE to make return-to-play decisions may reduce reinjury rates.

Effect of Earth Ground and Environment on Body-Centric Communications in the MHz Band

Directory of Open Access Journals (Sweden)

Katsuyuki Fujii

2012-01-01

Full Text Available Body area network (BAN research, which uses the human body as a transmission channel, has recently attracted considerable attention globally. Zimmerman first advocated the idea in 1995. Illustrations of the electric field streamlines around the human body and wearable devices with electrodes were drawn. In the pictures, the electrodes of the wearable devices constitute a closed circuit with the human body and the earth ground. However, analysis of the circuit has not been conducted. In this study, we model the human body shunted to earth ground in a radio anechoic chamber to analyze the electric field strength around it and clarify the effect of earth ground during BAN run time. The results suggest that earth ground has little influence on the human body and wearable devices. Only when the human body is directly grounded, the electric field near the feet area will decrease. The input impedance of the transmitter is approximately the same, and the received open-circuit voltage and current of the receiver are also the same. In addition, we elucidate that stable communications can be established by developing a closed circuit using earth ground as return path. When the external electronic devices and human body are shunted to earth ground, the received open-circuit voltage and current increase.

Advanced Curation: Solving Current and Future Sample Return Problems

Science.gov (United States)

Fries, M.; Calaway, M.; Evans, C.; McCubbin, F.

2015-01-01

Advanced Curation is a wide-ranging and comprehensive research and development effort at NASA Johnson Space Center that identifies and remediates sample related issues. For current collections, Advanced Curation investigates new cleaning, verification, and analytical techniques to assess their suitability for improving curation processes. Specific needs are also assessed for future sample return missions. For each need, a written plan is drawn up to achieve the requirement. The plan draws while upon current Curation practices, input from Curators, the analytical expertise of the Astromaterials Research and Exploration Science (ARES) team, and suitable standards maintained by ISO, IEST, NIST and other institutions. Additionally, new technologies are adopted on the bases of need and availability. Implementation plans are tested using customized trial programs with statistically robust courses of measurement, and are iterated if necessary until an implementable protocol is established. Upcoming and potential NASA missions such as OSIRIS-REx, the Asteroid Retrieval Mission (ARM), sample return missions in the New Frontiers program, and Mars sample return (MSR) all feature new difficulties and specialized sample handling requirements. The Mars 2020 mission in particular poses a suite of challenges since the mission will cache martian samples for possible return to Earth. In anticipation of future MSR, the following problems are among those under investigation: What is the most efficient means to achieve the less than 1.0 ng/sq cm total organic carbon (TOC) cleanliness required for all sample handling hardware? How do we maintain and verify cleanliness at this level? The Mars 2020 Organic Contamination Panel (OCP) predicts that organic carbon, if present, will be present at the "one to tens" of ppb level in martian near-surface samples. The same samples will likely contain wt% perchlorate salts, or approximately 1,000,000x as much perchlorate oxidizer as organic carbon

Fundamental volatility and stock returns : does fundamental volatility explain stock returns?

OpenAIRE

Selboe, Guner K.; Virdee, Jaspal Singh

2017-01-01

In this thesis, we investigate whether the fundamental uncertainty can explain the crosssection of stock returns. To measure the fundamental uncertainty, we estimate rolling standard deviations and accounting betas of four different fundamentals: revenues, gross profit, earnings and cash flows. The standard deviation and the beta of revenues significantly explain returns in the Fama-Macbeth procedure, but only appears significant among smaller stocks in the portfolio formation ...

Earth mortars and earth-lime renders

Directory of Open Access Journals (Sweden)

Maria Fernandes

2008-01-01

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

Classifying Returns as Extreme

DEFF Research Database (Denmark)

Christiansen, Charlotte

2014-01-01

I consider extreme returns for the stock and bond markets of 14 EU countries using two classification schemes: One, the univariate classification scheme from the previous literature that classifies extreme returns for each market separately, and two, a novel multivariate classification scheme tha...

Reliability and standard market design : a square plug and a round socket, the fundamental flaw of the market design

International Nuclear Information System (INIS)

Bekman, K.

2003-01-01

A electricity power system is designed and built to deliver reliable power supplies. A failure of a single component should not lead to the failure of the entire system. Oversupply results in prices at marginal cost of production, inadequate return on capital investment and economic failure of supplies. Uneconomic sources of supply would pull out in cases of oversupply. Competitive markets need flexible supply and demand and scarcity pricing in order to promote new investment. The problem with such a scenario is that scarcity reduces the level of reliability. An oversupply, while ensuring reliability, offers an inadequate return on capital. This presentation included several graphs depicting results of market failure with reference to NYMEX analysis of credit quality, NEPOOL summer capacity 2001, NYS summer capacity 2001, and PJM summer capacity 2001. A graph illustrating a New England 2002 load duration curve and its analysis was also included. According to the author, the market design is flawed because it does not pay for reliability. It fails to compensate generation for capital at risk, and it fails to address the fact that nearly half of the capacity supplies less than 10 per cent energy. He notes that the liquidity crisis will continue and grow unless changes are made and new entrants come into the market. 8 figs

Performance Study of Earth Networks Total Lightning Network using Rocket-Triggered Lightning Data in 2014

Science.gov (United States)

Heckman, S.

2015-12-01

Modern lightning locating systems (LLS) provide real-time monitoring and early warning of lightningactivities. In addition, LLS provide valuable data for statistical analysis in lightning research. It isimportant to know the performance of such LLS. In the present study, the performance of the EarthNetworks Total Lightning Network (ENTLN) is studied using rocket-triggered lightning data acquired atthe International Center for Lightning Research and Testing (ICLRT), Camp Blanding, Florida.In the present study, 18 flashes triggered at ICLRT in 2014 were analyzed and they comprise of 78negative cloud-to-ground return strokes. The geometric mean, median, minimum, and maximum for thepeak currents of the 78 return strokes are 13.4 kA, 13.6 kA, 3.7 kA, and 38.4 kA, respectively. The peakcurrents represent typical subsequent return strokes in natural cloud-to-ground lightning.Earth Networks has developed a new data processor to improve the performance of their network. Inthis study, results are presented for the ENTLN data using the old processor (originally reported in 2014)and the ENTLN data simulated using the new processor. The flash detection efficiency, stroke detectionefficiency, percentage of misclassification, median location error, median peak current estimation error,and median absolute peak current estimation error for the originally reported data from old processorare 100%, 94%, 49%, 271 m, 5%, and 13%, respectively, and those for the simulated data using the newprocessor are 100%, 99%, 9%, 280 m, 11%, and 15%, respectively. The use of new processor resulted inhigher stroke detection efficiency and lower percentage of misclassification. It is worth noting that theslight differences in median location error, median peak current estimation error, and median absolutepeak current estimation error for the two processors are due to the fact that the new processordetected more number of return strokes than the old processor.

The intensity of the Earth's magnetic field over the past 160 million years

NARCIS (Netherlands)

Juárez, M.T.; Tauxe, Lisa; Gee, J.S.; Pick, T.

1998-01-01

In contrast to our detailed knowledge of the directional behaviour of the Earth's magnetic field during geological and historical times, data constraining the past intensity of the field remain relatively scarce. This is mainly due to the difficulty in obtaining reliable palaeointensity

QR-GARCH-M Model for Risk-Return Tradeoff in U.S. Stock Returns and Business Cycles

OpenAIRE

Nyberg, Henri

2010-01-01

In the empirical finance literature findings on the risk return tradeoff in excess stock market returns are ambiguous. In this study, we develop a new QR-GARCH-M model combining a probit model for a binary business cycle indicator and a regime switching GARCH-in-mean model for excess stock market return with the business cycle indicator defining the regime. Estimation results show that there is statistically significant variation in the U.S. excess stock returns over the business cycle. Howev...

Cloud-based calculators for fast and reliable access to NOAA's geomagnetic field models

Science.gov (United States)

Woods, A.; Nair, M. C.; Boneh, N.; Chulliat, A.

2017-12-01

While the Global Positioning System (GPS) provides accurate point locations, it does not provide pointing directions. Therefore, the absolute directional information provided by the Earth's magnetic field is of primary importance for navigation and for the pointing of technical devices such as aircrafts, satellites and lately, mobile phones. The major magnetic sources that affect compass-based navigation are the Earth's core, its magnetized crust and the electric currents in the ionosphere and magnetosphere. NOAA/CIRES Geomagnetism (ngdc.noaa.gov/geomag/) group develops and distributes models that describe all these important sources to aid navigation. Our geomagnetic models are used in variety of platforms including airplanes, ships, submarines and smartphones. While the magnetic field from Earth's core can be described in relatively fewer parameters and is suitable for offline computation, the magnetic sources from Earth's crust, ionosphere and magnetosphere require either significant computational resources or real-time capabilities and are not suitable for offline calculation. This is especially important for small navigational devices or embedded systems, where computational resources are limited. Recognizing the need for a fast and reliable access to our geomagnetic field models, we developed cloud-based application program interfaces (APIs) for NOAA's ionospheric and magnetospheric magnetic field models. In this paper we will describe the need for reliable magnetic calculators, the challenges faced in running geomagnetic field models in the cloud in real-time and the feedback from our user community. We discuss lessons learned harvesting and validating the data which powers our cloud services, as well as our strategies for maintaining near real-time service, including load-balancing, real-time monitoring, and instance cloning. We will also briefly talk about the progress we achieved on NOAA's Big Earth Data Initiative (BEDI) funded project to develop API

Return Migration as Failure or Success?: The Determinants of Return Migration Intentions Among Moroccan Migrants in Europe.

Science.gov (United States)

de Haas, Hein; Fokkema, Tineke; Fihri, Mohamed Fassi

Different migration theories generate competing hypotheses with regard to determinants of return migration. While neoclassical migration theory associates migration to the failure to integrate at the destination, the new economics of labour migration sees return migration as the logical stage after migrants have earned sufficient assets and knowledge and to invest in their origin countries. The projected return is then likely to be postponed for sustained or indefinite periods if integration is unsuccessful. So, from an indication or result of integration failure return is rather seen as a measure of success. Drawing on recent survey data ( N  = 2,832), this article tests these hypotheses by examining the main determinants of return intention among Moroccan migrants across Europe. The results indicate that structural integration through labour market participation, education and the maintenance of economic and social ties with receiving countries do not significantly affect return intentions. At the same time, investments and social ties to Morocco are positively related, and socio-cultural integration in receiving countries is negatively related to return migration intentions. The mixed results corroborate the idea that there is no uniform process of (return) migration and that competing theories might therefore be partly complementary.

Standard practice for determining rail-to-Earth resistance

CERN Document Server

American Society for Testing and Materials. Philadelphia

1999-01-01

1.1 This practice covers the procedures necessary to follow for measuring resistance-to-earth of the running rails which are used as the conductors for returning the train operating current to the substation in electric mass transit systems. 1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Sleep and sleep disturbance in children: Reliability and validity of the Dutch version of the Child Sleep Habits Questionnaire.

Science.gov (United States)

Waumans, Ruth C; Terwee, Caroline B; Van den Berg, Gerrit; Knol, Dirk L; Van Litsenburg, Raphaële R L; Gemke, Reinoud J B J

2010-06-01

The Child Sleep Habits Questionnaire (CSHQ) was developed in the US for measuring medical and behavioral sleep disorders in school-aged children. This study was conducted to assess the reliability and structural validity of the Dutch version of the CSHQ. Population-based study. Questionnaires (n = 2385) were distributed to children in primary schools and daycare centers to be completed by the parent/guardian. An identical second questionnaire was distributed for test-retest and interobserver reliability, which were assessed using intraclass correlation, and compared with published data. Internal consistency was assessed by Cronbach alpha (per subscale). Validity was analyzed by confirmatory and exploratory factor analysis. School-aged children. None. The questionnaire was returned by 1502 (63%) parents, 47% returned the questionnaire for test-retest, and 32% for interobserver reliability. Test-retest reliability was moderate to good, ranging from 0.47 to 0.93. Interobserver reliability was moderate to good, ranging from 0.53 to 0.87, with the exception of Sleep duration. Cronbach alpha ranged from 0.47 to 0.68. In confirmatory factor analysis the domain structure of the original American CSHQ could not be confirmed. Exploratory factor analysis suggested a 4-factor structure rather than the original 8 domains. The CSHQ seems to have an adequate reliability and moderate internal consistency in a Dutch population with different sociocultural characteristics than the US population in which it was devised. Factor analysis suggests that translation, cultural background, or subscales of the original instrument may affect the performance of the CSHQ.

75 FR 76940 - Specified Tax Return Preparers Required To File Individual Income Tax Returns Using Magnetic...

Science.gov (United States)

2010-12-10

... DEPARTMENT OF THE TREASURY Internal Revenue Service 26 CFR Parts 1 and 301 [REG-100194-10] RIN 1545-BJ52 Specified Tax Return Preparers Required To File Individual Income Tax Returns Using Magnetic... for ``specified tax return prepares,''. FOR FURTHER INFORMATION CONTACT: Keith L. Brau at (202) 622...

Biodiesel production from residual oils recovered from spent bleaching earth

International Nuclear Information System (INIS)

Huang, Yi-Pin; Chang, James I.

2010-01-01

This work was to study technical and economic feasibilities of converting residual oils recovered from spent bleaching earth generated at soybean oil refineries into useable biodiesel. Experimental results showed that fatty acids in the SBE residual oil were hexadecenoic acid (58.19%), stearic acid (21.49%) and oleic acid (20.32%), which were similar to those of vegetable oils. The methyl ester conversion via a transesterification process gave a yield between 85 and 90%. The biodiesel qualities were in reasonable agreement with both EN 14214 and ASTM D6751 standards. A preliminary financial analysis showed that the production cost of biodiesel from SBE oils was significantly lower than the pre-tax price of fossil diesel or those made of vegetable oils or waste cooking oils. The effects of the crude oil price and the investment on the production cost and the investment return period were also conducted. The result showed that the investment would return faster at higher crude oil price. (author)

Destiny's Earth Observation Window

Science.gov (United States)

2002-01-01

Astronaut Michael J. Bloomfield, STS-110 mission commander, looks through the Earth observation window in the Destiny laboratory aboard the International Space Station (ISS). The STS-110 mission prepared the ISS for future spacewalks by installing and outfitting the S0 (S-zero) truss and the Mobile Transporter. The 43-foot-long S0 Truss, weighing in at 27,000 pounds, was the first of 9 segments that will make up the Station's external framework that will eventually stretch 356 feet (109 meters), or approximately the length of a football field. This central truss segment also includes a flatcar called the Mobile Transporter and rails that will become the first 'space railroad,' which will allow the Station's robotic arm to travel up and down the finished truss for future assembly and maintenance. The completed truss structure will hold solar arrays and radiators to provide power and cooling for additional international research laboratories from Japan and Europe that will be attached to the Station. Milestones of the STS-110 mission included the first time the ISS robotic arm was used to maneuver spacewalkers around the Station and marked the first time all spacewalks were based out of the Station's Quest Airlock. It was also the first Shuttle to use three Block II Main Engines. The Space Shuttle Orbiter Atlantis, STS-110 mission, was launched April 8, 2002 and returned to Earth April 19, 2002.

A Perishable Inventory Model with Return

Science.gov (United States)

Setiawan, S. W.; Lesmono, D.; Limansyah, T.

2018-04-01

In this paper, we develop a mathematical model for a perishable inventory with return by assuming deterministic demand and inventory dependent demand. By inventory dependent demand, it means that demand at certain time depends on the available inventory at that time with certain rate. In dealing with perishable items, we should consider deteriorating rate factor that corresponds to the decreasing quality of goods. There are also costs involved in this model such as purchasing, ordering, holding, shortage (backordering) and returning costs. These costs compose the total costs in the model that we want to minimize. In the model we seek for the optimal return time and order quantity. We assume that after some period of time, called return time, perishable items can be returned to the supplier at some returning costs. The supplier will then replace them in the next delivery. Some numerical experiments are given to illustrate our model and sensitivity analysis is performed as well. We found that as the deteriorating rate increases, returning time becomes shorter, the optimal order quantity and total cost increases. When considering the inventory-dependent demand factor, we found that as this factor increases, assuming a certain deteriorating rate, returning time becomes shorter, optimal order quantity becomes larger and the total cost increases.

Planetary protection protecting earth and planets against alien microbes

International Nuclear Information System (INIS)

Leys, N.

2006-01-01

Protecting Earth and planets against the invasion of 'alien life forms' is not military science fiction, but it is the peaceful daily job of engineers and scientists of space agencies. 'Planetary Protection' is preventing microbial contamination of both the target planet and the Earth when sending robots on interplanetary space mission. It is important to preserve the 'natural' conditions of other planets and to not bring with robots 'earthly microbes' (forward contamination) when looking for 'spores of extra terrestrial life'. The Earth and its biosphere must be protected from potential extraterrestrial biological contamination when returning samples of other planets to the Earth (backward contamination). The NASA-Caltech Laboratory for Planetary Protection of Dr. Kasthuri Venkateswaran at the Jet Propulsion Laboratory (JPL) (California, USA) routinely monitors and characterizes the microbes of NASA spacecraft assembly rooms and space robots prior to flight. They have repeatedly isolated Cupriavidus and Ralstonia strains pre-flight from spacecraft assembly rooms (floor and air) and surfaces of space robots such as the Mars Odyssey Orbiter (La Duc et al., 2003). Cupriavidus and Ralstonia strains have also been found in-flight, in ISS cooling water and Shuttle drinking water (Venkateswaran et al., Pyle et al., Ott et al., all unpublished). The main objective of this study is to characterise the Cupriavidus and Ralstonia strains isolated at JPL and compare them to the Cupriavidus metallidurans CH34T model strain, isolated from a Belgian contaminated soil and studied since 25 years at SCK-CEN and to enhance our knowledge by performing additional tests at JPL and gathering information regarding the environmental conditions and the cleaning and isolation methods used in such spacecraft assembling facilities

What Can Nature Teach Us About Improving Earth Science Data Access?

Science.gov (United States)

Young, S.

2012-12-01

Humans have collected earth observations data for centuries, helping us understand present conditions, allowing us to forecast the future, and giving us a window billions of years into the past. In the last 40 years the collection of earth observations data has increased on a truly massive and accelerating scale. Our abilities to collect new data have outpaced our abilities to access and use the data in all the ways users may expect. Mobile technology is a prime example. Smart telephones and tablet devices are proliferating rapidly; by 2016 there likely will be more smartphones than PCs on the planet. Earth data providers need to plan for and evolve to meet the needs, expectations, and capabilities of vast new numbers of mobile users. These users will not only consume data; many of them will also want to provide data via crowdsourcing or "citizen science" efforts. Can we channel the desire to provide citizen data in ways that help to ground-truth other observations, enrich the observations base, and improve data quality? Innovation will be key to meeting such challenges. Is it possible to innovate by studying the past? Does the earth system itself hold lessons that we can apply? We will examine what nature can teach us to foster sustainable innovation in our information technologies. Simplicity enables complexity; understanding complexity requires a return to simplicity. This presentation describes several user scenarios and examples of simplicity-complexity interactions to illustrate the connections with earth science data access.

A Method for Choosing the Best Samples for Mars Sample Return.

Science.gov (United States)

Gordon, Peter R; Sephton, Mark A

2018-05-01

Success of a future Mars Sample Return mission will depend on the correct choice of samples. Pyrolysis-FTIR can be employed as a triage instrument for Mars Sample Return. The technique can thermally dissociate minerals and organic matter for detection. Identification of certain mineral types can determine the habitability of the depositional environment, past or present, while detection of organic matter may suggest past or present habitation. In Mars' history, the Theiikian era represents an attractive target for life search missions and the acquisition of samples. The acidic and increasingly dry Theiikian may have been habitable and followed a lengthy neutral and wet period in Mars' history during which life could have originated and proliferated to achieve relatively abundant levels of biomass with a wide distribution. Moreover, the sulfate minerals produced in the Theiikian are also known to be good preservers of organic matter. We have used pyrolysis-FTIR and samples from a Mars analog ferrous acid stream with a thriving ecosystem to test the triage concept. Pyrolysis-FTIR identified those samples with the greatest probability of habitability and habitation. A three-tier scoring system was developed based on the detection of (i) organic signals, (ii) carbon dioxide and water, and (iii) sulfur dioxide. The presence of each component was given a score of A, B, or C depending on whether the substance had been detected, tentatively detected, or not detected, respectively. Single-step (for greatest possible sensitivity) or multistep (for more diagnostic data) pyrolysis-FTIR methods informed the assignments. The system allowed the highest-priority samples to be categorized as AAA (or A*AA if the organic signal was complex), while the lowest-priority samples could be categorized as CCC. Our methods provide a mechanism with which to rank samples and identify those that should take the highest priority for return to Earth during a Mars Sample Return mission. Key Words

Foreign currency returns and systematic risks

NARCIS (Netherlands)

Galsband, V.; Nitschka, T.

2015-01-01

We apply an empirical approximation of the intertemporal capital asset pricing model (ICAPM) to show that cross-sectional dispersion in currency returns can be rationalized by differences in currency excess returns' sensitivities to the market return's cash-flow news component. This finding echoes

Earth, Wind and Fire. Natural air conditioning; Earth, Wind and Fire. Natuurlijke airconditioning

Energy Technology Data Exchange (ETDEWEB)

Bronsema, B.

2013-06-07

Starting point for the Earth, Wind and Fire research, of which the sub-concepts of Ventec roof, Climate Cascade and Solar Chimney are an integral part of the (Architectural) building design, are the following hypotheses: (1) An integrated approach of Architecture / Constructions and Climate Design is capable of using the available ambient energy in the form of earth mass, wind, and sun, to condition the air mainly naturally in a building; (2) The sub-concepts can be modeled and validated, in order to be able to reliably support the design process in practice; and (3) The sub-concepts can individually or in combination contribute to the realization of zero energy buildings [Dutch] Airconditioning van gebouwen kan volledig met natuurlijke middelen, zonder mechanische ventilatie. Dat stelt de auteur in zijn proefschrift. Hij wil met vallend water, zon en wind een energiepositief kantoor realiseren. Bronsema is nu op zoek naar een gebouw voor een grootschalige praktijkproef met zijn Earth, Wind and Fire-concept. Het systeem bestaat uit drie hoofdonderdelen: het Ventecdak, de Klimaatcascade en de Zonneschoorsteen. Het Ventecdak zorgt voor aanvoer van verse en afvoer van vuile lucht door gebruikmaking van over- en onderdrukken. Die lucht wordt via de klimaatcascade toegevoerd en via een Zonneschoorsteen afgevoerd. Een mock-up van de Zonneschoorsteen is gerealiseerd als een elf meter hoge toren, die met opgevangen warmte van invallend zonlicht ventilatielucht verwarmt. Het op gang brengen van de luchtstroom gebeurt in de Klimaatcascade. Dit is een bouwkundige schacht waarin van bovenaf waterdruppels worden gesproeid waarmee de lucht kan worden gekoeld of verwarmd.

Magnetic force microscopy reveals meta-stable magnetic domain states that prevent reliable absolute palaeointensity experiments

NARCIS (Netherlands)

de Groot, Lennart; Fabian, Karl; Bakelaar, Iman A.; Dekkers, Mark J.

2014-01-01

Obtaining reliable estimates of the absolute palaeointensity of the Earth's magnetic field is notoriously difficult. The heating of samples in most methods induces magnetic alteration-a process that is still poorly understood, but prevents obtaining correct field values. Here we show induced changes

Time domain optical memories using rare earth ions

International Nuclear Information System (INIS)

Sellars, M.J.; Dyke, T.; Pryde, G.J.; Manson, N.B.

1998-01-01

Full text: Rare earth doped crystals are the chosen materials for the next generation of optical memories where the process of spectral holeburning can be employed to provide an extra dimension of frequency or time to spatial dimensions and with certain rare earth ions increases of the order of 10 7 in storage capacity can be achieved over conventional optical memories. Time domain techniques are preferred over frequency domain techniques and are now well developed. In these techniques arbitrary pulse sequences are stored in the material and read out at some later time with a single read pulse using a stimulated photon echo process. Long pulse sequences will enable more data to be stored but necessitates the use of materials with long dephasing times (corresponding to narrow spectral lines) and it is this characteristic of rare earth systems that makes them the preferred material for the new time domain optical memories. The storage time can range from hours to days but in a practical device will require refreshing or re-enforcing and this puts special requirements on the stability of the laser used for storing the information. The storage process itself can also be weak and more reliable storage can be achieved by recording the data several times with the same pulse sequence. For this to be successful the laser must be at held at a constant frequency and be stable in phase over the entire duration of the pulse sequence. The procedure of reinforcing the data sequence has been proposed before and attempted without attention to the laser frequency stability. However, if the laser is not stable although some data bits will be reinforced or increased in size others will be decreased or even erased. Indeed the reliability of the memory is degraded by the introducing the rewrite process. For our work we have developed a laser with the excellent stability and able to demonstrate reproducible reinforcement of the data sequence. Thus with the rewrite sequence we are able to

Biodigester Feasibility and Design for Space & Earth

Science.gov (United States)

Shutts, Stacy; Ewert, Mike; Bacon, Jack

2016-01-01

Anaerobic digestion converts organic waste into methane gas and fertilizer effluent. The ICA-developed prototype system is designed for planetary surface operation. It uses passive hydrostatic control for reliability, and is modular and redundant. The serpentine configuration accommodates tight geometric constraints similar to the ISS ECLSS rack architectures. Its shallow, low-tilt design enables (variable) lower-g convection than standard Earth (1 g) digesters. This technology will reuse and recycle materials including human waste, excess food, as well as packaging (if biodegradable bags are used).

Ultra Reliable Closed Loop Life Support for Long Space Missions

Science.gov (United States)

Jones, Harry W.; Ewert, Michael K.

2010-01-01

Spacecraft human life support systems can achieve ultra reliability by providing sufficient spares to replace all failed components. The additional mass of spares for ultra reliability is approximately equal to the original system mass, provided that the original system reliability is not too low. Acceptable reliability can be achieved for the Space Shuttle and Space Station by preventive maintenance and by replacing failed units. However, on-demand maintenance and repair requires a logistics supply chain in place to provide the needed spares. In contrast, a Mars or other long space mission must take along all the needed spares, since resupply is not possible. Long missions must achieve ultra reliability, a very low failure rate per hour, since they will take years rather than weeks and cannot be cut short if a failure occurs. Also, distant missions have a much higher mass launch cost per kilogram than near-Earth missions. Achieving ultra reliable spacecraft life support systems with acceptable mass will require a well-planned and extensive development effort. Analysis must determine the reliability requirement and allocate it to subsystems and components. Ultra reliability requires reducing the intrinsic failure causes, providing spares to replace failed components and having "graceful" failure modes. Technologies, components, and materials must be selected and designed for high reliability. Long duration testing is needed to confirm very low failure rates. Systems design should segregate the failure causes in the smallest, most easily replaceable parts. The system must be designed, developed, integrated, and tested with system reliability in mind. Maintenance and reparability of failed units must not add to the probability of failure. The overall system must be tested sufficiently to identify any design errors. A program to develop ultra reliable space life support systems with acceptable mass should start soon since it must be a long term effort.

Heating and thermal control of brazing technique to break contamination path for potential Mars sample return

Science.gov (United States)

Bao, Xiaoqi; Badescu, Mircea; Sherrit, Stewart; Bar-Cohen, Yoseph; Campos, Sergio

2017-04-01

The potential return of Mars sample material is of great interest to the planetary science community, as it would enable extensive analysis of samples with highly sensitive laboratory instruments. It is important to make sure such a mission concept would not bring any living microbes, which may possibly exist on Mars, back to Earth's environment. In order to ensure the isolation of Mars microbes from Earth's Atmosphere, a brazing sealing and sterilizing technique was proposed to break the Mars-to-Earth contamination path. Effectively, heating the brazing zone in high vacuum space and controlling the sample temperature for integrity are key challenges to the implementation of this technique. The break-thechain procedures for container configurations, which are being considered, were simulated by multi-physics finite element models. Different heating methods including induction and resistive/radiation were evaluated. The temperature profiles of Martian samples in a proposed container structure were predicted. The results show that the sealing and sterilizing process can be controlled such that the samples temperature is maintained below the level that may cause damage, and that the brazing technique is a feasible approach to breaking the contamination path.

Estimation of High-Frequency Earth-Space Radio Wave Signals via Ground-Based Polarimetric Radar Observations

Science.gov (United States)

Bolen, Steve; Chandrasekar, V.

2002-01-01

Expanding human presence in space, and enabling the commercialization of this frontier, is part of the strategic goals for NASA's Human Exploration and Development of Space (HEDS) enterprise. Future near-Earth and planetary missions will support the use of high-frequency Earth-space communication systems. Additionally, increased commercial demand on low-frequency Earth-space links in the S- and C-band spectra have led to increased interest in the use of higher frequencies in regions like Ku and Ka-band. Attenuation of high-frequency signals, due to a precipitating medium, can be quite severe and can cause considerable disruptions in a communications link that traverses such a medium. Previously, ground radar measurements were made along the Earth-space path and compared to satellite beacon data that was transmitted to a ground station. In this paper, quantitative estimation of the attenuation along the propagation path is made via inter-comparisons of radar data taken from the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) and ground-based polarimetric radar observations. Theoretical relationships between the expected specific attenuation (k) of spaceborne measurements with ground-based measurements of reflectivity (Zh) and differential propagation phase shift (Kdp) are developed for various hydrometeors that could be present along the propagation path, which are used to estimate the two-way path-integrated attenuation (PIA) on the PR return echo. Resolution volume matching and alignment of the radar systems is performed, and a direct comparison of PR return echo with ground radar attenuation estimates is made directly on a beam-by-beam basis. The technique is validated using data collected from the TExas and Florida UNderflights (TEFLUN-B) experiment and the TRMM large Biosphere-Atmosphere experiment in Amazonia (LBA) campaign. Attenuation estimation derived from this method can be used for strategiC planning of communication systems for

The return period analysis of natural disasters with statistical modeling of bivariate joint probability distribution.

Science.gov (United States)

Li, Ning; Liu, Xueqin; Xie, Wei; Wu, Jidong; Zhang, Peng

2013-01-01

New features of natural disasters have been observed over the last several years. The factors that influence the disasters' formation mechanisms, regularity of occurrence and main characteristics have been revealed to be more complicated and diverse in nature than previously thought. As the uncertainty involved increases, the variables need to be examined further. This article discusses the importance and the shortage of multivariate analysis of natural disasters and presents a method to estimate the joint probability of the return periods and perform a risk analysis. Severe dust storms from 1990 to 2008 in Inner Mongolia were used as a case study to test this new methodology, as they are normal and recurring climatic phenomena on Earth. Based on the 79 investigated events and according to the dust storm definition with bivariate, the joint probability distribution of severe dust storms was established using the observed data of maximum wind speed and duration. The joint return periods of severe dust storms were calculated, and the relevant risk was analyzed according to the joint probability. The copula function is able to simulate severe dust storm disasters accurately. The joint return periods generated are closer to those observed in reality than the univariate return periods and thus have more value in severe dust storm disaster mitigation, strategy making, program design, and improvement of risk management. This research may prove useful in risk-based decision making. The exploration of multivariate analysis methods can also lay the foundation for further applications in natural disaster risk analysis. © 2012 Society for Risk Analysis.

Stock return distribution in the BRICS

Directory of Open Access Journals (Sweden)

George Adu

2015-12-01

Full Text Available Stock returns in emerging market economies exhibit patterns that are distinctively different from developed countries: returns are noted to be highly volatile and autocorrelated, and long horizon returns are predictable. While these stylized facts are well established, the assumption underlying the distribution of returns is less understood. In particular, the empirical literature continues to rely on the normality assumption as a starting point, and most asset pricing models tend to overstretch this point. This paper questions the rationale behind this supposition and proceeds to test more formally for normality using multivariate joint test for skewness and kurtosis. Additionally, the paper extends the literature by examining a number of empirical regularities for Brazil, Russia, India, China and South Africa (the BRICS for short. Our main findings are that the distribution of stock returns for the BRICS exhibits peakedness with fatter and longer tails, and this is invariant to both the unit of measurement and the time horizon of returns. Volatility clustering is prevalent in all markets, and this decays exponentially for all but Brazil. The relationship between risk and return is found to be significant and risk premiums are prevalent in our sample.

Risk-return of Belgian SRI funds

OpenAIRE

Van Liedekerke, Luc; De Moor, Lieven; Vanwalleghem, Dieter

2007-01-01

We analyse the risk-return profile of Belgian SRI funds versus conventional investment funds. We apply a four-factor conditional Carhart model to establish whether there are significant differences in risk-return profile between an SRI portfolio and a conventional portfolio and test for learning effects in SRI funds. We show that there is no difference in risk-return profile between SRI and conventional funds. If return is not the problem, then what is it that limits the development of an SRI...

Impact Foam Testing for Multi-Mission Earth Entry Vehicle Applications

Science.gov (United States)

Glaab, Louis J.; Agrawal, Paul; Hawbaker, James

2013-01-01

Multi-Mission Earth Entry Vehicles (MMEEVs) are blunt-body vehicles designed with the purpose of transporting payloads from outer space to the surface of the Earth. To achieve high-reliability and minimum weight, MMEEVs avoid use of limited-reliability systems, such as parachutes and retro-rockets, instead using built-in impact attenuators to absorb energy remaining at impact to meet landing loads requirements. The Multi-Mission Systems Analysis for Planetary Entry (M-SAPE) parametric design tool is used to facilitate the design of MMEEVs and develop the trade space. Testing was conducted to characterize the material properties of several candidate impact foam attenuators to enhance M-SAPE analysis. In the current effort, two different Rohacell foams were tested to determine their thermal conductivity in support of MMEEV design applications. These applications include thermal insulation during atmospheric entry, impact attenuation, and post-impact thermal insulation in support of thermal soak analysis. Results indicate that for these closed-cell foams, the effect of impact is limited on thermal conductivity due to the venting of the virgin material gas and subsequent ambient air replacement. Results also indicate that the effect of foam temperature is significant compared to data suggested by manufacturer's specifications.

7 CFR 3560.305 - Return on investment.

Science.gov (United States)

2010-01-01

... 7 Agriculture 15 2010-01-01 2010-01-01 false Return on investment. 3560.305 Section 3560.305... AGRICULTURE DIRECT MULTI-FAMILY HOUSING LOANS AND GRANTS Financial Management § 3560.305 Return on investment. (a) Borrower's return on investment. Borrowers may receive a return on their investment (ROI) in...

Characteristics of donors who do or do not return to give blood and barriers to their return

Science.gov (United States)

Wevers, Anne; Wigboldus, Daniël H.J.; de Kort, Wim L.A.M.; van Baaren, Rick; Veldhuizen, Ingrid J.T.

2014-01-01

Background In the Netherlands about 50% of whole blood donors return to give blood after an invitation to donate. This study aimed to investigate the characteristics of donor return behaviour and to gain insight into the barriers to blood donation reported by the donors themselves. Materials and methods A total of 4,901 whole blood donors were invited to donate in week 39 of 2009. Barriers mentioned by donors who informed the blood bank for not donating were registered for 1 month. Logistic regression analyses assessed relevant characteristics of return behaviour, such as age and blood type, in men and women separately. Results Of the invited donors, 55% returned to give a donation, whereas 45% did not return. Male donors were more likely to return when they were older, had a higher previous return rate and had no past deferrals. The same pattern was found among women, but was less strong. The main barriers were: time constraints (35%), preference to postpone donation due to general physical problems although being eligible to donate (29%), and being ineligible to donate due to medical deferral criteria (9%). Discussion Specific donor characteristics are associated with return behaviour. Not donating due to time constraints could mean that donors do not feel the urgency of donating blood. Interventions targeted to increase commitment among specific donor groups should be tested further. PMID:23522891

Money growth and aggregate stock returns

OpenAIRE

Böing, Tobias; Stadtmann, Georg

2016-01-01

We empirically evaluate the predictive power of money growth measured by M2 for stock returns of the S&P 500 index. We use monthly US data and predict multiperiod returns over 1, 3, and 5 years with long-horizon regressions. In-sample regressions show that money growth is useful for predicting returns. Higher recent money growth has a significantly negative effect on subsequent returns of the S&P 500. An out-of-sample analysis shows that a simple model with money growth as a single predictor ...

Poetic Return in Afghanistan Persian Poem

Directory of Open Access Journals (Sweden)

Esmaeil Shafagh

2012-11-01

Full Text Available Abstract Poetic return movement was started by a group of poets like Moshtagh and Shole Esfehani in the second half of 12 century. Their goal was restoring Persian poem and deliverance of Hindi style decline. Esfahan’s poets initiative was considered only in Iran but in other Persian language and literature areas like India, Afghanistan and Transoxiana it was ignored. After the failure of constitutional Movement in Afghanistan, motion similar poetic return was happened that caused poetic themes, which had gone towards modernism, return to Hindi style again.The present paper attempts to analyze the poetic atmosphere in Afghanistan synchronous the poetic return movement in Iran and investigate socio- political backgrounds of return to Hindi style in Afghanistan after constitution failure.

Magnetic Partitioning Nanofluid for Rare Earth Extraction from Geothermal Fluids

Energy Technology Data Exchange (ETDEWEB)

McGrail, Bernard P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Thallapally, Praveen K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Liu, Jian [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Nune, Satish K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2017-08-21

Rare earth metals are critical materials in a wide variety of applications in generating and storing renewable energy and in designing more energy efficient devices. Extracting rare earth metals from geothermal brines is a very challenging problem due to the low concentrations of these elements and engineering challenges with traditional chemical separations methods involving packed sorbent beds or membranes that would impede large volumetric flow rates of geothermal fluids transitioning through the plant. We are demonstrating a simple and highly cost-effective nanofluid-based method for extracting rare earth metals from geothermal brines. Core-shell composite nanoparticles are produced that contain a magnetic iron oxide core surrounded by a shell made of silica or metal-organic framework (MOF) sorbent functionalized with chelating ligands selective for the rare earth elements. By introducing the nanoparticles at low concentration (≈0.05 wt%) into the geothermal brine after it passes through the plant heat exchanger, the brine is exposed to a very high concentration of chelating sites on the nanoparticles without need to pass through a large and costly traditional packed bed or membrane system where pressure drop and parasitic pumping power losses are significant issues. Instead, after a short residence time flowing with the brine, the particles are effectively separated out with an electromagnet and standard extraction methods are then applied to strip the rare earth metals from the nanoparticles, which are then recycled back to the geothermal plant. Recovery efficiency for the rare earths at ppm level has now been measured for both silica and MOF sorbents functionalized with a variety of chelating ligands. A detailed preliminary techno-economic performance analysis of extraction systems using both sorbents showed potential to generate a promising internal rate of return (IRR) up to 20%.

Radioactivity observed in the sodium iodide gamma-ray spectrometer returned on the Apollo 17 mission

Science.gov (United States)

Dyer, C. S.; Trombka, J. I.; Schmadebeck, R. L.; Eller, E.; Bielefeld, M. J.; Okelley, G. D.; Eldridge, J. S.; Northcutt, K. J.; Metzger, A. E.; Reedy, R. C.

1975-01-01

In order to obtain information on radioactive background induced in the Apollo 15 and 16 gamma-ray spectrometers (7 cm x 7 cm NaI) by particle irradiation during spaceflight, and identical detector was flown and returned to earth on the Apollo 17 mission. The induced radioactivity was monitored both internally and externally from one and a half hours after splashdown. When used in conjunction with a computation scheme for estimating induced activation from calculated trapped proton and cosmic-ray fluences, these results show an important contribution resulting from both thermal and energetic neutrons produced in the heavy spacecraft by cosmic-ray interactions.

Using Google Earth to conduct a neighborhood audit: reliability of a virtual audit instrument.

Science.gov (United States)

Clarke, Philippa; Ailshire, Jennifer; Melendez, Robert; Bader, Michael; Morenoff, Jeffrey

2010-11-01

Over the last two decades, the impact of community characteristics on the physical and mental health of residents has emerged as an important frontier of research in population health and health disparities. However, the development and evaluation of measures to capture community characteristics is still at a relatively early stage. The purpose of this work was to assess the reliability of a neighborhood audit instrument administered in the city of Chicago using Google Street View by comparing these "virtual" data to those obtained from an identical instrument administered "in-person". We find that a virtual audit instrument can provide reliable indicators of recreational facilities, the local food environment, and general land use. However, caution should be exercised when trying to gather more finely detailed observations. Using the internet to conduct a neighborhood audit has the potential to significantly reduce the costs of collecting data objectively and unobtrusively. Copyright © 2010 Elsevier Ltd. All rights reserved.

Common Factors in International Bond Returns

NARCIS (Netherlands)

Driessen, J.J.A.G.; Melenberg, B.; Nijman, T.E.

2000-01-01

In this paper we estimate and interpret the factors that jointly determine bond returns of different maturities in the US, Germany and Japan.We analyze both currency-hedged and unhedged bond returns.For currency-hedged bond returns, we find that five factors explain 96.5% of the variation of bond

Return-to-work coordination programmes for improving return to work in workers on sick leave.

Science.gov (United States)

Vogel, Nicole; Schandelmaier, Stefan; Zumbrunn, Thomas; Ebrahim, Shanil; de Boer, Wout El; Busse, Jason W; Kunz, Regina

2017-03-30

To limit long-term sick leave and associated consequences, insurers, healthcare providers and employers provide programmes to facilitate disabled people's return to work. These programmes include a variety of coordinated and individualised interventions. Despite the increasing popularity of such programmes, their benefits remain uncertain. We conducted a systematic review to determine the long-term effectiveness of return-to-work coordination programmes compared to usual practice in workers at risk for long-term disability. To assess the effects of return-to-work coordination programmes versus usual practice for workers on sick leave or disability. We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 11), MEDLINE, Embase, CINAHL and PsycINFO up to 1 November 2016. We included randomised controlled trials (RCTs) that enrolled workers absent from work for at least four weeks and randomly assigned them to return-to-work coordination programmes or usual practice. Two review authors independently screened titles, abstracts and full-text articles for study eligibility; extracted data; and assessed risk of bias from eligible trials. We contacted authors for additional data where required. We conducted random-effects meta-analyses and used the GRADE approach to rate the quality of the evidence. We identified 14 studies from nine countries that enrolled 12,568 workers. Eleven studies focused on musculoskeletal problems, two on mental health and one on both. Most studies (11 of 14) followed workers 12 months or longer. Risk of bias was low in 10 and high in 4 studies, but findings were not sensitive to their exclusion.We found no benefits for return-to-work coordination programmes on return-to-work outcomes.For short-term follow-up of six months, we found no effect on time to return to work (hazard ratio (HR) 1.32, 95% confidence interval (CI) 0.93 to 1.88, low-quality evidence), cumulative sickness absence (mean difference (MD) -16.18 work

Management approach recommendations. Earth Observatory Satellite system definition study (EOS)

Science.gov (United States)

1974-01-01

Management analyses and tradeoffs were performed to determine the most cost effective management approach for the Earth Observatory Satellite (EOS) Phase C/D. The basic objectives of the management approach are identified. Some of the subjects considered are as follows: (1) contract startup phase, (2) project management control system, (3) configuration management, (4) quality control and reliability engineering requirements, and (5) the parts procurement program.

26 CFR 301.6103(n)-1 - Disclosure of returns and return information in connection with written contracts or agreements...

Science.gov (United States)

2010-04-01

... administration purposes. 301.6103(n)-1 Section 301.6103(n)-1 Internal Revenue INTERNAL REVENUE SERVICE... and Returns Returns and Records § 301.6103(n)-1 Disclosure of returns and return information in... administration purposes. (a) General rule. (1) Pursuant to the provisions of section 6103(n) of the Internal...

The STS-95 crew participates in a media briefing before returning to JSC

Science.gov (United States)

1998-01-01

The day after their return to Earth on board the orbiter Discovery, members of the STS-95 crew participate in a media briefing at the Kennedy Space Center Press Site Auditorium before returning to the Johnson Space Center in Houston, Texas. From left to right are Lisa Malone, moderator and chief of NASA Public Affairs' Media Services at Kennedy Space Center; Mission Commander Curtis L. Brown Jr.; Pilot Steven W. Lindsey; Mission Specialist and Payload Commander Stephen K. Robinson; Mission Specialist Scott E. Parazynski; Mission Specialist Pedro Duque, with the European Space Agency (ESA); Payload Specialist Chiaki Mukai, with the National Space Development Agency of Japan (NASDA); and Payload Specialist John H. Glenn Jr., a senator from Ohio and one of the original seven Project Mercury astronauts. The STS-95 mission ended with landing at Kennedy Space Center's Shuttle Landing Facility at 12:04 p.m. EST on Nov. 7. The mission included research payloads such as the Spartan-201 solar- observing deployable spacecraft, the Hubble Space Telescope Orbital Systems Test Platform, the International Extreme Ultraviolet Hitchhiker, as well as a SPACEHAB single module with experiments on space flight and the aging process.

LIFE: Life Investigation For Enceladus A Sample Return Mission Concept in Search for Evidence of Life.

Science.gov (United States)

Tsou, Peter; Brownlee, Donald E; McKay, Christopher P; Anbar, Ariel D; Yano, Hajime; Altwegg, Kathrin; Beegle, Luther W; Dissly, Richard; Strange, Nathan J; Kanik, Isik

2012-08-01

Life Investigation For Enceladus (LIFE) presents a low-cost sample return mission to Enceladus, a body with high astrobiological potential. There is ample evidence that liquid water exists under ice coverage in the form of active geysers in the "tiger stripes" area of the southern Enceladus hemisphere. This active plume consists of gas and ice particles and enables the sampling of fresh materials from the interior that may originate from a liquid water source. The particles consist mostly of water ice and are 1-10 μ in diameter. The plume composition shows H(2)O, CO(2), CH(4), NH(3), Ar, and evidence that more complex organic species might be present. Since life on Earth exists whenever liquid water, organics, and energy coexist, understanding the chemical components of the emanating ice particles could indicate whether life is potentially present on Enceladus. The icy worlds of the outer planets are testing grounds for some of the theories for the origin of life on Earth. The LIFE mission concept is envisioned in two parts: first, to orbit Saturn (in order to achieve lower sampling speeds, approaching 2 km/s, and thus enable a softer sample collection impact than Stardust, and to make possible multiple flybys of Enceladus); second, to sample Enceladus' plume, the E ring of Saturn, and the Titan upper atmosphere. With new findings from these samples, NASA could provide detailed chemical and isotopic and, potentially, biological compositional context of the plume. Since the duration of the Enceladus plume is unpredictable, it is imperative that these samples are captured at the earliest flight opportunity. If LIFE is launched before 2019, it could take advantage of a Jupiter gravity assist, which would thus reduce mission lifetimes and launch vehicle costs. The LIFE concept offers science returns comparable to those of a Flagship mission but at the measurably lower sample return costs of a Discovery-class mission.

Space Studies of the Earth-Moon System, Planets, and Small Bodies of the Solar System (B) Past, Present and Future of Small Body Science and Exploration (B0.4)

Science.gov (United States)

Abell, Paul; Mazanek, Dan; Reeves, Dan; Chodas, Paul; Gates, Michele; Johnson, Lindley; Ticker, Ronald

2016-01-01

To achieve its long-term goal of sending humans to Mars, the National Aeronautics and Space Administration (NASA) plans to proceed in a series of incrementally more complex human space flight missions. Today, human flight experience extends only to Low- Earth Orbit (LEO), and should problems arise during a mission, the crew can return to Earth in a matter of minutes to hours. The next logical step for human space flight is to gain flight experience in the vicinity of the Moon. These cis-lunar missions provide a "proving ground" for the testing of systems and operations while still accommodating an emergency return path to the Earth that would last only several days. Cis-lunar mission experience will be essential for more ambitious human missions beyond the Earth-Moon system, which will require weeks, months, or even years of transit time. In addition, NASA has been given a Grand Challenge to find all asteroid threats to human populations and know what to do about them. Obtaining knowledge of asteroid physical properties combined with performing technology demonstrations for planetary defense provide much needed information to address the issue of future asteroid impacts on Earth. Hence the combined objectives of human exploration and planetary defense give a rationale for the Asteroid Re-direct Mission (ARM).

PHYS: Division of Physical Chemistry 258 - Properties and Origins of Cometary and Asteroidal Organic Matter Delivered to the Early Earth

Science.gov (United States)

Messenger, Scott; Nguyen, Ann

2017-01-01

Comets and asteroids may have contributed much of the Earth's water and organic matter. The Earth accretes approximately 4x10(exp 7) Kg of dust and meteorites from these sources every year. The least altered meteorites contain complex assemblages of organic compounds and abundant hydrated minerals. These carbonaceous chondrite meteorites probably derive from asteroids that underwent hydrothermal processing within the first few million years after their accretion. Meteorite organics show isotopic and chemical signatures of low-T ion-molecule and grain-surface chemistry and photolysis of icy grains that occurred in cold molecular clouds and the outer protoplanetary disk. These signatures have been overprinted by aqueously mediated chemistry in asteroid parent bodies, forming amino acids and other prebiotic molecules. Comets are much richer in organic matter but it is less well characterized. Comet dust collected in the stratosphere shows larger H and N isotopic anomalies than most meteorites, suggesting better preservation of primordial organics. Rosetta studies of comet 67P coma dust find complex organic matter that may be related to the macromolecular material that dominates the organic inventory of primitive meteorites. The exogenous organic material accreting on Earth throughout its history is made up of thousands of molecular species formed in diverse processes ranging from circumstellar outflows to chemistry at near absolute zero in dark cloud cores and the formative environment within minor planets. NASA and JAXA are currently flying sample return missions to primitive, potentially organic-rich asteroids. The OSIRIS-REx and Hayabusa2 missions will map their target asteroids, Bennu and Ryugu, in detail and return regolith samples to Earth. Laboratory analyses of these pristine asteroid samples will provide unprecedented views of asteroidal organic matter relatively free of terrestrial contamination within well determined geological context. Studies of

Computing the distribution of return levels of extreme warm temperatures for future climate projections

Energy Technology Data Exchange (ETDEWEB)

Pausader, M.; Parey, S.; Nogaj, M. [EDF/R and D, Chatou Cedex (France); Bernie, D. [Met Office Hadley Centre, Exeter (United Kingdom)

2012-03-15

In order to take into account uncertainties in the future climate projections there is a growing demand for probabilistic projections of climate change. This paper presents a methodology for producing such a probabilistic analysis of future temperature extremes. The 20- and 100-years return levels are obtained from that of the normalized variable and the changes in mean and standard deviation given by climate models for the desired future periods. Uncertainty in future change of these extremes is quantified using a multi-model ensemble and a perturbed physics ensemble. The probability density functions of future return levels are computed at a representative location from the joint probability distribution of mean and standard deviation changes given by the two combined ensembles of models. For the studied location, the 100-years return level at the end of the century is lower than 41 C with an 80% confidence. Then, as the number of model simulations is low to compute a reliable distribution, two techniques proposed in the literature (local pattern scaling and ANOVA) have been used to infer the changes in mean and standard deviation for the combinations of RCM and GCM which have not been run. The ANOVA technique leads to better results for the reconstruction of the mean changes, whereas the two methods fail to correctly infer the changes in standard deviation. As standard deviation change has a major impact on return level change, there is a need to improve the models and the different techniques regarding the variance changes. (orig.)

Knee functions and a return to sports activity in competitive athletes following anterior cruciate ligament reconstruction.

Science.gov (United States)

Nakayama, Y; Shirai, Y; Narita, T; Mori, A; Kobayashi, K

2000-06-01

We investigated knee functions and a return to sports in 50 competitive athlete patients treated with arthroscopic anterior cruciate ligament reconstruction using double-looped STG augmented by woven polyester at a 1-year follow-up. There were 25 males and 25 females with a mean age of 24.3 years (range: 19-39 years). The majority of preinjury sports were basketball, volleyball and soccer. Athletic rehabilitation including agility training and sports-specific training was started at 12 weeks. Fourty patients (80%) was rated as normal or nearly normal on the assessment of International Knee Documentation Commitee postoperatively. Fourty-eight patients (96%) obtained full range of motion, and the mean quadriceps muscle strength of the injured side was 91.3%of that of the uninjured side. As for a return to sports, 46 patients (92%) were able to do fully competitive sports at a mean of 8.1 postoperative months. These results suggest that arthroscopic reconstruction using augmented double-looped STG allows early athletic rehabilitation, and lead satisfactory outcome as well as a reliable and early return to preinjury level of sport activity for the majority of the competitive athlete patients.

Utility allowed returns and market extremes

International Nuclear Information System (INIS)

Murry, D.A.; Nan, G.D.; Harrington, B.M.

1993-01-01

In recent years interest rates have fluctuated from exceptionally high levels in the early 1980s to their current levels, the lowest in two decades. Observers and analysts generally have assumed that allowed returns by regulatory commissions follow the movement of interest rates; indeed some analysts use a risk premium method to estimate the cost of common equity, assuming a constant and linear relationship between interest rates and the cost of common equity. That suggests we could expect a relatively stable relationship between interest rates and allowed returns, as well. However, a simple comparison of allowed returns and interest rates shows that this is not the case in recent years. The relationship between market interest rates and the returns allowed by commissions varies and is obviously a great deal more complicated. Empirically, there appears to be only a narrow range where market interest rates significantly affect the allowed returns on common stock set by state commissions, at least for electric and combination utilities. If rates are at historically low levels, allowed returns based largely on market rates will hasten subsequent rate filings, and commissions appear to look beyond the low rate levels. Conversely, it appears that regulators do not let historically high market rates determine allowed returns either. At either high or low interest levels, caution seems to be the policy

Return to sports after shoulder arthroplasty

Science.gov (United States)

Johnson, Christine C; Johnson, Daniel J; Liu, Joseph N; Dines, Joshua S; Dines, David M; Gulotta, Lawrence V; Garcia, Grant H

2016-01-01

Many patients prioritize the ability to return to sports following shoulder replacement surgeries, including total shoulder arthroplasty (TSA), reverse total shoulder arthroplasty (RTSA), and hemiarthroplasty (HA). While activity levels after hip and knee replacements have been well-established in the literature, studies on this topic in the field of shoulder arthroplasty are relatively limited. A review of the literature regarding athletic activity after shoulder arthroplasty was performed using the PubMed database. All studies relevant to shoulder arthroplasty and return to sport were included. The majority of patients returned to their prior level of activity within six months following TSA, RTSA, and shoulder HA. Noncontact, low demand activities are permitted by most surgeons postoperatively and generally have higher return rates than contact sports or high-demand activities. In some series, patients reported an improvement in their ability to participate in sports following the arthroplasty procedure. The rates of return to sports following TSA (75%-100%) are slightly higher than those reported for HA (67%-76%) and RTSA (75%-85%). Patients undergoing TSA, RTSA, and shoulder HA should be counseled that there is a high probability that they will be able to return to their preoperative activity level within six months postoperatively. TSA has been associated with higher rates of return to sports than RTSA and HA, although this may reflect differences in patient population or surgical indication. PMID:27672564

On low-resistance neutral earthing mode in 20 kV overhead and cable networks

Directory of Open Access Journals (Sweden)

Mayorov Andrey

2017-01-01

Full Text Available The problems of justification and selection of the required single-phase short-circuit current values in cable and overhead networks of 20 kV with low-resistance neutral earthing are considered. It is shown that the desired values of the short-circuit current can be determined on the basis of harmonization of conflicting influencing factors: reliability of the relay protection and automation devices and required resistances of the earthing devices of electrical installations, including personnel safety. In this case, the main influencing factor is the electrical network structure and parameters

26 CFR 301.6019-1 - Gift tax returns.

Science.gov (United States)

2010-04-01

... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Gift tax returns. 301.6019-1 Section 301.6019-1... ADMINISTRATION PROCEDURE AND ADMINISTRATION Information and Returns Returns and Records § 301.6019-1 Gift tax returns. For provisions relating to requirement of gift tax returns, see §§ 25.6019-1 to 25.6019-4...

Reliability engineering

International Nuclear Information System (INIS)

Lee, Chi Woo; Kim, Sun Jin; Lee, Seung Woo; Jeong, Sang Yeong

1993-08-01

This book start what is reliability? such as origin of reliability problems, definition of reliability and reliability and use of reliability. It also deals with probability and calculation of reliability, reliability function and failure rate, probability distribution of reliability, assumption of MTBF, process of probability distribution, down time, maintainability and availability, break down maintenance and preventive maintenance design of reliability, design of reliability for prediction and statistics, reliability test, reliability data and design and management of reliability.

Stock Returns and Risk: Evidence from Quantile

Directory of Open Access Journals (Sweden)

Thomas C. Chiang

2012-12-01

Full Text Available This paper employs weighted least squares to examine the risk-return relation by applying high-frequency data from four major stock indexes in the US market and finds some evidence in favor of a positive relation between the mean of the excess returns and expected risk. However, by using quantile regressions, we find that the risk-return relation moves from negative to positive as the returns’ quantile increases. A positive risk-return relation is valid only in the upper quantiles. The evidence also suggests that intraday skewness plays a dominant role in explaining the variations of excess returns.

Sun-Earth National Program. 2006-2009 results and prospects

International Nuclear Information System (INIS)

Fontaine, Dominique; Vilmer, Nicole

2010-01-01

PNST (Programme National Soleil-Terre/Sun-Earth National Program) is dedicated to analysis of the Sun-Earth system, from generation of the solar magnetic field, flares and coronal mass ejections, until impact on the terrestrial magnetosphere, ionosphere and thermosphere. Research activities carried out in the frame of Programme National Soleil-Terre (PNST) rely on both ground-based and space-borne instruments. One of the main objectives of PNST is to stimulate coordinated studies and to optimize scientific return of these instruments. This document is the 2006-2009 scientific report of the program. It presents in the introduction some highlights, the main questions, the thematic reviews and the forces and weaknesses of the program. Then, part 2 is a review of the main scientific questions: mechanisms at the origin of the eruptive activity in plasmas; mechanisms involved in particles heating and acceleration; energy transfers at different scales in the plasma and dynamics of turbulence in this anisotropic medium; coupling mechanisms between the different plasma envelopes; Sun-Earth relations and space meteorology; interfaces with other programs (planetary plasmas, magnetism and sun-type stars activity). Part 3 presents the results and prospects of the ground and space instrumentation, of databases and numerical tools. Finally, the administrative and financial status of the program is summarized (Program structure and operation, budget, manpower, publications)

Space as a Tool for Astrobiology: Review and Recommendations for Experimentations in Earth Orbit and Beyond

Science.gov (United States)

Cottin, Hervé; Kotler, Julia Michelle; Billi, Daniela; Cockell, Charles; Demets, René; Ehrenfreund, Pascale; Elsaesser, Andreas; d'Hendecourt, Louis; van Loon, Jack J. W. A.; Martins, Zita; Onofri, Silvano; Quinn, Richard C.; Rabbow, Elke; Rettberg, Petra; Ricco, Antonio J.; Slenzka, Klaus; de la Torre, Rosa; de Vera, Jean-Pierre; Westall, Frances; Carrasco, Nathalie; Fresneau, Aurélien; Kawaguchi, Yuko; Kebukawa, Yoko; Nguyen, Dara; Poch, Olivier; Saiagh, Kafila; Stalport, Fabien; Yamagishi, Akihiko; Yano, Hajime; Klamm, Benjamin A.

2017-07-01

The space environment is regularly used for experiments addressing astrobiology research goals. The specific conditions prevailing in Earth orbit and beyond, notably the radiative environment (photons and energetic particles) and the possibility to conduct long-duration measurements, have been the main motivations for developing experimental concepts to expose chemical or biological samples to outer space, or to use the reentry of a spacecraft on Earth to simulate the fall of a meteorite. This paper represents an overview of past and current research in astrobiology conducted in Earth orbit and beyond, with a special focus on ESA missions such as Biopan, STONE (on Russian FOTON capsules) and EXPOSE facilities (outside the International Space Station). The future of exposure platforms is discussed, notably how they can be improved for better science return, and how to incorporate the use of small satellites such as those built in cubesat format.

Earth as an Exoplanet: Lessons in Recognizing Planetary Habitability

Science.gov (United States)

Meadows, Victoria; Robinson, Tyler; Misra, Amit; Ennico, Kimberly; Sparks, William B.; Claire, Mark; Crisp, David; Schwieterman, Edward; Bussey, D. Ben J.; Breiner, Jonathan

2015-01-01

Earth will always be our best-studied example of a habitable world. While extrasolar planets are unlikely to look exactly like Earth, they may share key characteristics, such as oceans, clouds and surface inhomogeneity. Earth's globally-averaged characteristics can therefore help us to recognize planetary habitability in data-limited exoplanet observations. One of the most straightforward ways to detect habitability will be via detection of 'glint', specular reflectance from an ocean (Robinson et al., 2010). Other methods include undertaking a census of atmospheric greenhouse gases, or attempting to measure planetary surface temperature and pressure, to determine if liquid water would be feasible on the planetary surface. Here we present recent research on detecting planetary habitability, led by the NASA Astrobiology Institute's Virtual Planetary Laboratory Team. This work includes a collaboration with the NASA Lunar Science Institute on the detection of ocean glint and ozone absorption using Lunar Crater Observation and Sensing Satellite (LCROSS) Earth observations (Robinson et al., 2014). This data/model comparison provides the first observational test of a technique that could be used to determine exoplanet habitability from disk-integrated observations at visible and near-infrared wavelengths. We find that the VPL spectral Earth model is in excellent agreement with the LCROSS Earth data, and can be used to reliably predict Earth's appearance at a range of phases relevant to exoplanet observations. Determining atmospheric surface pressure and temperature directly for a potentially habitable planet will be challenging due to the lack of spatial-resolution, presence of clouds, and difficulty in spectrally detecting many bulk constituents of terrestrial atmospheres. Additionally, Rayleigh scattering can be masked by absorbing gases and absorption from the underlying surface. However, new techniques using molecular dimers of oxygen (Misra et al., 2014) and nitrogen

Return to Golf After Lumbar Fusion.

Science.gov (United States)

Shifflett, Grant D; Hellman, Michael D; Louie, Philip K; Mikhail, Christopher; Park, Kevin U; Phillips, Frank M

Spinal fusion surgery is being increasingly performed, yet few studies have focused on return to recreational sports after lumbar fusion and none have specifically analyzed return to golf. Most golfers successfully return to sport after lumbar fusion surgery. Case series. Level 4. All patients who underwent 1- or 2-level primary lumbar fusion surgery for degenerative pathologies performed by a single surgeon between January 2008 and October 2012 and had at least 1-year follow-up were included. Patients completed a specifically designed golf survey. Surveys were mailed, given during follow-up clinic, or answered during telephone contact. A total of 353 patients met the inclusion and exclusion criteria, with 200 responses (57%) to the questionnaire producing 34 golfers. The average age of golfers was 57 years (range, 32-79 years). In 79% of golfers, preoperative back and/or leg pain significantly affected their ability to play golf. Within 1 year from surgery, 65% of patients returned to practice and 52% returned to course play. Only 29% of patients stated that continued back/leg pain limited their play. Twenty-five patients (77%) were able to play the same amount of golf or more than before fusion surgery. Of those providing handicaps, 12 (80%) reported the same or an improved handicap. More than 50% of golfers return to on-course play within 1 year of lumbar fusion surgery. The majority of golfers can return to preoperative levels in terms of performance (handicap) and frequency of play. This investigation offers insight into when golfers return to sport after lumbar fusion surgery and provides surgeons with information to set realistic expectations postoperatively.

Role of impact cratering for Mars sample return

International Nuclear Information System (INIS)

Schultz, P.H.

1988-01-01

The preserved cratering record of Mars indicates that impacts play an important role in deciphering Martian geologic history, whether as a mechanism to modify the lithosphere and atmosphere or as a tool to sample the planet. The various roles of impact cratering in adding a broader understanding of Mars through returned samples are examined. Five broad roles include impact craters as: (1) a process in response to a different planetary localizer environment; (2) a probe for excavating crustal/mantle materials; (3) a possible localizer of magmatic and hydrothermal processes; (4) a chronicle of changes in the volcanic, sedimentary, atmospheric, and cosmic flux history; and (5) a chronometer for extending the geologic time scale to unsampled regions. The evidence for Earth-like processes and very nonlunar styles of volcanism and tectonism may shift the emphasis of a sampling strategy away from equally fundamental issues including crustal composition, unit ages, and climate history. Impact cratering not only played an important active role in the early Martian geologic history, it also provides an important tool for addressing such issues

Simultaneous determination of dysprosium, holmium and erbium in high purity rare earth oxides by second order derivative spectrophotometry

International Nuclear Information System (INIS)

Anbu, M.; Prasada Rao, T.; Iyer, C. S. P.; Damodaran, A. D.

1996-01-01

High purity individual rare earth oxides are increasingly used as major components in lasers (Y 2 O 3 ), phosphors (YVO 3 , Eu 2 O 3 ), magnetic bubble memory films (Gd 2 O 3 ) and refractive-index lenses and fibre optics (La 2 O 3 ). The determination of individual lanthanides in high purity rare earth oxides is a more important and difficult task. This paper reports the utilization of higher order derivative spectrophotometry for the simultaneous determination of dysprosium, holmium and erbium in high purity rare earth oxides. The developed procedure is simple, reliable and allows the determination of 0.001 to 0.2% of dysprosium, holmium and erbium in several rare earth. (author). 9 refs, 2 figs, 2 tabs

Does Aggregated Returns Disclosure Increase Portfolio Risk Taking?

Science.gov (United States)

Beshears, John; Choi, James J; Laibson, David; Madrian, Brigitte C

2017-06-01

Many experiments have found that participants take more investment risk if they see returns less frequently, see portfolio-level returns (rather than each individual asset's returns), or see long-horizon (rather than one-year) historical return distributions. In contrast, we find that such information aggregation treatments do not affect total equity investment when we make the investment environment more realistic than in prior experiments. Previously documented aggregation effects are not robust to changes in the risky asset's return distribution or the introduction of a multi-day delay between portfolio choice and return realizations.

Catching Stardust and Bringing it Home: The Astronomical Importance of Sample Return

Science.gov (United States)

Brownlee, D.

2002-12-01

The return of lunar samples by the Apollo program provided the first opportunity to perform detailed laboratory studies of ancient solid materials from a known astronomical body. The highly detailed study of the samples, using the best available laboratory instruments and techniques, revolutionized our understanding of the Moon and provided fundamental insight into the remarkable and violent processes that occur early in the history of moons and terrestrial planets. This type of astronomical paleontology is only possible with samples and yet the last US sample return was made by Apollo 17- over thirty years ago! The NASA Stardust mission, began a new era of sample missions with its 1999 launch to retrieve samples from the short period comet Wild 2. Genesis (a solar wind collector) was launched in 2001, the Japanese MUSES-C asteroid sample return mission will launch in 2003 and Mars sample return missions are under study. All of these missions will use sophisticated ground-based instrumentation to provide types of information that cannot be obtained by astronomical and spacecraft remote sensing methods. In the case of Stardust, the goal is to determine the fundamental nature of the initial solid building blocks of solar systems at atomic-scale spatial resolution. The samples returned by the mission will be samples from the Kuiper Belt region and they are probably composed of submicron silicate and organic materials of both presolar and nebular origin. Unlocking the detailed records contained in the elemental, chemical, isotopic and mineralogical composition of these tiny components can only be appropriately explored with full power, precision and flexibility of laboratory instrumentation. Laboratory instrumentation has the advantage that is state-of-the-art and is not limited by serious considerations of power, mass, cost or even reliability. The comparison of the comet sample, accumulated beyond Neptune, with asteroidal meteorites that accumulated just beyond the

Earth, Wind and Fire. Natural air conditioning. Part 1. Research aims and methods; Earth, Wind and Fire. Natuurlijke airconditioning. Deel 1. Onderzoeksdoelen en -methoden

Energy Technology Data Exchange (ETDEWEB)

Bronsema, B. [Afdeling Architectural Engineering en Technology, Faculteit Bouwkunde, Technische Universiteit Delft TUD, Delft (Netherlands)

2013-07-15

The Earth, Wind and Fire concept transforms a building into a 'climate machine' which is powered by the natural forces and energy of the sun, wind, the mass of the earth and gravity. This concept consists of a Climate Cascade, a solar chimney and a Ventec roof, which have been tested in physical mock-ups. Simulation models have been validated on the basis of real measurements. This work has resulted in the creation of reliable tools for design practice [Dutch] Het Earth, Wind en Fire-concept voor natuurlijke airconditioning biedt meer zekerheid voor het realiseren van energieneutrale kantoorgebouwen dan mogelijk zou zijn door verbetering van bestaande technieken. Het concept maakt gebruik van de omgevingsenergie van aardmassa, wind en zon. Enerzijds wordt deze energie passief gebruikt voor het realiseren van een natuurlijke airconditioning, waarbij de gewenste luchtstromingen tot stand komen onder invloed van thermisch gedreven drukverschillen. Anderzijds worden zon en wind benut voor actieve energieopwekking, waardoor een gebouw in principe energieneutraal kan worden. Een dergelijk gebouw kan worden beschouwd als 'klimaatmachine', geactiveerd door zwaartekracht, wind en zon.

A Geochemical View on the Interplay Between Earth's Mantle and Crust

Science.gov (United States)

Chauvel, C.

2017-12-01

Over most of Earth history, oceanic and continental crust was created and destroyed. The formation of both types of crust involves the crystallization and differentiation of magmas producing by mantle melting. Their destruction proceeds by mechanical erosion and weathering above sea level, chemical alteration on the seafloor, and bulk recycling in subduction zones. All these processes enrich of some chemical element and deplete others but each process has its own effect on chemical elements. While the flux of material from mantle to crust is well understood, the return flux is much more complex. In contrast to mantle processes, erosion, weathering, chemical alteration and sedimentary processes strongly decouple elements such as the rare earths and high-field strength elements due to their different solubilities in surface fluids and mineralogical sorting during transport. Soluble elements such as strontium or uranium are quantitatively transported to the ocean by rivers and decoupled from less soluble elements. Over geological time, such decoupling significantly influences the extent to which chemical elements remain at the Earth's surface or find their way back to the mantle through subduction zones. For example, elements like Hf or Nd are retained in heavy minerals on continents whereas U and Sr are transported to the oceans and then in subduction zones to the mantle. The consequence is that different radiogenic isotopic systems give disparate age estimates for the continental crust; e.g, Hf ages could be too old. In subduction zones, chemical elements are also decoupled, due to contrasting behavior during dehydration or melting in subducting slabs. The material sent back into the mantle is generally enriched in non-soluble elements while most fluid-mobile elements return to the crust. This, in turn, affects the relationship between the Rb-Sr, Sm-Nd, Lu-Hf and U-Th-Pb isotopic systems and creates correlations unlike those based on magmatic processes. By

Is skeletal muscle ready for long-term spaceflight and return to gravity?

Science.gov (United States)

Riley, D. A.

1999-01-01

It is now clear that prevention of muscle debilitation during spaceflight will require a broader approach than simple exercise aimed at strengthening of the muscle fibers. The levels of several hormones and receptors are altered by unloading and must be returned to homeostasis. Pharmacotherapy and gene transfer strategies to raise the relative level of structural proteins may minimize the problems faced by astronauts in readapting to Earth-gravity. Up to now, we have only minimally exploited microgravity for advancing our understanding of muscle biology. A research laboratory in the space station with a centrifuge facility (gravity control) is essential for conducting basic research in this field. Microgravity has proven an excellent tool for noninvasively perturbing the synthesis of muscle proteins in the search for molecular signals and gene regulatory factors influencing differentiation, growth, maintenance and atrophy of muscle. Understanding the relation between blood flow and interstitial edema and between workload and subsequent structural failure are but two important problems that require serious attention. The roles of hormones and growth factors in regulating gene expression and their microgravity-induced altered production are other urgent issues to pursue. These types of studies will yield information that advances basic knowledge of muscle biology and offers insights into countermeasure design. This knowledge is likely to assist rehabilitation of diseased or injured muscles in humans on Earth, especially individuals in the more vulnerable aging population and persons participating in strenuous sports. Will the skeletal muscle system be prepared for the increased exposure to microgravity and the return to gravity loading without injury when space station is operational? The answer depends in large part on continued access to space and funding of ground-based models and flight experiments. The previous two decades of spaceflight research have described

Automatic collection of the rare-earths with post chromatography column detection

International Nuclear Information System (INIS)

David, P.; Metzger, G.; Repellin, M.

1987-01-01

The complete separation of rare-earths (in the aim of radio-isotopes measurement) requires High Performance Liquid Chromatography with ternary elution gradient. To automatize their collection with satisfying conditions, we have realized a non polluting, reliable and easy to operate detection method. This one is based on a derivation colorimetric system with arsenazo I (3 -(2 arsophenylazo 4.5) - dihydroxy - 2.7 naphtalene disulfonic acid)

Does Aggregated Returns Disclosure Increase Portfolio Risk Taking?

Science.gov (United States)

Beshears, John; Choi, James J.; Laibson, David; Madrian, Brigitte C.

2016-01-01

Many experiments have found that participants take more investment risk if they see returns less frequently, see portfolio-level returns (rather than each individual asset’s returns), or see long-horizon (rather than one-year) historical return distributions. In contrast, we find that such information aggregation treatments do not affect total equity investment when we make the investment environment more realistic than in prior experiments. Previously documented aggregation effects are not robust to changes in the risky asset’s return distribution or the introduction of a multi-day delay between portfolio choice and return realizations. PMID:28553012

Converting the ISS to an Earth-Moon Transport System Using Nuclear Thermal Propulsion

International Nuclear Information System (INIS)

Paniagua, John; Maise, George; Powell, James

2008-01-01

Using Nuclear Thermal Propulsion (NTP), the International Space Station (ISS) can be placed into a cyclic orbit between the Earth and the Moon for 2-way transport of personnel and supplies to a permanent Moon Base. The ISS cycler orbit apogees 470,000 km from Earth, with a period of 13.66 days. Once a month, the ISS would pass close to the Moon, enabling 2-way transport between it and the surface using a lunar shuttle craft. The lunar shuttle craft would land at a desired location on the surface during a flyby and return to the ISS during a later flyby. At Earth perigee 7 days later at 500 km altitude, there would be 2-way transport between it and Earth's surface using an Earth shuttle craft. The docking Earth shuttle would remain attached to the ISS as it traveled towards the Moon, while personnel and supplies transferred to a lunar shuttle spacecraft that would detach and land at the lunar base when the ISS swung around the Moon. The reverse process would be carried out to return personnel and materials from the Moon to the Earth. The orbital mechanics for the ISS cycle are described in detail. Based on the full-up mass of 400 metric tons for the ISS, an ISP of 900 seconds, and a delta V burn of 3.3 km/sec to establish the orbit, 200 metric tons of liquid H-2 propellant would be required. The 200 metric tons could be stored in 3 tanks, each 8 meters in diameter and 20 meters in length. An assembly of 3 MITEE NTP engines would be used, providing redundancy if an engine were to fail. Two different MITEE design options are described. Option 1 is an 18,000 Newton, 100 MW engine with a thrust to weight ratio of 6.6/1; Option 2 is a 180,000 Newton, 1000 MW engine with a thrust to weight ratio of 23/1. Burn times to establish the orbit are ∼1 hour for the large 3 engine assembly, and 10 hours for the small 3 engine assembly. Both engines would use W-UO2 cermet fuel at ∼2750 K which has demonstrated the capability to operate for at least 50 hours in 2750 K hydrogen

Residential PV system users' perception of profitability, reliability, and failure risk: An empirical survey in a local Japanese municipality

International Nuclear Information System (INIS)

Mukai, Toshihiro; Kawamoto, Shishin; Ueda, Yuzuru; Saijo, Miki; Abe, Naoya

2011-01-01

Although previous studies have addressed the reliability of residential PV systems in order to improve the dissemination of the systems among individual users and societies, few have examined users' perception of their own PV systems, which might contain solutions to firmly establish the system into society. First, the present paper examined the extent to which residential PV system users understand specification, reliability, and failure risk of their own systems. Second, causal factors affecting users' satisfaction with PV systems were examined. By analyzing data collected in Kakegawa City, this paper revealed that users did not appropriately understand the basic specifications of their residential PV systems, and in particular, the fact that the systems sometimes failed and therefore needed proper maintenance. Furthermore, a strong causal relationship between users' expectations of financial return from the system and their level of satisfaction was confirmed empirically. These results suggested that excessive focus on profitability and relatively low interest in the systems' reliability and failure risk should be addressed more to avoid problems that could potentially hamper the establishment of this technology into society. - Highlights: → We examined PV users' perception of its specification, reliability, and failure risk. → Data for analysis were collected by questionnaire survey in a Japanese local municipality. → We revealed users did not appropriately understand the basic specifications. → A strong causal relationship between users' expectations of financial return and their level of satisfaction was confirmed empirically.

Dynamic Acquisition and Retrieval Tool (DART) for Comet Sample Return : Session: 2.06.Robotic Mobility and Sample Acquisition Systems

Science.gov (United States)

Badescu, Mircea; Bonitz, Robert; Kulczycki, Erick; Aisen, Norman; Dandino, Charles M.; Cantrell, Brett S.; Gallagher, William; Shevin, Jesse; Ganino, Anthony; Haddad, Nicolas;

An Earth-sized planet with an Earth-like density.

Science.gov (United States)

Pepe, Francesco; Cameron, Andrew Collier; Latham, David W; Molinari, Emilio; Udry, Stéphane; Bonomo, Aldo S; Buchhave, Lars A; Charbonneau, David; Cosentino, Rosario; Dressing, Courtney D; Dumusque, Xavier; Figueira, Pedro; Fiorenzano, Aldo F M; Gettel, Sara; Harutyunyan, Avet; Haywood, Raphaëlle D; Horne, Keith; Lopez-Morales, Mercedes; Lovis, Christophe; Malavolta, Luca; Mayor, Michel; Micela, Giusi; Motalebi, Fatemeh; Nascimbeni, Valerio; Phillips, David; Piotto, Giampaolo; Pollacco, Don; Queloz, Didier; Rice, Ken; Sasselov, Dimitar; Ségransan, Damien; Sozzetti, Alessandro; Szentgyorgyi, Andrew; Watson, Christopher A

2013-11-21

Recent analyses of data from the NASA Kepler spacecraft have established that planets with radii within 25 per cent of the Earth's (R Earth symbol) are commonplace throughout the Galaxy, orbiting at least 16.5 per cent of Sun-like stars. Because these studies were sensitive to the sizes of the planets but not their masses, the question remains whether these Earth-sized planets are indeed similar to the Earth in bulk composition. The smallest planets for which masses have been accurately determined are Kepler-10b (1.42 R Earth symbol) and Kepler-36b (1.49 R Earth symbol), which are both significantly larger than the Earth. Recently, the planet Kepler-78b was discovered and found to have a radius of only 1.16 R Earth symbol. Here we report that the mass of this planet is 1.86 Earth masses. The resulting mean density of the planet is 5.57 g cm(-3), which is similar to that of the Earth and implies a composition of iron and rock.

Towards earth AntineutRino TomograpHy (EARTH)

NARCIS (Netherlands)

De Meijer, R. J.; Smit, F. D.; Brooks, F. D.; Fearick, R. W.; Wortche, H. J.; Mantovani, F.

2006-01-01

The programme Earth AntineutRino TomograpHy (EARTH) proposes to build ten underground facilities each hosting a telescope. Each telescope consists of many detector modules, to map the radiogenic heat sources deep in the interior of the Earth by utilising direction sensitive geoneutrino detection.

Solar sail trajectory design in the Earth-Moon circular restricted three body problem

Science.gov (United States)

Das, Ashwati

The quest to explore the Moon has helped resolve scientific questions, has spurred leaps in technology development, and has revealed Earth's celestial companion to be a gateway to other destinations. With a renewed focus on returning to the Moon in this decade, alternatives to chemical propulsion systems are becoming attractive methods to efficiently use scarce resources and support extended mission durations. Thus, an investigation is conducted to develop a general framework, that facilitates propellant-free Earth-Moon transfers by exploiting sail dynamics in combination with advantageous transfer options offered in the Earth-Moon circular restricted multi-body dynamical model. Both periodic orbits in the vicinity of the Earth-Moon libration points, and lunar-centric long-term capture orbits are incorporated as target destinations to demonstrate the applicability of the general framework to varied design scanarios, each incorporating a variety of complexities and challenges. The transfers are comprised of three phases - a spiral Earth escape, a transit period, and, finally, the capture into a desirable orbit in the vicinity of the Moon. The Earth-escape phase consists of spiral trajectories constructed using three different sail steering strategies - locally optimal, on/off and velocity tangent. In the case of the Earth-libration point transfers, naturally occurring flow structures (e.g., invariant manifolds) arising from the mutual gravitational interaction of the Earth and Moon are exploited to link an Earth departure spiral with a destination orbit. In contrast, sail steering alone is employed to establish a link between the Earth-escape phase and capture orbits about the Moon due to a lack of applicable natural structures for the required connection. Metrics associated with the transfers including flight-time and the influence of operational constraints, such as occultation events, are investigated to determine the available capabilities for Earth

Are there Diminishing Returns to R&D?

DEFF Research Database (Denmark)

Madsen, Jakob B.

Semi-endogenous models and, to some extent, also Schumpeterian models are based on the assumption of diminishing returns to R&D. This paper shows that the null hypothesis of constant returns to R&D cannot be rejected for the OECD countries......Semi-endogenous models and, to some extent, also Schumpeterian models are based on the assumption of diminishing returns to R&D. This paper shows that the null hypothesis of constant returns to R&D cannot be rejected for the OECD countries...

NEOCAM: Near Earth Object Chemical Analysis Mission: Bridging the Gulf between Telescopic Observations and the Chemical and Mineralogical Compositions of Asteroids or Diogenes A: Diagnostic Observation of the Geology of Near Earth Spectrally-Classified Asteroids

Science.gov (United States)

Nuth, Joseph A.

2009-01-01

Studies of meteorites have yielded a wealth of scientific information based on highly detailed chemical and isotopic studies possible only in sophisticated terrestrial laboratories. Telescopic studies have revealed an enormous (greater than 10(exp 5)) number of physical objects ranging in size from a few tens of meters to several hundred kilometers, orbiting not only in the traditional asteroid belt between Mars and Jupiter but also throughout the inner solar system. Many of the largest asteroids are classed into taxonomic groups based on their observed spectral properties and are designated as C, D. X, S or V types (as well as a wide range in sub-types). These objects are certainly the sources far the meteorites in our laboratories, but which asteroids are the sources for which meteorites? Spectral classes are nominally correlated to the chemical composition and physical characteristics of the asteroid itself based on studies of the spectral changes induced in meteorites due to exposure to a simulated space environment. While laboratory studies have produced some notable successes (e.g. the identification of the asteroid Vesta as the source of the H, E and D meteorite classes), it is unlikely that we have samples of each asteroidal spectral type in our meteorite collection. The correlation of spectral type and composition for many objects will therefore remain uncertain until we can return samples of specific asteroid types to Earth for analyses. The best candidates for sample return are asteroids that already come close to the Earth. Asteroids in orbit near 1 A.U. have been classified into three groups (Aten, Apollo & Amor) based on their orbital characteristics. These Near Earth Objects (NEOs) contain representatives of virtually all spectral types and sub-types of the asteroid population identified to date. Because of their close proximity to Earth, NEOs are prime targets for asteroid missions such as the NEAR-Shoemaker NASA Discovery Mission to Eros and the

Changing inclination of earth satellites using the gravity of the moon

Directory of Open Access Journals (Sweden)

Karla de Souza Torres

2006-01-01

Full Text Available We analyze the problem of the orbital control of an Earth's satellite using the gravity of the Moon. The main objective is to study a technique to decrease the fuel consumption of a plane change maneuver to be performed in a satellite that is in orbit around the Earth. The main idea of this approach is to send the satellite to the Moon using a single-impulsive maneuver, use the gravity field of the Moon to make the desired plane change of the trajectory, and then return the satellite to its nominal semimajor axis and eccentricity using a bi-impulsive Hohmann-type maneuver. The satellite is assumed to start in a Keplerian orbit in the plane of the lunar orbit around the Earth and the goal is to put it in a similar orbit that differs from the initial orbit only by the inclination. A description of the close-approach maneuver is made in the three-dimensional space. Analytical equations based on the patched conics approach are used to calculate the variation in velocity, angular momentum, energy, and inclination of the satellite. Then, several simulations are made to evaluate the savings involved. The time required by those transfers is also calculated and shown.

Regime switches in the risk-return trade-off

OpenAIRE

Marcellino, Massimiliano; Ghysels, Eric; Guerin, Pierre

2014-01-01

This paper deals with the estimation of the risk-return trade-off. We use a MIDAS model for the conditional variance and allow for possible switches in the risk-return relation through a Markov-switching specification. We find strong evidence for regime changes in the risk-return relation. This finding is robust to a large range of specifications. In the first regime characterized by low ex-post returns and high volatility, the risk-return relation is reversed, whereas the intuitive positive ...

ANALYSING TURKISH INDIVIDUAL PENSION SYSTEM FEES AND RETURNS

OpenAIRE

Peker, Ibrahim

2018-01-01

This study aims at categorizing, computing and analyzing fees and costs in Turkish Individual Pension System. To this end, net real returns after all costs were computed and these returns were compared with the disclosed fees and returns. Generally in practice, only fund management fees are taken into consideration for calculating net returns and with this method net annual average (geometric) return of the system is calculated as 2.01% for the 2008-2014 period. However, the results of this s...

Do expectancies of return to work and Job satisfaction predict actual return to work in workers with long lasting LBP?

Science.gov (United States)

Opsahl, Jon; Eriksen, Hege R; Tveito, Torill H

2016-11-17

Musculoskeletal disorders including low back pain have major individual and socioeconomic consequences as it often leads to disability and long-term sick leave and exclusion from working life. Predictors of disability and return to work often differ, and the dominant knowledge is on predictors for prolonged sick leave and disability. Therefore it is also important to identify key predictors for return to work. The aim of the study was to assess if overall job satisfaction and expectancies of return to work predicts actual return to work after 12 months, among employees with long lasting low back pain, and to assess if there were gender differences in the predictors. Data from the Cognitive interventions and nutritional supplements trial (CINS Trial) was used. Predictors for return to work were examined in 574 employees that had been on sick leave 2-10 months for low back pain, before entering the trial. Data were analysed with multiple logistic regression models stratified by gender, and adjusted for potential confounders. Regardless of gender high expectancies were a strong and significant predictor of return to work at 12 months, while high levels of job satisfaction were not a significant predictor. There were no differences in the levels of expectancies or overall job satisfaction between men and women. However, men had in general higher odds of returning to work compared with women. Among individuals with long lasting low back pain high expectancies of returning to work were strongly associated with successful return to work. We do not know what factors influence individual expectancies of return to work. Screening expectancies and giving individuals with low expectancies interventions with a goal to change expectancies of return to work, such as CBT or self-management interventions, may contribute to increase actual return to work. http://www.clinicaltrials.gov/ , with registration number NCT00463970 . The trial was registered at the 18th of April 2007.

KINERJA KEUANGAN KONVENSIONAL, ECONOMIC VALUE ADDED, DAN RETURN SAHAM

Directory of Open Access Journals (Sweden)

Bambang Sudiyatno

2011-09-01

Full Text Available Penelitian ini bertujuan untuk menguji pengaruh kinerja keuangan konvensional; Return on Asset (ROA, Return on Equity (ROE, Residual Income (RI, dan kinerja keuangan yang lebih modern; Economic Value Added (EVA terhadap return saham pada perusahaan-perusahaan dalam industry makanan dan minuman yang terdaftar di Bursa Efek Indonesia. Pengambilan sampel dalam penelitian ini menggunakan metode sensus, karena semua perusahaan dalam industry makanan dan minuman digunakan sebagai sampel. Namun dalam proses samplingnya mengunakan metode purposive sampling, yaitu menggunakan sampel dengan criteria-kriteria tertentu. Hasil penelitian menunjukkan bahwa Return on Asset (ROA dan Residual Income (RI berpengaruh positif dan secara statistik signifikan terhadap return saham pada level signifikansi 1%. Sedangkan Return on Equity (ROE berpengaruh negative dan secara statistik signifikan terhadap return saham pada level signifikansi 10%, dan Economic Value Added (ERA berpengaruh positif tetapi tidak signifikan terhadap return saham.This study aims to test the effect of conventional financial performance i.e. Return on Asset (ROA, Return on Equity (ROE, Residual Income (RI, and the more modern financial performance which is Economic Value Added (EVA toward stock returns on companies in the food and beverage industry listed in Indonesia Stock Exchange. Sampling technique in this study uses the census method, all companies in the food and beverage industry are used as a sample. The process of sampling using purposive sampling method. The result shows that Return On Asset (ROA and Residual Income (RI are positive and statistic significant impact on the stock returns at significance level 1%. While the Return on Equity (ROE is negative and statistic significant impact on the stock returns at significance level 10%, Economic Value Added (EVA is positive and statistic not significant impact on the stock returns.

THE RELIABILITY ANALYSIS OF EXISTING REINFORCED CONCRETE PILES IN PERMAFROST REGIONS

Directory of Open Access Journals (Sweden)

Vladimir S. Utkin

2017-06-01

Full Text Available The article describes the general problem of safe operation of buildings and structures with the dynamics of permafrost in Russia and other countries. The global warming on Earth will lead to global disasters such as failures of buildings and structures. The main reason of these failures will be a reduction of bearing capacity and the reliability of foundations. It is necessary to organize the observations (monitoring for the process of reducing the bearing capacity of foundations to prevent such accidents and reduce negative consequences, to development of preventive measures and operational methods for the piles reliability analysis. The main load-bearing elements of the foundation are reinforced concrete piles and frozen ground. Reinforced concrete piles have a tendency to decrease the bearing capacity and reliability of the upper (aerial part and the part in the soil. The article discusses the problem of reliability analysis of existing reinforced concrete piles in upper part in permafrost regions by the reason of pile degradation in the contact zone of seasonal thawing and freezing soil. The evaluation of the probability of failure is important in itself, but also it important for the reliability of foundation: consisting of piles and frozen soil. Authors offers the methods for reliability analysis of upper part of reinforced concrete piles in the contact zone with seasonally thawed soil under different number of random variables (fuzzy variables in the design mathematical model of a limit state by the strength criterion.

The Determinants of Return Migration: Evidence for Kosovo

Directory of Open Access Journals (Sweden)

Ardiana Gashi

2015-12-01

Full Text Available Return migration represents a potentially important contributor to economic development for countries that are large exporters of labor. This paper provides an analysis of the determinants of return migration to Kosovo, a country with an especially high level of recent emigration. The findings of this investigation suggest that there is a non-linear relationship between the age of the migrant and their probability of returning. In addition, the more educated migrants and those that have acquired additional education whilst abroad are more likely to return, whereas recent migrants, those that possess permanent resident status and have their family abroad are less likely to return. As expected, the stronger the family ties of a migrant with their home country, the more likely they are to return. Finally, migrants that are expected to invest in businesses in Kosovo are more inclined to return. Together these findings suggest that return migration may be an important contributor to economic development in Kosovo and policies are outlined that could strengthen this contribution.

Return Migration among Elderly, Chronically Ill Bosnian Refugees

DEFF Research Database (Denmark)

Handlos, Line Neerup; Olwig, Karen Fog; Bygbjerg, Ib Christian

2015-01-01

Elderly migrants constitute a considerable share of global return migration; nevertheless, literature on the health aspects of the return migration among these migrants is still scarce. This study explores the significance of return migration among elderly, chronically ill Bosnian refugees from D...... of illness, health did matter. Viewed as physical, social and mental well-being in line with WHO's definition of health, health was indeed one of the most important factors when the decision to return was made....... that physical health, in the sense of the absence of illness and easy access to necessary health-care services and medicines, was not highly prioritized when the decision was made whether or not to return. However, if health is regarded more broadly as involving more than mere physical health and the absence......Elderly migrants constitute a considerable share of global return migration; nevertheless, literature on the health aspects of the return migration among these migrants is still scarce. This study explores the significance of return migration among elderly, chronically ill Bosnian refugees from...

Systems reliability/structural reliability

International Nuclear Information System (INIS)

Green, A.E.

1980-01-01

The question of reliability technology using quantified techniques is considered for systems and structures. Systems reliability analysis has progressed to a viable and proven methodology whereas this has yet to be fully achieved for large scale structures. Structural loading variants over the half-time of the plant are considered to be more difficult to analyse than for systems, even though a relatively crude model may be a necessary starting point. Various reliability characteristics and environmental conditions are considered which enter this problem. The rare event situation is briefly mentioned together with aspects of proof testing and normal and upset loading conditions. (orig.)

Reliability Engineering

International Nuclear Information System (INIS)

Lee, Sang Yong

1992-07-01

This book is about reliability engineering, which describes definition and importance of reliability, development of reliability engineering, failure rate and failure probability density function about types of it, CFR and index distribution, IFR and normal distribution and Weibull distribution, maintainability and movability, reliability test and reliability assumption in index distribution type, normal distribution type and Weibull distribution type, reliability sampling test, reliability of system, design of reliability and functionality failure analysis by FTA.

Corporate Governance and Equity Returns

OpenAIRE

Uchida, Shigeru

2012-01-01

This paper analyses the relationship between corporate governance and equity returns from the small investors view point. A primary survey has been conducted to gather the data required to examine the link. Preliminary result of the study shows that the four elements of governance: board structure, transparency, fairness and responsibility are positively related with equity returns.

Effectiveness of Securities with Fuzzy Probabilistic Return

Directory of Open Access Journals (Sweden)

Krzysztof Piasecki

2011-01-01

Full Text Available The generalized fuzzy present value of a security is defined here as fuzzy valued utility of cash flow. The generalized fuzzy present value cannot depend on the value of future cash flow. There exists such a generalized fuzzy present value which is not a fuzzy present value in the sense given by some authors. If the present value is a fuzzy number and the future value is a random one, then the return rate is given as a probabilistic fuzzy subset on a real line. This kind of return rate is called a fuzzy probabilistic return. The main goal of this paper is to derive the family of effective securities with fuzzy probabilistic return. Achieving this goal requires the study of the basic parameters characterizing fuzzy probabilistic return. Therefore, fuzzy expected value and variance are determined for this case of return. These results are a starting point for constructing a three-dimensional image. The set of effective securities is introduced as the Pareto optimal set determined by the maximization of the expected return rate and minimization of the variance. Finally, the set of effective securities is distinguished as a fuzzy set. These results are obtained without the assumption that the distribution of future values is Gaussian. (original abstract

22 CFR 42.22 - Returning resident aliens.

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Returning resident aliens. 42.22 Section 42.22... Returning resident aliens. (a) Requirements for returning resident status. An alien shall be classifiable as... presented that: (1) The alien had the status of an alien lawfully admitted for permanent residence at the...

Volatility return intervals analysis of the Japanese market

Science.gov (United States)

Jung, W.-S.; Wang, F. Z.; Havlin, S.; Kaizoji, T.; Moon, H.-T.; Stanley, H. E.

2008-03-01

We investigate scaling and memory effects in return intervals between price volatilities above a certain threshold q for the Japanese stock market using daily and intraday data sets. We find that the distribution of return intervals can be approximated by a scaling function that depends only on the ratio between the return interval τ and its mean . We also find memory effects such that a large (or small) return interval follows a large (or small) interval by investigating the conditional distribution and mean return interval. The results are similar to previous studies of other markets and indicate that similar statistical features appear in different financial markets. We also compare our results between the period before and after the big crash at the end of 1989. We find that scaling and memory effects of the return intervals show similar features although the statistical properties of the returns are different.

Using Google Earth to Assess Shade for Sun Protection in Urban Recreation Spaces: Methods and Results.

Science.gov (United States)

Gage, R; Wilson, N; Signal, L; Barr, M; Mackay, C; Reeder, A; Thomson, G

2018-05-16

Shade in public spaces can lower the risk of and sun burning and skin cancer. However, existing methods of auditing shade require travel between sites, and sunny weather conditions. This study aimed to evaluate the feasibility of free computer software-Google Earth-for assessing shade in urban open spaces. A shade projection method was developed that uses Google Earth street view and aerial images to estimate shade at solar noon on the summer solstice, irrespective of the date of image capture. Three researchers used the method to separately estimate shade cover over pre-defined activity areas in a sample of 45 New Zealand urban open spaces, including 24 playgrounds, 12 beaches and 9 outdoor pools. Outcome measures included method accuracy (assessed by comparison with a subsample of field observations of 10 of the settings) and inter-rater reliability. Of the 164 activity areas identified in the 45 settings, most (83%) had no shade cover. The method identified most activity areas in playgrounds (85%) and beaches (93%) and was accurate for assessing shade over these areas (predictive values of 100%). Only 8% of activity areas at outdoor pools were identified, due to a lack of street view images. Reliability for shade cover estimates was excellent (intraclass correlation coefficient of 0.97, 95% CI 0.97-0.98). Google Earth appears to be a reasonably accurate and reliable and shade audit tool for playgrounds and beaches. The findings are relevant for programmes focused on supporting the development of healthy urban open spaces.

Reconciling the Mitscherlich's law of diminishing returns with Liebig's law of the minimum. Some results on crop modeling.

Science.gov (United States)

Ferreira, Iuri E P; Zocchi, Silvio S; Baron, Daniel

2017-11-01

Reliable fertilizer recommendations depend on the correctness of the crop production models fitted to the data, but generally the crop models are built empirically, neglecting important physiological aspects related with response to fertilizers, or they are based in laws of plant mineral nutrition seen by many authors as conflicting theories: the Liebig's Law of the Minimum and Mitscherlich's Law of Diminishing Returns. We developed a new approach to modelling the crop response to fertilizers that reconcile these laws. In this study, the Liebig's Law is applied at the cellular level to explain plant production and, as a result, crop models compatible with the Law of Diminishing Returns are derived. Some classical crop models appear here as special cases of our methodology, and a new interpretation for Mitscherlich's Law is also provided. Copyright © 2017 Elsevier Inc. All rights reserved.

Return currents in solar flares - Collisionless effects

Science.gov (United States)

Rowland, H. L.; Vlahos, L.

1985-01-01

If the primary, precipitating electrons in a solar flare are unstable to beam plasma interactions, it is shown that strong Langmuir turbulence can seriously modify the way in which a return current is carried by the background plasma. In particular, the return (or reverse) current will not be carried by the bulk of the electrons, but by a small number of high velocity electrons. For beam/plasma densities greater than 0.01, this can reduce the effects of collisions on the return current. For higher density beams where the return current could be unstable to current driven instabilities, the effects of strong turbulence anomalous resistivity is shown to prevent the appearance of such instabilities. Again in this regime, how the return current is carried is determined by the beam generated strong turbulence.

Rare earth metals, rare earth hydrides, and rare earth oxides as thin films

International Nuclear Information System (INIS)

Gasgnier, M.

1980-01-01

The review deals with pure rare earth materials such as rare earth metals, rare earth hydrides, and rare earth oxides as thin films. Several preparation techniques, control methods, and nature of possible contaminations of thin films are described. These films can now be produced in an extremely well-known state concerning chemical composition, structure and texture. Structural, electric, magnetic, and optical properties of thin films are studied and discussed in comparison with the bulk state. The greatest contamination of metallic rare earth thin films is caused by reaction with hydrogen or with water vapour. The compound with an f.c.c. structure is the dihydride LnH 2 (Ln = lanthanides). The oxygen contamination takes place after annealing at higher temperatures. Then there appears a compound with a b.c.c. structure which is the C-type sesquioxide C-Ln 2 O 3 . At room atmosphere dihydride light rare earth thin films are converted to hydroxide Ln(OH) 3 . For heavy rare earth thin films the oxinitride LnNsub(x)Osub(y) is observed. The LnO-type compound was never seen. The present review tries to set the stage anew for the investigations to be undertaken in the future especially through the new generations of electron microscopes

Value at Risk and Hedge Fund Return - Does High Risk Bring High Return?

OpenAIRE

Jing, Tao; Zhao, Hongxiang

2010-01-01

This paper mainly focuses on the correlation between live hedge fund return and their value at risk (VaR), and is based on the historical data from May 2000 to April 2010. The authors adopt portfolio level analyses and fund level cross-sectional regression, and find that there is significant positive correlation, both statistically and economically, between the hedge fund return and VaRs (parametric, non-parametric and GARCH). Further research is conducted by sub-dividing the overall period i...

Observations on the reliability of COTS-device-based solid state data recorders operating in low-earth orbit

International Nuclear Information System (INIS)

Underwood, C.I.

1999-01-01

This paper presents the results of Surrey Space Centre's experience in using different coding schemes and hardware configurations to protect data and protect data and software stored in COTS-device (Commercial-Off-The-Shelf) based memories on-board operational spacecraft in low Earth orbit. (author)

Validation and reliability of a Behcet's Syndrome Activity Scale in Korea.

Science.gov (United States)

Choi, Hyo Jin; Seo, Mi Ryoung; Ryu, Hee Jung; Baek, Han Joo

2016-01-01

We prepared a cross-cultural adaptation of the Behcet's Syndrome Activity Scale (BSAS) and evaluated its reliability and validity in Korea. Fifty patients with Behcet's disease (BD) who attended the Rheumatology Clinic of Gachon University Gil Medical Center were included in this study. The first BSAS questionnaire was administered at each clinic visit, and the second questionnaire was completed at home within 24 hours of the visit. A Behcet's Disease Current Activity Form (BDCAF) and a Behcet's Disease Quality of Life (BDQOL) form were also given to patients. The test-retest reliability was analyzed by intraclass correlation coefficients (ICC). To assess the validity, the total BSAS score was compared with the BDCAF score, the patient/physician global assessment, and the BDQOL by Spearman rank correlation. Twelve males and 38 females were enrolled. The mean age was 48.5 years and the mean disease duration was 6.7 years. Thirty-eight patients (76.0%) returned the questionnaire by mail. For the test-retest reliability, the two assessments were significantly correlated on all 10 items of the BSAS questionnaire (p < 0.05) and the total BSAS score (ICC, 0.925; p < 0.001). The total BSAS score was statistically correlated with the BDQOL, BDCAF, and patient/physician global assessment (p < 0.01). The Korean version of BSAS is a reliable and valid instrument to measure BD activity.

Rare earth industries: Upstream business

International Nuclear Information System (INIS)

2011-01-01

energy efficiency rely a lot on the use of rare earths. These include applications in energy efficient lighting, new and more reliable energy storage batteries as well as more efficient energy distribution mechanism. The growing demand for more efficient communication systems, not only in the world of business but also in defence and the military, is another significant driver of the global demand for rare earths. Mobility and miniaturisation, which feature prominently in the current specifications for telecommunications equipment's, rely a lot on the deployment of powerful and efficient magnetic technology. And rare earths have become a much sought after material in the latest magnets used in mobile phones, defence equipment's and computer hardware's. With the rise in the global investments in smart cities and intelligent communities, the demand for such communication products is destined to witness equally prolific expansion. This would inadvertently translate into a rising demand for rare earths. (author)

Linkage between company scores and stock returns

Directory of Open Access Journals (Sweden)

Saban Celik

2017-12-01

Full Text Available Previous studies on company scores conducted at firm-level, generally concluded that there exists a positive relation between company scores and stock returns. Motivated by these studies, this study examines the relationship between company scores (Corporate Governance Score, Economic Score, Environmental Score, and Social Score and stock returns, both at portfolio-level analysis and firm-level cross-sectional regressions. In portfolio-level analysis, stocks are sorted based on each company scores and quintile portfolio are formed with different levels of company scores. Then, existence and significance of raw returns and risk-adjusted returns difference between portfolios with the extreme company scores (portfolio 10 and portfolio 1 is tested. In addition, firm-level cross-sectional regression is performed to examine the significance of company scores effects with control variables. While portfolio-level analysis results indicate that there is no significant relation between company scores and stock returns; firm-level analysis indicates that economic, environmental, and social scores have effect on stock returns, however, significance and direction of these effects change, depending on the included control variables in the cross-sectional regression.

Mathematical Formulation of the Remote Electric and Magnetic Emissions of the Lightning Dart Leader and Return Stroke

Science.gov (United States)

Thiemann, Edward M. B.

Lightning detection and geolocation networks have found widespread use by the utility, air traffic control and forestry industries as a means of locating strikes and predicting imminent recurrence. Accurate lightning geolocation requires detecting VLF radio emissions at multiple sites using a distributed sensor network with typical baselines exceeding 150 km, along with precision time of arrival estimation to triangulate the origin of a strike. The trend has been towards increasing network accuracy without increasing sensor density by incorporating precision GPS synchronized clocks and faster front-end signal processing. Because lightning radio waveforms evolve as they propagate over a finitely conducting earth, and that measurements for a given strike may have disparate propagation path lengths, accurate models are required to determine waveform fiducials for precise strike location. The transition between the leader phase and return stroke phase may offer such a fiducial and warrants quantitative modeling to improve strike location accuracy. The VLF spectrum of the ubiquitous downward negative lightning strike is able to be modeled by the transfer of several Coulombs of negative charge from cloud to ground in a two-step process. The lightning stepped leader ionizes a plasma channel downward from the cloud at a velocity of approximately 0.05c, leaving a column of charge in its path. Upon connection with a streamer, the subsequent return stroke initiates at or near ground level and travels upward at an average but variable velocity of 0.3c. The return stroke neutralizes any negative charge along its path. Subsequent dart leader and return strokes often travel smoothly down the heated channel left by a preceding stroke, lacking the halting motion of the preceding initial stepped leader and initial return stroke. Existing lightning models often neglect the leader current and rely on approximations when solving for the return stroke. In this thesis, I present an

Planetary protection issues linked to human missions to Mars

Science.gov (United States)

Debus, A.

According to United Nations Treaties and handled presently by the Committee of Space Research COSPAR the exploration of the Solar System has to comply with planetary protection requirements The goal of planetary protection is to protect celestial bodies from terrestrial contamination and also to protect the Earth environment from an eventual biocontamination carried by return samples or by space systems returning to the Earth Mars is presently one of the main target at exobiology point of view and a lot of missions are operating on travel or scheduled for its exploration Some of them include payload dedicated to the search of life or traces of life and one of the goals of these missions is also to prepare sample return missions with the ultimate objective to walk on Mars Robotic missions to Mars have to comply with planetary protection specifications well known presently and planetary protection programs are implemented with a very good reliability taking into account an experience of 40 years now For sample return missions a set of stringent requirements have been approved by the COSPAR and technical challenges have now to be won in order to preserve Earth biosphere from an eventual contamination risk Sending astronauts on Mars will gather all these constraints added with the human dimension of the mission The fact that the astronauts are huge contamination sources for Mars and that they are also potential carrier of a contamination risk back to Earth add also ethical considerations to be considered For the preparation of a such

Inactive nurses in Taiwan: human capital, intention to return to hospital nursing, and incentives for returning.

Science.gov (United States)

Yu, Hsing-Yi; Tang, Fu-In; Chen, I-Ju; Yin, Teresa J C; Chen, Chu-Chieh; Yu, Shu

2016-04-01

To investigate inactive nurses' human capital, intention to return to hospital nursing and incentives for returning. Few studies have discussed the loss of human capital with regard to inactive nurses and how to attract them to return to clinical work. Systematic random sampling was used, with 328 subjects completing the mailed questionnaires, resulting in a response rate of 25.4%. Inactive nurses not only had moderate to high human capital (average years of nursing experience was 10.29, with moderate to high levels of nursing professional commitment and nursing competence) and were young. Forty-three percent of subjects reported intending to return to hospital nursing. Sufficient nurse staffing, greater safety in the working environment, and re-entry preparation programmes were incentives for returning. Recruiting inactive nurses back to hospital work is vital and feasible as inactive nurses had a moderate to high degree of human capital. The most feasible way is offering reasonable working conditions, in particular, providing sufficient staffing, a safe working environment and re-entry preparation programmes. The findings confirm the human capital of inactive nurses and provide concrete directions for nursing managers to follow when recruiting inactive nurses to hospital nursing. © 2015 John Wiley & Sons Ltd.

Reliability

OpenAIRE

Condon, David; Revelle, William

2017-01-01

Separating the signal in a test from the irrelevant noise is a challenge for all measurement. Low test reliability limits test validity, attenuates important relationships, and can lead to regression artifacts. Multiple approaches to the assessment and improvement of reliability are discussed. The advantages and disadvantages of several different approaches to reliability are considered. Practical advice on how to assess reliability using open source software is provided.

Student Practice Evaluation Form-Revised Edition online comment bank: development and reliability analysis.

Science.gov (United States)

Rodger, Sylvia; Turpin, Merrill; Copley, Jodie; Coleman, Allison; Chien, Chi-Wen; Caine, Anne-Maree; Brown, Ted

2014-08-01

The reliable evaluation of occupational therapy students completing practice education placements along with provision of appropriate feedback is critical for both students and for universities from a quality assurance perspective. This study describes the development of a comment bank for use with an online version of the Student Practice Evaluation Form-Revised Edition (SPEF-R Online) and investigates its reliability. A preliminary bank of 109 individual comments (based on previous students' placement performance) was developed via five stages. These comments reflected all 11 SPEF-R domains. A purpose-designed online survey was used to examine the reliability of the comment bank. A total of 37 practice educators returned surveys, 31 of which were fully completed. Participants were asked to rate each individual comment using the five-point SPEF-R rating scale. One hundred and two of 109 comments demonstrated satisfactory agreement with their respective default ratings that were determined by the development team. At each domain level, the intra-class correlation coefficients (ranging between 0.86 and 0.96) also demonstrated good to excellent inter-rater reliability. There were only seven items that required rewording prior to inclusion in the final SPEF-R Online comment bank. The development of the SPEF-R Online comment bank offers a source of reliable comments (consistent with the SPEF-R rating scale across different domains) and aims to assist practice educators in providing reliable and timely feedback to students in a user-friendly manner. © 2014 Occupational Therapy Australia.

Technology thrusts for future Earth science applications

Science.gov (United States)

Habib, Shahid

2001-02-01

This paper presents NASA's recent direction to invest in the critical science instrument and platform technologies in order to realize more reliable, frequent and versatile missions for future Earth Science measurements. Historically, NASA's Earth Science Enterprise has developed and flown science missions that have been large in size, mass and volume. These missions have taken much longer to implement due to technology development time, and have carried a large suite of instruments on a large spacecraft. NASA is now facing an era where the budget for the future years is more or less flat and the possibility for any major new start does not vividly appear on the horizon. Unfortunately, the scientific measurement needs for remote sensing have not shrunk to commensurate with the budget constraints. In fact, the challenges and scientific appetite in search of answers to a score of outstanding questions have been gradually expanding. With these factors in mind, for the last three years NASA has been changing its focus to concentrate on how to take advantage of smaller missions by relying on industry, and minimizing the overall mission life cycle by developing technologies that are independent of the mission implementation cycle. The major redirection of early investment in the critical technologies should eventually have its rewards and significantly reduce the mission development period. Needless to say, in the long run this approach should save money, minimize risk, promote or encourage partnering, allow for a rapid response to measurement needs, and enable frequent missions making a wider variety of earth science measurements. This paper gives an overview of some of the identified crucial technologies and their intended applications for meeting the future Earth Science challenges.

Technology Thrust for Future Earth Science Applications

Science.gov (United States)

Habib, Shahid

2000-01-01

This paper presents NASA's recent direction to invest in the critical science instrument and platform technologies in order to realize more reliable, frequent and versatile missions for future Earth Science measurements. Traditionally, NASA's Earth Science Enterprise has developed and flown science missions that have been large in size, weight and volume. These missions have taken much longer implementation due to technology development time and have carried a large suite of instruments on a large-size spacecraft. NASA is also facing an era where the budget for the future years is more or less flat and the possibility for any major new start does not vividly appear on the horizon. Unfortunately, the scientific goals have not shrunk to commensurate with the budget constraints. In fact, the challenges and scientific appetite in search of answers to a score of outstanding questions have been gradually expanding. With these factors in mind, for the last three years NASA has been changing its focus to concentrate on how to take advantage of smaller missions by relying on industry, and minimizing the overall life cycle by infusing technologies that are being developed independently of any planned mission's implementation cycle. The major redirection of early investment in the critical technologies should have its rewards and significantly reduce the mission development period. Needless to say, in the long run this approach should save money, minimize risk, promote or encourage partnering, and allow for more frequent missions or earth science measurements to occur. This paper gives an overview of some of the identified crucial technologies and their intended applications for meeting the future Earth Science challenges.

Urban flood return period assessment through rainfall-flood response modelling

DEFF Research Database (Denmark)

Murla, Damian; Thorndahl, Søren Liedtke

Intense rainfall can often cause severe floods, especially in urbanized areas, where population density or large impermeable areas are found. In this context, floods can generate a direct impact in a social-environmental-economic viewpoint. Traditionally, in design of Urban Drainage Systems (UDS......), correlation between return period (RP) of a given rainfall and RP of its consequent flood has been assumed to be linear (e.g.DS/EN752 (2008)). However, this is not always the case. Complex UDS, where diverse hydraulic infrastructures are often found, increase the heterogeneity of system response, which may...... cause an alteration of the mentioned correlation. Consequently, reliability on future urban planning, design and resilience against floods may be also affected by this misassumption. In this study, an assessment of surface flood RP across rainfall RP has been carried out at Lystrup, a urbanized...

Nodal price volatility reduction and reliability enhancement of restructured power systems considering demand-price elasticity

International Nuclear Information System (INIS)

Goel, L.; Wu, Qiuwei; Wang, Peng

2008-01-01

With the development of restructured power systems, the conventional 'same for all customers' electricity price is getting replaced by nodal prices. Electricity prices will fluctuate with time and nodes. In restructured power systems, electricity demands will interact mutually with prices. Customers may shift some of their electricity consumption from time slots of high electricity prices to those of low electricity prices if there is a commensurate price incentive. The demand side load shift will influence nodal prices in return. This interaction between demand and price can be depicted using demand-price elasticity. This paper proposes an evaluation technique incorporating the impact of the demand-price elasticity on nodal prices, system reliability and nodal reliabilities of restructured power systems. In this technique, demand and price correlations are represented using the demand-price elasticity matrix which consists of self/cross-elasticity coefficients. Nodal prices are determined using optimal power flow (OPF). The OPF and customer damage functions (CDFs) are combined in the proposed reliability evaluation technique to assess the reliability enhancement of restructured power systems considering demand-price elasticity. The IEEE reliability test system (RTS) is simulated to illustrate the developed techniques. The simulation results show that demand-price elasticity reduces the nodal price volatility and improves both the system reliability and nodal reliabilities of restructured power systems. Demand-price elasticity can therefore be utilized as a possible efficient tool to reduce price volatility and to enhance the reliability of restructured power systems. (author)

Exploring Longitudinal Risk-return Relationships

DEFF Research Database (Denmark)

Andersen, Torben J.; Bettis, Richard A.

2015-01-01

We study a longitudinal fit model of adaptation and its association with the longitudinal risk-return relationship. The model allows the firm to adjust its position in response to partial learning about a changing environment characterized by two path-dependent processes—a random walk and a stoch......We study a longitudinal fit model of adaptation and its association with the longitudinal risk-return relationship. The model allows the firm to adjust its position in response to partial learning about a changing environment characterized by two path-dependent processes—a random walk...... can lead to the inverse longitudinal risk-return relationships observed empirically. We discuss this apparent paradox and the possible resolution between mindless and conscious behavior as plausible causes of the longitudinal Bowman Paradox....

Reliability and minimal detectable difference in multisegment foot kinematics during shod walking and running.

Science.gov (United States)

Milner, Clare E; Brindle, Richard A

2016-01-01

There has been increased interest recently in measuring kinematics within the foot during gait. While several multisegment foot models have appeared in the literature, the Oxford foot model has been used frequently for both walking and running. Several studies have reported the reliability for the Oxford foot model, but most studies to date have reported reliability for barefoot walking. The purpose of this study was to determine between-day (intra-rater) and within-session (inter-trial) reliability of the modified Oxford foot model during shod walking and running and calculate minimum detectable difference for common variables of interest. Healthy adult male runners participated. Participants ran and walked in the gait laboratory for five trials of each. Three-dimensional gait analysis was conducted and foot and ankle joint angle time series data were calculated. Participants returned for a second gait analysis at least 5 days later. Intraclass correlation coefficients and minimum detectable difference were determined for walking and for running, to indicate both within-session and between-day reliability. Overall, relative variables were more reliable than absolute variables, and within-session reliability was greater than between-day reliability. Between-day intraclass correlation coefficients were comparable to those reported previously for adults walking barefoot. It is an extension in the use of the Oxford foot model to incorporate wearing a shoe while maintaining marker placement directly on the skin for each segment. These reliability data for walking and running will aid in the determination of meaningful differences in studies which use this model during shod gait. Copyright © 2015 Elsevier B.V. All rights reserved.

Earth Observatory Satellite system definition study. Report no. 4: Management approach recommendations

Science.gov (United States)

1974-01-01

A management approach for the Earth Observatory Satellite (EOS) which will meet the challenge of a constrained cost environment is presented. Areas of consideration are contracting techniques, test philosophy, reliability and quality assurance requirements, commonality options, and documentation and control requirements. The various functional areas which were examined for cost reduction possibilities are identified. The recommended management approach is developed to show the primary and alternative methods.

Sublethal Exposure to Diatomaceous Earth Increases Net Fecundity of Flour Beetles (Tribolium confusum) by Inhibiting Egg Cannibalism

Science.gov (United States)

Shostak, Allen W.

2014-01-01

Population regulation results from an interplay of numerous intrinsic and external factors, and for many insects cannibalism is such a factor. This study confirms a previously-reported observation that sublethal exposure to the fossilized remains of diatoms (i.e. diatomaceous earth) increases net fecundity (eggs produced minus eggs destroyed/day) of flour beetles, Tribolium confusum. The aim was to experimentally test two non-mutually-exclusive ecological mechanisms potentially responsible for the increased net fecundity: higher egg production and lower egg cannibalism. Adult T. confusum were maintained at low or high density in medium containing sublethal (0–4%) diatomaceous earth. Net fecundity increased up to 2.1× control values during diatomaceous earth exposure, and returned to control levels following removal from diatomaceous earth. Cannibalism assays on adults showed that diatomaceous earth reduced the number of eggs produced to 0.7× control values at low density and to 0.8× controls at high density, and also reduced egg cannibalism rates of adults to as little as 0.4× control values, but at high density only. Diatomaceous earth also reduced cannibalism by larvae on eggs to 0.3× control values. So, while the presence of diatomaceous earth reduced egg production, net fecundity increased as a result of strong suppression of the normal egg cannibalism by adults and larvae that occurs at high beetle density. Undisturbed cultures containing sublethal diatomaceous earth concentrations reached higher population densities than diatomaceous earth-free controls. Cohort studies on survival from egg to adult indicated that this population increase was due largely to decreased egg cannibalism by adult females. This is the first report of inhibition of egg cannibalism by diatomaceous earth on larval or adult insects. The ability of diatomaceous earth to alter cannibalism behavior without causing mortality makes it an ideal investigative tool for cannibalism

The Reference Return Ratio

DEFF Research Database (Denmark)

Nicolaisen, Jeppe; Faber Frandsen, Tove

2008-01-01

The paper introduces a new journal impact measure called The Reference Return Ratio (3R). Unlike the traditional Journal Impact Factor (JIF), which is based on calculations of publications and citations, the new measure is based on calculations of bibliographic investments (references) and returns...... (citations). A comparative study of the two measures shows a strong relationship between the 3R and the JIF. Yet, the 3R appears to correct for citation habits, citation dynamics, and composition of document types - problems that typically are raised against the JIF. In addition, contrary to traditional...

Return to nucleate boiling

International Nuclear Information System (INIS)

Shumway, R.W.

1985-01-01

This paper presents a collection of TMIN (temperature of return to nucleate boiling) correlations, evaluates them under several conditions, and compares them with a wide range of data. Purpose is to obtain the best one for use in a water reactor safety computer simulator known as TRAC-B. Return to nucleate boiling can occur in a reactor accident at either high or low pressure and flow rates. Most of the correlations yield unrealistic results under some conditions. A new correlation is proposed which overcomes many of the deficiencies

Different forms, reasons and motivations for return migration of persons who voluntarily decide to return to their countries of origin.

Science.gov (United States)

Callea, S

1986-03-01

Although the 1973 oil crisis did not have the drastic effects on immigration which were originally feared, it did end a period of quasi-liberal immigration policy, establish intense and effective international cooperation on immigration, and arouse great interest in immigration studies and research. This paper analyzes the situations arising as a result of the petroleum shortage and focuses on the conditions relating to the return of emigrants to Southern European countries. This new research draws attention to the following fundamental aspects of the immigration problem: 1) the emigrant's return to his homeland cannot be considered a factor in development; it is a positive element in development only if the right socioeconomic conditions exist in the country of origin. 2) Concern for children's education is one of the most common reasons for return. 3) A large percentage of emigrants are satisfied with their work abroad. 4) An emigrant's return potential is wasted due to the slight use that is made of the resources he offers. 5) Returning workers most often want to set up an independent enterprise. 6) Savings are generally used to buy a house or farm. 7) Vocational level does not increase significantly between emigration and returning, though this increase becomes greater the longer the emigrant stays abroad. 8) The number of returning emigrants is too slight to bring about any change in the country of origin. 9) Incentives and subsidies to encourage return have not had a considerable impact on the decision to return. Callea recommends that officials of the country of origin posted abroad be assigned to counsel returning emigrants on finding employment, attending vocational development courses, obtaining housing, accruing interests and savings, and on the problems and perspectives of sociocultural reintegration.

Reliability and Validity of the Work and Well-Being Inventory (WBI) for Employees.

Science.gov (United States)

Vendrig, A A; Schaafsma, F G

2018-06-01

Purpose The purpose of this study is to measure the psychometric properties of the Work and Wellbeing Inventory (WBI) (in Dutch: VAR-2), a screening tool that is used within occupational health care and rehabilitation. Our research question focused on the reliability and validity of this inventory. Methods Over the years seven different samples of workers, patients and sick listed workers varying in size between 89 and 912 participants (total: 2514), were used to measure the test-retest reliability, the internal consistency, the construct and concurrent validity, and the criterion and predictive validity. Results The 13 scales displayed good internal consistency and test-retest reliability. The constructive validity of the WBI could clearly be demonstrated in both patients and healthy workers. Confirmative factor analyses revealed a CFI >.90 for all scales. The depression scale predicted future work absenteeism (>6 weeks) because of a common mental disorder in healthy workers. The job strain scale and the illness behavior scale predicted long term absenteeism (>3 months) in workers with short-term absenteeism. The illness behavior scale moderately predicted return to work in rehab patients attending an intensive multidisciplinary program. Conclusions The WBI is a valid and reliable tool for occupational health practitioners to screen for risk factors for prolonged or future sickness absence. With this tool they will have reliable indications for further advice and interventions to restore the work ability.

Earth as a Tool for Astrobiology—A European Perspective

Science.gov (United States)

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

2017-07-01

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

[Sense of Coherence Scale according to Antonovsky as a possible predictor for return to work for cardiac surgery intensive care patients].

Science.gov (United States)

Benstoem, C; Wübker, R; Lüngen, M; Breuer, T; Marx, G; Autschbach, R; Goetzenich, A; Schnoering, H

2018-05-14

For cardiac surgery patients who were employed prior to surgery, the return to their professional life is of special importance. In addition to medical reasons, such as pre-existing conditions, the success of the operation or postoperative course and patient-intrinsic reasons, which can be assessed with the Sense of Coherence (SOC) scale by Antonovsky, may also play a role in the question of a possible return into working life. In this study 278 patients (invasive coronary artery bypass graft surgery and/or surgery on heart valves, age work. The cohort was stratified according to the time of return to work. Subsequently, the point of maximum sensitivity and specificity was determined for the total SOC score and the prediction power was considered. Of the 278 patients, 61 questionnaires (22%) were considered as eligible and included in the analysis. Of these, 47 participants had returned to work after undergoing cardiac surgery and 14 participants had not. We observed significant differences in SOC values between both groups (146.07 ± 29.76 versus 124.29 ± 28.8, p = 0.020). Patients that returned to work within the first 6 months after surgery showed even higher SOC scores (148.56 ± 28.98, p = 0.034). Patients with an SOC score life after cardiac surgery. The SOC is an easily obtainable score that reliably predicts the probability of return to work after cardiac surgery.

MPO-type single-mode multi-fiber connector: Low-loss and high-return-loss intermateability of APC-MPO connectors

Science.gov (United States)

Satake, Toshiaki; Nagasawa, Shinji; Hughes, Mike; Lutz, Sharon

2011-01-01

The electrical communication laboratory of NTT started the research of MT (Mechanically Transferable) connector in early 1980s. The initial goal was to realize a multi-fiber connector which can repeat low loss, stable, reliable and low-cost connections of subscriber optical fiber cable networks for more than 20 years period in the field. We review the multi-fiber alignment design with two guide pins, and following several technical improvements toward the final MT connector used in the commercial telecommunication networks. And then, we review development histories to reach to the low-loss, high-return-loss and reliable APC-MPO (Angled Physical Contact Multi-fiber Push On) connectors introduced in NTT COs and in Verizon's FTTH (Fiber To The Home) networks. In the latter half, we propose the low-loss intermateability design for connectors made by different suppliers in order to enable mass introductions into large scale systems. In addition we also describe an accurate connector loss presumption method for different lots' ferrules based on the MT ferrule dimension data before assembling the connectors. We believe with a wide intermateability of APC-MPO connector will increase its use in the fields. The APC-MPO connector manufactured based on the proposed design had low insertion losses of less than 0.25 dB at the same level of simplex connectors and the higher level of return losses higher than 65 dB.

Optimal Safety Earthing – Earth Electrode Sizing Using A ...

African Journals Online (AJOL)

In this paper a deterministic approach in the sizing of earth electrode using the permissible touch voltage criteria is presented. The deterministic approach is effectively applied in the sizing of the length of earth rod required for the safe earthing of residential and facility buildings. This approach ensures that the earthing ...

MANAJEMEN LABA, RETURN SAHAM, DAN KINERJA OPERASI SEBAGAI PEMODERASI

Directory of Open Access Journals (Sweden)

Farid Addy Sumantri

2017-09-01

Full Text Available The purpose of this study was to determine the indications of the practice of earnings management at the time of the IPO, one year after the IPO, and two years after the IPO. This study also examined the effect of earnings management on stock returns and operating performance in moderating the relationship between earnings management and stock returns. The study sample comprised 33 firms that go public in the year 2007 to 2011 using a purposive sampling method. Earnings management is proxied by discretionary accruals using the Modified Jones Model, which used proxy for the stock return is cummulative abnormal returns (CAR, while for the company's operating performance used proxy for the return on assets (ROA. The results showed that there were indications of earnings management at the time of the IPO, one year after the IPO, and two years after the IPO with a lower profit rate. No effect on earnings management is proxied by stock return cummulative abnormal returns (CAR. Operating performance of the company also can not moderate the relationship between earnings management with stock return.   Keywords: Earning Management, Initial Public Offering, Cummulative Abnormal Return, Return On Asset

The Mars Sample Return Lab(s) - Lessons from the Past and Implications for the Future

Science.gov (United States)

Allen, Carlton

2012-01-01

It has been widely understood for many years that an essential component of a Mars Sample Return mission is a Sample Receiving Facility (SRF). The purpose of such a facility would be to take delivery of the flight hardware that lands on Earth, open the spacecraft and extract the sample container and samples, and conduct an agreed upon test protocol, while ensuring strict containment and contamination control of the samples while in the SRF. Any samples that are found to be non-hazardous (or are rendered non-hazardous by sterilization) would then be transferred to long-term curation. Although the general concept of an SRF is relatively straightforward, there has been considerable discussion about implementation planning.

The Importance of Sample Return in Establishing Chemical Evidence for Life on Mars or Other Solar System Bodies

Science.gov (United States)

Glavin, D. P.; Conrad, P.; Dworkin, J. P.; Eigenbrode, J.; Mahaffy, P. R.

2011-01-01

The search for evidence of life on Mars and elsewhere will continue to be one of the primary goals of NASA s robotic exploration program over the next decade. NASA and ESA are currently planning a series of robotic missions to Mars with the goal of understanding its climate, resources, and potential for harboring past or present life. One key goal will be the search for chemical biomarkers including complex organic compounds important in life on Earth. These include amino acids, the monomer building blocks of proteins and enzymes, nucleobases and sugars which form the backbone of DNA and RNA, and lipids, the structural components of cell membranes. Many of these organic compounds can also be formed abiotically as demonstrated by their prevalence in carbonaceous meteorites [1], though, their molecular characteristics may distinguish a biological source [2]. It is possible that in situ instruments may reveal such characteristics, however, return of the right sample (i.e. one with biosignatures or having a high probability of biosignatures) to Earth would allow for more intensive laboratory studies using a broad array of powerful instrumentation for bulk characterization, molecular detection, isotopic and enantiomeric compositions, and spatially resolved chemistry that may be required for confirmation of extant or extinct Martian life. Here we will discuss the current analytical capabilities and strategies for the detection of organics on the Mars Science Laboratory (MSL) using the Sample Analysis at Mars (SAM) instrument suite and how sample return missions from Mars and other targets of astrobiological interest will help advance our understanding of chemical biosignatures in the solar system.

Bringing the environment down to earth.

Science.gov (United States)

Reinhardt, F L

1999-01-01

The debate on business and the environment has typically been framed in simple yes-or-no terms: "Does it pay to be green?" But the environment, like other business issues, requires a more complex approach--one that demands more than such all-or-nothing thinking. Managers need to ask instead, "Under what circumstances do particular kinds of environmental investments deliver returns to shareholders?" This article presents five approaches that managers can take to identify those circumstances and integrate the environment into their business thinking. These approaches will enable companies with the right industry structure, competitive position, and managerial skills to reconcile their responsibility to shareholders with the pressure to be faithful stewards of the earth's resources. Some companies can distance themselves from competitors by differentiating their products and commanding higher prices for them. Others may be able to "manage" their competitors by imposing a set of private regulations or by helping to shape the rules written by government officials. Still others may be able to cut costs and help the environment simultaneously. Almost all can learn to improve their management of risk and thus reduce the outlays associated with accidents, lawsuits, and boycotts. And some companies may even be able to make systemic changes that will redefine competition in their markets. All five approaches can help managers bring the environment down to earth. And that means bringing the environment back into the fold of business problems and determining when it really pays to be green.

Building a better search engine for earth science data

Science.gov (United States)

Armstrong, E. M.; Yang, C. P.; Moroni, D. F.; McGibbney, L. J.; Jiang, Y.; Huang, T.; Greguska, F. R., III; Li, Y.; Finch, C. J.

2017-12-01

Free text data searching of earth science datasets has been implemented with varying degrees of success and completeness across the spectrum of the 12 NASA earth sciences data centers. At the JPL Physical Oceanography Distributed Active Archive Center (PO.DAAC) the search engine has been developed around the Solr/Lucene platform. Others have chosen other popular enterprise search platforms like Elasticsearch. Regardless, the default implementations of these search engines leveraging factors such as dataset popularity, term frequency and inverse document term frequency do not fully meet the needs of precise relevancy and ranking of earth science search results. For the PO.DAAC, this shortcoming has been identified for several years by its external User Working Group that has assigned several recommendations to improve the relevancy and discoverability of datasets related to remotely sensed sea surface temperature, ocean wind, waves, salinity, height and gravity that comprise a total count of over 500 public availability datasets. Recently, the PO.DAAC has teamed with an effort led by George Mason University to improve the improve the search and relevancy ranking of oceanographic data via a simple search interface and powerful backend services called MUDROD (Mining and Utilizing Dataset Relevancy from Oceanographic Datasets to Improve Data Discovery) funded by the NASA AIST program. MUDROD has mined and utilized the combination of PO.DAAC earth science dataset metadata, usage metrics, and user feedback and search history to objectively extract relevance for improved data discovery and access. In addition to improved dataset relevance and ranking, the MUDROD search engine also returns recommendations to related datasets and related user queries. This presentation will report on use cases that drove the architecture and development, and the success metrics and improvements on search precision and recall that MUDROD has demonstrated over the existing PO.DAAC search

Multi-Mission Earth Vehicle Subsonic Dynamic Stability Testing and Analyses

Science.gov (United States)

Glaab, Louis J.; Fremaux, C. Michael

2013-01-01

Multi-Mission Earth Entry Vehicles (MMEEVs) are blunt-body vehicles designed with the purpose of transporting payloads from outer space to the surface of the Earth. To achieve high-reliability and minimum weight, MMEEVs avoid use of limited-reliability systems, such as parachutes, retro-rockets, and reaction control systems and rely on the natural aerodynamic stability of the vehicle throughout the Entry, Descent, and Landing (EDL) phase of flight. The Multi-Mission Systems Analysis for Planetary Entry (M-SAPE) parametric design tool is used to facilitate the design of MMEEVs for an array of missions and develop and visualize the trade space. Testing in NASA Langley?s Vertical Spin Tunnel (VST) was conducted to significantly improve M-SAPE?s subsonic aerodynamic models. Vehicle size and shape can be driven by entry flight path angle and speed, thermal protection system performance, terminal velocity limitations, payload mass and density, among other design parameters. The objectives of the VST testing were to define usable subsonic center of gravity limits, and aerodynamic parameters for 6-degree-of-freedom (6-DOF) simulations, for a range of MMEEV designs. The range of MMEEVs tested was from 1.8m down to 1.2m diameter. A backshell extender provided the ability to test a design with a much larger payload for the 1.2m MMEEV.

RADYBAN: A tool for reliability analysis of dynamic fault trees through conversion into dynamic Bayesian networks

International Nuclear Information System (INIS)

Montani, S.; Portinale, L.; Bobbio, A.; Codetta-Raiteri, D.

2008-01-01

In this paper, we present RADYBAN (Reliability Analysis with DYnamic BAyesian Networks), a software tool which allows to analyze a dynamic fault tree relying on its conversion into a dynamic Bayesian network. The tool implements a modular algorithm for automatically translating a dynamic fault tree into the corresponding dynamic Bayesian network and exploits classical algorithms for the inference on dynamic Bayesian networks, in order to compute reliability measures. After having described the basic features of the tool, we show how it operates on a real world example and we compare the unreliability results it generates with those returned by other methodologies, in order to verify the correctness and the consistency of the results obtained

Precautionary Principle and Mars Sample Return

Science.gov (United States)

Arnould, Jacques

Many space missions have today as an aim the exploration and the knowledge of the planet Mars; consequently, the return of Martian samples seems one of the next possible stages, at the horizon of about fifteen years. Devoted in the search of traces of life, passed or presents, such a mission presents a true stake not only from the scientific point of view but also from the ethical. Right now, the COSPAR specified the precautions to be taken to avoid or, at the very least, to limit the risk of contamination of the terrestrial biosphere by pathogenic the hitherto unknown ones. Are these recommendations sufficient? Do they concern only the scientific prudence or take truly counts of the good of humanity and the life on Earth? In the final analysis, is the incurred risk, even weak, to endanger this life worth the sorrow of it? Hitherto confined with the scientific circles of astronomy and astrobiology, this questioning could move the public opinion and this one would undoubtedly call some with the principle of precaution. In what this recourse would be relevant? The precaution aims indeed the hypothetical risks, not yet confirmed scientifically, but of which the possibility can be identified starting from empirical and scientific knowledge; such is well the case. But is it for as much possible to apply this principle to the case of the Martian samples, insofar as the objective of such a mission remains for the strictly scientific moment? Is it possible to manage the risks in the same manner when it is a question of appropriation and exploitation of the natural resources and energy (GMO, nuclear energy, etc.) and when it acts, in the case of Mars, that only search of the knowledge? How to manage the fundamental difference between the risks voluntarily taken and arbitrarily imposed, clarified and keep silent? The case of the return of the samples leads to the borders of the contemporary interrogations on the stakes and the benefits of science, on the share of risk

Reliability assessment of hydraulic cylinders considering service loads and flaw distribution

International Nuclear Information System (INIS)

Altamura, Alessandra; Beretta, Stefano

2012-01-01

Manufacturing process, service conditions and material properties are all necessary requirements to a good design of tubular mechanical components subjected to fatigue. The most common approach to this design is usually deterministic, where a fixed NDT threshold, related to flaw acceptance limit, is set. However many uncertainties are left aside, i.e. the failure probability related to the fatigue strength under applied loads. This paper addresses the reliability evaluation of tubular mechanical components carrying some flaws and subjected to cyclic internal pressure variation. The aim is comparing the probability of failure obtained under several assumptions. A reliability assessment model, based on a random variable approach, has been implemented by using the Monte Carlo method. The analysis of the results, from a case study based on load spectra measurements of hydraulic cylinders of earth moving machines, has consented to evaluate the most important factors influencing the fatigue life prediction of these components. Highlights: ► Reliability evaluation of tubular components subjected to variable internal pressure. ► The dispersion of the threshold controls the stochasticity of crack growth. ► A random variable model has been developed using Monte Carlo. ► Initial crack size and spectrum shape are key factors in reliability evaluation.

Launch and Assembly Reliability Analysis for Human Space Exploration Missions

Science.gov (United States)

Cates, Grant; Gelito, Justin; Stromgren, Chel; Cirillo, William; Goodliff, Kandyce

2012-01-01

NASA's future human space exploration strategy includes single and multi-launch missions to various destinations including cis-lunar space, near Earth objects such as asteroids, and ultimately Mars. Each campaign is being defined by Design Reference Missions (DRMs). Many of these missions are complex, requiring multiple launches and assembly of vehicles in orbit. Certain missions also have constrained departure windows to the destination. These factors raise concerns regarding the reliability of launching and assembling all required elements in time to support planned departure. This paper describes an integrated methodology for analyzing launch and assembly reliability in any single DRM or set of DRMs starting with flight hardware manufacturing and ending with final departure to the destination. A discrete event simulation is built for each DRM that includes the pertinent risk factors including, but not limited to: manufacturing completion; ground transportation; ground processing; launch countdown; ascent; rendezvous and docking, assembly, and orbital operations leading up to trans-destination-injection. Each reliability factor can be selectively activated or deactivated so that the most critical risk factors can be identified. This enables NASA to prioritize mitigation actions so as to improve mission success.

Evaluation of the return rate of volunteer blood donors

Directory of Open Access Journals (Sweden)

Adriana de Fátima Lourençon

2011-06-01

Full Text Available BACKGROUND: To convert first-time blood donors into regular volunteer donors is a challenge to transfusion services. OBJECTIVES: This study aims to estimate the return rate of first time donors of the Ribeirão Preto Blood Center and of other blood centers in its coverage region. METHODS: The histories of 115,553 volunteer donors between 1996 and 2005 were analyzed. Statistical analysis was based on a parametric long-term survival model that allows an estimation of the proportion of donors who never return for further donations. RESULTS: Only 40% of individuals return within one year after the first donation and 53% return within two years. It is estimated that 30% never return to donate. Higher return rates were observed among Black donors. No significant difference was found in non-return rates regarding gender, blood type, Rh blood group and blood collection unit. CONCLUSIONS: The low percentage of first-time donors who return for further blood donation reinforces the need for marketing actions and strategies aimed at increasing the return rates.

Return migration as failure or success? : The determinants of return migration intentions among Moroccan migrants in Europe

NARCIS (Netherlands)

de Haas, H.; Fokkema, T.; Fihri, M.F.

2015-01-01

Different migration theories generate competing hypotheses with regard to determinants of return migration. While neoclassical migration theory associates migration to the failure to integrate at the destination, the new economics of labour migration sees return migration as the logical stage after

ACL Return to Sport Guidelines and Criteria.

Science.gov (United States)

Davies, George J; McCarty, Eric; Provencher, Matthew; Manske, Robert C

2017-09-01

Because of the epidemiological incidence of anterior cruciate ligament (ACL) injuries, the high reinjury rates that occur when returning back to sports, the actual number of patients that return to the same premorbid level of competition, the high incidence of osteoarthritis at 5-10-year follow-ups, and the effects on the long-term health of the knee and the quality of life for the patient, individualizing the return to sports after ACL reconstruction (ACL-R) is critical. However, one of the challenging but unsolved dilemmas is what criteria and clinical decision making should be used to return an athlete back to sports following an ACL-R. This article describes an example of a functional testing algorithm (FTA) as one method for clinical decision making based on quantitative and qualitative testing and assessment utilized to make informed decisions to return an athlete to their sports safely and without compromised performance. The methods were a review of the best current evidence to support a FTA. In order to evaluate all the complicated domains of the clinical decision making for individualizing the return to sports after ACL-R, numerous assessments need to be performed including the biopsychosocial concepts, impairment testing, strength and power testing, functional testing, and patient-reported outcomes (PROs). The optimum criteria to use for individualizing the return to sports after ACL-R remain elusive. However, since this decision needs to be made on a regular basis with the safety and performance factors of the patient involved, this FTA provides one method of quantitatively and qualitatively making the decisions. Admittedly, there is no predictive validity of this system, but it does provide practical guidelines to facilitate the clinical decision making process for return to sports. The clinical decision to return an athlete back into competition has significant implications ranging from the safety of the athlete, to performance factors and actual

Global Variance Risk Premium and Forex Return Predictability

OpenAIRE

Aloosh, Arash

2014-01-01

In a long-run risk model with stochastic volatility and frictionless markets, I express expected forex returns as a function of consumption growth variances and stock variance risk premiums (VRPs)—the difference between the risk-neutral and statistical expectations of market return variation. This provides a motivation for using the forward-looking information available in stock market volatility indices to predict forex returns. Empirically, I find that stock VRPs predict forex returns at a ...

Modeling Earth Albedo for Satellites in Earth Orbit

DEFF Research Database (Denmark)

Bhanderi, Dan; Bak, Thomas

2005-01-01

Many satellite are influences by the Earthøs albedo, though very few model schemes exist.in order to predict this phenomenon. Earth albedo is often treated as noise, or ignored completely. When applying solar cells in the attitude hardware, Earth albedo can cause the attitude estimate to deviate...... with as much as 20 deg. Digital Sun sensors with Earth albedo correction in hardware exist, but are expensive. In addition, albedo estimates are necessary in thermal calculations and power budgets. We present a modeling scheme base4d on Eartht reflectance, measured by NASA's Total Ozone Mapping Spectrometer......, in which the Earth Probe Satellite has recorded reflectivity data daily since mid 1996. The mean of these data can be used to calculate the Earth albedo given the positions of the satellite and the Sun. Our results show that the albedo varies highly with the solar angle to the satellite's field of view...

Earth as an extrasolar planet: Earth model validation using EPOXI earth observations.

Science.gov (United States)

Robinson, Tyler D; Meadows, Victoria S; Crisp, David; Deming, Drake; A'hearn, Michael F; Charbonneau, David; Livengood, Timothy A; Seager, Sara; Barry, Richard K; Hearty, Thomas; Hewagama, Tilak; Lisse, Carey M; McFadden, Lucy A; Wellnitz, Dennis D

2011-06-01

The EPOXI Discovery Mission of Opportunity reused the Deep Impact flyby spacecraft to obtain spatially and temporally resolved visible photometric and moderate resolution near-infrared (NIR) spectroscopic observations of Earth. These remote observations provide a rigorous validation of whole-disk Earth model simulations used to better understand remotely detectable extrasolar planet characteristics. We have used these data to upgrade, correct, and validate the NASA Astrobiology Institute's Virtual Planetary Laboratory three-dimensional line-by-line, multiple-scattering spectral Earth model. This comprehensive model now includes specular reflectance from the ocean and explicitly includes atmospheric effects such as Rayleigh scattering, gas absorption, and temperature structure. We have used this model to generate spatially and temporally resolved synthetic spectra and images of Earth for the dates of EPOXI observation. Model parameters were varied to yield an optimum fit to the data. We found that a minimum spatial resolution of ∼100 pixels on the visible disk, and four categories of water clouds, which were defined by using observed cloud positions and optical thicknesses, were needed to yield acceptable fits. The validated model provides a simultaneous fit to Earth's lightcurve, absolute brightness, and spectral data, with a root-mean-square (RMS) error of typically less than 3% for the multiwavelength lightcurves and residuals of ∼10% for the absolute brightness throughout the visible and NIR spectral range. We have extended our validation into the mid-infrared by comparing the model to high spectral resolution observations of Earth from the Atmospheric Infrared Sounder, obtaining a fit with residuals of ∼7% and brightness temperature errors of less than 1 K in the atmospheric window. For the purpose of understanding the observable characteristics of the distant Earth at arbitrary viewing geometry and observing cadence, our validated forward model can be

Better understanding flow-restricted environments from hideout return analyses

International Nuclear Information System (INIS)

Ollar, Ph.; Viricel-Honorez, L.

1998-01-01

Understanding and controlling the chemical phenomena in flow-restricted areas of the secondary side of steam generators (SG) is a key point in fighting against corrosion (IGA) in these areas. Hence, more than 150 hideout returns from French plants are used to assess the chemical environment in flow-restricted areas. The influence of several parameters such as tube support plates design, SG blowdown flowrate and temperature at the end of hideout returns, on returned weights and on flow-restricted environments predicted by modelling are examined. A correlation between different operating and returned chemistry indexes (molar ratios), and IGA is sought: no link is found between IGA and Na/Cl molar ratio at the beginning of hideout returns. However, as IGA extends, the returned weights of sodium and chloride seem to decrease, suggesting a greater hideout and a lower hideout return efficiency, perhaps due to SG fouling, and/or a smaller hideout/hideout return thanks to an improved operating chemistry. Using the pH computed from hideout return data as an index for the presence of IGA is also studied: no correlation is found between the two. Improving plants chemistry is finally proposed, based on an optimization of hideout returns. (authors)

The Returns to Entrepreneurship

DEFF Research Database (Denmark)

Van Praag, Mirjam; Raknerud, Arvid

Empirical studies show low pecuniary returns of switching from wage employment to entrepreneurship. We reconsider the pecuniary gains of this switching by employing a two-stage procedure, where the randomness in the timing of inheritance transfers is used as an exclusion restriction to identify...... causal effects. The model is estimated on data covering the whole Norwegian population of individuals matched to the entire population of firms established in the period 2002-2011. The results indicate that the average returns to entrepreneurship are significantly negative for individuals entering...... entrepreneurship through self-employment and modest, but significantly positive, for incorporated startups....

The feasibility and application of using gravitational energy to allow efficient travel between earth and Mars

Science.gov (United States)

King, O. L.; Avvento, Gennaro J.

This paper discusses the feasibility and application of using gravitational energy attained in a planetary swing-by to control the trajectory of an interplanetary transfer vehicle (IPTV) - establishing nonstop round trip orbits between earth and Mars. Energy supplied by the swing-by process and supplemented by minor correction burns will allow efficient nonstop round trip travel between earth and Mars. The IPTV will have all the necessary support equipment to maintain the cargo (manned/unmanned) during transit. At the planetary 'landfall' points, the IPTV will not decelerate but will perform a swing-by maneuver returning to the planet of origin. Cargo elements will either depart or dock with the IPTV at the planetary approach asymptote. This will be the only component of the system to undergo propulsive maneuvers.

Digital Earth - A sustainable Earth

Science.gov (United States)

Mahavir

2014-02-01

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

Communication and collaboration among return-to-work stakeholders.

Science.gov (United States)

Russell, Elizabeth; Kosny, Agnieszka

2018-05-17

Workers who are injured or become ill on the job are best able to return-to-work when stakeholders involved in their case collaborate and communicate. This study examined health care providers' and case managers' engagement in rehabilitation and return-to-work following workplace injury or illness. In-depth interviews were conducted with 97 health care providers and 34 case managers in four Canadian provinces about their experiences facilitating rehabilitation and return-to-work, and interacting with system stakeholders. A qualitative thematic content analysis demonstrated two key findings. Firstly, stakeholders were challenged to collaborate as a result of: barriers to interdisciplinary and cross-professional communication; philosophical differences about the timing and appropriateness of return-to-work; and confusion among health care providers about the workers' compensation system. Secondly, these challenges adversely affected the co-ordination of patient care, and consequentially, injured workers often became information conduits, and effective and timely treatment and return-to-work was sometimes negatively impacted. Communication challenges between health care providers and case managers may negatively impact patient care and alienate treating health care providers. Discussion about role clarification, the appropriateness of early return-to-work, how paperwork shapes health care providers' role expectations, and strengthened inter-professional communication are considered. Implications for Rehabilitation Administrative and conceptual barriers in workers' compensation systems challenge collaboration and communication between health care providers and case managers. Injured workers may become conduits of incorrect information, resulting in adversarial relationships, overturned health care providers' recommendations, and their disengagement from rehabilitation and return-to-work. Stakeholders should clarify the role of health care providers during

26 CFR 301.6103(j)(1)-1 - Disclosures of return information reflected on returns to officers and employees of the...

Science.gov (United States)

2010-04-01

... related activities. 301.6103(j)(1)-1 Section 301.6103(j)(1)-1 Internal Revenue INTERNAL REVENUE SERVICE... and Returns Returns and Records § 301.6103(j)(1)-1 Disclosures of return information reflected on... related activities. (a) General rule. Pursuant to the provisions of section 6103(j)(1) of the Internal...

Predictability of Returns and Cash Flows

OpenAIRE

Ralph S.J. Koijen; Stijn Van Nieuwerburgh

2010-01-01

We review the literature on return and cash-flow growth predictability from the perspective of the present-value identity. We focus predominantly on recent work. Our emphasis is on U.S. aggregate stock return predictability, but we also discuss evidence from other asset classes and countries.

Return on Investment from Biochar Application

Science.gov (United States)

Current literature has yet to fully address the cost of biochar application or the return on investment to the grower. The objectives were to identify possible on-farm spreader equipment, spreader capacity, application expenses, and rate of return needed for growers to apply biochar economically. Bi...

Does graded return-to-work improve sick-listed workers' chance of returning to regular working hours?

Science.gov (United States)

Høgelund, Jan; Holm, Anders; McIntosh, James

2010-01-01

Using Danish register and survey data, we examine the effect of a national graded return-to-work program on the probability of sick-listed workers returning to regular working hours. During program participation, the sick-listed worker works fewer hours and receives the normal hourly wage for the hours worked and sickness benefit for the hours off work. When the worker's health improves, working hours are increased until the sick-listed worker is able to work regular hours. Taking account of unobserved differences between program participants and non-participants, we find that participation in the program significantly increases the probability of returning to regular working hours. Copyright 2009 Elsevier B.V. All rights reserved.

Low-energy near Earth asteroid capture using Earth flybys and aerobraking

Science.gov (United States)

Tan, Minghu; McInnes, Colin; Ceriotti, Matteo

2018-04-01

Since the Sun-Earth libration points L1 and L2 are regarded as ideal locations for space science missions and candidate gateways for future crewed interplanetary missions, capturing near-Earth asteroids (NEAs) around the Sun-Earth L1/L2 points has generated significant interest. Therefore, this paper proposes the concept of coupling together a flyby of the Earth and then capturing small NEAs onto Sun-Earth L1/L2 periodic orbits. In this capture strategy, the Sun-Earth circular restricted three-body problem (CRTBP) is used to calculate target Lypaunov orbits and their invariant manifolds. A periapsis map is then employed to determine the required perigee of the Earth flyby. Moreover, depending on the perigee distance of the flyby, Earth flybys with and without aerobraking are investigated to design a transfer trajectory capturing a small NEA from its initial orbit to the stable manifolds associated with Sun-Earth L1/L2 periodic orbits. Finally, a global optimization is carried out, based on a detailed design procedure for NEA capture using an Earth flyby. Results show that the NEA capture strategies using an Earth flyby with and without aerobraking both have the potential to be of lower cost in terms of energy requirements than a direct NEA capture strategy without the Earth flyby. Moreover, NEA capture with an Earth flyby also has the potential for a shorter flight time compared to the NEA capture strategy without the Earth flyby.

Attitude and Trajectory Estimation Using Earth Magnetic Field Data

Science.gov (United States)

Deutschmann, Julie; Bar-Itzhack, Itzhack Y.

1996-01-01

The magnetometer has long been a reliable, inexpensive sensor used in spacecraft momentum management and attitude estimation. Recent studies show an increased accuracy potential for magnetometer-only attitude estimation systems. Since the Earth's magnetic field is a function of time and position, and since time is known quite precisely, the differences between the computer and measured magnetic field components, as measured by the magnetometers throughout the entire spacecraft orbit, are a function of both the spacecraft trajectory and attitude errors. Therefore, these errors can be used to estimate both trajectory and attitude. Traditionally, satellite attitude and trajectory have been estimated with completely separate system, using different measurement data. Recently, trajectory estimation for low earth orbit satellites was successfully demonstrated in ground software using only magnetometer data. This work proposes a single augmented extended Kalman Filter to simultaneously and autonomously estimate both spacecraft trajectory and attitude with data from a magnetometer and either dynamically determined rates or gyro-measured body rates.

Motivational goals, group identifications, and psychosocial adjustment of returning migrants: The case of Jews returning to Russia.

Science.gov (United States)

Tartakovsky, Eugene; Patrakov, Eduard; Nikulina, Marina

2017-12-01

The present study investigated the motivational goals, group identifications, and psychosocial adjustment of Jews who returned to Russia after emigrating from the republics of the Former Soviet Union to different countries (n = 151). To gain a deeper understanding of these returning migrants, their traits were compared with those of Jews living in Russia who did not emigrate (n = 935). Compared to locals, returnees reported a higher preference for the openness to change and self-enhancement values and a lower preference for the conservation values; there was no difference in the self-transcendence values. Returning migrants had a relatively weak affiliation with the home country: they had a weaker identification with the home country than with the country of emigration, their identification with Russians was weaker than that among Jews who did not emigrate from Russia, and their intention to emigrate (again) from Russia was greater than that among locals. However, the Jewish identification of returning migrants was similar to that of locals. The adjustment of returning migrants varied across different dimensions: their economic adjustment was better than that of locals; however, the interpersonal adjustment of returnees was less successful than among locals. © 2016 International Union of Psychological Science.

Economic and accounting rates of return

NARCIS (Netherlands)

Feenstra, D.W.; Wang, H.

2000-01-01

The rate of return on invested capital is a central concept in financial analysis. The purpose of calculating the rate of return on investment in general is to measure the financial performance, to assess the desirability of a project and to make decisions on the valuation of firms. Financial

Parasitic diseases in the returning traveller

African Journals Online (AJOL)

2009-06-11

Jun 11, 2009 ... exception is infection with schistosomiasis after leisure activities in infested freshwater. (the water sports enthusiast returning from a sojourn on Lake Malawi .... are harbouring a 'blind passenger' from abroad. However, long-term travellers, both private or business, should be screened on return. A thorough ...

Sealed Planetary Return Canister (SPRC), Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Sample return missions have primary importance in future planetary missions. A basic requirement is that samples be returned in pristine, uncontaminated condition,...

Product return management

DEFF Research Database (Denmark)

Shaharudin, Mohd Rizaimy; Govindan, Kannan; Zailani, Suhaiza

2017-01-01

The aim of this study is to examine the extent to which product returns motivate manufacturing firms to adopt closed-loop supply chain activities that influence the effectiveness of reverse supply chains. The hypotheses have been tested using data from a sample of 150 environmental management...... system ISO 14001 certified manufacturing firms in Malaysia through the census sampling approach. The results of the empirical test using LISREL Version 8.70 for the structural equation modeling support the fundamental explanation of the influence of the institutional forces towards the adoption of closed...... eventually impacts the firm's effectiveness in the reverse supply chain. The findings also help managers to understand the factors that can improve the outcome of the adoption of closed-loop supply chain activities by intensifying the extent of involvement in product returns, which provides a valuable...

76 FR 17521 - Specified Tax Return Preparers Required To File Individual Income Tax Returns Using Magnetic Media

Science.gov (United States)

2011-03-30

... regulations reflect changes made to the law by the Worker, Homeownership, and Business Assistance Act of 2009... definition of a ``specified tax return preparer'' must electronically file Federal income tax returns that... of the Worker, Homeownership, and Business Assistance Act of 2009 (Pub. L. 111-92 (123 Stat. 2984...

Spatial abilities, Earth science conceptual understanding, and psychological gender of university non-science majors

Science.gov (United States)

Black, Alice A. (Jill)

Research has shown the presence of many Earth science misconceptions and conceptual difficulties that may impede concept understanding, and has also identified a number of categories of spatial ability. Although spatial ability has been linked to high performance in science, some researchers believe it has been overlooked in traditional education. Evidence exists that spatial ability can be improved. This correlational study investigated the relationship among Earth science conceptual understanding, three types of spatial ability, and psychological gender, a self-classification that reflects socially-accepted personality and gender traits. A test of Earth science concept understanding, the Earth Science Concepts (ESC) test, was developed and field tested from 2001 to 2003 in 15 sections of university classes. Criterion validity was .60, significant at the .01 level. Spearman/Brown reliability was .74 and Kuder/Richardson reliability was .63. The Purdue Visualization of Rotations (PVOR) (mental rotation), the Group Embedded Figures Test (GEFT) (spatial perception), the Differential Aptitude Test: Space Relations (DAT) (spatial visualization), and the Bem Inventory (BI) (psychological gender) were administered to 97 non-major university students enrolled in undergraduate science classes. Spearman correlations revealed moderately significant correlations at the .01 level between ESC scores and each of the three spatial ability test scores. Stepwise regression analysis indicated that PVOR scores were the best predictor of ESC scores, and showed that spatial ability scores accounted for 27% of the total variation in ESC scores. Spatial test scores were moderately or weakly correlated with each other. No significant correlations were found among BI scores and other test scores. Scantron difficulty analysis of ESC items produced difficulty ratings ranging from 33.04 to 96.43, indicating the percentage of students who answered incorrectly. Mean score on the ESC was 34

Making real-time reactive systems reliable

Science.gov (United States)

Marzullo, Keith; Wood, Mark

1990-01-01

A reactive system is characterized by a control program that interacts with an environment (or controlled program). The control program monitors the environment and reacts to significant events by sending commands to the environment. This structure is quite general. Not only are most embedded real time systems reactive systems, but so are monitoring and debugging systems and distributed application management systems. Since reactive systems are usually long running and may control physical equipment, fault tolerance is vital. The research tries to understand the principal issues of fault tolerance in real time reactive systems and to build tools that allow a programmer to design reliable, real time reactive systems. In order to make real time reactive systems reliable, several issues must be addressed: (1) How can a control program be built to tolerate failures of sensors and actuators. To achieve this, a methodology was developed for transforming a control program that references physical value into one that tolerates sensors that can fail and can return inaccurate values; (2) How can the real time reactive system be built to tolerate failures of the control program. Towards this goal, whether the techniques presented can be extended to real time reactive systems is investigated; and (3) How can the environment be specified in a way that is useful for writing a control program. Towards this goal, whether a system with real time constraints can be expressed as an equivalent system without such constraints is also investigated.

Return to football and long-term clinical outcomes after thumb ulnar collateral ligament suture anchor repair in collegiate athletes.

Science.gov (United States)

Werner, Brian C; Hadeed, Michael M; Lyons, Matthew L; Gluck, Joshua S; Diduch, David R; Chhabra, A Bobby

2014-10-01

To evaluate return to play after complete thumb ulnar collateral ligament (UCL) injury treated with suture anchor repair for both skill position and non-skill position collegiate football athletes and report minimum 2-year clinical outcomes in this population. For this retrospective study, inclusion criteria were complete rupture of the thumb UCL and suture anchor repair in a collegiate football athlete performed by a single surgeon who used an identical technique for all patients. Data collection included chart review, determination of return to play, and Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) outcomes. A total of 18 collegiate football athletes were identified, all of whom were evaluated for follow-up by telephone, e-mail, or regular mail at an average 6-year follow-up. Nine were skill position players; the remaining 9 played in nonskill positions. All players returned to at least the same level of play. The average QuickDASH score for the entire cohort was 1 out of 100; QuickDASH work score, 0 out of 100; and sport score, 1 out of 100. Average time to surgery for skill position players was 12 days compared with 43 for non-skill position players. Average return to play for skill position players was 7 weeks postoperatively compared with 4 weeks for non-skill position players. There was no difference in average QuickDASH overall scores or subgroup scores between cohorts. Collegiate football athletes treated for thumb UCL injuries with suture anchor repair had quick return to play, reliable return to the same level of activity, and excellent long-term clinical outcomes. Skill position players had surgery sooner after injury and returned to play later than non-skill position players, with no differences in final level of play or clinical outcomes. Management of thumb UCL injuries in collegiate football athletes can be safely and effectively tailored according to the demands of the player's football position. Therapeutic IV. Copyright © 2014

Stock returns and foreign investment in Brazil

OpenAIRE

Reis, Luciana; Meurer, Roberto; Da Silva, Sergio

2008-01-01

We examine the relationship between stock returns and foreign investment in Brazil, and find that the inflows of foreign investment boosted the returns from 1995 to 2005. There was a strong contemporaneous correlation, although not Granger-causality. Foreign investment along with the exchange rate, the influence of the world stock markets, and country risk can explain 73 percent of the changes that occurred in the stock returns over the period. We also find that positive feedback trading play...

INSTITUTIONAL OWNERSHIP LEVEL AND RISK-ADJUSTED RETURN

OpenAIRE

Isaiah, Chioma; Li, Meng (Emma)

2017-01-01

This paper examines the relationship between the level of institutional ownership andrisk-adjusted return on stocks. We find a significant positive relationship between the level ofinstitutional ownership on a stock and its risk-adjusted return. This result holds both in the longrun and in shorter time periods. Our findings suggest that all things being equal, it is possible toobtain risk-adjusted return by going short on the stocks with low institutional ownership andgoing long on those with...

76 FR 36996 - Extension of Time for Filing Returns

Science.gov (United States)

2011-06-24

... less time to complete accurate income tax returns and to provide timely information to the trust's... either chapter 7 or chapter 11 of Title 11 of the U.S. Code that is required to file an income tax return... estate or trust income tax return or failure to pay the amount shown as tax on the return. (g) Effective...

Rare earths

Energy Technology Data Exchange (ETDEWEB)

Cranstone, D A

1979-01-01

Rare earth elements are commonly extracted from the minerals monazite, bastnaesite, and xenotine. New uses for these elements are constantly developing; they have found applications in glass polishing, television tube phosphors, high-strength low-alloy steels, magnets, catalysts, refractory ceramics, and hydrogen sponge alloys. In Canada, rare earths have been produced as byproducts of the uranium mining industry, but there was no production of rare earths in 1978 or 1979. The world sources of and markets for the rare earth elements are discussed.

Psychometric investigation of the abbreviated concussion symptom inventory in a sample of U.S. Marines returning from combat.

Science.gov (United States)

Campbell, Justin S; Pulos, Steven; Haran, F Jay; Tsao, Jack W; Alphonso, Aimee L

2015-01-01

This study describes the psychometric investigation of an 11-item symptom checklist, the Abbreviated Concussion Symptom Inventory (ACSI). The ACSI is a dichotomously scored list of postconcussive symptoms associated with mild traumatic brain injury. The ACSI was administered to Marines (N = 1,435) within the 1st month of their return from combat deployments to Afghanistan. Psychometric analyses based upon nonparametric item response theory supported scoring the ACSI via simple summation of symptom endorsements; doing so produced a total score with good reliability (α = .802). Total scores were also found to significantly differentiate between different levels of head injury complexity during deployment, F(3, 1,431) = 100.75, p < .001. The findings support the use of the ASCI in research settings requiring a psychometrically reliable measure of postconcussion symptoms.

Sun-Earth National Program (PNST). 2010-2013 results and prospects

International Nuclear Information System (INIS)

2014-01-01

PNST (Programme National Soleil-Terre/Sun-Earth National Program) is dedicated to analysis of the Sun-Earth system, from generation of the solar magnetic field, flares and coronal mass ejections, until impact on the terrestrial magnetosphere, ionosphere and thermosphere. Research activities carried out in the frame of Programme National Soleil-Terre (PNST) rely on both ground-based and space-borne instruments. One of the main objectives of PNST is to stimulate coordinated studies and to optimize scientific return of these instruments. This document is the 2010-2013 scientific report of the program. It presents in the introduction the main questions and the 2010-2013 highlights. The 2010-2013 results and prospects are detailed in part 2: coupling mechanisms between the different plasma envelopes; multi-scale energy transport and turbulence; plasma acceleration and heating mechanisms; eruptive or impulsive activity in plasmas; space meteorology; perspectives. Part 3 deals with the interfaces with other programs (planetary plasmas, magnetism and sun-type stars activity). Part 4 presents the means, services and tools (ground and space instrumentation, databases and numerical tools). Finally, the administrative and financial status of the program is summarized (Program structure and operation, budget, manpower, publications)

27 CFR 41.112 - Tax return.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Tax return. 41.112 Section 41.112 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF... States Deferred Payment of Tax in Puerto Rico on Tobacco Products § 41.112 Tax return. The internal...

[Organising a successful return home].

Science.gov (United States)

Mézière, Anthony

Discharge from hospital is a major component of the quality and efficiency of the healthcare system. The failures of the return home of elderly people testify to the difficulties of applying guidelines in the area of hospital discharge. The action plan decided in the hospital for a successful return home can be jeopardised for personal, relational, functional and structural reasons originating from the different players involved in the hospital discharge. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Capital Structure and Stock Returns

OpenAIRE

Ivo Welch

2002-01-01

U.S. corporations do not issue and repurchase debt and equity to counteract the mechanistic effects of stock returns on their debt-equity ratios. Thus over one- to five-year horizons, stock returns can explain about 40 percent of debt ratio dynamics. Although corporate net issuing activity is lively and although it can explain 60 percent of debt ratio dynamics (long-term debt issuing activity being most capital structurerelevant), corporate issuing motives remain largely a mystery. When stock...

Return Migration among Elderly, Chronically Ill Bosnian Refugees

DEFF Research Database (Denmark)

Handlos, Line Neerup; Olwig, Karen Fog; Bygbjerg, Ib Christian

2015-01-01

Elderly migrants constitute a considerable share of global return migration; nevertheless, literature on the health aspects of the return migration among these migrants is still scarce. This study explores the significance of return migration among elderly, chronically ill Bosnian refugees from...... Denmark and the role of health issues in their decision to return. It is based on semi-structured interviews with 33 elderly, chronically ill Bosnian refugees who have moved back to Bosnia and Herzegovina, and 10 elderly, chronically ill Bosnian refugees who have remained in Denmark. The interviews show...

Mobility, return for development and sense of Europe: narratives of Moldavian immigrants returning from the European Union

Directory of Open Access Journals (Sweden)

Silvia Marcu

Full Text Available The article links migration, cross-border mobility and return for development embedded in terms of identity and approach to sense of Europe. Taking into account the global changes in Moldova, the paper examines the perceptions of mobility, return and identity of the Moldovans engaged in emigration in the countries of the European Union (EU. Utilising a multi-discipline approach and an in-depth qualitative interview technique, this article seeks to analyze how mobility and return can support social change and development of the country, and argues that people, who cross EU borders, living through the experience of emigration, acquire a pro-European mentality.

NASA's Earth Science Flight Program Meets the Challenges of Today and Tomorrow

Science.gov (United States)

Ianson, Eric E.

2016-01-01

NASA's capability for better understanding the current state of the Earth system. ESM and ESSP projects often involve partnerships with other US agencies and/or international organizations. This adds to the complexity of mission development, but allows for a greater scientific return on NASA's investments. The Earth Science Airborne Science Program provides manned and unmanned aircraft systems that further science and advance the use of satellite data. NASA uses these assets worldwide in campaigns to investigate extreme weather events, observe Earth system processes, obtain data for Earth science modeling activities, and calibrate instruments flying aboard Earth science spacecraft. The Airborne Science Program has six dedicated aircraft and access to many other platforms. The Earth Science Multi-Mission Operations program acquires, preserves, and distributes observational data from operating spacecraft to support Earth Science research focus areas. The Earth Observing System Data and Information System (EOSDIS), which has been in operations since 1994, primarily accomplishes this. EOSDIS acquires, processes, archives, and distributes Earth Science data and information products. The archiving of NASA Earth Science information happens at eight Distributed Active Archive Centers (DAACs) and four disciplinary data centers located across the United States. The DAACs specialize by topic area, and make their data available to researchers around the world. The DAACs currently house over 9 petabytes of data, growing at a rate of 6.4 terabytes per day. NASA's current Earth Science portfolio is responsive to the National Research Council (NRC) 2007 Earth Science Decadal Survey and well as the 2010 NASA Response to President Obama's Climate Plan. As the program evolves into the future it will leverage the lessons learned from the current missions in operations and development, and plan for adjustments to future objectives in response to the anticipated 2017 NRC Decadal Survey.

RETURNS OF PRIVATE EQUITY COMPARATIVE ANALYSES OF THE RETURNS OF VENTURE CAPITAL AND BUYOUT FUNDS IN EUROPE AND IN THE US

Directory of Open Access Journals (Sweden)

Becsky-Nagy Patrícia

2014-07-01

Full Text Available This paper focuses on the returns of two segments of Private Equity (PE market in Europe and in the US; Venture Capital (VC and Buyout (BO. Contrary to the publicly traded stocks where information about the trade of securities is public, the measuring of the returns of these asset classes is not unambiguous. The returns of PE investments are considered as confidential information therefore we only have estimations about the real characteristics of the financial performance of the PE industry. Although it is impossible to observe the whole industry it is important to chart its performance because PE plays an essential role in the financing of firms, especially firms at special stages of their lives and the more information the investors and companies have, the more effective PE market can be therefore it can contribute to economic growth, employment, innovation etc. In the literature PE, VC and BO are not distinguished properly and they are often used as synonyms. Despite their similarities, there are significant differences in the features of these types of investments. In this paper the authors present the return characteristics of the PE industry of Europe and the US with regard to the stage-focus of PE funds. The key findings of this paper are that in average the returns of BO funds exceeded the returns of VC funds in the US as well as in Europe. Not just according to the absolute value of the returns, but also according to its risk-return tradeoff BO seems to be a preferable investment. The same statements can be made in case of the European market. The US returns are higher than European VC returns, because compared to the US VC industry the European is undeveloped. On the other hand the gap between the performances of BO funds is not as significant as the difference of VC funds. While in the 90’s US BO funds outperformed the European ones, after the millennia European BO returns were higher. The analysis of returns reveals the

14 CFR 49.21 - Return of original conveyance.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Return of original conveyance. 49.21... RECORDING OF AIRCRAFT TITLES AND SECURITY DOCUMENTS General § 49.21 Return of original conveyance. If a person submitting a conveyance for recording wants the original returned to him, he must submit a true...

Theoretical and experimental studies of the waveforms associated with stratospheric infrasonic returns

Science.gov (United States)

Waxler, R.; Talmadge, C. L.; Blom, P.

2009-12-01

Theory predicts that for ground to ground infrasound propagation along paths which travel downwind, relative to the stratospheric jet, there is a shadow zone which ends about 200 km from the source where the first return from the stratosphere strikes the earth. With increasing range the single stratospheric arrival splits into two distinct arrivals, a fast arrival with the trace velocity of the effective sound speed at the stratopause, and a slower arrival with the trace velocity of the sound speed on the ground. To test the theory we have deployed eight infrasound arrays along an approximate line directly west of the site of the US Navy's Trident Missile rocket motor eliminations. The arrays were deployed during the summer of 2009 spaced roughly 10 km apart along a segment from 180 to 260 km west of the site. Comparisons between the theoretical predictions and the received data will be presented.

Rocking or rolling--perception of ambiguous motion after returning from space.

Directory of Open Access Journals (Sweden)

Gilles Clément

Full Text Available The central nervous system must resolve the ambiguity of inertial motion sensory cues in order to derive an accurate representation of spatial orientation. Adaptive changes during spaceflight in how the brain integrates vestibular cues with other sensory information can lead to impaired movement coordination, vertigo, spatial disorientation, and perceptual illusions after return to Earth. The purpose of this study was to compare tilt and translation motion perception in astronauts before and after returning from spaceflight. We hypothesized that these stimuli would be the most ambiguous in the low-frequency range (i.e., at about 0.3 Hz where the linear acceleration can be interpreted either as a translation or as a tilt relative to gravity. Verbal reports were obtained in eleven astronauts tested using a motion-based tilt-translation device and a variable radius centrifuge before and after flying for two weeks on board the Space Shuttle. Consistent with previous studies, roll tilt perception was overestimated shortly after spaceflight and then recovered with 1-2 days. During dynamic linear acceleration (0.15-0.6 Hz, ±1.7 m/s2 perception of translation was also overestimated immediately after flight. Recovery to baseline was observed after 2 days for lateral translation and 8 days for fore-aft translation. These results suggest that there was a shift in the frequency dynamic of tilt-translation motion perception after adaptation to weightlessness. These results have implications for manual control during landing of a space vehicle after exposure to microgravity, as it will be the case for human asteroid and Mars missions.

FINANCIAL RETURN ON ASSETS. THE IMPACT OF THE FINANCIAL RETURN ON ASSETS OVER THE COMPANY’S DEVELOPMENT

Directory of Open Access Journals (Sweden)

Constantin Căruntu

2009-11-01

Full Text Available The financial rate of return is a significant indicator for assessing the economic and financial performance of an enterprise for the internal diagnosis, as well as for the analysis required by the external partners. The financial return is a basic indicator which characterizes the business performances that is found directly under the trade policy (trade cost, efficiency of capital employed (economic profitability but also under the financial policy of the company. If the economic rate of return expresses a remuneration of the employed capital only in relation to operating activities, the financial rate of return quantifies a remuneration of the private capital trough all three types of activity: operational, financial and extraordinary. Starting from the consideration that the financial rate of return expresses the efficiency of equity or permanent capital use of the company we can state that it is of particular importance to the shareholders of the company, which considers according to it’s level whether their investments are justified and they will continue to support the business development through raising of fresh capital or abandonment for a limited period to one part of the dividends due. Managers, in turn, will be keen on maintaining an appropriate level of this rate, in order to retain their positions and to achieve the performance criteria of the company.

ISS EarthKam: Taking Photos of the Earth from Space

Science.gov (United States)

Haste, Turtle

2008-01-01

NASA is involved in a project involving the International Space Station (ISS) and an Earth-focused camera called EarthKam, where schools, and ultimately students, are allowed to remotely program the EarthKAM to take images. Here the author describes how EarthKam was used to help middle school students learn about biomes and develop their…

27 CFR 25.211 - Beer returned to brewery.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Beer returned to brewery..., DEPARTMENT OF THE TREASURY LIQUORS BEER Beer Returned to Brewery § 25.211 Beer returned to brewery. (a) General. Beer, produced in the United States, on which the brewer has paid or determined the tax may be...

Returning to sports after a back injury

Science.gov (United States)

... medlineplus.gov/ency/patientinstructions/000518.htm Returning to sports after a back injury To use the sharing ... Back pain - returning to sports Which Type of Sport is Best? In deciding when and if to ...

Multinomial-exponential reliability function: a software reliability model

International Nuclear Information System (INIS)

Saiz de Bustamante, Amalio; Saiz de Bustamante, Barbara

2003-01-01

The multinomial-exponential reliability function (MERF) was developed during a detailed study of the software failure/correction processes. Later on MERF was approximated by a much simpler exponential reliability function (EARF), which keeps most of MERF mathematical properties, so the two functions together makes up a single reliability model. The reliability model MERF/EARF considers the software failure process as a non-homogeneous Poisson process (NHPP), and the repair (correction) process, a multinomial distribution. The model supposes that both processes are statistically independent. The paper discusses the model's theoretical basis, its mathematical properties and its application to software reliability. Nevertheless it is foreseen model applications to inspection and maintenance of physical systems. The paper includes a complete numerical example of the model application to a software reliability analysis

Return Migration and Working Choices

OpenAIRE

TANI, Massimiliano; MAHUTEAU, Stéphane

2008-01-01

Collective Action to Support the Reintegration of Return Migrants in their Country of Origin (MIREM) This paper uses the recent survey carried out in the framework of the MIREM project on returnees to Algeria, Morocco and Tunisia and studies the duration of emigration and the labour force status upon returning. The results suggest that age and the year of emigration play a central role in the migration decision, but they do not support the hypothesis that the duration of migration is deter...

Slow return of displaced Southern Sudanese

Directory of Open Access Journals (Sweden)

Tim Morris

2007-07-01

Full Text Available The pace of repatriation of Sudanese refugees and return of IDP s to South Sudan has picked up but expectations at the time of the signing of the Comprehensive Peace Agreement (CPA CPA in January 2005 have yet to be realised. With all eyes on Darfur, assistance to sustain returns to South Sudan remains inadequate.

31 CFR 10.28 - Return of client's records.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Return of client's records. 10.28... § 10.28 Return of client's records. (a) In general, a practitioner must, at the request of a client, promptly return any and all records of the client that are necessary for the client to comply with his or...

Rare earth germanates

International Nuclear Information System (INIS)

Bondar', I.A.; Vinogradova, N.V.; Dem'yanets, L.N.

1983-01-01

Rare earth germanates attract close attention both as an independent class of compounds and analogues of a widely spread class of natural and synthetic minerals. The methods of rare earth germanate synthesis (solid-phase, hydrothermal) are considered. Systems on the basis of germanium and rare earth oxides, phase diagrams, phase transformations are studied. Using different chemical analysese the processes of rare earth germanate formation are investigated. IR spectra of alkali and rare earth metal germanates are presented, their comparative analysis being carried out. Crystal structures of the compounds, lattice parameters are studied. Fields of possible application of rare earth germanates are shown

Rare earth sulfates

International Nuclear Information System (INIS)

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

1986-01-01

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

Technology Development and Advanced Planning for Curation of Returned Mars Samples

Science.gov (United States)

Lindstrom, David J.; Allen, Carlton C.

2002-01-01

Safety Level 4) laboratories, while simultaneously maintaining cleanliness levels equaling those of state-of-the-art cleanrooms. Unique requirements for the processing of Mars samples have inspired a program to develop handling techniques that are much more precise and reliable than the approach (currently used for lunar samples) of employing gloved human hands in nitrogen-filled gloveboxes. Individual samples from Mars are expected to be much smaller than lunar samples, the total mass of samples returned by each mission being 0.5- 1 kg, compared with many tens of kg of lunar samples returned by each of the six Apollo missions. Smaller samples require much more of the processing to be done under microscopic observation. In addition, the requirements for cleanliness and high-level containment would be difficult to satisfy while using traditional gloveboxes. JSC has constructed a laboratory to test concepts and technologies important to future sample curation. The Advanced Curation Laboratory includes a new-generation glovebox equipped with a robotic arm to evaluate the usability of robotic and teleoperated systems to perform curatorial tasks. The laboratory also contains equipment for precision cleaning and the measurement of trace organic contamination.

CHOMIK -Sampling Device of Penetrating Type for Russian Phobos Sample Return Mission

Science.gov (United States)

Seweryn, Karol; Grygorczuk, Jerzy; Rickmann, Hans; Morawski, Marek; Aleksashkin, Sergey; Banaszkiewicz, Marek; Drogosz, Michal; Gurgurewicz, Joanna; Kozlov, Oleg E.; Krolikowska-Soltan, Malgorzata; Sutugin, Sergiej E.; Wawrzaszek, Roman; Wisniewski, Lukasz; Zakharov, Alexander

Measurements of physical properties of planetary bodies allow to determine many important parameters for scientists working in different fields of research. For example effective heat conductivity of the regolith can help with better understanding of processes occurring in the body interior. Chemical and mineralogical composition gives us a chance to better understand the origin and evolution of the moons. In principle such parameters of the planetary bodies can be determined based on three different measurement techniques: (i) in situ measurements (ii) measurements of the samples in laboratory conditions at the Earth and (iii) remote sensing measurements. Scientific missions which allow us to perform all type of measurements, give us a chance for not only parameters determination but also cross calibration of the instruments. Russian Phobos Sample Return (PhSR) mission is one of few which allows for all type of such measurements. The spacecraft will be equipped with remote sensing instruments like: spectrometers, long wave radar and dust counter, instruments for in-situ measurements -gas-chromatograph, seismometer, thermodetector and others and also robotic arm and sampling device. PhSR mission will be launched in November 2011 on board of a launch vehicle Zenit. About a year later (11 months) the vehicle will reach the Martian orbit. It is anticipated that it will land on Phobos in the beginning of 2013. A take off back will take place a month later and the re-entry module containing a capsule that will hold the soil sample enclosed in a container will be on its way back to Earth. The 11 kg re-entry capsule with the container will land in Kazakhstan in mid-2014. A unique geological penetrator CHOMIK dedicated for the Phobos Sample Return space mis-sion will be designed and manufactured at the Space Mechatronics and Robotics Laboratory, Space Research Centre Polish Academy of Sciences (SRC PAS) in Warsaw. Functionally CHOMIK is based on the well known MUPUS

DETERMINANTS OF RETURN ON EQUITY OF COOPERATIVE BANKS IN POLAND

Directory of Open Access Journals (Sweden)

Anna Bieniasz

2016-03-01

Full Text Available The aim of the study was to analyse the diversity of return on equity in the cooperative banks in Poland in 2010– 2014. The analysis was conducted using data of the Polish Financial Supervision Authority, on the basis of a modifi ed decomposition rate of return on equity. Assessment of the rate of return on equity was made in a size of banks, as determined by the value of assets. In addition, in order to determine the strength and direction of impact the individual components of the model on the formation of return on equity method was applied functional. The study suggests that cooperative banks eff ectively use the equity, because the rate of return on equity was signifi cantly higher than the rate of return on assets. The average return on assets in 2010–2014 was relatively lower in the largest banks and ranged from 0.7–0.9%, and the smallest banks return on assets was approximately 1%. In turn, the return on equity was higher at banks with major assets (over 200 million PLN. In 2013–2014 the rate of return both on assets and equity expressly declined. The main determinants of changes in return on equity were changing the multiplier reduction of profi t from banking activities by operating costs and costs of banking risk and return on assets, as well as measured result on banking activities.

Abnormal Returns and Contrarian Strategies

Directory of Open Access Journals (Sweden)

Ivana Dall'Agnol

2003-12-01

Full Text Available We test the hypothesis that strategies which are long on portfolios of looser stocks and short on portfolios of winner stocks generate abnormal returns in Brazil. This type of evidence for the US stock market was interpreted by The Bondt and Thaler (1985 as reflecting systematic evaluation mistakes caused by investors overreaction to news related to the firm performance. We found evidence of contrarian strategies profitability for horizons from 3 months to 3 years in a sample of stock returns from BOVESPA and SOMA from 1986 to 2000. The strategies are more profitable for shorter horizons. Therefore, there was no trace of the momentum effect found by Jagadeesh and Titman (1993 for the same horizons with US data. There are remaing unexplained positive returns for contrarian strategies after accounting for risk, size, and liquidity. We also found that the strategy profitability is reduced after the Real Plan, which suggests that the Brazilian stock market became more efficient after inflation stabilization.

The reliability and internal consistency of one-shot and flicker change detection for measuring individual differences in visual working memory capacity.

Science.gov (United States)

Pailian, Hrag; Halberda, Justin

2015-04-01

We investigated the psychometric properties of the one-shot change detection task for estimating visual working memory (VWM) storage capacity-and also introduced and tested an alternative flicker change detection task for estimating these limits. In three experiments, we found that the one-shot whole-display task returns estimates of VWM storage capacity (K) that are unreliable across set sizes-suggesting that the whole-display task is measuring different things at different set sizes. In two additional experiments, we found that the one-shot single-probe variant shows improvements in the reliability and consistency of K estimates. In another additional experiment, we found that a one-shot whole-display-with-click task (requiring target localization) also showed improvements in reliability and consistency. The latter results suggest that the one-shot task can return reliable and consistent estimates of VWM storage capacity (K), and they highlight the possibility that the requirement to localize the changed target is what engenders this enhancement. Through a final series of four experiments, we introduced and tested an alternative flicker change detection method that also requires the observer to localize the changing target and that generates, from response times, an estimate of VWM storage capacity (K). We found that estimates of K from the flicker task correlated with estimates from the traditional one-shot task and also had high reliability and consistency. We highlight the flicker method's ability to estimate executive functions as well as VWM storage capacity, and discuss the potential for measuring multiple abilities with the one-shot and flicker tasks.

Factor Structure in Commodity Futures Return and Volatility

DEFF Research Database (Denmark)

Christoffersen, Peter; Lunde, Asger; Olesen, Kasper Vinther

Using data on more than 750 million futures trades during 2004-2013, we analyze eight stylized facts of commodity price and volatility dynamics in the post financialization period. We pay particular attention to the factor structure in returns and volatility and to commodity market integration...... with the equity market. We find evidence of a factor structure in daily commodity futures returns. However, the factor structure in daily commodity futures volatility is even stronger than in returns. When computing model-free realized commodity betas with the stock market we find that they were high during 2008......-2010 but have since returned to the pre-crisis level close to zero. The common factor in commodity volatility is nevertheless clearly related to stock market volatility. We conclude that, while commodity markets appear to again be segmented from the equity market when only returns are considered, commodity...

Estimation of return levels against different return periods of extreme annual rainfall over Baluchistan

International Nuclear Information System (INIS)

Ali, M.; Jan, B.; Iqbal, J.

2012-01-01

Unprecedented heavy monsoon rainfall began in the last week of July 2010 in the Northern part of our country, causes floods in Baluchistan and Sindh. As the high frequency rainfall events are a significant cause of current severe flooding in Pakistan and any fluctuation in the level of such events may cause huge economic losses as well as social problem, urban structures (i.e. dams, urban drainage systems and flood). Statistical distributions are used to identify extremes of annual rainfall of different cities of Baluchistan (Quetta, Sibbi, Khuzdar, Lasbella, Dalbandin and Pasni) with their return periods. Analysis predicts that Gumbel Max. (GM) Distribution is the best fitted distribution for Sibbi and Lasbella while the GEV distribution is the best fitted for Quetta, Khuzdar, Dalbandin and Pasni. The analysis also suggests that different cities of Baluchistan have 30-years return period for getting more than 90 mm average daily rainfall while they have 100-years return period for receiving more than 118 mm daily rainfall. This suggests for suitable flood forecasting and improving the river structure in Baluchistan, Pakistan. (author)

reliability reliability

African Journals Online (AJOL)

eobe

Corresponding author, Tel: +234-703. RELIABILITY .... V , , given by the code of practice. However, checks must .... an optimization procedure over the failure domain F corresponding .... of Concrete Members based on Utility Theory,. Technical ...

Inventory control with product returns : The impact of imperfect information

NARCIS (Netherlands)

De Brito, M.P.; Laan, E.A.

2009-01-01

Product returns are characterized by considerable uncertainty on time and quantity. In the literature on inventory management for product return environments best forecasts of future returns are associated with methods that use the most information regarding product return history. In practice,

26 CFR 301.6103(j)(1)-1T - Disclosures of return information reflected on returns to officers and employees of the...

Science.gov (United States)

2010-04-01

... related activities (temporary). 301.6103(j)(1)-1T Section 301.6103(j)(1)-1T Internal Revenue INTERNAL... ADMINISTRATION Information and Returns Returns and Records § 301.6103(j)(1)-1T Disclosures of return information... § 301.6103(j)(1)-1(a) through (b)(3)(xxiv). (xxv) From Form 6765 (when filed with corporation income tax...

Satellite communication transponders and their reliability; Eisei tosai tsushin kiki oyobi shinraisei ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Ogawa, H [NTT Wireless System Laboratories, Kanagawa (Japan)

1994-11-01

The Engineering Test Satellite-VI is a large composite test satellite weighing two tons to perform different communication experiments. Adoption of the multi-beam satellite communication system has made possible to increase the transmission capacity, reduce the sizes of earth stations, and utilize frequencies more effectively. This paper describes the configuration of the relaying devices mounted thereon, the newly developed circuit technologies, and their reliability. The multi-beam satellite communication system mounts a number of transponders, with the frequency bands used divided into the 2.6/2.5 GHz band between the moving body and the satellite, the 6/4 GHz band for the channels between the earth stations and the satellite, and the 30/20 GHz band for the fixed communications. These arrangements were intended to achieve large size reduction as a result of applying the integrated circuit technology. The transmitters and the receivers corresponding to each beam are connected by using the satellite switches (16 inputs {times} 12 outputs). The parts used were general purpose ones rather than those specified in the MIL standards because of their number having reached so huge. Their reliability was ensured by long-term burn-in operations. 5 refs., 6 figs., 1 tab.

One-Step Direct Return Method For Mohr-Coulomb Plasticity

DEFF Research Database (Denmark)

Clausen, Johan; Damkilde, Lars; Andersen, Lars

2004-01-01

A new return method for the Mohr-Coulomb yield criteria is presented. The idea is to transform the problem into the principal direction and thereby achieve very simple formulas for calculating the elastic return stresses.......A new return method for the Mohr-Coulomb yield criteria is presented. The idea is to transform the problem into the principal direction and thereby achieve very simple formulas for calculating the elastic return stresses....

HUBUNGAN RETURN SAHAM DAN INFLASI DI INDONESIA

Directory of Open Access Journals (Sweden)

Nyoman Triaryati

2017-03-01

Full Text Available The effect of inflation to the stock return research had been held since three decades ago based on GeneralizeFisher’s Hypotheses, but ‘how inflation influenced stock return’ had become a debate until today. In Indonesiamost of the related research used inflation as one of the variables that influenced stock return despite of others inshort period of time. This research investigated the effect of inflation to the stock return in Indonesia within fifteenyears, which was divided into 3 (three periods of time reflecting different economic growth for each of it. Thepurpose of this allotment was to see the consistency how inflation influenced the stock market. Using a secondarydata from monthly inflation and IHSG period 1998 until 2012, included three hundred and sixty observation,simple regression model analyses was applied. This research acknowledged that inflation negatively influencedstock return in a long time period, but it did not exist in the short time period, except when the level of inflationreached 10%. In conclusion, inflation influence on the stock return was not ascertained by how long the investigationwas held but if there was any inflation rate reaching 10% within the period of investigation.

Measuring reliability under epistemic uncertainty: Review on non-probabilistic reliability metrics

Directory of Open Access Journals (Sweden)

Kang Rui

2016-06-01

Full Text Available In this paper, a systematic review of non-probabilistic reliability metrics is conducted to assist the selection of appropriate reliability metrics to model the influence of epistemic uncertainty. Five frequently used non-probabilistic reliability metrics are critically reviewed, i.e., evidence-theory-based reliability metrics, interval-analysis-based reliability metrics, fuzzy-interval-analysis-based reliability metrics, possibility-theory-based reliability metrics (posbist reliability and uncertainty-theory-based reliability metrics (belief reliability. It is pointed out that a qualified reliability metric that is able to consider the effect of epistemic uncertainty needs to (1 compensate the conservatism in the estimations of the component-level reliability metrics caused by epistemic uncertainty, and (2 satisfy the duality axiom, otherwise it might lead to paradoxical and confusing results in engineering applications. The five commonly used non-probabilistic reliability metrics are compared in terms of these two properties, and the comparison can serve as a basis for the selection of the appropriate reliability metrics.

Habit formation, surplus consumption and return predictability

DEFF Research Database (Denmark)

Engsted, Tom; Hyde, Stuart; Vinther Møller, Stig

2010-01-01

On an international post World War II dataset, we use an iterated GMM procedure to estimate and test the Campbell and Cochrane (1999, By force of habit: a consumption-based explanation of aggregate stock market behavior. Journal of Political Economy 107, 205–251.) habit formation model with a time......-varying risk-free rate. In addition, we analyze the predictive power of the surplus consumption ratio for future stock and bond returns. We find that, although there are important cross-country differences and economically significant pricing errors, for the majority of countries in our sample the model gets...... significant information about future stock returns, also during the 1990s. In addition, in most countries the surplus consumption ratio is also a powerful predictor of future bond returns. Thus, the surplus consumption ratio captures time-varying expected returns in both stock and bond markets....

Dynamic returns of beta arbitrage

OpenAIRE

Nascimento, Mafalda

2017-01-01

This thesis studies the patterns of the abnormal returns of the beta strategy. The topic can be helpful for professional investors, who intend to achieve a better performance in their portfolios. Following the methodology of Lou, Polk, & Huang (2016), the COBAR measure is computed in order to determine the levels of beta arbitrage in the market in each point in time. It is argued that beta arbitrage activity can have impact on the returns of the beta strategy. In fact, it is demonstrated that...

Returns on Investment in California County Departments of Public Health.

Science.gov (United States)

Brown, Timothy T

2016-08-01

To estimate the average return on investment for the overall activities of county departments of public health in California. I gathered the elements necessary to estimate the average return on investment for county departments of public health in California during the period 2001 to 2008-2009. These came from peer-reviewed journal articles published as part of a larger project to develop a method for determining return on investment for public health by using a health economics framework. I combined these elements by using the standard formula for computing return on investment, and performed a sensitivity analysis. Then I compared the return on investment for county departments of public health with the returns on investment generated for various aspects of medical care. The estimated return on investment from $1 invested in county departments of public health in California ranges from $67.07 to $88.21. The very large estimated return on investment for California county departments of public health relative to the return on investment for selected aspects of medical care suggests that public health is a wise investment.

Oil Volatility Risk and Expected Stock Returns

DEFF Research Database (Denmark)

Christoffersen, Peter; Pan, Xuhui (Nick)

After the financialization of commodity futures markets in 2004-05 oil volatility has become a strong predictor of returns and volatility of the overall stock market. Furthermore, stocks' exposure to oil volatility risk now drives the cross-section of expected returns. The difference in average...... return between the quintile of stocks with low exposure and high exposure to oil volatility is significant at 0.66% per month, and oil volatility risk carries a significant risk premium of -0.60% per month. In the post-financialization period, oil volatility risk is strongly related with various measures...

Solid Rocket Booster Large Main and Drogue Parachute Reliability Analysis

Science.gov (United States)

Clifford, Courtenay B.; Hengel, John E.

2009-01-01

The parachutes on the Space Transportation System (STS) Solid Rocket Booster (SRB) are the means for decelerating the SRB and allowing it to impact the water at a nominal vertical velocity of 75 feet per second. Each SRB has one pilot, one drogue, and three main parachutes. About four minutes after SRB separation, the SRB nose cap is jettisoned, deploying the pilot parachute. The pilot chute then deploys the drogue parachute. The drogue chute provides initial deceleration and proper SRB orientation prior to frustum separation. At frustum separation, the drogue pulls the frustum from the SRB and allows the main parachutes that are mounted in the frustum to unpack and inflate. These chutes are retrieved, inspected, cleaned, repaired as needed, and returned to the flight inventory and reused. Over the course of the Shuttle Program, several improvements have been introduced to the SRB main parachutes. A major change was the replacement of the small (115 ft. diameter) main parachutes with the larger (136 ft. diameter) main parachutes. Other modifications were made to the main parachutes, main parachute support structure, and SRB frustum to eliminate failure mechanisms, improve damage tolerance, and improve deployment and inflation characteristics. This reliability analysis is limited to the examination of the SRB Large Main Parachute (LMP) and drogue parachute failure history to assess the reliability of these chutes. From the inventory analysis, 68 Large Main Parachutes were used in 651 deployments, and 7 chute failures occurred in the 651 deployments. Logistic regression was used to analyze the LMP failure history, and it showed that reliability growth has occurred over the period of use resulting in a current chute reliability of R = .9983. This result was then used to determine the reliability of the 3 LMPs on the SRB, when all must function. There are 29 drogue parachutes that were used in 244 deployments, and no in-flight failures have occurred. Since there are no

Digital Earth – A sustainable Earth

International Nuclear Information System (INIS)

Mahavir

2014-01-01

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

Reliability Approach of a Compressor System using Reliability Block ...

African Journals Online (AJOL)

pc

2018-03-05

Mar 5, 2018 ... This paper presents a reliability analysis of such a system using reliability ... Keywords-compressor system, reliability, reliability block diagram, RBD .... the same structure has been kept with the three subsystems: air flow, oil flow and .... and Safety in Engineering Design", Springer, 2009. [3] P. O'Connor ...

Why Earth Science?

Science.gov (United States)

Smith, Michael J.

2004-01-01

This article briefly describes Earth science. The study of Earth science provides the foundation for an understanding of the Earth, its processes, its resources, and its environment. Earth science is the study of the planet in its entirety, how its lithosphere, atmosphere, hydrosphere, and biosphere work together as systems and how they affect…

Barriers to return to work after burn injuries.

Science.gov (United States)

Esselman, Peter C; Askay, Shelley Wiechman; Carrougher, Gretchen J; Lezotte, Dennis C; Holavanahalli, Radha K; Magyar-Russell, Gina; Fauerbach, James A; Engrav, Loren H

2007-12-01

To identify barriers to return to work after burn injury as identified by the patient. A cohort study with telephone interview up to 1 year. Hospital-based burn centers at 3 national sites. Hospitalized patients (N=154) meeting the American Burn Association criteria for major burn injury, employed at least 20 hours a week at the time of injury, and with access to a telephone after discharge. Patients were contacted via telephone every 2 weeks up to 4 months, then monthly up to 1 year after discharge. A return to work survey was used to identify barriers that prevented patients from returning to work. A graphic rating scale determined the impact of each barrier. By 1 year, 79.7% of patients returned to work. Physical and wound issues were barriers early after discharge. Although physical abilities continued to be a significant barrier up to 1 year, working conditions (temperature, humidity, safety) and psychosocial factors (nightmares, flashbacks, appearance concerns) became important issues in those with long-term disability. The majority of patients return to work after a burn injury. Although physical and work conditions are important barriers, psychosocial issues need to be evaluated and treated to optimize return to work.

Return to Experience and Initial Wage Level

DEFF Research Database (Denmark)

Sørensen, Kenneth Lykke; Vejlin, Rune Majlund

This paper estimates the relationship between initial wage and return to experience. We use a Mincer-like wage model to nonparametrically estimate this relationship allowing for an unobservable individual permanent effect in wages and unobservable individual return to experience. The relationship...

Frontiers of reliability

CERN Document Server

Basu, Asit P; Basu, Sujit K

1998-01-01

This volume presents recent results in reliability theory by leading experts in the world. It will prove valuable for researchers, and users of reliability theory. It consists of refereed invited papers on a broad spectrum of topics in reliability. The subjects covered include Bayesian reliability, Bayesian reliability modeling, confounding in a series system, DF tests, Edgeworth approximation to reliability, estimation under random censoring, fault tree reduction for reliability, inference about changes in hazard rates, information theory and reliability, mixture experiment, mixture of Weibul

Software reliability

CERN Document Server

Bendell, A

1986-01-01

Software Reliability reviews some fundamental issues of software reliability as well as the techniques, models, and metrics used to predict the reliability of software. Topics covered include fault avoidance, fault removal, and fault tolerance, along with statistical methods for the objective assessment of predictive accuracy. Development cost models and life-cycle cost models are also discussed. This book is divided into eight sections and begins with a chapter on adaptive modeling used to predict software reliability, followed by a discussion on failure rate in software reliability growth mo

Intergranular attack evaluation from hideout return

International Nuclear Information System (INIS)

Nordmann, F.; Dupin, M.; Menet, O.; Fiquet, J.-M.

1989-01-01

Intergranular Attack (IGA) is the secondary side corrosion mechanism on PWR steam generator tubing, which can occur most frequently even with a good waterchemistry. It has moderately developed in a few French units. Consequently, several remedies have been implemented, such as sodium content decrease in makeup water and application of more stringent chemistry specifications. In order to evaluate the local chemistry in restricted areas where IGA may occur, a large hideout return programme has been carried out on many units. It shows that free alkalinity returning during shutdown is usually ranging from 0.5 to 5 g of sodium per steam generator, and that the required time to let it return is about 40 hours. However, high temperature pH calculations indicate that such an amount of alkalinity can correspond to a potentially corrosive solution in restricted areas, where a concentration factor of 10 5 to 10 7 can be reached, inducing a pH of 10 at 300 o C. Studies are still in progress in order to define when a shutdown should be required to allow hideout return and help to prevent IGA. (author)

Nurses' views about returning to practice after a career break.

Science.gov (United States)

Durand, Mary Alison; Randhawa, Gurch

Shortages in nursing staff have led to recruitment campaigns targeting nurses who have left the profession. The present study explored reasons why career-break nurses decide for or against a return to practice, as well as perceptions of nursing following return. Semistructured interview were conducted with 24 nurses who had returned recently to the profession and 28 nurses on a "career break". Findings revealed that those who returned did so when their personal circumstances allowed, and half returned as bank nurses in order to work flexible, family-friendly hours. Some non-returners reported that they could not afford to return because of childcare costs. Although still a caring one, the nurse's role is seen by returners as becoming increasingly technologically and administratively demanding. Flexibility with regard to working practices, increased salaries and demonstrating that it values its staff, were highlighted by interviewees generally as priority issues for the NHS if it wishes to recruit career-break nurses.

Algorithmic mechanisms for reliable crowdsourcing computation under collusion.

Science.gov (United States)

Fernández Anta, Antonio; Georgiou, Chryssis; Mosteiro, Miguel A; Pareja, Daniel

2015-01-01

We consider a computing system where a master processor assigns a task for execution to worker processors that may collude. We model the workers' decision of whether to comply (compute the task) or not (return a bogus result to save the computation cost) as a game among workers. That is, we assume that workers are rational in a game-theoretic sense. We identify analytically the parameter conditions for a unique Nash Equilibrium where the master obtains the correct result. We also evaluate experimentally mixed equilibria aiming to attain better reliability-profit trade-offs. For a wide range of parameter values that may be used in practice, our simulations show that, in fact, both master and workers are better off using a pure equilibrium where no worker cheats, even under collusion, and even for colluding behaviors that involve deviating from the game.

Validation and reliability of a Behcet’s Syndrome Activity Scale in Korea

Science.gov (United States)

Choi, Hyo Jin; Seo, Mi Ryoung; Ryu, Hee Jung; Baek, Han Joo

2016-01-01

Background/Aims: We prepared a cross-cultural adaptation of the Behcet’s Syndrome Activity Scale (BSAS) and evaluated its reliability and validity in Korea. Methods: Fifty patients with Behcet’s disease (BD) who attended the Rheumatology Clinic of Gachon University Gil Medical Center were included in this study. The first BSAS questionnaire was administered at each clinic visit, and the second questionnaire was completed at home within 24 hours of the visit. A Behcet’s Disease Current Activity Form (BDCAF) and a Behcet’s Disease Quality of Life (BDQOL) form were also given to patients. The test-retest reliability was analyzed by intraclass correlation coefficients (ICC). To assess the validity, the total BSAS score was compared with the BDCAF score, the patient/physician global assessment, and the BDQOL by Spearman rank correlation. Results: Twelve males and 38 females were enrolled. The mean age was 48.5 years and the mean disease duration was 6.7 years. Thirty-eight patients (76.0%) returned the questionnaire by mail. For the test-retest reliability, the two assessments were significantly correlated on all 10 items of the BSAS questionnaire (p < 0.05) and the total BSAS score (ICC, 0.925; p < 0.001). The total BSAS score was statistically correlated with the BDQOL, BDCAF, and patient/physician global assessment (p < 0.01). Conclusions: The Korean version of BSAS is a reliable and valid instrument to measure BD activity. PMID:26767871

Earth observation from the manned low Earth orbit platforms

Science.gov (United States)

Guo, Huadong; Dou, Changyong; Zhang, Xiaodong; Han, Chunming; Yue, Xijuan

2016-05-01

The manned low Earth orbit platforms (MLEOPs), e.g., the U.S. and Russia's human space vehicles, the International Space Station (ISS) and Chinese Tiangong-1 experimental space laboratory not only provide laboratories for scientific experiments in a wide range of disciplines, but also serve as exceptional platforms for remote observation of the Earth, astronomical objects and space environment. As the early orbiting platforms, the MLEOPs provide humans with revolutionary accessibility to the regions on Earth never seen before. Earth observation from MLEOPs began in early 1960s, as a part of manned space flight programs, and will continue with the ISS and upcoming Chinese Space Station. Through a series of flight missions, various and a large amount of Earth observing datasets have been acquired using handheld cameras by crewmembers as well as automated sophisticated sensors onboard these space vehicles. Utilizing these datasets many researches have been conducted, demonstrating the importance and uniqueness of studying Earth from a vantage point of MLEOPs. For example, the first, near-global scale digital elevation model (DEM) was developed from data obtained during the shuttle radar topography mission (SRTM). This review intends to provide an overview of Earth observations from MLEOPs and present applications conducted by the datasets collected by these missions. As the ISS is the most typical representative of MLEOPs, an introduction to it, including orbital characteristics, payload accommodations, and current and proposed sensors, is emphasized. The advantages and challenges of Earth observation from MLEOPs, using the ISS as an example, is also addressed. At last, a conclusive note is drawn.

System Reliability Engineering

International Nuclear Information System (INIS)

Lim, Tae Jin

2005-02-01

This book tells of reliability engineering, which includes quality and reliability, reliability data, importance of reliability engineering, reliability and measure, the poisson process like goodness of fit test and the poisson arrival model, reliability estimation like exponential distribution, reliability of systems, availability, preventive maintenance such as replacement policies, minimal repair policy, shock models, spares, group maintenance and periodic inspection, analysis of common cause failure, and analysis model of repair effect.

Return to experience and initial wage level

DEFF Research Database (Denmark)

Sørensen, K.L.; Vejlin, R.

2014-01-01

This paper estimates the relationship between initial wage and return to experience. We use a Mincer-like wage model to non-parametrically estimate this relationship allowing for an unobservable individual permanent effect in wages and unobservable individual return to experience. The relationshi...

Legal institutions, strategic default, and stock returns

NARCIS (Netherlands)

Favara, G.; Schroth, E.; Valta, P.

2008-01-01

This paper studies the impact of legal institutions on stock returns. More specifically, we examine how differences in debt enforcement and creditor protection around the world affect stock returns of individual firms. We hypothesize that if legal institutions prevent shareholders from engaging in

Husbands' return migration and wives' occupational choices

NARCIS (Netherlands)

Mahe, Clotilde

2017-01-01

Exploiting the documented effect of migration on occupational choice upon return to their origin country with data from Egypt, we establish a link between return migration of men and their wives' time use through within-couple occupational interdependence. Seemingly Unrelated Regression model

Remote sensing image fusion in the context of Digital Earth

International Nuclear Information System (INIS)

Pohl, C

2014-01-01

The increase in the number of operational Earth observation satellites gives remote sensing image fusion a new boost. As a powerful tool to integrate images from different sensors it enables multi-scale, multi-temporal and multi-source information extraction. Image fusion aims at providing results that cannot be obtained from a single data source alone. Instead it enables feature and information mining of higher reliability and availability. The process required to prepare remote sensing images for image fusion comprises most of the necessary steps to feed the database of Digital Earth. The virtual representation of the planet uses data and information that is referenced and corrected to suit interpretation and decision-making. The same pre-requisite is valid for image fusion, the outcome of which can directly flow into a geographical information system. The assessment and description of the quality of the results remains critical. Depending on the application and information to be extracted from multi-source images different approaches are necessary. This paper describes the process of image fusion based on a fusion and classification experiment, explains the necessary quality measures involved and shows with this example which criteria have to be considered if the results of image fusion are going to be used in Digital Earth

Risk-return relationship in a complex adaptive system.

Directory of Open Access Journals (Sweden)

Kunyu Song

Full Text Available For survival and development, autonomous agents in complex adaptive systems involving the human society must compete against or collaborate with others for sharing limited resources or wealth, by using different methods. One method is to invest, in order to obtain payoffs with risk. It is a common belief that investments with a positive risk-return relationship (namely, high risk high return and vice versa are dominant over those with a negative risk-return relationship (i.e., high risk low return and vice versa in the human society; the belief has a notable impact on daily investing activities of investors. Here we investigate the risk-return relationship in a model complex adaptive system, in order to study the effect of both market efficiency and closeness that exist in the human society and play an important role in helping to establish traditional finance/economics theories. We conduct a series of computer-aided human experiments, and also perform agent-based simulations and theoretical analysis to confirm the experimental observations and reveal the underlying mechanism. We report that investments with a negative risk-return relationship have dominance over those with a positive risk-return relationship instead in such a complex adaptive systems. We formulate the dynamical process for the system's evolution, which helps to discover the different role of identical and heterogeneous preferences. This work might be valuable not only to complexity science, but also to finance and economics, to management and social science, and to physics.

Risk-return relationship in a complex adaptive system.

Science.gov (United States)

Song, Kunyu; An, Kenan; Yang, Guang; Huang, Jiping

2012-01-01

For survival and development, autonomous agents in complex adaptive systems involving the human society must compete against or collaborate with others for sharing limited resources or wealth, by using different methods. One method is to invest, in order to obtain payoffs with risk. It is a common belief that investments with a positive risk-return relationship (namely, high risk high return and vice versa) are dominant over those with a negative risk-return relationship (i.e., high risk low return and vice versa) in the human society; the belief has a notable impact on daily investing activities of investors. Here we investigate the risk-return relationship in a model complex adaptive system, in order to study the effect of both market efficiency and closeness that exist in the human society and play an important role in helping to establish traditional finance/economics theories. We conduct a series of computer-aided human experiments, and also perform agent-based simulations and theoretical analysis to confirm the experimental observations and reveal the underlying mechanism. We report that investments with a negative risk-return relationship have dominance over those with a positive risk-return relationship instead in such a complex adaptive systems. We formulate the dynamical process for the system's evolution, which helps to discover the different role of identical and heterogeneous preferences. This work might be valuable not only to complexity science, but also to finance and economics, to management and social science, and to physics.

Seismic waves in 3-D: from mantle asymmetries to reliable seismic hazard assessment

Science.gov (United States)

Panza, Giuliano F.; Romanelli, Fabio

2014-10-01

A global cross-section of the Earth parallel to the tectonic equator (TE) path, the great circle representing the equator of net lithosphere rotation, shows a difference in shear wave velocities between the western and eastern flanks of the three major oceanic rift basins. The low-velocity layer in the upper asthenosphere, at a depth range of 120 to 200 km, is assumed to represent the decoupling between the lithosphere and the underlying mantle. Along the TE-perturbed (TE-pert) path, a ubiquitous LVZ, about 1,000-km-wide and 100-km-thick, occurs in the asthenosphere. The existence of the TE-pert is a necessary prerequisite for the existence of a continuous global flow within the Earth. Ground-shaking scenarios were constructed using a scenario-based method for seismic hazard analysis (NDSHA), using realistic and duly validated synthetic time series, and generating a data bank of several thousands of seismograms that account for source, propagation, and site effects. Accordingly, with basic self-organized criticality concepts, NDSHA permits the integration of available information provided by the most updated seismological, geological, geophysical, and geotechnical databases for the site of interest, as well as advanced physical modeling techniques, to provide a reliable and robust background for the development of a design basis for cultural heritage and civil infrastructures. Estimates of seismic hazard obtained using the NDSHA and standard probabilistic approaches are compared for the Italian territory, and a case-study is discussed. In order to enable a reliable estimation of the ground motion response to an earthquake, three-dimensional velocity models have to be considered, resulting in a new, very efficient, analytical procedure for computing the broadband seismic wave-field in a 3-D anelastic Earth model.

Software Reuse Within the Earth Science Community

Science.gov (United States)

Marshall, James J.; Olding, Steve; Wolfe, Robert E.; Delnore, Victor E.

2006-01-01

Scientific missions in the Earth sciences frequently require cost-effective, highly reliable, and easy-to-use software, which can be a challenge for software developers to provide. The NASA Earth Science Enterprise (ESE) spends a significant amount of resources developing software components and other software development artifacts that may also be of value if reused in other projects requiring similar functionality. In general, software reuse is often defined as utilizing existing software artifacts. Software reuse can improve productivity and quality while decreasing the cost of software development, as documented by case studies in the literature. Since large software systems are often the results of the integration of many smaller and sometimes reusable components, ensuring reusability of such software components becomes a necessity. Indeed, designing software components with reusability as a requirement can increase the software reuse potential within a community such as the NASA ESE community. The NASA Earth Science Data Systems (ESDS) Software Reuse Working Group is chartered to oversee the development of a process that will maximize the reuse potential of existing software components while recommending strategies for maximizing the reusability potential of yet-to-be-designed components. As part of this work, two surveys of the Earth science community were conducted. The first was performed in 2004 and distributed among government employees and contractors. A follow-up survey was performed in 2005 and distributed among a wider community, to include members of industry and academia. The surveys were designed to collect information on subjects such as the current software reuse practices of Earth science software developers, why they choose to reuse software, and what perceived barriers prevent them from reusing software. In this paper, we compare the results of these surveys, summarize the observed trends, and discuss the findings. The results are very

Earth Rotation

Science.gov (United States)

Dickey, Jean O.

1995-01-01

The study of the Earth's rotation in space (encompassing Universal Time (UT1), length of day, polar motion, and the phenomena of precession and nutation) addresses the complex nature of Earth orientation changes, the mechanisms of excitation of these changes and their geophysical implications in a broad variety of areas. In the absence of internal sources of energy or interactions with astronomical objects, the Earth would move as a rigid body with its various parts (the crust, mantle, inner and outer cores, atmosphere and oceans) rotating together at a constant fixed rate. In reality, the world is considerably more complicated, as is schematically illustrated. The rotation rate of the Earth's crust is not constant, but exhibits complicated fluctuations in speed amounting to several parts in 10(exp 8) [corresponding to a variation of several milliseconds (ms) in the Length Of the Day (LOD) and about one part in 10(exp 6) in the orientation of the rotation axis relative to the solid Earth's axis of figure (polar motion). These changes occur over a broad spectrum of time scales, ranging from hours to centuries and longer, reflecting the fact that they are produced by a wide variety of geophysical and astronomical processes. Geodetic observations of Earth rotation changes thus provide insights into the geophysical processes illustrated, which are often difficult to obtain by other means. In addition, these measurements are required for engineering purposes. Theoretical studies of Earth rotation variations are based on the application of Euler's dynamical equations to the problem of finding the response of slightly deformable solid Earth to variety of surface and internal stresses.

Lidar 2009 - All Returns

Data.gov (United States)

Kansas Data Access and Support Center — LIDAR-derived binary (.las) files containing classified points of all returns. We have 3 classifications Unclassified, Ground, Low points. The average Ground Sample...

Returns on Investment in California County Departments of Public Health

Science.gov (United States)

2016-01-01

Objectives. To estimate the average return on investment for the overall activities of county departments of public health in California. Methods. I gathered the elements necessary to estimate the average return on investment for county departments of public health in California during the period 2001 to 2008–2009. These came from peer-reviewed journal articles published as part of a larger project to develop a method for determining return on investment for public health by using a health economics framework. I combined these elements by using the standard formula for computing return on investment, and performed a sensitivity analysis. Then I compared the return on investment for county departments of public health with the returns on investment generated for various aspects of medical care. Results. The estimated return on investment from $1 invested in county departments of public health in California ranges from $67.07 to $88.21. Conclusions. The very large estimated return on investment for California county departments of public health relative to the return on investment for selected aspects of medical care suggests that public health is a wise investment. PMID:27310339

Exploring consumer online product returning behavior : Chinese e-consumers’ perspective

OpenAIRE

Zhu, Yijun

2018-01-01

In the retail world, product returns are a common practice by consumers. Many businesses have been attempting to obtain more sales by providing customers with lenient return policies as well as customer-friendly return processes and procedures. Over the past decade, the issue of product returns by consumers is on the rise and drawing increased attention from practitioners and researchers. The objective of this thesis is to explore Chinese e-consumers’ perception of fraudulent returning beh...

Analyse Risk-Return Paradox: Evidence from Electricity Sector of Pakistan

OpenAIRE

Naqi Shah, Sadia; Qayyum, Abdul

2016-01-01

This study analyse risk return relationship of the electricity companies of Pakistan by using the log return series of these electricity companies. Financial time series data have the property of autoregressive heteroscedasticity so move towards the GARCH family test. As the study want to analyse the risk return relationship so, GARCH-M Model of Engel et al (1987) is used, who empirically found relationship between risk and return. Results show that risk return in case of Pakistan electricity...

Returns management in the supply chain

Directory of Open Access Journals (Sweden)

Anna Maria Jeszka

2014-09-01

Full Text Available Background:  The aim of this exploratory empirical research was to evaluate the level of cooperation in the area of reverse logistics between selected retail chains and logistics operators and suppliers; to identify and evaluate the influence the procedures of handling returns have on the relationships with customers, cost reduction, value recovery, inventory reduction and increasing profitability; as well as determining to what extent logistics operators are involved in the procedures of handling returns in the analysed chains. Methods: Based on the literature and the experience of researchers from developed countries a questionnaire was constructed which was subsequently used to conduct empirical research in selected retail chains operating in two provinces in Poland. The questionnaire survey involved the sales personnel of selected retail chains in the clothing industry. Overall, 105 questionnaires were collected and analysed. Results: Various aspects of cooperation with suppliers and logistics operators in respect of handling returns were evaluated. Most indicators of cooperation were evaluated favourably, with the exception of joint access to the database, the use of inventory data available online, and access to information from the warehouse, which received low marks from the respondents. In the case of the studied stores, some of the activities in the area of reverse logistics are outsourced; for example, obtaining products from users, logistics, and the transport of returns are typically done by an outside operator. Inspection, sorting, appraisal, repairs, as well as the sales of refurbished products are usually performed within the studied retail corporations. Conclusions: The research has shown that the retail chains developed very good programmes for handling returns in the supply chain, as evidenced by the presented and highly rated indicators of cooperation, with the exception of information exchange where there is still much

A reliability simulation language for reliability analysis

International Nuclear Information System (INIS)

Deans, N.D.; Miller, A.J.; Mann, D.P.

1986-01-01

The results of work being undertaken to develop a Reliability Description Language (RDL) which will enable reliability analysts to describe complex reliability problems in a simple, clear and unambiguous way are described. Component and system features can be stated in a formal manner and subsequently used, along with control statements to form a structured program. The program can be compiled and executed on a general-purpose computer or special-purpose simulator. (DG)

Return to the workforce following infective endocarditis

DEFF Research Database (Denmark)

Butt, Jawad H.; Kragholm, Kristian; Dalager-Pedersen, Michael

2018-01-01

Background The ability to return to work after infective endocarditis (IE) holds important socioeconomic consequences for both patients and society, yet data on this issue are sparse. We examined return to the workforce and associated factors in IE patients of working age. Methods Using Danish...

A study of operational and testing reliability in software reliability analysis

International Nuclear Information System (INIS)

Yang, B.; Xie, M.

2000-01-01

Software reliability is an important aspect of any complex equipment today. Software reliability is usually estimated based on reliability models such as nonhomogeneous Poisson process (NHPP) models. Software systems are improving in testing phase, while it normally does not change in operational phase. Depending on whether the reliability is to be predicted for testing phase or operation phase, different measure should be used. In this paper, two different reliability concepts, namely, the operational reliability and the testing reliability, are clarified and studied in detail. These concepts have been mixed up or even misused in some existing literature. Using different reliability concept will lead to different reliability values obtained and it will further lead to different reliability-based decisions made. The difference of the estimated reliabilities is studied and the effect on the optimal release time is investigated

Anoxygenic photosynthesis modulated Proterozoic oxygen and sustained Earth's middle age

Science.gov (United States)

Johnston, D. T.; Wolfe-Simon, F.; Pearson, A.; Knoll, A. H.

2009-01-01

Molecular oxygen (O2) began to accumulate in the atmosphere and surface ocean ca. 2,400 million years ago (Ma), but the persistent oxygenation of water masses throughout the oceans developed much later, perhaps beginning as recently as 580–550 Ma. For much of the intervening interval, moderately oxic surface waters lay above an oxygen minimum zone (OMZ) that tended toward euxinia (anoxic and sulfidic). Here we illustrate how contributions to primary production by anoxygenic photoautotrophs (including physiologically versatile cyanobacteria) influenced biogeochemical cycling during Earth's middle age, helping to perpetuate our planet's intermediate redox state by tempering O2 production. Specifically, the ability to generate organic matter (OM) using sulfide as an electron donor enabled a positive biogeochemical feedback that sustained euxinia in the OMZ. On a geologic time scale, pyrite precipitation and burial governed a second feedback that moderated sulfide availability and water column oxygenation. Thus, we argue that the proportional contribution of anoxygenic photosynthesis to overall primary production would have influenced oceanic redox and the Proterozoic O2 budget. Later Neoproterozoic collapse of widespread euxinia and a concomitant return to ferruginous (anoxic and Fe2+ rich) subsurface waters set in motion Earth's transition from its prokaryote-dominated middle age, removing a physiological barrier to eukaryotic diversification (sulfide) and establishing, for the first time in Earth's history, complete dominance of oxygenic photosynthesis in the oceans. This paved the way for the further oxygenation of the oceans and atmosphere and, ultimately, the evolution of complex multicellular organisms. PMID:19805080

Human reliability

International Nuclear Information System (INIS)

Embrey, D.E.

1987-01-01

Concepts and techniques of human reliability have been developed and are used mostly in probabilistic risk assessment. For this, the major application of human reliability assessment has been to identify the human errors which have a significant effect on the overall safety of the system and to quantify the probability of their occurrence. Some of the major issues within human reliability studies are reviewed and it is shown how these are applied to the assessment of human failures in systems. This is done under the following headings; models of human performance used in human reliability assessment, the nature of human error, classification of errors in man-machine systems, practical aspects, human reliability modelling in complex situations, quantification and examination of human reliability, judgement based approaches, holistic techniques and decision analytic approaches. (UK)

Return Predictability, Model Uncertainty, and Robust Investment

DEFF Research Database (Denmark)

Lukas, Manuel

Stock return predictability is subject to great uncertainty. In this paper we use the model confidence set approach to quantify uncertainty about expected utility from investment, accounting for potential return predictability. For monthly US data and six representative return prediction models, we...... find that confidence sets are very wide, change significantly with the predictor variables, and frequently include expected utilities for which the investor prefers not to invest. The latter motivates a robust investment strategy maximizing the minimal element of the confidence set. The robust investor...... allocates a much lower share of wealth to stocks compared to a standard investor....

An Earth-sized planet with an Earth-like density

DEFF Research Database (Denmark)

Pepe, Francesco; Cameron, Andrew Collier; Latham, David W.

2013-01-01

significantly larger than the Earth. Recently, the planet Kepler-78b was discovered(8) and found to have a radius of only 1.16R(circle plus). Here we report that the mass of this planet is 1.86 Earth masses. The resulting mean density of the planet is 5.57 g cm(-3), which is similar to that of the Earth...

The Impact of Perceived Hospital Service Quality on the Satisfaction and Patients' Return; A Case Study in Feiz Medical Eye Center

Directory of Open Access Journals (Sweden)

Mahmud Naderi Beni

2018-03-01

Full Text Available Background and Objectives: Nowadays, with the appearance of competitive environment, quality of services is important. The sector of health has a special status compared with other sectors of services. Patients determine the quality of services that are provided by hospitals which are regarded as large and complex service organizations within the health system. The aim of this study was to investigate the relationship between perceived service quality, perceived services value, patients’ satisfaction, word of mouth advertising and tendency to patients’ return. Material and Methods: This study was a descriptive and functional and from aspect of results, is practical and was done by one cross-sectional and fieldwork. The sample of study of 135 health care receivers, who were referred at least once from Feiz eye clinic in Isfahan were selected by using Cochran formula and stratified with random sampling. The data collected with a questionnaire which its reliability and validity were confirmed. The collected data were analyzed with SPSS and Smart PLS2 software. Results: The findings showed that all indices have acceptable load factor. Perceived service quality had a significant positive impact on perceived value (0.57 and patient satisfaction (0.28. Perceived value had a significant positive effect on patients’ satisfaction and patients’ return. Also, patients’ satisfaction had effect on word of mouth advertising and word of mouth advertising had effect on the patients’ return. Conclusion: The results of the study indicated that perceived value and patients’ satisfaction meditate between the relationship of perceived service quality and patients’ return. In addition, the indirect effect of perceived value on patients’ return, with changeable mediation of patients’ satisfaction is more than direct effect. Also, among the variables, patients’ satisfaction had greatest effect on patients return.

26 CFR 1.6031(a)-1 - Return of partnership income.

Science.gov (United States)

2010-04-01

... 26 Internal Revenue 13 2010-04-01 2010-04-01 false Return of partnership income. 1.6031(a)-1...) INCOME TAX (CONTINUED) INCOME TAXES Information Returns § 1.6031(a)-1 Return of partnership income. (a) Domestic partnerships—(1) Return required. Except as provided in paragraphs (a)(3) and (c) of this section...

Tick size and stock returns

Science.gov (United States)

Onnela, Jukka-Pekka; Töyli, Juuso; Kaski, Kimmo

2009-02-01

Tick size is an important aspect of the micro-structural level organization of financial markets. It is the smallest institutionally allowed price increment, has a direct bearing on the bid-ask spread, influences the strategy of trading order placement in electronic markets, affects the price formation mechanism, and appears to be related to the long-term memory of volatility clustering. In this paper we investigate the impact of tick size on stock returns. We start with a simple simulation to demonstrate how continuous returns become distorted after confining the price to a discrete grid governed by the tick size. We then move on to a novel experimental set-up that combines decimalization pilot programs and cross-listed stocks in New York and Toronto. This allows us to observe a set of stocks traded simultaneously under two different ticks while holding all security-specific characteristics fixed. We then study the normality of the return distributions and carry out fits to the chosen distribution models. Our empirical findings are somewhat mixed and in some cases appear to challenge the simulation results.

Fun and Games: using Games and Immersive Exploration to Teach Earth and Space Science

Science.gov (United States)

Reiff, P. H.; Sumners, C.

2011-12-01

We have been using games to teach Earth and Space Science for over 15 years. Our software "TicTacToe" has been used continuously at the Houston Museum of Natural Science since 2002. It is the single piece of educational software in the "Earth Forum" suite that holds the attention of visitors the longest - averaging over 10 minutes compared to 1-2 minutes for the other software kiosks. We now have question sets covering solar system, space weather, and Earth science. In 2010 we introduced a new game technology - that of immersive interactive explorations. In our "Tikal Explorer", visitors use a game pad to navigate a three-dimensional environment of the Classic Maya city of Tikal. Teams of students climb pyramids, look for artifacts, identify plants and animals, and site astronomical alignments that predict the annual return of the rains. We also have a new 3D exploration of the International Space Station, where students can fly around and inside the ISS. These interactive explorations are very natural to the video-game generation, and promise to bring educational objectives to experiences that had previously been used strictly for gaming. If space permits, we will set up our portable Discovery Dome in the poster session for a full immersive demonstration of these game environments.

Beyond reliability, multi-state failure analysis of satellite subsystems: A statistical approach

International Nuclear Information System (INIS)

Castet, Jean-Francois; Saleh, Joseph H.

2010-01-01

Reliability is widely recognized as a critical design attribute for space systems. In recent articles, we conducted nonparametric analyses and Weibull fits of satellite and satellite subsystems reliability for 1584 Earth-orbiting satellites launched between January 1990 and October 2008. In this paper, we extend our investigation of failures of satellites and satellite subsystems beyond the binary concept of reliability to the analysis of their anomalies and multi-state failures. In reliability analysis, the system or subsystem under study is considered to be either in an operational or failed state; multi-state failure analysis introduces 'degraded states' or partial failures, and thus provides more insights through finer resolution into the degradation behavior of an item and its progression towards complete failure. The database used for the statistical analysis in the present work identifies five states for each satellite subsystem: three degraded states, one fully operational state, and one failed state (complete failure). Because our dataset is right-censored, we calculate the nonparametric probability of transitioning between states for each satellite subsystem with the Kaplan-Meier estimator, and we derive confidence intervals for each probability of transitioning between states. We then conduct parametric Weibull fits of these probabilities using the Maximum Likelihood Estimation (MLE) approach. After validating the results, we compare the reliability versus multi-state failure analyses of three satellite subsystems: the thruster/fuel; the telemetry, tracking, and control (TTC); and the gyro/sensor/reaction wheel subsystems. The results are particularly revealing of the insights that can be gleaned from multi-state failure analysis and the deficiencies, or blind spots, of the traditional reliability analysis. In addition to the specific results provided here, which should prove particularly useful to the space industry, this work highlights the importance

Stage IV in electrical resistivity return to alpha-iron

International Nuclear Information System (INIS)

Poltavtseva, V.P.

2004-01-01

Full text: In compliance with the model of two interstitial atoms, in returning the electrical resistivity increment, the stage IV, related to migration of mono vacancies, should exist. Unfortunately, for alpha-iron there is no any reliable proof of existence of the stage IV (450-630 K) up to now. As a rule, the annealing stages revealed within this temperature range are considered as related to impurity effects. This paper is aimed at detection of the stage IV in returning the electrical resistivity increment in alpha-iron by means of irradiation of the materials differing in purity degree (99.99 and 99.8 %) by 30 MeV protons capable to create large amount of point defects and small clusters in BCC metals. By author opinion, it will make it possible to reach the radiation defect/vacancy concentrations comparable with contents of impurities (C and N) and, thus, to obtain an information about their migration. As a result of irradiation by protons at 270 K up to the fluence comprising 2.3·10 21 m -2 (0.001 dpa), the following has been found: - an increase in the electrical resistivity at 330 K is 0.84 and 0.61 nΩ·m for the alpha-iron purity degree 99.99 and 99.8 % respectively; - in the 99.99 % purity degree alpha-iron the process of electrical resistivity restoration comes to an end completely at 563 K, whereas in alpha-iron with larger content of impurity - at nearly 600 K; - in the 99.99% purity degree alpha iron electrical resistivity return spectrum a single wide peak centered at 445 K and two smeared peaks below 400 and higher than 490 K are revealed. As the impurity content increases, the 464 K peak changes the 445 K peak, which is about twice lower. Besides, a peak at 377 K occurs, and the peak at a temperature higher than 500 K, in contrast to the 99.99 % purity degree alpha-iron, has a point of inflection at 590 K. On a base of the data obtained, one may conclude that the stage centered around 445 K is of intrinsic nature, and the 99.99 % purity degree

DESIGNING THE RETURN MIGRATION OF ROMANIAN STUDENTS

Directory of Open Access Journals (Sweden)

Magdalena VELCIU

2017-05-01

Full Text Available Romanian youth migration is an increasing phenomenon, due to subjective and objective factors as economical reasons, professional carrer and increasingly more international competition for talent. In these circumstances, the present article aims to evaluate determinant factors that contribute to the decision of Romanian graduates to return national labour market. We sustain that young Romanians consider carefully and hardly decide their professional future. A particular attention is given to their personal reasons and motivations as well as family and friends network. For designing returning factors we present the results of a questionnaire survey, asking young pupils and students about their future educational way and personal reasons underlying the decision to study in a foreign country and taking into consideration the returning decision. As far international student migration is seen as a first step to migration for work, our work desires to fight for returning home of Romanian well-educated graduates.

Fluctuation behaviors of financial return volatility duration

Science.gov (United States)

Niu, Hongli; Wang, Jun; Lu, Yunfan

2016-04-01

It is of significantly crucial to understand the return volatility of financial markets because it helps to quantify the investment risk, optimize the portfolio, and provide a key input of option pricing models. The characteristics of isolated high volatility events above certain threshold in price fluctuations and the distributions of return intervals between these events arouse great interest in financial research. In the present work, we introduce a new concept of daily return volatility duration, which is defined as the shortest passage time when the future volatility intensity is above or below the current volatility intensity (without predefining a threshold). The statistical properties of the daily return volatility durations for seven representative stock indices from the world financial markets are investigated. Some useful and interesting empirical results of these volatility duration series about the probability distributions, memory effects and multifractal properties are obtained. These results also show that the proposed stock volatility series analysis is a meaningful and beneficial trial.

Return to play in elite rugby union: application of global positioning system technology in return-to-running programs.

Science.gov (United States)

Reid, Laura C; Cowman, Jason R; Green, Brian S; Coughlan, Garrett F

2013-05-01

Global positioning systems (GPS) are widely used in sport settings to evaluate the physical demands on players in training and competition. The use of these systems in the design and implementation of rehabilitation and return-to-running programs has not yet been elucidated. To demonstrate the application of GPS technology in the management of return to play in elite-club Rugby Union. Case series. Professional Rugby Union club team. 8 elite Rugby Union players (age 27.86 ± 4.78 y, height 1.85 ± 0.08 m, weight 99.14 ± 9.96 kg). Players wore GPS devices for the entire duration of a club game. Variables of locomotion speed and distance were measured. Differences in physical demands between playing positions were observed for all variables. An analysis of the position-specific physical demands measured by GPS provides key information regarding the level and volume of loads sustained by a player in a game environment. Using this information, sports-medicine practitioners can develop rehabilitation and return-to-running protocols specific to the player position to optimize safe return to play.

Reliability Calculations

DEFF Research Database (Denmark)

Petersen, Kurt Erling

1986-01-01

Risk and reliability analysis is increasingly being used in evaluations of plant safety and plant reliability. The analysis can be performed either during the design process or during the operation time, with the purpose to improve the safety or the reliability. Due to plant complexity and safety...... and availability requirements, sophisticated tools, which are flexible and efficient, are needed. Such tools have been developed in the last 20 years and they have to be continuously refined to meet the growing requirements. Two different areas of application were analysed. In structural reliability probabilistic...... approaches have been introduced in some cases for the calculation of the reliability of structures or components. A new computer program has been developed based upon numerical integration in several variables. In systems reliability Monte Carlo simulation programs are used especially in analysis of very...

Risk-Return Trade-Off for European Stock Markets

OpenAIRE

Aslanidis, Nektarios; Christiansen, Charlotte; Savva, Christos S.

2015-01-01

This paper adopts dynamic factor models with macro-finance predictors to revisit the intertemporal risk-return relation in five large European stock markets. We identify country specific, Euro area, and global factors to determine the conditional moments of returns considering the role of higher-order moments as additional measures of risk. The preferred combination of factors varies across countries. In the linear model, there is a strong but negative relation between conditional returns and...

Understanding the Puzzling Risk-Return Relationship for Housing

OpenAIRE

Lu Han

2013-01-01

Standard theory predicts a positive relationship between risk and return, yet recent data show that housing returns vary positively with risk in some markets but negatively in others. This paper rationalizes these cross-market differences in the risk-return relationship for housing, and in so doing, explains the puzzling negative relationship. The paper shows that when the current house provides a hedge against the risk associated with the future housing consumption, households are willing to...

26 CFR 301.6063-1 - Signing of partnership returns.

Science.gov (United States)

2010-04-01

... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Signing of partnership returns. 301.6063-1 Section 301.6063-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED....6063-1 Signing of partnership returns. For provisions relating to the signing of returns of partnership...

Investment Strategy Based on Aviation Accidents: Are there abnormal returns?

Directory of Open Access Journals (Sweden)

Marcos Rosa Costa

2013-06-01

Full Text Available This article investigates whether an investment strategy based on aviation accidents can generate abnormal returns. We performed an event study considering all the aviation accidents with more than 10 fatalities in the period from 1998 to 2009 and the stock market performance of the respective airlines and aircraft manufacturers in the days after the event. The tests performed were based on the model of Campbell, Lo & MacKinlay (1997 for definition of abnormal returns, by means of linear regression between the firms’ stock returns and the return of a market portfolio used as a benchmark. This enabled projecting the expected future returns of the airlines and aircraft makers, for comparison with the observed returns after each event. The result obtained suggests that an investment strategy based on aviation accidents is feasible because abnormal returns can be obtained in the period immediately following an aviation disaster.

Aggregate Unemployment Decreases Individual Returns to Education

Science.gov (United States)

Ammermueller, Andreas; Kuckulenz, Anja; Zwick, Thomas

2009-01-01

Aggregate unemployment may affect individual returns to education through qualification-specific responses in participation and wage bargaining. This paper shows that an increase in regional unemployment by 1% decreases returns to education by 0.005 percentage points. This implies that higher skilled employees are better sheltered from labour…

Returnable containers: an example of reverse logistics

NARCIS (Netherlands)

L.G. Kroon (Leo); G.M.C. Vrijens

1996-01-01

textabstractConsiders the application of returnable containers as an example of reverse logistics. A returnable container is a type of secondary packaging that can be used several times in the same form, in contrast with traditional cardboard boxes. For this equipment to be used, a system for the

Validity and reliability of naturalistic driving scene categorization Judgments from crowdsourcing.

Science.gov (United States)

Cabrall, Christopher D D; Lu, Zhenji; Kyriakidis, Miltos; Manca, Laura; Dijksterhuis, Chris; Happee, Riender; de Winter, Joost

2018-05-01

A common challenge with processing naturalistic driving data is that humans may need to categorize great volumes of recorded visual information. By means of the online platform CrowdFlower, we investigated the potential of crowdsourcing to categorize driving scene features (i.e., presence of other road users, straight road segments, etc.) at greater scale than a single person or a small team of researchers would be capable of. In total, 200 workers from 46 different countries participated in 1.5days. Validity and reliability were examined, both with and without embedding researcher generated control questions via the CrowdFlower mechanism known as Gold Test Questions (GTQs). By employing GTQs, we found significantly more valid (accurate) and reliable (consistent) identification of driving scene items from external workers. Specifically, at a small scale CrowdFlower Job of 48 three-second video segments, an accuracy (i.e., relative to the ratings of a confederate researcher) of 91% on items was found with GTQs compared to 78% without. A difference in bias was found, where without GTQs, external workers returned more false positives than with GTQs. At a larger scale CrowdFlower Job making exclusive use of GTQs, 12,862 three-second video segments were released for annotation. Infeasible (and self-defeating) to check the accuracy of each at this scale, a random subset of 1012 categorizations was validated and returned similar levels of accuracy (95%). In the small scale Job, where full video segments were repeated in triplicate, the percentage of unanimous agreement on the items was found significantly more consistent when using GTQs (90%) than without them (65%). Additionally, in the larger scale Job (where a single second of a video segment was overlapped by ratings of three sequentially neighboring segments), a mean unanimity of 94% was obtained with validated-as-correct ratings and 91% with non-validated ratings. Because the video segments overlapped in full for

EarthLabs - Investigating Hurricanes: Earth's Meteorological Monsters

Science.gov (United States)

McDaris, J. R.; Dahlman, L.; Barstow, D.

2007-12-01

Earth science is one of the most important tools that the global community needs to address the pressing environmental, social, and economic issues of our time. While, at times considered a second-rate science at the high school level, it is currently undergoing a major revolution in the depth of content and pedagogical vitality. As part of this revolution, labs in Earth science courses need to shift their focus from cookbook-like activities with known outcomes to open-ended investigations that challenge students to think, explore and apply their learning. We need to establish a new model for Earth science as a rigorous lab science in policy, perception, and reality. As a concerted response to this need, five states, a coalition of scientists and educators, and an experienced curriculum team are creating a national model for a lab-based high school Earth science course named EarthLabs. This lab course will comply with the National Science Education Standards as well as the states' curriculum frameworks. The content will focus on Earth system science and environmental literacy. The lab experiences will feature a combination of field work, classroom experiments, and computer access to data and visualizations, and demonstrate the rigor and depth of a true lab course. The effort is being funded by NOAA's Environmental Literacy program. One of the prototype units of the course is Investigating Hurricanes. Hurricanes are phenomena which have tremendous impact on humanity and the resources we use. They are also the result of complex interacting Earth systems, making them perfect objects for rigorous investigation of many concepts commonly covered in Earth science courses, such as meteorology, climate, and global wind circulation. Students are able to use the same data sets, analysis tools, and research techniques that scientists employ in their research, yielding truly authentic learning opportunities. This month-long integrated unit uses hurricanes as the story line by

Sovereign Risk and Currently Returns

DEFF Research Database (Denmark)

Della Corte, Pasquale; Sarno, Lucio; Schmeling, Maik

We empirically investigate the relation between sovereign risk and exchange rates for a broad set of currencies. An increase in the credit default swap (CDS) spread of a country is accompanied by a significant depreciation of the exchange rate. More generally, CDS spread changes have substantial...... explanatory power for currency returns which is largely driven by shocks to global credit risk. Consistent with the notion that sovereign risk is priced, we find that a country's exposure to global credit risk forecasts excess returns to trading exchange rates as well as to trading on the volatility, skewness...

Sovereign Risk and Currency Returns

DEFF Research Database (Denmark)

Della Corte, Pasquale; Sarno, Lucio; Schmeling, Maik

We empirically investigate the relation between sovereign risk and exchange rates for a broad set of currencies. An increase in the credit default swap (CDS) spread of a country is accompanied by a significant depreciation of the exchange rate. More generally, CDS spread changes have substantial...... explanatory power for currency returns which is largely driven by shocks to global credit risk. Consistent with the notion that sovereign risk is priced, we find that a country's exposure to global credit risk forecasts excess returns to trading exchange rates as well as to trading on the volatility, skewness...

Reliability in the utility computing era: Towards reliable Fog computing

DEFF Research Database (Denmark)

Madsen, Henrik; Burtschy, Bernard; Albeanu, G.

2013-01-01

This paper considers current paradigms in computing and outlines the most important aspects concerning their reliability. The Fog computing paradigm as a non-trivial extension of the Cloud is considered and the reliability of the networks of smart devices are discussed. Combining the reliability...... requirements of grid and cloud paradigms with the reliability requirements of networks of sensor and actuators it follows that designing a reliable Fog computing platform is feasible....

Return to golf after spine surgery.

Science.gov (United States)

Abla, Adib A; Maroon, Joseph C; Lochhead, Richard; Sonntag, Volker K H; Maroon, Adara; Field, Melvin

2011-01-01

no published evidence indicates when patients can resume golfing after spine surgery. The objective of this study is to provide data from surveys sent to spine surgeons. a survey of North American Spine Society members was undertaken querying the suggested timing of return to golf. Of 1000 spine surgeons surveyed, 523 responded (52.3%). The timing of recommended return to golf and the reasons were questioned for college/professional athletes and avid and recreational golfers of both sexes. Responses were tallied for lumbar laminectomy, lumbar microdiscectomy, lumbar fusion, and anterior cervical discectomy with fusion. the most common recommended time for return to golf was 4-8 weeks after lumbar laminectomy and lumbar microdiscectomy, 2-3 months after anterior cervical fusion, and 6 months after lumbar fusion. The results showed a statistically significant increase in the recommended time to resume golf after lumbar fusion than after cervical fusion in all patients (p golf after spine surgery depends on many variables, including the general well-being of patients in terms of pain control and comfort when golfing. This survey serves as a guide that can assist medical practitioners in telling patients the average times recommended by surgeons across North America regarding return to golf after spine surgery.

Infrared remote sensing of Earth degassing - Ground study

Directory of Open Access Journals (Sweden)

P. Strobl

2005-06-01

Full Text Available Geodynamical processes e.g., volcanoes, often cause degassing at the Earth surface. The geogas emanates via mineral springs, water mofettes, or dry mofettes. It is assumed that the emerging gas influences the temperature of the spring or mofette water, respectively and the surface temperature of the soil at and around the dry gas vents. This causes a thermal anomaly in comparison to the close vicinity. Under specific conditions this effect should be extractable from remotely acquired infrared images allowing detection, mapping and monitoring of gas vents/springs within large areas and short times. This article describes preparatory investigations for which emanating Earth gas was simulated by leading compressed air into the ground and releasing it in some depth via a metal lance. The thermal effect at the surface was observed from a nearby thermovision camera in summer and winter under varying meteorological conditions. A procedure was developed to reliably identify gas release areas within the recorded thermal images of the scene. The investigations are aiming at studies to be performed later in the Western Bohemia (Czech Republic earthquake swarm region where especially CO2 of magmatic origin from European SubContinental Mantle (ESCM emanates.

Efficient Return Algorithms For Associated Plasticity With Multiple Yield Planes

DEFF Research Database (Denmark)

Clausen, Johan Christian; Damkilde, Lars; Andersen, Lars

2006-01-01

of such criteria. The return formulae are in closed form and no iteration is required. The method accounts for three types of stress return: Return to a single yield plane, to a discontinuity line at the intersection of two yield planes and to a discontinuity point at the intersection between three or more yield...... planes. The infinitesimal and the consistent elastoplastic constitutive matrix are calculated for each type of stress return, as are the conditions to ascertain which type of return is required. The method is exemplified with the Mohr-Coulomb yield criterion....

Dependent systems reliability estimation by structural reliability approach

DEFF Research Database (Denmark)

Kostandyan, Erik; Sørensen, John Dalsgaard

2014-01-01

Estimation of system reliability by classical system reliability methods generally assumes that the components are statistically independent, thus limiting its applicability in many practical situations. A method is proposed for estimation of the system reliability with dependent components, where...... the leading failure mechanism(s) is described by physics of failure model(s). The proposed method is based on structural reliability techniques and accounts for both statistical and failure effect correlations. It is assumed that failure of any component is due to increasing damage (fatigue phenomena...... identification. Application of the proposed method can be found in many real world systems....

What stock market returns to expect for the future?

Science.gov (United States)

Diamond, P A

2000-01-01

In evaluating proposals for reforming Social Security that involve stock investments, the Office of the Chief Actuary (OCACT) has generally used a 7.0 percent real return for stocks. The 1994-96 Advisory Council specified that OCACT should use that return in making its 75-year projections of investment-based reform proposals. The assumed ultimate real return on Treasury bonds of 3.0 percent implies a long-run equity premium of 4.0 percent. There are two equity-premium concepts: the realized equity premium, which is measured by the actual rates of return; and the required equity premium, which investors expect to receive for being willing to hold available stocks and bonds. Over the past two centuries, the realized premium was 3.5 percent on average, but 5.2 percent for 1926 to 1998. Some critics argue that the 7.0 percent projected stock returns are too high. They base their arguments on recent developments in the capital market, the current high value of the stock market, and the expectation of slower economic growth. Increased use of mutual funds and the decline in their costs suggest a lower required premium, as does the rising fraction of the American public investing in stocks. The size of the decrease is limited, however, because the largest cost savings do not apply to the very wealthy and to large institutional investors, who hold a much larger share of the stock market's total value than do new investors. These trends suggest a lower equity premium for projections than the 5.2 percent of the past 75 years. Also, a declining required premium is likely to imply a temporary increase in the realized premium because a rising willingness to hold stocks tends to increase their price. Therefore, it would be a mistake during a transition period to extrapolate what may be a temporarily high realized return. In the standard (Solow) economic growth model, an assumption of slower long-run growth lowers the marginal product of capital if the savings rate is constant

After a career break: supporting women returning to ICT

OpenAIRE

Herman, Clem

2011-01-01

This is a case study of an initiative to support women returning to ICT after a career break, which was run in the UK and Ireland between 2005 and 2011.The article starts by outlining how the UK government’s concern about women failing return to SET careers led to the setting up of a national campaign (RETURN) to address this issue. A brief overview of previous research about women’s reasons for leaving ICT employment and the difficulties and barriers they encounter in returning to work, sets...

The risks and returns of stock investment in a financial market

Science.gov (United States)

Li, Jiang-Cheng; Mei, Dong-Cheng

2013-03-01

The risks and returns of stock investment are discussed via numerically simulating the mean escape time and the probability density function of stock price returns in the modified Heston model with time delay. Through analyzing the effects of delay time and initial position on the risks and returns of stock investment, the results indicate that: (i) There is an optimal delay time matching minimal risks of stock investment, maximal average stock price returns and strongest stability of stock price returns for strong elasticity of demand of stocks (EDS), but the opposite results for weak EDS; (ii) The increment of initial position recedes the risks of stock investment, strengthens the average stock price returns and enhances stability of stock price returns. Finally, the probability density function of stock price returns and the probability density function of volatility and the correlation function of stock price returns are compared with other literatures. In addition, good agreements are found between them.

Leaving from and returning to nursing practice: contributing factors.

Science.gov (United States)

Jamieson, Isabel; Taua, Chris

2009-07-01

Many nurses leave nursing and never return. Others return after a period of time. Given the global shortage of nurses a better understanding of these movements is needed. The present study focused on nurses who had been out of nursing for more than five years, and explored factors that influenced their leaving and return to practice. All the nurses who had undertaken a Competency Assessment Programme at a given New Zealand tertiary institution during 2005 were invited to participate. Of the 70 questionnaires mailed out 32 (44.5%) were completed and returned. Quantitative data were analysed using Microsoft Excel, and the qualitative data were coded and analysed by means of content analysis. For each, leaving and returning, three key issues emerged. Nurses left for personal reasons, to seek a career change, or because of poor working conditions. They returned when they had the personal freedom to do so, for fiscal reasons, or because they were motivated by some sense of unfinished business. These findings indicate that it is important for educators involved with Competency Assessment Programmes to collaborate with employers in ensuring that there are opportunities for re-entry to positive work environments, with a degree of flexibility that suits the demographic characteristics of those nurses returning to practice.

Industry Returns and the Fisher Effect.

OpenAIRE

Boudoukh, Jacob; Richardson, Matthew; Whitelaw, Robert F

1994-01-01

The authors investigate the cross-sectional relation between industry-sorted stock returns and expected inflation, and they find that this relation is linked to cyclical movements in industry output. Stock returns of noncyclical industries tend to covary positively with expected inflation, while the reverse holds for cyclical industries. From a theoretical perspective, the authors describe a model that captures both (1) the cross-sectional variation in these relations across industries and (2...

Red-emitting alkaline-earth rare-earth pentaoxometallates powders ...

Indian Academy of Sciences (India)

Moisture-insensitive metal carboxylates that are mostly liquids at room temperature have been first applied to ... alkaline-earth ion, or possibly even a rare-earth ion and alkali metal ... sion spectra of the powders were recorded on a fluorescent.

Consumption Risk and the Cross Section of Expected Returns.

Science.gov (United States)

Parker, Jonathan A.; Julliard, Christian

2005-01-01

This paper evaluates the central insight of the consumption capital asset pricing model that an asset's expected return is determined by its equilibrium risk to consumption. Rather than measure risk by the contemporaneous covariance of an asset's return and consumption growth, we measure risk by the covariance of an asset's return and consumption…

Return to Play

Science.gov (United States)

Mangan, Marianne

2013-01-01

Call it physical activity, call it games, or call it play. Whatever its name, it's a place we all need to return to. In the physical education, recreation, and dance professions, we need to redesign programs to address the need for and want of play that is inherent in all of us.

Feature discrimination/identification based upon SAR return variations

Science.gov (United States)

Rasco, W. A., Sr.; Pietsch, R.

1978-01-01

A study of the statistics of The look-to-look variation statistics in the returns recorded in-flight by a digital, realtime SAR system are analyzed. The determination that the variations in the look-to-look returns from different classes do carry information content unique to the classes was illustrated by a model based on four variants derived from four look in-flight SAR data under study. The model was limited to four classes of returns: mowed grass on a athletic field, rough unmowed grass and weeds on a large vacant field, young fruit trees in a large orchard, and metal mobile homes and storage buildings in a large mobile home park. The data population in excess of 1000 returns represented over 250 individual pixels from the four classes. The multivariant discriminant model operated on the set of returns for each pixel and assigned that pixel to one of the four classes, based on the target variants and the probability distribution function of the four variants for each class.

Earth - South America (first frame of Earth Spin Movie)

Science.gov (United States)

1990-01-01

This color image of the Earth was obtained by Galileo at about 6:10 a.m. Pacific Standard Time on Dec. 11, 1990, when the spacecraft was about 1.3 million miles from the planet during the first of two Earth flybys on its way to Jupiter. The color composite used images taken through the red, green and violet filters. South America is near the center of the picture, and the white, sunlit continent of Antarctica is below. Picturesque weather fronts are visible in the South Atlantic, lower right. This is the first frame of the Galileo Earth spin movie, a 500- frame time-lapse motion picture showing a 25-hour period of Earth's rotation and atmospheric dynamics.

Exiting and Returning to the Parental Home for Boomerang Kids.

Science.gov (United States)

Sandberg-Thoma, Sara E; Snyder, Anastasia R; Jang, Bohyun Joy

2015-06-01

Young adults commonly exit from and return to the parental home, yet few studies have examined the motivation behind these exits and returns using a life course framework. Using data from the National Longitudinal Survey of Youth 1997, the authors examined associations between mental health problems and economic characteristics and exits from (n = 8,162), and returns to (n = 6,530), the parental home during the transition to adulthood. The average age of the respondents was 24 years. The authors found evidence that mental health and economic characteristics were related to home leaving and returning. Emotional distress was associated with earlier exits from, and returns to, the parental home; alcohol problems were associated with earlier returns to the parental home. The findings regarding economic resources were unexpectedly mixed. Greater economic resources were linked to delayed exits from, and earlier returns to, the parental home. The implications of these findings for young adults are discussed.

Returns to Schooling in Less Developed Countries: New Evidence from Zambia

DEFF Research Database (Denmark)

Nielsen, Helena Skyt; Westergård-Nielsen, Niels Chr.

2001-01-01

In our analysis of returns to schooling in Zambia, we look at the rural and urban population separately, and estimate the returns to schooling in each region based on a selection model in two stages. For urban areas we find that the returns to primary schooling are nil whereas the returns to scho...... to schooling beyond primary school are higher. For rural areas we find that the returns to primary schooling are positive and no different from the returns to education beyond primary school. Udgivelsesdato: JAN...

Analyzing the reliability of shuffle-exchange networks using reliability block diagrams

International Nuclear Information System (INIS)

Bistouni, Fathollah; Jahanshahi, Mohsen

2014-01-01

Supercomputers and multi-processor systems are comprised of thousands of processors that need to communicate in an efficient way. One reasonable solution would be the utilization of multistage interconnection networks (MINs), where the challenge is to analyze the reliability of such networks. One of the methods to increase the reliability and fault-tolerance of the MINs is use of various switching stages. Therefore, recently, the reliability of one of the most common MINs namely shuffle-exchange network (SEN) has been evaluated through the investigation on the impact of increasing the number of switching stage. Also, it is concluded that the reliability of SEN with one additional stage (SEN+) is better than SEN or SEN with two additional stages (SEN+2), even so, the reliability of SEN is better compared to SEN with two additional stages (SEN+2). Here we re-evaluate the reliability of these networks where the results of the terminal, broadcast, and network reliability analysis demonstrate that SEN+ and SEN+2 continuously outperform SEN and are very alike in terms of reliability. - Highlights: • The impact of increasing the number of stages on reliability of MINs is investigated. • The RBD method as an accurate method is used for the reliability analysis of MINs. • Complex series–parallel RBDs are used to determine the reliability of the MINs. • All measures of the reliability (i.e. terminal, broadcast, and network reliability) are analyzed. • All reliability equations will be calculated for different size N×N

Beyond 3-D: The New Spectrum of Lidar Applications for Earth and Ecological Sciences

Science.gov (United States)

Eitel, Jan U. H.; Hofle, Bernhard; Vierling, Lee A.; Abellan, Antonio; Asner, Gregory P.; Deems, Jeffrey S.; Glennie, Craig L.; Joerg, Phillip C.; LeWinter, Adam L.; Magney, Troy S.;

Maternal perspectives on postpartum return to the workplace.

Science.gov (United States)

Nichols, Mary R; Roux, Gayle M

2004-01-01

To describe maternal perceptions about postpartum return to the workplace. The research framework was McCubbin and McCubbin's Resiliency Model of Family Stress, Adjustment, and Adaptation. Employed, postpartum women, who resided in six different states, were recruited from day care and primary care settings to participate in this descriptive study. Seventy-four employed, married women, who returned to the workplace within one year after childbirth. As part of a larger study, perceptions about combining multiple roles after return to the workplace are the focus for this report. Participants responded to open-ended questions about their return to the workplace during the first months after giving birth. Content analysis of those responses resulted in two major categories, Resiliency Challenges: Negative Aspects (role conflict/overload, family stress, family/child issues, finances, psychosocial issues) and Resiliency Building: Positive Aspects (social support, maternal role satisfaction, positive adaptation, career role satisfaction). The data support the premise that employed women view returning to the workforce as having more challenges than they expected because the experience was viewed as being mostly negative. Preparing for return to the workplace is an important, but neglected, topic that needs to be addressed and defined more clearly in the literature. Therefore, future research is needed to identify resources and interventions that will help women experience fewer challenges associated with postpartum employment.

26 CFR 1.6017-1 - Self-employment tax returns.

Science.gov (United States)

2010-04-01

... 26 Internal Revenue 13 2010-04-01 2010-04-01 false Self-employment tax returns. 1.6017-1 Section 1... (CONTINUED) INCOME TAXES Tax Returns Or Statements § 1.6017-1 Self-employment tax returns. (a) In general. (1) Every individual, other than a nonresident alien, having net earnings from self-employment, as defined...

Investigating different factors influencing on return of private banks

Directory of Open Access Journals (Sweden)

Pegah Motamedi

2013-09-01

Full Text Available Return of Investment has always been an interesting area of research among academics as well as investors. Although capital asset pricing model (CAPM is capable of estimating risk of investment, many people argue that CAPM is not able to predict long-term return, properly. This paper presents an empirical investigation to find the effects of different financial figures including systematic risk (Beta, size of firm, ratio of book value to market share, volume of trade and the ratio of price/earnings (P/E on return of private banks in Iran. The study gathers the necessary information over the period 2005-2011 from private banks in Iran. The study uses multiple regression technique to find the effects of mentioned variables on return of private banks. The results indicate that there are some meaningful and positive relationship between return of banks and systematic risk (Beta, size, volume of trade and P/E. The study also finds some meaningful and reverse relationship between bank return and book value on market value.

VOLATILITY AND KURTOSIS OF DAILY STOCK RETURNS AT MSE

Directory of Open Access Journals (Sweden)

Zoran Ivanovski

2015-12-01

Full Text Available Prominent financial stock pricing models are built on assumption that asset returns follow a normal (Gaussian distribution. However, many authors argue that in the practice stock returns are often characterized by skewness and kurtosis, so we test the existence of the Gaussian distribution of stock returns and calculate the kurtosis of several stocks at the Macedonian Stock Exchange (MSE. Obtaining information about the shape of distribution is an important step for models of pricing risky assets. The daily stock returns at Macedonian Stock Exchange (MSE are characterized by high volatility and non-Gaussian behaviors as well as they are extremely leptokurtic. The analysis of MSE time series stock returns determine volatility clustering and high kurtosis. The fact that daily stock returns at MSE are not normally distributed put into doubt results that rely heavily on this assumption and have significant implications for portfolio management. We consider this stock market as good representatives of emerging markets. Therefore, we argue that our results are valid for other similar emerging stock markets.

The Returns to Quality in Graduate Education

Science.gov (United States)

Stevenson, Adam

2016-01-01

This paper estimates the monetary return to quality in US graduate education, controlling for cognitive ability and self-selection across award level, program quality, and field-of-study. In most program types, I cannot reject the hypothesis of no returns to either degree completion or program quality. Important exceptions include master's…

Managing Returns in a Catalog Distribution Center

Science.gov (United States)

Gates, Joyce; Stuart, Julie Ann; Bonawi-tan, Winston; Loehr, Sarah

2004-01-01

The research team of the Purdue University in the United States developed an algorithm that considers several different factors, in addition to cost, to help catalog distribution centers process their returns more efficiently. A case study to teach the students important concepts involved in developing a solution to the returns disposition problem…

Conditional Relationship Between Beta and Return in the US Stock Market

Directory of Open Access Journals (Sweden)

Bing XIAO

2016-04-01

Full Text Available According to the CAPM, risk is measured by the beta, and the relation between required expected return and beta is linear. This paper examines the conditional relationship between beta and return in the US stock market. The conditional covariances and variances used to estimate beta are modeled as an ARCH process. The beta return relationship is tested upon the sign of the excess market return. The implication of the sign of the excess market return follows Morelli (2011. This study shows the importance of recognizing the sign of the excess market return when testing the beta-return relationship. The approach also allows us to distinguish the size effect and the effect of economic cycles.

Building a Dashboard of the Planet with Google Earth and Earth Engine

Science.gov (United States)

Moore, R. T.; Hancher, M.

2016-12-01

In 2005 Google Earth, a popular 3-D virtual globe, was first released. Scientists immediately recognized how it could be used to tell stories about the Earth. From 2006 to 2009, the "Virtual Globes" sessions of AGU included innovative examples of scientists and educators using Google Earth, and since that time it has become a commonplace tool for communicating scientific results. In 2009 Google Earth Engine, a cloud-based platform for planetary-scale geospatial analysis, was first announced. Earth Engine was initially used to extract information about the world's forests from raw Landsat data. Since then, the platform has proven highly effective for general analysis of georeferenced data, and users have expanded the list of use cases to include high-impact societal issues such as conservation, drought, disease, food security, water management, climate change and environmental monitoring. To support these use cases, the platform has continuously evolved with new datasets, analysis functions, and user interface tools. This talk will give an overview of the latest Google Earth and Earth Engine functionality that allow partners to understand, monitor and tell stories about of our living, breathing Earth. https://earth.google.com https://earthengine.google.com

Inaugeral lecture - Meteorite impacts on Earth and on the Earth ...

African Journals Online (AJOL)

There is some controversial evidence for the theory that the first life on Earth itself may have been transported here on meteorites from Mars. The possibility of a major meteorite impact on Earth in the near future emphasizes the dramatic nature of these recent discoveries, which are having deep impacts in the Earth sciences ...

Highly-reliable laser diodes and modules for spaceborne applications

Science.gov (United States)

Deichsel, E.

2017-11-01

Laser applications become more and more interesting in contemporary missions such as earth observations or optical communication in space. One of these applications is light detection and ranging (LIDAR), which comprises huge scientific potential in future missions. The Nd:YAG solid-state laser of such a LIDAR system is optically pumped using 808nm emitting pump sources based on semiconductor laser-diodes in quasi-continuous wave (qcw) operation. Therefore reliable and efficient laser diodes with increased output powers are an important requirement for a spaceborne LIDAR-system. In the past, many tests were performed regarding the performance and life-time of such laser-diodes. There were also studies for spaceborne applications, but a test with long operation times at high powers and statistical relevance is pending. Other applications, such as science packages (e.g. Raman-spectroscopy) on planetary rovers require also reliable high-power light sources. Typically fiber-coupled laser diode modules are used for such applications. Besides high reliability and life-time, designs compatible to the harsh environmental conditions must be taken in account. Mechanical loads, such as shock or strong vibration are expected due to take-off or landing procedures. Many temperature cycles with high change rates and differences must be taken in account due to sun-shadow effects in planetary orbits. Cosmic radiation has strong impact on optical components and must also be taken in account. Last, a hermetic sealing must be considered, since vacuum can have disadvantageous effects on optoelectronics components.

Statistics of return intervals between long heartbeat intervals and their usability for online prediction of disorders

International Nuclear Information System (INIS)

Bogachev, Mikhail I; Bunde, Armin; Kireenkov, Igor S; Nifontov, Eugene M

2009-01-01

We study the statistics of return intervals between large heartbeat intervals (above a certain threshold Q) in 24 h records obtained from healthy subjects. We find that both the linear and the nonlinear long-term memory inherent in the heartbeat intervals lead to power-laws in the probability density function P Q (r) of the return intervals. As a consequence, the probability W Q (t; Δt) that at least one large heartbeat interval will occur within the next Δt heartbeat intervals, with an increasing elapsed number of intervals t after the last large heartbeat interval, follows a power-law. Based on these results, we suggest a method of obtaining a priori information about the occurrence of the next large heartbeat interval, and thus to predict it. We show explicitly that the proposed method, which exploits long-term memory, is superior to the conventional precursory pattern recognition technique, which focuses solely on short-term memory. We believe that our results can be straightforwardly extended to obtain more reliable predictions in other physiological signals like blood pressure, as well as in other complex records exhibiting multifractal behaviour, e.g. turbulent flow, precipitation, river flows and network traffic.

SEL monitoring of the earth's energetic particle radiation environment

International Nuclear Information System (INIS)

Sauer, H.H.

1989-01-01

The Space Environment Laboratory (SEL) of the National Oceanic and Atmospheric Administration (NOAA) maintains instruments on board the GOES series of geostationary satellites, and aboard the NOAA/TIROS series of low-altitude, polar-orbiting satellites, which provide monitoring of the energetic particle radiation environment as well as monitoring the geostationary magnetic field and the solar x-ray flux. The data are used by the SEL Space Environment Services Center (SESC) to help provide real-time monitoring and forecasting of the state of the near earth environment and its disturbances, and to maintain a source of reliable information to research and operational activities of a variety of users

ON SUN-TO-EARTH PROPAGATION OF CORONAL MASS EJECTIONS

International Nuclear Information System (INIS)

Liu, Ying D.; Luhmann, Janet G.; Möstl, Christian; Bale, Stuart D.; Lin, Robert P.; Lugaz, Noé; Davies, Jackie A.

2013-01-01

We investigate how coronal mass ejections (CMEs) propagate through, and interact with, the inner heliosphere between the Sun and Earth, a key question in CME research and space weather forecasting. CME Sun-to-Earth kinematics are constrained by combining wide-angle heliospheric imaging observations, interplanetary radio type II bursts, and in situ measurements from multiple vantage points. We select three events for this study, the 2012 January 19, 23, and March 7 CMEs. Different from previous event studies, this work attempts to create a general picture for CME Sun-to-Earth propagation and compare different techniques for determining CME interplanetary kinematics. Key results are obtained concerning CME Sun-to-Earth propagation: (1) the Sun-to-Earth propagation of fast CMEs can be approximately formulated into three phases: an impulsive acceleration, then a rapid deceleration, and finally a nearly constant speed propagation (or gradual deceleration); (2) the CMEs studied here are still accelerating even after the flare maximum, so energy must be continuously fed into the CME even after the time of the maximum heating and radiation has elapsed in the corona; (3) the rapid deceleration, presumably due to interactions with the ambient medium, mainly occurs over a relatively short timescale following the acceleration phase; and (4) CME-CME interactions seem a common phenomenon close to solar maximum. Our comparison between different techniques (and data sets) has important implications for CME observations and their interpretations: (1) for the current cases, triangulation assuming a compact CME geometry is more reliable than triangulation assuming a spherical front attached to the Sun for distances below 50-70 solar radii from the Sun, but beyond about 100 solar radii we would trust the latter more; (2) a proper treatment of CME geometry must be performed in determining CME Sun-to-Earth kinematics, especially when the CME propagation direction is far away from the

Analysis of factors influencing return to work after total hip arthroplasty.

Science.gov (United States)

Truszczyńska, Aleksandra; Rąpała, Kazimierz; Tarnowski, Adam; Kucharczyk, Wojciech

2013-10-31

BACKGROUND. Patients who undergo total hip arthroplasty (THA) find it difficult to return to work. OBJECTIVES. Analysis of factors influencing return to work after THA. Assessment of patients' quality of life and its impact on their attitude to work. MATERIAL AND METHODS. We studied patients operated on for degenerative hip disease at the Department of Orthopaedic Surgery of Medical Centre of Postgraduate Education in Otwock between 2007 and 2012. The total number of the patients was 400; however, we chose only those patients who were younger than 65 and still in employment. The study population consisted of 54 of these patients. The mean patient age was 55.89 (±7.424). There were 29 men (57.3%) and 25 women (46.3%). RESULTS. 32 patients (59.3%) returned to work. There was a statistically significant difference regarding the attitude to work and return to work. An overwhelming majority of the patients who returned to work--31 out of 32 (96.6%)--liked their jobs. The 12 patients (22.22%) who did not return to work declared their intention to apply for a disability pension. The patients who returned to work assessed their physical health as better than the patients who did not return to work. CONCLUSIONS. 1. 40.7% of patients after THA did not return to preoperative employment. The reasons for not returning were not medical, because elimination of pain and an increased range of motion made return to work possible. 2. The perception of the quality of physical and psychological health among patients with THA who returned to work was significantly better than among those who did not return.

Heuristics for Relevancy Ranking of Earth Dataset Search Results

Science.gov (United States)

Lynnes, Christopher; Quinn, Patrick; Norton, James

2016-01-01

As the Variety of Earth science datasets increases, science researchers find it more challenging to discover and select the datasets that best fit their needs. The most common way of search providers to address this problem is to rank the datasets returned for a query by their likely relevance to the user. Large web page search engines typically use text matching supplemented with reverse link counts, semantic annotations and user intent modeling. However, this produces uneven results when applied to dataset metadata records simply externalized as a web page. Fortunately, data and search provides have decades of experience in serving data user communities, allowing them to form heuristics that leverage the structure in the metadata together with knowledge about the user community. Some of these heuristics include specific ways of matching the user input to the essential measurements in the dataset and determining overlaps of time range and spatial areas. Heuristics based on the novelty of the datasets can prioritize later, better versions of data over similar predecessors. And knowledge of how different user types and communities use data can be brought to bear in cases where characteristics of the user (discipline, expertise) or their intent (applications, research) can be divined. The Earth Observing System Data and Information System has begun implementing some of these heuristics in the relevancy algorithm of its Common Metadata Repository search engine.

Endogenous time-varying risk aversion and asset returns.

Science.gov (United States)

Berardi, Michele

2016-01-01

Stylized facts about statistical properties for short horizon returns in financial markets have been identified in the literature, but a satisfactory understanding for their manifestation is yet to be achieved. In this work, we show that a simple asset pricing model with representative agent is able to generate time series of returns that replicate such stylized facts if the risk aversion coefficient is allowed to change endogenously over time in response to unexpected excess returns under evolutionary forces. The same model, under constant risk aversion, would instead generate returns that are essentially Gaussian. We conclude that an endogenous time-varying risk aversion represents a very parsimonious way to make the model match real data on key statistical properties, and therefore deserves careful consideration from economists and practitioners alike.

What Is the Expected Return on a Stock?

DEFF Research Database (Denmark)

Martin, Ian; Wagner, Christian

We derive a formula that expresses the expected return on a stock in terms of the risk-neutral variance of the market and the stock's excess risk-neutral variance relative to the average stock. These components can be computed from index and stock option prices; the formula has no free parameters....... We test the theory in-sample by running panel regressions of stock returns onto risk-neutral variances. The formula performs well at 6-month and 1-year forecasting horizons, and our predictors drive out beta, size, book-to-market, and momentum. Out-of-sample, we find that the formula outperforms...... a range of competitors in forecasting individual stock returns. Our results suggest that there is considerably more variation in expected returns, both over time and across stocks, than has previously been acknowledged....

What is the Expected Return on a Stock?

DEFF Research Database (Denmark)

Martin, Ian; Wagner, Christian

We derive a formula that expresses the expected return on a stock in terms of the risk-neutral variance of the market and the stock’s excess risk-neutral variance relative to the average stock. These components can be computed from index and stock option prices; the formula has no free parameters....... We test the theory in-sample by running panel regressions of stock returns onto risk-neutral variances. The formula performs well at 6-month and 1-year forecasting horizons, and our predictors drive out beta, size, book-to-market, and momentum. Out-of-sample, we find that the formula outperforms...... a range of competitors in forecasting individual stock returns. Our results suggest that there is considerably more variation in expected returns, both over time and across stocks, than has previously been acknowledged....

Reliability data banks

International Nuclear Information System (INIS)

Cannon, A.G.; Bendell, A.

1991-01-01

Following an introductory chapter on Reliability, what is it, why it is needed, how it is achieved and measured, the principles of reliability data bases and analysis methodologies are the subject of the next two chapters. Achievements due to the development of data banks are mentioned for different industries in the next chapter, FACTS, a comprehensive information system for industrial safety and reliability data collection in process plants are covered next. CREDO, the Central Reliability Data Organization is described in the next chapter and is indexed separately, as is the chapter on DANTE, the fabrication reliability Data analysis system. Reliability data banks at Electricite de France and IAEA's experience in compiling a generic component reliability data base are also separately indexed. The European reliability data system, ERDS, and the development of a large data bank come next. The last three chapters look at 'Reliability data banks, - friend foe or a waste of time'? and future developments. (UK)

An Introduction To Reliability

International Nuclear Information System (INIS)

Park, Kyoung Su

1993-08-01

This book introduces reliability with definition of reliability, requirement of reliability, system of life cycle and reliability, reliability and failure rate such as summary, reliability characteristic, chance failure, failure rate which changes over time, failure mode, replacement, reliability in engineering design, reliability test over assumption of failure rate, and drawing of reliability data, prediction of system reliability, conservation of system, failure such as summary and failure relay and analysis of system safety.

Macro factors in oil futures returns

International Nuclear Information System (INIS)

Le Pen, Yannick; Sevi, Benoit

2012-01-01

We investigate the macro factors that can explain the monthly oil futures return for the NYMEX WTI futures contract for the time period 1993:11 to 2010:03. We build a new database of 187 real and nominal macro-economic variables from developed and emerging countries and resort to the large factor approximate model to extract 9 factors from this dataset. We then regress crude oil return on several combinations of these factors. Our best model explains around 38% of the variability of oil futures return. More interestingly, the factor which has the largest influence on crude oil price is related to real variables from emerging countries. This result confirms the latest finding in the literature that the recent evolution in oil price is attributable to change in supply and demand conditions and not to the large increase in trading activity from speculators. (authors)

26 CFR 1.857-10 - Information returns.

Science.gov (United States)

2010-04-01

... 26 Internal Revenue 9 2010-04-01 2010-04-01 false Information returns. 1.857-10 Section 1.857-10 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Real Estate Investment Trusts § 1.857-10 Information returns. Nothing in §§ 1.857-8 and 1...

26 CFR 1.6013-1 - Joint returns.

Science.gov (United States)

2010-04-01

... for the right of an executor to file a late separate return for a deceased spouse and thereby... respect to the decedent may be made only by his executor or administrator, as defined in paragraph (c) of... respect of which the joint return is made; (ii) No executor or administrator has been appointed at or...

46 CFR 111.05-11 - Hull return.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Hull return. 111.05-11 Section 111.05-11 Shipping COAST... REQUIREMENTS Equipment Ground, Ground Detection, and Grounded Systems § 111.05-11 Hull return. (a) A vessel's hull must not carry current as a conductor except for the following systems: (1) Impressed current...

27 CFR 28.220 - Notice of return.

Science.gov (United States)

2010-04-01

... OF THE TREASURY LIQUORS EXPORTATION OF ALCOHOL Exportation of Wine With Benefit of Drawback § 28.220 Notice of return. If an exporter desires to return wine to a bonded wine cellar or wholesale liquor... wine cellar from which withdrawn; (b) Date and serial number of the Form 1582-A (5120.24) on which the...

Return to the workforce following coronary artery bypass grafting

DEFF Research Database (Denmark)

Butt, Jawad H; Rørth, Rasmus; Kragholm, Kristian

2018-01-01

Background Returning to the workforce after coronary artery bypass grafting (CABG) holds important socioeconomic consequences not only for patients, but the society as well. Yet data on this issue are limited. We examined return to the workforce and associated factors in patients of working age.......0%) patients had returned to the workforce, 614 (10.2%) were on paid sick leave, 267 (4.4%) received disability pension, 250 (4.1%) were on early retirement, 57 (0.9%) had died, and 16 (0.3%) had emigrated. Factors associated with return to the workforce were identified using multivariable logistic regression...