Space Power Theory: Controlling the Medium Without Weapons in Space

National Research Council Canada - National Science Library

Wilkerson, Don L

2008-01-01

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

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

Directory of Open Access Journals (Sweden)

N.S. Khalifa

2013-12-01

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

Natural Hazards of the Space Environment

Science.gov (United States)

Evans, Steven W.; Kross, Dennis A. (Technical Monitor)

2000-01-01

Spacecraft in Low Earth Orbit (LEO) are subject to numerous environmental hazards. Here I'll briefly discuss three environment factors that pose acute threats to the survival of spacecraft systems and crew: atmospheric drag, impacts by meteoroids and orbital debris, and ionizing radiation. Atmospheric drag continuously opposes the orbital motion of a satellite, causing the orbit to decay. This decay will lead to reentry if not countered by reboost maneuvers. Orbital debris is a by-product of man's activities in space, and consists of objects ranging in size from miniscule paint chips to spent rocket stages and dead satellites. Ionizing radiation experienced in LEO has several components: geomagnetically trapped protons and electrons (Van Allen belts); energetic solar particles; galactic cosmic rays; and albedo neutrons. These particles can have several types of prompt harmful effects on equipment and crew, from single-event upsets, latchup, and burnout of electronics, to lethal doses to crew.All three types of prompt threat show some dependence on the solar activity cycle. Atmospheric drag mitigation and large debris avoidance require propulsive maneuvers. M/OD and ionizing radiation require some form of shielding for crew and sensitive equipment. Limiting exposure time is a mitigation technique for ionizing radiation and meteor streams.

Space environment durability of beta cloth in LDEF thermal blankets

Science.gov (United States)

Linton, Roger C.; Whitaker, Ann F.; Finckenor, Miria M.

1993-01-01

Beta cloth performance for use on long-term space vehicles such as Space Station Freedom (S.S. Freedom) requires resistance to the degrading effects of the space environment. The major issues are retention of thermal insulating properties through maintaining optical properties, preserving mechanical integrity, and generating minimal particulates for contamination-sensitive spacecraft surfaces and payloads. The longest in-flight test of beta cloth's durability was on the Long Duration Exposure Facility (LDEF), where it was exposed to the space environment for 68 months. The LDEF contained 57 experiments which further defined the space environment and its effects on spacecraft materials. It was deployed into low-Earth orbit (LEO) in Apr. 1984 and retrieved Jan. 1990 by the space shuttle. Among the 10,000 plus material constituents and samples onboard were thermal control blankets of multilayer insulation with a beta cloth outer cover and Velcro attachments. These blankets were exposed to hard vacuum, thermal cycling, charged particles, meteoroid/debris impacts, ultraviolet (UV) radiation, and atomic oxygen (AO). Of these space environmental exposure elements, AO appears to have had the greatest effect on the beta cloth. The beta cloth analyzed in this report came from the MSFC Experiment S1005 (Transverse Flat-Plate Heat Pipe) tray oriented approximately 22 deg from the leading edge vector of the LDEF satellite. The location of the tray on LDEF and the placement of the beta cloth thermal blankets are shown. The specific space environment exposure conditions for this material are listed.

Space Environments and Spacecraft Effects Organization Concept

Science.gov (United States)

Edwards, David L.; Burns, Howard D.; Miller, Sharon K.; Porter, Ron; Schneider, Todd A.; Spann, James F.; Xapsos, Michael

2012-01-01

The National Aeronautics and Space Administration (NASA) is embarking on a course to expand human presence beyond Low Earth Orbit (LEO) while also expanding its mission to explore the solar system. Destinations such as Near Earth Asteroids (NEA), Mars and its moons, and the outer planets are but a few of the mission targets. Each new destination presents an opportunity to increase our knowledge of the solar system and the unique environments for each mission target. NASA has multiple technical and science discipline areas specializing in specific space environments disciplines that will help serve to enable these missions. To complement these existing discipline areas, a concept is presented focusing on the development of a space environments and spacecraft effects (SENSE) organization. This SENSE organization includes disciplines such as space climate, space weather, natural and induced space environments, effects on spacecraft materials and systems and the transition of research information into application. This space environment and spacecraft effects organization will be composed of Technical Working Groups (TWG). These technical working groups will survey customers and users, generate products, and provide knowledge supporting four functional areas: design environments, engineering effects, operational support, and programmatic support. The four functional areas align with phases in the program mission lifecycle and are briefly described below. Design environments are used primarily in the mission concept and design phases of a program. Engineering effects focuses on the material, component, sub-system and system-level selection and the testing to verify design and operational performance. Operational support provides products based on real time or near real time space weather to mission operators to aid in real time and near-term decision-making. The programmatic support function maintains an interface with the numerous programs within NASA, other federal

Space Environments and Effects Concept: Transitioning Research to Operations and Applications

Science.gov (United States)

Edwards, David L.; Spann, James; Burns, Howard D.; Schumacher, Dan

2012-01-01

The National Aeronautics and Space Administration (NASA) is embarking on a course to expand human presence beyond Low Earth Orbit (LEO) while expanding its mission to explore the solar system. Destinations such as Near Earth Asteroids (NEA), Mars and its moons, and the outer planets are but a few of the mission targets. NASA has established numerous offices specializing in specific space environments disciplines that will serve to enable these missions. To complement these existing discipline offices, a concept focusing on the development of space environment and effects application is presented. This includes space climate, space weather, and natural and induced space environments. This space environment and effects application is composed of 4 topic areas; characterization and modeling, engineering effects, prediction and operation, and mitigation and avoidance. These topic areas are briefly described below. Characterization and modeling of space environments will primarily focus on utilization during Program mission concept, planning, and design phases. Engineering effects includes materials testing and flight experiments producing data to be used in mission planning and design phases. Prediction and operation pulls data from existing sources into decision-making tools and empirical data sets to be used during the operational phase of a mission. Mitigation and avoidance will develop techniques and strategies used in the design and operations phases of the mission. The goal of this space environment and effects application is to develop decision-making tools and engineering products to support the mission phases of mission concept through operations by focusing on transitioning research to operations. Products generated by this space environments and effects application are suitable for use in anomaly investigations. This paper will outline the four topic areas, describe the need, and discuss an organizational structure for this space environments and effects

LEO P: AN UNQUENCHED VERY LOW-MASS GALAXY

International Nuclear Information System (INIS)

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

2015-01-01

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

LEO P: AN UNQUENCHED VERY LOW-MASS GALAXY

Energy Technology Data Exchange (ETDEWEB)

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

2015-10-20

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

Analysis of SEL on Commercial SRAM Memories and Mixed-Field Characterization of a Latchup Detection Circuit for LEO Space Applications

Science.gov (United States)

Secondo, R.; Alía, R. Garcia; Peronnard, P.; Brugger, M.; Masi, A.; Danzeca, S.; Merlenghi, A.; Vaillé, J.-R.; Dusseau, L.

2017-08-01

A single event latchup (SEL) experiment based on commercial static random access memory (SRAM) memories has recently been proposed in the framework of the European Organization for Nuclear Research (CERN) Latchup Experiment and Student Satellite nanosatellite low Earth orbit (LEO) space mission. SEL characterization of three commercial SRAM memories has been carried out at the Paul Scherrer Institut (PSI) facility, using monoenergetic focused proton beams and different acquisition setups. The best target candidate was selected and a circuit for SEL detection has been proposed and tested at CERN, in the CERN High Energy AcceleRator Mixed-field facility (CHARM). Experimental results were carried out at test locations representative of the LEO environment, thus providing a full characterization of the SRAM cross sections, together with the analysis of the single-event effect and total ionizing dose of the latchup detection circuit in relation to the particle spectra expected during mission. The setups used for SEL monitoring are described, and details of the proposed circuit components and topology are presented. Experimental results obtained both at PSI and at CHARM facilities are discussed.

Wholesale debris removal from LEO

Science.gov (United States)

Levin, Eugene; Pearson, Jerome; Carroll, Joseph

2012-04-01

Recent advances in electrodynamic propulsion make it possible to seriously consider wholesale removal of large debris from LEO for the first time since the beginning of the space era. Cumulative ranking of large groups of the LEO debris population and general limitations of passive drag devices and rocket-based removal systems are analyzed. A candidate electrodynamic debris removal system is discussed that can affordably remove all debris objects over 2 kg from LEO in 7 years. That means removing more than 99% of the collision-generated debris potential in LEO. Removal is performed by a dozen 100-kg propellantless vehicles that react against the Earth's magnetic field. The debris objects are dragged down and released into short-lived orbits below ISS. As an alternative to deorbit, some of them can be collected for storage and possible in-orbit recycling. The estimated cost per kilogram of debris removed is a small fraction of typical launch costs per kilogram. These rates are low enough to open commercial opportunities and create a governing framework for wholesale removal of large debris objects from LEO.

Design and Implementation of a Space Environment Simulation Toolbox for Small Satellites

DEFF Research Database (Denmark)

Amini, Rouzbeh; Larsen, Jesper A.; Izadi-Zamanabadi, Roozbeh

2005-01-01

This paper presents a developed toolbox for space environment model in SIMULINK that facilitates development and design of Attitude Determination and Control Systems (ADCS) for a Low Earth Orbit (LEO) spacecraft. The toolbox includes, among others, models of orbit propagators, disturbances, Earth...... gravity field, Earth magnetic field and eclipse. The structure and facilities within the toolbox are described and exemplified using a student satellite case (AAUSAT-II). The validity of developed models is confirmed by comparing the simulation results with the realistic data obtained from the Danish...

10th meeting of the International Conference on Protection of Materials and Structures from Space Environment

CERN Document Server

Tagawa, Masahito; Kimoto, Yugo; Protection of Materials and Structures From the Space Environment

2013-01-01

The goals of the 10th International Space Conference on “Protection of Materials and Structures from Space Environment” ICPMSE-10J, since its inception in 1992, have been to facilitate exchanges between members of the various engineering and science disciplines involved in the development of space materials, including aspects of LEO, GEO and Deep Space environments, ground-based qualification, and in-flight experiments and lessons learned from operational vehicles that are closely interrelated to disciplines of the atmospheric sciences, solar-terrestrial interactions and space life sciences. The knowledge of environmental conditions on and around the Moon, Mars, Venus and the low Earth orbit as well as other possible candidates for landing such as asteroids have become an important issue, and protecting both hardware and human life from the effects of space environments has taken on a new meaning in light of the increased interest in space travel and colonization of other planets.  And while many materia...

FCAPD Protective Coating for Space Tethers, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Alameda Applied Sciences Corporation (AASC) proposes to demonstrate extended service lifetime of space tethers in the Low Earth Orbit (LEO) environment by using...

Materials selection for long life in LEO: a critical evaluation of atomic oxygen testing with thermal atom systems

International Nuclear Information System (INIS)

Koontz, S.L.; Kuminecz, J.; Leger, L.; Nordine, P.

1988-01-01

The use of thermal atom test methods as a materials selection and screening technique for low-Earth orbit (LEO) spacecraft is critically evaluated. The chemistry and physics of thermal atom environments are compared with the LEO environment. The relative reactivities of a number of materials determined to be in thermal atom environments are compared to those observed in LEO and in high quality LEO simulations. Reaction efficiencies measured in a new type of thermal atom apparatus are one-hundredth to one-thousandth those observed in LEO, and many materials showing nearly identical reactivities in LEO show relative reactivities differing by as much as a factor of 8 in thermal atom systems. A simple phenomenological kinetic model for the reaction of oxygen atoms with organic materials can be used to explain the differences in reactivity in different environments. Certain specific thermal test environments can be used as reliable materials screening tools. Using thermal atom methods to predict material lifetime in LEO requires direct calibration of the method against LEO data or high quality simulation data for each material

An Overview of the Space Environments and Spacecraft Effects Organization Concept

Science.gov (United States)

Edwards, David L.; Burns, Howard D.; Garrett, Henry B.; Miller, Sharon K.; Peddie, Darilyn; Porter Ron; Spann, James F.; Xapsos, Michael A.

2012-01-01

The National Aeronautics and Space Administration (NASA) is embarking on a course to expand human presence beyond Low Earth Orbit (LEO) while also expanding its mission to explore our Earth, and the solar system. Destinations such as Near Earth Asteroids (NEA), Mars and its moons, and the outer planets are but a few of the mission targets. Each new destination presents an opportunity to increase our knowledge on the solar system and the unique environments for each mission target. NASA has multiple technical and science discipline areas specializing in specific space environments fields that will serve to enable these missions. To complement these existing discipline areas, a concept is presented focusing on the development of a space environment and spacecraft effects (SESE) organization. This SESE organization includes disciplines such as space climate, space weather, natural and induced space environments, effects on spacecraft materials and systems, and the transition of research information into application. This space environment and spacecraft effects organization will be composed of Technical Working Groups (TWG). These technical working groups will survey customers and users, generate products, and provide knowledge supporting four functional areas: design environments, engineering effects, operational support, and programmatic support. The four functional areas align with phases in the program mission lifecycle and are briefly described below. Design environments are used primarily in the mission concept and design phases of a program. Environment effects focuses on the material, component, sub-system, and system-level response to the space environment and include the selection and testing to verify design and operational performance. Operational support provides products based on real time or near real time space weather to mission operators to aid in real time and near-term decision-making. The programmatic support function maintains an interface with

PCVs Estimation and their Impacts on Precise Orbit Determination of LEOs

Science.gov (United States)

Chunmei, Z.; WANG, X.

2017-12-01

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

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

Science.gov (United States)

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

2006-01-01

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

Embrittlement of MISSE 5 Polymers After 13 Months of Space Exposure

Science.gov (United States)

Guo, Aobo; Yi, Grace T.; Ashmead, Claire C.; Mitchell, Gianna G.; deGroh, Kim K.

2012-01-01

Understanding space environment induced degradation of spacecraft materials is essential when designing durable and stable spacecraft components. As a result of space radiation, debris impacts, atomic oxygen interaction, and thermal cycling, the outer surfaces of space materials degrade when exposed to low Earth orbit (LEO). The objective of this study was to measure the embrittlement of 37 thin film polymers after LEO space exposure. The polymers were flown aboard the International Space Station and exposed to the LEO space environment as part of the Materials International Space Station Experiment 5 (MISSE 5). The samples were flown in a nadir-facing position for 13 months and were exposed to thermal cycling along with low doses of atomic oxygen, direct solar radiation and omnidirectional charged particle radiation. The samples were analyzed for space-induced embrittlement using a bend-test procedure in which the strain necessary to induce surface cracking was determined. Bend-testing was conducted using successively smaller mandrels to apply a surface strain to samples placed on a semi-suspended pliable platform. A pristine sample was also tested for each flight sample. Eighteen of the 37 flight samples experienced some degree of surface cracking during bend-testing, while none of the pristine samples experienced any degree of cracking. The results indicate that 49 percent of the MISSE 5 thin film polymers became embrittled in the space environment even though they were exposed to low doses (approx.2.75 krad (Si) dose through 127 mm Kapton) of ionizing radiation.

Beta cloth durability assessment for Space Station Freedom (SSF) Multi-Layer Insulation (MLI) blanket covers

International Nuclear Information System (INIS)

Koontz, S.L.; Jacobs, S.; Le, J.

1993-03-01

MLI blankets for the Space Station Freedom (SSF) must comply with general program requirements and recommendations for long life and durability in the low-Earth orbit (LEO) environment. Atomic oxygen and solar ultraviolet/vacuum ultraviolet are the most important factors in the SSF natural environment which affect materials life. Two types of Beta cloth (Teflon coated woven glass fabric), which had been proposed as MLI blanket covers, were tested for long-term durability in the LEO environment. General resistance to atomic oxygen attack and permeation were evaluated in the high velocity atomic oxygen beam system at Los Alamos National Laboratories. Long-term exposure to the LEO environment was simulated in the laboratory using a radio frequency oxygen plasma asher. The plasma asher treated Beta cloth specimens were tested for thermo-optical properties and mechanical durability. Space exposure data from the Long Duration Exposure Facility and the Intelsat Solar Array Coupon were also used in the durability assessment. Beta cloth fabricated to Rockwell specification MBO 135-027 (Chemglas 250) was shown to have acceptable durability for general use as an MLI blanket cover material in the LEO environment while Sheldahl G414500 should be used only in locations which are protected from direct Ram atomic oxygen

Atmosphere composition monitor for space station and advanced missions application

International Nuclear Information System (INIS)

Wynveen, R.A.; Powell, F.T.

1987-01-01

Long-term human occupation of extraterrestrial locations may soon become a reality. The National Aeronautics and Space Administration (NASA) has recently completed the definition and preliminary design of the low earth orbit (LEO) space station. They are now currently moving into the detailed design and fabrication phase of this space station and are also beginning to analyze the requirements of several future missions that have been identified. These missions include, for example, Lunar and Mars sorties, outposts, bases, and settlements. A requirement of both the LEO space station and future missions are environmental control and life support systems (ECLSS), which provide a comfortable environment for humans to live and work. The ECLSS consists of several major systems, including atmosphere revitalization system (ARS), atmosphere pressure and composition control system, temperature and humidity control system, water reclamation system, and waste management system. Each of these major systems is broken down into subsystems, assemblies, units, and instruments. Many requirements and design drivers are different for the ECLSS of the LEO space station and the identified advanced missions (e.g., longer mission duration). This paper discusses one of the ARS assemblies, the atmosphere composition monitor assembly (ACMA), being developed for the LEO space station and addresses differences that will exist for the ACMA of future missions

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

Science.gov (United States)

Logue, T.; L'Abbate, M.

2016-12-01

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

SPACE RADIATION ENVIRONMENT MONITORED BY KITSAT-1 AND KITSAT-2

Directory of Open Access Journals (Sweden)

Y. H. Shin

1996-06-01

Full Text Available The results of space radiation experiments carried out on board the first two Korean technology demonstration microsatellites are presented in this paper. The first satellite, KITSAT-1, launched in August 1992, carries a radiation monitoring payload called cosmic ray experiment(CRE for characterizing the low-earth orbit(LEO radiation environment. The CRE consists of two sub-systems: the cosmic particle experiment (CPE and the total dose experiment(TDE. In addition, single event upset(SEUrates of the program memory and the RAM disk are also monitored. The second satellite, KITSAT-2, launched in September 1993, carries a newly developed 32-bit on-board computer(OBC, KASCOM(KAIST satellite computer in addition to OBC186. SEUs ocurred in the KASCOM, as well as in the program memory and RAM disk memory, have been monitored since the beginning of the satellite operation. These two satellites, which are very similar in structures but different in orbits, provide a unique opportunity to study the effects of the radiation environment characterized by the orbit.

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

Science.gov (United States)

Moll, Florian

2017-10-01

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

Petróleo

OpenAIRE

Celso Fernando Lucchesi

1998-01-01

COM MENOS DE 50 anos de atividade empresarialmente organizada a exploração de petróleo no Brasil encontra-se em fase de mudança com a aprovação, em 1997, da nova legislação do setor de petróleo. Descreve-se neste trabalho o período pré-Petrobras (1858 a 1953) e a exclusividade da Petrobras (1954 a 1997) que resultou no expressivo volume de reservas de petróleo no país, da ordem de 17 bilhões de barris de óleo equivalente no final de 1997. Projetos de produção já iniciados elevarão a produção ...

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

Science.gov (United States)

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

2010-01-01

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

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

Science.gov (United States)

Pardini, Carmen; Anselmo, Luciano

2018-04-01

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

Ground-Laboratory to In-Space Atomic Oxygen Correlation for the PEACE Polymers

Science.gov (United States)

Stambler, Arielle H.; Inoshita, Karen E.; Roberts, Lily M.; Barbagallo, Claire E.; de Groh, Kim K.; Banks, Bruce A.

2009-01-01

The Materials International Space Station Experiment 2 (MISSE 2) Polymer Erosion and Contamination Experiment (PEACE) polymers were exposed to the environment of low Earth orbit (LEO) for 3.95 years from 2001 to 2005. There were forty-one different PEACE polymers, which were flown on the exterior of the International Space Station (ISS) in order to determine their atomic oxygen erosion yields. In LEO, atomic oxygen is an environmental durability threat, particularly for long duration mission exposures. Although space flight experiments, such as the MISSE 2 PEACE experiment, are ideal for determining LEO environmental durability of spacecraft materials, ground-laboratory testing is often relied upon for durability evaluation and prediction. Unfortunately, significant differences exist between LEO atomic oxygen exposure and atomic oxygen exposure in ground-laboratory facilities. These differences include variations in species, energies, thermal exposures and radiation exposures, all of which may result in different reactions and erosion rates. In an effort to improve the accuracy of ground-based durability testing, ground-laboratory to in-space atomic oxygen correlation experiments have been conducted. In these tests, the atomic oxygen erosion yields of the PEACE polymers were determined relative to Kapton H using a radio-frequency (RF) plasma asher (operated on air). The asher erosion yields were compared to the MISSE 2 PEACE erosion yields to determine the correlation between erosion rates in the two environments. This paper provides a summary of the MISSE 2 PEACE experiment; it reviews the specific polymers tested as well as the techniques used to determine erosion yield in the asher, and it provides a correlation between the space and ground-laboratory erosion yield values. Using the PEACE polymers' asher to in-space erosion yield ratios will allow more accurate in-space materials performance predictions to be made based on plasma asher durability evaluation.

Effects of simulated space environmental parameters on six commercially available composite materials

International Nuclear Information System (INIS)

Funk, J.G.; Sykes, G.F. Jr.

1989-04-01

The effects of simulated space environmental parameters on microdamage induced by the environment in a series of commercially available graphite-fiber-reinforced composite materials were determined. Composites with both thermoset and thermoplastic resin systems were studied. Low-Earth-Orbit (LEO) exposures were simulated by thermal cycling; geosynchronous-orbit (GEO) exposures were simulated by electron irradiation plus thermal cycling. The thermal cycling temperature range was -250 F to either 200 F or 150 F. The upper limits of the thermal cycles were different to ensure that an individual composite material was not cycled above its glass transition temperature. Material response was characterized through assessment of the induced microcracking and its influence on mechanical property changes at both room temperature and -250 F. Microdamage was induced in both thermoset and thermoplastic advanced composite materials exposed to the simulated LEO environment. However, a 350 F cure single-phase toughened epoxy composite was not damaged during exposure to the LEO environment. The simuated GEO environment produced microdamage in all materials tested

Lasers in space.

CSIR Research Space (South Africa)

Michaelis, MM

2008-04-01

Full Text Available cube, laser beam reflectors, placed on the Moon half a century ago. These early achievements will soon be followed by a plethora of experiments involving lasers in low earth orbit (LEO) or at Lagrange points. And not much later, laser communications... will stretch out as far as Mars and beyond. One important low Earth orbit (LEO) application is the removal of space debris by Earth based or LEO relayed lasers as promoted by Phipps et al.3. Another is military communication. The prominent L1 laser space...

Ionic electroactive polymer artificial muscles in space applications.

Science.gov (United States)

Punning, Andres; Kim, Kwang J; Palmre, Viljar; Vidal, Frédéric; Plesse, Cédric; Festin, Nicolas; Maziz, Ali; Asaka, Kinji; Sugino, Takushi; Alici, Gursel; Spinks, Geoff; Wallace, Gordon; Must, Indrek; Põldsalu, Inga; Vunder, Veiko; Temmer, Rauno; Kruusamäe, Karl; Torop, Janno; Kaasik, Friedrich; Rinne, Pille; Johanson, Urmas; Peikolainen, Anna-Liisa; Tamm, Tarmo; Aabloo, Alvo

2014-11-05

A large-scale effort was carried out to test the performance of seven types of ionic electroactive polymer (IEAP) actuators in space-hazardous environmental factors in laboratory conditions. The results substantiate that the IEAP materials are tolerant to long-term freezing and vacuum environments as well as ionizing Gamma-, X-ray, and UV radiation at the levels corresponding to low Earth orbit (LEO) conditions. The main aim of this material behaviour investigation is to understand and predict device service time for prolonged exposure to space environment.

Space Flight Ionizing Radiation Environments

Science.gov (United States)

Koontz, Steve

2017-01-01

The space-flight ionizing radiation (IR) environment is dominated by very high-kinetic energy-charged particles with relatively smaller contributions from X-rays and gamma rays. The Earth's surface IR environment is not dominated by the natural radioisotope decay processes. Dr. Steven Koontz's lecture will provide a solid foundation in the basic engineering physics of space radiation environments, beginning with the space radiation environment on the International Space Station and moving outward through the Van Allen belts to cislunar space. The benefits and limitations of radiation shielding materials will also be summarized.

NASA Space Environments Technical Discipline Team Space Weather Activities

Science.gov (United States)

Minow, J. I.; Nicholas, A. C.; Parker, L. N.; Xapsos, M.; Walker, P. W.; Stauffer, C.

2017-12-01

The Space Environment Technical Discipline Team (TDT) is a technical organization led by NASA's Technical Fellow for Space Environments that supports NASA's Office of the Chief Engineer through the NASA Engineering and Safety Center. The Space Environments TDT conducts independent technical assessments related to the space environment and space weather impacts on spacecraft for NASA programs and provides technical expertise to NASA management and programs where required. This presentation will highlight the status of applied space weather activities within the Space Environment TDT that support development of operational space weather applications and a better understanding of the impacts of space weather on space systems. We will first discuss a tool that has been developed for evaluating space weather launch constraints that are used to protect launch vehicles from hazardous space weather. We then describe an effort to better characterize three-dimensional radiation transport for CubeSat spacecraft and processing of micro-dosimeter data from the International Space Station which the team plans to make available to the space science community. Finally, we will conclude with a quick description of an effort to maintain access to the real-time solar wind data provided by the Advanced Composition Explorer satellite at the Sun-Earth L1 point.

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

Science.gov (United States)

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

2002-08-01

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

Space Ethics and Protection of the Space Environment

Science.gov (United States)

Williamson, Mark

2002-01-01

The construction of the International Space Station in low Earth orbit and the formulation of plans to search for life on Mars - one day by means of manned missions - indicate that mankind is intent on making the space environment part of its domain. Publicity surrounding space tourism, in-space `burials' and the sale of lunar `real estate' suggests that, some time in the 21st century, the space environment will become an extraterrestrial extension of our current business and domestic environment. This prompts the question of our collective attitude towards the space environment and the degree to which we should regulate its use and protect it for future generations. What, indeed, are the ethical considerations of space exploration and development? Ethics can be defined as "the philosophical study of the moral value of human conduct, and of the rules or principles that ought to govern it". More practically, it represents "an approved code of behaviour" adopted, for example, by a group or profession. If a set of ethics is to be developed for space, it is important that what we refer to as the `space community', or `space profession', is intimately involved. Indeed, if it is not, the profession risks having the job done for it, for example by politicians and members of the general public, who for their own reasons may wish to place restrictions on space development, or ban it altogether. The terrestrial nuclear power industry, for example, has already suffered this fate, while widespread ignorance of the subject has led to a moratorium on the use of RTGs in spacecraft. However, there is a danger in the discussion of ethics that consideration is confined to the philosophical aspects, thus excusing those involved from providing practical solutions to the problems that emerge. The fact that mankind has already affected, and arguably damaged, the space environment transports the discussion beyond the philosophical realm. This paper offers a pragmatic analysis of one

Controlling the Growth of Future LEO Debris Populations with Active Debris Removal

Science.gov (United States)

Liou, J.-C.; Johnson, N. L.; Hill, N. M.

2008-01-01

Active debris removal (ADR) was suggested as a potential means to remediate the low Earth orbit (LEO) debris environment as early as the 1980s. The reasons ADR has not become practical are due to its technical difficulties and the high cost associated with the approach. However, as the LEO debris populations continue to increase, ADR may be the only option to preserve the near-Earth environment for future generations. An initial study was completed in 2007 to demonstrate that a simple ADR target selection criterion could be developed to reduce the future debris population growth. The present paper summarizes a comprehensive study based on more realistic simulation scenarios, including fragments generated from the 2007 Fengyun-1C event, mitigation measures, and other target selection options. The simulations were based on the NASA long-term orbital debris projection model, LEGEND. A scenario, where at the end of mission lifetimes, spacecraft and upper stages were moved to 25-year decay orbits, was adopted as the baseline environment for comparison. Different annual removal rates and different ADR target selection criteria were tested, and the resulting 200-year future environment projections were compared with the baseline scenario. Results of this parametric study indicate that (1) an effective removal strategy can be developed based on the mass and collision probability of each object as the selection criterion, and (2) the LEO environment can be stabilized in the next 200 years with an ADR removal rate of five objects per year.

ISS Local Environment Spectrometers (ISLES)

Science.gov (United States)

Krause, Linda Habash; Gilchrist, Brian E.

2014-01-01

In order to study the complex interactions between the space environment surrounding the ISS and the ISS surface materials, we propose to use lowcost, high-TRL plasma sensors on the ISS robotic arm to probe the ISS space environment. During many years of ISS operation, we have been able to condut effective (but not perfect) extravehicular activities (both human and robotic) within the perturbed local ISS space environment. Because of the complexity of the interaction between the ISS and the LEO space environment, there remain important questions, such as differential charging at solar panel junctions (the so-called "triple point" between conductor, dielectric, and space plasma), increased chemical contamination due to ISS surface charging and/or thruster activation, water dumps, etc, and "bootstrap" charging of insulating surfaces. Some compelling questions could synergistically draw upon a common sensor suite, which also leverages previous and current MSFC investments. Specific questions address ISS surface charging, plasma contactor plume expansion in a magnetized drifting plasma, and possible localized contamination effects across the ISS.

The ESA Space Environment Information System (SPENVIS)

Science.gov (United States)

Heynderickx, D.; Quaghebeur, B.; Evans, H. D. R.

2002-01-01

facilitates multiple runs with different orbital or shielding configurations. SPENVIS features a number of models and tools for evaluating spacecraft charging. The DERA DICTAT tool for evaluation of internal charging calculates the electron current that passes through a conductive shield and becomes deposited inside a dielectric, and predicts whether an electrostatic discharge will occur. SPENVIS has implemented the DERA EQUIPOT non-geometrical tool for assessing material susceptibility to charging in typical orbital environments, including polar and GEO environments. SPENVIS Also includes SOLARC, for assessment of the current collection and the floating potential of solar arrays in LEO. Finally, the system features access to data from surface charging events on CRRES and the Russian Gorizont spacecraft, in the form of spectrograms and double Maxwellian fit parameters. SPENVIS also contains an active, integrated version of the ECSS Space Environment Standard, and access to in-flight data. Apart from radiation and plasma environments, SPENVIS includes meteoroid and debris models, atmospheric models (including atomic oxygen), and magnetic field models implemented by means of the UNILIB library for magnetic coordinate evaluation, magnetic field line tracing and drift shell tracing. The UNILIB library is freely accessible from the Web (http://www.magnet.oma.be/unilib/) for downloading in the form of a Fortran object library for different platforms (DecAlpha, SunOS, HPUX and PC/MS-Windows).

Space Environment Modeling

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes presentation materials and outputs from operational space environment models produced by the NOAA Space Weather Prediction Center (SWPC) and...

Space radiation dosimetry in low-Earth orbit and beyond

International Nuclear Information System (INIS)

Benton, E.R.; Benton, E.V.

2001-01-01

Space radiation dosimetry presents one of the greatest challenges in the discipline of radiation protection. This is a result of both the highly complex nature of the radiation fields encountered in low-Earth orbit (LEO) and interplanetary space and of the constraints imposed by spaceflight on instrument design. This paper reviews the sources and composition of the space radiation environment in LEO as well as beyond the Earth's magnetosphere. A review of much of the dosimetric data that have been gathered over the last four decades of human space flight is presented. The different factors affecting the radiation exposures of astronauts and cosmonauts aboard the International Space Station (ISS) are emphasized. Measurements made aboard the Mir Orbital Station have highlighted the importance of both secondary particle production within the structure of spacecraft and the effect of shielding on both crew dose and dose equivalent. Roughly half the dose on ISS is expected to come from trapped protons and half from galactic cosmic rays (GCRs). The dearth of neutron measurements aboard LEO spacecraft and the difficulty inherent in making such measurements have led to large uncertainties in estimates of the neutron contribution to total dose equivalent. Except for a limited number of measurements made aboard the Apollo lunar missions, no crew dosimetry has been conducted beyond the Earth's magnetosphere. At the present time we are forced to rely on model-based estimates of crew dose and dose equivalent when planning for interplanetary missions, such as a mission to Mars. While space crews in LEO are unlikely to exceed the exposure limits recommended by such groups as the NCRP, dose equivalents of the same order as the recommended limits are likely over the course of a human mission to Mars

Advantage of Animal Models with Metabolic Flexibility for Space Research Beyond Low Earth Orbit

Science.gov (United States)

Griko, Yuri V.; Rask, Jon C.; Raychev, Raycho

2017-01-01

As the worlds space agencies and commercial entities continue to expand beyond Low Earth Orbit (LEO), novel approaches to carry out biomedical experiments with animals are required to address the challenge of adaptation to space flight and new planetary environments. The extended time and distance of space travel along with reduced involvement of Earth-based mission support increases the cumulative impact of the risks encountered in space. To respond to these challenges, it becomes increasingly important to develop the capability to manage an organisms self-regulatory control system, which would enable survival in extraterrestrial environments. To significantly reduce the risk to animals on future long duration space missions, we propose the use of metabolically flexible animal models as pathfinders, which are capable of tolerating the environmental extremes exhibited in spaceflight, including altered gravity, exposure to space radiation, chemically reactive planetary environments and temperature extremes.In this report we survey several of the pivotal metabolic flexibility studies and discuss the importance of utilizing animal models with metabolic flexibility with particular attention given to the ability to suppress the organism's metabolism in spaceflight experiments beyond LEO. The presented analysis demonstrates the adjuvant benefits of these factors to minimize damage caused by exposure to spaceflight and extreme planetary environments. Examples of microorganisms and animal models with dormancy capabilities suitable for space research are considered in the context of their survivability under hostile or deadly environments outside of Earth. Potential steps toward implementation of metabolic control technology in spaceflight architecture and its benefits for animal experiments and manned space exploration missions are discussed.

Ground-Laboratory to In-Space Atomic Oxygen Correlation for the Polymer Erosion and Contamination Experiment (PEACE) Polymers

Science.gov (United States)

Stambler, Arielle H.; Inoshita, Karen E.; Roberts, Lily M.; Barbagallo, Claire E.; deGroh, Kim K.; Banks, Bruce A.

2011-01-01

The Materials International Space Station Experiment 2 (MISSE 2) Polymer Erosion and Contamination Experiment (PEACE) polymers were exposed to the environment of low Earth orbit (LEO) for 3.95 years from 2001 to 2005. There were 41 different PEACE polymers, which were flown on the exterior of the International Space Station (ISS) in order to determine their atomic oxygen erosion yields. In LEO, atomic oxygen is an environmental durability threat, particularly for long duration mission exposures. Although spaceflight experiments, such as the MISSE 2 PEACE experiment, are ideal for determining LEO environmental durability of spacecraft materials, ground-laboratory testing is often relied upon for durability evaluation and prediction. Unfortunately, significant differences exist between LEO atomic oxygen exposure and atomic oxygen exposure in ground-laboratory facilities. These differences include variations in species, energies, thermal exposures and radiation exposures, all of which may result in different reactions and erosion rates. In an effort to improve the accuracy of ground-based durability testing, ground-laboratory to in-space atomic oxygen correlation experiments have been conducted. In these tests, the atomic oxygen erosion yields of the PEACE polymers were determined relative to Kapton H using a radio-frequency (RF) plasma asher (operated on air). The asher erosion yields were compared to the MISSE 2 PEACE erosion yields to determine the correlation between erosion rates in the two environments. This paper provides a summary of the MISSE 2 PEACE experiment; it reviews the specific polymers tested as well as the techniques used to determine erosion yield in the asher, and it provides a correlation between the space and ground laboratory erosion yield values. Using the PEACE polymers asher to in-space erosion yield ratios will allow more accurate in-space materials performance predictions to be made based on plasma asher durability evaluation.

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-12-01

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

Mitochondrial genome of the African lion Panthera leo leo.

Science.gov (United States)

Ma, Yue-ping; Wang, Shuo

2015-01-01

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

The Space Station Freedom - International cooperation and innovation in space safety

Science.gov (United States)

Rodney, George A.

1989-01-01

The Space Station Freedom (SSF) being developed by the United States, European Space Agency (ESA), Japan, and Canada poses novel safety challenges in design, operations, logistics, and program management. A brief overview discloses many features that make SSF a radical departure from earlier low earth orbit (LEO) space stations relative to safety management: size and power levels; multiphase manned assembly; 30-year planned lifetime, with embedded 'hooks and scars' forevolution; crew size and skill-mix variability; sustained logistical dependence; use of man, robotics and telepresence for on-orbit maintenance of station and free-flyer systems; closed-environment recycling; use of automation and expert systems; long-term operation of collocated life-sciences and materials-science experiments, requiring control and segregation of hazardous and chemically incompatible materials; and materials aging in space.

Investigating fundamental physics and space environment with a dedicated Earth-orbiting spacecraft

Science.gov (United States)

Peron, Roberto

The near-Earth environment is a place of first choice for performing fundamental physics experiments, given its proximity to Earth and at the same time being relatively quiet dynamically for particular orbital arrangements. This environment also sees a rich phenomenology for what concerns gravitation. In fact, the general theory of relativity is an incredibly accurate description of gravitational phenomenology. However, its overall validity is being questioned by the theories that aim at reconciling it with the microscopic domain. Challenges come also from the ‘mysteries’ of Dark Matter and Dark Energy, though mainly at scales from the galactic up to the cosmological. It is therefore important to precisely test the consequences of the theory -- as well as those of competing ones -- at all the accessible scales. At the same time, the development of high-precision experimental space techniques, which are needed for tests in fundamental physics, opens the way to complementary applications. The growth of the (man-made) orbital debris population is creating problems to the future development of space. The year 2009 witnessed the first accidental collision between two satellites in orbit (Iridium and Cosmos) that led to the creation of more debris. International and national agencies are intervening by issuing and/or adopting guidelines to mitigate the growth of orbital debris. A central tenet of these guidelines requires a presence in space shorter than 25 years to satellites in low Earth orbit (LEO) after the conclusion of their operational lives. However, the determination of the natural lifetime of a satellite in LEO is very uncertain due to a large extent to the short-term and long-term variability of the atmospheric density in LEO and the comparatively low-accuracy of atmospheric density models. Many satellites orbiting in the 500-1200 km region with circular or elliptical orbits will be hard pressed to establish before flight whether or not they meet the 25

Information Space, Information Field, Information Environment

Directory of Open Access Journals (Sweden)

Victor Ya. Tsvetkov

2014-08-01

Full Text Available The article analyzes information space, information field and information environment; shows that information space can be natural and artificial; information field is substantive and processual object and articulates the space property; information environment is concerned with some object and acts as the surrounding in relation to it and is considered with regard to it. It enables to define information environment as a subset of information space. It defines its passive description. Information environment can also be defined as a subset of information field. It corresponds to its active description.

Leo Spacecraft Charging Design Guidelines: A Proposed NASA Standard

Science.gov (United States)

Hillard, G. B.; Ferguson, D. C.

2004-01-01

Over the past decade, Low Earth Orbiting (LEO) spacecraft have gradually required ever-increasing power levels. As a rule, this has been accomplished through the use of high voltage systems. Recent failures and anomalies on such spacecraft have been traced to various design practices and materials choices related to the high voltage solar arrays. NASA Glenn has studied these anomalies including plasma chamber testing on arrays similar to those that experienced difficulties on orbit. Many others in the community have been involved in a comprehensive effort to understand the problems and to develop practices to avoid them. The NASA Space Environments and Effects program, recognizing the timeliness of this effort, commissioned and funded a design guidelines document intended to capture the current state of understanding. This document, which was completed in the spring of 2003, has been submitted as a proposed NASA standard. We present here an overview of this document and discuss the effort to develop it as a NASA standard.

Characteristics of trapped proton anisotropy at Space Station Freedom altitudes

Science.gov (United States)

Armstrong, T. W.; Colborn, B. L.; Watts, J. W.

1990-01-01

The ionizing radiation dose for spacecraft in low-Earth orbit (LEO) is produced mainly by protons trapped in the Earth's magnetic field. Current data bases describing this trapped radiation environment assume the protons to have an isotropic angular distribution, although the fluxes are actually highly anisotropic in LEO. The general nature of this directionality is understood theoretically and has been observed by several satellites. The anisotropy of the trapped proton exposure has not been an important practical consideration for most previous LEO missions because the random spacecraft orientation during passage through the radiation belt 'averages out' the anisotropy. Thus, in spite of the actual exposure anisotropy, cumulative radiation effects over many orbits can be predicted as if the environment were isotropic when the spacecraft orientation is variable during exposure. However, Space Station Freedom will be gravity gradient stabilized to reduce drag, and, due to this fixed orientation, the cumulative incident proton flux will remain anisotropic. The anisotropy could potentially influence several aspects of Space Station design and operation, such as the appropriate location for radiation sensitive components and experiments, location of workstations and sleeping quarters, and the design and placement of radiation monitors. Also, on-board mass could possible be utilized to counteract the anisotropy effects and reduce the dose exposure. Until recently only omnidirectional data bases for the trapped proton environment were available. However, a method to predict orbit-average, angular dependent ('vector') trapped proton flux spectra has been developed from the standard omnidirectional trapped proton data bases. This method was used to characterize the trapped proton anisotropy for the Space Station orbit (28.5 degree inclination, circular) in terms of its dependence on altitude, solar cycle modulation (solar minimum vs. solar maximum), shielding thickness

Space and Atmospheric Environments: From Low Earth Orbits to Deep Space

Science.gov (United States)

Barth, Janet L.

2003-01-01

Natural space and atmospheric environments pose a difficult challenge for designers of technological systems in space. The deleterious effects of environment interactions with the systems include degradation of materials, thermal changes, contamination, excitation, spacecraft glow, charging, radiation damage, and induced background interference. Design accommodations must be realistic with minimum impact on performance while maintaining a balance between cost and risk. The goal of applied research in space environments and effects is to limit environmental impacts at low cost relative to spacecraft cost and to infuse enabling and commercial off-the-shelf technologies into space programs. The need to perform applied research to understand the space environment in a practical sense and to develop methods to mitigate these environment effects is frequently underestimated by space agencies and industry. Applied science research in this area is critical because the complexity of spacecraft systems is increasing, and they are exposed simultaneously to a multitude of space environments.

Space Environment Information System (SPENVIS)

Science.gov (United States)

Kruglanski, Michel; de Donder, Erwin; Messios, Neophytos; Hetey, Laszlo; Calders, Stijn; Evans, Hugh; Daly, Eamonn

SPENVIS is an ESA operational software developed and maintained at BIRA-IASB since 1996. It provides standardized access to most of the recent models of the hazardous space environment, through a user-friendly Web interface (http://www.spenvis.oma.be/). The system allows spacecraft engineers to perform a rapid analysis of environmental problems related to natural radiation belts, solar energetic particles, cosmic rays, plasmas, gases, magnetic fields and micro-particles. Various reporting and graphical utilities and extensive help facilities are included to allow engineers with relatively little familiarity to produce reliable results. SPENVIS also contains an active, integrated version of the ECSS Space Environment Standard and access to in-flight data on the space environment. Although SPENVIS in the first place is designed to help spacecraft designers, it is also used by technical universities in their educational programs. In the framework of the ESA Space Situational Awareness Preparatory Programme, SPENVIS will be part of the initial set of precursor services of the Space Weather segment. SPENVIS includes several engineering models to assess to effects of the space environment on spacecrafts such as surface and internal charging, energy deposition, solar cell damage and SEU rates. The presentation will review how such models could be connected to in situ measurements or forecasting models of the space environment in order to produce post event analysis or in orbit effects alert. The last developments and models implemented in SPENVIS will also be presented.

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

Science.gov (United States)

Ruttley, Tara M.; Robinson, Julie A.

2010-01-01

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

Secure space-to-space interferometric communications and its nexus to the physics of quantum entanglement

Science.gov (United States)

Duarte, F. J.

2016-12-01

The history of the probability amplitude equation | ψ > = ( | x , y > - | y , x > ) applicable to quanta pairs, propagating in different directions with entangled polarizations, is reviewed and traced back to the 1947-1949 period. The interferometric Dirac foundations common to | ψ > = ( | x , y > - | y , x > ) and the generalized N-slit interferometric equation, for indistinguishable quanta, are also described. The results from a series of experiments on N-slit laser interferometers, with intra interferometric propagation paths up to 527 m, are reviewed. Particular attention is given to explain the generation of interferometric characters, for secure space-to-space communications, which immediately collapse on attempts of interception. The design of a low divergence N-slit laser interferometer for low Earth orbit-low Earth orbit (LEO-LEO), and LEO-geostationary Earth orbit (LEO-GEO), secure interferometric communications is described and a weight assessment is provided.

Mitigating Aviation Communication and Satellite Orbit Operations Surprises from Adverse Space Weather

Science.gov (United States)

Tobiska, W. Kent

2008-01-01

Adverse space weather affects operational activities in aviation and satellite systems. For example, large solar flares create highly variable enhanced neutral atmosphere and ionosphere electron density regions. These regions impact aviation communication frequencies as well as precision orbit determination. The natural space environment, with its dynamic space weather variability, is additionally changed by human activity. The increase in orbital debris in low Earth orbit (LEO), combined with lower atmosphere CO2 that rises into the lower thermosphere and causes increased cooling that results in increased debris lifetime, adds to the environmental hazards of navigating in near-Earth space. This is at a time when commercial space endeavors are posed to begin more missions to LEO during the rise of the solar activity cycle toward the next maximum (2012). For satellite and aviation operators, adverse space weather results in greater expenses for orbit management, more communication outages or aviation and ground-based high frequency radio used, and an inability to effectively plan missions or service customers with space-based communication, imagery, and data transferal during time-critical activities. Examples of some revenue-impacting conditions and solutions for mitigating adverse space weather are offered.

Gengibre (zingiber officinale roscoe brasileiro: aspectos gerais, óleo essencial e oleoresina. parte 2 - secagem, óleo essencial e oleoresina

Directory of Open Access Journals (Sweden)

Mauro Taveira Magalhães

1997-08-01

Full Text Available A partir de amostras de gengibre (Zingiber officinale Roscoe do tipo "Gigante", oriundas das diversas localidades produtoras do Brasil, procurou-se estabelecer as melhores condições de processamento e verificar a qualidade do óleo essencial e da oleoresina obtidos. A composição do óleo essencial de gengibre gigante varia de acordo com a técnica de extração e o estado do rizoma. Os óleos essenciais de rizomas frescos e secos foram comparados através de seus índices físico-químicos e composição por CG. São apresentadas as características do óleo essencial do rizoma seco obtido por arraste direto a vapor. Nas oleoresinas obtidas com diferentes solventes determinou-se o teor de óleo essencial. O gengibre comercial brasileiro fornece óleo essencial num rendimento de 2,2% e oleoresina em rendimentos que variam de 6,91-10,90% (etanol, 2,53-5,62% (acetona e 3,35-3,91% (dicloroetano, sendo alternativas interessantes de utilização.

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

Science.gov (United States)

Walker, R.; Martin, C.

It is predicted that the space debris population in low Earth orbit (LEO) will continue to grow and in an exponential manner in the long-term due to an increasing rate of collisions between large objects, unless internationally-accepted space debris mitigation measures are adopted soon. Such measures are aimed at avoiding the future generation of space debris objects and primarily need to be effective in preventing significant long-term growth in the debris population, even in the potential scenario of an increase in future space activity. It is also important that mitigation measures can limit future debris population levels, and therefore the underlying collision risk to space missions, to the lowest extent possible. However, for their wide acceptance, the cost of implementation associated with mitigation measures needs to be minimised as far as possible. Generally, a lower collision risk will cost more to achieve and vice versa, so it is necessary to strike a balance between cost and risk in order to find a cost-effective set of mitigation measures. In this paper, clear criteria are established in order to assess the cost-effectiveness of space debris mitigation measures. A full cost-risk-benefit trade-off analysis of numerous mitigation scenarios is presented. These scenarios consider explosion prevention and post-mission disposal of space systems, including de-orbiting to limited lifetime orbits and re-orbiting above the LEO region. The ESA DELTA model is used to provide long-term debris environment projections for these scenarios as input to the benefit and risk parts of the trade-off analysis. Manoeuvre requirements for the different post-mission disposal scenarios were also calculated in order to define the cost-related element. A 25-year post-mission lifetime de-orbit policy, combined with explosion prevention and mission-related object limitation, was found to be the most cost-effective solution to the space debris problem in LEO. This package would also

Leo

Science.gov (United States)

Murdin, P.

2000-11-01

(the Lion; abbrev. Leo, gen. Leonis; area 947 sq. deg.) A northern zodiacal constellation which lies between Cancer and Virgo, and culminates at midnight in early March. It represents the Nemean lion that, in Greek mythology, Hercules killed as the first of his 12 labors. Its brightest stars were cataloged by Ptolemy (c. AD 100-175) in the Almagest....

«Somos petróleo»

OpenAIRE

Drum, Duskin

2017-01-01

Resumen «Somos petróleo» es un experimento de práctica-como-investigación creado para indagar sobre la manera como los norteamericanos conceptualizan sus relaciones con el petróleo. Durante el performance los participantes leyeron en voz alta emulaciones del testimonio diplomático Gwich'in sobre ser pueblo caribú. En las emulaciones, el texto es el mismo salvo que se reemplaza la palabra «caribú» por «petróleo». Los Gwich'in son un pueblo indígena cuyas tierras de origen se sitúan en el nores...

Short and long term efficiencies of debris risk reduction measures: Application to a European LEO mission

Science.gov (United States)

Lang, T.; Kervarc, R.; Bertrand, S.; Carle, P.; Donath, T.; Destefanis, R.; Grassi, L.; Tiboldo, F.; Schäfer, F.; Kempf, S.; Gelhaus, J.

2015-01-01

Recent numerical studies indicate that the low Earth orbit (LEO) debris environment has reached a point such that even if no further space launches were conducted, the Earth satellite population would remain relatively constant for only the next 50 years or so. Beyond that, the debris population would begin to increase noticeably, due to the production of collisional debris (Liou and Johnson, 2008). Measures to be enforced play thus a major role to preserve an acceptable space mission risk and ensure sustainable space activities. The identification of such measures and the quantification of their efficiency over time for LEO missions is of prime concern in the decision-making process, as it has been investigated for the last few decades by the Inter-Agency Space Debris Coordination Committee (IADC). This paper addresses the final results of a generic methodology and the characteristics of a tool developed to assess the efficiency of the risk reduction measures identified for the Sentinel-1 (S1) mission. This work is performed as part of the 34-month P2-ROTECT project (Prediction, Protection & Reduction of OrbiTal Exposure to Collision Threats), funded by the European Union within the Seventh Framework Programme. Three ways of risk reduction have been investigated, both in short and long-term, namely: better satellite protection, better conjunction prediction, and cleaner environment. According to our assumptions, the S1 mission vulnerability evaluations in the long term (from 2093 to 2100) show that full compliance to the mitigation measures leads to a situation twice safer than that induced by an active debris removal of 5 objects per year in a MASTER2009 Business-As-Usual context. Because these measures have visible risk reduction effects in the long term, complementary measures with short response time are also studied. In the short term (from 2013 to 2020), a better prediction of the conjunctions is more efficient than protecting the satellite S1 itself. By

Handover aspects for a Low Earth Orbit (LEO) CDMA Land Mobile Satellite (LMS) system

Science.gov (United States)

Carter, P.; Beach, M. A.

1993-01-01

This paper addresses the problem of handoff in a land mobile satellite (LMS) system between adjacent satellites in a low earth orbit (LEO) constellation. In particular, emphasis is placed on the application of soft handoff in a direct sequence code division multiple access (DS-CDMA) LMS system. Soft handoff is explained in terms of terrestrial macroscopic diversity, in which signals transmitted via several independent fading paths are combined to enhance the link quality. This concept is then reconsidered in the context of a LEO LMS system. A two-state Markov channel model is used to simulate the effects of shadowing on the communications path from the mobile to each satellite during handoff. The results of the channel simulation form a platform for discussion regarding soft handoff, highlighting the potential merits of the scheme when applied in a LEO LMS environment.

System survivability in nuclear and space environments

International Nuclear Information System (INIS)

Rudie, N.J.

1987-01-01

Space systems must operate in the hostile natural environment of space. In the event of a war, these systems may also be exposed to the radiation environments created by the explosions of nuclear warheads. The effects of these environments on a space system and hardening techniques are discussed in the paper

Petróleo

Directory of Open Access Journals (Sweden)

Celso Fernando Lucchesi

1998-08-01

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

Space environment studies for the SZ-4 spacecraft

International Nuclear Information System (INIS)

Ye Zonghai

2004-01-01

The space environment, especially the solar-terrestrial space environment, has close bearings on mankind's astronautical activities. An overview is presented of the space environment and safeguard services on the 'SZ' series of spacecraft, with special reference to the SZ-4 spacecraft. These include monitoring of the space environment on SZ-4, studies on its distribution, variation and effects on astronautical performance, as well as space environment forecasts for safe launching, normal operation and safe return of SZ-4. Current progress both in China and overseas is covered

Situative Space Tracking within Smart Environments

DEFF Research Database (Denmark)

Surie, Dipak; Jäckel, Florian; Janlert, Lars-Erik

2010-01-01

This paper describes our efforts in modeling and tracking a human agent’s situation based on his/her possibilities to perceive and act upon objects (both physical and virtual) within smart environments. A Situative Space Model is proposed. WLAN signal-strength-based situative space tracking syste......-laboratory smart home environment where a global precision of 83.4% and a global recall of 88.6% were obtained.......This paper describes our efforts in modeling and tracking a human agent’s situation based on his/her possibilities to perceive and act upon objects (both physical and virtual) within smart environments. A Situative Space Model is proposed. WLAN signal-strength-based situative space tracking system...

Evasive Maneuvers in Space Debris Environment and Technological Parameters

Directory of Open Access Journals (Sweden)

Antônio D. C. Jesus

2012-01-01

Full Text Available We present a study of collisional dynamics between space debris and an operational vehicle in LEO. We adopted an approach based on the relative dynamics between the objects on a collisional course and with a short warning time and established a semianalytical solution for the final trajectories of these objects. Our results show that there are angular ranges in 3D, in addition to the initial conditions, that favor the collisions. These results allowed the investigation of a range of technological parameters for the spacecraft (e.g., fuel reserve that allow a safe evasive maneuver (e.g., time available for the maneuver. The numerical model was tested for different values of the impact velocity and relative distance between the approaching objects.

Sizing of "Mother Ship and Catcher" Concepts for LEO Small Debris Capture

Science.gov (United States)

Bacon, John B.

2009-01-01

Most Low Earth Orbit (LEO) debris lies in a limited number of inclination "bands" associated with launch latitudes, or with specific useful orbit inclinations (such as polar orbits). Such narrow inclination bands generally have a uniform spread over all possible Right Ascensions of Ascending Node (RAANs), creating a different orbit plane for nearly every piece of debris. This complicates concept of rendezvous and capture for debris removal. However, a low-orbiting satellite will always phase in RAAN faster than debris objects in higher orbits at the same inclination, potentially solving the problem. Such a base can serve as a single space-based launch facility (a "mother ship") that can tend and then send tiny individual catcher devices for each debris object, as the facility drifts into the same RAAN as the higher object. This presentation will highlight characteristic system requirements of such an architecture, including structural and navigation requirements, power, mass and dV budgets for both the mother ship and the mass-produced common catcher devices that would clean out selected inclination bands. The altitude and inclination regime over which a band is to be cleared, the size distribution of the debris, and the inclusion of additional mission priorities all affect the sizing of the system. It is demonstrated that major LEO hazardous debris reductions can be realized in each band with a single LEO launch of a single mother ship, with simple attached catchers of total mass less than typical commercial LEO launch capability.

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

Science.gov (United States)

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

1999-01-01

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

Space Debris and Observational Astronomy

Science.gov (United States)

Seitzer, Patrick

2018-01-01

Since the launch of Sputnik 1 in 1957, astronomers have faced an increasing number of artificial objects contaminating their images of the night sky. Currently almost 17000 objects larger than 10 cm are tracked and have current orbits in the public catalog. Active missions are only a small fraction of these objects. Most are inactive satellites, rocket bodies, and fragments of larger objects: all space debris. Several mega-constellations are planned which will increase this number by 20% or more in low Earth orbit (LEO). In terms of observational astronomy, this population of Earth orbiting objects has three implications: 1) the number of streaks and glints from spacecraft will only increase. There are some practical steps that can be taken to minimize the number of such streaks and glints in astronomical imaging data. 2) The risk to damage to orbiting astronomical telescopes will only increase, particularly those in LEO. 3) If you are working on a plan for an orbiting telescope project, then there are specific steps that must be taken to minimize space debris generation during the mission lifetime, and actions to safely dispose of the spacecraft at end of mission to prevent it from becoming space debris and a risk to other missions. These steps may involve sacrifices to mission performance and lifetime, but are essential in today's orbital environment.

Status Report of Simulated Space Radiation Environment Facility

Energy Technology Data Exchange (ETDEWEB)

Kang, Phil Hyun; Nho, Young Chang; Jeun, Joon Pyo; Choi, Jae Hak; Lim, Youn Mook; Jung, Chan Hee; Jeon, Young Kyu

2007-11-15

The technology for performance testing and improvement of materials which are durable at space environment is a military related technology and veiled and securely regulated in advanced countries such as US and Russia. This core technology cannot be easily transferred to other country too. Therefore, this technology is the most fundamental and necessary research area for the successful establishment of space environment system. Since the task for evaluating the effects of space materials and components by space radiation plays important role in satellite lifetime extension and running failure percentage decrease, it is necessary to establish simulated space radiation facility and systematic testing procedure. This report has dealt with the status of the technology to enable the simulation of space environment effects, including the effect of space radiation on space materials. This information such as the fundamental knowledge of space environment and research status of various countries as to the simulation of space environment effects of space materials will be useful for the research on radiation hardiness of the materials. Furthermore, it will be helpful for developer of space material on deriving a better choice of materials, reducing the design cycle time, and improving safety.

Status Report of Simulated Space Radiation Environment Facility

International Nuclear Information System (INIS)

Kang, Phil Hyun; Nho, Young Chang; Jeun, Joon Pyo; Choi, Jae Hak; Lim, Youn Mook; Jung, Chan Hee; Jeon, Young Kyu

2007-11-01

The technology for performance testing and improvement of materials which are durable at space environment is a military related technology and veiled and securely regulated in advanced countries such as US and Russia. This core technology cannot be easily transferred to other country too. Therefore, this technology is the most fundamental and necessary research area for the successful establishment of space environment system. Since the task for evaluating the effects of space materials and components by space radiation plays important role in satellite lifetime extension and running failure percentage decrease, it is necessary to establish simulated space radiation facility and systematic testing procedure. This report has dealt with the status of the technology to enable the simulation of space environment effects, including the effect of space radiation on space materials. This information such as the fundamental knowledge of space environment and research status of various countries as to the simulation of space environment effects of space materials will be useful for the research on radiation hardiness of the materials. Furthermore, it will be helpful for developer of space material on deriving a better choice of materials, reducing the design cycle time, and improving safety

Introducing Leo LT - the "three-headed lion"

Index Scriptorium Estoniae

2008-01-01

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

Leo II PC

Data.gov (United States)

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

Low earth orbit environmental effects on the space station photovoltaic power generation systems

International Nuclear Information System (INIS)

Nahra, H.K.

1977-01-01

A summary of the Low Earth Orbital Environment, its impact on the photovoltaic power systems of the space station and the solutions implemented to resolve the environmental concerns or issues are described. Low Earth Orbital Environment (LEO) presents several concerns to the photovoltaic power systems of the space station. These concerns include atomic oxygen interaction with the polymeric substrate of the solar arrays, ionized environment effects on the array operating voltage, the effects of the meteoroids and debris impacts and penetration through the different layers of the solar cells and their circuits, and the high energy particle and radiation effects on the overall solar array performance. Potential solutions to some of the degrading environmental interactions that will provide the photovoltaic power system of the space station with the desired life are also summarized

Space plasma observations - observations of solar-terrestrial environment. Space Weather Forecast

International Nuclear Information System (INIS)

Sagawa, Eiichi; Akioka, Maki

1996-01-01

The space environment becomes more important than ever before because of the expansion in the utilization of near-earth space and the increase in the vulnerability of large scale systems on the ground such as electrical power grids. The concept of the Space Weather Forecast program emerged from the accumulation of understanding on basic physical processes and from our activities as one of the regional warning centers of the international network of space environment services. (author)

The Resolved Stellar Population of Leo A

Science.gov (United States)

Tolstoy, Eline

1996-05-01

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

Three near term commercial markets in space and their potential role in space exploration

Science.gov (United States)

Gavert, Raymond B.

2001-02-01

Independent market studies related to Low Earth Orbit (LEO) commercialization have identified three near term markets that have return-on-investment potential. These markets are: (1) Entertainment (2) Education (3) Advertising/sponsorship. Commercial activity is presently underway focusing on these areas. A private company is working with the Russians on a commercial module attached to the ISS that will involve entertainment and probably the other two activities as well. A separate corporation has been established to commercialize the Russian Mir Space Station with entertainment and promotional advertising as important revenue sources. A new startup company has signed an agreement with NASA for commercial media activity on the International Space Station (ISS). Profit making education programs are being developed by a private firm to allow students to play the role of an astronaut and work closely with space scientists and astronauts. It is expected that the success of these efforts on the ISS program will extend to exploration missions beyond LEO. The objective of this paper is to extrapolate some of the LEO commercialization experiences to see what might be expected in space exploration missions to Mars, the Moon and beyond. .

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

Science.gov (United States)

Liou, Jer-Chyi

2012-01-01

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

Ionizing Radiation Environment on the International Space Station: Performance vs. Expectations for Avionics and Material

Science.gov (United States)

Koontz, Steven L.; Boeder, Paul A.; Pankop, Courtney; Reddell, Brandon

2005-01-01

The role of structural shielding mass in the design, verification, and in-flight performance of International Space Station (ISS), in both the natural and induced orbital ionizing radiation (IR) environments, is reported. Detailed consideration of the effects of both the natural and induced ionizing radiation environment during ISS design, development, and flight operations has produced a safe, efficient manned space platform that is largely immune to deleterious effects of the LEO ionizing radiation environment. The assumption of a small shielding mass for purposes of design and verification has been shown to be a valid worst-case approximation approach to design for reliability, though predicted dependences of single event effect (SEE) effects on latitude, longitude, SEP events, and spacecraft structural shielding mass are not observed. The Figure of Merit (FOM) method over predicts the rate for median shielding masses of about 10g/cm(exp 2) by only a factor of 3, while the Scott Effective Flux Approach (SEFA) method overestimated by about one order of magnitude as expected. The Integral Rectangular Parallelepiped (IRPP), SEFA, and FOM methods for estimating on-orbit (Single Event Upsets) SEU rates all utilize some version of the CREME-96 treatment of energetic particle interaction with structural shielding, which has been shown to underestimate the production of secondary particles in heavily shielded manned spacecraft. The need for more work directed to development of a practical understanding of secondary particle production in massive structural shielding for SEE design and verification is indicated. In contrast, total dose estimates using CAD based shielding mass distributions functions and the Shieldose Code provided a reasonable accurate estimate of accumulated dose in Grays internal to the ISS pressurized elements, albeit as a result of using worst-on-worst case assumptions (500 km altitude x 2) that compensate for ignoring both GCR and secondary particle

Energy considerations in the partial space elevator

Science.gov (United States)

Woo, Pamela; Misra, Arun K.

2014-06-01

The space elevator has been proposed as an alternate method for space transportation. A partial elevator is composed of a tether of several hundreds of kilometres, held vertically in tension between two end masses, with its centre of orbit placed at the geosynchronous orbit. A spacecraft can dock at the lower end, and then use the climber on the elevator to ascend to higher altitudes. In this paper, energy calculations are performed, to determine whether a partial elevator can provide sufficient savings in operational costs, compared to the traditional rocket-powered launch. The energy required to launch a spacecraft from a Low Earth Orbit (LEO) to the geostationary orbit (GEO) is calculated for two trajectories. In the first trajectory, the spacecraft travels from LEO to GEO via a Hohmann transfer. In the second trajectory, the spacecraft travels from LEO to the lower end of the partial space elevator with a Hohmann transfer, and then uses the elevator to climb to GEO. The total energy required is compared between the two trajectories. The effects of tether length, spacecraft-to-climber mass ratio, altitude of LEO, and tether material are investigated.

Radiation environment in space

International Nuclear Information System (INIS)

Goka, Tateo; Koga, Kiyokazu; Matsumoto, Haruhisa; Komiyama, Tatsuo; Yasuda, Hiroshi

2011-01-01

Japanese Experiment Module (Kibo) had been build into the International Space Station (ISS), which is a multipurpose manned facility and laboratory and is operated in orbit at about 400 km in altitude. Two Japanese astronauts stayed in the ISS for long time (4.5 and 5.5 months) for the first time. Space radiation exposure is one of the biggest safety issues for astronauts to stay for such a long duration in space. This special paper is presenting commentary on space radiation environment in ISS, neutrons measurements and light particles (protons and electrons) measurements, the instruments, radiation exposure management for Japanese astronauts and some comments in view of health physics. (author)

Space environments and their effects on space automation and robotics

Science.gov (United States)

Garrett, Henry B.

1990-01-01

Automated and robotic systems will be exposed to a variety of environmental anomalies as a result of adverse interactions with the space environment. As an example, the coupling of electrical transients into control systems, due to EMI from plasma interactions and solar array arcing, may cause spurious commands that could be difficult to detect and correct in time to prevent damage during critical operations. Spacecraft glow and space debris could introduce false imaging information into optical sensor systems. The presentation provides a brief overview of the primary environments (plasma, neutral atmosphere, magnetic and electric fields, and solid particulates) that cause such adverse interactions. The descriptions, while brief, are intended to provide a basis for the other papers presented at this conference which detail the key interactions with automated and robotic systems. Given the growing complexity and sensitivity of automated and robotic space systems, an understanding of adverse space environments will be crucial to mitigating their effects.

Computer simulation of spacecraft/environment interaction

International Nuclear Information System (INIS)

Krupnikov, K.K.; Makletsov, A.A.; Mileev, V.N.; Novikov, L.S.; Sinolits, V.V.

1999-01-01

This report presents some examples of a computer simulation of spacecraft interaction with space environment. We analysed a set data on electron and ion fluxes measured in 1991-1994 on geostationary satellite GORIZONT-35. The influence of spacecraft eclipse and device eclipse by solar-cell panel on spacecraft charging was investigated. A simple method was developed for an estimation of spacecraft potentials in LEO. Effects of various particle flux impact and spacecraft orientation are discussed. A computer engineering model for a calculation of space radiation is presented. This model is used as a client/server model with WWW interface, including spacecraft model description and results representation based on the virtual reality markup language

Computer simulation of spacecraft/environment interaction

CERN Document Server

Krupnikov, K K; Mileev, V N; Novikov, L S; Sinolits, V V

1999-01-01

This report presents some examples of a computer simulation of spacecraft interaction with space environment. We analysed a set data on electron and ion fluxes measured in 1991-1994 on geostationary satellite GORIZONT-35. The influence of spacecraft eclipse and device eclipse by solar-cell panel on spacecraft charging was investigated. A simple method was developed for an estimation of spacecraft potentials in LEO. Effects of various particle flux impact and spacecraft orientation are discussed. A computer engineering model for a calculation of space radiation is presented. This model is used as a client/server model with WWW interface, including spacecraft model description and results representation based on the virtual reality markup language.

Space Weather, Environment and Societies

CERN Document Server

Lilensten, Jean

2006-01-01

Our planet exists within a space environment affected by constantly changing solar atmosphere producing cosmic particles and electromagnetic waves. This "space weather" profoundly influences the performance of our technology because we primarily use two means for transmitting information and energy; namely, electromagnetic waves and electricity. On an everyday basis, we have developed methods to cope with the normal conditions. However, the sun remains a fiery star whose 'angry' outbursts can potentially destroy spacecrafts, kill astronauts, melt electricity transformers, stop trains, and generally wreak havoc with human activities. Space Weather is the developing field within astronomy that aims at predicting the sun’s violent activity and minimizing the impacts on our daily lives. Space Weather, Environment, and Societies explains why our technological societies are so dependent on solar activity and how the Sun disturbs the transmission of information and energy. Footnotes expand specific points and the ...

LEOS 2002: summer electronics and signal processing symposium

International Nuclear Information System (INIS)

Karadzhinov, Ljupcho; Ivanovski, Zoran

2002-01-01

LEOS 2002 was the first Macedonian symposium on electronics and signal processing. It was organized in recognition to a growing need to exchange the research results as well as to raise competent discussions among different research groups from both academic and industrial environment in Macedonia. The topics covered in this meeting were defined by the IEEE experts as follows: Power Electronics, Industrial Electronics, Signal Processing, Image and Video Processing, Instrumentation and Measurements, Engineering in Medicine and Biology, Electron Devices and Automatic Control. Papers were mainly from Macedonia, but there was one invited lecture

International Space Station External Contamination Environment for Space Science Utilization

Science.gov (United States)

Soares, Carlos E.; Mikatarian, Ronald R.; Steagall, Courtney A.; Huang, Alvin Y.; Koontz, Steven; Worthy, Erica

2014-01-01

The International Space Station (ISS) is the largest and most complex on-orbit platform for space science utilization in low Earth orbit. Multiple sites for external payloads, with exposure to the associated natural and induced environments, are available to support a variety of space science utilization objectives. Contamination is one of the induced environments that can impact performance, mission success and science utilization on the vehicle. The ISS has been designed, built and integrated with strict contamination requirements to provide low levels of induced contamination on external payload assets. This paper addresses the ISS induced contamination environment at attached payload sites, both at the requirements level as well as measurements made on returned hardware, and contamination forecasting maps being generated to support external payload topology studies and science utilization.

Viiv enne kojuminekut / Leo Kunnas ; interv. Helen Arak

Index Scriptorium Estoniae

Kunnas, Leo, 1967-

2006-01-01

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

Space station propulsion requirements study

Science.gov (United States)

Wilkinson, C. L.; Brennan, S. M.

1985-01-01

Propulsion system requirements to support Low Earth Orbit (LEO) manned space station development and evolution over a wide range of potential capabilities and for a variety of STS servicing and space station operating strategies are described. The term space station and the overall space station configuration refers, for the purpose of this report, to a group of potential LEO spacecraft that support the overall space station mission. The group consisted of the central space station at 28.5 deg or 90 deg inclinations, unmanned free-flying spacecraft that are both tethered and untethered, a short-range servicing vehicle, and a longer range servicing vehicle capable of GEO payload transfer. The time phasing for preferred propulsion technology approaches is also investigated, as well as the high-leverage, state-of-the-art advancements needed, and the qualitative and quantitative benefits of these advancements on STS/space station operations. The time frame of propulsion technologies applicable to this study is the early 1990's to approximately the year 2000.

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

OpenAIRE

Ayda Karina León Ayala

2011-01-01

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

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

NARCIS (Netherlands)

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

2007-01-01

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

Space radiation environment

International Nuclear Information System (INIS)

Garrett, H.B.

1998-01-01

Coupled with the increasing concern over trapped radiation effects on microelectronics, the availability of new data, long term changes in the Earth's magnetic field, and observed variations in the trapped radiation fluxes have generated the need for better, more comprehensive tools for modeling and predicting the Earth's trapped radiation environment and its effects on space systems. The objective of this report is to describe the current status of those efforts and review methods for attacking the issues associated with modeling the trapped radiation environment in a systematic, practical fashion. The ultimate goal will be to point the way to increasingly better methods of testing, designing, and flying reliable microelectronic systems in the Earth's radiation environment. The review will include a description of the principal models of the trapped radiation environment currently available--the AE8 and AP8 models. Recent results rom radiation experiments on spacecraft such as CRRES, SAMPEX, and CLEMENTINE will then be described. (author)

Space Weather Monitoring for ISS Space Environments Engineering and Crew Auroral Observations

Science.gov (United States)

Minow, Joseph I.; Pettit, Donald R.; Hartman, William A.

2012-01-01

The awareness of potentially significant impacts of space weather on spaceand ground ]based technological systems has generated a strong desire in many sectors of government and industry to effectively transform knowledge and understanding of the variable space environment into useful tools and applications for use by those entities responsible for systems that may be vulnerable to space weather impacts. Essentially, effectively transitioning science knowledge to useful applications relevant to space weather has become important. This talk will present proven methodologies that have been demonstrated to be effective, and how in the current environment those can be applied to space weather transition efforts.

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

Index Scriptorium Estoniae

Kunnas, Leo, 1967-

2006-01-01

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

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

Science.gov (United States)

Tobiska, W. Kent

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

LEO 1.0. An assistant software for maintenance of corroded reinforced concrete structures

International Nuclear Information System (INIS)

Gerard, B.; Petre-Lazar, I.

1998-04-01

The reinforced concrete structures capacity to fulfill the users requirements decreases in time and a constant preoccupation for the maintenance is required at EDF. In order to ease up the site investigations, a computer program - LEO - is developed. Its general layout is proposed in this document. LEO 1.0 is developed to be applied to corroded reinforced concrete structures. A simplified model based on the main mechanisms of the steel corrosion in concrete has been developed. It can quantify the influence of the reinforcement corrosion on the structure performances. A probabilistic calculus which takes into account the variability of the input data (material properties, environment, etc.) was also performed using PROBAN computer code. This type of analysis quantifies the time evolution of the structure (incubation, initiation, propagation, collapse). (author)

Erosion Results of the MISSE 7 Polymers Experiment and Zenith Polymers Experiment After 1.5 Years of Space Exposure

Science.gov (United States)

De Groh, Kim K.; Banks, Bruce A.; Yi, Grace T.; Haloua, Athena; Imka, Emily C.; Mitchell, Gianna G.; Asmar, Olivia C.; Leneghan, Halle A.; Sechkar, Edward A.

2016-01-01

Polymers and other oxidizable materials on the exterior of spacecraft in the low Earth orbit (LEO) space environment can be eroded due to reaction with atomic oxygen (AO). Therefore, in order to design durable spacecraft it is important to know the LEO AO erosion yield (E(sub y), volume loss per incident oxygen atom) of materials susceptible to AO reaction. Two spaceflight experiments, the Polymers Experiment and the Zenith Polymers Experiment, were developed to determine the AO E(sub y) of various polymers flown in ram, wake or zenith orientations in LEO. These experiments were flown as part of the Materials International Space Station Experiment 7 (MISSE 7) mission for 1.5 years on the exterior of the International Space Station (ISS). The experiments included Kapton H(TradeMark) witness samples for AO fluence determination in ram and zenith orientations. The Polymers Experiment also included samples to determine whether AO erosion of high and low ash containing polymers is dependent on fluence. This paper provides an overview of the MISSE 7 mission, a description of the flight experiments with details on the polymers flown, the characterization techniques used, the AO fluence for each exposure orientation, and the LEO E(sub y) results. The E(sub y) values ranged from 7.99x10(exp -28)cu cm/atom for TiO2/Al2O3 coated Teflon(TradeMark) fluorinated ethylene propylene (FEP) flown in the ram orientation to 1.22x10(exp -23cu cm/atom for polyvinyl alcohol (PVOH) flown in the zenith orientation. The E(sub y) of similar samples flown in different orientations has been compared to help determine solar exposure and associated heating effects on AO erosion. The E(sub y) data from these ISS spaceflight experiments provides valuable information for LEO spacecraft design purposes.

Systems Analysis of In-Space Manufacturing Applications for the International Space Station and the Evolvable Mars Campaign

Science.gov (United States)

Owens, Andrew C.; De Weck, Olivier L.

2016-01-01

Maintenance logistics support is a significant challenge for extended human operations in space, especially for missions beyond Low Earth Orbit (LEO). For missions to Mars (such as NASA's Evolvable Mars Campaign (EMC)), where timely resupply or abort in the event of emergency will not be possible, maintenance logistics mass is directly linked to the Probability of Loss of Crew (P(LoC)), and the cost of driving down risk is an exponential increase in mass requirements. The logistics support strategies that have maintained human operations in LEO will not be effective for these deep space missions. In-Space Manufacturing (ISM) is a promising technological solution that could reduce logistics requirements, mitigate risks, and augment operational capabilities, enabling Earth- independent human spaceflight. This paper reviews maintenance logistics challenges for spaceflight operations in LEO and beyond, and presents a summary of selected results from a systems analysis of potential ISM applications for the ISS and EMC. A quantitative modeling framework and sample assessment of maintenance logistics and risk reduction potential of this new technology is also presented and discussed.

A review of the findings of the plasma diagnostic package and associated laboratory experiments: Implications of large body/plasma interactions for future space technology

Science.gov (United States)

Murphy, Gerald B.; Lonngren, Karl E.

1986-01-01

The discoveries and experiments of the Plasma Diagnostic Package (PDP) on the OSS 1 and Spacelab 2 missions are reviewed, these results are compared with those of other space and laboratory experiments, and the implications for the understanding of large body interactions in a low Earth orbit (LEO) plasma environment are discussed. First a brief review of the PDP investigation, its instrumentation and experiments is presented. Next a summary of PDP results along with a comparison of those results with similar space or laboratory experiments is given. Last of all the implications of these results in terms of understanding fundamental physical processes that take place with large bodies in LEO is discussed and experiments to deal with these vital questions are suggested.

Óleo funcional na dieta de vacas leiteiras

OpenAIRE

Jesus, Elmeson Ferreira de [UNESP

2015-01-01

O presente estudo teve como objetivo avaliar os efeitos da inclusão de óleo funcional composto de ácido anacárdico, cardol e cardanol (óleo da castanha de cajú) e ácido ricinoleico (óleo de mamona) na dieta de vacas em lactação sobre consumo, digestibilidade aparente total da matéria seca e nutrientes, fermentação ruminal, produção e composição do leite, síntese de proteína microbiana, perfil metabólico, balanço de nitrogênio e energia. Foram utilizadas vinte e quatro vacas pluriparas da raça...

Mutagenic effects of space environment and protons on rice

International Nuclear Information System (INIS)

Wang Cailian; Chen Qiufang; Shen Mei

1998-07-01

Dry seeds of 5 rice varieties were carried by recoverable satellite for space mutation, and were irradiated by 4∼8 MeV protons with various doses. The mutagenic effects was studied. The results indicated that the space environment could cause chromosomal structure aberration and had stimulating mitosis action in root tip cells. As compared with γ-rays and protons, the effects of space environment flight were lower on chromosomal aberration but were significantly higher on mitosis index. Space environment and protons induce high frequency of chlorophyll deficient mutation and mutation in plant height and heading date in M 2 generation. Frequency of beneficial mutation induced by space environment and protons were higher than those induced by γ-rays

VARIABILITY AND STAR FORMATION IN LEO T, THE LOWEST LUMINOSITY STAR-FORMING GALAXY KNOWN TODAY

Energy Technology Data Exchange (ETDEWEB)

Clementini, Gisella; Cignoni, Michele; Ramos, Rodrigo Contreras; Federici, Luciana; Tosi, Monica [INAF, Osservatorio Astronomico di Bologna, I-40127 Bologna (Italy); Ripepi, Vincenzo; Marconi, Marcella; Musella, Ilaria, E-mail: gisella.clementini@oabo.inaf.it, E-mail: rodrigo.contreras@oabo.inaf.it, E-mail: luciana.federici@oabo.inaf.it, E-mail: monica.tosi@oabo.inaf.it, E-mail: michele.cignoni@unibo.it, E-mail: ripepi@na.astro.it, E-mail: marcella@na.astro.it, E-mail: ilaria@na.astro.it [INAF, Osservatorio Astronomico di Capodimonte, I-80131 Napoli (Italy)

2012-09-10

We present results from the first combined study of variable stars and star formation history (SFH) of the Milky Way 'ultra-faint' dwarf (UFD) galaxy Leo T, based on F606W and F814W multi-epoch archive observations obtained with the Wide Field Planetary Camera 2 on board the Hubble Space Telescope. We have detected 14 variable stars in the galaxy. They include one fundamental-mode RR Lyrae star and 11 Anomalous Cepheids with periods shorter than 1 day, thus suggesting the occurrence of multiple star formation episodes in this UFD, of which one about 10 Gyr ago produced the RR Lyrae star. A new estimate of the distance to Leo T of 409{sup +29}{sub -27} kpc (distance modulus of 23.06 {+-} 0.15 mag) was derived from the galaxy's RR Lyrae star. Our V, V - I color-magnitude diagram (CMD) of Leo T reaches V {approx} 29 mag and shows features typical of a galaxy in transition between dwarf irregular and dwarf spheroidal types. A quantitative analysis of the SFH, based on the comparison of the observed V, V - I CMD with the expected distribution of stars for different evolutionary scenarios, confirms that Leo T has a complex SFH dominated by two enhanced periods about 1.5 and 9 Gyr ago, respectively. The distribution of stars and gas shows that the galaxy has a fairly asymmetric structure.

Environmental Durability Issues for Solar Power Systems in Low Earth Orbit

Science.gov (United States)

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

1994-01-01

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

The Near-Earth Space Radiation Environment

Science.gov (United States)

Xapsos, Michael

2008-01-01

This viewgraph presentation reviews the effects of the Near-Earth space radiation environment on NASA missions. Included in this presentation is a review of The Earth s Trapped Radiation Environment, Solar Particle Events, Galactic Cosmic Rays and Comparison to Accelerator Facilities.

Advanced Engineering Environments for Space Transportation System Development

Science.gov (United States)

Thomas, L. Dale; Smith, Charles A.; Beveridge, James

2000-01-01

There are significant challenges facing today's launch vehicle industry. Global competition, more complex products, geographically-distributed design teams, demands for lower cost, higher reliability and safer vehicles, and the need to incorporate the latest technologies quicker, all face the developer of a space transportation system. Within NASA, multiple technology development and demonstration projects are underway toward the objectives of safe, reliable, and affordable access to space. New information technologies offer promising opportunities to develop advanced engineering environments to meet these challenges. Significant advances in the state-of-the-art of aerospace engineering practice are envisioned in the areas of engineering design and analytical tools, cost and risk tools, collaborative engineering, and high-fidelity simulations early in the development cycle. At the Marshall Space Flight Center, work has begun on development of an advanced engineering environment specifically to support the design, modeling, and analysis of space transportation systems. This paper will give an overview of the challenges of developing space transportation systems in today's environment and subsequently discuss the advanced engineering environment and its anticipated benefits.

Lead-Free Experiment in a Space Environment

Science.gov (United States)

Blanche, J. F.; Strickland, S. M.

2012-01-01

This Technical Memorandum addresses the Lead-Free Technology Experiment in Space Environment that flew as part of the seventh Materials International Space Station Experiment outside the International Space Station for approximately 18 months. Its intent was to provide data on the performance of lead-free electronics in an actual space environment. Its postflight condition is compared to the preflight condition as well as to the condition of an identical package operating in parallel in the laboratory. Some tin whisker growth was seen on a flight board but the whiskers were few and short. There were no solder joint failures, no tin pest formation, and no significant intermetallic compound formation or growth on either the flight or ground units.

Space Environment Testing of Photovoltaic Array Systems at NASA's Marshall Space Flight Center

Science.gov (United States)

Phillips, Brandon S.; Schneider, Todd A.; Vaughn, Jason A.; Wright, Kenneth H., Jr.

2015-01-01

To successfully operate a photovoltaic (PV) array system in space requires planning and testing to account for the effects of the space environment. It is critical to understand space environment interactions not only on the PV components, but also the array substrate materials, wiring harnesses, connectors, and protection circuitry (e.g. blocking diodes). Key elements of the space environment which must be accounted for in a PV system design include: Solar Photon Radiation, Charged Particle Radiation, Plasma, and Thermal Cycling. While solar photon radiation is central to generating power in PV systems, the complete spectrum includes short wavelength ultraviolet components, which photo-ionize materials, as well as long wavelength infrared which heat materials. High energy electron radiation has been demonstrated to significantly reduce the output power of III-V type PV cells; and proton radiation damages material surfaces - often impacting coverglasses and antireflective coatings. Plasma environments influence electrostatic charging of PV array materials, and must be understood to ensure that long duration arcs do not form and potentially destroy PV cells. Thermal cycling impacts all components on a PV array by inducing stresses due to thermal expansion and contraction. Given such demanding environments, and the complexity of structures and materials that form a PV array system, mission success can only be ensured through realistic testing in the laboratory. NASA's Marshall Space Flight Center has developed a broad space environment test capability to allow PV array designers and manufacturers to verify their system's integrity and avoid costly on-orbit failures. The Marshall Space Flight Center test capabilities are available to government, commercial, and university customers. Test solutions are tailored to meet the customer's needs, and can include performance assessments, such as flash testing in the case of PV cells.

Características do óleo essencial de capim-citronela em função de espaçamento, altura e época de corte Essential oil characteristics from citronella grass depending on planting space, cutting height and harvesting time

Directory of Open Access Journals (Sweden)

Cláudia A Marco

2007-09-01

Full Text Available A importância do capim-citronela (Cymbopogon winterianum Jowitt. tem crescido nos últimos anos no mercado de produtos naturais, devido à grande procura pelo seu óleo essencial. Neste trabalho, objetivou-se avaliar a influência do espaçamento (50 x 50; 50 x 80 e 80 x 80 cm, altura (15 e 30 cm do solo e época de corte (quatro, seis e oito meses após o plantio na produção e qualidade do óleo essencial de capim-citronela. Desenvolveu-se um ensaio na Fazenda Experimental Vale do Curu (FEVC, pertencente ao Centro de Ciências Agrárias, da Universidade Federal do Ceará, em Pentecoste - CE, no período de setembro de 2002 a setembro de 2003. Os tratamentos foram arranjados como fatorial 3 x 3 x 2, dispostos em blocos casualizados, com três repetições. Plantas colhidas quatro meses após o plantio apresentaram significativamente maior produção de óleo essencial se cortadas a 30 cm de altura. Já plantas colhidas seis meses após o plantio apresentaram maior produção de óleo essencial se cortadas a 15 cm de altura. Para plantas colhidas oito meses após o plantio, a altura de corte não interferiu na produção de óleo essencial. Para espaçamentos mais largos (80 x 80 cm, a produção de óleo essencial foi significativamente mais alta para plantas cortadas a 15 cm, acontecendo o inverso no espaçamento menor (50 x 50 cm. Quando foram avaliados os constituintes citronelol + citronelal observou-se que seus teores foram significativamente mais elevados em plantas cultivadas no espaçamento intermediário, colhidas após os seis meses e a 30 cm de altura. Já o teor de geraniol foi superior em plantas colhidas quatro meses após o plantio, porém não houve influência do espaçamento e altura de corte sobre o seu teor.Citronella grass (Cymbopogon winterianum Jowitt. has grown in importance due to an increasing demand of the essential oil. The influence of spacing (50 x 50; 50 x 80 e 80 x 80 cm, cutting height (15 and 30 cm above

Survival of spores of the UV-resistant Bacillus subtilis strain MW01 after exposure to low-earth orbit and simulated martian conditions: data from the space experiment ADAPT on EXPOSE-E.

Science.gov (United States)

Wassmann, Marko; Moeller, Ralf; Rabbow, Elke; Panitz, Corinna; Horneck, Gerda; Reitz, Günther; Douki, Thierry; Cadet, Jean; Stan-Lotter, Helga; Cockell, Charles S; Rettberg, Petra

2012-05-01

In the space experiment "Molecular adaptation strategies of microorganisms to different space and planetary UV climate conditions" (ADAPT), bacterial endospores of the highly UV-resistant Bacillus subtilis strain MW01 were exposed to low-Earth orbit (LEO) and simulated martian surface conditions for 559 days on board the European Space Agency's exposure facility EXPOSE-E, mounted outside the International Space Station. The survival of B. subtilis MW01 spores from both assays (LEO and simulated martian conditions) was determined by a colony-formation assay after retrieval. It was clearly shown that solar extraterrestrial UV radiation (λ≥110 nm) as well as the martian UV spectrum (λ≥200 nm) was the most deleterious factor applied; in some samples only a few spore survivors were recovered from B. subtilis MW01 spores exposed in monolayers. However, if shielded from solar irradiation, about 8% of MW01 spores survived in LEO conditions, and 100% survived in simulated martian conditions, compared to the laboratory controls. The results demonstrate the effect of shielding against the high inactivation potential of extraterrestrial solar UV radiation, which limits the chances of survival of even the highly UV-resistant strain of B. subtilis MW01 in the harsh environments of outer space and the martian surface.

The ionizing radiation environment in space and its effects

International Nuclear Information System (INIS)

Adams, Jim; Falconer, David; Fry, Dan

2012-01-01

The ionizing radiation environment in space poses a hazard for spacecraft and space crews. The hazardous components of this environment are reviewed and those which contribute to radiation hazards and effects identified. Avoiding the adverse effects of space radiation requires design, planning, monitoring and management. Radiation effects on spacecraft are avoided largely though spacecraft design. Managing radiation exposures of space crews involves not only protective spacecraft design and careful mission planning. Exposures must be managed in real time. The now-casting and forecasting needed to effectively manage crew exposures is presented. The techniques used and the space environment modeling needed to implement these techniques are discussed.

Growth and characterization of AlxGa1-xN LEO substrates

International Nuclear Information System (INIS)

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

2006-01-01

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

Improved Space Object Orbit Determination Using CMOS Detectors

Science.gov (United States)

Schildknecht, T.; Peltonen, J.; Sännti, T.; Silha, J.; Flohrer, T.

2014-09-01

CMOS-sensors, or in general Active Pixel Sensors (APS), are rapidly replacing CCDs in the consumer camera market. Due to significant technological advances during the past years these devices start to compete with CCDs also for demanding scientific imaging applications, in particular in the astronomy community. CMOS detectors offer a series of inherent advantages compared to CCDs, due to the structure of their basic pixel cells, which each contains their own amplifier and readout electronics. The most prominent advantages for space object observations are the extremely fast and flexible readout capabilities, feasibility for electronic shuttering and precise epoch registration, and the potential to perform image processing operations on-chip and in real-time. The major challenges and design drivers for ground-based and space-based optical observation strategies have been analyzed. CMOS detector characteristics were critically evaluated and compared with the established CCD technology, especially with respect to the above mentioned observations. Similarly, the desirable on-chip processing functionalities which would further enhance the object detection and image segmentation were identified. Finally, we simulated several observation scenarios for ground- and space-based sensor by assuming different observation and sensor properties. We will introduce the analyzed end-to-end simulations of the ground- and space-based strategies in order to investigate the orbit determination accuracy and its sensitivity which may result from different values for the frame-rate, pixel scale, astrometric and epoch registration accuracies. Two cases were simulated, a survey using a ground-based sensor to observe objects in LEO for surveillance applications, and a statistical survey with a space-based sensor orbiting in LEO observing small-size debris in LEO. The ground-based LEO survey uses a dynamical fence close to the Earth shadow a few hours after sunset. For the space-based scenario

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

Science.gov (United States)

Padgen, Mike

2017-01-01

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

Solar/Space Environment Data (Satellites)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) monitors the geospace and solar environments using a variety of space weather sensors aboard its fleet of...

LET calibration for CR-39 detectors in different oxygen environments

International Nuclear Information System (INIS)

Zhou, D.; Semones, E.; Weyland, M.; Benton, E.R.

2007-01-01

High LET (linear energy transfer) radiation is the main contributor to the radiation field in low Earth orbit (LEO) in terms of dose equivalent. CR-39 plastic nuclear track detectors (PNTDs) can measure the LET spectrum and charge spectrum for the complicated radiation field in space. Previous research indicated that the sensitivity of CR-39 is different for CR-39 PNTDs working in different oxygen environments. LET calibration for CR-39 detectors in different oxygen environments is needed. Almost all the previous LET calibration work was carried out for CR-39 detectors in good-oxygen condition, LET calibration work for CR-39 in poor-oxygen condition has not been conducted until our work. Systematic LET calibrations were carried out by JSC-SRAG (Space Radiation Analysis Group) for CR-39 detectors working in different oxygen environments and abundant results of LET calibrations were obtained. This paper introduces the method for CR-39 LET calibration, presents and discusses the calibration results and some applications

Assessment of environmental effects on Space Station Freedom Electrical Power System

Science.gov (United States)

Lu, Cheng-Yi; Nahra, Henry K.

1991-01-01

Analyses of EPS (electrical power system) interactions with the LEO (low earth orbit) environment are described. The results of these analyses will support EPS design so as to be compatible with the natural and induced environments and to meet power, lifetime, and performance requirements. The environmental impacts to the Space Station Freedom EPS include aerodynamic drag, atomic oxygen erosion, ultraviolet degradation, VXB effect, ionizing radiation dose and single event effects, electromagnetic interference, electrostatic discharge, plasma interactions (ion sputtering, arcing, and leakage current), meteoroid and orbital debris threats, thermal cycling effects, induced current and voltage potential differences in the SSF due to induced electric field, and contamination degradation.

Overview of fiber optics in the natural space environment

International Nuclear Information System (INIS)

Barnes, C.; Dorsky, L.; Johnston, A.; Bergman, L.; Stassinopoulos, E.

1991-01-01

The potential applications of fiber-optic (FO) systems in spacecraft which will be exposed to the space radiation environment are discussed in view of tests conducted aboard the Long-Duration Exposure Facility and the Comet Rendezvous and Asteroid Flyby spacecraft. Attention is given to anticipated trends in the use of FO in spacecraft communications systems. The natural space radiation environment is noted to be far more benign than the military space environment, which encompasses displacement-damage effects due to significant neutron influences

The Orbital Space Environment and Space Situational Awareness Domain Ontology - Toward an International Information System for Space Data

Science.gov (United States)

Rovetto, R.

2016-09-01

The orbital space environment is home to natural and artificial satellites, debris, and space weather phenomena. As the population of orbital objects grows so do the potential hazards to astronauts, space infrastructure and spaceflight capability. Orbital debris, in particular, is a universal concern. This and other hazards can be minimized by improving global space situational awareness (SSA). By sharing more data and increasing observational coverage of the space environment we stand to achieve that goal, thereby making spaceflight safer and expanding our knowledge of near-Earth space. To facilitate data-sharing interoperability among distinct orbital debris and space object catalogs, and SSA information systems, I proposed ontology in (Rovetto, 2015) and (Rovetto and Kelso, 2016). I continue this effort toward formal representations and models of the overall domain that may serve to improve peaceful SSA and increase our scientific knowledge. This paper explains the project concept introduced in those publications, summarizing efforts to date as well as the research field of ontology development and engineering. I describe concepts for an ontological framework for the orbital space environment, near-Earth space environment and SSA domain. An ontological framework is conceived as a part of a potential international information system. The purpose of such a system is to consolidate, analyze and reason over various sources and types of orbital and SSA data toward the mutually beneficial goals of safer space navigation and scientific research. Recent internationals findings on the limitations of orbital data, in addition to existing publications on collaborative SSA, demonstrate both the overlap with this project and the need for datasharing and integration.

The development of a cislunar space infrastructure

Science.gov (United States)

Buck, C. A.; Johnson, A. S.; Mcglinchey, J. M.; Ryan, K. D.

1989-01-01

The primary objective of this Advanced Mission Design Program is to define the general characteristics and phased evolution of a near-Earth space infrastructure. The envisioned foundation includes a permanently manned, self-sustaining base on the lunar surface, a space station at the Libration Point between earth and the moon (L1), and a transportation system that anchors these elements to the Low Earth Orbit (LEO) station. The implementation of this conceptual design was carried out with the idea that the infrastructure is an important step in a larger plan to expand man's capabilities in space science and technology. Such expansion depends on low cost, reliable, and frequent access to space for those who wish to use the multiple benefits of this environment. The presence of a cislunar space infrastructure would greatly facilitate the staging of future planetary missions, as well as the full exploration of the lunar potential for science and industry. The rationale for, and a proposed detailed scenario in support of, the cislunar space infrastructure are discussed.

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

International Nuclear Information System (INIS)

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

2014-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2014-08-01

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

Development of a software package for determination of geodynamic parameters from combined processing of SLR data from LAGEOS and LEO

Directory of Open Access Journals (Sweden)

Konstantin Ebauer

2017-05-01

Results of different solutions with the use of only LAGEOS data or LAGEOS plus LEO satellites data are presented. Pole coordinates obtained from both solutions show comparable accuracy relative to IERS 08 C04 solution. As for UT1 corrections in terms of Length-of-Day an additional improvement in accuracy is found: 1.0 ms for LAGEOS and 0.2 ms for the combined LAGEOS + LEO solution. Time series of the estimated degree-2 gravity field coefficients show a very good agreement with results of the Center of Space Research (Austin/USA. As a final remark, some future mandatory steps are outlined.

Multiple wavelength spectral system simulating background light noise environment in satellite laser communications

Science.gov (United States)

Lu, Wei; Sun, Jianfeng; Hou, Peipei; Xu, Qian; Xi, Yueli; Zhou, Yu; Zhu, Funan; Liu, Liren

2017-08-01

Performance of satellite laser communications between GEO and LEO satellites can be influenced by background light noise appeared in the field of view due to sunlight or planets and some comets. Such influences should be studied on the ground testing platform before the space application. In this paper, we introduce a simulator that can simulate the real case of background light noise in space environment during the data talking via laser beam between two lonely satellites. This simulator can not only simulate the effect of multi-wavelength spectrum, but also the effects of adjustable angles of field-of-view, large range of adjustable optical power and adjustable deflection speeds of light noise in space environment. We integrate these functions into a device with small and compact size for easily mobile use. Software control function is also achieved via personal computer to adjust these functions arbitrarily. Keywords:

Desempenho de um trator agrícola de pneus, funcionando com misturas de óleo diesel e óleo de soja reutilizado

Directory of Open Access Journals (Sweden)

Wagner da Cunha Siqueira

2011-10-01

Full Text Available No Brasil, a forma de energia alternativa mais atraente tem sido a biomassa e, mais recentemente, os óleos vegetais residuais e in natura. Portanto, objetivou-se, com este trabalho, avaliar o desempenho na tomada de potência de um trator agrícola de pneus, utilizando misturas de óleo Diesel (OD com óleo de soja reutilizádo (OSR. Primeiramente, foi realizado um estudo de densidade das misturas, comportamento da temperatura do óleo Diesel no sistema de alimentação de combustível do motor e análises de viscosidades das misturas em estudo. Após as análises, verificou-se, por meio de ensaios dinamométricos, o desempenho do motor alimentado com misturas de OD com OSR, em diferentes proporções. As principais conclusões deste trabalho foram: a para as avaliações na tomada de potência, a mistura de 25% OD com 75% OSR apresentou a maior potência entre as demais misturas; b o consumo especifico e os torques demonstraram tendência a maiores valores com o acréscimo da percentagem de OSR às misturas.

The Oxygen and Nitrogen Abundance of Leo A and GR 8

Science.gov (United States)

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

1999-05-01

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

Space Debris Elimination (SpaDE)

Data.gov (United States)

National Aeronautics and Space Administration — The amount of debris in low Earth orbit (LEO) has increased rapidly over the last twenty years. This prevalence of debris increases the likelihood of cascading...

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

International Nuclear Information System (INIS)

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

2010-01-01

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

ASI's space automation and robotics programs: The second step

Science.gov (United States)

Dipippo, Simonetta

1994-01-01

The strategic decisions taken by ASI in the last few years in building up the overall A&R program, represent the technological drivers for other applications (i.e., internal automation of the Columbus Orbital Facility in the ESA Manned Space program, applications to mobile robots both in space and non-space environments, etc...). In this context, the main area of application now emerging is the scientific missions domain. Due to the broad range of applications of the developed technologies, both in the in-orbit servicing and maintenance of space structures and scientific missions, ASI foresaw the need to have a common technological development path, mainly focusing on: (1) control; (2) manipulation; (3) on-board computing; (4) sensors; and (5) teleoperation. Before entering into new applications in the scientific missions field, a brief overview of the status of the SPIDER related projects is given, underlining also the possible new applications for the LEO/GEO space structures.

Environment monitoring from space

International Nuclear Information System (INIS)

Takagi, M.

1994-01-01

Environmental problems such as acid rain, ozone depletion, deforestation, erosion, and the greenhouse effect are of increasing concern, and continuous earth observation from artificial satellites has been contributing significant information on the environment since the 1960s. Earth observation from space has the advantages of wide area coverage at potentially high resolutions, periodic and long-term observation capability, data acquisition with uniform quality and repeatability, and ability to observe using different types of sensors. Problems to be solved in earth observation include the need for preprocessing of satellite data, understanding the relationship between observed physical parameters and objects, and the high volume of data for processing. In Japan, a research project on the higher-order utilization of remote sensing data from space was organized in 1985, and the results led to recognition of the importance of satellite observation. It was then decided to undertake a program to improve the understanding of the earth environment by satellite. Five research plans were selected: a basic study on earth observation by microwaves; global change analysis of the biosphere; a study of the physical process of the water cycle over land; a study of air-sea interaction; and higher-order processing of earth observation information. In recognition of the international nature of satellite data, as well as the capabilities of Canada and Japan in computer, communication, and multimedia technologies, bilateral cooperation is proposed in the area of earth environment information systems based on satellite observation

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

International Nuclear Information System (INIS)

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

2009-01-01

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

ISS External Contamination Environment for Space Science Utilization

Science.gov (United States)

Soares, Carlos; Mikatarian, Ron; Steagall, Courtney; Huang, Alvin; Koontz, Steven; Worthy, Erica

2014-01-01

(1) The International Space Station is the largest and most complex on-orbit platform for space science utilization in low Earth orbit, (2) Multiple sites for external payloads, with exposure to the associated natural and induced environments, are available to support a variety of space science utilization objectives, (3) Contamination is one of the induced environments that can impact performance, mission success and science utilization on the vehicle, and (4)The ISS has been designed, built and integrated with strict contamination requirements to provide low levels of induced contamination on external payload assets.

A Cis-Lunar Propellant Infrastructure for Flexible Path Exploration and Space Commerce

Science.gov (United States)

Oeftering, Richard C.

2012-01-01

This paper describes a space infrastructure concept that exploits lunar water for propellant production and delivers it to users in cis-lunar space. The goal is to provide responsive economical space transportation to destinations beyond low Earth orbit (LEO) and enable in-space commerce. This is a game changing concept that could fundamentally affect future space operations, provide greater access to space beyond LEO, and broaden participation in space exploration. The challenge is to minimize infrastructure development cost while achieving a low operational cost. This study discusses the evolutionary development of the infrastructure from a very modest robotic operation to one that is capable of supporting human operations. The cis-lunar infrastructure involves a mix of technologies including cryogenic propellant production, reusable lunar landers, propellant tankers, orbital transfer vehicles, aerobraking technologies, and electric propulsion. This cislunar propellant infrastructure replaces Earth-launched propellants for missions beyond LEO. It enables users to reach destinations with smaller launchers or effectively multiplies the user s existing payload capacity. Users can exploit the expanded capacity to launch logistics material that can then be traded with the infrastructure for propellants. This mutually beneficial trade between the cis-lunar infrastructure and propellant users forms the basis of in-space commerce.

El petróleo como repelente de Phlebotomus

Directory of Open Access Journals (Sweden)

Marshall Hertig

1943-09-01

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

Morfometria testicular de cabritos alimentados com óleo de licuri (Syagrus coronata

Directory of Open Access Journals (Sweden)

L.P. Barbosa

2012-08-01

Full Text Available Determinou-se o desenvolvimento testicular de caprinos pré-púberes alimentados com óleo de licuri (Syagrus coronata na dieta. Foram utilizados 19 cabritos ¾ Boer, recém-desmamados, com média de idade de três meses. Os animais, submetidos a um período de 75 dias de confinamento, receberam alimentação composta por: farelo de milho, farelo de soja, feno picado de tifton 85 e de óleo de licuri com base na matéria seca. Os animais foram distribuídos em quatro grupos: sem lipídio adicional (n= 5; com 1,5% de óleo de licuri (n= 5; com 3,0% de óleo de licuri (n= 5; e com 4,5% de óleo de licuri (n= 4. As avaliações de peso corporal e de biometria testicular foram realizadas quinzenalmente. Após o período de confinamento, os animais foram abatidos para determinação do peso dos testículos, peso dos epidídimos e índice gonadossomático. A adição de óleo de licuri em até 4,5% na dieta de caprinos pré-púberes não alterou o desenvolvimento testicular com base nas características da biometria e morfometria testicular, indicando que a inclusão de até 4,5% de óleo de licuri na dieta pode ser utilizada.

AIR MEETS SPACE: SHAPING THE FUTURE OF COMMERCIAL SPACE TRAFFIC: I. STUDY INTRODUCTION AND INITIAL RESULTS

OpenAIRE

Tüllmann, Ralph; Arbinger, Christian; Baskcomb, Stuart; Berdermann, Jens; Fiedler, Hauke; Klock, Erich; Schildknecht, Thomas

2016-01-01

There are high expectations for a globally growing market of commercial space travel which is likely to turn in the next 10 to 20 years into a multi-billion Euro business. Those growth expectations are also backed up by OneWeb’s order of about 700 small satellites which are likely to be brought into LEO via air launches and by a continuously growing LEO launch rate showing an increase of about 60% in the last decade. Advances in electric propulsion and spacecraft design (CubeSats) hel...

Space Analogue Environments: Are the Populations Comparable?

Science.gov (United States)

Sandal, G. M.

Background: Much of our present understanding about psychology in space is based on studies of groups operating in so-called analogue environments where personnel are exposed to many of the same stressors as those experienced by astronauts in space. One possible problem with extrapolating results is that personnel operating in various hazardous and confined environments might differ in characteristics influencing coping, interaction, and performance. The object of this study was to compare the psychological similarity of these populations in order to get a better understanding of whether this extrapolation is justifiable. The samples investigated include polar crossings (N= 22), personnel on Antarctic research stations (N= 183), several military occupations (N= 187), and participants in space simulation studies (N=20). Methods: Personnel in each of these environments were assessed using the Personality Characteristic Inventory (PCI) and Utrecht Coping List (UCL). The PCI is a multidimensional trait assessment battery that measures various aspects of achievement orientation and social competence. The UCL is a questionnaire designed to assess habitual coping strategies when encountering stressful or demanding situations. Results: Only minor differences in use of habitual coping strategies were evident across the different samples. In relation to personality scores, the military subjects and participants in space simulation studies indicated higher competitiveness and negative instrumentality compared to both the personnel on Antarctic research stations and participants in polar expedition. Among the personnel on Antarctic research stations, significant gender differences were found with women scoring lower on competitiveness, negative instrumentality and impatience/irritability. Compared to the other samples, the participants in polar expeditions were found to be more homogeneous in personality and no significant gender differences were evident on the traits that

Research on the Design of Public Space Environment for Aging Society

Science.gov (United States)

Fang, Gu; Soo, Kim Chul

2018-03-01

This paper studies the living space environment suitable for the elderly, because the elderly and the disabled have become increasingly prominent social problems. Through the discussion of the humanistic environment design method of the elderly and the disabled, the paper puts forward a new environment design which has the traditional characteristics and adapts to the new society to care for the elderly (the disabled).By studying and analyzing the background of social aging, the theory of public space environment design and the needs of the elderly, it is pointed out that the design of public space environment in the aged society needs to be implemented in detail design. The number of elderly people in public space will increase, give full attention to the public space outdoor environment quality, for the elderly to provide a variety of environmental facilities have long-term significance.

Overview of the MISSE 7 Polymers and Zenith Polymers Experiments After 1.5 Years of Space Exposure

Science.gov (United States)

Yi, Grace T.; de Groh, Kim K.; Banks, Bruce A.; Haloua, Athena; Imka, Emily C.; Mitchell, Gianna G.

2013-01-01

As part of the Materials International Space Station Experiment 7 (MISSE 7), two experiments called the Polymers Experiment and the Zenith Polymers Experiment were flown on the exterior of the International Space Station (ISS) and exposed to the low Earth orbit (LEO) space environment for 1.5 years. The Polymers Experiment contained 47 samples, which were flown in a ram or wake flight orientation. The objectives of the Polymers Experiment were to determine the LEO atomic oxygen erosion yield (Ey, volume loss per incident oxygen atoms, given in cu cm/atom) of the polymers, and to determine if atomic oxygen erosion of high and low ash containing polymers is dependent on fluence. The Zenith Polymers Experiment was flown in a zenith flight orientation. The primary objective of the Zenith Polymers Experiment was to determine the effect of solar exposure on the erosion of fluoropolymers. Kapton H (DuPont, Wilmington, DE) was flown in each experiment for atomic oxygen fluence determination. This paper provides an introduction to both the MISSE 7 Polymers Experiment and the MISSE 7 Zenith Polymers Experiment, and provides initial erosion yield results.

The Influence of Free Space Environment in the Mission Life Cycle: Material Selection

Science.gov (United States)

Edwards, David L.; Burns, Howard D.; de Groh, Kim K.

2014-01-01

The natural space environment has a great influence on the ability of space systems to perform according to mission design specification. Understanding the natural space environment and its influence on space system performance is critical to the concept formulation, design, development, and operation of space systems. Compatibility with the natural space environment is a primary factor in determining the functional lifetime of the space system. Space systems being designed and developed today are growing in complexity. In many instances, the increased complexity also increases its sensitivity to space environmental effects. Sensitivities to the natural space environment can be tempered through appropriate design measures, material selection, ground processing, mitigation strategies, and/or the acceptance of known risks. The design engineer must understand the effects of the natural space environment on the space system and its components. This paper will discuss the influence of the natural space environment in the mission life cycle with a specific focus on the role of material selection.

BAVP: Blockchain-Based Access Verification Protocol in LEO Constellation Using IBE Keys

Directory of Open Access Journals (Sweden)

Songjie Wei

2018-01-01

Full Text Available LEO constellation has received intensive research attention in the field of satellite communication. The existing centralized authentication protocols traditionally used for MEO/GEO satellite networks cannot accommodate LEO satellites with frequent user connection switching. This paper proposes a fast and efficient access verification protocol named BAVP by combining identity-based encryption and blockchain technology. Two different key management schemes with IBE and blockchain, respectively, are investigated, which further enhance the authentication reliability and efficiency in LEO constellation. Experiments on OPNET simulation platform evaluate and demonstrate the effectiveness, reliability, and fast-switching efficiency of the proposed protocol. For LEO networks, BAVP surpasses the well-known existing solutions with significant advantages in both performance and scalability which are supported by theoretical analysis and simulation results.

Passivation Strategies on Board Airbus ds Leo Pcdus

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Lapeña Emilio

2017-01-01

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

Three Canted Radiator Panels to Provide Adequate Cooling for Instruments on Slewing Spacecraft in LEO

Science.gov (United States)

Choi, Michael K.

2012-01-01

Certain free-flying spacecraft in low Earth orbit (LEO) or payloads on the International Space Station (ISS) are required to slew to point the telescopes at targets. Instrument detectors and electronics require cooling. Traditionally a planar thermal radiator is used. The temperature of such a radiator varies significantly when the spacecraft slews because its view factors to space vary significantly. Also for payloads on the ISS, solar impingement on the radiator is possible. These thermal adversities could lead to inadequate cooling for the instrument. This paper presents a novel thermal design concept that utilizes three canted radiator panels to mitigate this problem. It increases the overall radiator view factor to cold space and reduces the overall solar or albedo flux absorbed per unit area of the radiator.

Refinação de óleos vegetais e fracionamento contínuo de óleo de Palma

OpenAIRE

Mota, Daniel Santos

2016-01-01

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

Concept for an International Standard related to Space Weather Effects on Space Systems

Science.gov (United States)

Tobiska, W. Kent; Tomky, Alyssa

There is great interest in developing an international standard related to space weather in order to specify the tools and parameters needed for space systems operations. In particular, a standard is important for satellite operators who may not be familiar with space weather. In addition, there are others who participate in space systems operations that would also benefit from such a document. For example, the developers of software systems that provide LEO satellite orbit determination, radio communication availability for scintillation events (GEO-to-ground L and UHF bands), GPS uncertainties, and the radiation environment from ground-to-space for commercial space tourism. These groups require recent historical data, current epoch specification, and forecast of space weather events into their automated or manual systems. Other examples are national government agencies that rely on space weather data provided by their organizations such as those represented in the International Space Environment Service (ISES) group of 14 national agencies. Designers, manufacturers, and launchers of space systems require real-time, operational space weather parameters that can be measured, monitored, or built into automated systems. Thus, a broad scope for the document will provide a useful international standard product to a variety of engineering and science domains. The structure of the document should contain a well-defined scope, consensus space weather terms and definitions, and internationally accepted descriptions of the main elements of space weather, its sources, and its effects upon space systems. Appendices will be useful for describing expanded material such as guidelines on how to use the standard, how to obtain specific space weather parameters, and short but detailed descriptions such as when best to use some parameters and not others; appendices provide a path for easily updating the standard since the domain of space weather is rapidly changing with new advances

Teamwork in high-risk environments analogous to space

Science.gov (United States)

Kanki, Barbara G.

1990-01-01

Mountaineering expeditions combine a number of factors which make them potentially good analogs to the planetary exploration facet of long-duration space missions. A study of mountain climbing teams was conducted in order to evaluate the usefulness of the environment as a space analog and to specifically identify the factors and issues surrounding teamwork and 'successful' team performance in two mountaineering environments. This paper focuses on social/organizational factors, including team size and structure, leadership styles and authority structure which were found in the sample of 22 climb teams (122 individuals). The second major issue discussed is the construction of a valid performance measure in this high-risk environment.

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

Index Scriptorium Estoniae

Kunnas, Leo, 1967-

2006-01-01

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

Simulating cosmic radiation absorption and secondary particle production of solar panel layers of Low Earth Orbit (LEO) satellite with GEANT4

Science.gov (United States)

Yiǧitoǧlu, Merve; Veske, Doǧa; Nilüfer Öztürk, Zeynep; Bilge Demirköz, Melahat

2016-07-01

All devices which operate in space are exposed to cosmic rays during their operation. The resulting radiation may cause fatal damages in the solid structure of devices and the amount of absorbed radiation dose and secondary particle production for each component should be calculated carefully before the production. Solar panels are semiconductor solid state devices and are very sensitive to radiation. Even a short term power cut-off may yield a total failure of the satellite. Even little doses of radiation can change the characteristics of solar cells. This deviation can be caused by rarer high energetic particles as well as the total ionizing dose from the abundant low energy particles. In this study, solar panels planned for a specific LEO satellite, IMECE, are analyzed layer by layer. The Space Environment Information System (SPENVIS) database and GEANT4 simulation software are used to simulate the layers of the panels. The results obtained from the simulation will be taken in account to determine the amount of radiation protection and resistance needed for the panels or to revise the design of the panels.

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

Science.gov (United States)

Männel, Benjamin; Rothacher, Markus

2017-08-01

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

The Living With a Star Space Environment Testbed Program

Science.gov (United States)

Barth, Janet; LaBel, Kenneth; Day, John H. (Technical Monitor)

2001-01-01

NASA has initiated the Living with a Star (LWS) Program to develop the scientific understanding to address the aspects of the Connected Sun-Earth system that affects life and society. The Program Architecture includes science missions, theory and modeling and Space Environment Testbeds (SET). This current paper discusses the Space Environment Testbeds. The goal of the SET program is to improve the engineering approach to accomodate and/or mitigate the effects of solar variability on spacecraft design and operations. The SET Program will infuse new technologies into the space programs through collection of data in space and subsequent design and validation of technologies. Examples of these technologies are cited and discussed.

Living with a Star Space Environment Testbed

Science.gov (United States)

Barth, Janet

2003-01-01

Summary of activities: (1) FYO1 NRA - Model development and data mining. (2) FY03 NRA - Flight investigations. (3) SET carrier development. (4) Study for accommodation of SET carrier to support advanced detectors. (5) Collaboration with other programs: LWS TR&T to maximize synergy between TR&T space environment research and SET space environment effects research. LWS Data System to optimize dissemination of SET data. NASA Electronic Parts and Packaging Program to leverage ground testing of technologies. Defense Threat Reduction Agency to leverage ground testing and common interests in advanced detectors. and Air Force Research Laboratory to leverage flight opportunities. (6) Education and Public Outreach.

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

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FENG Laiping

2017-05-01

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

The Erosion of Diamond and Highly Oriented Pyrolytic Graphite After 1.5 Years of Space Exposure

Science.gov (United States)

De Groh, Kim K.; Banks, Bruce A.

2018-01-01

Polymers and other oxidizable materials on the exterior of spacecraft in the low Earth orbit (LEO) space environment can be eroded due to reaction with atomic oxygen (AO). Therefore, in order to design durable spacecraft, it is important to know the LEO AO erosion yield (Ey, volume loss per incident oxygen atom) of materials susceptible to AO reaction. The Polymers Experiment was developed to determine the AO Ey of various polymers and other materials flown in ram and wake orientations in LEO. The experiment was flown as part of the Materials International Space Station Experiment 7 (MISSE 7) mission for 1.5 years on the exterior of the International Space Station (ISS). As part of the experiment, a sample containing Class 2A diamond (100 plane) and highly oriented pyrolytic graphite (HOPG, basal and edge planes) was exposed to ram AO and characterized for erosion. The materials were salt-sprayed prior to flight to provide isolated sites of AO protection. The Ey of the samples was determined through post-flight electron microscopy recession depth measurements. The experiment also included a Kapton H witness sample for AO fluence determination. This paper provides an overview of the MISSE 7 mission, a description of the flight experiment, the characterization techniques used, the mission AO fluence, and the LEO Ey results for diamond and HOPG (basal and edge planes). The data is compared to the Ey of pyrolytic graphite exposed to four years of space exposure as part of the MISSE 2 mission. The results indicate that diamond erodes, but with a very low Ey of 1.58 +/- 0.04 x 10(exp -26) cm(exp 3)/atom. The different HOPG planes displayed significantly different amounts of erosion from each other. The HOPG basal plane had an Ey of 1.05 +/- 0.08 x 10(exp -24) cm(exp 3)/atom while the edge plane had a lower Ey of only 5.38 +/- 0.90 x 10(exp -25) -cm(exp 3)/atom. The Ey data from this ISS spaceflight experiment provides valuable information for understanding of chemistry

A New Method of Space Travel Optimized for Space Tourism and Colonization

Science.gov (United States)

Turek, Philip A.

2006-01-01

High costs associated with expendable rockets are stifling the development of permanent space colonies. A new method of space travel is presented that enjoys significantly increased performance and reduced cost relative to competing concepts. Based on recycling the kinetic energy of an arriving spacecraft, up to 200 MW of average electrical power is generated and sustained for 2 minutes, and is immediately applied in launching a departing partner spacecraft. The resulting required delta vee for a round trip between low Earth orbit (LEO) and geosynchronous orbit (GEO) drops from 7.6 km/s to 0.54 km/s when 3 recycling stations with an 80 % energy coupling efficiency are used to exchange kinetic energy between 8 partner spacecraft transiting the same route. This method is well suited for round trip high volume space travel such as space tourism traffic to LEO, lunar orbit, and beyond. As the kinetic energy of an arriving spacecraft is the power source for launching departing spacecraft, nascent lunar colonies can electrically launch 26,000 kg payloads long before sustained 100 MW level power supplies become locally available. A pair of recycling stations at an orbiting space colony construction site provides a resource of net impulse, net torque, and electrical power to the colony irrespective of the contents of the arriving payloads. Kinetic energy recycling technology, configuration, operations, and near Earth applications are described.

Óleos essenciais e vegetais no controle in vitro de Colletotrichum gloeosporioides

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K. RAMOS

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

Leo Tolstoy the Spiritual Educator

Science.gov (United States)

Moulin, Dan

2008-01-01

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

The Living With a Star Space Environment Testbed Experiments

Science.gov (United States)

Xapsos, Michael A.

2014-01-01

The focus of the Living With a Star (LWS) Space Environment Testbed (SET) program is to improve the performance of hardware in the space radiation environment. The program has developed a payload for the Air Force Research Laboratory (AFRL) Demonstration and Science Experiments (DSX) spacecraft that is scheduled for launch in August 2015 on the SpaceX Falcon Heavy rocket. The primary structure of DSX is an Evolved Expendable Launch Vehicle (EELV) Secondary Payload Adapter (ESPA) ring. DSX will be in a Medium Earth Orbit (MEO). This oral presentation will describe the SET payload.

A study of dynamical behavior of space environment

Science.gov (United States)

Wu, S. T.

1974-01-01

Studies have covered a wide range of problems in the space environment, such as the problems of the dynamical behavior of the thermosphere, hydromagnetic wave propagation in the ionosphere, and interplanetary space environment. The theories used to analyze these problems range from a continuum theory of magnetohydrodynamics to the kinetic theory of free molecular flow. This is because the problems encountered covered the entire range of the Knudsen number (i.e., the ratio of mean free path to the characteristic length). Significant results are summarized.

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

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T. Reubelt

2003-01-01

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

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

Index Scriptorium Estoniae

Karpin, Leo, 1946-2014

2004-01-01

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

Implementation of National Space Policy on US Air Force End of Life Operations and Orbital Debris Mitigation

Science.gov (United States)

2012-06-01

Space Development and Test Directorate, Kirtland AFB, NM, 87117 Recent changes to US space policy regarding the execution of satellite End of Life ( EOL ...procedures have been driven by the rising significance of the orbital debris problem in Low Earth Orbit (LEO). Therefore current EOL plans are...considerations for writing operational EOL plans, with special applicability to military missions and focus on LEO satellites that are unable to relocate

Future In-Space Operations (FISO): A Working Group and Community Engagement

Science.gov (United States)

Thronson, Harley; Lester, Dan

2013-01-01

Long-duration human capabilities beyond low Earth orbit (LEO), either in support of or as an alternative to lunar surface operations, have been assessed at least since the late 1960s. Over the next few months, we will present short histories of concepts for long-duration, free-space human habitation beyond LEO from the end of the Apollo program to the Decadal Planning Team (DPT)/NASA Exploration Team (NExT), which was active in 1999 2000 (see Forging a vision: NASA s Decadal Planning Team and the origins of the Vision for Space Exploration , The Space Review, December 19, 2005). Here we summarize the brief existence of the Future In-Space Operations (FISO) working group in 2005 2006 and its successor, a telecon-based colloquium series, which we co-moderate.

Materials International Space Station Experiment (MISSE): Overview, Accomplishments and Future Needs

Science.gov (United States)

deGroh, Kim K.; Jaworske, Donald A.; Pippin, Gary; Jenkins, Philip P.; Walters, Robert J.; Thibeault, Sheila A.; Palusinski, Iwona; Lorentzen, Justin R.

2014-01-01

Materials and devices used on the exterior of spacecraft in low Earth orbit (LEO) are subjected to environmental threats that can cause degradation in material properties, possibly threatening spacecraft mission success. These threats include: atomic oxygen (AO), ultraviolet and x-ray radiation, charged particle radiation, temperature extremes and thermal cycling, micrometeoroid and debris impacts, and contamination. Space environmental threats vary greatly based on spacecraft materials, thicknesses and stress levels, and the mission environment and duration. For more than a decade the Materials International Space Station Experiment (MISSE) has enabled the study of the long duration environmental durability of spacecraft materials in the LEO environment. The overall objective of MISSE is to test the stability and durability of materials and devices in the space environment in order to gain valuable knowledge on the performance of materials in space, as well as to enable lifetime predictions of new materials that may be used in future space flight. MISSE is a series of materials flight experiments, which are attached to the exterior of the International Space Station (ISS). Individual experiments were loaded onto suitcase-like trays, called Passive Experiment Containers (PECs). The PECs were transported to the ISS in the Space Shuttle cargo bay and attached to, and removed from, the ISS during extravehicular activities (EVAs). The PECs were retrieved after one or more years of space exposure and returned to Earth enabling post-flight experiment evaluation. MISSE is a multi-organization project with participants from the National Aeronautics and Space Administration (NASA), the Department of Defense (DoD), industry and academia. MISSE has provided a platform for environmental durability studies for thousands of samples and numerous devices, and it has produced many tangible impacts. Ten PECs (and one smaller tray) have been flown, representing MISSE 1 through MISSE

Modeling of space environment impact on nanostructured materials. General principles

Science.gov (United States)

Voronina, Ekaterina; Novikov, Lev

2016-07-01

In accordance with the resolution of ISO TC20/SC14 WG4/WG6 joint meeting, Technical Specification (TS) 'Modeling of space environment impact on nanostructured materials. General principles' which describes computer simulation methods of space environment impact on nanostructured materials is being prepared. Nanomaterials surpass traditional materials for space applications in many aspects due to their unique properties associated with nanoscale size of their constituents. This superiority in mechanical, thermal, electrical and optical properties will evidently inspire a wide range of applications in the next generation spacecraft intended for the long-term (~15-20 years) operation in near-Earth orbits and the automatic and manned interplanetary missions. Currently, ISO activity on developing standards concerning different issues of nanomaterials manufacturing and applications is high enough. Most such standards are related to production and characterization of nanostructures, however there is no ISO documents concerning nanomaterials behavior in different environmental conditions, including the space environment. The given TS deals with the peculiarities of the space environment impact on nanostructured materials (i.e. materials with structured objects which size in at least one dimension lies within 1-100 nm). The basic purpose of the document is the general description of the methodology of applying computer simulation methods which relate to different space and time scale to modeling processes occurring in nanostructured materials under the space environment impact. This document will emphasize the necessity of applying multiscale simulation approach and present the recommendations for the choice of the most appropriate methods (or a group of methods) for computer modeling of various processes that can occur in nanostructured materials under the influence of different space environment components. In addition, TS includes the description of possible

COMPONENTES MINORITÁRIOS DO ÓLEO DE MAMONA (Ricinus comunnis L.

Directory of Open Access Journals (Sweden)

Elina Bastos Caramão

2007-12-01

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

EFEITO DE ÓLEOS ESSENCIAIS CÍTRICOS SOBRE Agrotis ipsilon (HUFNAGEL (LEPIDOPTERA:NOCTUIDAE

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Ingrid Schimidt Kaiser

2017-01-01

Full Text Available A utilização de plantas inseticidas é cada vez mais frequente no controle de pragas. As plantas podem produzir diferentes compostos com atividade inseticida. Os óleos essenciais destacam-se dentre estes compostos, possuindo diferentes modos de ação inseticida, podendo ser uma ferramenta útil no manejo integrado de pragas. O objetivo deste trabalho é avaliar o efeito de óleos essenciais cítricos e seu composto majoritário D-limonemo visando sua adoção como métodos alternativos de controle de Agrotis ipsilon (Hufnagel (Lepidoptera: Noctuidae. Para a realização do experimento foram utilizadas 50 lagartas de 1º ínstar por tratamento. Foram aplicados os óleos essenciais com auxilio do aerógrafo, sendo utilizado na concentração de 10% v v-1 para os óleos cítricos e o D-limoneno e para testemunha foi pulverizado água destilada. A avaliação foi realizada após 24, 48 e 72 horas verificando o número de lagartas mortas. Não foi observado efeito tóxico dos óleos essenciais cítricos e do D-limoneno sobre as lagartas de A. ipsilon. Deste modo, os óleos essenciais testados não são eficazes no controle da praga.

Study of LEO-SAT microwave link for broad-band mobile satellite communication system

Science.gov (United States)

Fujise, Masayuki; Chujo, Wataru; Chiba, Isamu; Furuhama, Yoji; Kawabata, Kazuaki; Konishi, Yoshihiko

1993-01-01

In the field of mobile satellite communications, a system based on low-earth-orbit satellites (LEO-SAT's) such as the Iridium system has been proposed. The LEO-SAT system is able to offer mobile telecommunication services in high-latitude areas. Rain degradation, fading and shadowing are also expected to be decreased when the system is operated at a high elevation angle. Furthermore, the propagation delay generated in the LEO-SAT system is less pronounced than that in the geostationary orbit satellite (GEO-SAT) system and, in voice services, the effect of the delay is almost negligible. We proposed a concept of a broad-band mobile satellite communication system with LEO-SAT's and Optical ISL. In that system, a fixed L-band (1.6/1.5 GHz) multibeam is used to offer narrow band service to the mobile terminals in the entire area covered by a LEO-SAT and steerable Ka-band (30/20 GHz) spot beams are used for the wide band service. In this paper, we present results of a study of LEO-SAT microwave link between a satellite and a mobile terminal for a broad-band mobile satellite communication system. First, the results of link budget calculations are presented and the antennas mounted on satellites are shown. For a future mobile antenna technology, we also show digital beamforming (DBF) techniques. DBF, together with modulation and/or demodulation, is becoming a key technique for mobile antennas with advanced functions such as antenna pattern calibration, correction, and radio interference suppression. In this paper, efficient DBF techniques for transmitting and receiving are presented. Furthermore, an adaptive array antenna system suitable for this LEO-SAT is presented.

Carbon fiber CVD coating by carbon nanostructured for space materials protection against atomic oxygen

Science.gov (United States)

Pastore, Roberto; Bueno Morles, Ramon; Micheli, Davide

2016-07-01

In recent years, the emphasis in space research has been shifting from space exploration to commercialization of space. In order to utilize space for commercial purposes it is necessary to understand the low earth orbit (LEO) space environment where most of the activities will be carried out. The studies on the LEO environment are mainly focused towards understanding the effect of atomic oxygen (AO) on spacecraft materials. In the first few shuttle flights, materials looked frosty because they were actually being eroded and textured: AO reacts with organic materials on spacecraft exteriors, gradually damaging them. When a spacecraft travel in LEO (where crewed vehicles and the International Space Station fly), the AO formed from the residual atmosphere can react with the spacecraft surfaces, causing damage to the vehicle. Polymers are widely used in space vehicles and systems as structural materials, thermal blankets, thermal control coatings, conformal coatings, adhesives, lubricants, etc. Exposure of polymers and composites to the space environment may result in different detrimental effects via modification of their chemical, electrical, thermal, optical and mechanical properties as well as surface erosion. The major degradation effects in polymers are due to their exposure to atomic oxygen, vacuum ultraviolet and synergistic effects, which result in different damaging effects by modification of the polymer's chemical properties. In hydrocarbon containing polymers the main AO effect is the surface erosion via chemical reactions and the release of volatile reaction products associated with the mass loss. The application of a thin protective coating to the base materials is one of the most commonly used methods of preventing AO degradation. The purpose is to provide a barrier between base material and AO environment or, in some cases, to alter AO reactions to inhibit its diffusion. The effectiveness of a coating depends on its continuity, porosity, degree of

POLIURETANOS BASEADOS EM ÓLEO DE MAMONA

Directory of Open Access Journals (Sweden)

Heliberto José Limberger

2013-12-01

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

The near coastal environment monitored from space

International Nuclear Information System (INIS)

Szekielda, K.H.

1977-01-01

The optical information required for monitoring the marine environment from space is discussed and applied for the near coastal area. By categorizing coastal features it is possible to recognize coastal regions to a high degree and to indentify water masses derived from land sources and sewage dumping sites. It is concluded that monitoring from space can be used as a tool in environmental planning. (orig.) [de

Eestikeelseid filosoofiaraamatuid oodates / Leo Luks, Margus Ott

Index Scriptorium Estoniae

Luks, Leo, 1976-

2016-01-01

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

Space Weather Impacts on Spacecraft Operations: Identifying and Establishing High-Priority Operational Services

Science.gov (United States)

Lawrence, G.; Reid, S.; Tranquille, C.; Evans, H.

2013-12-01

Space Weather is a multi-disciplinary and cross-domain system defined as, 'The physical and phenomenological state of natural space environments. The associated discipline aims, through observation, monitoring, analysis and modelling, at understanding and predicting the state of the Sun, the interplanetary and planetary environments, and the solar and non-solar driven perturbations that affect them, and also at forecasting and nowcasting the potential impacts on biological and technological systems'. National and Agency-level efforts to provide services addressing the myriad problems, such as ESA's SSA programme are therefore typically complex and ambitious undertakings to introduce a comprehensive suite of services aimed at a large number and broad range of end users. We focus on some of the particular threats and risks that Space Weather events pose to the Spacecraft Operations community, and the resulting implications in terms of User Requirements. We describe some of the highest-priority service elements identified as being needed by the Operations community, and outline some service components that are presently available, or under development. The particular threats and risks often vary according to orbit, so the particular User Needs for Operators at LEO, MEO and GEO are elaborated. The inter-relationship between these needed service elements and existing service components within the broader Space Weather domain is explored. Some high-priority service elements and potential correlation with Space Weather drivers include: solar array degradation and energetic proton storms; single event upsets at GEO and solar proton events and galactic cosmic rays; surface charging and deep dielectric charging at MEO and radiation belt dynamics; SEUs at LEO and the South Atlantic Anomaly and its variability. We examine the current capability to provide operational services addressing such threats and identify some advances that the Operations community can expect to benefit

USA Space Debris Environment, Operations, and Research Updates

Science.gov (United States)

Liou, J.-C.

2018-01-01

) assessment for the Joint Polar Satellite System (JPSS) provided the following findings - Millimeter-sized orbital debris pose the highest penetration risk to most operational spacecraft in LEO - The most effective means to collect direct measurement data on millimetersized debris above 600 km altitude is to conduct in situ measurements - There is currently no in situ data on such small debris above 600 km altitude Since the orbital debris population follows a power-law size distribution, there are many more millimeter-sized debris than the large tracked objects - Current conjunction assessments and collision avoidance maneuvers against the tracked objects (which are typically 10 cm and larger) only address a small fraction (<1%) of the mission-ending risk from orbital debris To address the millimeter-sized debris data gap above 600 km, NASA has recently developed an innovative in situ measurement instrument - the Space Debris Sensor (SDS) - One maneuver was conducted to avoid the ISS

The Living With a Star Program Space Environment Testbed

Science.gov (United States)

Barth, Janet; Day, John H. (Technical Monitor)

2001-01-01

This viewgraph presentation describes the objective, approach, and scope of the Living With a Star (LWS) program at the Marshall Space Flight Center. Scientists involved in the project seek to refine the understanding of space weather and the role of solar variability in terrestrial climate change. Research and the development of improved analytic methods have led to increased predictive capabilities and the improvement of environment specification models. Specifically, the Space Environment Testbed (SET) project of LWS is responsible for the implementation of improved engineering approaches to observing solar effects on climate change. This responsibility includes technology development, ground test protocol development, and the development of a technology application model/engineering tool.

Desempenho na barra de tração de um trator agrícola de pneus, alimentado com misturas de óleo diesel e óleo de soja reutilizado

Directory of Open Access Journals (Sweden)

Wagner da Cunha Siqueira

2013-12-01

Full Text Available O petróleo é a principal fonte de energia para motores de combustão interna, possibilitando sua transformação em energia mecânica. A dependência do petróleo conduz à necessidade de alternativas, mediante o cultivo de matérias-primas renováveis. Os problemas atuais são os custos dos biocombustíveis, que são maiores que dos derivados do petróleo, e o fato de que não existem muitos motores de combustão adequados ao uso de óleos vegetais. Em vista disso, são necessárias mais investigações quanto às técnicas de produção e de refino dos biocombustíveis e, ainda, à adequação de motores ao uso de óleos vegetais, para que estes possam ser uma alternativa viável. O objetivo deste trabalho foi caracterizar as diferentes misturas e avaliar o desempenho de um trator agrícola de pneus, utilizando misturas de óleo Diesel (OD com óleo de soja reutilizável (OSR. Primeiramente, foi realizado um estudo de densidade, viscosidade das misturas e comportamento da temperatura do OD no sistema de alimentação de combustível no motor. Após as análises, verificou-se, por meio de ensaios na barra de tração, o desempenho das misturas de OD e OSR. As principais conclusões deste trabalho foram: a densidade e viscosidade das misturas sofrem variações com o aumento da quantidade de OSR e com a variação da temperatura. Para as avaliações na barra de tração, os melhores resultados observados no rendimento do trator foram verificados com o aumento das percentagens de mistura (25% OSR, para carga N, 25, 75 e 100% OSR, para a quarta marcha, como carga, e 75 e 100% OSR, para a terceira, segunda e primeira marcha, como carga.

Analysis of the Thermo-Elastic Response of Space Reflectors to Simulated Space Environment

Science.gov (United States)

Allegri, G.; Ivagnes, M. M.; Marchetti, M.; Poscente, F.

2002-01-01

The evaluation of space environment effects on materials and structures is a key matter to develop a proper design of long duration missions: since a large part of satellites operating in the earth orbital environment are employed for telecommunications, the development of space antennas and reflectors featured by high dimensional stability versus space environment interactions represents a major challenge for designers. The structural layout of state of the art space antennas and reflectors is very complex, since several different sensible elements and materials are employed: particular care must be placed in evaluating the actual geometrical configuration of the reflectors operating in the space environment, since very limited distortions of the designed layout can produce severe effects on the quality of the signal both received and transmitted, especially for antennas operating at high frequencies. The effects of thermal loads due to direct sunlight exposition and to earth and moon albedo can be easily taken into account employing the standard methods of structural analysis: on the other hand the thermal cycling and the exposition to the vacuum environment produce a long term damage accumulation which affects the whole structure. The typical effects of the just mentioned exposition are the outgassing of polymeric materials and the contamination of the exposed surface, which can affect sensibly the thermo-mechanical properties of the materials themselves and, therefore, the structural global response. The main aim of the present paper is to evaluate the synergistic effects of thermal cycling and of the exposition to high vacuum environment on an innovative antenna developed by Alenia Spazio S.p.a.: to this purpose, both an experimental and numerical research activity has been developed. A complete prototype of the antenna has been exposed to the space environment simulated by the SAS facility: this latter is constituted by an high vacuum chamber, equipped by

Fictional space in participatory design of engaging interactive environments

DEFF Research Database (Denmark)

Dindler, Christian

2010-01-01

practices of visitors and museum knowledge. The second and larger part of the contribution addresses the issue of shaping design inquiries. This part is summarized through the overarching notion of fictional space denoting a perspective on the creation of a design space where established norms...... spaces for museums and science centres. The dissertation is composed of seven research papers framed by a general overview that summarises the arguments made in the papers and outlines related work and research method. The contribution reflects a dual yet intertwined concern for understanding engagement...... in exhibition spaces and shaping design inquiries around the notion of engaging interactive environments. The first part of the contribution relates to conceptualising aspects of engagement in relation to interactive environments. The perspective of participatory engagement is presented as an overarching...

Martian Feeling: An Analogue Study to Simulate a Round-Trip to Mars using the International Space Station

Science.gov (United States)

Felix, C. V.; Gini, A.

When talking about human space exploration, Mars missions are always present. It is clear that sooner or later, humanity will take this adventure. Arguably the most important aspect to consider for the success of such an endeavour is the human element. The safety of the crew throughout a Martian mission is a top priority for all space agencies. Therefore, such a mission should not take place until all the risks have been fully understood and mitigated. A mission to Mars presents unique human and technological challenges in terms of isolation, confinement, autonomy, reliance on mission control, communication delays and adaptation to different gravity levels. Analogue environments provide the safest way to simulate these conditions, mitigate the risks and evaluate the effects of long-term space travel on the crew. Martian Feeling is one of nine analogue studies, from the Mars Analogue Path (MAP) report [1], proposed by the TP Analogue group of ISU Masters class 2010. It is an integrated analogue study which simulates the psychological, physiological and operational conditions that an international, six-person, mixed gender crew would experience on a mission to Mars. Set both onboard the International Space Station (ISS) and on Earth, the Martian Feeling study will perform a ``dress rehearsal'' of a mission to Mars. The study proposes to test both human performance and operational procedures in a cost-effective manner. Since Low Earth Orbit (LEO) is more accessible than other space-based locations, an analogue studies in LEO would provide the required level of realism to a simulated transit mission to Mars. The sustained presence of microgravity and other elements of true spaceflight are features of LEO that are neither currently feasible nor possible to study in terrestrial analogue sites. International collaboration, economics, legal and ethical issues were considered when the study was proposed. As an example of international collaboration, the ISS would

Space Radiation: The Number One Risk to Astronaut Health beyond Low Earth Orbit

Science.gov (United States)

Chancellor, Jeffery C.; Scott, Graham B. I.; Sutton, Jeffrey P.

2014-01-01

Projecting a vision for space radiobiological research necessitates understanding the nature of the space radiation environment and how radiation risks influence mission planning, timelines and operational decisions. Exposure to space radiation increases the risks of astronauts developing cancer, experiencing central nervous system (CNS) decrements, exhibiting degenerative tissue effects or developing acute radiation syndrome. One or more of these deleterious health effects could develop during future multi-year space exploration missions beyond low Earth orbit (LEO). Shielding is an effective countermeasure against solar particle events (SPEs), but is ineffective in protecting crew members from the biological impacts of fast moving, highly-charged galactic cosmic radiation (GCR) nuclei. Astronauts traveling on a protracted voyage to Mars may be exposed to SPE radiation events, overlaid on a more predictable flux of GCR. Therefore, ground-based research studies employing model organisms seeking to accurately mimic the biological effects of the space radiation environment must concatenate exposures to both proton and heavy ion sources. New techniques in genomics, proteomics, metabolomics and other “omics” areas should also be intelligently employed and correlated with phenotypic observations. This approach will more precisely elucidate the effects of space radiation on human physiology and aid in developing personalized radiological countermeasures for astronauts. PMID:25370382

Space Radiation: The Number One Risk to Astronaut Health beyond Low Earth Orbit

Directory of Open Access Journals (Sweden)

Jeffery C. Chancellor

2014-09-01

Full Text Available Projecting a vision for space radiobiological research necessitates understanding the nature of the space radiation environment and how radiation risks influence mission planning, timelines and operational decisions. Exposure to space radiation increases the risks of astronauts developing cancer, experiencing central nervous system (CNS decrements, exhibiting degenerative tissue effects or developing acute radiation syndrome. One or more of these deleterious health effects could develop during future multi-year space exploration missions beyond low Earth orbit (LEO. Shielding is an effective countermeasure against solar particle events (SPEs, but is ineffective in protecting crew members from the biological impacts of fast moving, highly-charged galactic cosmic radiation (GCR nuclei. Astronauts traveling on a protracted voyage to Mars may be exposed to SPE radiation events, overlaid on a more predictable flux of GCR. Therefore, ground-based research studies employing model organisms seeking to accurately mimic the biological effects of the space radiation environment must concatenate exposures to both proton and heavy ion sources. New techniques in genomics, proteomics, metabolomics and other “omics” areas should also be intelligently employed and correlated with phenotypic observations. This approach will more precisely elucidate the effects of space radiation on human physiology and aid in developing personalized radiological countermeasures for astronauts.

The Living With a Star Space Environment Testbed Payload

Science.gov (United States)

Xapsos, Mike

2015-01-01

This presentation outlines a brief description of the Living With a Star (LWS) Program missions and detailed information about the Space Environment Testbed (SET) payload consisting of a space weather monitor and carrier containing 4 board experiments.

Near-Space Microwave Radar Remote Sensing: Potentials and Challenge Analysis

Directory of Open Access Journals (Sweden)

Qicong Peng

2010-03-01

Full Text Available Near-space, defined as the region between 20 km and 100 km, offers many new capabilities that are not accessible to low earth orbit (LEO satellites and airplanes, because it is above storm and not constrained by either the orbital mechanics of satellites or the high fuel consumption of airplanes. By placing radar transmitter/receiver in near-space platforms, many functions that are currently performed with satellites or airplanes could be performed in a cheaper way. Inspired by these advantages, this paper introduces several near-space vehicle-based radar configurations, such as near-space passive bistatic radar and high-resolution wide-swath (HRWS synthetic aperture radar (SAR. Their potential applications, technical challenges and possible solutions are investigated. It is shown that near-space is a satisfactory solution to some specific remote sensing applications. Firstly, near-space passive bistatic radar using opportunistic illuminators offers a solution to persistent regional remote sensing, which is particularly interest for protecting homeland security or monitoring regional environment. Secondly, near-space provides an optimal solution to relative HRWS SAR imaging. Moreover, as motion compensation is a common technical challenge for the described radars, an active transponder-based motion compensation is also described.

Radiation Effects in the Space Telecommunications Environment

Energy Technology Data Exchange (ETDEWEB)

Fleetwood, Daniel M.; Winokur, Peter S.

1999-05-17

Trapped protons and electrons in the Earth's radiation belts and cosmic rays present significant challenges for electronics that must operate reliably in the natural space environment. Single event effects (SEE) can lead to sudden device or system failure, and total dose effects can reduce the lifetime of a telecommmiications system with significant space assets. One of the greatest sources of uncertainty in developing radiation requirements for a space system is accounting for the small but finite probability that the system will be exposed to a massive solar particle event. Once specifications are decided, standard laboratory tests are available to predict the total dose response of MOS and bipolar components in space, but SEE testing of components can be more challenging. Prospects are discussed for device modeling and for the use of standard commercial electronics in space.

Radiation Effects in the Space Telecommunications Environment

International Nuclear Information System (INIS)

Fleetwood, Daniel M.; Winokur, Peter S.

1999-01-01

Trapped protons and electrons in the Earth's radiation belts and cosmic rays present significant challenges for electronics that must operate reliably in the natural space environment. Single event effects (SEE) can lead to sudden device or system failure, and total dose effects can reduce the lifetime of a telecommmiications system with significant space assets. One of the greatest sources of uncertainty in developing radiation requirements for a space system is accounting for the small but finite probability that the system will be exposed to a massive solar particle event. Once specifications are decided, standard laboratory tests are available to predict the total dose response of MOS and bipolar components in space, but SEE testing of components can be more challenging. Prospects are discussed for device modeling and for the use of standard commercial electronics in space

The Effect of Dose Rate on Composite Durability When Exposed to a Simulated Long-Term Lunar Radiation Environment

Science.gov (United States)

Rojdev, Kristina; O'Rourke, Mary Jane; Hill, Charles; Nutt, Steven; Atwell, William

2011-01-01

Human exploration of space beyond low Earth orbit (LEO) requires a safe living and working environment for crew. Composite materials are one type of material being investigated by NASA as a multi-functional structural approach to habitats for long-term use in space or on planetary surfaces with limited magnetic fields and atmosphere. These materials provide high strength with the potential for decreased weight and increased radiation protection of crew and electronics when compared with conventional aluminum structures. However, these materials have not been evaluated in a harsh radiation environment, as would be experienced outside of LEO or on a planetary surface. Thus, NASA has been investigating the durability of select composite materials in a long-term radiation environment. Previously, NASA exposed composite samples to a simulated, accelerated 30-year radiation treatment and tensile stresses similar to those of a habitat pressure vessel. The results showed evidence of potential surface oxidation and enhanced cross-linking of the matrix. As a follow-on study, we performed the same accelerated exposure alongside an exposure with a decreased dose rate. The slower dose ]rate is comparable to a realistic scenario, although still accelerated. Strain measurements were collected during exposure and showed that with a fastdose rate, the strain decreased with time, but with a slow ]dose rate, the strain increased with time. After the radiation exposures, samples were characterized via tensile tests, flexure tests, Fourier Transform Infrared Spectroscopy (FTIR), and Differential Scanning Calorimetry (DSC). The results of these tests will be discussed.

Space Transportation Infrastructure Supported By Propellant Depots

Science.gov (United States)

Smitherman, David; Woodcock, Gordon

2012-01-01

A space transportation infrastructure is described that utilizes propellant depot servicing platforms to support all foreseeable missions in the Earth-Moon vicinity and deep space out to Mars. The infrastructure utilizes current expendable launch vehicle (ELV) systems such as the Delta IV Heavy, Atlas V, and Falcon 9, for all crew, cargo, and propellant launches to orbit. Propellant launches are made to Low-Earth-Orbit (LEO) Depot and an Earth-Moon Lagrange Point 1 (L1) Depot to support a new reusable in-space transportation vehicles. The LEO Depot supports missions to Geosynchronous Earth Orbit (GEO) for satellite servicing and to L1 for L1 Depot missions. The L1 Depot supports Lunar, Earth-Sun L2 (ESL2), Asteroid and Mars Missions. New vehicle design concepts are presented that can be launched on current 5 meter diameter ELV systems. These new reusable vehicle concepts include a Crew Transfer Vehicle (CTV) for crew transportation between the LEO Depot, L1 Depot and missions beyond L1; a new reusable lunar lander for crew transportation between the L1 Depot and the lunar surface; and Mars orbital Depot are based on International Space Station (ISS) heritage hardware. Data provided includes the number of launches required for each mission utilizing current ELV systems (Delta IV Heavy or equivalent) and the approximate vehicle masses and propellant requirements. Also included is a discussion on affordability with ideas on technologies that could reduce the number of launches required and thoughts on how this infrastructure include competitive bidding for ELV flights and propellant services, developments of new reusable in-space vehicles and development of a multiuse infrastructure that can support many government and commercial missions simultaneously.

Long-term behavior of stellar flare activity in AD Leo

International Nuclear Information System (INIS)

Pettersen, B.R.

1984-01-01

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

8-12 GHz Radio Observations of Flare Activity On M dwarf CN Leo

Science.gov (United States)

Wofford, Alia; Villadsen, Jackie; Quintana, Elisa; Barclay, Thomas; Thackeray, Beverly

2018-01-01

Red dwarfs are cool stars that make up 70% of all stars. Red dwarfs can be utilized to detect potentially habitable planets but they have particularly strong magnetic activity that can be detrimental to orbiting planets’ atmospheres and habitability. A coronal mass ejection (CME) is an eruption of magnetized plasma from the star that is ejected into the interplanetary medium which can erode a planet’s atmosphere daily. Based on the sun CMEs are expected to produce very bright radio bursts along with optical flares. We are using M dwarf CN Leo, a well studied flare star that was in the K2 campaign field in summer 2017, as a template to understand the relationship between radio and optical flares and the space weather conditions impacting M dwarf planets. Using radio frequencies ranging from 0.22 GHz-12 GHz we search for simultaneous radio bursts and optical flares to infer if CMEs, flares or aurorae are occurring on the star. I will present the 8-12 GHz radio data from eight 1.5-hour observations with simultaneous optical data. CN Leo produced a bright non-thermal radio flare that lasted approximately for a day during two consecutive observations, with a gyrosynchrotron emission mechanism.

Ionizing radiation risks to Satellite Power Systems (SPS) workers in space

Energy Technology Data Exchange (ETDEWEB)

1980-12-01

A reference Satellite Power System (SPS) has been designed by NASA and its contractors for the purposes of evaluating the concept and carrying out assessments of the various consequences of development, including those on the health of the space workers. The Department of Energy has responsibility for directing various assessments. Present planning calls for the SPS workers to move from Earth to a low earth orbit (LEO) at an altitude of 500 kilometers; to travel by a transfer ellipse (TE) trajectory to a geosynchronous orbit (GEO) at an altitude of 36,000 kilometers; and to remain in GEO orbit for about 90 percent of the total time aloft. The radiation risks to the health of workers who will construct and maintain solar power satellites in the space environment are studied. The charge to the committee was: (a) to evaluate the radiation environment estimated for the Reference System which could represent a hazard; (b) to assess the possible somatic and genetic radiation hazards; and (c) to estimate the risks to the health of SPS workers due to space radiation exposure, and to make recommendations based on these conclusions. Details are presented. (WHK)

Challenges for future space power systems

International Nuclear Information System (INIS)

Brandhorst, H.W. Jr.

1989-01-01

Forecasts of space power needs are presented. The needs fall into three broad categories: survival, self-sufficiency, and industrialization. The cost of delivering payloads to orbital locations and from Low Earth Orbit (LEO) to Mars are determined. Future launch cost reductions are predicted. From these projections the performances necessary for future solar and nuclear space power options are identified. The availability of plentiful cost effective electric power and of low cost access to space are identified as crucial factors in the future extension of human presence in space

Estudo experimental e de modelagem da fluidodinâmica de sistemas água/óleo

OpenAIRE

Fiorese, Eliana Kátia

2004-01-01

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Química Diversas operações e procedimentos na indústria do petróleo estão relacionados ao deslocamento imiscível de um fluido por outro, podendo-se citar: a elevação natural e artificial do óleo a partir dos poços, o bombeamento através de dutos de óleos de viscosidade elevada mediante a injeção conjunta de água e a recuperação secundária de petróleo. A eficiência de...

First laser measurements to space debris in Poland

Science.gov (United States)

Lejba, Paweł; Suchodolski, Tomasz; Michałek, Piotr; Bartoszak, Jacek; Schillak, Stanisław; Zapaśnik, Stanisław

2018-05-01

The Borowiec Satellite Laser Ranging station (BORL 7811, Borowiec) being a part of the Space Research Centre of the Polish Academy of Sciences (SRC PAS) went through modernization in 2014-2015. One of the main tasks of the modernization was the installation of a high-energy laser module dedicated to space debris tracking. Surelite III by Continuum is a Nd:YAG pulse laser with 10 Hz repetition rate, a pulse width of 3-5 ns and a pulse energy of 450 mJ for green (532 nm). This new laser unit was integrated with the SLR system at Borowiec performing standard satellite tracking. In 2016 BORL 7811 participated actively to the observational campaigns related to the space debris targets from LEO region managed by the Space Debris Study Group (SDSG) of the International Laser Ranging Service (ILRS). Currently, Borowiec station regularly tracks 36 space debris from the LEO regime, including typical rocket bodies (Russian/Chinese) and cooperative targets like the inactive TOPEX/Poseidon, ENVISAT, OICETS and others. In this paper the first results of space debris laser measurements obtained by the Borowiec station in period August 2016 - January 2017 are presented. The results gained by the SRC PAS Borowiec station confirm the rotation of the defunct TOPEX/Poseidon satellite which spins with a period of approximately 10 s. The novelty of this work is the presentation of the sample results of the Chinese CZ-2C R/B target (NORAD catalogue number 31114) which is equipped (probably) with retroreflectors. Laser measurements to space debris is a very desirable topic for the next years, especially in the context of the Space Surveillance and Tracking (SST) activity. Some targets are very easy to track like defunct ENVISAT or TOPEX/Poseidon. On the other hand, there is a big population of different LEO targets with different orbital and physical parameters, which are challenging for laser ranging like small irregular debris and rocket boosters.

Geocenter Motion Derived from GNSS and SLR Tracking Data of LEO

Science.gov (United States)

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

2017-12-01

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

Space Environment Effects on Materials at Different Positions and Operational Periods of ISS

Science.gov (United States)

Kimoto, Yugo; Ichikawa, Shoichi; Miyazaki, Eiji; Matsumoto, Koji; Ishizawa, Junichiro; Shimamura, Hiroyuki; Yamanaka, Riyo; Suzuki, Mineo

2009-01-01

A space materials exposure experiment was condcuted on the exterior of the Russian Service Module (SM) of the International Space Station (ISS) using the Micro-Particles Capturer and Space Environment Exposure Device (MPAC&SEED) of the Japan Aerospace Exploration Agency (JAXA). Results reveal artificial environment effects such as sample contamination, attitude change effects on AO fluence, and shading effects of UV on ISS. The sample contamination was coming from ISS components. The particles attributed to micrometeoroids and/or debris captured by MPAC might originate from the ISS solar array. Another MPAC&SEED will be aboard the Exposure Facility of the Japanese Experiment Module, KIBO Exposure Facility (EF) on ISS. The JEM/MPAC&SEED is attached to the Space Environment Data Acquisition Equipment-Attached Payload (SEDA-AP) and is exposed to space. Actually, SEDA-AP is a payload on EF to be launched by Space Shuttle flight 2J/A. In fact, SEDA-AP has space environment monitors such as a high-energy particle monitor, atomic oxygen monitor, and plasma monitor to measure in-situ natural space environment data during JEM/MPAC&SEED exposure. Some exposure samples for JEM/MPAC&SEED are identical to SM/MPAC&SEED samples. Consequently, effects on identical materials at different positions and operation periods of ISS will be evaluated. This report summarizes results from space environment monitoring samples for atomic oxygen analysis on SM/MPAC&SEED, along with experimental plans for JEM/MPAC&SEED.

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

Directory of Open Access Journals (Sweden)

Rosa Maria Souto de Sousa

2012-03-01

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

Thermally Induced Vibrations of the Hubble Space Telescope's Solar Array 3 in a Test Simulated Space Environment

Science.gov (United States)

Early, Derrick A.; Haile, William B.; Turczyn, Mark T.; Griffin, Thomas J. (Technical Monitor)

2001-01-01

NASA Goddard Space Flight Center and the European Space Agency (ESA) conducted a disturbance verification test on a flight Solar Array 3 (SA3) for the Hubble Space Telescope using the ESA Large Space Simulator (LSS) in Noordwijk, the Netherlands. The LSS cyclically illuminated the SA3 to simulate orbital temperature changes in a vacuum environment. Data acquisition systems measured signals from force transducers and accelerometers resulting from thermally induced vibrations of the SAI The LSS with its seismic mass boundary provided an excellent background environment for this test. This paper discusses the analysis performed on the measured transient SA3 responses and provides a summary of the results.

Potencial antifúngico e toxicidade de óleos essenciais da família lamiaceae

OpenAIRE

Rosema Santin

2013-01-01

Plantas medicinais e óleos essenciais representam um importante papel na terapêutica, tanto na cura como também na prevenção de diferentes enfermidades, sendo esta prática medicinal uma das mais antigas formas de tratamento. Devido à utilização dos óleos essenciais na terapêutica e a importância do conhecimento do pontencial de toxicidade destes, objetivou-se: (i) identificar os principais componentes químicos dos óleos essenciais de Origanum vulgare (orégano), Origanum majorana (manjerona) e...

Actividad anticaries de una crema dental con propóleos

OpenAIRE

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

2000-01-01

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

América Latina: petróleo y conflicto

Directory of Open Access Journals (Sweden)

Luis Humberto Hernández

2008-01-01

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

Optimization of application execution in the GridSpace environment

NARCIS (Netherlands)

Malawski, M.; Kocot, J.; Ryszka, I.; Bubak, M.; Wieczorek, M.; Fahringer, T.

2008-01-01

This paper describes an approach to optimization of execution of applications in the GridSpace environment. In this environment operations are invoked on special objects which reside on Grid resources what requires a specific approach to optimization of execution. This approach is implemented in the

Measuring the Earth’s Magnetic Field from Space

DEFF Research Database (Denmark)

Olsen, Nils; Hulot, G.; Sabaka, T. J.

2010-01-01

Observations of the Earth’s magnetic field from low-Earth orbiting (LEO) satellites started very early on, more than 50 years ago. Continuous such observations, relying on more advanced technology and mission concepts, have however only been available since 1999. The unprecedented time-space...... coverage of this recent data set opened revolutionary new possibilities for monitoring, understanding and exploring the Earth’s magnetic field. In the near future, the three-satellite Swarm constellation concept to be launched by ESA, will not only ensure continuity of such measurements, but also provide...... enhanced possibilities to improve on our ability to characterize and understand the many sources that produce this field. In the present paper we review and discuss the advantages and drawbacks of the various LEO space magnetometry concepts that have been used so far, and report on the motivations that led...

Efeito de enzimas hidrolíticas no comportamento reológico do óleo de palma cru

Directory of Open Access Journals (Sweden)

FREITAS Suely P.

1998-01-01

Full Text Available No processamento tradicional de extração de óleo de palma, uma quantidade substancial do produto é perdida na fibra - durante a etapa de prensagem do fruto - e na borra - durante a etapa de clarificação do óleo cru. A viscosidade deste constitui a principal dificuldade de separação do óleo dos demais componentes da mistura. A eficiência de recuperação do óleo é usualmente melhorada por adição de água, no tanque de clarificação. Neste trabalho avaliou-se os efeitos da diluição e do tratamento enzimático no comportamento reológico do óleo de palma cru. Estes dados são importantes para estimar a velocidade de separação do óleo nos tanques de clarificação e/ou nos decanters das usinas comerciais. O óleo cru utilizado neste estudo foi recolhido em uma unidade comercial sendo composto de 65% de água, 30% de óleo e 5% de sólidos. A hidrólise enzimática foi conduzida usando como agentes hidrolisantes uma enzima comercial (viscozyme da Novo Nordisk e um preparado enzimático produzido no CTAA. Pode-se constatar que quanto mais diluída a amostra maior é a redução na viscosidade após a hidrólise enzimática. Para uma taxa de deformação fixa em 6s-1, o tratamento enzimático do óleo cru a 60°C reduziu a viscosidade do mesmo em cerca de 29% enquanto a adição de 20% de água em cerca de 35%. A combinação da diluição com 20% de água seguida de tratamento enzimático reduziu a viscosidade do óleo cru em cerca de 75%.

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

OpenAIRE

Valéria da Silva Santos

2014-01-01

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

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

OpenAIRE

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

2016-01-01

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

Planetary and Space Simulation Facilities PSI at DLR for Astrobiology

Science.gov (United States)

Rabbow, E.; Rettberg, P.; Panitz, C.; Reitz, G.

2008-09-01

Ground based experiments, conducted in the controlled planetary and space environment simulation facilities PSI at DLR, are used to investigate astrobiological questions and to complement the corresponding experiments in LEO, for example on free flying satellites or on space exposure platforms on the ISS. In-orbit exposure facilities can only accommodate a limited number of experiments for exposure to space parameters like high vacuum, intense radiation of galactic and solar origin and microgravity, sometimes also technically adapted to simulate extraterrestrial planetary conditions like those on Mars. Ground based experiments in carefully equipped and monitored simulation facilities allow the investigation of the effects of simulated single environmental parameters and selected combinations on a much wider variety of samples. In PSI at DLR, international science consortia performed astrobiological investigations and space experiment preparations, exposing organic compounds and a wide range of microorganisms, reaching from bacterial spores to complex microbial communities, lichens and even animals like tardigrades to simulated planetary or space environment parameters in pursuit of exobiological questions on the resistance to extreme environments and the origin and distribution of life. The Planetary and Space Simulation Facilities PSI of the Institute of Aerospace Medicine at DLR in Köln, Germany, providing high vacuum of controlled residual composition, ionizing radiation of a X-ray tube, polychromatic UV radiation in the range of 170-400 nm, VIS and IR or individual monochromatic UV wavelengths, and temperature regulation from -20°C to +80°C at the sample size individually or in selected combinations in 9 modular facilities of varying sizes are presented with selected experiments performed within.

CARACTERIZAÇÃO QUÍMICA E ATIVIDADE MUTAGÊNICA DO ÓLEO ESSENCIAL DE Lippia alba

Directory of Open Access Journals (Sweden)

Thammyres de Assis Alves

2017-01-01

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

BAVP: Blockchain-Based Access Verification Protocol in LEO Constellation Using IBE Keys

OpenAIRE

Wei, Songjie; Li, Shuai; Liu, Peilong; Liu, Meilin

2018-01-01

LEO constellation has received intensive research attention in the field of satellite communication. The existing centralized authentication protocols traditionally used for MEO/GEO satellite networks cannot accommodate LEO satellites with frequent user connection switching. This paper proposes a fast and efficient access verification protocol named BAVP by combining identity-based encryption and blockchain technology. Two different key management schemes with IBE and blockchain, respectively...

Reading space characteristics in campus environment

Science.gov (United States)

Tampubolon, A. C.; Kusuma, H. E.

2018-03-01

Reading activity is a part of daily learning activities that are usually done by college students and takes place in the facilities that are provided by the campus. However, students tend to have a perception of a particular location that is considered appropriate with the activities undertaken. This study identified students’ perceptions of reading space characteristics in campus environment which are considered able to accommodate reading activity. Exploratory qualitative research methods were used to collect data from selected types of space and the reasons for the students in choosing the specifics space to do their reading. The results showed that students do not only use library facilities as a support unit of academic activities. This study found that students tend to use some places with non-library function, such as students’ union room, hallway, and classroom. Students perceive reading space by its physical and social characteristics. The physical consist of ambiance, quiet place, tranquility, availability of facilities, the level of coolness, lighting, location accessibility, connection with nature, convenience furniture, air quality, aesthetics, the flexibility of activities, the crowd of place, the level of shade, outdoor, ownership, and indoor. While the social characteristics of the reading space are to have privacy, favorable reading position, and the presence of others.

Rendimento e Características Físicas dos Óleos de Nim (Azadirachta indica e Mamona (Ricinus communis

Directory of Open Access Journals (Sweden)

Juarez Benigno Paes

Full Text Available A pesquisa objetivou avaliar o rendimento e a viscosidade de óleos de nim (Azadirachta indica e mamona (Ricinus communis. Os frutos de nim foram coletados no Núcleo de Pesquisa do Semiárido, em Patos, Paraíba, e os de mamona, às margens do Rio Espinharas, Patos e em Igaracy, Paraíba. Os frutos foram beneficiados no Laboratório de Tecnologia de Produtos Florestais, em Patos. Foram retiradas amostras de sementes para a determinação do teor de umidade e do rendimento em óleos. Os óleos foram extraídos com álcool etílico absoluto e empregados no preparo de soluções com os óleos de nim e mamona. Determinaram-se a densidade e a viscosidade das soluções. A mamona teve menor teor de umidade e rendimento em óleo que o nim. A densidade e a viscosidade do óleo de nim foram menores que o da mamona. Uma maior quantidade de óleos de mamona proporcionou aumento na densidade e na viscosidade das soluções preparadas.

The Star Formation History of the Local Group Dwarf Galaxy Leo I

Science.gov (United States)

Gallart, Carme; Freedman, Wendy L.; Aparicio, Antonio; Bertelli, Giampaolo; Chiosi, Cesare

1999-11-01

We present a quantitative analysis of the star formation history (SFH) of the Local Group dSph galaxy Leo I, from the information in its Hubble Space Telescope [(V-I),I] color-magnitude diagram (CMD). It reaches the level of the oldest main-sequence turnoffs, and this allows us to retrieve the SFH in considerable detail. The method we use is based on comparing, via synthetic CMDs, the expected distribution of stars in the CMD for different evolutionary scenarios with the observed distribution. We consider the SFH to be composed by the SFR(t), the chemical enrichment law Z(t), the initial mass function (IMF), and a function β(f,q) controlling the fraction f and mass ratio distribution q of binary stars. We analyze a set of ~=50 combinations of four Z(t), three IMFs, and more than four β(f,q). For each of them, the best SFR(t) is searched for among ~=6x107 models. The comparison between the observed CMD and the model CMDs is done through χ2ν minimization of the differences in the number of stars in a set of regions of the CMD, chosen to sample stars of different ages or in specific stellar evolutionary phases. We empirically determine the range of χ2ν values that indicate acceptable models for our set of data using tests with models with known SFHs. Our solution for the SFH of Leo I defines a minimum of χ2ν in a well-defined position of the parameter space, and the derived SFR(t) is robust, in the sense that its main characteristics are unchanged for different combinations of the remaining parameters. However, only a narrow range of assumptions for Z(t), IMF, and β(f,q) result in a good agreement between the data and the models, namely, Z=0.0004, a IMF Kroupa et al. or slightly steeper, and a relatively large fraction of binary stars, with f=0.3-0.6, q>0.6, and an approximately flat IMF for the secondaries, or particular combinations of these parameters that would produce a like fraction of similar mass binaries. Most star formation activity (70% to 80

Effect of LEO cycling on 125 Ah advanced design IPV nickel-hydrogen flight cells - An update

Science.gov (United States)

Smithrick, John J.; Hall, Stephen W.

1991-01-01

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

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

Science.gov (United States)

Smithrick, John J.; Hall, Stephen W.

1991-01-01

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

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

Science.gov (United States)

Smithrick, John J.; Hall, Stephen W.

1991-01-01

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

Public spaces and urban sustainability in the tropical built environment

Science.gov (United States)

Yusof, Y. M.; Kozlowski, M.

2018-01-01

Sustainability is an overarching sense of responsibility towards the future. On a city-wide level, urban sustainability incorporates a wide body of changes especially as they relate to the built environment, all of which intended at creating a livable place. This paper discusses existing public spaces in view of their achievement against a set of criteria for the built environment. The paper introduces performance design criteria for the tropical built environment. The key findings indicate that long-term strategies, guidance and directions for the city and region can achieve development which corresponds to local climate, synergies and provide a higher proportion of public spaces that offer something for everyone.

Estudo da composição química de gasóleos comerciais

OpenAIRE

Silva, Filipe Pereira e

2010-01-01

No presente trabalho foram estudadas a composição química em termos percentuais dos compostos PIONA (n-parafinas, isoparafinas, olefinas, naftenos e aromáticos) e algumas propriedades físicas de diferentes classes de gasóleos comerciais utilizados em veículos rodoviários e um gasóleo para aquecimento. O gasóleo, uma fracção do crude, é um composto de extrema complexidade com milhares de diferentes moléculas na sua composição. Dividem-se sobretudo em parafinas (alcanos) lineares ou ramifica...

The LEO PCDU EVO - A Modular and Flexible Concept for Low to Medium Power LEO & Scientific Missions

Directory of Open Access Journals (Sweden)

Lapeña Emilio

2017-01-01

Market trend towards volume & mass reduction, plus new required capabilities (in particular End of Life Passivation and Launch Off to support multiple launch justify the need for a new LEO PCDU EVO generation. This paper will deal with a simple question with no immediate answer: how to save 20% PCDU mass and volume while keeping or improving existing performances.

Can Telescopes Help Leo Satellites Dodge Most Lethal Impacts?

Science.gov (United States)

GUDIEL, ANDREA; Carroll, Joseph; Rowe, David

2018-01-01

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

Book Review: Physics of the Space Environment

Science.gov (United States)

Holman, Gordon D.

1998-01-01

Space physics, narrowly defined as the study of Earth's plasma environment, has had an identity crisis throughout its relatively brief existence as a discipline. - The limited and often serendipitous nature of the data requires the research style of an astrophysicist. However, the in situ observations and instrumentation that are central to the field are quite different from the remote observations and instrumentation of astronomy. Compared to neutral gases, the wealth of additional phenomena and the complexity associated with magnetized plasmas and their interaction leaves little in common with the atmospheric scientist. Although the phenomena studied in space physics are ultimately important to astrophysics, the intimate measurements of plasma properties provide a greater commonality with the plasma physicist. Space physics has experienced something of a renaissance in the past few years. The interdisciplinary umbrella "Solar-Terrestrial Physics" or "Sun-Earth Connection" has stimulated an increasing interaction of space physicists, solar physicists and atmospheric scientists. Spectacular images of the Sun from Yohkoh and SOHO and solar-activity-related damage to communications satellites have increased the public's awareness of and interest in "space weather". The dangers of energetic particles and currents in space to technological systems and to future space exploration have elevated space physics observations from interesting scientific measurements that can be included on a space probe to critically important measurements that must be made.

A strategy for investment in space resource utilization

Science.gov (United States)

Mendell, Wendell W.

During the first quarter of the next Century, space transportation systems will be capable of routine flights of humans and cargo to the Moon. The general acceptance of permanent human presence in space, as exemplified by at least two manned stations in LEO at that time, will lead to one or more staffed outposts on the Moon. Whether such outposts evolve into sustained, growing settlements will depend, in part, on whether the economic context attracts substantial private investment. A planetary surface provides a material and gravitational environment distinct from that of an orbiting space station and thus provides a setting familiar to non-aerospace sectors of terrestrial industry. Examination of current trends in terms of historical processes which operate on new frontiers suggests that the limited markets and unfamiliar technologies associated with space commercialization today may change dramatically in 20 years when lunar resources are accessible. However, the uncertainty and vagueness of such projections discourages investment at a useful scale unless a strategy for technology development can be implemented which provides tangible and marketable benefits in the intermediate term. At the present time technologies can be identified (a) that will be required (and therefore valuable) at the time of lunar settlement and (b) whose development can be planned to yield marketable intermediate products on Earth. Formation of pre-competitive, collaborative research consortia in the industrial sector could reduce technical and economic risk in the early stages and could promote a favorable political environment for the future growth of space activities.

Variable stars in the Leo A dwarf galaxy (DDO 69)

Science.gov (United States)

Hoessel, John G.; Saha, A.; Krist, John; Danielson, G. Edward

1994-01-01

Observations of the Leo A dwarf galaxy, obtained over the period from 1980 to 1991 are reported. Forty two separate Charge Coupled Devices (CCD) frames were searched for variable stars. A total of 14 suspected variables were found, 9 had sufficient coverage for period determination, and 5 had Cepheid light curves. Four of these stars fit well on a P-L relation and yield a distance modulus, after correction for Galactic foreground extinction, of m-M = 26.74. This corresponds to a distance of 2.2 Mpc, placing Leo A near the Local Group zero-velocity surface.

Óleos e gosduras vegetais: composição e tecnologia

Directory of Open Access Journals (Sweden)

Luiz Antonio Gioielli

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

Espaçamento de plantio e intervalos de colheita na biomassa e no óleo essencial de gerânio Plant spacing and harvest intervals on biomass and essential oil of geranium

Directory of Open Access Journals (Sweden)

Arie F Blank

2012-12-01

Full Text Available O gerânio (Pelargonium graveolens é uma erva aromática e seu óleo essencial é comumente utilizado na constituição de fármacos e cosméticos no mundo. A planta adapta-se bem às condições climáticas do nordeste brasileiro, mas são escassos os dados sobre seu rendimento quantitativo e qualitativo. O objetivo do trabalho foi avaliar a influência de espaçamento de plantas e intervalos de colheita em gerânio na produção de biomassa e de óleo essencial. Foram testados três espaçamentos de plantio (50x50, 50x60 e 50x80 cm e três intervalos de colheita (8, 12 e 16 semanas. Os maiores valores totais de massa fresca e seca de folhas e caules (2679,04 g m-2; 424,62 g m-2; 1035,08 g m-2; 136,85 g m-2, respectivamente e rendimento de óleo essencial (7,56 mL m-2, que são características de interesse direto para o mercado, foram obtidos em intervalo de colheita de oito semanas e no espaçamento de 50x50 cm. Nas demais variáveis analisadas, houve pouca diferenciação entre os tratamentos, contudo, períodos longos de colheita são menos produtivos, pois houve queda nos valores de todas as variáveis nas ultimas colheitas de cada intervalo. Assim, melhores resultados de quantidade e qualidade para o gerânio foram obtidos com intervalo de 8 semanas e no espaçamento 50x50 cm.Geranium (Pelargonium graveolens is an aromatic herb and its essential oil is commonly used in the creation of drugs and cosmetics worldwide. The plant is well adapted to the climatic conditions of the Brazilian northeast, but there are few data on its quantitative and qualitative yield. The aim of this study was to evaluate the influence of plant spacing and harvest intervals of geranium on the production of biomass and essential oil. Three different plant spacings (50x50, 50x60 and 50x80 cm and three harvest intervals (8, 12 and 16 weeks were tested. The highest values of total fresh and dry weight of leaves and stems (2679.04 g m-2; 424.62 g m-2; 1035.08 g m-2

Operational support to collision avoidance activities by ESA's space debris office

Science.gov (United States)

Braun, V.; Flohrer, T.; Krag, H.; Merz, K.; Lemmens, S.; Bastida Virgili, B.; Funke, Q.

2016-09-01

third-party missions not operated from the European Space Operations Centre (ESOC). Finally, we provide statistics on the identified conjunction events, taking into account the known significant changes in the LEO orbital environment and share ESA's experience along with recent examples.

Assessing Built Environment Walkability using Activity-Space Summary Measures.

Science.gov (United States)

Tribby, Calvin P; Miller, Harvey J; Brown, Barbara B; Werner, Carol M; Smith, Ken R

There is increasing emphasis on active transportation, such as walking, in transportation planning as a sustainable form of mobility and in public health as a means of achieving recommended physical activity and better health outcomes. A research focus is the influence of the built environment on walking, with the ultimate goal of identifying environmental modifications that invite more walking. However, assessments of the built environment for walkability are typically at a spatially disaggregate level (such as street blocks) or at a spatially aggregate level (such as census block groups). A key issue is determining the spatial units for walkability measures so that they reflect potential walking behavior. This paper develops methods for assessing walkability within individual activity spaces : the geographic region accessible to an individual during a given walking trip. We first estimate street network-based activity spaces using the shortest path between known trip starting/ending points and a travel time budget that reflects potential alternative paths. Based on objective walkability measures of the street blocks, we use three summary measures for walkability within activity spaces: i) the average walkability score across block segments (representing the general level of walkability in the activity space); ii) the standard deviation (representing the walkability variation), and; iii) the network autocorrelation (representing the spatial coherence of the walkability pattern). We assess the method using data from an empirical study of built environment walkability and walking behavior in Salt Lake City, Utah, USA. We visualize and map these activity space summary measures to compare walkability among individuals' trips within their neighborhoods. We also compare summary measures for activity spaces versus census block groups, with the result that they agree less than half of the time.

Leo Esakia on duality in modal and intuitionistic logics

CERN Document Server

Bezhanishvili, Guram

2014-01-01

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

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

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A.D. SOUZA

2015-01-01

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

Impact of space environment on stability of medicines: Challenges and prospects.

Science.gov (United States)

Mehta, Priti; Bhayani, Dhara

2017-03-20

To upkeep health of astronauts in a unique, isolated, and extreme environment of space is the primary goal for a successful space mission, hence, safe and efficacious medications are essential for the wellness of astronauts. Space medication has been challenged with problems related to efficacy. Along with altered physiology, one of the possible reasons could be instability of space medications in the presence of harsh spaceflight environmental conditions. Altered physical and chemical stability can result in reduced potency which can result in reduced efficacy. Right now, medicines from the International Space Station are replaced before their expiration. But, for longer duration missions to Mars or any other asteroid, there will not be any chance of replacement of medicines. Hence, it is desired that medicines maintain the shelf-life throughout the space mission. Stability of medicines used for short term or long term space missions cannot be judged by drug stability guidelines based on terrestrial environmental factors. Unique environmental conditions related to spaceflight include microgravity, excessive vibration, hard vacuum, humidity variation, temperature differences and excessive radiation, which may cause instability of medicines. This write-up provides a review of the problem and countermeasure approaches for pharmaceuticals exposed to the space environment. The first part of the article discusses thought processes behind outlining of International Conference on Harmonization drug stability guidelines, Q1A (R2) and Q1B, and its acceptance limits for accelerated stability study. The second part of the article describes the difference in the radiation environment of deep space compared to radiation environment inside the space shuttle based on penetration power of different types of radiation. In the third part of the article, various promising approaches are listed which can be used for assurance of space medicine stability. One of the approaches is the

O preço do petróleo como factor global: análise sectorial

OpenAIRE

Martinho, Isabel Rodrigues

2010-01-01

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

Efeito de enzimas hidrolíticas no comportamento reológico do óleo de palma cru

OpenAIRE

FREITAS,Suely P.; SILVA,Fernando C.; LAGO,Regina C.A.; COURI,Sonia

1998-01-01

No processamento tradicional de extração de óleo de palma, uma quantidade substancial do produto é perdida na fibra - durante a etapa de prensagem do fruto - e na borra - durante a etapa de clarificação do óleo cru. A viscosidade deste constitui a principal dificuldade de separação do óleo dos demais componentes da mistura. A eficiência de recuperação do óleo é usualmente melhorada por adição de água, no tanque de clarificação. Neste trabalho avaliou-se os efeitos da diluição e do tratamento ...

THE STELLAR INITIAL MASS FUNCTION OF ULTRA-FAINT DWARF GALAXIES: EVIDENCE FOR IMF VARIATIONS WITH GALACTIC ENVIRONMENT

Energy Technology Data Exchange (ETDEWEB)

Geha, Marla [Astronomy Department, Yale University, New Haven, CT 06520 (United States); Brown, Thomas M.; Tumlinson, Jason; Kalirai, Jason S.; Avila, Roberto J.; Ferguson, Henry C. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Simon, Joshua D. [Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Kirby, Evan N. [Department of Physics and Astronomy, University of California Irvine, 4129 Frederick Reines Hall, Irvine, CA 92697 (United States); VandenBerg, Don A. [Department of Physics and Astronomy, University of Victoria, P.O. Box 3055, Victoria, BC V8W 3P6 (Canada); Munoz, Ricardo R. [Departamento de Astronomia, Universidad de Chile, Casilla 36-D, Santiago (Chile); Guhathakurta, Puragra, E-mail: marla.geha@yale.edu, E-mail: tbrown@stsci.edu, E-mail: tumlinson@stsci.edu [UCO/Lick Observatory and Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)

2013-07-01

We present constraints on the stellar initial mass function (IMF) in two ultra-faint dwarf (UFD) galaxies, Hercules and Leo IV, based on deep Hubble Space Telescope Advanced Camera for Surveys imaging. The Hercules and Leo IV galaxies are extremely low luminosity (M{sub V} = -6.2, -5.5), metal-poor (([Fe/H]) = -2.4, -2.5) systems that have old stellar populations (>11 Gyr). Because they have long relaxation times, we can directly measure the low-mass stellar IMF by counting stars below the main-sequence turnoff without correcting for dynamical evolution. Over the stellar mass range probed by our data, 0.52-0.77 M{sub Sun }, the IMF is best fit by a power-law slope of {alpha}= 1.2{sub -0.5}{sup +0.4} for Hercules and {alpha} = 1.3 {+-} 0.8 for Leo IV. For Hercules, the IMF slope is more shallow than a Salpeter ({alpha} = 2.35) IMF at the 5.8{sigma} level, and a Kroupa ({alpha} = 2.3 above 0.5 M{sub Sun }) IMF slope at 5.4{sigma} level. We simultaneously fit for the binary fraction, f{sub binary}, finding f{sub binary}= 0.47{sup +0.16}{sub -0.14} for Hercules, and 0.47{sup +0.37}{sub -0.17} for Leo IV. The UFD binary fractions are consistent with that inferred for Milky Way stars in the same mass range, despite very different metallicities. In contrast, the IMF slopes in the UFDs are shallower than other galactic environments. In the mass range 0.5-0.8 M{sub Sun }, we see a trend across the handful of galaxies with directly measured IMFs such that the power-law slopes become shallower (more bottom-light) with decreasing galactic velocity dispersion and metallicity. This trend is qualitatively consistent with results in elliptical galaxies inferred via indirect methods and is direct evidence for IMF variations with galactic environment.

ESTUDO TRIBOLÓGICO DE ÓLEOS BIODEGRADÁVEIS DE COCO E DE RÍCINO ATRAVÉS DE ENSAIOS ABRASIVOS

Directory of Open Access Journals (Sweden)

jaciana silva de santana

2010-11-01

Full Text Available Em substituição aos óleos minerais, os óleos biodegradáveis vêm proporcionando uma grande alternativa ao mercado, uma vez que o mesmo diminui os impactos ambientais. Com a finalidade de avaliar o desempenho do óleo de rícino (refinado e bruto e o óleo de coco comparando-os com os óleos minerais SAE 20W50 SJ e W40, realizaram-se ensaios tribológicos de desgaste na configuração pino-contra-cilindro de aço AISI 52100. As superfícies das amostras metálicas foram confeccionadas por torneamento e lixamento, utilizando-se lixas de diferentes granulometrias, seguidas por limpeza com banho ultrassônico e pesagem antes e após a realização dos ensaios. Os corpos-de-prova foram analisados antes dos ensaios no microscópio óptico. A dureza do aço AISI 52100 foi medida utilizando-se um durômetro Rockwell. O óleo foi caracterizado através de ensaios de densidade e tensão superficial (Souza et. al., 2007. A eficiência da ação do lubrificante foi avaliada através da taxa de desgaste calculada para as amostras utilizando-se a equação de Archard e através da microscopia eletrônica de varredura (MEV. Segundo resultados da taxa de desgaste, os óleos vegetais de rícino e coco obtiveram valores de 88,89 % e 33,33 % menores que para os óleos W40 e SAE 20W50 SJ, respectivamente. Sendo assim, os óleos vegetais possuem propriedades tribológicas equivalentes e até superiores às dos óleos minerais estudados.

Utilização da Energia de Dietas para Frangos de Corte Formuladas com Óleo Ácido de Soja

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Vieira SL

2002-01-01

Full Text Available O produto comercialmente chamado "óleo ácido de soja", resulta da acidificação da borra residual do processo de refino do óleo de soja. Este tem sido muito utilizado na indústria de rações animais, ainda que com vários questinamentos a cerca de sua eficiência, tais como a adulteração com outros ácidos graxos de baixo valor nutricional, nível de peroxidação, presença de impurezas, e valores energéticos não confiáveis. Neste estudo, foi avaliado o desempenho de frangos de corte consumindo dietas contendo óleo de soja ou óleo ácido de soja nos níveis de 4 e 8% ou a mistura das duas fontes em partes iguais de 2 e 4% cada. Essas dietas foram fornecidas para frangos de corte alojados em baterias climatizadas a partir dos 7 dias de idade. As aves que receberam misturas equivalentes de óleo ácido de soja e óleo de soja apresentaram menor peso corporal no final do experimento (aos 42 dias quando comparadas com aquelas que consumiram apenas óleo ou óleo ácido de soja, independentemente do nível adicionado. O nível de inclusão de óleo de soja ou óleo ácido de soja não influenciou o peso final das aves. Foi verificado maior consumo de ração pelos animais que receberam dietas de menor nível de inclusão, o que contribuiu para piorar a conversão alimentar dos mesmos. O óleo ácido de soja demonstrou ser uma fonte energética alternativa de alto potencial econômico para uso em dietas comerciais para frangos de corte, apresentando valor energético de 8.114 kcal EMAn/kg de MS, valor 5% inferior ao determinado para o óleo de soja degomado.

El íleo biliar: una revisión de la literatura médica

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C.F. Ploneda-Valencia

2017-07-01

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

Protection from Induced Space Environments Effects on the International Space Station

Science.gov (United States)

Soares, Carlos; Mikatarian, Ron; Stegall, Courtney; Schmidl, Danny; Huang, Alvin; Olsen, Randy; Koontz, Steven

2010-01-01

The International Space Station (ISS) is one of the largest, most complex multinational scientific projects in history and protection from induced space environments effects is critical to its long duration mission as well as to the health of the vehicle and safety of on-orbit operations. This paper discusses some of the unique challenges that were encountered during the design, assembly and operation of the ISS and how they were resolved. Examples are provided to illustrate the issues and the risk mitigation strategies that were developed to resolve these issues. Of particular importance are issues related with the interaction of multiple spacecraft as in the case of ISS and Visiting Vehicles transporting crew, hardware elements, cargo and scientific payloads. These strategies are applicable to the development of future long duration space systems, not only during design, but also during assembly and operation of these systems.

The Near-Earth Space Radiation for Electronics Environment

Science.gov (United States)

Stassinopoulos, E. G.; LaBel, K. A.

2004-01-01

The earth's space radiation environment is described in terms of: a) charged particles as relevant to effects on spacecraft electronics, b) the nature and distribution of trapped and transiting radiation, and c) their effect on electronic components.

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

Science.gov (United States)

Smithrick, John J.; Hall, Stephen W.

1992-01-01

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

Application of the NASCAP Spacecraft Simulation Tool to Investigate Electrodynamic Tether Current Collection in LEO

Science.gov (United States)

Adams, Mitzi; HabashKrause, Linda

2012-01-01

Recent interest in using electrodynamic tethers (EDTs) for orbital maneuvering in Low Earth Orbit (LEO) has prompted the development of the Marshall ElectroDynamic Tether Orbit Propagator (MEDTOP) model. The model is comprised of several modules which address various aspects of EDT propulsion, including calculation of state vectors using a standard orbit propagator (e.g., J2), an atmospheric drag model, realistic ionospheric and magnetic field models, space weather effects, and tether librations. The natural electromotive force (EMF) attained during a radially-aligned conductive tether results in electrons flowing down the tether and accumulating on the lower-altitude spacecraft. The energy that drives this EMF is sourced from the orbital energy of the system; thus, EDTs are often proposed as de-orbiting systems. However, when the current is reversed using satellite charged particle sources, then propulsion is possible. One of the most difficult challenges of the modeling effort is to ascertain the equivalent circuit between the spacecraft and the ionospheric plasma. The present study investigates the use of the NASA Charging Analyzer Program (NASCAP) to calculate currents to and from the tethered satellites and the ionospheric plasma. NASCAP is a sophisticated set of computational tools to model the surface charging of three-dimensional (3D) spacecraft surfaces in a time-varying space environment. The model's surface is tessellated into a collection of facets, and NASCAP calculates currents and potentials for each one. Additionally, NASCAP provides for the construction of one or more nested grids to calculate space potential and time-varying electric fields. This provides for the capability to track individual particles orbits, to model charged particle wakes, and to incorporate external charged particle sources. With this study, we have developed a model of calculating currents incident onto an electrodynamic tethered satellite system, and first results are shown

Effects of a Closed Space Environment on Gene Expression in Hair Follicles of Astronauts in the International Space Station

Data.gov (United States)

National Aeronautics and Space Administration — In recent times long-term stay has become a common occurrence in the International Space Station (ISS). However adaptation to the space environment can sometimes...

Key issues of multiple access technique for LEO satellite communication systems

Institute of Scientific and Technical Information of China (English)

温萍萍; 顾学迈

2004-01-01

The large carrier frequency shift caused by the high-speed movement of satellite (Doppler effects) and the propagation delay on the up-down link are very critical issues in an LEO satellite communication system, which affects both the selection and the implementation of a suitable access method. A Doppler based multiple access technique is used here to control the flow and an MPRMA-HS protocol is proposed for the application in LEO satellite communication systems. The extended simulation trials prove that the proposed scheme seems to be a very promising access method.

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

Directory of Open Access Journals (Sweden)

Peter Hobart

2012-07-01

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

Leo satellite-based telecommunication network concepts

Science.gov (United States)

Aiken, John G.; Swan, Peter A.; Leopold, Ray J.

1991-01-01

Design considerations are discussed for Low Earth Orbit (LEO) satellite based telecommunications networks. The satellites are assumed to be connected to each other via intersatellite links. They are connected to the end user either directly or through gateways to other networks. Frequency reuse, circuit switching, packet switching, call handoff, and routing for these systems are discussed by analogy with terrestrial cellular (mobile radio) telecommunication systems.

OPTEL-μ LEO to ground laser communications terminal: flight design and status of the EQM development project

Science.gov (United States)

Baister, G.; Greger, R.; Bacher, M.; Stumpf, M.; Francou, L.; Buchheim, K.

2017-09-01

The OPTEL-μ terminal is designed to transmit data generated on-board LEO satellites to an optical ground station at a data rate of 2 Gbps. This would allow operators of LEO satellites to downlink the large amounts of data being generated by their payload to ground. To make this technology attractive to LEO satellite user community the design of the OPTEL-μ has minimal impact to the spacecraft resources.

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-12-20

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

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

Science.gov (United States)

Smithrick, John J.; Hall, Stephen W.

1990-01-01

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

Challenging Christianity: Leo Tolstoy and Religious Education

Science.gov (United States)

Moulin, Dan

2009-01-01

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

Research Progress and Prospect of GNSS Space Environment Science

Directory of Open Access Journals (Sweden)

YAO Yibin

2017-10-01

Full Text Available Troposphere and ionosphere are two important components of the near-earth space environment. They are close to the surface of the earth and have great influence on human life. The developments of Global Navigation Satellite System (GNSS over the past several decades provide a great opportunity for the GNSS-based space environment science. This review summarizes the research progress and prospect of the GNSS-based research of the Earth's troposphere and ionosphere. On the tropospheric perspective, modeling of the key tropospheric parameters and inversion of precipitable water vapor (PWV are dominant researching fields. On the ionospheric perspective, 2D/3D ionospheric models and regional/global ionospheric monitoring are dominant researching fields.

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

Science.gov (United States)

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

2018-04-01

Leo T is the lowest mass gas-rich galaxy currently known and studies of its gas content help us understand how such marginal galaxies survive and form stars. We present deep neutral hydrogen (H I) observations from the Westerbork Synthesis Radio Telescope in order to understand its H I distribution and potential for star formation. We find a larger H I line flux than the previously accepted value, resulting in a 50% larger H I mass of 4.1 × 105 M⊙. The additional H I flux is from low surface brightness emission that was previously missed; with careful masking this emission can be recovered even in shallower data. We perform a Gaussian spectral decomposition to find a cool neutral medium component (CNM) with a mass of 3.7 × 104 M⊙, or almost 10% of the total H I mass. Leo T has no H I emission extending from the main H I body, but there is evidence of interaction with the Milky Way circumgalactic medium in both a potential truncation of the H I body and the offset of the peak H I distribution from the optical center. The CNM component of Leo T is large when compared to other dwarf galaxies, even though Leo T is not currently forming stars and has a lower star formation efficiency than other gas-rich dwarf galaxies. However, the H I column density associated with the CNM component in Leo T is low. One possible explanation is the large CNM component is not related to star formation potential but rather a recent, transient phenomenon related to the interaction of Leo T with the Milky Way circumgalactic medium. The reduced datacube (FITS file) is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/612/A26

Human Pathophysiological Adaptations to the Space Environment

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Gian C. Demontis

2017-08-01

Full Text Available Space is an extreme environment for the human body, where during long-term missions microgravity and high radiation levels represent major threats to crew health. Intriguingly, space flight (SF imposes on the body of highly selected, well-trained, and healthy individuals (astronauts and cosmonauts pathophysiological adaptive changes akin to an accelerated aging process and to some diseases. Such effects, becoming manifest over a time span of weeks (i.e., cardiovascular deconditioning to months (i.e., loss of bone density and muscle atrophy of exposure to weightlessness, can be reduced through proper countermeasures during SF and in due time are mostly reversible after landing. Based on these considerations, it is increasingly accepted that SF might provide a mechanistic insight into certain pathophysiological processes, a concept of interest to pre-nosological medicine. In this article, we will review the main stress factors encountered in space and their impact on the human body and will also discuss the possible lessons learned with space exploration in reference to human health on Earth. In fact, this is a productive, cross-fertilized, endeavor in which studies performed on Earth yield countermeasures for protection of space crew health, and space research is translated into health measures for Earth-bound population.

The contribution of woody plant materials on the several conditions in a space environment

Science.gov (United States)

Tomita-Yokotani, Kaori; Baba, Keiichi; Suzuki, Toshisada; Kimura, Shunta; Sato, Seigo; Katoh, Hiroshi; Abe, Yusuke; Katayama, Takeshi

Woody plant materials have several utilization elements in our habitation environment on earth. The studies of woody plants under a space-environment in the vegetable kingdom have a high contribution to the study of various and exotic environmental responses, too. Woody plants can produce an excess oxygen, woody materials for the living cabin, and provide a biomass by cultivating crops and other species of creatures. Tree material would become to be a tool in closed bio-ecosystems such as an environment in a space. We named the trees used as material for the experiment related to space environments “CosmoBon”, small tree bonsai. Japanese cherry tree, “Sakura”, is famous and lovely tree in Japan. One species of “Sakura”, “Mamezakura, Prunus incisa”, is not only lovely tree species, but also suitable tree for the model tree of our purpose. The species of Prunus incisa is originally grown in volcano environment. That species of Sakura is originally grown on Mt. Fuji aria, oligotrophic place. We will try to build the best utilization usage of woody plant under the space environment by “Mamezakura” as a model tree. Here, we will show the importance of uniformity of materials when we will use the tree materials in a space environment. We will also discuss that tree has a high possibility of utilization under the space environments by using our several results related to this research.

Moore'i seadus ja meie tulevik / Leo Võhandu

Index Scriptorium Estoniae

Võhandu, Leo, 1929-

2006-01-01

Kiibifirma Intel üks asutajaid Gordon Moore väitis 1965. aastal, et transistorite arv kiibil topeldub iga kahe aastaga ehk loomulik areng ei ole lineaarne, vaid eksponentsiaalne (astmeline). TTÜ emeriitprofessor Moore'i seaduse mõjust ühiskonna arengule. Vt. samas: Leo Võhandu

THE LEO IV DWARF SPHEROIDAL GALAXY: COLOR-MAGNITUDE DIAGRAM AND PULSATING STARS

International Nuclear Information System (INIS)

Moretti, Maria Ida; Dall'Ora, Massimo; Ripepi, Vincenzo

2009-01-01

We present the first V, B - V color-magnitude diagram of the Leo IV dwarf spheroidal galaxy, a faint Milky Way satellite recently discovered by the Sloan Digital Sky Survey. We have obtained B, V time-series photometry reaching about half a magnitude below the Leo IV turnoff, which we detect at V = 24.7 mag, and have performed the first study of the variable star population. We have identified three RR Lyrae stars (all fundamental-mode pulsators, RRab) and one SX Phoenicis variable in the galaxy. In the period-amplitude diagram the Leo IV RR Lyrae stars are located close to the loci of Oosterhoff type I systems and the evolved fundamental-mode RR Lyrae stars in the Galactic globular cluster M3. However, their mean pulsation period, (Pab) = 0.655 days, would suggest an Oosterhoff type II classification for this galaxy. The RR Lyrae stars trace very well the galaxy's horizontal branch, setting its average magnitude at (V RR ) = 21.48 ± 0.03 mag (standard deviation of the mean). This leads to a distance modulus of μ 0 = 20.94 ± 0.07 mag, corresponding to a distance of 154 ± 5 kpc, by adopting for the Leo IV dSph a reddening E(B - V) = 0.04 ± 0.01 mag and a metallicity of [Fe/H] = -2.31 ± 0.10.

Modeling of Complex Material Systems in Extreme Environments for Space Technology

Data.gov (United States)

National Aeronautics and Space Administration — Among the many enabling technologies of space research is the design of materials which are stable in the environments of interest for a given application. At the...

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

Science.gov (United States)

Smithrick, John J.; Hall, Stephen W.

1991-01-01

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

Space - A unique environment for process modeling R&D

Science.gov (United States)

Overfelt, Tony

1991-01-01

Process modeling, the application of advanced computational techniques to simulate real processes as they occur in regular use, e.g., welding, casting and semiconductor crystal growth, is discussed. Using the low-gravity environment of space will accelerate the technical validation of the procedures and enable extremely accurate determinations of the many necessary thermophysical properties. Attention is given to NASA's centers for the commercial development of space; joint ventures of universities, industries, and goverment agencies to study the unique attributes of space that offer potential for applied R&D and eventual commercial exploitation.

Effects of space environment on biological characteristics of melanoma B16 cells

International Nuclear Information System (INIS)

Geng Chuanying; Xiang Qing; Xu Mei; Li Hongyan; Xu Bo; Fang Qing; Tang Jingtian; Guo Yupeng

2006-01-01

Objective: To examine the effects of space environment on biological characteristics of melanoma B16 Cells. Methods: B16 cells were carried to the space (in orbit for 8 days, circle the earth 286 times) by the 20th Chinese recoverable satellite, and then harvested and monocloned. 110 strains of space B16 cells were obtained in total. Ten strains of space B16 cells were selected and its morphological changes were examined with the phasecontrast microscope. Flow cytometry and MTT assay were carried out to evaluate the cell cycle and cell viability. Results Morphological changes were observed in the space cells, and melainin granules on the surface in some cells. It was demonstrated by MTF assay that space cells viability varied muti- directionally. It was showed by flow cytometry analysis that G1 phase of space cells was prolonged, S phase shortened. Conclusion: Space environment may change the biological characteristics of melanoma B16 cells. (authors)

New NASA Technologies for Space Exploration

Science.gov (United States)

Calle, Carlos I.

2015-01-01

NASA is developing new technologies to enable planetary exploration. NASA's Space Launch System is an advance vehicle for exploration beyond LEO. Robotic explorers like the Mars Science Laboratory are exploring Mars, making discoveries that will make possible the future human exploration of the planet. In this presentation, we report on technologies being developed at NASA KSC for planetary exploration.

Power system for production, construction, life support and operations in space

International Nuclear Information System (INIS)

Sovie, R.J.

1988-01-01

As one looks to man's future in space it becomes obvious that unprecedented amounts of power are required for the exploration, colonization, and exploitation of space. Activities envisioned include interplanetary travel and LEO to GEO transport using electric propulsion, Earth and lunar observatories, advance space stations, free-flying manufacturing platforms, communications platforms, and eventually evolutionary lunar and Mars bases. These latter bases would start as camps with modest power requirements (kWes) and evolve to large bases as manufacturing, food production, and life support materials are developed from lunar raw materials. These latter activities require very robust power supplies (MWes). The advanced power system technologies being pursued by NASA to fulfill these future needs are described. Technologies discussed will include nuclear, photovoltaic, and solar dynamic space power systems, including energy storage, power conditioning, power transmission, and thermal management. The state-of-the-art and gains to be made by technology advancements will be discussed. Mission requirements for a variety of applications (LEO, GEO, lunar, and Martian) will be treated, and data for power systems ranging from a few kilowatts to megawatt power systems will be represented. In addition the space power technologies being initiated under NASA's new Civilian Space Technology Initiative (CSTI) and Space Leadership Planning Group Activities will be discussed

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

OpenAIRE

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

2016-01-01

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

Wastes in space

International Nuclear Information System (INIS)

2011-01-01

As human space activities have created more wastes on low and high Earth orbits over the past 50 years than the solar system injected meteorites over billions of years, this report gives an overview of this problem. It identifies the origins of these space debris and wastes (launchers, combustion residues, exploitation wastes, out-of-use satellites, accidental explosions, accidental collisions, voluntary destructions, space erosion), and proposes a stock list of space wastes. Then, it distinguishes the situation for the different orbits: low Earth orbit or LEO (traffic, presence of the International Space Station), medium Earth orbits or MEO (traffic, operating satellites, wastes), geostationary Earth orbit or GEO (traffic, operating satellites, wastes). It also discusses wastes and bacteria present on the moon (due to Apollo missions or to crash tests). It evokes how space and nuclear industry is concerned, and discusses the re-entry issue (radioactive boomerang, metallic boomerang). It also indicates elements of international law

Performances of Saft Lithium-Ion Cells in LEO Cycling

Directory of Open Access Journals (Sweden)

Prevot D.

2017-01-01

The article will thus present the whole LEO cycling results available for the two cells, and will provide afterwards the correlation status of Saft Li-ion Model (SLIM with all the experimental data acquired.

Cholangiocarcinoma of intrahepatic bile ducts with disseminated metastases in an African lion (Panthera leo).

Science.gov (United States)

Lepri, Elvio; Sforna, Monica; Brachelente, Chiara; Chiara, Brachelente; Vitellozzi, Giovanni; Giovanni, Vitellozzi

2013-06-01

A cholangiocarcinoma is reported in an 18-yr-old, female African lion (Panthera leo). The primary tumor consisted of multifocal to coalescing, hepatic, white-yellow masses distributed throughout the liver lobes. Metastases were present in regional lymph nodes, peritoneal surface, and lungs. Histologically, the tumor was characterized by a tubular pattern with alcian- and periodic acid-Schiff-positive secretory material in cystic spaces. The neoplastic cells were positive to broad-spectrum cytokeratins. Histochemical and immunohistochemical stains were consistent with bile duct carcinoma. Biliary tumors arising from the gallbladder have been reported in lions. However, to the authors' knowledge, this is the first case of intrahepatic bile duct carcinoma reported in an African lion.

An optimal beam alignment method for large-scale distributed space surveillance radar system

Science.gov (United States)

Huang, Jian; Wang, Dongya; Xia, Shuangzhi

2018-06-01

Large-scale distributed space surveillance radar is a very important ground-based equipment to maintain a complete catalogue for Low Earth Orbit (LEO) space debris. However, due to the thousands of kilometers distance between each sites of the distributed radar system, how to optimally implement the Transmitting/Receiving (T/R) beams alignment in a great space using the narrow beam, which proposed a special and considerable technical challenge in the space surveillance area. According to the common coordinate transformation model and the radar beam space model, we presented a two dimensional projection algorithm for T/R beam using the direction angles, which could visually describe and assess the beam alignment performance. Subsequently, the optimal mathematical models for the orientation angle of the antenna array, the site location and the T/R beam coverage are constructed, and also the beam alignment parameters are precisely solved. At last, we conducted the optimal beam alignment experiments base on the site parameters of Air Force Space Surveillance System (AFSSS). The simulation results demonstrate the correctness and effectiveness of our novel method, which can significantly stimulate the construction for the LEO space debris surveillance equipment.

Utilização de óleos vegetais como bases lubrificantes

OpenAIRE

Matos, Paulo Roberto Rodrigues de

2011-01-01

A demanda dos óleos lubrificantes é cada vez maior na crescente economia brasileira. A utilização de bases vegetais em substituição às minerais poderá trazer benefícios socioeconômicos e ambientais para o país. O objetivo deste trabalho foi verificar a capacidade lubrificante de óleos vegetais e adequá-los em função do seu uso potencial como lubrificante, tendo em vista a variedade de aplicações possíveis. Espera-se com isso obter alguns lubrificantes de base vegetal específicos para aplicaçõ...

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

Directory of Open Access Journals (Sweden)

Viktor N. Chkhaidze

2017-11-01

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

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

Directory of Open Access Journals (Sweden)

Ana Karina Mauro Barroso

2014-01-01

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

MISSE 2 PEACE Polymers Experiment Atomic Oxygen Erosion Yield Error Analysis

Science.gov (United States)

McCarthy, Catherine E.; Banks, Bruce A.; deGroh, Kim, K.

2010-01-01

Atomic oxygen erosion of polymers in low Earth orbit (LEO) poses a serious threat to spacecraft performance and durability. To address this, 40 different polymer samples and a sample of pyrolytic graphite, collectively called the PEACE (Polymer Erosion and Contamination Experiment) Polymers, were exposed to the LEO space environment on the exterior of the International Space Station (ISS) for nearly 4 years as part of the Materials International Space Station Experiment 1 & 2 (MISSE 1 & 2). The purpose of the PEACE Polymers experiment was to obtain accurate mass loss measurements in space to combine with ground measurements in order to accurately calculate the atomic oxygen erosion yields of a wide variety of polymeric materials exposed to the LEO space environment for a long period of time. Error calculations were performed in order to determine the accuracy of the mass measurements and therefore of the erosion yield values. The standard deviation, or error, of each factor was incorporated into the fractional uncertainty of the erosion yield for each of three different situations, depending on the post-flight weighing procedure. The resulting error calculations showed the erosion yield values to be very accurate, with an average error of 3.30 percent.

Caracterização físico-química de misturas de óleos vegetais para fins alimentares.

OpenAIRE

ALMEIDA, K. M. de; MEDEIROS, E. P. de; GOMES, J. P.; SOUSA, E. P. de; SANTOS, J. W. dos

2014-01-01

Objetivou-se, com este trabalho, a elaboração e caracterização de misturas especiais de óleos vegetais para fins alimentícios, com base nos óleos de amendoim, gergelim, maracujá e soja. Os óleos de amendoim e gergelim foram extraídos de sementes das cultivares BRS-Havana e BRS-Seda, respectivamente, cedidas pela Embrapa Algodão enquanto o óleo de maracujá foi adquirido no comércio de São Paulo e o de soja no de Campina Grande. As misturas foram elaboradas com base em uma matriz de planejament...

TOXICIDADE DE ÓLEOS ESSENCIAIS PARA O CONTROLE DE Tetranychus urticae KOCH, 1836 (ACARI: TETRANYCHIDAE

Directory of Open Access Journals (Sweden)

Camila Santos Teixeira

2017-04-01

Full Text Available O ácaro rajado é considerado uma importante praga agrícola, causando danos em diferentes cultivos. O controle à base de acaricidas químicos pode vir a causar problemas ambientais e à saúde do homem. Desta forma o uso de óleos essenciais obtidos de produtos botânicos é uma alternativa no controle de pragas por apresentar baixo efeito residual, sendo objetivo deste trabalho avaliar a mortalidade e o efeito na fertilidade de fêmeas adultas de Tetranychus urticae submetidas a tratamentos com óleos essenciais de laranja doce e limoneno, fornecidos pela empresa Ferquima Indústria e Comércio LTDA., e pela empresa Pack Indústria e Comércio de Produtos Agropecuários LTDA., respectivamente. Para avaliar a ação fumigante do óleo essencial sobre os ácaros foram realizados testes submetendo fêmeas adultas de T. urticae à dose pura do óleo essencial utilizando as dosagens de 5, 15 e 25 µL em câmaras de fumigação. Após o período de exposição ao óleo foi contabilizado o número de ácaros mortos e a quantidade de ovos depositados. Os resultados não foram significativos para mortalidade e para fertilidade de fêmeas adultas de T. urticae.

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

Directory of Open Access Journals (Sweden)

P.R.B. GOMES

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

Phylogeographic Patterns in Africa and High Resolution Delineation of Genetic Clades in the Lion (Panthera leo)

NARCIS (Netherlands)

Bertola, L.D.; Jongbloed, H.; van der Gaag, K.J.; de Knijff, P.; Yamaguchi, N.; Hooghiemstra, H.; Bauer, H.; Henschel, P.; White, P.A.; Driscoll, C.A.; Tende, T.; Ottosson, U.; Saidu, Y.; Vrieling, K.; de Iongh, H.H.

2016-01-01

Comparative phylogeography of African savannah mammals shows a congruent pattern in which populations in West/Central Africa are distinct from populations in East/Southern Africa. However, for the lion, all African populations are currently classified as a single subspecies (Panthera leo leo), while

Biodiesel produzido com óleo de frango - DOI: 10.4025/actascitechnol.v30i1.3203

Directory of Open Access Journals (Sweden)

Luis Fernando Souza Gomes

2008-05-01

Full Text Available O Brasil ocupa local de destaque no desenvolvimento e uso de fontes renováveis de energia, por causa da sua grande extensão territorial, clima e várias alternativas. Uma destas é a produção de biodiesel, o qual pode substituir o óleo diesel, diminuindo os impactos ao meio ambiente. Na cadeia produtiva de carne de frango, é gerado um resíduo, óleo de frango, com potencial para produção de biodiesel. Neste trabalho, foram determinadas características físico-químicas que podem influenciar nas reações de transesterificação do óleo de frango. Foi levantado o potencial de produção de óleo de frango nas cooperativas da região oeste do Estado do Paraná e rendimento em biodiesel.

TDRS-1 single event upsets and the effect of the space environment

International Nuclear Information System (INIS)

Wilkinson, D.C.; Daughtridge, S.C.; Stone, J.L.; Sauer, H.H.; Darling, P.

1991-01-01

The systematic recording of Single Event Upsets on TDRS-1 from 1984 to 1990 allows correlations to be drawn between those upsets and the space environment. In this paper, ground based neutron monitor data are used to illustrate the long-term relationship between galactic cosmic rays and TDRS-1 upsets. The short-term effects of energetic solar particles are illustrated with space environment data from GOES-7

The Objectives of NASA's Living with a Star Space Environment Testbed

Science.gov (United States)

Barth, Janet L.; LaBel, Kenneth A.; Brewer, Dana; Kauffman, Billy; Howard, Regan; Griffin, Geoff; Day, John H. (Technical Monitor)

2001-01-01

NASA is planning to fly a series of Space Environment Testbeds (SET) as part of the Living With A Star (LWS) Program. The goal of the testbeds is to improve and develop capabilities to mitigate and/or accommodate the affects of solar variability in spacecraft and avionics design and operation. This will be accomplished by performing technology validation in space to enable routine operations, characterize technology performance in space, and improve and develop models, guidelines and databases. The anticipated result of the LWS/SET program is improved spacecraft performance, design, and operation for survival of the radiation, spacecraft charging, meteoroid, orbital debris and thermosphere/ionosphere environments. The program calls for a series of NASA Research Announcements (NRAs) to be issued to solicit flight validation experiments, improvement in environment effects models and guidelines, and collateral environment measurements. The selected flight experiments may fly on the SET experiment carriers and flights of opportunity on other commercial and technology missions. This paper presents the status of the project so far, including a description of the types of experiments that are intended to fly on SET-1 and a description of the SET-1 carrier parameters.

Simulated Space Environment Effects on a Candidate Solar Sail Material

Science.gov (United States)

Kang, Jin Ho; Bryant, Robert G.; Wilkie, W. Keats; Wadsworth, Heather M.; Craven, Paul D.; Nehls, Mary K.; Vaughn, Jason A.

2017-01-01

For long duration missions of solar sails, the sail material needs to survive harsh space environments and the degradation of the sail material controls operational lifetime. Therefore, understanding the effects of the space environment on the sail membrane is essential for mission success. In this study, we investigated the effect of simulated space environment effects of ionizing radiation, thermal aging and simulated potential damage on mechanical, thermal and optical properties of a commercial off the shelf (COTS) polyester solar sail membrane to assess the degradation mechanisms on a feasible solar sail. The solar sail membrane was exposed to high energy electrons (about 70 keV and 10 nA/cm2), and the physical properties were characterized. After about 8.3 Grad dose, the tensile modulus, tensile strength and failure strain of the sail membrane decreased by about 20 95%. The aluminum reflective layer was damaged and partially delaminated but it did not show any significant change in solar absorbance or thermal emittance. The effect on mechanical properties of a pre-cracked sample, simulating potential impact damage of the sail membrane, as well as thermal aging effects on metallized PEN (polyethylene naphthalate) film will be discussed.

PROSPECÇÃO TECNOLÓGICA DE ÓLEO ESSENCIAL DE AROEIRA-DA-PRAIA (Schinus terebinthifolius Raddi.)

OpenAIRE

Mendonça, Valéria Melo; Instituto Federal de Sergipe (IFS) Departamento: Curso Superior Tecnólogo em Agroecologia; Silva-Mann, Renata; Universidade Federal de Sergipe Departamento de Engenharia Agronômica; Rabbani, Allívia Rouse Carregosa; Universidade Federal de Sergipe (UFS) Departamento: Departamento de Engenharia Agronômica

2014-01-01

A aroeira-da-praia (Schinusterebinthifolius Raddi.) é uma espécie brasileira com grande importânciano cenário mundial por diversas características de interesse, dentre elas, oóleo essencial por seu valor fitoterápico. Com o intuito de verificarinformações sobre o uso do óleo essencial desta planta foi realizada umaprospecção em bancos de dados de pesquisa científica, tecnológica e de patentes.Existem muitos trabalhos acadêmicos sobre a aroeira-da-praia, mas poucos sobreóleo essência e número ...

Petróleo, Royalties e Pobreza

Directory of Open Access Journals (Sweden)

Gicélia Mendes da Silva

2009-08-01

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

Space Environment Automated Alerts and Anomaly Analysis Assistant (SEA^5) for NASA

Data.gov (United States)

National Aeronautics and Space Administration — We propose to develop a comprehensive analysis and dissemination system (Space Environment Automated Alerts  & Anomaly Analysis Assistant: SEA5) that will...

Avaliação toxicológica do óleo essencial de Piper aduncum L.

Directory of Open Access Journals (Sweden)

Pergentino J. C. Sousa

Full Text Available Este trabalho teve como objetivo a avaliação da toxidade aguda e subaguda do óleo essencial de Piper aduncum pela determinação da DL50 em camundongos e a análise dos parâmetros bioquímicos e hematológicos em ratos. A planta é utilizada na medicina popular da região amazônica em diversas doenças e no seu óleo essencial o constituinte majoritário é o fenilpropanóide dilapiol, com propriedades inseticida, fungicida, bactericida, larvicida e moluscicida. A DL50 foi de 2,400 ± 191,7 mg/kg. O óleo essencial não alterou de maneira significativa os parâmetros hematológicos e bioquímicos em relação ao controle no tratamento subagudo, exceto a redução da creatinina. O valor da DL50 e os resultados observados nos parâmetros hematológicos e bioquímicos sugerem que o óleo essencial apresenta toxidade baixa.

On public space design for Chinese urban residential area based on integrated architectural physics environment evaluation

Science.gov (United States)

Dong, J. Y.; Cheng, W.; Ma, C. P.; Tan, Y. T.; Xin, L. S.

2017-04-01

The residential public space is an important part in designing the ecological residence, and a proper physics environment of public space is of greater significance to urban residence in China. Actually, the measure to apply computer aided design software into residential design can effectively avoid an inconformity of design intent with actual using condition, and a negative impact on users due to bad architectural physics environment of buildings, etc. The paper largely adopts a design method of analyzing architectural physics environment of residential public space. By analyzing and evaluating various physics environments, a suitability assessment is obtained for residential public space, thereby guiding the space design.

Anaesthesia in austere environments: literature review and considerations for future space exploration missions.

Science.gov (United States)

Komorowski, Matthieu; Fleming, Sarah; Mawkin, Mala; Hinkelbein, Jochen

2018-01-01

Future space exploration missions will take humans far beyond low Earth orbit and require complete crew autonomy. The ability to provide anaesthesia will be important given the expected risk of severe medical events requiring surgery. Knowledge and experience of such procedures during space missions is currently extremely limited. Austere and isolated environments (such as polar bases or submarines) have been used extensively as test beds for spaceflight to probe hazards, train crews, develop clinical protocols and countermeasures for prospective space missions. We have conducted a literature review on anaesthesia in austere environments relevant to distant space missions. In each setting, we assessed how the problems related to the provision of anaesthesia (e.g., medical kit and skills) are dealt with or prepared for. We analysed how these factors could be applied to the unique environment of a space exploration mission. The delivery of anaesthesia will be complicated by many factors including space-induced physiological changes and limitations in skills and equipment. The basic principles of a safe anaesthesia in an austere environment (appropriate training, presence of minimal safety and monitoring equipment, etc.) can be extended to the context of a space exploration mission. Skills redundancy is an important safety factor, and basic competency in anaesthesia should be part of the skillset of several crewmembers. The literature suggests that safe and effective anaesthesia could be achieved by a physician during future space exploration missions. In a life-or-limb situation, non-physicians may be able to conduct anaesthetic procedures, including simplified general anaesthesia.

Alterações oxidativas em óleos de algodão, girassol e palma utilizados em frituras de mandioca palito congelada

Directory of Open Access Journals (Sweden)

M. S. CORSINI

2008-10-01

Full Text Available

O presente trabalho teve como objetivo avaliar as alterações oxidativas produzidas nos óleos de algodão, girassol e palma, durante o processo de fritura descontínua de mandioca palito congelada. As frituras foram conduzidas em uma fritadeira elétrica doméstica, onde o óleo foi aquecido, à temperatura de 180°C, por 25 horas, com reposição de óleo fresco. Os resultados obtidos das determinações analíticas foram submetidos às análises de variância, em esquema fatorial, no delineamento inteiramente casualizado, de modo a determinar a influência dos fatores óleos e tempos de fritura sobre as alterações nos óleos e no produto. Os resultados mostraram que as menores alterações ocorreram para o óleo de palma, mais saturado. Para os óleos de algodão e girassol, mais insaturados, verificou-se que ao longo dos tempos de frituras ocorreu um aumento da formação dos compostos de degradação e diminuiu a estabilidade oxidativa. Apesar das diferenças na composição em ácidos graxos, os óleos estudados não apresentaram, em nenhuma análise, valores acima dos limites recomendados, independentemente do tempo de aquecimento. PALAVRAS-CHAVE: Óleos vegetais; alterações oxidativas; estabilidade oxidativa; frituras.

Space station systems analysis study. Part 2, Volume 2. [technical report

Science.gov (United States)

1977-01-01

Specific system options are defined and identified for a cost effective space station capable of orderly growth with regard to both function and orbit location. Selected program options are analyzed and configuration concepts are developed to meet objectives for the satellite power system, earth servicing, space processing, and supporting activities. Transportation systems are analyzed for both LEO and GEO orbits.

Prediction of Thermal Environment in a Large Space Using Artificial Neural Network

Directory of Open Access Journals (Sweden)

Hyun-Jung Yoon

2018-02-01

Full Text Available Since the thermal environment of large space buildings such as stadiums can vary depending on the location of the stands, it is important to divide them into different zones and evaluate their thermal environment separately. The thermal environment can be evaluated using physical values measured with the sensors, but the occupant density of the stadium stands is high, which limits the locations available to install the sensors. As a method to resolve the limitations of installing the sensors, we propose a method to predict the thermal environment of each zone in a large space. We set six key thermal factors affecting the thermal environment in a large space to be predicted factors (indoor air temperature, mean radiant temperature, and clothing and the fixed factors (air velocity, metabolic rate, and relative humidity. Using artificial neural network (ANN models and the outdoor air temperature and the surface temperature of the interior walls around the stands as input data, we developed a method to predict the three thermal factors. Learning and verification datasets were established using STAR CCM+ (2016.10, Siemens PLM software, Plano, TX, USA. An analysis of each model’s prediction results showed that the prediction accuracy increased with the number of learning data points. The thermal environment evaluation process developed in this study can be used to control heating, ventilation, and air conditioning (HVAC facilities in each zone in a large space building with sufficient learning by ANN models at the building testing or the evaluation stage.

A Comprehensive CFD Tool for Aerothermal Environment Around Space Vehicles, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The goal of this SBIR project is to develop an innovative, high fidelity computational tool for accurate prediction of aerothermal environment around space vehicles....

A Comprehensive CFD Tool for Aerothermal Environment Around Space Vehicles, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The goal of this SBIR project is to develop an innovative, high fidelity computational tool for accurate prediction of aerothermal environment around space vehicles....

Redução de inóculo de Aphelenchoides besseyi em sementes de Brachiaria brizantha tratadas com óleos essenciais

Directory of Open Access Journals (Sweden)

Thalita Suelen Avelar Monteiro

2014-07-01

Full Text Available Óleos essenciais foram testados com o objetivo de controlar Aphelenchoides besseyi em sementes de Brachiaria brizantha cv. 'Marandu'. Sementes naturalmente infestadas por A. besseyi foram tratadas com óleos essenciais de mostarda (Brassica nigra, canela (Cinnamomum zeylanicum, verbena (Lippia citriodora e Bioprotector (r (produto comercial composto por extratos e óleos essenciais derivados de plantas, nas concentrações de 0,5% e 1,0%. Avaliou-se também o efeito dos tratamentos após aplicação direta nos juvenis (ensaio in vitro. Todos os óleos tiveram sua efetividade reduzida no ensaio em semente (in vivo em relação ao ensaio in vitro. Os tratamentos não erradicaram o nematoide das sementes, sendo que os óleos essenciais de canela e verbena, nas concentrações 0,5% e 1,0%, Bioprotector (r a 1,0% e óleo de mostarda a 1,0% reduziram o nível populacional do nematoide em sementes contaminadas. O óleo de mostarda a 1,0% destacou-se dos demais por ter apresentado ação nematicida sem alterar a germinação das sementes.

Hinnangud võtmeesinejatele / Leo Voogt ; inglise keelest tõlkinud Kristina Pai

Index Scriptorium Estoniae

Voogt, Leo

2012-01-01

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

Criação de valor sustentável e o óleo de palma no Brasil

OpenAIRE

Almeida, Julio Ribeiro

2012-01-01

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

Rapid thermal cycling of new technology solar array blanket coupons

Science.gov (United States)

Scheiman, David A.; Smith, Bryan K.; Kurland, Richard M.; Mesch, Hans G.

1990-01-01

NASA Lewis Research Center is conducting thermal cycle testing of a new solar array blanket technologies. These technologies include test coupons for Space Station Freedom (SSF) and the advanced photovoltaic solar array (APSA). The objective of this testing is to demonstrate the durability or operational lifetime of the solar array interconnect design and blanket technology within a low earth orbit (LEO) or geosynchronous earth orbit (GEO) thermal cycling environment. Both the SSF and the APSA array survived all rapid thermal cycling with little or no degradation in peak performance. This testing includes an equivalent of 15 years in LEO for SSF test coupons and 30 years of GEO plus ten years of LEO for the APSA test coupon. It is concluded that both the parallel gap welding of the SSF interconnects and the soldering of the APSA interconnects are adequately designed to handle the thermal stresses of space environment temperature extremes.

Atmospheric and Space Sciences: Ionospheres and Plasma Environments

Science.gov (United States)

Yiǧit, Erdal

2018-01-01

The SpringerBriefs on Atmospheric and Space Sciences in two volumes presents a concise and interdisciplinary introduction to the basic theory, observation & modeling of atmospheric and ionospheric coupling processes on Earth. The goal is to contribute toward bridging the gap between meteorology, aeronomy, and planetary science. In addition recent progress in several related research topics, such atmospheric wave coupling and variability, is discussed. Volume 1 will focus on the atmosphere, while Volume 2 will present the ionospheres and the plasma environments. Volume 2 is aimed primarily at (research) students and young researchers that would like to gain quick insight into the basics of space sciences and current research. In combination with the first volume, it also is a useful tool for professors who would like to develop a course in atmospheric and space physics.

The binary fraction of stars in dwarf galaxies: the case of Leo II

OpenAIRE

Spencer, Meghin; Mateo, Mario; Walker, Matthew; Olszewski, Edward; McConnachie, Alan; Kirby, Evan; Koch, Andreas

2017-01-01

We combine precision radial velocity data from four different published works of the stars in the Leo II dwarf spheroidal galaxy. This yields a data set that spans 19 years, has 14 different epochs of observation, and contains 372 unique red giant branch stars, 196 of which have repeat observations. Using this multi-epoch data set, we constrain the binary fraction for Leo II. We generate a suite of Monte Carlo simulations that test different binary fractions using Bayesian analysis and determ...

Neighbourhood green space, social environment and mental health: an examination in four European cities.

Science.gov (United States)

Ruijsbroek, Annemarie; Mohnen, Sigrid M; Droomers, Mariël; Kruize, Hanneke; Gidlow, Christopher; Gražulevičiene, Regina; Andrusaityte, Sandra; Maas, Jolanda; Nieuwenhuijsen, Mark J; Triguero-Mas, Margarita; Masterson, Daniel; Ellis, Naomi; van Kempen, Elise; Hardyns, Wim; Stronks, Karien; Groenewegen, Peter P

2017-07-01

This study examines the relationship between neighbourhood green space, the neighbourhood social environment (social cohesion, neighbourhood attachment, social contacts), and mental health in four European cities. The PHENOTYPE study was carried out in 2013 in Barcelona (Spain), Stoke-on-Trent (United Kingdom), Doetinchem (The Netherlands), and Kaunas (Lithuania). 3771 adults living in 124 neighbourhoods answered questions on mental health, neighbourhood social environment, and amount and quality of green space. Additionally, audit data on neighbourhood green space were collected. Multilevel regression analyses examined the relation between neighbourhood green space and individual mental health and the influence of neighbourhood social environment. Mental health was only related to green (audit) in Barcelona. The amount and quality of neighbourhood green space (audit and perceived) were related to social cohesion in Doetinchem and Stoke-on-Trent and to neighbourhood attachment in Doetinchem. In all four cities, mental health was associated with social contacts. Neighbourhood green was related to mental health only in Barcelona. Though neighbourhood green was related to social cohesion and attachment, the neighbourhood social environment seems not the underlying mechanism for this relationship.

Effects of the space environment on the health and safety of space workers

Science.gov (United States)

Hull, W. E.

1980-07-01

Large numbers of individuals are required to work in space to assemble and operate a Solar Power Satellite. The physiological and behavioral consequences for large groups of men and women who perform complex tasks in the vehicular or extravehicular environments over long periods of orbital stay time were considered. The most disturbing consequences of exposure to the null gravity environment found relate to: (1) a generalized cardiovascular deconditioning along with loss of a significant amount of body fluid volume; (2) loss of bone minerals and muscle mass; and (3) degraded performance of neutral mechanisms which govern equilibrium and spatial orientation.

Effects of the space environment on the health and safety of space workers

Science.gov (United States)

Hull, W. E.

1980-01-01

Large numbers of individuals are required to work in space to assemble and operate a Solar Power Satellite. The physiological and behavioral consequences for large groups of men and women who perform complex tasks in the vehicular or extravehicular environments over long periods of orbital stay time were considered. The most disturbing consequences of exposure to the null gravity environment found relate to: (1) a generalized cardiovascular deconditioning along with loss of a significant amount of body fluid volume; (2) loss of bone minerals and muscle mass; and (3) degraded performance of neutral mechanisms which govern equilibrium and spatial orientation.

Effect of science laboratory centrifuge of space station environment

Science.gov (United States)

Searby, Nancy

1990-01-01

It is argued that it is essential to have a centrifuge operating during manned space station operations. Background information and a rationale for the research centrifuge are given. It is argued that we must provide a controlled acceleration environment for comparison with microgravity studies. The lack of control groups in previous studies throws into question whether the obseved effects were the result of microgravity or not. The centrifuge could be used to provide a 1-g environment to supply specimens free of launch effects for long-term studies. With the centrifuge, the specimens could be immediately transferred to microgravity without undergoing gradual acclimation. Also, the effects of artificial gravity on humans could be investigated. It is also argued that the presence of the centrifuge on the space station will not cause undo vibrations or other disturbing effects.

Compensation of an attitude disturbance torque caused by magnetic substances in LEO satellites

Science.gov (United States)

Inamori, Takaya; Wang, Jihe; Saisutjarit, Phongsatorn; Ohsaki, Hiroyuki

This research considers an attitude disturbance torque caused by ferromagnetic substances in a LEO satellite. In most LEO satellite missions, a gravity gradient torque, solar pressure torque, aerodynamic torque, and magnetic dipole moment torque are considered for their attitude control systems, however, the effect of the ferromagnetic substances causing a disturbance torque in the geomagnetic field is not considered in previous satellite missions. The ferromagnetic substances such as iron cores of MTQs and a magnetic hysteresis damper for a passive attitude control system are used in various small satellites. These substances cause a disturbance torque which is almost the same magnitude of the dipole magnetic disturbance and the dominant disturbance in the worst cases. This research proposes a method to estimate and compensate for the effect of the ferromagnetic substances using an extended Kalman filter. From simulation results, the research concludes that the proposed method is useful and attractive for precise attitude control for LEO satellite missions.

Oncogenesis of melanoma B16 cell clones mutagenized by space environment

International Nuclear Information System (INIS)

Guo Yupeng; Yang Hongsheng; Tang Jingtian; Xu Mei; Geng Chuanying; Fang Qing; Xu Bo; Li Hongyan; Xiang Xing; Pan Lin

2005-01-01

Objective: To explore the oncogenesis of the melanoma B16 cell clones mutagenized by space environment, and find the B16 cell clones with remarkably mutated immunogenicity. Methods: B16 cells were carried by the Chinese 20th recoverable satellite to the outer space, and were harvested after 18 days' spaceflight and then monocloned. Four cell clones, which were randomly selected from the total 110 clones obtained , and the control clone were routinely cultured. The cultured cells were injected to 10 groups of C57BL/6J mice, 82.1 mice in each group. Five groups of mice received hypodermic injection and another 5 groups of mice received abdominal injection. The survival time was observed in abdominal injection groups. The mice in hypodermic injection groups were sacrificed after 14 days, the tumor, spleen and thymus were weighted, and the serum IL-2 concentration was determined. Moreover, the melanoma tumor tissues were examined histopathologically. Results: An experiment program suitable to screening space mutagenesis of B16 tumor cell clones in vivo and the observation indices were basically established. One clone was found out which was remarkably different from the control clone in latent period of tumor formation, tumor weight, survival time of the tumor-bearing mice and the expression of IL-2. Conclusions: Cultured melanoma B16 cells could be mutated by outer space environment. The further study will be focused on the influence of space environment on immunogenicity of mutagenized B16 cells. (authors)

Analysis on Space Environment from the Anomalies of Geosynchronous Satellites

Directory of Open Access Journals (Sweden)

Jaejin Lee

2009-12-01

Full Text Available While it is well known that space environment can produce spacecraft anomaly, defining space environment effects for each anomalies is difficult. This is caused by the fact that spacecraft anomaly shows various symptoms and reproducing it is impossible. In this study, we try to find the conditions of when spacecraft failures happen more frequently and give satellite operators useful information. Especially, our study focuses on the geosynchronous satellites which cost is high and required high reliability. We used satellite anomaly data given by Satellite News Digest which is internet newspaper providing space industry news. In our analysis, 88 anomaly cases occurred from 1997 to 2008 shows bad corelation with Kp index. Satellite malfunctions were likely to happen in spring and fall and in local time from midnight to dawn. In addition, we found the probability of anomaly increase when high energy electron flux is high. This is more clearly appeared in solar minimum than maximum period.

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

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Taciany Ferreira de Souza

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

Composição química e atividade in vitro de três óleos essenciais sobre Colletotrichum gloeosporioides do maracujazeiro

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C.F. Aquino

2014-01-01

Full Text Available Objetivou-se avaliar a ação de diferentes concentrações de óleos essenciais de três plantas medicinais sobre o crescimento micelial, a produção e a germinação de conídios de Colletotrichum gloeosporioides (Penz.. Utilizou-se os óleos essenciais de Lippia sidoides Cham., Cymbopogon citratus (DC Stapf. e Ocimum gratissimum L. em cinco concentrações (0 µL mL-1, 1 µL mL-1, 3 µL mL-1, 5 µL mL-1 e 7 µL mL-1 com 4 repetições no delineamento inteiramente casualizado, em esquema fatorial 5x3. Os óleos foram analisados por cromatografia gasosa acoplada com espectrometria de massas. Para todas as características verificou-se efeito significativo da interação "Óleo" versus "Concentração". O óleo essencial de C. citratus proporcionou a maior inibição do crescimento micelial em todas as concentrações testadas. Os outros óleos não se diferenciaram, exceto a partir da concentração de 5 µL mL-1, onde o óleo de L. sidoides foi superior ao óleo de O. gratissimum. Na produção e germinação de conídios, o óleo de C. citratus, foi superior aos óleos de L. sidoides e de O. gratissimum nas concentrações de 1 µL mL-1 e 3 µL mL-1, inibindo completamente a produção e germinação a partir da concentração de 3 µL mL-1. As concentrações influenciam em todas as variáveis, ajustando-se à equação do modelo linear. Observa-se o decréscimo nessas, à medida em que se aumentam as concentrações dos óleos testados. Os óleos essenciais testados possuem efeito fungitóxico e fungistático.

Specification of the near-Earth space environment with SHIELDS

International Nuclear Information System (INIS)

Jordanova, Vania Koleva; Delzanno, Gian Luca; Henderson, Michael Gerard; Godinez, Humberto C.; Jeffery, Christopher Andrew Munn

2017-01-01

Here, predicting variations in the near-Earth space environment that can lead to spacecraft damage and failure is one example of “space weather” and a big space physics challenge. A project recently funded through the Los Alamos National Laboratory (LANL) Directed Research and Development (LDRD) program aims at developing a new capability to understand, model, and predict Space Hazards Induced near Earth by Large Dynamic Storms, the SHIELDS framework. The project goals are to understand the dynamics of the surface charging environment (SCE), the hot (keV) electrons representing the source and seed populations for the radiation belts, on both macro- and micro-scale. Important physics questions related to particle injection and acceleration associated with magnetospheric storms and substorms, as well as plasma waves, are investigated. These challenging problems are addressed using a team of world-class experts in the fields of space science and computational plasma physics, and state-of-the-art models and computational facilities. A full two-way coupling of physics-based models across multiple scales, including a global MHD (BATS-R-US) embedding a particle-in-cell (iPIC3D) and an inner magnetosphere (RAM-SCB) codes, is achieved. New data assimilation techniques employing in situ satellite data are developed; these provide an order of magnitude improvement in the accuracy in the simulation of the SCE. SHIELDS also includes a post-processing tool designed to calculate the surface charging for specific spacecraft geometry using the Curvilinear Particle-In-Cell (CPIC) code that can be used for reanalysis of satellite failures or for satellite design.

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

Directory of Open Access Journals (Sweden)

Maria Isabel Morgan Martins

2016-10-01

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

The Leo I color-magnitude diagram

International Nuclear Information System (INIS)

Reid, N.; Mould, J.

1991-01-01

The R-and I-band photometry of the Leo I dwarf galaxy is presented. A relatively narrow giant branch is found, Implying an abundance range of no more than Fe/H/= - 0.7 to - 1.3. This is in contrast to the results is found by Fox and Pritchet (1987) from BV CCD photometry. The distance modulus is estimated as (m - M) = 21.85 + or - 0.15, based on the luminosity of the tip of the red giant branch. 15 refs

Uso de óleo essencial de orégano, salinomicina e bacitracina de zinco na dieta de frangos de corte

Directory of Open Access Journals (Sweden)

Patricia Maria Meneghetti Pulici

2014-09-01

Full Text Available O presente trabalho teve como objetivo avaliar dietas com óleo essencial de orégano, associado ou não com salinomicina, como alternativa à bacitracina de zinco sobre o desempenho zootécnico de frangos de corte. Foram utilizados 600 pintos de um dia de idade, machos, da linhagem Cobb® 500, criados até 42 dias de idade em boxes com cama de casca de arroz providos de comedouros tubulares e bebedouros nipple. O delineamento foi inteiramente casualizado, com seis dietas e 10 repetições de 10 aves cada. As dietas experimentais à base de milho e farelo de soja foram: controle positivo – antibiótico (bacitracina de zinco + 0,05% de anticoccidiano (salinomicina, controle negativo – dieta basal (DB sem aditivos, DB + 0,05% de salinomicina e 0,03% de óleo essencial de orégano (Orego-Stim®, DB + 0,03% de óleo essencial de orégano, DB + 0,05% de salinomicina e 0,05% de óleo essencial de orégano, DB + 0,05% de óleo essencial de orégano. Não foi encontrado efeito da utilização do óleo de orégano até 21 dias no desempenho das aves. Nos demais períodos, aos 35 e 42 dias, o desempenho das aves tratadas com 0,03% de óleo essencial de orégano + salinomicina apresentou resultados semelhantes ao controle positivo, levando à conclusão de que a dose de 0,03% de óleo essencial de orégano + salinomicina pode substituir a bacitracina de zinco + salinomicina em dietas para frangos de corte.

The Space Mission Design Example Using LEO Bolos

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Oleg Nizhnik

2013-12-01

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

Electro-Mechanical Systems for Extreme Space Environments

Science.gov (United States)

Mojarradi, Mohammad M.; Tyler, Tony R.; Abel, Phillip B.; Levanas, Greg

2011-01-01

Exploration beyond low earth orbit presents challenges for hardware that must operate in extreme environments. The current state of the art is to isolate and provide heating for sensitive hardware in order to survive. However, this protection results in penalties of weight and power for the spacecraft. This is particularly true for electro-mechanical based technology such as electronics, actuators and sensors. Especially when considering distributed electronics, many electro-mechanical systems need to be located in appendage type locations, making it much harder to protect from the extreme environments. The purpose of this paper to describe the advances made in the area of developing electro-mechanical technology to survive these environments with minimal protection. The Jet Propulsion Lab (JPL), the Glenn Research Center (GRC), the Langley Research Center (LaRC), and Aeroflex, Inc. over the last few years have worked to develop and test electro-mechanical hardware that will meet the stringent environmental demands of the moon, and which can also be leveraged for other challenging space exploration missions. Prototype actuators and electronics have been built and tested. Brushless DC actuators designed by Aeroflex, Inc have been tested with interface temperatures as low as 14 degrees Kelvin. Testing of the Aeroflex design has shown that a brushless DC motor with a single stage planetary gearbox can operate in low temperature environments for at least 120 million cycles (measured at motor) if long life is considered as part of the design. A motor control distributed electronics concept developed by JPL was built and operated at temperatures as low as -160 C, with many components still operational down to -245 C. Testing identified the components not capable of meeting the low temperature goal of -230 C. This distributed controller is universal in design with the ability to control different types of motors and read many different types of sensors. The controller

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

NARCIS (Netherlands)

Hoogmoed, M.S.

1995-01-01

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

Apparent rotation properties of space debris extracted from photometric measurements

Science.gov (United States)

Šilha, Jiří; Pittet, Jean-Noël; Hamara, Michal; Schildknecht, Thomas

2018-02-01

Knowledge about the rotation properties of space debris objects is essential for the active debris removal missions, accurate re-entry predictions and to investigate the long-term effects of the space environment on the attitude motion change. Different orbital regions and object's physical properties lead to different attitude states and their change over time. Since 2007 the Astronomical Institute of the University of Bern (AIUB) performs photometric measurements of space debris objects. To June 2016 almost 2000 light curves of more than 400 individual objects have been acquired and processed. These objects are situated in all orbital regions, from low Earth orbit (LEO), via global navigation systems orbits and high eccentricity orbit (HEO), to geosynchronous Earth orbit (GEO). All types of objects were observed including the non-functional spacecraft, rocket bodies, fragmentation debris and uncorrelated objects discovered during dedicated surveys. For data acquisition, we used the 1-meter Zimmerwald Laser and Astrometry Telescope (ZIMLAT) at the Swiss Optical Ground Station and Geodynamics Observatory Zimmerwald, Switzerland. We applied our own method of phase-diagram reconstruction to extract the apparent rotation period from the light curve. Presented is the AIUB's light curve database and the obtained rotation properties of space debris as a function of object type and orbit.

TIROS-N/NOAA A-J space environment monitor subsystem. Technical memo

International Nuclear Information System (INIS)

Seale, R.A.; Bushnell, R.H.

1987-04-01

The Space Environment Monitor (SEM), which is incorporated as a subsystem in the TIROS-N and NOAA A-J satellites, is described. The SEM consists of a Total Energy Detector (TED), a Medium Energy Proton and Electron Detector (MEPED), a High Energy Proton and Alpha Detector (HEPAD) and a Data Processing Unit (DPU). The detectors are intended to provide near-real-time particle data for use in the Space Environment Service Center of National Oceanic and Atmospheric Administration (NOAA) and to provide a long-term scientific data base. Telemeter codes, data reduction, and test instructions are given

BUSEFL: The Boston University Space Environment Forecast Laboratory

International Nuclear Information System (INIS)

Contos, A.R.; Sanchez, L.A.; Jorgensen, A.M.

1996-01-01

BUSEFL (Boston University Space Environment Forecast Laboratory) is a comprehensive, integrated project to address the issues and implications of space weather forecasting. An important goal of the BUSEFL mission is to serve as a testing ground for space weather algorithms and operational procedures. One such algorithm is the Magnetospheric Specification and Forecast Model (MSFM), which may be implemented in possible future space weather prediction centers. Boston University Student-satellite for Applications and Training (BUSAT), the satellite component of BUSEFL, will incorporate four experiments designed to measure (1) the earth close-quote s magnetic field, (2) distribution of energetic electrons trapped in the earth close-quote s radiation belts, (3) the mass and charge composition of the ion fluxes along the magnetic field lines and (4) the auroral forms at the foot of the field line in the auroral zones. Data from these experiments will be integrated into a ground system to evaluate space weather prediction codes. Data from the BUSEFL mission will be available to the scientific community and the public through media such as the World Wide Web (WWW). copyright 1996 American Institute of Physics

MODELAGEM TERMODINÂMICA DO FRACIONAMENTO DO ÓLEO DE MANTEIGA COM FLUIDOS SUPERCRÍTICOS

Directory of Open Access Journals (Sweden)

Guilherme B. M. NEVES

1997-12-01

Full Text Available O fracionamento do óleo de manteiga em frações de propriedades físicas e químicas diferentes mostra-se uma possível solução para o problema do excedente de óleo de manteiga no mercado internacional, despertando interesse em seu estudo. Com o objetivo de se modelar o equilíbrio de fases neste processo, foi feito um agrupamento dos 1331 triglicerídeos presentes no óleo de manteiga em 14 famílias. Assim, os componentes de uma mesma família possuem um comportamento semelhante quando expostos ao CO2 Supercrítico (CO2 SC. A seguir, utilizando a Equação de Peng-Robinson, realizou-se o cálculo do equilíbrio de fases no sistema óleo de manteiga/CO2, sendo o óleo de manteiga representado por uma mistura de 14 componentes hipotéticos, as famílias. Foram desenvolvidas correlações para a temperatura e pressão críticas e parâmetros de interação binária das famílias. O modelo foi capaz de correlacionar dados obtidos da literatura. As predições do equilíbrio de fases estão em excelente concordância com os dados obtidos pelos autores deste trabalho para os sistemas de óleo de manteiga/CO2. O procedimento mostrado aqui aplica-se não só ao dióxido de carbono supercrítico mas também a outros fluidos ou misturas de fluidos supercríticos, e também não somente ao óleo de manteiga, mas a todos os óleos/gorduras cuja constituição principal sejam triglicerídeos.Fractionation of butter oil into fractions with different physical and chemical properties is a possible solution for the problem of the excess of butter oil in the international market. With the objective of modeling the phase equilibria, the 1331 triglycerides were grouped into 14 families according to the number of carbons. Components belonging to the same family are considered to exhibit similar behavior when exposed to supercritical carbon dioxide (SC CO2. Using the Peng-Robinson equation of state, phase equilibrium calculations were performed for the butter

Óleos essenciais de folhas de diversas espécies: propriedades antioxidantes e antibacterianas no crescimento espécies patogênicas

Directory of Open Access Journals (Sweden)

Cíntia Alvarenga Santos Fraga Miranda

Full Text Available RESUMO Os óleos essenciais apresentam possibilidade de serem empregados nas indústrias de alimentos, bebidas, produtos de higiene pessoal e cosméticos para evitar ou reduzir a deterioração lipídica e a contaminação por micro-organismos. Este trabalho teve como objetivos avaliar as propriedades funcionais antimicrobianas e antioxidantes de óleos essenciais de folhas frescas de Coniza bonariensis, Parthenium hysterophorus, Tithonia diversifolia, Ambrosia polystachya, Hedychium coronarium e Baccharis dracunculifolia, extraídos por hidrodestilação. O potencial antioxidante foi avaliado pelas metodologias do consumo do radical DPPH e da inibição da oxidação do sistema β-caroteno/ácido linoleico. A sensibilidade das bactérias Salmonella Cholerasuis, Listeria monocytogenes, Staphylococcus aureus e Escherichia coli frente aos óleos essenciais foi determinada pela utilização do método de difusão em cavidade ágar. Os óleos essenciais destacaram-se pelo elevado conteúdo de terpenoides. Todos os óleos essenciais avaliados pela metodologia do sequestro do radical DPPH não apresentaram CI50 significativos. Pela metodologia do β-caroteno/ácido linoleico, os óleos essenciais de T. diversifolia e H. coronarium não apresentaram atividades significativas e os de C. bonariensis, P. hysterophorus, A. polystachya, e B. dracunculifolia apresentaram CI50 superiores a maior concentração avaliada. Os óleos essenciais das espécies C. bonariensis, T. diversifolia, H. coronarium e de B. dracunculifolia apresentaram atividade antibacteriana para bactérias Gramnegativas e Gram-positivas, com exceção do óleo volátil de P. hysterophorus, que não impediu o crescimento de nenhuma das cepas bacterianas testadas. O óleo essencial de A. polystachya apresentou potencial antibacteriano apenas nas cepas de S. aureus.

LDEF materials: An overview of the interim findings

International Nuclear Information System (INIS)

Stein, B.A.

1992-01-01

The flight and retrieval of the National Aeronautics and Space Administration's Long Duration Exposure Facility (LDEF) provided an opportunity for the study of the low-Earth orbit (LEO) environment and long-duration space environmental effect (SEE) on materials that are unparalleled in the history of the U.S. space program. The 5.8-year flight of LDEF greatly enhanced the potential value of materials data from LDEF to the international SEE community, compared to that of the original 1-year flight plan. The remarkable flight attitude stability of LDEF enables specific analyses of various individual and combined effects of LEO environmental parameters on identical materials of the same space vehicle. NASA recognized the potential by forming the LDEF Space Environmental Effects on Materials Special Investigation Group (MSIG) to address the greatly expanded materials and LEO space environment parameter analysis opportunities available in the LDEF structure, experiment trays, and corollary measurements, so that the combined value of all LDEF materials data to current and future space missions will be assessed and documented. This paper provides an overview of the interim LDEF materials findings of the Principal Investigators and the Materials Special Investigation Group. These revelations are based on observations of LEO environmental effects on materials made in-space during LDEF retrieval and during LDEF tray deintegration at the Kennedy Space Center, and on findings of approximately 1.5 years of laboratory analyses of LDEF materials by the LDEF materials scientists. These findings were extensively reviewed and discussed at the MSIG-sponsored LDEF Materials Workshop '91. The results are presented in a format which categorizes the revelations as clear findings or confusing/unexplained findings and resultant needs for new space materials developments and ground simulation testing/analytical modeling

The contamination of personal space : boundary construction in a prison environment

NARCIS (Netherlands)

Sibley, David; van Hoven, Bettina

In this paper, inmates in dormitories in a prison in New Mexico, USA, talk about their everyday lives. We are particularly interested in the ways in which they think about space. Their principal concern appears to be the definition of personal space in an environment where boundaries are weak. The

From outer space to Earth-The social significance of isolated and confined environment research in human space exploration

Science.gov (United States)

Tachibana, Koji; Tachibana, Shoichi; Inoue, Natsuhiko

2017-11-01

Human space exploration requires massive budgets every fiscal year. Especially under severe financial constraint conditions, governments are forced to justify to society why spending so much tax revenue for human space exploration is worth the cost. The value of human space exploration might be estimated in many ways, but its social significance and cost-effectiveness are two key ways to gauge that worth. Since these measures should be applied country by country because sociopolitical conditions differ in each country and must be taken into consideration, the study on the social significance of human space exploration must take the coloration of a case-study. This paper, focusing on the case of Japan with surveying Japanese literary and national documents as well as taking its sociopolitical conditions into account, examines the social significance of human space exploration. First, we give an overview of the circumstances surrounding Japan's human space exploration program. Derived from the statements of such relevant parties as scholars, journalists, policy makers, and astronauts, this overview indicates that the main concerns about human space exploration in Japan are its social significance and cost-effectiveness (Section 1). Next, an overview of behavioral science-an essential field for human space exploration (referred to in this paper as space behavioral science) that provides support for astronauts-is presented from the perspective of stress research in isolated and confined environments (Section 2). We then give two examples of where such knowledge from space behavioral science research has been applied to terrestrial isolated and confined environments. One is JAXA's support in 2009 for people who were vulnerable to infection by a new strain of flu and accordingly placed in an isolated and confined facility under the Infectious Disease Law and the Quarantine Law. The other is NASA's support in 2010 for Chilean mine workers who were trapped 700 m

Creating the Thermal Environment for Safely Testing the James Webb Space Telescope at the Johnson Space Center's Chamber A

Science.gov (United States)

Homan, Jonathan L.; Lauterbach, John; Garcia, Sam

2016-01-01

Chamber A is the largest thermal vacuum chamber at the Johnson Space Center and is one of the largest space environment chambers in the world. The chamber is 19.8 m (65 ft) in diameter and 36.6 m (120 ft) tall and is equipped with cryogenic liquid nitrogen panels (shrouds) and gaseous helium shrouds to create a simulated space environment. The chamber was originally built to support testing of the Apollo Service and Command Module for lunar missions, but underwent major modifications to be able to test the James Webb Space Telescope in a simulated deep space environment. To date seven tests have been performed in preparation of testing the flight optics for the James Webb Space Telescope (JWST). Each test has had a uniquie thermal profile and set of thermal requirements for cooling down and warming up, controlling contamination, and releasing condensed air. These range from temperatures from 335K to 15K, with tight uniformity and controllability for maintining thermal stability and pressure control. One unique requirement for two test was structurally proof loading hardware by creating thermal gradients at specific temperatures. This paper will discuss the thermal requirements and goals of the tests, the original requirements of the chamber thermal systems for planned operation, and how the new requirements were met by the team using the hardware, system flexiblilty, and engineering creativity. It will also discuss the mistakes and successes to meet the unique goals, especially when meeting the thermal proof load.

Capacidade antioxidante total de óleos vegetais comestíveis: determinantes químicos e sua relação com a qualidade dos óleos Total antioxidant capacity of edible vegetable oils: chemical determinants and associations with oil quality

Directory of Open Access Journals (Sweden)

Vanessa Naciuk Castelo-Branco

2011-02-01

Full Text Available A capacidade antioxidante total de óleos vegetais comestíveis é determinada por sua composição físico-química e pode estar associada a atributos de qualidade dos óleos, especialmente a sua bioatividade e possivelmente a sua estabilidade oxidativa. Este artigo apresenta os fundamentos dos ensaios de capacidade antioxidante total e avalia criticamente os ensaios aplicáveis na análise de óleos e os pontos críticos nas aplicações dos ensaios para a análise dessas amostras. Discute-se o potencial papel dos componentes químicos dos óleos comestíveis como determinantes da capacidade antioxidante total, assim como a possível relação da capacidade antioxidante com a bioatividade e a estabilidade oxidativa dos óleos. Finalmente, discutem-se evidências de que, caso seja sistematicamente investigado em trabalhos experimentais futuros, o uso de ensaios de capacidade antioxidante total na análise de óleos vegetais pode contribuir para integrar o conhecimento da composição química com a bioatividade e possivelmente com a estabilidade de óleos vegetais específicos. Dessa forma, os ensaios de capacidade antioxidante apresentam potencial para aplicação no controle da qualidade integral de óleos comestíveis.The total antioxidant capacity of edible vegetable oils is determined by their physical-chemical composition and might be associated with their quality attributes, especially with bioactivity and possibly with oxidative stability. The current review presents the fundamentals of total antioxidant capacity assays and critically evaluates the assays applicable to the analysis of oils. The role of the chemical components of edible oils as determinants of total antioxidant capacity is discussed, as well as the potential associations between antioxidant capacity and bioactivity or oxidative stability of the selected oils. Finally, we discuss evidences that, if systematically addressed in future experimental work, the application of

Towards the Next Generation of Space Environment Prediction Capabilities.

Science.gov (United States)

Kuznetsova, M. M.

2015-12-01

Since its establishment more than 15 years ago, the Community Coordinated Modeling Center (CCMC, http://ccmc.gsfc.nasa.gov) is serving as an assess point to expanding collection of state-of-the-art space environment models and frameworks as well as a hub for collaborative development of next generation space weather forecasting systems. In partnership with model developers and international research and operational communities the CCMC integrates new data streams and models from diverse sources into end-to-end space weather impacts predictive systems, identifies week links in data-model & model-model coupling and leads community efforts to fill those gaps. The presentation will highlight latest developments, progress in CCMC-led community-wide projects on testing, prototyping, and validation of models, forecasting techniques and procedures and outline ideas on accelerating implementation of new capabilities in space weather operations.

Urban Public Space Context and Cognitive Psychology Evolution in Information Environment

Science.gov (United States)

Feng, Chen; Xu, Hua-wei

2017-11-01

The rapid development of information technology has had a great impact on the understanding of urban environment, which brings different spatially psychological experience. Information and image transmission has been full with the streets, both the physical space and virtual space have been unprecedentedly blended together through pictures, images, electronic media and other tools, which also stimulates people’s vision and psychology and gives birth to a more complex form of urban space. Under the dual role of spatial mediumlization and media spatialization, the psychological cognitive pattern of urban public space context is changing.

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

African Journals Online (AJOL)

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

Healing environments in cancer treatment and care. Relations of space and practice in hematological cancer treatment.

Science.gov (United States)

Høybye, Mette Terp

2013-02-01

Given the growing attention to the importance of design in shaping healing hospital environments this study extends the understanding of healing environments, beyond causal links between environmental exposure and health outcome by elucidating how environments and practices interrelate. The study was conducted as an ethnographic fieldwork from March 2011 to September 2011 at the Department of Haematology at Odense University Hospital, Denmark, systematically using participant observation and interviews as research strategies. It included 20 patients, four of who were followed closely over an extended time period. Through thematic analysis five key concepts emerged about the social dynamics of hospital environments: practices of self; creating personal space; social recognition; negotiating space; and ambiguity of space and care. Through these concepts, the study demonstrates how the hospital environment is a flow of relations between space and practice that changes and challenges a structural idea of design and healing. Patients' sense of healing changes with the experience of progression in treatment and the capacity of the hospital space to incite an experience of homeliness and care. Furthermore, cancer patients continuously challenge the use and limits of space by individual objects and practices of privacy and home. Healing environments are complex relations between practices, space and care, where recognition of the individual patient's needs, values and experiences is key to developing the environment to support the patient quality of life. The present study holds implications for practice to inform design of future hospital environments for cancer treatment. The study points to the importance for being attentive to the need for flexible spaces in hospitals that recognize the dynamics of healing, by providing individualized care, relating to the particular and changing needs of patients supporting their potential and their challenged condition with the best

PRODUÇÃO DE PETRÓLEO E IMPACTOS AMBIENTAIS: ALGUMAS CONSIDERAÇÕES

Directory of Open Access Journals (Sweden)

Silas Sarkiz da Silva Martins

2015-12-01

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

Crystal Growth and Other Materials Physical Researches in Space Environment

Science.gov (United States)

Pan, Mingxiang

Material science researches in space environment are based on reducing the effects of buoyancy driven transport, the effects of atomic oxygen, radiation, extremes of heat and cold and the ultrahigh vacuum, so as to unveil the underlying fundamental phenomena, lead maybe to new potential materials or new industrial processes and develop space techniques. Currently, research program on materials sciences in Chinese Manned Space Engineering (CMSE) is going on. More than ten projects related to crystal growth and materials processes are selected as candidates to be executed in Shenzhou spacecraft, Tiangong Space Laboratory and Chinese Space Station. In this talk, we will present some examples of the projects, which are being prepared and executed in the near future flight tasks. They are both basic and applied research, from discovery to technology.

Crew behavior and performance in space analog environments

Science.gov (United States)

Kanki, Barbara G.

1992-01-01

The objectives and the current status of the Crew Factors research program conducted at NASA-Ames Research Center are reviewed. The principal objectives of the program are to determine the effects of a broad class of input variables on crew performance and to provide guidance with respect to the design and management of crews assigned to future space missions. A wide range of research environments are utilized, including controlled experimental settings, high fidelity full mission simulator facilities, and fully operational field environments. Key group processes are identified, and preliminary data are presented on the effect of crew size, type, and structure on team performance.

VirtualSpace: A vision of a machine-learned virtual space environment

Science.gov (United States)

Bortnik, J.; Sarno-Smith, L. K.; Chu, X.; Li, W.; Ma, Q.; Angelopoulos, V.; Thorne, R. M.

2017-12-01

Space borne instrumentation tends to come and go. A typical instrument will go through a phase of design and construction, be deployed on a spacecraft for several years while it collects data, and then be decommissioned and fade into obscurity. The data collected from that instrument will typically receive much attention while it is being collected, perhaps in the form of event studies, conjunctions with other instruments, or a few statistical surveys, but once the instrument or spacecraft is decommissioned, the data will be archived and receive progressively less attention with every passing year. This is the fate of all historical data, and will be the fate of data being collected by instruments even at the present time. But what if those instruments could come alive, and all be simultaneously present at any and every point in time and space? Imagine the scientific insights, and societal gains that could be achieved with a grand (virtual) heliophysical observatory that consists of every current and historical mission ever deployed? We propose that this is not just fantasy but is imminently doable with the data currently available, with the present computational resources, and with currently available algorithms. This project revitalizes existing data resources and lays the groundwork for incorporating data from every future mission to expand the scope and refine the resolution of the virtual observatory. We call this project VirtualSpace: a machine-learned virtual space environment.

Overview of the Space Launch System Ascent Aeroacoustic Environment Test Program

Science.gov (United States)

Herron, Andrew J.; Crosby, William A.; Reed, Darren K.

2016-01-01

Characterization of accurate flight vehicle unsteady aerodynamics is critical for component and secondary structure vibroacoustic design. The Aerosciences Branch at the National Aeronautics and Space Administration (NASA) Marshall Space Flight Center has conducted a test at the NASA Ames Research Center (ARC) Unitary Plan Wind Tunnels (UPWT) to determine such ascent aeroacoustic environments for the Space Launch System (SLS). Surface static pressure measurements were also collected to aid in determination of local environments for venting, CFD substantiation, and calibration of the flush air data system located on the launch abort system. Additionally, this test supported a NASA Engineering and Safety Center study of alternate booster nose caps. Testing occurred during two test campaigns: August - September 2013 and December 2013 - January 2014. Four primary model configurations were tested for ascent aeroacoustic environment definition. The SLS Block 1 vehicle was represented by a 2.5% full stack model and a 4% truncated model. Preliminary Block 1B payload and manned configurations were also tested, using 2.5% full stack and 4% truncated models respectively. This test utilized the 11 x 11 foot transonic and 9 x 7 foot supersonic tunnel sections at the ARC UPWT to collect data from Mach 0.7 through 2.5 at various total angles of attack. SLS Block 1 design environments were developed primarily using these data. SLS Block 1B preliminary environments have also been prepared using these data. This paper discusses the test and analysis methodology utilized, with a focus on the unsteady data collection and processing.

"Lomonosov" Satellite—Space Observatory to Study Extreme Phenomena in Space

Science.gov (United States)

Sadovnichii, V. A.; Panasyuk, M. I.; Amelyushkin, A. M.; Bogomolov, V. V.; Benghin, V. V.; Garipov, G. K.; Kalegaev, V. V.; Klimov, P. A.; Khrenov, B. A.; Petrov, V. L.; Sharakin, S. A.; Shirokov, A. V.; Svertilov, S. I.; Zotov, M. Y.; Yashin, I. V.; Gorbovskoy, E. S.; Lipunov, V. M.; Park, I. H.; Lee, J.; Jeong, S.; Kim, M. B.; Jeong, H. M.; Shprits, Y. Y.; Angelopoulos, V.; Russell, C. T.; Runov, A.; Turner, D.; Strangeway, R. J.; Caron, R.; Biktemerova, S.; Grinyuk, A.; Lavrova, M.; Tkachev, L.; Tkachenko, A.; Martinez, O.; Salazar, H.; Ponce, E.

2017-11-01

The "Lomonosov" space project is lead by Lomonosov Moscow State University in collaboration with the following key partners: Joint Institute for Nuclear Research, Russia, University of California, Los Angeles (USA), University of Pueblo (Mexico), Sungkyunkwan University (Republic of Korea) and with Russian space industry organizations to study some of extreme phenomena in space related to astrophysics, astroparticle physics, space physics, and space biology. The primary goals of this experiment are to study: Ultra-high energy cosmic rays (UHECR) in the energy range of the Greizen-Zatsepin-Kuzmin (GZK) cutoff; Ultraviolet (UV) transient luminous events in the upper atmosphere; Multi-wavelength study of gamma-ray bursts in visible, UV, gamma, and X-rays; Energetic trapped and precipitated radiation (electrons and protons) at low-Earth orbit (LEO) in connection with global geomagnetic disturbances; Multicomponent radiation doses along the orbit of spacecraft under different geomagnetic conditions and testing of space segments of optical observations of space-debris and other space objects; Instrumental vestibular-sensor conflict of zero-gravity phenomena during space flight. This paper is directed towards the general description of both scientific goals of the project and scientific equipment on board the satellite. The following papers of this issue are devoted to detailed descriptions of scientific instruments.

A research on the excavation, support, and environment control of large scale underground space

Energy Technology Data Exchange (ETDEWEB)

Kang, Pil Chong; Kwon, Kwang Soo; Jeong, So Keul [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

1995-12-01

With the growing necessity of the underground space due to the deficiency of above-ground space, the size and shape of underground structures tend to be complex and diverse. This complexity and variety force the development of new techniques for rock mass classification, excavation and supporting of underground space, monitoring and control of underground environment. All these techniques should be applied together to make the underground space comfortable. To achieve this, efforts have been made on 5 different areas; research on the underground space design and stability analysis, research on the techniques for excavation of rock by controlled blasting, research on the development of monitoring system to forecast the rock behaviour of underground space, research on the environment inspection system in closed space, and research on dynamic analysis of the airflow and environmental control in the large geos-spaces. The 5 main achievements are improvement of the existing structure analysis program(EXCRACK) to consider the deformation and failure characteristics of rock joints, development of new blasting design (SK-cut), prediction of ground vibration through the newly proposed wave propagation equation, development and In-Situ application of rock mass deformation monitoring system and data acquisition software, and trial manufacture of the environment inspection system in closed space. Should these techniques be applied to the development of underground space, prevention of industrial disaster, cut down of construction cost, domestication of monitoring system, improvement of tunnel stability, curtailment of royalty, upgrade of domestic technologies will be brought forth. (Abstract Truncated)

Much Lower Launch Costs Make Resupply Cheaper than Recycling for Space Life Support

Science.gov (United States)

Jones, Harry W.

2017-01-01

The development of commercial launch vehicles by SpaceX has greatly reduced the cost of launching mass to Low Earth Orbit (LEO). Reusable launch vehicles may further reduce the launch cost per kilogram. The new low launch cost makes open loop life support much cheaper than before. Open loop systems resupply water and oxygen in tanks for crew use and provide disposable lithium hydroxide (LiOH) in canisters to remove carbon dioxide. Short human space missions such as Apollo and shuttle have used open loop life support, but the long duration International Space Station (ISS) recycles water and oxygen and removes carbon dioxide with a regenerative molecular sieve. These ISS regenerative and recycling life support systems have significantly reduced the total launch mass needed for life support. But, since the development cost of recycling systems is much higher than the cost of tanks and canisters, the relative cost savings have been much less than the launch mass savings. The Life Cycle Cost (LCC) includes development, launch, and operations. If another space station was built in LEO, resupply life support would be much cheaper than the current recycling systems. The mission most favorable to recycling would be a long term lunar base, since the resupply mass would be large, the proximity to Earth would reduce the need for recycling reliability and spares, and the launch cost would be much higher than for LEO due to the need for lunar transit and descent propulsion systems. For a ten-year lunar base, the new low launch costs make resupply cheaper than recycling systems similar to ISS life support.

Robust online belief space planning in changing environments: Application to physical mobile robots

KAUST Repository

Agha-mohammadi, Ali-akbar

2014-05-01

© 2014 IEEE. Motion planning in belief space (under motion and sensing uncertainty) is a challenging problem due to the computational intractability of its exact solution. The Feedback-based Information RoadMap (FIRM) framework made an important theoretical step toward enabling roadmap-based planning in belief space and provided a computationally tractable version of belief space planning. However, there are still challenges in applying belief space planners to physical systems, such as the discrepancy between computational models and real physical models. In this paper, we propose a dynamic replanning scheme in belief space to address such challenges. Moreover, we present techniques to cope with changes in the environment (e.g., changes in the obstacle map), as well as unforeseen large deviations in the robot\\'s location (e.g., the kidnapped robot problem). We then utilize these techniques to implement the first online replanning scheme in belief space on a physical mobile robot that is robust to changes in the environment and large disturbances. This method demonstrates that belief space planning is a practical tool for robot motion planning.

Reproduction in the space environment: Part I. Animal reproductive studies

Science.gov (United States)

Santy, P. A.; Jennings, R. T.; Craigie, D.

1990-01-01

Mankind's exploration and colonization of the frontier of space will ultimately depend on men's and women's ability to live, work, and reproduce in the space environment. This paper reviews animal studies, from microorganisms to mammals, done in space or under space-simulated conditions, which identify some of the key areas which might interfere with human reproductive physiology and/or embryonic development. Those space environmental factors which impacted almost all species included: microgravity, artificial gravity, radiation, and closed life support systems. These factors may act independently and in combination to produce their effects. To date, there have been no studies which have looked at the entire process of reproduction in any animal species. This type of investigation will be critical in understanding and preventing the problems which will affect human reproduction. Part II will discuss these problems directly as they relate to human physiology.

Farming of Vegetables in Space-Limited Environments

Science.gov (United States)

He, Jie

2015-10-01

Vegetables that contain most of the essential components of human nutrition are perishable and cannot be stocked. To secure vegetable supply in space limited cities such as Singapore, there are different farming methods to produce vegetables. These include low-cost urban community gardening and innovative rooftop and vertical farms integrated with various technologies such as hydroponics, aquaponics and aeroponics. However, for large-scale vegetable production in space-limited Singapore, we need to develop farming systems that not only increase productivity many-fold per unit of land but also produce all types of vegetable, all year-round for today and the future. This could be resolved through integrated vertical aeroponic farming system. Manipulation of root-zone (RZ) environments such as cooling the RZ, modifying mineral nutrients and introducing elevated RZ CO2 using aeroponics can further boost crop productivity beyond what can be achieved from more efficient use of land area. We could also adopt energy saving light emitting diodes (LEDs) for vertical aeroponic farming system to promote uniform growth and to improve the utilisation of limited space via shortening the growth cycle, thus improving vegetable production in a cost-effective manner.

A new concept for high-cycle-life LEO: Rechargeable MnO2-hydrogen

Science.gov (United States)

Appleby, A. J.; Dhar, H. P.; Kim, Y. J.; Murphy, O. J.

1989-01-01

The nickel-hydrogen secondary battery system, developed in the early 1970s, has become the system of choice for geostationary earth orbit (GEO) applications. However, for low earth orbit (LEO) satellites with long expected lifetimes the nickel positive limits performance. This requires derating of the cell to achieve very long cycle life. A new system, rechargeable MnO2-Hydrogen, which does not require derating, is described here. For LEO applications, it promises to have longer cycle life, high rate capability, a higher effective energy density, and much lower self-discharge behavior than those of the nickel-hydrogen system.

The Role of Cis-Lunar Space in Future Global Space Exploration

Science.gov (United States)

Bobskill, Marianne R.; Lupisella, Mark L.

2012-01-01

Cis-lunar space offers affordable near-term opportunities to help pave the way for future global human exploration of deep space, acting as a bridge between present missions and future deep space missions. While missions in cis-lunar space have value unto themselves, they can also play an important role in enabling and reducing risk for future human missions to the Moon, Near-Earth Asteroids (NEAs), Mars, and other deep space destinations. The Cis-Lunar Destination Team of NASA's Human Spaceflight Architecture Team (HAT) has been analyzing cis-lunar destination activities and developing notional missions (or "destination Design Reference Missions" [DRMs]) for cis-lunar locations to inform roadmap and architecture development, transportation and destination elements definition, operations, and strategic knowledge gaps. The cis-lunar domain is defined as that area of deep space under the gravitational influence of the earth-moon system. This includes a set of earth-centered orbital locations in low earth orbit (LEO), geosynchronous earth orbit (GEO), highly elliptical and high earth orbits (HEO), earth-moon libration or "Lagrange" points (E-ML1 through E-ML5, and in particular, E-ML1 and E-ML2), and low lunar orbit (LLO). To help explore this large possibility space, we developed a set of high level cis-lunar mission concepts in the form of a large mission tree, defined primarily by mission duration, pre-deployment, type of mission, and location. The mission tree has provided an overall analytical context and has helped in developing more detailed design reference missions that are then intended to inform capabilities, operations, and architectures. With the mission tree as context, we will describe two destination DRMs to LEO and GEO, based on present human space exploration architectural considerations, as well as our recent work on defining mission activities that could be conducted with an EML1 or EML2 facility, the latter of which will be an emphasis of this

A Numerical Approach to Estimate the Ballistic Coefficient of Space Debris from TLE Orbital Data

Science.gov (United States)

Narkeliunas, Jonas

2016-01-01

Low Earth Orbit (LEO) is full of space debris, which consist of spent rocket stages, old satellites and fragments from explosions and collisions. As of 2009, more than 21,000 orbital debris larger than 10 cm are known to exist], and while it is hard to track anything smaller than that, the estimated population of particles between 1 and 10 cm in diameter is approximately 500,000, whereas small as 1 cm exceeds 100 million. These objects orbit Earth with huge kinetic energies speeds usually exceed 7 kms. The shape of their orbit varies from almost circular to highly elliptical and covers all LEO, a region in space between 160 and 2,000 km above sea level. Unfortunately, LEO is also the place where most of our active satellites are situated, as well as, International Space Station (ISS) and Hubble Space Telescope, whose orbits are around 400 and 550 km above sea level, respectively.This poses a real threat as debris can collide with satellites and deal substantial damage or even destroy them.Collisions between two or more debris create clouds of smaller debris, which are harder to track and increase overall object density and collision probability. At some point, the debris density couldthen reach a critical value, which would start a chain reaction and the number of space debris would grow exponentially. This phenomenon was first described by Kessler in 1978 and he concluded that it would lead to creation of debris belt, which would vastly complicate satellite operations in LEO. The debris density is already relatively high, as seen from several necessary debris avoidance maneuvers done by Shuttle, before it was discontinued, and ISS. But not all satellites have a propulsion system to avoid collision, hence different methods need to be applied. One of the proposed collision avoidance concepts is called LightForce and it suggests using photon pressure to induce small orbital corrections to deflect debris from colliding. This method is very efficient as seen from

Challenges for future space power systems

International Nuclear Information System (INIS)

Brandhorst, H.W. Jr.

1989-01-01

The future appears rich in missions that will extend the frontiers of knowledge, human presence in space, and opportunities for profitable commerce. The key to success of these ventures is the availability of plentiful, cost effective electric power and assured, low cost access to space. While forecasts of space power needs are problematic, an assessment of future needs based on terrestrial experience was made. These needs fall into three broad categories-survival, self sufficiency and industrialization. The cost of delivering payloads to orbital locations from low earth orbit (LEO) to Mars was determined and future launch cost reductions projected. From these factors, then, projections of the performance necessary for future solar and nuclear space power options were made. These goals are largely dependent upon orbital location and energy storage needs

Degradação de óleos lubrificantes em motores estacionários movidos a biogas

Directory of Open Access Journals (Sweden)

Djessica Brum

2018-01-01

Full Text Available Com o crescente interesse do uso de biogás como fonte de energia elétrica por meio de motores ciclo Otto, as condições de trabalho destes motores se tornam relevantes para maior eficiência de conversão energética e maior tempo de uso. A utilização correta de óleos lubrificantes permite ampliar a quantidade de horas motor, sem necessidade de troca. Avaliar a qualidade e a degradação dos óleos lubrificantes neste sistema torna-se uma premissa importante, uma vez que o óleo degradado diminui a capacidade de proteção nas peças móveis do motor e aumenta o superaquecimento do sistema. A contaminação por agentes externos eleva a chance do desenvolvimento de borras e aumentando a corrosão de peças. Este trabalho realizou o controle de qualidade de óleos lubrificantes em motores estacionários movidos a biogás. Os óleos foram analisados por espectrofotometria na região do infravermelho, na qual foram verificadas as bandas de oxidação, presença de água, fuligem, nitratos e sulfato, sendo determinada também a acidez total do óleo lubrificante, de acordo com a norma ASTM D4739, preconizada pela Resolução ANP nº 10/2000. O principal problema encontrado foi a quantidade de água presente nos motores, acima do limite de 0,03%, indicando algum problema de vazamento/contaminação no motor. Os testes controlados com diferentes gases apresentaram pouca variação em relação à comparação com ar, ao controle utilizado e ao gás N2, sendo que os principais parâmetros afetados foram a oxidação e a acidez, pois os outros parâmetros não apresentaram diferenças significativas entre si.

CosmoBon, tree research team, for studying utilization of woody plant in space environment

Science.gov (United States)

Tomita-Yokotani, Kaori; Yamashita, Masamichi; Hashimoto, Hirofumi; Sato, Seigo; Baba, Keiichi; Chida, Yukari

2012-07-01

We are proposing to raise woody plants in space for several applications and plant science, as Tree research team, TRT. Trees produce excess oxygen, wooden materials for living cabin, and provide biomass for cultivating mushroom and insect as for the space agriculture. Excellent tree shapes which would be deeply related to wood formation improve quality of life under stressful environment in outer space. We have the serious problem about their size. Bonsai is one of the Japanese traditional arts. We have been investigating the tension wood formation under exotic gravitational environment using Bonsai. CosmoBon is the small tree Bonsai for our space experiment. The tension wood formation in CosmoBon was confirmed as the same as that in the natural trees. Our goal is to examine feasibility to grow various species of trees in space as bioresource for space agriculture.

Space Weather opportunities from the Swarm mission including near real time applications

DEFF Research Database (Denmark)

Stolle, Claudia; Floberghagen, Rune; Luehr, Hermann

2013-01-01

Sophisticated space weather monitoring aims at nowcasting and predicting solar-terrestrial interactions because their effects on the ionosphere and upper atmosphere may seriously impact advanced technology. Operating alert infrastructures rely heavily on ground-based measurements and satellite...... these products in timely manner will add significant value in monitoring present space weather and helping to predict the evolution of several magnetic and ionospheric events. Swarm will be a demonstrator mission for the valuable application of LEO satellite observations for space weather monitoring tools....

Studies of Earth Space Environment and Sudden Disappearances of Solar Prominences

National Research Council Canada - National Science Library

Huang, Tian-Sen

2005-01-01

With the support from AFOSR's Minority University Program, we worked on research of Sun-Earth space environment, conducted daily solar observation programs, improved solar instruments, and established...

Recent Progress on the Second Generation CMORPH: LEO-IR Based Precipitation Estimates and Cloud Motion Vector

Science.gov (United States)

Xie, Pingping; Joyce, Robert; Wu, Shaorong

2015-04-01

As reported at the EGU General Assembly of 2014, a prototype system was developed for the second generation CMORPH to produce global analyses of 30-min precipitation on a 0.05olat/lon grid over the entire globe from pole to pole through integration of information from satellite observations as well as numerical model simulations. The second generation CMORPH is built upon the Kalman Filter based CMORPH algorithm of Joyce and Xie (2011). Inputs to the system include rainfall and snowfall rate retrievals from passive microwave (PMW) measurements aboard all available low earth orbit (LEO) satellites, precipitation estimates derived from infrared (IR) observations of geostationary (GEO) as well as LEO platforms, and precipitation simulations from numerical global models. Key to the success of the 2nd generation CMORPH, among a couple of other elements, are the development of a LEO-IR based precipitation estimation to fill in the polar gaps and objectively analyzed cloud motion vectors to capture the cloud movements of various spatial scales over the entire globe. In this presentation, we report our recent work on the refinement for these two important algorithm components. The prototype algorithm for the LEO IR precipitation estimation is refined to achieve improved quantitative accuracy and consistency with PMW retrievals. AVHRR IR TBB data from all LEO satellites are first remapped to a 0.05olat/lon grid over the entire globe and in a 30-min interval. Temporally and spatially co-located data pairs of the LEO TBB and inter-calibrated combined satellite PMW retrievals (MWCOMB) are then collected to construct tables. Precipitation at a grid box is derived from the TBB through matching the PDF tables for the TBB and the MWCOMB. This procedure is implemented for different season, latitude band and underlying surface types to account for the variations in the cloud - precipitation relationship. At the meantime, a sub-system is developed to construct analyzed fields of

Modified-Collins cryocooler for zero-boiloff storage of cryogenic fuels in space

Science.gov (United States)

Hannon, Charles L.; Krass, Brady; Hogan, Jake; Brisson, John

2012-06-01

Future lunar and planetary explorations will require the storage of cryogenic propellants, particularly liquid oxygen (LOX) and liquid hydrogen (LH2), in low earth orbit (LEO) for periods of time ranging from days to months, and possibly longer. Without careful thermal management, significant quantities of stored liquid cryogens can be lost due to boil-off. Boil-off can be minimized by a variety of passive means including insulation, sun shades and passive radiational cooling. However, it has been shown that active cooling using space cryocoolers has the potential to result in Zero Boil-Off (ZBO) and the launch-mass savings using active cooling exceeds that of passive cooling of LOX for mission durations in LEO of less than 1 week, and for LH2 after about 2 months in LEO. Large-scale DC-flow cryogenic refrigeration systems operate at a fraction of the specific power levels required by small-scale AC-flow cryocoolers. The efficiency advantage of DC-flow cryogenic cycles motivates the current development of a cryocooler based on a modification of the Collins Cycle. The modified Collins cycle design employs piston type expanders that support high operating pressure ratios, electromagnetic valves that enable "floating pistons", and recuperative heat transfer. This paper will describe the design of a prototype Modified-Collins cryocooler for ZBO storage of cryogenic fuels in space.

Erosion Data from the MISSE 8 Polymers Experiment After 2 Years of Space Exposure on the International Space Station

Science.gov (United States)

de Groh, Kim K.; Banks, Bruce A.; Asmar, Olivia C.; Yi, Grace T.; Mitchell, Gianna G.; Guo, Aobo; Sechkar, Edward A.

2016-01-01

The Polymers Experiment was exposed to the low Earth orbit (LEO) space environment for 2.14 and 2.0 years as part of the Materials International Space Station Experiment 8 (MISSE 8) and the Optical Reflector Materials Experiment-III (ORMatE-III), respectively. The experiment contained 42 samples, which were flown in either ram, wake, or zenith orientations. The primary objective was to determine the effect of solar exposure on the atomic oxygen erosion yield (Ey) of fluoropolymers. This paper provides an overview of the experiment with details on the polymers flown, the characterization techniques used, the atomic oxygen fluence for each exposure orientation, and the LEO Ey results. The Ey values for the fluoropolymers range from 1.45 x 10(exp -25) cm(exp 3)/atom for white Tedlar Registered Trademark? (polyvinyl fluoride with white titanium dioxide pigment) flown in the ram orientation to 6.32 x 10(exp -24) cm(exp 3)/atom for aluminized-Teflon Registered Trademark? fluorinated ethylene propylene (Al-FEP) flown in the zenith orientation. Erosion yield data for FEP flown in ram, wake and zenith orientations are compared, and the Ey was found to be highly dependent on orientation, hence environmental exposure. Teflon FEP had an order of magnitude higher Ey when flown in the zenith direction (6.32 x10(exp -24) cm(exp3)/atom) as compared to the ram direction (2.37 x 10(exp -25) cm(exp 3)/atom). The Ey of FEP was found to increase with a direct correlation to the solar exposure/AO fluence ratio showing the effect of solar radiation and/or heating due to solar exposure on FEP erosion. In addition, back-surface carbon painted FEP (C-FEP) flown in the zenith orientation had a significantly higher Ey than clear FEP or Al-FEP further indicating that heating has a significant impact on the erosion of FEP, particularly in the zenith orientation.

Space Environment Modelling with the Use of Artificial Intelligence Methods

Science.gov (United States)

Lundstedt, H.; Wintoft, P.; Wu, J.-G.; Gleisner, H.; Dovheden, V.

1996-12-01

Space based technological systems are affected by the space weather in many ways. Several severe failures of satellites have been reported at times of space storms. Our society also increasingly depends on satellites for communication, navigation, exploration, and research. Predictions of the conditions in the satellite environment have therefore become very important. We will here present predictions made with the use of artificial intelligence (AI) techniques, such as artificial neural networks (ANN) and hybrids of AT methods. We are developing a space weather model based on intelligence hybrid systems (IHS). The model consists of different forecast modules, each module predicts the space weather on a specific time-scale. The time-scales range from minutes to months with the fundamental time-scale of 1-5 minutes, 1-3 hours, 1-3 days, and 27 days. Solar and solar wind data are used as input data. From solar magnetic field measurements, either made on the ground at Wilcox Solar Observatory (WSO) at Stanford, or made from space by the satellite SOHO, solar wind parameters can be predicted and modelled with ANN and MHD models. Magnetograms from WSO are available on a daily basis. However, from SOHO magnetograms will be available every 90 minutes. SOHO magnetograms as input to ANNs will therefore make it possible to even predict solar transient events. Geomagnetic storm activity can today be predicted with very high accuracy by means of ANN methods using solar wind input data. However, at present real-time solar wind data are only available during part of the day from the satellite WIND. With the launch of ACE in 1997, solar wind data will on the other hand be available during 24 hours per day. The conditions of the satellite environment are not only disturbed at times of geomagnetic storms but also at times of intense solar radiation and highly energetic particles. These events are associated with increased solar activity. Predictions of these events are therefore

Living with a Star (LWS) Space Environment Testbeds (SET), Mission Carrier Overview and Capabilities

Science.gov (United States)

Patschke, Robert; Barth, Janet; Label, Ken; Mariano, Carolyn; Pham, Karen; Brewer, Dana; Cuviello, Michael; Kobe, David; Wu, Carl; Jarosz, Donald

2004-01-01

NASA has initiated the Living With a Star (LWS) Program to develop the scientific understanding to address the aspects of the Connected Sun-Earth system that affect life and society. A goal of the program is to bridge the gap between science, engineering, and user application communities. This will enable future science, operational, and commercial objectives in space and atmospheric environments by improving engineering approaches to the accommodation and/or mitigation of the effects of solar variability on technological systems. The three program elements of the LWS Program are Science Missions; Targeted Research and Technology; and Space Environment Testbeds (SETS). SET is an ideal platform for small experiments performing research on space environment effects on technologies and on the mitigation of space weather effects. A short description of the LWS Program will be given, and the SET will be described in detail, giving the mission objectives, available carrier services, and upcoming flight opportunities.

The Effects of Space Environment on Wireless Communication Devices' Performance

OpenAIRE

Landon, Hillyard; Dennison, JR

2012-01-01

This project evaluates the effects of the space environment on small radio hardware devices called Bluetooth (a proprietary open wireless technology standard for exchanging data over short distances) chips (hoovers). When electronics are exposed to the harsh environment outside the Earth's atmosphere, they sometimes do not perform as expected. The USU Getaway Away Special (GAS) team is now in the design stages of launching a CubeSat (a 10 cm cubed autonomous satellite to fly in Low Earth Orbi...

Operational environments for electrical power wiring on NASA space systems

Science.gov (United States)

Stavnes, Mark W.; Hammoud, Ahmad N.; Bercaw, Robert W.

1994-01-01

Electrical wiring systems are used extensively on NASA space systems for power management and distribution, control and command, and data transmission. The reliability of these systems when exposed to the harsh environments of space is very critical to mission success and crew safety. Failures have been reported both on the ground and in flight due to arc tracking in the wiring harnesses, made possible by insulation degradation. This report was written as part of a NASA Office of Safety and Mission Assurance (Code Q) program to identify and characterize wiring systems in terms of their potential use in aerospace vehicles. The goal of the program is to provide the information and guidance needed to develop and qualify reliable, safe, lightweight wiring systems, which are resistant to arc tracking and suitable for use in space power applications. This report identifies the environments in which NASA spacecraft will operate, and determines the specific NASA testing requirements. A summary of related test programs is also given in this report. This data will be valuable to spacecraft designers in determining the best wiring constructions for the various NASA applications.

"Winterização" de óleo de pescado via solvente Winterization of fish oil with solvent

Directory of Open Access Journals (Sweden)

Daniele Colembergue Cunha

2009-03-01

Full Text Available O fracionamento de óleos via "winterização" consiste numa cristalização fracionada, na qual os triacilgliceróis de óleos e gorduras são separados pela cristalização parcial na fase líquida. O objetivo deste trabalho consistiu na determinação das variáveis significativas e das condições operacionais do processo de "winterização" via solvente do óleo de pescado. Como matéria-prima empregou-se o óleo de pescado bruto de indústrias pesqueiras, o qual foi branqueado. Na etapa de "winterização", o óleo branqueado foi resfriado progressivamente em três estágios, de 30 ºC até -5 ºC. Foram estudados os seguintes fatores: tipo de solvente, proporção de solvente e agitação no segundo estágio do resfriamento. As composições de ácidos graxos dos óleos de pescado foram determinadas através de cromatografia gasosa. Foram analisadas as variações percentuais dos ácidos graxos insaturados e dos ácidos graxos saturados. As condições recomendadas para o processo foram o emprego de hexano como solvente, na proporção de 40% em relação à massa de óleo, e sem o emprego de agitação no segundo estágio do resfriamento. Sob tais condições, obteve-se um óleo com teor de ácidos graxos poli-insaturados (PUFA de 64,3%, sendo observado um aumento no percentual dos ácidos graxos insaturados de aproximadamente 9,2% e uma redução de 13,4% dos saturados, em relação ao óleo branqueado de pescado.The process of winterization consists of fractional crystallization, in which the triglycerides of oils and fats are separate by the partial crystallization in the liquid phase. The objective of this work was to evaluate significant variables and the operational conditions in the solvent winterization process of the fish oil. The crude fish oil from fishery industries was bleached and used as raw material. During the winterization step, the bleached oil was cooled progressively from 30 ºC to 5 ºC in three phases. The solvent

Healing environments in cancer treatment and care. Relations of space and practice in hematological cancer treatment

DEFF Research Database (Denmark)

Høybye, Mette Terp

2013-01-01

of the individual patient ’ s needs, values and experiences is key to developing the environment to support the patient quality of life. The present study holds implications for practice to inform design of future hospital environments for cancer treatment. The study points to the importance for being attentive...... these concepts, the study demonstrates how the hospital environment is a fl ow of relations between space and practice that changes and challenges a structural idea of design and healing. Patients ’ sense of healing changes with the experience of progression in treatment and the capacity of the hospital space...... to incite an experience of homeliness and care. Furthermore, cancer patients continuously challenge the use and limits of space by individual objects and practices of privacy and home. Discussion. Healing environments are complex relations between practices, space and care, where recognition...

CosmoBon for studying wood formation under exotic gravitational environment for future space agriculture

Science.gov (United States)

Tomita-Yokotani, Kaori; Baba, Keiichi; Suzuki, Toshisada; Funada, Ryo; Nakamura, Teruko; Hashimoto, Hirofumi; Yamashita, Masamichi; Cosmobon, Jstwg

We are proposing to raise woody plants in space for several applications and plant science. Japanese flowering cherry tree is one of a candidate for these studies. Mechanism behind sensing gravity and controlling shape of tree has been studied quite extensively. Even molecular mechanism for the response of plant against gravity has been investigated quite intensively for various species, woody plants are left behind. Morphology of woody branch growth is different from that of stem growth in herbs. Morphology in tree is strongly dominated by the secondary xylem formation. Nobody knows the tree shape grown under the space environment. If whole tree could be brought up to space as research materials, it might provide important scientific knowledge. Furthermore, trees produce excess oxygen, wooden materials for living cabin, and provide biomass for cultivating mushroom and insect as for the space agriculture. Excellent tree shapes which would be deeply related to wood formation improve quality of life under stressful environment in outer space. The serious problem would be their size. Bonsai is one of the Japanese traditional arts. We can study secondly xylem formation, wood formation, under exotic gravitational environment using Bonsai. "CosmoBon" is the small tree Bonsai for our space experiment. It has been recognized that the reaction wood in CosmoBon is formed similar to natural trees. Our goal is to examine feasibility to grow various species of trees in space as bioresource for space agriculture.

Louis Althusser, Leo Strauss, and Democratic Leadership

OpenAIRE

Tamulis, Bron Cohen

2014-01-01

In taking up the topic of political leadership, I seek to analyze the legacy of social science in light of the sobering political events of the twentieth century. This dissertation is a composite study of the work of two philosophers, and, specifically, what they endeavored to accomplish by thinking and writing on the subject of politics. I concentrated on the post-War landscape, and the philosophers Louis Althusser and Leo Strauss, in order to analyze the way in which the figure of Machiav...

The Initial Nine Space Settlements

Science.gov (United States)

Gale, Anita E.; Edwards, Richard P.

2003-01-01

The co-authors describe a chronology of space infrastructure development illustrating how each element of infrastructure enables development of subsequent more ambitious infrastructure. This is likened to the ``Southern California freeway phenomenon'', wherein a new freeway built in a remote area promotes establishment of gas stations, restaurants, hotels, housing, and eventually entire new communities. The chronology includes new launch vehicles, inter-orbit vehicles, multiple LEO space stations, lunar mining, on-orbit manufacturing, tourist destinations, and supporting technologies required to make it all happen. The space settlements encompassed by the chronology are in Earth orbit (L5 and L4), on the lunar surface, in Mars orbit, on the Martian surface, and in the asteroid belt. Each space settlement is justified with a business rationale for construction. This paper is based on materials developed for Space Settlement Design Competitions that enable high school students to experience the technical and management challenges of working on an industry proposal team.

Comparison of Space Debris Environment Models: ORDEM2000, MASTER-2001, MASTER-2005 and MASTER-2009

OpenAIRE

Kanemitsu, Yuki; 赤星, 保浩; Akahoshi, Yasuhiro; 鳴海, 智博; Narumi, Tomohiro; Faure, Pauline; 松本, 晴久; Matsumoto, Haruhisa; 北澤, 幸人; Kitazawa, Yukihito

2012-01-01

Hypervelocity impact by space debris on spacecraft is one of the most important issues for space development and operation, especially considering the growing amount of space debris in recent years. It is therefore important for spacecraft design to evaluate the impact risk by using environment models. In this paper, the authors compared the results of the debris impact flux in low Earth orbit, as calculated by four debris environment engineering models -NASA's ORDEM2000 and ESA's MASTER-2001...

El fin del petróleo

OpenAIRE

Fontaine, Guillaume

2007-01-01

En el momento en que los demócratas de los Estados Unidos han encabezado, al parecer, la cruzada mundial contra el cambio climático, quizá no es inútil leer (o releer) el ensayo del periodista Paul Roberts, publicado a finales del 2004 bajo el título llamativo de "El fin del petróleo". En efecto, cuando se reactivan las recetas del "charity business" (como eran los megaconciertos contra la hambruna y la sequía en Somalia, o para la liberación de Mandela) para salvar nuestro planeta, y m...

BioSentinel: Developing a Space Radiation Biosensor

Science.gov (United States)

Santa Maria, Sergio R.

2015-01-01

BioSentinel is an autonomous fully self-contained science mission that will conduct the first study of the biological response to space radiation outside low Earth orbit (LEO) in over 40 years. The 4-unit (4U) BioSentinel biosensor system, is housed within a 6-Unit (6U) spacecraft, and uses yeast cells in multiple independent microfluidic cards to detect and measure DNA damage that occurs in response to ambient space radiation. Cell growth and metabolic activity will be measured using a 3-color LED detection system and a metabolic indicator dye with a dedicated thermal control system per fluidic card.

Geopolítica y petróleo. La nueva dependencia energética

OpenAIRE

Zeraoui, Zidane

2010-01-01

Este artículo, sobre geopolítica y petróleo, busca analizar la actual geopolítica internacional en función de la variable petrolera. Con el alza del precio del crudo a casi US $150 el barril, el “oro negro” se ha convertido más que nunca en un instrumento de poder global. Por otra parte, la demanda cada vez más apremiante de petróleo, por China e India, está empujando no solamente el precio de los hidrocarburos, sino también la pugna por el control de los yacimientos a nivel mundial o por lo ...

On the Implementation of a European Space Traffic Management System - I. A White Paper

OpenAIRE

Tüllmann, Ralph; Arbinger, Christian; Baskcomb, Stuart; Berdermann, Jens; Fiedler, Hauke; Klock, Erich; Schildknecht, Thomas

2017-01-01

There are high expectations for a global commercial space travel market which is expected to turn into a multi-billion Euro business in the next two decades. Several key players in the space business, companies like Virgin Galactic, SpaceX, Blue Origin or SNC are preparing to serve this market by developing their own ballistic reusable space vehicles to carry humans and cargo payloads into suborbital and Low Earth Orbit (LEO) space. Europe’s single stage to orbit concepts, e.g., REL’s Skylon ...

Application of Advanced Materials Protecting from Influence of Free Space Environment

Science.gov (United States)

Dotsenko, Oleg; Shovkoplyas, Yuriy

2016-07-01

High cost and low availability of the components certified for use in the space environment forces satellite designers to using industrial and even commercial items. Risks associated with insufficient knowledge about behavior of these components in radiation environment are parried, mainly, by careful radiating designing of a satellite where application of special protective materials with improved space radiation shielding characteristics is one of the most widely used practices. Another advantage of protective materials application appears when a satellite designer needs using equipment in more severe space environment conditions then it has been provided at the equipment development. In such cases only expensive repeated qualification of the equipment hardness can be alternative to protective materials application. But mostly this way is unacceptable for satellite developers, being within strong financial and temporal restrictions. To apply protective materials effectively, the developer should have possibility to answer the question: "Where inside a satellite shall I place these materials and what shall be their shape to meet the requirements on space radiation hardness with minimal mass and volume expenses?" At that, the minimum set of requirements on space radiation hardness include: ionizing dose, nonionizing dose, single events, and internal charging. The standard calculative models and experimental techniques, now in use for space radiation hardness assurance of a satellite are unsuitable for the problem solving in such formulation. The sector analysis methodology, widely used in satellite radiating designing, is applicable only for aluminium shielding and doesn't allow taking into account advantages of protective materials. The programs simulating transport of space radiations through a substance with the use of Monte-Carlo technique, such as GEANT4, FLUKA, HZETRN and others, are fully applicable in view of their capabilities; but time required for

DISILICIDE BASE REFRACTORY METAL COATINGS IN SPACE ENVIRONMENT

Energy Technology Data Exchange (ETDEWEB)

Bocarsly, Sidney I.

1963-03-15

Studies of probable effects of space environment exposure of Durak B'' (a Chromizing Corp. proprietary disilicide coating) coated Mo are described. It was concluded that, in a high-temperature environment, solar radiation will not affect the material system. Sputtering will not cause a structural problem, but it may cause a change in optical properties. Meteoroids may cause coating spalling and minimum to possibly total failure. Some protection system will probably be necessary. Vacuum will cause some coating evaporation. The rate will be temperature-dependent and probably of a low order. The possible problem area is that the evaporation appears to occur preferentially at crack sites. Ionized nitrogen and hydrogen may react with the coating and charge physical or mechanical properties. (A.G.W.)

A low earth orbit dynamic model for the proton anisotropy validation

Science.gov (United States)

Badavi, Francis F.

2011-11-01

Ionizing radiation measurements at low earth orbit (LEO) form the ideal tool for the experimental validation of radiation environmental models, nuclear transport code algorithms and nuclear reaction cross sections. Indeed, prior measurements on the space transportation system (STS; shuttle) have provided vital information impacting both the environmental models and the nuclear transport code development by requiring dynamic models of the LEO environment. Previous studies using computer aided design (CAD) models of the international space station (ISS) have demonstrated that the dosimetric prediction for a spacecraft at LEO requires the description of an environmental model with accurate anisotropic as well as dynamic behavior. This paper describes such a model for the trapped proton. The described model is a component of a suite of codes collectively named GEORAD (GEOmagnetic RADiation) which computes cutoff rigidity, trapped proton and trapped electron environments. The web version of GEORAD is named OLTARIS (On-line Tool for the Assessment of Radiation in Space). GEORAD suite is applicable to radiation environment prediction at LEO, medium earth orbit (MEO) and geosynchronous earth orbit (GEO) at quiet solar periods. GEORAD interest is in the study of long term effect of the trapped environment and therefore it does not account for any short term external field contribution due to solar activity. With the concentration of the paper on the LEO protons only, the paper presents the validation of the trapped proton model within GEORAD with reported measurements from the compact environment anomaly sensor (CEASE) science instrument package, flown onboard the tri-service experiment-5 (TSX-5) satellite during the period of June 2000 to July 2006. The spin stabilized satellite was flown in a 410 × 1710 km, 69° inclination elliptical orbit, allowing it to be exposed to a broad range of the LEO regime. The paper puts particular emphasize on the validation of the

Crescimento vegetativo e produção de óleo essencial de hortelã‑pimenta cultivada sob malhas

Directory of Open Access Journals (Sweden)

Andressa Giovannini Costa

2012-04-01

Full Text Available O objetivo deste trabalho foi avaliar o crescimento vegetativo e o teor, o rendimento e a composição química do óleo essencial de hortelã‑pimenta (Mentha piperita cultivada sob diferentes malhas, no Município de Lavras, MG. As mudas de hortelã‑pimenta foram cultivadas em cinco ambientes: pleno sol, malha preta, malha aluminizada, malha azul e malha vermelha, todas com 50% de irradiância. Utilizou-se o delineamento experimental inteiramente casualizado, com quatro repetições e cinco plantas por parcela. Foram avaliados os parâmetros: crescimento vegetativo, teor, rendimento e análise química do óleo essencial. Plantas de hortelã‑pimenta cultivadas em pleno sol e sob malhas preta e vermelha produziram maior biomassa seca de folhas e maiores teores e rendimentos do óleo essencial. Entretanto, a pleno sol, o óleo essencial das plantas apresentou maior teor de mentol e, sob as malhas preta e azul, de mentofurano. Portanto, é possível manipular o crescimento das plantas e a produção e a composição química do óleo essencial de hortelã‑pimenta mediante o cultivo sob malhas ou pleno sol.

Tempo de destilação e perfil volátil do óleo essencial de aroeira da praia (Schinus terebinthifolius) em Sergipe

OpenAIRE

Oliveira, L.F.M.; Oliveira Jr, L.F.G.; Santos, M.C.; Narain, N.; Leite Neta, M.T.S.

2014-01-01

Aos frutos e óleos essenciais da aroeira da praia (Schinus terebinthifolius) atribui-se atividade antimicrobiana sobre bactérias gram positivas além de ação anti-inflamatória. O óleo essencial da aroeira é utilizado no tratamento de micoses, sendo a sua atividade antifúngica atribuída à alta concentração de monoterpenos. Este estudo teve como objetivo determinar o melhor rendimento de destilação de óleo essencial de sementes e folhas da aroeira e os componentes químicos do óleo essencial nos ...

Geostationary Communications Satellites as Sensors for the Space Weather Environment: Telemetry Event Identification Algorithms

Science.gov (United States)

Carlton, A.; Cahoy, K.

2015-12-01

Reliability of geostationary communication satellites (GEO ComSats) is critical to many industries worldwide. The space radiation environment poses a significant threat and manufacturers and operators expend considerable effort to maintain reliability for users. Knowledge of the space radiation environment at the orbital location of a satellite is of critical importance for diagnosing and resolving issues resulting from space weather, for optimizing cost and reliability, and for space situational awareness. For decades, operators and manufacturers have collected large amounts of telemetry from geostationary (GEO) communications satellites to monitor system health and performance, yet this data is rarely mined for scientific purposes. The goal of this work is to acquire and analyze archived data from commercial operators using new algorithms that can detect when a space weather (or non-space weather) event of interest has occurred or is in progress. We have developed algorithms, collectively called SEER (System Event Evaluation Routine), to statistically analyze power amplifier current and temperature telemetry by identifying deviations from nominal operations or other events and trends of interest. This paper focuses on our work in progress, which currently includes methods for detection of jumps ("spikes", outliers) and step changes (changes in the local mean) in the telemetry. We then examine available space weather data from the NOAA GOES and the NOAA-computed Kp index and sunspot numbers to see what role, if any, it might have played. By combining the results of the algorithm for many components, the spacecraft can be used as a "sensor" for the space radiation environment. Similar events occurring at one time across many component telemetry streams may be indicative of a space radiation event or system-wide health and safety concern. Using SEER on representative datasets of telemetry from Inmarsat and Intelsat, we find events that occur across all or many of

Space Shuttle Orbiter logistics - Managing in a dynamic environment

Science.gov (United States)

Renfroe, Michael B.; Bradshaw, Kimberly

1990-01-01

The importance and methods of monitoring logistics vital signs, logistics data sources and acquisition, and converting data into useful management information are presented. With the launch and landing site for the Shuttle Orbiter project at the Kennedy Space Center now totally responsible for its own supportability posture, it is imperative that logistics resource requirements and management be continually monitored and reassessed. Detailed graphs and data concerning various aspects of logistics activities including objectives, inventory operating levels, customer environment, and data sources are provided. Finally, some lessons learned from the Shuttle Orbiter project and logistics options which should be considered by other space programs are discussed.

NASA Orbital Debris Large-Object Baseline Population in ORDEM 3.0

Science.gov (United States)

Krisco, Paula H.; Vavrin, A. B.; Anz-Meador, P. D.

2013-01-01

The NASA Orbital Debris Program Office (ODPO) has created and validated high fidelity populations of the debris environment for the latest Orbital Debris Engineering Model (ORDEM 3.0). Though the model includes fluxes of objects 10 um and larger, this paper considers particle fluxes for 1 cm and larger debris objects from low Earth orbit (LEO) through Geosynchronous Transfer Orbit (GTO). These are validated by several reliable radar observations through the Space Surveillance Network (SSN), Haystack, and HAX radars. ORDEM 3.0 populations were designed for the purpose of assisting, debris researchers and sensor developers in planning and testing. This environment includes a background derived from the LEO-to-GEO ENvironment Debris evolutionary model (LEGEND) with a Bayesian rescaling as well as specific events such as the FY-1C anti-satellite test, the Iridium 33/Cosmos 2251 accidental collision, and the Soviet/Russian Radar Ocean Reconnaissance Satellite (RORSAT) sodium-potassium droplet releases. The environment described in this paper is the most realistic orbital debris population larger than 1 cm, to date. We describe derivations of the background population and added specific populations. We present sample validation charts of our 1 cm and larger LEO population against Space Surveillance Network (SSN), Haystack, and HAX radar measurements.

Bioestímulo e bioaumento na remediação de solo contaminado com óleo lubrificante usado escala piloto

OpenAIRE

Graciane Silva

2010-01-01

O óleo lubrificante mineral é amplamente utilizado no cenário mundial no funcionamento de máquinas e motores. No entanto, o ciclo de vida deste petro-derivado resulta na geração de um resíduo (óleo lubrificante usado), o qual é nocivo ao meio ambiente quando não descartado adequadamente ou reciclado. No Brasil, apesar das normas que tratam especificamente do armazenamento, recolhimento e destino de óleo lubrificante usado, grande parte do mesmo ainda é despejado diretamente no meio ambiente, ...

Crescimento, esporulação e viabilidade de fungos entomopatogênicos em meios contendo diferentes concentrações do óleo de nim (Azadirachta indica

Directory of Open Access Journals (Sweden)

Marques Renata Paro

2004-01-01

Full Text Available A associação de extratos de origem vegetal com fungos entomopatogênicos pode aumentar a eficiência do controle biológico de pragas, reduzir custos e impactos ambientais. No presente trabalho, avaliou-se, através da concentração inibitória mínima, o efeito do óleo de nim (NIM-I-GO sobre o crescimento, esporulação e viabilidade de Metarhizium anisopliae, Beauveria bassiana e Paecilomyces farinosus. Utilizou-se o meio BDA, contendo diferentes concentrações de óleo de nim (C1: 5% de óleo de nim, e sucessivamente concentrações iguais a fraction one-half da concentração anterior, até C11: 0,0048% de óleo de nim. O óleo de nim reduziu o crescimento de colônias de B. bassiana e P. farinosus, que não diferiram significativamente do controle apenas na concentração C11, mas para M. anisopliae o mesmo efeito foi observado com 0,039% de óleo de nim (C8. A esporulação também foi significativamente reduzida pelo óleo de nim, exceto na concentração C11 para B. bassiana; contudo, não se verificou efeito do óleo na viabilidade de esporos dos fungos.

ALFALFA DISCOVERY OF THE NEARBY GAS-RICH DWARF GALAXY LEO P. III. AN EXTREMELY METAL DEFICIENT GALAXY

Energy Technology Data Exchange (ETDEWEB)

Skillman, Evan D.; Berg, Danielle A.; Olive, Keith A.; McQuinn, Kristen B. W., E-mail: skillman@astro.umn.edu, E-mail: berg@astro.umn.edu, E-mail: olive@physics.umn.edu, E-mail: kmcquinn@astro.umn.edu [Minnesota Institute for Astrophysics, School of Physics and Astronomy, University of Minnesota, 116 Church St. SE, Minneapolis, MN 55455 (United States); and others

2013-07-01

We present KPNO 4 m and LBT/MODS spectroscopic observations of an H II region in the nearby dwarf irregular galaxy Leo P discovered recently in the Arecibo ALFALFA survey. In both observations, we are able to accurately measure the temperature sensitive [O III] {lambda}4363 line and determine a ''direct'' oxygen abundance of 12 + log(O/H) = 7.17 {+-} 0.04. Thus, Leo P is an extremely metal deficient (XMD) galaxy, and, indeed, one of the most metal deficient star-forming galaxies ever observed. For its estimated luminosity, Leo P is consistent with the relationship between luminosity and oxygen abundance seen in nearby dwarf galaxies. Leo P shows normal {alpha} element abundance ratios (Ne/O, S/O, and Ar/O) when compared to other XMD galaxies, but elevated N/O, consistent with the ''delayed release'' hypothesis for N/O abundances. We derive a helium mass fraction of 0.2509{sup +0.0184}{sub -0.0123}, which compares well with the WMAP + BBN prediction of 0.2483 {+-} 0.0002 for the primordial helium abundance. We suggest that surveys of very low mass galaxies compete well with emission line galaxy surveys for finding XMD galaxies. It is possible that XMD galaxies may be divided into two classes: the relatively rare XMD emission line galaxies which are associated with starbursts triggered by infall of low-metallicity gas and the more common, relatively quiescent XMD galaxies like Leo P, with very low chemical abundances due to their intrinsically small masses.

Sensor Systems for Vehicle Environment Perception in a Highway Intelligent Space System

Science.gov (United States)

Tang, Xiaofeng; Gao, Feng; Xu, Guoyan; Ding, Nenggen; Cai, Yao; Ma, Mingming; Liu, Jianxing

2014-01-01

A Highway Intelligent Space System (HISS) is proposed to study vehicle environment perception in this paper. The nature of HISS is that a space sensors system using laser, ultrasonic or radar sensors are installed in a highway environment and communication technology is used to realize the information exchange between the HISS server and vehicles, which provides vehicles with the surrounding road information. Considering the high-speed feature of vehicles on highways, when vehicles will be passing a road ahead that is prone to accidents, the vehicle driving state should be predicted to ensure drivers have road environment perception information in advance, thereby ensuring vehicle driving safety and stability. In order to verify the accuracy and feasibility of the HISS, a traditional vehicle-mounted sensor system for environment perception is used to obtain the relative driving state. Furthermore, an inter-vehicle dynamics model is built and model predictive control approach is used to predict the driving state in the following period. Finally, the simulation results shows that using the HISS for environment perception can arrive at the same results detected by a traditional vehicle-mounted sensors system. Meanwhile, we can further draw the conclusion that using HISS to realize vehicle environment perception can ensure system stability, thereby demonstrating the method's feasibility. PMID:24834907

Composição química e concentração mínima bactericida de dezesseis óleos essenciais sobre Escherichia coli enterotoxigênica

Directory of Open Access Journals (Sweden)

A.A. SOUZA

2016-03-01

Full Text Available RESUMO Este trabalho teve por objetivo avaliar o efeito bactericida in vitro de dezesseis óleos essenciais sobre Escherichia coli enterotoxigênica (ETEC. Dentre os óleos essenciais estudados, três foram extraídos in situ por arraste a vapor e treze foram adquiridos comercialmente. Todos os óleos foram analisados por CG-EM e CG-DIC. A atividade bactericida foi avaliada pelo método de microdiluição utilizando-se caldo triptona de soja e microplacas de poliestireno de 96 poços, com posterior plaqueamento das culturas em ágar triptona de soja. Os óleos essenciais de Cinnamomum cassia e de Thymus vulgaris apresentaram concentração mínima bactericida (CMB de 0,12% e 0,25%, respectivamente. Já os óleos comerciais de Syzygium aromaticum e Origanum vulgare apresentaram ambos CMB de 0,50% e os óleos extraídos in situ de Cymbopogon citratus e Origanum vulgare apresentaram ambos CMB de 1,00%. Os dezesseis óleos essenciais apresentaram composição química qualitativa e quantitativa distintas. As análises químicas dos óleos essenciais de Cinnamomum cassia e de Thymus vulgaris tiveram a presença majoritária de E-cinamaldeído (84,52% e timol (50,89%. Conclui-se que os óleos de C. cassia e T. vulgaris foram os mais eficazes na inibição do crescimento in vitro dessa bactéria, a qual possui diferentes níveis de sensibilidade dependendo da composição química do óleo.

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

Directory of Open Access Journals (Sweden)

M.A. Juárez-Parra

2015-10-01

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

JPL Space Telecommunications Radio System Operating Environment

Science.gov (United States)

Lux, James P.; Lang, Minh; Peters, Kenneth J.; Taylor, Gregory H.; Duncan, Courtney B.; Orozco, David S.; Stern, Ryan A.; Ahten, Earl R.; Girard, Mike

2013-01-01

A flight-qualified implementation of a Software Defined Radio (SDR) Operating Environment for the JPL-SDR built for the CoNNeCT Project has been developed. It is compliant with the NASA Space Telecommunications Radio System (STRS) Architecture Standard, and provides the software infrastructure for STRS compliant waveform applications. This software provides a standards-compliant abstracted view of the JPL-SDR hardware platform. It uses industry standard POSIX interfaces for most functions, as well as exposing the STRS API (Application Programming In terface) required by the standard. This software includes a standardized interface for IP components instantiated within a Xilinx FPGA (Field Programmable Gate Array). The software provides a standardized abstracted interface to platform resources such as data converters, file system, etc., which can be used by STRS standards conformant waveform applications. It provides a generic SDR operating environment with a much smaller resource footprint than similar products such as SCA (Software Communications Architecture) compliant implementations, or the DoD Joint Tactical Radio Systems (JTRS).

Atividade inseticida do óleo essencial de Hyptis marrubioides no controle de Zabrotes subfasciatus (Coleoptera, Chrysomelidae, Bruchinae

Directory of Open Access Journals (Sweden)

Marcelo Barboza de Mello

2014-02-01

Full Text Available Sabe-se que uma grande porcentagem da produção e do armazenamento dos grãos de feijão é perdida pelo consumo de insetos. Este trabalho teve como objetivo avaliar a atividade inseticida do óleo essencial de Hyptis marrubioides no controle de Zabrotes subfasciatus. A extração do óleo essencial foi realizada pelo método de hidrodestilação em aparelho de Clevenger, por uma hora e meia e o ensaio biológico foi conduzido no Laboratório de Microscopia/IFSULDEMINAS, Campus Muzambinho. O delineamento experimental utilizado foi inteiramente casualizado, constituído de cinco concentrações de óleo essencial (0,0; 6,25%; 12,5%; 25% e 50%, com quatro repetições contendo um casal de Z. subfasciatus por repetição. Realizou-se o teste de mortalidade e inibição de oviposição. Utilizou-se três grãos de feijão tratados com 5 microlitros (μL de solução e três não tratados, caracterizando assim um teste com chance de escolha. Como controle, utilizou-se 100 μL de álcool 70%. Após a aplicação dos tratamentos, observou-se a reação dos indivíduos de Z. subfasciatus, evidenciando que os Tempos Letais (TL diminuem conforme há um aumento e contato direto dos insetos com as concentrações do óleo essencial de H. marrubioides. A aplicação do óleo essencial foi bastante efetiva, pois ocorreu mortalidade total dos insetos adultos e nenhuma oviposição. O intervalo de tempo de 28 minutos foi suficiente para provocar mortalidade de todos os indivíduos. Foi possível observar que o óleo essencial de H. marrubioides possui efeito inseticida sobre Z. subfasciatus, podendo auxiliar no manejo integrado de Z. subfasciatus em feijão armazenado.

A Morphing Radiator for High-Turndown Thermal Control of Crewed Space Exploration Vehicles

Science.gov (United States)

Cognata, Thomas J.; Hardtl, Darren; Sheth, Rubik; Dinsmore, Craig

2015-01-01

Spacecraft designed for missions beyond low earth orbit (LEO) face a difficult thermal control challenge, particularly in the case of crewed vehicles where the thermal control system (TCS) must maintain a relatively constant internal environment temperature despite a vastly varying external thermal environment and despite heat rejection needs that are contrary to the potential of the environment. A thermal control system is in other words required to reject a higher heat load to warm environments and a lower heat load to cold environments, necessitating a quite high turndown ratio. A modern thermal control system is capable of a turndown ratio of on the order of 12:1, but for crew safety and environment compatibility these are massive multi-loop fluid systems. This paper discusses the analysis of a unique radiator design which employs the behavior of shape memory alloys (SMA) to vary the turndown of, and thus enable, a single-loop vehicle thermal control system for space exploration vehicles. This design, a morphing radiator, varies its shape in response to facesheet temperature to control view of space and primary surface emissivity. Because temperature dependence is inherent to SMA behavior, the design requires no accommodation for control, instrumentation, nor power supply in order to operate. Thermal and radiation modeling of the morphing radiator predict a turndown ranging from 11.9:1 to 35:1 independent of TCS configuration. Stress and deformation analyses predict the desired morphing behavior of the concept. A system level mass analysis shows that by enabling a single loop architecture this design could reduce the TCS mass by between 139 kg and 225 kg. The concept is demonstrated in proof-of-concept benchtop tests.

Actividade antimicrobiana do óleo essencial do Foeniculum vulgare Miller Antimicrobial activity of Foeniculum vulgare Miller essential oil

Directory of Open Access Journals (Sweden)

M. T. Tinoco

2007-01-01

Full Text Available O Foeniculum vulgare Mill. subsp. vulgare é uma planta espontânea da região mediterrânea, pertencente à família Apiaceae. O seu óleo essencial, principalmente o dos frutos secos, é amplamente utilizado nas indústrias alimentar, farmacêutica, cosmética e perfumaria. Neste trabalho, pretendeu-se avaliar a actividade antimicrobiana do óleo essencial dos frutos verdes e das folhas da variedade de funcho doce colhido no Alentejo, na região de Évora, e relacionar essa actividade com a respectiva composição química. A extracção dos óleos essenciais foi efectuada por hidrodestilação e a sua análise foi feita por GC-FID e GC-MS. No óleo das folhas foram identificados como componentes maioritários os fenilpropanóides anetol, fenchona e estragol e o monoterpeno a-felandreno, enquanto que o óleo dos frutos apresentou como constituintes predominantes anetol e fenchona. A actividade antimicrobiana dos óleos foi avaliada face às estirpes Staphylococcus aureus, Escherichia coli, Saccharomyces spp., Fusarium oxysporum e Penicillium sp.. Os óleos essenciais apresentaram actividade antimicrobiana contra S. aureus, Saccharomyces spp. e Fusarium oxysporum.Foeniculum vulgare Mill. ssp. vulgare is a spontaneous plant of Mediterranean region that belongs to the Apiaceae family. Its essential oil is used as additives in food, pharmaceutical, cosmetic and perfume industries mainly that one obtained from dried seeds. The main goal of this work were to evaluate the antimicrobial activity of essential oils obtained from fresh leaves and unripe seeds of sweet fennel, collected in Évora-Alentejo, in face of their chemical composition. The extraction of the essentials oils was made by hydrodistillation. Chemical analyses were carried out by GC-FID and GCMS. Phenylpropanoides anethole, fenchone, estragole and the monoterpene aphellandrene were the most abundant compounds of leaves essential oil. Seeds essential oil showed as main components

Leo Tolstoy's theory of sleep.

Science.gov (United States)

Vein, Alla A

2008-03-01

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

Triagem de métodos de purificação de óleos com acidez elevada para produção de biodiesel

OpenAIRE

Daniel Grabauskas

2013-01-01

O presente estudo teve como objetivo selecionar procedimentos de purificação de óleos vegetais, com enfoque na desacidificação, comparando a eficiência de métodos de refino alternativos (adsorção e extração liquido-liquido) com o convencional (alcalino). Para tanto, foram utilizados óleos com baixo impacto na cadeia alimentícia, como óleo de andíroba e óleo de macaúba, visando contribuir para a ampliação de matérias-primas lipídicas na produção de biodiesel. A triagem do método de purificação...

A comparison of propulsion systems for potential space mission applications

International Nuclear Information System (INIS)

Harvego, E.A.; Sulmeisters, T.K.

1987-01-01

A derivative of the NERVA nuclear rocket engine was compared with a chemical propulsion system and a nuclear electric propulsion system to assess the relative capabilities of the different propulsion system options for three potential space missions. The missions considered were (1) orbital transfer from low earth orbit (LEO) to geosynchronous earth orbit (GEO), (2) LEO to a lunar base, and (3) LEO to Mars. The results of this comparison indicate that the direct-thrust NERVA-derivative nuclear rocket engine has the best performance characteristics for the missions considered. The combined high thrust and high specific impulse achievable with a direct-thrust nuclear stage permits short operating times (transfer times) comparable to chemical propulsion systems, but with considerably less required propellant. While nuclear-electric propulsion systems are more fuel efficient than either direct-nuclear or chemical propulsion, they are not stand-alone systems, since their relatively low thrust levels require the use of high-thrust ferry or lander stages in high gravity applications such as surface-to-orbit propulsion. The extremely long transfer times and inefficient trajectories associated with electric propulsion systems were also found to be a significant drawback

Essential oils for rust control on coffee plants Óleos essenciais no controle da ferrugem em cafeeiro

Directory of Open Access Journals (Sweden)

Ricardo Borges Pereira

2012-02-01

Full Text Available Rust is considered the most important disease in coffee because it causes severe defoliation in plants and, consequently, reduction in productivity. This study evaluated the in vitro effect of essential oils of cinnamon, citronella, lemongrass, clove, tea tree, thyme, neem and eucalyptus on the germination of urediniospores of Hemileia vastatrix; the effectiveness of these oils to control rust on seedlings of coffee cultivars Catucaí 2SL, Catuaí IAC 62 and Mundo Novo 379/19 in the greenhouse; and the effect of more promising oils on urediniospores of H. vastatrix by transmission electron microscopy (TEM. All the essential oils inhibited the germination of urediniospores with increasing concentrations. All oils promoted partial control of the disease in the greenhouse. However, the oils of thyme, clove and citronella, at a concentration of 1000 µL L-1, were most effective in controlling the disease on cultivars Catucaí 2SL, Catuaí IAC 62 and Mundo Novo 379/19, respectively. The images generated in TEM showed that urediniospores exposed to oils of clove, citronella and thyme promoted cellular disorganization and cytoplasmic vacuolization, which was more pronounced in urediniospores exposed to citronella oil. The oils of thyme, clove and citronella are promising for the control of rust in coffee.A ferrugem é considerada a doença de maior importância no cafeeiro, pois causa acentuada desfolha nas plantas e, consequentemente, redução na produtividade. Este trabalho avaliou o efeito in vitro de óleos essenciais de canela, citronela, capim-limão, cravo-da-índia, árvore-de-chá, tomilho, nim e eucalipto na germinação de urediniósporos de Hemileia vastatrix; a eficácia desses óleos no controle da ferrugem em mudas de cafeeiro das cultivares Catucaí 2SL, Catuaí IAC 62 e Mundo Novo 379/19 em casa de vegetação; e o efeito dos óleos mais promissores sobre urediniósporos de H. vastatrix por meio de microscopia eletrônica de transmiss

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

African Journals Online (AJOL)

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

Sustainable Shaping of Urban Spaces in the Context of the Environment

Directory of Open Access Journals (Sweden)

Joanna Agnieszka Pawłowicz

2017-11-01

Full Text Available The natural environment is of great importance when it comes to developing a city, as it shapes its spaces, defines its roles and performs climatic and protective functions. Industrialization often requires removing landscape obstacles and vegetation to erect new buildings. An urban planner, though, should be aware of the borders that must not be crossed. Designing new streets and buildings should follow a sustainable growth pattern, if the city landscape and its climatic conditions are to improve for generations to come. This paper discusses the aspects of planning and managing urban spaces in such a way as to provide their users with healthy and comfortable living conditions. The paper is based on a survey conducted to gather the opinions of members of a city community on the environment in which they live.

Acción antimicrobiana de extracto etanólico de propóleos sobre estreptococos mutans

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Patricia Alejandra Vaculik

2014-12-01

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

ANÁLISE DO IMPACTO DOS ROYALTIES DO PETRÓLEO NO DESENVOLVIMENTO LOCAL DOS MUNICÍPIOS POTIGUARES

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Ridalvo Medeiros Alves de Oliveira

2009-12-01

Full Text Available Os royalties do petróleo são compensações financeiras consequentes da exploração de petróleo ou gás natural. Devido à relevância da receita dos royalties do petróleo para a política fiscal e de desenvolvimento econômico do Rio Grande do Norte, e em particular, para os municípios que compõem a Área de Petróleo Potiguar, se fez necessário estabelecer um estudo sobre as suas influências na dinâmica socioeconômica dessa região. O objetivo geral desse artigo é investigar as contribuições das receitas extraordinárias, originadas da atividade industrial de petróleo no território potiguar, para a melhoria da qualidade de vida destes municípios. Assim, através da evolução dos índices de IDH-M vislumbrou-se observar se os royalties têm contribuído para o desenvolvimento humano nos municípios em estudo. Os dados para a pesquisa foram obtidos junto ao IBGE, ANP e FERMURN, e para analisar aevolução das duas variáveis – royalties e IDH-M – foi utilizada a metodologia descritiva. Ao final do artigo conclui-se que um dos fatores que ocasionaram na melhoria da dinâmica de desenvolvimento dos municípios da região foi o incremento dessa receita extraordinária nosorçamentos municipais, permitindo investimentos em programas que possibilitaram melhoria nas variáveis: renda, longevidade e educação. O resultado do coeficiente de Pearson (0,689apresentou que existe uma correlação positiva entre as variáveis no período de 1995 a 2000.

Experimental Results of Thin-Film Photovoltaic Cells in a Low Density LEO Plasma Environment: Ground Tests

Science.gov (United States)

Galofaro, Joel T.; Vayner, Boris V.

2006-01-01

Plasma ground testing results, conducted at the Glenn Research Center (GRC) National Plasma Interaction (N-PI) Facility, are presented for a number of thin-film photovoltaic cells. The cells represent a mix of promising new technologies identified by the Air Force Research Laboratory (AFRL) under the CYGNUS Space Science Technology Experiment (SSTE-4) Program. The current ground tests are aimed at characterizing the performance and survivability of thin film technologies in the harsh low earth orbital space environment where they will be flown. Measurements of parasitic current loss, charging/dielectric breakdown of cover-slide coatings and arcing threshold tests are performed for each individual cell. These measurements are followed by a series of experiments designed to test for catastrophic arc failure mechanisms. A special type of power supply, called a solar array simulator (SAS) with adjustable voltage and current limits on the supply s output, is employed to bias two adjacent cells at a predetermined voltage and current. The bias voltage is incrementally ramped up until a sustained arc results. Sustained arcs are precursors to catastrophic arc failure where the arc current rises to a maximum value for long timescales often ranging between 30 to 100 sec times. Normal arcs by comparison, are short lived events with a timescale between 10 to 30 sec. Sustained arcs lead to pyrolization with extreme cell damage and have been shown to cause the loss of entire array strings in solar arrays. The collected data will be used to evaluate the suitability of thin-film photovoltaic technologies for future space operations.

Mid-Infrared Observations of Possible Intergalactic Star Forming Regions in the Leo Ring

Science.gov (United States)

Giroux, Mark; Smith, B.; Struck, C.

2011-05-01

Within the Leo group of galaxies lies a gigantic loop of intergalactic gas known as the Leo Ring. Not clearly associated with any particular galaxy, its origin remains uncertain. It may be a primordial intergalactic cloud alternatively, it may be a collision ring, or have a tidal origin. Combining archival Spitzer images of this structure with published UV and optical data, we investigate the mid-infrared properties of possible knots of star formation in the ring. These sources are very faint in the mid-infrared compared to star forming regions in the tidal features of interacting galaxies. This suggests they are either deficient in dust, or they may not be associated with the ring.

CONSISTÊNCIA DE MISTURA DE GORDURAS HIDROGENADAS E ÓLEO DE SOJA

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SIMÕES Ilka Sumiyoshi

1998-01-01

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

General Public Space Travel and Tourism. Volume 1; Executive Summary

Science.gov (United States)

ONeil, Daniel (Compiler); Bekey, Ivan; Mankins, John; Rogers, Thomas F.; Stallmer, Eric W.

1998-01-01

Travel and tourism is one of the world's largest businesses. Its gross revenues exceed $400 billion per year in the U.S. alone, and it is our second largest employer. U.S. private sector business revenues in the space information area now approximate $10 billion per year, and are increasing rapidly. Not so in the human spaceflight area. After spending $100s of billions (1998 dollars) in public funds thereon, and continuing to spend over $5 billion per year, the government is still the only customer for human spaceflight goods and services. Serious and detailed consideration was first given to the possibility of space being opened up to trips by the general public three decades ago, and some initial attempts to do so were made a dozen years ago. But the difficulties were great and the Challenger disaster put an end to them. In recent years professional space tourism studies have been conducted in the United Kingdom, Germany and, especially, Japan. In the U.S., technological progress has been pronounced; we have had nearly a decade's experience in seeing our astronauts travel to-from low Earth orbit (LEO) safely, and we expect to commence assembly of a LEO space station housing a half-dozen people this year. Too, NASA and our space industry now have new and promising space transportation development programs underway, especially the X-33 and X-34 programs, and some related, further generation, basic technology development programs. And five private companies are also working on the design of new surface - LEO vehicles. The first professional space tourism market studies have been conducted in several countries in the past few years, especially in Japan and here. The U.S. study makes it clear that, conceptually, tens of millions of us would like to take a trip to space if we could do so with reasonable safety, comfort and reliability, and at an acceptable price. Initial businesses will address the desires of those willing to pay a greater price and accept a greater

EFEITO DA SECAGEM E DO ARMAZENAMENTO DAS SEMENTES DE PINHÃO-MANSO (Jatropha curcas L. NA QUALIDADE DO ÓLEO

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Leonnardo Cruvinel Furquim

2014-10-01

Full Text Available O objetivo do presente trabalho foi avaliar a influência da secagem e do armazenamento de sementes de pinhão-manso na qualidade do óleo produzido. O experimento de secagem foi realizado com 5 variações de temperatura: 30, 40, 50, 60 e 70 °C, até a umidade de 9,3 ± 1,1% de base seca. O experimento de armazenamento foi realizado variando-se a condição e armazenamento: Ambiente do Laboratório (26 ± 3 °C; 55 ± 12% UR, Câmara Refrigerada do tipo B.O.D. (5 ± 1 °C; 79 ± 5% UR e Câmara Climatizada com aparelho de ar condicionado (18 ± 1 °C; 53 ± 7% UR; e o tempo de armazenamento: 2 e 4 meses. Os óleos foram avalizados em teor de óleo e os índices de acidez, peróxido e iodo. A secagem das sementes proporcionou elevação considerável no potencial de rancificação em temperaturas maiores ou iguais a 30 °C, revelando que secagens à temperaturas menores recomendável. Os armazenamentos das sementes nas câmaras climatizadas e refrigeradas apresentaram perdas na qualidade do óleo, com alto potencial de rancificação e de hidrólise dos óleos, respectivamente, revelando que o armazenamento em condições naturais é a mais indicada na manutenção da qualidade do óleo de pinhão-manso.

TOXICIDADE DE ÓLEOS ESSENCIAIS PARA O CONTROLE DE Tetranychus urticae KOCH, 1836 (ACARI: TETRANYCHIDAE)

OpenAIRE

Camila Santos Teixeira; Camila Costabeber Nunes; Romário Vargas; José Romário de Carvalho; Hugo Bolsoni Zago

2017-01-01

O ácaro rajado é considerado uma importante praga agrícola, causando danos em diferentes cultivos. O controle à base de acaricidas químicos pode vir a causar problemas ambientais e à saúde do homem. Desta forma o uso de óleos essenciais obtidos de produtos botânicos é uma alternativa no controle de pragas por apresentar baixo efeito residual, sendo objetivo deste trabalho avaliar a mortalidade e o efeito na fertilidade de fêmeas adultas de Tetranychus urticae submetidas a tratamentos com óleo...

NASA Strategy to Safely Live and Work in the Space Radiation Environment

Science.gov (United States)

Cucinotta, Francis; Wu, Honglu; Corbin, Barbara; Sulzman, Frank; Kreneck, Sam

2007-01-01

This viewgraph document reviews the radiation environment that is a significant potential hazard to NASA's goals for space exploration, of living and working in space. NASA has initiated a Peer reviewed research program that is charged with arriving at an understanding of the space radiation problem. To this end NASA Space Radiation Laboratory (NSRL) was constructed to simulate the harsh cosmic and solar radiation found in space. Another piece of the work was to develop a risk modeling tool that integrates the results from research efforts into models of human risk to reduce uncertainties in predicting risk of carcinogenesis, central nervous system damage, degenerative tissue disease, and acute radiation effects acute radiation effects.

Development of the KARI Space Debris Collision Risk Management System (KARISMA)

Science.gov (United States)

Kim, Hae-Dong; Lee, Sang-Cherl; Cho, Dong-Hyun; Seong, Jae-Dong

2018-05-01

Korea has been operating multi-purpose low-earth orbit (LEO) satellites such as the Korea multi-purpose satellite (KOMPSAT) since 1999 and the Communication, Ocean, and Meteorological Satellite (COMS), which was launched into geostationary orbit in 2006. The Korea Aerospace Research Institute (KARI) consequently became concerned about the deteriorating space debris environment. This led to the instigation, in 2011, of a project to develop the KARI space debris collision risk management system (KARISMA). In 2014, KARISMA was adopted as an official tool at the KARI ground station and is operated to mitigate collision risks while being continuously upgraded with input from satellite operators. The characteristics and architecture of KARISMA are described with detailed operational views. The user-friendly user interfaces including 2D and 3D displays of the results, conjunction geometries, and so on, are described in detail. The results of our analysis of the space collision risk faced by the KOMPSAT satellites as determined using KARISMA are presented, as well as optimized collision avoidance maneuver planning with maneuvering strategies for several conjunction events. Consequently, the development of KARISMA to provide detailed descriptions is expected to contribute significantly to satellite operators and owners who require tools with many useful functions to mitigate collision risk.

The Design Space of Multi-Language Development Environments

DEFF Research Database (Denmark)

Pfeiffer, Rolf-Helge; Wasowski, Andrzej

2014-01-01

Non-trivial software systems integrate many artifacts expressed in multiple modeling and program- ming languages. However, even though these artifacts heavily depend on each other, existing development envi- ronments do not sufficiently support handling relations between artifacts in different...... languages. By means of a literature survey, tool prototyping and experiments we study the design space of multi-language development environments (MLDEs)—tools that consider the cross-language relations as first artifacts. We ask: what is the state of the art in the MLDE space? What are the design choices...... and challenges faced by tool builders? To what extent MLDEs are desired by users, and for what support features? Our main conclusions are that (a) cross-language re- lations are ubiquitous and troublesome in multi-language systems, (b) users highly appreciated cross-language sup- port mechanisms of MLDEs and (c...

Designing new collaborative learning spaces in clinical environments: experiences from a children's hospital in Australia.

Science.gov (United States)

Bines, Julie E; Jamieson, Peter

2013-09-01

Hospitals are complex places that provide a rich learning environment for students, staff, patients and their families, professional groups and the community. The "new" Royal Children's Hospital opened in late 2011. Its mission is focused on improving health and well-being of children and adolescents through leadership in healthcare, research and education. Addressing the need to create "responsive learning environments" aligned with the shift to student-centred pedagogy, two distinct learning environments were developed within the new Royal Children's Hospital; (i) a dedicated education precinct providing a suite of physical environments to promote a more active, collaborative and social learning experience for education and training programs conducted on the Royal Children's Hospital campus and (ii) a suite of learning spaces embedded within clinical areas so that learning becomes an integral part of the daily activities of this busy Hospital environment. The aim of this article is to present the overarching educational principles that lead the design of these learning spaces and describe the opportunities and obstacles encountered in the development of collaborative learning spaces within a large hospital development.

Stent-assisted coiling of intracranial aneurysms using LEO stents: long-term follow-up in 153 patients.

Science.gov (United States)

Sedat, Jacques; Chau, Yves; Gaudart, Jean; Sachet, Marina; Beuil, Stephanie; Lonjon, Michel

2018-02-01

Coiling associated with placement of a self-expandable intracranial stent has improved the treatment of intracranial wide-necked aneurysms. Little is known, however, about the durability of this treatment. The purpose of this report is to present our experience with the LEO stent and to evaluate the complications, effectiveness, and long-term results of this technique. We analyzed the records of 155 intracranial unruptured aneurysms that were treated by stent-assisted coiling with a LEO stent between 2008 and 2012. Procedural, early post-procedural, and delayed complications were recorded. Clinical and angiographic follow-up of patients was conducted over a period of at least 36 months. No procedural mortality was observed. One-month morbidity was observed in 14 out of 153 patients (9,15%). One hundred thirty-eight patients (with 140 aneurysms) had clinical and angiographic follow-up for more than 36 months. No aneurysm rupture was observed during follow-up. Four patients presented an intra-stent stenosis at 8 months, and 6 patients who had an early recurrence were retreated. Final results showed 85% complete occlusion, 13% neck remnants, and 2% stable incomplete occlusion. Stent-assisted coiling with the LEO stent is a safe and effective treatment for unruptured intracranial aneurysms. The long-term clinical outcomes with the LEO stent are excellent with a high rate of complete occlusion that is stable over time.

Uso de Leersia hexandra (Poaceae) en la fitorremediación de suelos contaminados con petróleo fresco e intemperizado

OpenAIRE

Arias-Trinidad, Alfredo; Rivera-Cruz, María del Carmen; Roldán-Garrigós, Antonio; Aceves-Navarro, Lorenzo Armando; Quintero-Lizaola, Roberto; Hernández-Guzmán, Javier

2017-01-01

ResumenLa industria petrolera ha generado derrames crónicos de petróleo y su acumulación en Gleysoles en zonas anegadas en el estado de Tabasco, en el sureste de México. El anegamiento es un factor que limita el uso de tecnologías de remediación por el alto costo y los bajos niveles de degradación del petróleo, sin embargo, Leersia hexandra Sw. es un pasto que crece en estas zonas contaminadas con petróleo intemperizado. El objetivo del estudio fue evaluar la densidad de bacterias, producción...

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

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E.R. Lorenzetti

2011-01-01

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

Experience of Multisensory Environments in Public Space among People with Visual Impairment

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Gavin R. Jenkins

2015-07-01

Full Text Available This qualitative study explored the role of sensory characteristics embedded in the built environment and whether they support or hinder people with visual impairment in their use of public spaces. An online survey link was e-mailed to the presidents and committee members of each state’s chapters and associations of the National Federation of the Blind in the United States, resulting in 451 direct invitations to participate. Written responses of the survey questions from 48 respondents with visual impairment were analyzed. Three main themes: Barriers, Supporters, and Context-Dependence emerged from the respondents’ experience of multisensory characteristics within the built environment. The four subthemes subsumed in Barriers were: (1 Population specific design, (2 Extreme sensory backgrounds, (3 Uneven ground surfaces and objects, and (4 Inconsistent lighting. For Supporters, respondents provided specific examples of various sensory characteristics in built environments, including audible cues and echoes, smells, tactile quality of the ground surface, and temperature. Context-Dependence referred to the effects of sensory characteristics embedded in public spaces depending on one’s vision condition, the proximity to the sensory cues and the purpose of the activities one was performing at that moment. Findings provide occupational therapy practitioners an in-depth understanding of the transactional relationship between embedded sensory characteristics in the built environment, occupations, and people with visual impairment in order to make appropriate modifications or removal of barriers that affect occupational performance and engagement. Suggestions for occupational therapists as well as architects, designers, planners, policy makers/legislators related to functional sensory cues in the design of built environments were provided to increase accessibility in the use of public spaces by people with visual impairment.

Experience of Multisensory Environments in Public Space among People with Visual Impairment.

Science.gov (United States)

Jenkins, Gavin R; Yuen, Hon K; Vogtle, Laura K

2015-07-23

This qualitative study explored the role of sensory characteristics embedded in the built environment and whether they support or hinder people with visual impairment in their use of public spaces. An online survey link was e-mailed to the presidents and committee members of each state's chapters and associations of the National Federation of the Blind in the United States, resulting in 451 direct invitations to participate. Written responses of the survey questions from 48 respondents with visual impairment were analyzed. Three main themes: Barriers, Supporters, and Context-Dependence emerged from the respondents' experience of multisensory characteristics within the built environment. The four subthemes subsumed in Barriers were: (1) Population specific design, (2) Extreme sensory backgrounds, (3) Uneven ground surfaces and objects, and (4) Inconsistent lighting. For Supporters, respondents provided specific examples of various sensory characteristics in built environments, including audible cues and echoes, smells, tactile quality of the ground surface, and temperature. Context-Dependence referred to the effects of sensory characteristics embedded in public spaces depending on one's vision condition, the proximity to the sensory cues and the purpose of the activities one was performing at that moment. Findings provide occupational therapy practitioners an in-depth understanding of the transactional relationship between embedded sensory characteristics in the built environment, occupations, and people with visual impairment in order to make appropriate modifications or removal of barriers that affect occupational performance and engagement. Suggestions for occupational therapists as well as architects, designers, planners, policy makers/legislators related to functional sensory cues in the design of built environments were provided to increase accessibility in the use of public spaces by people with visual impairment.

O petróleo e a governança energética global: dilemas contemporâneos

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Enrique Carlos Natalino

2017-12-01

Full Text Available O artigo se propõe a analisar a problemática do petróleo e as suas múltiplas implicações para a governança global contemporânea. O petróleo é mais o estratégico insumo energético do planeta, capaz de levar as nações a alcançar a prosperidade ou até a conflitos armados. Seria possível pensar numa aproximação entre a gestão do petróleo na cena internacional e as discussões mais amplas acerca da concepção de espaços internacionais mais horizontais, participativos e democráticos? Nessa direção, o artigo busca investigar a trajetória do petróleo como commodity energética mundial e o seu impacto na economia e na política contemporâneas. A hipótese do trabalho é que a governança petrolífera mundial nas primeiras duas décadas do século XXI tem sido baseada não apenas em regras de mercado, nacionalismo e cálculos realistas de poder, mas em possibilidades efetivas de cooperação internacional e de ganhos mútuos.

Carrier Plus: A sensor payload for Living With a Star Space Environment Testbed (LWS/SET)

Science.gov (United States)

Marshall, Cheryl J.; Moss, Steven; Howard, Regan; LaBel, Kenneth A.; Grycewicz, Tom; Barth, Janet L.; Brewer, Dana

2003-01-01

The Defense Threat Reduction Agency (DTR4) and National Aeronautics and Space Administration (NASA) Goddard Space Flight Center are collaborating to develop the Carrier Plus sensor experiment platform as a capability of the Space Environments Testbed (SET). The Space Environment Testbed (SET) provides flight opportunities for technology experiments as part of NASA's Living With a Star (LWS) program. The Carrier Plus will provide new capability to characterize sensor technologies such as state-of-the-art visible focal plane arrays (FPAs) in a natural space radiation environment. The technical objectives include on-orbit validation of recently developed FPA technologies and performance prediction methodologies, as well as characterization of the FPA radiation response to total ionizing dose damage, displacement damage and transients. It is expected that the sensor experiment will carry 4-6 FPAs and associated radiation correlative environment monitors (CEMs) for a 2006-2007 launch. Sensor technology candidates may include n- and p-charge coupled devices (CCDs), active pixel sensors (APS), and hybrid CMOS arrays. The presentation will describe the Carrier Plus goals and objectives, as well as provide details about the architecture and design. More information on the LWS program can be found at http://lws.gsfc.nasa.gov/. Business announcements for LWS/SET and program briefings are posted at http://lws-set.gsfc.nasa.gov

International Space Station (ISS) Bacterial Filter Elements (BFEs): Filter Efficiency and Pressure Testing of Returned Units

Science.gov (United States)

Green, Robert D.; Agui, Juan H.; Vijayakumar, R.

2017-01-01

The air revitalization system aboard the International Space Station (ISS) provides the vital function of maintaining a clean cabin environment for the crew and the hardware. This becomes a serious challenge in pressurized space compartments since no outside air ventilation is possible, and a larger particulate load is imposed on the filtration system due to lack of sedimentation due to the microgravity environment in Low Earth Orbit (LEO). The ISS Environmental Control and Life Support (ECLS) system architecture in the U.S. Segment uses a distributed particulate filtration approach consisting of traditional High-Efficiency Particulate Adsorption (HEPA) media filters deployed at multiple locations in each U.S. Segment module; these filters are referred to as Bacterial Filter Elements, or BFEs. These filters see a replacement interval, as part of maintenance, of 2-5 years dependent on location in the ISS. In this work, we present particulate removal efficiency, pressure drop, and leak test results for a sample set of 8 BFEs returned from the ISS after filter replacement. The results can potentially be utilized by the ISS Program to ascertain whether the present replacement interval can be maintained or extended to balance the on-ground filter inventory with extension of the lifetime of ISS beyond 2024. These results can also provide meaningful guidance for particulate filter designs under consideration for future deep space exploration missions.

Caracterização fitoquímica do óleo de soja adicionado de extrato de Portulaca oleracea L.

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Neuza Jorge

Full Text Available RESUMO Este trabalho teve como principais objetivos medir o teor de compostos fenólicos totais e a atividade antioxidante do extrato de Portulaca oleracea L., além de avaliar a estabilidade oxidativa e a retenção dos compostos fitoquímicos presentes no óleo de soja adicionado de antioxidantes sintéticos (TBHQ e BHT e naturais (Extrato de Portulaca oleracea L.. Os tratamentos: óleo de soja (OS, óleo de soja adicionado de 100 mg/kg TBHQ (TBHQ, óleo de soja adicionado de 100 mg/kg BHT (BHT e óleo de soja adicionado de 100 mg/kg extrato (Extrato foram submetidos à termoxidação a 180 oC, por cinco horas. O extrato apresentou 99,5 mg EAG/100 g de compostos fenólicos totais e 84,6%, 35,5% e 1,8 µM Trolox/100 g de atividade antioxidante para DPPH, sistema β-caroteno/ácido linoleico e FRAP, respectivamente. A estabilidade oxidativa do tratamento Extrato foi inferior à do TBHQ, que apresentou o maior período de indução (7,6 h. Após aquecimento, os tratamentos TBHQ e Extrato apresentaram maior capacidade de retenção de tocoferóis e fitosteróis, atingindo valores acima de 88 e 87%, respectivamente. Percentagens similares de ácidos graxos poli-insaturados foram encontradas nos tratamentos OS e Extrato. O extrato de beldroega na concentração 100 mg/kg foi capaz de reduzir as alterações sofridas pelo óleo de soja após aquecimento e pode ser utilizado como substituto natural de antioxidantes sintéticos.

Tempo de destilação e perfil volátil do óleo essencial de aroeira da praia (Schinus terebinthifolius em Sergipe

Directory of Open Access Journals (Sweden)

L.F.M. Oliveira

2014-06-01

Full Text Available Aos frutos e óleos essenciais da aroeira da praia (Schinus terebinthifolius atribui-se atividade antimicrobiana sobre bactérias gram positivas além de ação anti-inflamatória. O óleo essencial da aroeira é utilizado no tratamento de micoses, sendo a sua atividade antifúngica atribuída à alta concentração de monoterpenos. Este estudo teve como objetivo determinar o melhor rendimento de destilação de óleo essencial de sementes e folhas da aroeira e os componentes químicos do óleo essencial nos diversos períodos de destilação. Cem gramas de cada material foram destilados em aparato de Clevenger durante 2,5h, 4,0h, 5,5h e 7,0h. O material destilado foi analisado por cromatografia a gás acoplada a espectrofotômetro de massas, onde foi obtido o perfil cromatográfico do material. As sementes de aroeira apresentaram maiores quantidades de óleo essencial, quando comparadas com as folhas em todos os períodos de destilação. O óleo essencial de aroeira mostrou perfil volátil formado principalmente por mono e sesquiterpenos.

Adaptation of radiation shielding code to space environment

International Nuclear Information System (INIS)

Okuno, Koichi; Hara, Akihisa

1992-01-01

Recently, the trend to the development of space has heightened. To the development of space, many problems are related, and as one of them, there is the protection from cosmic ray. The cosmic ray is the radiation having ultrahigh energy, and there was not the radiation shielding design code that copes with cosmic ray so far. Therefore, the high energy radiation shielding design code for accelerators was improved so as to cope with the peculiarity that cosmic ray possesses. Moreover, the calculation of the radiation dose equivalent rate in the moon base to which the countermeasures against cosmic ray were taken was simulated by using the improved code. As the important countermeasures for the safety protection from radiation, the covering with regolith is carried out, and the effect of regolith was confirmed by using the improved code. Galactic cosmic ray, solar flare particles, radiation belt, the adaptation of the radiation shielding code HERMES to space environment, the improvement of the three-dimensional hadron cascade code HETCKFA-2 and the electromagnetic cascade code EGS 4-KFA, and the cosmic ray simulation are reported. (K.I.)

Actividad antimicrobiana de extractos etanólicos de propóleos obtenidos de abejas Apis mellifera.

Directory of Open Access Journals (Sweden)

Boris Daniel Velasquez

2017-06-01

Full Text Available Propóleos es uno de los productos de la colmena que actualmente viene ganando interés por parte de los investigadores, ya que sus propiedades fisicoquímicas y biológicas, han sido ampliamente reconocidas por su capacidad terapéutica contra una variedad de patógenos humanos y animales, al igual que por su uso potencial contra varios Fitopatógenos. Los estudios demuestran que propóleos es una sustancia compleja, constituida, en promedio, por 300 compuestos diferentes, esta riqueza de compuestos está correlacionada con el origen botánico del cual se obtienen las resinas. Colombia es rica en diversidad botánica, perfilando al país con un alto potencial para obtener propóleos de excelente calidad, los cuales con estudios juiciosos, se constituiría estos últimos como alternativas novedosas para el control y el tratamiento de gran variedad de patógenos causantes de enfermedades.

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

Index Scriptorium Estoniae

2004-01-01

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

Analyses of Hubble Space Telescope Aluminized-Teflon Multilayer Insulation Blankets Retrieved After 19 Years of Space Exposure

Science.gov (United States)

de Groh, Kim K.; Perry, Bruce A.; Mohammed, Jelila S.; Banks, Bruce

2015-01-01

Since its launch in April 1990, the Hubble Space Telescope (HST) has made many important observations from its vantage point in low Earth orbit (LEO). However, as seen during five servicing missions, the outer layer of multilayer insulation (MLI) has become increasingly embrittled and has cracked in many areas. In May 2009, during the 5th servicing mission (called SM4), two MLI blankets were replaced with new insulation and the space-exposed MLI blankets were retrieved for degradation analyses by teams at NASA Glenn Research Center (GRC) and NASA Goddard Space Flight Center (GSFC). The retrieved MLI blankets were from Equipment Bay 8, which received direct sunlight, and Equipment Bay 5, which received grazing sunlight. Each blanket was divided into several regions based on environmental exposure and/or physical appearance. The aluminized-Teflon (DuPont, Wilmington, DE) fluorinated ethylene propylene (Al-FEP) outer layers of the retrieved MLI blankets have been analyzed for changes in optical, physical, and mechanical properties, along with chemical and morphological changes. Pristine and as-retrieved samples (materials) were heat treated to help understand degradation mechanisms. When compared to pristine material, the analyses have shown how the Al-FEP was severely affected by the space environment. Most notably, the Al-FEP was highly embrittled, fracturing like glass at strains of 1 to 8 percent. Across all measured properties, more significant degradation was observed for Bay 8 material as compared to Bay 5 material. This paper reviews the tensile and bend-test properties, density, thickness, solar absorptance, thermal emittance, x-ray photoelectron spectroscopy (XPS) and energy dispersive spectroscopy (EDS) elemental composition measurements, surface and crack morphologies, and atomic oxygen erosion yields of the Al-FEP outer layer of the retrieved HST blankets after 19 years of space exposure.

Fontes de óleo na dieta e sua influência no desempenho e na imunidade de frangos de corte

Directory of Open Access Journals (Sweden)

Marcos F. Pinto