WorldWideScience

Sample records for survived atmospheric entry

  1. Spore-Forming Thermophilic Bacterium within Artificial Meteorite Survives Entry into the Earth's Atmosphere on FOTON-M4 Satellite Landing Module.

    Science.gov (United States)

    Slobodkin, Alexander; Gavrilov, Sergey; Ionov, Victor; Iliyin, Vyacheslav

    2015-01-01

    One of the key conditions of the lithopanspermia hypothesis is that microorganisms situated within meteorites could survive hypervelocity entry from space through the Earth's atmosphere. So far, all experimental proof of this possibility has been based on tests with sounding rockets which do not reach the transit velocities of natural meteorites. We explored the survival of the spore-forming thermophilic anaerobic bacterium, Thermoanaerobacter siderophilus, placed within 1.4-cm thick basalt discs fixed on the exterior of a space capsule (the METEORITE experiment on the FOTON-M4 satellite). After 45 days of orbital flight, the landing module of the space vehicle returned to Earth. The temperature during the atmospheric transit was high enough to melt the surface of basalt. T. siderophilus survived the entry; viable cells were recovered from 4 of 24 wells loaded with this microorganism. The identity of the strain was confirmed by 16S rRNA gene sequence and physiological tests. This is the first report on the survival of a lifeform within an artificial meteorite after entry from space orbit through Earth's atmosphere at a velocity that closely approached the velocities of natural meteorites. The characteristics of the artificial meteorite and the living object applied in this study can serve as positive controls in further experiments on testing of different organisms and conditions of interplanetary transport.

  2. Spore-Forming Thermophilic Bacterium within Artificial Meteorite Survives Entry into the Earth's Atmosphere on FOTON-M4 Satellite Landing Module.

    Directory of Open Access Journals (Sweden)

    Alexander Slobodkin

    Full Text Available One of the key conditions of the lithopanspermia hypothesis is that microorganisms situated within meteorites could survive hypervelocity entry from space through the Earth's atmosphere. So far, all experimental proof of this possibility has been based on tests with sounding rockets which do not reach the transit velocities of natural meteorites. We explored the survival of the spore-forming thermophilic anaerobic bacterium, Thermoanaerobacter siderophilus, placed within 1.4-cm thick basalt discs fixed on the exterior of a space capsule (the METEORITE experiment on the FOTON-M4 satellite. After 45 days of orbital flight, the landing module of the space vehicle returned to Earth. The temperature during the atmospheric transit was high enough to melt the surface of basalt. T. siderophilus survived the entry; viable cells were recovered from 4 of 24 wells loaded with this microorganism. The identity of the strain was confirmed by 16S rRNA gene sequence and physiological tests. This is the first report on the survival of a lifeform within an artificial meteorite after entry from space orbit through Earth's atmosphere at a velocity that closely approached the velocities of natural meteorites. The characteristics of the artificial meteorite and the living object applied in this study can serve as positive controls in further experiments on testing of different organisms and conditions of interplanetary transport.

  3. Atmospheric Entry Experiments at IRS

    Science.gov (United States)

    Auweter-Kurtz, M.; Endlich, P.; Herdrich, G.; Kurtz, H.; Laux, T.; Löhle, S.; Nazina, N.; Pidan, S.

    2002-01-01

    Entering the atmosphere of celestial bodies, spacecrafts encounter gases at velocities of several km/s, thereby being subjected to great heat loads. The thermal protection systems and the environment (plasma) have to be investigated by means of computational and ground facility based simulations. For more than a decade, plasma wind tunnels at IRS have been used for the investigation of TPS materials. Nevertheless, ground tests and computer simulations cannot re- place space flights completely. Particularly, entry mission phases encounter challenging problems, such as hypersonic aerothermodynamics. Concerning the TPS, radiation-cooled materials used for reuseable spacecrafts and ablator tech- nologies are of importance. Besides the mentioned technologies, there is the goal to manage guidance navigation, con- trol, landing technology and inflatable technologies such as ballutes that aim to keep vehicles in the atmosphere without landing. The requirement to save mass and energy for planned interplanetary missions such as Mars Society Balloon Mission, Mars Sample Return Mission, Mars Express or Venus Sample Return mission led to the need for manoeuvres like aerocapture, aero-breaking and hyperbolic entries. All three are characterized by very high kinetic vehicle energies to be dissipated by the manoeuvre. In this field flight data are rare. The importance of these manoeuvres and the need to increase the knowledge of required TPS designs and behavior during such mission phases point out the need of flight experiments. As result of the experience within the plasma diagnostic tool development and the plasma wind tunnel data base, flight experiments like the PYrometric RE-entry EXperiment PYREX were developed, fully qualified and successfully flown. Flight experiments such as the entry spectrometer RESPECT and PYREX on HOPE-X are in the conceptual phase. To increase knowledge in the scope of atmospheric manoeuvres and entries, data bases have to be created combining both

  4. Hypersonic Flight Mechanics. [for atmospheric entry trajectories

    Science.gov (United States)

    Busemann, A.; Vinh, N. X.; Culp, R. D.

    1976-01-01

    The effects of aerodynamic forces on trajectories at orbital speeds are discussed in terms of atmospheric models. The assumptions for the model are spherical symmetry, nonrotating, and an exponential atmosphere. The equations of flight, and the performance in extra-atmospheric flight are discussed along with the return to the atmosphere, and the entry. Solutions of the exact equations using directly matched asymptotic expansions are presented.

  5. Orion Capsule Handling Qualities for Atmospheric Entry

    Science.gov (United States)

    Tigges, Michael A.; Bihari, Brian D.; Stephens, John-Paul; Vos, Gordon A.; Bilimoria, Karl D.; Mueller, Eric R.; Law, Howard G.; Johnson, Wyatt; Bailey, Randall E.; Jackson, Bruce

    2011-01-01

    Two piloted simulations were conducted at NASA's Johnson Space Center using the Cooper-Harper scale to study the handling qualities of the Orion Command Module capsule during atmospheric entry flight. The simulations were conducted using high fidelity 6-DOF simulators for Lunar Return Skip Entry and International Space Station Return Direct Entry flight using bank angle steering commands generated by either the Primary (PredGuid) or Backup (PLM) guidance algorithms. For both evaluations, manual control of bank angle began after descending through Entry Interface into the atmosphere until drogue chutes deployment. Pilots were able to use defined bank management and reversal criteria to accurately track the bank angle commands, and stay within flight performance metrics of landing accuracy, g-loads, and propellant consumption, suggesting that the pilotability of Orion under manual control is both achievable and provides adequate trajectory performance with acceptable levels of pilot effort. Another significant result of these analyses is the applicability of flying a complex entry task under high speed entry flight conditions relevant to the next generation Multi Purpose Crew Vehicle return from Mars and Near Earth Objects.

  6. Evolved atmospheric entry corridor with safety factor

    Science.gov (United States)

    Liang, Zixuan; Ren, Zhang; Li, Qingdong

    2018-02-01

    Atmospheric entry corridors are established in previous research based on the equilibrium glide condition which assumes the flight-path angle to be zero. To get a better understanding of the highly constrained entry flight, an evolved entry corridor that considers the exact flight-path angle is developed in this study. Firstly, the conventional corridor in the altitude vs. velocity plane is extended into a three-dimensional one in the space of altitude, velocity, and flight-path angle. The three-dimensional corridor is generated by a series of constraint boxes. Then, based on a simple mapping method, an evolved two-dimensional entry corridor with safety factor is obtained. The safety factor is defined to describe the flexibility of the flight-path angle for a state within the corridor. Finally, the evolved entry corridor is simulated for the Space Shuttle and the Common Aero Vehicle (CAV) to demonstrate the effectiveness of the corridor generation approach. Compared with the conventional corridor, the evolved corridor is much wider and provides additional information. Therefore, the evolved corridor would benefit more to the entry trajectory design and analysis.

  7. Competitive Dynamics of Market Entry: Scale and Survival

    Directory of Open Access Journals (Sweden)

    John W. UPSON

    2017-06-01

    Full Text Available Market entry is the essence of strategy and is largely viewed as a dichotomous event: entry or no entry. What has not been acknowledged is the uniqueness of each market entry. Our study highlights the scale of market entry in the context of multipoint competition. We assert that entry scale varies based on the risk of market incumbent retaliation. Theory suggests that when risk associated with retaliation are low, firms enter with large scale and when associated risks are high, firms enter with low scale. Further, survival is viewed as dependent on following theory. We argue and find supporting evidence that firms behave in the opposite manner and do so to their own benefit, thereby revealing a unique discrepancy between theory and practice among 75 product market entries by 27 firms.

  8. Mars Entry Atmospheric Data System Modeling, Calibration, and Error Analysis

    Science.gov (United States)

    Karlgaard, Christopher D.; VanNorman, John; Siemers, Paul M.; Schoenenberger, Mark; Munk, Michelle M.

    2014-01-01

    The Mars Science Laboratory (MSL) Entry, Descent, and Landing Instrumentation (MEDLI)/Mars Entry Atmospheric Data System (MEADS) project installed seven pressure ports through the MSL Phenolic Impregnated Carbon Ablator (PICA) heatshield to measure heatshield surface pressures during entry. These measured surface pressures are used to generate estimates of atmospheric quantities based on modeled surface pressure distributions. In particular, the quantities to be estimated from the MEADS pressure measurements include the dynamic pressure, angle of attack, and angle of sideslip. This report describes the calibration of the pressure transducers utilized to reconstruct the atmospheric data and associated uncertainty models, pressure modeling and uncertainty analysis, and system performance results. The results indicate that the MEADS pressure measurement system hardware meets the project requirements.

  9. Atmospheric Entry Studies for Venus Missions: 45 Sphere-Cone Rigid Aeroshells and Ballistic Entries

    Science.gov (United States)

    Prabhu, Dinesh K.; Spilker, Thomas R.; Allen, Gary A., Jr.; Hwang, Helen H.; Cappuccio, Gelsomina; Moses, Robert W.

    2013-01-01

    The present study considers direct ballistic entries into the atmosphere of Venus using a 45deg sphere-cone rigid aeroshell, a legacy shape that has been used successfully in the past in the Pioneer Venus Multiprobe Mission. For a number of entry mass and heatshield diameter combinations (i.e., various ballistic coefficients) and entry velocities, the trajectory space in terms of entry flight path angles between skip out and -30deg is explored with a 3DoF trajectory code, TRAJ. From these trajectories, the viable entry flight path angle space is determined through the use of mechanical and thermal performance limits on the thermal protection material and science payload; the thermal protection material of choice is entry-grade carbon phenolic, for which a material thermal response model is available. For mechanical performance, a 200 g limit is placed on the peak deceleration load experienced by the science instruments, and 10 bar is assumed as the pressure limit for entry-grade carbon-phenolic material. For thermal performance, inflection points in the total heat load distribution are used as cut off criteria. Analysis of the results shows the existence of a range of critical ballistic coefficients beyond which the steepest possible entries are determined by the pressure limit of the material rather than the deceleration load limit.

  10. Mars Atmospheric Entry Integrated Navigation with Partial Intermittent Measurements

    Directory of Open Access Journals (Sweden)

    Tai-shan Lou

    2017-01-01

    Full Text Available Signal degradation suffered by the vehicle is a combination brownout and blackout during Mars atmospheric entry. The communications brownout means that signal fades and blackout means that the signal is lost completely. The communications brownout and blackout periods are analyzed and predicted with an altitude and velocity profiles. In the brownout period, the range measurements between the vehicle and the orbiters are modeled as intermittent measurements with the radio signal arrival probabilities, which are distributed as a Rayleigh distribution of the electron number density around the entry vehicle. A new integrated navigation strategy during the Mars atmospheric entry phase is proposed to consider the probabilities of the radio measurements in the communications brownout and blackout periods under the IMU/beacon scenario based on the information filter with intermittent measurements. Numerical navigation simulations are designed to show the performance of the proposed navigation strategy under the integrated navigation scenario.

  11. Communications Blackout Predictions for Atmospheric Entry of Mars Science Laboratory

    Science.gov (United States)

    Morabito, David D.; Edquist, Karl

    2005-01-01

    The Mars Science Laboratory (MSL) is expected to be a long-range, long-duration science laboratory rover on the Martian surface. MSL will provide a significant milestone that paves the way for future landed missions to Mars. NASA is studying options to launch MSL as early as 2009. MSL will be the first mission to demonstrate the new technology of 'smart landers', which include precision landing and hazard avoidance in order to -land at scientifically interesting sites that would otherwise be unreachable. There are three elements to the spacecraft; carrier (cruise stage), entry vehicle, and rover. The rover will have an X-band direct-to-Earth (DTE) link as well as a UHF proximity link. There is also a possibility of an X-band proximity link. Given the importance of collecting critical event telemetry data during atmospheric entry, it is important to understand the ability of a signal link to be maintained, especially during the period near peak convective heating. The received telemetry during entry (or played back later) will allow for the performance of the Entry-Descent-Landing technologies to be assessed. These technologies include guided entry for precision landing, hazard avoidance, a new sky-crane landing system and powered descent. MSL will undergo an entry profile that may result in a potential communications blackout caused by ionized plasma for short periods near peak heating. The vehicle will use UHF and possibly X-band during the entry phase. The purpose of this report is to quantify or bound the likelihood of any such blackout at UHF frequencies (401 MHz) and X-band frequencies (8.4 GHz). Two entry trajectory scenarios were evaluated: a stressful entry trajectory to quantify an upper-bound for any possible blackout period, and a nominal likely trajectory to quantify likelihood of blackout for such cases.

  12. On the Use of Atmosphere Models in Re-Entry Predictions

    Science.gov (United States)

    Klinkrad, H.

    1996-12-01

    The catalog of the Space Surveillance Network (SSN) of US Space Command (USSpaceCom) contains more than 7600 objects larger than 10 cm. On the average, one of these objects re-enters the earth atmosphere every day, and every second day there is a re-entry of a decommissioned spacecraft or upper stage (which together account for more than 40% of the catalog population). The vast majority of these re-entries is entailing an extremely low risk potential, since most of the structures are disintegrated and burnt up during an extended heat flux and g-load exposure under shallow entry angles. In some instances, however, a non negligible risk from ground impact or ground/atmosphere pollution may arise in case of very massive objects (e.g. Skylab with 75t and Salyut-7 with 40t), objects which were designed to survive re-entry (e.g. China-40 capsule), or spacecraft with hazardous payloads (e.g. Kosmos-954 and 1402 which were equipped with reactors containing 50kg of radioactive material). In such cases, ESOC performs re-entry predictions which are communicated to international points of contact as input to their emergency plans (if necessary). The prediction of uncontrolled re-entries is based on a propagation of the perturbed orbital motion of a spacecraft up to the point of disintegration (at about 80km altitude). The drag coefficient is determined from a least squares retro-fit over a history of observations of the semi-major axis. Apart from the attitude dynamics and associated cross-section variations, the major uncertainty in re-entry predictions is due to inadequate modeling of the atmosphere, and in particular of the air density. At standard operating altitudes of LEO satellites atmosphere models can be assumed accurate to within 10% to 15% rms in density for well known atmospheric parameters. Due to the lack of underlying data, density models become less reliable below 200km altitude where the critical phase of a re-entry begins. Moreover, in case of prediction

  13. Outer planet atmospheric entry probes - An overview of technology readiness

    Science.gov (United States)

    Vojvodich, N. S.; Reynolds, R. T.; Grant, T. L.; Nachtsheim, P. R.

    1975-01-01

    Entry probe systems for characterizing, by in situ measurements, the atmospheric properties, chemical composition, and cloud structure of the planets Saturn, Uranus, and Jupiter are examined from the standpoint of unique mission requirements, associated subsystem performance, and degree of commonality of design. Past earth entry vehicles (PAET) and current planetary spacecraft (Pioneer Venus probes and Viking lander) are assessed to identify the extent of potential subsystem inheritance, as well as to establish the significant differences, in both form and function, relative to outer planet requirements. Recent research results are presented and reviewed for the most critical probe technology areas, including: science accommodation, telecommunication, and entry heating and thermal protection. Finally presented is a brief discussion of the use of decision analysis techniques for quantifying various probe heat-shield test alternatives and performance risk.

  14. ABLATION AND CHEMICAL ALTERATION OF COSMIC DUST PARTICLES DURING ENTRY INTO THE EARTH’S ATMOSPHERE

    Energy Technology Data Exchange (ETDEWEB)

    Rudraswami, N. G.; Prasad, M. Shyam; Dey, S.; Fernandes, D. [National Institute of Oceanography (Council of Scientific and Industrial Research), Dona Paula, Goa 403004 (India); Plane, J. M. C.; Feng, W.; Carrillo-Sánchez, J. D., E-mail: rudra@nio.org [School of Chemistry, University of Leeds, Leeds LS2 9JT (United Kingdom)

    2016-12-01

    Most dust-sized cosmic particles undergo ablation and chemical alteration during atmospheric entry, which alters their original properties. A comprehensive understanding of this process is essential in order to decipher their pre-entry characteristics. The purpose of the study is to illustrate the process of vaporization of different elements for various entry parameters. The numerical results for particles of various sizes and various zenith angles are treated in order to understand the changes in chemical composition that the particles undergo as they enter the atmosphere. Particles with large sizes (> few hundred μ m) and high entry velocities (>16 km s{sup −1}) experience less time at peak temperatures compared to those that have lower velocities. Model calculations suggest that particles can survive with an entry velocity of 11 km s{sup −1} and zenith angles (ZA) of 30°–90°, which accounts for ∼66% of the region where particles retain their identities. Our results suggest that the changes in chemical composition of MgO, SiO{sub 2}, and FeO are not significant for an entry velocity of 11 km s{sup −1} and sizes <300 μ m, but the changes in these compositions become significant beyond this size, where FeO is lost to a major extent. However, at 16 km s{sup −1} the changes in MgO, SiO{sub 2}, and FeO are very intense, which is also reflected in Mg/Si, Fe/Si, Ca/Si, and Al/Si ratios, even for particles with a size of 100 μ m. Beyond 400 μ m particle sizes at 16 km s{sup −1}, most of the major elements are vaporized, leaving the refractory elements, Al and Ca, suspended in the troposphere.

  15. Notes on Earth Atmospheric Entry for Mars Sample Return Missions

    Science.gov (United States)

    Rivell, Thomas

    2006-01-01

    The entry of sample return vehicles (SRVs) into the Earth's atmosphere is the subject of this document. The Earth entry environment for vehicles, or capsules, returning from the planet Mars is discussed along with the subjects of dynamics, aerodynamics, and heat transfer. The material presented is intended for engineers and scientists who do not have strong backgrounds in aerodynamics, aerothermodynamics and flight mechanics. The document is not intended to be comprehensive and some important topics are omitted. The topics considered in this document include basic principles of physics (fluid mechanics, dynamics and heat transfer), chemistry and engineering mechanics. These subjects include: a) fluid mechanics (aerodynamics, aerothermodynamics, compressible fluids, shock waves, boundary layers, and flow regimes from subsonic to hypervelocity; b) the Earth s atmosphere and gravity; c) thermal protection system design considerations; d) heat and mass transfer (convection, radiation, and ablation); e) flight mechanics (basic rigid body dynamics and stability); and f) flight- and ground-test requirements; and g) trajectory and flow simulation methods.

  16. Design and Simulation Tools for Planetary Atmospheric Entry Vehicles, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Atmospheric entry is one of the most critical phases of flight during planetary exploration missions. During the design of an entry vehicle, experimental and...

  17. Communications Blackout Prediction for Atmospheric Entry of Mars Science Laboratory

    Science.gov (United States)

    Morabito, David; Edquist, Karl

    2005-01-01

    When a supersonic spacecraft enters a planetary atmosphere with v >> v(sub sound), a shock layer forms in the front of the body. An ionized sheath of plasma develops around the spacecraft, which results from the ionization of the atmospheric constituents as they are compressed and heated by the shock or heated within the boundary layer next to the surface. When the electron density surrounding the spacecraft becomes sufficiently high, communications can be disrupted (attenuation/blackout). During Mars Science Laboratory's (MSL's) atmospheric entry there will likely be a communication outage due to charged particles on the order of 60 to 100 seconds using a UHF link frequency looking out the shoulders of the wake region to orbiting relay asset. A UHF link looking out the base region would experience a shorter duration blackout, about 35 seconds for the stressed trajectory and possibly no blackout for the nominal trajectory. There is very little likelihood of a communications outage using X-band (however, X-band is not currently planned to be used during peak electron density phase of EDL).

  18. Dissociative recombination in reactive flows related to planetary atmospheric entries

    Directory of Open Access Journals (Sweden)

    Bultel Arnaud

    2015-01-01

    Full Text Available The Dissociative Recombination (DR processes play a significant role in plasma chemistry. This article illustrates this role from the modeling point of view in the case of reactive flows related to atmospheric entry plasmas. Two situations are investigated, for which the studied plasma is nitrogen. The first configuration corresponds to the relaxation process behind a strong shock wave moving at high Mach number in a shock tube, the second one to the recombination taking place in an expanding plasma flowing in a diverging nozzle. In both cases, the collisional-radiative model CoRaM-N2, involving N2, N, N2+, N+ and electrons, is implemented in an Eulerian 1D code able to compute the aerodynamic fields; calculations are performed in standard conditions. We show that, according to the rate coefficients used for the DR processes, the population density of the charged species especially N2+ is strongly modified only for the post-shock flow.

  19. Analysis of Atmospheric Mesoscale Models for Entry, Descent and Landing

    Science.gov (United States)

    Kass, D. M.; Schofield, J. T.; Michaels, T. I.; Rafkin, S. C. R.; Richardson, M. I.; Toigo, A. D.

    2003-01-01

    Each Mars Exploration Rover (MER) is sensitive to the martian winds encountered near the surface during the Entry, Descent and Landing (EDL) process. These winds are strongly influenced by local (mesoscale) conditions. In the absence of suitable wind observations, wind fields predicted by martian mesoscale atmospheric models have been analyzed to guide landing site selection. Two different models were used, the MRAMS model and the Mars MM5 model. In order to encompass both models and render their results useful to the EDL engineering team, a series of statistical techniques were applied to the model results. These analyses cover the high priority landing sites during the expected landing times (1200 to 1500 local time). The number of sites studied is limited by the computational and analysis cost of the mesoscale models.

  20. Elaboration of collisional-radiative models applied to atmospheric entry into the Earth and Mars atmospheres

    OpenAIRE

    Annaloro, Julien

    2013-01-01

    The hypersonic entry of a body into the upper layers of a planetary atmosphere leads to the formation of a plasma resulting from the intense compression of the incident gas. This compression takes place within a shock layer in non-equilibrium, the knowledge of which is partial. This prevents a precise assessment of the convective, radiative and catalytic parts of the parietal heat flux required for the sizing of the thermal protection system of the entering body. The latter contributions stro...

  1. Titan Lifting Entry & Atmospheric Flight (T-LEAF) Science Mission

    Science.gov (United States)

    Lee, G.; Sen, B.; Ross, F.; Sokol, D.

    2016-12-01

    Northrop Grumman has been developing the Titan Lifting Entry & Atmospheric Flight (T-LEAF) sky rover to roam the lower atmosphere and observe at close quarters the lakes and plains of Saturn's ocean moon, Titan. T-LEAF also supports surface exploration and science by providing precision delivery of in-situ instruments to the surface of Titan. T-LEAF is a highly maneuverable sky rover and its aerodynamic shape (i.e., a flying wing) does not restrict it to following prevailing wind patterns on Titan, but allows mission operators to chart its course. This freedom of mobility allows T-LEAF to follow the shorelines of Titan's methane lakes, for example, or to target very specific surface locations. We will present a straw man concept of T-LEAF, including size, mass, power, on-board science payloads and measurement, and surface science dropsonde deployment CONOPS. We will discuss the various science instruments and their vehicle level impacts, such as meteorological and electric field sensors, acoustic sensors for measuring shallow depths, multi-spectral imagers, high definition cameras and surface science dropsondes. The stability of T-LEAF and its long residence time on Titan will provide for time to perform a large aerial survey of select prime surface targets deployment of dropsondes at selected locations surface measurements that are coordinated with on-board remote measurements communication relay capabilities to orbiter (or Earth). In this context, we will specifically focus upon key factors impacting the design and performance of T-LEAF science: science payload accommodation, constraints and opportunities characteristics of flight, payload deployment and measurement CONOPS in the Titan atmosphere. This presentation will show how these factors provide constraints as well as enable opportunities for novel long duration scientific studies of Titan's surface.

  2. Optimization of a Hot Structure Aeroshell and Nose Cap for Mars Atmospheric Entry

    Science.gov (United States)

    Langston, Sarah L.; Lang, Christapher G.; Samareh, Jamshid A.; Daryabeigi, Kamran

    2016-01-01

    The National Aeronautics and Space Administration (NASA) is preparing to send humans beyond Low Earth Orbit and eventually to the surface of Mars. As part of the Evolvable Mars Campaign, different vehicle configurations are being designed and considered for delivering large payloads to the surface of Mars. Weight and packing volume are driving factors in the vehicle design, and the thermal protection system (TPS) for planetary entry is a technology area which can offer potential weight and volume savings. The feasibility and potential benefits of a ceramic matrix composite hot structure concept for different vehicle configurations are explored in this paper, including the nose cap for a Hypersonic Inflatable Aerodynamic Decelerator (HIAD) and an aeroshell for a mid lift-to-drag (Mid L/D) concept. The TPS of a planetary entry vehicle is a critical component required to survive the severe aerodynamic heating environment during atmospheric en- try. The current state-of-the-art is an ablative material to protect the vehicle from the heat load. The ablator is bonded to an underlying structure, which carries the mechanical loads associated with entry. The alternative hot structure design utilizes an advanced carbon-carbon material system on the outer surface of the vehicle, which is exposed to the severe heating and acts as a load carrying structure. The preliminary design using the hot structure concept and the ablative concept is determined for the spherical nose cap of the HIAD entry vehicle and the aeroshell of the Mid L/D entry vehicle. The results of the study indicate that the use of hot structures for both vehicle concepts leads to a feasible design with potential weight and volume savings benefits over current state-of-the-art TPS technology that could enable future missions.

  3. Atmospheric Mars Entry and Landing Investigations & Analysis (AMELIA) by ExoMars 2016 Schiaparelli Entry Descent Module

    Science.gov (United States)

    Ferri, F.; Karatekin, O.; Aboudan, A.; VanHove, B.; Colombatti, C.; Bettanini, C.; Debei, S.; Lewis, S.; Forget, F.

    2017-09-01

    On the 19th October 2016, Schiaparelli, the Entry Demonstrator Module (EDM) of the ESA ExoMars Program entered into the martian atmosphere. Although it did not complete a safe landing on Mars, it transmitted data throughout its descent to the surface, until the loss of signal at 1 minute before the expected touch-down on Mars' surface. From the flight data, we reconstruct the actual dynamics of the vehicle during its descent towards Mars's surface and retrieve the atmospheric profile, in terms of density, pressure and temperature, along its trajectory for atmospheric investigations.

  4. Ablation and chemical alteration of cosmic dust particles during entry into the earth`s atmosphere

    Digital Repository Service at National Institute of Oceanography (India)

    Rudraswami, N.G.; ShyamPrasad, M.; Dey, S.; Plane, J.M.C.; Feng, W.; Carrillo-Sanchez, J.D.; Fernandes, D.

    , 2015a, b, 2016a, b). The deviations in chemical compositions from the precursors occur due to modification by melting and vaporization as these particles entry into the Earth’s atmosphere. These modifications are dominated by loss of elements based... on their relative volatilities and other physical processes parameterized by some key variables used such as size, density, entry velocity, angle of entry apart from others (Love and Brownlee, 1991; Rudraswami et al., 2015a, 2016a). The ongoing discussion involves...

  5. Atmospheric Entry Heating of Macro- and Micrometeorites: A Comparative Study

    Science.gov (United States)

    Greenwood, R. C.; Hutchison, R.

    1993-07-01

    Deceleration in the Earth's atmosphere causes frictional heating in micrometeorites. The duration and maximum temperature attained are a function of the entry angle, mass, and initial velocity of the particle [1]. Frictional heating may deplete volatile elements, in particular S and Zn [2], cause partial or total melting, and lead to the formation of magnetite rims [3]. To improve our understanding of the processes involved in atmospheric heating we are undertaking a comparative investigation using both micrometeorites and larger samples. Compared to micrometeorites, which decelerate above 70km, larger meteorites experience significant atmospheric heating at much lower altitudes [1]. As a consequence there are some significant differences between their respective fusion products [4]. However, one advantage of using fusion crust as an analogue for melted micrometeorites is that melted and unmelted material can be directly compared. In view of estimates that meteorite ablation losses may be as much as 90% [5] we are also interested in assessing whether such material has been sampled by recent micrometeorite surface collections [6]. Method: 45 particles hand picked from the 50-100 micrometer fraction collected during the 1991 EUROMET Antarctic expedition [6] were mounted and polished in Orsay, France. Back-scattered electron images of each particle were taken and the major and minor element composition determined using a Cameca SX-50 WDS microprobe. Analytical work on a second batch of these particles is in progress. Raster-beam analysis (integrated area 4.5 cm^2) of the central unheated portion of a crusted stone from the Cold Bokkeveld (CM2) shower and major element characterization of its fusion crust were carried out using an Hitachi S2500 analytical SEM. Results: Fusion crust enclosing Cold Bokkeveld varies in thickness from 500-1200 micrometers and is composed of two distinct zones, an outer highly-vesicular glassy layer 100-600 micrometers thick, and an inner

  6. Fractionation and fragmentation of glass cosmic spherules during atmospheric entry

    Digital Repository Service at National Institute of Oceanography (India)

    Rudraswami, N.G.; ShyamPrasad, M.; Babu, E.V.S.S.K.; VijayaKumar, T.; Feng, W.; Plane, J.M.C.

    in vaporization of Fe and other volatile elements such as S, Na, and K from the silicate spherule, resulting in the enrichment of SiO2, MgO, and CaO in weight percent. Calculations with a chemical ablation model suggest an entry velocity of approx. 11–16 km...

  7. Experimental Modeling of Sterilization Effects for Atmospheric Entry Heating on Microorganisms

    Science.gov (United States)

    Schubert, Wayne W.; Spry, James A.; Ronney, Paul D.; Pandian, Nathan R.; Welder, Eric

    2012-01-01

    The objective of this research was to design, build, and test an experimental apparatus for studying the parameters of atmospheric entry heating, and the inactivation of temperature-resistant bacterial spores. The apparatus is capable of controlled, rapid heating of sample coupons to temperatures of 200 to 350 C and above. The vacuum chamber permits operation under vacuum or special atmospheric gas mixtures.

  8. Rigidized Deployable Lifting Brake for Atmospheric Entry Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Aerobraking to reduce velocity for planetary capture and landing has long been assumed for use on Mars missions because Mars has an atmosphere, and the use of...

  9. Feasability Analysis And Preliminary Design Of An Atmospheric Re-Entry CubeSat Demonstrator

    Science.gov (United States)

    Bailet, Billes; Asma, Cem O.; Muylaert, Jean; Magin, Thierry

    2011-05-01

    The feasibility analysis of the Re-entry CubeSat demonstrator developed by the von Karman Institute is presented in this paper. The launch of the demonstrator has been scheduled for June 2014. It represents an ideal cost-efficient platform for re-entry flight test and validation of thermal protection system (TPS) materials. The CubeSat comprises a standard double-unit platform with sensors for atmospheric research and the functional unit for essential satellite operations. A third unit accommodating an ablative heat shield is added to protect the vehicle against the extreme aerothermal conditions for the re-entry. The preliminary design of the vehicle results in a payload of minimum 300 g collecting data all along the re-entry trajectory including the maximal heat flux conditions. Finally, the tools developed have been used to carry a first analysis of the range of possible applications and flight conditions for different re-entry scenarios.

  10. Atmosphere Assessment for MARS Science Laboratory Entry, Descent and Landing Operations

    Science.gov (United States)

    Cianciolo, Alicia D.; Cantor, Bruce; Barnes, Jeff; Tyler, Daniel, Jr.; Rafkin, Scot; Chen, Allen; Kass, David; Mischna, Michael; Vasavada, Ashwin R.

    2013-01-01

    On August 6, 2012, the Mars Science Laboratory rover, Curiosity, successfully landed on the surface of Mars. The Entry, Descent and Landing (EDL) sequence was designed using atmospheric conditions estimated from mesoscale numerical models. The models, developed by two independent organizations (Oregon State University and the Southwest Research Institute), were validated against observations at Mars from three prior years. In the weeks and days before entry, the MSL "Council of Atmospheres" (CoA), a group of atmospheric scientists and modelers, instrument experts and EDL simulation engineers, evaluated the latest Mars data from orbiting assets including the Mars Reconnaissance Orbiter's Mars Color Imager (MARCI) and Mars Climate Sounder (MCS), as well as Mars Odyssey's Thermal Emission Imaging System (THEMIS). The observations were compared to the mesoscale models developed for EDL performance simulation to determine if a spacecraft parameter update was necessary prior to entry. This paper summarizes the daily atmosphere observations and comparison to the performance simulation atmosphere models. Options to modify the atmosphere model in the simulation to compensate for atmosphere effects are also presented. Finally, a summary of the CoA decisions and recommendations to the MSL project in the days leading up to EDL is provided.

  11. Radon entry into buildings: Effects of atmospheric pressure fluctuations and building structural factors

    International Nuclear Information System (INIS)

    Robinson, A.L.

    1996-05-01

    An improved understanding of the factors that control radon entry into buildings is needed in order to reduce the public health risks caused by exposure to indoor radon. This dissertation examines three issues associated with radon entry into buildings: (1) the influence of a subslab gravel layer and the size of the openings between the soil and the building interior on radon entry; (2) the effect of atmospheric pressure fluctuations on radon entry; and (3) the development and validation of mathematical models which simulate radon and soil-gas entry into houses. Experiments were conducted using two experimental basements to examine the influence of a subslab gravel layer on advective radon entry driven by steady indoor-outdoor pressure differences. These basement structures are identical except that in one the floor slab lies directly on native soil whereas in the other the slab lies on a high-permeability gravel layer. The measurements indicate that a high permeability subslab gravel layer increases the advective radon entry rate into the structure by as much as a factor of 30. The magnitude of the enhancement caused by the subslab gravel layer depends on the area of the openings in the structure floor; the smaller the area of these openings the larger the enhancement in the radon entry rate caused by the subslab gravel layer. A three-dimensional, finite-difference model correctly predicts the effect of a subslab gravel layer and open area configuration on advective radon entry driven by steady indoor-outdoor pressure differences; however, the model underpredicts the absolute entry rate into each structure by a factor of 1.5

  12. Preentry communication design elements for outer planets atmospheric entry probe

    Science.gov (United States)

    1976-01-01

    Four related tasks are discussed for data transmission from a probe prior to entering the atmosphere of Jupiter to an orbiting spacecraft in a trajectory past the planet: (1) link analysis and design; (2) system conceptual design; (3) Doppler measurement analysis; and (4) an electronically despun antenna. For tasks 1, 3, and 4, an analytical approach was developed and combined with computational capability available to produce quantitative results corresponding to requirements and constraints given by NASA, ARC. One constraint having a major impact on the numerical results of the link analysis was the assumption of a nonsteerable antenna on a spinning orbiter. Other constraints included the interplanetary trajectory and the approach trajectory. Because the Jupiter Orbiter Probe (JOP) program is currently in a state of evolution, all requirements and constraints applied during this study are subject to change. However, the relationships of parameters as developed will remain valid and will aid in planning Jupiter missions.

  13. ENTRYSAT: A 3U Cubesat to Study the Re-Entry Atmospheric Environment

    Science.gov (United States)

    Garcia, R. F.; Chaix, J.; Mimoun, D.; EntrySat student Team

    2014-04-01

    The EntrySat is a 3U CubeSat designed to study the uncontrolled atmospheric re-entry. The project, developed by ISAE in collaboration with ONERA, is funded by CNES and is intended to be launched in January 2016, in the context of the QB50 network. The scientific goal is to relate the kinematics of the satellite with the aerothermodynamic environment during re-entry. In particular, data will be compared with the computations of MUSIC/FAST, a new 6-degree of freedom code developed by ONERA to predict the trajectory of space debris. According to these requirements, the satellite will measure the temperature, pressure, heat flux, and drag force during re-entry, as well as the trajectory and attitude of the satellite. One of the major technological challenges is the retrieval of data during the re-entry phase, which will be based on the Iridium satellite network. The system design is based on the use of commercial COTS components, and is mostly developed by students from ISAE. As such, the EntrySat has an important educational value in the formation of young engineers.

  14. Oxidation and evaporation of sulfur species at atmospheric entry of iron sulfide fine particles

    Science.gov (United States)

    Isobe, H.; Murozono, K.

    2017-12-01

    Micrometeorites have the most abundant flux in current accumulation of planetary materials to the Earth. Micrometeorites are heated and reacted with upper atmosphere at atmospheric entry. Evaporation of meteoritic materials, especially sulfur species, may have environmental effect at upper atmosphere (e.g. Court and Sephton, 2011; Tomkins et al., 2016). Troilite is typical FeS phase in chondritic meteorites. In this study, quick heating and cooling experiments of FeS reagent particles were carried out with a fine particles free falling apparatus with controlled gas flow (Isobe and Gondo, 2013). Starting material reagent is inhomogeneous mixture of troilite, iron oxide and iron metal. Oxygen fugacity was controlled to FMQ +1.5 log unit. Maximum temperature of the particles was higher than 1400°C for approximately 0.5 seconds. Run products with rounded shape and smooth surface show the particles were completely melted. Chemical compositions of particles analyzed on cross sections are generally well homogenized from inhomogeneous starting materials by complete melting. Molar ratios of Fe in melted regions are close to 0.5, while compositions of S and O are various. Varieties of S and O compositions show various degree of oxidation and evaporation of sulfur. Distribution of compositions of melted regions in Fe-S-O system is plotted in liquidus compositions of FeO and FeS saturated melt. Troilite in micrometeorite is melted and oxidized by atmospheric entry. Compositions of FeS melt in fine spherules are following Fe-S-O phase relations even in a few seconds. Molar ratios of Fe in melt are close to 0.5, while compositions of S and O are various. Varieties of S and O compositions show various degree of oxidation and evaporation of sulfur. Evaporation of sulfur from meteoritic materials in atmospheric entry heating may depend on oxygen fugacity of the upper atmosphere. Sulfur supply from meteoritic materials to atmosphere may be limited on planets with oxygen

  15. The effects of the diurnal atmospheric variability on entry, descent and landing on Mars

    Directory of Open Access Journals (Sweden)

    Marčeta D.

    2014-01-01

    Full Text Available Landing on Mars is extremely challenging task due to the fact that the Martian atmosphere is the most hostile environment in the Solar system to perform the entry, descent and landing (EDL process, because it is thick enough to create substantial heating of the entry vehicle but not thick enough to reduce its velocity to the one necessary for safe landing. Beside this, the atmosphere is very dynamic mainly due to high eccentricity of the Martian orbit, obliquity of the orbital to the equatorial plane and close alignment of the winter solstice and the orbital perihelion. Although seasonal variations of atmospheric parameters are significantly larger than the diurnal, it is very important to analyze diurnal cycles as they can significantly change vertical and horizontal atmospheric profiles in very short time intervals. This can present a serious threat to missions which have very precise timings and specific requirements such as the requirement for the daytime landing to enable ground images acquisition during the descent and landing phase. A 3-degrees-of-freedom trajectory integration routine was combined with the Mars Global Reference Atmospheric Model (Mars-GRAM to identify the dependence of the EDL profiles on the diurnal cycles of atmospheric parameters throughout the Martian year. The obtained results show that the influence of the diurnal cycles is the largest at the equator and decreases relatively symmetrically towards the poles with a slightly stronger influence in the northern hemisphere. Also, there is a significant influence of the orbital position of Mars on the effect of diurnal atmospheric variations which causes that, around the orbital perihelion and winter solstice, there is some kind of inversion of the dependance of optimal entry timing on latitude of the landing site comparing to the rest of the Martian year. [Projekat Ministarstva nauke Republike Srbije, br. 176002

  16. EntrySat: A 3U CubeStat to study the reentry atmospheric environment

    Science.gov (United States)

    Anthony, Sournac; Raphael, Garcia; David, Mimoun; Jeremie, Chaix

    2016-04-01

    ISAE France Entrysat has for main scientific objective the study of uncontrolled atmospheric re-entry. This project, is developed by ISAE in collaboration with ONERA and University of Toulouse, is funded by CNES, in the overall frame of the QB50 project. This nano-satellite is a 3U Cubesat measuring 34*10*10 cm3, similar to secondary debris produced during the break up of a spacecraft. EntrySat will collect the external and internal temperatures, pressure, heat flux, attitude variations and drag force of the satellite between ≈150 and 90 km before its destruction in the atmosphere, and transmit them during the re-entry using the IRIDIUM satellite network. The result will be compared with the computations of MUSIC/FAST, a new 6-degree of freedom code developed by ONERA to predict the trajectory of space debris. In order to fulfil the scientific objectives, the satellite will acquire 18 re-entry sensors signals, convert them and compress them, thanks to an electronic board developed by ISAE students in cooperation with EREMS. In order to transmit these data every second during the re-entry phase, the satellite will use an IRIDIUM connection. In order to keep a stable enough attitudes during this phase, a simple attitude orbit and control system using magnetotorquers and an inertial measurement unit (IMU) is developed at ISAE by students. A commercial GPS board is also integrated in the satellite into Entry Sat to determine its position and velocity which are necessary during the re-entry phase. This GPS will also be used to synchronize the on-board clock with the real-time UTC data. During the orbital phase (≈2 year) EntrySat measurements will be recorded transmitted through a more classical "UHF/VHF" connection. Preference for presentation: Poster Most suitable session: Author for correspondence: Dr Raphael F. Garcia ISAE 10, ave E. Belin, 31400 Toulouse, France Raphael.GARCIA@isae.fr +33 5 61 33 81 14

  17. Simulation-Based Analysis of Reentry Dynamics for the Sharp Atmospheric Entry Vehicle

    Science.gov (United States)

    Tillier, Clemens Emmanuel

    1998-01-01

    This thesis describes the analysis of the reentry dynamics of a high-performance lifting atmospheric entry vehicle through numerical simulation tools. The vehicle, named SHARP, is currently being developed by the Thermal Protection Materials and Systems branch of NASA Ames Research Center, Moffett Field, California. The goal of this project is to provide insight into trajectory tradeoffs and vehicle dynamics using simulation tools that are powerful, flexible, user-friendly and inexpensive. Implemented Using MATLAB and SIMULINK, these tools are developed with an eye towards further use in the conceptual design of the SHARP vehicle's trajectory and flight control systems. A trajectory simulator is used to quantify the entry capabilities of the vehicle subject to various operational constraints. Using an aerodynamic database computed by NASA and a model of the earth, the simulator generates the vehicle trajectory in three-dimensional space based on aerodynamic angle inputs. Requirements for entry along the SHARP aerothermal performance constraint are evaluated for different control strategies. Effect of vehicle mass on entry parameters is investigated, and the cross range capability of the vehicle is evaluated. Trajectory results are presented and interpreted. A six degree of freedom simulator builds on the trajectory simulator and provides attitude simulation for future entry controls development. A Newtonian aerodynamic model including control surfaces and a mass model are developed. A visualization tool for interpreting simulation results is described. Control surfaces are roughly sized. A simple controller is developed to fly the vehicle along its aerothermal performance constraint using aerodynamic flaps for control. This end-to-end demonstration proves the suitability of the 6-DOF simulator for future flight control system development. Finally, issues surrounding real-time simulation with hardware in the loop are discussed.

  18. Composition of the earth's atmosphere by shock-layer radiometry during the PAET entry probe experiment.

    Science.gov (United States)

    Whiting, E. E.; Arnold, J. O.; Page, W. A.; Reynolds, R. M.

    1973-01-01

    A determination of the composition of the earth's atmosphere obtained from onboard radiometer measurements of the spectra emitted from the bow shock layer of a high-speed entry probe is reported. The N2, O2, CO2, and noble gas concentrations in the earth's atmosphere were determined to good accuracy by this technique. The results demonstrate unequivocally the feasibility of determining the composition of an unknown planetary atmosphere by means of a multichannel radiometer viewing optical emission from the heated atmospheric gases in the region between the bow shock wave and the vehicle surface. The spectral locations in this experiment were preselected to enable the observation of CN violet, N2(+) first negative and atomic oxygen emission at 3870, 3910, and 7775 A, respectively. The atmospheric gases were heated and compressed by the shock wave to a peak temperature of about 6100 K and a corresponding pressure of 0.4 atm. Complete descriptions of the data analysis technique and the onboard radiometer and its calibration are given.

  19. Long-life mission reliability for outer planet atmospheric entry probes

    Science.gov (United States)

    Mccall, M. T.; Rouch, L.; Maycock, J. N.

    1976-01-01

    The results of a literature analysis on the effects of prolonged exposure to deep space environment on the properties of outer planet atmospheric entry probe components are presented. Materials considered included elastomers and plastics, pyrotechnic devices, thermal control components, metal springs and electronic components. The rates of degradation of each component were determined and extrapolation techniques were used to predict the effects of exposure for up to eight years to deep space. Pyrotechnic devices were aged under accelerated conditions to an equivalent of eight years in space and functionally tested. Results of the literature analysis of the selected components and testing of the devices indicated that no severe degradation should be expected during an eight year space mission.

  20. Utilizing Mars Global Reference Atmospheric Model (Mars-GRAM 2005) to Evaluate Entry Probe Mission Sites

    Science.gov (United States)

    Justh, Hilary L.; Justus, Carl G.

    2008-01-01

    The Mars Global Reference Atmospheric Model (Mars-GRAM 2005) is an engineering-level atmospheric model widely used for diverse mission applications. An overview is presented of Mars-GRAM 2005 and its new features. The "auxiliary profile" option is one new feature of Mars-GRAM 2005. This option uses an input file of temperature and density versus altitude to replace the mean atmospheric values from Mars-GRAM's conventional (General Circulation Model) climatology. Any source of data or alternate model output can be used to generate an auxiliary profile. Auxiliary profiles for this study were produced from mesoscale model output (Southwest Research Institute's Mars Regional Atmospheric Modeling System (MRAMS) model and Oregon State University's Mars mesoscale model (MMM5) model) and a global Thermal Emission Spectrometer (TES) database. The global TES database has been specifically generated for purposes of making Mars-GRAM auxiliary profiles. This data base contains averages and standard deviations of temperature, density, and thermal wind components, averaged over 5-by-5 degree latitude-longitude bins and 15 degree Ls bins, for each of three Mars years of TES nadir data. The Mars Science Laboratory (MSL) sites are used as a sample of how Mars-GRAM' could be a valuable tool for planning of future Mars entry probe missions. Results are presented using auxiliary profiles produced from the mesoscale model output and TES observed data for candidate MSL landing sites. Input parameters rpscale (for density perturbations) and rwscale (for wind perturbations) can be used to "recalibrate" Mars-GRAM perturbation magnitudes to better replicate observed or mesoscale model variability.

  1. Dynamic Mesh CFD Simulations of Orion Parachute Pendulum Motion During Atmospheric Entry

    Science.gov (United States)

    Halstrom, Logan D.; Schwing, Alan M.; Robinson, Stephen K.

    2016-01-01

    This paper demonstrates the usage of computational fluid dynamics to study the effects of pendulum motion dynamics of the NASAs Orion Multi-Purpose Crew Vehicle parachute system on the stability of the vehicles atmospheric entry and decent. Significant computational fluid dynamics testing has already been performed at NASAs Johnson Space Center, but this study sought to investigate the effect of bulk motion of the parachute, such as pitching, on the induced aerodynamic forces. Simulations were performed with a moving grid geometry oscillating according to the parameters observed in flight tests. As with the previous simulations, OVERFLOW computational fluid dynamics tool is used with the assumption of rigid, non-permeable geometry. Comparison to parachute wind tunnel tests is included for a preliminary validation of the dynamic mesh model. Results show qualitative differences in the flow fields of the static and dynamic simulations and quantitative differences in the induced aerodynamic forces, suggesting that dynamic mesh modeling of the parachute pendulum motion may uncover additional dynamic effects.

  2. Re-entry Flight Experiments Lessons Learned - The Atmospheric Reentry Demonstrator ARD

    National Research Council Canada - National Science Library

    Paulat, J. C; Boukhobza, P

    2007-01-01

    .... This paper provides with a summary of the ARD flight data and presents some lessons learned that can be avantageously used for the development of future re-entry vehicles with precise landing capabilities...

  3. From Exit to Entry: Long-term Survival and Transmission of Salmonella

    Directory of Open Access Journals (Sweden)

    Landon L. Waldner

    2012-10-01

    Full Text Available Salmonella spp. are a leading cause of human infectious disease worldwide and pose a serious health concern. While we have an improving understanding of pathogenesis and the host-pathogen interactions underlying the infection process, comparatively little is known about the survival of pathogenic Salmonella outside their hosts. This review focuses on three areas: (1 in vitro evidence that Salmonella spp. can survive for long periods of time under harsh conditions; (2 observations and conclusions about Salmonella persistence obtained from human outbreaks; and (3 new information revealed by genomic- and population-based studies of Salmonella and related enteric pathogens. We highlight the mechanisms of Salmonella persistence and transmission as an essential part of their lifecycle and a prerequisite for their evolutionary success as human pathogens.

  4. Explosion of comet Shoemaker-Levy 9 on entry into the Jovian atmosphere.

    Science.gov (United States)

    Mac Low, M M; Zahnle, K

    1994-10-10

    We use the astrophysical hydrocode ZEUS to compute high-resolution models of the disruption and deceleration of cometary fragments striking Jupiter. We find that simple analytic and semianalytic models work well for kilometer-size impactors. We show that previous numerical models that placed the explosion much deeper in the atmosphere failed to fully resolve important gasdynamical instabilities. These instabilities tear the comet apart, greatly increase its effective cross section, and bring it to an abrupt halt. A 1 km diameter fragment loses over 90% of its kinetic energy within a single scale height at an atmospheric pressure of order 10 bars. For all practical purposes, it explodes.

  5. Potential of Glassy Carbon and Silicon Carbide Photonic Structures as Electromagnetic Radiation Shields for Atmospheric Re-entry

    Science.gov (United States)

    Komarevskiy,Nikolay; Shklover, Valery; Braginsky, Leonid; Hafner, Christian; Lawson, John W.

    2012-01-01

    During high-velocity atmospheric entries, space vehicles can be exposed to strong electromagnetic radiation from ionized gas in the shock layer. Glassy carbon (GC) and silicon carbide (SiC) are candidate thermal protection materials due to their high melting point and also their good thermal and mechanical properties. Based on data from shock tube experiments, a significant fraction of radiation at hypersonic entry conditions is in the frequency range from 215 to 415 THz. We propose and analyze SiC and GC photonic structures to increase the reflection of radiation in that range. For this purpose, we performed numerical optimizations of various structures using an evolutionary strategy. Among the considered structures are layered, porous, woodpile, inverse opal and guided-mode resonance structures. In order to estimate the impact of fabrication inaccuracies, the sensitivity of the reflectivity to structural imperfections is analyzed. We estimate that the reflectivity of GC photonic structures is limited to 38% in the aforementioned range, due to material absorption. However, GC material can be effective for photonic reflection of individual, strong spectral line. SiC on the other hand can be used to design a good reflector for the entire frequency range.

  6. Optimum three-dimensional atmospheric entry from the analytical solution of Chapman's exact equations

    Science.gov (United States)

    Busemann, A.; Vinh, N. X.; Culp, R. D.

    1974-01-01

    The general solution for the optimum three-dimensional aerodynamic control of a lifting vehicle entering a planetary atmosphere is developed. A set of dimensionless variables, modified Chapman variables, is introduced. The resulting exact equations of motion, referred to as Chapman's exact equations, have the advantage that they are completely free of the physical characteristics of the vehicle. Furthermore, a completely general lift-drag relationship is used in the derivation. The results obtained apply to any type of vehicle of arbitrary weight, dimensions and shape, having an arbitrary drag polar, and entering any planetary atmosphere. The aerodynamic controls chosen are the lift coefficient and the bank angle. General optimum control laws for these controls are developed. Several earlier particular solutions are shown to be special cases of this general result. Results are valid for both free and constrained terminal position.

  7. Digital simulation of a communication link for Pioneer Saturn Uranus atmospheric entry probe, part 1

    Science.gov (United States)

    Hinrichs, C. A.

    1975-01-01

    A digital simulation study is presented for a candidate modulator/demodulator design in an atmospheric scintillation environment with Doppler, Doppler rate, and signal attenuation typical of the conditions of an outer planet atmospheric probe. The simulation results indicate that the mean channel error rate with and without scintillation are similar to theoretical characterizations of the link. The simulation gives information for calculating other channel statistics and generates a quantized symbol stream on magnetic tape from which error correction decoding is analyzed. Results from the magnetic tape data analyses are also included. The receiver and bit synchronizer are modeled in the simulation at the level of hardware component parameters rather than at the loop equation level and individual hardware parameters are identified. The atmospheric scintillation amplitude and phase are modeled independently. Normal and log normal amplitude processes are studied. In each case the scintillations are low pass filtered. The receiver performance is given for a range of signal to noise ratios with and without the effects of scintillation. The performance is reviewed for critical reciever parameter variations.

  8. Solution of the exact equations for three-dimensional atmospheric entry using directly matched asymptotic expansions

    Science.gov (United States)

    Busemann, A.; Vinh, N. X.; Culp, R. D.

    1976-01-01

    The problem of determining the trajectories, partially or wholly contained in the atmosphere of a spherical, nonrotating planet, is considered. The exact equations of motion for three-dimensional, aerodynamically affected flight are derived. Modified Chapman variables are introduced and the equations are transformed into a set suitable for analytic integration using asymptotic expansions. The trajectory is solved in two regions: the outer region, where the force may be considered a gravitational field with aerodynamic perturbations, and the inner region, where the force is predominantly aerodynamic, with gravity as a perturbation. The two solutions are matched directly. A composite solution, valid everywhere, is constructed by additive composition. This approach of directly matched asymptotic expansions applied to the exact equations of motion couched in terms of modified Chapman variables yields an analytical solution which should prove to be a powerful tool for aerodynamic orbit calculations.

  9. Survival of microbial cultures on mineral while passing dense layers of the atmosphere

    Science.gov (United States)

    Viacheslav, Ilyin; Novikova, Nataliya; Deshevaya, Elena; Polikarpov, Nikolay; Slobodkin, Alexander; Gavrilov, Sergey; Ionov, Viktor; Morozova, Julia

    The purpose of the experiment is to study the possibility of extremophilic microorganisms survival in meteorite-like mineral while passing through the dense layers of the atmosphere. For this purpose cultures of bacteria were placed into the holes made in basalt pieces fixed to the outer wall of the spacecraft Bion M1. Control: similar materials placed in the outer container, prevented from overheating in the dense layers of the atmosphere by lid. In the flight experiment five strains of thermophilic bacteria and 2 strains of hyperthermophilic archaea from the collection of the Institute of Microbiology, RAS were used. In addition, microorganisms were selected from the collection of the Institute of Biomedical Problems, isolated from the environment objects of ISS: 10 fungal cultures and a culture of bacteria Bacillus pumilus. For thermophiles and hyperthermophiles the ability to redox interactions with minerals is considered as a priority physiological property. Ability of thermophiles to anaerobic growth also meets the conditions of the experiment - testing cell survival of microorganisms in the conditions of extraterrestrial space and ancient anaerobic atmosphere of the Earth. After 30-days flight in orbit control all spore-forming microorganisms have been successfully survived. Hyperthermophilic archaea growth in all control was significantly less intensive. Meanwhile, in one experimental samples there was obtained signs of survival of spore forming bacteria culture Carboxydocella ferrireducens. However, the maximum concentration of cells was 2 orders of magnitude below the values characteristic of an actively growing culture of the microorganism. Due to damage of holes in the stone, this result was obtained only in one replicate and for final prove of survival of C. ferrireducens when returning through the dense layers of the atmosphere it is necessary to repeat the experiment It should be noted that an important indicator of the possibility of survival of C

  10. Predicting risk of entry into foster care from early childhood experiences: A survival analysis using LONGSCAN data.

    Science.gov (United States)

    English, Diana J; Thompson, Richard; White, Catherine Roller

    2015-07-01

    This study examined whether a multi-domain model of maltreatment informed by an ecological framework-including factors related to the child, caregiver, family, neighborhood, and dimensions of maltreatment experience-predicted entry into foster care between the ages of 4 and 18 among children with no prior foster care experience. To determine which factors predict entry into foster care, secondary data analyses were conducted utilizing a sub-sample from LONGSCAN (Longitudinal Studies of Child Abuse and Neglect) of 942 children and their primary caregivers. Results demonstrate that there are important predictors for entry into out-of-home placement across multiple ecological domains. Characteristics related to child, caregiver, and family characteristics, and neighborhood context, as well as dimensions of maltreatment (particularly emotional maltreatment), predicted risk of placement in out-of-home care. Implications for child welfare practice are discussed. This examination of the effects of multiple ecological domains adds to our understanding of children's risk of removal and entry into out-of-home placement. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. The glutamate decarboxylase acid resistance mechanism affects survival of Listeria monocytogenes LO28 in modified atmosphere-packaged foods.

    Science.gov (United States)

    Francis, G A; Scollard, J; Meally, A; Bolton, D J; Gahan, C G M; Cotter, P D; Hill, C; O'Beirne, D

    2007-12-01

    The contribution of the glutamate decarboxylase (GAD) acid resistance system to survival and growth of Listeria monocytogenes LO28 in modified atmosphere-packaged foods was examined. The survival and growth of the wild-type LO28 and four GAD deletion mutants (DeltagadA, DeltagadB, DeltagadC, DeltagadAB) in packaged foods (minced beef, lettuce, dry coleslaw mix) during storage at 4, 8 and 15 degrees C were studied. Survival and growth patterns varied with strain, product type, gas atmosphere and storage temperature. In minced beef, the wild-type LO28 survived better (P lettuce, gadA played the most important role, while the gadB and gadC genes played the greatest role in packaged coleslaw (at 15 degrees C). This work demonstrates that elements of the GAD system play significant roles in survival of L. monocytogenes LO28 during storage in modified atmosphere-packaged foods. A better understanding of how L. monocytogenes behaves in modified atmosphere-packaged foods, and how it responds to elevated carbon dioxide atmospheres.

  12. A Study on Re-entry Predictions of Uncontrolled Space Objects for Space Situational Awareness

    Science.gov (United States)

    Choi, Eun-Jung; Cho, Sungki; Lee, Deok-Jin; Kim, Siwoo; Jo, Jung Hyun

    2017-12-01

    The key risk analysis technologies for the re-entry of space objects into Earth’s atmosphere are divided into four categories: cataloguing and databases of the re-entry of space objects, lifetime and re-entry trajectory predictions, break-up models after re-entry and multiple debris distribution predictions, and ground impact probability models. In this study, we focused on re- entry prediction, including orbital lifetime assessments, for space situational awareness systems. Re-entry predictions are very difficult and are affected by various sources of uncertainty. In particular, during uncontrolled re-entry, large spacecraft may break into several pieces of debris, and the surviving fragments can be a significant hazard for persons and properties on the ground. In recent years, specific methods and procedures have been developed to provide clear information for predicting and analyzing the re-entry of space objects and for ground-risk assessments. Representative tools include object reentry survival analysis tool (ORSAT) and debris assessment software (DAS) developed by National Aeronautics and Space Administration (NASA), spacecraft atmospheric re-entry and aerothermal break-up (SCARAB) and debris risk assessment and mitigation analysis (DRAMA) developed by European Space Agency (ESA), and semi-analytic tool for end of life analysis (STELA) developed by Centre National d’Etudes Spatiales (CNES). In this study, various surveys of existing re-entry space objects are reviewed, and an efficient re-entry prediction technique is suggested based on STELA, the life-cycle analysis tool for satellites, and DRAMA, a re-entry analysis tool. To verify the proposed method, the re-entry of the Tiangong-1 Space Lab, which is expected to re-enter Earth’s atmosphere shortly, was simulated. Eventually, these results will provide a basis for space situational awareness risk analyses of the re-entry of space objects.

  13. Effect of controlled atmosphere storage, modified atmosphere packaging and gaseous ozone treatment on the survival of Salmonella Enteritidis on cherry tomatoes.

    Science.gov (United States)

    Daş, Elif; Gürakan, G Candan; Bayindirli, Alev

    2006-08-01

    In recent years, outbreaks of infections associated with raw and minimally processed fruits and vegetables have been reported. The objective of this study was to analyse the growth/survival of Salmonella Enteritidis at spot-inoculated or stem-injected cherry tomatoes during passive modified atmosphere packaging (MAP), controlled atmosphere (CA) and to compare the results with those of air storage at 7 and 22 degrees C. During MAP, the gas composition equilibrated to 6% O2/4% CO2. CO2 level was maintained as 5% through the term of CA storage at 7 and 22 degrees C. The results demonstrate that S. Enteritidis can survive and/or grow during the storage of tomatoes depending on the location site of the pathogen on fruit, suspension cell density and storage temperature. During MAP, CA and air storage, S. Enteritidis with initial population of 7.0 log10 cfu/tomato survived on tomato surfaces with an approximate decrease of 4.0-5.0 log10 cfu/tomato in population within the storage period; however, in the case of initial population of 3.0 log10 cfu/tomato, cells died completely on day 4 during MAP storage and on day 6 during both CA and air storage. The death rate of S. Enteritidis on the surfaces of tomatoes that were stored in MAP was faster than that of stored in air and in CA. Storage temperature was effective on the survival of S. Enteritidis for the samples stored at ambient atmosphere; cells died completely on day 6 at 7 degrees C and on day 8 at 22 degrees C. Stem scars provided protective environments for Salmonella; an approximate increase of 1.0 log10 cfu/tomato in stem-scar population was observed during MAP, CA and air storage at 22 degrees C within the period of 20 days. Cells survived with no significant change in number at 7 degrees C. During the research, the effect of ozone treatment (5-30 mg/l ozone gas for 0-20 min) was also considered for surface sanitation before storage. Gaseous ozone treatment has bactericidal effect on S. Enteritidis, inoculated on

  14. An electromagnetic method for removing the communication blackout with a space vehicle upon re-entry into the atmosphere

    Science.gov (United States)

    Cheng, Jianjun; Jin, Ke; Kou, Yong; Hu, Ruifeng; Zheng, Xiaojing

    2017-03-01

    When a hypersonic vehicle travels in the Earth and Mars atmosphere, the surface of the vehicle is surrounded by a plasma layer, which is an envelope of ionized air, created from the compression and heat of the atmosphere by the shock wave. The vehicles will lose contact with ground stations known as the reentry communication blackout. Based on the magnetohydrodynamic framework and electromagnetic wave propagation theory, an analytical model is proposed to describe the effect of the effectiveness of electromagnetic mitigation scheme on removing the reentry communication blackout. C and Global Positioning System (GPS) bands, two commonly used radio bands for communication, are taken as the cases to discuss the effectiveness of the electromagnetic field mitigation scheme. The results show that the electron density near the antenna of vehicles can be reduced by the electromagnetic field, and the required external magnetic field strength is far below the one in the magnetic window method. The directions of the external electric field and magnetic field have a significant impact on the effectiveness of the mitigation scheme. Furthermore, the effect of electron collisions on the required applied electromagnetic field is discussed, and the result indicates that electron collisions are a key factor to analyze the electromagnetic mitigation scheme. Finally, the feasible regions of the applied electromagnetic field for eliminating blackout are given. These investigations could have a significant benefit on the design and optimization of electromagnetic mitigation scheme for the blackout problem.

  15. Survival of Salmonella spp. in minced meat packaged under vacuum and modified atmosphere.

    Science.gov (United States)

    Djordjević, Jasna; Bošković, Marija; Starčević, Marija; Ivanović, Jelena; Karabasil, Nedjeljko; Dimitrijević, Mirjana; Lazić, Ivana Branković; Baltić, Milan Ž

    2018-02-12

    The effect of different modified atmosphere packaging regimes on the behavior of Salmonella spp. on minced meat was studied. Minced meat was experimentally contaminated with a Salmonella spp. cocktail (S. Enteritidis, S. Typhimurium, S. Infantis and S. Arizonae), packaged under vacuum or modified atmosphere with initial headspaces containing 20%O 2 /50%CO 2 /30%N 2 and 20%O 2 /30%CO 2 /50%N 2 ) and stored at 3±1°C for 12 days. Samples were analyzed for Salmonella spp., viable and lactic acid bacteria count every third day. Salmonella spp. counts decreased during storage in all packaging types, with reductions of about 1.5logCFU/g. A significant difference (pmodified atmospheres, although there was no significant difference in Salmonella spp. count between meat packaged in 50%CO 2 , and meat packaged in 30%CO 2 . At the end of the study, there were significant differences (pmodified atmosphere, and the lowest counts were noted in meat packaged in modified atmosphere with 50%CO 2 . Copyright © 2018 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  16. Survival of resistant starch during the processing of atmospheric and vacuum fried instant noodles

    Directory of Open Access Journals (Sweden)

    Maria Gabriela VERNAZA

    Full Text Available Abstract The objective was to develop instant noodles (IN made by atmospheric and vacuum frying processes, with addition of 10% of three different sources of resistant starch: resistant starch type 2 (RS2, resistant starch type 3 (RS3 and green banana flour (GBF aiming the increasing of the fibre content. The IN obtained by atmospheric frying lost water faster and absorbed more fat. However, for both frying treatments, the RS3 noodles absorbed the least amount of oil. The greatest loss of RS occurred during the cooking stage. RS2 and GBF noodles presented a loss of RS of around 30% during steam cooking, while the RS3 approximately 18%. The frying process decreased RS content of noodles, however, during both frying process, the samples with the highest RS content at all frying times were noodles containing RS3. When comparing products obtained after 90 and 120 s of atmospheric and vacuum frying, respectively, it was observed that, although the frying time in vacuum process was longer, higher RS values were obtained for the three different formulations. The vacuum frying process has advantages due to the lower fat absorption (3% less, lighter colour and a reduced conversion of RS to digestible starch, compared to atmospheric frying.

  17. Cubesat Application for Planetary Entry (CAPE) Missions: Micro-Reentry Capsule (MIRCA)

    Science.gov (United States)

    Esper, Jaime

    2014-01-01

    The Cubesat Application for Planetary Entry Missions (CAPE) concept describes a high-performing Cubesat system which includes a propulsion module and miniaturized technologies capable of surviving atmospheric entry heating, while reliably transmitting scientific and engineering data. The Micro Return Capsule (MIRCA) is CAPEs first planetary entry probe flight prototype. Within this context, this paper briefly describes CAPEs configuration and typical operational scenario, and summarizes ongoing work on the design and basic aerodynamic characteristics of the prototype MIRCA vehicle. CAPE not only opens the door to new planetary mission capabilities, it also offers relatively low-cost opportunities especially suitable to university participation.

  18. Nonthermal atmospheric pressure plasma enhances mouse limb bud survival, growth, and elongation.

    Science.gov (United States)

    Chernets, Natalie; Zhang, Jun; Steinbeck, Marla J; Kurpad, Deepa S; Koyama, Eiki; Friedman, Gary; Freeman, Theresa A

    2015-01-01

    The enhanced differentiation of mesenchymal cells into chondrocytes or osteoblasts is of paramount importance in tissue engineering and regenerative therapies. A newly emerging body of evidence demonstrates that appendage regeneration is dependent on reactive oxygen species (ROS) production and signaling. Thus, we hypothesized that mesenchymal cell stimulation by nonthermal (NT)-plasma, which produces and induces ROS, would (1) promote skeletal cell differentiation and (2) limb autopod development. Stimulation with a single treatment of NT-plasma enhanced survival, growth, and elongation of mouse limb autopods in an in vitro organ culture system. Noticeable changes included enhanced development of digit length and definition of digit separation. These changes were coordinated with enhanced Wnt signaling in the distal apical epidermal ridge (AER) and presumptive joint regions. Autopod development continued to advance for approximately 144 h in culture, seemingly overcoming the negative culture environment usually observed in this in vitro system. Real-time quantitative polymerase chain reaction analysis confirmed the up-regulation of chondrogenic transcripts. Mechanistically, NT-plasma increased the number of ROS positive cells in the dorsal epithelium, mesenchyme, and the distal tip of each phalange behind the AER, determined using dihydrorhodamine. The importance of ROS production/signaling during development was further demonstrated by the stunting of digital outgrowth when anti-oxidants were applied. Results of this study show NT-plasma initiated and amplified ROS intracellular signaling to enhance development of the autopod. Parallels between development and regeneration suggest that the potential use of NT-plasma could extend to both tissue engineering and clinical applications to enhance fracture healing, trauma repair, and bone fusion.

  19. Physics-Based Modeling of Meteor Entry and Breakup

    Science.gov (United States)

    Prabhu, Dinesh K.; Agrawal, Parul; Allen, Gary A., Jr.; Bauschlicher, Charles W., Jr.; Brandis, Aaron M.; Chen, Yih-Kang; Jaffe, Richard L.; Palmer, Grant E.; Saunders, David A.; Stern, Eric C.; hide

    2015-01-01

    A new research effort at NASA Ames Research Center has been initiated in Planetary Defense, which integrates the disciplines of planetary science, atmospheric entry physics, and physics-based risk assessment. This paper describes work within the new program and is focused on meteor entry and breakup.Over the last six decades significant effort was expended in the US and in Europe to understand meteor entry including ablation, fragmentation and airburst (if any) for various types of meteors ranging from stony to iron spectral types. These efforts have produced primarily empirical mathematical models based on observations. Weaknesses of these models, apart from their empiricism, are reliance on idealized shapes (spheres, cylinders, etc.) and simplified models for thermal response of meteoritic materials to aerodynamic and radiative heating. Furthermore, the fragmentation and energy release of meteors (airburst) is poorly understood.On the other hand, flight of human-made atmospheric entry capsules is well understood. The capsules and their requisite heatshields are designed and margined to survive entry. However, the highest speed Earth entry for capsules is 13 kms (Stardust). Furthermore, Earth entry capsules have never exceeded diameters of 5 m, nor have their peak aerothermal environments exceeded 0.3 atm and 1 kW/sq cm. The aims of the current work are: (i) to define the aerothermal environments for objects with entry velocities from 13 to 20 kms; (ii) to explore various hypotheses of fragmentation and airburst of stony meteors in the near term; (iii) to explore the possibility of performing relevant ground-based tests to verify candidate hypotheses; and (iv) to quantify the energy released in airbursts. The results of the new simulations will be used to anchor said risk assessment analyses. With these aims in mind, state-of-the-art entry capsule design tools are being extended for meteor entries. We describe: (i) applications of current simulation tools to

  20. RITD - Re-entry: Inflatable Technology Development in Russian Collaboration

    Science.gov (United States)

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

    2014-04-01

    A new generation of inflatable Entry, Descent and Landing System (EDLS) for Mars has been developed. It is used in both the initial atmospheric entry and atmospheric descent before the semi-hard impact of the penetrator into Martian surface. The EDLS applicability to Earth's atmosphere is studied by the EU/RITD [1] project. Project focuses on the analysis and tests of the transonic behaviour of this compact and light weight payload entry system at the Earth re-entry.

  1. Survival of lactic acid and chlorine dioxide treated Campylobacter jejuni under suboptimal conditions of pH, temperature and modified atmosphere

    DEFF Research Database (Denmark)

    Smigic, Nada; Rajkovic, Andreja; Nielsen, Dennis Sandris

    2010-01-01

    Campylobacter jejuni cells treated with lactic acid (LA, 3% lactic acid, pH 4.0, 2 min) or chlorine dioxide (ClO(2), 20 ppm, 2 min) were inoculated in Bolton broth (pH 6.0) and incubated under 80% O(2)/20% N(2), 80% CO(2)/20% N(2), air or micro-aerophilic (10% CO(2)/85% N(2)/5% O(2)) atmosphere, at 4 degrees C...... during 7 days. Treatment with water served as a control. The most suppressive atmosphere for the survival of C. jejuni was O(2)-rich atmosphere, followed by air, micro-aerophilic and CO(2)-rich atmosphere. The survival of C. jejuni was dependent on the type of initial decontamination treatment...... on their pH(i) values. The pH(i) response was independent on the surrounding atmosphere since similar distribution of the subpopulations was observed for all tested atmospheres. However, the pH(i) response was dependent on the initial decontamination treatment. The investigation of intracellular parameters...

  2. Hypersonic and planetary entry flight mechanics

    Science.gov (United States)

    Vinh, N. X.; Busemann, A.; Culp, R. D.

    1980-01-01

    The book treats hypersonic flight trajectories and atmospheric entry flight mechanics in light of their importance for space shuttle entry. Following a review of the structures of planetary atmospheres and aerodynamic forces, equations are derived for flight over a spherical planet, and the performance of long-range hypervelocity vehicles in extra-atmospheric flight is analyzed. Consideration is then given to vehicle trajectories in the powered and atmospheric reentry phases of flight, and several first-order solutions are derived for various planetary entry situations. The second-order theory of Loh for entry trajectories is presented along with the classical theories of Yaroshevskii and Chapman for entry into planetary atmospheres, and the thermal problems encountered in hypersonic flight are analyzed. A unified theory for entry into planetary atmospheres is then introduced which allows the performance of a general type of lifting vehicle to be studied, and applied to the analysis of orbit contraction due to atmospheric drag, flight with lift modulation and lateral maneuvers.

  3. Growth and survival of Escherichia coli O157:H7 on fresh-cut apples in modified atmospheres at abusive temperatures.

    Science.gov (United States)

    Gunes, Gurbuz G; Hotchkiss, Joseph H

    2002-10-01

    The effects of reduced-O2 and elevated-CO2 modified atmospheres (MAs) and abusive temperatures on the growth and survival of E. coli O157:H7, yeast, and molds and on changes in the visual quality of fresh-cut apples were evaluated. High-CO1 and low-O2 (> or = 15% and atmospheres inhibited the growth of the pathogen on apple slices at 15 and 20 degrees C. However, the population of the pathogen increased by 1 log cycle after 2 weeks of storage in air. The high-CO2 MA resulted in the inhibition of yeast and mold growth, less browning, and better visual quality than did air and ambient-CO2 atmospheres. The results of this study confirm that E. coli O157:H7 can grow on apple slices in air. These results also show that these organisms survive but are inhibited in MAs with high CO2 levels at abusive temperatures. An MA can increase the shelf life of fresh-cut apples by improving retention of visual quality and inhibiting yeast and molds. Thus, contamination of minimally processed apples with E. coli O157:H7 can be a safety issue for both air- and MA-packaged cut apples.

  4. Excess Entry, Entry Regulation, and Entrant's Incentive

    OpenAIRE

    Kim, Jaehong

    2001-01-01

    Excess entry theorem, which shows that the free market can generate too many firms, is a theoretic base for entry regulation. When the current market is a monopoly, entry is considered as excessive if the social welfare under the post-entry Cournot-Nash equilibrium, net of entry coast, is lower than that under monopoly. However, this paper argues that, even if this is true, limiting entry is not an optimal choice of the benevolent government. The entrant has an incentive to produce more than ...

  5. Effect of electron irradiation and packaging atmosphere on the survival of Aeromonas hydrophila in minced poultry meat

    Energy Technology Data Exchange (ETDEWEB)

    Stecchini, M.L.; Sarais, I.; Del Torre, M. [Dipartimento di Scienze degli Alimenti, Udine (Italy); Fuochi, P.G. [Istituto FRAE-CNR, Bologna (Italy)

    1995-10-01

    Resistance to electron irradiation of Aeromonas hydrophila inoculated in minced poultry meat packed in presence of air or under vacuum was examined. Surviving bacteria were counted on starch ampicillin agar containing 100 {mu}g/ml of ampicillin. Radiation resistance, expressed as D{sub 10} values, was calculated from the survival curves and found to be 0.12 and 0.14 kGy in poultry meat packed in air or under vacuum respectively. Storage at 2{sup o}C of meat samples irradiated at 0.5 kGy further reduced the number of A. hydrophila. (Author).

  6. Effect of electron irradiation and packaging atmosphere on the survival of Aeromonas hydrophila in minced poultry meat

    International Nuclear Information System (INIS)

    Stecchini, M.L.; Sarais, I.; Del Torre, M.; Fuochi, P.G.

    1995-01-01

    Resistance to electron irradiation of Aeromonas hydrophila inoculated in minced poultry meat packed in presence of air or under vacuum was examined. Surviving bacteria were counted on starch ampicillin agar containing 100 μg/ml of ampicillin. Radiation resistance, expressed as D 10 values, was calculated from the survival curves and found to be 0.12 and 0.14 kGy in poultry meat packed in air or under vacuum respectively. Storage at 2 o C of meat samples irradiated at 0.5 kGy further reduced the number of A. hydrophila. (Author)

  7. Effect of electron irradiation and packaging atmosphere on the survival of aeromonas hydrophila in minced poultry meat

    Science.gov (United States)

    Stecchini, M. L.; Sarais, I.; Del Torre, M.; Fuochi, P. G.

    1995-02-01

    Resistance to electron irradiation of Aeromonas hydrophila inoculated in minced poultry meat packed in presence of air or under vacuum was examined. Surviving bacteria were counted on starch ampicillin agar containing 100 μg/ml of ampicillin. Radiation resistance, expressed as D 10 values, was calculated from the survival curves and found to be 0.12 and 0.12 kGy in poultry meat packed in air or under vacuum respectively. Storage at 2°C of meat samples irradiated at 0.5 kGy further reduced the number of A. hydrophila.

  8. Cubesat Application for Planetary Entry (CAPE) Missions: Micro-Return Capsule (MIRCA)

    Science.gov (United States)

    Esper, Jaime

    2016-01-01

    The Cubesat Application for Planetary Entry Missions (CAPE) concept describes a high-performing Cubesat system which includes a propulsion module and miniaturized technologies capable of surviving atmospheric entry heating, while reliably transmitting scientific and engineering data. The Micro Return Capsule (MIRCA) is CAPE's first planetary entry probe flight prototype. Within this context, this paper briefly describes CAPE's configuration and typical operational scenario, and summarizes ongoing work on the design and basic aerodynamic characteristics of the prototype MIRCA vehicle. CAPE not only opens the door to new planetary mission capabilities, it also offers relatively low-cost opportunities especially suitable to university participation. In broad terms, CAPE consists of two main functional components: the "service module" (SM), and "CAPE's entry probe" (CEP). The SM contains the subsystems necessary to support vehicle targeting (propulsion, ACS, computer, power) and the communications capability to relay data from the CEP probe to an orbiting "mother-ship". The CEP itself carries the scientific instrumentation capable of measuring atmospheric properties (such as density, temperature, composition), and embedded engineering sensors for Entry, Descent, and Landing (EDL). The first flight of MIRCA was successfully completed on 10 October 2015 as a "piggy-back" payload onboard a NASA stratospheric balloon launched from Ft. Sumner, NM.

  9. US Ports of Entry

    Data.gov (United States)

    Department of Homeland Security — HSIP Non-Crossing Ports-of-Entry A Port of Entry is any designated place at which a CBP officer is authorized to accept entries of merchandise to collect duties, and...

  10. Orion Entry Handling Qualities Assessments

    Science.gov (United States)

    Bihari, B.; Tiggers, M.; Strahan, A.; Gonzalez, R.; Sullivan, K.; Stephens, J. P.; Hart, J.; Law, H., III; Bilimoria, K.; Bailey, R.

    2011-01-01

    The Orion Command Module (CM) is a capsule designed to bring crew back from the International Space Station (ISS), the moon and beyond. The atmospheric entry portion of the flight is deigned to be flown in autopilot mode for nominal situations. However, there exists the possibility for the crew to take over manual control in off-nominal situations. In these instances, the spacecraft must meet specific handling qualities criteria. To address these criteria two separate assessments of the Orion CM s entry Handling Qualities (HQ) were conducted at NASA s Johnson Space Center (JSC) using the Cooper-Harper scale (Cooper & Harper, 1969). These assessments were conducted in the summers of 2008 and 2010 using the Advanced NASA Technology Architecture for Exploration Studies (ANTARES) six degree of freedom, high fidelity Guidance, Navigation, and Control (GN&C) simulation. This paper will address the specifics of the handling qualities criteria, the vehicle configuration, the scenarios flown, the simulation background and setup, crew interfaces and displays, piloting techniques, ratings and crew comments, pre- and post-fight briefings, lessons learned and changes made to improve the overall system performance. The data collection tools, methods, data reduction and output reports will also be discussed. The objective of the 2008 entry HQ assessment was to evaluate the handling qualities of the CM during a lunar skip return. A lunar skip entry case was selected because it was considered the most demanding of all bank control scenarios. Even though skip entry is not planned to be flown manually, it was hypothesized that if a pilot could fly the harder skip entry case, then they could also fly a simpler loads managed or ballistic (constant bank rate command) entry scenario. In addition, with the evaluation set-up of multiple tasks within the entry case, handling qualities ratings collected in the evaluation could be used to assess other scenarios such as the constant bank angle

  11. Irradiation and modified atmosphere packaging of endive influences survival and regrowth of Listeria monocytogenes and product sensory qualities

    International Nuclear Information System (INIS)

    Niemira, B.A.; Fan Xuetong; Sokorai, K.J.B.

    2005-01-01

    Cut pieces of endive were inoculated with Listeria monocytogenes, packaged in gas-impermeable bags in air, 5/5/90% or 10/10/80% CO 2 , O 2 and N2 ('Air-0', '5/5' and '10/10', respectively) and irradiated to 0.0 (control), 0.3 or 0.6 kGy. At various times during refrigerated storage, samples were taken and a determination made of (a) total microflora, (b) L. monocytogenes, (c) headspace gas composition, (d) color and (e) texture. Irradiation reduced initial microbial counts in a dose-dependant manner. Bacteria regrew during storage on Air-0 samples, but not on 5/5 or 10/10 samples. In each of the three atmospheres, O 2 declined and CO 2 increased, irrespective of radiation dose. Irradiated leaf material in Air-0 tended to retain color attributes during storage better than non-irradiated; color retention was more variable under 5/5 and 10/10 packaging. After 8 days, maximum shear force relative to the initial level was significantly reduced in 5/5 at all radiation doses, was not significantly changed in Air-0, and was dose-dependent in 10/10. By 14 days, the texture of all samples had degraded significantly. These results indicate that irradiation and modified atmosphere packaging can be combined to prevent the regrowth of L. monocytogenes during post-irradiation refrigerated storage, thereby improving product safety

  12. Irradiation and modified atmosphere packaging of endive influences survival and regrowth of Listeria monocytogenes and product sensory qualities

    Science.gov (United States)

    Niemira, Brendan A.; Fan, Xuetong; Sokorai, Kimberly J. B.

    2005-01-01

    Cut pieces of endive were inoculated with Listeria monocytogenes, packaged in gas-impermeable bags in air, 5/5/90% or 10/10/80% CO 2, O 2 and N2 ("Air-0", "5/5" and "10/10", respectively) and irradiated to 0.0 (control), 0.3 or 0.6 kGy. At various times during refrigerated storage, samples were taken and a determination made of (a) total microflora, (b) L. monocytogenes, (c) headspace gas composition, (d) color and (e) texture. Irradiation reduced initial microbial counts in a dose-dependant manner. Bacteria regrew during storage on Air-0 samples, but not on 5/5 or 10/10 samples. In each of the three atmospheres, O 2 declined and CO 2 increased, irrespective of radiation dose. Irradiated leaf material in Air-0 tended to retain color attributes during storage better than non-irradiated; color retention was more variable under 5/5 and 10/10 packaging. After 8 days, maximum shear force relative to the initial level was significantly reduced in 5/5 at all radiation doses, was not significantly changed in Air-0, and was dose-dependent in 10/10. By 14 days, the texture of all samples had degraded significantly. These results indicate that irradiation and modified atmosphere packaging can be combined to prevent the regrowth of L. monocytogenes during post-irradiation refrigerated storage, thereby improving product safety.

  13. Effects of carbon monoxide-modified atmosphere packaging and irradiation on E. coli K12 survival and raw beef quality.

    Science.gov (United States)

    Ramamoorthi, L; Toshkov, S; Brewer, M S

    2009-11-01

    The objective of this study was to evaluate the combined effects of irradiation and carbon monoxide in modified atmosphere packaging (CO-MAP) on total plate counts, Escherichia coli K12, color, and odor of fresh beef during refrigerated storage. Beef was packaged aerobically or in CO-MAP, and irradiated at 0, 0.5, 1.0, 1.5 or 2.0kGy then held at 4°C for 28days. Raw beef odor decreased and acid/sour, rancid and grassy odors increased starting on day 14. Initially, no difference existed for visual green color scores due to gas atmosphere. After 14days of storage, aerobically packaged beef was greener and less red than CO-MAP packaged beef. The a∗ value of CO-MAP packaged beef was higher than that of aerobically packaged beef. Red color of CO-MAP packaged samples decreased slightly in some irradiated samples after 14days of storage. On day 0 and thereafter, no coliforms were detect after irradiation at 1.5 or 2.0kGy regardless of packaging format. These findings suggest that CO-MAP could be used to preserve beef color irradiated at doses sufficient to reduce microbial loads to safe levels during 28days of storage.

  14. Effects of vegetable type, package atmosphere and storage temperature on growth and survival of Escherichia coli O157:H7 and Listeria monocytogenes.

    Science.gov (United States)

    Francis, G A; O'Beirne, D

    2001-08-01

    The survival and growth of Escherichia coli O157:H7 (ATCC 43888 and NCTC 12900) and Listeria monocytogenes (ATCC 19114 and NCTC 11994) during storage (4 and 8 degrees C) on ready-to-use (RTU) packaged vegetables (lettuce, swedes (rutabaga), dry coleslaw mix, soybean sprouts) were studied. The vegetables were sealed within oriented polypropylene packaging film, and modified atmospheres developed in packs during storage due to produce respiration. Survival and growth patterns were dependent on vegetable type, package atmosphere, storage temperature and bacterial strain. Populations of L. monocytogenes and E. coli O157:H7 increased (Plettuce (8 degrees C). L. monocytogenes populations also increased (by approximately 1 log cycle) on packaged swedes, did not change significantly (P>0.05) in packages of soybean sprouts and decreased by approximately 1.5 log cycles (P<0.05) on coleslaw mix (8 degrees C). E. coli O157:H7 populations on packaged coleslaw and soybean sprouts increased (by 1.5 to 2.5 log cycles) up to day 5, but declined during subsequent storage (8 degrees C). On packaged swedes (8 degrees C), populations of E. coli O157:H7 strain ATCC 43888 increased (by approximately 1 log cycle) during storage, whereas populations of strain 12900 increased between days 2 and 5, and declined during subsequent storage. Reducing the storage temperature from 8 to 4 degrees C reduced the growth of L. monocytogenes and E. coli O157:H7 on packaged RTU vegetables. However, viable populations remained at the end of the storage period at 4 degrees C.

  15. Effect of ionizing radiation dose, temperature, and atmosphere on the survival of Salmonella typhimurium in sterile, mechanically deboned chicken meat.

    Science.gov (United States)

    Thayer, D W; Boyd, G

    1991-02-01

    The response to gamma radiation (0 to 3.60 kGy; 100 krad = 1 kGy) of Salmonella typhimurium was tested in otherwise sterile, mechanically deboned chicken meat (MDCM) in the absence of competing microflora. Response was determined at temperatures of -20 to +20 C and when the MDCM was packaged in vacuum or in the presence of air. A central composite response-surface design was used to test the response of the pathogen to the treatments in a single experiment. Predictive equations were developed from the analyses of variances of the resulting data. The accuracy of each predictive equation was tested by further studies of the effects of gamma radiation on S. typhimurium in the presence or absence of air at -20, 0, and +20 C. All data were then analyzed to refine the predictive equations further. Both the original and the refined equations adequately predicted the response of S. typhimurium in MDCM to gamma radiation doses up to 3.60 kGy in the presence of air or in vacuo. Gamma irradiation was significantly more lethal for S. typhimurium in the presence of air and at higher temperatures. The final equations predict a reduction in the number of surviving Salmonella in MDCM irradiated to 1.50 kGy at -20 C of 2.53 logs in air or 2.12 logs if irradiated in vacuum. If the contaminated MDCM were to receive a dose of 3.0 kGy at -20 C in air, the number of Salmonella would be decreased by 4.78 logs, and if irradiated in vacuum, by 4.29 logs.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Effect of ionizing radiation dose, temperature, and atmosphere on the survival of Salmonella typhimurium in sterile, mechanically deboned chicken meat

    International Nuclear Information System (INIS)

    Thayer, D.W.; Boyd, G.

    1991-01-01

    The response to gamma radiation (0 to 3.60 kGy; 100 krad = 1 kGy) of Salmonella typhimurium was tested in otherwise sterile, mechanically deboned chicken meat (MDCM) in the absence of competing microflora. Response was determined at temperatures of -20 to +20 C and when the MDCM was packaged in vacuum or in the presence of air. A central composite response-surface design was used to test the response of the pathogen to the treatments in a single experiment. Predictive equations were developed from the analyses of variances of the resulting data. The accuracy of each predictive equation was tested by further studies of the effects of gamma radiation on S. typhimurium in the presence or absence of air at -20, 0, and +20 C. All data were then analyzed to refine the predictive equations further. Both the original and the refined equations adequately predicted the response of S. typhimurium in MDCM to gamma radiation doses up to 3.60 kGy in the presence of air or in vacuo. Gamma irradiation was significantly more lethal for S. typhimurium in the presence of air and at higher temperatures. The final equations predict a reduction in the number of surviving Salmonella in MDCM irradiated to 1.50 kGy at -20 C of 2.53 logs in air or 2.12 logs if irradiated in vacuum. If the contaminated MDCM were to receive a dose of 3.0 kGy at -20 C in air, the number of Salmonella would be decreased by 4.78 logs, and if irradiated in vacuum, by 4.29 logs

  17. Preemption and entry timing

    NARCIS (Netherlands)

    Martin, Xavier; Teece, D.; Augier, M.

    2013-01-01

    Entry timing research examines how firm performance varies, possibly non-monotonically, with the order (also known as order of entry) or elapsed time since first entry into a new market. While the pre-emption literature in economics focuses on assumptions for a first entrant to monopolize a market,

  18. Adapting Mars Entry, Descent and Landing System for Earth

    Science.gov (United States)

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

    2013-09-01

    In 2001 - 2011 an inflatable Entry, Descent and Landing System (EDLS) for Martian atmosphere was developed by FMI and the MetNet team. This MetNet Mars Lander EDLS is used in both the initial deceleration during atmospheric entry and in the final deceleration before the semi-hard impact of the penetrator to Martian surface. The EDLS design is ingenious and its applicability to Earth's atmosphere is studied in the on-going project. In particular, the behavior of the system in the critical transonic aerodynamic (from hypersonic to subsonic) regime will be investigated. This project targets to analyze and test the transonic behavior of this compact and light weight payload entry system to Earth's atmosphere [1]. Scaling and adaptation for terrestrial atmospheric conditions, instead of a completely new design, is a favorable approach for providing a new re-entry vehicle for terrestrial space applications.

  19. Effect of rosemary essential oil and modified-atmosphere packaging (MAP) on meat quality and survival of pathogens in poultry fillets.

    Science.gov (United States)

    Kahraman, Tolga; Issa, Ghassan; Bingol, Enver Baris; Kahraman, Beren Basaran; Dumen, Emek

    2015-06-01

    The effect of rosemary (Rosmarinus officinalis L.) essential oil (REO) and modified-atmosphere packaging (MAP) on the survival of certain pathogens (Salmonella Typhimurium and Listeria monocytogenes) in poultry fillets and on their meat quality during 7 days of refrigerated storage were investigated. Because REO at 0.05% and 0.1% had weak antibacterial activity and REO at 0.3%, 0.5% and 1.0% imparted unacceptable organoleptic properties, only REO at 0.2% was used to treat the poultry meat. The results showed that adding 0.2% REO to poultry fillets did not reduce the size of the population of S. Typhimurium and L. monocytogenes. However, REO treatment significantly decreased the L* (lightness) value and increased the a* (redness) value of stored fillets, and adding REO in combination with MAP reduced the level of lipid oxidation. In conclusion, in a suitable combination, REO can be applied to improve the quality of meat, but further studies should be conducted to determine the appropriate commercial level for different meat products.

  20. Effect of rosemary essential oil and modified-atmosphere packaging (MAP) on meat quality and survival of pathogens in poultry fillets

    Science.gov (United States)

    Kahraman, Tolga; Issa, Ghassan; Bingol, Enver Baris; Kahraman, Beren Basaran; Dumen, Emek

    2015-01-01

    The effect of rosemary (Rosmarinus officinalis L.) essential oil (REO) and modified-atmosphere packaging (MAP) on the survival of certain pathogens (Salmonella Typhimurium and Listeria monocytogenes) in poultry fillets and on their meat quality during 7 days of refrigerated storage were investigated. Because REO at 0.05% and 0.1% had weak antibacterial activity and REO at 0.3%, 0.5% and 1.0% imparted unacceptable organoleptic properties, only REO at 0.2% was used to treat the poultry meat. The results showed that adding 0.2% REO to poultry fillets did not reduce the size of the population of S. Typhimurium and L. monocytogenes. However, REO treatment significantly decreased the L* (lightness) value and increased the a* (redness) value of stored fillets, and adding REO in combination with MAP reduced the level of lipid oxidation. In conclusion, in a suitable combination, REO can be applied to improve the quality of meat, but further studies should be conducted to determine the appropriate commercial level for different meat products. PMID:26273279

  1. Fresh-cut lettuce in modified atmosphere packages stored at improper temperatures supports enterohemorrhagic E. coli isolates to survive gastric acid challenge.

    Science.gov (United States)

    Chua, D; Goh, K; Saftner, R A; Bhagwat, A A

    2008-04-01

    Incidences of foodborne outbreaks involving enterohemorrhagic Escherichia coli strains with mutations in a key regulatory gene, rpoS, have been reported. Incentives, if any, for losing this regulatory function are not clear since the RpoS regulator is required for the expression of several environmental stress tolerance genes. RpoS also positively regulates 2 of the 3 acid-resistance systems of E. coli under aerobic growth conditions and enables the pathogen to survive gastric acid challenge. We selected 7 enterohemorrhagic E. coli isolates, 6 of which are known to carry defective rpoS gene, and then analyzed resistance to synthetic gastric juice after the strains were inoculated on fresh-cut lettuce and stored under modified atmosphere packaging (MAP) conditions. Subatmospheric oxygen partial pressures in MAP enabled all 6 rpoS-defective isolates to induce acid resistance over the 8-d storage period if the temperature was >or= 15 degrees C. No acid resistance was induced for MAP-stored lettuce left at temperatures lettuce packed and stored under aerobic conditions. The data underscore the impending danger of abusive storage temperatures especially with regard to the application of MAP to extend the shelf life of fresh produce. The results also highlight the biological significance of having multiple acid-resistance pathways and the complex regulatory network of enterohemorrhagic E. coli strains.

  2. Entry at Venus

    Science.gov (United States)

    Venkatapathy, Ethiraj; Smith, Brandon

    2016-01-01

    This is lecture to be given at the IPPW 2016, as part of the 2 day course on Short Course on Destination Venus: Science, Technology and Mission Architectures. The attached presentation material is intended to be introduction to entry aspects of Venus in-situ robotic missions. The presentation introduces the audience to the aerodynamic and aerothermodynamic aspects as well as the loads, both aero and thermal, generated during entry. The course touches upon the system design aspects such as TPS design and both high and low ballistic coefficient entry system concepts that allow the science payload to be protected from the extreme entry environment and yet meet the mission objectives.

  3. Complications of ventricular entry during craniotomy for brain tumor resection.

    Science.gov (United States)

    John, Jessin K; Robin, Adam M; Pabaney, Aqueel H; Rammo, Richard A; Schultz, Lonni R; Sadry, Neema S; Lee, Ian Y

    2017-08-01

    OBJECTIVE Recent studies have demonstrated that periventricular tumor location is associated with poorer survival and that tumor location near the ventricle limits the extent of resection. This finding may relate to the perception that ventricular entry leads to further complications and thus surgeons may choose to perform less aggressive resection in these areas. However, there is little support for this view in the literature. This study seeks to determine whether ventricular entry is associated with more complications during craniotomy for brain tumor resection. METHODS A retrospective analysis of patients who underwent craniotomy for tumor resection at Henry Ford Hospital between January 2010 and November 2012 was conducted. A total of 183 cases were reviewed with attention to operative entry into the ventricular system, postoperative use of an external ventricular drain (EVD), subdural hematoma, hydrocephalus, and symptomatic intraventricular hemorrhage (IVH). RESULTS Patients in whom the ventricles were entered had significantly higher rates of any complication (46% vs 21%). Complications included development of subdural hygroma, subdural hematoma, intraventricular hemorrhage, subgaleal collection, wound infection, urinary tract infection/deep venous thrombosis, hydrocephalus, and ventriculoperitoneal (VP) shunt placement. Specifically, these patients had significantly higher rates of EVD placement (23% vs 1%, p entry (11% vs 0%, p = 0.001) with 3 of 4 of these patients having a large ventricular entry (defined here as entry greater than a pinhole [entry). Furthermore, in a subset of glioblastoma patients with and without ventricular entry, Kaplan-Meier estimates for survival demonstrated a median survival time of 329 days for ventricular entry compared with 522 days for patients with no ventricular entry (HR 1.13, 95% CI 0.65-1.96; p = 0.67). CONCLUSIONS There are more complications associated with ventricular entry during brain tumor resection than in

  4. Double entry bookkeeping vs single entry bookkeeping

    Directory of Open Access Journals (Sweden)

    Ileana Andreica

    2016-11-01

    Full Text Available Abstract: A financial management eficiently begin, primarily, with an accounting record kept in the best possible conditions, this being conditioned on the adoption of a uniform forms, rational, clear and simple accounting. Throughout history, there have been known two forms of accounting: the simple and double entry. Romanian society after 1990 underwent a substantial change in social structure, the sector on which put a great emphasis being private, that of small manufacturers, peddler, freelance, who work independently and authorized or as associative form (family enterprises, various associations (owners, tenants, etc., liberal professions, etc.. They are obliged to keep a simple bookkeeping, because they have no juridical personality. Companies with legal personality are required to keep double entry bookkeeping; therefore, knowledge and border demarcation between the two forms of organisation of accounting is an essential. The material used for this work is mainly represented by the financial and accounting documents, by the analysis of the economic, by legislative updated sources, and as the method was used the comparison method, using hypothetical data, in case of an authorized individual and a legal entity. Based on the chosen material, an authorized individual (who perform single entry accounting system and a juridical entity (who perform double entry accounting system were selected comparative case studies, using hypothetical data, were analysed advantages and disadvantages in term of fiscal, if using two accounting systems, then were highlighted some conclusion that result.

  5. Relict olivines in micrometeorites: Precursors and interactions in the earth`s atmosphere

    Digital Repository Service at National Institute of Oceanography (India)

    Rudraswami, N.G.; ShyamPrasad, M.; Dey, S.; Fernandes, D.; Plane, J.M.C.; Feng, W.; Taylor, S.; Carrillo-Sanchez, J.D.

    is therefore useful for identifying the range of chondrites that contributes to the flux of micrometeorites (Steele, 1985a,b; Steele, 1992). The survival of the relict grains also 3    constrains the temperature the particle may have experienced during.... In contrast, the bulk chemical composition of a particle may alter depending on the heating experienced during atmospheric entry, and is typically close to CI composition (Kurat et al., 1994; Brownlee et al., 1997; Taylor et al., 2000; Rudraswami et al...

  6. Border Crossing Entry Data

    Data.gov (United States)

    Department of Transportation — The Bureau of Transportation Statistics (BTS) Border Crossing/Entry Data provides summary statistics for inbound crossings at the U.S.-Canadian and the U.S.-Mexican...

  7. Meteor Entry and Breakup Based on Evolution of NASAs Entry Capsule Design Tools

    Science.gov (United States)

    Prabku, Dinesh K.; Saunders, D.; Stern, E.; Chen, Y.-K.; Allen, G.; Agrawal, P.; Jaffe, R.; White, S.; Tauber, M.; Bauschlicher, C.; hide

    2015-01-01

    Physics of atmospheric entry of meteoroids was an active area of research at NASA ARC up to the early 1970s (e.g., the oft-cited work of Baldwin and Sheaffer). However, research in the area seems to have ended with the Apollo program, and any ties with an active international meteor physics community seem to have significantly diminished thereafter. In the decades following the 1970s, the focus of entry physics at NASA ARC has been on improvement of the math models of shock-layer physics (especially in chemical kinetics and radiation) and thermal response of ablative materials used for capsule heatshields. With the overarching objectives of understanding energy deposition into the atmosphere and fragmentation, could these modern analysis tools and processes be applied to the problem of atmospheric entry of meteoroids as well? In the presentation we will explore: (i) the physics of atmospheric entries of meteoroids using our current state-of-the-art tools and processes, (ii) the influence of shape (and shape change) on flow characteristics, and (iii) how multiple bodies interact.

  8. Entry: direct control or regulation?

    NARCIS (Netherlands)

    Perotti, E.; Vorage, M.

    2009-01-01

    We model a setting in which citizens form coalitions to seek preferential entry to a given market. The lower entry the higher firm profits and political contributions, but the lower social welfare. Politicians choose to either control entry directly and be illegally bribed, or regulate entry using a

  9. Job-hopping and New Firm Survival

    DEFF Research Database (Denmark)

    Failla, Virgilio

    higher chances of survival (Delmar and Shane, 2003). However, only few studies examine the characteristics of the pre-entry experience. Gimeno et al. (1997) differentiate between a general pre-entry human capital (i.e. knowledge and know-how which can be useful independently of the new venture...

  10. Effects of oxygen-depleted atmospheres on survival and growth of Listeria monocytogenes on fresh-cut Iceberg lettuce stored at mild abuse commercial temperatures.

    Science.gov (United States)

    O'Beirne, David; Gomez-Lopez, Vicente; Tudela, Juan A; Allende, Ana; Gil, Maria I

    2015-06-01

    The effects of oxygen-depleted atmospheres, 0.25% O2+12% CO2 (balance N2) and 2% O2 + 6% CO2 (balance N2), on growth of Listeria monocytogenes on fresh-cut Iceberg lettuce were determined. The study was carried out at mild abuse temperatures using controlled atmosphere chambers. During storage at a constant temperature of 7 °C, growth was enhanced at the lower oxygen level of 0.25% O2 by Day 10. Over 17 days of storage at temperatures designed to mimic mild abuse commercial conditions, there were again significantly higher counts under 0.25% O2 from Day 10 onwards. These were 0.9 and 0.7 log cycles higher on Days 14 and 17, respectively. When a model lettuce agar medium was used to eliminate possible interactions with competing flora the direct effects of the atmosphere enhancing the growth of L. monocytogenes was also observed. It is concluded that use of very O2-depleted atmospheres for control of enzymatic browning of fresh-cut Iceberg lettuce may introduce a potential hazard under some commercial conditions. There is a need for greater vigilance and possibly additional measures to ensure consumer safety. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Deployable Entry-system Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Deployable Entry-system ProjecT (ADEPT) will develop requirements for the ADEPT flight test.  Prior entry systems used high mass thermal protection...

  12. Endogenous Entry in Contests

    OpenAIRE

    John Morgan; Henrik Orzen; Martin Sefton

    2008-01-01

    We report the results of laboratory experiments on rent-seeking contests with endogenous participation. Theory predicts that (a) contest entry and rent-seeking expenditures increase with the size of the prize; and (b) earnings are equalized between the contest and the outside option. While the directional predictions offered in (a) are supported in the data, the level predictions are not. Prediction (b) is not supported in the data: When the prize is large, contest participants earn more than...

  13. Lunar Entry Downmode Options for Orion

    Science.gov (United States)

    Smith, Kelly M.; Rea, Jeremy

    2016-01-01

    For Exploration Missions 1 and 2, the Orion capsules will be entering the Earth's atmosphere with speeds in excess of 11 km/s. In the event of a degraded Guidance, Navigation, and Control system, attempting the nominal guided entry may be inadvisable due to the potential for failures that result in a loss of vehicle (or crew, when crew are aboard). In such a case, a method of assuring Earth capture, water landing, and observence of trajectory constraints (heating, loads) is desired. Such a method should also be robust to large state uncertainty and variations in entry interface states. This document will explore four approaches evaluated and their performance in ensuring a safe return of the Orion capsule in the event of onboard system degradation.

  14. The X-37 Demonstrator Re-Entry

    Science.gov (United States)

    2004-01-01

    Pictured is an artist's concept of the X-37 Demonstrator re-entry. After being launched from the cargo bay of a Shuttle as a secondary payload, the X-37 remains on-orbit up to 21 days performing a variety of experiments before re-entering the Earth's atmosphere and landing. These vehicles supported the Agency's goal of dramatically reducing the cost of access to space in attempt to define the future of space transportation. The X-37 program was discontinued in 2003.

  15. Entry and Exit Dynamics of Nascent Business Owners

    DEFF Research Database (Denmark)

    Rocha, Vera; Carneiro, Anabela; Varum, Celeste

    2015-01-01

    This paper reports a comprehensive study on the dynamics of nascent business owners using a unique longitudinal matched employer–employee dataset. We follow over 157,000 individuals who leave paid employment and become business owners during the period 1992–2007. The contributions of this paper...... are twofold. First, we analyze both entry and exit, identifying and characterizing different profiles of individuals leaving paid employment to become business owners, and distinguishing exits by dissolution from exits by ownership transfer. Second, we provide new evidence on how particular experiences...... in the labor market and entry modes shape the post-entry dynamics of nascent business owners. By differentiating between different entry and exit routes, this paper provides new evidence on different human capital patterns among nascent business owners and on key determinants of entrepreneurial survival. Our...

  16. Macrophage Sphingolipids are Essential for the Entry of Mycobacteria.

    Science.gov (United States)

    Viswanathan, Gopinath; Jafurulla, Md; Kumar, G Aditya; Raghunand, Tirumalai R; Chattopadhyay, Amitabha

    2018-03-08

    Mycobacteria are intracellular pathogens that can invade and survive within host macrophages. Mycobacterial infections remain a major cause of mortality and morbidity worldwide, with serious concerns of emergence of multi and extensively drug-resistant tuberculosis. While significant advances have been made in identifying mycobacterial virulence determinants, the detailed molecular mechanism of internalization of mycobacteria into host cells remains poorly understood. Although several studies have highlighted the crucial role of sphingolipids in mycobacterial growth, persistence and establishment of infection, the role of sphingolipids in the entry of mycobacteria into host cells is not known. In this work, we explored the role of host membrane sphingolipids in the entry of Mycobacterium smegmatis into J774A.1 macrophages. Our results show that metabolic depletion of sphingolipids in host macrophages results in a significant reduction in the entry of M. smegmatis. Importantly, the entry of Escherichia coli into host macrophages under similar conditions remained invariant, implying the specificity of the requirement of sphingolipids in mycobacterial entry. To the best of our knowledge, our results constitute the first report demonstrating the role of host macrophage sphingolipids in the entry of mycobacteria. Our results could help in the development of novel therapeutic strategies targeting sphingolipid-mediated entry of mycobacteria into host cells. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Mars Science Laboratory (MSL) Entry, Descent, and Landing Instrumentation (MEDLI): Complete Flight Data Set

    Science.gov (United States)

    Cheatwood, F. McNeil; Bose, Deepak; Karlgaard, Christopher D.; Kuhl, Christopher A.; Santos, Jose A.; Wright, Michael J.

    2014-01-01

    The Mars Science Laboratory (MSL) entry vehicle (EV) successfully entered the Mars atmosphere and landed the Curiosity rover safely on the surface of the planet in Gale crater on August 6, 2012. MSL carried the MSL Entry, Descent, and Landing (EDL) Instrumentation (MEDLI). MEDLI delivered the first in-depth understanding of the Mars entry environments and the response of the entry vehicle to those environments. MEDLI was comprised of three major subsystems: the Mars Entry Atmospheric Data System (MEADS), the MEDLI Integrated Sensor Plugs (MISP), and the Sensor Support Electronics (SSE). Ultimately, the entire MEDLI sensor suite consisting of both MEADS and MISP provided measurements that were used for trajectory reconstruction and engineering validation of aerodynamic, atmospheric, and thermal protection system (TPS) models in addition to Earth-based systems testing procedures. This report contains in-depth hardware descriptions, performance evaluation, and data information of the three MEDLI subsystems.

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

    Science.gov (United States)

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

    2015-10-01

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

  19. 50 CFR 679.83 - Rockfish Program entry level fishery.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Rockfish Program entry level fishery. 679.83 Section 679.83 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF...

  20. Advertising and generic market entry.

    Science.gov (United States)

    Königbauer, Ingrid

    2007-03-01

    The effect of purely persuasive advertising on generic market entry and social welfare is analysed. An incumbent has the possibility to invest in advertising which affects the prescribing physician's perceived relative qualities of the brand-name and the generic version of the drug. Advertising creates product differentiation and can induce generic market entry which is deterred without differentiation due to strong Bertrand competition. However, over-investment in advertising can deter generic market entry under certain conditions and reduces welfare as compared to accommodated market entry.

  1. RITD — Adapting Mars Entry, Descent and Landing System for Earth

    Science.gov (United States)

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

    2014-06-01

    The EDLS applicability to Earth’s atmosphere is studied by the EU/RITD project. Project focuses to the analysis and tests of the transonic behaviour of this compact and light weight payload entry system at the Earth re-entry.

  2. The combined efficacy of carvacrol and modified atmosphere packaging on the survival of Salmonella, Campylobacter jejuni and lactic acid bacteria on turkey breast cutlets.

    Science.gov (United States)

    Nair, Divek V T; Kiess, Aaron; Nannapaneni, Rama; Schilling, Wes; Sharma, Chander Shekhar

    2015-08-01

    The primary objective of this study was to determine the efficacy of carvacrol in combination with modified atmosphere packaging (MAP) in reducing Salmonella on turkey breast cutlets stored at 4 °C. In experiment I, carvacrol (0.5, 1, and 2% v/v) was applied as surface treatment and samples were stored under aerobic condition or as surface and dip treatments followed by storage in an environment of 100% carbon dioxide. The findings of the experiment I revealed the synergistic activity of carvacrol with carbon dioxide in reducing Salmonella when used as dip treatment compared to the surface treatment. In experiment II, turkey breast cutlets were dip treated with carvacrol (0.25, 0.5, and 1% v/v) for 30 s and stored under MAP (95% carbon dioxide and 5% oxygen) to evaluate the efficacy against Salmonella, Campylobacter jejuni and lactic acid bacteria on turkey breast cutlets. In experiment II, the combined application of carvacrol and MAP resulted in 1.0-2.0 log CFU/g reduction (P ≤ 0.05) of both Salmonella and Campylobacter on turkey breast cutlets for 7 d storage at 4 °C. MAP alone and in combination with carvacrol reduced lactic acid bacteria (P ≤ 0.05) on cutlets stored at 4 °C for 21 d period. There was no difference (P ≤ 0.05) in meat color among treatments and controls except for an increased paleness of meat (P ≤ 0.05) observed for the 1% carvacrol treated cutlets stored under MAP after 21 d of storage. The high concentration of carbon dioxide and carvacrol treatments did not cause any alteration in meat pH (P ≤ 0.05). In conclusion, carvacrol was effective at a low concentration of 0.25% (v/v) in reducing Salmonella and C. jejuni by ∼1.0 log CFU/g when stored under MAP. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Biologically Inspired Radiation-Reflecting Ablator (BIRRA) for Enabling Entry Descent and Landing Missions to Gas Giant Planets or Radiation-Intensive Environments

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop and demonstrate a radiationreflecting thermal protection system (TPS) to enable missions where radiative heating during atmospheric entry is...

  4. Safety concerns for first entry operations of orbiting spacecraft

    Science.gov (United States)

    Wilson, Steven H.; Limero, Thomas F.; James, John T.

    1994-01-01

    The Space Station Freedom crew will face operational problems unique to the spacecraft environment due to the absence of convection currents and the confined atmosphere within the habitable modules. Airborne contaminants from the materials offgassing or contingency incidents like thermodegradation may accumulate until they reach hazardous concentrations. Flow modeling and experiences from previous space flight missions confirm that caution must be exercised during first-entry operations. A review of the first-entry procedures performed during the Skylab Program will be presented to highlight the necessity for carefully planned operations. Many of the environmental conditions that can be expected on the Space Station are analogous to those which exist in confined storage or work spaces in the industrial setting. Experience with closed-loop environmental operations (e.g., atmospheric control of submarines) have also demonstrated that the buildup of trace contaminant gases could result in conditions that lead to mission termination or loss of crew. Consequently, some first-entry issues for the Station can be addressed by comparing them to familiar techniques developed on Earth. The instruments of the Environmental Health System (EHS) will provide the necessary monitoring capability to protect crew health and safety during the planned first-entry procedures of the MTC phase of the SSF Program. The authors of this paper will describe those procedures and will cite an example of the consequences when proper first-entry procedures are not followed.

  5. Survival analysis

    International Nuclear Information System (INIS)

    Badwe, R.A.

    1999-01-01

    The primary endpoint in the majority of the studies has been either disease recurrence or death. This kind of analysis requires a special method since all patients in the study experience the endpoint. The standard method for estimating such survival distribution is Kaplan Meier method. The survival function is defined as the proportion of individuals who survive beyond certain time. Multi-variate comparison for survival has been carried out with Cox's proportional hazard model

  6. 19 CFR 191.143 - Drawback entry.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Drawback entry. 191.143 Section 191.143 Customs... entry. (a) Filing of entry. Drawback entries covering these foreign-built jet aircraft engines shall be filed on Customs Form 7551, modified to show that the entry covers jet aircraft engines processed under...

  7. 19 CFR 122.42 - Aircraft entry.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Aircraft entry. 122.42 Section 122.42 Customs... AIR COMMERCE REGULATIONS Aircraft Entry and Entry Documents; Electronic Manifest Requirements for..., and Overflying the United States § 122.42 Aircraft entry. (a) By whom. Entry shall be made by the...

  8. 19 CFR 132.24 - Entry.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Entry. 132.24 Section 132.24 Customs Duties U.S... Importation of Absolute Quota Merchandise § 132.24 Entry. Unless a formal entry or entry by appraisement is required, a mail entry on Customs Form 3419 shall be issued and forwarded with the package to the...

  9. 19 CFR 4.9 - Formal entry.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Formal entry. 4.9 Section 4.9 Customs Duties U.S... FOREIGN AND DOMESTIC TRADES Arrival and Entry of Vessels § 4.9 Formal entry. (a) General. Section 4.3 provides which vessels are subject to formal entry and where and when entry must be made. The formal entry...

  10. Staging atmospheres

    DEFF Research Database (Denmark)

    Bille, Mikkel; Bjerregaard, Peter; Sørensen, Tim Flohr

    2015-01-01

    The article introduces the special issue on staging atmospheres by surveying the philosophical, political and anthropological literature on atmosphere, and explores the relationship between atmosphere, material culture, subjectivity and affect. Atmosphere seems to occupy one of the classic...

  11. The Next Generation of Planetary Atmospheric Probes

    Science.gov (United States)

    Houben, Howard

    2005-01-01

    Entry probes provide useful insights into the structures of planetary atmospheres, but give only one-dimensional pictures of complex four-dimensional systems that vary on all temporal and spatial scales. This makes the interpretation of the results quite challenging, especially as regards atmospheric dynamics. Here is a planetary meteorologist's vision of what the next generation of atmospheric entry probe missions should be: Dedicated sounding instruments get most of the required data from orbit. Relatively simple and inexpensive entry probes are released from the orbiter, with low entry velocities, to establish ground truth, to clarify the vertical structure, and for adaptive observations to enhance the dataset in preparation for sensitive operations. The data are assimilated onboard in real time. The products, being immediately available, are of immense benefit for scientific and operational purposes (aerobraking, aerocapture, accurate payload delivery via glider, ballooning missions, weather forecasts, etc.).

  12. Corporate Author Entries. Revision 5

    International Nuclear Information System (INIS)

    Hendricks, P.L.

    1986-05-01

    This reference authority has been created and is maintained to provide standard forms for recording the names of organizations consistently in bibliographic citations. This revision includes approximately 42,000 entries established since 1973

  13. Currency union entries and trade

    OpenAIRE

    Nitsch, Volker

    2005-01-01

    Recent research suggests that adopting a common currency increases bilateral trade. In this paper, I explore experiences of currency union entry in the post-war period and find no effect on trade. Previous results derived from a large panel data set (covering more than 200 countries from 1948 through 1997) appear to depend crucially on the assumption of symmetry between currency union exits and entries: While countries leaving a currency union experience significant declines in trade, currenc...

  14. The COMPLEXity in herpesvirus entry.

    Science.gov (United States)

    Sathiyamoorthy, Karthik; Chen, Jia; Longnecker, Richard; Jardetzky, Theodore S

    2017-06-01

    Enveloped viruses have evolved diverse transmembrane proteins and protein complexes to enable host cell entry by regulating and activating membrane fusion in a target cell-specific manner. In general terms, the entry process requires a receptor binding step, an activation step and a membrane fusion step, which can be encoded within a single viral protein or distributed among multiple viral proteins. HIV and influenza virus, for example, encode all of these functions in a single trimeric glycoprotein, HIV env or influenza virus hemagglutinin (HA). In contrast, herpesviruses have the host receptor binding, activation and fusogenic roles distributed among multiple envelope glycoproteins (ranging from three to six), which must coordinate their functions at the site of fusion. Despite the apparent complexity in the number of viral entry proteins, herpesvirus entry is fundamentally built around two core glycoprotein entities: the gHgL complex, which appears to act as an 'activator' of entry, and the gB protein, which is thought to act as the membrane 'fusogen'. Both are required for all herpesvirus fusion and entry. In many herpesviruses, gHgL either binds host receptors directly or assembles into larger complexes with additional viral proteins that bind host receptors, conferring specificity to the cells that are targeted for infection. These gHgL entry complexes (ECs) are centrally important to activating gB-mediated membrane fusion and establishing viral tropism, forming membrane bridging intermediates before gB triggering. Here we review recent structural and functional studies of Epstein-Barr virus (EBV) and Cytomegalovirus (CMV) gHgL complexes that provide a framework for understanding the role of gHgL in herpesvirus entry. Furthermore, a recently determined EM model of Herpes Simplex virus (HSV) gB embedded in exosomes highlights how gB conformational changes may promote viral and cellular membrane fusion. Copyright © 2017. Published by Elsevier B.V.

  15. Simulation of the ATV Re-Entry Obsrvations

    Science.gov (United States)

    Bastida Virgili, B.; Krag, H.; Lips, T.; De Pasquale, E.

    2010-09-01

    The first ATV was launched on 9th March 2008 and, after a successful mission, the last phase was a controlled destructive re-entry on 29th September 2008, shortly after 13:30 UTC, in which the remains of the ATV and its load fell into the South Pacific Ocean. In order to better understand the re-entry processes, an insitu optical observation campaign was launched to record and analyze the ATV controlled re-entry with several instruments on board of two airplanes and also from the ISS. This observation campaign was successful and triggered several different still-ongoing studies on the extraction and analysis of data to draw conclusions on the adequacy of the re-entry break-up and explosion models used for the safety analysis of the ATV re-entry. This paper addresses the validation process for ESA’s model for re-entry survivability and on-ground risk assessment for explosive re-entry events using the observation data. The underlying rationale is to improve the models for the benefit of planning and execution of future controlled re-entries and in risk calculation in case of uncontrolled ones. The re-entry trajectory of the ATV, the explosive event and the trajectories of the fragments are simulated with the existing ESA tools and the EVOLVE explosion model. Additional software has been developed to simulate airborne sensor field of view(FOV) crossings based on the aircraft trajectories, attitude profile, sensor mounts and FOVs. Sensor performance and object radiation are modeled in order to generate synthetic images for the different sensors in the ISS and the two airplanes. These synthetic images and synthetic videos are compared with the available reentry observations of the ATV. This paper will present the software and techniques to generate synthetic imagery. It will give results of the comparison between the simulated and the real trajectories and fragmentation and explain the subsequent validation process of the ESA re-entry tools and the potential

  16. Authorized Generic Entry prior to Patent Expiry: Reassessing Incentives for Independent Generic Entry

    OpenAIRE

    Appelt, Silvia

    2010-01-01

    Patent holders frequently attempt to mitigate the loss of monopoly power by authorizing generic entry prior to patent expiry (early entry). Competition in off-patent pharmaceutical markets may be adversely affected if early entry substantially impairs the attractiveness of subsequent market entry. I examine generic entry decisions made in the course of recent patent expiries to quantify the impact of early entry on incentives for generic entry. Using unique micro data and accounting for th...

  17. Clustered survival data with left-truncation

    DEFF Research Database (Denmark)

    Eriksson, Frank; Martinussen, Torben; Scheike, Thomas H.

    2015-01-01

    Left-truncation occurs frequently in survival studies, and it is well known how to deal with this for univariate survival times. However, there are few results on how to estimate dependence parameters and regression effects in semiparametric models for clustered survival data with delayed entry....... Surprisingly, existing methods only deal with special cases. In this paper, we clarify different kinds of left-truncation and suggest estimators for semiparametric survival models under specific truncation schemes. The large-sample properties of the estimators are established. Small-sample properties...

  18. 19 CFR 163.3 - Entry records.

    Science.gov (United States)

    2010-04-01

    ... import transaction shall be prepared to produce or transmit to Customs, in accordance with § 163.6(a), any entry records which may be demanded by Customs. If entry records submitted to Customs not pursuant to a demand are returned by Customs, or if production of entry records at the time of entry is waived...

  19. 32 CFR 809a.3 - Unauthorized entry.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Unauthorized entry. 809a.3 Section 809a.3... ENTRY POLICY, CIVIL DISTURBANCE INTERVENTION AND DISASTER ASSISTANCE Installation Entry Policy § 809a.3 Unauthorized entry. Under Section 21 of the Internal Security Act of 1950 (50 U.S.C. 797), any directive issued...

  20. 19 CFR 10.78 - Entry.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Entry. 10.78 Section 10.78 Customs Duties U.S... Entry. (a) No entry shall be required for fish or other marine products taken on the high seas by... foreign merchandise. (d) Products of an American fishery shall be entitled to free entry although prepared...

  1. 19 CFR 146.62 - Entry.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Entry. 146.62 Section 146.62 Customs Duties U.S...) FOREIGN TRADE ZONES Transfer of Merchandise From a Zone § 146.62 Entry. (a) General. Entry for foreign..., Customs Form 7501, or other applicable Customs forms. If entry is made on Customs Form 3461, the person...

  2. Lunar Entry Downmode Options for Orion

    Science.gov (United States)

    Smith, Kelly; Rea, Jeremy

    2016-01-01

    Traditional ballistic entry does not scale well to higher energy entry trajectories. Clutch algorithm is a two-stage approach with the capture stage and load relief stage. Clutch may offer expansion of the operational entry corridor. Clutch is a candidate solution for Exploration Mission-2's degraded entry mode.

  3. 19 CFR 147.11 - Entry.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Entry. 147.11 Section 147.11 Customs Duties U.S...) TRADE FAIRS Procedure for Importation § 147.11 Entry. (a) Made in name of fair operator. All entries of... Government for all duties and charges due the United States on account of such entries. (b) Merchandise...

  4. 19 CFR 4.8 - Preliminary entry.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Preliminary entry. 4.8 Section 4.8 Customs Duties... VESSELS IN FOREIGN AND DOMESTIC TRADES Arrival and Entry of Vessels § 4.8 Preliminary entry. (a) Generally. Preliminary entry allows a U.S. or foreign vessel arriving under circumstances that require it to formally...

  5. Trading Robustness Requirements in Mars Entry Trajectory Design

    Science.gov (United States)

    Lafleur, Jarret M.

    2009-01-01

    One of the most important metrics characterizing an atmospheric entry trajectory in preliminary design is the size of its predicted landing ellipse. Often, requirements for this ellipse are set early in design and significantly influence both the expected scientific return from a particular mission and the cost of development. Requirements typically specify a certain probability level (6-level) for the prescribed ellipse, and frequently this latter requirement is taken at 36. However, searches for the justification of 36 as a robustness requirement suggest it is an empirical rule of thumb borrowed from non-aerospace fields. This paper presents an investigation into the sensitivity of trajectory performance to varying robustness (6-level) requirements. The treatment of robustness as a distinct objective is discussed, and an analysis framework is presented involving the manipulation of design variables to effect trades between performance and robustness objectives. The scenario for which this method is illustrated is the ballistic entry of an MSL-class Mars entry vehicle. Here, the design variable is entry flight path angle, and objectives are parachute deploy altitude performance and error ellipse robustness. Resulting plots show the sensitivities between these objectives and trends in the entry flight path angles required to design to these objectives. Relevance to the trajectory designer is discussed, as are potential steps for further development and use of this type of analysis.

  6. Jovian atmospheres

    International Nuclear Information System (INIS)

    Allison, M.; Travis, L.D.

    1986-10-01

    A conference on the atmosphere of Jupiter produced papers in the areas of thermal and ortho-para hydrogen structure, clouds and chemistry, atmospheric structure, global dynamics, synoptic features and processes, atmospheric dynamics, and future spaceflight opportunities. A session on the atmospheres of Uranus and Neptune was included, and the atmosphere of Saturn was discussed in several papers

  7. Pre-X Experimental Re-Entry Lifting Body: Design of Flight Test Experiments for Critical Aerothermal Phenomena

    Science.gov (United States)

    2007-06-01

    PRE-X EXPERIMENTAL RE-ENTRY LIFTING BODY: DESIGN OF FLIGHT TEST EXPERIMENTS FOR CRITICAL AEROTHERMAL PHENOMENA Paolo Baiocco * * CNES...ACRONYMS ACS Attitude Control System AEDB Aero Dynamic Data Base AoA Angle of Attack ARD Atmospheric Re-entry Demonstrator ATD Aero Termo ...1 Baiocco, P. (2007) Pre-X Experimental Re-entry Lifting Body: Design of Flight Test Experiments for Critical Aerothermal Phenomena. In Flight

  8. Atmospheric Models for Aerocapture

    Science.gov (United States)

    Justus, C. G.; Duvall, Aleta L.; Keller, Vernon W.

    2004-01-01

    There are eight destinations in the solar System with sufficient atmosphere for aerocapture to be a viable aeroassist option - Venus, Earth, Mars, Jupiter, Saturn and its moon Titan, Uranus, and Neptune. Engineering-level atmospheric models for four of these targets (Earth, Mars, Titan, and Neptune) have been developed for NASA to support systems analysis studies of potential future aerocapture missions. Development of a similar atmospheric model for Venus has recently commenced. An important capability of all of these models is their ability to simulate quasi-random density perturbations for Monte Carlo analyses in developing guidance, navigation and control algorithm, and for thermal systems design. Similarities and differences among these atmospheric models are presented, with emphasis on the recently developed Neptune model and on planned characteristics of the Venus model. Example applications for aerocapture are also presented and illustrated. Recent updates to the Titan atmospheric model are discussed, in anticipation of applications for trajectory and atmospheric reconstruct of Huygens Probe entry at Titan.

  9. Economics of entry into marriage

    OpenAIRE

    Bowmaker, Simon W.

    2009-01-01

    This thesis contains three studies on the economics of entry into marriage; a life event that has been shown to have significant implications for the well-being (economic and otherwise) of men, women and their children. The first study examines the effect of family background on the timing of first marriage of 7,853 individuals born in 1970 in Great Britain. Hazard model analysis reveals that high levels of parental resources serve to delay entry into marriage for both males and femal...

  10. OA 2014-5 Dataset - Limited Entry and Open Access cost earnings survey collecting 2014-15 data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project collects economic data from vessel owners participating in the West Coast limited entry fixed gear and open access groundfish, salmon, crab, and shrimp...

  11. Woven TPS – A Revolutionary Approach to Tailorable TPS Design & Manufacturing for Thermal Management Systems & Entry, Descent & Landing Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — The thermal protection material system (TPS) is the barrier that protects the space vehicle from atmospheric entry heating. Woven TPS is a concept that leverages the...

  12. Delayed School Entry in Uganda

    Science.gov (United States)

    Moyi, Peter

    2011-01-01

    Since 1997 Uganda has seen a large increase in school enrolment. Despite this increased enrolment, universal education has remained elusive. Many children enrol in school, but not at the recommended age, and they drop out before completing school. This article focuses on one of these problems--delayed school entry. What household factors are…

  13. Atmospheric Habitable Zones in Y Dwarf Atmospheres

    International Nuclear Information System (INIS)

    Yates, Jack S.; Palmer, Paul I.; Biller, Beth; Cockell, Charles S.

    2017-01-01

    We use a simple organism lifecycle model to explore the viability of an atmospheric habitable zone (AHZ), with temperatures that could support Earth-centric life, which sits above an environment that does not support life. To illustrate our model, we use a cool Y dwarf atmosphere, such as WISE J085510.83–0714442.5, whose 4.5–5.2 μ m spectrum shows absorption features consistent with water vapor and clouds. We allow organisms to adapt to their atmospheric environment (described by temperature, convection, and gravity) by adopting different growth strategies that maximize their chance of survival and proliferation. We assume a constant upward vertical velocity through the AHZ. We found that the organism growth strategy is most sensitive to the magnitude of the atmospheric convection. Stronger convection supports the evolution of more massive organisms. For a purely radiative environment, we find that evolved organisms have a mass that is an order of magnitude smaller than terrestrial microbes, thereby defining a dynamical constraint on the dimensions of life that an AHZ can support. Based on a previously defined statistical approach, we infer that there are of the order of 10"9 cool Y brown dwarfs in the Milky Way, and likely a few tens of these objects are within 10 pc from Earth. Our work also has implications for exploring life in the atmospheres of temperate gas giants. Consideration of the habitable volumes in planetary atmospheres significantly increases the volume of habitable space in the galaxy.

  14. Atmospheric Habitable Zones in Y Dwarf Atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Yates, Jack S.; Palmer, Paul I. [School of GeoSciences, University of Edinburgh (United Kingdom); Biller, Beth; Cockell, Charles S., E-mail: j.s.yates@ed.ac.uk [Centre for Exoplanet Science, University of Edinburgh (United Kingdom)

    2017-02-20

    We use a simple organism lifecycle model to explore the viability of an atmospheric habitable zone (AHZ), with temperatures that could support Earth-centric life, which sits above an environment that does not support life. To illustrate our model, we use a cool Y dwarf atmosphere, such as WISE J085510.83–0714442.5, whose 4.5–5.2 μ m spectrum shows absorption features consistent with water vapor and clouds. We allow organisms to adapt to their atmospheric environment (described by temperature, convection, and gravity) by adopting different growth strategies that maximize their chance of survival and proliferation. We assume a constant upward vertical velocity through the AHZ. We found that the organism growth strategy is most sensitive to the magnitude of the atmospheric convection. Stronger convection supports the evolution of more massive organisms. For a purely radiative environment, we find that evolved organisms have a mass that is an order of magnitude smaller than terrestrial microbes, thereby defining a dynamical constraint on the dimensions of life that an AHZ can support. Based on a previously defined statistical approach, we infer that there are of the order of 10{sup 9} cool Y brown dwarfs in the Milky Way, and likely a few tens of these objects are within 10 pc from Earth. Our work also has implications for exploring life in the atmospheres of temperate gas giants. Consideration of the habitable volumes in planetary atmospheres significantly increases the volume of habitable space in the galaxy.

  15. Heatshield for Extreme Entry Environment Technology (HEEET) - Enabling Missions Beyond Heritage Carbon Phenolic

    Science.gov (United States)

    Ellerby, D.; Beerman, A.; Blosser, M.; Boghozian, T.; Chavez-Garcia, J.; Chinnapongse, R.; Fowler, M.; Gage, P.; Gasch, M.; Gonzales, G.; hide

    2015-01-01

    This poster provides an overview of the requirements, design, development and testing of the 3D Woven TPS being developed under NASA's Heatshield for Extreme Entry Environment Technology (HEEET) project. Under this current program, NASA is working to develop a Thermal Protection System (TPS) capable of surviving entry into Venus or Saturn. A primary goal of the project is to build and test an Engineering Test Unit (ETU) to establish a Technical Readiness Level (TRL) of 6 for this technology by 2017.

  16. Heatshield for Extreme Entry Environment Technology (HEEET) for Missions to Saturn and Beyond

    Science.gov (United States)

    Ellerby, D.; Blosser, M.; Chinnapongse, R.; Fowler, M.; Gasch, M.; Hamm, K.; Kazemba, C.; Ma, J.; Milos, F.; Nishioka, O.; hide

    2015-01-01

    This poster provides an overview of the requirements, design, development and testing of the 3D Woven TPS being developed under NASAs Heatshield for Extreme Entry Environment Technology (HEEET) project. Under this current program, NASA is working to develop a Thermal Protection System (TPS) capable of surviving entry into Saturn. A primary goal of the project is to build and test an Engineering Test Unit (ETU) to establish a Technical Readiness Level (TRL) of 6 for this technology by 2017.

  17. Heatshield for Extreme Entry Environment Technology (HEEET) Development and Maturation Status for NF Missions

    Science.gov (United States)

    Ellerby, D.; Blosser, M.; Boghozian, T.; Chavez-Garcia, J.; Chinnapongse, R.; Fowler, M.; Gage, P.; Gasch, M.; Gonzales, G.; Hamm, K.; hide

    2016-01-01

    This poster provides an overview of the requirements, design, development and testing of the 3D Woven TPS being developed under NASA's Heatshield for Extreme Entry Environment Technology (HEEET) project. Under this current program, NASA is working to develop a Thermal Protection System (TPS) capable of surviving entry into Saturn. A primary goal of the project is to build and test an Engineering Test Unit (ETU) to establish a Technical Readiness Level (TRL) of 6 for this technology by 2017.

  18. Heatshield for Extreme Entry Environment Technology (HEEET) Development and Maturation Status

    Science.gov (United States)

    Ellerby, D.; Boghozian, T.; Driver, D.; Chavez-Garcia, J.; Fowler, M.; Gage, P.; Gasch, M.; Gonzales, G.; Kazemba, C.; Kellermann, C.; hide

    2018-01-01

    This poster provides an overview of the requirements, design, development and testing of the 3D (Three Dimensional) Woven TPS (Thermal Protection System) being developed under NASA's Heatshield for Extreme Entry Environment Technology (HEEET) project. Under this current program, NASA is working to develop a TPS capable of surviving entry into Saturn. A primary goal of the project is to build and test an Engineering Test Unit (ETU) to establish a Technical Readiness Level (TRL) of 6 for this technology by 2017.

  19. Orion Entry Performance-Based Center-of-Gravity Box

    Science.gov (United States)

    Rea, Jeremy R.

    2010-01-01

    The Orion capsule is designed both for Low Earth Orbit missions to the ISS and for missions to the moon. For ISS class missions, the capsule will use an Apollo-style direct entry. For lunar return missions, depending on the timing of the mission, the capsule could perform a direct entry or a skip entry of up to 4800 n.mi. in order to land in the coastal waters of California. The physics of atmospheric re-entry determine the capability of the Orion vehicle. For a given vehicle mass and shape, physics tells us that the driving parameters for an entry vehicle are the hypersonic lift-to-drag ratio (L/D) and the flight path angle at entry interface (gamma(sub EI)). The design of the Orion atmospheric re-entry must meet constraints during both nominal and dispersed flight conditions on landing accuracy, heating rate, total heat load, sensed acceleration, and proper disposal of the Service Module. These constraints define an entry corridor in the space of L/D-gamma(sub EI); if the vehicle falls within this corridor, then all constraints are met. The gamma(sub EI) dimension of the corridor can be further constrained by the gloads experienced during emergency entries. Thus, the entry performance for the Orion vehicle can be described completely by the L/D. Bounds on the hypersonic L/D necessary to achieve all the mission requirements can be defined for the given entry corridor. Landing accuracy performance drives the lower limit on L/D. In order to achieve the desired landing accuracy, a minimum L/D must be ensured. The design of the Thermal Protection System (TPS) drives the upper limit on L/D. A higher L/D can drive mass into the design of the TPS. Conversely, once the TPS is designed, the L/D must be ensured to stay below a certain limit in order for the TPS to stay within its design envelop. The L/D must stay within its upper and lower bounds during dispersed flight conditions. L/D is a function of both the aerodynamics and the center-of-gravity (CG) of the vehicle. The

  20. Post-entry and volcanic contaminant abundances of zinc, copper, selenium, germanium and gallium in stratospheric micrometeorites

    Science.gov (United States)

    Rietmeijer, Frans J. M.

    1995-01-01

    Some fraction of Zn, Cu, Se, Ga and Ge in chondritic interplanetary dust particles (IDPs) collected in the lower stratosphere between 1981 May and 1984 June has a volcanic origin. I present a method to evaluate the extent of this unavoidable type of stratospheric contamination for individual particles. The mass-normalized abundances for Cu and Ge as a function of mass-normalized stratospheric residence time show their time-integrated stratospheric aerosol abundances. The Zn, Se and Ga abundances show a subdivision into two groups that span approximately two-year periods following the eruptions of the Mount St. Helens (1980 May) and El Chichon (1982 April) volcanoes. Elemental abundances in particles collected at the end of each two-year period indicate low, but not necessarily ambient, volcanic stratospheric abundances. Using this time-integrated baseline, I calculate the straospheric contaminant fractions in nine IDPs and show that Zn, SE and Ga abundances in chondritic IDPs derive in part from stratospheric aerosol contaminants. Post-entry elemental abundances (i.e., the amount that survived atmospheric entry heating of the IDP) show enrichments relative to the CI abundances but in a smaller number of particles than previously suggested.

  1. Atmospheric contamination

    International Nuclear Information System (INIS)

    Gruetter, Juerg

    1997-01-01

    It is about the levels of contamination in center America, the population's perception on the problem, effects of the atmospheric contamination, effects in the environment, causes of the atmospheric contamination, possibilities to reduce the atmospheric contamination and list of Roeco Swisscontac in atmospheric contamination

  2. Planetary entry, descent, and landing technologies

    Science.gov (United States)

    Pichkhadze, K.; Vorontsov, V.; Polyakov, A.; Ivankov, A.; Taalas, P.; Pellinen, R.; Harri, A.-M.; Linkin, V.

    2003-04-01

    Martian meteorological lander (MML) is intended for landing on the Martian surface in order to monitor the atmosphere at landing point for one Martian year. MMLs shall become the basic elements of a global network of meteorological mini-landers, observing the dynamics of changes of the atmospheric parameters on the Red Planet. The MML main scientific tasks are as follows: (1) Study of vertical structure of the Martian atmosphere throughout the MML descent; (2) On-surface meteorological observations for one Martian year. One of the essential factors influencing the lander's design is its entry, descent, and landing (EDL) sequence. During Phase A of the MML development, five different options for the lander's design were carefully analyzed. All of these options ensure the accomplishment of the above-mentioned scientific tasks with high effectiveness. CONCEPT A (conventional approach): Two lander options (with a parachute system + airbag and an inflatable airbrake + airbag) were analyzed. They are similar in terms of fulfilling braking phases and completely analogous in landing by means of airbags. CONCEPT B (innovative approach): Three lander options were analyzed. The distinguishing feature is the presence of inflatable braking units (IBU) in their configurations. SELECTED OPTION (innovative approach): Incorporating a unique design approach and modern technologies, the selected option of the lander represents a combination of the options analyzed in the framework of Concept B study. Currently, the selected lander option undergoes systems testing (Phase D1). Several MMLs can be delivered to Mars in frameworks of various missions as primary or piggybacking payload: (1) USA-led "Mars Scout" (2007); (2) France-led "NetLander" (2007/2009); (3) Russia-led "Mars-Deimos-Phobos sample return" (2007); (4) Independent mission (currently under preliminary study); etc.

  3. 19 CFR 141.68 - Time of entry.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Time of entry. 141.68 Section 141.68 Customs... (CONTINUED) ENTRY OF MERCHANDISE Presentation of Entry Papers § 141.68 Time of entry. (a) When entry documentation is filed without entry summary. When the entry documentation is filed in proper form without an...

  4. Modelling survival

    DEFF Research Database (Denmark)

    Ashauer, Roman; Albert, Carlo; Augustine, Starrlight

    2016-01-01

    well GUTS, calibrated with short-term survival data of Gammarus pulex exposed to four pesticides, can forecast effects of longer-term pulsed exposures. Thirdly, we tested the ability of GUTS to estimate 14-day median effect concentrations of malathion for a range of species and use these estimates...

  5. Survival Analysis

    CERN Document Server

    Miller, Rupert G

    2011-01-01

    A concise summary of the statistical methods used in the analysis of survival data with censoring. Emphasizes recently developed nonparametric techniques. Outlines methods in detail and illustrates them with actual data. Discusses the theory behind each method. Includes numerous worked problems and numerical exercises.

  6. Flavivirus Entry Receptors: An Update

    Directory of Open Access Journals (Sweden)

    Manuel Perera-Lecoin

    2013-12-01

    Full Text Available Flaviviruses enter host cells by endocytosis initiated when the virus particles interact with cell surface receptors. The current model suggests that flaviviruses use at least two different sets of molecules for infectious entry: attachment factors that concentrate and/or recruit viruses on the cell surface and primary receptor(s that bind to virions and direct them to the endocytic pathway. Here, we present the currently available knowledge regarding the flavivirus receptors described so far with specific attention to C-type lectin receptors and the phosphatidylserine receptors, T-cell immunoglobulin and mucin domain (TIM and TYRO3, AXL and MER (TAM. Their role in flavivirus attachment and entry as well as their implication in the virus biology will be discussed in depth.

  7. HMSRP Hawaiian Monk Seal Survival Factors

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains records of survival factors recorded by PSD personnel and cooperating scientists as part of the ongoing monk seal population assessment...

  8. Oceanographic Trawl Data - Ocean Survival of Salmonids

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A study to evaluate the role of changing ocean conditions on growth and survival of juvenile salmon from the Columbia River basin as they enter the Columbia River...

  9. Zooplankton Data - Ocean Survival of Salmonids

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A study to evaluate the role of changing ocean conditions on growth and survival of juvenile salmon from the Columbia River basin as they enter the Columbia River...

  10. Juvenile Salmonid Metrics - Ocean Survival of Salmonids

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A study to evaluate the role of changing ocean conditions on growth and survival of juvenile salmon from the Columbia River basin as they enter the Columbia River...

  11. CTD Oceanographic Data - Ocean Survival of Salmonids

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A study to evaluate the role of changing ocean conditions on growth and survival of juvenile salmon from the Columbia River basin as they enter the Columbia River...

  12. 27 CFR 19.321 - Entry.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Entry. 19.321 Section 19... TREASURY LIQUORS DISTILLED SPIRITS PLANTS Production § 19.321 Entry. Pursuant to the production gauge, the proprietor shall make appropriate entry for (a) deposit of the spirits on bonded premises for storage or...

  13. 10 CFR 1048.3 - Unauthorized entry.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Unauthorized entry. 1048.3 Section 1048.3 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) TRESPASSING ON STRATEGIC PETROLEUM RESERVE FACILITIES AND OTHER PROPERTY § 1048.3 Unauthorized entry. Unauthorized entry into or upon an SPR facility or real property...

  14. Sunk costs, entry deterrence, and financial constraints

    NARCIS (Netherlands)

    Arping, S.; Diaw, K.M.

    2008-01-01

    This paper studies how sunk costs affect a financially constrained incumbent's ability to deter entry into its market. Sunk costs make it less attractive to the incumbent to accommodate entry by liquidating assets in place and exiting the market. This may render entry by a prospective rival

  15. 46 CFR 147A.25 - Entry.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Entry. 147A.25 Section 147A.25 Shipping COAST GUARD... During Fumigation § 147A.25 Entry. (a) No person may enter the spaces that immediately adjoin the space that is fumigated during fumigation unless entry is for emergency purposes or the space is tested and...

  16. The Canyon Diablo impact event: Projectile motion through the atmosphere

    Science.gov (United States)

    Artemieva, N.; Pierazzo, E.

    2009-03-01

    Meteor Crater is one of the first impact structures systematically studied on Earth. Its location in arid northern Arizona has been ideal for the preservation of the structure and the surviving meteoric material. The recovery of a large amount of meteoritic material in and around the crater has allowed a rough reconstruction of the impact event: an iron object 50 m in diameter impacted the Earth’s surface after breaking up in the atmosphere. The details of the disruption, however, are still debated. The final crater morphology (deep, bowl-shaped crater) rules out the formation of the crater by an open or dispersed swarm of fragments, in which the ratio of swarm radius to initial projectile radius Cd is larger than 3 (the final crater results from the sum of the craters formed by individual fragments). On the other hand, the lack of significant impact melt in the crater has been used to suggest that the impactor was slowed down to 12 km/s by the atmosphere, implying significant fragmentation and fragments’ separation up to 4 initial radii. This paper focuses on the problem of entry and motion through the atmosphere for a possible Canyon Diablo impactor as a first but necessary step for constraining the initial conditions of the impact event which created Meteor Crater. After evaluating typical models used to investigate meteoroid disruption, such as the pancake and separated fragment models, we have carried out a series of hydrodynamic simulations using the 3D code SOVA to model the impactor flight through the atmosphere, both as a continuum object and a disrupted swarm. Our results indicate that the most probable pre-atmospheric mass of the Meteor Crater projectile was in the range of 4ṡ108 to 1.2ṡ109 kg (equivalent to a sphere 46-66 m in diameter). During the entry process the projectile lost probably 30% to 70% of its mass, mainly because of mechanical ablation and gross fragmentation. Even in the case of a tight swarm of particles (Cd crater

  17. Planetary entry aerothermodynamics. I - Technology requirements and experimental facilities

    Science.gov (United States)

    Olstad, W. B.

    1974-01-01

    Consideration has been given to the entry of vehicles into the atmospheres of all planets with the exception of Pluto and to missions for returning samples to Earth from all the planets (excepting Pluto), the satellites of Mars, Jupiter, and Saturn, the Moon, the asteroids, and certain comets. The efficient planning of the space missions including the appropriate design of the spacecraft requires that operational and environmental parameter values for the large range of mission options included be adequately known. The need to obtain the data required as a basis for the computational studies involved makes it necessary to conduct a comprehensive experimental research program. Details concerning the experimental facilities employed in this program are discussed, giving attention to shock tubes, the planetary-entry radiation facility, ballistic ranges, an expansion tube, a hypersonic tetrafluoromethane tunnel, and arcjet facilities.

  18. The Adaptable, Deployable Entry and Placement Technology (ADEPT)

    Science.gov (United States)

    Wercinski, Paul

    2017-01-01

    The initial system-level development of the nano-ADEPT architecture will culminate in the launch of a 0.7 meter deployed diameter ADEPT sounding rocket flight experiment named, SR-1. Launch is planned for August 2017. The test will utilize the NASA Flight Opportunities Program sounding rocket platform provided by UP Aerospace to launch SR-1 to an apogee over 100 km and achieve re-entry conditions with a peak velocity near Mach 3. The SR-1 flight experiment will demonstrate most of the primary end-to-end mission stages including: launch in a stowed configuration, separation and deployment in exo-atmospheric conditions, and passive ballistic re-entry of a 70-degree half-angle faceted cone geometry.

  19. Astronomy and Atmospheric Optics

    Science.gov (United States)

    Cowley, Les; Gaina, Alex

    2011-12-01

    The authors discusse the insuccess of the observation of the Total Eclipse of the Moon from 10 december 2011 in Romania and relate them with meteoconditions. Only a very short part of the last penumbral phase was observed, while the inital part and the totality was not observed due to very dense clouds. The change in color and brightness during this phase was signaled. Meanwhile, there is an area of science where clouds are of great use and interest. This area is Atmospheric optics, while the science which study clouds is meteorology. Clouds in combination with Solar and Moon light could give rise to a variety of strange, rare and unobvious phenomena in the atmosphere (sky), sometimes confused with Unidentified Flying Objects (UFO). The importance of meteorology for astronomy and atmospheric optics is underlined and an invitation to astronomers to use unfavourable days for athmospheric observations was sent. The web address of the site by Les Cowley, designed for atmospheric optics phenomena is contained in the text of the entry.

  20. Venus Global Reference Atmospheric Model

    Science.gov (United States)

    Justh, Hilary L.

    2017-01-01

    Venus Global Reference Atmospheric Model (Venus-GRAM) is an engineering-level atmospheric model developed by MSFC that is widely used for diverse mission applications including: Systems design; Performance analysis; Operations planning for aerobraking, Entry, Descent and Landing, and aerocapture; Is not a forecast model; Outputs include density, temperature, pressure, wind components, and chemical composition; Provides dispersions of thermodynamic parameters, winds, and density; Optional trajectory and auxiliary profile input files Has been used in multiple studies and proposals including NASA Engineering and Safety Center (NESC) Autonomous Aerobraking and various Discovery proposals; Released in 2005; Available at: https://software.nasa.gov/software/MFS-32314-1.

  1. Spacecraft precision entry navigation using an adaptive sigma point Kalman filter bank

    Science.gov (United States)

    Heyne, Martin Cornelius

    This work documents the development of a sigma point Kalman filter for the purpose of precision spacecraft navigation during the atmospheric entry, descent and landing phase. The use of the sigma point Kalman filter is driven by the desire to avoid complex partial derivatives associated with the standard extended Kalman filter. The strategy increases the likelihood that the navigation algorithm will be compatible with the Electra. Using Mars Exploration Rover Spirit (MER-A) and the Mars Science Laboratory (MSL) data, experiments were conducted to validate the proposed navigation concept. Beginning at atmospheric entry interface, the hypersonic entry phase is considered and the navigation architecture performance is quantified. Using the sigma point Kalman filter as the main computational unit, a filter bank for environmental parameter identification is investigated. The focus of the investigation is atmospheric parameter identification. The MER-A mission is used to verify the ability of the filter bank to make appropriate selections. The navigation architecture is implemented on the Electra programmable radio, a flight hardware communication node available on spacecraft build for Mars exploration. The investigations show that the sigma point Kalman filter structure is very applicable to the atmospheric entry navigation problem. When used in conjunction with the filter bank concept, the overall navigation architecture is shown to be able to improve navigation accuracy over standard dead-reckoning, while providing robustness to uncertainties in the atmosphere. The navigation algorithm is successfully hosted on the Electra programmable radio and is capable of processing actual MER inertial measurement data.

  2. Workforce re-entry for Japanese unemployed dental hygienists.

    Science.gov (United States)

    Usui, Y; Miura, H

    2015-02-01

    The aim of this study was to define the profile of unemployed dental hygienists who could be enticed to re-enter the workforce and the factors that could facilitate their re-entry into the dental field in Japan. The questionnaire was mailed with a postage-paid return envelope to a sample of 3095 licensed dental hygienists. A 50.4% response rate (S = 1477) was observed. The rate of working dental hygienists was 60.3% (n = 891), and of unemployed dental hygienists was 39.7% (n = 586). Of the latter, 31.9% (n = 187) stated intentions of returning to the workplace. The unemployed dental hygienists seeking employment were more often married and had more children, compared with working dental hygienists currently. This group also had significantly fewer total service years. Moreover, only 11.96% of them belonged to the Japan Dental Hygienists' Association, and 41.3% of those attended training workshops. According to their response, they perceived their top three major barriers to re-entry as 'lack sufficient dental hygiene skill', 'child rearing' and 'poor working atmosphere'. 'Flexibility in the work schedule' and 'location' were the most important factors for re-entry from their perspective. There were not many dental hygienists hoping to return to the dental field. The findings suggested that strategies to encourage non-practicing dental hygienists to re-entry should be emphasized in the areas of a flexible working atmosphere, easy access to information on how to return to practice and guidance on how to maintain professionalism during inactivity. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Venus Atmospheric Maneuverable Platform (VAMP)

    Science.gov (United States)

    Griffin, K.; Sokol, D.; Lee, G.; Dailey, D.; Polidan, R.

    2013-12-01

    We have explored a possible new approach to Venus upper atmosphere exploration by applying recent Northrop Grumman (non-NASA) development programs to the challenges associated with Venus upper atmosphere science missions. Our concept is a low ballistic coefficient (gas, wing span, vehicle mass, power supply, propulsion, materials considerations, structural elements, subsystems, and packaging. The interaction between the VAMP vehicle and the supporting orbiter will also be discussed. In this context, we will specifically focus upon four key factors impacting the design and performance of VAMP: 1. Feasibility of and options for the deployment of the vehicle in space 2. Entry into the Venus atmosphere, including descent profile, heat rate, total heat load, stagnation temperature, control, and entry into level flight 3. Characteristics of flight operations and performance in the Venus atmosphere: altitude range, latitude and longitude access, day/night performance, aircraft performance (aerodynamics, power required vs. power available, propulsion, speed, percent buoyancy), performance sensitivity to payload weight 4. Science payload accommodation, constraints, and opportunities We will discuss interdependencies of the above factors and the manner in which the VAMP strawman's characteristics affect the CONOPs and the science objectives. We will show how the these factors provide constraints as well as enable opportunities for novel long duration scientific studies of the Venus upper atmosphere that support VEXAG goals 2 and 3. We will also discuss how the VAMP platform itself can facilitate some of these science measurements.

  4. 19 CFR 143.12 - Form of entry.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Form of entry. 143.12 Section 143.12 Customs... (CONTINUED) SPECIAL ENTRY PROCEDURES Appraisement Entry § 143.12 Form of entry. Application for an entry by appraisement shall be made in triplicate on the entry summary, Customs Form 7501. ...

  5. 19 CFR 143.23 - Form of entry.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Form of entry. 143.23 Section 143.23 Customs... (CONTINUED) SPECIAL ENTRY PROCEDURES Informal Entry § 143.23 Form of entry. Except for the types of... section) and all conditions for free entry are met at the time of entry, which may be released upon the...

  6. Entry, Descent, and Landing technological barriers and crewed MARS vehicle performance analysis

    Science.gov (United States)

    Subrahmanyam, Prabhakar; Rasky, Daniel

    2017-05-01

    Mars has been explored historically only by robotic crafts, but a crewed mission encompasses several new engineering challenges - high ballistic coefficient entry, hypersonic decelerators, guided entry for reaching intended destinations within acceptable margins for error in the landing ellipse, and payload mass are all critical factors for evaluation. A comprehensive EDL parametric analysis has been conducted in support of a high mass landing architecture by evaluating three types of vehicles -70° Sphere Cone, Ellipsled and SpaceX hybrid architecture called Red Dragon as potential candidate options for crewed entry vehicles. Aerocapture at the Martian orbit of about 400 km and subsequent Entry-from-orbit scenarios were investigated at velocities of 6.75 km/s and 4 km/s respectively. A study on aerocapture corridor over a range of entry velocities (6-9 km/s) suggests that a hypersonic L/D of 0.3 is sufficient for a Martian aerocapture. Parametric studies conducted by varying aeroshell diameters from 10 m to 15 m for several entry masses up to 150 mt are summarized and results reveal that vehicles with entry masses in the range of about 40-80 mt are capable of delivering cargo with a mass on the order of 5-20 mt. For vehicles with an entry mass of 20 mt to 80 mt, probabilistic Monte Carlo analysis of 5000 cases for each vehicle were run to determine the final landing ellipse and to quantify the statistical uncertainties associated with the trajectory and attitude conditions during atmospheric entry. Strategies and current technological challenges for a human rated Entry, Descent, and Landing to the Martian surface are presented in this study.

  7. Atmospheric Models for Aeroentry and Aeroassist

    Science.gov (United States)

    Justus, C. G.; Duvall, Aleta; Keller, Vernon W.

    2005-01-01

    Eight destinations in the Solar System have sufficient atmosphere for aeroentry, aeroassist, or aerobraking/aerocapture: Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune, plus Saturn's moon Titan. Engineering-level atmospheric models for Earth, Mars, Titan, and Neptune have been developed for use in NASA's systems analysis studies of aerocapture applications. Development has begun on a similar atmospheric model for Venus. An important capability of these models is simulation of quasi-random perturbations for Monte Carlo analyses in developing guidance, navigation and control algorithms, and for thermal systems design. Characteristics of these atmospheric models are compared, and example applications for aerocapture are presented. Recent Titan atmospheric model updates are discussed, in anticipation of applications for trajectory and atmospheric reconstruct of Huygens Probe entry at Titan. Recent and planned updates to the Mars atmospheric model, in support of future Mars aerocapture systems analysis studies, are also presented.

  8. Automated entry control system for nuclear facilities

    International Nuclear Information System (INIS)

    Ream, W.K.; Espinoza, J.

    1985-01-01

    An entry control system to automatically control access to nuclear facilities is described. The design uses a centrally located console, integrated into the regular security system, to monitor the computer-controlled passage into and out of sensitive areas. Four types of entry control points are used: an unmanned enclosed portal with metal and SNM detectors for contraband detection with positive personnel identification, a bypass portal for contraband search after a contraband alarm in a regular portal also with positive personnel identification, a single door entry point with positive personnel identification, and a single door entry point with only a magnetic card-type identification. Security force action is required only as a response to an alarm. The integration of the entry control function into the security system computer is also described. The interface between the entry control system and the monitoring security personnel utilizing a color graphics display with touch screen input is emphasized. 2 refs., 7 figs

  9. Preventing re-entry to foster care.

    Science.gov (United States)

    Carnochan, Sarah; Rizik-Baer, Daniel; Austin, Michael J

    2013-01-01

    Re-entry to foster care generally refers to circumstances in which children who have been discharged from foster care to be reunified with their family of origin, adopted, or provided kinship guardianship are returned to foster care. In the context of the federal performance measurement system, re-entry refers specifically to a return to foster care following an unsuccessful reunification. The federal Children and Family Services Review measures re-entry to foster care with a single indicator, called the permanency of reunification indicator, one of four indicators comprising the reunification composite measure. This review focuses on research related to the re-entry indicator, including the characteristics of children, caregivers and families, as well as case and child welfare services that are associated with a higher or lower risk of re-entry to foster care. Promising post-reunification services designed to prevent re-entry to foster care are described.

  10. 50 CFR 660.382 - Limited entry fixed gear fishery management measures.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Limited entry fixed gear fishery management measures. 660.382 Section 660.382 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST...

  11. 50 CFR 660.333 - Limited entry fishery-eligibility and registration.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Limited entry fishery-eligibility and registration. 660.333 Section 660.333 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST COAST STATES...

  12. 50 CFR 660.231 - Limited entry fixed gear sablefish primary fishery.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Limited entry fixed gear sablefish primary fishery. 660.231 Section 660.231 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST COAST STATES...

  13. Passivity Analysis for Non-Linear, Non-Stationary Entry Capsules : Rotational Motion

    NARCIS (Netherlands)

    Mooij, E.

    2011-01-01

    To analyze the passivity of non-linear, time-varying systems we study an entry capsule that enters the atmosphere in a lift-down configuration (i.e., a bank angle larger than 90º) to avoid skipping flight, and which is controlled by a Reaction Control System only. Deriving the passivity conditions

  14. Optimal firm growth under the threat of entry

    Science.gov (United States)

    Kort, Peter M.; Wrzaczek, Stefan

    2015-01-01

    The paper studies the incumbent-entrant problem in a fully dynamic setting. We find that under an open-loop information structure the incumbent anticipates entry by overinvesting, whereas in the Markov perfect equilibrium the incumbent slightly underinvests in the period before the entry. The entry cost level where entry accommodation passes into entry deterrence is lower in the Markov perfect equilibrium. Further we find that the incumbent’s capital stock level needed to deter entry is hump shaped as a function of the entry time, whereas the corresponding entry cost, where the entrant is indifferent between entry and non-entry, is U-shaped. PMID:26435573

  15. Optimal firm growth under the threat of entry.

    Science.gov (United States)

    Kort, Peter M; Wrzaczek, Stefan

    2015-10-01

    The paper studies the incumbent-entrant problem in a fully dynamic setting. We find that under an open-loop information structure the incumbent anticipates entry by overinvesting, whereas in the Markov perfect equilibrium the incumbent slightly underinvests in the period before the entry. The entry cost level where entry accommodation passes into entry deterrence is lower in the Markov perfect equilibrium. Further we find that the incumbent's capital stock level needed to deter entry is hump shaped as a function of the entry time, whereas the corresponding entry cost, where the entrant is indifferent between entry and non-entry, is U-shaped.

  16. Atmospheric electricity

    CERN Document Server

    Chalmers, J Alan

    1957-01-01

    Atmospheric Electricity brings together numerous studies on various aspects of atmospheric electricity. This book is composed of 13 chapters that cover the main problems in the field, including the maintenance of the negative charge on the earth and the origin of the charges in thunderstorms. After a brief overview of the historical developments of atmospheric electricity, this book goes on dealing with the general principles, results, methods, and the MKS system of the field. The succeeding chapters are devoted to some aspects of electricity in the atmosphere, such as the occurrence and d

  17. Atmospheric Neutrinos

    Directory of Open Access Journals (Sweden)

    Takaaki Kajita

    2012-01-01

    Full Text Available Atmospheric neutrinos are produced as decay products in hadronic showers resulting from collisions of cosmic rays with nuclei in the atmosphere. Electron-neutrinos and muon-neutrinos are produced mainly by the decay chain of charged pions to muons to electrons. Atmospheric neutrino experiments observed zenith angle and energy-dependent deficit of muon-neutrino events. It was found that neutrino oscillations between muon-neutrinos and tau-neutrinos explain these data well. This paper discusses atmospheric neutrino experiments and the neutrino oscillation studies with these neutrinos.

  18. Chemical inhibitors of the calcium entry channel TRPV6.

    Science.gov (United States)

    Landowski, Christopher P; Bolanz, Katrin A; Suzuki, Yoshiro; Hediger, Matthias A

    2011-02-01

    Calcium entry channels in the plasma membrane are thought to play a major role in maintaining cellular Ca(2+) levels, crucial for growth and survival of normal and cancer cells. The calcium-selective channel TRPV6 is expressed in prostate, breast, and other cancer cells. Its expression coincides with cancer progression, suggesting that it drives cancer cell growth. However, no specific inhibitors for TRPV6 have been identified thus far. To develop specific TRPV6 inhibitors, we synthesized molecules based on the lead compound TH-1177, reported to inhibit calcium entry channels in prostate cancer cells in vitro and in vivo. We found that one of our compounds (#03) selectively inhibited TRPV6 over five times better than TRPV5, whereas TH-1177 and the other synthesized compounds preferentially inhibited TRPV5. The IC(50) value for growth inhibition by blocking endogenous Ca(2+) entry channels in the LNCaP human prostate cancer cell line was 0.44 ± 0.07 μM compared to TH-1177 (50 ± 0.4 μM). These results suggest that compound #03 is a relatively selective and potent inhibitor for TRPV6 and that it is an interesting lead compound for the treatment of prostate cancer and other cancers of epithelial origin.

  19. Energy Information Data Base: corporate author entries

    International Nuclear Information System (INIS)

    1980-06-01

    One of the controls for information entered into the data bases created and maintained by the DOE Technical Information Center is the standardized name for the corporate entity or the corporate author. The purpose of Energy Information Data Base: Corporate Author Entries is to provide a means for the consistent citing of the names of organizations in bibliographic records. These entries serve as guides for users of the DOE/RECON computerized data bases who want to locate information originating in particular organizations. The entries in this revision include the corporate entries used in report bibliographic citations since 1973 and list approximately 28,000 corporate sources

  20. Predicting the Diversity of Foreign Entry Modes

    DEFF Research Database (Denmark)

    Hashai, Niron; Geisler Asmussen, Christian; Benito, Gabriel

    2007-01-01

    This paper expands entry mode literature by referring to multiple modes exerted in different value chain activities within and across host markets, rather than to a single entry mode at the host market level. Scale of operations and knowledge intensity are argued to affect firms' entry mode...... diversity across value chain activities and host markets. Analyzing a sample of Israeli based firms we show that larger firms exhibit a higher degree of entry mode diversity both across value chain activities and across host markets. Higher levels of knowledge intensity are also associated with more...

  1. Gene Therapy Targeting HIV Entry

    Directory of Open Access Journals (Sweden)

    Chuka Didigu

    2014-03-01

    Full Text Available Despite the unquestionable success of antiretroviral therapy (ART in the treatment of HIV infection, the cost, need for daily adherence, and HIV-associated morbidities that persist despite ART all underscore the need to develop a cure for HIV. The cure achieved following an allogeneic hematopoietic stem cell transplant (HSCT using HIV-resistant cells, and more recently, the report of short-term but sustained, ART-free control of HIV replication following allogeneic HSCT, using HIV susceptible cells, have served to both reignite interest in HIV cure research, and suggest potential mechanisms for a cure. In this review, we highlight some of the obstacles facing HIV cure research today, and explore the roles of gene therapy targeting HIV entry, and allogeneic stem cell transplantation in the development of strategies to cure HIV infection.

  2. Shock Radiation Tests for Saturn and Uranus Entry Probes

    Science.gov (United States)

    Cruden, Brett A.; Bogdanoff, David W.

    2017-01-01

    This paper describes a test series in the Electric Arc Shock Tube at NASA Ames Research Center with the objective of quantifying shock-layer radiative heating magnitudes for future probe entries into Saturn and Uranus atmospheres. Normal shock waves are measured in Hydrogen-Helium mixtures (89:11 by volume) at freestream pressures between 13-66 Pa (0.1-0.5 Torr) and velocities from 20-30 kms. No shock layer radiation is detected within measurement limits below 25 kms, a finding consistent with predictions for Uranus entries. Between 25-30 kms, radiance is quantified from the Vacuum Ultraviolet through Near Infrared, with focus on the Lyman-a and Balmer series lines of Hydrogen. Shock profiles are analyzed for electron number density and electronic state distribution. The shocks do not equilibrate over several cm, and in many cases the state distributions are non-Boltzmann. Radiation data are compared to simulations of Decadal Survey entries for Saturn and shown to be as much as 8x lower than predicted with the Boltzmann radiation model. Radiance is observed in front of the shock layer, the characteristics of which match the expected diffusion length.

  3. Border Crossing/Entry Data - Border Crossing/Entry Data Time Series tool

    Data.gov (United States)

    Department of Transportation — The dataset is known as “Border Crossing/Entry Data.” The Bureau of Transportation Statistics (BTS) Border Crossing/Entry Data provides summary statistics to the...

  4. Atmospheric electrodynamics

    International Nuclear Information System (INIS)

    Volland, H.

    1984-01-01

    The book Atmospheric Electrodynamics, by Hans Voland is reviewed. The book describes a wide variety of electrical phenomena occurring in the upper and lower atmosphere and develops the mathematical models which simulate these processes. The reviewer finds that the book is of interest to researchers with a background in electromagnetic theory but is of only limited use as a reference work

  5. Atmospheric Dispositifs

    DEFF Research Database (Denmark)

    Wieczorek, Izabela

    2015-01-01

    , the conceptual foundations and protocols for the production of atmosphere in architecture might be found beneath the surface of contemporary debates. In this context, the notion of atmospheric dispositif – illustrated through an oeuvre of the German architect Werner Ruhnau and its theoretical and historical...

  6. Analytic theory of orbit contraction due to atmospheric drag

    Science.gov (United States)

    Vinh, N. X.; Longuski, J. M.; Busemann, A.; Culp, R. D.

    1979-01-01

    Theory of space vehicle flight in near vacuum and in a planetary atmosphere is unified for the case of a spherically symmetric atmosphere with exponential variation of density with height. Dimensionless equations of motion are established that bridge the gap between satellite theory and entry theory. Integration is done by Poincare's method of perturbations. Solutions for the dimensionless semimajor axis are numerically obtained.

  7. Urban atmospheres.

    Science.gov (United States)

    Gandy, Matthew

    2017-07-01

    What is an urban atmosphere? How can we differentiate an 'atmosphere' from other facets of urban consciousness and experience? This essay explores some of the wider cultural, political, and philosophical connotations of atmospheres as a focal point for critical reflections on space and subjectivity. The idea of an 'affective atmosphere' as a distinctive kind of mood or shared corporeal phenomenon is considered in relation to recent developments in phenomenology, extended conceptions of agency, and new understandings of materialism. The essay draws in particular on the changing characteristics of air and light to reflect on different forms of sensory experience and their wider cultural and political connotations. The argument highlights some of the tensions and anomalies that permeate contemporary understandings of urban atmospheres.

  8. Hayabusa Re-Entry: Trajectory Analysis and Observation Mission Design

    Science.gov (United States)

    Cassell, Alan M.; Winter, Michael W.; Allen, Gary A.; Grinstead, Jay H.; Antimisiaris, Manny E.; Albers, James; Jenniskens, Peter

    2011-01-01

    On June 13th, 2010, the Hayabusa sample return capsule successfully re-entered Earth s atmosphere over the Woomera Prohibited Area in southern Australia in its quest to return fragments from the asteroid 1998 SF36 Itokawa . The sample return capsule entered at a super-orbital velocity of 12.04 km/sec (inertial), making it the second fastest human-made object to traverse the atmosphere. The NASA DC-8 airborne observatory was utilized as an instrument platform to record the luminous portion of the sample return capsule re-entry (60 sec) with a variety of on-board spectroscopic imaging instruments. The predicted sample return capsule s entry state information at 200 km altitude was propagated through the atmosphere to generate aerothermodynamic and trajectory data used for initial observation flight path design and planning. The DC- 8 flight path was designed by considering safety, optimal sample return capsule viewing geometry and aircraft capabilities in concert with key aerothermodynamic events along the predicted trajectory. Subsequent entry state vector updates provided by the Deep Space Network team at NASA s Jet Propulsion Laboratory were analyzed after the planned trajectory correction maneuvers to further refine the DC-8 observation flight path. Primary and alternate observation flight paths were generated during the mission planning phase which required coordination with Australian authorities for pre-mission approval. The final observation flight path was chosen based upon trade-offs between optimal viewing requirements, ground based observer locations (to facilitate post-flight trajectory reconstruction), predicted weather in the Woomera Prohibited Area and constraints imposed by flight path filing deadlines. To facilitate sample return capsule tracking by the instrument operators, a series of two racetrack flight path patterns were performed prior to the observation leg so the instruments could be pointed towards the region in the star background where

  9. 76 FR 82315 - Agency Information Collection Activities: Entry/Immediate Delivery Application and Simplified Entry

    Science.gov (United States)

    2011-12-30

    ... SECURITY U.S. Customs and Border Protection Agency Information Collection Activities: Entry/Immediate Delivery Application and Simplified Entry AGENCY: U.S. Customs and Border Protection, Department of... Budget (OMB) for review and approval in accordance with the Paperwork Reduction Act: Entry/Immediate...

  10. Energy Data Base: corporate author entries

    International Nuclear Information System (INIS)

    Hendricks, P.L.

    1982-08-01

    Corporate author entries provide a means for consistent citing of the names of organizations in bibliographic records in the data bases of the DOE Technical Information Center. These entries serve as guides for users of the DOE/RECON computerized data bases who want to locate information originating in particular organizations

  11. Entry and Competition in Differentiated Products Markets

    NARCIS (Netherlands)

    Schaumans, C.B.C.; Verboven, F.L.

    2011-01-01

    We propose a methodology for estimating the competition effects from entry when firms sell differentiated products. We first derive precise conditions under which Bres- nahan and Reiss'entry threshold ratios (ETRs) can be used to test for the presence and to measure the magnitude of competition

  12. 32 CFR 245.27 - Data entry.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Data entry. 245.27 Section 245.27 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY OF DEFENSE (CONTINUED) MISCELLANEOUS... Under ESCAT § 245.27 Data entry. Aircraft will file IFR or VFR flight plans, assigned a discrete...

  13. On Entry Deterrence and Imperfectly Observable Commitment

    DEFF Research Database (Denmark)

    Poulsen, Anders

    2001-01-01

    We analyse a simple entry-deterrence game, where a `Potential Intruder' only imperfectly observes the decision of an `Incumbent' to commit or to not commit to fight any entry by the Potential Intruder. Our game generalises the one studied in Bonanno (1992) by allowing for a richer information...

  14. 21 CFR 1316.05 - Entry.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Entry. 1316.05 Section 1316.05 Food and Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE ADMINISTRATIVE FUNCTIONS, PRACTICES, AND PROCEDURES Administrative Inspections § 1316.05 Entry. An inspection shall be carried out by an inspector. Any such...

  15. 46 CFR 197.482 - Logbook entries.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Logbook entries. 197.482 Section 197.482 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE OCCUPATIONAL SAFETY AND HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations Records § 197.482 Logbook entries. (a) The person-in...

  16. Adaptive Text Entry for Mobile Devices

    DEFF Research Database (Denmark)

    Proschowsky, Morten Smidt

    The reduced size of many mobile devices makes it difficult to enter text with them. The text entry methods are often slow or complicated to use. This affects the performance and user experience of all applications and services on the device. This work introduces new easy-to-use text entry methods...... for mobile devices and a framework for adaptive context-aware language models. Based on analysis of current text entry methods, the requirements to the new text entry methods are established. Transparent User guided Prediction (TUP) is a text entry method for devices with one dimensional touch input. It can...... be touch sensitive wheels, sliders or similar input devices. The interaction design of TUP is done with a combination of high level task models and low level models of human motor behaviour. Three prototypes of TUP are designed and evaluated by more than 30 users. Observations from the evaluations are used...

  17. Atmospheric Chemistry of Micrometeoritic Organic Compounds

    Science.gov (United States)

    Kress, M. E.; Belle, C. L.; Pevyhouse, A. R.; Iraci, L. T.

    2011-01-01

    Micrometeorites approx.100 m in diameter deliver most of the Earth s annual accumulation of extraterrestrial material. These small particles are so strongly heated upon atmospheric entry that most of their volatile content is vaporized. Here we present preliminary results from two sets of experiments to investigate the fate of the organic fraction of micrometeorites. In the first set of experiments, 300 m particles of a CM carbonaceous chondrite were subject to flash pyrolysis, simulating atmospheric entry. In addition to CO and CO2, many organic compounds were released, including functionalized benzenes, hydrocarbons, and small polycyclic aromatic hydrocarbons. In the second set of experiments, we subjected two of these compounds to conditions that simulate the heterogeneous chemistry of Earth s upper atmosphere. We find evidence that meteor-derived compounds can follow reaction pathways leading to the formation of more complex organic compounds.

  18. 19 CFR 142.16 - Entry summary documentation.

    Science.gov (United States)

    2010-04-01

    ... documentation, one copy of the entry document and the commercial invoice, or the documentation filed in place of... 19 Customs Duties 2 2010-04-01 2010-04-01 false Entry summary documentation. 142.16 Section 142.16... TREASURY (CONTINUED) ENTRY PROCESS Entry Summary Documentation § 142.16 Entry summary documentation. (a...

  19. 19 CFR 144.11 - Form of entry.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Form of entry. 144.11 Section 144.11 Customs... (CONTINUED) WAREHOUSE AND REWAREHOUSE ENTRIES AND WITHDRAWALS Requirements and Procedures for Warehouse Entry § 144.11 Form of entry. (a) Entry. The documentation required by § 142.3 of this chapter shall be filed...

  20. 19 CFR 142.2 - Time for filing entry.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Time for filing entry. 142.2 Section 142.2 Customs... (CONTINUED) ENTRY PROCESS Entry Documentation § 142.2 Time for filing entry. (a) General rule: After arrival of merchandise. Merchandise for which entry is required will be entered within 15 calendar days after...

  1. Ensuring survival.

    Science.gov (United States)

    Sadik, N

    1992-12-01

    The global population growth rate has been 1.7% since 1975, while for developing countries it is 2.1%. UN projections are for population to grow from 5.5 billion in 1992 to 10 billion by 2050. Sustainable development is only possible when population growth is balanced with available resources. UN medium population projections of 7.8 billion by 2050 can be reached with 187 million more couples practicing family planning (FP) by the year 2000. Within the past 20 years, 1 billion people, mostly from developed countries, have enjoyed economic growth, but have contributed polluting technologies, excessive waste, and environmentally dangerous economic practices. The generations to come will be affected by the continuance of these practices by the 1 billion affluent population. The bottom billion are mired in poverty and high population growth and survival, needs that hinder their country's economic development, upset fragile ecosystems, and destroy the balance between human beings and the environment. International migration on a large scale could be the by-product of population growth. Progress has been made since the 1974 UN Conference on Population in Bucharest. There are still, however, vulnerable populations, the poorest households, the landless and small-holder families, urban squatters and slum dwellers, those living in low lying deltas and along coasts, and women. Women control family resources and their micro environment. Sustainable development is not possible without the elimination of prejudice against women. Reproductive freedom for women must be a priority. High quality, readily available FP services are also needed for those desiring this. The difficulty is in providing FP services that conform to a woman's social and cultural background and personal needs; success is dependent on involving women in the process and holding men more responsible for FP. Development means allowing for the legitimate aspirations of the majority not just the specialized

  2. Facilitation of school re-entry and peer acceptance of children with cancer

    DEFF Research Database (Denmark)

    Helms, A. S.; Schmiegelow, K.; Brok, J.

    2016-01-01

    reviewed using the PRISMA model for reporting reviews. Statistical calculations for the meta-analyses were done using Review Manager 5.2. The metaanalyses showed significant effects of school re-entry programmes in terms of enhancing academic achievement in children with cancer (P = 0.008) and lowering......Increased survival rates from childhood cancer call for efforts to reintegrate children with cancer back into their academic and social environments. The aims of this study were to: (1) review and analyse the existing literature on school re-entry interventions for children with cancer; and (2...

  3. Effects of wall roughness and entry length on void profile in vertical bubbly flow

    International Nuclear Information System (INIS)

    Takamasa, Tomoji

    1988-01-01

    An experimental study of upward air-water bubbly two-phase flow in an entry region was performed with various rough wall test tubes. The objective of the work is to clarify the effects of wall roughness and entry length on void profile. The fluid flows in the vertical circular test tube of 25 mm I.D. under nearly atmospheric pressure, at room temperature. The void profile changes from a pattern similar in appearance to the saddle shape which has local void peaks near the wall, into the power law shape whose curve is approximated by a power law formula, with increasing wall roughness and/or entry length. That is, wall roughness and entry length have a similar effect upon void profile. There are two patterns in the power law shape, a pattern with sharp center peak and a pattern with obtuse center peak. As wall roughness and/or entry length increase, the void profile changes from the former pattern to the latter pattern. At enough long entry length (L/D ≅ 150), every void profile has almost the same power law shape independent of wall roughness. Some void profiles are asymmetric to the axis. (author)

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

    Science.gov (United States)

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

    2016-01-01

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

  5. Space Science in Action: Earth's Atmosphere [Videotape].

    Science.gov (United States)

    1999

    In this videotape recording, students learn about the layers of the atmosphere and why each is important to the survival of life on the planet. Students discover why the atmosphere is responsible for weather and see how special aircraft actually fly into hurricanes. Students build their own working barometer in a hands-on activity. Contents…

  6. Physical security workshop summary: entry control

    International Nuclear Information System (INIS)

    Eaton, M.J.

    1982-01-01

    Entry control hardware has been used extensively in the past to assist security forces in separating the authorized from the unauthorized at the plant perimeter. As more attention is being focused on the insider threat, these entry control elements are being used to extend the security inspectors' presence into the plant by compartmentalizing access and monitoring vital components. This paper summarizes the experiences expressed by the participants at the March 16 to 19, 1982 INMM Physical Protection Workshop in utilizing access control and contraband detection hardware for plant wide entry control applications

  7. Foreign Entry and Heterogeneous Growth of Firms

    DEFF Research Database (Denmark)

    Deng, Paul Duo; Jefferson, Gary H.

    We adopt the framework of Schumpeterian creative destruction formalized by Aghion et al. (2009) to analyze the impact of foreign entry on the productivity growth of domestic firms. In the face of foreign entry, domestic firms exhibit heterogeneous patterns of growth depending on their technological...... distance from foreign firms. Domestic firms with smaller technological distance from their foreign counterparts tend to experience faster productivity growth, while firms with larger technological distance tend to lag further behind. We test this hypothesis using a unique firm-level data of Chinese...... manufacturing. Our empirical results confirm that foreign entry indeed generates strong heterogeneous growth patterns among domestic firms....

  8. Structures and Mechanisms Design Concepts for Adaptive Deployable Entry Placement Technology

    Science.gov (United States)

    Yount, Bryan C.; Arnold, James O.; Gage, Peter J.; Mockelman, Jeffrey; Venkatapathy, Ethiraj

    2012-01-01

    System studies have shown that large deployable aerodynamic decelerators such as the Adaptive Deployable Entry and Placement Technology (ADEPT) concept can revolutionize future robotic and human exploration missions involving atmospheric entry, descent and landing by significantly reducing the maximum heating rate, total heat load, and deceleration loads experienced by the spacecraft during entry [1-3]. ADEPT and the Hypersonic Inflatable Aerodynamic Decelerator (HIAD) [4] share the approach of stowing the entry system in the shroud of the launch vehicle and deploying it to a much larger diameter prior to entry. The ADEPT concept provides a low ballistic coefficient for planetary entry by employing an umbrella-like deployable structure consisting of ribs, struts and a fabric cover that form an aerodynamic decelerator capable of undergoing hypersonic flight. The ADEPT "skin" is a 3-D woven carbon cloth that serves as a thermal protection system (TPS) and as a structural surface that transfers aerodynamic forces to the underlying ribs [5]. This paper focuses on design activities associated with integrating ADEPT components (cloth, ribs, struts and mechanisms) into a system that can function across all configurations and environments of a typical mission concept: stowed during launch, in-space deployment, entry, descent, parachute deployment and separation from the landing payload. The baseline structures and mechanisms were selected via trade studies conducted during the summer and fall of 2012. They are now being incorporated into the design of a ground test article (GTA) that will be fabricated in 2013. It will be used to evaluate retention of the stowed configuration in a launch environment, mechanism operation for release, deployment and locking, and static strength of the deployed decelerator. Of particular interest are the carbon cloth interfaces, underlying hot structure, (Advanced Carbon- Carbon ribs) and other structural components (nose cap, struts, and

  9. Atmospheric Photochemistry

    Science.gov (United States)

    Massey, Harrie; Potter, A. E.

    1961-01-01

    The upper atmosphere offers a vast photochemical laboratory free from solid surfaces, so all reactions take place in the gaseous phase. At 30 km altitude the pressure has fallen to about one-hundredth of that at ground level, and we shall, rather arbitrarily, regard the upper atmosphere as beginning at that height. By a little less than 100 km the pressure has fallen to 10(exp -3) mm Hg and is decreasing by a power of ten for every 15 km increase in altitude. Essentially we are concerned then with the photochemistry of a nitrogen-oxygen mixture under low-pressure conditions in which photo-ionization, as well as photodissociation, plays an important part. Account must also be taken of the presence of rare constituents, such as water vapour and its decomposition products, including particularly hydroxyl, oxides of carbon, methane and, strangely enough, sodium, lithium and calcium. Many curious and unfamiliar reactions occur in the upper atmosphere. Some of them are luminescent, causing the atmosphere to emit a dim light called the airglow. Others, between gaseous ions and neutral molecules, are almost a complete mystery at this time. Similar interesting phenomena must occur in other planetary atmospheres, and they might be predicted if sufficient chemical information were available.

  10. Energy Information Data Base: corporate author entries

    International Nuclear Information System (INIS)

    1980-03-01

    One of the controls for information entered into the data bases created and maintained by the DOE Technical Information Center is the standardized name for the corporate entity or the corporate author. The purpose of Energy Information Data Base: Corporate Author Entries (TID-4585-R1) and this supplemental list of authorized or standardized corporate entries is to provide a means for the consistent citing of the names of organizations in bibliographic records. In general, an entry in Corporate Author Entries consists of the seven-digit code number assigned to the particular corporate entity, the two-letter country code, the largest element of the corporate name, the location of the corporate entity, and the smallest element of the corporate name (if provided). This supplement [DOE/TIC-4585-R1(Suppl.5)] contains additions to the base document (TID-4585-R1) and is intended to be used with that publication

  11. Tactile Data Entry System, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Building on our successful Phase I Tactile Data Entry program, Barron Associates proposes development of a Glove-Enabled Computer Operations (GECO) system to permit...

  12. Border Crossing/Entry Data - Boarder Crossing

    Data.gov (United States)

    Department of Transportation — Border Crossing/Entry Data provides summary statistics for incoming crossings at the U.S.-Canadian and the U.S.-Mexican border at the port level. Data are available...

  13. Market entry strategies into the BRIC countries

    DEFF Research Database (Denmark)

    Boyd, Britta; Dyhr Ulrich, Anna Marie

    2014-01-01

    Based on a sample of 177 exporting SMEs, this study investigates what market entry strategy is used by Danish family and non-family businesses. From a resource-based view, three critical internal factors (risk, flexibility and control) affecting the entry mode choice into the BRIC markets...... compared to non-family firms. Furthermore, the Danish exporters regarded China as being the most established of the four BRIC markets which could be seen in their willingness to use high control entry modes in China. Finally, non-family firms are more concerned about higher flexibility and lower control...... when entering the BRIC markets. In contrast, family firms choose high commitment entry modes which involve high risk and low flexibility when entering the BRIC markets. Further implications discuss the suitability of export strategies to BRIC markets for managers of Danish family and non-family firms....

  14. Delayed Entry Program Attrition: A Multivariate Analysis

    National Research Council Canada - National Science Library

    Ogren, Margery

    1999-01-01

    This thesis uses binary logit models to examine the effects of personal background characteristics and local area economic conditions on an individual's likelihood to leave the Delayed Entry Program (DEP...

  15. The Effects of Entry in Bilateral Oligopoly

    Directory of Open Access Journals (Sweden)

    Alex Dickson

    2013-06-01

    Full Text Available The purpose of this paper is to study the effects of entry into the market for a single commodity in which both sellers and buyers are permitted to interact strategically. With the inclusion of an additional seller, the market is quasi-competitive: the price falls and volume of trade increases, as expected. However, contrary to the conventional wisdom, existing sellers’ payoffs may increase. The conditions under which entry by new sellers raises the equilibrium payoffs of existing sellers are derived. These depend in an intuitive way on the elasticity of a strategic analog of demand and the market share of existing sellers, and encompass entirely standard economic environments. Similar results are derived relating to the entry of additional buyers and the effects of entry on both sides of the market are investigated.

  16. Atmospheric thermodynamics

    CERN Document Server

    Iribarne, J V

    1973-01-01

    The thermodynamics of the atmosphere is the subject of several chapters in most textbooks on dynamic meteorology, but there is no work in English to give the subject a specific and more extensive treatment. In writing the present textbook, we have tried to fill this rather remarkable gap in the literature related to atmospheric sciences. Our aim has been to provide students of meteorology with a book that can playa role similar to the textbooks on chemical thermodynamics for the chemists. This implies a previous knowledge of general thermodynamics, such as students acquire in general physics courses; therefore, although the basic principles are reviewed (in the first four chapters), they are only briefly discussed, and emphasis is laid on those topics that will be useful in later chapters, through their application to atmospheric problems. No attempt has been made to introduce the thermodynamics of irreversible processes; on the other hand, consideration of heterogeneous and open homogeneous systems permits a...

  17. Developing Quantitative Models for Auditing Journal Entries

    OpenAIRE

    Argyrou, Argyris

    2013-01-01

    The thesis examines how the auditing of journal entries can detect and prevent financial statement fraud. Financial statement fraud occurs when an intentional act causes financial statements to be materially misstated. Although it is not a new phenomenon, financial statement fraud has attracted much publicity in the wake of numerous cases of financial malfeasance (e.g. ENRON, WorldCom). Existing literature has provided limited empirical evidence on the link between auditing journal entrie...

  18. Advanced Restricted Area Entry Control System (ARAECS)

    OpenAIRE

    Appleton, Robert; Casillas, Jose; Scales, Gregory; Green, Robert; Niehoff, Mellissa; Fitzgerald, David; Ouellette, David

    2014-01-01

    Approved for public release; distribution is unlimited The Navy requires a capability for effective and efficient entry control for restricted areas that house critical assets. This thesis describes an Advanced Restricted Area Entry Control System (ARAECS) to meet this requirement. System requirements were obtained from existing governing documentation as well as stakeholder inputs. A functional architecture was developed and then modeled using the Imagine That Inc. ExtendSim tool. Factors...

  19. Entry and exit decisions under uncertainty

    DEFF Research Database (Denmark)

    Kongsted, Hans Christian

    1996-01-01

    This paper establishes the general deterministic limit that corresponds to Dixit's model of entry and exit decisions under uncertainty. The interlinked nature of decisions is shown to be essential also in the deterministic limit. A numerical example illustrates the result......This paper establishes the general deterministic limit that corresponds to Dixit's model of entry and exit decisions under uncertainty. The interlinked nature of decisions is shown to be essential also in the deterministic limit. A numerical example illustrates the result...

  20. Nipah virus entry can occur by macropinocytosis

    International Nuclear Information System (INIS)

    Pernet, Olivier; Pohl, Christine; Ainouze, Michelle; Kweder, Hasan; Buckland, Robin

    2009-01-01

    Nipah virus (NiV) is a zoonotic biosafety level 4 paramyxovirus that emerged recently in Asia with high mortality in man. NiV is a member, with Hendra virus (HeV), of the Henipavirus genus in the Paramyxoviridae family. Although NiV entry, like that of other paramyxoviruses, is believed to occur via pH-independent fusion with the host cell's plasma membrane we present evidence that entry can occur by an endocytic pathway. The NiV receptor ephrinB2 has receptor kinase activity and we find that ephrinB2's cytoplasmic domain is required for entry but is dispensable for post-entry viral spread. The mutation of a single tyrosine residue (Y304F) in ephrinB2's cytoplasmic tail abrogates NiV entry. Moreover, our results show that NiV entry is inhibited by constructions and drugs specific for the endocytic pathway of macropinocytosis. Our findings could potentially permit the rapid development of novel low-cost antiviral treatments not only for NiV but also HeV.

  1. Models of radon entry: A review

    International Nuclear Information System (INIS)

    Gadgil, A.J.

    1991-08-01

    This paper reviews existing models of radon entry into houses. The primary mechanism of radon entry in houses with high indoor concentrations is, in most cases, convective entry of radon bearing soil-gas from the surrounding soil. The driving force for this convective entry is the small indoor-outdoor pressure difference arising from the stack effect and other causes. Entry points for the soil-gas generally are the cracks or gaps in the building substructure, or though other parts of the building shell in direct contact with the soil, although entry may also occur by flow though permeable concrete or cinder block walls of the substructure. Models using analytical solutions to idealized geometrical configurations with simplified boundary conditions obtain analytical tractability of equations to be solved at the cost of severe approximations; their strength is in the insights they offer with their solutions. Models based on lumped parameters attempt to characterize the significant physical behavioral characteristics of the soil-gas and radon flow. When realistic approximations are desired for the boundary conditions and terms in the governing equations, numerical models must be used; these are usually based on finite difference or finite element solutions to the governing equations. Limited data are now available for experimental verification of model predictions. The models are briefly reviewed and their strengths and limitations are discussed

  2. Mars 2020 Entry, Descent and Landing Instrumentation (MEDLI2)

    Science.gov (United States)

    Bose, Deepak; Wright, Henry; White, Todd; Schoenenberger, Mark; Santos, Jose; Karlgaard, Chris; Kuhl, Chris; Oishi, TOmo; Trombetta, Dominic

    2016-01-01

    This paper will introduce Mars Entry Descent and Landing Instrumentation (MEDLI2) on NASA's Mars2020 mission. Mars2020 is a flagship NASA mission with science and technology objectives to help answer questions about possibility of life on Mars as well as to demonstrate technologies for future human expedition. Mars2020 is scheduled for launch in 2020. MEDLI2 is a suite of instruments embedded in the heatshield and backshell thermal protection systems of Mars2020 entry vehicle. The objectives of MEDLI2 are to gather critical aerodynamics, aerothermodynamics and TPS performance data during EDL phase of the mission. MEDLI2 builds up the success of MEDLI flight instrumentation on Mars Science Laboratory mission in 2012. MEDLI instrumentation suite measured surface pressure and TPS temperature on the heatshield during MSL entry into Mars. MEDLI data has since been used for unprecedented reconstruction of aerodynamic drag, vehicle attitude, in-situ atmospheric density, aerothermal heating, transition to turbulence, in-depth TPS performance and TPS ablation. [1,2] In addition to validating predictive models, MEDLI data has highlighted extra margin available in the MSL forebody TPS, which can potentially be used to reduce vehicle parasitic mass. MEDLI2 expands the scope of instrumentation by focusing on quantities of interest not addressed in MEDLI suite. The type the sensors are expanded and their layout on the TPS modified to meet these new objectives. The paper will provide key motivation and governing requirements that drive the choice and the implementation of the new sensor suite. The implementation considerations of sensor selection, qualification, and demonstration of minimal risk to the host mission will be described. The additional challenges associated with mechanical accommodation, electrical impact, data storage and retrieval for MEDLI2 system, which extends sensors to backshell will also be described.

  3. Sensitivity of Asteroid Impact Risk to Uncertainty in Asteroid Properties and Entry Parameters

    Science.gov (United States)

    Wheeler, Lorien; Mathias, Donovan; Dotson, Jessie L.; NASA Asteroid Threat Assessment Project

    2017-10-01

    A central challenge in assessing the threat posed by asteroids striking Earth is the large amount of uncertainty inherent throughout all aspects of the problem. Many asteroid properties are not well characterized and can range widely from strong, dense, monolithic irons to loosely bound, highly porous rubble piles. Even for an object of known properties, the specific entry velocity, angle, and impact location can swing the potential consequence from no damage to causing millions of casualties. Due to the extreme rarity of large asteroid strikes, there are also large uncertainties in how different types of asteroids will interact with the atmosphere during entry, how readily they may break up or ablate, and how much surface damage will be caused by the resulting airbursts or impacts.In this work, we use our Probabilistic Asteroid Impact Risk (PAIR) model to investigate the sensitivity of asteroid impact damage to uncertainties in key asteroid properties, entry parameters, or modeling assumptions. The PAIR model combines physics-based analytic models of asteroid entry and damage in a probabilistic Monte Carlo framework to assess the risk posed by a wide range of potential impacts. The model samples from uncertainty distributions of asteroid properties and entry parameters to generate millions of specific impact cases, and models the atmospheric entry and damage for each case, including blast overpressure, thermal radiation, tsunami inundation, and global effects. To assess the risk sensitivity, we alternately fix and vary the different input parameters and compare the effect on the resulting range of damage produced. The goal of these studies is to help guide future efforts in asteroid characterization and model refinement by determining which properties most significantly affect the potential risk.

  4. Terminal altitude maximization for Mars entry considering uncertainties

    Science.gov (United States)

    Cui, Pingyuan; Zhao, Zeduan; Yu, Zhengshi; Dai, Juan

    2018-04-01

    Uncertainties present in the Mars atmospheric entry process may cause state deviations from the nominal designed values, which will lead to unexpected performance degradation if the trajectory is designed merely based on the deterministic dynamic model. In this paper, a linear covariance based entry trajectory optimization method is proposed considering the uncertainties presenting in the initial states and parameters. By extending the elements of the state covariance matrix as augmented states, the statistical behavior of the trajectory is captured to reformulate the performance metrics and path constraints. The optimization problem is solved by the GPOPS-II toolbox in MATLAB environment. Monte Carlo simulations are also conducted to demonstrate the capability of the proposed method. Primary trading performances between the nominal deployment altitude and its dispersion can be observed by modulating the weights on the dispersion penalty, and a compromised result referring to maximizing the 3σ lower bound of the terminal altitude is achieved. The resulting path constraints also show better satisfaction in a disturbed environment compared with the nominal situation.

  5. Medical student satisfaction, coping and burnout in direct-entry versus graduate-entry programmes.

    Science.gov (United States)

    DeWitt, Dawn; Canny, Benedict J; Nitzberg, Michael; Choudri, Jennifer; Porter, Sarah

    2016-06-01

    There is ongoing debate regarding the optimal length of medical training, with concern about the cost of prolonged training. Two simultaneous tracks currently exist in Australia: direct entry from high school and graduate entry for students with a bachelor degree. Medical schools are switching to graduate entry based on maturity, academic preparedness and career-choice surety. We tested the assumption that graduate entry is better by exploring student preferences, coping, burnout, empathy and alcohol use. From a potential pool of 2188 participants, enrolled at five Australian medical schools, a convenience sample of 688 (31%) first and second year students completed a survey in the middle of the academic year. Participants answered questions about demographics, satisfaction and coping and completed three validated instruments. Over 90% of students preferred their own entry-type, though more graduate-entry students were satisfied with their programme (82.4% versus 65.3%, p students in self-reported coping or in the proportion of students meeting criteria for burnout (50.7% versus 51.2%). Direct-entry students rated significantly higher for empathy (concern, p = 0.022; personal distress, p = 0.031). Graduate-entry students reported significantly more alcohol use and hazardous drinking (30.0% versus 22.8%; p = 0.017). Our multi-institution data confirm that students are generally satisfied with their choice of entry pathway and do not confirm significant psychosocial benefits of graduate entry. Overall, our data suggest that direct-entry students cope with the workload and psychosocial challenges of medical school, in the first 2 years, as well as graduate-entry students. Burnout and alcohol use should be addressed in both pathways. Despite studies showing similar academic outcomes, and higher total costs, more programmes in Australia are becoming graduate entry. Further research on non-cognitive issues and outcomes is needed so that universities, government

  6. marine survival ecosystem indicators - Estimating the ecosystem indicators of anadromous salmonids in the Puget Sound region

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The objective of this project is to develop a simple approach for estimating the marine survival and causes of trends in survival. Data is a summary of ecosystem...

  7. Auditor human capital and audit firm survival - The Dutch audit industry in 1930-1992

    NARCIS (Netherlands)

    Brocheler, [No Value; Maijoor, S; van Witteloostuijn, A; Bröcheler, V.

    2004-01-01

    This paper studies the relationship between auditor human capital and audit firm survival. Specifically, the effects are investigated of the human capital of auditors on the survival chances of newly established audit firms. Human capital is analyzed both at the time of entry of a new audit firm and

  8. 19 CFR 141.52 - Separate entries for different portions.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Separate entries for different portions. 141.52... Entry § 141.52 Separate entries for different portions. If the port director is satisfied that there... conduct of Customs business, separate entries may be made for different portions of all merchandise...

  9. 50 CFR 26.22 - General exception for entry.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false General exception for entry. 26.22 Section... (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM PUBLIC ENTRY AND USE Public Entry § 26.22 General exception for entry. (a) Any person entering or using any national wildlife refuge will comply with the...

  10. 19 CFR 143.25 - Information on entry form.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Information on entry form. 143.25 Section 143.25 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) SPECIAL ENTRY PROCEDURES Informal Entry § 143.25 Information on entry form. Each...

  11. 19 CFR 141.5 - Time limit for entry.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Time limit for entry. 141.5 Section 141.5 Customs... (CONTINUED) ENTRY OF MERCHANDISE Liability for Duties and Requirement To Enter Merchandise § 141.5 Time limit for entry. Merchandise for which entry is required will be entered within 15 calendar days after...

  12. 30 CFR 877.11 - Written consent for entry.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Written consent for entry. 877.11 Section 877... ABANDONED MINE LAND RECLAMATION RIGHTS OF ENTRY § 877.11 Written consent for entry. Written consent from the... to enter lands in order to carry out reclamation activities. Nonconsensual entry by exercise of the...

  13. 50 CFR 91.16 - Submission procedures for entry.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Submission procedures for entry. 91.16... Entering the Contest § 91.16 Submission procedures for entry. (a) Each contestant may submit only one entry. Each entry must be accompanied by a non-refundable entrance fee and a completed and signed Reproduction...

  14. 19 CFR 145.24 - Amendment of entry.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Amendment of entry. 145.24 Section 145.24 Customs... (CONTINUED) MAIL IMPORTATIONS Administrative Review of Mail Entries § 145.24 Amendment of entry. If the port director is satisfied that the objection is valid and timely, he shall amend the mail entry. If the duty...

  15. The Mars Science Laboratory (MSL) Entry, Descent And Landing Instrumentation (MEDLI): Hardware Performance and Data Reconstruction

    Science.gov (United States)

    Little, Alan; Bose, Deepak; Karlgaard, Chris; Munk, Michelle; Kuhl, Chris; Schoenenberger, Mark; Antill, Chuck; Verhappen, Ron; Kutty, Prasad; White, Todd

    2013-01-01

    The Mars Science Laboratory (MSL) Entry, Descent and Landing Instrumentation (MEDLI) hardware was a first-of-its-kind sensor system that gathered temperature and pressure readings on the MSL heatshield during Mars entry on August 6, 2012. MEDLI began as challenging instrumentation problem, and has been a model of collaboration across multiple NASA organizations. After the culmination of almost 6 years of effort, the sensors performed extremely well, collecting data from before atmospheric interface through parachute deploy. This paper will summarize the history of the MEDLI project and hardware development, including key lessons learned that can apply to future instrumentation efforts. MEDLI returned an unprecedented amount of high-quality engineering data from a Mars entry vehicle. We will present the performance of the 3 sensor types: pressure, temperature, and isotherm tracking, as well as the performance of the custom-built sensor support electronics. A key component throughout the MEDLI project has been the ground testing and analysis effort required to understand the returned flight data. Although data analysis is ongoing through 2013, this paper will reveal some of the early findings on the aerothermodynamic environment that MSL encountered at Mars, the response of the heatshield material to that heating environment, and the aerodynamic performance of the entry vehicle. The MEDLI data results promise to challenge our engineering assumptions and revolutionize the way we account for margins in entry vehicle design.

  16. Atmospheric monitoring

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    Radioactivity in air was measured by a network of continuously operating air samplers at nineteen locations near the Site perimeter and five locations somewhat distant from the Site. The Site perimeter samplers provided for general coverage in all directions but with emphasis in the prevalent downwind directions to the south and east of the Site including the communities of Benton City, Richland, Pasco, Connell, and Othello. The distant air sample locations provided background airborne radioactivity data for comparison. These samplers were located at Sunnyside, Moses Lake, Washtucna, Walla Walla, and at McNary Dam. Airborne radionuclide concentrations during 1982 were lower than those observed in 1981 because of the gradual decline of atmospheric fallout associated with a foreign atmospheric nuclear test that occurred in the fall of 1980. Airborne radioactivity data collected during 1982 did not indicate the presence of detectable levels of Hanford origin radionuclides in the offsite environs

  17. Atmospheric materiality

    DEFF Research Database (Denmark)

    Wieczorek, Izabela

    2016-01-01

    A disjunction between the material and the immaterial has been at the heart of the architectural debate for decades. In this dialectic tension, the notion of atmosphere which increasingly claims attention in architectural discourse seems to be parallactic, leading to the re-evaluation of perceptual...... experience and, consequently, to the conceptual and methodological shifts in the production of space, and hence in the way we think about materiality. In this context, architectural space is understood as a contingent construction – a space of engagement that appears to us as a result of continuous...... and complex interferences revealed through our perception; ‘the atmospheric’ is explored as a spatial and affective quality as well as a sensory background, and materiality as a powerful and almost magical agency in shaping of atmosphere. Challenging existing dichotomies and unraveling intrinsic...

  18. Impact of the entry site on late outcome in acute Stanford type B aortic dissection†.

    Science.gov (United States)

    Kitamura, Tadashi; Torii, Shinzo; Oka, Norihiko; Horai, Tetsuya; Itatani, Keiichi; Yoshii, Takeshi; Nakamura, Yuki; Shibata, Miyuki; Tamura, Tomoki; Araki, Haruna; Matsunaga, Yoshikiyo; Sato, Hajime; Miyaji, Kagami

    2015-11-01

    This study aimed to investigate whether the entry site of acute type B aortic dissection affects late outcomes. Inpatient and outpatient records were retrospectively reviewed. We identified 224 cases of acute type B aortic dissection between 1998 and 2013. Of these 224 patients, 168 were men and the age was 64.2 ± 12.6 (range 23-94) years, from which 130 presented with the entry at a location downstream of the distal aortic arch, 67 with the entry at the outer curvature of the distal aortic arch and 27 with the entry at the inner curvature. At the initial presentation, 127 patients had descending false lumen thrombosis. The 30-day mortality rate was 2%, and 8% of patients had malperfusion. The entry at the outer curvature was associated with a higher risk of 30-day mortality. Patients with the entry at a location downstream were significantly older, and had a higher chance for primarily thrombosed descending false lumen and a lower risk of malperfusion. At follow-up (6.0 ± 4.1 years), the actuarial survival rates were 97, 83 and 60%, freedoms from open aortic surgery were 96, 91 and 86%, aortic intervention were 73, 66 and 63% and aortic events were 71, 60 and 52% at 1, 5 and 10 years, respectively. Multivariate logistic regression analysis revealed that the outer curvature entry and maximum aortic diameter were correlated with open aortic surgery, aortic intervention and aortic events. Of the 127 patients with primarily thrombosed false lumen, the outer curvature entry was significantly correlated with aortic events. The primary entry at the outer curvature of the distal aortic arch, as well as the large aortic diameter, is associated with a higher risk of late open aortic surgery, aortic intervention and aortic events in acute type B aortic dissection. Thus, the entry site should be taken into consideration in the establishment of an appropriate treatment indication of type B aortic dissection. © The Author 2015. Published by Oxford University Press on behalf

  19. Entry into first marriage in China

    Directory of Open Access Journals (Sweden)

    Li Ma

    2017-10-01

    Full Text Available Background: China has experienced substantial socioeconomic and institutional changes over the past few decades. The literature has documented a variety of demographic changes during this time, including the delay and decline of marriage and the recent prevalence of cohabitation. However, we have little knowledge about how the Chinese enter into marriage. Objective: This study demonstrates the diversification of first marriage entry over time. Methods: We applied event-history analysis to longitudinal data from the China Family Panel Studies (2010-2012 waves and estimated the competing risks of the identified marriage entry types. The observation covered the period from 1960 to 2012. Results: Our estimations from the competing models demonstrated four notable types of first marriage entry, including a general decline in the traditional 'direct marriage,' a rise and decline in 'conception marriage,' and two recently increasing innovative practices of 'cohabitation marriage' and 'cohabitation and conception marriage.' The 1980s marked a turning point when traditional family practices began to decay and innovative family practices began to emerge and spread. Conclusions: The diversification of marriage entry in China since the 1980s occurred in tandem with the development of China's economic reform and 'opening-up' policies. This simultaneity exemplifies the notion that socioeconomic changes at the macro level interact with family behavior changes at the individual level. Contribution: This study demonstrates an increasingly wide array of marriage entry types over time, reflecting the evolution of marriage behaviors from tradition to modernity in contemporary Chinese society.

  20. Entry control system for large populations

    International Nuclear Information System (INIS)

    Merillat, P.D.

    1982-01-01

    An Entry Control System has been developed which is appropriate for use at an installation with a large population requiring access over a large area. This is accomplished by centralizing the data base management and enrollment functions and decentralizing the guard-assisted, positive personnel identification and access functions. Current information pertaining to all enrollees is maintained through user-friendly enrollment stations. These stations may be used to enroll individuals, alter their area access authorizations, change expiration dates, and other similar functions. An audit trail of data base alterations is provided to the System Manager. Decentrailized systems exist at each area to which access is controlled. The central system provides these systems with the necessary entry control information to allow them to operate microprocessor-driven entry control devices. The system is comprised of commercially available entry control components and is structured such that it will be able to incorporate improved devices as technology porogresses. Currently, access is granted to individuals who possess a valid credential, have current access authorization, can supply a memorized personal identification number, and whose physical hand dimensions match their profile obtained during enrollment. The entry control devices report misuses as security violations to a Guard Alarm Display and Assessment System

  1. Skip entry trajectory planning and guidance

    Science.gov (United States)

    Brunner, Christopher William

    A numerical predictor-corrector (NPC) method for trajectory planning and closed-loop guidance of low lift-to-drag (L/D) ratio vehicles during the skip entry phase of a lunar-return mission is presented. The strategy calls for controlling the trajectory by modulation of the magnitude of the vehicle's bank angle. The magnitude of the bank angle used in the skip phase is determined by satisfying the downrange requirement to the landing site. The problem is formulated as a nonlinear univariate root-finding problem. Full three degree of freedom (3DOF) nonlinear trajectory dynamics are included to achieve high accuracy of the landing prediction. In addition, the proposed approach automatically yields a direct entry trajectory when the downrange is such that a skip entry is no longer necessary. The same algorithm repeatedly applied on-board in every guidance cycle realizes closed-loop guidance in the skip entry phase. A number of issues are identified and addressed that are critical in closed-loop implementations. Extensive 3DOF dispersion simulations are performed to evaluate the performance of the proposed approach, and the results demonstrate very reliable and robust performance of the algorithm in highly stressful dispersed conditions. Comparison is made between the proposed algorithm and an earlier skip algorithm developed for the Apollo space program. It is shown that the proposed algorithm is superior to the Apollo algorithm especially when used for entries with long downranges.

  2. Effect of Cognitive Entry Behaviors and Affective Entry Characteristics on Learning Level

    Science.gov (United States)

    Çaliskan, Muhittin

    2014-01-01

    In this study, the effect of cognitive entry behaviors and affective entry characteristics on learning level was investigated. The study was conducted on 258 first year students attending the Faculty of Education in the autumn semester of the 2011-2012 academic year. The study was conducted using the relational survey model and data was collected…

  3. Juvenile Salmonid Trophic Data - Ocean Survival of Salmonids

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A study to evaluate the role of changing ocean conditions on growth and survival of juvenile salmon from the Columbia River basin as they enter the Columbia River...

  4. Juvenile Salmonid Necropsy Data - Ocean Survival of Salmonids

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A study to evaluate the role of changing ocean conditions on growth and survival of juvenile salmon from the Columbia River basin as they enter the Columbia River...

  5. Juvenile Salmonid Parasite Data - Ocean Survival of Salmonids

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A study to evaluate the role of changing ocean conditions on growth and survival of juvenile salmon from the Columbia River basin as they enter the Columbia River...

  6. Bird Distribution and Abundance - Ocean Survival of Salmonids

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A study to evaluate the role of changing ocean conditions on growth and survival of juvenile salmon from the Columbia River basin as they enter the Columbia River...

  7. Egg to Fry - Chinook Egg-to-Fry Survival

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Few estimates of Chinook egg-to-fry survival exist despite the fact that this is thought to be one of the life stages limiting production of many listed Chinook...

  8. Space Shuttle and Hypersonic Entry

    Science.gov (United States)

    Campbell, Charles H.; Gerstenmaier, William H.

    2014-01-01

    Fifty years of human spaceflight have been characterized by the aerospace operations of the Soyuz, of the Space Shuttle and, more recently, of the Shenzhou. The lessons learned of this past half decade are important and very significant. Particularly interesting is the scenario that is downstream from the retiring of the Space Shuttle. A number of initiatives are, in fact, emerging from in the aftermath of the decision to terminate the Shuttle program. What is more and more evident is that a new era is approaching: the era of the commercial usage and of the commercial exploitation of space. It is probably fair to say, that this is the likely one of the new frontiers of expansion of the world economy. To make a comparison, in the last 30 years our economies have been characterized by the digital technologies, with examples ranging from computers, to cellular phones, to the satellites themselves. Similarly, the next 30 years are likely to be characterized by an exponential increase of usage of extra atmospheric resources, as a result of more economic and efficient way to access space, with aerospace transportation becoming accessible to commercial investments. We are witnessing the first steps of the transportation of future generation that will drastically decrease travel time on our Planet, and significantly enlarge travel envelope including at least the low Earth orbits. The Steve Jobs or the Bill Gates of the past few decades are being replaced by the aggressive and enthusiastic energy of new entrepreneurs. It is also interesting to note that we are now focusing on the aerospace band, that lies on top of the aeronautical shell, and below the low Earth orbits. It would be a mistake to consider this as a known envelope based on the evidences of the flights of Soyuz, Shuttle and Shenzhou. Actually, our comprehension of the possible hypersonic flight regimes is bounded within really limited envelopes. The achievement of a full understanding of the hypersonic flight

  9. Animal evolution and atmospheric pO2: is there a link between gradual animal adaptation to terrain elevation due to Ural orogeny and survival of subsequent hypoxic periods?

    Science.gov (United States)

    Kurbel, Sven

    2014-10-22

    Considering evolution of terrestrial animals as something happening only on flat continental plains seems wrong. Many mountains have arisen and disappeared over the geologic time scale, so in all periods some areas of high altitude existed, with reduced oxygen pressure (pO2) and increased aridity. During orogeny, animal species of the raising terrain can slowly adapt to reduced oxygen levels.This review proposes that animal evolution was often driven by atmospheric oxygen availability. Transitions of insect ancestors and amphibians out of water are here interpreted as events forced by the lack of oxygen in shallow and warm water during Devonian. Hyperoxia during early Carboniferous allowed giant insects to be predators of lowlands, forcing small amphibians to move to higher terrains, unsuitable to large insects due to reduced pO2. In arid mountainous habitats, ascended animals evolved in early reptiles with more efficient lungs and improved circulation. Animals with alveolar lungs became the mammalian ancestors, while those with respiratory duct lungs developed in archosaurs. In this interpretation, limb precursors of wings and pneumatised bones might have been adaptations for moving on steep slopes.Ural mountains have risen to an estimated height of 3000 m between 318 and 251 Mya. The earliest archosaurs have been found on the European Ural side, estimated 275 Myr old. It is proposed that Ural orogeny slowly elevated several highland habitats within the modern Ural region to heights above 2500 m. Since this process took near 60 Myr, animals in these habitats fully to adapted to hypoxia.The protracted P-Tr hypoxic extinction event killed many aquatic and terrestrial animals. Devastated lowland areas were repopulated by mammaliaformes that came down from mountainous areas. Archosaurs were better adapted to very low pO2, so they were forced to descend to the sea level later when the lack of oxygen became severe. During the Triassic period, when the relative content

  10. Modes and orders of market entry

    DEFF Research Database (Denmark)

    Ulhøi, John Parm

    2012-01-01

    (first-mover or follower). Invention is understood as the conversion of human creativity, time and financial resources into new ideas. Innovation in turn reflects the practical and financial return on such investments. While there is little disagreement about what an innovator strategy is, imitative......This paper focuses on the initial questions of how and when to enter a market from the perspective of a firm. By entry mode is meant a firm’s strategy (innovation or imitation) for entering the market in response to environmental changes. Entry order refers to the related issue of market timing...... strategies are more ambiguous. Based on a corporate technology and innovation strategy perspective, the paper reconceptualises and extends existing modes and orders of market entry, and in particular clarifies the ambiguity associated with imitative strategies. Four distinct imitator strategies...

  11. Financial Performance of Entry Mode Decisions

    DEFF Research Database (Denmark)

    Boyd, Britta; Dyhr Ulrich, Anna Marie; Hollensen, Svend

    2012-01-01

    Based on a survey of 170 Danish SMEs the paper examines influences on entry mode choices and the financial outcome of these decisions. The main research objectives are divided into two steps: Step 1: To determine the factors influencing the choice of foreign entry modes by Danish companies. Step 2......: To determine the relationship between the choice of entry mode and export performance, measured in terms of financial outcome. Drawing from transaction cost theory the authors develop and test a model where different factors affect the level of control chosen by the parent company. This study contributes...... and implications are provided for companies willing to invest more into foreign markets in order to achieve a higher degree of control and better financial results....

  12. Influence of distal entry tears in acute type B aortic dissection after thoracic endovascular aortic repair.

    Science.gov (United States)

    Zhu, Chenmou; Huang, Bin; Zhao, Jichun; Ma, Yukui; Yuan, Ding; Yang, Yi; Xiong, Fei; Wang, Tiehao

    2017-08-01

    This study evaluated the clinical influence of distal entry tears in acute type B aortic dissection (ATBAD) after thoracic endovascular aortic repair (TEVAR). From August 2009 to December 2014, the clinical outcomes of 130 patients who underwent TEVAR for ATBAD were retrospectively analyzed. According to whether distal entry tears existed after TEVAR, patients were divided into group A (n = 25, absence of distal entry tears) and group B (n = 105, presence of distal entry tears). We evaluated clinical outcomes, including mortality and morbidity in early and late follow-up, as well as aortic remolding. Late aortic events were defined as aortic dissection-related events occurring >30 days from the initial TEVAR procedures, which consisted of endoleak, retrograde type A aortic dissection, aortic enlargement, late rupture, repeat dissection, and stent-induced new entry tear. The study comprised 130 patients (114 men [87.7%] and 16 women [12.3%)] with a mean age of 53.71 years. The 30-day mortality was 3.1%, and early morbidity included type I endoleak, 3.1%, organ failure, 3.8%; stroke, 3.1%; spinal cord ischemia, 0%; and early rupture 1.5%. The overall survival rate by Kaplan-Meier analysis at 1, 3, and 5 years was 93.8%, 89.5%, and 79.2%, respectively. There were no significant differences in early morbidity and 30-day mortality and late survival between group A and group B. However, group A had a significantly lower rate of late aortic events than group B (P = .028 by log-rank test). Meanwhile, group A had better aortic remolding than group B in complete thrombosis of the thoracic aorta at 12 months postoperatively (100% vs 83.5%; P = .029). This study demonstrated that TEVAR for ATBAD had low perioperative morbidity and mortality and satisfactory midterm outcome. Distal entry tears increase the occurrence of late aortic events and inhibit aortic remolding but do not have a significantly negative effect on late survival. Repairing all entry tears to restore

  13. Survival estimates - Survival estimates for the passage of juvenile salmonids through Snake and Columbia River dams and reservoirs

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This BPA-funded study provides estimates of smolt survival and travel time through individual reaches and reaches combined in the Snake and Columbia Rivers...

  14. Project Prometheus and Future Entry Probe Missions

    Science.gov (United States)

    Spilker, Thomas R.

    2005-01-01

    A viewgraph presentation on project Prometheus and future entry probe missions is shown. The topics include: 1) What Is Project Prometheus?; 2) What Capabilities Can Project Prometheus Offer? What Mission Types Are Being Considered?; 3) Jupiter Icy Moons Orbiter (JIMO); 4) How Are Mission Opportunities Changing?; 5) Missions Of Interest a Year Ago; 6) Missions Now Being Considered For Further Study; 7) Galileo-Style (Conventional) Probe Delivery; 8) Galileo-Style Probe Support; 9) Conventional Delivery and Support of Multiple Probes; 10) How Entry Probe Delivery From an NEP Vehicle Is Different; and 11) Concluding Remarks.

  15. Entry Mode and Performance of Nordic Firms

    DEFF Research Database (Denmark)

    Wulff, Jesper

    2015-01-01

    This study investigates whether the relationship between mode of international market entry and non-location bound international experience is weaker for firms that are large or have a high foreign to total sales ratio, labeled multinational experience. Empirical evidence based on 250 foreign mar...... including the proposed moderating effect, on average, yield higher post-entry performance. This study sheds light on inconsistent results found in previous research investigating the impact of international experience and has practical implications for managerial decision-making....

  16. Automated Re-Entry System using FNPEG

    Science.gov (United States)

    Johnson, Wyatt R.; Lu, Ping; Stachowiak, Susan J.

    2017-01-01

    This paper discusses the implementation and simulated performance of the FNPEG (Fully Numerical Predictor-corrector Entry Guidance) algorithm into GNC FSW (Guidance, Navigation, and Control Flight Software) for use in an autonomous re-entry vehicle. A few modifications to FNPEG are discussed that result in computational savings -- a change to the state propagator, and a modification to cross-range lateral logic. Finally, some Monte Carlo results are presented using a representative vehicle in both a high-fidelity 6-DOF (degree-of-freedom) sim as well as in a 3-DOF sim for independent validation.

  17. Heatshield for Extreme Entry Environment Technology (HEEET) Development Status

    Science.gov (United States)

    Ellerby, Don; Gage, Peter; Kazemba, Cole; Mahzari, Milad; Nishioka, Owen; Peterson, Keith; Stackpoole, Mairead; Venkatapathy, Ethiraj; Young, Zion; Poteet, Carl; hide

    2016-01-01

    The Heat shield for Extreme Entry Environment Technology (HEEET) Project is a NASA STMD and SMD co-funded effort. The goal is to develop and mission infuse a new ablative Thermal Protection System that can withstand extreme entry. It is targeted to support NASAs high priority missions, as defined in the latest decadal survey, to destinations such as Venus and Saturn in-situ robotic science missions. Entry into these planetary atmospheres results in extreme heating. The entry peak heat-flux and associated pressure are estimated to be between one and two orders of magnitude higher than those experienced by Mars Science Laboratory or Lunar return missions. In the recent New Frontiers community announcement NASA has indicated that it is considering providing an increase to the PI managed mission cost (PIMMC) for investigations utilizing the Heat Shield for Extreme Entry Environment Technology (HEEET) and in addition, NASA is considering limiting the risk assessment to only their accommodation on the spacecraft and the mission environment. The HEEET ablative TPS utilizes 3D weaving technology to manufacture a dual layer material architecture. The 3-D weaving allows for flat panels to be woven. The dual layer consists of a top layer designed to withstand the extreme external environment while the inner or insulating layer by design, is designed to achieve low thermal conductivity, and it keeps the heat from conducting towards the structure underneath. Both arc jet testing combined with material properties have been used to develop thermal response models that allows for comparison of performance with heritage carbon phenolic. A 50 mass efficiency is achieved by the dual layer construct compared to carbon phenolic for a broad range of missions both to Saturn and Venus. The 3-D woven flat preforms are molded to achieve the shape as they are compliant and then resin infusion with curing forms a rigid panels. These panels are then bonded on to the aeroshell structure. Gaps

  18. Crown sealing and buckling instability during water entry of spheres

    KAUST Repository

    Marston, J. O.

    2016-04-05

    We present new observations from an experimental investigation of the classical problem of the crown splash and sealing phenomena observed during the impact of spheres onto quiescent liquid pools. In the experiments, a 6 m tall vacuum chamber was used to provide the required ambient conditions from atmospheric pressure down to of an atmosphere, whilst high-speed videography was exploited to focus primarily on the above-surface crown formation and ensuing dynamics, paying particular attention to the moments just prior to the surface seal. In doing so, we have observed a buckling-type azimuthal instability of the crown. This instability is characterised by vertical striations along the crown, between which thin films form that are more susceptible to the air flow and thus are drawn into the closing cavity, where they atomize to form a fine spray within the cavity. To elucidate to the primary mechanisms and forces at play, we varied the sphere diameter, liquid properties and ambient pressure. Furthermore, a comparison between the entry of room-temperature spheres, where the contact line pins around the equator, and Leidenfrost spheres (i.e. an immersed superheated sphere encompassed by a vapour layer), where there is no contact line, indicates that the buckling instability appears in all crown sealing events, but is intensified by the presence of a pinned contact line. © 2016 Cambridge University Press.

  19. Female entrepreneurial networks and foreign market entry

    DEFF Research Database (Denmark)

    Rosenbaum, Gitte Ohrt

    2017-01-01

    The purpose of this paper is to explore the role of networks in the 116 foreign market entries (FMEs) of women-owned small businesses. A multiple case study based on semi-structured interviews with eight female entrepreneurs in the Danish fashion design industry. The results show that contrary...

  20. Foreign entry, cultural barriers and learning

    NARCIS (Netherlands)

    H.G. Barkema (Harry); J.H.J. Bell (John); J.M.E. Pennings

    1996-01-01

    textabstractThis paper examines the longevity of foreign entries. Hypotheses are developed on the mode (start-ups vs. acquisitions) and ownership structure (wholly owned vs. joint ventures) in relation to cultural distance. The hypotheses are tested within a framework of organizational learning,

  1. Thinking and Reading for Entry Level Workers.

    Science.gov (United States)

    Allentown Literacy Council, PA.

    A pilot project demonstrated that cooperative training programs are effective and cost efficient for small businesses. Common entry-level reading and thinking tasks were identified in a variety of occupational areas. Five growing occupational areas were identified: industrial/machine operator; health care; food preparation; hotel/hospitality; and…

  2. Correlation Between Entry Requirements and Academic ...

    African Journals Online (AJOL)

    In this study, the investigator examines the correlation between entry requirements and academic performance of undergraduate students at the University of Buea. The quality of performance on the Cameroon General Certificate Examination at the Advanced Level is the predictor while the criterion is the cumulative grade ...

  3. Perceptions regarding strategic and structural entry barriers

    NARCIS (Netherlands)

    Lutz, C.H.M.; Kemp, R.G.M.; Dijkstra, S.G.

    2010-01-01

    This article uses factor analysis to identify the underlying dimensions of strategic and structural entry barriers. We find that, in the perception of firms, both types of barriers are important and that the effectiveness of strategic barriers depends on attributes of the market structure. Based on

  4. Perceptions regarding strategic and structural entry barriers

    NARCIS (Netherlands)

    Lutz, Clemens H. M.; Kemp, Ron G. M.; Dijkstra, S. Gerhard

    This article uses factor analysis to identify the underlying dimensions of strategic and structural entry barriers. We find that, in the perception of firms, both types of barriers are important and that the effectiveness of strategic barriers depends on attributes of the market structure. Based on

  5. Entry modes of European firms in Vietnam

    Directory of Open Access Journals (Sweden)

    Daniel Simonet

    2012-09-01

    Full Text Available Purpose: The purpose of the paper is to explore the entry modes of EU firms setting up operations in Vietnam. Design/methodology/approach: we use a case study approach on Haymarket, Cadbury, Creative Education, Fairchild, Aventis and Artemisinin and Farming International using interviews from managerial professionals in Vietnam. Findings: Despite the fact that Vietnam has been opening up for more than 20 years, licensing is the preferred entry mode because of the risks involved in venturing with local firms; that preference signals a low level commitment and a high perception of risk and state interference. In line with Vietnam transition to state - rather than private market - capitalism, a foreign company opting for a joint-venture will do so with a state-owned rather than privately-owned company. The choice of a subsidiary can be explained by the lack of trust in partners and institutions, not by improvement in the socio-political environment. Limitations: In determining the entry mode strategy, the paper focuses on the Uppsala school’s “psychic distance” (e.g. cultural distance, lack of trust rather than on firm-specific advantages (Rugman, 1980; 2006. Key-words: international entry mode; emerging markets; subsidiary; joint-venture; India; Vietnam

  6. 76 FR 15841 - Entry of Merchandise

    Science.gov (United States)

    2011-03-22

    ... DEPARTMENT OF HOMELAND SECURITY Bureau of Customs and Border Protection DEPARTMENT OF THE TREASURY 19 CFR Part 141 Entry of Merchandise CFR Correction In Title 19 of the Code of Federal Regulations, Parts 141 to 199, revised as of April 1, 2010, on page 6, the second general authority citation for part...

  7. Shuttle Entry Imaging Using Infrared Thermography

    Science.gov (United States)

    Horvath, Thomas; Berry, Scott; Alter, Stephen; Blanchard, Robert; Schwartz, Richard; Ross, Martin; Tack, Steve

    2007-01-01

    During the Columbia Accident Investigation, imaging teams supporting debris shedding analysis were hampered by poor entry image quality and the general lack of information on optical signatures associated with a nominal Shuttle entry. After the accident, recommendations were made to NASA management to develop and maintain a state-of-the-art imagery database for Shuttle engineering performance assessments and to improve entry imaging capability to support anomaly and contingency analysis during a mission. As a result, the Space Shuttle Program sponsored an observation campaign to qualitatively characterize a nominal Shuttle entry over the widest possible Mach number range. The initial objectives focused on an assessment of capability to identify/resolve debris liberated from the Shuttle during entry, characterization of potential anomalous events associated with RCS jet firings and unusual phenomenon associated with the plasma trail. The aeroheating technical community viewed the Space Shuttle Program sponsored activity as an opportunity to influence the observation objectives and incrementally demonstrate key elements of a quantitative spatially resolved temperature measurement capability over a series of flights. One long-term desire of the Shuttle engineering community is to calibrate boundary layer transition prediction methodologies that are presently part of the Shuttle damage assessment process using flight data provided by a controlled Shuttle flight experiment. Quantitative global imaging may offer a complementary method of data collection to more traditional methods such as surface thermocouples. This paper reviews the process used by the engineering community to influence data collection methods and analysis of global infrared images of the Shuttle obtained during hypersonic entry. Emphasis is placed upon airborne imaging assets sponsored by the Shuttle program during Return to Flight. Visual and IR entry imagery were obtained with available airborne

  8. Survival pathways under stress

    Indian Academy of Sciences (India)

    First page Back Continue Last page Graphics. Survival pathways under stress. Bacteria survive by changing gene expression. pattern. Three important pathways will be discussed: Stringent response. Quorum sensing. Proteins performing function to control oxidative damage.

  9. Connecting Atmospheric Science and Atmospheric Models for Aerocaptured Missions to Titan and the Outer Planets

    Science.gov (United States)

    Justus, C. G.; Duvall, Aleta; Keller, Vernon W.

    2003-01-01

    Many atmospheric measurement systems, such as the sounding instruments on Voyager, gather atmospheric information in the form of temperature versus pressure level. In these terms, there is considerable consistency among the mean atmospheric profiles of the outer planets Jupiter through Neptune, including Titan. On a given planet or on Titan, the range of variability of temperature versus pressure level due to seasonal, latitudinal, and diurnal variations is also not large. However, many engineering needs for atmospheric models relate not to temperature versus pressure level but atmospheric density versus geometric altitude. This need is especially true for design and analysis of aerocapture systems. Aerocapture drag force available for aerocapture is directly proportional to atmospheric density. Available aerocapture "corridor width" (allowable range of atmospheric entry angle) also depends on height rate of change of atmospheric density, as characterized by density scale height. Characteristics of hydrostatics and the gas law equation mean that relatively small systematic differences in temperature-versus-pressure profiles can integrate at high altitudes to very large differences in density-versus-altitude profiles. Thus a given periapsis density required to accomplish successful aerocapture can occur at substantially different altitudes (approx. 150 - 300 km) on the various outer planets, and significantly different density scale heights (approx. 20 - 50 km) can occur at these periapsis altitudes. This paper will illustrate these effects and discuss implications for improvements in atmospheric measurements to yield significant impact on design of aerocapture systems for future missions to Titan and the outer planets. Relatively small- scale atmospheric perturbations, such as gravity waves, tides, and other atmospheric variations can also have significant effect on design details for aerocapture guidance and control systems. This paper will also discuss benefits

  10. Coronaviruses induce entry-independent, continuous macropinocytosis.

    Science.gov (United States)

    Freeman, Megan Culler; Peek, Christopher T; Becker, Michelle M; Smith, Everett Clinton; Denison, Mark R

    2014-08-05

    Macropinocytosis is exploited by many pathogens for entry into cells. Coronaviruses (CoVs) such as severe acute respiratory syndrome (SARS) CoV and Middle East respiratory syndrome CoV are important human pathogens; however, macropinocytosis during CoV infection has not been investigated. We demonstrate that the CoVs SARS CoV and murine hepatitis virus (MHV) induce macropinocytosis, which occurs late during infection, is continuous, and is not associated with virus entry. MHV-induced macropinocytosis results in vesicle internalization, as well as extended filopodia capable of fusing with distant cells. MHV-induced macropinocytosis requires fusogenic spike protein on the cell surface and is dependent on epidermal growth factor receptor activation. Inhibition of macropinocytosis reduces supernatant viral titers and syncytia but not intracellular virus titers. These results indicate that macropinocytosis likely facilitates CoV infection through enhanced cell-to-cell spreading. Our studies are the first to demonstrate virus use of macropinocytosis for a role other than entry and suggest a much broader potential exploitation of macropinocytosis in virus replication and host interactions. Importance: Coronaviruses (CoVs), including severe acute respiratory syndrome (SARS) CoV and Middle East respiratory syndrome CoV, are critical emerging human pathogens. Macropinocytosis is induced by many pathogens to enter host cells, but other functions for macropinocytosis in virus replication are unknown. In this work, we show that CoVs induce a macropinocytosis late in infection that is continuous, independent from cell entry, and associated with increased virus titers and cell fusion. Murine hepatitis virus macropinocytosis requires a fusogenic virus spike protein and signals through the epidermal growth factor receptor and the classical macropinocytosis pathway. These studies demonstrate CoV induction of macropinocytosis for a purpose other than entry and indicate that viruses

  11. RTLS entry ranging analysis. [space shuttle reentry trajectory

    Science.gov (United States)

    Crull, T. J.

    1975-01-01

    Definition of the ranging capability of a mission 3A return-to-launch-site entry is reported. The limits on downrange and crossrange are established at the initiation of RTLS entry so that terminal area energy management interface conditions were achieved satisfactorily. The downrange and crossrange limits were defined for both nominal RTLS entry conditions and a composite set of dispersed RTLS entry conditions. The results indicate a wide range of acceptable downrange and crossrange positions are available at RTLS entry initiation for nominal conditions. This is greatly reduced when dispersions are considered. For dispersed RTLS entry conditions, an 18 nautical mile range of acceptable downranges is available at zero crossrange.

  12. Atmospheric Smell

    DEFF Research Database (Denmark)

    Stenslund, Anette

    revealed how a museum-staged hospital atmosphere of an art installation was directly addressed owing to its smell. Curiously, this observation speaks against prevailing literature portraying smell as the ‘mute sense’, and what is more, the museum display did not alter smell curatorially. Rather, smell......, hospital-based and museum-staged. Prompted by the ambition to acknowledge the museum’s need to have its activities rooted in thorough investigation of the given culture on show, the dual analytical disposition is a sine qua non spanning varied fields and disciplines. The conceptual discussion offered...... in the thesis is spurred on by philosophical phenomenology predominantly paired with sociological and anthropological theory. It finds support in empirical work from both a hospital and a museum setting. Thus, it draws on a three-month ethnographic fieldwork conducted in 2012 in a Danish hospital, including...

  13. 19 CFR 141.61 - Completion of entry and entry summary documentation.

    Science.gov (United States)

    2010-04-01

    ... mailed to agent. If an importer of record desires to have refunds, bills, or notices of liquidation..., CBP Form 7501; the transportation entry and manifest of goods, CBP Form 7512, when used to document an...

  14. Market Entry Strategies : Case: McDonald's entry on the Russian market

    OpenAIRE

    Karataev, Oleg

    2015-01-01

    The thesis considers the entry strategy and development of the company McDonald's into international markets. The theoretical aspects of the entry strategy of the company into the international markets. Analyzes the key features of the development of McDonald's in Russia. Investigated the prospects of the company in international markets. In theoretic part there was regarded some important aspects of international strategic management, such as: strategic alternatives, elements and levels o...

  15. Finding Atmospheric Composition (AC) Metadata

    Science.gov (United States)

    Strub, Richard F..; Falke, Stefan; Fiakowski, Ed; Kempler, Steve; Lynnes, Chris; Goussev, Oleg

    2015-01-01

    The Atmospheric Composition Portal (ACP) is an aggregator and curator of information related to remotely sensed atmospheric composition data and analysis. It uses existing tools and technologies and, where needed, enhances those capabilities to provide interoperable access, tools, and contextual guidance for scientists and value-adding organizations using remotely sensed atmospheric composition data. The initial focus is on Essential Climate Variables identified by the Global Climate Observing System CH4, CO, CO2, NO2, O3, SO2 and aerosols. This poster addresses our efforts in building the ACP Data Table, an interface to help discover and understand remotely sensed data that are related to atmospheric composition science and applications. We harvested GCMD, CWIC, GEOSS metadata catalogs using machine to machine technologies - OpenSearch, Web Services. We also manually investigated the plethora of CEOS data providers portals and other catalogs where that data might be aggregated. This poster is our experience of the excellence, variety, and challenges we encountered.Conclusions:1.The significant benefits that the major catalogs provide are their machine to machine tools like OpenSearch and Web Services rather than any GUI usability improvements due to the large amount of data in their catalog.2.There is a trend at the large catalogs towards simulating small data provider portals through advanced services. 3.Populating metadata catalogs using ISO19115 is too complex for users to do in a consistent way, difficult to parse visually or with XML libraries, and too complex for Java XML binders like CASTOR.4.The ability to search for Ids first and then for data (GCMD and ECHO) is better for machine to machine operations rather than the timeouts experienced when returning the entire metadata entry at once. 5.Metadata harvest and export activities between the major catalogs has led to a significant amount of duplication. (This is currently being addressed) 6.Most (if not all

  16. Entry Location and Entry Timing (ELET Decision Model for International Construction Firms

    Directory of Open Access Journals (Sweden)

    Che Maznah Mat Isa

    2014-09-01

    Full Text Available This paper proposes a model for entry location (EL and entry timing (ET decisions to guide construction firms in accessing targeted international markets.  Neglecting to properly choose the right combination of the entry location and entry timing (ELET decisions can lead to poor performance of the firms’ international ventures.  The sampling frame was from the Malaysian construction firms that have undertaken and completed projects abroad.  Survey questionnaires sent to 115 firms registered with Construction Industry Development Board (CIDB Malaysia, operating in more than 50 countries, achieved a 39.1 per cent response rate. Based on a comprehensive statistical analysis of survey data it was found that the mutually inclusive significant factors that influenced the firms’ ELET decisions were: the firm’s ability to assess market signals and opportunities, international experience, financial capacity, competencies and capabilities (project management, specialist expertise and technology, resources (level of knowledge based on research and development, experience in similar works, financial support from the home country banks, technical complexities of projects and availability of funds for projects.  Hence, the present research builds on and extends the literature on the ELET decisions in a more integrated way. Keywords: Entry location, entry timing, resource-based view, international markets, Malaysian construction firms.

  17. Atmospheric Models/Global Atmospheric Modeling

    Science.gov (United States)

    1998-09-30

    Atmospheric Models /Global Atmospheric Modeling Timothy F. Hogan Naval Research Laboratory Monterey, CA 93943-5502 phone: (831) 656-4705 fax: (831...to 00-00-1998 4. TITLE AND SUBTITLE Atmospheric Models /Global Atmospheric Modeling 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...initialization of increments, improved cloud prediction, and improved surface fluxes) have been transition to 6.4 (Global Atmospheric Models , PE 0603207N, X-0513

  18. The HIV-1 Entry Process: A Stoichiometric View.

    Science.gov (United States)

    Brandenberg, Oliver F; Magnus, Carsten; Regoes, Roland R; Trkola, Alexandra

    2015-12-01

    HIV-1 infection starts with fusion of the viral and the host cell membranes, a process mediated by the HIV-1 envelope glycoprotein trimer. The number of trimers required to complete membrane fusion, referred to as HIV-1 entry stoichiometry, remains under debate. A precise definition of HIV-1 entry stoichiometry is important as it reflects the efficacy of the viral entry process and steers the infectivity of HIV-1 virion populations. Initial estimates suggested a unanimous entry stoichiometry across HIV-1 strains while recent findings showed that HIV-1 strains can differ in entry stoichiometry. Here, we review current analyses of HIV-1 entry stoichiometry and point out future research directions to further define the interplay between entry stoichiometry, virus entry fitness, transmission, and susceptibility to antibody neutralization. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Optimization of Observation Strategy to Improve Re-entry Prediction of Objects in HEO

    Science.gov (United States)

    Rasotto, M.; Di Mauro, G.; Massari, M.; Di Lizia, P.; Armellin, R.; Funke, Q.; Flohrer, T.

    2016-09-01

    During the last decade the number of space debris moving on high elliptical orbit (HEO) has grown fast. Many of these resident space objects (RSO) consist of medium and large spent upper stages of launch vehicles, whose atmosphere re-entry might violate on-ground casualty risk constraints. Increasing the accuracy of re-entry predictions for this class of RSO is therefore a key issue to limit the hazards on the Earth assets. Traditional computational methods are mainly based on the exploitation of Two Line Elements (TLEs), provided by the United States Strategic Command (USSTRATCOM) and currently the only public data source available for these kind of analyses. TLE data however, are characterized by low accuracies, and in general come without any uncertainty information, thus limiting the achievable precision of the re-entry estimates. Better results on the other hand, can be obtained through the exploitation of observational data provided by one or more Earth sensors. Despite the benefits, this approach introduces a whole new set of complexities, mainly related with the design of proper observation campaigns. This paper presents a method based on evolutionary algorithms, for the optimization of observation strategies. The effectiveness of the proposed approach is demonstrated through dedicated examples, in which re-entry predictions, attainable with existing and ideal sensor architectures, are compared with corresponding results derived from TLE data.

  20. An innovative navigation scheme for Mars entry using dynamic pressure measurement

    Science.gov (United States)

    Deng, Jianfeng; Gao, Ai; Zong, Hua; Cui, Pingyuan

    2017-11-01

    Complete observability of dynamic system is a major concern of navigation in Mars precision landing exploration missions. It is demonstrated that, however, the current measurements used for navigation during Mars entry cannot guarantee the complete observability of the dynamic system. This paper proposes an integrated navigation scheme for Mars entry phase using the dynamic pressure and accelerations from inertial measurement unit (IMU). The dynamic pressure derived from the Mars Entry Atmospheric Data System (MEADS), and the triaxle accelerations from IMU are integrated in a filter as navigation measurements to increase the dynamic system observability and perform state estimation on-board. Afterward, the perturbation of the dynamic caused by parameter uncertainties is built. In order to address the impact of perturbation on state estimation, an adaptive estimator based on modified mixture-of-expert framework is given. Numerical simulation results demonstrate that the proposed integrated navigation scheme can ensure the complete observability of the dynamic system, and the state estimation are converged with entry time after the dynamic pressure has built up.

  1. Resin-Impregnated Carbon Ablator: A New Ablative Material for Hyperbolic Entry Speeds

    Science.gov (United States)

    Esper, Jaime; Lengowski, Michael

    2012-01-01

    Ablative materials are required to protect a space vehicle from the extreme temperatures encountered during the most demanding (hyperbolic) atmospheric entry velocities, either for probes launched toward other celestial bodies, or coming back to Earth from deep space missions. To that effect, the resin-impregnated carbon ablator (RICA) is a high-temperature carbon/phenolic ablative thermal protection system (TPS) material designed to use modern and commercially viable components in its manufacture. Heritage carbon/phenolic ablators intended for this use rely on materials that are no longer in production (i.e., Galileo, Pioneer Venus); hence the development of alternatives such as RICA is necessary for future NASA planetary entry and Earth re-entry missions. RICA s capabilities were initially measured in air for Earth re-entry applications, where it was exposed to a heat flux of 14 MW/sq m for 22 seconds. Methane tests were also carried out for potential application in Saturn s moon Titan, with a nominal heat flux of 1.4 MW/sq m for up to 478 seconds. Three slightly different material formulations were manufactured and subsequently tested at the Plasma Wind Tunnel of the University of Stuttgart in Germany (PWK1) in the summer and fall of 2010. The TPS integrity was well preserved in most cases, and results show great promise.

  2. Multi entry framework for financial and risk reporting

    OpenAIRE

    Staszkiewicz, Piotr W.

    2011-01-01

    Author challenges one of the oldest accounting double bookkeeping rules, used since 1494, and proposes instead application of the quadruple accounting entry. He presents the concept of the multiply accounting entry for the risk financial statements and risk management. The development gap concept is described and introduces a simplified entry and reporting example. Model is illustrated with a number of financial-risk statements and attributes including the journal entries. The potential co...

  3. Dependency of radon entry on pressure difference

    International Nuclear Information System (INIS)

    Kokotti, H.; Kalliokoski, P.

    1992-01-01

    Radon levels, ventilation rate and pressure differences were monitored continuously in four apartment houses with different ventilation systems. Two of them were ventilated by mechanical exhaust, one by mechanical supply and exhaust, and one by natural ventilation. The two-storey houses were constructed from concrete elements on a slab and located on a gravel esker. It was surprising to find that increasing the ventilation rate increased levels of radon in the apartments. Increased ventilation caused increased outdoor-indoor pressure difference, which in turn increased the entry rate of radon and counteracted the diluting effect of ventilation. The increase was significant when the outdoor-indoor pressure difference exceeded 5 Pa. Especially in the houses with mechanical exhaust ventilation the pressure difference was the most important factor of radon entry rate, and contributed up to several hundred Bq m -3 h -1 . (Author)

  4. Available hardware for automated entry control

    International Nuclear Information System (INIS)

    Holmes, J.P.

    1990-01-01

    Automated entry control has become an increasingly important issue at facilities where budget constraints are limiting options for manned entry control points. Ongoing work at Sandia National Laboratories is attempting to establish a data base for use by facility security managers working the problem of how to maintain security on a limited budget. Sandia National Laboratories conducted a performance test of the following biometric verifiers: (1) voice verifier by Alpha Microsystems of Santa Ana, California; (2) signature dynamics verifier by Autosig Systems of Irving, Texas; (3) voice verifier by Ecco Industries of Danvers, Massachusetts (now International Electronics); (4) retinal pattern verifier by EyeDentify of Portland, Oregon; (5) fingerprint verifier by Identix of Sunnyvale, California; and (6) hand geometry verifier by Recognition Systems of San Jose, California

  5. System for histogram entry, retrieval, and plotting

    International Nuclear Information System (INIS)

    Kellogg, M.; Gallup, J.M.; Shlaer, S.; Spencer, N.

    1977-10-01

    This manual describes the systems for producing histograms and dot plots that were designed for use in connection with the Q general-purpose data-acquisition system. These systems allow for the creation of histograms; the entry, retrieval, and plotting of data in the form of histograms; and the dynamic display of scatter plots as data are acquired. Although the systems are designed for use with Q, they can also be used as a part of other applications. 3 figures

  6. Entry Mistakes, Entrepreneurial Boldness and Optimism

    OpenAIRE

    Brocas, Isabelle; Carrillo, Juan D

    1999-01-01

    We analyze the investment decision of a population of time inconsistent entrepreneurs who overweight current payoffs relative to future returns. We show that, in order to avoid inefficient procrastination, agents may find it optimal to keep optimistic priors about their chances of success and 'blindly invest'. This explains entrepreneurial boldness and entry mistakes (or an excessive level of investment in the economy) without assuming the existence of boundedly rational, 'intrinsically optim...

  7. Perceptions regarding strategic and structural entry barriers

    OpenAIRE

    Lutz, C.H.M.; Kemp, R.G.M.; Dijkstra, S.G.

    2010-01-01

    This article uses factor analysis to identify the underlying dimensions of strategic and structural entry barriers. We find that, in the perception of firms, both types of barriers are important and that the effectiveness of strategic barriers depends on attributes of the market structure. Based on the seven generic factors, a conjoint analysis is carried out to identify the most important factors perceived by firms. The conjoint analysis shows that in particular the barriers rooted in three ...

  8. Capacity and Entry Deterrence under Demand Uncertainty

    DEFF Research Database (Denmark)

    Poddar, Sougata

    I consider a two period model with an incumbent firm and a potential entrant each of whom produces a homogeneous good. There is a demand uncertainty: it can be high or low and it realizes in the second period. The question I ask: How by choosing capacity at an earlier period of actual production ...... affects the incumbent's decision regarding entry deterrence/accommodation. I compare the results with the case where there is no uncertainty...

  9. Computational modelling of meiotic entry and commitment

    OpenAIRE

    Bhola, Tanvi; Kapuy, Orsolya; Vinod, P. K.

    2018-01-01

    In response to developmental and environmental conditions, cells exit the mitotic cell cycle and enter the meiosis program to generate haploid gametes from diploid germ cells. Once cells decide to enter the meiosis program they become irreversibly committed to the completion of meiosis irrespective of the presence of cue signals. How meiotic entry and commitment occur due to the dynamics of the regulatory network is not well understood. Therefore, we constructed a mathematical model of the re...

  10. 32 CFR 643.11 - Rights of entry.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Rights of entry. 643.11 Section 643.11 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL PROPERTY REAL ESTATE General § 643.11 Rights of entry. Pending the signing of the formal instrument, no right of entry will be...

  11. 31 CFR 337.6 - Conversions to book-entry.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Conversions to book-entry. 337.6... HOUSING ADMINISTRATION DEBENTURES Certificated Debentures § 337.6 Conversions to book-entry. Upon implementation of the book-entry debenture system, to be announced in advance by separate public notice, all new...

  12. Dynamics in car ownership: the role of entry into parenthood

    NARCIS (Netherlands)

    Oakil, A.T.M.; Manting, D.; Nijland, H.

    2016-01-01

    This study investigates the impact of entry into parenthood on changes in car ownership. If entry into parenthood affects changes in car ownership, then delay or offset of entry into parenthood might also be an important explanation of recent car travel trends of young adults. This study analysed

  13. 7 CFR 1493.490 - Proof of entry.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Proof of entry. 1493.490 Section 1493.490 Agriculture... Guarantee Program Operations § 1493.490 Proof of entry. (a) Diversion. The diversion of commodities covered..., unless expressly authorized by the GSM. (b) Records of proof of entry. Exporters must obtain and maintain...

  14. 7 CFR 1493.290 - Proof of entry.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Proof of entry. 1493.290 Section 1493.290 Agriculture... Program (FGP) Operations § 1493.290 Proof of entry. (a) Diversion. The diversion of goods covered by a... prohibited, unless expressly authorized by the GSM. (b) Records of proof of entry. Exporters must obtain and...

  15. Optimal firm growth under the threat of entry

    NARCIS (Netherlands)

    Kort, Peter; Wrzaczek, S.

    2015-01-01

    The paper studies the incumbent-entrant problem in a fully dynamic setting. We find that under an open-loop information structure the incumbent anticipates entry by overinvesting, whereas in the Markov perfect equilibrium the incumbent slightly underinvests in the period before the entry. The entry

  16. 33 CFR 160.107 - Denial of entry.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Denial of entry. 160.107 Section... § 160.107 Denial of entry. Each District Commander or Captain of the Port, subject to recognized principles of international law, may deny entry into the navigable waters of the United States or to any port...

  17. 30 CFR 842.13 - Right of entry.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Right of entry. 842.13 Section 842.13 Mineral... INSPECTION AND ENFORCEMENT PROCEDURES FEDERAL INSPECTIONS AND MONITORING § 842.13 Right of entry. (a) Each... right of entry to, upon, and through any coal exploration or surface coal mining and reclamation...

  18. 7 CFR 1493.100 - Proof of entry.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Proof of entry. 1493.100 Section 1493.100 Agriculture....100 Proof of entry. (a) Diversion. The diversion of commodities covered by a GSM-102 or GSM-103... expressly authorized by the GSM. (b) Records of proof of entry. Exporters must obtain and maintain records...

  19. 19 CFR 191.154 - Filing the entry.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Filing the entry. 191.154 Section 191.154 Customs... (CONTINUED) DRAWBACK Merchandise Exported From Continuous Customs Custody § 191.154 Filing the entry. (a... office a direct export drawback entry on Customs Form 7551 in duplicate. (b) Merchandise transported to...

  20. 30 CFR 721.12 - Right of entry.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Right of entry. 721.12 Section 721.12 Mineral... REGULATIONS FEDERAL INSPECTIONS § 721.12 Right of entry. (a) Authorized representatives of the Secretary..., shall have the right of entry to, upon, or through any surface coal mining and reclamation operations or...

  1. 30 CFR 840.12 - Right of entry.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Right of entry. 840.12 Section 840.12 Mineral... of entry. (a) Within its jurisdiction, the State regulatory authority shall have authority that grants its representatives a right of entry to, upon, and through any coal exploration or surface coal...

  2. 9 CFR 98.20 - Embryos refused entry.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Embryos refused entry. 98.20 Section...-and-Mouth Disease Exists § 98.20 Embryos refused entry. If any embryos are determined to be ineligible for importation into the United States upon arrival at the port of entry, the importer must remove the...

  3. 9 CFR 98.9 - Embryos refused entry.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Embryos refused entry. 98.9 Section 98.9 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... Disease; and Embryos of Horses and Asses § 98.9 Embryos refused entry. Any embryo refused entry into the...

  4. 36 CFR 13.1160 - Restrictions on vessel entry.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Restrictions on vessel entry. 13.1160 Section 13.1160 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE... Vessel Permits § 13.1160 Restrictions on vessel entry. The superintendent will allow vessel entry in...

  5. 19 CFR 143.16 - Substitution of warehouse entry.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Substitution of warehouse entry. 143.16 Section 143.16 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT... warehouse entry. The importer may substitute an entry for warehouse at any time within 1 year from the date...

  6. Cloud Computing with iPlant Atmosphere.

    Science.gov (United States)

    McKay, Sheldon J; Skidmore, Edwin J; LaRose, Christopher J; Mercer, Andre W; Noutsos, Christos

    2013-10-15

    Cloud Computing refers to distributed computing platforms that use virtualization software to provide easy access to physical computing infrastructure and data storage, typically administered through a Web interface. Cloud-based computing provides access to powerful servers, with specific software and virtual hardware configurations, while eliminating the initial capital cost of expensive computers and reducing the ongoing operating costs of system administration, maintenance contracts, power consumption, and cooling. This eliminates a significant barrier to entry into bioinformatics and high-performance computing for many researchers. This is especially true of free or modestly priced cloud computing services. The iPlant Collaborative offers a free cloud computing service, Atmosphere, which allows users to easily create and use instances on virtual servers preconfigured for their analytical needs. Atmosphere is a self-service, on-demand platform for scientific computing. This unit demonstrates how to set up, access and use cloud computing in Atmosphere. Copyright © 2013 John Wiley & Sons, Inc.

  7. Attacking 22 entries in rugby union: running demands and differences between successful and unsuccessful entries.

    Science.gov (United States)

    Tierney, P; Tobin, D P; Blake, C; Delahunt, E

    2017-12-01

    Global Positioning System (GPS) technology is commonly utilized in team sports, including rugby union. It has been used to describe the average running demands of rugby union. This has afforded an enhanced understanding of the physical fitness requirements for players. However, research in team sports has suggested that training players relative to average demands may underprepare them for certain scenarios within the game. To date, no research has investigated the running demands of attacking 22 entries in rugby union. Additionally, no research has been undertaken to determine whether differences exist in the running intensity of successful and unsuccessful attacking 22 entries in rugby union. The first aim of this study was to describe the running intensity of attacking 22 entries. The second aim of this study was to investigate whether differences exist in the running intensity of successful and unsuccessful attacking 22 entries. Running intensity was measured using meters per minute (m min -1 ) for (a) total distance, (b) running distance, (c) high-speed running distance, and (d) very high-speed running distance. This study provides normative data for the running intensity of attacking 22 entries in rugby union. Forwards achieved greater high-speed running intensity in successful (3.6 m min -1 ) compared to unsuccessful (1.8 m min -1 ) attacking 22 entries. Forwards should try and achieve greater high-speed running intensity in attacking 22 entries to increase the likelihood of successful outcomes during this period of gameplay. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Entry zone of iliac screw fixation to maintain proper entry width and screw length.

    Science.gov (United States)

    Park, Soo-An; Kwak, Dai-Soon; You, Sung-Lim

    2015-11-01

    To evaluate the entry zone of iliac screw fixation to maintain proper entry width and screw length. Computed tomography images of pelvic bones from 90 human cadavers were reconstructed into 3-dimensional models. In each model, a sectional image crossing the posterior superior iliac spine (PSIS) and anterior inferior iliac spine (AIIS) and consecutive sectional images up to 20 mm superiorly and inferiorly from the PSIS with 1-mm intervals aiming the AIIS were obtained. One virtual iliac screw with 10-mm diameter was introduced onto the PSIS at the middle and at the lateral and medial 1/4 points on the prominence of the posterior iliac spine. The entry width of the bony prominence and the corresponding maximal screw length available were evaluated for each entry point. The entry width was smallest on the inferior 20 mm (4.7 ± 3.0 mm) and gradually increased up to the superior 10 mm (19.1 ± 3.9 mm) sectional images. The maximal screw length was smallest on the superior 20 mm (76.7 ± 39.7 mm) and gradually increased down to the inferior 10 mm (112.3 ± 15.1 mm) sectional images. The maximal screw lengths were significantly greatest at the most medial point and smallest at the most lateral point on the superior 20- and 10-mm sectional images and at the PSIS. The iliac screw fixation entry zone to maintain proper screw length and entry width is outlined from 20 mm superiorly to 10 mm inferiorly from the PSIS and is located more medially from the prominence of the posterior iliac spine.

  9. Titan Imagery with Keck AO during and after Probe Entry

    Energy Technology Data Exchange (ETDEWEB)

    de Pater, I; Adamkovics, M; Bouchez, A H; Brown, M E; Gibbard, S G; Marchis, F; Roe, H G; Schaller, E L; Young, E

    2006-02-03

    We present adaptive optics data from the 10-m W.M. Keck telescope that were taken during the time the Huygens probe descended through Titan's atmosphere, and on the days following touch-down. The spatial resolution of the images is typically {approx}0.04-inch, or {approx}240 km on Titan (60 km/pixel). No probe entry signal was detected at levels exceeding 0.8 {micro}Jy (3-{sigma}) per pixel (0.01-inch), which although within the range of predicted flux levels, cannot constrain any models. We present data on Titan's surface, troposphere and stratosphere during the days following probe entry, when the solar phase angle varied from 0.05{sup o} up to 0.8{sup o}, with the Sun in the West. Contrary to expectation, the data often showed the East side to be brightest. Adding data obtained with Keck and Gemini over the past few years reveals that the East-West asymmetry can be explained by a combination of the solar phase angle effect together with a general preponderance of haze on Titan's East or morning hemisphere. The troposphere was characterized by quiescent weather; only a few small clouds were present near the south pole, at typical altitudes of 30-40 km. While stratospheric haze was prominent over the northern hemisphere, tropospheric haze dominated the south, from the S. pole up to latitudes of {approx} -45{sup o}. An intriguing observation is that obtained at 1.22 {micro}m, which revealed haze in the form of a collar at -60{sup o}, in contrast to the polar haze cap as usually seen. A comparison of narrow band JHK images of Titan's surface with that obtained by Cassini ISS shows a striking resemblance in small-scale features. After a decent attempt to remove the atmosphere from the images, the surface contrast between dark and bright areas may be larger at 2 {micro}m than at 1.6 and 1.3 {micro}m. If true, this could imply that the dark areas on Titan's surface are covered by a coarser grained frost than the bright areas, and/or that there

  10. Route of entry and tissue distribution of Yersinia ruckeri in experimentally infected rainbow trout Oncorhynchus mykiss.

    Science.gov (United States)

    Tobback, E; Decostere, A; Hermans, K; Ryckaert, J; Duchateau, L; Haesebrouck, F; Chiers, K

    2009-04-27

    Yersinia ruckeri is the causative agent of enteric redmouth disease, which leads to significant losses in salmonid aquaculture worldwide. Despite the significance of the disease, little information is available on the pathogenesis. In this study, the portal of entry was investigated using a contact-exposure infection method in rainbow trout Oncorhynchus mykiss with 4 different Y. ruckeri strains. Bacteriological and histological examination revealed the presence of high numbers of bacteria in the gills immediately after infection resulting in a rapid spread of Y. ruckeri in the internal organs. However, only a virulent strain was able to survive and multiply in the host, causing septicaemia and death several days after infection. These findings indicate that gills may be an important site of entry and that Y. ruckeri virulence is related to immune evasion.

  11. Numerical modelling of radon-222 entry into houses: An outline of techniques and results

    DEFF Research Database (Denmark)

    Andersen, C.E.

    2001-01-01

    Numerical modelling is a powerful tool for studies of soil gas and radon-222 entry into houses. It is the purpose of this paper to review some main techniques and results. In the past, modelling has focused on Darcy flow of soil gas (driven by indoor–outdoor pressure differences) and combined......, fractures, moisture, non-uniform soil temperature, non-Darcy flow of gas, and flow caused by changes in the atmospheric pressure. Numerical models can be used to estimate the importance of specific factors for radon entry. Models are also helpful when results obtained in special laboratory or test structure...... experiments need to be extrapolated to more general situations (e.g. to real houses or even to other soil–gas pollutants). Finally, models provide a cost-effective test bench for improved designs of radon prevention systems. The paper includes a summary of transport equations and boundary conditions...

  12. Entry, Descent, and Landing Performance for a Mid-Lift-to-Drag Ratio Vehicle at Mars

    Science.gov (United States)

    Johnson, Breanna J.; Braden, Ellen M.; Sostaric, Ronald R.; Cerimele, Christopher J.; Lu, Ping

    2018-01-01

    In an effort to mature the design of the Mid-Lift-to-Drag ratio Rigid Vehicle (MRV) candidate of the NASA Evolvable Mars Campaign (EMC) architecture study, end-to-end six-degree-of-freedom (6DOF) simulations are needed to ensure a successful entry, descent, and landing (EDL) design. The EMC study is assessing different vehicle and mission architectures to determine which candidate would be best to deliver a 20 metric ton payload to the surface of Mars. Due to the large mass payload and the relatively low atmospheric density of Mars, all candidates of the EMC study propose to use Supersonic Retro-Propulsion (SRP) throughout the descent and landing phase, as opposed to parachutes, in order to decelerate to a subsonic touchdown. This paper presents a 6DOF entry-to-landing performance and controllability study with sensitivities to dispersions, particularly in the powered descent and landing phases.

  13. Exporting Complex Digital Products: Motives and Entry Modes

    DEFF Research Database (Denmark)

    Rask, Morten

    2005-01-01

    When the product is digital, it will most often be distributed directly to the customer through the Internet, and therefore the entry modes, considered in this paper, are different flavors of the entry mode called direct export: Virtual export channel are generally understood as the entry mode fo...... for digital product providers. However other types of entry modes like what wee call direct digital export with F2F-sales, direct digital export with F2F-support and virtual sales subsidiary are entry modes that respond to a higher degree of pre- and after-sales complexity....

  14. Exporting Complex Digital Products: Motives and Entry Modes

    DEFF Research Database (Denmark)

    Rask, Morten

    2005-01-01

    When the product is digital, it will most often be distributed directly to the customer through the Internet, and therefore, the entry modes, considered in this paper, are different flavors of the entry mode called direct export: virtual export channel is generally understood as the entry mode...... for digital product providers. However, other types of entry modes like what we call direct digital export with F2F-sales, direct digital export with F2F-support, and virtual sales subsidiary are entry modes that respond to a higher degree of pre- and postsales complexity....

  15. Mars Global Reference Atmospheric Model 2010 Version: Users Guide

    Science.gov (United States)

    Justh, H. L.

    2014-01-01

    This Technical Memorandum (TM) presents the Mars Global Reference Atmospheric Model 2010 (Mars-GRAM 2010) and its new features. Mars-GRAM is an engineering-level atmospheric model widely used for diverse mission applications. Applications include systems design, performance analysis, and operations planning for aerobraking, entry, descent and landing, and aerocapture. Additionally, this TM includes instructions on obtaining the Mars-GRAM source code and data files as well as running Mars-GRAM. It also contains sample Mars-GRAM input and output files and an example of how to incorporate Mars-GRAM as an atmospheric subroutine in a trajectory code.

  16. S.O.S. Surviving or Surviving

    Science.gov (United States)

    Hersh, Richard H.; Whiteman, James

    1973-01-01

    A High School course, General Studies Survival Curriculum, was designed to aid students in problem solving in a complex society. Areas of concern were psychology, consumer economics, environmental studies, law and society, religion and values, ethnic studies, applied aesthetics, creative studies, occupations and futurism. (JB)

  17. Analysis and Optimization of Entry Stability in Underground Longwall Mining

    Directory of Open Access Journals (Sweden)

    Yubing Gao

    2017-11-01

    Full Text Available For sustainable utilization of limited coal resources, it is important to increase the coal recovery rate and reduce mine accidents, especially those occurring in the entry (gateroad. Entry stabilities are vital for ventilation, transportation and other essential services in underground coal mining. In the present study, a finite difference model was built to investigate stress evolutions around the entry, and true triaxial tests were carried out at the laboratory to explore entry wall stabilities under different mining conditions. The modeling and experimental results indicated that a wide coal pillar was favorable for entry stabilities, but oversize pillars caused a serious waste of coal resources. As the width of the entry wall decreased, the integrated vertical stress, induced by two adjacent mining panels, coupled with each other and experienced an increase on the entry wall, which inevitably weakened the stability of the entry. Therefore, mining with coal pillars always involves a tradeoff between economy and safety. To address this problem, an innovative non-pillar mining technique by optimizing the entry surrounding structures was proposed. Numerical simulation showed that the deformation of the entry roof decreased by approximately 66% after adopting the new approach, compared with that using the conventional mining method. Field monitoring indicated that the stress condition of the entry was significantly improved and the average roof pressure decreased by appropriately 60.33% after adopting the new technique. This work provides an economical and effective approach to achieve sustainable exploitation of underground coal resources.

  18. Entry, Descent, and Landing Communications for the 2011 Mars Science Laboratory

    Science.gov (United States)

    Abilleira, Fernando; Shidner, Jeremy D.

    2012-01-01

    The Mars Science Laboratory (MSL), established as the most advanced rover to land on the surface of Mars to date, launched on November 26th, 2011 and arrived to the Martian Gale Crater during the night of August 5th, 2012 (PDT). MSL will investigate whether the landing region was ever suitable to support carbon-based life, and examine rocks, soil, and the atmosphere with a sophisticated suite of tools. This paper addresses the flight system requirement by which the vehicle transmitted indications of the following events using both X-band tones and UHF telemetry to allow identification of probable root causes should a mission anomaly have occurred: Heat-Rejection System (HRS) venting, completion of the cruise stage separation, turn to entry attitude, atmospheric deceleration, bank angle reversal commanded, parachute deployment, heatshield separation, radar ground acquisition, powered descent initiation, rover separation from the descent stage, and rover release. During Entry, Descent, and Landing (EDL), the flight system transmitted a UHF telemetry stream adequate to determine the state of the spacecraft (including the presence of faults) at 8 kbps initiating from cruise stage separation through at least one minute after positive indication of rover release on the surface of Mars. The flight system also transmitted X-band semaphore tones from Entry to Landing plus one minute although since MSL was occulted, as predicted, by Mars as seen from the Earth, Direct-To-Earth (DTE) communications were interrupted at approximately is approx. 5 min after Entry ( approximately 130 prior to Landing). The primary data return paths were through the Deep Space Network (DSN) for DTE and the existing Mars network of orbiting assets for UHF, which included the Mars Reconnaissance Orbiter (MRO), Mars Odyssey (ODY), and Mars Express (MEX) elements. These orbiters recorded the telemetry data stream and returned it back to Earth via the DSN. The paper also discusses the total power

  19. Hydroelastic slamming of flexible wedges: Modeling and experiments from water entry to exit

    Science.gov (United States)

    Shams, Adel; Zhao, Sam; Porfiri, Maurizio

    2017-03-01

    Fluid-structure interactions during hull slamming are of great interest for the design of aircraft and marine vessels. The main objective of this paper is to establish a semi-analytical model to investigate the entire hydroelastic slamming of a wedge, from the entry to the exit phase. The structural dynamics is described through Euler-Bernoulli beam theory and the hydrodynamic loading is estimated using potential flow theory. A Galerkin method is used to obtain a reduced order modal model in closed-form, and a Newmark-type integration scheme is utilized to find an approximate solution. To benchmark the proposed semi-analytical solution, we experimentally investigate fluid-structure interactions through particle image velocimetry (PIV). PIV is used to estimate the velocity field, and the pressure is reconstructed by solving the incompressible Navier-Stokes equations from PIV data. Experimental results confirm that the flow physics and free-surface elevation during water exit are different from water entry. While water entry is characterized by positive values of the pressure field, with respect to the atmospheric pressure, the pressure field during water exit may be less than atmospheric. Experimental observations indicate that the location where the maximum pressure in the fluid is attained moves from the pile-up region to the keel, as the wedge reverses its motion from the entry to the exit stage. Comparing experimental results with semi-analytical findings, we observe that the model is successful in predicting the free-surface elevation and the overall distribution of the hydrodynamic loading on the wedge. These integrated experimental and theoretical analyses of water exit problems are expected to aid in the design of lightweight structures, which experience repeated slamming events during their operation.

  20. Hepatitis C virus utilizes VLDLR as a novel entry pathway.

    Science.gov (United States)

    Ujino, Saneyuki; Nishitsuji, Hironori; Hishiki, Takayuki; Sugiyama, Kazuo; Takaku, Hiroshi; Shimotohno, Kunitada

    2016-01-05

    Various host factors are involved in the cellular entry of hepatitis C virus (HCV). In addition to the factors previously reported, we discovered that the very-low-density lipoprotein receptor (VLDLR) mediates HCV entry independent of CD81. Culturing Huh7.5 cells under hypoxic conditions significantly increased HCV entry as a result of the expression of VLDLR, which was not expressed under normoxic conditions in this cell line. Ectopic VLDLR expression conferred susceptibility to HCV entry of CD81-deficient Huh7.5 cells. Additionally, VLDLR-mediated HCV entry was not affected by the knockdown of cellular factors known to act as HCV receptors or HCV entry factors. Because VLDLR is expressed in primary human hepatocytes, our results suggest that VLDLR functions in vivo as an HCV receptor independent of canonical CD81-mediated HCV entry.

  1. Finite Element Modeling and Analysis of Mars Entry Aeroshell Baseline Concept

    Science.gov (United States)

    Ahmed, Samee W.; Lane, Brittney M.

    2017-01-01

    The structure that is developed and analyzed in this project must be able to survive all the various load conditions that it will encounter along its course to Mars with the minimal amount of weight and material. At this stage, the goal is to study the capability of the structure using a finite element model (FEM). This FEM is created using a python script, and is numerically solved in Nastran. The purpose of the model is to achieve an optimization of mass given specific constraints on launch and entry. The generation and analysis of the baseline Rigid Mid-Range Lift to Drag Ratio Aeroshell model is a continuation and an improvement on previous work done for the FEM. The model is generated using Python programming with the axisymmetric placement of nodes for beam and shell elements. The shells are assigned a honeycomb sandwich material with an aluminum honeycomb core and composite face sheets, and the beams are assigned the same material as the shell face sheets. There are two load cases assigned to the model: Earth launch and Mars entry. The Earth launch case consists of pressure, gravity, and vibration loads, and the Mars entry case consists of just pressure and gravity loads. The Earth launch case was determined to be the driving case, though the analyses are performed for both cases to ensure the constraints are satisfied. The types of analysis performed with the model are design optimization, statics, buckling, normal modes, and frequency response, the last of which is only for the Earth launch load case. The final results indicated that all of the requirements are satisfied except the thermal limits, which could not yet be tested, and the normal modes for the Mars entry. However, the frequency limits during Mars entry are expected to be much higher than the lower frequency limits set for the analysis. In addition, there are still improvements that can be made in order to reduce the weight while still meeting all requirements.

  2. Adaptive Deployable Entry and Placement Technology (ADEPT)

    Data.gov (United States)

    National Aeronautics and Space Administration — The ADEPT project is a new, advanced heat shield design to protect payloads and landers delivered to planetary bodies with atmospheres. ADEPT is a mechanically...

  3. Aircraft Survivability. Spring 2011

    Science.gov (United States)

    2011-01-01

    panel exhibiting telltale signs and critical fragments were identified and collected. The weapon employed against the aircraft was correctly assessed...701C engines (for FCR- equipped Apache Longbows), and a fully integrated cockpit. In addition, the aircraft received improved survivability...sustained analytical contributions to improve the survivability and effectiveness of US military aircraft and weapon systems. These contributions

  4. Low Cost Entry, Descent, and Landing (EDL) Instrumentation for Planetary Missions

    Science.gov (United States)

    Hwang, H. H.; Munk, M. M.; Dillman, R. A.; Mahzari, M.; Swanson, G. T.; White, T. R.

    2016-01-01

    Missions that involve traversing through a planetary atmosphere are unique opportunities that require elements of entry, descent, and landing (EDL). Many aspects of the EDL sequence are qualified using analysis and simulation due to the inability to conduct appropriate ground tests, however validating flight data are often lacking, especially for missions not involving Earth re-entry. NASA has made strategic decisions to collect EDL flight data in order to improve future mission designs. For example, MEDLI1 and EFT-1 gathered hypersonic pressure and in-depth temperature data in the thermal protection system (TPS). However, the ability to collect EDL flight data from the smaller competed missions, such as Discovery and New Frontiers, has been limited in part due to the Principal Investigator-managed cost-caps (PIMCC). The recent NASA decision to consider EDL instrumentation earlier in the mission design cycle led to the inclusion of a requirement in the Discovery 2014 Announcement of Opportunity which requires all missions that involve EDL to include an Engineering Science Investigation (ESI).2 The ESI would involve sensors for aerothermal environment and TPS; atmosphere, aerodynamics, and flight dynamics; atmospheric decelerator; and/or vehicle structure.3 The ESI activity would be funded outside of the PIMCC.

  5. Atmosphere: Power, Critique, Politics

    DEFF Research Database (Denmark)

    Albertsen, Niels

    2016-01-01

    This paper hans three interrelated parts. First, atmosphere is approached through the concept of power. Atmospheres 'grip' us directly or mediate power indirectly by manipulating moods and evoking emotions. How does atmosphere relate to different conceptions of power? Second, atmospheric powers may...... be critiqued. Which conception of critique can be involved? Third, critiquing atmospheric powers can generate political conflict. How does atmospheric disputes relate to conceptions of politics and the political?...

  6. PDBsum: Structural summaries of PDB entries.

    Science.gov (United States)

    Laskowski, Roman A; Jabłońska, Jagoda; Pravda, Lukáš; Vařeková, Radka Svobodová; Thornton, Janet M

    2018-01-01

    PDBsum is a web server providing structural information on the entries in the Protein Data Bank (PDB). The analyses are primarily image-based and include protein secondary structure, protein-ligand and protein-DNA interactions, PROCHECK analyses of structural quality, and many others. The 3D structures can be viewed interactively in RasMol, PyMOL, and a JavaScript viewer called 3Dmol.js. Users can upload their own PDB files and obtain a set of password-protected PDBsum analyses for each. The server is freely accessible to all at: http://www.ebi.ac.uk/pdbsum. © 2017 The Protein Society.

  7. Business entry and window of opportunity

    DEFF Research Database (Denmark)

    Tegtmeier, Silke; Kurczewska, Agnieszka

    2017-01-01

    This paper explores the nascence period - the time between idea generation and business entry -among women entrepreneurs with a graduate degree. To address this research problem and to better understand the specifics of a window of opportunity, we combine selected theories of human and social...... capital and set up three hypotheses regarding the influence of different factors on the nascence period. To test our hypotheses, we used a representative sample of 678 graduate women entrepreneurs in Germany and ran a logit regression on the nascence period. The estimated model revealed two main factors...

  8. Tides in the Martian atmosphere, and other topics

    Science.gov (United States)

    Withers, Paul Gareth

    2003-11-01

    The dynamics of the martian upper atmosphere are not well-understood. I have identified the dominant tidal modes present in the upper atmosphere by comparing density measurements from the aerobraking of the Mars Global Surveyor spacecraft to predictions from classical tidal theory. Other observations and general circulation models have also provided constraints. I have presented a justification for why topography has a strong influence on the tides in the upper atmosphere. I have also studied sol-to-sol variations in density at fixed altitude, latitude, longitude, season, and time of day. I have developed a novel “Balanced Arch” technique to derive pressures and temperature from these density measurements that also estimates the zonal wind speed in the atmosphere. These are the first measurements of winds in the martian upper atmosphere. This technique can also be applied to anticipated data from Titan to measure winds in its upper atmosphere. I have developed techniques to derive density, pressure, and temperature profiles from entry accelerometer data, used them to investigate the entry of Mars Pathfinder, and discovered that surprisingly accurate temperature profiles can be derived without using any aerodynamic information at all. I have also investigated techniques to derive atmospheric properties from the Doppler shift in telemetry from a spacecraft during atmospheric entry and found that a surprisingly robust estimate of temperature at peak acceleration can be derived. I have discovered a network of tectonic ridges in the otherwise bland northern plains of Mars and studied their implications for a possible ocean in that area. I have tested the hypothesis that the formation of lunar crater Giordano Bruno was witnessed in 1178 AD and rejected it due to the lack of any observations of the immense meteor storm that must have followed the crater's formation.

  9. Atmospheric Models for Mars Aerocapture

    Science.gov (United States)

    Justus, C. G.; Duvall, Aleta; Keller, Vernon W.

    2005-01-01

    level Mars atmospheric model. Applications include systems design, performance analysis, and operations planning for aerobraking, entry descent and landing, and aerocapture. Typical Mars aerocapture periapsis altitudes (for systems with rigid- aeroshell heat shields) are about 50 km. This altitude is above the 0-40 km height range covered by Mars Global Surveyor Thermal Emission Spectrometer (TES) nadir observations. Recently, TES limb sounding data have been made available, spanning more than two Mars years (more than 200,000 data profiles) with altitude coverage up to about 60 km, well within the height range of interest for aerocapture. Results are presented comparing Mars-GRAM atmospheric density with densities from TES nadir and limb sounding observations. A new Mars-GRAM feature is described which allows individual TES nadir or limb profiles to be extracted from the large TES databases, and to be used as an optional replacement for standard Mars-GRAM background (climatology) conditions. For Monte-Carlo applications such as aerocapture guidance and control studies, Mars-GRAM perturbations are available using these TES profile background conditions.

  10. Text Entry by Gazing and Smiling

    Directory of Open Access Journals (Sweden)

    Outi Tuisku

    2013-01-01

    Full Text Available Face Interface is a wearable prototype that combines the use of voluntary gaze direction and facial activations, for pointing and selecting objects on a computer screen, respectively. The aim was to investigate the functionality of the prototype for entering text. First, three on-screen keyboard layout designs were developed and tested (n=10 to find a layout that would be more suitable for text entry with the prototype than traditional QWERTY layout. The task was to enter one word ten times with each of the layouts by pointing letters with gaze and select them by smiling. Subjective ratings showed that a layout with large keys on the edge and small keys near the center of the keyboard was rated as the most enjoyable, clearest, and most functional. Second, using this layout, the aim of the second experiment (n=12 was to compare entering text with Face Interface to entering text with mouse. The results showed that text entry rate for Face Interface was 20 characters per minute (cpm and 27 cpm for the mouse. For Face Interface, keystrokes per character (KSPC value was 1.1 and minimum string distance (MSD error rate was 0.12. These values compare especially well with other similar techniques.

  11. Energy Data Base corporate author entries

    International Nuclear Information System (INIS)

    Hendricks, P.L.

    1984-04-01

    The US Department of Energy is one of three agencies funding the major portion of government-supported research. One of the ways to locate the results of this research is to find reports in the Energy Data Base (EDB), the comprehensive data base of the Office of Scientific and Technical Information, Technical Information Center, and in publications derived therefrom by referring to the corporate organization performing the research. This information field has been established as an index point retrievable in on-line searching and is included as an index in printed publications. To provide consistent citing of names in bibliographic entries, this authority has been created and maintained as a means of entry of corporate names into the EDB. To locate such information, one can (1) use the seven-digit code number assigned to the corporate entity of interest (enter, for example, IC=9506086) or (2) use one word at a time from the corporate name given (enter, for example, CS=Dominion)

  12. 19 CFR 18.11 - Entry; classes of goods for which entry is authorized; form used.

    Science.gov (United States)

    2010-04-01

    ... of entry, or (2) for merchandise in general-order warehouse at any time within 6 months from the date... commodity and chief fiber content (e.g., men's cotton jeans or women's wool sweaters); Net weight of the... consignee may be entered for consumption or warehouse at the port of first arrival, and the remainder...

  13. Essays on international market entry : Strategic alliance governance and product segment entry

    NARCIS (Netherlands)

    Eapen, A.

    2007-01-01

    This dissertation consists of three empirical studies on the entry and evolution of foreign firms in a new market. The common thread through these three essays is a focus on the scope of the foreign firm in a host country, and on how this scope is shaped by local firms and environments. The first

  14. The Carancas meteorite impact crater, Peru: Geologic surveying and modeling of crater formation and atmospheric passage

    Science.gov (United States)

    Kenkmann, T.; Artemieva, N. A.; Wünnemann, K.; Poelchau, M. H.; Elbeshausen, D.; Núñez Del Prado, H.

    2009-08-01

    The recent Carancas meteorite impact event caused a worldwide sensation. An H4-5 chondrite struck the Earth south of Lake Titicaca in Peru on September 15, 2007, and formed a crater 14.2 m across. It is the smallest, youngest, and one of two eye-witnessed impact crater events on Earth. The impact violated the hitherto existing view that stony meteorites below a size of 100 m undergo major disruption and deceleration during their passage through the atmosphere and are not capable of producing craters. Fragmentation occurs if the strength of the meteoroid is less than the aerodynamic stresses that occur in flight. The small fragments that result from a breakup rain down at terminal velocity and are not capable of producing impact craters. The Carancas cratering event, however, demonstrates that meter-sized stony meteoroids indeed can survive the atmospheric passage under specific circumstances. We present results of a detailed geologic survey of the crater and its ejecta. To constrain the possible range of impact parameters we carried out numerical models of crater formation with the iSALE hydrocode in two and three dimensions. Depending on the strength properties of the target, the impact energies range between approximately 100-1000 MJ (0.024- 0.24 t TNT). By modeling the atmospheric traverse we demonstrate that low cosmic velocities (12- 14 kms-1) and shallow entry angles (<20°) are prerequisites to keep aerodynamic stresses low (<10 MPa) and thus to prevent fragmentation of stony meteoroids with standard strength properties. This scenario results in a strong meteoroid deceleration, a deflection of the trajectory to a steeper impact angle (40-60°), and an impact velocity of 350-600 ms-1, which is insufficient to produce a shock wave and significant shock effects in target minerals. Aerodynamic and crater modeling are consistent with field data and our microscopic inspection. However, these data are in conflict with trajectories inferred from the analysis of

  15. First-Order Simulation of Strewn Debris Fields Accompanying Exoatmospheric Re-entry Vehicle Fragmentation by Hypervelocity Impact

    Science.gov (United States)

    1994-09-01

    available information from satellite on- orbit and laboratory collisions. Atmospheric fragment re-entry is modelled using an exponentially dense...interceptions se caracterisent par des etendues de debris mesurant des centaines de kilometres. Si I’ on suppose une distribution uniforme des fragments, on...tests and on- orbit collisions. Much of this work is necessarily speculative: the dynamics of hypervelocity collisions and material behaviour under

  16. An automated entry control system for nuclear facilities

    International Nuclear Information System (INIS)

    Ream, W.K.; Espinoza, J.

    1985-01-01

    An entry control system to automatically control access to nuclear facilities is described. The design uses a centrally located console, integrated into the regular security system, to monitor the computer-controlled passage into and out of sensitive areas. Four types of entry control points are used: an unmanned enclosed portal with metal and SNM detectors for contraband detection with positive personnel identification, a bypass portal for contraband search after a contraband alarm in a regular portal also with positive personnel identification, a single door entry point with positive personnel identification, and a single door entry point with only a magnetic card-type identification. Security force action is required only as a response to an alarm. The integration of the entry control function into the security system computer is also described. The interface between the entry control system and the monitoring security personnel utilizing a color graphics display with touch screen input is emphasized

  17. Orthopoxvirus species and strain differences in cell entry

    Energy Technology Data Exchange (ETDEWEB)

    Bengali, Zain; Satheshkumar, P.S. [Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-3210 (United States); Moss, Bernard, E-mail: bmoss@nih.gov [Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-3210 (United States)

    2012-11-25

    Vaccinia virus (VACV) enters cells by a low pH endosomal route or by direct fusion with the plasma membrane. We previously found differences in entry properties of several VACV strains: entry of WR was enhanced by low pH, reduced by bafilomycin A1 and relatively unaffected by heparin, whereas entry of IHD-J, Copenhagen and Elstree were oppositely affected. Since binding and entry modes may have been selected by specific conditions of in vitro propagation, we now examined the properties of three distinct, recently isolated cowpox viruses and a monkeypox virus as well as additional VACV and cowpox virus strains. The recent isolates were more similar to WR than to other VACV strains, underscoring the biological importance of endosomal entry by orthopoxviruses. Sequence comparisons, gene deletions and gene swapping experiments indicated that viral determinants, other than or in addition to the A26 and A25 'fusion-suppressor' proteins, impact entry properties.

  18. Plutonium in the atmosphere: A global perspective.

    Science.gov (United States)

    Thakur, P; Khaing, H; Salminen-Paatero, S

    2017-09-01

    A number of potential source terms have contributed plutonium isotopes to the atmosphere. The atmospheric nuclear weapon tests conducted between 1945 and 1980 and the re-entry of the burned SNAP-9A satellite in 1964, respectively. It is generally believed that current levels of plutonium in the stratosphere are negligible and compared with the levels generally found at surface-level air. In this study, the time trend analysis and long-term behavior of plutonium isotopes ( 239+240 Pu and 238 Pu) in the atmosphere were assessed using historical data collected by various national and international monitoring networks since 1960s. An analysis of historical data indicates that 239+240 Pu concentration post-1984 is still frequently detectable, whereas 238 Pu is detected infrequently. Furthermore, the seasonal and time-trend variation of plutonium concentration in surface air followed the stratospheric trends until the early 1980s. After the last Chinese test of 1980, the plutonium concentrations in surface air dropped to the current levels, suggesting that the observed concentrations post-1984 have not been under stratospheric control, but rather reflect the environmental processes such as resuspension. Recent plutonium atmospheric air concentrations data show that besides resuspension, other environmental processes such as global dust storms and biomass burning/wildfire also play an important role in redistributing plutonium in the atmosphere. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Surviving Sepsis Campaign

    DEFF Research Database (Denmark)

    Rhodes, Andrew; Evans, Laura E; Alhazzani, Waleed

    2017-01-01

    OBJECTIVE: To provide an update to "Surviving Sepsis Campaign Guidelines for Management of Sepsis and Septic Shock: 2012". DESIGN: A consensus committee of 55 international experts representing 25 international organizations was convened. Nominal groups were assembled at key international meeting...

  20. Europe's Revolving Doors: Import Competition and Endogenous Firm Entry Institutions

    OpenAIRE

    Povilas Lastauskas

    2013-01-01

    The close relationship between politics and enterprises made the revolving door wide open and reinforced business influence on political decisions. This paper analyses the relationship between firm entry institutions and import competition inside the EU. Though there is a clear tendency for entry and startup costs to decrease over time and particularly in space, I challenge the view that greater openness to trade automatically leads to improved firm entry institutions. My model enables calcul...

  1. 33 CFR 151.08 - Denial of entry.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Denial of entry. 151.08 Section... Treaty as it Pertains to Pollution from Ships General § 151.08 Denial of entry. (a) Unless a ship is... COTP may deny the entry of a ship to a port or terminal under § 158.110(b) if— (1) The port or terminal...

  2. 48 CFR 252.225-7013 - Duty-free entry.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Duty-free entry. 252.225... Clauses 252.225-7013 Duty-free entry. As prescribed in 225.1101(4), use the following clause: Duty-Free Entry (DEC 2009) (a) Definitions. As used in this clause— (1) “Component” means any item supplied to the...

  3. 9 CFR 98.6 - Ports of entry.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Ports of entry. 98.6 Section 98.6... Disease; and Embryos of Horses and Asses § 98.6 Ports of entry. An embryo shall not be imported into the United States unless at a port of entry listed in § 93.303 for horses, § 93.403 for ruminants, or § 93...

  4. Forcible Entry and the German Invasion of Norway, 1940

    National Research Council Canada - National Science Library

    Richardson, Michael

    2001-01-01

    ...? Forcible entry is the introduction of an aggregation of military personnel, weapons systems, vehicles, and necessary support, or a combination thereof, embarked for the purpose of gaining access...

  5. Methodological aspects of journaling a dynamic adjusting entry model

    Directory of Open Access Journals (Sweden)

    Vlasta Kašparovská

    2011-01-01

    Full Text Available This paper expands the discussion of the importance and function of adjusting entries for loan receivables. Discussion of the cyclical development of adjusting entries, their negative impact on the business cycle and potential solutions has intensified during the financial crisis. These discussions are still ongoing and continue to be relevant to members of the professional public, banking regulators and representatives of international accounting institutions. The objective of this paper is to evaluate a method of journaling dynamic adjusting entries under current accounting law. It also expresses the authors’ opinions on the potential for consistently implementing basic accounting principles in journaling adjusting entries for loan receivables under a dynamic model.

  6. An Integrated Approach for Entry Mission Design and Flight Simulations

    Science.gov (United States)

    Lu, Ping; Rao, Prabhakara

    2004-01-01

    An integrated approach for entry trajectory design, guidance, and simulation is proposed. The key ingredients for this approach are an on-line 3 degree-of-freedom entry trajectory planning algorithm and the entry guidance algorithm that generates the guidance gains automatically. When fully developed, such a tool could enable end-bend entry mission design and simulations in 3DOF and 6DOF mode from de-orbit burn to the TAEM interface and beyond, all in one key stroke. Some preliminary examples of such a capability are presented in this paper that demonstrate the potential of this type of integrated environment.

  7. Radon entry into a simple test structure

    DEFF Research Database (Denmark)

    Andersen, C.E.; Søgaard-Hansen, J.; Majborn, B.

    1992-01-01

    membrane, and soil gas enters the cylinder through a changeable interface in the bottom. The depressurisation of the cylinder is controlled by a mass-flow controller, thereby limiting the influence of natural driving forces. Pressures, temperatures and radon concentrations are measured continuously...... in the cylinder and in selected locations in the soil. In this paper, the test structure is described, and initial results concerning the transport of soil gas and radon under steady-state conditions are reported. It is found that the soil in the vicinity of the structure is partially depleted with respect......A simple test structure for studies of radon entry into houses has been constructed at a field site at Riso National Laboratory. It consists of a 40 1, stainless-steel cylinder placed in a 0.52 m deep quadratic excavation with a side length of 2.4 m. The excavation is lined with an airtight...

  8. Regulated portals of entry into the cell

    Science.gov (United States)

    Conner, Sean D.; Schmid, Sandra L.

    2003-03-01

    The plasma membrane is the interface between cells and their harsh environment. Uptake of nutrients and all communication among cells and between cells and their environment occurs through this interface. `Endocytosis' encompasses several diverse mechanisms by which cells internalize macromolecules and particles into transport vesicles derived from the plasma membrane. It controls entry into the cell and has a crucial role in development, the immune response, neurotransmission, intercellular communication, signal transduction, and cellular and organismal homeostasis. As the complexity of molecular interactions governing endocytosis are revealed, it has become increasingly clear that it is tightly coordinated and coupled with overall cell physiology and thus, must be viewed in a broader context than simple vesicular trafficking.

  9. Home infusion: overcoming the barriers to entry.

    Science.gov (United States)

    Franklin, David M

    2010-01-01

    The field of pharmacy service is evolving rapidly, as is the delivery of healthcare in general. From patients with infectious diseases dying because there was nothing available to fight the infections, to the involvement of an episodic-based model of care with patients traversing inpatient- and outpatient-based delivery systems, to the new frontier of chronic care and with supports such as the one by the Centers for Disease Control that hospital-acquired infections are killing about 100,000 Americans every year, the home infusion business has become a major alternative to in-hospital treatment. This article discusses the barriers to entry into the home infusion business and assists in the evaluation of a home infusion reimbursement organization.

  10. Impact Foam Testing for Multi-Mission Earth Entry Vehicle Applications

    Science.gov (United States)

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

    2013-01-01

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

  11. Characteristics of the GOCE Orbit in the Re-Entry Phase

    Science.gov (United States)

    Hamm, Johann; Lengsfeld, Alexander; Kekce, Ugur; Pape, Werner; Shabanloui, Akbar; Naeimi, Majid; Flury, Jakob

    2015-03-01

    The GOCE de-orbiting phase was started as the Ion thruster was switched off on 21st October 2013. Beginning with this, the transition from the Drag-Free and Attitude Control System (DFACS) to Fine Pointing Mode (FPM) started, so the Gradiometer was no longer in the attitude control loop. On 11th of November 2013, the de-orbiting phase ended with the re-entry of GOCE in the Earth’s atmosphere, near to the Falkland Islands. As a part of a research project, we analyzed the 20 days of the GOCE data during de-orbiting phase. We investigate: Electrostatic Gravity Gradiometer (EGG), DFACS Accelerometer data, Magneto-Torques Currents (MTR) data, Precise Science Orbits (PSO) data, Satellite to Satellite Tracking (SST) data and Atmospheric Models (MSISE-90, NRMSISE-00).

  12. Two Bistable Switches Govern M Phase Entry.

    Science.gov (United States)

    Mochida, Satoru; Rata, Scott; Hino, Hirotsugu; Nagai, Takeharu; Novák, Béla

    2016-12-19

    The abrupt and irreversible transition from interphase to M phase is essential to separate DNA replication from chromosome segregation. This transition requires the switch-like phosphorylation of hundreds of proteins by the cyclin-dependent kinase 1 (Cdk1):cyclin B (CycB) complex. Previous studies have ascribed these switch-like phosphorylations to the auto-activation of Cdk1:CycB through the removal of inhibitory phosphorylations on Cdk1-Tyr15 [1, 2]. The positive feedback in Cdk1 activation creates a bistable switch that makes mitotic commitment irreversible [2-4]. Here, we surprisingly find that Cdk1 auto-activation is dispensable for irreversible, switch-like mitotic entry due to a second mechanism, whereby Cdk1:CycB inhibits its counteracting phosphatase (PP2A:B55). We show that the PP2A:B55-inhibiting Greatwall (Gwl)-endosulfine (ENSA) pathway is both necessary and sufficient for switch-like phosphorylations of mitotic substrates. Using purified components of the Gwl-ENSA pathway in a reconstituted system, we found a sharp Cdk1 threshold for phosphorylation of a luminescent mitotic substrate. The Cdk1 threshold to induce mitotic phosphorylation is distinctly higher than the Cdk1 threshold required to maintain these phosphorylations-evidence for bistability. A combination of mathematical modeling and biochemical reconstitution show that the bistable behavior of the Gwl-ENSA pathway emerges from its mutual antagonism with PP2A:B55. Our results demonstrate that two interlinked bistable mechanisms provide a robust solution for irreversible and switch-like mitotic entry. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Parvoviral host range and cell entry mechanisms.

    Science.gov (United States)

    Cotmore, Susan F; Tattersall, Peter

    2007-01-01

    Parvoviruses elaborate rugged nonenveloped icosahedral capsids of approximately 260 A in diameter that comprise just 60 copies of a common core structural polypeptide. While serving as exceptionally durable shells, capable of protecting the single-stranded DNA genome from environmental extremes, the capsid also undergoes sequential conformational changes that allow it to translocate the genome from its initial host cell nucleus all the way into the nucleus of its subsequent host. Lacking a duplex transcription template, the virus must then wait for its host to enter S-phase before it can initiate transcription and usurp the cell's synthetic pathways. Here we review cell entry mechanisms used by parvoviruses. We explore two apparently distinct modes of host cell specificity, first that used by Minute virus of mice, where subtle glycan-specific interactions between host receptors and residues surrounding twofold symmetry axes on the virion surface mediate differentiated cell type target specificity, while the second involves novel protein interactions with the canine transferrin receptor that allow a mutant of the feline leukopenia serotype, Canine parvovirus, to bind to and infect dog cells. We then discuss conformational shifts in the virion that accompany cell entry, causing exposure of a capsid-tethered phospholipase A2 enzymatic core that acts as an endosomolytic agent to mediate virion translocation across the lipid bilayer into the cell cytoplasm. Finally, we discuss virion delivery into the nucleus, and consider the nature of transcriptionally silent DNA species that, escaping detection by the cell, might allow unhampered progress into S-phase and hence unleash the parvoviral Trojan horse.

  14. Founding a business inspired by close entrepreneurial ties: Does it matter for survival?

    NARCIS (Netherlands)

    de Jong, J.P.J.; Marsili, O.

    2015-01-01

    Founding a business may be inspired by close entrepreneurial ties, that is, business-owning relatives or friends. We analyze if and when such inspiration is associated with post-entry survival. Drawing on longitudinal data on 942 founders, we find a positive relationship only if founders start by

  15. Investigation of Non-Equilibrium Radiation for Earth Entry

    Science.gov (United States)

    Brandis, A. M.; Johnston, C. O.; Cruden, B. A.

    2016-01-01

    For Earth re-entry at velocities between 8 and 11.5 km/s, the accuracy of NASA's computational uid dynamic and radiative simulations of non-equilibrium shock layer radiation is assessed through comparisons with measurements. These measurements were obtained in the NASA Ames Research Center's Electric Arc Shock Tube (EAST) facility. The experiments were aimed at measuring the spatially and spectrally resolved radiance at relevant entry conditions for both an approximate Earth atmosphere (79% N2 : 21% O2 by mole) as well as a more accurate composition featuring the trace species Ar and CO2 (78.08% N2 : 20.95% O2 : 0.04% CO2 : 0.93% Ar by mole). The experiments were configured to target a wide range of conditions, of which shots from 8 to 11.5 km/s at 0.2 Torr (26.7 Pa) are examined in this paper. The non-equilibrium component was chosen to be the focus of this study as it can account for a significant percentage of the emitted radiation for Earth re-entry, and more importantly, non-equilibrium has traditionally been assigned a large uncertainty for vehicle design. The main goals of this study are to present the shock tube data in the form of a non-equilibrium metric, evaluate the level of agreement between the experiment and simulations, identify key discrepancies and to examine critical aspects of modeling non-equilibrium radiating flows. Radiance pro les integrated over discreet wavelength regions, ranging from the Vacuum Ultra Violet (VUV) through to the Near Infra-Red (NIR), were compared in order to maximize both the spectral coverage and the number of experiments that could be used in the analysis. A previously defined non-equilibrium metric has been used to allow comparisons with several shots and reveal trends in the data. Overall, LAURA/HARA is shown to under-predict EAST by as much as 40% and over-predict by as much as 12% depending on the shock speed. DPLR/NEQAIR is shown to under-predict EAST by as much as 50% and over-predict by as much as 20% depending

  16. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from GILLISS in the North Atlantic Ocean from 1977-05-05 to 1977-09-02 (NODC Accession 7800461)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This entry contains the results from the Outer Continental Shelf Study (OCS) benchmark study in the North Atlantic which ran May 5 to September 2, 1977 from the R/V...

  17. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from KNORR in the North Atlantic Ocean from 1977-11-22 to 1977-12-04 (NODC Accession 7800462)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This entry contains the results from the Outer Continental Shelf Study (OCS) benchmark study in the North Atlantic which ran November to December 1977 from the R/V...

  18. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from GYRE in the North Atlantic Ocean from 1977-05-05 to 1977-05-25 (NODC Accession 7800460)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This entry contains the results from the Outer Continental Shelf study (OCS) benchmark study in the North Atlantic which ran during the month of May 77 from the R/V...

  19. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from ISLAS ORCADAS in the North Atlantic Ocean from 1976-11-03 to 1976-12-18 (NCEI Accession 8100429)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This entry contains bottle cast data, collected by ISLAS ORCADAS SHIP (cruise 11) between November 3, 1976 to December 18, 1976, in the North Atlantic Ocean. This...

  20. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from GYRE in the North Atlantic Ocean from 1977-02-10 to 1977-03-07 (NODC Accession 7800459)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This entry contains the results from the Outer Continental Shelf Study (OCS) Benchmark Study in the North Atlantic which ran from February 10 to March 7, 1977 from...

  1. An Examination of Market Entry Perspectives in Emerging Markets

    Directory of Open Access Journals (Sweden)

    Marvin O. Bates

    2017-11-01

    Full Text Available Purpose – The purpose of this article is to describe the marketing-oriented market entry approaches that businesses are currently using across the three levels of the world economic pyramid (i.e., WEP. These levels are the Top-tier, the Middle-tier, and the Base of the Pyramid-tier (i.e., BoP-tier. Methodology – The literature of the BoP was reviewed, and market entry approaches were itemized across the three WEP levels. Secondly, BoP strategic theorists including Prahalad identified the need for a BoP marketing focus replacing the traditional 4Ps marketing approach (i.e., Product, Price, Place and Promotion with the BoP-specific 4As marketing approach (i.e., Awareness, Affordability, Access and Availability. This 4As marketing approach is discussed. Findings – New marketing-oriented market-entry approaches are proposed for each of the three WEP levels. These approaches are based on where in the WEP the firm currently exists, and where in the WEP the firm desires to refocus market-entry activities; identified approaches include: inter-country expansion, intra-country entry, adjacent market entry, and extended market entry. Secondly, the absence of a clearly articulated marketing strategy for middle-tier markets was observed. Practical implications – This article has two specific applications. First, it summarizes the evolving market entry perspectives to provide a context for future market research in both emerging markets and the pre-emerging BoP markets. Second, the future requirement for an articulated marketing strategy for middle-tier markets is suggested. Originality – This article examined existing market entry approaches across all three levels of the WEP, inclusive of the BoP economic level. The language used to clarify market entry movements was extended, providing a specificity of description not previously found in either the existing market entry or BoP literature.

  2. STILL AROUND? BARRIERS TO ENTRY IN SOLO MEDICAL PRACTICE IN SUBURBAN SETTINGS

    Directory of Open Access Journals (Sweden)

    Roger Lee Mendoz

    2017-03-01

    Full Text Available BACKGROUND Unlike many other countries, only 19% of physicians remain independent or solo practitioners in the United States. This study seeks to determine if entry barriers to solo practice exist in physician services markets with a predominantly suburban patient base. Any entry barrier will play a critical role in a wide variety of competition and income-related issues in these markets. MATERIALS AND METHODS This study hypothesizes that substantial deterrence to entry is present in suburban settings where physician competition is typically much less than metropolitan areas. Information about their competitive position was obtained from solo primary care physicians (PCPs and specialists in southern New Jersey municipalities. Two-sample t - tests (α =0.05 ascertained whether the means differences of these two groups are statistically significant for the population from which they were sampled. Regression coefficients were computed for the magnitude of differences in barrier impact between samples. RESULTS Adapting the Orr model, E = ß0 e ß 1 (πp -π* e ß 2 Q . S ß 3 µ, to this study allowed us to estimate the overall height of entry barriers to suburban solo practice. The study finds that entry barriers tend to have moderate effects on PCPs, with the exception of legal and regulatory compliance which are just as burdensome to specialists. Risk and insurance, capital, advertising, research and development (R & D as well as market concentration are far more challenging to solo specialists mainly due to overuse of already costly tests, procedures, and medications by specialists for "defensive medicine," and heavy reliance on specialists by PCPs. Labor costs are associated with several barriers. CONCLUSION Despite their declining population, market entry (and presumably survival of solo physicians is not as straightforward of a phenomenon as conjectural and anecdotal evidence might suggest. Medical specialty offers an explanatory variable

  3. Legitimacy of Entry-Oriented Strategy in DeBakey I Dissection in the Era of Endovascular Therapy.

    Science.gov (United States)

    Ghazy, Tamer; Kappert, Utz; Hoffmann, Ralf-Thorsten; Hegelmann, Helena; Fajfrova, Zuzana; Eraqi, Mohamed; Matschke, Klaus; Weiss, Norbert; Mahlmann, Adrian

    2017-10-24

    Legitimacy of entry-oriented therapy for DeBakey I aortic dissection is of eminent importance in the era of emerging ascending aorta endovascular therapy. This study aims to evaluate early, midterm, and reintervention results of entry-oriented operative strategy compared to more aggressive strategies for treatment of DeBakey type I aortic dissection with an isolated intimal tear in the ascending aorta. This study prospectively followed 98 consecutive patients who received an operation for DeBakey type I aortic dissection with the intimal tear in the ascending aorta between 2007 and 2013 for up to 6 years. Follow-up included survival, medical therapy, CT-imaging results, and reinterventions. Patients were grouped into entry-oriented (group I) receiving an isolated replacement of the ascending aorta and/or hemiarch (65 patients); and aggressive therapy (group II) receiving a replacement of the ascending aorta and complete aortic arch (33 patients). Results: The in-hospital mortality was 19% and 23% respectively. The 3-year survival was 52% and 47% respectively (P = .193). Group II showed no advantage regarding persistence or progression of the dissection, thrombosis of false lumen, increase in aortic diameter, peripheral organ malperfusion (as assessed by follow-up computed tomography imaging) or freedom from reintervention. Conclusion: In treating DeBakey I aortic dissection with an entry tear in the ascending aorta, it might be legitimate to adopt an entry-oriented operative strategy. Further research is also needed to clearly describe the indication of extending the operative strategy in such cases.

  4. Atmospheric composition change: Ecosystems–Atmosphere interactions

    DEFF Research Database (Denmark)

    Fowler, D.; Pilegaard, Kim; Sutton, M.A.

    2009-01-01

    Ecosystems and the atmosphere: This review describes the state of understanding the processes involved in the exchange of trace gases and aerosols between the earth's surface and the atmosphere. The gases covered include NO, NO2, HONO, HNO3, NH3, SO2, DMS, Biogenic VOC, O3, CH4, N2O and particles...

  5. Atmospheric composition change: Ecosystems-Atmosphere interactions

    NARCIS (Netherlands)

    Fowler, D.; Pilegaard, K.; Sutton, M.A.; Ambus, P.; Raivonen, M.; Duyzer, J.; Simpson, D.; Fagerli, H.; Fuzzi, S.; Schjoerring, J.K.; Granier, C.; Neftel, A.; Isaksen, I.S.A.; Laj, P.; Maione, M.; Monks, P.S.; Burkhardt, J.; Daemmgen, U.; Neirynck, J.; Personne, E.; Wichink Kruit, R.J.; Butterbach-Bahl, K.; Flechard, C.; Tuovinen, J.P.; Coyle, M.; Gerosa, G.; Loubet, B.; Altimir, N.; Gruenhage, L.; Ammann, C.; Cieslik, S.; Paoletti, E.; Mikkelsen, T.N.; Ro-Poulsen, H.; Cellier, P.; Cape, J.N.; Horvath, L.; Loreto, F.; Niinemets, U.; Palmer, P.I.; Rinne, J.; Misztal, P.; Nemitz, E.; Nilsson, D.; Pryor, S.; Gallagher, M.W.; Vesala, T.; Skiba, U.; Brueggemann, N.; Zechmeister-Boltenstern, S.; Williams, J.; O'Dowd, C.; Facchini, M.C.; Leeuw, de G.; Flossman, A.; Chaumerliac, N.; Erisman, J.W.

    2009-01-01

    Ecosystems and the atmosphere: This review describes the state of understanding the processes involved in the exchange of trace gases and aerosols between the earth's surface and the atmosphere. The gases covered include NO, NO2, HONO, HNO3, NH3, SO2, DMS, Biogenic VOC, O-3, CH4, N2O and particles

  6. Taking entry heating credit to address planetary protection bio-burden limits

    Science.gov (United States)

    Witte, J.; Clark, B.; Linch, S.; Johnson, M.; Bomba, K.; Oakman, K.; Tice, N.; Kast, W.; Willcockson, W.

    In 2005 NASA will launch a large orbiting science observatory, the Mars Reconnaissance Orbiter (MRO), for what should be a 5.4-year mission. High resolution imaging of the surface is a principle goal of the mission. One consequence of this goal however is the need for a low science orbit. Unfortunately this orbit fails the required 20-year orbit life requirements set in NASA Policy Guideline. So rather than sacrifice the science goals of the mission by raising the science orbit, the MRO Project chose to be the first orbiter to pursue the bio-burden reduction approach. Because the orbiter is so large, cleaning only is insufficient to achieve the bio-burden threshold requirement in NASA Policy. This presentation outlines one of the processes developed to reduce bio-burden by taking credit for hardware that will either never reach the surface or achieves high temperature during entry due to ablation and aero-heating. Lockheed Martin engineers developed a process to perform what is called breakup and burn-up analysis. This process considers the assumptions that go into modeling and into decision methods that result on structural degradation branching points. Structural degradation rate is driven by thermal properties of the hardware. These branching points produce multiple trajectory bodies of their own. Assumptions of body shape, mass and velocity drive the rate aero-heating in the entry trajectory. As entry velocity decays so does the available entry heating. In the end, an inventory of all the SC hardware is done in terms of Exempt (burned-up or sufficiently heated) and Non-exempt (survived to surface) components. © Lockheed Martin Corporation A companion paper by the Jet Propulsion Laboratory discusses how this data is integrated into the overall bio-burden assessment activity and the derivation of the Implementation Plan.

  7. Re-entry Flight Experiments Lessons Learned - The Atmospheric Reentry Demonstrator ARD

    Science.gov (United States)

    2007-06-01

    and internal radiative heat transfer , conductive heat transfer in the complete calorimeter, and non-linear thermal properties of the materials... transfer coefficient hr is the recovery enthalpy β is the cold face heat loss coefficient Preliminary assessment of elementary uncertainties has...26-29, 2001. [R7] Vincent P., “Ariane 5: Ambiance thermique – procédure d’exploitation des fluxmètres vol”, EADS-ST Technical Note A5-NT-A-1-2093

  8. Nonlinear Aerodynamic ROM-Structural ROM Methodology for Inflatable Aeroelasticity in Hypersonic Atmospheric Entry, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — ZONA Technology proposes to develop an innovative nonlinear structural reduced order model (ROM) - nonlinear aerodynamic ROM methodology for the inflatable...

  9. Direct Simulation Monte Carlo for Atmospheric Entry. 1. Theoretical Basis and Physical Models

    Science.gov (United States)

    2009-09-01

    of Nonequilibrium Flow in Low Power Hydrogen Arcjets ,” Physics of Fluids. Vol. 9, 1997, pp. 3086-3095. [47] Gallis, M.A. and Harvey, J.K., “Atomic...method (DSMC) has evolved over 40 years into a powerful numerical technique for the computation of complex, nonequilibrium gas flows. In this context...nonequilibrium means that the velocity distribution function is not in an equilibrium form due to a low number of intermolecular collisions within a

  10. Flexible Transpiration Cooled Thermal Protection System for Inflatable Atmospheric Capture and Entry Systems, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Andrews Space, Inc. proposes an innovative transpiration cooled aerobrake TPS design that is thermally protective, structurally flexible, and lightweight. This...

  11. Flexible Transpiration Cooled Thermal Protection System for Inflatable Atmospheric Capture and Entry Systems, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Andrews Space, Inc. proposes an innovative transpiration cooled aerobrake TPS design that is thermally protective, structurally flexible, and lightweight. This...

  12. Evaluating changes in the elemental composition of micrometeorites during entry into the earth`s atmosphere

    Digital Repository Service at National Institute of Oceanography (India)

    Rudraswami, N.G.; ShyamPrasad, M.; Dey, S.; Plane, J.M.C.; Feng, W.; Taylor, S.

    similar way (Fig.10d). The slow vaporization of Ca and Al can be useful for identifying the 9    precursors from Ca/Si and Al/Si ratios. The disadvantage is the difficulty involved in considering the chemical composition of the particle which does...

  13. Operational experience in the Langley expansion tube with various test gases. [for atmospheric entry simulation

    Science.gov (United States)

    Miller, C. G.

    1977-01-01

    The Langley Expansion Tube is an operational facility capable of producing good quality, highly repeatable, quasi-steady flow for test times sufficient to establish flow about blunt axisymmetric and two-dimensional models. Due to the capability of testing with arbitrary test gases, a wide range of real-gas, hypersonic-hypervelocity flow conditions may be generated. However, for a given test gas, the range of operating conditions producing useful flow is shown to be rather limited; hence, the facility yields a given flow condition for a given test gas, and variation in flow conditions comes about by using different test gases. Data are presented for operations using air and carbon dioxide as test gases. The driver gas was unheated helium at a nominal pressure of 5000 psi (34.5 MN sq m).

  14. Comparison of Direct Trocar Entry and Veress Needle Entry in Laparoscopic Bariatric Surgery: Randomized Controlled Trial.

    Science.gov (United States)

    Ertugrul, Ismail; Kayaalp, Cuneyt; Yagci, Mehmet Ali; Sumer, Fatih; Karagul, Servet; Tolan, Kerem

    2015-11-01

    We aimed to compare the direct trocar insertion (DTI) and Veress needle insertion (VNI) techniques in laparoscopic bariatric surgery. Eighty-one patients scheduled for bariatric surgery at Inonu University, Malatya, Turkey, were included in this study. In 39 patients, a bladed retractable nonoptical trocar was used for DTI, and VNI was performed in 42 patients. Intraoperative access-related parameters were compared. Data were analyzed with Student's t and chi-squared tests. A P value of Successful entry rates in the first attempt, CO2 consumptions, failed attempt rates, and overall intraoperative complication rates were similar. However, in the DTI group, 2 patients had mesenteric injuries, and 1 of them required conversion to open surgery due to the mesenteric hemorrhage. DTI in obese patients significantly shortens the entry time, but there can be severe complications with DTI when a nonoptical bladed trocar is used blindly. Actually, neither method can be recommended for entry into the abdomen in this population based on our results. If the surgeon has to choose a nonoptical trocar in bariatric surgery, preference for the VNI technique instead of the DTI technique is safer.

  15. DEBRISK, a Tool for Re-Entry Risk Analysis

    Science.gov (United States)

    Omaly, P.; Spel, M.

    2012-01-01

    An act of French parliament, adopted in 2008, imposes satellite constructors to evaluate the end-of-life operations in order to assure the risk mitigation of their satellites. One important element in this evaluation is the estimation of the mass and impact energy of the satellite debris after atmospheric re-entry. For this purpose, CNES has developed the tool DEBRISK which allows the operator to simulate the re-entry phase and to study the demise altitudes or impact energy of the individual fragments of the original satellite. DEBRISK is based on the so called object based approach. Using this approach, a breakup altitude is assumed where the satellite disintegrates due to the pressure loads. This altitude is typically around 78 km. After breakup, the satellite structure is modelled by a parent-child approach, where each child has its birth criterion. In the simplest approach the child is born after demise of the parent object. This could be the case of an object A containing an object B which is in the interior of object A and thus not exposed to the atmosphere. Each object is defined by: - its shape, attitude and dimensions, - the material along with their physical properties - the state and velocity vectors. The shape, attitude and dimensions define the aerodynamic drag of the object which is input to the 3DOF trajectory modelling. The aerodynamic mass used in the equation of motion is defined as the sum of the object's own mass and the mass of the object's offspring. A new born object inherits the state vector of the parent object. The shape, attitude and dimensions also define the heating rates experienced by the object. The heating rate is integrated in time up to the point where the melting temperature is reached. The mass of melted material is computed from the excess heat and the material properties. After each step the amount of ablated material is determined using the lumped mass approach and is peeled off from the object, updating mass and shape of the

  16. Modeling radon entry into houses with basements: Model description and verification

    International Nuclear Information System (INIS)

    Revzan, K.L.; Fisk, W.J.; Gadgil, A.J.

    1991-01-01

    We model radon entry into basements using a previously developed three-dimensional steady-state finite difference model that has been modified in the following ways: first, cylindrical coordinates are used to take advantage of the symmetry of the problem in the horizontal plant; second, the configuration of the basement has been made more realistic by incorporating the concrete footer; third, a quadratic relationship between the pressure and flow in the L-shaped gap between slab, footer, and wall has been employed; fourth, the natural convection of the soil gas which follows from the heating of the basement in winter has been taken into account. The temperature field in the soil is determined from the equation of energy conservation, using the basement, surface, and deep-soil temperatures as boundary conditions. The pressure field is determined from Darcy's law and the equation of mass conservation (continuity), assuming that there is no flow across any boundary except the soil surface (atmospheric pressure) and the opening in the basement shell (fixed pressure). After the pressure and temperatures field have been obtained the velocity field is found from Darcy's law. Finally, the radon concentration field is found from the equation of mass-transport. The convective radon entry rate through the opening or openings is then calculated. In this paper we describe the modified model, compare the predicted radon entry rates with and without the consideration of thermal convection, and compare the predicted rates with determined from data from 7 houses in the Spokane River valley of Washington and Idaho. Although the predicted rate is much lower than the mean of the rates determined from measurements, errors in the measurement of soil permeability and variations in the permeability of the area immediately under the basement slab, which has a significant influence on the pressure field, can account for the range of entry rates inferred from the data. 25 refs., 8 figs

  17. Atmospheric-pressure plasma jet

    Science.gov (United States)

    Selwyn, Gary S.

    1999-01-01

    Atmospheric-pressure plasma jet. A .gamma.-mode, resonant-cavity plasma discharge that can be operated at atmospheric pressure and near room temperature using 13.56 MHz rf power is described. Unlike plasma torches, the discharge produces a gas-phase effluent no hotter than 250.degree. C. at an applied power of about 300 W, and shows distinct non-thermal characteristics. In the simplest design, two concentric cylindrical electrodes are employed to generate a plasma in the annular region therebetween. A "jet" of long-lived metastable and reactive species that are capable of rapidly cleaning or etching metals and other materials is generated which extends up to 8 in. beyond the open end of the electrodes. Films and coatings may also be removed by these species. Arcing is prevented in the apparatus by using gas mixtures containing He, which limits ionization, by using high flow velocities, and by properly shaping the rf-powered electrode. Because of the atmospheric pressure operation, no ions survive for a sufficiently long distance beyond the active plasma discharge to bombard a workpiece, unlike low-pressure plasma sources and conventional plasma processing methods.

  18. Foreign Bank Entry and Credit Allocation in Emerging Markets

    NARCIS (Netherlands)

    Degryse, H.A.; Havrylchyk, O.; Jurzyk, E.; Kozak, S.

    2009-01-01

    We employ a unique data set containing bank-specific information to explore how foreign bank entry determines credit allocation in emerging markets. We investigate the impact of the mode of foreign entry (greenfield or takeover) on banks’ portfolio allocation to borrowers with different degrees of

  19. 19 CFR 146.63 - Entry for consumption.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Entry for consumption. 146.63 Section 146.63... TREASURY (CONTINUED) FOREIGN TRADE ZONES Transfer of Merchandise From a Zone § 146.63 Entry for consumption... status may be entered for consumption from a zone. (b) Zone-restricted merchandise. Merchandise in a zone...

  20. Racial/Ethnic Disparities in ADHD Diagnosis by Kindergarten Entry

    Science.gov (United States)

    Morgan, Paul L.; Hillemeier, Marianne M.; Farkas, George; Maczuga, Steve

    2014-01-01

    Background: Whether and to what extent racial/ethnic disparities in attention-deficit/hyperactivity disorder (ADHD) diagnosis occur by kindergarten entry is currently unknown. We investigated risk factors associated with an ADHD diagnosis by kindergarten entry generally, and specifically whether racial/ethnic disparities in ADHD diagnosis occur by…

  1. 18 CFR 33.5 - Proposed accounting entries.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Proposed accounting... § 33.5 Proposed accounting entries. If the applicant is required to maintain its books of account in... present proposed accounting entries showing the effect of the transaction with sufficient detail to...

  2. Entry Times Distribution for Dynamical Balls on Metric Spaces

    Science.gov (United States)

    Haydn, N.; Yang, F.

    2017-04-01

    We show that the entry and return times for dynamical balls (Bowen balls) is exponential for systems that have an α -mixing invariant measure with certain regularities. We also show that systems modeled by Young's tower has exponential entry time distribution for dynamical balls. We also apply the results to conformal maps and expanding maps on the interval.

  3. The Importance of Prior Probabilities for Entry Page Search

    NARCIS (Netherlands)

    Kraaij, W.; Westerveld, T.H.W.; Hiemstra, Djoerd

    An important class of searches on the world-wide-web has the goal to find an entry page (homepage) of an organisation. Entry page search is quite different from Ad Hoc search. Indeed a plain Ad Hoc system performs disappointingly. We explored three non-content features of web pages: page length,

  4. 46 CFR 154.1828 - Spaces containing cargo vapor: Entry.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Spaces containing cargo vapor: Entry. 154.1828 Section... Spaces containing cargo vapor: Entry. (a) No person may enter a cargo handling space without the... toxic vapors and has an oxygen concentration of at least 19.5 percent oxygen by volume; or (2) Those...

  5. 47 CFR 11.14 - Primary Entry Point (PEP) System.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Primary Entry Point (PEP) System. 11.14 Section 11.14 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL EMERGENCY ALERT SYSTEM (EAS) General § 11.14 Primary Entry Point (PEP) System. The PEP system is a nationwide network of broadcast...

  6. 19 CFR 143.35 - Procedure for electronic entry summary.

    Science.gov (United States)

    2010-04-01

    ... will submit certified entry summary data electronically through ABI. Data will be validated and, if the transmission is found error-free, will be accepted. If it is determined through selectivity criteria and review of data that documentation is required for further processing of the entry summary, Customs will so...

  7. Decreasing Entry into a Restricted Area Using a Visual Barrier

    Science.gov (United States)

    Feliciano, Leilani; Vore, Jessica; LeBlanc, Linda A.; Baker, Jonathan C.

    2004-01-01

    Wandering is a difficult-to-manage behavior problem for individuals with cognitive impairments that can jeopardize safety if an individual enters a hazardous area or becomes lost. This study investigated the effects of a cloth barrier on entry into an unsafe area. The cloth barrier reduced entry into the restricted area and had high treatment…

  8. 27 CFR 478.23 - Right of entry and examination.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Right of entry and... Administrative and Miscellaneous Provisions § 478.23 Right of entry and examination. (a) Except as provided in... of a criminal investigation of a person or persons other than the licensee, (2) For insuring...

  9. Welfare Effects of Entry into International Markets with Licensing

    Science.gov (United States)

    Ferreira, F. A.; Ferreira, Fl.

    2008-10-01

    We study the effects of entry of a foreign firm on domestic welfare in the presence of licensing, when the entrant is technologically inferior to the incumbent. We show that foreign entry increases domestic welfare for intermediate (respectively, sufficiently large) technological differences between the firms under licensing with fixed fee (respectively, output royalty).

  10. 50 CFR 300.188 - Ports of entry.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Ports of entry. 300.188 Section 300.188 Wildlife and Fisheries INTERNATIONAL FISHING AND RELATED ACTIVITIES INTERNATIONAL FISHERIES REGULATIONS International Trade Documentation and Tracking Programs for Highly Migratory Species § 300.188 Ports of entry...

  11. Safe Veress Needle Intraperitoneal Placement and Safer Laparoscopic Entry.

    Science.gov (United States)

    Vilos, George; Vilos, Angelos; Jacob, George P; Abu-Rafea, Basim; Ternamian, Artin

    2018-02-06

    Fifty percent of laparoscopic bowel and vascular injuries occur at the time of entry. These serious complications can lead to significant morbidity and even mortality. This video demonstrates 3 techniques that have been developed to minimize the risk of these injuries during entry. Step-by-step description of 3 techniques that can be used as a highly reliable and safe method of obtaining intraperitoneal entry during laparoscopy. Caudal displacement of the umbilicus before insertion of the veress needle allows for a median displacement of 6 cm between the site of entry and the common iliac vessels. An entry pressure of less than 9 mm Hg is suggestive of successful intraperitoneal entry. The left upper quadrant should be used in specific cases instead of the umbilicus as the point of entry for the veress needle. The use of a visualized trocarless cannula instead of a conventional primary trocar for entry after insufflation allows for real-time recognition of injury and converts linear penetrating force to radial torque. These 3 techniques can help decrease the risk and improve intraoperative recognition of serious bowel and vascular injuries during laparoscopy. Copyright © 2018 American Association of Gynecologic Laparoscopists. Published by Elsevier Inc. All rights reserved.

  12. 48 CFR 5.003 - Governmentwide point of entry.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Governmentwide point of entry. 5.003 Section 5.003 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION ACQUISITION PLANNING PUBLICIZING CONTRACT ACTIONS 5.003 Governmentwide point of entry. For any requirement in...

  13. Entry ramps in the Nagel-Schreckenberg model

    DEFF Research Database (Denmark)

    Pedersen, Morten Monrad; Ruhoff, Peder Thusgaard

    2002-01-01

    This paper describes a way of including entry ramps in the Nagel-Schreckenberg traffic model. The idea is to place what are called shadow cars on a highway next to cars on entry ramps, which enables the drivers to take ramp cars into account. The model is shown to capture important real...

  14. Strategic advantage and the optimal exercise of entry options

    NARCIS (Netherlands)

    Perotti, E.C.; Rossetto, S.

    2001-01-01

    We investigate the timing and the valuation of strategic investment aimed at enhancing entry opportunities in related market segments. As demand is uncertain, entry options should be exercised at the optimal time, trading off the market share gain against the option to wait until more information is

  15. 46 CFR Sec. 2 - Submission of repair entries.

    Science.gov (United States)

    2010-10-01

    ... MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION A-NATIONAL SHIPPING AUTHORITY GENERAL AGENT'S RESPONSIBILITY IN CONNECTION WITH FOREIGN REPAIR CUSTOM'S ENTRIES Sec. 2 Submission of repair entries. At the... with the District Director of Customs as defined in 19 CFR 1.1(d) an affidavit on Custom's Form 3417...

  16. 19 CFR 146.64 - Entry for warehouse.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Entry for warehouse. 146.64 Section 146.64 Customs... (CONTINUED) FOREIGN TRADE ZONES Transfer of Merchandise From a Zone § 146.64 Entry for warehouse. (a) Foreign... status may not be entered for warehouse from a zone. Merchandise in nonprivileged foreign status...

  17. 7 CFR 1499.8 - Entry and handling of commodities.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Entry and handling of commodities. 1499.8 Section 1499.8 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT....8 Entry and handling of commodities. (a) The participant shall make all necessary arrangements for...

  18. 7 CFR 1599.8 - Entry and handling of commodities.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Entry and handling of commodities. 1599.8 Section... PROGRAM § 1599.8 Entry and handling of commodities. (a) The participant shall make all necessary arrangements for receiving the donated commodities in the targeted country, including obtaining appropriate...

  19. Demographic and academic-related differences between standard-entry and graduate-entry nursing students: a prospective correlational survey.

    Science.gov (United States)

    Everett, Bronwyn; Salamonson, Yenna; Trajkovski, Suza; Fernandez, Ritin

    2013-07-01

    Students who enroll in graduate-entry nursing programs are described as more highly motivated, scoring higher in most learning strategies, and achieving greater academic success than standard-entry nursing students. A prospective correlational design was used to compare the demographic and academic-related characteristics of standard-entry and graduate-entry nursing students in their first year of study. Between 2007 and 2011, students enrolled in the Bachelor of Nursing, Standard Entry and the Bachelor Nursing, Graduate Entry at a large Australian university were surveyed in the first year of their program. Data included English-language usage and time spent in paid work, as well as four dimensions of Pintrich's Motivated Strategies for Learning Questionnaire. Survey data was linked to students' academic grades at the end of the semester. A total of 730 students completed the survey and consented to collection of their academic grades. Graduate-entry students were more likely to be older (28.6 vs. 24.3 years, P groups for use of Extrinsic Goal Orientation as a learning strategy, the graduate-entry students were more likely to identify Peer Learning, Help Seeking and Critical Thinking as strategies for learning than the standard-entry students (P group of students achieved a higher mean GPA (4.8 vs. 4.0, P groups, lower levels of English-language proficiency and increased time spent in paid work were predictors of poorer academic performance. Similar to US-based studies, demographic and academic-related differences were identified between standard-entry and graduate-entry nursing students. However, the study also highlights lower levels of English-language proficiency and increased time spent in paid work negatively impacted academic performance in both groups of nursing students. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Planetary Atmospheric Electricity

    CERN Document Server

    Leblanc, F; Yair, Y; Harrison, R. G; Lebreton, J. P; Blanc, M

    2008-01-01

    This volume presents our contemporary understanding of atmospheric electricity at Earth and in other solar system atmospheres. It is written by experts in terrestrial atmospheric electricity and planetary scientists. Many of the key issues related to planetary atmospheric electricity are discussed. The physics presented in this book includes ionisation processes in planetary atmospheres, charge generation and separation, and a discussion of electromagnetic signatures of atmospheric discharges. The measurement of thunderstorms and lightning, including its effects and hazards, is highlighted by articles on ground and space based instrumentation, and new missions.Theory and modelling of planetary atmospheric electricity complete this review of the research that is undertaken in this exciting field of space science. This book is an essential research tool for space scientists and geoscientists interested in electrical effects in atmospheres and planetary systems. Graduate students and researchers who are new to t...

  1. Our shared atmosphere

    Science.gov (United States)

    Our atmosphere is a precious and fascinating resource, providing air to breath, shielding us from harmful ultraviolet radiation (UV), and maintaining a comfortable climate. Since the industrial revolution, people have significantly altered the composition of the atmosphere throu...

  2. Multiple radon entry modeling in a house with a cellar.

    Science.gov (United States)

    Wang, F; Ward, I C

    1999-06-01

    Combining a computational fluid dynamics (CFD) model and a multi-zonal model, a study was carried out on radon entry through the complex substructure of a house with a cellar. The uniqueness of the radon entry problem in this type of house was due to the involvement of two radon entry routes to two chambers: the cellar and the living area of the house. Soil gas carrying radon was driven through the two routes by two coupled disturbance pressures in the chambers. The effects of temperature differences were considered as another driving force for the radon entry. Examined in this study were the effects of the geometry of the substructure, air permeability of the soil, air-tightness of the cellar shell, and cellar ventilation on radon entry to both the cellar and the living area. The ground floor covering on top of the soil outside a cellar wall increased radon entry through this wall by about 68%, as radon built up to a very high level under the covering. The effect of cellar ventilation was found as follows: the cellar ventilation created a layer of airflow in the soil under the ground floor; the flow passed over a crack in the ground floor, the entry route to the living area, diluting the radon in the area. Hence, the soil gas entering the living area carried less radon. Cellar ventilation seems more effective in reducing radon entry to the living area in a more permeable soil and leaky cellar shell; a moderate cellar ventilation condition achieved 77% reduction in radon entry to the area. When permeability of these two materials was lower and soil radon content remained the same, the chances of radon entry was also lower; hence, the indoor radon level was lower and no radon control was needed. When such soil contains high radon concentration, other mitigation measures must be sought.

  3. Comparison of single-entry and double-entry two-step couple screening for cystic fibrosis carriers

    NARCIS (Netherlands)

    tenKate, LP; Verheij, JBGM; Wildhagen, MF; Hilderink, HBM; Kooij, L; Verzijl, JG; Habbema, JDF

    1996-01-01

    Both single-entry two-step (SETS) couple screening and double-entry two-step (DETS) couple screening have been recommended as methods to screen for cystic fibrosis gene carriers. In this paper we compare the expected results from both types of screening. In general, DETS results in a higher

  4. Swiss Army Pathogen: The Salmonella Entry Toolkit

    Directory of Open Access Journals (Sweden)

    Peter J. Hume

    2017-08-01

    Full Text Available Salmonella causes disease in humans and animals ranging from mild self-limiting gastroenteritis to potentially life-threatening typhoid fever. Salmonellosis remains a considerable cause of morbidity and mortality globally, and hence imposes a huge socio-economic burden worldwide. A key property of all pathogenic Salmonella strains is the ability to invade non-phagocytic host cells. The major determinant of this invasiveness is a Type 3 Secretion System (T3SS, a molecular syringe that injects virulence effector proteins directly into target host cells. These effectors cooperatively manipulate multiple host cell signaling pathways to drive pathogen internalization. Salmonella does not only rely on these injected effectors, but also uses several other T3SS-independent mechanisms to gain entry into host cells. This review summarizes our current understanding of the methods used by Salmonella for cell invasion, with a focus on the host signaling networks that must be coordinately exploited for the pathogen to achieve its goal.

  5. HTCC: Broad Range Inhibitor of Coronavirus Entry.

    Directory of Open Access Journals (Sweden)

    Aleksandra Milewska

    Full Text Available To date, six human coronaviruses have been known, all of which are associated with respiratory infections in humans. With the exception of the highly pathogenic SARS and MERS coronaviruses, human coronaviruses (HCoV-NL63, HCoV-OC43, HCoV-229E, and HCoV-HKU1 circulate worldwide and typically cause the common cold. In most cases, infection with these viruses does not lead to severe disease, although acute infections in infants, the elderly, and immunocompromised patients may progress to severe disease requiring hospitalization. Importantly, no drugs against human coronaviruses exist, and only supportive therapy is available. Previously, we proposed the cationically modified chitosan, N-(2-hydroxypropyl-3-trimethylammonium chitosan chloride (HTCC, and its hydrophobically-modified derivative (HM-HTCC as potent inhibitors of the coronavirus HCoV-NL63. Here, we show that HTCC inhibits interaction of a virus with its receptor and thus blocks the entry. Further, we demonstrate that HTCC polymers with different degrees of substitution act as effective inhibitors of all low-pathogenic human coronaviruses.

  6. Molecular Biology of Rotavirus Entry and Replication

    Science.gov (United States)

    Ruiz, Marie Christine; Leon, Theresa; Diaz, Yuleima; Michelangeli, Fabian

    2009-01-01

    Rotavirus is a nonenveloped, double-stranded, RNA virus belonging to the Reoviridae family and is the major etiological agent of viral gastroenteritis in young children and young animals. Remarkable progress in the understanding of the rotavirus cycle has been made in the last 10 years. The knowledge of viral replication thus far acquired is based on structural studies, the expression and coexpression of individual viral proteins, silencing of individual genes by siRNAs, and the effects that these manipulations have on the physiology of the infected cell. The functions of the individual rotavirus proteins have been largely dissected; however, the interactions between them and with cell proteins, and the molecular mechanisms of virus replication, are just beginning to be understood. These advancements represent the basis for the development of effective vaccination and rational therapeutic strategies to combat rotavirus infection and diarrhea syndromes. In this paper, we review and try to integrate the new knowledge about rotavirus entry, replication, and assembly, and pose some of the questions that remain to be solved. PMID:20024520

  7. Atmospheric water harvester

    African Journals Online (AJOL)

    2017-09-10

    Sep 10, 2017 ... ... involve condensation and precipitation. So, in order to examine the potential water in the atmosphere, atmospheric water harvester model was developed since it is one of the sustainable alternative water resources [6]. Normally, the atmosphere contains water in the form of water vapor, moisture and so ...

  8. Atmospheric refraction : a history

    NARCIS (Netherlands)

    Lehn, WH; van der Werf, S

    2005-01-01

    We trace the history of atmospheric refraction from the ancient Greeks up to the time of Kepler. The concept that the atmosphere could refract light entered Western science in the second century B.C. Ptolemy, 300 years later, produced the first clearly defined atmospheric model, containing air of

  9. Network ties and survival

    DEFF Research Database (Denmark)

    Acheampong, George; Narteh, Bedman; Rand, John

    2017-01-01

    of the SCPFs in Ghana. Distribution ties are associated with negative survival chances and this is not even reversed if the human capital of the owner increases although managers with higher human capital and higher distribution ties experience positive effects. Industry ties are associated with positive ties...

  10. Education for Survival

    Science.gov (United States)

    Aldrich, Richard

    2010-01-01

    This article provides a brief overview of current approaches to education and concludes that none of these is sufficient to meet the challenges that now face the human race. It argues instead for a new concept of education for survival. (Contains 1 note.)

  11. Multinationals and plant survival

    DEFF Research Database (Denmark)

    Bandick, Roger

    2010-01-01

    -parametric estimates show that domestic MNE plants are more likely to exit the market than other plants, also when controlling for plant-specific differences. Finally, foreign presence in the market seems to have had a negative impact on the survival rate of plants in non-exporting non- MNEs, but not to have affected...

  12. Artists’ Survival Rate

    DEFF Research Database (Denmark)

    Bille, Trine; Jensen, Søren

    2017-01-01

    The literature of cultural economics generally finds that an artistic education has no significant impact on artists’ income and careers in the arts. In our research, we have readdressed this question by looking at the artists’ survival in the arts occupations. The results show that an artistic...... education has a significant impact on artists’ careers in the arts and we find important industry differences....

  13. Survivability via Control Objectives

    Energy Technology Data Exchange (ETDEWEB)

    CAMPBELL,PHILIP L.

    2000-08-11

    Control objectives open an additional front in the survivability battle. A given set of control objectives is valuable if it represents good practices, it is complete (it covers all the necessary areas), and it is auditable. CobiT and BS 7799 are two examples of control objective sets.

  14. Flexible survival regression modelling

    DEFF Research Database (Denmark)

    Cortese, Giuliana; Scheike, Thomas H; Martinussen, Torben

    2009-01-01

    Regression analysis of survival data, and more generally event history data, is typically based on Cox's regression model. We here review some recent methodology, focusing on the limitations of Cox's regression model. The key limitation is that the model is not well suited to represent time-varyi...

  15. Education for Survival.

    Science.gov (United States)

    Allen, James E., Jr.

    In this address, James E. Allen, Jr., Assistant Secretary for Education and U.S. Commissioner of Education, discusses the relationship of education to the problem of ecological destruction. He states that the solutions to the problems of air, water, and soil pollution may be found in redirected education. This "education for survival" can serve to…

  16. Mars Atmospheric Characterization Using Advanced 2-Micron Orbiting Lidar

    Science.gov (United States)

    Singh, U.; Engelund, W.; Refaat, T.; Kavaya, M.; Yu, J.; Petros, M.

    2015-01-01

    Mars atmospheric characterization is critical for exploring the planet. Future Mars missions require landing massive payloads to the surface with high accuracy. The accuracy of entry, descent and landing (EDL) of a payload is a major technical challenge for future Mars missions. Mars EDL depends on atmospheric conditions such as density, wind and dust as well as surface topography. A Mars orbiting 2-micron lidar system is presented in this paper. This advanced lidar is capable of measuring atmospheric pressure and temperature profiles using the most abundant atmospheric carbon dioxide (CO2) on Mars. In addition Martian winds and surface altimetry can be mapped, independent of background radiation or geographical location. This orbiting lidar is a valuable tool for developing EDL models for future Mars missions.

  17. Estimation of survival rates and abundance of green turtles along the U.S. West Coast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — To determine abundance and survival rates of the east Pacific green turtles in the northern most foraging grounds, the turtle research groups at SWFSC have been...

  18. Continuum in HIV care from entry to ART initiation in rural KwaZulu-Natal, South Africa.

    Science.gov (United States)

    Plazy, Mélanie; Dray-Spira, Rosemary; Orne-Gliemann, Joanna; Dabis, François; Newell, Marie-Louise

    2014-06-01

    To quantify time from entry in HIV care until Antiretroviral therapy (ART) initiation and identify factors associated with ART initiation in rural KwaZulu-Natal, South Africa. Adults ≥16 years entering the decentralised Hlabisa ART programme between 2007 and 2011 were followed until June 2013. Median survival times to ART initiation from date of programme entry and from date of ART eligibility were estimated with Kaplan-Meier methods. Associated factors were evaluated in Cox regressions, censoring for deaths. Of 37 749 adults (71.6% female), 17 638 (46.7%) initiated ART. Nearly half (46.9%) met the CD4 criteria for treatment eligibility at programme entry. Among the 20 039 individuals not yet ART-eligible at entry, only 62.5% were retained in care with at least one further CD4 measurement, of whom 6688 subsequently became ART-eligible. Overall, 65.5% of the 24 398 ART-eligible individuals initiated ART over the study period. ART initiation was more likely in women (P CD4 count (P CD4 count at eligibility. In this rural programme, continuation of care remains challenging, especially in men and younger adults. ART initiation is more likely in those engaged prior eligibility than in those entering HIV care only late in their HIV disease. © 2014 John Wiley & Sons Ltd.

  19. Ambulatory surgery center and general hospital competition: entry decisions and strategic choices.

    Science.gov (United States)

    Al-Amin, Mona; Housman, Michael

    2012-01-01

    General hospitals are consistently under pressure to control cost and improve quality. In addition to mounting payers' demands, hospitals operate under evolving market conditions that might threaten their survival. While hospitals traditionally were concerned mainly with competition from other hospitals, today's reimbursement schemes and entrepreneurial activities encouraged the proliferation of outpatient facilities such as ambulatory surgery centers (ASCs) that can jeopardize hospitals' survival. The purpose of this article was to examine the relationship between ASCs and general hospitals. More specifically, we apply the niche overlap theory to study the impact that competition between ASCs and general hospitals has on the survival chances of both of these organizational populations. Our analysis examined interpopulation competition in models of organizational mortality and market demand. We utilized Cox proportional hazard models to evaluate the impact of competition from each on ASC and hospital exit while controlling for market factors. We relied on two data sets collected and developed by Florida's Agency for Health Care Administration: outpatient facility licensure data and inpatient and outpatient surgical procedure data. Although ASCs do tend to exit markets in which there are high levels of ASC competition, we found no evidence to suggest that ASC exit rates are affected by hospital density. On the other hand, hospitals not only tend to exit markets with high levels of hospital competition but also experience high exit rates in markets with high ASC density. The implications from our study differ for ASCs and hospitals. When making decisions about market entry, ASCs should choose their markets according to the following: demand for outpatient surgery, number of physicians who would practice in the surgery center, and the number of surgery centers that already exist in the market. Hospitals, on the other hand, should account for competition from ASCs

  20. Comparison of Mars Atmospheric Density Estimates from Models to Measurements from Mars Global Surveyor (MGS) Data

    Science.gov (United States)

    Justh, Hilary L.; Justus, C. G.

    2009-01-01

    A recent study (Desai, 2008) has shown that the actual landing sites of Mars Pathfinder, the Mars Exploration Rovers (Spirit and Opportunity) and the Phoenix Mars Lander have been further downrange than predicted by models prior to landing Desai's reconstruction of their entries into the Martian atmosphere showed that the models consistently predicted higher densities than those found upon entry, descent and landing. Desai's results have raised a question as to whether there is a systemic problem within Mars atmospheric models. Proposal is to compare Mars atmospheric density estimates from Mars atmospheric models to measurements made by Mars Global Surveyor (MGS). Comparison study requires the completion of several tasks that would result in a greater understanding of reasons behind the discrepancy found during recent landings on Mars and possible solutions to this problem.

  1. Development of the alternate entry port for the ATF

    International Nuclear Information System (INIS)

    Parsa, Z.

    1993-05-01

    We discussed a second entry port for the Accelerator Test Facility (ATF) injection system at Brookhaven National Laboratory, which consists of a photocathode rf gun and a straight - ahead beamline directly into the 50 MeV linac. The proposed second entry port should improve the beam quality and lower the emittance needed for FEL (Free Electron Laser), and laser - acceleration experiments. A discussion on the laser driven high brightness photoelectrons through the primary entry port (a low energy 180 degrees achromatic double bend transport line) now in operation, and a beam analysis for the proposed secondary port is also given

  2. Comparable stocks, boundedly rational stock markets and IPO entry rates.

    Directory of Open Access Journals (Sweden)

    Jay Chok

    Full Text Available In this study, we examine how initial public offerings (IPO entry rates are affected when stock markets are boundedly rational and IPO firms infer information from their counterparts in the market. We hypothesize a curvilinear relationship between the number of comparable stocks and initial public offerings (IPO entry rates into the NASDAQ Stock Exchange. Furthermore, we argue that trading volume and changes in stock returns partially mediates the relationship between the number of comparable stocks and IPO entry rates. The statistical evidence provides strong support for the hypotheses.

  3. Comparable stocks, boundedly rational stock markets and IPO entry rates.

    Science.gov (United States)

    Chok, Jay; Qian, Jifeng

    2013-01-01

    In this study, we examine how initial public offerings (IPO) entry rates are affected when stock markets are boundedly rational and IPO firms infer information from their counterparts in the market. We hypothesize a curvilinear relationship between the number of comparable stocks and initial public offerings (IPO) entry rates into the NASDAQ Stock Exchange. Furthermore, we argue that trading volume and changes in stock returns partially mediates the relationship between the number of comparable stocks and IPO entry rates. The statistical evidence provides strong support for the hypotheses.

  4. Predicting academic outcomes in an Australian graduate entry medical programme.

    Science.gov (United States)

    Puddey, Ian B; Mercer, Annette

    2014-02-15

    Predictive validity studies for selection criteria into graduate entry courses in Australia have been inconsistent in their outcomes. One of the reasons for this inconsistency may have been failure to have adequately considered background disciplines of the graduates as well as other potential confounding socio-demographic variables that may influence academic performance. Graduate entrants into the MBBS at The University of Western Australia between 2005 and 2012 were studied (N = 421). They undertook a 6-month bridging course, before joining the undergraduate-entry students for Years 3 through 6 of the medical course. Students were selected using their undergraduate Grade Point Average (GPA), Graduate Australian Medical School Admissions Test scores (GAMSAT) and a score from a standardised interview. Students could apply from any background discipline and could also be selected through an alternative rural entry pathway again utilising these 3 entry scores. Entry scores, together with age, gender, discipline background, rural entry status and a socioeconomic indicator were entered into linear regression models to determine the relative influence of each predictor on subsequent academic performance in the course. Background discipline, age, gender and selection through the rural pathway were variously related to each of the 3 entry criteria. Their subsequent inclusion in linear regression models identified GPA at entry, being from a health/allied health background and total GAMSAT score as consistent independent predictors of stronger academic performance as measured by the weighted average mark for the core units completed throughout the course. The Interview score only weakly predicted performance later in the course and mainly in clinically-based units. The association of total GAMSAT score with academic performance was predominantly dictated by the score in GAMSAT Section 3 (Reasoning in the biological and physical sciences) with Section 1 (Reasoning in the

  5. Survival after blood transfusion

    DEFF Research Database (Denmark)

    Kamper-Jørgensen, Mads; Ahlgren, Martin; Rostgaard, Klaus

    2008-01-01

    of transfusion recipients in Denmark and Sweden followed for up to 20 years after their first blood transfusion. Main outcome measure was all-cause mortality. RESULTS: A total of 1,118,261 transfusion recipients were identified, of whom 62.0 percent were aged 65 years or older at the time of their first...... the SMR remained significantly 1.3-fold increased. CONCLUSION: The survival and relative mortality patterns among blood transfusion recipients were characterized with unprecedented detail and precision. Our results are relevant to assessments of the consequences of possible transfusion-transmitted disease......BACKGROUND: Long-term survival of transfusion recipients has rarely been studied. This study examines short- and long-term mortality among transfusion recipients and reports these as absolute rates and rates relative to the general population. STUDY DESIGN AND METHODS: Population-based cohort study...

  6. Streptococcus equi subsp zooepidemicus Invades and Survives in Epithelial Cells

    DEFF Research Database (Denmark)

    Skive, Bolette; Rohde, Manfred; Molinari, Gabriella

    2017-01-01

    showed three morphologically different types of invasion for both bacterial strains. The main port of entry was through large invaginations in the epithelial cell membrane. Pili-like bacterial appendages were observed when the S. zooepidemicus cells were in close proximity to the epithelial cells...... protection assays. Both S. zooepidemicus strains investigated were able to invade epithelial cells although at different magnitudes. The immunofluorescence data showed significantly higher adhesion and invasion rates for strain 1-4a when compared to strain S31A1. S. zooepidemicus was able to survive...

  7. Survival analysis models and applications

    CERN Document Server

    Liu, Xian

    2012-01-01

    Survival analysis concerns sequential occurrences of events governed by probabilistic laws.  Recent decades have witnessed many applications of survival analysis in various disciplines. This book introduces both classic survival models and theories along with newly developed techniques. Readers will learn how to perform analysis of survival data by following numerous empirical illustrations in SAS. Survival Analysis: Models and Applications: Presents basic techniques before leading onto some of the most advanced topics in survival analysis.Assumes only a minimal knowledge of SAS whilst enablin

  8. Game Changing Transformable Entry System Technology Applicability to Robotic Venus Science Missions

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovative adpative deployable entry and placement technology (ADEPT), also known as transformable entry system technology (TEST) concept, akin to an umbrella,...

  9. Guidance and Control for Entry Vehicles with Deployable Hypersonic Decelerators

    Data.gov (United States)

    National Aeronautics and Space Administration — Entry, descent, and landing (EDL) missions to date have mostly relied on technology developed in the 1960s and 70s. Future EDL missions of interest at Earth, Mars,...

  10. Identifying Midshipmen for Academic Assistance Using Entry Variables

    National Research Council Canada - National Science Library

    Watson, Arthur

    2001-01-01

    ...) to assist midshipmen experiencing academic difficulty. The purpose of this study was to develop an empirical approach to selecting first- year Naval Academy Midshipmen for academic intervention based upon objective initial entry data...

  11. The state-of-the-art port of entry workshop

    Energy Technology Data Exchange (ETDEWEB)

    Godfrey, B.

    1995-05-01

    The increased demand for freight movements through international ports of entry and the signing of the North American Free Trade Agreement (NAFTA) have increased freight traffic at border ports of entry. The State-of-the-Art Port of Entry Workshop initiated a dialogue among technologists and stakeholders to explore the potential uses of technology at border crossings and to set development priorities. International ports of entry are both information and labor intensive, and there are many promising technologies that could be used to provide timely information and optimize inspection resources. Participants universally held that integration of technologies and operations is critical to improving port services. A series of Next Steps was developed to address stakeholder issues and national priorities, such as the National Transportation Policy and National Drug Policy. This report documents the views of the various stakeholders and technologists present at the workshop and outlines future directions of study.

  12. 19 CFR 122.26 - Entry and clearance.

    Science.gov (United States)

    2010-04-01

    ... AIR COMMERCE REGULATIONS Private Aircraft § 122.26 Entry and clearance. Private aircraft, as defined... information as set forth in § 122.22(c), and grants electronic clearance via electronic mail or telephone...

  13. 50 CFR 635.41 - Products denied entry.

    Science.gov (United States)

    2010-10-01

    ... ADMINISTRATION, DEPARTMENT OF COMMERCE ATLANTIC HIGHLY MIGRATORY SPECIES Restrictions on Imports § 635.41... by a vessel under the jurisdiction of Bolivia or Georgia will be denied entry into the United States...

  14. 19 CFR 141.19 - Declaration of entry.

    Science.gov (United States)

    2010-04-01

    ... of consignee—(1) Authorized agent with knowledge of the facts. When entry is made in a consignee's name by an agent who has knowledge of the facts and who is authorized under a proper power of attorney...

  15. Multidisciplinary Design Under Uncertainty for Entry Vehicles, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The physical difficulty of designing entry vehicles originates from the large degree of coupling between the various disciplines involved in the design. Every...

  16. Multidisciplinary Design Under Uncertainty for Entry Vehicles, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The physical difficulty of designing entry vehicles originates from the large degree of coupling between the various disciplines involved in the design. Every...

  17. AIRLINE COMPETITION: Barriers to Entry Continue in Some Domestic Markets

    National Research Council Canada - National Science Library

    1998-01-01

    .... Airline deregulation has led to lower fares and better service for most air travelers largely because of increased competition spurred by the entry of new airlines into the industry and established...

  18. 77 FR 5681 - Establishment of Global Entry Program

    Science.gov (United States)

    2012-02-06

    ... personalized smart card. Upon entry and exit, Privium members place their Privium smart card into a reader and.... The individual's iris information is then compared against the iris information stored on the card...

  19. The choice of foreign entry modes in a control perspective

    DEFF Research Database (Denmark)

    Dyhr Ulrich, Anna Marie; Boyd, Britta; Hollensen, Svend

    The aim of this article is to investigate the choice of entry modes for international markets in a control perspective. A survey from The Confederation of Danish Industry with 234 Danish small- and medium sized enterprises served as a data base. The entry modes are categorized into three groups d...... turnover. The factors: personal networks and the interruption of the international activities were the most significant factors for the choice of intermediate mode (joint ventures and strategic alliances)....... depending on the control that the company has over its activities abroad. The paper examines selected factors that influence the ‘entry modes’ of Danish SMEs in different strategic settings. Results show that the most deciding factor for the choice of high control entry mode (subsidiary) was the factor...

  20. Heat Shield for Extreme Entry Environment Technology (HEEET)

    Data.gov (United States)

    National Aeronautics and Space Administration — HEEET is developing an efficient and innovative Thermal Protection System that can protect science payloads during entry where the heating is 2 orders of magnitude...

  1. Forecast and capacity planning for Nogales' ports of entry : [summary].

    Science.gov (United States)

    2009-12-01

    This document provides the final report of the activities performed under the project : Nogales POEs Traffic Study: Forecast and Capacity Planning for Nogales Ports of Entry : sponsored by the Arizona Department of Transportation (ADOT) under Gran...

  2. AIRLINE COMPETITION: Barriers to Entry Continue in Some Domestic Markets

    National Research Council Canada - National Science Library

    1998-01-01

    ... airlines into new markets. As we reported in 1996 and 1997, however, some airports have not experienced such entry and thus have experienced higher fares and/or less convenient service since deregulation...

  3. The Hera Entry Probe Mission to Saturn, an ESA M-class mission proposal

    Science.gov (United States)

    Mousis, O.; Atkinson, D. H.; Spilker, T.; Venkatapathy, E.; Poncy, J.; Coustenis, A.; Reh, K.

    2015-10-01

    A fundamental goal of solar system exploration is to understand the origin of the solar system, the initial stages, conditions, and processes by which the solar system formed, how the formation process was initiated, and the nature of the interstellar seed material from which the solar system was born. Key to understanding solar system formation and subsequent dynamical and chemical evolution is the origin and evolution of the giant planets and their atmospheres. Additionally, the atmospheres of the giant planets serve as laboratories to better understand the atmospheric chemistries, dynamics, processes, and climates on all planets in the solar system including Earth, offer a context and provide a ground truth for exoplanets and exoplanetary systems,and have long been thought to play a critical role in the development of potentially habitable planetary systems. Remote sensing observations are limited when used to study the bulk atmospheric composition of the giant planets of our solar system. A remarkable example of the value of in situ probe measurements is illustrated by the exploration of Jupiter, where key measurements such as noble gases abundances and the precise measurement of the helium mixing ratio have only been made available through in situ measurements by the Galileo probe. Representing the only method providing ground-truth to connect the remote sensing inferences with physical reality, in situ measurements have only been accomplished twice in the history of outer solar system exploration, via the Galileo probe for Jupiter and the Huygens probe for Titan. In situ measurements provide access to atmospheric regions that are beyond the reach of remote sensing, enabling the dynamical, chemical and aerosol-forming processes at work from the thermosphere to the troposphere below the cloud decks to be studied. A proposal for a Saturn entry probe mission named Hera was recently submitted to the European Space Agency Medium Class mission announcement of

  4. Fair weather atmospheric electricity

    International Nuclear Information System (INIS)

    Harrison, R G

    2011-01-01

    Not long after Franklin's iconic studies, an atmospheric electric field was discovered in 'fair weather' regions, well away from thunderstorms. The origin of the fair weather field was sought by Lord Kelvin, through development of electrostatic instrumentation and early data logging techniques, but was ultimately explained through the global circuit model of C.T.R. Wilson. In Wilson's model, charge exchanged by disturbed weather electrifies the ionosphere, and returns via a small vertical current density in fair weather regions. New insights into the relevance of fair weather atmospheric electricity to terrestrial and planetary atmospheres are now emerging. For example, there is a possible role of the global circuit current density in atmospheric processes, such as cloud formation. Beyond natural atmospheric processes, a novel practical application is the use of early atmospheric electrostatic investigations to provide quantitative information on past urban air pollution.

  5. Pluto's atmosphere near perihelion

    International Nuclear Information System (INIS)

    Trafton, L.M.

    1989-01-01

    A recent stellar occultation has confirmed predictions that Pluto has an atmosphere which is sufficiently thick to uniformly envelope the planet and to extend far above the surface. Pluto's atmosphere consists of methane and perhaps other volatile gases at temperatures below their freezing points; it should regulate the surface temperature of its volatile ices to a globally uniform value. As Pluto approaches and passes through perihelion, a seasonal maximum in the atmospheric bulk and a corresponding minimum in the exposed volatile ice abundance is expected to occur. The lag in maximum atmospheric bulk relative to perihelion will be diagnostic of the surface thermal properties. An estimate of Pluto's atmospheric bulk may result if a global darkening (resulting from the disappearance of the seasonally deposited frosts) occurs before the time of maximum atmospheric bulk. The ice deposited shortly after perihelion may be diagnostic of the composition of Pluto's volatile reservoir

  6. Atmosphere physics and chemistry

    International Nuclear Information System (INIS)

    Delmas, R.; Megie, G.; Peuch, V.H.

    2005-10-01

    Since the 1970's, the awareness about the atmospheric pollution threat has led to a spectacular development of the researches on the complex interactions between the chemical composition of the atmosphere and the climate. This book makes a synthesis of the state-of-the-art in this very active domain of research. Content: introduction, atmosphere dynamics and transport, matter-radiation interaction and radiant transfer, physico-chemical processes, atmospheric aerosol and heterogenous chemistry, anthropic and natural emissions and deposition, stratospheric chemical system, tropospheric chemical system, polluted boundary layer, paleo-environments and ice archives, role of atmospheric chemistry in global changes, measurement principles and instruments, numerical modeling, experimental strategy, regulation and management of the atmospheric environment, index. (J.S.)

  7. Principles of safe abdominal entry in laparoscopic gynecologic surgery

    Directory of Open Access Journals (Sweden)

    Jongrak Thepsuwan

    2013-11-01

    Full Text Available Laparoscopic gynecologic surgery has been widely used with a range of benefits. However, there are complications that are related to the abdominal entry process. Serious complications are gastrointestinal tract and major blood vessel injuries. This review introduces the recent available literature to prevent and eliminate the laparoscopic entry complications. The open entry technique is associated with a significant reduction of failed entry, compared to the closed entry technique; however there is no difference in the incidence of visceral or vascular injury. Laparoscopic entry by the left upper abdomen (i.e., Palmer's point or the middle upper abdomen (i.e., the Lee-Huang point could be considered in patients with suspected periumbilical adhesions or a history of umbilical hernia, or after three failed attempts of insufflation at the umbilicus. The Lee-Huang point has its own benefit for the operative laparoscopy in large pelvic pathologies and gynecology malignancy cases. The angle of Veress needle insertion varies from 45° in nonobese women to 90° in extraordinarily obese women. The high intra-peritoneal pressure entries, which range from 20 mmHg to 25 mmHg, minimize the risk of vascular injury. Therefore, this will not adversely affect the cardiopulmonary function in healthy women. The Veress intraperitoneal pressure (<10 mmHg is a reliable indicator of correct intraperitoneal placement of the Veress needle. The elevation of anterior abdominal wall for placement of a Veress needle increases the risks of failed entry and shows no advantage in regard to vascular or visceral complications. Surgeons should continue to increase their knowledge of anatomy, their training, and their experience to decrease laparoscopic complications.

  8. Finger Based Techniques for Nonvisual Touchscreen Text Entry

    OpenAIRE

    Fakrudeen, Mohammed; Yousef, Sufian; Miraz, Mahdi H.; Hussein, AbdelRahman Hamza

    2017-01-01

    This research proposes Finger Based Technique (FBT) for non-visual touch screen device interaction designed for blind users. Based on the proposed technique, the blind user can access virtual keys based on finger holding positions. Three different models have been proposed. They are Single Digit Finger-Digit Input (FDI), Double Digit FDI for digital text entry, and Finger-Text Input (FTI) for normal text entry. All the proposed models were implemented with voice feedback while enabling touch ...

  9. Candidate Medical Countermeasures Targeting Ebola Virus Cell Entry

    Science.gov (United States)

    2017-03-31

    antibodies and small molecules [6]. Here, we 26 focus on one aspect of candidate antiviral research , i.e., EBOV cell-entry inhibitors. 27 Ebola virus... Antiviral research 125 1-7 (2016). 604 91. Pécheur EI, Borisevich V, Halfmann P et al. The synthetic antiviral drug arbidol inhibits 605 globally...Weidner T et al. Identification of entry inhibitors of Ebola virus 655 pseudotyped vectors from a myxobacterial compound library. Antiviral research 132

  10. Design features of an automated entry control system

    International Nuclear Information System (INIS)

    Reynolds, D.A.

    1978-01-01

    Features of an entry control system designed to automatically control access to nuclear facilities is described. Control independent of variable human factors is stressed, but security force action is required for assessment and response as a result of an alarm. A design based on a distributed processing capability is utilized. Flexibility and generality are emphasized in an effort to maximize applicability to the entry-control problem faced by nuclear facilities upgrading security as a result of the Safeguards Program

  11. Cupid's Arrow: An Innovative Nanosat to Sample Venus' Upper Atmosphere

    Science.gov (United States)

    Bienstock, Bernie; Darrach, Murray; Madzunkov, Stojan; Sotin, Christophe

    2016-01-01

    In NASA's Discovery 2014 AO, the opportunity to propose a Technology Demonstration Opportunity (TDO) to enhance the primary mission was specified. For the Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy (VERITAS) mission, we elected to include the Cupid's Arrow nanosat TDO to sample and measure the abundances of noble gases and their isotopic ratios in Venus's upper atmosphere below the homopause. This paper will provide a basic overview of the VERITAS mission, with a focus on the Cupid's Arrow concept including a description of the mission, spacecraft design, and JPL's quadrupole ion trap mass spectrometer (QITMS) instrument specifications and design. In previous planetary entry probe mission designs, particularly at Venus, engineers w ere focused on entry and descent. A landed probe was also proposed for the New Frontiers SAGE mission. For Cupid's Arrow, the nanosat is designed to skim through the upper atmosphere, just below the homopause, in order to sample the atmosphere, perform the analysis, and then exit the atmosphere to transmit its data to the orbiting VERITAS spacecraft. Cupid's Arrow is a compelling addition to the VERITAS geology mission. A key missing link in our understanding of Venus' evolution is the noble gas abundances and their isotopic ratios. Not since Pioneer Venus have these measurements been made in the Venus atmosphere and never in the upper atmosphere, just below the homopause, to the degree of accuracy that will be accomplished by VERITAS' Cupid's Arrow nanosat.Such measurements were ranked as the number 1 investigation of the number 1 objective of the goal "Atmospheric Formation, Evolution, and Climate History ".

  12. SNAP: Small Next-generation Atmospheric Probe Concept

    Science.gov (United States)

    Sayanagi, K. M.; Dillman, R. A.; Atkinson, D. H.; Li, J.; Saikia, S.; Simon, A. A.; Spilker, T. R.; Wong, M. H.; Hope, D.

    2017-12-01

    We present a concept for a small, atmospheric probe that could be flexibly added to future missions that orbit or fly-by a giant planet as a secondary payload, which we call the Small Next-generation Atmospheric Probe (SNAP). SNAP's main scientific objectives are to determine the vertical distribution of clouds and cloud-forming chemical species, thermal stratification, and wind speed as a function of depth. As a case study, we present the advantages, cost and risk of adding SNAP to the future Uranus Orbiter and Probe flagship mission; in combination with the mission's main probe, SNAP would perform atmospheric in-situ measurements at a second location, and thus enable and enhance the scientific objectives recommended by the 2013 Planetary Science Decadal Survey and the 2014 NASA Science Plan to determine atmospheric spatial variabilities. We envision that the science objectives can be achieved with a 30-kg entry probe 0.5m in diameter (less than half the size of the Galileo probe) that reaches 5-bar pressure-altitude and returns data to Earth via the carrier spacecraft. As the baseline instruments, the probe will carry an Atmospheric Structure Instrument (ASI) that measures the temperature, pressure and acceleration, a carbon nanotube-based NanoChem atmospheric composition sensor, and an Ultra-Stable Oscillator (USO) to conduct a Doppler Wind Experiment (DWE). We also catalog promising technologies currently under development that will strengthen small atmospheric entry probe missions in the future. While SNAP is applicable to multiple planets, we examine the feasibility, benefits and impacts of adding SNAP to the Uranus Orbiter and Probe flagship mission. Our project is supported by NASA PSDS3 grant NNX17AK31G.

  13. Sources of atmospheric ammonia

    International Nuclear Information System (INIS)

    Harriss, R.C.; Michaels, J.T.

    1982-01-01

    The information available on factors that influence emissions from the principal societal sources of ammonia to the atmosphere, namely combustion processes, volatilization of farm animal wastes, and volatilization of fertilizers, is reviewed. Emission factors are established for each major source of atmospheric ammonia. The factors are then multiplied by appropriate source characterization descriptors to obtain calculated fluxes of ammonia to the atmosphere on a state-by-state basis for the United States

  14. Three-stage entry game: The strategic effects of advertising

    Directory of Open Access Journals (Sweden)

    Kuzmanović Marija

    2011-01-01

    Full Text Available This paper analyzes the effects of investment in advertising in the three-stage entry game model with one incumbent and one potential entrant firm. It is shown that if a game theory is applied, under particular conditions, advertising can be used as a strategic weapon in the market entry game. Depending on the level of the advertising interaction factor, conditions for over-investment in advertising for strategic purposes are given. Furthermore, three specific cases are analyzed: strictly predatory advertising, informative advertising and the case when one firm’s advertising cannot directly influence the other firm's profit. For each of them, depending on the costs of advertising and marginal costs, equilibrium is determined, and conditions under which it is possible to deter the entry are given. It is shown that if the value of the advertising interaction factor increases, power of using advertising as a weapon to deter entry into the market decreases. Thus, in the case of informative advertising, advertising cannot be used as a tool for deterring entry into the market, while in the case of predatory advertising, it can. Also, we have proved that in the case of strictly informative advertising an over-investment never occurs, while in the two other cases, there is always over-investment either to deter or to accommodate the entry.

  15. Exploiting Herpes Simplex Virus Entry for Novel Therapeutics

    Directory of Open Access Journals (Sweden)

    Deepak Shukla

    2013-06-01

    Full Text Available Herpes Simplex virus (HSV is associated with a variety of diseases such as genital herpes and numerous ocular diseases. At the global level, high prevalence of individuals who are seropositive for HSV, combined with its inconspicuous infection, remains a cause for major concern. At the molecular level, HSV entry into a host cell involves multiple steps, primarily the interaction of viral glycoproteins with various cell surface receptors, many of which have alternate substitutes. The molecular complexity of the virus to enter a cell is also enhanced by the existence of different modes of viral entry. The availability of many entry receptors, along with a variety of entry mechanisms, has resulted in a virus that is capable of infecting virtually all cell types. While HSV uses a wide repertoire of viral and host factors in establishing infection, current therapeutics aimed against the virus are not as diversified. In this particular review, we will focus on the initial entry of the virus into the cell, while highlighting potential novel therapeutics that can control this process. Virus entry is a decisive step and effective therapeutics can translate to less virus replication, reduced cell death, and detrimental symptoms.

  16. Dynamics of ambulatory surgery centers and hospitals market entry.

    Science.gov (United States)

    Housman, Michael; Al-Amin, Mona

    2013-08-01

    In this article, we investigate the diversity of healthcare delivery organizations by comparing the market determinants of hospitals entry rates with those of ambulatory surgery centers (ASCs). Unlike hospitals, ASCs is one of the growing populations of specialized healthcare delivery organizations. There are reasons to believe that firm entry patterns differ within growing organizational populations since these markets are characterized by different levels of organizational legitimacy, technological uncertainty, and information asymmetry. We compare the entry patterns of firms in a mature population of hospitals to those of firms within a growing population of ASCs. By using patient-level datasets from the state of Florida, we break down our explanatory variables by facility type (ASC vs. hospital) and utilize negative binomial regression models to evaluate the impact of niche density on ASC and hospital entry. Our results indicate that ASCs entry rates is higher in markets with overlapping ASCs while hospitals entry rates are less in markets with overlapping hospitals and ASCs. These results are consistent with the notion that firms in growing populations tend to seek out crowded markets as they compete to occupy the most desirable market segments while firms in mature populations such as general hospitals avoid direct competition. © The Author(s) 2013 Reprints and permissions:]br]sagepub.co.uk/journalsPermissions.nav.

  17. Thermal Testing of Woven TPS Materials in Extreme Entry Environments

    Science.gov (United States)

    Gonzales, G.; Stackpoole, M.

    2014-01-01

    NASAs future robotic missions to Venus and outer planets, namely, Saturn, Uranus, Neptune, result in extremely high entry conditions that exceed the capabilities of current mid density ablators (PICA or Avcoat). Therefore mission planners assume the use of a fully dense carbon phenolic heatshield similar to what was flown on Pioneer Venus and Galileo. Carbon phenolic (CP) is a robust TPS however its high density and thermal conductivity constrain mission planners to steep entries, high heat fluxes, high pressures and short entry durations, in order for CP to be feasible from a mass perspective. In 2012 the Game Changing Development Program in NASAs Space Technology Mission Directorate funded NASA ARC to investigate the feasibility of a Woven Thermal Protection System to meet the needs of NASAs most challenging entry missions. The high entry conditions pose certification challenges in existing ground based test facilities. Recent updates to NASAs IHF and AEDCs H3 high temperature arcjet test facilities enable higher heatflux (2000 Wcm2) and high pressure (5 atm) testing of TPS. Some recent thermal tests of woven TPS will be discussed in this paper. These upgrades have provided a way to test higher entry conditions of potential outer planet and Venus missions and provided a baseline against carbon phenolic material. The results of these tests have given preliminary insight to sample configuration and physical recession profile characteristics.

  18. Acceptions of the "death"entry in language dictionaries

    Directory of Open Access Journals (Sweden)

    Jessica Camara Siqueira

    2013-08-01

    Full Text Available Language dictionaries present the meaning of an entry in a way not restricted to linguistic information, since we also have interdisciplinary and contextual aspects that dialogue with socio-cultural issues in which the entry is inserted. Considering the potential character of the study of contextual meanings, the “death” entry was chosen to carry out a comparative analysis among language dictionaries. The choice was motivated by the recurrence of this entry in ancient and contemporary dictionaries, and the fact of its having a concept that allows various historical, social and ideological discussions. The goal is to reveal the different nuances of the “death” entry in language dictionaries, observing four main aspects: etymology, diachrony, synonymic construction and meaning of “death” in school dictionaries. Based on lexicographical studies of classical authors, we did a comparative analysis of meanings of “death” in different types of language dictionaries. We found that in each group dictionary we may find traces of ideological choices in the construction of the contextual meaning of the “death” entry.

  19. Systematic screening of viral entry inhibitors using surface plasmon resonance.

    Science.gov (United States)

    Kumar, Penmetcha K R

    2017-11-01

    Viral binding and entry into host cells for various viruses have been studied extensively, yielding a detailed understanding of the overall viral entry process. As cell entry is an essential and requisite process by which a virus initiates infection, it is an attractive target for therapeutic intervention. The advantages of targeting viral entry are an extracellular target site, relatively easy access for biological interventions, and lower toxicity. Several cell-based strategies and biophysical techniques have been used to screen compounds that block viral entry. These studies led to the discovery of inhibitors against HIV, HCV, influenza, Ebola, and RSV. In recent years, several compounds screened by fragment-based drug discovery have been approved as drugs or are in the final stages of clinical trials. Among fragment screening technologies, surface plasmon resonance has been widely used because it provides accurate information on binding kinetics, allows real-time monitoring of ligand-drug interactions, requires very small sample amounts to perform analyses, and requires no modifications to or labeling of ligands. This review focuses on surface plasmon resonance-based schemes for screening viral entry inhibitors. Copyright © 2017 John Wiley & Sons, Ltd.

  20. Effects ok ikea's entry into a furniture production cluster

    Directory of Open Access Journals (Sweden)

    Vasco Eiriz

    2016-04-01

    Full Text Available The entry of a multinational into a cluster, a geographic agglomeration in a given place or region of predominantly small and medium enterprises specialized in a given industry or related industries, impacts the incumbent in the cluster. Aiming to identify the main effects of a multinational entry on the firms’ strategy in a cluster, it was analyzed the entry of IKEA, a Swedish multinational, into the cluster of furniture production in Paços de Ferreira and Paredes, in Portugal. In this study, the data collection technique to access primary data was a survey. The sample has small enterprises, which is similar to the structure of firms in the studied cluster. Results show that more than half the sample thinks that the entry of the multinational had not affected them. However, the firms that acknowledge a significant impact, assess that impact as negative. The competitiveness factors that have improved more significantly after IKEA’s entry were new product development and exporting strategies. The main responses of incumbent firms to the multinational entry were internationalization and the development of generic strategies of differentiation and focus based on differentiation.

  1. SAEVe: A Long Duration Small Sat Class Venus Lander - Seismic and Atmospheric Exploration of Venus

    Science.gov (United States)

    Kremic, Tibor; Ghail, Richard; Gilmore, Martha; Hunter, Gary; Kiefer, Walter; Limaye, Sanjay; Pauken, Michael; Tolbert, Carol; Wilson, Colin

    2017-01-01

    NASA's science mission directorate has put increasing emphasis on innovative, smaller, and lower cost missions to achieve their science objectives. One example of this was the recent call by the Planetary Science Division for cube and small satellite concepts expected to cost $100M or less, not including launch and weighing less than 180kg. Over 100 proposals were submitted suggesting that indeed this is a size of mission worthy of being considered in future planning. Nineteen missions were selected for study, one being a long-lived Venus mission called SAEVe, for Seismic and Atmospheric Exploration of Venus. The science objectives and relevance of SAEVe include: Is Venus seismically active? What can we learn about its crust (thickness and composition) and its interior (lithosphere, mantle, and core)? What can be learned about its evolutionary history or about the planet / atmosphere interactions? SAEVe begins to address these science questions with simple, but capable, instrumented probes that can survive on the surface of Venus and take temporal measurements over months something never attempted before. The data returned will further our understanding of the solar system and Earth, and aid in meeting the NASA Science Plan goal to ascertain the content, origin, and evolution of the solar system and the chemical and physical processes in our solar system. SAEVe is delivered to Venus as a ride-along on another mission to Venus. Its two small probes are placed into the Venus atmosphere via a single Stardust-like entry capsule, are ejected at different times, free fall, and decelerate in the thickening atmosphere to touchdown under 8 m/s2 or less. The probes will begin taking measurements and transmitting important parameters at or near the surface and will focus on measurements like seismic activity, heat flux, wind speed and direction, basic chemical abundances, temperature, and pressure. At preset intervals, the probes acquire the science measurements and beam the

  2. Applied survival analysis using R

    CERN Document Server

    Moore, Dirk F

    2016-01-01

    Applied Survival Analysis Using R covers the main principles of survival analysis, gives examples of how it is applied, and teaches how to put those principles to use to analyze data using R as a vehicle. Survival data, where the primary outcome is time to a specific event, arise in many areas of biomedical research, including clinical trials, epidemiological studies, and studies of animals. Many survival methods are extensions of techniques used in linear regression and categorical data, while other aspects of this field are unique to survival data. This text employs numerous actual examples to illustrate survival curve estimation, comparison of survivals of different groups, proper accounting for censoring and truncation, model variable selection, and residual analysis. Because explaining survival analysis requires more advanced mathematics than many other statistical topics, this book is organized with basic concepts and most frequently used procedures covered in earlier chapters, with more advanced topics...

  3. Understanding Callisto's Atmosphere

    Science.gov (United States)

    Spencer, John

    2016-10-01

    We plan to address first-order questions about the nature and origin of the mysterious atmosphere of Callisto, including its composition, longitudinal distribution, formation, and support mechanisms. This investigation is made possible by the remarkable sensitivity of the COS instrument, which has recently detected faint 1304 A and 1356 A O I emission from Callisto's leading / Jupiter-facing quadrant. The emission is probably due to dissociation of O2 molecules in Callisto's atmosphere by photo-electrons, and resonant scattering from an extended atomic O corona. We suspect, from Galileo ionospheric data, that the atmosphere may be much denser, and brighter in emission, on the trailing hemisphere, as expected for a sputter-generated atmosphere, and propose to test the sputter generation hypothesis with 4-orbit COS integrations on the leading and trailing hemispheres. If the trailing side emissions are indeed brighter, the improved SNR there will also allow much improved determination of atmospheric and coronal composition and optical depth. The observations will set the stage for, and aid in planning of, the extensive observations of Callisto's environment planned for the JUICE mission. Because Callisto's atmospheric oxygen emissions are indirectly illuminated by sunlight, which is uniform and quantifiable, it is much easier to understand atmospheric spatial distribution, and thus origin, than on Europa and Ganymede were emissions depend on magnetospheric excitation which is spatially variable and poorly understood. Callisto's atmosphere thus provides a unique chance to better understand the oxygen atmospheres of all the icy Galilean moons.

  4. Designing Dynamic Atmospheres

    DEFF Research Database (Denmark)

    Kinch, Sofie; Højlund, Marie

    2012-01-01

    This paper addresses the notion of atmospheres from a designerly perspective, and discusses temporal challenges facing interaction designers when acknowledging the dynamic character of it. As atmospheres are created in the relation between body, space, and time, a pragmatic approach seems useful,....... The potentials and implica-­‐ tions are presented through a design case, Kidkit, highlighting temporality as design parametre within interaction design.......This paper addresses the notion of atmospheres from a designerly perspective, and discusses temporal challenges facing interaction designers when acknowledging the dynamic character of it. As atmospheres are created in the relation between body, space, and time, a pragmatic approach seems useful...

  5. Atmospheric Measurements Laboratory (AML)

    Data.gov (United States)

    Federal Laboratory Consortium — The Atmospheric Measurements Laboratory (AML) is one of the nation's leading research facilities for understanding aerosols, clouds, and their interactions. The AML...

  6. Io's tenuous atmosphere

    International Nuclear Information System (INIS)

    Johnson, T.V.; Matson, D.L.

    1989-01-01

    An evaluation is made of observational evidence adduced to date for the various extant models of the Io atmosphere. SO2 and its various photochemical products have been noted to play a major role in the atmosphere; such atomic species as Na and K are present in smaller quantities, and play an important role in the atmosphere's ion chemistry. The vapor pressure equilibrium between condensed SO 2 on the surface and the atmospheric gas is an important factor in the global control of SO 2 gas distribution, but cannot account for the neutral densities at the terminator required for ionospheric models in view of realistic surface temperature distributions

  7. Effects of smolt release timing and size on the survival of hatchery-origin coho salmon in the Strait of Georgia

    Science.gov (United States)

    Irvine, J. R.; O'Neill, M.; Godbout, L.; Schnute, J.

    2013-08-01

    Altering release sizes and timings of coho salmon smolts from hatcheries in the Strait of Georgia will not reverse the precipitous survival declines of the past three decades. We modeled the effects on survival of ocean entry year, mean smolt size (weight), and release day. Ocean entry year was by far the most important. During 1979-2006, smolt to adult survivals declined similarly for hatchery and wild coho salmon, although wild salmon consistently survived at higher rates. Best models differed among hatcheries, implying location-specific differences in the optimal size and timing of release. At four of five hatcheries, heavier smolts survived significantly better than lighter smolts. At one hatchery, a significant interaction between ocean entry year and smolt weight reflected an increased positive effect of weight later in the time series. At two Vancouver Island hatcheries, early release groups appeared to survive better than later releases in early years, while later release groups survived best in recent years. We recommend: (1) hatchery managers release coho salmon smolts throughout the outmigration period of higher surviving wild coho salmon smolts and (2) an experimental approach using hatcheries to evaluate density-dependent effects on coho salmon growth and survival.

  8. The effects on the atmosphere of a major nuclear exchange

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    Most of the earth's population would survive the immediate horrors of a nuclear holocaust, but what long-term climatological changes would affect their ability to secure food and shelter. This sobering report considers the effects of fine dust from ground-level detonations, of smoke from widespread fires, and of chemicals released into the atmosphere. The authors use mathematical models of atmospheric processes and data from natural situations - e.g., volcanic eruptions and arctic haze - to draw their conclusions

  9. Consultant survival guide.

    Science.gov (United States)

    Haque, Sahena

    2014-04-01

    Taking up a new consultant post can be both exciting and daunting. Once the elation of completing years of training and successfully securing a valued position has subsided, the reality of the task ahead becomes apparent. A new consultant needs to develop a number of skills to develop as a clinical leader and understand the processes within the National Health Service (NHS) that enable service development and innovation. In a programme packed with esteemed speakers, the Royal College of Physicians' one-day conference, Consultants' survival guide: how to succeed as a new consultant provided practical tips and advice for senior trainees and new consultants.

  10. Nuclear War Survival Skills

    Energy Technology Data Exchange (ETDEWEB)

    Kearny, C.H.

    2002-06-24

    The purpose of this book is to provide Americans with information and instructions that will significantly increase their chances of surviving a possible nuclear attack. It brings together field-tested instructions that, if followed by a large fraction of Americans during a crisis that preceded an attack, could save millions of lives. The author is convinced that the vulnerability of our country to nuclear threat or attack must be reduced and that the wide dissemination of the information contained in this book would help achieve that objective of our overall defense strategy.

  11. Survival curves for irradiated cells

    International Nuclear Information System (INIS)

    Gibson, D.K.

    1975-01-01

    The subject of the lecture is the probability of survival of biological cells which have been subjected to ionising radiation. The basic mathematical theories of cell survival as a function of radiation dose are developed. A brief comparison with observed survival curves is made. (author)

  12. The Small Next-generation Atmospheric Probe (SNAP) for Exploration of the Ice Giants - A PSDS3 Mission Concept Study

    Science.gov (United States)

    Atkinson, David H.; Sayanagi, Kunio M.; Dillman, robert A.; Hope, Drew J.; Li, Jing; Saikia, Sarag J.; Simon, Amy A.; Spilker, Thomas R.; Wong, Michael H.

    2017-10-01

    The Small Next-generation Atmospheric Probe (SNAP) mission concept was selected under the NASA Planetary Science Deep Space Small Satellite (PSDS3) call. Envisioned as a secondary probe on a future ice giant flagship mission nominally comprising an orbiter and primary probe, SNAP would provide measurements of spatially variable atmospheric properties such as the abundances of key volatiles, the distribution of clouds and cloud-forming chemical species, thermal stratification and stability of the atmosphere, and the vertical profile of zonal wind speeds at the probe descent location. In addition to Uranus and Neptune, the SNAP design is also a viable Saturn entry probe.The SNAP mission concept would comprise a 30-kg entry probe with a diameter of ~0.5m (less than half the size of the Galileo probe) that could descend through at least 5-bars. The baseline payload would include an atmospheric structure instrument to measure the altitude profile of atmospheric pressure and temperature, an atmospheric composition sensor, and an ultrastable oscillator to enable radio science measurements including Doppler wind tracking. An identical ultrastable oscillator would be carried within the probe relay link receiver hardware on the carrier spacecraft. All probe data, including pre-entry and entry calibration and housekeeping data, entry accelerometry, and descent pressures, temperatures, composition, and zonal winds, would be returned to Earth by utilizing the carrier as a relay station.The in-situ atmospheric investigations enabled by SNAP would lead to an improved understanding of the chemical and physical processes that shape giant planet atmospheres, which in turn would shed light on the formation and evolution processes of the giant planets and the Solar System. The composition measurements would also provide chemical evidence addressing theories of planetary migration, thereby improving the understanding of the giant planets' role in promoting a habitable planetary systems.

  13. Does cancer reduce labor market entry? Evidence for prime-age females.

    Science.gov (United States)

    Moran, John R; Short, Pamela Farley

    2014-06-01

    Existing studies of the labor market status of cancer survivors have focused on the extent to which cancer disrupts the employment of individuals who were working when diagnosed with cancer. We examine how surviving cancer affects labor market entry and usual hours of work among females aged 28 to 54 years who were not working when first diagnosed. We find that prime-age females have employment rates 2 to 6 years after diagnosis that are 12 percentage points lower than otherwise similar women who were initially out of the labor force, full-time employment rates that are 10 percentage points lower, and usual hours of work that are 5 hours per week lower. These estimates are somewhat larger than estimates for prime-age women employed at the time of diagnosis and highlight the importance of considering nonworking females when assessing the economic and psychosocial burden of cancer.

  14. Nuclear war survival skills

    International Nuclear Information System (INIS)

    Kearney, C.H.

    1979-09-01

    This book includes chapters on psychological preparations, warning and communications, and evacuation. It describes the building of expedient shelters, their ventilation and cooling, the purification and storage of adequate water, the processing and cooking of whole grains and legumes, fallout meters, protection against fires and carbon monoxide, and expedient furnishings for shelters. Other chapters cover sanitation and preventive medicine, medical advice for nuclear survivors lacking the help of doctors, improvised footwear and clothing, and advice on minimum preparations that can be made at low cost and should be made before a crisis arises. One appendix of the handbook gives detailed, field-tested instructions for building six types of earth-covered expedient fallout shelters, with criteria to guide the choice of which shelter to build. Others contain instructions for making an efficient shelter-ventilating pump and a homemade fallout meter that is accurate and dependable with inexpensive materials found in most households. This report is primarily a compilation and summary of civil defense measures and inventions developed at ORNL over the past 14 years and field-tested in six states, from Florida to Utah. It is the first comprehensive handbook of survival information for use by untrained citizens who want to improve their chances of surviving a possible nuclear attack. Sections may be easily excerpted and reproduced for mass distribution through news media

  15. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from GEORGENE and SITKA SPRUCE in the NW Pacific from 1982-07-14 to 1983-09-16 (NODC Accession 8400020)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The entry contains data collected from R/V SITKA SPRUCE and other platforms from NW Pacific (limit-180) from July 14, 1982 to August 16, 1983. Log sheets containing...

  16. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from UNKNOWN in the Gulf of Mexico and Tampa Bay from 1961-01-08 to 1972-12-26 (NCEI Accession 8700331)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This accession contains multiple entries of Microfiche data that was provided by the Bureau of Commercial Fisheries, Fish and Wildlife Service, National Marine...

  17. Adaptable Deployable Entry & Placement Technology (ADEPT) for Cubesat Delivery to Mars Surface

    Science.gov (United States)

    Wercinski, Paul

    2014-01-01

    The Adaptable, Deployable Entry and Placement Technology (ADEPT), uses a mechanical skeleton to deploy a revolutionary carbon fabric system that serves as both heat shield and primary structure during atmospheric entry. The NASA ADEPT project, currently funded by the Game Changing Development Program in STMD is currently focused on 1m class hypersonic decelerators for the delivery of very small payloads ( 5 kg) to locations of interest in an effort to leverage low-cost platforms to rapidly mature the technology while simultaneously delivering high-value science. Preliminary mission design and aerothermal performance testing in arcjets have shown the ADEPT system is quite capable of safe delivery of cubesats to Mars surface. The ability of the ADEPT to transit to Mars in a stowed configuration (similar to an umbrella) provides options for integration with the Mars 2020 cruise stage, even to consider multiple ADEPTs. System-level test campaigns are underway for FY15 execution or planning for FY16. These include deployment testing, wind tunnel testing, system-level arc jet testing, and a sounding rocket flight test. The goal is system level maturation (TRL 6) at a 1m class Mars design reference mission configuration.

  18. Thermographic Imaging of the Space Shuttle During Re-Entry Using a Near Infrared Sensor

    Science.gov (United States)

    Zalameda, Joseph N.; Horvath, Thomas J.; Kerns, Robbie V.; Burke, Eric R.; Taylor, Jeff C.; Spisz, Tom; Gibson, David M.; Shea, Edward J.; Mercer, C. David; Schwartz, Richard J.; hide

    2012-01-01

    High resolution calibrated near infrared (NIR) imagery of the Space Shuttle Orbiter was obtained during hypervelocity atmospheric re-entry of the STS-119, STS-125, STS-128, STS-131, STS-132, STS-133, and STS-134 missions. This data has provided information on the distribution of surface temperature and the state of the airflow over the windward surface of the Orbiter during descent. The thermal imagery complemented data collected with onboard surface thermocouple instrumentation. The spatially resolved global thermal measurements made during the Orbiter s hypersonic re-entry will provide critical flight data for reducing the uncertainty associated with present day ground-to-flight extrapolation techniques and current state-of-the-art empirical boundary-layer transition or turbulent heating prediction methods. Laminar and turbulent flight data is critical for the validation of physics-based, semi-empirical boundary-layer transition prediction methods as well as stimulating the validation of laminar numerical chemistry models and the development of turbulence models supporting NASA s next-generation spacecraft. In this paper we provide details of the NIR imaging system used on both air and land-based imaging assets. The paper will discuss calibrations performed on the NIR imaging systems that permitted conversion of captured radiant intensity (counts) to temperature values. Image processing techniques are presented to analyze the NIR data for vignetting distortion, best resolution, and image sharpness. Keywords: HYTHIRM, Space Shuttle thermography, hypersonic imaging, near infrared imaging, histogram analysis, singular value decomposition, eigenvalue image sharpness

  19. Quality of data entry using single entry, double entry and automated forms processing--an example based on a study of patient-reported outcomes

    DEFF Research Database (Denmark)

    Paulsen, Aksel; Overgaard, Søren; Lauritsen, Jens Martin

    2012-01-01

    The clinical and scientific usage of patient-reported outcome measures is increasing in the health services. Often paper forms are used. Manual double entry of data is defined as the definitive gold standard for transferring data to an electronic format, but the process is laborious. Automated...

  20. Urban atmospheric contamination

    International Nuclear Information System (INIS)

    Baldasano Jose, M.

    1997-01-01

    The problems of contamination are not only limited to this century, pale pathology evidences of the effects of the contamination of the air exist in interiors in the health of the old ones; the article mention the elements that configure the problem of the atmospheric contamination, atmospheric pollutants and emission sources, orography condition and effects induced by the urbanization process

  1. The Power of Atmosphere

    DEFF Research Database (Denmark)

    Wieczorek, Izabela

    2014-01-01

    composed of bubbles of affects – that is, the particles that are charged with power and normativity. References Grtiffero, T. (2014 (2010)). Atmospheres: Aesthetics of Emotional Spaces. Ashgate Philippopoulos-Mihalopoulos, A. (2013). Atmospheres of law: Senses, affects, lawscapes, in Emotion, Space...

  2. Atmosphere and Heritage

    DEFF Research Database (Denmark)

    Ventzel Riis, Nina

    2012-01-01

    -between of the materials. This is what we identify as atmosphere, an enveloping phenomenon that surrounds and affects our sensuous system and well-being when we approach, enter, stay or move in a building. When we leave the building again we carry this atmospheric multi-sensory experience with us without adequate methods...

  3. Geoengineering Responses to Climate Change Selected Entries from the Encyclopedia of Sustainability Science and Technology

    CERN Document Server

    Vaughan, Naomi

    2013-01-01

    Failure by the international community to make substantive progress in reducing CO2 emissions, coupled with recent evidence of accelerating climate change, has brought increasing urgency to the search for additional remediation approaches.  This book presents a selection of state-of-the-art geoengineering methods for deliberately reducing the effects of anthropogenic climate change, either by actively removing greenhouse gases from the atmosphere or by decreasing the amount of sunlight absorbed at the Earth’s surface.  These methods contrast with more conventional mitigation approaches which focus on reducing emissions of greenhouse gases, especially carbon dioxide. Geoengineering technologies could become a key tool to be used in conjunction with emissions reduction to limit the magnitude of climate change.  Featuring authoritative, peer-reviewed entries from the Encyclopedia of Sustainability Science and Technology, this book presents a wide range of climate change remediation technologies. Examines th...

  4. Time-varying Entry Heating Profile Replication with a Rotating Arc Jet Test Article

    Science.gov (United States)

    Grinstead, Jay Henderson; Venkatapathy, Ethiraj; Noyes, Eric A.; Mach, Jeffrey J.; Empey, Daniel M.; White, Todd R.

    2014-01-01

    A new approach for arc jet testing of thermal protection materials at conditions approximating the time-varying conditions of atmospheric entry was developed and demonstrated. The approach relies upon the spatial variation of heat flux and pressure over a cylindrical test model. By slowly rotating a cylindrical arc jet test model during exposure to an arc jet stream, each point on the test model will experience constantly changing applied heat flux. The predicted temporal profile of heat flux at a point on a vehicle can be replicated by rotating the cylinder at a prescribed speed and direction. An electromechanical test model mechanism was designed, built, and operated during an arc jet test to demonstrate the technique.

  5. Climate change: Bio-technologies are facing a huge challenge. Why is climate changing? Control and measurement of greenhouse gases in the atmosphere. Soils at the heart of climate change. Between pollution and climate change, the survival of soil organisms. Modelling microbial degradation in soils to analyse greenhouse gas releases. A threat against plant health. The opinion of the seed industry. Truly living clouds. Language, the other stake of the struggle against climate changes

    International Nuclear Information System (INIS)

    Salas y Melia, David; Delmotte, Marc; Chenu, Claire; Chevallier, Tiphaine; Mougin, Christian; Lamy, Isabelle; Caquet, Thierry; Garnier, Patricia; Sache, Ivan; Pagesse, Pierre; Amato, Pierre; Desprez, Basile; Vernet, Agnes

    2015-01-01

    As the Rio Earth Summit in 1992 decided to react to limit the irrecoverable global warming, this publication, through several articles, outlines that this issue has not progressed at all after 23 years on a political point of view, and has even regressed with respect to initially defined objectives, but has progressed in terms of understanding of climate change under the influence of our production modes, notably in the agriculture sector. Thus, the articles discuss or recall the origin and process of climate change, how greenhouse gas emissions are controlled and measured, how soil are impacted or play a role in climate change as the survival of soil organisms is at stake under the pressure of pollution and climate change, how climate change can be a threat for plants, how the seed industry perceives these issues, how micro-organisms present in the air and clouds are now a topic in atmosphere sciences. The last article discusses the importance of intelligibility of scientific publications on these issues

  6. Improving laboratory data entry quality using Six Sigma.

    Science.gov (United States)

    Elbireer, Ali; Le Chasseur, Julie; Jackson, Brooks

    2013-01-01

    The Uganda Makerere University provides clinical laboratory support to over 70 clients in Uganda. With increased volume, manual data entry errors have steadily increased, prompting laboratory managers to employ the Six Sigma method to evaluate and reduce their problems. The purpose of this paper is to describe how laboratory data entry quality was improved by using Six Sigma. The Six Sigma Quality Improvement (QI) project team followed a sequence of steps, starting with defining project goals, measuring data entry errors to assess current performance, analyzing data and determining data-entry error root causes. Finally the team implemented changes and control measures to address the root causes and to maintain improvements. Establishing the Six Sigma project required considerable resources and maintaining the gains requires additional personnel time and dedicated resources. After initiating the Six Sigma project, there was a 60.5 percent reduction in data entry errors from 423 errors a month (i.e. 4.34 Six Sigma) in the first month, down to an average 166 errors/month (i.e. 4.65 Six Sigma) over 12 months. The team estimated the average cost of identifying and fixing a data entry error to be $16.25 per error. Thus, reducing errors by an average of 257 errors per month over one year has saved the laboratory an estimated $50,115 a year. The Six Sigma QI project provides a replicable framework for Ugandan laboratory staff and other resource-limited organizations to promote quality environment. Laboratory staff can deliver excellent care at a lower cost, by applying QI principles. This innovative QI method of reducing data entry errors in medical laboratories may improve the clinical workflow processes and make cost savings across the health care continuum.

  7. Neural stem cell-derived exosomes mediate viral entry

    Directory of Open Access Journals (Sweden)

    Sims B

    2014-10-01

    Full Text Available Brian Sims,1,2,* Linlin Gu,3,* Alexandre Krendelchtchikov,3 Qiana L Matthews3,4 1Division of Neonatology, Department of Pediatrics, 2Department of Cell, Developmental, and Integrative Biology, 3Division of Infectious Diseases, Department of Medicine, 4Center for AIDS Research, University of Alabama at Birmingham, Birmingham, AL, USA *These authors contributed equally to this work Background: Viruses enter host cells through interactions of viral ligands with cellular receptors. Viruses can also enter cells in a receptor-independent fashion. Mechanisms regarding the receptor-independent viral entry into cells have not been fully elucidated. Exosomal trafficking between cells may offer a mechanism by which viruses can enter cells.Methods: To investigate the role of exosomes on cellular viral entry, we employed neural stem cell-derived exosomes and adenovirus type 5 (Ad5 for the proof-of-principle study. Results: Exosomes significantly enhanced Ad5 entry in Coxsackie virus and adenovirus receptor (CAR-deficient cells, in which Ad5 only had very limited entry. The exosomes were shown to contain T-cell immunoglobulin mucin protein 4 (TIM-4, which binds phosphatidylserine. Treatment with anti-TIM-4 antibody significantly blocked the exosome-mediated Ad5 entry.Conclusion: Neural stem cell-derived exosomes mediated significant cellular entry of Ad5 in a receptor-independent fashion. This mediation may be hampered by an antibody specifically targeting TIM-4 on exosomes. This set of results will benefit further elucidation of virus/exosome pathways, which would contribute to reducing natural viral infection by developing therapeutic agents or vaccines. Keywords: neural stem cell-derived exosomes, adenovirus type 5, TIM-4, viral entry, phospholipids

  8. Intensifying the Atmospheric

    DEFF Research Database (Denmark)

    Liebst, Lasse Suonperä

    2012-01-01

    understanding of atmospheres as aesthetically ‘radiating’ from the surfaces of space, thinks physiognomically, the article argues for a spatial morphological perspective on atmospheres. Thus, post-phenomeno¬logically, it is argued that the atmospheric given is given by the density of pedestrians, which...... are ‘compressed’ by the spatial morphologies of urban space. In this perspective atmospheres are to be understood as an emergent property that develops when the spatial morphological compression of urban life passes a certain threshold, that is, when the affective rhythm of the urban assemblages becomes...... sufficiently intense. All things considered, the paper should be read as a sociological contribution to theoretically reconstruct the concept of urban atmospheres in the light of spatial morphology....

  9. Titan's Lower Atmosphere

    Science.gov (United States)

    Griffith, Caitlin Ann

    2007-09-01

    Saturn's largest moon, Titan, sports an atmosphere 10 times thicker than Earth's. Like Earth, the moon's atmosphere is N2 based and possesses a rich organic chemistry. In addition, similar to the terrestrial hydrological cycle, Titan has a methane cycle, with methane clouds, rain and seas. Presently, there is a revolution in our understanding of the moon, as data flows in and is analyzed from the NASA and ESA Cassini-Huygens mission. For example, seas were detected only this year. Here I will discuss the evolution of our understanding of Titan's atmosphere, its composition, chemistry, dynamics and origin. Current open questions will also be presented. Studies of Titan's atmosphere began and evolved to the present state in less time than that of a single scientist's career. This short interlude of activity demonstrates the rigors of the scientific method, and raises enticing questions about the workings and evolution of an atmosphere.

  10. Molecular line parameters for the atmospheric trace molecule spectroscopy experiment

    Science.gov (United States)

    Brown, L. R.; Farmer, C. B.; Toth, R. A.; Rinsland, Curtis P.

    1987-01-01

    During its first mission in 1985 onboard Spacelab 3, the ATMOS (atmospheric trace molecule spectroscopy) instrument, a high speed Fourier transform spectrometer, produced a large number of high resolution infrared solar absorption spectra recorded in the occultation mode. The analysis and interpretation of these data in terms of composition, chemistry, and dynamics of the earth's upper atmosphere required good knowledge of the molecular line parameters for those species giving rise to the absorptions in the atmospheric spectra. This paper describes the spectroscopic line parameter database compiled for the ATMOS experiment and referenced in other papers describing ATMOS results. With over 400,000 entries, the linelist catalogs parameters of 46 minor and trace species in the 1-10,000/cm region.

  11. Landing site considerations for atmosphere structure and meteorology

    Science.gov (United States)

    Seiff, Alvin; Haberle, R.; Murphy, J.

    1994-01-01

    The goal of the ASI/MET experiments is to extend our knowledge of Mars atmosphere structure and meteorology over that established by the Viking mission. The two in situ soundings of Mars atmosphere by Vikings 1 and 2 were highly similar, but radio occultations and infrared soundings have shown large variability in atmosphere structure on Mars with latitude, season, and terrain elevation. It would be of great interest to obtain an in situ sounding showing strong contrast in thermal structure with the Viking profiles. These would be expected to occur in the winter season, in the southern hemisphere, or at polar latitudes. These options are ruled out by Pathfinder Mission constraints, which place the entry in low, northern latitudes in mid summer, with small seasonal difference from the two Viking landers, and small latitude difference from Viking 1.

  12. Mars 2020 Entry, Descent, and Landing Instrumentation 2 (MEDLI2) Sensor Suite

    Science.gov (United States)

    Hwang, Helen; Wright, Henry; Kuhl, Chris; Schoenenberger, Mark; White, Todd; Karlgaard, Chris; Mahzari, Milad; Oishi, Tomo; Pennington, Steve; Trombetta, Nick; hide

    2017-01-01

    The Mars 2020 Entry, Descent, and Landing Instrumentation 2 (MEDLI2) sensor suite seeks to address the aerodynamic, aerothermodynamic, and thermal protection system (TPS) performance issues during atmospheric entry, descent, and landing of the Mars 2020 mission. Based on the highly successful instrumentation suite that flew on Mars Science Laboratory (MEDLI), the new sensor suite expands on the types of measurements and also seeks to answer questions not fully addressed by the previous mission. Sensor Package: MEDLI2 consists of 7 pressure transducers, 17 thermal plugs, 2 heat flux sensors, and one radiometer. The sensors are distributed across both the heatshield and backshell, unlike MEDLI (the first sensor suite), which was located solely on the heat-shield. The sensors will measure supersonic pressure on the forebody, a pressure measurement on the aftbody, near-surface and in-depth temperatures in the heatshield and backshell TPS materials, direct total heat flux on the aftbody, and direct radiative heating on the aftbody. Instrument Development: The supersonic pressure transducers, the direct heat flux sensors, and the radiometer all were tested during the development phase. The status of these sensors, including the piezo-resistive pressure sensors, will be presented. The current plans for qualification and calibration for all of the sensors will also be discussed. Post-Flight Data Analysis: Similar to MEDLI, the estimated flight trajectory will be reconstructed from the data. The aerodynamic parameters that will be reconstructed will be the axial force coefficient, freestream Mach number, base pressure, atmospheric density, and winds. The aerothermal quantities that will be determined are the heatshield and backshell aero-heating, turbulence transition across the heatshield, and TPS in-depth performance of PICA. By directly measuring the radiative and total heat fluxes on the back-shell, the convective portion of the heat flux will be estimated. The status

  13. 14 CFR 121.709 - Airworthiness release or aircraft log entry.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airworthiness release or aircraft log entry... Airworthiness release or aircraft log entry. (a) No certificate holder may operate an aircraft after maintenance... appropriate entry in the aircraft log. (b) The airworthiness release or log entry required by paragraph (a) of...

  14. 14 CFR 135.443 - Airworthiness release or aircraft maintenance log entry.

    Science.gov (United States)

    2010-01-01

    ... maintenance log entry. 135.443 Section 135.443 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... release or aircraft maintenance log entry. (a) No certificate holder may operate an aircraft after... (2) An appropriate entry in the aircraft maintenance log. (b) The airworthiness release or log entry...

  15. 48 CFR 552.270-9 - Inspection-Right of Entry.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Inspection-Right of Entry... Inspection—Right of Entry. As prescribed in 570.603, insert the following clause: Inspection—Right of Entry... the purposes of entry, to determine the potential or actual compliance by the Offeror or Lessor with...

  16. Advanced entry guidance algorithm with landing footprint computation

    Science.gov (United States)

    Leavitt, James Aaron

    The design and performance evaluation of an entry guidance algorithm for future space transportation vehicles is presented. The algorithm performs two functions: on-board trajectory planning and trajectory tracking. The planned longitudinal path is followed by tracking drag acceleration, as is done by the Space Shuttle entry guidance. Unlike the Shuttle entry guidance, lateral path curvature is also planned and followed. A new trajectory planning function for the guidance algorithm is developed that is suitable for suborbital entry and that significantly enhances the overall performance of the algorithm for both orbital and suborbital entry. In comparison with the previous trajectory planner, the new planner produces trajectories that are easier to track, especially near the upper and lower drag boundaries and for suborbital entry. The new planner accomplishes this by matching the vehicle's initial flight path angle and bank angle, and by enforcing the full three-degree-of-freedom equations of motion with control derivative limits. Insights gained from trajectory optimization results contribute to the design of the new planner, giving it near-optimal downrange and crossrange capabilities. Planned trajectories and guidance simulation results are presented that demonstrate the improved performance. Based on the new planner, a method is developed for approximating the landing footprint for entry vehicles in near real-time, as would be needed for an on-board flight management system. The boundary of the footprint is constructed from the endpoints of extreme downrange and crossrange trajectories generated by the new trajectory planner. The footprint algorithm inherently possesses many of the qualities of the new planner, including quick execution, the ability to accurately approximate the vehicle's glide capabilities, and applicability to a wide range of entry conditions. Footprints can be generated for orbital and suborbital entry conditions using a pre

  17. Surviving relatives after suicide

    DEFF Research Database (Denmark)

    Nørrelykke, Helle; Cohrt, Pernille

    We would like to focus on the surviving relatives after suicides, because it is generally accepted that it is especially difficult to recover after the loss from suicide and because we know as a fact that one suicide affects five persons on average. Every year approximately 700 people commit...... suicide in Denmark. This means that at least 400 people undergo the trauma it is when one of their near relatives commits suicide. We also know that the loss from suicide involves a lot of conflicting feelings - like anger, shame, guilt and loss and that the lack of therapy/treatment of these difficult...... for treatment for the relatives. In the wake of this policy document a national organization for relatives after suicide and a national network for those who attempt suicide occurred. Both organizations are formed by voluntary subscription and both organizations offer acute emergency relief, conversation groups...

  18. Hera - an ESA M-class Saturn Entry Probe Mission Proposal

    Science.gov (United States)

    Atkinson, D. H.; Mousis, O.; Spilker, T. R.; Venkatapathy, E.; Poncy, J.; Coustenis, A.; Reh, K. R.

    2015-12-01

    A fundamental goal of solar system exploration is to understand the origin of the solar system, the initial stages, conditions, and processes by which the solar system formed, how the formation process was initiated, and the nature of the interstellar seed material from which the solar system was born. Key to understanding solar system formation and subsequent dynamical and chemical evolution is the origin and evolution of the giant planets and their atmospheres. Additionally, the atmospheres of the giant planets serve as laboratories to better understand the atmospheric chemistries, dynamics, processes, and climates on all planets in the solar system including Earth, offer a context and provide a ground truth for exoplanets and exoplanetary systems, and have long been thought to play a critical role in the development of potentially habitable planetary systems. Remote sensing observations are limited when used to study the bulk atmospheric composition of the giant planets of our solar system. A remarkable example of the value of in situ measurements is provided by measurements of Jupiter's noble gas abundances and helium mixing ratio by the Galileo probe. In situ measurements provide direct access to atmospheric regions that are beyond the reach of remote sensing, enabling the dynamical, chemical and aerosol-forming processes at work from the thermosphere to the troposphere below the cloud decks to be studied. Studies for a newly proposed Saturn atmospheric entry probe mission named Hera is being prepared for the upcoming European Space Agency Medium Class (M5) mission announcement of opportunity. A solar powered mission, Hera will take approximately 8 years to reach Saturn and will carry instruments to measure the composition, structure, and dynamics of Saturn's atmosphere. In the context of giant planet science provided by the Galileo, Juno, and Cassini missions to Jupiter and Saturn, the Hera Saturn probe will provide critical measurements of composition

  19. Rhadinovirus host entry by co-operative infection.

    Science.gov (United States)

    Lawler, Clara; Milho, Ricardo; May, Janet S; Stevenson, Philip G

    2015-03-01

    Rhadinoviruses establish chronic infections of clinical and economic importance. Several show respiratory transmission and cause lung pathologies. We used Murid Herpesvirus-4 (MuHV-4) to understand how rhadinovirus lung infection might work. A primary epithelial or B cell infection often is assumed. MuHV-4 targeted instead alveolar macrophages, and their depletion reduced markedly host entry. While host entry was efficient, alveolar macrophages lacked heparan - an important rhadinovirus binding target - and were infected poorly ex vivo. In situ analysis revealed that virions bound initially not to macrophages but to heparan⁺ type 1 alveolar epithelial cells (AECs). Although epithelial cell lines endocytose MuHV-4 readily in vitro, AECs did not. Rather bound virions were acquired by macrophages; epithelial infection occurred only later. Thus, host entry was co-operative - virion binding to epithelial cells licensed macrophage infection, and this in turn licensed AEC infection. An antibody block of epithelial cell binding failed to block host entry: opsonization provided merely another route to macrophages. By contrast an antibody block of membrane fusion was effective. Therefore co-operative infection extended viral tropism beyond the normal paradigm of a target cell infected readily in vitro; and macrophage involvement in host entry required neutralization to act down-stream of cell binding.

  20. A Gestalt approach to Gram-negative entry.

    Science.gov (United States)

    Silver, Lynn L

    2016-12-15

    A major obstacle confronting the discovery and development of new antibacterial agents to combat resistant Gram-negative (GN) organisms is the lack of a rational process for endowing compounds with properties that allow (or promote) entry into the bacterial cytoplasm. The major permeability difference between GN and Gram-positive (GP) bacteria is the GN outer membrane (OM) which is a permeability barrier itself and potentiates efflux pumps that expel compounds. Based on the fact that OM-permeable and efflux-deleted GNs are sensitive to many anti-GP drugs, recent efforts to approach the GN entry problem have focused on ways of avoiding efflux and transiting or compromising the OM, with the tacit assumption that this could allow entry of compounds into the GN cytoplasm. But bypassing the OM and efflux obstacles does not take into account the additional requirement of penetrating the cytoplasmic membrane (CM) whose sieving properties appear to be orthogonal to that of the OM. That is, tailoring compounds to transit the OM may well compromise their ability to enter the cytoplasm. Thus, a Gestalt approach to understanding the chemical requirements for GN entry seems a useful adjunct. This might consist of characterizing compounds which reach the cytoplasm, grouping (or binning) by routes of entry and formulating chemical 'rules' for those bins. This will require acquisition of data on large numbers of compounds, using non-activity-dependent methods of measuring accumulation in the cytoplasm. Copyright © 2016 Elsevier Ltd. All rights reserved.