Science.gov

Sample records for re-entry

  1. Re-entry Experiment Launch

    NASA Video Gallery

    On August 10, 2009, NASA successfully launched the Inflatable Re-entry Vehicle Experiment (IRVE) and proved that spacecraft can use inflatable heat shields to reduce speed and provide protection du...

  2. Shadowgraph Images of Re-entry Vehicles

    NASA Technical Reports Server (NTRS)

    1960-01-01

    These four shadowgraph images represent early re-entry vehicle concepts. A shadowgraph is a process that makes visible the disturbances that occur in a fluid flow at high velocity, in which light passing through a flowing fluid is refracted by the density gradients in the fluid resulting in bright and dark areas on a screen placed behind the fluid.H. Julian Allen pioneered and developed the Blunt Body Theory which made possible the heat shield designs that were embodied in the Mercury, Gemini and Apollo space capsules, enabling astronauts to survive the firey re-entry into Earth's atmosphere. A blunt body produces a shockwave in front of the vehicle--visible in the photo--that actually shields the vehicle from excessive heating. As a result, blunt body vehicles can stay cooler than pointy, low drag vehicles.

  3. Assessment of the ATV-1 Re-Entry Observation Campaign for Future Re-Entry Missions

    NASA Astrophysics Data System (ADS)

    Lips, T.; Lohle, S.; Marynowsky, T.; Rees, D.; Stenbeak-Nielsen, H. C.; Beks, M. L.; Hatton, J.

    2010-09-01

    This paper summarizes the midterm results of the currently ongoing ESA study “Assessment of the ATV-1 Reentry Observation Campaign for Future Re-entry Missions”. The primary objective of this study is to investigate the data obtained during a joint ESA/NASA airborne observation campaign of the destructive re-entry of ATV-1 Jules Verne which occurred on September 29, 2008. The presented results are focused on spectroscopic fragment characterization(material identification), frame-by-frame fragment tracking(manual and automatic) for various video recordings, 3D triangulation of the tracked fragments, and fragment propagation until complete demise or ground impact, including the actual size and location of the ATV-1 debris footprint. Fragment propagation analyses comprise also the derivation of aerodynamic fragment properties and potential delta velocities. These parameters are of high importance for the re-entry safety analysis for ATV-2 Johannes Kepler.

  4. Orbit re-entry experiment vehicle development

    NASA Astrophysics Data System (ADS)

    Yamamoto, Masataka; Yamawaki, Kouji; Akimoto, Toshio; Murakami, Atsushi; Inaba, Motoyuki; Kaneko, Yutaka; Shimoda, Takayuki; Ishii, Yasuo; Izumi, Tatsushi; Kawano, Isao

    1992-08-01

    An overview of the Orbital Re-entry Experiment (OREX) vehicle development, including detail design, analyses on the overall system, guidance and control, propulsion, and data acquisition systems is presented. The outline of the experiment vehicle is shown. OREX flight is analyzed and the splash down point variance ellipse is shown. Vehicle body aerodynamic characteristics were analyzed and validated by supersonic wind tunnel and dynamically balanced wind tunnel tests. Analyses on onboard equipment environmental resistance, controllability from on orbit to re-entry phases and navigation and guidance of the space plane were conducted. It was confirmed that there was no problem on the guidance and control system. Review on the propellant volume and analyses on the propulsion system performance, propulsion system heat exchanger performance, and thruster and piping system temperature were conducted and possibility of hard starting of the 150 N hydrazine thruster was noticed. RF (Radio Frequency) link analyses were conducted around Tanegashima, Ogasawara, and the splash down area and prospect of continuously acquiring good link margin for 300 seconds was obtained. Semi unitized structure of truncated cone shape with main body made of aluminum alloy, which has application record for rockets, laid with skin, stringers, and frames was employed for the structure. Data acquisition systems for tracking and operation, including those at Tanegashima, Ogasawara, Christmas, down range ship, and airplane tracking stations were studied.

  5. Tethered space recovery vehicle deployment/re-entry demonstration

    NASA Technical Reports Server (NTRS)

    Florence, D.

    1988-01-01

    The feasibility of utilizing existing Space Re-entry Vehicle (SRV) hardware for a Shuttle Orbiter-based tethered SRV deployment and re-entry demonstration using the Small Expendable Deployer System has been investigated. Options for mounting the SRV in the Orbiter, modifications and additions required to the existing SRV hardware have been defined. Flight demonstration scenarios from the Orbiter have been investigated, and re-entry motion and targeting uncertainties have been determined.

  6. An Evaluation Guide for College Women's Re-entry Programs.

    ERIC Educational Resources Information Center

    Mezirow, Jack; Rose, Amy D.

    Since 1970, over 300 community colleges have established re-entry programs designed especially for women who are either continuing their education or entering the job market after an extended hiatus. Re-entry programs vary in scope and in the nature of services provided, with some offering specific skills on vocational training, and others…

  7. ISS Update: ATV-3 ReEntry Breakup Recorder

    NASA Video Gallery

    ISS Update Commentator Pat Ryan talks with Dr. William Ailor, Principal Investigator for the ReEntry Breakup Recorder (REBR) for The Aerospace Corporation. Ailor talks about capturing data as Europ...

  8. A hypersonic parachute for low-temperature re-entry

    NASA Astrophysics Data System (ADS)

    Krischke, M.; Lorenzini, E. C.; Sabath, D.

    1995-09-01

    Atmospheric re-entry, even when initiated from a circular low-Earth orbit, requires heavy heat shields, ablative materials or radiative dissipation techniques. Semi-analytical and numerical simulations of the atmospheric re-entry from low-Earth orbits of a capsule with a 20-km, attached, heat resistant tether have shown that the thermal input flux on the capsule is reduced by more than one order of magnitude with respect to a comparable re-entry without tether. Long tethers have low ballistic coefficients and a large surface for heat dissipation. Moreover, a long tether is stabilized by gravity gradient and consequently tends to maintain a high angle of attack with respect to the wind velocity. The exposed surface of a 20-km-long 1-mm diameter tether is 20 m 2, which is much larger than the cross section of a re-entry capsule. The resulting strong drag decelerates the capsule during re-entry like a conceivable hypersonic parachute would do. This paper describes the methods and results of the simulation of the SEDS endmass re-entry with different tethers.

  9. Missile Aerodynamics for Ascent and Re-entry

    NASA Technical Reports Server (NTRS)

    Watts, Gaines L.; McCarter, James W.

    2012-01-01

    Aerodynamic force and moment equations are developed for 6-DOF missile simulations of both the ascent phase of flight and a tumbling re-entry. The missile coordinate frame (M frame) and a frame parallel to the M frame were used for formulating the aerodynamic equations. The missile configuration chosen as an example is a cylinder with fixed fins and a nose cone. The equations include both the static aerodynamic coefficients and the aerodynamic damping derivatives. The inclusion of aerodynamic damping is essential for simulating a tumbling re-entry. Appended information provides insight into aerodynamic damping.

  10. Calibration of Radar Based Re-Entry Predictions

    NASA Astrophysics Data System (ADS)

    Lemmens, S.; Bastida Virgili, B.; Flohrer, T.; Gini, F.; Krag, H.; Steiger, C.

    2015-03-01

    The availability of GPS observations via the telemetry during GOCE’s (Gravity Field and Steady-State Ocean Circulation Explorer) entire re-entry campaign enabled the generation of high quality orbit products which can be used as input to re-entry predictions. These high precision orbits can be used as reference to assess the quality of orbits generated from other sources. Here we verify the accuracy of orbits based on radar tracking data, obtained by dedicated observations with the Tracking & Imaging Radar system from the Fraunhofer High Frequency Physics and Radar Techniques institute, with respect to the a post-processed GPS based reference orbit. This leads to time-depended quantification of the orbit determination uncertainties on the re-entry predictions. Furthermore, the ballistic coefficient determined by the orbit determination and its time dependent evolution can be used to a priori estimate the attitude behaviour of GOCE, which can be compared to the telemetry. The attitude behaviour can be analysed by the use of inverse synthetic aperture radar (ISAR) images, also obtained by dedicated observation by TIRA. The effect of adding this knowledge on the attitude evolution to the re-entry predictions is evaluated.

  11. Childhood cancer survivors' school (re)entry: Australian parents' perceptions.

    PubMed

    McLoone, J K; Wakefield, C E; Cohn, R J

    2013-07-01

    Starting or returning to school after intense medical treatment can be academically and socially challenging for childhood cancer survivors. This study aimed to evaluate the school (re)entry experience of children who had recently completed cancer treatment. Forty-two semi-structured telephone interviews were conducted to explore parents' perceptions of their child's (re)entry to school after completing treatment (23 mothers, 19 fathers, parent mean age 39.5 years; child mean age 7.76 years). Interviews were analysed using the framework of Miles and Huberman and emergent themes were organised using QSR NVivo8. Parents closely monitored their child's school (re)entry and fostered close relationships with their child's teacher to ensure swift communication of concerns should they arise. The most commonly reported difficulty related to aspects of peer socialisation; survivors either displayed a limited understanding of social rules such as turn taking, or related more to older children or teachers relative to their peers. Additionally, parents placed a strong emphasis on their child's overall personal development, above academic achievement alone. Improved parent, clinician and teacher awareness of the importance of continued peer socialisation during the treatment period is recommended in order to limit the ongoing ramifications this may have on school (re)entry post-treatment completion.

  12. Controlled Re-Entry of the H-IIB Launch Vehicle Upper Stage with the Use of the Re-Entry Safety System

    NASA Astrophysics Data System (ADS)

    Ida, K.; Mori, S.; Sakamoto, K.; Ikeda, S.; Sato, T.; Kawabata, H.

    2012-01-01

    On January 22, 2011, during flight No. 2 of the H-IIB launch vehicle, the Japan Aerospace Exploration Agency (JAXA) succeeded in performing a controlled re-entry experiment for the upper stage. This is the first time this has been done for the upper stage of a Japanese launch vehicle. For flight No. 1, the upper stage performed a random re- entry. With a view to avoiding debris generation and debris-related impact accidents, JAXA resolved to develop a more refined re-entry process. Consequently, the "Re-entry Safety System" was developed in order to achieve controlled re-entry with certainty. After one orbit, while executing controlled re-entry, the Re-entry Safety System monitored the upper stage's function and orbit. Subsequently, a command disengaging the lockout of the deorbit manoeuvre was issued from ground and re-entry commenced. The details of the Re-entry Safety System, which facilitated the controlled re-entry, are described herein.

  13. Inflatable Re-entry Vehicle Experiment (IRVE-4) Overview

    NASA Technical Reports Server (NTRS)

    Litton, Daniel K.; Bose, David M.; Cheatwood, F. McNeil; Hughes, Stephen; Wright, Henry S.; Lindell, Michael C.; Derry, Stephen D.; Olds, Aaron

    2011-01-01

    The suite of Inflatable Re-Entry Vehicle Experiments (IRVE) is designed to further our knowledge and understanding of Hypersonic Inflatable Aerodynamic Decelerators (HIADs). Before infusion into a future mission, three challenges need to be addressed: surviving the heat pulse during re-entry, demonstrating system performance at relevant scales, and demonstrating controllability in the atmosphere. IRVE-4 will contribute to a better understanding of controllability by characterizing how a HIAD responds to a set of controlled inputs. The ability to control a HIAD is vital for missions that are g-limited, require precision targeting and guidance for aerocapture or entry, descent, and landing. The IRVE-4 flight test will focus on taking a first look into controlling a HIAD. This paper will give an overview of the IRVE-4 mission including the control response portion of the flight test sequence, and will provide a review of the mission s development.

  14. Re-entry and reintegration: returning home after combat.

    PubMed

    Doyle, Michael E; Peterson, Kris A

    2005-01-01

    Soldier life exists on a continuum of readiness for deployment. Re-entry and reintegration-the return home and reunion with family and community-key the success of the deployment cycle. In current and projected future operations, the Army and society will both bear the burden of this re-entry and re-integration. Programs and procedures in place work towards improving communication, mitigating distress and resolving crises during reentry and reintegration. Key elements include: inclusion of families and communities early into the planning for reentry and reintegration; normalization (non-medicalization of distress); easy access to behavioral health professionals; and education of families on resources and benefits. Through broad collaboration, maximal benefit to the Soldier, family members and society be realized.

  15. Control Surface Seals Investigated for Re- Entry Vehicles

    NASA Technical Reports Server (NTRS)

    Dunlap, Patrick H.; Steinetz, Bruce M.

    2003-01-01

    Re-entry vehicles generally use control surfaces (e.g., rudders, body flaps, and elevons) to steer or guide them as they pass into and through the Earth s atmosphere. High temperature seals are required around control surfaces both along hinge lines and in areas where control surface edges seal against the vehicle body to limit hot gas ingestion and the transfer of heat to underlying low-temperature structures. Working with the NASA Johnson Space Center, the Seals Team at the NASA Glenn Research Center completed a series of tests on the baseline seal design for the rudder/fin control surface interfaces of the X-38 vehicle. This seal application was chosen as a case study to evaluate a currently available control surface seal design for applications in future re-entry vehicles. The structures of the rudder/fin assembly and its associated seals are shown in the following illustration.

  16. FLPP IXV Re-Entry Vehicle, Aerodynamic Characterisation

    NASA Astrophysics Data System (ADS)

    Belmont, J.-P.; Cantinaud, O.; Tribot, J.-P.; Walloschek, T.

    2009-01-01

    The European Space Agency ESA, has engaged in 2004, the IXV project (Intermediate eXperimental Vehicle) which is part of the FLPP (Future Launcher Preparatory Programme) aiming at answering to critical technological issues, while supporting the future generation launchers and improving in general European capabilities in the strategic field of atmospheric re-entry for space transportation, exploration, and scientific applications. The IXV key mission and system objectives are the design, development, manufacturing, assembling and on- ground to in-flight verification of an autonomous European lifting and aerodynamically controlled re- entry system, integrating the critical re-entry technologies at the system level. The current IXV vehicle is a slender body type exhibiting rounded shape and thick body. Since the beginning of the IXV project, an aerodynamic data base (AEDB) has been built up and continuously updated integrating the additional information mainly provided by means of CFD. The AEDB includes nominal aerodynamic data, a new set of free molecular aerodynamic coefficients as well as aerodynamic uncertainties. Through the phase B2/C1, complementary computations were performed (CFSE, EPFL, ASTRIUM, TAS, DAA) as well as wind tunnel tests such as ONERA S4ma, DLR H2K, DNW/NLR SST, FOI T1500. All data were analyzed and compared enabling the consolidation of the nominal aerodynamic and aerodynamic uncertainties as well. The paper presents the logic of work based on the system engineering plan with emphasis on the different prediction tools used aiming the final aerodynamic characterization of the IXV configuration.

  17. Coronas-F Orbit Monitoring and Re-Entry Prediction

    NASA Technical Reports Server (NTRS)

    Ivanov, N. M.; Kolyuka, Yu. F.; Afanasieva, T. I.; Gridchina, T. A.

    2007-01-01

    Russian scientific satellite CORONAS-F was launched on July, 31, 2001. The object was inserted in near-circular orbit with the inclination 82.5deg and a mean altitude approx. 520 km. Due to the upper atmosphere drag CORONAS-F was permanently descended and as a result on December, 6, 2005 it has finished the earth-orbital flight, having lifetime in space approx. 4.5 years. The satellite structural features and its flight attitude control led to the significant variations of its ballistic coefficient during the flight. It was a cause of some specific difficulties in the fulfillment of the ballistic and navigation support of this space vehicle flight. Besides the main mission objective CORONAS-F also has been selected by the Inter-Agency Space Debris Coordination Committee (IADC) as a target object for the next regular international re-entry test campaign on a program of surveillance and re-entry prediction for the hazard space objects within their de-orbiting phases. Spacecraft (S/C) CORONAS-F kept its working state right up to the end of the flight - down to the atmosphere entry. This fact enabled to realization of the additional research experiments, concerning with an estimation of the atmospheric density within the low earth orbits (LEO) of the artificial satellites, and made possible to continue track the S/C during final phase of its flight by means of Russian regular command & tracking system, used for it control. Thus there appeared a unique possibility of using for tracking S/C at its de-orbiting phase not only passive radar facilities, belonging to the space surveillance systems and traditionally used for support of the IADC re-entry test campaigns, but also more precise active trajectory radio-tracking facilities from the ground control complex (GCC) applied for this object. Under the corresponding decision of the Russian side such capability of additional high-precise tracking control of the CORONAS-F flight in this period of time has been implemented

  18. ELECTRA © Launch and Re-Entry Safety Analysis Tool

    NASA Astrophysics Data System (ADS)

    Lazare, B.; Arnal, M. H.; Aussilhou, C.; Blazquez, A.; Chemama, F.

    2010-09-01

    French Space Operation Act gives as prime objective to National Technical Regulations to protect people, properties, public health and environment. In this frame, an independent technical assessment of French space operation is delegated to CNES. To perform this task and also for his owns operations CNES needs efficient state-of-the-art tools for evaluating risks. The development of the ELECTRA© tool, undertaken in 2007, meets the requirement for precise quantification of the risks involved in launching and re-entry of spacecraft. The ELECTRA© project draws on the proven expertise of CNES technical centers in the field of flight analysis and safety, spaceflight dynamics and the design of spacecraft. The ELECTRA© tool was specifically designed to evaluate the risks involved in the re-entry and return to Earth of all or part of a spacecraft. It will also be used for locating and visualizing nominal or accidental re-entry zones while comparing them with suitable geographic data such as population density, urban areas, and shipping lines, among others. The method chosen for ELECTRA© consists of two main steps: calculating the possible reentry trajectories for each fragment after the spacecraft breaks up; calculating the risks while taking into account the energy of the fragments, the population density and protection afforded by buildings. For launch operations and active re-entry, the risk calculation will be weighted by the probability of instantaneous failure of the spacecraft and integrated for the whole trajectory. ELECTRA©’s development is today at the end of the validation phase, last step before delivery to users. Validation process has been performed in different ways: numerical application way for the risk formulation; benchmarking process for casualty area, level of energy of the fragments entries and level of protection housing module; best practices in space transportation industries concerning dependability evaluation; benchmarking process for

  19. Flap effectiveness appraisal for winged re-entry vehicles

    NASA Astrophysics Data System (ADS)

    de Rosa, Donato; Pezzella, Giuseppe; Donelli, Raffaele S.; Viviani, Antonio

    2016-05-01

    The interactions between shock waves and boundary layer are commonplace in hypersonic aerodynamics. They represent a very challenging design issue for hypersonic vehicle. A typical example of shock wave boundary layer interaction is the flowfield past aerodynamic surfaces during control. As a consequence, such flow interaction phenomena influence both vehicle aerodynamics and aerothermodynamics. In this framework, the present research effort describes the numerical activity performed to simulate the flowfield past a deflected flap in hypersonic flowfield conditions for a winged re-entry vehicle.

  20. New tool allows selective multi-lateral re-entry

    SciTech Connect

    1997-05-01

    This article overviews the world`s first application of a downhole tool installed after the drilling and completion of a lateral borehole from a larger backbone casing, to allow future access to the lateral using through-tubing, coiled tubing operations. The system described is based on the Multi Lateral Selective Re-Entry System, or MLR (trademark), supplied by Pressure Control Engineering Ltd. (PCE) of Poole, Dorset, England. Primary equipment used in creating the lateral completion and its tieback to the backbone liner was supplied by Sperry Sun.

  1. Investigations of Control Surface Seals for Re-entry Vehicles

    NASA Technical Reports Server (NTRS)

    Dunlap, Patrick H., Jr.; Steinetz, Bruce M.; Curry, Donald M.; DeMange, Jeffrey J.; Rivers, H. Kevin; Hsu, Su-Yuen

    2002-01-01

    Re-entry vehicles generally require control surfaces (e.g., rudders, body flaps) to steer them during flight. Control surface seals are installed along hinge lines and where control surface edges move close to the vehicle body. These seals must operate at high temperatures and limit heat transfer to underlying structures to prevent them from overheating and causing possible loss of vehicle structural integrity. This paper presents results for thermal analyses and mechanical testing conducted on the baseline rudder/fin seal design for the X-38 re-entry vehicle. Exposure of the seals in a compressed state at the predicted peak seal temperature of 1900 F resulted in loss of seal resiliency. The vertical Inconel rudder/fin rub surface was re-designed to account for this loss of resiliency. Room temperature compression tests revealed that seal unit loads and contact pressures were below limits set to protect Shuttle thermal tiles on the horizontal sealing surface. The seals survived an ambient temperature 1000 cycle scrub test over sanded Shuttle tiles and were able to disengage and re-engage the tile edges during testing. Arc jet tests confirmed the need for seals in the rudder/fin gap location because a single seal caused a large temperature drop (delta T = 1710 F) in the gap.

  2. Atomic and molecular data for spacecraft re-entry plasmas

    NASA Astrophysics Data System (ADS)

    Celiberto, R.; Armenise, I.; Cacciatore, M.; Capitelli, M.; Esposito, F.; Gamallo, P.; Janev, R. K.; Laganà, A.; Laporta, V.; Laricchiuta, A.; Lombardi, A.; Rutigliano, M.; Sayós, R.; Tennyson, J.; Wadehra, J. M.

    2016-06-01

    The modeling of atmospheric gas, interacting with the space vehicles in re-entry conditions in planetary exploration missions, requires a large set of scattering data for all those elementary processes occurring in the system. A fundamental aspect of re-entry problems is represented by the strong non-equilibrium conditions met in the atmospheric plasma close to the surface of the thermal shield, where numerous interconnected relaxation processes determine the evolution of the gaseous system towards equilibrium conditions. A central role is played by the vibrational exchanges of energy, so that collisional processes involving vibrationally excited molecules assume a particular importance. In the present paper, theoretical calculations of complete sets of vibrationally state-resolved cross sections and rate coefficients are reviewed, focusing on the relevant classes of collisional processes: resonant and non-resonant electron-impact excitation of molecules, atom–diatom and molecule–molecule collisions as well as gas-surface interaction. In particular, collisional processes involving atomic and molecular species, relevant to Earth (N2, O2, NO), Mars (CO2, CO, N2) and Jupiter (H2, He) atmospheres are considered.

  3. Fixed-trim re-entry guidance analysis

    NASA Technical Reports Server (NTRS)

    Gracey, C.; Cliff, E. M.; Lutze, F. H.; Kelley, H. J.

    1981-01-01

    The terminal guidance problem for a fixed-trim re-entry body is formulated with the objective of synthesizing a closed-loop steering law. A transformation of variables and subsequent linearization of the motion, with the sight-line to the target as a reference, reduces the order of the state system for the guidance problem. The reduced order system, although nonlinear and time-varying, is simple enough to lend itself to synthesis of a class of guidance laws. A generalization of the feedforward device of classical control theory is successfully employed for compensation of roll autopilot lags. The proposed steering law exhibits superior miss-distance performance in a computational comparison with existing fixed-trim guidance laws.

  4. GPK-2 re-entry and deepening -- a technical report

    SciTech Connect

    Baumgartner, J.; Gerard, A.; Barla, R.; Socomine, S.A.

    1999-01-01

    Between mid February to end of May 1999 (in 104 days) the well GPK2 at the Soultz HDR site was successfully re-entered and deepened from 3876 m to a final depth of 5084 m and fully completed. Re-entry included the pulling of the existing 321 1 m long internal 9 5/8-inch by 7-inch casing string, fishing of a submersible pump and some 150 m of 2 3/8-inch tubing, sealing of a major loss zone and opening of a 6 1/4-inch well section in granite (3211-3876 m) to 8 1/2-inch hole size. The well was extended to 5048 m in 8 1/2'' hole size and again completed with a floating 9 5/8-inch by 7-inch casing string. The casing shoe is at 4431 m. A bottom hole core was taken in the depth range 5048-5051 m. The core recovery was app. 40%. A pilot hole in 6 1/4-inch was drilled from 5051-5084 m for in situ stress measurements using the hydraulic fracturing technique. The re-entry and deepening of the well GPK2 was accompanied by several technical developments. New casing packer elements based on inflatable metal shells were developed in a close cooperation between SOCOMINE and MeSy GmbH (patent pending). These packer elements were successfully integrated into the completion of the well. The full weight of the casing string is supported by these elements which are filled with and imbedded in cement. High temperature cementing strategies (up to 170-190 C) for the complex saline fluids encountered in Soultz (High Magnesium Resistant Cements) were developed in a cooperation between Schlumberger Dowell (Vechta), SOCOMINE, SII of Houston, Ruhr-University Bochum, BGR Hannover and IFP Paris. The development of several high temperature logging tools (200 C range, 6-arm caliper, PTF probe) was initiated with CSMA (Cornwall) during the preparation of the deepening of GPK2. Initial scientific investigations included borehole logging (NGS, CLIPER, ARI, UBI, TEMPERATURE), geological investigations (cuttings, core) and seismic monitoring while drilling. During the first temperature log performed

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

    NASA Technical Reports Server (NTRS)

    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

  6. Re-Entry, Recruitment, and Retention: A Community Relations Model for Sacramento City College.

    ERIC Educational Resources Information Center

    White, Maureen E.

    Enrollment statistics and projections confirm the importance of focusing community college student recruitment and retention efforts on re-entry students. Re-entry students are a distinct and growing population whose educational requirements often differ from those of younger, traditional students. The literature on adult learners indicates that:…

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

    NASA Astrophysics Data System (ADS)

    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

  8. Passivity analysis for a winged re-entry vehicle

    SciTech Connect

    Mooij, E.

    2014-12-10

    Application of simple adaptive control (SAC) theory to the design of guidance and control systems for winged re-entry vehicles has been proven successful. To apply SAC to these non-linear and non-stationary systems, it needs to be Almost Strictly Passive (ASP), which is an extension of the Almost Strictly Positive Real (ASPR) condition for linear, time-invariant systems. To fulfill the ASP condition, the controlled, non-linear system has to be minimum-phase (i.e., the zero dynamics is stable), and there is a specific condition for the product of output and input matrix. Earlier studies indicate that even the linearised system is not ASPR. The two problems at hand are: 1) the system is non-minimum phase when flying with zero bank angle, and 2) whenever there is hybrid control, e.g., yaw control is established by combined reaction and aerodynamic control for the major part of flight, the second ASPR condition cannot be met. In this paper we look at both issues, the former related to the guidance system and the latter to the attitude-control system. It is concluded that whenever the nominal bank angle is zero, the passivity conditions can never be met, and guidance should be based on nominal commands and a redefinition of those whenever the error becomes too large. For the remaining part of the trajectory, the passivity conditions are marginally met, but it is proposed to add feedforward compensators to alleviate these conditions. The issue of hybrid control is avoided by redefining the controls with total control moments and adding a so-called control allocator. Deriving the passivity conditions for rotational motion, and evaluating these conditions along the trajectory shows that the (non-linear) winged entry vehicle is ASP. The sufficient conditions to apply SAC for attitude control are thus met.

  9. Passivity analysis for a winged re-entry vehicle

    NASA Astrophysics Data System (ADS)

    Mooij, E.

    2014-12-01

    Application of simple adaptive control (SAC) theory to the design of guidance and control systems for winged re-entry vehicles has been proven successful. To apply SAC to these non-linear and non-stationary systems, it needs to be Almost Strictly Passive (ASP), which is an extension of the Almost Strictly Positive Real (ASPR) condition for linear, time-invariant systems. To fulfill the ASP condition, the controlled, non-linear system has to be minimum-phase (i.e., the zero dynamics is stable), and there is a specific condition for the product of output and input matrix. Earlier studies indicate that even the linearised system is not ASPR. The two problems at hand are: 1) the system is non-minimum phase when flying with zero bank angle, and 2) whenever there is hybrid control, e.g., yaw control is established by combined reaction and aerodynamic control for the major part of flight, the second ASPR condition cannot be met. In this paper we look at both issues, the former related to the guidance system and the latter to the attitude-control system. It is concluded that whenever the nominal bank angle is zero, the passivity conditions can never be met, and guidance should be based on nominal commands and a redefinition of those whenever the error becomes too large. For the remaining part of the trajectory, the passivity conditions are marginally met, but it is proposed to add feedforward compensators to alleviate these conditions. The issue of hybrid control is avoided by redefining the controls with total control moments and adding a so-called control allocator. Deriving the passivity conditions for rotational motion, and evaluating these conditions along the trajectory shows that the (non-linear) winged entry vehicle is ASP. The sufficient conditions to apply SAC for attitude control are thus met.

  10. Spacecraft destruction during re-entry - latest results and development of the SCARAB software system

    NASA Astrophysics Data System (ADS)

    Lips, T.; Fritsche, B.; Koppenwallner, G.; Klinkrad, H.

    2004-01-01

    The calculation of destructive re-entries and the prediction of the related ground risk potential due to fragment objects reaching the ground have become of high interest in the past years. This was also evident during the re-entry of the MIR space station in 2001. In 1995, under ESA contract, HTG started an international cooperation with other companies and institutes to develop the SCARAB software system (Spacecraft Atmospheric Re-Entry and Aerothermal Break-Up). SCARAB is a quasi-deterministic tool, modeling a re-entry object down to sub-system level. The resulting aerodynamic parameters and mass distribution allow calculating a realistic 6D re-entry trajectory. Geometry and mass are continuously updated during calculation. Multi-level fragmentations due to different destruction processes are considered. The SCARAB software has been applied to several projects, namely ATV (ESA), ROSAT (Germany), Ariane-5 (ESA) and BeppoSAX (Italy). The practical application of SCARAB to project work has been demonstrated. In addition SCARAB has been compared with NASA's ORSAT code. It has also been verified with experimental data gained from re-entry vehicles, break-up observations and wind-tunnel tests. SCARAB is now on the way to become the European standard software for re-entry destruction analysis.

  11. Inflatable Re-Entry Vehicle Experiment (IRVE) Design Overview

    NASA Technical Reports Server (NTRS)

    Hughes, Stephen J.; Dillman, Robert A.; Starr, Brett R.; Stephan, Ryan A.; Lindell, Michael C.; Player, Charles J.; Cheatwood, F. McNeil

    2005-01-01

    Inflatable aeroshells offer several advantages over traditional rigid aeroshells for atmospheric entry. Inflatables offer increased payload volume fraction of the launch vehicle shroud and the possibility to deliver more payload mass to the surface for equivalent trajectory constraints. An inflatable s diameter is not constrained by the launch vehicle shroud. The resultant larger drag area can provide deceleration equivalent to a rigid system at higher atmospheric altitudes, thus offering access to higher landing sites. When stowed for launch and cruise, inflatable aeroshells allow access to the payload after the vehicle is integrated for launch and offer direct access to vehicle structure for structural attachment with the launch vehicle. They also offer an opportunity to eliminate system duplication between the cruise stage and entry vehicle. There are however several potential technical challenges for inflatable aeroshells. First and foremost is the fact that they are flexible structures. That flexibility could lead to unpredictable drag performance or an aerostructural dynamic instability. In addition, durability of large inflatable structures may limit their application. They are susceptible to puncture, a potentially catastrophic insult, from many possible sources. Finally, aerothermal heating during planetary entry poses a significant challenge to a thin membrane. NASA Langley Research Center and NASA's Wallops Flight Facility are jointly developing inflatable aeroshell technology for use on future NASA missions. The technology will be demonstrated in the Inflatable Re-entry Vehicle Experiment (IRVE). This paper will detail the development of the initial IRVE inflatable system to be launched on a Terrier/Orion sounding rocket in the fourth quarter of CY2005. The experiment will demonstrate achievable packaging efficiency of the inflatable aeroshell for launch, inflation, leak performance of the inflatable system throughout the flight regime, structural

  12. A re-entry tachycardia triggered by the spontaneous interruption of an atrial tachycardia.

    PubMed

    Buttà, Carmelo; Tuttolomondo, Antonino; Di Raimondo, Domenico; Giarrusso, Lucia; Miceli, Giuseppe; Cuttitta, Francesco; La Rosa, Donata; Licata, Giuseppe; Pinto, Antonio

    2015-01-01

    The common atrioventricular nodal re-entry tachycardia is the most common form of paroxysmal supraventricular tachycardia. It starts frequently with a supraventricular ectopic beat that, on finding the fast pathway in refractory period, travels in the slow pathway as to appear as a prolongation of the PR interval on the ECG. In this study, we show a singular case of a common atrioventricular nodal re-entry tachycardia triggered by the spontaneous interruption of an atrial tachycardia.

  13. The technology for wireline re-entry of deep ocean boreholes employed for the Dianaut Program

    NASA Astrophysics Data System (ADS)

    Floury, Luc; Gable, Robert

    1992-03-01

    More than 850 holes have been drilled in the world's oceans over the past 24 years, in connection with the Deep Sea Drilling Project (DSDP) and the Ocean Drilling Program (ODP). At least 45 of these holes were fitted with a re-entry cone and many were cased through the sedimentary and unconsolidated layers, allowing hole re-entry with a drill string from a drilling vessel and wireline logging to the drill stem. Re-entry of seafloor drill holes with a wireline logger positioned on the seabed was first successfully accomplished during the FARE program. The DIANAUT program was a scientific application of seafloor wireline re-entry utilizing the logging shuttle ‘Nadia’ in combination with the manned submersible ‘Nautile’. The Nadia re-entry logging system was successfully seated in drill re-entry cones of three boreholes in the Atlantic Ocean (water depths of 1666, 4485, and, 4976 m) and logging operations with different probes (temperature, heat-pulse flowmeter, BHTV, fluid sampler, magnetometer) were performed from the seafloor with full logging control and data acquisition from the Nautile. In the near future the logging shuttle ‘Nadia’ could be developed into a support facility for long-term downhole measurements and later into an unmanned seafloor logging system.

  14. Longitudinal stability analysis of a suborbital re-entry demonstrator for a deployable capsule

    NASA Astrophysics Data System (ADS)

    Iacovazzo, Michele; Carandente, Valerio; Savino, Raffaele; Zuppardi, Gennaro

    2015-01-01

    In the field of atmospheric re-entry technology several research and industrial projects are based on the design of deployable, umbrella-like Thermal Protection Systems (TPSs) and aero-brakes. These systems are made of flexible, high temperature resistant fabrics, folded at launch and deployed in space for de-orbit and re-entry operations. This technology is very promising for low cost research and industrial applications, but requires to be validated by experimental flight tests. The University of Naples "Federico II" is currently working on the development of different down-scaled technological demonstrators for this kind of capsule to be launched by different classes of sounding rockets. In the present work an aerodynamic longitudinal stability analysis for a possible, suborbital re-entry demonstrator, has been performed in continuum and rarefied regimes. The longitudinal stability behavior of the capsule, along the entire re-entry path, has been investigated in the whole range of angle of attack and, in particular, around the nominal and the reverse equilibrium re-entry attitudes (i.e. around 0° and 180°, respectively) to implement a proper re-entry strategy able not to compromise the effectiveness of the flying system.

  15. Spacecraft destruction during re-entry - latest results and developments of the SCARAB software system

    NASA Astrophysics Data System (ADS)

    Lips, T.; Fritsche, B.; Koppenwallner, G.; Klinkrad, H.

    Not only since the re-entry of the MIR space station in 2001 the calculation of destructive re-entry and the prediction of ground risk potential due to space debris objects reaching the ground have become of high interest. Already in 1995 HTG started in an international cooperation with other companies and institutes under ESA contract the development of the SCARAB software system (SpaceCraft Atmospheric Re-entry and Aerothermal Break-up). SCARAB is a deterministic tool. The re-entry object is completely modelled down to sub-system level. The resulting aerodynamic parameters and mass distribution allow calculating a realistic 6D re-entry trajectory. Geometry and mass are continuously updated during calculation. Multi-level fragmentations due to different destruction processes are considered. The SCARAB software has been applied to several projects, namely ATV (Europe), ROSAT (Germany), Ariane-5 (Europe) and BeppoSAX (Italy). The practical application of SCARAB to project work has been demonstrated. In addition SCARAB has been tested against the NASA ORSAT code. It has also been verified with experimental data gained from re-entry vehicles, break-up observations and wind-tunnel tests. SCARAB is now on the way to become the European standard software for re-entry destruction analysis. This paper will give an overview of the latest results of applications of the software and a description of the interactive development process to fit the different needs of each project. The key features of planned future releases will be presented.

  16. Ongoing Capabilities and Developments of Re-Entry Plasma Ground Tests at EADS-ASTRIUM

    NASA Technical Reports Server (NTRS)

    Jullien, Pierre

    2008-01-01

    During re-entry, spacecrafts are subjected to extreme thermal loads. On mars, they may go through dust storms. These external heat loads are leading the design of re-entry vehicles or are affecting it for spacecraft facing solid propellant jet stream. Sizing the Thermal Protection System require a good knowledge of such solicitations and means to model and reproduce them on earth. Through its work on European projects, ASTRIUM has developed the full range of competences to deal with such issues. For instance, we have designed and tested the heat-shield of the Huygens probe which landed on Titan. In particular, our plasma generators aim to reproduce a wide variety of re-entry conditions. Heat loads are generated by the huge speed of the probes. Such conditions cannot be fully reproduced. Ground tests focus on reproducing local aerothermal loads by using slower but hotter flows. Our inductive plasma torch enables to test little samples at low TRL. Amongst the arc-jets, one was design to test architecture design of ISS crew return system and others fit more severe re-entry such as sample returns or Venus re-entry. The last developments aimed in testing samples in seeded flows. First step was to design and test the seeding device. Special diagnostics characterizing the resulting flow enabled us to fit it to the requirements.

  17. Trajectory Design and Control for the Compton Gamma Ray Observatory Re-Entry

    NASA Technical Reports Server (NTRS)

    Hoge, Susan; Vaughn, Frank; Bauer, Frank H. (Technical Monitor)

    2000-01-01

    The Compton Gamma Ray Observatory (CGRO) controlled re-entry operation was successfully conducted in June of 2000. The surviving parts of the spacecraft landed in the Pacific Ocean within the predicted footprint. The design of the maneuvers to control the trajectory to accomplish this re-entry presented several challenges. These challenges included timing and duration of the maneuvers, fuel management, post maneuver position knowledge, collision avoidance with other spacecraft, accounting for the break-up of the spacecraft into several pieces with a wide range of ballistic coefficients, and ensuring that the impact footprint would remain within the desired landing area in the event of contingencies. This paper presents the initial re-entry trajectory design and the evolution of the design into the maneuver sequence used for the re-entry. The paper discusses the constraints on the trajectory design, the modifications made to the initial design and the reasons behind these modifications. Data from the re-entry operation are presented.

  18. Application of the FADS system on the Re-entry Module

    NASA Astrophysics Data System (ADS)

    Zhen, Huang

    2016-07-01

    The aerodynamic model for Flush Air Data Sensing System (FADS) is built based on the surface pressure distribution obtained through the pressure orifices laid on specific positions of the surface,and the flight parameters,such as angle of attack,angle of side-slip,Mach number,free-stream static pressure and dynamic pressure are inferred from the aerodynamic model.The flush air data sensing system (FADS) has been used on several flight tests of aircraft and re-entry vehicle,such as,X-15,space shuttle,F-14,X-33,X-43A and so on. This paper discusses the application of the FADS on the re-entry module with blunt body to obtain high-precision aerodynamic parameters.First of all,a basic theory and operating principle of the FADS is shown.Then,the applications of the FADS on typical aircrafts and re-entry vehicles are described.Thirdly,the application mode on the re-entry module with blunt body is discussed in detail,including aerodynamic simulation,pressure distribution,trajectory reconstruction and the hardware shoule be used,such as flush air data sensing system(FADS),inertial navigation system (INS),data acquisition system,data storage system.Finally,ablunt module re-entry flight test from low earth orbit (LEO) is planned to obtain aerodynamic parameters and amend the aerodynamic model with this FADS system data.The results show that FADS system can be applied widely in re-entry module with blunt bodies.

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

    NASA Technical Reports Server (NTRS)

    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.

  20. Exploring Efficacy in Negotiating Support: Women Re-Entry Students in Higher Education

    ERIC Educational Resources Information Center

    Filipponi-Berardinelli, Josephine Oriana

    2013-01-01

    The existing literature on women re-entry students reveals that women students concurrently struggle with family, work, and sometimes health issues. Women students often do not receive adequate support from their partners or from other sources in helping manage the multiple roles that compete for their time, and often face constraints that affect…

  1. Recognition of Tacit Skills: Sustaining Learning Outcomes in Adult Learning and Work Re-Entry

    ERIC Educational Resources Information Center

    Evans, Karen; Kersh, Natasha; Kontiainen, Seppo

    2004-01-01

    This paper is based on the project "Recognition of Tacit Skills and Knowledge in Work Re-entry" carried out as a part of the ESRC-funded Research Network "Improving Incentives to Learning in the Workplace". The network aims to contribute to improved practice among a wide range of practitioners. The study has investigated the part played by tacit…

  2. Northern Kentucky University ReEntry Center, 1980-1990. 10 Year Anniversary Celebration.

    ERIC Educational Resources Information Center

    Northern Kentucky Univ., Highland Heights.

    The original poems and articles contained in this publication were submitted by individuals who have either been through the programs offered by the ReEntry Center at Northern Kentucky University or have otherwise had their lives touched and changed by the center's existence. They are intended to illustrate the growth and achievement that these…

  3. Re-entry Women: Part-Time Enrollment, Full-Time Commitment. Field Evaluation Draft.

    ERIC Educational Resources Information Center

    Hall, Roberta M.

    Barriers re-entry women often face as they enroll, or attempt to enroll, in undergraduate and graduate degree programs on a part-time basis are discussed, and recommendations for change are offered. A wide range of possible actions is outlined so that institutions can pursue those most appropriate to their individual circumstances. Suggestions on…

  4. International Space Station as an Observation Platform for Hypersonic Re-Entry of its Visiting Vehicles

    NASA Technical Reports Server (NTRS)

    Bacon, John B.

    2001-01-01

    The International Space Station (ISS) will receive an armada of visiting supply vehicles during its life in orbit. Over 500 tons of material will be destroyed in targeted re-entries of these vehicles. Because all such re-entries lie in the same orbital plane of the station, and because the visiting vehicles typically deorbit within a few hours of departure, the ISS will usually be within sight of the re-entry process, at a range of only 300-600 kilometers. This vantage point offers an unprecedented opportunity for systematically measuring hypersonic destructive processes. This paper examines the integrated operational constraints of the ISS, its supply vehicles, and candidate sensors which can be employed in the scientific observation of the re-entry process. It is asserted the ISS program has the potential to reduce the worldwide risks from future deorbiting spacecraft, through systematic experimental characterization of the factors which affect the rupture, debris survival, and footprint size of its visiting vehicle fleet.

  5. Trajectory Design and Control for the Compton Gamma Ray Observatory Re-Entry

    NASA Technical Reports Server (NTRS)

    Hoge, Susan; Vaughn, Frank J., Jr.

    2001-01-01

    The Compton Gamma Ray Observatory (CGRO) controlled re-entry operation was successfully conducted in June of 2000. The surviving parts of the spacecraft landed in the Pacific Ocean within the nominal impact target zone. The design of the maneuvers to control the trajectory to accomplish this re-entry presented several challenges. These challenges included the timing and duration of the maneuvers, propellant management, post-maneuver state determination, collision avoidance with other spacecraft, accounting for the break-up of the spacecraft into several pieces with a wide range of ballistic coefficients, and ensuring that the impact footprint would remain within the desired impact target zone in the event of contingencies. This paper presents the initial re-entry trajectory design and traces the evolution of that design into the maneuver sequence used for the re-entry. The paper also discusses the spacecraft systems and operational constraints imposed on the trajectory design and the required modifications to the initial design based on those constraints. Data from the reentry operation are also presented.

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

    NASA Astrophysics Data System (ADS)

    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.

  7. Side Jet/Cross Flow Interaction at Hypersonic Re-entry Conditions

    NASA Astrophysics Data System (ADS)

    Adeli, R.; Seiler, F.

    Since decades control jets are commonly used for steering re-entry vehicles, e.g. the Apollo capsules, the Space Shuttles and were also used for the "SpaceShipOne" mission and recently direct to the flight path of missiles.

  8. IXV re-entry demonstrator: Mission overview, system challenges and flight reward

    NASA Astrophysics Data System (ADS)

    Angelini, Roberto; Denaro, Angelo

    2016-07-01

    The Intermediate eXperimental Vehicle (IXV) is an advanced re-entry demonstrator vehicle aimed to perform in-flight experimentation of atmospheric re-entry enabling systems and technologies. The IXV integrates key technologies at the system level, with significant advancements on Europe's previous flying test-beds. The project builds on previous achievements at system and technology levels, and provides a unique and concrete way of establishing and consolidating Europe's autonomous position in the strategic field of atmospheric re-entry. The IXV mission and system objectives are the design, development, manufacturing, assembling and on-ground to in-flight verification of an autonomous European lifting and aerodynamically controlled reentry system, integrating critical re-entry technologies at system level. Among such critical technologies of interest, special attention is paid to aerodynamic and aerothermodynamics experimentation, including advanced instrumentation for aerothermodynamics phenomena investigations, thermal protections and hot-structures, guidance, navigation and flight control through combined jets and aerodynamic surfaces (i.e. flaps), in particular focusing on the technologies integration at system level for flight. Following the extensive detailed design, manufacturing, qualification, integration and testing of the flight segment and ground segment elements, IXV has performed a full successful flight on February 11th 2015. After the launch with the VEGA launcher form the CSG spaceport in French Guyana, IXV has performed a full nominal mission ending with a successful splashdown in the Pacific Ocean. During Flight Phase, the IXV space and ground segments worked perfectly, implementing the whole flight program in line with the commanded maneuvers and trajectory prediction, performing an overall flight of 34.400 km including 7.600 km with hot atmospheric re-entry in automatic guidance, concluding with successful precision landing at a distance of ~1

  9. Aerothermodynamics of generic re-entry vehicle with a series of aerospikes at nose

    NASA Astrophysics Data System (ADS)

    Yadav, Rajesh; Velidi, Gurunadh; Guven, Ugur

    2014-03-01

    Re-entry of a blunt nosed vehicle is one of the most intriguing problems in any space programme. Especially in light of various space tourism possibilities, there are many works concerning re-entry of commercial blunt nosed space vehicles. In this paper, a generic blunt body re-entry model represented by a hemisphere-cylinder, fitted axisymmetrically with an aerodisk aerospike at the nose is investigated numerically with commercially available control volume based axisymmetric flow solver. The scaled down re-entry model has a base diameter of 40 mm and an overall length of 100 mm. A 6 mm diameter aerospike fitted axisymmetrically at the nose has a hemispherical cap from which another aerospike of 4 mm diameter protrudes which again has a hemispherical cap. Two dimensional compressible, axisymmetric Navier Stokes Equations are solved for a turbulent hypersonic flow of a 5 species, chemically reacting air in thermal equilibrium with free stream conditions of Mach no., static pressure and temperature of 10.1, 16,066 Pa and 216.65 K, respectively. The results are compared with that of re-entry model without any aerospike. Among the cases investigated, the spiked blunt body having two aerospikes in series with lengths l1 and l2 equal to 30 and 20 respectively and overall length-to-diameter ratio of 1.5 showed a favourable reduction in the peak reattachment heat flux along with high reduction in aerodynamic drag and thus stands as a prospective case for blunt body nose configuration for hypersonic flight.

  10. State Policies Affecting the "Adult Re-Entry Pipeline" in Postsecondary Education: Results of a Fifty-State Inventory

    ERIC Educational Resources Information Center

    Boeke, Marianne; Zis, Stacey; Ewell, Peter

    2011-01-01

    With support from the Bill and Melinda Gates Foundation, the National Center for Higher Education Management Systems (NCHEMS) is engaged in a two year project centered on state policies that foster student progression and success in the "adult re-entry pipeline." The adult re-entry pipeline consists of the many alternative pathways to obtain a…

  11. A Novel 'Cheese Wire' Technique for Stent Positioning Following Difficult Iliac Artery Subintimal Dissection and Aortic Re-Entry

    SciTech Connect

    Watkinson, A. F.

    2009-07-15

    Subintimal wire dissection is a well-established method for traversing difficult vascular occlusions. This technique relies on re-entry of the true lumen distal to the occlusion, which may be difficult in diseased vessels with significant calcification. This case report describes a novel 'cheese wire' technique to allow stent positioning without the use of proprietary re-entry devices.

  12. Recovery, Transportation and Acceptance to the Curation Facility of the Hayabusa Re-Entry Capsule

    NASA Technical Reports Server (NTRS)

    Abe, M.; Fujimura, A.; Yano, H.; Okamoto, C.; Okada, T.; Yada, T.; Ishibashi, Y.; Shirai, K.; Nakamura, T.; Noguchi, T.; Okazaki, R.; Zolensky, M.; Sandford, S.; Ireland, T.; Ueno, M.; Mukai, T.; Yoshikawa, M.; Yamada, T.; Kuninaka, H.; Kawaguchi, J.

    2011-01-01

    The "Hayabusa" re-entry capsule was safely carried into the clean room of Sagamihara Planetary Sample Curation Facility in JAXA on June 18, 2010. After executing computed tomographic (CT) scanning, removal of heat shield, and surface cleaning of sample container, the sample container was enclosed into the clean chamber. After opening the sample container and residual gas sampling in the clean chamber, optical observation, sample recovery, sample separation for initial analysis will be performed. This curation work is continuing for several manths with some selected member of Hayabusa Asteroidal Sample Preliminary Examination Team (HASPET). We report here on the 'Hayabusa' capsule recovery operation, and transportation and acceptance at the curation facility of the Hayabusa re-entry capsule.

  13. SHEFEX - the vehicle and sub-systems for a hypersonic re-entry flight experiment

    NASA Astrophysics Data System (ADS)

    Turner, John; Hörschgen, Marcus; Turner, Peter; Ettl, Josef; Jung, Wolfgang; Stamminger, Andreas

    2005-08-01

    The purpose of the Sharp Edge Flight Experiment (SHEFEX) is to investigate the aerodynamic behaviour and thermal problems of an unconventional shape for re-entry vehicles, comprising multi-facetted surfaces with sharp edges. The main object of this experiment is the correlation of numerical analysis with real flight data in terms of the aerodynamic effects and structural concept for the thermal protection system (TPS). The Mobile Rocket Base of the German Aerospace Center (DLR) is responsible for the test flight of SHEFEX on a two stage unguided solid propellant sounding rocket which is required to provide a velocity of the order of March 7 for more than 30 seconds during atmospheric re-entry. This paper discusses the problems associated with the mission requirements and the solutions developed for the vehicle and sub-systems.

  14. Development Of Metallic Thermal Protection System For The Expert Re-Entry Vehicle: Design Verification

    NASA Astrophysics Data System (ADS)

    Fatemi, Javad

    2011-05-01

    The thermal protection system of the EXPERT re-entry vehicle is subjected to accelerations, vibrations, acoustic and shock loads during launch and aero-heating loads and aerodynamic forces during re-entry. To fully understand the structural and thermomechanical performances of the TPS, heat transfer analysis, thermal stress analysis, and thermal buckling analysis must be performed. This requires complex three-dimensional thermal and structural models of the entire TPS including the insulation and sensors. Finite element (FE) methods are employed to assess the thermal and structural response of the TPS to the mechanical and aerothermal loads. The FE analyses results are used for the design verification and design improvement of the EXPERT thermal protection system.

  15. Aerothermodynamic and stability analyses of a deployable re-entry capsule

    NASA Astrophysics Data System (ADS)

    Carandente, Valerio; Zuppardi, Gennaro; Savino, Raffaele

    2014-01-01

    Recent research projects, in the field of atmospheric re-entry technology, are focused on the design of deployable, umbrella-like Thermal Protection Systems (TPSs). These TPSs are made of flexible high temperature resistant fabrics, folded at launch and deployed in space for de-orbit and re-entry operations. In the present paper two possible sphere-cone configurations for the TPS have been investigated from an aerodynamic point of view. The analyzed configurations are characterized by the same reentry mass and maximum diameter, but have different half-cone angles (45° and 60°). The analyses involve both the evaluation of thermal and aerodynamic loads and the assessment of the capsule longitudinal stability. The aerothermodynamic analysis has been performed for the completely deployed heat shield in transitional and continuum regimes, while the longitudinal stability has been analyzed in free molecular, transitional and continuum regimes, also taking into consideration the heat shield deployment sequence at high altitudes.

  16. A preliminary study of the air data sensing problem on a re-entry vehicle

    NASA Astrophysics Data System (ADS)

    Hettena, E.

    1995-03-01

    A brief review of different measurement techniques for speed, pressure, and temperature on a re-entry vehicle is given in order to evaluate their applicability and limitations to the design of an air data system. A pressure-sensors based air data system is then assumed and an engineering aerodynamic model is used to investigate the influence of the measurement errors on the relevant air data parameters necessary for light guidance and control.

  17. Test of Re-Entry Systems at Estrange Using Sounding Rockets and Stratospheric Balloons

    NASA Astrophysics Data System (ADS)

    Lockowandt, C.; Abrahamsson, M.; Florin, G.

    2015-09-01

    Stratospheric balloons and sounding rockets can provide an ideal in-flight platform for performing re-entry and other high speed tests off different types of vehicles and techniques. They are also ideal platforms for testing different types of recovery systems such as airbrakes and parachutes. This paper expands on some examples of platforms and missions for drop tests from balloons as well as sounding rockets launched from Esrange Space Center, a facility run by Swedish Space Corporation SSC in northern Sweden.

  18. Predictors of re-entry into the child protection system in Singapore: a cumulative ecological-transactional risk model.

    PubMed

    Li, Dongdong; Chu, Chi Meng; Ng, Wei Chern; Leong, Wai

    2014-11-01

    This study examines the risk factors of re-entry for 1,750 child protection cases in Singapore using a cumulative ecological-transactional risk model. Using administrative data, the present study found that the overall percentage of Child Protection Service (CPS) re-entry in Singapore is 10.5% based on 1,750 cases, with a range from 3.9% (within 1 year) to 16.5% (within 8 years after case closure). One quarter of the re-entry cases were observed to occur within 9 months from case closure. Seventeen risk factors, as identified from the extant literature, were tested for their utility to predict CPS re-entry in this study using a series of Cox regression analyses. A final list of seven risk factors (i.e., children's age at entry, case type, case closure result, duration of case, household income, family size, and mother's employment status) was used to create a cumulative risk score. The results supported the cumulative risk model in that higher risk score is related to higher risk of CPS re-entry. Understanding the prevalence of CPS re-entry and the risk factors associated with re-entry is the key to informing practice and policy in a culturally relevant way. The results from this study could then be used to facilitate critical case management decisions in order to enhance positive outcomes of families and children in Singapore's care system.

  19. Re-Entries: New strategies in development zones at the Orinoco Oil Belt

    SciTech Connect

    Gonzalez, R.; Briceno, M.; Figueroa, J.; Bolanos, C.

    1996-08-01

    Drilling of horizontal wells in Venezuela began in the Orinoco Oil Belt with the wells CI-87 and CI-97 in the J-20 block, drilled in 1989 and 1990, respectively. Well CI-87 produces up to 1000 BPD without steam injection. Due to the success of this well, the exploitation strategy was oriented toward re-entry and sidetracking wells with mechanical problems, high water cut and low potential. The purpose of this programme was to enhance drainage patterns, access new reservoirs through existing bores, and increase oil production while reducing per-barrel costs. Eighteen (18) wells were re-drilled in different pay zones such as O-12, O-13, O-14 and O-15 with horizontal sections between a thousand feet and one thousand six hundred feet. Those wells were completed with progressive cavity pumps, sucker rod beam pumps and electrical submersible pumps. Presented in this paper are the results of the re-entries at the Orinoco Oil Belt and the future re-entry strategy.

  20. Study on Mini Re-Entry System Using Deployable Membrane Aeroshell

    NASA Astrophysics Data System (ADS)

    Koyama, Masashi; Suzuki, Kojiro; Imamura, Osamu; Yamada, Kazuhiko

    An aeroshell made from membrane material have an advantage of reduction in the aerodynamic heating, because its small mass and large area enable us to make the low-ballistic-coefficient flight, in which the vehicle decelerates at very high altitude with low atmospheric density. In this paper, we propose a new concept of mini re-entry system for small satellites. This vehicle is called "FEATHER" (Flexible Expanded Aeroshell with Tiny payload Harness for Entry and Recovery). "FEATHER" is a novel re-entry and recovery system, featuring the autonomous aeroshell deployment, the low-ballistic-coefficient re-entry with less severe aerodynamicc heating and so on. FEATHER is composed of the membrane aeroshell made from the high-temperature cloth called ZYLON®, an outer frame made of Shape Memory Alloy (SMA) and a payload. When the aeroshell receives the aerodynamic heating, the temperature of SMA frame rises and restores the circular shape as memorized beforehand. Then the membrane aeroshell is automatically deployed. Therefore the vehicle can achieve the low-ballistic-coefficient flight with a drastic reduction in the aerodynamic heating without any additional sensors, controllers and actuators. The preliminary studies made on FEATHER system so far including the hypersonic wind tunnel experiments are presented in this paper.

  1. Airborne Observation of the Hayabusa Sample Return Capsule Re-Entry

    NASA Technical Reports Server (NTRS)

    Grinstead, Jay H.; Jenniskens, Peter; Cassell, Alan M.; Albers, James; Winter, Michael W.

    2011-01-01

    NASA Ames Research Center and the SETI Institute collaborated on an effort to observe the Earth re-entry of the Japan Aerospace Exploration Agency's Hayabusa sample return capsule. Hayabusa was an asteroid exploration mission that retrieved a sample from the near-Earth asteroid Itokawa. Its sample return capsule re-entered over the Woomera Prohibited Area in southern Australia on June 13, 2010. Being only the third sample return mission following NASA's Genesis and Stardust missions, Hayabusa's return was a rare opportunity to collect aerothermal data from an atmospheric entry capsule returning at superorbital speeds. NASA deployed its DC-8 airborne laboratory and a team of international researchers to Australia for the re-entry. For approximately 70 seconds, spectroscopic and radiometric imaging instruments acquired images and spectra of the capsule, its wake, and destructive re-entry of the spacecraft bus. Once calibrated, spectra of the capsule will be interpreted to yield data for comparison with and validation of high fidelity and engineering simulation tools used for design and development of future atmospheric entry system technologies. A brief summary of the Hayabusa mission, the preflight preparations and observation mission planning, mission execution, and preliminary spectral data are documented.

  2. Targeting of cytosolic phospholipase A2α impedes cell cycle re-entry of quiescent prostate cancer cells

    PubMed Central

    Yao, Mu; Xie, Chanlu; Kiang, Mei-Yee; Teng, Ying; Harman, David; Tiffen, Jessamy; Wang, Qian; Sved, Paul; Bao, Shisan; Witting, Paul; Holst, Jeff; Dong, Qihan

    2015-01-01

    Cell cycle re-entry of quiescent cancer cells has been proposed to be involved in cancer progression and recurrence. Cytosolic phospholipase A2α (cPLA2α) is an enzyme that hydrolyzes membrane glycerophospholipids to release arachidonic acid and lysophospholipids that are implicated in cancer cell proliferation. The aim of this study was to determine the role of cPLA2α in cell cycle re-entry of quiescent prostate cancer cells. When PC-3 and LNCaP cells were rendered to a quiescent state, the active form of cPLA2α with a phosphorylation at Ser505 was lower compared to their proliferating state. Conversely, the phospho-cPLA2α levels were resurgent during the induction of cell cycle re-entry. Pharmacological inhibition of cPLA2α with Efipladib upon induction of cell cycle re-entry inhibited the re-entry process, as manifested by refrained DNA synthesis, persistent high proportion of cells in G0/G1 and low percentage of cells in S and G2/M phases, together with a stagnant recovery of Ki-67 expression. Simultaneously, Efipladib prohibited the emergence of Skp2 while maintained p27 at a high level in the nuclear compartment during cell cycle re-entry. Inhibition of cPLA2α also prevented an accumulation of cyclin D1/CDK4, cyclin E/CDK2, phospho-pRb, pre-replicative complex proteins CDC6, MCM7, ORC6 and DNA synthesis-related protein PCNA during induction of cell cycle re-entry. Moreover, a pre-treatment of the prostate cancer cells with Efipladib during induction of cell cycle re-entry subsequently compromised their tumorigenic capacity in vivo. Hence, cPLA2α plays an important role in cell cycle re-entry by quiescent prostate cancer cells. PMID:26416244

  3. Dynamics of circus movement re-entry across canine Purkinje fibre-muscle junctions.

    PubMed

    Gilmour, R F; Watanabe, M

    1994-05-01

    1. To determine the cellular electrophysiological mechanisms for unidirectional conduction block and re-entrant excitation, single cycles of circus movement re-entry were induced in canine Purkinje fibre-papillary muscle preparations containing two Purkinje fibre-muscle junctions (PMJs). The preparations were mounted in a partitioned tissue bath that permitted independent superfusion of each PMJ. The pre-existing dispersion of refractoriness between PMJs was accentuated by superfusing PMJ1 with normal Tyrode solution or Tyrode solution containing 6-8 mM KCl and superfusing PMJ2 with Tyrode solution containing 0.5 mM heptanol and 4-10 mM KCl. 2. Premature stimuli delivered to the Purkinje fibre induced unidirectional anterograde conduction block at PMJ2. Conduction proceeded from Purkinje cells to papillary muscle at PMJ1 and from papillary muscle retrogradely across the previously blocked PMJ2. 3. The difference in refractory periods between the two PMJs defined a range of premature coupling intervals within which re-entry was inducible. Conduction block at the PMJ occurred in papillary muscle at short coupling intervals and in the Purkinje fibre at longer intervals. 4. Once initiated, re-entry could be reset or annihilated by properly timed subthreshold current pulses delivered to cells at the PMJ. 5. To define better the mechanisms for conduction block and re-entry, an analytical model was developed using non-linear regression analysis to derive equations from the experimental results. Varying parameters within the constraints of the model reproduced the key features of the rate-dependent conduction block observed experimentally. Critical elements of the model included the induction of significant activation delays at short diastolic intervals and a reduction in the rate of action potential duration restitution after exposure to heptanol. 6. These results help to establish the conditions necessary for induction of one-dimensional circus movement re-entry and to

  4. An activation-repolarization time metric to predict localized regions of high susceptibility to re-entry

    PubMed Central

    Child, Nicholas; Bishop, Martin J.; Hanson, Ben; Coronel, Ruben; Opthof, Tobias; Bourkens, Bastiaan; Walton, Richard; Efimov, Igor; Bostock, Julian; Hill, Yolanda; Rinaldi, Christopher A; Razavi, Reza; Gill, Jaswinder; Taggart, Peter

    2015-01-01

    Background Initiation of re-entrant ventricular tachycardia (VT) involves complex interactions between activation and repolarization wavefronts. Recent experimental work has identified the time interval between S2 repolarization proximal to a line of functional block and the activation at the adjacent distal side, as a critical determinant of re-entry. Objective We hypothesized: (1) an algorithm could be developed which would generate a spatial map of this interval (designated the “re-entry vulnerability index”-RVI); (2) that this would accurately identify a pathway of re-entry as well as rotor formation in animal experiments and in a computational model; and, (3) that it would be possible to generate an RVI map in humans during routine clinical procedures and co-register with anatomical and electrophysiological features. Methods and Results An algorithm was developed which sampled all points on a multielectrode grid and calculated RVI between all pairs of electrodes within a given radius. The algorithm successfully identified the spatial region with increased susceptibility to re-entry in an established Langendorff pig heart model and the site of re-entry and rotor formation in an optically mapped sheep heart model and corresponding computational simulations. The feasibility of RVI mapping was evaluated during a clinical procedure by co-registering with the anatomy and physiology in a patient undergoing a VT ablation. Conclusions We developed an algorithm to calculate a re-entry vulnerability index from intervals between local repolarization and activation times at all adjacent points over a multielectrode grid. The algorithm accurately identified the region of re-entry in two animal models of functional re-entry. The possibility of clinical application was demonstrated in a patient with VT. PMID:25863160

  5. Flow Redistribution Between Legs and Brain During STS 93 Re-Entry and Landing

    NASA Technical Reports Server (NTRS)

    Arbeille, P.; Meck, J.; Porcher, M.; Benavides, E.; Martin, D. S.; South, D. A.; Ribeiro, C.; Westover, A.

    2003-01-01

    The objective was to quantify bit by bit the arterial hemodynamic response to the successive acceleration induced fluid shifts during re-entry and landing. Method: The astronaut instrumented himself with a flat Doppler probe fixed on the skin, a blood pressure arm cuff, and 3 ECG electrodes. The ICMS (integrated cardiovascular monitoring system, 15x15x25 cu cm, battery powered) designed to monitor Blood pressure, ECG, cerebral and femoral flows was fixed below the astronaut sit in the middeck. Recordings started 5 minutes before de-orbiting (TIG) and stopped 5 min after wheels stop. Results. During re-entry blood pressure increased by 20% at TIG, and then by 25 to 30% during the highest Gz accelerations (approx 1 S g ) . The cerebral flow remained decreased by 10 to 15% below inflight value all during the Entry and landing phases. Conversely the femoral flow increased at TIG and entry ( + l0 to 20%), recovered at 0.lg, and then decreased in proportion with the Gz acceleration (-10% to -40% from 0.5g to 1.5g). The reduction in Femoral flow was associated with an opposite variation in lower limb vascular resistance. Consequently the cerebral flow/femoral flow ratio decreased at TIG and entry (-20%), and then increased according to the Gz acceleration level ( + l0 to +40% from 0.5 to 1.5g). Conclusion: During orthostatic tests (Stand LBNP tests) the cerebral to femoral flow ratio allowed to quantify the efficiency of the flow redistribution between these 2 areas and predicted orthostatic intolerance. In the present case the astronaut was found orthostatically tolerant at postflight tilt tests, but we suggest that during re-entry this parameter could predict the occurrence of syncope in severely disadapted astronauts.

  6. Sensor Fusion of Gaussian Mixtures for Ballistic Target Tracking in the Re-Entry Phase.

    PubMed

    Lu, Kelin; Zhou, Rui

    2016-01-01

    A sensor fusion methodology for the Gaussian mixtures model is proposed for ballistic target tracking with unknown ballistic coefficients. To improve the estimation accuracy, a track-to-track fusion architecture is proposed to fuse tracks provided by the local interacting multiple model filters. During the fusion process, the duplicate information is removed by considering the first order redundant information between the local tracks. With extensive simulations, we show that the proposed algorithm improves the tracking accuracy in ballistic target tracking in the re-entry phase applications. PMID:27537883

  7. Ablative performance of carbon-carbon nosetips in simulated re-entry environments

    NASA Technical Reports Server (NTRS)

    Nestler, D. E.

    1977-01-01

    A summary is presented of ablation performance data for carbon-carbon nosetip models obtained over a range of pressures from 10 to 168 atm. Two classes of tests are reviewed: (1) steady state, in which a constant environment is imposed on the model, and (2) ramp, in which the pressure is increased from 10 to 80 atmospheres to simulate re-entry pressure history. Comparison of arc test parameters with typical reentry vehicle parameters is included, to assess the adequacy of the test simulation. Based on this comparison, recommendations are made for facility developments which would yield improved simulation capability for reentry vehicle nosetip ablative performance.

  8. Sensor Fusion of Gaussian Mixtures for Ballistic Target Tracking in the Re-Entry Phase

    PubMed Central

    Lu, Kelin; Zhou, Rui

    2016-01-01

    A sensor fusion methodology for the Gaussian mixtures model is proposed for ballistic target tracking with unknown ballistic coefficients. To improve the estimation accuracy, a track-to-track fusion architecture is proposed to fuse tracks provided by the local interacting multiple model filters. During the fusion process, the duplicate information is removed by considering the first order redundant information between the local tracks. With extensive simulations, we show that the proposed algorithm improves the tracking accuracy in ballistic target tracking in the re-entry phase applications. PMID:27537883

  9. Simulation of launch and re-entry acceleration profiles for testing of shuttle and unmanned microgravity research payloads.

    PubMed

    Cassanto, J M; Ziserman, H I; Chapman, D K; Korszun, Z R; Todd, P

    1988-01-01

    Microgravity experiments designed for execution in Get-Away Special canisters, Hitchhiker modules, and Reusable Re-entry Satellites will be subjected to launch and re-entry accelerations. Crew-dependent provisions for preventing acceleration damage to equipment or products will not be available for these payloads during flight; therefore, the effects of launch and re-entry accelerations on all aspects of such payloads must be evaluated prior to flight. A procedure was developed for conveniently simulating the launch and re-entry acceleration profiles of the Space Shuttle (3.3 and 1.7 x g maximum, respectively) and of two versions of NASA's proposed materials research Re-usable Re-entry Satellite (8 x g maximum in one case and 4 x g in the other). By using the 7 m centrifuge of the Gravitational Plant Physiology Laboratory in Philadelphia it was found possible to simulate the time dependence of these 5 different acceleration episodes for payload masses up to 59 kg. A commercial low-cost payload device, the "Materials Dispersion Apparatus" of Instrumentation Technology Associates was tested for (1) integrity of mechanical function, (2) retention of fluid in its compartments, and (3) integrity of products under simulated re-entry g-loads. In particular, the sharp rise from 1 g to maximum g-loading that occurs during re-entry in various unmanned vehicles was successfully simulated, conditions were established for reliable functioning of the MDA, and crystals of 5 proteins suspended in compartments filled with mother liquor were subjected to this acceleration load.

  10. Simulation of launch and re-entry acceleration profiles for testing of shuttle and unmanned microgravity research payloads

    NASA Astrophysics Data System (ADS)

    Cassanto, J. M.; Ziserman, H. I.; Chapman, D. K.; Korszun, Z. R.; Todd, P.

    Microgravity experiments designed for execution in Get-Away Special canisters, Hitchhiker modules, and Reusable Re-entry Satellites will be subjected to launch and re-entry accelerations. Crew-dependent provisions for preventing acceleration damage to equipment or products will not be available for these payloads during flight; therefore, the effects of launch and re-entry accelerations on all aspects of such payloads must be evaluated prior to flight. A procedure was developed for conveniently simulating the launch and re-entry acceleration profiles of the Space Shuttle (3.3 and 1.7 × g maximum, respectively) and of two versions of NASA's proposed materials research Re-usable Re-entry Satellite (8 × g maximum in one case and 4 × g in the other). By using the 7 m centrifuge of the Gravitational Plant Physiology Laboratory in Philadelphia it was found possible to simulate the time dependence of these 5 different acceleration episodes for payload masses up to 59 kg. A commercial low-cost payload device, the “Materials Dispersion Apparatus” of Instrumentation Technology Associates was tested for (1) integrity of mechanical function, (2) retention of fluid in its compartments, and (3) integrity of products under simulated re-entry g-loads. In particular, the sharp rise from 1 g to maximum g-loading that occurs during re-entry in various unmanned vehicles was successfully simulated, conditions were established for reliable functioning of the MDA, and crystals of 5 proteins suspended in compartments filled with mother liquor were subjected to this acceleration load.

  11. Incarcerated Women's Relationship-based Strategies to Avoid Drug Use After Community Re-Entry

    PubMed Central

    Snell-Rood, Claire; Staton-Tindall, Michele; Victor, Grant

    2016-01-01

    While recent research has stressed the supportive role that family and friends play for incarcerated persons as they reenter the community, drug-using incarcerated women reentering the community often have to rely on family, community, and intimate relationships that have played a role in their substance abuse and criminalization. In this study the authors conducted qualitative analysis of clinical sessions with rural, drug-using women (N = 20) in a larger prison-based HIV risk reduction intervention in Kentucky during 2012–2014 to examine incarcerated women's perceptions of the role of their family, community, and intimate relationships in their plans to decrease their substance abuse upon community re-entry. Women stressed the obstacles to receiving support in many of their family and drug-using relationships after community re-entry. Nonetheless, they asserted that changes in their relationships could support their desires to end their substance abuse by setting limits on and using their positive relationships, particularly with their children, to motivate them to change. Interventions to promote incarcerated women's health behavior changes—including substance abuse—must acknowledge the complex social environments in which they live. PMID:26643029

  12. SHEFEX II - Aerodynamic Re-Entry Controlled Sharp Edge Flight Experiment

    NASA Astrophysics Data System (ADS)

    Longo, J. M. A.; Turner, J.; Weihs, H.

    2009-01-01

    In this paper the basic goals and architecture of the SHEFEX II mission is presented. Also launched by a two staged sounding rocket system SHEFEX II is a consequent next step in technology test and demonstration. Considering all experience and collected flight data obtained during the SHEFEX I Mission, the test vehicle has been re-designed and extended by an active control system, which allows active aerodynamic control during the re-entry phase. Thus, ceramic based aerodynamic control elements like rudders, ailerons and flaps, mechanical actuators and an automatic electronic control unit has been implemented. Special focus is taken on improved GNC Elements. In addition, some other experiments including an actively cooled thermal protection element, advanced sensor equipment, high temperature antenna inserts etc. are part of the SHEFEX II experimental payload. A final 2 stage configuration has been selected considering Brazilian solid rocket boosters derived from the S 40 family. During the experiment phase a maximum entry velocity of Mach around 10 is expected for 50 seconds. Considering these flight conditions, the heat loads are not representative for a RLV re-entry, however, it allows to investigate the principal behaviour of such a facetted ceramic TPS, a sharp leading edge at the canards and fins and all associated gas flow effects and their structural response.

  13. Instrumentation Of C-Sic Tiles To Quantify Their Mechanical Behavior During Atmospheric Re-Entry

    NASA Astrophysics Data System (ADS)

    Pereira, C.; Romano, R.; Walz, S.; Schwarz, R.; Fremont, E.; Girard, F.

    2011-05-01

    The windward surfaces of re-entry vehicles are exposed to large thermal gradients and pressure loadings which result in changes to the surface topology and high transient loading of fixation elements. In particular positive steps result in local aero-thermodynamic effects with increased thermal loading of the adjacent tiles. An objective of the in-flight instrumentation of IXV is to document the aerodynamic and thermal loads on the tiles including deflection and the evolution of steps along the vehicle. To this end a combination of high temperature strain gauges and thermocouples will be placed at the metallic stand-offs behind the highest loaded tiles and on one half of the nose cap attachments. The deflection at the edges of the tiles and the steps will be measured using linear variable differential sensors (L VDT). This paper presents background information, the rationale for the chosen measurement points, the design evolution and the validation of the instrumentation both in terms of functionality and ability to withstand the launch and re-entry environment of the IXV

  14. Thermographic Imaging of the Space Shuttle During Re-Entry Using a Near Infrared Sensor

    NASA Technical Reports Server (NTRS)

    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.; Tack, Steve; Bush, Brett C.; Dantowitz, Ronald F.; Kozubal, Marek J.

    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

  15. Introduction to the Dianaut Program: A scientific wireline re-entry in deep ocean boreholes

    NASA Astrophysics Data System (ADS)

    Robert Gable; DIANAUT Shipboard Party

    1992-03-01

    Downhole measurements were successfully made, during the DIANAUT program, in three Deep Sea Drilling Project (DSDP) holes in the North Atlantic, utilizing the wireline re-entry capability of the French logging shuttle Nadia which, seated in the drill re-entry cone, provides a completely stable platform with precise control of depth and logging speed. Logging activities included temperature profiles, borehole televiewer logs, flowmeter measurements, fluid sampling, and a three-component magnetometer profile. The different parameters were measured to study the heat transfer regime and hydrogeological processes within the oceanic crust as a function of age and distance from the ridge axis. Interpretation of the data obtained from holes 333A, 395A, and 534A, drilled in rocks ranging in age from 3.5 to 154 m.y., provide evidence of cold seawater circulation in the upper permeable layer of the young crust (sites 333A and 395A), thus maintaining very low temperatures and heat flow; higher temperatures were obtained from the older crust at site 534A.

  16. Introduction to the DIANAUT program: A scientific wireline re-entry in deep ocean boreholes

    NASA Astrophysics Data System (ADS)

    Gable, Robert

    1992-03-01

    Downhole measurements were successfully made, during the DIANAUT program, in three Deep Sea Drilling Project (DSDP) holes in the North Atlantic, utilizing the wireline re-entry capability of the French logging shuttle Nadia which, seated in the drill re-entry cone, provides a completely stable platform with precise control of depth and logging speed. Logging activities included temperature profiles, borehole televiewer logs, flowmeter measurements, fluid sampling, and a three-component magnetometer profile. The different parameters were measured to study the heat transfer regime and hydrogeological processes within the oceanic crust as a function of age and distance from the ridge axis. Interpretation of the data obtained from holes 333A, 395A, and 534A, drilled in rocks ranging in age from 3.5 to 154 m.y., provide evidence of cold seawater circulation in the upper permeable layer of the young crust (sites 333A and 395A), thus maintaining very low temperatures and heat flow; higher temperatures were obtained from the older crust at site 534A.

  17. Casualty Risk Assessment Controlled Re-Entry of EPS - Ariane 5ES - ATV Mission

    NASA Astrophysics Data System (ADS)

    Arnal, M.-H.; Laine, N.; Aussilhou, C.

    2012-01-01

    To fulfil its mission of compliance check to the French Space Operations Act, CNES has developed ELECTRA© tool in order to estimate casualty risk induced by a space activity (like rocket launch, controlled or un-controlled re-entry on Earth of a space object). This article describes the application of such a tool for the EPS controlled re-entry during the second Ariane 5E/S flight (Johannes Kepler mission has been launched in February 2011). EPS is the Ariane 5E/S upper composite which is de-orbited from a 260 km circular orbit after its main mission (release of the Automated Transfer Vehicle - ATV). After a brief description of the launcher, the ATV-mission and a description of all the failure cases taken into account in the mission design (which leads to "back-up scenarios" into the flight software program), the article will describe the steps which lead to the casualty risk assessment (in case of failure) with ELECTRA©. In particular, the presence on board of two propulsive means of de-orbiting (main engine of EPS, and 4 ACS longitudinal nozzles in case of main engine failure or exhaustion) leads to a low remaining casualty risk.

  18. Near-Optimal Re-Entry Trajectories for Reusable Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Chou, H.-C.; Ardema, M. D.; Bowles, J. V.

    1997-01-01

    A near-optimal guidance law for the descent trajectory for earth orbit re-entry of a fully reusable single-stage-to-orbit pure rocket launch vehicle is derived. A methodology is developed to investigate using both bank angle and altitude as control variables and selecting parameters that maximize various performance functions. The method is based on the energy-state model of the aircraft equations of motion. The major task of this paper is to obtain optimal re-entry trajectories under a variety of performance goals: minimum time, minimum surface temperature, minimum heating, and maximum heading change; four classes of trajectories were investigated: no banking, optimal left turn banking, optimal right turn banking, and optimal bank chattering. The cost function is in general a weighted sum of all performance goals. In particular, the trade-off between minimizing heat load into the vehicle and maximizing cross range distance is investigated. The results show that the optimization methodology can be used to derive a wide variety of near-optimal trajectories.

  19. Dynamic and Static High Temperature Resistant Ceramic Seals for X- 38 re-Entry Vehicle

    NASA Astrophysics Data System (ADS)

    Handrick, Karin E.; Curry, Donald M.

    2002-01-01

    In a highly successful partnership, NAS A, ESA, DLR (German Space Agency) and European industry are building the X-38, V201 re-entry spacecraft, the prototype of the International Space Station's Crew Return Vehicle (CRV). This vehicle would serve both as an ambulance for medical emergencies and as an evacuation vehicle for the Space Station. The development of essential systems and technologies for a reusable re-entry vehicle is a first for Europe, and sharing the development of an advanced re-entry spacecraft with foreign partners is a first for NASA. NASA, in addition to its subsystem responsibilities, is performing overall X-38 vehicle system engineering and integration, will launch V201 on the Space Shuttle, deliver flight data for post-flight analysis and assessment and is responsible for development and manufacture of structural vehicle components and thermal protection (TPS) tiles. The major European objective for cooperation with NASA on X-38 was to establish a clear path through which key technologies needed for future space transportation systems could be developed and validated at affordable cost and with controlled risk. Europe has taken the responsibility to design and manufacture hot control surfaces like metallic rudders and ceramic matrix composites (CMC) body flaps, thermal protection systems such as CMC leading edges, the CMC nose cap and -skirt, insulation, landing gears and elements of the V201 primary structure. Especially hot control surfaces require extremely high temperature resistant seals to limit hot gas ingestion and transfer of heat to underlying low-temperature structures to prevent overheating of these structures and possible loss of the vehicle. Complex seal interfaces, which have to fulfill various, tight mission- and vehicle-related requirements exist between the moveable ceramic body flaps and the bottom surface of the vehicle, between the rudder and fin structure and the ceramic leading edge panel and TPS tiles. While NASA

  20. Laboratory-experiments on shear-flow instabilities in a re-entry sheath

    NASA Astrophysics Data System (ADS)

    Niemann, C.; Ashour-Abdalla, M.; Clark, S. E.; Niehoff, D.; Schaeffer, D. B.; Constantin, C. G.; Schriver, D.; El Alaoui, M.; Sotnikov, V. I.

    2013-10-01

    Shear-flow instabilities in the plasma sheath surrounding re-entry vehicles and hypersonic aircraft can be detrimental to radio-communication but have not been investigated experimentally in detail. We present measurements of plasma-fluctuations in the lower-hybrid range, created in a laser-produced plasma plume that closely resembles a reentry sheath (1011-1013 cm-3, 1-20 eV). Shear-flow instabilities form in the diamagnetic current layer of the laser-produced plasma (20 J) exploding at hypersonic speed (M > 10) into a preformed magnetic field (400 G). Electric- and magnetic-field gradients are characterized with magnetic flux probes over large spatial (20 cm) and temporal scales, while the plasma parameters are measured via optical Thomson scattering. The frequency spectrum of plasma pulsations is investigated with biased Langmuir probes. The data is compared to simulations performed with a 2D PIC Darwin code. Work supported by the AFRL.

  1. Probabilities of escape, re-entry, and orbit decay due to misdirected injection maneuvers

    NASA Astrophysics Data System (ADS)

    Longuski, James M.

    1992-04-01

    Whenever a space vehicle is injected from low earth orbit to high orbit or to escape, there is a small probability of misdirection. Once misdirection is assumed, then up to three major families of trajectories may result: escape, re-entry, or orbit decay. Analytic models of these trajectories provide contours on the injection sphere. Analytic integration of the areas between the contours gives the relative probability of each family occurring. The approximate analytic models are much faster in providing solutions than the numerical methods currently in use and have comparable accuracy. The new method provides a useful tool in the safety analysis of both single and multistage injection maneuvers. Recent applications have included analysis of the Galileo and the Ulysses injections into interplanetary trajectories.

  2. European Experimental Re-Entry Testbed EXPERT: Qualification of Payloads for Flight

    NASA Astrophysics Data System (ADS)

    Ratti, F.; Gavira, J.; Thirkettle, A. C.; Erba, F.; Muylaert, J.-M.; Walpot, L.; Rembiasz, J. M.

    2009-01-01

    The European Experimental Re-entry Test-bed EXPERT is developed by the European Space Agency (ESA) as part of its General Technological Research Program (GSTP). The aim of EXPERT is to improve the understanding of critical aero-thermodynamic phenomena associated with hypersonic re-entry flights. The EXPERT project provides an opportunity to the scientific community and industries throughout Europe to propose and perform experiments in order to obtain aero-thermodynamic data for the validation of numerical models and of ground to flight extrapolation methodologies. During the last years an intense activity has been performed at ESA in order to select the most suitable experiments, bring them to a mature design, manufacture the qualification model and qualify the experiments for flight. ESA staffs coordinated and supported the work of the principal investigators of the experiments from European institutions and industrial organizations in order to maximize the scientific output in compliance with the budget resources made available to the EXPERT project and the programmatic constraints. EXPERT is a re-entry capsule having the shape of a blunted cone. The front part consists of a nose made of ceramic material developed at DLR Stuttgart. No ablative material is implemented so as not to contaminate the specific measurements of Payloads on board. The ceramic nose hosts a set of experiments: the Flush Air Data System (FADS) developed by HTG aiming at collecting free flow data required for post flight analysis, the pyrometer PYREX developed at IRS in Stuttgart collecting data on the temperature and heat flux of the ceramic nose, and the IRS spectrometer RESPECT aiming at resolving the different species generated in the plasma region during re-entry. The sides of the blunted cone are protected by a metallic thermal protection system in which several experiments are located. Two Payloads developed by IRS and VKI are dedicated to the measurement of catalytic effects. One aims

  3. The use of inflatable structures for re-entry of orbiting vehicles

    NASA Astrophysics Data System (ADS)

    Kendall, Robert T.; Maddox, Arthur R.

    1990-10-01

    Inflatable recovery systems offer the unique advantage that a large high-drag shape can be stored initially in a relatively small package. The resulting shapes decelerate rapidly with lower heating inputs than other types of re-entry vehicles. Recent developments have led to some light-weight materials, with little thermal protection, can withstand the heating inputs to such vehicles. As a result, inflatable recovery vehicles offer a simple, reliable and economical way to return various vehicles from orbit. This paper examines the application of this concept to a large and a small vehicle with the accompanying dynamics that might be expected. More complex systems could extend the concept to emergency personnel escape systems, payload abort and satellite recovery systems.

  4. Inflatable re-Entry and Descent Technology - Results of the IRDT-2 Mission and Future Applications

    NASA Astrophysics Data System (ADS)

    Walther, S.

    2002-01-01

    This paper will present the results of the second IRDT flight, a mission which is planned for May 2002. The first testflight successfully demonstrated its performance in 2000. The Inflatable Re-entry and Descent Technology (IRDT), an innovative lightweight return technology, is designed to provide significant mass and cost savings compared to conventionally fixed heat shield and parachute systems for returning elements from space. This technology is highly attractive for a broad range of applications, e.g. return of small capsules, larger objects like ATV or launcher elements from an Earth orbit and may also be used for planetary missions. IRDT can be adapted to existing vehicles or be used as baseline for new vehicles. Potential future application scenarios, e.g. a Download System to return payload from the ISS, will also be described.

  5. The Advanced Re-Entry Vehicle (ARV) a Development Step from ATV Toward Manned Transportation Systems

    NASA Astrophysics Data System (ADS)

    Bottacini, M.; Berthe, P.; Vo, X.; Pietsch, K.

    2011-08-01

    The Advanced Re-entry Vehicle (ARV) programme has been undertaken by Europe with the objective to contribute to the preparation of a future European crew transportation system, while providing a valuable logistic support to the ISS through an operational cargo return system. This development would allow: - the early acquisition of critical technologies; - the design, development and testing of elements suitable for the follow up human rated transportation system. These vehicles should also serve future LEO infrastructures and exploration missions. With the aim to satisfy the above objectives a team composed by major European industries and led by EADS Astrium Space Transportation is currently conducting the phase A of the programme under contract with the European Space Agency (ESA). Two vehicle versions are being investigated: a Cargo version, transporting cargo only to/from the ISS, and a Crew version, which will allow the transfer of both crew and cargo to/from the ISS. The ARV Cargo version, in its present configuration, is composed of three modules. The Versatile Service Module (VSM) provides to the system the propulsion/GNC for orbital manoeuvres and attitude control and the orbital power generation. Its propulsion system and GNC shall be robust enough to allow its use for different launch stacks and different LEO missions in the future. The Un-pressurised Cargo Module (UCM) provides the accommodation for about 3000 kg of un-pressurised cargo and is to be sufficiently flexible to ensure the transportation of: - orbital infrastructure components (ORU's); - scientific / technological experiments; - propellant for re-fuelling, re-boost (and deorbiting) of the ISS. The Re-entry Module (RM) provides a pressurized volume to accommodate active/passive cargo (2000 kg upload/1500 kg download). It is conceived as an expendable conical capsule with spherical heat- hield, interfacing with the new docking standard of the ISS, i.e. it carries the IBDM docking system, on a

  6. The Advanced Re-Entry Vehicle (ARV) A Development Step From ATV Toward Manned Transportation Systems

    NASA Astrophysics Data System (ADS)

    Bottacini, Massimiliano; Berthe, Philippe; Vo, Xavier; Pietsch, Klaus

    2011-05-01

    The Advanced Re-entry Vehicle (ARV) programme has been undertaken by Europe with the objective to contribute to the preparation of a future European crew transportation system, while providing a valuable logistic support to the ISS through an operational cargo return system. This development would allow: - the early acquisition of critical technologies; - the design, development and testing of elements suitable for the follow up human rated transportation system. These vehicles should also serve future LEO infrastructures and exploration missions. With the aim to satisfy the above objectives a team composed by major European industries and led by EADS Astrium Space Transportation is currently conducting the phase A of the programme under contract with the European Space Agency (ESA). Two vehicle versions are being investigated: a Cargo version, transporting cargo only to/from the ISS, and a Crew version, which will allow the transfer of both crew and cargo to/from the ISS. The ARV Cargo version, in its present configuration, is composed of three modules. The Versatile Service Module (VSM) provides to the system the propulsion/GNC for orbital manoeuvres and attitude control and the orbital power generation. Its propulsion system and GNC shall be robust enough to allow its use for different launch stacks and different LEO missions in the future. The Un-pressurised Cargo Module (UCM) provides the accommodation for about 3000 kg of unpressurised cargo and is to be sufficiently flexible to ensure the transportation of: - orbital infrastructure components (ORU’s); - scientific / technological experiments; - propellant for re-fuelling, re-boost (and de-orbiting) of the ISS. The Re-entry Module (RM) provides a pressurized volume to accommodate active/passive cargo (2000 kg upload/1500 kg download). It is conceived as an expendable conical capsule with spherical heat-shield, interfacing with the new docking standard of the ISS, i.e. it carries the IBDM docking system, on

  7. Static mechanical strain induces capillary endothelial cell cycle re-entry and sprouting

    NASA Astrophysics Data System (ADS)

    Zeiger, A. S.; Liu, F. D.; Durham, J. T.; Jagielska, A.; Mahmoodian, R.; Van Vliet, K. J.; Herman, I. M.

    2016-08-01

    Vascular endothelial cells are known to respond to a range of biochemical and time-varying mechanical cues that can promote blood vessel sprouting termed angiogenesis. It is less understood how these cells respond to sustained (i.e., static) mechanical cues such as the deformation generated by other contractile vascular cells, cues which can change with age and disease state. Here we demonstrate that static tensile strain of 10%, consistent with that exerted by contractile microvascular pericytes, can directly and rapidly induce cell cycle re-entry in growth-arrested microvascular endothelial cell monolayers. S-phase entry in response to this strain correlates with absence of nuclear p27, a cyclin-dependent kinase inhibitor. Furthermore, this modest strain promotes sprouting of endothelial cells, suggesting a novel mechanical ‘angiogenic switch’. These findings suggest that static tensile strain can directly stimulate pathological angiogenesis, implying that pericyte absence or death is not necessarily required of endothelial cell re-activation.

  8. Viscous code prediction of re-entry vehicle roll torque based on ablated surface topology

    NASA Astrophysics Data System (ADS)

    Szostowski, D. J.; Lowe, D. L.; Nestler, D. E.

    1982-06-01

    A new approach is developed for modeling roll torque due to ablated surface features of tape-wrapped, carbon-phenolic heatshields. The approach stems from preferential and random asymmetric topological characteristics observed on material specimens from ground test models and recovered re-entry vehicles. Roll torque contributions from each type of surface feature are determined from aerodynamic models coupled to an integral viscous technique. The dominant roll-producing mechanisms are shown to be warp yarn bias surface roughness and the formation of asymmetric char ledges. Comparisons with flight test roll histories validate the framework for the roll modeling technique, including predictions for a class of vehicle differing substantially from the one for which the model was developed.

  9. Measurement of lateral launch loads on re-entry vehicles using SWAT

    SciTech Connect

    Mayes, R.L.

    1993-11-01

    The Sum of Weighted Accelerations Technique (SWAT) has been developed at Sandia National Laboratories to infer dynamic forces acting on free elastic structures from acceleration measurements. A derivative of SWAT known as SWAT TEEM (Sum of Weighted Accelerations using Tome Eliminated Elastic Modes) is utilized. This paper describes experiments demonstrating how this technology can be applied to measure lateral launch loads on Re-entry Vehicle (RV) payloads. A technique to determine the number of sensors and best locations is described. Experiments are performed to excite a structure to which a mockup RV is mounted. Acceleration measurements on the RV are used to reconstruct the lateral force acting at the RV base, and these results are compared to measured results.

  10. Numerical Flight Mechanics Analysis Of The SHEFEX I Ascent And Re-Entry Phases

    NASA Astrophysics Data System (ADS)

    Bartolome Calvo, Javier; Eggers, Thino

    2011-08-01

    The SHarp Edge Flight EXperiment (SHEFEX) I provides a huge amount of scientific data to validate numerical tools in hypersonic flows. These data allow the direct comparison of flight measurements with the current numerical tools available at DLR. Therefore, this paper is devoted to apply a recently developed direct coupling between aerodynamics and flight dynamics to the SHEFEX I flight. In a first step, mission analyses are carried out using the trajectory optimization program REENT 6D coupled to missile DATCOM. In a second step, the direct coupling between the trajectory program and the DLR TAU code, in which the unsteady Euler equations including rigid body motion are solved, is applied to analyze some interesting parts of ascent and re-entry phases of the flight experiment. The agreement of the numerical predictions with the obtained flight data is satisfactory assuming a variable fin deflection angle.

  11. Levels and determinants of pesticide exposure in re-entry workers in vineyards: results of the PESTEXPO study.

    PubMed

    Baldi, Isabelle; Lebailly, P; Bouvier, G; Rondeau, V; Kientz-Bouchart, V; Canal-Raffin, M; Garrigou, A

    2014-07-01

    Physical contact with branches, leaves, fruit or vegetables in previously treated crops is responsible for the transfer of pesticides to the worker's skin in agricultural tasks such as harvesting, pruning, thinning, cutting or sorting. Few studies have documented workers' exposure during re-entry in vineyards. In the PESTEXPO study, we described levels of exposure and analyzed their determinants during re-entry and harvesting in vineyards in the Bordeaux area, France. Between 2002 and 2007, volunteers performing re-entry tasks (N=46 days) or harvesting (N=48 days) after dithiocarbamate or folpet treatment were observed. Detailed information on the tasks was collected and dermal contamination was assessed using patches placed on the skin and hand-washing at the end of each working phase. Daily median contamination was 1 967.7 μl of mixture during re-entry (90(e) percentile: 5 045.3 μl) and 18.7 μl during harvesting (90(e) percentile: 911.4 μl). The type of task was the parameter found to be the most strongly associated with contamination. For re-entry, the highest contaminations were observed during raising of wires and cutting of branches. During the harvest, the contamination was maximal for grape-picking. The delay since the last treatment and the rate of active ingredient per hectare played a role, together with other factors such as meteorological factors, crop and farm characteristics, gloves and clothes. Our results underline the necessity to take into account exposures during re-entry and harvest when considering pesticide exposure, both for epidemiological research and preventive action.

  12. FLPP IXV Re-Entry Vehicle, Supersonic Charectisation Based on DNW SST Wind Tunnel Tests and CFD

    NASA Astrophysics Data System (ADS)

    Kapteijn, C.; Maseland, H.; Chiarelli, C.; Mareschi, V.; Tribot, J.-P.; Binetti, P.; Walloscheck, T.

    2009-01-01

    The European Space Agency ESA, has engaged in 2004, the IXV project (Intermediate eXperimental Vehicle) which is part of the FLPP (Future Launcher Preparatory Programme) aiming at answering to critical technological issues for controlled re-entry, while supporting the future generation launchers and to improve in general European capabilities in the strategic field of atmospheric re-entry for future space transportation, exploration and scientific applications. The IXV key mission and system objectives are the design, development, manufacturing, assembling and on- ground to in-flight verification of an autonomous European lifting and aerodynamically controlled re- entry system, integrating the critical re- entry technologies at the system level. In particular, the IXV shall demonstrate system integrated key technologies such as lifting flight control by means of aerodynamic surfaces that are one of the main primary objectives of the experimental investigation. Lifting and aerodynamic controlled re-entry represents a significant capability advancement with respect to the ballistic re-entry of capsules like the ARD. Since hypersonic aerodynamics is essentially different from supersonic aerodynamics, the current mission is to perform an atmospheric re-entry in combination with a safe recovery the in supersonic flight regime. However, mission extension to trimmed transonic flight is under consideration based on a preliminary analysis of the aerodynamic characteristics of the IXV configuration. Since the beginning of the IXV project, an aerodynamic data base (AEDB) has been built up and continuously updated integrating the additional information mainly provided by means of CFD (ie: Euler and Navier-Stokes) and lately also by means of WTTs. This AEDB serves for flying qualities analysis and for re-entry simulations. During the development phase B2/C1, the effectiveness of the control surfaces and their impact on te vehicle's aerodynamic forces in the supersonic regime is

  13. Development and application of an empirical probability distribution for the prediction error of re-entry body maximum dynamic pressure

    NASA Technical Reports Server (NTRS)

    Lanzi, R. James; Vincent, Brett T.

    1993-01-01

    The relationship between actual and predicted re-entry maximum dynamic pressure is characterized using a probability density function and a cumulative distribution function derived from sounding rocket flight data. This paper explores the properties of this distribution and demonstrates applications of this data with observed sounding rocket re-entry body damage characteristics to assess probabilities of sustaining various levels of heating damage. The results from this paper effectively bridge the gap existing in sounding rocket reentry analysis between the known damage level/flight environment relationships and the predicted flight environment.

  14. Advanced Key Technologies for Hot Control Surfaces in Space Re- Entry Vehicles

    NASA Astrophysics Data System (ADS)

    Dogigli, Michael; Pradier, Alain; Tumino, Giorgio

    2002-01-01

    (1)MAN Technologie AG, D- 86153 Augsburg, Germany (2,3) ESA, 2200 Noordwijk ZH, The Netherlands Current space re-entry vehicles (e.g. X-38 vehicle 201, the prototype of the International Space Station's Crew Return Vehicle (CRV)) require advanced control surfaces (so called body flaps). Such control surfaces allow the design of smaller and lighter vehicles as well as faster re-entries (compared to the US Shuttle). They are designed as light-weight structures that need no metallic parts, need no mass or volume consuming heat sinks to protect critical components (e.g. bearings) and that can be operated at temperatures of more than 1600 "C in air transferring high mechanical loads (dynamic 40 kN, static 70 kN) at the same time. Because there is a need for CRV and also for Reusable Launch Vehicles (RLV) in future, the European Space Agency (ESA) felt compelled to establish a "Future European Space Transportation and Investigation Program,, (FESTIP) and a "General Support for Technology Program,, (GSTP). One of the main goals of these programs was to develop and qualify key-technologies that are able to master the above mentioned challenging requirements for advanced hot control surfaces and that can be applied for different vehicles. In 1996 MAN Technologie has started the development of hot control surfaces for small lifting bodies in the national program "Heiü Strukturen,,. One of the main results of this program was that especially the following CMC (Ceramic Matrix Composite) key technologies need to be brought up to space flight standard: Complex CMC Structures, CMC Bearings, Metal-to-CMC Joining Technologies, CMC Fasteners, Oxidation Protection Systems and Static and Dynamic Seals. MAN Technologie was contracted by ESA to continue the development and qualification of these key technologies in the frame of the FESTIP and the GSTP program. Development and qualification have successfully been carried out. The key technologies have been applied for the X-38 vehicle

  15. Evaluation of the Seattle Public Schools' 1983-84 Re-Entry Program. Report No. 84-13.

    ERIC Educational Resources Information Center

    Ramey, Madelaine

    This report evaluates the Seattle Public School District's 1983-84 re-entry program for suspended and expelled students in terms of seven expected student behavioral outcomes and Outreach/Intake Services Unit objectives. The program's purpose is to assist these students in improving the attitudes and/or behaviors which lead to disciplinary action.…

  16. STD 105: Process Groups as an Instructional Medium for Re-entry Women at Paul D. Camp Community College.

    ERIC Educational Resources Information Center

    Creamer, Elizabeth; Duggin, Molly; Kidd, Ronald

    1999-01-01

    An effective team-based, group-oriented personal development from a woman's perspective course explores the effects of several issues on the re-entry woman: the role that society and culture play in influencing women's vocational choices; women's roles; the economic necessity of work; stress; and relationships. A team-based approach provides a…

  17. The Role of Counselling and Parental Encouragement on Re-Entry of Adolescents into Secondary Schools in Abia State, Nigeria

    ERIC Educational Resources Information Center

    Alika, Henrietta Ijeoma; Ohanaka, Blessing Ijeoma

    2013-01-01

    This paper examined the role of counselling, and parental encouragement on re-entry of adolescents into secondary school in Abia State, Nigeria. A total of 353 adolescents who re-entered school were selected from six secondary schools in the State through a simple random sampling technique. A validated questionnaire was used for data analysis.…

  18. An Exploration of Factors Reducing Recidivism Rates of Formerly Incarcerated Youth with Disabilities Participating in a Re-Entry Intervention

    ERIC Educational Resources Information Center

    Unruh, Deanne K.; Gau, Jeff M.; Waintrup, Miriam G.

    2009-01-01

    Juvenile offenders are costly to our society in terms of the monetary and social expenditures from the legal system, victims' person costs, and incarceration. The re-entry and community reintegration outcomes for formerly incarcerated youth with a disabling condition are bleak compared to peers without disabilities. In this study, we examined the…

  19. Does Offender Gambling on the inside Continue on the outside? Insights from Correctional Professionals on Gambling and Re-Entry

    ERIC Educational Resources Information Center

    Williams, D. J.; Walker, Gordon J.

    2009-01-01

    This study brings to light a neglected topic of particular importance--offender gambling issues within the context of re-entry into the community. Fifteen correctional professionals from Nevada (high gambling availability) and Utah (no legalized gambling) participated in semi-structured interviews to provide insights into how gambling may impact…

  20. Report on Annual Women's Re-Entry Program Workshop (4th, Albuquerque, New Mexico, July 31, 1981).

    ERIC Educational Resources Information Center

    Maria, Arietta

    This report briefly describes presentations made at a re-entry workshop which was sponsored by the New Mexico Commission on the Status of Women. The 45 participants included representatives from post-secondary programs and institutions throughout the state. The purpose of this workshop was to provide information to state institutions and agencies…

  1. Career Assessment, Remediation, Education, Employment, and Re-entry Program (CAREER). El Paso Community College Career Grant. Final Report.

    ERIC Educational Resources Information Center

    LaFleur, Carol A.

    Objectives of the Career Assessment, Remediation, Education, Employment, and Re-entry (CAREER) project were to establish a series of intensive, short-term job training programs using competency-based instruction to serve Hispanic persons who were economically disadvantaged, displaced, unemployed, or underemployed, as well as Hispanic females who…

  2. Vocational Interest as a Correlate of Re-Entry of Girls into School in Edo State, Nigeria: Implications for Counselling

    ERIC Educational Resources Information Center

    Alika, Ijeoma Henrietta; Egbochuku, Elizabeth Omotunde

    2012-01-01

    The study investigated the relationship between vocational interest socio-economic status and re-entry of girls into school in Edo State. The research design adopted was correlational because it sought to establish the relationship between the independent variable and the dependent variable. A sample size of 306 girls who re-enrolled in institutes…

  3. Cast Glance Near Infrared Imaging Observations of the Space Shuttle During Hypersonic Re-Entry

    NASA Technical Reports Server (NTRS)

    Tack, Steve; Tomek, Deborah M.; Horvath, Thomas J.; Verstynen, Harry A.; Shea, Edward J.

    2010-01-01

    High resolution calibrated infrared imagery of the Space Shuttle was obtained during hypervelocity atmospheric entries of the STS-119, STS-125 and STS128 missions and has provided information on the distribution of surface temperature and the state of the airflow over the windward surface of the Orbiter during descent. This data collect was initiated by NASA s Hypersonic Thermodynamic Infrared Measurements (HYTHIRM) team and incorporated the use of air- and land-based optical assets to image the Shuttle during atmospheric re-entry. The HYTHIRM objective is to develop and implement a set of mission planning tools designed to establish confidence in the ability of an existing optical asset to reliably acquire, track and return global quantitative surface temperatures of the Shuttle during entry. On Space Shuttle Discovery s STS-119 mission, NASA flew a specially modified thermal protection system tile and instrumentation package to monitor heating effects from boundary layer transition during re-entry. On STS-119, the windward airflow on the port wing was deliberately disrupted by a four-inch wide and quarter-inch tall protuberance built into the modified tile. In coordination with this flight experiment, a US Navy NP-3D Orion aircraft was flown 28 nautical miles below Discovery and remotely monitored surface temperature of the Orbiter at Mach 8.4 using a long-range infrared optical package referred to as Cast Glance. Approximately two months later, the same Navy Cast Glance aircraft successfully monitored the surface temperatures of the Orbiter Atlantis traveling at approximately Mach 14.3 during its return from the successful Hubble repair mission. In contrast to Discovery, Atlantis was not part of the Boundary Layer Transition (BLT) flight experiment, thus the vehicle was not configured with a protuberance on the port wing. In September 2009, Cast Glance was again successful in capturing infrared imagery and monitoring the surface temperatures on Discovery s next

  4. FLPP IXV Re-entry Vehicle, Transonic Characterisation Based on FOI T1500 Wind Tunnel Tests and CFD

    NASA Astrophysics Data System (ADS)

    Torngren, L.; Chiarelli, C.; Mareschi, V.; Tribot, J.-P.; Binetti, P.; Walloschek, T.

    2009-01-01

    The European Space Agency ESA, has engaged in 2004, the IXV project (Intermediate eXperimental Vehicle) which is part of the FLPP (Future Launcher Preparatory Programme) aiming at answering to critical technological issues, while supporting the future generation launchers and to improve in general European capabilities in the strategic field of atmospheric re-entry for space transportation, exploration and scientific applications. The IXV key mission and system objectives are the design, development, manufacturing, assembling and on-ground to in-flight verification of an autonomous European lifting and aerodynamically controlled re-entry system, integrating the critical re-entry technologies at the system level. The current IXV vehicle is a slender body type exhibiting rounded shape, thick body controlled by means of two control surfaces. The current mission is to perform an atmospheric re- entry ended by a safe recovery in supersonic regime. A potential extension of the flight domain down to the transonic regime was proposed to be analyzed. The objectives were to study the capability of the IXV for flying autonomously enabling a recovery of the vehicle by means of a subsonic parachute based DRS. The vehicle designed for the hypersonic speeds integrating a large base with only two control surfaces located close to the plane of symmetry is definitively not tuned for transonic ones. CFD done by Thales Alenia Space and wind tunnel activities involving FOI T1500 facility contributed to built up an Aerodynamic Data Base (AEDB) to be used as inputs for flying qualities analysis and re-entry simulations. The paper presents the main objectives of the transonic activities with emphasis on CFD and WTT including a description of the different prediction tools and discussing the main outcomes of the current data comparisons.

  5. Re-Entry Women Students in Higher Education: A Model for Non-Traditional Support Programs in Counseling and Career Advisement.

    ERIC Educational Resources Information Center

    Karr-Kidwell, PJ

    A model program of support for non-traditional women students has been developed at Texas Woman's University (TWU). Based on a pilot study, several steps were taken to assist these re-entry students at TWU. For example, in spring semester of 1983, a committee for re-entry students was established, with a student organization--Women in…

  6. Neutral composition measurements by the Pioneer Venus Neutral Mass Spectrometer during orbiter re-entry

    NASA Technical Reports Server (NTRS)

    Kasprzak, W. T.; Niemann, H. B.; Hedin, A. E.; Bougher, S. W.; Hunten, D. M.

    1993-01-01

    Measurements by the Pioneer Venus Orbiter Neutral Mass Spectrometer (ONMS) instrument during Orbiter re-entry have been made from 18-24 hours local solar time, above 170 km, of He, and from midnight to 4.5 hours below 200 km of He, N, O, CO, N2, and CO2. Preliminary results indicate that in the post-midnight sector He is the dominant species above 170 km, O the dominant species from 140-170 km and CO2 the dominant species below 140 km. Estimated scale height temperatures for He, O, and CO2 of about 105-120 K are similar to those observed in 1978-1980 at higher solar activity. The densities at 1 am local solar time and at 150 km are within 35% of those measured earlier. The He bulge is also similar to that observed in 1978-1980 confirming that thermosphere superrotation is still present. Comparison with the results of a Venus Thermosphere General Circulation Model suggests the nightside is not sensitive to changes in solar activity due to the isolation of the day and night thermospheres. apparently, the relatively small changes in the dayside thermosphere with solar activity have little impact on the nightside thermosphere.

  7. Neutral Composition Measurements by the Pioneer Venus Neutral Mass Spectrometer During Orbiter Re-Entry

    NASA Technical Reports Server (NTRS)

    Kasprzak, W. T.; Niemann, H. B.; Hedin, A. E.; Bougher, S. W.; Hunten, D. M.

    1993-01-01

    Measurements by the Pioneer Venus Orbiter Neutral Mass Spectrometer (ONMS) instrument during Orbiter re-entry have been made from 18-24 hours local solar time, above 170 km, of He, and from midnight to 4.5 hours below 200 km of He, N, O, CO, N2, and CO2. Preliminary results indicate that in the post-midnight sector He is the dominant species above 170 km, O the dominant species from 140-170 km and CO2 the dominant species below 140 km. Estimated scale height temperatures for He, O and CO2 of about 105-120 K are similar to those observed in 1978-80 at higher solar activity. The densities at 1 am local solar time and at 150 km are within 35% of those measured earlier. The He bulge is also similar to that observed in 1978-80 confirming that thermosphere superrotation is still present. Comparison with the results of a Venus Thermosphere General Circulation Model suggests the nightside is not sensitive to changes in solar activity due to the isolation of the day and night thermospheres. Apparently, the relatively small changes in the dayside thermosphere with solar activity have little impact on the nightside thermosphere.

  8. Mathematical Interpretation of Observational Data of the Stardust SRC Re-Entry

    NASA Astrophysics Data System (ADS)

    Gritsevich, M. I.

    2009-01-01

    STARDUST spacecraft was launched on February 7, 1999. STARDUST is the first U.S. Space mission dedicated solely to the exploration of a comet, and the first robotic mission designed to return extraterrestrial material from outside the orbit of the Moon. But studying of observational data of the STARDUST Sample Return Capsule's (SRC) entry into Earth's atmosphere on January 15, 2006, also represent a big interest. At a velocity of 12.8 km/s (assumed to be at an altitude of 125 km) SRC was the fastest ever attempted re-entry of a human made space vehicle. The return trajectory of the SRC is very similar to that of natural cosmic bodies. Entry begins when the spacecraft reorients for SRC release from the spacecraft bus and ends with parachute deployment. In the present report, an analytical model of the atmospheric entry is calculated using the data of actual observations, by selecting the parameters describing rate of deceleration of the body during its hypersonic flight. Model was applied to the observational data of STARDUST Sample Return Capsule (a hypersonic phase). The estimate of mass of SRC obtained using the data of actual observations is quite close to its real value of 45.8 kg.

  9. A Flight Study of a Power-Off Landing Technique Applicable to Re-Entry Vehicles

    NASA Technical Reports Server (NTRS)

    Bray, Richard S.; Drinkwater, Fred J.; White, Maurice D.

    1960-01-01

    A power-off landing technique, applicable to aircraft of configurations presently being considered for manned re-entry vehicles, has been developed and flight tested at Ames Research Center. The flight tests used two configurations of an airplane for which the values of maximum lift-drag ratios were 4.0 and 2.8. Twenty-four idle-power approaches were made to an 8000-foot runway with touchdown point and airspeed accuracies of +/-600 feet and +/-10 knots, respectively. The landing pattern used was designed to provide an explicitly defined flight path for the pilot and, yet, to require no external guidance other than the pilot's view from the cockpit. The initial phase of the approach pattern is a constant high-speed descent from altitude aimed at a ground reference point short of the runway threshold. At a specified altitude and speed, a constant g pull-out is made to a shallow flight path along which the air-plane decelerates to the touchdown point. Repeatability and safety are inherent because of the reduced number of variables requiring pilot judgment, and because of the fact that a missed approach is evident at speeds and altitudes suitable for safe ejection. The accuracy and repeatability of the pattern are indicated by the measured results. The proposed pattern appears to be particularly suitable for configurations having unusual drag variations with speed in the lower speed regime, since the pilot is not required to control speed in the latter portions of the pattern.

  10. A multiblock analysis for shuttle orbiter re-entry heating from Mach 24 to Mach 12

    NASA Technical Reports Server (NTRS)

    Gnoffo, Peter A.; Weilmuenster, K. J.; Alter, Stephen J.

    1993-01-01

    A multiblock, laminar heating analysis for the shuttle orbiter at three trajectory points ranging from Mach 24.3 to Mach 12.86 on re-entry is described. The analysis is performed using the Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA) with both a seven species chemical nonequilibrium model and an equilibrium model. A finite-catalytic-wall model appropriate for shuttle tiles at a radiative equilibrium wall temperature is applied. Computed heating levels are generally in good agreement with the flight data though a few rather large discrepancies remain unexplained. The multiblock relaxation strategy partitions the flowfield into manageable blocks requiring a fraction of the computational resources (time and memory) required by a full domain approach. In hot, the computational cost for a solution at even a single trajectory point would be prohibitively expensive at the given resolution without the multiblock approach. Converged blocks are reassembled to enable a fully coupled converged solution over the entire vehicle, starting from a nearly converged initial condition.

  11. Re-Entry Aeroheating Analysis of Tile-Repair Augers for the Shuttle Orbiter

    NASA Technical Reports Server (NTRS)

    Mazaheri, Ali R.; Wood, William A.

    2007-01-01

    Computational re-entry aerothermodynamic analysis of the Space Shuttle Orbiter s tile overlay repair (TOR) sub-assembly is presented. Entry aeroheating analyses are conducted to characterize the aerothermodynamic environment of the TOR and to provide necessary inputs for future TOR thermal and structural analyses. The TOR sub-assembly consists of a thin plate and several augers and spacers that serve as the TOR fasteners. For the computational analysis, the Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA) is used. A 5-species non-equilibrium chemistry model with a finite rate catalytic recombination model and a radiation equilibrium wall condition are used. It is assumed that wall properties are the same as reaction cured glass (RCG) properties with a surface emissivity of epsilon = 0.89. Surface heat transfer rates for the TOR and tile repair augers (TRA) are computed at a STS-107 trajectory point corresponding to Mach 18 free stream conditions. Computational results show that the average heating bump factor (BF), which is a ratio of local heat transfer rate to a design reference point located at the damage site, for the auger head alone is about 1.9. It is also shown that the average BF for the combined auger and washer heads is about 2.0.

  12. Ceramic Adhesive and Methods for On-Orbit Repair of Re-Entry Vehicles

    NASA Technical Reports Server (NTRS)

    Riedell, James A.; Easler, Timothy E.

    2013-01-01

    This adhesive is capable of repairing damaged leading edge components of reentry vehicles while in space, and is novel with regard to its ability to be applied in the vacuum of space, and in a microgravity environment. Once applied, the adhesive provides thermal and oxidation protection to the substrate (in this case, reinforced carbon/carbon composites, RCCs) during re-entry of a space vehicle. Although there may be many formulations for repair adhesives, at the time of this reporting, this is the first known adhesive capable of an on-orbit repair. The adhesive is an engineered ceramic material composed of a pre-ceramic polymer and refractory powders in the form of a paste or putty that can be applied to a scratched, cracked, or fractured composite surface, covering and protecting the damaged area. The adhesive is then "cured" with a heat cycle, thereby cross-linking the polymer into a hardened material and bonding it to the substrate. During the heat of reentry, the material is converted to a ceramic coating that provides thermal and oxidative stability to the repaired area, thus allowing the vehicle to pass safely from space into the upper atmosphere. Ceramic powders such as SiC, ZrB2 and Y2O3 are combined with allylhydridopolycarbosilane (AHPCS) resin, and are mixed to form a paste adhesive. The material is then applied to the damaged area by brush, spatula, trowel, or other means to fill cracks, gaps, and holes, or used to bond patches onto the damaged area. The material is then cured, in a vacuum, preferably at 250F (approximately equal to 121C) for two hours. The re-entry heating of the vehicle at temperatures in excess of 3,000F (approximately equal to 1,650C) then converts this material into a ceramic coating. This invention has demonstrated advantages in resistance to high temperatures, as was demonstrated in more than 100 arc-jet tests in representative environments at NASA. Extensive testing verified oxidation protection for the repaired substrate (RCC

  13. An Automated Method to Compute Orbital Re-Entry Trajectories with Heating Constraints

    NASA Technical Reports Server (NTRS)

    Zimmerman, Curtis; Dukeman, Greg; Hanson, John; Fogle, Frank R. (Technical Monitor)

    2002-01-01

    Determining how to properly manipulate the controls of a re-entering re-usable launch vehicle (RLV) so that it is able to safely return to Earth and land involves the solution of a two-point boundary value problem (TPBVP). This problem, which can be quite difficult, is traditionally solved on the ground prior to flight. If necessary, a nearly unlimited amount of time is available to find the "best" solution using a variety of trajectory design and optimization tools. The role of entry guidance during flight is to follow the pre-determined reference solution while correcting for any errors encountered along the way. This guidance method is both highly reliable and very efficient in terms of onboard computer resources. There is a growing interest in a style of entry guidance that places the responsibility of solving the TPBVP in the actual entry guidance flight software. Here there is very limited computer time. The powerful, but finicky, mathematical tools used by trajectory designers on the ground cannot in general be made to do the job. Nonconvergence or slow convergence can result in disaster. The challenges of designing such an algorithm are numerous and difficult. Yet the payoff (in the form of decreased operational costs and increased safety) can be substantial. This paper presents an algorithm that incorporates features of both types of guidance strategies. It takes an initial RLV orbital re-entry state and finds a trajectory that will safely transport the vehicle to a Terminal Area Energy Management (TAEM) region. During actual flight, the computed trajectory is used as the reference to be flown by a more traditional guidance method.

  14. An Automated Method to Compute Orbital Re-entry Trajectories with Heating Constraints

    NASA Technical Reports Server (NTRS)

    Zimmerman, Curtis; Dukeman, Greg; Hanson, John; Fogle, Frank R. (Technical Monitor)

    2002-01-01

    Determining how to properly manipulate the controls of a re-entering re-usable launch vehicle (RLV) so that it is able to safely return to Earth and land involves the solution of a two-point boundary value problem (TPBVP). This problem, which can be quite difficult, is traditionally solved on the ground prior to flight. If necessary, a nearly unlimited amount of time is available to find the 'best' solution using a variety of trajectory design and optimization tools. The role of entry guidance during flight is to follow the pre- determined reference solution while correcting for any errors encountered along the way. This guidance method is both highly reliable and very efficient in terms of onboard computer resources. There is a growing interest in a style of entry guidance that places the responsibility of solving the TPBVP in the actual entry guidance flight software. Here there is very limited computer time. The powerful, but finicky, mathematical tools used by trajectory designers on the ground cannot in general be converted to do the job. Non-convergence or slow convergence can result in disaster. The challenges of designing such an algorithm are numerous and difficult. Yet the payoff (in the form of decreased operational costs and increased safety) can be substantiaL This paper presents an algorithm that incorporates features of both types of guidance strategies. It takes an initial RLV orbital re-entry state and finds a trajectory that will safely transport the vehicle to Earth. During actual flight, the computed trajectory is used as the reference to be flown by a more traditional guidance method.

  15. [Sternal re-entry using the retractor for harvesting internal thoracic artery].

    PubMed

    Niinami, H; Takeuchi, Y

    2002-06-01

    The number of redo cardiac operations, especially coronary artery bypass grafting (CABG), has recently been increasing mainly due to the failure of saphenous vein grafts. Re-opening a median sternotomy is troublesome, because of possible adhesion of the heart to the sternum. Preoperative computed tomography is quite useful and helpful in determining the degree of the adhesion of the heart and ascending aorta to the back of the sternum. We report here a safe and useful technique for sternal re-entry using a retractor for harvesting the internal thoracic artery (ITA). When re-opening a median sternotomy the incision is made to the sternal wires; the wires are then cut and removed. Small rake retractors, which are connected to the ITA retractor, are hooked to both ends of the left side of the sternum. The ITA retractor is gently wound up to lift up the sternum. An oscillating saw is then applied to divide the anterior table of the sternum. When the posterior table of the sternum is carefully divided, the left side of the sternum is automatically elevated slightly. Complete division of the sternum can be confirmed by this slight elevation. If the left side of the sternum is elevated a little bit more by the ITA retractor, the dissection of the adhesion between the sternum and the heart can be performed without assistance. This technique is most beneficial for a case of redo CABG with the use of the left ITA, but it can be applied in any patients who previously underwent median sternotomy.

  16. Assessment Of The Aerodynamic And Aerothermodynamic Performance Of The USV-3 High-Lift Re-Entry Vehicle

    NASA Astrophysics Data System (ADS)

    Pezzella, Giuseppe; Richiello, Camillo; Russo, Gennaro

    2011-05-01

    This paper deals with the aerodynamic and aerothermodynamic trade-off analysis carried out with the aim to design a hypersonic flying test bed (FTB), namely USV3. Such vehicle will have to be launched with a small expendable launcher and shall re-enter the Earth atmosphere allowing to perform several experiments on critical re-entry phenomena. The demonstrator under study is a re-entry space glider characterized by a relatively simple vehicle architecture able to validate hypersonic aerothermodynamic design database and passenger experiments, including thermal shield and hot structures. Then, a summary review of the aerodynamic characteristics of two FTB concepts, compliant with a phase-A design level, has been provided hereinafter. Indeed, several design results, based both on engineering approach and computational fluid dynamics, are reported and discussed in the paper.

  17. Romance, recovery & community re-entry for criminal justice involved women: Conceptualizing and measuring intimate relationship factors and power

    PubMed Central

    Walt, Lisa C.; Hunter, Bronwyn; Salina, Doreen; Jason, Leonard

    2015-01-01

    Researchers have suggested that interpersonal relationships, particularly romantic relationships, may influence women’s attempts at substance abuse recovery and community re-entry after criminal justice system involvement. The present paper evaluates relational and power theories to conceptualize the influence of romantic partner and romantic relationship qualities on pathways in and out of substance abuse and crime. The paper then combines these conceptualizations with a complementary empirical analysis to describe an ongoing research project that longitudinally investigates these relational and power driven factors on women’s substance abuse recovery and community re-entry success among former substance abusing, recently criminally involved women. This paper is designed to encourage the integration of theory and empirical analysis by detailing how each of these concepts are operationalized and measured. Future research and clinical implications are also discussed. PMID:25750487

  18. Analysis of Electromagnetic Wave Propagation in a Magnetized Re-Entry Plasma Sheath Via the Kinetic Equation

    NASA Technical Reports Server (NTRS)

    Manning, Robert M.

    2009-01-01

    Based on a theoretical model of the propagation of electromagnetic waves through a hypersonically induced plasma, it has been demonstrated that the classical radiofrequency communications blackout that is experienced during atmospheric reentry can be mitigated through the appropriate control of an external magnetic field of nominal magnitude. The model is based on the kinetic equation treatment of Vlasov and involves an analytical solution for the electric and magnetic fields within the plasma allowing for a description of the attendant transmission, reflection and absorption coefficients. The ability to transmit through the magnetized plasma is due to the magnetic windows that are created within the plasma via the well-known whistler modes of propagation. The case of 2 GHz transmission through a re-entry plasma is considered. The coefficients are found to be highly sensitive to the prevailing electron density and will thus require a dynamic control mechanism to vary the magnetic field as the plasma evolves through the re-entry phase.

  19. Putting principals back into practice: an evaluation of a re-entry course for vocationally trained doctors.

    PubMed Central

    Baker, M; Williams, J; Petchey, R

    1997-01-01

    BACKGROUND: Current recruitment difficulties in general practice have sharpened the interest of the profession in non-principals. No re-entry course for general practice has previously been run in the UK. AIM: To design and evaluate a re-entry course for general practice. METHOD: A re-entry course was developed to help doctors return to general practice as principals. A telephone interview was carried out with each delegate prior to their attendance on the course and was repeated one month and six months after the course to measure any change in career intentions and the perceived benefit of attending the course. RESULTS: Six months after the course, 11 out of 14 delegates had taken positive steps to return to general practice or had increased their time commitment to medicine. This contrasts with only one of the control group having made any steps to change career. CONCLUSION: The course was evaluated and found to be beneficial, particularly in terms of increasing the confidence of the delegates. PMID:9463984

  20. Aerothermodynamic performance and thermal protection design for blunt re-entry bodies at L/D = 0.3

    NASA Technical Reports Server (NTRS)

    Caram, Jose M.; Kowal, T. J.

    1993-01-01

    Aerodynamic heating and thermal protection design analyses were performed for three blunt re-entry bodies at an L/D = 0.3 returning from low earth orbit. These configurations consisted of a scaled up Apollo command module, a Viking re-entry vehicle, and an Aeroassist Flight Experiment (AFE) aerobrake, each with a maximum diameter of 4.42 m. The aerothermodynamic analysis determined the equilibrium stagnation point heating rate and heat load for nominal and 3-sigma re-entry trajectories and the distribution of heating along the pitch and yaw planes for each of the vehicles at the time of highest heat flux. Using the predicted heating rates and heating distributions, a Thermal Protection System (TPS) design with flight certified materials was tailored for each of the configurations. Results indicated that the heating to the corner of the Viking aeroshell would exceed current limits of reusable tile material. Also, the maximum heating for the AFE would be 15 percent greater than the maximum heating for the Apollo flying the same trajectory. TPS designs showed no significant advantage in TPS weight between the different vehicles; however, heat-shield areal density comparisons showed the Apollo configuration to be the most efficient in terms of TPS weight.

  1. Cardiovascular effects of anti-G suit and cooling garment during space shuttle re-entry and landing

    NASA Technical Reports Server (NTRS)

    Perez, Sondra A.; Charles, John B.; Fortner, G. William; Hurst, Victor 4th; Meck, Janice V.

    2003-01-01

    BACKGROUND: Many cardiovascular changes associated with spaceflight reduce the ability of the cardiovascular system to oppose gravity on return to Earth, leaving astronauts susceptible to orthostatic hypotension during re-entry and landing. Consequently, an anti-G suit was developed to protect arterial pressure during re-entry. A liquid cooling garment (LCG) was then needed to alleviate the thermal stress resulting from use of the launch and entry suit. METHODS: We studied 34 astronauts on 22 flights (4-16 d). Subjects were studied 10 d before launch and on landing day. Preflight, crewmembers were suited with their anti-G suits set to the intended inflation for re-entry. Three consecutive measurements of heart rate and arterial pressure were obtained while seated and then again while standing. Three subjects who inflated the anti-G suits also donned the LCG for landing. Arterial pressure and heart rate were measured every 5 min during the de-orbit maneuver, through maximum G-loading (max-G) and touch down (TD). After TD, crew-members again initiated three seated measurements followed by three standing measurements. RESULTS: Astronauts with inflated anti-G suits had higher arterial pressure than those who did not have inflated anti-G suits during re-entry and landing (133.1 +/- 2.5/76.1 +/- 2.1 vs. 128.3 +/- 4.2/79.3 +/- 2.9, de-orbit; 157.3 +/- 4.5/102.1 +/- 3.6 vs. 145.2 +/- 10.5/95.7 + 5.5, max-G; 159.6 +/- 3.9/103.7 +/- 3.3 vs. 134.1 +/- 5.1/85.7 +/- 3.1, TD). In the group with inflated anti-G suits, those who also wore the LCG exhibited significantly lower heart rates than those who did not (75.7 +/- 11.5 vs. 86.5 +/- 6.2, de-orbit; 79.5 +/- 24.8 vs. 112.1 +/- 8.7, max-G; 84.7 +/- 8.0 vs. 110.5 +/- 7.9, TD). CONCLUSIONS: The anti-G suit is effective in supporting arterial pressure. The addition of the LCG lowers heart rate during re-entry.

  2. Further Investigations of Control Surface Seals for the X-38 Re-Entry Vehicle

    NASA Technical Reports Server (NTRS)

    Dunlap, Patrick H., Jr.; Steinetz, Bruce M.; Curry, Donald M.; Newquist, Charles W.; Verzemnieks, Juris

    2001-01-01

    NASA is currently developing the X-38 vehicle that will be used to demonstrate the technologies required for a potential crew return vehicle (CRV) for the International Space Station. This vehicle would serve both as an ambulance for medical emergencies and as an evacuation vehicle for the Space Station. Control surfaces on the X-38 (body flaps and rudder/fin assemblies) require high temperature seals to limit hot gas ingestion and transfer of heat to underlying low-temperature structures to prevent over-temperature of these structures and possible loss of the vehicle. NASAs Johnson Space Center (JSC) and Glenn Research Center (GRC) are working together to develop and evaluate seals for these control surfaces. This paper presents results for compression. flow, scrub, and arc jet tests conducted on the baseline X-38 rudder/fin seal design. Room temperature seal compression tests were performed at low compression levels to determine load versus linear compression, preload. contact area, stiffness. and resiliency characteristics under low load conditions. For all compression levels that were tested, unit loads and contact pressures for the seals were below the 5 lb/in. and 10 psi limits required to limit the loads on the adjoining Shuttle thermal tiles that the seals will contact. Flow rates through an unloaded (i.e. 0% compression) double arrangement were twice those of a double seal compressed to the 20% design compression level. The seals survived an ambient temperature 1000 cycle scrub test over relatively rough Shuttle tile surfaces. The seals were able to disengage and re-engage the edges of the rub surface tiles while being scrubbed over them. Arc jet tests were performed to experimentally determine anticipated seal temperatures for representative flow boundary conditions (pressures and temperatures) under simulated vehicle re-entry conditions. Installation of a single seat in the gap of the test fixture caused a large temperature drop (1710 F) across the seal

  3. A case study of non-traditional students re-entry into college physics and engineering

    NASA Astrophysics Data System (ADS)

    Langton, Stewart Gordon

    Two groups of students in introductory physics courses of an Access Program for engineering technologies were the subjects of this study. Students with a wide range of academic histories and abilities were enrolled in the program; many of the students were re-entry and academically unprepared for post-secondary education. Five years of historical data were evaluated to use as a benchmark for revised instruction. Data were gathered to describe the pre-course academic state of the students and their academic progress during two physics courses. Additional information was used to search for factors that might constrain academic success and as feedback for the instructional methods. The data were interpreted to regulate constructivist design features for the physics courses. The Engineering Technology Access Program was introduced to meet the demand from non-traditional students for admission to two-year engineering' technology programs, but who did not meet normal academic requirements. The duration of the Access Program was two terms for electronic and computer engineering students and three terms for civil and mechanical engineering students. The sequence of mathematics and physics courses was different for the two groups. The Civil/Mechanical students enrolled in their first mathematics course before undertaking their first physics course. The first mathematics and physics courses for the Electronics students were concurrent. Academic success in the two groups was affected by this difference. Over a five-year period the success rate of students graduating with a technology diploma was approximately twenty-five percent. Results from this study indicate that it was possible to reduce the very high attrition in the combined Access/Technology Programs. While the success rate for the Electronics students increased to 38% the rate for the Civil/Mechanical students increased dramatically to 77%. It is likely that several factors, related to the extra term in the Access

  4. Aero-thermo-dynamic analysis of a low ballistic coefficient deployable capsule in Earth re-entry

    NASA Astrophysics Data System (ADS)

    Zuppardi, G.; Savino, R.; Mongelluzzo, G.

    2016-10-01

    The paper deals with a microsatellite and the related deployable recovery capsule. The aero-brake is folded at launch and deployed in space and is able to perform a de-orbiting controlled re-entry. This kind of capsule, with a flexible, high temperature resistant fabric, thanks to its lightness and modulating capability, can be an alternative to the current "conventional" recovery capsules. The present authors already analyzed the trajectory and the aerodynamic behavior of low ballistic coefficient capsules during Earth re-entry and Mars entry. In previous studies, aerodynamic longitudinal stability analysis and evaluation of thermal and aerodynamic loads for a possible suborbital re-entry demonstrator were carried out in both continuum and rarefied regimes. The present study is aimed at providing preliminary information about thermal and aerodynamic loads and longitudinal stability for a similar deployable capsule, as well as information about the electronic composition of the plasma sheet and its possible influence on radio communications at the altitudes where GPS black-out could occur. Since the computer tests were carried out at high altitudes, therefore in rarefied flow fields, use of Direct Simulation Monte Carlo codes was mandatory. The computations involved both global aerodynamic quantities (drag and longitudinal moment coefficients) and local aerodynamic quantities (heat flux and pressure distributions along the capsule surface). The results verified that the capsule at high altitude (150 km) is self-stabilizing; it is stable around the nominal attitude or at zero angle of attack and unstable around the reverse attitude or at 180° angle of attack. The analysis also pointed out the presence of extra statically stable equilibrium trim points.

  5. Evaluation of the Positive Re-Entry in Corrections Program: A Positive Psychology Intervention With Prison Inmates.

    PubMed

    Huynh, Kim H; Hall, Brittany; Hurst, Mark A; Bikos, Lynette H

    2015-08-01

    Two groups of male inmates (n = 31, n = 31) participated in the Positive Re-Entry in Corrections Program (PRCP). This positive psychology intervention focused on teaching offenders skills that facilitate re-entry into the community. Offenders participated in weekly lectures, discussions, and homework assignments focused on positive psychology principles. The two groups differed in duration of treatment (8 weeks and 12 weeks). Participants completed pre- and post-intervention measures of gratitude, hope, and life satisfaction. Using a 2 × 2 mixed design ANOVA, we hypothesized that the intervention (with two between-subjects levels of 8 and 12 weeks) and duration (with two repeated measures levels of pre and post) of treatment would moderate pre- to post-intervention change. Results indicated significant differences on pre- and post-intervention scores for both groups of offenders on all measures. The analysis did not yield statistically significant differences between groups, demonstrating no additive benefits from the inclusion of four additional sessions, thus saving time and money for correctional programming and funding. This research supports the use of positive psychology in prison interventions.

  6. Surgical Re-entry of an Intentionally Replanted Periodontally Compromised Tooth Treated with Platelet Rich Fibrin (PRF): Hopeless to Hopeful

    PubMed Central

    Srinath, Rashmi; Prakash, Shobha

    2016-01-01

    Intentional replantation is generally contraindicated in periodontally compromised teeth however, there are reports suggesting that it can be a successful treatment alternative for periodontally involved hopeless teeth. Currently there is dearth of evidence regarding the success of this therapy, especially evidence for the effectiveness of autologous platelet rich fibrin is lacking. We present a case report of a 23-year-old male patient with periodontally hopeless left maxillary central incisor having bone loss extending beyond root apex. The tooth was gently extracted and replanted utilizing root conditioning and combined regenerative therapy (Xenograft, PRF and Type I Collagen Membrane). Surgical re-entry at nine months revealed bone formation in the apical third of the tooth. At one year, 87% radiographic bone gain was accomplished. The improvement in the clinical and radiographic parameters reinforced by the re-entry surgery findings strongly suggest that intentional replantation may be a cost-effective substitute to implants and tooth supported prosthesis in situations where conventional periodontal therapy would yield compromised outcomes. PMID:27504421

  7. Surgical Re-entry of an Intentionally Replanted Periodontally Compromised Tooth Treated with Platelet Rich Fibrin (PRF): Hopeless to Hopeful.

    PubMed

    Ryana, Haneet Kour; Srinath, Rashmi; Prakash, Shobha

    2016-06-01

    Intentional replantation is generally contraindicated in periodontally compromised teeth however, there are reports suggesting that it can be a successful treatment alternative for periodontally involved hopeless teeth. Currently there is dearth of evidence regarding the success of this therapy, especially evidence for the effectiveness of autologous platelet rich fibrin is lacking. We present a case report of a 23-year-old male patient with periodontally hopeless left maxillary central incisor having bone loss extending beyond root apex. The tooth was gently extracted and replanted utilizing root conditioning and combined regenerative therapy (Xenograft, PRF and Type I Collagen Membrane). Surgical re-entry at nine months revealed bone formation in the apical third of the tooth. At one year, 87% radiographic bone gain was accomplished. The improvement in the clinical and radiographic parameters reinforced by the re-entry surgery findings strongly suggest that intentional replantation may be a cost-effective substitute to implants and tooth supported prosthesis in situations where conventional periodontal therapy would yield compromised outcomes.

  8. Surgical Re-entry of an Intentionally Replanted Periodontally Compromised Tooth Treated with Platelet Rich Fibrin (PRF): Hopeless to Hopeful.

    PubMed

    Ryana, Haneet Kour; Srinath, Rashmi; Prakash, Shobha

    2016-06-01

    Intentional replantation is generally contraindicated in periodontally compromised teeth however, there are reports suggesting that it can be a successful treatment alternative for periodontally involved hopeless teeth. Currently there is dearth of evidence regarding the success of this therapy, especially evidence for the effectiveness of autologous platelet rich fibrin is lacking. We present a case report of a 23-year-old male patient with periodontally hopeless left maxillary central incisor having bone loss extending beyond root apex. The tooth was gently extracted and replanted utilizing root conditioning and combined regenerative therapy (Xenograft, PRF and Type I Collagen Membrane). Surgical re-entry at nine months revealed bone formation in the apical third of the tooth. At one year, 87% radiographic bone gain was accomplished. The improvement in the clinical and radiographic parameters reinforced by the re-entry surgery findings strongly suggest that intentional replantation may be a cost-effective substitute to implants and tooth supported prosthesis in situations where conventional periodontal therapy would yield compromised outcomes. PMID:27504421

  9. Advanced Models for Prediction of High Altitude Aero-Thermal Loads of a Space Re-entry Vehicle

    NASA Astrophysics Data System (ADS)

    Votta, R.; Schettino, A.; Bonfiglioli, A.

    2011-05-01

    The analysis of the rarefaction effects in predicting the main aero-thermal loads of a Space re-entry vehicle is presented. It is well known that the Navier-Stokes equations fail in rarefied regimes and other approaches must be used. In the present paper different configurations have been simulated by using the Direct Simulation Monte Carlo method. Moreover, slip flow boundary conditions have been implemented in a Navier-Stokes code in order to extend the validity of the continuum approach to the transitional flow regime. Finally, bridging formulas for high altitude aerodynamics of winged bodies have been used. Firstly, two simple geometries have been analysed, specifically designed to study the phenomenon of shock wave boundary layer interaction: a hollow cylinder flare, for which some experiments are available; and a blunt-nosed flat plate/flap model designed and tested at the Italian Aerospace Research Centre. The other configurations taken into account are, respectively, an experimental winged re-entry vehicle and a capsule, for which global aerodynamic coefficients and local wall heating have been determined with different approaches. The Navier-Stokes code with slip flow boundary conditions has shown good predicting capabilities compared with experiments in the hollow cylinder flare case; however, for the winged vehicle and capsule cases, the CFD results are not fully satisfactory and the Monte Carlo method remains the most reliable approach, together with the bridging formula, that provides good results for the aerodynamic coefficients.

  10. Re-entry communication through a plasma sheath using standing wave detection and adaptive data rate control

    NASA Astrophysics Data System (ADS)

    Xie, Kai; Yang, Min; Bai, Bowen; Li, Xiaoping; Zhou, Hui; Guo, Lixin

    2016-01-01

    Radio blackout during the re-entry has puzzled the aerospace industry for decades and has not yet been completely resolved. To achieve a continuous data link in the spacecraft's re-entry period, a simple and practicable communication method is proposed on the basis that (1) the electromagnetic-wave backscatter of the plasma sheath affects the voltage standing wave ratio (VSWR) of the antenna, and the backscatter is negatively correlated to transmission components, and (2) the transmission attenuation caused by the plasma sheath reduces the channel capacity. We detect the voltage standing wave ratio changes of the antenna and then adjust the information rate to accommodate the varying channel capacity, thus guaranteeing continuous transmission (for fewer critical data). The experiment was carried out in a plasma generator with an 18-cm-thick and 30-cm-diameter hollow propagation path, and the adaptive communication was implemented using spread spectrum frequency, shift key modulation with a variable spreading factor. The experimental results indicate that, when the over-threshold of VSWR was detected, the bit rate reduced to 250 bps from 4 Mbps automatically and the tolerated plasma density increased by an order of magnitude, which validates the proposed scheme. The proposed method has little additional cost, and the adaptive control does not require a feedback channel. The method is therefore applicable to data transmission in a single direction, such as that of a one-way telemetry system.

  11. Novel Hybrid Ablative/Ceramic Layered Composite for Earth Re-entry Thermal Protection: Microstructural and Mechanical Performance

    NASA Astrophysics Data System (ADS)

    Triantou, K.; Mergia, K.; Marinou, A.; Vekinis, G.; Barcena, J.; Florez, S.; Perez, B.; Pinaud, G.; Bouilly, J.-M.; Fischer, W. P. P.

    2015-04-01

    In view of spacecraft re-entry applications into planetary atmospheres, hybrid thermal protection systems based on layered composites of ablative materials and ceramic matrix composites are investigated. Joints of ASTERM™ lightweight ablative material with Cf/SiC (SICARBON™) were fabricated using commercial high temperature inorganic adhesives. Sound joints without defects are produced and very good bonding of the adhesive with both base materials is observed. Mechanical shear tests under ambient conditions and in liquid nitrogen show that mechanical failure always takes place inside the ablative material with no decohesion of the interface of the adhesive layer with the bonded materials. Surface treatment of the ablative surface prior to bonding enhances both the shear strength and the ultimate shear strain by up to about 60%.

  12. Ionospheric errors at L-band for satellite and re-entry object tracking in the new equatorial-anomaly region

    SciTech Connect

    Pakula, W.A.; Klobuchar, J.A.; Anderson, D.N.; Doherty, P.H.

    1990-05-03

    The ionosphere can significantly limit the accuracy of precise tracking of satellites and re-entry objects, especially in the equatorial anomaly region of the world where the electron density is the highest. The determine typical changes induced by the ionosphere, the Fully Analytic Ionospheric Model, (FAIM), was used to model range and range-rate errors over Kwajalein Island, located near the equatorial anomaly region in the Pacific. Model results show that range-rate errors of up to one foot per second can occur at L-band for certain, near-vertical re-entry object trajectories during high solar activity daytime conditions.

  13. A Novel Device for True Lumen Re-Entry After Subintimal Recanalization of Superficial Femoral Arteries: First-in-Man Experience and Technical Description

    SciTech Connect

    Airoldi, Flavio Faglia, Ezio Losa, Sergio Tavano, Davide; Latib, Azeem; Mantero, Manuela Lanza, Gaetano Clerici, Giacomo

    2011-02-15

    Subintimal angioplasty (SAP) is frequently performed for the treatment of critical limb ischemia (CLI) and has been recognized as an effective technique for these patients. Nevertheless, this approach is limited by the lack of controlled re-entry into the true lumen of the target vessel. We describe a novel device for true lumen re-entry after subintimal recanalization of superficial femoral arteries (SFA). We report our experience with six patients treated between April 2009 and January 2010 with a novel system designed to facilitate true lumen re-entry. The device was advanced by ipsilateral antegrade approach through a 6-French sheath. Successful reaccess into the true lumen was obtained in five of six patients without complications. The patient in whom the reaccess to the true lumen was not possible underwent successful bypass surgery. At 30 days follow-up, the SFA was patent in all patients according to echo-Doppler examination. Our preliminary experience indicates that this novel re-entry device increases the success rate of percutaneous revascularization of chronically occluded SFA.

  14. An Investigation of the Re-Entry Adjustment of Indians Who Studied in the U.S.A. Occasional Papers in Intercultural Learning, Number 17.

    ERIC Educational Resources Information Center

    Hansel, Bettina

    This study explored the readjustment experience of 49 Indians who came to the United States to study and then returned to their home country. Interviews revealed that most experienced some stress or difficulty after their re-entry, with problems ranging from initial anxiety about getting a job or shock at the crowded conditions, pollution, or the…

  15. Application of a Near Infrared Imaging System for Thermographic Imaging of the Space Shuttle during Hypersonic Re-Entry

    NASA Technical Reports Server (NTRS)

    Zalameda, Joseph N.; Tietjen, Alan B.; Horvath, Thomas J.; Tomek, Deborah M.; Gibson, David M.; Taylor, Jeff C.; Tack, Steve; Bush, Brett C.; Mercer, C. David; Shea, Edward J.

    2010-01-01

    observations confirmed the challenge of a long-range acquisition during re-entry. These challenges are due to unknown atmospheric conditions, image saturation, vibration etc. This provides the motivation for the use of a digital NIR sensor. The characterizations performed on the digital NIR sensor included radiometric, spatial, and spectral measurements using blackbody radiation sources and known targets. An assessment of the collected data for three Space Shuttle atmospheric re-entries, STS-119, STS-125, and STS-128, are provided along with a description of various events of interest captured using the digital NIR imaging system such as RCS firings and boundary layer transitions. Lastly the process used to convert the raw image counts to quantitative temperatures is presented along with comparisons to the Space Shuttle's onboard thermocouples.

  16. A finite difference approximation for dynamic calculation of vertical free hanging slender risers in re-entry application

    NASA Astrophysics Data System (ADS)

    Wang, Sheng-wei; Xu, Xue-song; Yao, Bao-heng; Lian, Lian

    2012-12-01

    The dynamic calculations of slender marine risers, such as Finite Element Method (FEM) or Modal Expansion Solution Method (MESM), are mainly for the slender structures with their both ends hinged to the surface and bottom. However, for the re-entry operation, risers held by vessels are in vertical free hanging state, so the displacement and velocity of lower joint would not be zero. For the model of free hanging flexible marine risers, the paper proposed a Finite Difference Approximation (FDA) method for its dynamic calculation. The riser is divided into a reasonable number of rigid discrete segments. And the dynamic model is established based on simple Euler-Bernoulli Beam Theory concerning tension, shear forces and bending moments at each node along the cylindrical structures, which is extendible for different boundary conditions. The governing equations with specific boundary conditions for riser's free hanging state are simplified by Keller-box method and solved with Newton iteration algorithm for a stable dynamic solution. The calculation starts when the riser is vertical and still in calm water, and its behavior is obtained along time responding to the lateral forward motion at the top. The dynamic behavior in response to the lateral parametric excitation at the top is also proposed and discussed in this paper.

  17. A Mission Concept: Re-Entry Hopper-Aero-Space-Craft System on-Mars (REARM-Mars)

    NASA Technical Reports Server (NTRS)

    Davoodi, Faranak

    2013-01-01

    Future missions to Mars that would need a sophisticated lander, hopper, or rover could benefit from the REARM Architecture. The mission concept REARM Architecture is designed to provide unprecedented capabilities for future Mars exploration missions, including human exploration and possible sample-return missions, as a reusable lander, ascend/descend vehicle, refuelable hopper, multiple-location sample-return collector, laboratory, and a cargo system for assets and humans. These could all be possible by adding just a single customized Re-Entry-Hopper-Aero-Space-Craft System, called REARM-spacecraft, and a docking station at the Martian orbit, called REARM-dock. REARM could dramatically decrease the time and the expense required to launch new exploratory missions on Mars by making them less dependent on Earth and by reusing the assets already designed, built, and sent to Mars. REARM would introduce a new class of Mars exploration missions, which could explore much larger expanses of Mars in a much faster fashion and with much more sophisticated lab instruments. The proposed REARM architecture consists of the following subsystems: REARM-dock, REARM-spacecraft, sky-crane, secure-attached-compartment, sample-return container, agile rover, scalable orbital lab, and on-the-road robotic handymen.

  18. The application of quaternions and other spatial representations to the reconstruction of re-entry vehicle motion.

    SciTech Connect

    De Sapio, Vincent

    2010-09-01

    The analysis of spacecraft kinematics and dynamics requires an efficient scheme for spatial representation. While the representation of displacement in three dimensional Euclidean space is straightforward, orientation in three dimensions poses particular challenges. The unit quaternion provides an approach that mitigates many of the problems intrinsic in other representation approaches, including the ill-conditioning that arises from computing many successive rotations. This report focuses on the computational utility of unit quaternions and their application to the reconstruction of re-entry vehicle (RV) motion history from sensor data. To this end they will be used in conjunction with other kinematic and data processing techniques. We will present a numerical implementation for the reconstruction of RV motion solely from gyroscope and accelerometer data. This will make use of unit quaternions due to their numerical efficacy in dealing with the composition of many incremental rotations over a time series. In addition to signal processing and data conditioning procedures, algorithms for numerical quaternion-based integration of gyroscope data will be addressed, as well as accelerometer triangulation and integration to yield RV trajectory. Actual processed flight data will be presented to demonstrate the implementation of these methods.

  19. A Novel Fenestration Technique for Abdominal Aortic Dissection Membranes Using a Combination of a Needle Re-entry Catheter and the 'Cheese-wire' Technique

    SciTech Connect

    Kos, Sebastian; Guerke, Lorenz; Jacob, Augustinus L.

    2011-12-15

    Purpose: This study was designed to demonstrate the applicability of a combined needle-based re-entry catheter and 'cheese-wire' technique for fenestration of abdominal aortic dissection membranes. Methods: Four male patients (mean age: 65 years) with acute complicated aortic type B dissections were treated at our institution by fenestrating the abdominal aortic dissection membrane using a hybrid technique. This technique combined an initial membrane puncture with a needle-based re-entry catheter using a transfemoral approach. A guidewire was passed through the re-entry catheter and across the membrane. Using a contralateral transfemoral access, this guidewire was then snared, creating a through-and-through wire access. The membrane was then fenestrated using the cheese-wire maneuver. Results: We successfully performed: (a) membrane puncture; (b) guidewire passage; (c) guidewire snaring; and (d) cheese-wire maneuver in all four cases. After this maneuver, decompression of the false lumen and acceptable arterial inflow into the true lumen was observed in all cases. The dependent visceral arteries were reperfused. In one case, portions of the fenestrated membrane occluded the common iliac artery, which was immediately and successfully stented. In another case, long-standing intestinal hypoperfusion before the fenestration resulted in reperfusion-related shock and intraoperative death of the patient. Conclusions: The described hybrid approach for fenestration of dissection membranes is technically feasible and may be established as a therapeutic method in cases with a complicated type B dissection.

  20. Protective Effects of the Launch/Entry Suit (LES) and the Liquid Cooling Garment(LCG) During Re-entry and Landing After Spaceflight

    NASA Technical Reports Server (NTRS)

    Perez, Sondra A.; Charles, John B.; Fortner, G. William; Hurst, Victor, IV; Meck, Janice V.

    2002-01-01

    Heart rate and arterial pressure were measured during shuttle re-entry, landing and initial standing in crewmembers with and without inflated anti-g suits and with and without liquid cooling garments (LCG). Preflight, three measurements were obtained seated, then standing. Prior to and during re-entry, arterial pressure and heart rate were measured every five minutes until wheels stop (WS). Then crewmembers initiated three seated and three standing measurements. In subjects without inflated anti-g suits, SBP and DBP were significantly lower during preflight standing (P = 0.006; P = 0.001 respectively) and at touchdown (TD) (P = 0.001; P = 0.003 respectively); standing SBP was significantly lower after WS. on-LeG users developed significantly higher heart rates during re-entry (P = 0.029, maxG; P = 0.05, TD; P = 0.02, post-WS seated; P = 0.01, post-WS standing) than LCG users. Our data suggest that the anti-g suit is effective, but the combined anti-g suit with LCG is more effective.

  1. The ESA/NASA Multi-Aircraft ATV-1 Re-Entry Campaign: Analysis of Airborne Intensified Video Observations from the NASA/JSC Experiment

    NASA Technical Reports Server (NTRS)

    Barker, Ed; Maley, Paul; Mulrooney, Mark; Beaulieu, Kevin

    2009-01-01

    In September 2008, a joint ESA/NASA multi-instrument airborne observing campaign was conducted over the Southern Pacific ocean. The objective was the acquisition of data to support detailed atmospheric re-entry analysis for the first flight of the European Automated Transfer Vehicle (ATV)-1. Skilled observers were deployed aboard two aircraft which were flown at 12.8 km altitude within visible range of the ATV-1 re-entry zone. The observers operated a suite of instruments with low-light-level detection sensitivity including still cameras, high speed and 30 fps video cameras, and spectrographs. The collected data has provided valuable information regarding the dynamic time evolution of the ATV-1 re-entry fragmentation. Specifically, the data has satisfied the primary mission objective of recording the explosion of ATV-1's primary fuel tank and thereby validating predictions regarding the tanks demise and the altitude of its occurrence. Furthermore, the data contains the brightness and trajectories of several hundred ATV-1 fragments. It is the analysis of these properties, as recorded by the particular instrument set sponsored by NASA/Johnson Space Center, which we present here.

  2. Atrial fibrillation driven by micro-anatomic intramural re-entry revealed by simultaneous sub-epicardial and sub-endocardial optical mapping in explanted human hearts

    PubMed Central

    Hansen, Brian J.; Zhao, Jichao; Csepe, Thomas A.; Moore, Brandon T.; Li, Ning; Jayne, Laura A.; Kalyanasundaram, Anuradha; Lim, Praise; Bratasz, Anna; Powell, Kimerly A.; Simonetti, Orlando P.; Higgins, Robert S.D.; Kilic, Ahmet; Mohler, Peter J.; Janssen, Paul M.L.; Weiss, Raul; Hummel, John D.; Fedorov, Vadim V.

    2015-01-01

    Aims The complex architecture of the human atria may create physical substrates for sustained re-entry to drive atrial fibrillation (AF). The existence of sustained, anatomically defined AF drivers in humans has been challenged partly due to the lack of simultaneous endocardial–epicardial (Endo–Epi) mapping coupled with high-resolution 3D structural imaging. Methods and results Coronary-perfused human right atria from explanted diseased hearts (n = 8, 43–72 years old) were optically mapped simultaneously by three high-resolution CMOS cameras (two aligned Endo–Epi views (330 µm2 resolution) and one panoramic view). 3D gadolinium-enhanced magnetic resonance imaging (GE-MRI, 80 µm3 resolution) revealed the atrial wall structure varied in thickness (1.0 ± 0.7–6.8 ± 2.4 mm), transmural fiber angle differences, and interstitial fibrosis causing transmural activation delay from 23 ± 11 to 43 ± 22 ms at increased pacing rates. Sustained AF (>90 min) was induced by burst pacing during pinacidil (30–100 µM) perfusion. Dual-sided sub-Endo–sub-Epi optical mapping revealed that AF was driven by spatially and temporally stable intramural re-entry with 107 ± 50 ms cycle length and transmural activation delay of 67 ± 31 ms. Intramural re-entrant drivers were captured primarily by sub-Endo mapping, while sub-Epi mapping visualized re-entry or ‘breakthrough’ patterns. Re-entrant drivers were anchored on 3D micro-anatomic tracks (15.4 ± 2.2 × 6.0 ± 2.3 mm2, 2.9 ± 0.9 mm depth) formed by atrial musculature characterized by increased transmural fiber angle differences and interstitial fibrosis. Targeted radiofrequency ablation of the tracks verified these re-entries as drivers of AF. Conclusions Integrated 3D structural–functional mapping of diseased human right atria ex vivo revealed that the complex atrial microstructure caused significant differences between Endo vs. Epi activation during pacing and sustained AF driven by intramural re-entry anchored

  3. Angular and Linear Velocity Estimation for a Re-Entry Vehicle Using Six Distributed Accelerometers: Theory, Simulation and Feasibility

    SciTech Connect

    Clark, G

    2003-04-28

    This report describes a feasibility study. We are interested in calculating the angular and linear velocities of a re-entry vehicle using six acceleration signals from a distributed accelerometer inertial measurement unit (DAIMU). Earlier work showed that angular and linear velocity calculation using classic nonlinear ordinary differential equation (ODE) solvers is not practically feasible, due to mathematical and numerical difficulties. This report demonstrates the theoretical feasibility of using model-based nonlinear state estimation techniques to obtain the angular and linear velocities in this problem. Practical numerical and calibration issues require additional work to resolve. We show that the six accelerometers in the DAIMU are not sufficient to provide observability, so additional measurements of the system states are required (e.g. from a Global Positioning System (GPS) unit). Given the constraint that our system cannot use GPS, we propose using the existing on-board 3-axis magnetometer to measure angular velocity. We further show that the six nonlinear ODE's for the vehicle kinematics can be decoupled into three ODE's in the angular velocity and three ODE's in the linear velocity. This allows us to formulate a three-state Gauss-Markov system model for the angular velocities, using the magnetometer signals in the measurement model. This re-formulated model is observable, allowing us to build an Extended Kalman Filter (EKF) for estimating the angular velocities. Given the angular velocity estimates from the EKF, the three ODE's for the linear velocity become algebraic, and the linear velocity can be calculated by numerical integration. Thus, we do not need direct measurements of the linear velocity to provide observability, and the technique is mathematically feasible. Using a simulation example, we show that the estimator adds value over the numerical ODE solver in the presence of measurement noise. Calculating the velocities in the presence of

  4. Numerical and experimental study of the thermal degradation process during the atmospheric re-entry of a TiAl6V4 tank

    NASA Astrophysics Data System (ADS)

    Prévereaud, Y.; Vérant, J.-L.; Balat-Pichelin, M.; Moschetta, J.-M.

    2016-05-01

    To answer the question of space debris survivability during atmospheric entry ONERA uses its software named MUSIC/FAST. So, the first part of this paper is dedicated to the presentation of the ONERA tool and its validation by comparison with flight data and CFD computations. However, the influence of oxidation on the thermal degradation process and material properties in atmospheric entry conditions is still unknown. A second step is then devoted to the presentation of an experimental campaign investigating TA6V oxidation in atmospheric entry conditions, as the most of the debris found on ground are made of this material. Experiments have been realized using the MESOX facility implemented at the 6 kW solar furnace in PROMES-CNRS laboratory. Finally, an application of MUSIC/FAST is proposed on the atmospheric re-entry of a generic TA6V tank. Aiming at degradation assessment, a sensitive study to initial conditions is conducted. To complete computational analysis regarding degradation process by melting, a numerical analysis of the influence of oxidation on the thermal wall degradation during the tank atmospheric re-entry is presented as well.

  5. Facilitation of school re-entry and peer acceptance of children with cancer: a review and meta-analysis of intervention studies.

    PubMed

    Helms, A S; Schmiegelow, K; Brok, J; Johansen, C; Thorsteinsson, T; Simovska, V; Larsen, H B

    2016-01-01

    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) discuss the importance of peer involvement in the treatment. Relevant databases were searched using equivalent search algorithms and six studies were selected that target children with cancer and/or their classmates. Two authors independently reviewed the literature for data extraction. The articles were reviewed using the PRISMA model for reporting reviews. Statistical calculations for the meta-analyses were done using Review Manager 5.2. The meta-analyses showed significant effects of school re-entry programmes in terms of enhancing academic achievement in children with cancer (P = 0.008) and lowering their levels of depression (P = 0.05). Increased knowledge among classmates was associated with less fear and a more positive attitude towards the child with cancer. Due to limited numbers of patients, lack of control groups, and the diversity of intervention strategies used in previous studies, there is a need for intervention programmes exploring the optimal path for the reintegration of children with cancer into the education system and into their peer groups.

  6. SiC/C Multi-Layered Sensor for Measurement of Recession Rate of Oxidation Protection Coating during Re-Entry from Space

    NASA Astrophysics Data System (ADS)

    Hatta, Hiroshi; Kawashima, Ayaka; Koyama, Masashi; Ookita, Hiroshi; Shiota, Ichiro

    In order to develop reusable space vehicle, it is important to ensure sufficient reliability of thermal protection systems under re-entry environments. For such a purpose, a sensor system to detect a recession rate of anti-oxidation SiC coating on carbon-carbon composite was attempted to be developed. This sensor consisted of multi-layered SiC/carbon coating on a SiC substrate, and high temperature oxidation damage of SiC in the multi-layered coating can be detected by the change of electric resistant of the coating caused by oxidation of carbon layers. In the present paper, conceptual design of the sensor was presented and several required technologies to develop the sensor were discussed. The discussion included how to form the multilayered coating and measuring technique of the electric resistance at high temperatures.

  7. African American Female Offender's Use of Alternative and Traditional Health Services After Re-Entry: Examining the Behavioral Model for Vulnerable Populations.

    PubMed

    Oser, Carrie B; Bunting, Amanda M; Pullen, Erin; Stevens-Watkins, Danelle

    2016-01-01

    This is the first known study to use the Gelberg-Andersen Behavioral Model for Vulnerable Populations to predict African American women's use of three types of health services (alternative, hospitalization, and ambulatory) in the 18 months after release from prison. In the multivariate models, the most robust predictors of all three types of service utilization were in the vulnerable theoretical domains. Alternative health services were predicted by ethnic community membership, higher religiosity, and HIV/HCV. Hospitalizations were predicted by the lack of barriers to health care and disability. Ambulatory office visits were predicted by more experiences of gendered racism, a greater number of physical health problems, and HIV/HCV. Findings highlight the importance of cultural factors and HIV/HCV in obtaining both alternative and formal health care during community re-entry. Clinicians and policymakers should consider the salient role that the vulnerable domain plays in offender's accessing health services.

  8. African American Female Offender's Use of Alternative and Traditional Health Services After Re-Entry: Examining the Behavioral Model for Vulnerable Populations.

    PubMed

    Oser, Carrie B; Bunting, Amanda M; Pullen, Erin; Stevens-Watkins, Danelle

    2016-01-01

    This is the first known study to use the Gelberg-Andersen Behavioral Model for Vulnerable Populations to predict African American women's use of three types of health services (alternative, hospitalization, and ambulatory) in the 18 months after release from prison. In the multivariate models, the most robust predictors of all three types of service utilization were in the vulnerable theoretical domains. Alternative health services were predicted by ethnic community membership, higher religiosity, and HIV/HCV. Hospitalizations were predicted by the lack of barriers to health care and disability. Ambulatory office visits were predicted by more experiences of gendered racism, a greater number of physical health problems, and HIV/HCV. Findings highlight the importance of cultural factors and HIV/HCV in obtaining both alternative and formal health care during community re-entry. Clinicians and policymakers should consider the salient role that the vulnerable domain plays in offender's accessing health services. PMID:27133515

  9. Detection of Acoustic/Infrasonic/Seismic Waves Generated by Hypersonic Re-Entry of the HAYABUSA Capsule and Fragmented Parts of the Spacecraft

    NASA Astrophysics Data System (ADS)

    Yamamoto, Masa-Yuki; Ishihara, Yoshiaki; Hiramatsu, Yoshihiro; Kitamura, Kazuki; Ueda, Masayoshi; Shiba, Yasuo; Furumoto, Muneyoshi; Fujita, Kazuhisa

    2011-10-01

    Acoustic/infrasonic/seismic waves were observed during the re-entry of the Japanese asteroid explorer ``HAYABUSA'' at 6 ground sites in Woomera, Australia, on 2010 June 13. Overpressure values of infrasound waves were detected at 3 ground sites in a range from 1.3 Pa, 1.0 Pa, and 0.7 Pa with each distance of 36.9 km, 54.9 km, and 67.8 km, respectively, apart from the SRC trajectory. Seismic waveforms through air-to-ground coupling processes were also detected at 6 sites, showing a one-to-one correspondence to infrasound waves at all simultaneous observation sites. Audible sound up to 1 kHz was recorded at one site with a distance of 67.8 km. The mother spacecraft was fragmented from 75 km down to 38 km with a few explosive enhancements of emissions. A persistent train of HAYABUSA re-entry was confirmed at an altitude range of between 92 km down to 82 km for about 3 minutes. Light curves of 136 fragmented parts of the spacecraft were analyzed in detail based on video observations taken at multiple ground sites, being classified into three types of fragmentations, i.e., melting, explosive, and re-fragmented types. In a comparison between infrasonic waves and video-image analyses, regarding the generation of sonic-boom type shock waves by hypersonically moving artificial meteors, both the sample return capsule and fragmented parts of the mother spacecraft, at an altitude of 40 ± 1 km were confirmed with a one-to-one correspondence with each other.

  10. Varying types of circus movement re-entry with both normal and dissociated contralateral conduction causing different right and left atrial rhythms in canine atrial flutter.

    PubMed

    Yamauchi, S; Boineau, J P; Schuessler, R B; Cox, J L

    1998-03-01

    The purpose of this study was to develop an animal model of atrial flutter (AFL) or fibrillation (AFB) and to determine precisely the pathway of atrial activation during arrhythmias induced by programmed stimulation. In 10 dogs, a shunt from the left subclavian artery to the left upper pulmonary vein was created to produce left atrial enlargement. Five months later, using programmed electrical stimulation, it was possible to induce 17 sustained atrial tachycardias in 9 of the 10 dogs, including 9 episodes of AFL caused by circus movement re-entry, 6 episodes of focal tachycardia, and 2 episodes of AFB. Short cycle length left atrial tachycardias caused by either circus movement or a focus did not propagate in a uniform 1:1 pattern to the right atrium (RA), resulting in RA dissociation. In these arrhythmias, complex wavefronts from both current and preceding left atrial cycles coexisted in the RA. Circus movement was associated with a spectrum of different re-entrant pathways with different path lengths. These differences in the path length were determined by various ways in which obstacles such as the superior vena cava and orifice of the right atrial appendage or pulmonary vein orifices were combined by contiguous areas of functional block.

  11. Treatment of a large periradicular defect using guided tissue regeneration: A case report of 2 years follow-up and surgical re-entry

    PubMed Central

    Gurav, Abhijit Ningappa; Shete, Abhijeet Rajendra; Naiktari, Ritam

    2015-01-01

    Periradicular (PR) bone defects are common sequelae of chronic endodontic lesions. Sometimes, conventional root canal therapy is not adequate for complete resolution of the lesion. PR surgeries may be warranted in such selected cases. PR surgery provides a ready access for the removal of pathologic tissue from the periapical region, assisting in healing. Recently, the regeneration of the destroyed PR tissues has gained more attention rather than repair. In order to promote regeneration after apical surgery, the principle of guided tissue regeneration (GTR) has proved to be useful. This case presents the management of a large PR lesion in a 42-year-old male subject. The PR lesion associated with 21, 11 and 12 was treated using GTR membrane, fixated with titanium minipins. The case was followed up for 2 years radiographically, and a surgical re-entry confirmed the re-establishment of the lost labial plate. Thus, the principle of GTR may immensely improve the clinical outcome and prognosis of an endodontically involved tooth with a large PR defect. PMID:26941526

  12. Implications of the Turing completeness of reaction-diffusion models, informed by GPGPU simulations on an XBox 360: cardiac arrhythmias, re-entry and the Halting problem.

    PubMed

    Scarle, Simon

    2009-08-01

    In the arsenal of tools that a computational modeller can bring to bare on the study of cardiac arrhythmias, the most widely used and arguably the most successful is that of an excitable medium, a special case of a reaction-diffusion model. These are used to simulate the internal chemical reactions of a cardiac cell and the diffusion of their membrane voltages. Via a number of different methodologies it has previously been shown that reaction-diffusion systems are at multiple levels Turing complete. That is, they are capable of computation in the same manner as a universal Turing machine. However, all such computational systems are subject to a limitation known as the Halting problem. By constructing a universal logic gate using a cardiac cell model, we highlight how the Halting problem therefore could limit what it is possible to predict about cardiac tissue, arrhythmias and re-entry. All simulations for this work were carried out on the GPU of an XBox 360 development console, and we also highlight the great gains in computational power and efficiency produced by such general purpose processing on a GPU for cardiac simulations.

  13. Caenorhabditis elegans Cyclin D/CDK4 and Cyclin E/CDK2 Induce Distinct Cell Cycle Re-Entry Programs in Differentiated Muscle Cells

    PubMed Central

    Korzelius, Jerome; The, Inge; Ruijtenberg, Suzan; Prinsen, Martine B. W.; Portegijs, Vincent; Middelkoop, Teije C.; Groot Koerkamp, Marian J.; Holstege, Frank C. P.; Boxem, Mike; van den Heuvel, Sander

    2011-01-01

    Cell proliferation and differentiation are regulated in a highly coordinated and inverse manner during development and tissue homeostasis. Terminal differentiation usually coincides with cell cycle exit and is thought to engage stable transcriptional repression of cell cycle genes. Here, we examine the robustness of the post-mitotic state, using Caenorhabditis elegans muscle cells as a model. We found that expression of a G1 Cyclin and CDK initiates cell cycle re-entry in muscle cells without interfering with the differentiated state. Cyclin D/CDK4 (CYD-1/CDK-4) expression was sufficient to induce DNA synthesis in muscle cells, in contrast to Cyclin E/CDK2 (CYE-1/CDK-2), which triggered mitotic events. Tissue-specific gene-expression profiling and single molecule FISH experiments revealed that Cyclin D and E kinases activate an extensive and overlapping set of cell cycle genes in muscle, yet failed to induce some key activators of G1/S progression. Surprisingly, CYD-1/CDK-4 also induced an additional set of genes primarily associated with growth and metabolism, which were not activated by CYE-1/CDK-2. Moreover, CYD-1/CDK-4 expression also down-regulated a large number of genes enriched for catabolic functions. These results highlight distinct functions for the two G1 Cyclin/CDK complexes and reveal a previously unknown activity of Cyclin D/CDK-4 in regulating metabolic gene expression. Furthermore, our data demonstrate that many cell cycle genes can still be transcriptionally induced in post-mitotic muscle cells, while maintenance of the post-mitotic state might depend on stable repression of a limited number of critical cell cycle regulators. PMID:22102824

  14. Spectroscopic Observation of the Stardust Re-Entry in the Near UV with SLIT: Deduction of Surface Temperatures and Plasma Radiation

    NASA Technical Reports Server (NTRS)

    Winter, Michael W.; Trumble, Kerry A.

    2010-01-01

    Thermal radiation of the heat-shield and the emission of the post-shock layer around the Stardust capsule, during its re-entry, were detected by a NASA-led observation campaign aboard NASA's DC-8 airborne observatory involving teams from several nations. The German SLIT experiment used a conventional spectrometer, in a Czerny-Turner configuration (300 mm focal length and a 600 lines/mm grating), fed by fiber optics, to cover a wavelength range from 324 nm to 456 nm with a pixel resolution of 0.08 nm. The reentering spacecraft was tracked m uansuinaglly a camera with a view angle of 20 degrees, and light from the capsule was collected using a small mirror telescope with a view angle of only 0.45 degrees. Data were gathered with a measurement frequency of 5 Hz in a 30-second time interval around the point of maximum heating until the capsule left the field of view. The emission of CN (as a major ablation product), N2(+) and different atoms were monitored successfully during that time. Due to the nature of the experimental set up, spatial resolution of the radiation field was not possible. Therefore, all measured values represent an integration of radiation from the visible part of the glowing heat shield, and from the plasma in the post-shock region. Further, due to challenges in tracking not every spectrum gathered contained data. The measured spectra can be split up into two parts: (i) continuum spectra which represent a superposition of the heat shield radiation and the continuum radiation of potential dust particles in the plasma, and (ii) line spectra from the plasma in the shock layer. Planck temperatures (interpreted as the surface temperatures of the Stardust heat shield) were determined assuming either a constant surface temperature, or a temperature distribution deduced from numerical simulation. The constant surface temperatures are in good agreement with numerical simulations, but the peak values at the stagnation point are significantly lower than those

  15. The endocrine dyscrasia that accompanies menopause and andropause induces aberrant cell cycle signaling that triggers re-entry of post-mitotic neurons into the cell cycle, neurodysfunction, neurodegeneration and cognitive disease.

    PubMed

    Atwood, Craig S; Bowen, Richard L

    2015-11-01

    This article is part of a Special Issue "SBN 2014". Sex hormones are physiological factors that promote neurogenesis during embryonic and fetal development. During childhood and adulthood these hormones support the maintenance of brain structure and function via neurogenesis and the formation of dendritic spines, axons and synapses required for the capture, processing and retrieval of information (memories). Not surprisingly, changes in these reproductive hormones that occur with menopause and during andropause are strongly correlated with neurodegeneration and cognitive decline. In this connection, much evidence now indicates that Alzheimer's disease (AD) involves aberrant re-entry of post-mitotic neurons into the cell cycle. Cell cycle abnormalities appear very early in the disease, prior to the appearance of plaques and tangles, and explain the biochemical, neuropathological and cognitive changes observed with disease progression. Intriguingly, a recent animal study has demonstrated that induction of adult neurogenesis results in the loss of previously encoded memories while decreasing neurogenesis after memory formation during infancy mitigated forgetting. Here we review the biochemical, epidemiological and clinical evidence that alterations in sex hormone signaling associated with menopause and andropause drive the aberrant re-entry of post-mitotic neurons into an abortive cell cycle that leads to neurite retraction, neuron dysfunction and neuron death. When the reproductive axis is in balance, gonadotropins such as luteinizing hormone (LH), and its fetal homolog, human chorionic gonadotropin (hCG), promote pluripotent human and totipotent murine embryonic stem cell and neuron proliferation. However, strong evidence supports menopausal/andropausal elevations in the LH:sex steroid ratio as driving aberrant mitotic events. These include the upregulation of tumor necrosis factor; amyloid-β precursor protein processing towards the production of mitogenic Aβ; and

  16. Ringo/cyclin-dependent kinase and mitogen-activated protein kinase signaling pathways regulate the activity of the cell fate determinant Musashi to promote cell cycle re-entry in Xenopus oocytes.

    PubMed

    Arumugam, Karthik; MacNicol, Melanie C; Wang, Yiying; Cragle, Chad E; Tackett, Alan J; Hardy, Linda L; MacNicol, Angus M

    2012-03-23

    Cell cycle re-entry during vertebrate oocyte maturation is mediated through translational activation of select target mRNAs, culminating in the activation of mitogen-activated protein kinase and cyclin B/cyclin-dependent kinase (CDK) signaling. The temporal order of targeted mRNA translation is crucial for cell cycle progression and is determined by the timing of activation of distinct mRNA-binding proteins. We have previously shown in oocytes from Xenopus laevis that the mRNA-binding protein Musashi targets translational activation of early class mRNAs including the mRNA encoding the Mos proto-oncogene. However, the molecular mechanism by which Musashi function is activated is unknown. We report here that activation of Musashi1 is mediated by Ringo/CDK signaling, revealing a novel role for early Ringo/CDK function. Interestingly, Musashi1 activation is subsequently sustained through mitogen-activated protein kinase signaling, the downstream effector of Mos mRNA translation, thus establishing a positive feedback loop to amplify Musashi function. The identified regulatory sites are present in mammalian Musashi proteins, and our data suggest that phosphorylation may represent an evolutionarily conserved mechanism to control Musashi-dependent target mRNA translation.

  17. Dynamics of atmospheric re-entry

    NASA Astrophysics Data System (ADS)

    Regan, Frank J.; Anandakrishnan, Satya M.

    1993-03-01

    The present volume on dynamics of atmospheric reentry is an extention of the original book, Reentry Vehicle Dynamics. Topics addressed include atmospheric models, earth's form and gravitational field, axis transformations, force and moment equations, Keplerian motion, reentry vehicle particle mechanics, decoys and the identification of reentry vehicles, and particle motion in maneuvering reentry vehicles. Attention is also given to angular motion during the exoatmospheric (Keplerian) phase, a flowfield description, angular motion during reentry, error analysis, and inertial guidance.

  18. Re-Entry Women: Annotated Bibliography.

    ERIC Educational Resources Information Center

    Porterfield, Patricia Lamb

    This is an annotated bibliography on topics related to reentry women. Topic categories include general and administrative issues, programs and services, needs assessment and evaluation, counseling and personal development, career planning and job placement, curriculum and instruction, admissions and recruiting, and financial aid. Annotations cite…

  19. Re-entry survivability and risk

    NASA Astrophysics Data System (ADS)

    Fudge, Michael L.

    1998-11-01

    This paper is the culmination of the research effort which was reported on last year while still in-progress. As previously reported, statistical methods for expressing the impact risk posed to space systems in general [and the International Space Station (ISS) in particular] by other resident space objects have been examined. One of the findings of this investigation is that there are legitimate physical modeling reasons for the common statistical expression of the collision risk. A combination of statistical methods and physical modeling is also used to express the impact risk posed by reentering space systems to objects of interest (e.g., people and property) on Earth. One of the largest uncertainties in the expressing of this risk is the estimation of survivable material which survives reentry to impact Earth's surface. This point was demonstrated in dramatic fashion in January 1997 by the impact of an intact expendable launch vehicle (ELV) upper stage near a private residence in the continental United States. Since approximately half of the missions supporting ISS will utilize ELVs, it is appropriate to examine the methods used to estimate the amount and physical characteristics of ELV debris surviving reentry to impact Earth's surface. This report details reentry survivability estimation methodology, including the specific methodology used by ITT Systems' (formerly Kaman Sciences) 'SURVIVE' model. The major change to the model in the last twelve months has been the increase in the fidelity with which upper- atmospheric aerodynamics has been modeled. This has resulted in an adjustment in the factor relating the amount of kinetic energy loss to the amount of heating entering and reentering body, and also validated and removed the necessity for certain empirically-based adjustments made to the theoretical heating expressions. Comparisons between empirical results (observations of objects which have been recovered on Earth after surviving reentry) and SURVIVE estimates are presented for selected generic upper stage or spacecraft components, a Soyuz launch vehicle second stage, and for a Delta II launch vehicle second stage and its significant components. Significant similarity is demonstrated between the type and dispersion pattern of the recovered debris from the January 1997 Delta II 2nd stage event and the simulation of that reentry and breakup.

  20. A new Green's function Monte Carlo algorithm for the solution of the two-dimensional nonlinear Poisson–Boltzmann equation: Application to the modeling of the communication breakdown problem in space vehicles during re-entry

    SciTech Connect

    Chatterjee, Kausik; Roadcap, John R.; Singh, Surendra

    2014-11-01

    The objective of this paper is the exposition of a recently-developed, novel Green's function Monte Carlo (GFMC) algorithm for the solution of nonlinear partial differential equations and its application to the modeling of the plasma sheath region around a cylindrical conducting object, carrying a potential and moving at low speeds through an otherwise neutral medium. The plasma sheath is modeled in equilibrium through the GFMC solution of the nonlinear Poisson–Boltzmann (NPB) equation. The traditional Monte Carlo based approaches for the solution of nonlinear equations are iterative in nature, involving branching stochastic processes which are used to calculate linear functionals of the solution of nonlinear integral equations. Over the last several years, one of the authors of this paper, K. Chatterjee has been developing a philosophically-different approach, where the linearization of the equation of interest is not required and hence there is no need for iteration and the simulation of branching processes. Instead, an approximate expression for the Green's function is obtained using perturbation theory, which is used to formulate the random walk equations within the problem sub-domains where the random walker makes its walks. However, as a trade-off, the dimensions of these sub-domains have to be restricted by the limitations imposed by perturbation theory. The greatest advantage of this approach is the ease and simplicity of parallelization stemming from the lack of the need for iteration, as a result of which the parallelization procedure is identical to the parallelization procedure for the GFMC solution of a linear problem. The application area of interest is in the modeling of the communication breakdown problem during a space vehicle's re-entry into the atmosphere. However, additional application areas are being explored in the modeling of electromagnetic propagation through the atmosphere/ionosphere in UHF/GPS applications.

  1. A new Green's function Monte Carlo algorithm for the solution of the two-dimensional nonlinear Poisson-Boltzmann equation: Application to the modeling of the communication breakdown problem in space vehicles during re-entry

    NASA Astrophysics Data System (ADS)

    Chatterjee, Kausik; Roadcap, John R.; Singh, Surendra

    2014-11-01

    The objective of this paper is the exposition of a recently-developed, novel Green's function Monte Carlo (GFMC) algorithm for the solution of nonlinear partial differential equations and its application to the modeling of the plasma sheath region around a cylindrical conducting object, carrying a potential and moving at low speeds through an otherwise neutral medium. The plasma sheath is modeled in equilibrium through the GFMC solution of the nonlinear Poisson-Boltzmann (NPB) equation. The traditional Monte Carlo based approaches for the solution of nonlinear equations are iterative in nature, involving branching stochastic processes which are used to calculate linear functionals of the solution of nonlinear integral equations. Over the last several years, one of the authors of this paper, K. Chatterjee has been developing a philosophically-different approach, where the linearization of the equation of interest is not required and hence there is no need for iteration and the simulation of branching processes. Instead, an approximate expression for the Green's function is obtained using perturbation theory, which is used to formulate the random walk equations within the problem sub-domains where the random walker makes its walks. However, as a trade-off, the dimensions of these sub-domains have to be restricted by the limitations imposed by perturbation theory. The greatest advantage of this approach is the ease and simplicity of parallelization stemming from the lack of the need for iteration, as a result of which the parallelization procedure is identical to the parallelization procedure for the GFMC solution of a linear problem. The application area of interest is in the modeling of the communication breakdown problem during a space vehicle's re-entry into the atmosphere. However, additional application areas are being explored in the modeling of electromagnetic propagation through the atmosphere/ionosphere in UHF/GPS applications.

  2. Second-order analytic solutions for re-entry trajectories

    NASA Astrophysics Data System (ADS)

    Kim, Eun-Kyou

    1993-01-01

    With the development of aeroassist technology, either for near-earth orbital transfer with or without a plane change or for planetary aerocapture, it is of interest to have accurate analytic solutions for reentry trajectories in an explicit form. Starting with the equations of motion of a non-thrusting aerodynamic vehicle entering a non-rotating spherical planetary atmosphere, a normalization technique is used to transform the equations into a form suitable for an analytic integration. Then, depending on the type of planar entry modes with a constant angle-of-attack, namely, ballistic fly-through, lifting skip, and equilibrium glide trajectories, the first-order solutions are obtained with the appropriate simplification. By analytic continuation, the second-order solutions for the altitude, speed, and flight path angle are derived. The closed form solutions lead to explicit forms for the physical quantities of interest, such as the deceleration and aerodynamic heating rates. The analytic solutions for the planar case are extended to three-dimensional skip trajectories with a constant bank angle. The approximate solutions for the heading and latitude are developed to the second order. In each type of trajectory examined, explicit relations among the principal variables are in a form suitable for guidance and navigation purposes. The analytic solutions have excellent agreement with the numerical integrations. They also provide some new results which were not reported in the existing classical theory.

  3. The secret of guided missile re-entry

    NASA Astrophysics Data System (ADS)

    Chen, Jingzhong; An, Sehua

    1986-06-01

    The history and development of reentry vehicles especially as related to guided missiles is studied. The development of fiber reinforced composites to avoid the combustion of reentry vehicle heads is described. The ionization of molecules caused by high temperature friction with the air during high speed reeentry is briefly described. Reentry remote sensing as an important basis for developing configuration and predicting accuracy of point of impact of the guided missile is also discussed.

  4. Coiled tubing used for slim hole re-entry

    SciTech Connect

    Traonmilin, E. ); Newman, K. )

    1992-02-17

    A coiled tubing unit with slim hole tools successfully re-entered and cored an existing Elf Aquitaine vertical well in the Paris basin in France. This experiment proved that coiled tubing could be used to drill, core, and test a slim hole well. Elf Aquitaine studied the use of coiled tubing for drilling inexpensive exploration wells in the Paris basin. As a result of this study, Elf believed that coiled tubing exploration drilling could significantly reduce exploration costs. This paper reports on a number of questions raised by this study: Can coiled tubing be used effectively to drill slim open hole How would the drilling rate compare with that of a conventional drilling rig If the rate were too slow, coiled tubing might not be economical. Can a straight vertical well be drilled Coiled tubing pipe has a residual curvature from bending over the reel and gooseneck. Will this curvature make it impossible to drill straight Can the coiled tubing also be used to take cores Once the hole is drilled, can it be tested with coiled tubing

  5. ARV Re-Entry Module Aerodynmics And Aerothermodynamics

    NASA Astrophysics Data System (ADS)

    Scheer, Heloise; Tran, Philippe; Berthe, Philippe

    2011-05-01

    Astrium-ST is the prime contractor of ARV phase A and is especially in charge of designing the Reentry Module (RM). The RM aeroshape has been defined following a trade-off. High level system requirements were derived with particular attention paid on minimum lift-over-drag ratio, trim incidence, centre-of-gravity lateral off-set and box size, volumetric efficiency, attitude at parachute deployment, flight heritage and aeroheating. Since moderate cross-range and thus L/D ratio were required, the aeroshape trade-off has been performed among blunt capsule candidates. Two front- shield families were considered: spherical (Apollo/ARD/Soyuz type) and sphero-conical (CTV type) segment front-shield. The rear-cone angle was set to 20° for internal pressurized volume and accommodation purposes. Figures of merit were assessed and a spherical front- shield of ARD type with a 20° rear-cone section was selected and proposed for further investigations. Maximum benefits will be taken from ARD flight heritage. CFD and WTT campaigns plans will be presented including preliminary results.

  6. STS-107 Debris Characterization Using Re-entry Imaging

    NASA Technical Reports Server (NTRS)

    Raiche, George A.

    2009-01-01

    Analysis of amateur video of the early reentry phases of the Columbia accident is discussed. With poor video quality and little theoretical guidance, the analysis team estimated mass and acceleration ranges for the debris shedding events observed in the video. Camera calibration and optical performance issues are also described.

  7. Re-Entry Simulation and Landing Area for YES2

    NASA Technical Reports Server (NTRS)

    Calzada, Silvia

    2005-01-01

    The REST simulator includes many parameters: a) Inertial <-> Fix to Earth reference system; b) Geodetic <-> Geocentric coordinates; c) Rotational velocity of the Atmosphere; d) Effect of the rotation of the Earth; e) Bulge effect of the Earth; f) Spherical harmonic expansion for the Earth s gravitational potential, J2 (zonal); g) Heat flux, temperature in the wall; h) Drag coefficient for different regimes; i) Flow regime status; j) Density model NRLMSISE-00; k) Wind model HWM-93; l) G2S atmospheric model with the latest meteorological conditions and m) Landing area (Monte Carlo Simulations)

  8. Secondary Level Re-Entry of Young Canadian Adult Learners

    ERIC Educational Resources Information Center

    MacGregor, Cassandra; Ryan, Thomas G.

    2011-01-01

    This paper illuminates and details some of the traits, pressures and semi-autonomy of the young adult between the ages of 18 and 24 who must confront the barriers and challenges upon returning to secondary school within the high school and the adult education centre context. Focusing on these young adults is fundamentally important to begin to…

  9. Thermal Analysis of Small Re-Entry Probe

    NASA Technical Reports Server (NTRS)

    Agrawal, Parul; Prabhu, Dinesh K.; Chen, Y. K.

    2012-01-01

    The Small Probe Reentry Investigation for TPS Engineering (SPRITE) concept was developed at NASA Ames Research Center to facilitate arc-jet testing of a fully instrumented prototype probe at flight scale. Besides demonstrating the feasibility of testing a flight-scale model and the capability of an on-board data acquisition system, another objective for this project was to investigate the capability of simulation tools to predict thermal environments of the probe/test article and its interior. This paper focuses on finite-element thermal analyses of the SPRITE probe during the arcjet tests. Several iterations were performed during the early design phase to provide critical design parameters and guidelines for testing. The thermal effects of ablation and pyrolysis were incorporated into the final higher-fidelity modeling approach by coupling the finite-element analyses with a two-dimensional thermal protection materials response code. Model predictions show good agreement with thermocouple data obtained during the arcjet test.

  10. Re-entry vehicle shape for enhanced performance

    NASA Technical Reports Server (NTRS)

    Brown, James L. (Inventor); Garcia, Joseph A. (Inventor); Prabhu, Dinesh K. (Inventor)

    2008-01-01

    A convex shell structure for enhanced aerodynamic performance and/or reduced heat transfer requirements for a space vehicle that re-enters an atmosphere. The structure has a fore-body, an aft-body, a longitudinal axis and a transverse cross sectional shape, projected on a plane containing the longitudinal axis, that includes: first and second linear segments, smoothly joined at a first end of each the first and second linear segments to an end of a third linear segment by respective first and second curvilinear segments; and a fourth linear segment, joined to a second end of each of the first and second segments by curvilinear segments, including first and second ellipses having unequal ellipse parameters. The cross sectional shape is non-symmetric about the longitudinal axis. The fourth linear segment can be replaced by a sum of one or more polynomials, trigonometric functions or other functions satisfying certain constraints.

  11. An uncommon case of spontaneous conversion from AV re-entry tachycardia to AV nodal re-entry tachycardia in a patient with dual tachycardia.

    PubMed

    Zeljković, Ivan; Benko, Ivica; Manola, Šime; Radeljić, Vjekoslav; Pavlović, Nikola

    2015-01-01

    We report the case of a 46-year old patient in whom an electrophysiology study (EP) was performed due to paroxysmal supraventricular tachycardia documented in 12-lead ECG. During the EP study, supraventricular tachycardia was induced easily and it corresponded to orthodromic AV reentry tachycardia (AVRT) using a concealed left free wall accessory pathway. However, during the study AVRT spontaneously and repeatedly converted to the typical slow-fast AV node reentry tachycardia (AVNRT). Both accessory and AV nodal slow pathways were ablated, due to the finding that both AVRT and AVNRT were independently inducible during the EP study. PMID:27134441

  12. An uncommon case of spontaneous conversion from AV re-entry tachycardia to AV nodal re-entry tachycardia in a patient with dual tachycardia

    PubMed Central

    Zeljković, Ivan; Benko, Ivica; Manola, Šime; Radeljić, Vjekoslav; Pavlović, Nikola

    2016-01-01

    We report the case of a 46-year old patient in whom an electrophysiology study (EP) was performed due to paroxysmal supraventricular tachycardia documented in 12-lead ECG. During the EP study, supraventricular tachycardia was induced easily and it corresponded to orthodromic AV reentry tachycardia (AVRT) using a concealed left free wall accessory pathway. However, during the study AVRT spontaneously and repeatedly converted to the typical slow-fast AV node reentry tachycardia (AVNRT). Both accessory and AV nodal slow pathways were ablated, due to the finding that both AVRT and AVNRT were independently inducible during the EP study. PMID:27134441

  13. Simulators for the X-38/CRV Parafoil and Re-Entry Phases

    NASA Technical Reports Server (NTRS)

    Delgado, Frank J.; Arcioni, Marco

    2000-01-01

    The X38/CRV is unique in several aspects: it does not afford the pilot a forward view through a window and it utilizes a parafoil in the final landing flight phase. As a result of some of these unique attributes the prototype on-board displays will need to provide enhanced situation awareness to aid a crew member in supervising the onboard GNC software to select a landing site, and possible obstacle avoidance during the final flight phase. In the ESA/ESTEC visualization prototype system the scene is visualized using MultiGen OpenFlight models on high-end SGI machines. The Parafoil Guidance Navigation and Control (PGNC) algorithms are being developed as a joint NASA/ESA venture. These algorithms will be used onboard the vehicle to create nominal flight trajectories for the vehicle to follow. These same algorithms are also used as parafoil simulators in our augmented situation awareness system we are developing. The output of the parafoil simulator is displayed on a Windows-based computer running the LandForm FlightVision software. The FlightVision software is used to create the synthetic environment displays and all the necessary HUD symbology. Maps, such as aeronautical charts, as well as satellite imagery are optionally overlaid on the 3D-terrain model to provide additional situation awareness for the crew.

  14. Astrometric and Photometric Analysis of the September 2008 ATV-1 Re-Entry Event

    NASA Technical Reports Server (NTRS)

    Mulrooney, Mark K.; Barker, Edwin S.; Maley, Paul D.; Beaulieu, Kevin R.; Stokely, Christopher L.

    2008-01-01

    NASA utilized Image Intensified Video Cameras for ATV data acquisition from a jet flying at 12.8 km. Afterwards the video was digitized and then analyzed with a modified commercial software package, Image Systems Trackeye. Astrometric results were limited by saturation, plate scale, and imposed linear plate solution based on field reference stars. Time-dependent fragment angular trajectories, velocities, accelerations, and luminosities were derived in each video segment. It was evident that individual fragments behave differently. Photometric accuracy was insufficient to confidently assess correlations between luminosity and fragment spatial behavior (velocity, deceleration). Use of high resolution digital video cameras in future should remedy this shortcoming.

  15. Psychosocial needs of HIV-positive individuals seeking workforce re-entry.

    PubMed

    Arns, P G; Martin, D J; Chernoff, R A

    2004-04-01

    With the advent of more effective treatments and corresponding improvement in morbidity and mortality, people living with HIV and AIDS are increasingly considering a return to the workplace. This study examined subjective and objective indicators of need among a sample of 235 HIV-infected individuals entering a vocational rehabilitation programme for people with HIV. In addition to help with training and job placement, participants indicated a need for assistance with finances, money management, housing access and access to health care, as well as with alcohol or drug problems, legal problems and social relationships. Subsequent to learning of their diagnoses, the sample reported a median decrement in financial resources of 60%. Over half had experienced housing instability in the year prior to entering the study, including 15% who had been homeless, even though most were linked to case management services. A third had used illegal drugs in the prior month, 41% drank to intoxication and 20% lacked even monthly phone contact with friends. Results suggest that back to work programmes for people with HIV and AIDS will need to address a broad range of psychosocial issues beyond job training and placement. PMID:15203430

  16. Rudder/Fin Seal Investigations for the X-38 Re-Entry Vehicle

    NASA Technical Reports Server (NTRS)

    Dunlap, Patrick H., Jr.; Steinetz, Bruce M.; Curry, Donald M.

    2000-01-01

    NASA is currently developing the X-38 vehicle that will be used to demonstrate the technologies required for a crew return vehicle (CRV) for the International Space Station. The X-38 control surfaces require high temperature seals to limit hot gas ingestion and transfer of heat to underlying low-temperature structures to prevent over-temperature of these structures and possible loss of the vehicle. This paper presents results for thermal analyses and flow and compression tests conducted on as-received and thermally exposed seals for the rudder/fin location of the X-38. A thermal analysis of the rudder/fin dual seal assembly based on representative heating rates on the windward surface of the rudder/fin area predicted a peak seal temperature of 1900 F. The temperature-exposed seals were heated in a compressed state at 1900 F corresponding to the predicted peak temperature. Room temperature compression tests were performed to determine load versus linear compression, preload, contact area, stiffness, and resiliency characteristics for the as-received and temperature-exposed seals. Temperature exposure resulted in permanent set and loss of resiliency in these seals. Unit loads and contact pressures for the seals were below the five pounds/inch and ten psi limits set to limit the loads on the Shuttle thermal tiles that the seals seal against in the rudder/fin location. Measured seal flow rates for a double seal were about 4.5 times higher than the preliminary seal flow goal. The seal designs examined in this study are expected to be able to endure the high temperatures that they will be exposed to for a single-use life. Tests performed herein combined with future analyses, arc jet tests, and scrubbing tests will be used to select the final seal design for this application.

  17. Rudder/Fin Seal Investigations for the X-38 Re-Entry Vehicle

    NASA Technical Reports Server (NTRS)

    Dunlap, Patrick H., Jr.; Steinetz, Bruce M.; Curry, Donald M.

    2000-01-01

    NASA is currently developing the X-38 vehicle that will be used to demonstrate the technologies required for a crew return vehicle (CRV) for the International Space Station. The X-38 control surfaces require high temperature seals to limit hot gas ingestion and transfer of heat to underlying low-temperature structures to prevent over-temperature of these structures and possible loss of the vehicle. This paper presents results for thermal analyses and flow and compression tests conducted on as-received and thermally exposed seals for the rudder/fin location of the X-38. A thermal analysis of the rudder/fin dual seal assembly based on representative heating rates on the windward surface of the rudder/fin area predicted a peak seal temperature of 1900 F. The temperature-exposed seals were heated in a compressed state at 1900 F corresponding to the predicted peak temperature. Room temperature compression tests were performed to determine load versus linear compression, preload, contact area, stiffness, and resiliency characteristics for the as-received and temperature-exposed seals. Temperature exposure resulted in permanent set and loss of resiliency in these seals. Unit loads and contact pressures for the seals were below the 5 lb/in. and 10 psi limits set to limit the loads on the Shuttle thermal tiles that the seals seal against in the rudder/fin location. Measured seal flow rates for a double seal were about 4.5 times higher than the preliminary seal flow goal. The seal designs examined in this study are expected to be able to endure the high temperatures that they will be exposed to for a single-use life. Tests performed herein combined with future analyses, arc jet tests, and scrubbing tests will be used to select the final seal design for this application.

  18. Current Status on Radiation Modeling for the Hayabusa Re-entry

    NASA Technical Reports Server (NTRS)

    Winter, Michael W.; McDaniel, Ryan D.; Chen, Yih-Kang; Liu, Yen; Saunders, David

    2011-01-01

    On June 13, 2010 the Japanese Hayabusa capsule performed its reentry into the Earths atmosphere over Australia after a seven year journey to the asteroid Itokawa. The reentry was studied by numerous imaging and spectroscopic instruments onboard NASA's DC-8 Airborne Laboratory and from three sites on the ground, in order to measure surface and plasma radiation generated by the Hayabusa Sample Return Capsule (SRC). Post flight, the flow solutions were recomputed to include the whole flow field around the capsule at 11 points along the reentry trajectory using updated trajectory information. Again, material response was taken into account to obtain most reliable surface temperature information. These data will be used to compute thermal radiation of the glowing heat shield and plasma radiation by the shock/post-shock layer system to support analysis of the experimental observation data. For this purpose, lines of sight data are being extracted from the flow field volume grids and plasma radiation will be computed using NEQAIR [4] which is a line-by-line spectroscopic code with one-dimensional transport of radiation intensity. The procedures being used were already successfully applied to the analysis of the observation of the Stardust reentry [5].

  19. Navigation support for the Salyut-7/Kosmos-1686 orbiting complex near re-entry

    NASA Astrophysics Data System (ADS)

    Lobachev, V.; Pochukaev, V.; Ivanov, N.; Dzesov, R.; Bidenko, N.; Iastrebov, V.; Glotov, V.; Zhukov, V.; Korsakov, V.; Kir'anov, V.

    In 1986, the 40 ton composite spacecraft (Salyut-7/Kosmos-1686) was raised to a higher altitude which was deemed sufficient to survive the peak solar activity of cycle 22. Atmospheric drag effects proved greater than expected and the vehicle reentered the earth's atmosphere on February 7, 1991. The navigation support provided by the mission control center in this final phase, during which the spacecraft complex was only partially controllable, is described.

  20. Adult Re-Entry Students: Experiences Preceding Entry into a Rural Appalachian Community College

    ERIC Educational Resources Information Center

    Genco, Jessica T.

    2007-01-01

    Mountain Empire Community College (MECC)'s service region covers the extreme southwestern corner of Virginia and includes four counties and one city: Dickenson, Lee, Scott, and Wise Counties, and the city of Norton. With a service region population of 93,000 residents, MECC currently serves over 5,000 students annually (Mountain Empire Community…

  1. Improving Career Re-entry Outcomes for People with Multiple Sclerosis: A Comparison of Two Approaches.

    ERIC Educational Resources Information Center

    Rumrill, Phillip D.; Roessler, Richard T.; Cook, Bryan G.

    1998-01-01

    Reentry workers with multiple sclerosis (n=23) participated with employers and rehabilitation counselors in training seminars; 14 received traditional job search intervention. After 16 weeks, 11 of the 37 had reentered the labor force. Most already had high self-efficacy and career maturity. (SK)

  2. Numerical Study of Flow Augmented Thermal Management for Entry and Re-Entry Environments

    NASA Technical Reports Server (NTRS)

    Cheng, Gary C.; Neroorkar, Kshitij D.; Chen, Yen-Sen; Wang, Ten-See; Daso, Endwell O.

    2007-01-01

    The use of a flow augmented thermal management system for entry and re-entr environments is one method for reducing heat and drag loads. This concept relies on jet penetration from supersonic and hypersonic counterflowing jets that could significantly weaken and disperse the shock-wave system of the spacecraft flow field. The objective of this research effort is to conduct parametric studies of the supersonic flow over a 2.6% scale model of the Apollo capsule, with and without the counterflowing jet, using time-accurate and steady-state computational fluid dynamics simulations. The numerical studies, including different freestream Mach number angle of attack counterflowing jet mass flow rate, and nozzle configurations, were performed to examine their effect on the drag and beat loads and to explore the counternowing jet condition. The numerical results were compared with the test data obtained from transonic blow-down wind-tunnel experiments conducted independently at NASA MSFC.

  3. Advanced particulate fibrous composite for thermal control of re-entry vehicles

    NASA Technical Reports Server (NTRS)

    White, Susan; Lee, Siu-Chun; Grzesik, Jan

    1993-01-01

    Combining the selectively reflective properties of particulate reflective coatings with the low density and high temperature capability of ceramic fibrous materials results in a novel composite material with useful optical properties. Numerical predictions of the radiative properties of zirconia and silica composites for a range of mixture fractions and wavelengths show the improvements attainable by dispersing spheres throughout a fiber matrix. The radiation conductance is controlled by the percentage of spheres in the composite. Results show that specific wavelength domains are controlled by either the spheres or the fibers, so the optical properties can be tailored for reentry applications.

  4. Preparing Communities for Re-Entry of Offenders with Mental Illness: The ACTION Approach

    ERIC Educational Resources Information Center

    Vogel, Wendy M.; Noether, Chan D.; Steadman, Henry J.

    2007-01-01

    Approximately 900,000 people with active symptoms of serious mental illness are booked annually into U.S. jails. Of these, about three quarters have a co-occurring substance use disorder. When these people return to the community they have multiple, complex and interrelated treatment needs, which are often exacerbated by release into the…

  5. Spectroscopic Analysis Of The Hayabusa Re-Entry Using Airborne And Ground Based Equipment

    NASA Astrophysics Data System (ADS)

    Lohle, Stefan; Marynowski, Thomas; Mezger, Andreas

    2011-08-01

    The Hayabusa sample return capsule, which contained precious asteroid samples, re-entered the Earth’s atmosphere on June 13, 2010. An ablative carbon-phenolic thermal protection system (TPS) was used to enable a safe return for the small capsule and the containing samples. A research aircraft operated by NASA has been setup with a wide range of imaging and spectrographic cameras for remote sensing of the radiation of the Hayabusa capsule during its entry flight. We developed for this mission a new instrument aiming to measure the translational temperature from the line broadening of heated atmospheric gases in their plasma state. Therefore, a scanning Fabry-Perot interferometer was setup aboard the aircraft. Using an imaging spectrograph and an intensified camera it was possible to detect atomic oxygen and nitrogen emissions simultaneously with high resolution. We supported also the ground based observation with an infrared camera and a wide range miniature fibre spectrometer. The paper presents the setup of both, the airborne instrument and the ground based setup as well as first look results from the successful observation mission.

  6. Spectroscopic Analysis of the Hayabusa Re-Entry Using Airborne and Ground Based Equipment

    NASA Astrophysics Data System (ADS)

    2011-08-01

    The Hayabusa sample return capsule, which contained precious asteroid samples, re-entered the Earth's atmosphere on June 13, 2010. An ablative carbon-phenolic thermal protection system (TPS) was used to enable a safe return for the small capsule and the containing samples. A research aircraft operated by NASA has been setup with a wide range of imaging and spectrographic cameras for remote sensing of the radiation of the Hayabusa capsule during its entry flight. We developed for this mission a new instrument aiming to measure the translational temperature from the line broadening of heated atmospheric gases in their plasma state. Therefore, a scanning Fabry-Perot interferometer was setup aboard the aircraft. Using an imaging spectrograph and an intensified camera it was possible to detect atomic oxygen and nitrogen emissions simultaneously with high resolution. We supported also the ground based observation with an infrared camera and a wide range miniature fibre spectrometer. The paper presents the setup of both, the airborne instrument and the ground based setup as well as first look results from the successful observation mission.

  7. What drives hydrophobic polymer collapse and re-entry transitions in miscible good solvents?

    NASA Astrophysics Data System (ADS)

    Rodriguez Ropero, Francisco; Hajari, Timir; van der Vegt, Nico F. A.

    Herein, we study co-nonsolvency of poly(N-isopropylacrylamide) (PNiPAM) in methanol aqueous solutions. Our results show that both the coil-to-globule transition at low methanol concentrations and the globule-to-coil re-entrance at high methanol concentrations are entropy driven. At low alcohol content, methanol preferentially binds to the PNiPAM globule and drives polymer collapse. Rather than being driven by electrostatic, hydrogen bonding or bridging-type interactions with the globule, preferential methanol binding is found to result from a significant increase of the chain configurational entropy, stabilizing methanol-enriched globular structures over wet globular structures in neat water. The globule-to-coil re-entrance at high methanol concentrations is instead driven by changes in solvent-excluded volume of the coil and globular states imparted by a decrease in solvent density with increasing methanol content of the solution. The co-nonsolvency mechanism proposed in this contribution provides a new angle on how to develop Coarse Grained simulation models for responsive soft matter systems. Moreover, several of the solvation effects described in this contribution can be incorporated in theories for cosolvent-induced conformational transitions in dilute polymer solutions. This research was supported by the German Research Foundation (DFG) within the Collaborative Research Center ``Multiscale Simulation Methods for Soft Matter Systems'' (SFB-TRR146).

  8. The HYTHIRM Project: Flight Thermography of the Space Shuttle During the Hypersonic Re-entry

    NASA Technical Reports Server (NTRS)

    Horvath, Thomas J.; Tomek, Deborah M.; Berger, Karen T.; Zalameda, Joseph N.; Splinter, Scott C.; Krasa, Paul W.; Schwartz, Richard J.; Gibson, David M.; Tietjen, Alan B.; Tack, Steve

    2010-01-01

    This report describes a NASA Langley led endeavor sponsored by the NASA Engineering Safety Center, the Space Shuttle Program Office and the NASA Aeronautics Research Mission Directorate to demonstrate a quantitative thermal imaging capability. A background and an overview of several multidisciplinary efforts that culminated in the acquisition of high resolution calibrated infrared imagery of the Space Shuttle during hypervelocity atmospheric entry is presented. The successful collection of thermal data has demonstrated the feasibility of obtaining remote high-resolution infrared imagery during hypersonic flight for the accurate measurement of surface temperature. To maximize science and engineering return, the acquisition of quantitative thermal imagery and capability demonstration was targeted towards three recent Shuttle flights - two of which involved flight experiments flown on Discovery. In coordination with these two Shuttle flight experiments, a US Navy NP-3D aircraft was flown between 26-41 nautical miles below Discovery and remotely monitored surface temperature of the Orbiter at Mach 8.4 (STS-119) and Mach 14.7 (STS-128) using a long-range infrared optical package referred to as Cast Glance. This same Navy aircraft successfully monitored the Orbiter Atlantis traveling at approximately Mach 14.3 during its return from the successful Hubble repair mission (STS-125). The purpose of this paper is to describe the systematic approach used by the Hypersonic Thermodynamic Infrared Measurements team to develop and implement a set of mission planning tools designed to establish confidence in the ability of an imaging platform to reliably acquire, track and return global quantitative surface temperatures of the Shuttle during entry. The mission planning tools included a pre-flight capability to predict the infrared signature of the Shuttle. Such tools permitted optimization of the hardware configuration to increase signal-to-noise and to maximize the available dynamic range while mitigating the potential for saturation. Post flight, analysis tools were used to assess atmospheric effects and to convert the 2-D intensity images to 3-D temperature maps of the windward surface. Comparison of the spatially resolved global thermal measurements to surface thermocouples and CFD prediction is made. Successful demonstration of a quantitative, spatially resolved, global temperature measurement on the Shuttle suggests future applications towards hypersonic flight test programs within NASA, DoD and DARPA along with flight test opportunities supporting NASA's project Constellation.

  9. NASA's DC-8 Lab Heads to Record Hayabusa Re-entry

    NASA Video Gallery

    A planeload of scientists plan to catch a glimpse of the fiery return to Earth of the Japanese spacecraft Hayabusa over Australia from NASA's DC-8 flying laboratory on June 13, 2010. Scientists and...

  10. Evaluation of non-intrusive flow measurement techniques for a re-entry flight experiment

    NASA Technical Reports Server (NTRS)

    Miles, R. B.; Santavicca, D. A.; Zimmermann, M.

    1983-01-01

    This study evaluates various non-intrusive techniques for the measurement of the flow field on the windward side of the Space Shuttle orbiter or a similar reentry vehicle. Included are linear (Rayleigh, Raman, Mie, Laser Doppler Velocimetry, Resonant Doppler Velocimetry) and nonlinear (Coherent Anti-Stokes Raman, Laser-Induced Fluorescence) light scattering, electron-beam fluorescence, thermal emission, and mass spectroscopy. Flow-field properties were taken from a nonequilibrium flow model by Shinn, Moss, and Simmonds at the NASA Langley Research Center. Conclusions are, when possible, based on quantitative scaling of known laboratory results to the conditions projected. Detailed discussion with researchers in the field contributed further to these conclusions and provided valuable insights regarding the experimental feasibility of each of the techniques.

  11. CARINA - A space vehicle with re-entry capabilities for microgravity experiments

    NASA Astrophysics Data System (ADS)

    Borriello, G.; Sansone, A.; Ricciardi, A.

    1992-08-01

    An Italian autonomous space vehicle with recovery capabilities, named CARINA (Capsula di Rientro Non Abitata), is described with special attention given to the technological developments in areas pertaining to the reentry system, including reentry aerothermodynamics and the design of the thermal protection system. Consideration is also given to the configuration of the CARINA vehicle (comprised of the expendable Service Module and the Apollo-like Reentry Module), the subsystems and their performances, the mission life cycle, the microgravity utilization aspects, and the programmatic aspects.

  12. Re-entry: online virtual worlds as a healing space for veterans

    NASA Astrophysics Data System (ADS)

    Morie, Jacquelyn Ford

    2009-02-01

    We describe a project designed to use the power of online virtual worlds as a place of camaraderie and healing for returning United States military veterans-a virtual space that can help them deal with problems related to their time of service and also assist in their reintegration into society. This veterans' space is being built in Second Life®, a popular immersive world, under consultation with medical experts and psychologists, with several types of both social and healing activities planned. In addition, we address several barrier issues with virtual worlds, including lack of guides or helpers to ensure the participants have a quality experience. To solve some of these issues, we are porting the advanced intelligence of the ICT's virtual human characters to avatars in Second Life®, so they will be able to greet the veterans, converse with them, guide them to relevant activities, and serve as informational agents for healing options. In this way such "avatar agents" will serve as autonomous intelligent characters that bring maximum engagement and functionality to the veterans' space. This part of the effort expands online worlds beyond their existing capabilities, as currently a human being must operate each avatar in the virtual world; few autonomous characters exist. As this project progresses we will engage in an iterative design process with veteran participants who will be able to advise us, along with the medical community, on what efforts are well suited to, and most effective within, the virtual world.

  13. Effecting Successful Community Re-Entry: Systems of Care Community Based Mental Health Services

    ERIC Educational Resources Information Center

    Estes, Rebecca I.; Fette, Claudette; Scaffa, Marjorie E.

    2005-01-01

    The need for system reform for child and adolescent mental health services, long recognized as a vital issue, continues to challenge mental health professionals. While past legislation has not adequately addressed the issues, the 2003 President's New Freedom Commission may begin to reorient mental health systems toward recovery. Supported by this…

  14. Parallel, Gradient-Based Anisotropic Mesh Adaptation for Re-entry Vehicle Configurations

    NASA Technical Reports Server (NTRS)

    Bibb, Karen L.; Gnoffo, Peter A.; Park, Michael A.; Jones, William T.

    2006-01-01

    Two gradient-based adaptation methodologies have been implemented into the Fun3d refine GridEx infrastructure. A spring-analogy adaptation which provides for nodal movement to cluster mesh nodes in the vicinity of strong shocks has been extended for general use within Fun3d, and is demonstrated for a 70 sphere cone at Mach 2. A more general feature-based adaptation metric has been developed for use with the adaptation mechanics available in Fun3d, and is applicable to any unstructured, tetrahedral, flow solver. The basic functionality of general adaptation is explored through a case of flow over the forebody of a 70 sphere cone at Mach 6. A practical application of Mach 10 flow over an Apollo capsule, computed with the Felisa flow solver, is given to compare the adaptive mesh refinement with uniform mesh refinement. The examples of the paper demonstrate that the gradient-based adaptation capability as implemented can give an improvement in solution quality.

  15. Atrioventricular Nodal Re-entry Tachycardia in Identical Twins: A Case Report and Literature Review.

    PubMed

    Barake, Walid; Caldwell, Jane; Baranchuk, Adrian

    2013-01-01

    This report details the case of 17 year old identical twins who both presented with paroxysmal supraventricular tachycardia (PSVT). Electrophysiological studies revealed atrioventricular nodal reentry tachycardia (AVNRT) in both twins. Successful but technically challenging slow pathway ablation was performed in both twins. This is the first reported case of confirmed AVNRT in identical twins which adds strong evidence to heritability of the dual AV node physiology and AVNRT. A review of the current literature regarding PSVT in monozygotic twins is provided. PMID:23329875

  16. Re-Entry Women: A Selective Review of the Educational Process, Career Choice, and Interest Measurement.

    ERIC Educational Resources Information Center

    Tittle, Carol K.; Denker, Elenor R.

    Opportunities and barriers in post secondary education for the mature woman are the focus of the first part of this review. Barriers including college restrictions, family resistance, and financial problems as well as attitudinal and self-concept characteristics are discussed. Opportunities are presented in a review of counseling considerations…

  17. Re-Entry Women: A Selective Review of the Educational Process, Career Choice, and Interest Measurement

    ERIC Educational Resources Information Center

    Tittle, Carol Kehr; Denker, Elenor Rubin

    1977-01-01

    Some factors related to the reentry of adult females to post secondary education, as reported in recent literature, are reviewed. Barriers and opportunities in continuing education, current theories and research on career choice for women, and sex bias in counseling and interest inventories are discussed. (GDC)

  18. CFD Analysis of Tile-Repair Augers for the Shuttle Orbiter Re-Entry Aeroheating

    NASA Technical Reports Server (NTRS)

    Mazaheri, Ali R.

    2007-01-01

    A three-dimensional aerothermodynamic model of the shuttle orbiter's tile overlay repair (TOR) sub-assembly is presented. This sub-assembly, which is an overlay that covers the damaged tiles, is modeled as a protuberance with a constant thickness. The washers and augers that serve as the overlay fasteners are modeled as cylindrical protuberances with constant thicknesses. Entry aerothermodynamic cases are studied to provide necessary inputs for future thermal analyses and to support the space-shuttle return-to-flight effort. The NASA Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA) is used to calculate heat transfer rate on the surfaces of the tile overlay repair and augers. Gas flow is modeled as non-equilibrium, five species air in thermal equilibrium. Heat transfer rate and surface temperatures are analyzed and studied for a shuttle orbiter trajectory point at Mach 17.85. Computational results show that the average heat transfer rate normalized with respect to its value at body point 1800 is about BF=1.9 for the auger head. It is also shown that the average BF for the auger and washer heads is about BF=2.0.

  19. Astronaut Thermal Exposure: Re-Entry After Low Earth Orbit Rescue Mission

    NASA Technical Reports Server (NTRS)

    Gillis, David B.; Hamilton, Douglas; Ilcus, Stana; Stepaniak, Phil; Son, Chang; Bue, Grant

    2009-01-01

    The STS-125 mission, launched May 11, 2009, is the final servicing mission to the Hubble Space Telescope. The repair mission's EVA tasks are described, including: installing a new wide field camera; installing the Cosmic Origins Spectrograph; repairing the Space Telescope Imaging Spectrograph; installing a new outer blanket layer; adding a Soft Capture and Rendezvous System for eventual controlled deorbit in about 2014; replacing the 'A' side Science Instrument Command and Data Handling module; repairing the Advanced Camera for surveys; and, replacing the rate sensor unit gyroscopes, fine guidance sensors and 3 batteries. Additionally, the Shuttle crew cabin thermal environment is described. A CFD model of per person CO2 demonstrates a discrepancy between crew breathing volume and general mid-deck levels of CO2. A follow-on CFD analysis of the mid-deck temperature distribution is provided. Procedural and engineering mitigation plans are presented to counteract thermal exposure upon reentry to the Earth atmosphere. Some of the procedures include: full cold soak the night prior to deorbit; modifying deck stowage to reduce interference with air flow; and early securing of avionics post-landing to reduce cabin thermal load prior to hatch opening. Engineering mitigation activities include modifying the location of the aft starboard ICUs, eliminating the X3 stack and eliminating ICU exhaust air directed onto astronauts; improved engineering data of ICU performance; and, verifying the adequacy of mid-deck temperature control using CFD models in addition to lumped parameter models. Post-mitigation CFD models of mid-deck temperature profiles and distribution are provided.

  20. Data re-entry overload: time for a paradigm shift in maternity IT?

    PubMed Central

    Fawdry, Rupert; Bewley, Susan; Cumming, Grant; Perry, Helga

    2011-01-01

    This paper provides an overview of maternity information technology (IT) in Britain, questioning the usability, effectiveness and cost efficiency of the current models of implementation of electronic maternity records. UK experience of hand-held paper obstetric notes and computerized records reveals fundamental problems in the relationship between the two complementary methods of recording maternity data. The assumption that paper records would inevitably be replaced by electronic substitutes has proven false; the rigidity of analysable electronic records has led to immense incompatibility problems. The flexibility of paper records has distinct advantages that have so far not been sufficiently acknowledged. It is suggested that continuing work is needed to encourage the standardization of electronic maternity records, via a new co-creative, co-development approach and continuing international electronic community debate. PMID:21969478

  1. Offer Flexible Learning Opportunities to Encourage Re-entry and Completion

    ERIC Educational Resources Information Center

    Hyslop, Alisha

    2007-01-01

    Several years ago, leaders at Vanguard-Sentinel Career Centers, located in northwestern Ohio, began looking at the issue of student motivation. They were concerned that some students, even in their career-based programs, were falling through the cracks. For a variety of reasons, these students were not successful in the traditional high school…

  2. Hypersonic Flight and the Re-Entry Problem: The Twenty-First Wright Brothers Lecture

    NASA Technical Reports Server (NTRS)

    Allen, H. Julian

    1958-01-01

    Up to this point the discussion of the problems of rocket vehicles has been confined to the effects of phenomena which have in the past been important ones for lower speed aircraft and will continue to be important for aircraft of all speeds. Now with considerable extension of both speed and altitude, other phenomena also become important. The nature of some problems will be altered, as a result, and new problems, of course, will be encountered. First, it is well to note that our interest in bluff bodies for ballistic vehicles in particular, and in rounded-nosed bodies generally, has changed our emphasis in aerodynamics. The detached bow waves which occur with such bodies at high supersonic speeds complicate the calculations of the flow-field characteristics. In the present period, much attention is being given to such studies. In addition, at the very high altitudes attained by most of the rocket-craft, the mean free path of air molecules can be of the same order, or long, compared to the dimensions of the vehicles. Thus, slip-flow and free-molecule-flow studies are of interest, particularly for satellite vehicles." The aerodynatnicist must deal with air having unfamiliar states and properties. Second, at hypersonic speeds where, for example, air is greatly decelerated, it may undergo considerable change in composition, the degree of change depending upon many factors. Dissociation of oxygen and nitrogen molecules can occur and, in addition, thermal ionization of many of the constituents. It is naturally to be expected that the convective heat transfer will, as a result, be altered from what it was for the "perfect" gas, and this has been the subject of much recent research effort. Moreover, the decelerated gas becomes capable of radiating energy and the radiative heat transfer must generally be considered for hypersonic vehicles, particularly for long-range ballistic rockets. It is not only the aerodynamic heating problems that are affected. The fact that at very high air temperature the gas becomes electrically conductive introduces new problems in radio wave transmission and reception. In addition, a conducting gas flow can, of course, be influenced by a magnetic field. The study of such flows, which has been termed "magneto gas dynamics," is still in too primitive a state to indicate how important a role it can play, but many interesting possibilities suggest themselves. Third, our experience with airplanes powered by air-breathing engines has naturally been restricted to the stratosphere, or lower. Our ignorance increases with altitude. For rockets, literally, "the sky's the limit," and it is not surprising that a great emphasis has now been placed on obtaining a more thorough understanding of the whole atmosphere. These studies are not aimed at an understanding of the chemical and physical characteristics alone, but also of the occurrence of high-energy particles, from meteors to cosmic rays, and the nature of the problems they will promote.

  3. A Re-Entry Program for Peacekeeping Soldiers: Promoting Personal and Career Transition.

    ERIC Educational Resources Information Center

    Westwood, Marvin J.; Black, Timothy G.; McLean, Holly B.

    2002-01-01

    Describes a program developed to assist with military personnel's transition back into Canadian society by aiding with their personal and career readjustment. Group-based life review and therapeutic enactment counseling interventions are used to identify critical incidents and facilitate the resolution of stress-related reactions soldiers have…

  4. Predicting Boundary-Layer Transition on Space-Shuttle Re-Entry

    NASA Technical Reports Server (NTRS)

    Berry, Scott; Horvath, Tom; Merski, Ron; Liechty, Derek; Greene, Frank; Bibb, Karen; Buck, Greg; Hamilton, Harris; Weilmuenster, Jim; Campbell, Chuck; Bouslog, Stan; Kirk, Ben; Bourland, Garry; Cassady, Amy; Anderson, Brian; Reda, Dan; Reuther, James; Kinder, Gerry; Chao, Dennis; Hyatt, Jay; Barnwell, Maria; Wang, K. C.; Schneider, Steve

    2008-01-01

    The BLT Prediction Tool ("BLT" signifies "Boundary Layer Transition") is provided as part of the Damage Assessment Team analysis package, which is utilized for analyzing local aerothermodynamics environments of damaged or repaired space-shuttle thermal protection tiles. Such analyses are helpful in deciding whether to repair launch-induced damage before re-entering the terrestrial atmosphere.

  5. Atrioventricular Nodal Re-entry Tachycardia in Identical Twins: A Case Report and Literature Review

    PubMed Central

    Barake, Walid; Caldwell, Jane; Baranchuk, Adrian

    2013-01-01

    This report details the case of 17 year old identical twins who both presented with paroxysmal supraventricular tachycardia (PSVT). Electrophysiological studies revealed atrioventricular nodal reentry tachycardia (AVNRT) in both twins. Successful but technically challenging slow pathway ablation was performed in both twins. This is the first reported case of confirmed AVNRT in identical twins which adds strong evidence to heritability of the dual AV node physiology and AVNRT. A review of the current literature regarding PSVT in monozygotic twins is provided. PMID:23329875

  6. Entry, Descent, and Landing Operations Analysis for the Genesis Re-Entry Capsule

    NASA Technical Reports Server (NTRS)

    Desai, Prasun N.; Lyons, Dan T.

    2005-01-01

    On September 8, 2004, the Genesis spacecraft returned to Earth after spending 29 months about the sun-Earth libration point collecting solar wind particles. Four hours prior to Earth arrival, the entry capsule containing the samples was released for entry and subsequent landing at the Utah Test and Training Range. This paper provides an overview of the entry, descent, and landing trajectory analysis that was performed during the Mission Operations Phase leading up to final approach to Earth. The operations effort accurately delivered the entry capsule to the desired landing site. The final landing location was 8.3 km from the target, and was well within the allowable landing area. Preliminary reconstruction analyses indicate that the actual entry trajectory was very close to the pre-entry prediction.

  7. Re-Entry Trauma: Asian Re-Integration after Study in the West

    ERIC Educational Resources Information Center

    Pritchard, Rosalind

    2011-01-01

    Many students who re-locate from host to home country are said to undergo a process of reverse culture shock akin to bereavement, involving stages of a grieving process. This has been likened to a "W-curve" in which feelings fluctuate before reaching a more balanced state. The present study examined the re-acculturation of Taiwanese and Sri Lankan…

  8. Ares I-X First Stage Internal Aft Skirt Re-Entry Heating Data and Modeling

    NASA Technical Reports Server (NTRS)

    Schmitz, Craig P.; Tashakkor, Scott B.

    2011-01-01

    The CLVSTATE engineering code is being used to predict Ares-I launch vehicle first stage reentry aerodynamic heating. An engineering analysis is developed which yields reasonable predictions for the timing of the first stage aft skirt thermal curtain failure and the resulting internal gas temperatures. The analysis is based on correlations of the Ares I-X internal aft skirt gas temperatures and has been implemented into CLVSTATE. Validation of the thermal curtain opening models has been accomplished using additional Ares I-X thermocouple, calorimeter and pressure flight data. In addition, a technique which accounts for radiation losses at high altitudes has been developed which improves the gas temperature measurements obtained by the gas temperature probes (GTP). Updates to the CLVSTATE models are shown to improve the accuracy of the internal aft skirt heating predictions which will result in increased confidence in future vehicle designs

  9. High-power laser-experiments on shear-flow instabilities in a re-entry sheath

    NASA Astrophysics Data System (ADS)

    Niemann, C.; Ashour-Abdalla, M.; Clark, S. E.; Niehoff, D.; Schaeffer, D.; Constantin, C.; Schriver, D.; El-Alaoui, M.

    2013-12-01

    Microscopic plasma fluctuations in the reentry sheath surrounding hypersonic aircraft can be detrimental to radio-communication but can only be limitedly studied in-situ. Here we present new measurements of plasma-fluctuations in the lower-hybrid range, created in a laser-produced plasma plume that closely resembles a reentry sheath (10E11-10E13 cm-3, 1-20 eV). Shear-flow instabilities form in the diamagnetic current layer of the laser-produced plasma (20 J) exploding at hypersonic speed (M>10) into a preformed magnetic field (400 G). Electric- and magnetic-field gradients are characterized with magnetic flux probes over large temporal and spatial (20 cm) scales. The frequency spectrum of plasma pulsations is investigated with biased Langmuir probes, while the plasma parameters are measured via optical Thomson scattering. The data is used to benchmark simulations performed with a 2D PIC code.

  10. Potential of glassy carbon and silicon carbide photonic structures as electromagnetic radiation shields for atmospheric re-entry.

    PubMed

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

    2012-06-18

    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.

  11. A Grounded Theory Study of the Re-Entry Process of Teen Parents' Return to School after Dropping Out

    ERIC Educational Resources Information Center

    Melton, Brenda L.

    2013-01-01

    Without the rich stories of the experiences of teen parents who drop out of school and then re-enter, we do not have a total picture of the dropout phenomenon and how best to address the issues for this marginalized group. Using the research strategies of Charmaz' social constructivist grounded theory, Melton has gathered detailed stories about…

  12. Returning Home: Scholars Say More Research is Needed on the Societal Re-Entry of the Formerly Incarcerated

    ERIC Educational Resources Information Center

    Roach, Ronald

    2005-01-01

    Since the late 1960s, politicians and policymakers have talked tough on crime and have passed tough laws to build prisons and to prescribe lengthy sentences for the criminally convicted. In the past five years, however, public attention has focused on a criminal justice issue to which politicians and other public officials previously paid little…

  13. An adaptive grid method for computing the high speed 3D viscous flow about a re-entry vehicle

    NASA Technical Reports Server (NTRS)

    Bockelie, Michael J.; Smith, Robert E.

    1992-01-01

    An algebraic solution adaptive grid generation method that allows adapting the grid in all three coordinate directions is presented. Techniques are described that maintain the integrity of the original vehicle definition for grid point movement on the vehicle surface and that avoid grid cross over in the boundary layer portion of the grid lying next to the vehicle surface. The adaptive method is tested by computing the Mach 6 hypersonic three dimensional viscous flow about a proposed Martian entry vehicle.

  14. Histone acetyltransferase HAT4 modulates navigation across G2/M and re-entry into G1 in Leishmania donovani

    PubMed Central

    Yadav, Aarti; Chandra, Udita; Saha, Swati

    2016-01-01

    Histone acetyltransferases impact multiple processes. This study investigates the role of histone acetyltransferase HAT4 in Leishmania donovani. Though HAT4 was dispensable for survival, its elimination decreased cell viability and caused cell cycle defects, with HAT4-nulls experiencing an unusually long G2/M. Survival of HAT4-nulls in macrophages was also substantially compromised. DNA microarray analysis revealed that HAT4 modestly regulated the expression of only a select number of genes, thus not being a major modulator of global gene expression. Significantly, cdc20 was among the downregulated genes. To ascertain if decreased expression of cdc20 was responsible for HAT4-null growth and cell cycle defects we expressed LdCdc20 ectopically in HAT4-nulls. We found this to alleviate the aberrant growth and cell cycle progression patterns displayed by HAT4-nulls, with cells navigating G2/M phase and re-entering G1 phase smoothly. HAT4-nulls expressing LdCdc20 ectopically showed survival rates comparable to wild type within macrophages, suggesting that G2/M defects were responsible for poor survival of HAT4-nulls within host cells also. These are the first data analyzing the in vivo functional role of HAT4 in any trypanosomatid. Our results directly demonstrate for the first time a role for Cdc20 in regulating trypanosomatid G2/M events, opening avenues for further research in this area. PMID:27272906

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

    NASA Technical Reports Server (NTRS)

    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.

  16. Quantum Scattering Study of Ro-Vibrational Excitations in N+N(sub 2) Collisions under Re-entry Conditions

    NASA Technical Reports Server (NTRS)

    Wang, Dunyou; Stallcop, James R.; Dateo, Christopher E.; Schwenke, David W.; Huo, Winifred M.

    2004-01-01

    A three-dimensional time-dependent quantum dynamics approach using a recently developed ab initio potential energy surface is applied to study ro-vibrational excitation in N+N2 exchange scattering for collision energies in the range 2.1- 3.2 eV. State-to-state integral exchange cross sections are examined to determine the distribution of excited rotational states of N(sub 2). The results demonstrate that highly-excited rotational states are produced by exchange scattering and furthermore, that the maximum value of (Delta)j increases rapidly with increasing collision energies. Integral exchange cross sections and exchange rate constants for excitation to the lower (upsilon = 0-3) vibrational energy levels are presented as a function of the collision energy. Excited-vibrational-state distributions for temperatures at 2,000 K and 10,000 K are included.

  17. Inducing myoblast re-entry into the cell cycle: a potential mechanism for laser-enhanced skeletal muscle regeneration

    NASA Astrophysics Data System (ADS)

    Liu, T.; Fang, Y.; Zhang, C. P.; Chen, P.; Wang, C. Z.; Kang, H. X.; Shen, B. J.; Liang, J.; Fu, X. B.

    2014-09-01

    This study investigated the effect of low-level laser irradiation (LLLI) on the cell cycle and proliferative activity of cultured myoblasts, and sought to elucidate the possible cellular mechanism by which LLLI promotes the regeneration of skeletal muscle in vivo. Primary myoblasts isolated from rat hindlegs were irradiated with helium-neon laser light at different energy densities. Distributions of cell-cycle subpopulations and the expression of cell-cycle regulatory proteins in myoblasts were assessed using flow cytometric analysis and western blot assay. It was found that laser irradiation stimulated cell-cycle entry; induced the expression of cyclin A and cyclin D; and increased cell proliferation index and bromodeoxyuridine incorporation as compared to the unirradiated control cells, indicating LLLI augmented the number of proliferative myoblasts in the S phase and G2/M phase of the cell cycle. These results suggest that LLLI at certain fluxes and wavelengths could activate quiescent myoblasts, leading to cell division and facilitating new myofiber formation. This could contribute to the improvement of skeletal muscle regeneration following trauma and myopathic diseases.

  18. High-G testing of MEMS mechanical non-volatile memory and silicon re-entry switch.

    SciTech Connect

    Baker, Michael Sean; Pohl, Kenneth Roy

    2005-10-01

    Two different Sandia MEMS devices have been tested in a high-g environment to determine their performance and survivability. The first test was performed using a drop-table to produce a peak acceleration load of 1792 g's over a period of 1.5 ms. For the second test the MEMS devices were assembled in a gun-fired penetrator and shot into a cement target at the Army Waterways Experiment Station in Vicksburg Mississippi. This test resulted in a peak acceleration of 7191 g's for a duration of 5.5 ms. The MEMS devices were instrumented using the MEMS Diagnostic Extraction System (MDES), which is capable of driving the devices and recording the device output data during the high-g event, providing in-flight data to assess the device performance. A total of six devices were monitored during the experiments, four mechanical non-volatile memory devices (MNVM) and two Silicon Reentry Switches (SiRES). All six devices functioned properly before, during, and after each high-g test without a single failure. This is the first known test under flight conditions of an active, powered MEMS device at Sandia.

  19. Potential of glassy carbon and silicon carbide photonic structures as electromagnetic radiation shields for atmospheric re-entry.

    PubMed

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

    2012-06-18

    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. PMID:22714482

  20. Piloted Simulator Tests of a Guidance System which Can Continously Predict Landing Point of a Low L/D Vehicle During Atmosphere Re-Entry

    NASA Technical Reports Server (NTRS)

    Wingrove, Rodney C.; Coate, Robert E.

    1961-01-01

    The guidance system for maneuvering vehicles within a planetary atmosphere which was studied uses the concept of fast continuous prediction of the maximum maneuver capability from existing conditions rather than a stored-trajectory technique. used, desired touchdown points are compared with the maximum range capability and heating or acceleration limits, so that a proper decision and choice of control inputs can be made by the pilot. In the method of display and control a piloted fixed simulator was used t o demonstrate the feasibility od the concept and to study its application to control of lunar mission reentries and recoveries from aborts.

  1. Entry and re-entry into informal care-giving over a 3-year prospective study among older people in Nairobi slums, Kenya.

    PubMed

    Chepngeno-Langat, Gloria

    2014-09-01

    This paper analyses data from a 3-year prospective study to understand the factors associated with becoming a caregiver to a person with a chronic illness and examines the dynamics among caregivers over time. A total of 1485 participants were drawn from a study conducted in the slums of Nairobi, Kenya. Two waves of data collected in 2006 for the baseline and a follow-up in 2009 were used. Information on the demographic, self-reported health and socioeconomic characteristics such as education, sources of livelihood and employment status was used. Age was a significant factor in becoming a caregiver, but there were no significant differences by gender or marital status. New caregivers and those with more than one care-giving episode had a higher socioeconomic position than non-caregivers. Caregivers also had poorer health compared with non-caregivers, highlighting the association between being a caregiver and negative health outcomes. Additionally, having cared for someone with a HIV-related illness compared with other chronic conditions increased the likelihood of subsequently caring for another person in need of long-term care. This may be due to the heterosexual mode of HIV transmission in sub-Saharan Africa, hence clustering of infection within family or married couples. This finding draws attention to the need to provide timely interventions to caregivers for people with HIV-related illness who are likely to end up providing care to multiple care recipients. Furthermore, there is a need to enhance the indispensable contribution of informal caregivers through incorporating their role within the continuum of care for effective HIV and AIDS management. Overall, informal caregivers to persons with chronic illnesses perform the tasks of care-giving without any formal support from health or social services. Therefore, it is crucial to initiate policies and programmes to ease the burden of care that is borne by informal caregivers.

  2. Lay-out of a re-usable re-entry vehicle required in a future European low earth orbit scenario

    NASA Astrophysics Data System (ADS)

    Uebelhack, H. T.; Fave, J.

    1984-10-01

    The design concept of a reusable unmanned semiballistic-reentry spacecraft to provide raw materials and return processed materials from a European automated space production facility in LEO is presented and illustrated with drawings, diagrams, graphs, and tables of parameters. A typical mission scenario includes Ariane launch; rendezvous and docking for sample exchange; center-of-mass trimming by adjustment of the load after dedocking; updating of inertial systems; deorbiting to a ballistic arc by means of four 400-N thrusters; atmospheric flight from 100-km altitude at path angle 4 deg, lift/drag ratio 0.2, and maximum deceleration 5 g; and final deceleration and landing using three-stage drogue and main-parachutes, an air-bag system, and landing gears.

  3. Where is Merlin When I Need Him? The Barriers to Higher Education are Still in Place: Recent Re-Entry Experience

    ERIC Educational Resources Information Center

    Colvin, Benie B.

    2013-01-01

    While the GI bill after WWII encouraged education for the older students, the combination of baby boomers and the rise of feminism have prompted a new wave of returning students to academia. The nontraditional student since the 1970s has often been an older female returning for a graduate degree. Making the decision to return has not been easy,…

  4. Biomaterial bridges enable regeneration and re-entry of corticospinal tract axons into the caudal spinal cord after SCI: Association with recovery of forelimb function.

    PubMed

    Pawar, Kiran; Cummings, Brian J; Thomas, Aline; Shea, Lonnie D; Levine, Ariel; Pfaff, Sam; Anderson, Aileen J

    2015-10-01

    Severed axon tracts fail to exhibit robust or spontaneous regeneration after spinal cord injury (SCI). Regeneration failure reflects a combination of factors, including the growth state of neuronal cell bodies and the regeneration-inhibitory environment of the central nervous system. However, while spared circuitry can be retrained, target reinnervation depends on longitudinally directed regeneration of transected axons. This study describes a biodegradable implant using poly(lactide-co-glycolide) (PLG) bridges as a carrier scaffold to support regeneration after injury. In order to detect regeneration of descending neuronal tracts into the bridge, and beyond into intact caudal parenchyma, we developed a mouse cervical implantation model and employed Crym:GFP transgenic mice. Characterization of Crym:GFP mice revealed that descending tracts, including the corticospinal tract, were labeled by green fluorescent protein (GFP), while ascending sensory neurons and fibers were not. Robust co-localization between GFP and neurofilament-200 (NF-200) as well as GFP and GAP-43 was observed at both the rostral and caudal bridge/tissue interface. No evidence of similar regeneration was observed in mice that received gelfoam at the lesion site as controls. Minimal co-localization between GFP reporter labeling and macrophage markers was observed. Taken together, these data suggest that axons originating from descending fiber tracts regenerated, entered into the PLG bridge at the rostral margin, continued through the bridge site, and exited to re-enter host tissue at the caudal edge of the intact bridge. Finally, regeneration through implanted bridges was associated with a reduction in ipsilateral forelimb errors on a horizontal ladder task. PMID:26134079

  5. Experiment lithopanspermia: test of interplanetary transfer and re-entry process of epi- and endolithic microbial communities in the FOTON-M3 Mission

    NASA Astrophysics Data System (ADS)

    de La Torre Noetzel, Rosa

    The Lithopanspermia hypothesis assumes that impact-expelled rocks serve as interplanetary transfer vehicles for microorganisms colonizing those rocks. It requires that the microorganisms survive (1) the impact ejection process from the planet of origin; (2) travelling through space; (3) capture and landing on another planet. In the experiment "Lithopanspermia" on board of the FOTON-M3 satellite (14.09.07) steps 2 and 3 of this scenario have been experimentally tested. Assay systems for step 2 were the bipolar epilithic lichen species Rhizocarpon geographicum and Xanthoria elegans on their natural rock substrate as well as their reproduction structures, microbial communities from atacamás halites Chroococcidiopsiss, endolithic communities of Anabaena and Nostoc, and the vagrant lichen species Aspicilia fruticulosa. The samples were exposed to outer space conditions within the BIOPAN-6 facility of ESA. Preparatory space simulation studies (UV solar spectrum radiation and vacuum at 10-2 Pa) performed at the Spasolab-Laboratory of INTA (March-April 2007), have demonstrated the suitability of those lichen species. After flight (10 days exposure to harsh space conditions in low Earth orbit at about 300 km altitude) and recovery, the survival capacity of the microbial communities has been assayed. First analyses have confirmed a fast recovery of the biological activity (chlorophyll a- fluorescence) of the lichens, similar to the high survival rates observed in the experiment LICHENS onboard of the Foton-M2 mission (de la Torre et al., 2007; Sancho et al., 2007). There were no significant changes in relation with the pre-flight values of the epilithic-, endolithicand vagrant lichen samples. First results of Confocal Scanning Laser Microscopy have demonstrated a high vitality of epilithic samples. Ultrastructural changes are being analyzed by Transmission Electron Microscopy and Cryoscanning. Furthermore, concerning the germination capacity of ascospores of Xanthoria elegans up to now no differences were detected between the controls (90 References: De la Torre et al. (2007) BIOPAN experiment LICHENS on the Foton-M2 mission: pre-flight verification tests of the Rhizocarpon geographicum-granite ecosystem, Adv. Space Res. 40, 1665-1671, doi:10.1016/jasr.2007.02.022. Sancho L. et al. (2007) Lichens survive in space. Astrobiology, 7, 443-454. St¨ffler D, et al. (2007) Experimental evidence for the o potential impact ejection of viable microorganisms from Mars and Mars-like planets Icarus, 186, 585-588. Horneck et al. (2007) Microbial rock inhabitants survive hypervelocity impacts on Mars-like host planets: First phase of Lithopanspermia experimentally tested, Astrobiology, in press.

  6. Side-Branch and Coaxial Intravascular Ultrasound Guided Wire Re-Entry after Failed Retrograde Approach of Chronic Total Occlusion Intervention

    PubMed Central

    Chou, Ruey-Hsing; Lai, Chih-Hung; Lu, Tse-Min

    2016-01-01

    Intravascular ultrasound (IVUS) can provide valuable information during the intervention of difficult chronic total occlusion (CTO) lesion. Stumpless CTO lesions with an adjacent side branch are associated with a significantly lower success rate because the proper entry point is not always clearly identified and the guidewires easily slip into the side branch. Herein we presented a case of a stumpless middle left circumflex (LCX) artery CTO lesion with auto-collateral from obtuse marginal branch. Initially, we positioned the IVUS into the side-branch to find the entry point of LCX-CTO lesion. However, the punctured wire went into the false lumen. A retrograde approach was tried but later failed. Therefore, we used IVUS to find the entry point where the true lumen transited to the false lumen, and used a stiff guidewire to puncture the entry point. After we confirmed with IVUS that the whole guidewire was in the true lumen, we deployed 3 drug-eluting stents. The final angiogram showed TIMI 3 flow with preservation of all side branches. The patient was angina-free during the 6-month follow-up. By presenting this case, we have demonstrated the application of both side-branch and coaxial IVUS-guided recanalization technique in the stumpless CTO lesion. PMID:27274179

  7. HYTHIRM Radiance Modeling and Image Analyses in Support of STS-119, STS-125 and STS-128 Space Shuttle Hypersonic Re-entries

    NASA Technical Reports Server (NTRS)

    Gibson, David M.; Spisz, Thomas S.; Taylor, Jeff C.; Zalameda, Joseph N.; Horvath, Thomas J.; Tomek, Deborah M.; Tietjen, Alan B.; Tack, Steve; Bush, Brett C.

    2010-01-01

    We provide the first geometrically accurate (i.e., 3-D) temperature maps of the entire windward surface of the Space Shuttle during hypersonic reentry. To accomplish this task we began with estimated surface temperatures derived from CFD models at integral high Mach numbers and used them, the Shuttle's surface properties and reasonable estimates of the sensor-to-target geometry to predict the emitted spectral radiance from the surface (in units of W sr-1 m-2 nm-1). These data were converted to sensor counts using properties of the sensor (e.g. aperture, spectral band, and various efficiencies), the expected background, and the atmosphere transmission to inform the optimal settings for the near-infrared and midwave IR cameras on the Cast Glance aircraft. Once these data were collected, calibrated, edited, registered and co-added we formed both 2-D maps of the scene in the above units and 3-D maps of the bottom surface in temperature that could be compared with not only the initial inputs but also thermocouple data from the Shuttle itself. The 3-D temperature mapping process was based on the initial radiance modeling process. Here temperatures were guessed for each node in a well-resolved 3-D framework, a radiance model was produced and compared to the processed imagery, and corrections to the temperature were estimated until the iterative process converged. This process did very well in characterizing the temperature structure of the large asymmetric boundary layer transition the covered much of the starboard bottom surface of STS-119 Discovery. Both internally estimated accuracies and differences with CFD models and thermocouple measurements are at most a few percent. The technique did less well characterizing the temperature structure of the turbulent wedge behind the trip due to limitations in understanding the true sensor resolution. (Note: Those less inclined to read the entire paper are encouraged to read an Executive Summary provided at the end.)

  8. Redox regulation of cell-cycle re-entry: cyclin D1 as a primary target for the mitogenic effects of reactive oxygen and nitrogen species.

    PubMed

    Burch, Peter M; Heintz, Nicholas H

    2005-01-01

    Reactive oxygen and nitrogen species inhibit or promote cell proliferation by modulating the cell signaling pathways that dictate decisions between cell survival, proliferation, and death. In the growth factor-dependent pathways that regulate mitogenesis, numerous positive and negative effectors of signaling are influenced by physiological fluctuations of oxidants, including receptor tyrosine kinases, small GTPases, mitogen-activated protein kinases, protein phosphatases, and transcription factors. The same mitogenic pathways that are sensitive to oxidant levels also directly regulate the expression of cyclin D1, a labile factor required for progression through the G1 phase on the cell cycle. Because the transition from G0 to G1 is the only phase of the cell cycle that is not regulated by cyclin-dependent kinases, but rather by redox-dependent signaling pathways, expression of cyclin D1 represents a primary regulatory node for the dose-dependent effects of oxidants on the induction of cell growth. We suggest that expression of cyclin D1 represents a useful marker for assessing the integration of proliferative and growth inhibitory effects of oxidants on the redox-dependent signaling events that control reentry into the cell cycle.

  9. Roundtable on Constructing and Coping with Incarceration and Family Re-Entry: Perspectives from the Field (Philadelphia, Pennsylvania, November 15-16, 2001). Fathers and Families Second-Tier Roundtable Series.

    ERIC Educational Resources Information Center

    Pennsylvania Univ., Philadelphia. National Center on Fathers and Families.

    Issues of incarceration and its effects on parents, children, families, and communities are as much human development concerns as policy dilemmas. This report synthesizes the discussion of these concerns and their implications for policy, practice, and research as presented at the National Center on Fathers and Families'"Roundtable on Constructing…

  10. Locking Nut with Stress-Distributing Insert

    NASA Technical Reports Server (NTRS)

    Daniels, Christopher C.

    2010-01-01

    Reusable holders have been devised for evaluating high-temperature, plasma-resistant re-entry materials, especially fabrics. Typical material samples tested support thermal-protection-system damage repair requiring evaluation prior to re-entry into terrestrial atmosphere. These tests allow evaluation of each material to withstand the most severe predicted re-entry conditions.

  11. Adaptable Holders for Arc-Jet Screening Candidate Thermal Protection System Repair Materials

    NASA Technical Reports Server (NTRS)

    Riccio, Joe; Milhoan, Jim D.

    2010-01-01

    Reusable holders have been devised for evaluating high-temperature, plasma-resistant re-entry materials, especially fabrics. Typical material samples tested support thermal-protection-system damage repair requiring evaluation prior to re-entry into terrestrial atmosphere. These tests allow evaluation of each material to withstand the most severe predicted re-entry conditions.

  12. PIRATES: A Program for Offenders Transitioning into the World of Work

    ERIC Educational Resources Information Center

    Musgrove, Kate Racoff; Derzis, Nicholas C.; Shippen, Margaret E.; Brigman, Holly E.

    2012-01-01

    The study assessed the effectiveness of the Preparing Inmates for Re-Entry through Assistance, Training, and Employment Skills (PIRATES) group, which focused on improving dysfunctional career thoughts. Participants were male offenders (n = 14) enrolled in a re-entry training class. Results showed a statistically significant decrease in…

  13. The IXV vehicle model identification subsystem: Off-line estimation framework

    NASA Astrophysics Data System (ADS)

    Béjar-Romero, J. A.; Bidaux-Sokolowski, A.; Maina, S.; Preaud, J. P.

    2016-07-01

    The Intermediate eXperimental Vehicle (IXV) is an ESA re-entry technological platform built to verify in-flight the performance of critical re-entry technologies. The successful flight of the IXV provides the key elements to consolidate the knowledge necessary for the development of future European re-entry systems. The exploitation of in-flight data represents a cornerstone for this flying test bench. In this frame the IXV Vehicle Model Identification subsystem, VMI, represents those steps, techniques and algorithms that shall be applied to the collected data in order to improve the prediction capabilities for future design of re-entry vehicles and specifically to: Improve IXV flight dynamics model. Validate aerodynamic prediction methods based on Wind Tunnel Tests, WTT, and Computational Fluid Dynamics, CFD. Validate the vehicle model identification process and tools.

  14. 28 CFR 552.11 - Searches of inmates.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... housing unit (see 28 CFR part 541, subpart B), leaving the institution, or re-entry into an institution... devices. Inspection of an inmate using electronic devices (for example, metal detector, or...

  15. 28 CFR 552.11 - Searches of inmates.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... housing unit (see 28 CFR part 541, subpart B), leaving the institution, or re-entry into an institution... devices. Inspection of an inmate using electronic devices (for example, metal detector, or...

  16. 28 CFR 552.11 - Searches of inmates.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... housing unit (see 28 CFR part 541, subpart B), leaving the institution, or re-entry into an institution..., such as an otoscope, tongue blade, short nasal speculum, and simple forceps. A digital or...

  17. 28 CFR 552.11 - Searches of inmates.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... housing unit (see 28 CFR part 541, subpart B), leaving the institution, or re-entry into an institution..., such as an otoscope, tongue blade, short nasal speculum, and simple forceps. A digital or...

  18. 28 CFR 552.11 - Searches of inmates.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... housing unit (see 28 CFR part 541, subpart B), leaving the institution, or re-entry into an institution..., such as an otoscope, tongue blade, short nasal speculum, and simple forceps. A digital or...

  19. Chase Plane Video Of Historic SpaceX Splashdown

    NASA Video Gallery

    During the re-entry of SpaceX's Dragon capsule, NASA and the United States Navy flew a P-3 Orion Cast Glance aircraft to capture airborne views of the spacecraft's descent. The aircraft, based at t...

  20. The X-38 V-201 Flap Actuator Mechanism

    NASA Technical Reports Server (NTRS)

    Hagen, Jeff; Moore, Landon; Estes, Jay; Layer, Chris

    2004-01-01

    The X-38 Crew Rescue Vehicle V-201 space flight test article was designed to achieve an aerodynamically controlled re-entry from orbit in part through the use of two body mounted flaps on the lower rear side. These flaps are actuated by an electromechanical system that is partially exposed to the re-entry environment. These actuators are of a novel configuration and are unique in their requirement to function while exposed to re-entry conditions. The authors are not aware of any other vehicle in which a major actuator system was required to function throughout the complete re-entry profile while parts of the actuator were directly exposed to the ambient environment.

  1. Development of a Parachute System for Deceleration of Flying Vehicles in Supersonic Regimes

    NASA Astrophysics Data System (ADS)

    Pilyugin, N. N.; Khlebnikov, V. S.

    2010-09-01

    Aerodynamic problems arising during design and development of braking systems for re-entry vehicles are analyzed. Aerodynamic phenomena and laws valid in a supersonic flow around a pair of bodies having different shapes are studied. Results of this research can be used in solving application problems (arrangement and optimization of experiments; design and development of various braking systems for re-entry vehicles moving with supersonic speeds in the atmosphere).

  2. Procedure Planning: Anatomical Determinants of Strategy

    PubMed Central

    Hanratty, Colm; Walsh, Simon

    2014-01-01

    In contemporary practice there are three main methods that can be employed when attempting to open a chronic total occlusion (CTO) of a coronary artery; antegrade or retrograde wire escalation, antegrade dissection re-entry and retrograde dissection re-entry. This editorial will attempt to clarify the anatomical features that can be identified to help when deciding which of these strategies to employ initially and help understand the reasons for this decision. PMID:24694102

  3. The IXV guidance, navigation and control subsystem: Development, verification and performances

    NASA Astrophysics Data System (ADS)

    Marco, Victor; Contreras, Rafael; Sanchez, Raul; Rodriguez, Guillermo; Serrano, Daniel; Kerr, Murray; Fernandez, Vicente; Haya-Ramos, Rodrigo; Peñin, Luis F.; Ospina, Jose A.; De Zaiacomo, Gabriale; Bejar-Romero, Juan Antonio; Yague, Ricardo; Zaccagnino, Elio; Preaud, Jean-Philippe

    2016-07-01

    The Intermediate eXperimental Vehicle (IXV) [1] is an ESA re-entry lifting body demonstrator built to verify in-flight the performance of critical re-entry technologies. The IXV was launched on February the 11th, 2015, aboard Europe's Vega launcher. The IXV´s flight and successful recovery represents a major step forward with respect to previous European re-entry experience with the Atmospheric Re-entry Demonstrator (ARD) [2], flown in October 1998. The increased in-flight manoeuvrability achieved from the lifting body solution permitted the verification of technologies over a wider re-entry corridor. Among other objectives, which included the characterisation of the re-entry environment through a variety of sensors, special attention was paid to Guidance, Navigation and Control (GNC) aspects, including the guidance algorithms for the lifting body, the use of the inertial measurement unit measurements with GPS updates for navigation, and the flight control by means of aerodynamic flaps and reaction control thrusters. This paper presents the overall Design, Development and Verification logic that has been successfully followed by the GNC and Flight Management (FM) subsystem of the IXV. It also focuses on the interactions between the GNC and the System, Avionics and OBSW development lifecycles and how an integrated and incremental verification process has been implemented by ensuring the maximum representativeness and reuse through all stages.

  4. Infrasonic Observations of the Final Flight of Space Shuttle Atlantis

    NASA Astrophysics Data System (ADS)

    Jones, K. R.; Hart, D. M.

    2011-12-01

    Infrasound arrivals from the July 2011 Space Shuttle Atlantis launch and re-entry were observed ~2,500 km away at Sandia's (SNL) Facility for Acceptance, Calibration and Testing (FACT) seven-element infrasound array. Space Shuttle Atlantis (STS-135) launched from the Kennedy Space Center (Florida) on July 8, 2011 for its final 14 day mission, culminating in a successful re-entry and landing on July 21, 2011. Infrasound from both the launch and the re-entry were clearly observed at the SNL FACT array due to the seasonal zonal wind reversals in the stratosphere and the quiet of early morning for the re-entry. In the northern hemisphere summer infrasound sources originating east of the array are observed more clearly than sources west of the array. While both the launch and re-entry were observed, the duration of detection, trace velocity, and correlation across the array varied. The launch was detected at the array for ~2 minutes while the re-entry was observed for a considerably greater amount of time, ~25 minutes. The launch of the shuttle produced less detectable infrasound because the trajectory carried the shuttle east, away from the array and disturbed the atmosphere to a lesser extent than at re-entry. During re-entry the shuttle passed much closer to the array, displaced more atmosphere, and generated infrasound for a longer period of time. The correlation across the array increased dramatically over background, peaking above 0.4 for the launch and over 0.9 for re-entry. In both cases the trace velocity stabilized between 0.35 and 0.38 km/s above background. Using FK processing we determined a back azimuth for the launch that correlated well to the location of the launch site at ~100°. Due to the higher, supersonic velocities of the shuttle and the atmospheric disturbance of re-entry, we were able to calculate several back azimuths over the duration of the observed signal. The back azimuths correlated very well with trajectory data provided by NASA and

  5. Base flow investigation of the Apollo AS-202 Command Module

    NASA Astrophysics Data System (ADS)

    Walpot, Louis M. G.; Wright, Michael J.; Noeding, Peter; Schrijer, Ferry

    2012-01-01

    A major contributor to the overall vehicle mass of re-entry vehicles is the afterbody thermal protection system. This is due to the large acreage (equal or bigger than that of the forebody) to be protected. The present predictive capabilities for base flows are comparatively lower than those for windward flowfields and offer therefore a substantial potential for improving the design of future re-entry vehicles. To that end, it is essential to address the accuracy of high fidelity CFD tools exercised in the US and EU, which motivates a thorough investigation of the present status of hypersonic flight afterbody heating. This paper addresses the predictive capabilities of afterbody flow fields of re-entry vehicles investigated in the frame of the NATO/RTO-RTG-043 task group. First, the verification of base flow topologies on the basis of available wind-tunnel results performed under controlled supersonic conditions (i.e. cold flows devoid of reactive effects) is performed. Such tests address the detailed characterization of the base flow with particular emphasis on separation/reattachment and their relation to Mach number effects. The tests have been performed on an Apollo-like re-entry capsule configuration. Second, the tools validated in the frame of the previous effort are exercised and appraised against flight-test data collected during the Apollo AS-202 re-entry.

  6. Thermal investigation of nuclear waste disposal in space

    NASA Technical Reports Server (NTRS)

    Wilkinson, C. L.

    1981-01-01

    A thermal analysis has been conducted to determine the allowable size and response of bare and shielded nuclear waste forms in both low earth orbit and at 0.85 astronomical units. Contingency conditions of re-entry with a 45 deg and 60 deg aeroshell are examined as well as re-entry of a spherical shielded waste form. A variety of shielded schemes were examined and the waste form thermal response for each determined. Two optimum configurations were selected. The thermal response of these two shielded waste configurations to indefinite exposure to ground conditions following controlled and uncontrolled re-entry is determined. In all cases the prime criterion is that waste containment must be maintained.

  7. Intermediate experimental vehicle, ESA program aerodynamics-aerothermodynamics key technologies for spacecraft design and successful flight

    NASA Astrophysics Data System (ADS)

    Dutheil, Sylvain; Pibarot, Julien; Tran, Dac; Vallee, Jean-Jacques; Tribot, Jean-Pierre

    2016-07-01

    With the aim of placing Europe among the world's space players in the strategic area of atmospheric re-entry, several studies on experimental vehicle concepts and improvements of critical re-entry technologies have paved the way for the flight of an experimental space craft. The successful flight of the Intermediate eXperimental Vehicle (IXV), under ESA's Future Launchers Preparatory Programme (FLPP), is definitively a significant step forward from the Atmospheric Reentry Demonstrator flight (1998), establishing Europe as a key player in this field. The IXV project objectives were the design, development, manufacture and ground and flight verification of an autonomous European lifting and aerodynamically controlled reentry system, which is highly flexible and maneuverable. The paper presents, the role of aerodynamics aerothermodynamics as part of the key technologies for designing an atmospheric re-entry spacecraft and securing a successful flight.

  8. Tetrahedral lander

    NASA Technical Reports Server (NTRS)

    Roberts, Michael L. (Inventor)

    1993-01-01

    An apparatus and method is disclosed for decelerating and absorbing impact of a re-entry vehicle suitable for payloads that are relatively light as well as payloads weighing several tons or more. The apparatus includes four inflatable legs displaced equidistantly from each other around a capsule or housing which contains a payload. The legs are inflated at a designated altitude after entering earth's atmosphere to slow the descent of the re-entry vehicle. Connected between each of the four legs are drag inducing surfaces that deploy as the legs inflate. The drag inducing surfaces are triangularly shaped with one such surface being connected between each pair of legs for a total of six drag inducing surfaces. The legs have drag inducing outer surfaces which act to slow the descent of the re-entry vehicle.

  9. Ceramic Foams for TPS Applications

    NASA Technical Reports Server (NTRS)

    Stockpoole, Mairead

    2003-01-01

    Ceramic foams have potential in many areas of Thermal Protection Systems (TPS) including acreage and tile leading edges as well as being suitable as a repair approach for re-entry vehicles. NASA Ames is conducting ongoing research in developing lower-density foams from pre-ceramic polymer routes. One of the key factors to investigate, when developing new materials for re-entry applications, is their oxidation behavior in the appropriate re-entry environment which can be simulated using ground based arc jet (plasma jet) testing. Arc jet testing is required to provide the appropriate conditions (stagnation pressures, heat fluxes, enthalpies, heat loads and atmospheres) encountered during flight. This work looks at the response of ceramic foams (Si systems) exposed to simulated reentry environments and investigates the influence of microstructure and composition on the material? response. Other foam properties (mechanical and thermal) will also be presented.

  10. Advances in procedural techniques--antegrade.

    PubMed

    Wilson, William; Spratt, James C

    2014-05-01

    There have been many technological advances in antegrade CTO PCI, but perhaps most importantly has been the evolution of the "hybrid' approach where ideally there exists a seamless interplay of antegrade wiring, antegrade dissection re-entry and retrograde approaches as dictated by procedural factors. Antegrade wire escalation with intimal tracking remains the preferred initial strategy in short CTOs without proximal cap ambiguity. More complex CTOs, however, usually require either a retrograde or an antegrade dissection re-entry approach, or both. Antegrade dissection re-entry is well suited to long occlusions where there is a healthy distal vessel and limited "interventional" collaterals. Early use of a dissection re-entry strategy will increase success rates, reduce complications, and minimise radiation exposure, contrast use as well as procedural times. Antegrade dissection can be achieved with a knuckle wire technique or the CrossBoss catheter whilst re-entry will be achieved in the most reproducible and reliable fashion by the Stingray balloon/wire. It should be avoided where there is potential for loss of large side branches. It remains to be seen whether use of newer dissection re-entry strategies will be associated with lower restenosis rates compared with the more uncontrolled subintimal tracking strategies such as STAR and whether stent insertion in the subintimal space is associated with higher rates of late stent malapposition and stent thrombosis. It is to be hoped that the algorithms, which have been developed to guide CTO operators, allow for a better transfer of knowledge and skills to increase uptake and acceptance of CTO PCI as a whole. PMID:24694104

  11. Survival of lichens and bacteria exposed to outer space conditions - Results of the Lithopanspermia experiments

    NASA Astrophysics Data System (ADS)

    de la Torre, Rosa; Sancho, Leopoldo G.; Horneck, Gerda; Ríos, Asunción de los; Wierzchos, Jacek; Olsson-Francis, Karen; Cockell, Charles S.; Rettberg, Petra; Berger, Thomas; de Vera, Jean-Pierre P.; Ott, Sieglinde; Frías, Jesus Martinez; Melendi, Pablo Gonzalez; Lucas, Maria Mercedes; Reina, Manuel; Pintado, Ana; Demets, René

    2010-08-01

    In the space experiments Lithopanspermia, experimental support was provided to the likelihood of the lithopanspermia concept that considers a viable transport of microorganisms between the terrestrial planets by means of meteorites. The rock colonising lichens Rhizocarpon geographicum and Xanthoria elegans, the vagrant lichen Aspicilia fruticulosa, and endolithic and endoevaporitic communities of cyanobacteria and bacteria with their natural rock substrate were exposed to space for 10 days onboard the Biopan facility of the European Space Agency (ESA). Biopan was closed during launch and re-entry. In addition, in the Stone facility, one sample of R. geographicum on its natural granitic substrate was attached at the outer surface of the re-entry capsule close to the stagnation point, only protected by a thin cover of glass textolite. Post-flight analysis, which included determination of the photosynthetic activity, LIVE/DEAD staining, and germination capacity of the ascospores, demonstrated that all three lichen were quite resistant to outer space conditions, which include the full spectrum of solar extraterrestrial electromagnetic radiation or selected wavelength ranges. This high resistance of the lichens to space appears to be due to their symbiotic nature and protection by their upper pigmented layer, the cortex. In contrast, the rock- or halite-inhabiting bacteria were severely damaged by the same exposure. After atmospheric re-entry, the granite of the Stone sample was transformed into a glassy, nearly homogenous material, with several friction striae. None of the lichen cells survived this re-entry process. The data suggest that lichens are suitable candidates for testing the concept of lithopanspermia, because they are extremely resistant to the harsh environment of outer space. The more critical event is the atmospheric re-entry after being captured by a planet. Experiments simulating the re-entry process of a microbe-carrying meteoroid did not show any

  12. A Summary of the 1989 NACADA Award-Winning Research Proposals.

    ERIC Educational Resources Information Center

    NACADA Journal, 1989

    1989-01-01

    Research proposals funded by the National Academic Advising Association are summarized. Topics include adult student retention factors, high-risk students' learning processes, undergraduate engineering performance predictors, traditional and computerized advising in research universities, re-entry women, advisor training through case studies,…

  13. 76 FR 12076 - Privacy Act of 1974; System of Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-04

    ... and Workload Records (December 30, 2008; 73 FR 79850). Changes: * * * * * Authority for maintenance of...-and- Materials, Labor-Hour, and Letter Contracts.'' * * * * * Retention and disposal: Delete entry and...) and computer screens automatically lock after a preset period of inactivity with re-entry...

  14. Thermal Vacuum Facility for Testing Thermal Protection Systems

    NASA Technical Reports Server (NTRS)

    Daryabeigi, Kamran; Knutson, Jeffrey R.; Sikora, Joseph G.

    2002-01-01

    A thermal vacuum facility for testing launch vehicle thermal protection systems by subjecting them to transient thermal conditions simulating re-entry aerodynamic heating is described. Re-entry heating is simulated by controlling the test specimen surface temperature and the environmental pressure in the chamber. Design requirements for simulating re-entry conditions are briefly described. A description of the thermal vacuum facility, the quartz lamp array and the control system is provided. The facility was evaluated by subjecting an 18 by 36 in. Inconel honeycomb panel to a typical re-entry pressure and surface temperature profile. For most of the test duration, the average difference between the measured and desired pressures was 1.6% of reading with a standard deviation of +/- 7.4%, while the average difference between measured and desired temperatures was 7.6% of reading with a standard deviation of +/- 6.5%. The temperature non-uniformity across the panel was 12% during the initial heating phase (t less than 500 sec.), and less than 2% during the remainder of the test.

  15. High performance multiplier processor for use with aerospace microcomputers. [MC 68000

    SciTech Connect

    Pierce, P.E.

    1980-01-01

    An MC 68000-based microcomputer including a hardware multiplier processor has been designed for a re-entry vehicle navigation and control application. The microcomputer is discussed with emphasis on the multiplier processor architecture, software control, and theory of operation. 2 figures.

  16. Effective Stack Design in Air Pollution Control.

    ERIC Educational Resources Information Center

    Clarke, John H.

    1968-01-01

    Stack design problems fall into two general caterories--(1) those of building re-entry, and (2) those of general area pollution. Extensive research has developed adequate information, available in the literature, to permit effective stack design. A major roadblock to effective design has been the strong belief by architects and engineers that high…

  17. Flexible Learning Options: The Experiences and Perceptions of Regional Youth

    ERIC Educational Resources Information Center

    Msapenda, Vanessa; Hudson, Cate

    2013-01-01

    Over the past few decades a variety of alternative or re-entry educational programs have been developed in Australia as an approach to address early school leaving and promote engagement with learning. In South Australia, one of the largest initiatives has been the implementation of Flexible Learning Programs (FLPs) as part of the State…

  18. Conceptual Design of Super-Orbital Earth Entry Flight Experiment using a Submarine-Launched Vehicle

    NASA Astrophysics Data System (ADS)

    Na, Jae-Jeong; Baek, Seung-Wook; Park, Chul

    2006-11-01

    A conceptual study is performed to propose that a super-orbital re-entry flight experiment be conducted using a Russian submarine-launched VOLNA launch system. The purpose of the experiment is to study the flow phenomena and the heatshield behavior in the planetary-Earth return entry. Because the three-stage launcher produces a re-entry velocity of only up to 7 km/s, a solid rocket booster must be used to accelerate the re-entry vehicle during its descent. An inviscid Newtonian analysis is made to estimate the aerodynamic coefficients. The weight of system is estimated using a method developed by NASA and it is iteratively coupled with a three-degree-of-freedom flight trajectory calculation. The result shows that, using a STAR 27 solid rocket engine, re-entry velocity of nearly 11 km/s can be attained for a body of nose radius of 0.39 m with a scientific payload of up to 15 kg.

  19. Proceedings of the Annual Midwest Research-to-Practice Conference in Adult and Continuing Education (2nd, DeKalb, Illinois, November 4-5, 1983).

    ERIC Educational Resources Information Center

    Northern Illinois Univ., De Kalb. Coll. of Continuing Education.

    These proceedings consist of 26 presentations. They include, in alphabetical order by author, "Time and Distance: Crucial Factors in Selection of Training and Vocation by Re-entry Women" (Cynthia Bagley), "Using Learner Surveys to Enhance Continuing Education Programs" (Carol Brown), "Designing Inservice Training as a Learning System: The Case of…

  20. Traumatic Brain Injury and Its Effect on Students

    ERIC Educational Resources Information Center

    Rosenthal, Stacy B.

    2012-01-01

    Over one million people suffer a traumatic brain injury every year, many of whom are students between the ages of 5 and 18. Using a qualitative case study approach, I wanted to discover the specific factors that both impede and help the school re-entry process for students in grades kindergarten through twelve so that these students can return to…

  1. Continuing Education for Women: Current Developments.

    ERIC Educational Resources Information Center

    Wells, Jean A.

    Continuing education for women has become a significant component of out educational system, as evidenced by the estimated over 500 continuing education courses, services, and programs for adult women offered throughout the country. Past emphasis of these programs had been in assisting housewives interested in job-entry or re-entry and/or…

  2. ACUTE STUDIES OF INHALED CHLORINE IN F344 RATS SUGGEST ALTERNATIVE TO HABER'S RULE FOR RISK EXTRAPOLATIONS

    EPA Science Inventory

    Chlorine (CI2), a high-production volume air pollutant, is an irritant of interest to homeland security. Risk assessment approaches to establish egress or re-entry levels typically use an assumption based on Haber's Rule and apply a concentration times duration ("C x t") adjustme...

  3. Steam disinfestation as a methyl bromide alternative in California cut flower nurseries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Steam may be an effective alternative to methyl bromide in cut flower production in California. Advantages of steam include broad spectrum pest control and a zero hour re-entry interval. The principle disadvantage of sheet steaming is cost effectiveness due to current energy prices and application...

  4. Of Radicals and DREAMers: Harnessing Exceptionality to Challenge Immigration Control

    ERIC Educational Resources Information Center

    Heredia, Luisa Laura

    2015-01-01

    This article contributes to the literature on undocumented youth activism and citizenship by assessing undocumented youth's challenges to a growing regime of migration control in the US. It uses Doug McAdam's tactical interaction as an analytical lens to explore two consecutive high-risk campaigns, ICE infiltrations and expulsion/re-entry. In this…

  5. Water-Repellency Probe

    NASA Technical Reports Server (NTRS)

    Rosen, Charles D.; Mitchell, Shirley M.; Jolly, Stanley R.; Jackson, Richard G.; Fleming, Scott T.; Roberts, William J.; Bell, Daniel R., III

    1996-01-01

    Instrument yielding presence or absence of waterproofing agent at any given depth in blanket developed. In original application, blankets in question part of space shuttle thermal protection system. Instrument utilized to determine extent of waterproofing "burnout" due to re-entry heating and adverse environment exposure.

  6. Normal and abnormal electrical propagation in the small intestine.

    PubMed

    Lammers, W J E P

    2015-02-01

    As in other muscular organs, small intestinal motility is determined to a large degree by the electrical activities that occur in the smooth muscle layers of the small intestine. In recent decades, the interstitial cells of Cajal, located in the myenteric plexus, have been shown to be responsible for the generation and propagation of the electrical impulse: the slow wave. It was also known that the slow waves as such do not cause contraction, but that the action potentials ('spikes') that are generated by the slow waves are responsible for the contractions. Recording from large number of extracellular electrodes simultaneously is one method to determine origin and pattern of propagation of these electrical signals. This review reports the characteristics of slow wave propagation through the intestinal tube, the occurrence of propagation blocks along its length, which explains the well-known decrease in frequency, and the specific propagation pattern of the spikes that follow the slow waves. But the value of high-resolution mapping is highest in discovering and analysing mechanisms of arrhythmias in the gut. Most recently, circus movements (also called 're-entries') have been described in the small intestine in several species. Moreover, several types of re-entries have now been described, some similar to what may occur in the heart, such as functional re-entries, but others more unique to the small intestine, such as circumferential re-entry. These findings seem to suggest the possibilities of hitherto unknown pathologies that may be present in the small intestine.

  7. Impact of Teenage Motherhood on the Academic Performance in Public Primary Schools in Bungoma County, Kenya

    ERIC Educational Resources Information Center

    Barmao-Kiptanui, Catherine; Kindiki, Jonah Nyaga; Lelan, Joseph K.

    2015-01-01

    Teenage pregnancy and motherhood is a concern in both developed and developing countries and is a complex reality of contemporary society however the re-entry of teenage mothers into the school system continues to demand attention as society's negative attitude towards pregnant girls and teenage mothers persists. Those who do return to school…

  8. Developing Survival Skills Workshops for Urban Women.

    ERIC Educational Resources Information Center

    Thurston, Linda P.; Greenwood, Charles R.

    Survival Skills for Urban Women is a series of 10 3-hour workshops designed for low-income minority women. The workshops cover the following topics: (1) assertiveness; (2) personal health; (3) nutrition; (4) money management; (5) child management; (6) legal rights; (7) self-advocacy; (8) crisis coping; (9) community resources; and (10) re-entry to…

  9. Step-Up to College: A Special Summer Program for Youth. Summer, 1980.

    ERIC Educational Resources Information Center

    Smith, Janet D.; And Others

    The Step-Up to College Program was initiated in the summer of 1980 to provide basic skills instruction in English and mathematics for incoming freshmen, re-entry adult students, and high school students and adults considering college. Program participants who were enrolled in both the English and math courses (N=125) were asked to take part in a…

  10. Minority/Underrepresented Student Enrollment Enhancement.

    ERIC Educational Resources Information Center

    Bush, Adolf; And Others

    In order to better serve minority students and other underrepresented groups, Fresno City College, in California, implemented two innovative programs: the Re-Entry Student Conference (RESC) and the Registration-To-Go (RTG) program. The RESC was a 2-day enrollment program designed to attract students from the Fresno area over the age of 25. Many of…

  11. HL-20 Wax Model

    NASA Technical Reports Server (NTRS)

    1993-01-01

    A numerically machined wax pattern of the NASA HL-20 orbital re-entry lifting body was cut from a CAD/CAM file. This nine-inch wax model was later used in a lost wax investment casting process to replicate the pattern in ceramic for wind-tunnel aero-heating studies

  12. Teacher Supplies to DCPS 1987-88.

    ERIC Educational Resources Information Center

    Holmes, Dennis H.; And Others

    Sources of supply of teachers relevant to District of Columbia Public Schools (DCPS) are discussed in this monograph. Subgroups traditionally available for recruitment into teaching include: (1) newly trained teachers; (2) migrating teachers; (3) re-entry teachers; (4) non-education majors; and (5) second-career professionals. The subgroups which…

  13. Laminectomy retractor: a useful tool for redo sternotomy.

    PubMed

    Saxena, Pankaj; Zimmet, Adam D

    2014-11-01

    Sternal re-entry represents a critical step during redo cardiac surgery. We describe a simple method that relies on opening of the posterior table of the sternum with a laminectomy retractor after dividing the anterior table with an oscillating saw.

  14. 77 FR 30297 - Privacy Act of 1974; U.S. Customs and Border Protection, DHS/CBP-006-Automated Targeting System...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-22

    ... titled, U.S. Customs and Border Protection, DHS/CBP-006--Automated Targeting System (ATS) 72 FR 43650.... Customs and Border Protection, DHS/CBP-006--Automated Targeting System (ATS) 72 FR 43650, August 6, 2007... crossing card, birth certificate, certificate of naturalization, re-entry permit, military card)...

  15. Studies of the Use of the Kuder Occupational Interest Survey with Mature Women.

    ERIC Educational Resources Information Center

    Denker, Elenor R.; Tittle, Carol K.

    Due to the increase of re-entry women in college, investigation of interest inventories for this particular population has become essential. Four studies involving 239 mature women are reported which examine the effect of changing instructions on expressed interests; the expressed satisfaction of mature women with KOIS results; the extent of…

  16. The microbiology of spacecraft hardware: lessons learned from the planetary protection activities on the Beagle 2 spacecraft.

    PubMed

    Pillinger, Judith M; Pillinger, C T; Sancisi-Frey, S; Spry, J A

    2006-01-01

    We consider the aseptic assembly of the Beagle 2 Mars probe and how the requirements of COSPAR planetary protection category IVa were achieved. Several areas for future investigation became apparent. An ESA mission is outlined in which a microbial bioburden is recovered after Earth orbit to assess viability following re-entry through the atmosphere.

  17. Women Emerge in the Seventies. University Women: A Series of Essays, Volume III.

    ERIC Educational Resources Information Center

    Swoboda, Marian J., Ed.; Roberts, Audrey J., Ed.

    This monograph reviews the role of women in the development of public higher education at the University of Wisconsin with special focus on the period of the 1970s. Essays are presented in the categories of the politicization of women, curriculum, language, athletics, lifestyle, and the re-entry woman. Essays include: "The Women's Movement and the…

  18. CPAS Parachute Testing, Model Development, & Verification

    NASA Technical Reports Server (NTRS)

    Romero, Leah M.

    2013-01-01

    Capsule Parachute Assembly System (CPAS) is the human rated parachute system for the Orion vehicle used during re-entry. Similar to Apollo parachute design. Human rating requires additional system redundancy. A Government Furnished Equipment (GFE) project responsible for: Design; Development testing; Performance modeling; Fabrication; Qualification; Delivery

  19. Right thoracotomy approach for repair of recurrent or complex coarctation of the aorta using an extra-anatomic ascending aorta to descending aorta bypass graft off-pump.

    PubMed

    Tabry, Imad F; Zachariah, Zachariah P

    2013-01-01

    A previously described but rarely used surgical technique for the repair of complex or recurrent coarctation of the aorta through a right thoracotomy approach is presented in detail. It has the advantages of being simple and avoiding left chest re-entry, median sternotomy and cardiopulmonary bypass altogether.

  20. Effect of adult screwworm male size on mating competence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Screwworms, Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae), were devastating pests in parts of North America and Central America before their eradication by means of the sterile insect technique (SIT). Now, a barrier is maintained to prevent re-entry of screwworms from endemic regions t...

  1. Temporal Organization of the Brain: Neurocognitive Mechanisms and Clinical Implications

    ERIC Educational Resources Information Center

    Dawson, Kim A.

    2004-01-01

    The synchrony between the individual brain and its environment is maintained by a system of internal clocks that together reflect the temporal organization of the organism. Extending the theoretical work of Edelman and others, the temporal organization of the brain is posited as functioning through "'re-entry" and "'temporal tagging"' and binds…

  2. Descriptions of Community by People with Spinal Cord Injuries: Concepts to Inform Community Integration and Community Rehabilitation

    ERIC Educational Resources Information Center

    Kuipers, Pim; Kendall, Melissa B.; Amsters, Delena; Pershouse, Kiley; Schuurs, Sarita

    2011-01-01

    Effective measurement and optimization of re-entry into the community after injury depends on a degree of understanding of how those injured persons actually perceive their community. In light of the limited research about foundational concepts regarding community integration after spinal cord injury, this study investigated how a large number of…

  3. Strypi VII R launch vehicle

    SciTech Connect

    Wente, H.A.

    1982-01-01

    The Strypi VII R is a three-stage solid propellant launch vehicle designed to boost payloads ranging from 50 to 300 pounds to re-entry environment conditions. The first stage, a fin-stabilized ballistic rocket boosts the final two stages into an exoatmospheric trajectory where an attitude control system (ACS) precesses the spinning stages into the re-entry attitude. The ACS section is then jettisoned, and ignition of the spin-stabilized upper stages is initiated at a time determined to provide a zero angle-of-attack at beginning of re-entry. Four vehicles have been flown carrying three different re-entry test vehicles. Originally designed for use with a Castor II motor, the highly aluminized propellant in the first stage spinning environment contributed to a case rupture resulting in failure of the second flight. The last two flights were flown successfully using Castor I motors. Typically, the Strypi VII R can boost a 100 lbm RV to a speed of 19,500 fps on a flight path of -30 degrees at 300,000 feet altitude.

  4. Career Development Curriculum for Single Parents/Homemakers.

    ERIC Educational Resources Information Center

    Malott, Karen; Taylor, Angela

    This core curriculum, in use at the Homemaker ReEntry Center at Northern Kentucky University, provides three units of materials that teachers can use to help homemakers make the transition to the world of work. The first unit, on personal development, covers such topics such as self-esteem, self-awareness, goal setting, decision making, sex role…

  5. The IXV experience, from the mission conception to the flight results

    NASA Astrophysics Data System (ADS)

    Tumino, G.; Mancuso, S.; Gallego, J.-M.; Dussy, S.; Preaud, J.-P.; Di Vita, G.; Brunner, P.

    2016-07-01

    The atmospheric re-entry domain is a cornerstone of a wide range of space applications, ranging from reusable launcher stages developments, robotic planetary exploration, human space flight, to innovative applications such as reusable research platforms for in orbit validation of multiple space applications technologies. The Intermediate experimental Vehicle (IXV) is an advanced demonstrator which has performed in-flight experimentation of atmospheric re-entry enabling systems and technologies aspects, with significant advancements on Europe's previous flight experiences, consolidating Europe's autonomous position in the strategic field of atmospheric re-entry. The IXV mission objectives were the design, development, manufacturing, assembling and on-ground to in-flight verification of an autonomous European lifting and aerodynamically controlled reentry system, integrating critical re-entry technologies at system level. Among such critical technologies of interest, special attention was paid to aerodynamic and aerothermodynamics experimentation, including advanced instrumentation for aerothermodynamics phenomena investigations, thermal protections and hot-structures, guidance, navigation and flight control through combined jets and aerodynamic surfaces (i.e. flaps), in particular focusing on the technologies integration at system level for flight, successfully performed on February 11th, 2015.

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

    NASA Astrophysics Data System (ADS)

    Heilimo, Jyri; Harri, Ari-Matti; Aleksashkin, Sergey; Koryanov, Vsevolod; Arruego, Ignacio; Schmidt, Walter; Haukka, Harri; Finchenko, Valery; Martynov, Maxim; Ostresko, Boris; Ponomarenko, Andrey; Kazakovtsev, Viktor; Martin, Susanna; Siili, Tero

    2014-05-01

    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 to the analysis and tests of the transonic behaviour of this compact and light weight payload entry system at the Earth re-entry. 1. EDLS for Earth The dynamical stability of the craft is analysed, concentrating on the most critical part of the atmospheric re-entry, the transonic phase. In Martian atmosphere the MetNet vehicle stability during the transonic phase is understood. However, in the more dense Earth's atmosphere, the transonic phase is shorter and turbulence more violent. Therefore, the EDLS has to be sufficiently dynamically stable to overcome the forces tending to deflect the craft from its nominal trajectory and attitude. The preliminary design of the inflatable EDLS for Earth will be commenced once the scaling of the re-entry system and the dynamical stability analysis have been performed. The RITD-project concentrates on mission and applications achievable with the current MetNet-type (i.e. 'Mini-1' category) of lander, and on requirements posed by other type Earth re-entry concepts. 2. Entry Angle Determination for Mini-1 - lander For successful Earth landing, the suitable re-entry angle and velocity with specific descent vehicle (DV) mass and heat flux parameters need to be determined. These key parameters in determining the Earth re-entry for DV are: qmax (kW/m2): maximal specific heat flux, Q (MJ/m2): specific integral heat flux to DV front shield, m (kg): descent vehicle (DV) mass, V (m/s): re-entry velocity and Θ (deg.): flight-path angle at Earth re-entry For Earth re-entry, the calculation results in the optimal value of entry velocity for MetNet ('Mini-1' category) -type lander, with mass of 22kg, being

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

    NASA Astrophysics Data System (ADS)

    Heilimo, Jyri; Aleksashkin, Sergey; Martynov, Maxim; Schmidt, Walter; Harri, Ari-Matti; Vsevolod Koryanov, D.; Kazakovtcev, Victor; Haukka, Harri; Arruego, Ignacio; Finchenko, Valery; Ostresko, Boris; Ponomarenko, Andrei; Martin, Susanna; Siili, Tero

    Abstract A new generation of inflatable Entry, Descent and Landing System (EDLS) or 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 to the analysis and tests of the transonic behaviour of this compact and light weight payload entry system at the Earth re-entry 1. EDLS for Earth The dynamical stability of the craft is analysed, concentrating on the most critical part of the atmospheric re-entry, the transonic phase. In Martian atmosphere the MetNet vehicle stability during the transonic phase is understood. However, in the more dense Earth’s atmosphere, the transonic phase is shorter and turbulence more violent. Therefore, the EDLS has to be sufficiently dynamically stable to overcome the forces tending to deflect the craft from its nominal trajectory and attitude. The preliminary design of the inflatable EDLS for Earth will be commenced once the scaling of the re-entry system and the dynamical stability analysis have been performed. The RITD-project concentrates on mission and applications achievable with the current MetNet-type (i.e. “Mini-1” category) of lander, and on requirements posed by other type Earth re-entry concepts. 2. Entry Angle Determination for Mini-1 - lander For successful Earth landing, the suitable re-entry angle and velocity with specific descent vehicle (DV) mass and heat flux parameters need to be determined. These key parameters in determining the Earth re-entry for DV are: - qmax (kW/m2): maximal specific heat flux, - Q (MJ/m2): specific integral heat flux to DV front shield, - m (kg): descent vehicle (DV) mass, - V (m/s): re-entry velocity and - theta(deg.): flight-path angle at Earth re-entry For Earth re-entry, the calculation results in the optimal value of entry velocity for MetNet (“Mini-1” category) -type

  8. Effect of regional differences in cardiac cellular electrophysiology on the stability of ventricular arrhythmias: a computational study

    NASA Astrophysics Data System (ADS)

    Clayton, Richard H.; Holden, Arun V.

    2003-01-01

    Re-entry is an important mechanism of cardiac arrhythmias. During re-entry a wave of electrical activation repeatedly propagates into recovered tissue, rotating around a rod-like filament. Breakdown of a single re-entrant wave into multiple waves is believed to underlie the transition from ventricular tachycardia to ventricular fibrillation. Several mechanisms of breakup have been identified including the effect of anisotropic conduction in the ventricular wall. Cells in the inner and outer layers of the ventricular wall have different action potential durations (APD), and support re-entrant waves with different periods. The aim of this study was to use a computational approach to study twisting and breakdown in a transmural re-entrant wave spanning these regions, and examine the relative role of this effect and anisotropic conduction. We used a simplified model of action potential conduction in the ventricular wall that we modified so that it supported stable re-entry in an anisotropic model with uniform APD. We first examined the effect of regional differences on breakdown in an isotropic model with transmural differences in APD, and found that twisting of the re-entrant filament resulted in buckling and breakdown during the second cycle of re-entry. We found that breakdown was amplified in the anisotropic model, resulting in complex activation in the region of longest APD. This study shows that regional differences in cardiac electrophysiology are a potentially important mechanism for destabilizing re-entry and may act synergistically with other mechanisms to mediate the transition from ventricular tachycardia to ventricular fibrillation.

  9. [Paroxysmal supraventricular tachycardia-mechanisms, diagnostic, and treatment].

    PubMed

    Tanner, Hildegard

    2014-02-01

    Paroxysmal supraventricular tachycardia have their origin above the His bundle. However, this definition has a historical origin and is imprecise regarding AV-reentry tachycardia using an accessory pathways since this tachycardia use the ventricule a part of the reentry-circuit. The most common supraventricular tachycardia is the atrioventricular nodal re-entry tachycardia, which is caused by a re-entrant tachycardia that involves the AV node and the atrial tissue followed by the atrioventricular re-entry tachycardia using an accessory pathway. More prevalent are sinus tachycardia, which is often physiologic and atrial fibrillation/flutter which are covered in detail by other articles within this issue of Therapeutischen Umschau. Therefore, the main topic of this review is the discussion of the mechanisms, diagnosis and treatment of AV nodal reentry tachycardia, AV reentry tachycardia using an accessory pathway and to a less extent focal atrial tachycardia.

  10. Application of Magnetohydrodynamics (MHD) and Recent Research Trend

    NASA Astrophysics Data System (ADS)

    Harada, Nobuhiro

    As the applications of Magnetohydrodynamic (MHD) energy conversion, research and development for high-efficiency and low emission electric power generation system, MHD accelerations and/or MHD thrusters, and flow control around hypersonic and re-entry vehicles are introduced. For closed cycle MHD power generation, high-efficiency MHD single system is the most hopeful system and space power system using mixed inert gas (MIG) working medium is proposed. For open cycle MHD, high-efficiency coal fired MHD system with CO2 recovery has been proposed. As inverse process of MHD power generation, MHD accelerators/thrusters are expected as the next generation propulsion system. Heat flux reduction to protect re-entry vehicles is expected by an MHD process for safety return from space missions.

  11. HYSHOT-2 Aerodynamics

    NASA Astrophysics Data System (ADS)

    Cain, T.; Owen, R.; Walton, C.

    2005-02-01

    The scramjet flight test Hyshot-2, flew on the 30 July 2002. The programme, led by the University of Queensland, had the primary objective of obtaining supersonic combustion data in flight for comparison with measurements made in shock tunnels. QinetiQ was one of the sponsors, and also provided aerodynamic data and trajectory predictions for the ballistic re-entry of the spinning sounding rocket. The unconventional missile geometry created by the nose-mounted asymmetric-scramjet in conjunction with the high angle of attack during re-entry makes the problem interesting. This paper presents the wind tunnel measurements and aerodynamic calculations used as input for the trajectory prediction. Indirect comparison is made with data obtained in the Hyshot-2 flight using a 6 degree-of-freedom trajectory simulation.

  12. Decreased milk drinking causing flecainide toxicity in an older child

    PubMed Central

    Thompson, Ben; Mangat, Jasveer; Barton, Chris; Hawcutt, Daniel B

    2012-01-01

    Flecainide is a class IC antiarrhythmic agent, used frequently in all age groups for the treatment of tachyarrhythmias. Flecainide blocks the voltage-gated sodium channel in the myocardium, leading to prolongation of depolarisation resulting in slowed conduction velocity. Within a paediatric population, flecainide is indicated primarily for supraventricular tachycardia resulting from atrioventricular nodal re-entry and accessory pathway mediated re-entry. It can be considered for use in patients with atrial tachycardia, fascicular ventricular tachycardia, benign right ventricular outflow tract tachycardia and paroxysmal atrial fibrillation. It is well documented to cause paradoxical proarryhthmia in children, with evidence that milk can reduce absorption in infants. The authors present the case of an older child whose flecainide levels were persistently subtherapeutic until he reduced his milk intake. At this time he developed symptoms of severe flecainide toxicity associated with increased levels. PMID:22729333

  13. Health status of people with work-related musculoskeletal disorders in return to work programs: a Malaysian study.

    PubMed

    Murad, Mohd Suleiman; O'Brien, Lisa; Farnworth, Louise; Chien, Chi-Wen

    2013-07-01

    This study examined the health status of injured workers with musculoskeletal disorders enrolled in the Malaysian Return to Work (RTW) program. The 102 participants were categorized into three RTW groups: Off-work (n = 30, 29.4%), Re-entry (n = 44, 43.1%), and Maintenance (n = 28, 27.5%). Overall health status, as measured by the SF-36 version 2, of the workers exhibited below average compared to the internationally established normative population, with their physical health component summary rated lower than mental health. Across the different groups, significant differences were found in role-physical, vitality, bodily pain, general health, and mental health. However, the mean values of these variables were higher in the Maintenance group and were found significant. The current health status of injured workers at Off-work and Re-entry phases was significantly low and warranted to be improved by involving other health professionals such as occupational therapists, ergonomists, and psychologists. PMID:23855610

  14. The employment of a high density plasma jet for the investigation of thermal protection materials

    NASA Astrophysics Data System (ADS)

    Kezelis, R.; Grigaitiene, V.; Levinskas, R.; Brinkiene, K.

    2014-05-01

    This paper describes the results of tests of thermal protection materials (TPM) at conditions that simulate the atmospheric re-entry of space vehicles, tested by means of a high velocity and enthalpy air plasma jet generated with a dc plasma torch. Such a high velocity and enthalpy air plasma jet allows us to investigate TPM by simulating heat flux values varying with time in accordance with real re-entry altitudes and trajectories. The main research interests include the measurements of plasma flow temperature and heat flux for the testing of materials used for thermal protection systems of space vehicles. The test results of investigations of light composite thermal protective system material and graphite are presented.

  15. Ballistic target tracking algorithm based on improved particle filtering

    NASA Astrophysics Data System (ADS)

    Ning, Xiao-lei; Chen, Zhan-qi; Li, Xiao-yang

    2015-10-01

    Tracking ballistic re-entry target is a typical nonlinear filtering problem. In order to track the ballistic re-entry target in the nonlinear and non-Gaussian complex environment, a novel chaos map particle filter (CMPF) is used to estimate the target state. CMPF has better performance in application to estimate the state and parameter of nonlinear and non-Gassuian system. The Monte Carlo simulation results show that, this method can effectively solve particle degeneracy and particle impoverishment problem by improving the efficiency of particle sampling to obtain the better particles to part in estimation. Meanwhile CMPF can improve the state estimation precision and convergence velocity compared with EKF, UKF and the ordinary particle filter.

  16. Folding of Polymer Chains in Early Stage of Crystallization

    NASA Astrophysics Data System (ADS)

    Yuan, Shichen; Miyoshi, Toshikazu

    Understanding the structural formation of long polymer chains in the early stage of crystallization is one of the long-standing problems in polymer science. Using solid state NMR, we investigated chain trajectory of isotactic polypropylene in the mesomorphic nano-domains formed via rapid and deep quenching. Comparison of experimental and simulated 13C-13C Double Quantum (DQ) buildup curves demonstrated that instead of random re-entry models and solidification models, individual chains in the mesomorphic form iPP adopt adjacent reentry sequences with an average folding number of = 3-4 (assuming an adjacent re-entry fraction of of 100%) during mesomorphic formation process via nucleation and growth in the early stage. This work was financially supported by the National Science Foundation (Grant DMR-1105829 and 1408855) and startup funds from the UA.

  17. New motors solve UBD and HPHT problems

    SciTech Connect

    Stewart, D.; Susman, H.

    1997-08-01

    There are two particular areas where industry contractors have been pushing current downhole motor technology to the limits of its capabilities--high temperature (HPHT) and underbalanced (UBD) operations. Economic incentives for slimhole, short-radius re-entry and multilateral wells have been well established, but until recently, the options for this kind of work have been limited. The increased use of coiled tubing has introduced additional challenges for motor manufacturers, with greater emphasis on shortness for ease of rig-up and steerability. These challenges are addressed by a unique new motor that promises benefits for coiled tubing drilling, re-entry work and multilateral drilling, as well as for geothermal wells.

  18. Remote Controlled Orbiter Capability

    NASA Technical Reports Server (NTRS)

    Garske, Michael; delaTorre, Rafael

    2007-01-01

    The Remote Control Orbiter (RCO) capability allows a Space Shuttle Orbiter to perform an unmanned re-entry and landing. This low-cost capability employs existing and newly added functions to perform key activities typically performed by flight crews and controllers during manned re-entries. During an RCO landing attempt, these functions are triggered by automation resident in the on-board computers or uplinked commands from flight controllers on the ground. In order to properly route certain commands to the appropriate hardware, an In-Flight Maintenance (IFM) cable was developed. Currently, the RCO capability is reserved for the scenario where a safe return of the crew from orbit may not be possible. The flight crew would remain in orbit and await a rescue mission. After the crew is rescued, the RCO capability would be used on the unmanned Orbiter in an attempt to salvage this national asset.

  19. Impact analysis of Minuteman III Payload Transporter Type III

    SciTech Connect

    Stirbis, P.P.

    1993-12-01

    An analysis of the impact of the Minuteman III Payload Transporter Type III into a nonyielding target at 46 m.p.h. and 30 m.p.h., and into a yielding target at 46 m.p.h. is presented. The analysis considers the structural response of the tiedown system which secures the Minuteman III re-entry system to the floor of the payload transporter. A finite element model of the re-entry system, its tiedown system, which includes tie-rods and shear pins, and the pallet plate which is attached to the transporter floating plate, was constructed. Because accelerations of the payload transporter are not known, acceleration data from one-quarter scale testing of the Safe Secure Trailer was used to investigate the response of the tiedown system. These accelerations were applied to the pallet plate. The ABAQUS computer code was used to predict the forces in the members of the tiedown system.

  20. Development and flight qualification of the C-SiC thermal protection systems for the IXV

    NASA Astrophysics Data System (ADS)

    Buffenoir, François; Zeppa, Céline; Pichon, Thierry; Girard, Florent

    2016-07-01

    The Intermediate experimental Vehicle (IXV) atmospheric re-entry demonstrator, developed within the FLPP (Future Launcher Preparatory Programme) and funded by ESA, aimed at developing a demonstration vehicle that gave Europe a unique opportunity to increase its knowledge in the field of advanced atmospheric re-entry technologies. A key technology that has been demonstrated in real conditions through the flight of this ambitious vehicle is the thermal protection system (TPS) of the Vehicle. Within this programme, HERAKLES, Safran Group, has been in charge of the TPS of the windward and nose assemblies of the vehicle, and has developed and manufactured SepcarbInox® ceramic matrix composite (CMC) protection systems that provided a high temperature resistant non ablative outer mould line (OML) for enhanced aerodynamic control. The design and flight justification of these TPS has been achieved through extensive analysis and testing:

  1. Monitoring of Thermal Protection Systems Using Robust Self-Organizing Optical Fiber Sensing Networks

    NASA Technical Reports Server (NTRS)

    Richards, Lance

    2013-01-01

    The general aim of this work is to develop and demonstrate a prototype structural health monitoring system for thermal protection systems that incorporates piezoelectric acoustic emission (AE) sensors to detect the occurrence and location of damaging impacts, and an optical fiber Bragg grating (FBG) sensor network to evaluate the effect of detected damage on the thermal conductivity of the TPS material. Following detection of an impact, the TPS would be exposed to a heat source, possibly the sun, and the temperature distribution on the inner surface in the vicinity of the impact measured by the FBG network. A similar procedure could also be carried out as a screening test immediately prior to re-entry. The implications of any detected anomalies in the measured temperature distribution will be evaluated for their significance in relation to the performance of the TPS during re-entry. Such a robust TPS health monitoring system would ensure overall crew safety throughout the mission, especially during reentry

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

    NASA Astrophysics Data System (ADS)

    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.

  3. Flutter Analysis of the Shuttle Tile Overlay Repair Concept

    NASA Technical Reports Server (NTRS)

    Bey, Kim S.; Scott, Robert C.; Bartels, Robert E.; Waters, William A.; Chen, Roger

    2007-01-01

    The Space Shuttle tile overlay repair concept, developed at the NASA Johnson Space Center, is designed for on-orbit installation over an area of damaged tile to permit safe re-entry. The thin flexible plate is placed over the damaged area and secured to tile at discreet points around its perimeter. A series of flutter analyses were performed to determine if the onset of flutter met the required safety margins. Normal vibration modes of the panel, obtained from a simplified structural analysis of the installed concept, were combined with a series of aerodynamic analyses of increasing levels of fidelity in terms of modeling the flow physics to determine the onset of flutter. Results from these analyses indicate that it is unlikely that the overlay installed at body point 1800 will flutter during re-entry.

  4. Efficacy of MTA and CEM Cement with Collagen Membranes for Treatment of Class II Furcation Defects

    PubMed Central

    Ghanbari, Habib Ollah; Taheri, Morteza; Abolfazli, Salman; Asgary, Saeed; Gharechahi, Maryam

    2014-01-01

    Objectives: This study aimed to compare the efficacy of MTA and CEM cement in Class II furcation defects in human mandibular molars. Materials and Methods: Forty furcation defects were treated in 16 patients with chronic periodontitis. The clinical parameters of probing depth (PD), vertical and horizontal clinical attachment levels (VCAL and HCAL), open vertical and horizontal furcation depths (OVFD and OHFD), and gingival margin level (GML) were measured at baseline and at 3- and 6-month (re-entry surgery) postoperatively. Data were analyzed at a significance level of P<0.05. Results: Use of MTA and CEM caused significant decreases in PD, VCAL, HCAL, OVFD and OHFD at re-entry, with no statistically significant differences between the two treatment options in soft and hard tissue parameters. Conclusion: Both treatment modalities caused significant gains in attachment levels and bone fills, proving efficacy for treatment of Class II furcation involvements. PMID:25628670

  5. Evidence for an interplay between cell cycle progression and the initiation of differentiation between life cycle forms of African trypanosomes

    PubMed Central

    1994-01-01

    Successful transmission of the African trypanosome between the mammalian host blood-stream and the tsetse fly vector involves dramatic alterations in the parasite's morphology and biochemistry. This differentiation through to the tsetse midgut procyclic form is accompanied by re-entry into a proliferative cell cycle. Using a synchronous differentiation model and a variety of markers diagnostic for progress through both differentiation and the cell cycle, we have investigated the interplay between these two processes. Our results implicate a relationship between the trypanosome cell cycle position and the perception of the differentiation signal and demonstrate that irreversible commitment to the differentiation occurs rapidly after induction. Furthermore, we show that re-entry into the cell cycle in the differentiating population is synchronous, and that once initiated, progress through the differentiation pathway can be uncoupled from progress through the cell cycle. PMID:8195296

  6. Post-Flight Analysis of GPSR Performance During Orion Exploration Flight Test 1

    NASA Technical Reports Server (NTRS)

    Barker, Lee; Mamich, Harvey; McGregor, John

    2016-01-01

    On 5 December 2014, the first test flight of the Orion Multi-Purpose Crew Vehicle executed a unique and challenging flight profile including an elevated re-entry velocity and steeper flight path angle to envelope lunar re-entry conditions. A new navigation system including a single frequency (L1) GPS receiver was evaluated for use as part of the redundant navigation system required for human space flight. The single frequency receiver was challenged by a highly dynamic flight environment including flight above low Earth orbit, as well as single frequency operation with ionospheric delay present. This paper presents a brief description of the GPS navigation system, an independent analysis of flight telemetry data, and evaluation of the GPSR performance, including evaluation of the ionospheric model employed to supplement the single frequency receiver. Lessons learned and potential improvements will be discussed.

  7. Characteristics of air pollutant dispersion around a high-rise building.

    PubMed

    Zhang, Y; Kwok, K C S; Liu, X-P; Niu, J-L

    2015-09-01

    A numerical wind tunnel model was proposed. The computed results of the pollutant diffusion around a typical Hong Kong high-rise building model (at a linear scale of 1:30), were found to show a similar trend to the outcomes of self-conducted experimental measurements that the pathways of pollutant migration for windward and leeward pollutant emission are different. For the case with windward pollutant emission at the 3rd floor within a re-entry, the pollutant migrated downwards due to the downwash created by the wind. In contrast, for the case with leeward pollution emission, dispersion is dominated by intense turbulent mixing in the near wake and characterized by the upward migration of the pollutant in the leeward re-entry. The simulated results of haze-fog (HF) studies confirm that the pathway of pollutant migration is dominated by wind-structure interaction and buoyancy effect only plays a minor role in the dispersion process. PMID:25989454

  8. Modern Endodontic Principles. Part 5: Obturation.

    PubMed

    Darcey, James; Roudsari, Reza Vahid; Jawad, Sarra; Taylor, Carly; Hunter, Mark

    2016-03-01

    Once cleaning and shaping is complete the clinician must obturate the canal. There are many different materials and techniques available each with their own discrete advantages and disadvantages. Whichever technique is used, the goal is to seal the entire prepared length of the root canal. This paper describes how best this may be achieved. CPD/Clinical Relevance: It is incumbent on the clinician to ensure that once the canal has been prepared it is sealed from bacterial re-entry. PMID:27188127

  9. Molecular simulation of the intercrystalline phase of chain molecules

    NASA Astrophysics Data System (ADS)

    Balijepalli, Sudhakar; Rutledge, Gregory C.

    1998-10-01

    Off-lattice Monte Carlo simulations of the interphase between crystals for freely rotating chains are reported. Both conformational and topological spaces are sampled during a single simulation. The transition region between the crystal and the amorphous phase is characterized in terms of density, bond orientation order, and interfacial energy. The topology of the interphase is quantified in terms of loop and bridge chain populations, and the position of loop re-entry sites.

  10. Aeroheating and Aerodynamic CFD Validation And Prediction for The X-38 Program

    NASA Technical Reports Server (NTRS)

    Loomis, Mark P.; Venkatapathy, Ethiraj; Papadopoulos, Periklis; Davies, Carol B.; Berry, Scott; Horvath, Tom; Campbell, Charles

    2004-01-01

    This paper presents the results of a computational fluid dynamics validation exercise using the General Aerodynamic Simulation Program (GASP) code for vehicles under consideration for the X-38 program. The scope of the exercise involved simulation and comparison with wind tunnel aeroheating and aerodynamic data in the hypersonic regime. In addition, simulations were performed and results are presented for the full-scale flight vehicle along an expected re- entry trajectory.

  11. A guidance concept for hypersonic aerospacecrafts

    NASA Astrophysics Data System (ADS)

    Ishimoto, Shinji

    In this paper a guidance concept for hypersonic re-entry flights is presented. The method uses a closed-form guidance technique based on a drag acceleration reference profile. A guidance law for range control is developed. It employs a physical relation between vehicle energy and range instead of a prediction-correction technique used for Shuttle entry guidance. Simulation results show that the algorithm provides good performance.

  12. Reentry control to a drag vs. energy profile

    NASA Astrophysics Data System (ADS)

    Roenneke, Axel J.; Markl, Abert

    We present trajectory control for a winged re-entry vehicle based on drag versus energy guidance. A linear control law is derived to track the drag reference guaranteeing satisfactory drag error dynamics. For the controller design, the vehicle's motion in the vertical plane is transformed into a drag state space, and the transformed system is linearized along the drag reference. Flight simulation results show that the control system operates effectively while subject to considerable atmospheric variations.

  13. Boundary Layer Transition Protuberance Tests at NASA JSC Arc-Jet Facility

    NASA Technical Reports Server (NTRS)

    Larin, Max E.; Marichalar, Jeremiah J.; Kinder, Gerald R.; Campbell, Charles H.; Riccio, Joseph R.; Nguyen, Tien Q.; Del Papa, Steven V.; Pulsonetti, Maria V.

    2010-01-01

    A series of tests conducted recently at the NASA JSC arc -jet test facility demonstrated that a protruding tile material can survive the exposure to the high enthalpy flows characteristic of the Space Shuttle Orbiter re-entry environments. The tests provided temperature data for the protuberance and the surrounding smooth tile surfaces, as well as the tile bond line. The level of heating needed to slump the protuberance material was achieved. Protuberance failure mode was demonstrated.

  14. Millimeter Wave Communication through Plasma

    NASA Technical Reports Server (NTRS)

    Bastin, Gary L.

    2008-01-01

    Millimeter wave communication through plasma at frequencies of 35 GHz or higher shows promise in maintaining communications connectivity during rocket launch and re-entry, critical events which are typically plagued with communication dropouts. Extensive prior research into plasmas has characterized the plasma frequency at these events, and research at the Kennedy Space Center is investigating the feasibility of millimeter communication through these plasma frequencies.

  15. Heat pipe cooling system with sensible heat sink

    NASA Technical Reports Server (NTRS)

    Silverstein, Calvin C.

    1988-01-01

    A heat pipe cooling system which employs a sensible heat sink is discussed. With this type of system, incident aerodynamic heat is transported via a heat pipe from the stagnation region to the heat sink and absorbed by raising the temperature of the heat sink material. The use of a sensible heat sink can be advantageous for situations where the total mission heat load is limited, as it is during re-entry, and a suitable radiation sink is not available.

  16. John Glenn - Mini Biography

    NASA Technical Reports Server (NTRS)

    1963-01-01

    Mini Biography of John Glenn, as it was up to 1962. From film to tape transfer of the film 'Friendship 7 - John Glenn' Depicts the historical orbital flight of John Glenn aboard 'Friendship 7', launched on February 20, 1962. Footage of staff at tracking stations worldwide and at Goddard Space Flight Center. Launch from cape canaveral. Flight tracking, re-entry, landing and recovery of Friendship 7.

  17. The Sanford Laboratory at Homestake: Progress and Opportunities

    NASA Astrophysics Data System (ADS)

    Alonso, Jose

    2009-12-01

    The Homestake mine in Lead, South Dakota has been selected as the site for DUSEL. With private and State funds, re-entry activities have begun, and have achieved the de-watering and accessibility of the important 4850 level. Early science programs in geology, hydrology, and biology have been ongoing for over a year. LUX and MAJORANA, two large physics experiments, will be deployed in the Davis campus at 4850 when rehabilitation of this area is complete.

  18. U.S. rainfall satellite missions in flux

    NASA Astrophysics Data System (ADS)

    Zielinski, Sarah

    NASA's Tropical Rainfall Measuring Mission (TRMM) received a reprieve in September when the agency decided to continue the mission until at least fiscal year 2009 and possibly until 2012. Earlier agency plans had called for discontinuing TRMM this year while the satellite still had enough fuel for a controlled re-entry.Despite the TRMM reprieve, however, the U.S. National Oceanic and Atmospheric Administration (NOAA) is already preparing for TRMM's replacement, the Global Precipitation Measurement (GPM) mission.

  19. Probability distribution of von Mises stress in the presence of pre-load.

    SciTech Connect

    Segalman, Daniel Joseph; Field, Richard V.,; Reese, Garth M.

    2013-04-01

    Random vibration under preload is important in multiple endeavors, including those involving launch and re-entry. There are some methods in the literature to begin to address this problem, but there is nothing that accommodates the existence of preloads and the necessity of making probabilistic statements about the stress levels likely to be encountered. An approach to achieve to this goal is presented along with several simple illustrations.

  20. STS-87 Commander Kevin R. Kregel in white room

    NASA Technical Reports Server (NTRS)

    1997-01-01

    STS-87 Commander Kevin Kregel is assisted with his ascent and re- entry flight suit in the white room at Launch Pad 39B by Danny Wyatt, NASA quality assurance specialist. STS-87 is the fourth flight of the United States Microgravity Payload and Spartan-201. A veteran of two space flights (STS-70 and -78), Kregel has logged more than 618 hours in space.

  1. Normal and abnormal electrical propagation in the small intestine.

    PubMed

    Lammers, W J E P

    2015-02-01

    As in other muscular organs, small intestinal motility is determined to a large degree by the electrical activities that occur in the smooth muscle layers of the small intestine. In recent decades, the interstitial cells of Cajal, located in the myenteric plexus, have been shown to be responsible for the generation and propagation of the electrical impulse: the slow wave. It was also known that the slow waves as such do not cause contraction, but that the action potentials ('spikes') that are generated by the slow waves are responsible for the contractions. Recording from large number of extracellular electrodes simultaneously is one method to determine origin and pattern of propagation of these electrical signals. This review reports the characteristics of slow wave propagation through the intestinal tube, the occurrence of propagation blocks along its length, which explains the well-known decrease in frequency, and the specific propagation pattern of the spikes that follow the slow waves. But the value of high-resolution mapping is highest in discovering and analysing mechanisms of arrhythmias in the gut. Most recently, circus movements (also called 're-entries') have been described in the small intestine in several species. Moreover, several types of re-entries have now been described, some similar to what may occur in the heart, such as functional re-entries, but others more unique to the small intestine, such as circumferential re-entry. These findings seem to suggest the possibilities of hitherto unknown pathologies that may be present in the small intestine. PMID:25156937

  2. Catalycity of Zirconia and of ZrB2-Based Ultra-High Temperature Ceramics

    NASA Astrophysics Data System (ADS)

    Balat-Pichelin, M.; Passarelli, M.; Scatteia, L.; Alfano, D.

    2009-01-01

    Catalytic recombination of dissociated atmospheric oxygen molecules on the surface of thermal protection systems located on nose and leading edges is a significant additional heat source during the atmospheric re-entry of a space vehicle. Typically, thermal protection systems (TPS) of re-entry vehicles are designed considering the constituent materials as fully catalytic, a strongly conservative assumption that can lead to marked structural over-dimensioning of the TPS overall mass required. However, mass, performance, and cost considerations in future re-usable re-entry vehicles require a more sensible design approach based upon a more realistic assumption of partial catalycity. Ground test simulation under atmospheric reentry conditions is therefore necessary to characterize and select base materials for TPS. Very high temperature and low pressure air plasma are reproduced within the MESOX facility - out of equilibrium plasma - with a degree of dissociation of oxygen reaching 80 % for an earth entry phase. In this paper, experimental results are given on the catalytic properties of Ultra-High Temperature Ceramics based on zirconium- and hafnium- diborides: these ceramic compounds represent a promising class of new TPS materials for the manufacturing of slender- shaped hot structures in hypersonic re-entry vehicles. Two different UHTC compounds, produced by hot pressing and machined into their final shape by mean of electrical discharge machining or, alternatively, by diamond-tooling were tested in the temperature range 900-2500 K. Three different kinds of zirconia (sintering additives) were also tested in the same temperature range. The effects of the crystalline structure of zirconia materials and the one of surface machining for the zirconium diboride based ceramics are underlined.

  3. On-ground casualty risk reduction by structural design for demise

    NASA Astrophysics Data System (ADS)

    Lemmens, Stijn; Funke, Quirin; Krag, Holger

    2015-06-01

    In recent years, awareness concerning the on-ground risk posed by un-controlled re-entering space systems has increased. On average over the past decade, an object with mass above 800 kg re-enters every week from which only a few, e.g. ESA's GOCE in 2013 and NASA's UARS in 2011, appeared prominent in international media. Space agencies and nations have discussed requirements to limit the on-ground risk for future missions. To meet the requirements, the amount of debris falling back on Earth has to be limited in number, mass and size. Design for demise (D4D) refers to all measures taken in the design of a space object to increase the potential for demise of the object and its components during re-entry. SCARAB (Spacecraft Atmospheric Re-entry and Break-Up) is ESA's high-fidelity tool which analyses the thermal and structural effects of atmospheric re-entry on spacecraft with a finite-element approach. For this study, a model of a representative satellite is developed in SCARAB to serve as test-bed for D4D analyses on a structural level. The model is used as starting point for different D4D approaches based on increasing the exposure of the satellite components to the aero-thermal environment, as a way to speed up the demise. Statistical bootstrapping is applied to the resulting on-ground fragment lists in order to compare the different re-entry scenarios and to determine the uncertainties of the results. Moreover, the bootstrap results can be used to analyse the casualty risk estimator from a theoretical point of view. The risk reductions for the analysed D4D techniques are presented with respect to the reference scenario for the modelled representative satellite.

  4. Size Distribution of Genesis Solar Wind Array Collector Fragments Recovered

    NASA Technical Reports Server (NTRS)

    Allton, J. H.; Stansbery, E. K.; McNamara, K. M.

    2005-01-01

    Genesis launched in 2001 with 271 whole and 30 half hexagonally-shaped collectors mounted on 5 arrays, comprised of 9 materials described in [1]. The array collectors were damaged during re-entry impact in Utah in 2004 [2], breaking into many smaller pieces and dust. A compilation of the number and approximate size of the fragments recovered was compiled from notes made during the field packaging performed in the Class 10,000 cleanroom at Utah Test and Training Range [3].

  5. The prospect of responsive spacecraft using aeroassisted, trans-atmospheric maneuvers

    NASA Astrophysics Data System (ADS)

    Bettinger, Robert A.

    Comprised of exo- and trans-atmospheric trajectory segments, atmospheric re-entry represents a complex dynamical event which traditionally signals the mission end-of-life for low-Earth orbit (LEO) spacecraft, both manned and unmanned. Transcending this paradigm, atmospheric re-entry can be employed as a means of operational maneuver whereby the aerodynamic forces of the upper atmosphere can be exploited to create an aeroassisted maneuver. Utilizing a notional trans-atmospheric, lifting re-entry vehicle with L/D=6, the first phase of research demonstrates the terrestrial reachability potential for skip entry aeroassisted maneuvers. By overflying a geographically diverse set of sample ground targets, comparative analysis indicates a significant savings in DeltaV expenditure for skip entry compared with planar phasing and simple plane change exo-atmospheric maneuvers. In the second phase, the Design of Experiments method of orthogonal arrays provides optimal vehicle and skip entry trajectory designs by employing main effects and Pareto front analysis. Depending on the chosen re-circularization altitude, the coupled optimal design can achieve an inclination change of 19.91 deg with 50-85% less DeltaV than a simple plane change. Finally, the third phase introduces the descent-boost aeroassisted maneuver as an alternative to combined Hohmann and bi-elliptic transfers in order to perform LEO injection. Compared with bi-elliptic transfers, simulations demonstrate that a lifting re-entry vehicle with L/D=6 performing a descent-boost maneuver requires 6-12% less DeltaV for injection into orbits lower than 650 km. In addition, the third phase also introduces the "Maneuver Performance Number" as a dimensionless means of comparative effectiveness analysis for both exo- and trans-atmospheric maneuvers.

  6. Detection of atrial-flutter and atrial-fibrillation waveforms by fetal magnetocardiogram.

    PubMed

    Kandori, A; Hosono, T; Kanagawa, T; Miyashita, S; Chiba, Y; Murakami, M; Miyashita, T; Tsukada, K

    2002-03-01

    Two cases of fetal tachycardia are reported: atrial flutter and fibrillation. The waveforms from each case were detected by fetal magnetocardiograms (FMCGs) using a 64-channel superconducting quantum interference device (SQUID) system. Because the magnitude of supraventricular arrhythmia signals is very weak, two subtraction methods were used to detect the fetal MCG waveforms: subtraction of the maternal MCG signal, and subtraction of the fetal ORS complex signal. It was found that atrial-flutter waveforms showed a cyclic pattern and that atrial-fibrillation waveforms showed f-waves with a random atrial rhythm. Fast Fourier transform analysis determined the main frequency of the atrial flutter to be about 7Hz, and the frequency distribution of atrial fibrillation consisted of small, broad peaks. To visualise the current pattern, current-arrow maps, which simplify the observation of pseudo-current patterns in fetal hearts, of the averaged atrial flutter and fibrillation waveforms were produced. The map of the atrial flutter had a circular pattern, indicating a re-entry circuit, and the map of the atrial fibrillation indicated one wavelet, which was produced by a micro-re-entry circuit. It is thus concluded that an FMCG can detect supraventricular arrhythmia, which can be characterised by re-entry circuits, in fetuses. PMID:12043803

  7. Impact of Vehicle Flexibility on IRVE-II Flight Dynamics

    NASA Technical Reports Server (NTRS)

    Bose, David M.; Toniolo, Matthew D.; Cheatwood, F. M.; Hughes, Stephen J.; Dillman, Robert A.

    2011-01-01

    The Inflatable Re-entry Vehicle Experiment II (IRVE-II) successfully launched from Wallops Flight Facility (WFF) on August 17, 2009. The primary objectives of this flight test were to demonstrate inflation and re-entry survivability, assess the thermal and drag performance of the reentry vehicle, and to collect flight data for refining pre-flight design and analysis tools. Post-flight analysis including trajectory reconstruction outlined in O Keefe3 demonstrated that the IRVE-II Research Vehicle (RV) met mission objectives but also identified a few anomalies of interest to flight dynamics engineers. Most notable of these anomalies was high normal acceleration during the re-entry pressure pulse. Deflection of the inflatable aeroshell during the pressure pulse was evident in flight video and identified as the likely cause of the anomaly. This paper provides a summary of further post-flight analysis with particular attention to the impact of aeroshell flexibility on flight dynamics and the reconciliation of flight performance with pre-flight models. Independent methods for estimating the magnitude of the deflection of the aeroshell experienced on IRVE-II are discussed. The use of the results to refine models for pre-flight prediction of vehicle performance is then described.

  8. Conceptual design of an Orbital Debris Defense System

    NASA Technical Reports Server (NTRS)

    Bedillion, Erik; Blevins, Gary; Bohs, Brian; Bragg, David; Brown, Christopher; Casanova, Jose; Cribbs, David; Demko, Richard; Henry, Brian; James, Kelly

    1994-01-01

    Man made orbital debris has become a serious problem. Currently NORAD tracks over 7000 objects in orbit and less than 10 percent of these are active payloads. Common estimates are that the amount of debris will increase at a rate of 10 percent per year. Impacts of space debris with operational payloads or vehicles is a serious risk to human safety and mission success. For example, the impact of a 0.2 mm diameter paint fleck with the Space Shuttle Challenger window created a 2 mm wide by 0.6 mm deep pit. The cost to replace the window was over $50,000. A conceptual design for a Orbital Debris Defense System (ODDS) is presented which considers a wide range of debris sizes, orbits and velocities. Two vehicles were designed to collect and remove space debris. The first would attach a re-entry package to de-orbit very large debris, e.g. inactive satellites and spent upper stages that tend to break up and form small debris. This vehicle was designed to contain several re-entry packages, and be refueled and resupplied with more re-entry packages as needed. The second vehicle was designed to rendezvous with and capture debris ranging from 10 cm to 2 m. Due to tracking limitations, no technically feasible method for collecting debris below 10 cm in size could be devised; it must be accomplished through international regulations which reduce the accumulation of space debris.

  9. The IXV Ground Segment design, implementation and operations

    NASA Astrophysics Data System (ADS)

    Martucci di Scarfizzi, Giovanni; Bellomo, Alessandro; Musso, Ivano; Bussi, Diego; Rabaioli, Massimo; Santoro, Gianfranco; Billig, Gerhard; Gallego Sanz, José María

    2016-07-01

    The Intermediate eXperimental Vehicle (IXV) is an ESA re-entry demonstrator that performed, on the 11th February of 2015, a successful re-entry demonstration mission. The project objectives were the design, development, manufacturing and on ground and in flight verification of an autonomous European lifting and aerodynamically controlled re-entry system. For the IXV mission a dedicated Ground Segment was provided. The main subsystems of the IXV Ground Segment were: IXV Mission Control Center (MCC), from where monitoring of the vehicle was performed, as well as support during pre-launch and recovery phases; IXV Ground Stations, used to cover IXV mission by receiving spacecraft telemetry and forwarding it toward the MCC; the IXV Communication Network, deployed to support the operations of the IXV mission by interconnecting all remote sites with MCC, supporting data, voice and video exchange. This paper describes the concept, architecture, development, implementation and operations of the ESA Intermediate Experimental Vehicle (IXV) Ground Segment and outlines the main operations and lessons learned during the preparation and successful execution of the IXV Mission.

  10. Conceptual design of an Orbital Debris Defense System

    NASA Astrophysics Data System (ADS)

    Bedillion, Erik; Blevins, Gary; Bohs, Brian; Bragg, David; Brown, Christopher; Casanova, Jose; Cribbs, David; Demko, Richard; Henry, Brian; James, Kelly

    1994-08-01

    Man made orbital debris has become a serious problem. Currently NORAD tracks over 7000 objects in orbit and less than 10 percent of these are active payloads. Common estimates are that the amount of debris will increase at a rate of 10 percent per year. Impacts of space debris with operational payloads or vehicles is a serious risk to human safety and mission success. For example, the impact of a 0.2 mm diameter paint fleck with the Space Shuttle Challenger window created a 2 mm wide by 0.6 mm deep pit. The cost to replace the window was over $50,000. A conceptual design for a Orbital Debris Defense System (ODDS) is presented which considers a wide range of debris sizes, orbits and velocities. Two vehicles were designed to collect and remove space debris. The first would attach a re-entry package to de-orbit very large debris, e.g. inactive satellites and spent upper stages that tend to break up and form small debris. This vehicle was designed to contain several re-entry packages, and be refueled and resupplied with more re-entry packages as needed. The second vehicle was designed to rendezvous with and capture debris ranging from 10 cm to 2 m. Due to tracking limitations, no technically feasible method for collecting debris below 10 cm in size could be devised; it must be accomplished through international regulations which reduce the accumulation of space debris.

  11. Orbiter Trajectory Analysis for a Two-Stage Reusable Launch Vehicle

    NASA Technical Reports Server (NTRS)

    Cowling, Adam L.

    2011-01-01

    Trajectory analysis performed on NASA's reference two-stage-to-orbit launch vehicle upper stage will be presented. The work was completed in support of the Hypersonics Multidisciplinary Analysis and Optimization effort for the NASA-Air Force Joint System Study. Three degree-of-freedom (3-DOF) untrimmed trajectory analysis was performed for the orbiter ascent, closure and re-entry. An iterative closure process resulted in a 333,000 lb initial mass for the orbiter. The re-entry trajectory satisfied heating constraints for all payload out cases and met the constraints with reduced margins for payload in cases. Abort trajectories for engine out at staging, engine out during ascent, and failure to circularize in orbit, gave insight to the robustness of the orbiter. A trimmed ascent trajectory defined an engine gimbal location and the body flap angle best suited for maximizing injected mass. A trimmed re-entry trajectory revealed a need to update the trim routine to accommodate full flap aerodynamic data.

  12. Sonic hedgehog initiates cochlear hair cell regeneration through downregulation of retinoblastoma protein

    SciTech Connect

    Lu, Na; Chen, Yan; Wang, Zhengmin; Chen, Guoling; Lin, Qin; Chen, Zheng-Yi; Li, Huawei

    2013-01-11

    Highlights: Black-Right-Pointing-Pointer Shh activation in neonatal cochleae enhances sensory cell proliferation. Black-Right-Pointing-Pointer Proliferating supporting cells can transdifferentiate into hair cells. Black-Right-Pointing-Pointer Shh promotes proliferation by transiently modulating pRb activity. Black-Right-Pointing-Pointer Shh inhibits pRb by inhibiting transcription and increasing phosphorylation of pRb. -- Abstract: Cell cycle re-entry by cochlear supporting cells and/or hair cells is considered one of the best approaches for restoring hearing loss as a result of hair cell damage. To identify mechanisms that can be modulated to initiate cell cycle re-entry and hair cell regeneration, we studied the effect of activating the sonic hedgehog (Shh) pathway. We show that Shh signaling in postnatal rat cochleae damaged by neomycin leads to renewed proliferation of supporting cells and hair cells. Further, proliferating supporting cells are likely to transdifferentiate into hair cells. Shh treatment leads to inhibition of retinoblastoma protein (pRb) by increasing phosphorylated pRb and reducing retinoblastoma gene transcription. This results in upregulation of cyclins B1, D2, and D3, and CDK1. These results suggest that Shh signaling induces cell cycle re-entry in cochlear sensory epithelium and the production of new hair cells, in part by attenuating pRb function. This study provides an additional route to modulate pRb function with important implications in mammalian hair cell regeneration.

  13. Effects of Low Activity Solar Cycle on Orbital Debris Lifetime

    NASA Technical Reports Server (NTRS)

    Cable, Samual B.; Sutton, Eric K.; Lin, chin S.; Liou, J.-C.

    2011-01-01

    Long duration of low solar activity in the last solar minimum has an undesirable consequence of extending the lifetime of orbital debris. The AFRL TacSat-2 satellite decommissioned in 2008 has finally re-entered into the atmosphere on February 5th after more than one year overdue. Concerning its demise we have monitored its orbital decay and monthly forecasted Tacsat-2 re-entry since September 2010 by using the Orbital Element Prediction (OEP) model developed by the AFRL Orbital Drag Environment program. The model combines estimates of future solar activity with neutral density models, drag coefficient models, and an orbit propagator to predict satellite lifetime. We run the OEP model with solar indices forecast by the NASA Marshall Solar Activity Future Estimation model, and neutral density forecast by the MSIS-00 neutral density model. Based on the two line elements in 2010 up to mid September, we estimated at a 50% confidence level TacSat-2's re-entry time to be in early February 2011, which turned out to be in good agreement with Tacsat-2's actual re-entry date. The potential space weather effects of the coming low activity solar cycle on satellite lifetime and orbital debris population are examined. The NASA long-term orbital debris evolutionary model, LEGEND, is used to quantify the effects of solar flux on the orbital debris population in the 200-600 km altitude environment. The results are discussed for developing satellite orbital drag application product.

  14. Cell cycle inhibition as a strategy for treatment of central nervous system diseases which must not block normal neurogenesis

    PubMed Central

    Liu, Da-Zhi; Ander, Bradley P.; Sharp, Frank R.

    2009-01-01

    Classically, the cell cycle is regarded as the central process leading to cellular proliferation. However, increasing evidence over the last decade supports the notion that neuronal cell cycle re-entry results in post-mitotic death. A mature neuron that re-enters the cell cycle can neither advance to a new G0 quiescent state nor revert to its earlier G0 state. This presents a critical dilemma to the neuron from which death may be an unavoidable, but necessary, outcome for adult neurons attempting to complete the cell cycle. In contrast, tumor cells that undergo aberrant cell cycle re-entry divide and can survive. Thus, cell cycle inhibition strategies are of interest in cancer treatment, but may also represent an important means of protecting neurons. In this review, we put forth the concept of the “expanded cell cycle” and summarize the cell cycle proteins, signal transduction events and mitogenic molecules that can drive a neuron into the cell cycle in various CNS diseases. We also discuss the pharmacological approaches that interfere with the mitogenic pathways and prevent mature neurons from attempting cell cycle re-entry, protecting them from cell death. Lastly, future attempts at blocking the cell cycle to rescue mature neurons from injury should be designed so as to not block normal neurogenesis. PMID:19944161

  15. Dynamical and thermal qualification of the C-SiC nose for the IXV

    NASA Astrophysics Data System (ADS)

    Buffenoir, François; Escafre, David; Brault, Tiana; Rival, Loic; Girard, Florent

    2016-07-01

    The Intermediate experimental Vehicle (IXV) atmospheric re-entry demonstrator, developed within the FLPP (Future Launcher Preparatory Program) and funded by ESA, was aimed at developing a demonstration vehicle that gave Europe a unique opportunity to increase its knowledge in the field of advanced atmospheric re-entry technologies. Within this program, HERAKLES, Safran Group, was in charge of the TPS of the windward and nose assemblies of the vehicle, and has developed and manufactured SepcarbInox® Ceramic Matrix Composite (CMC) protection systems that provided a high temperature resistant nonablative outer mold line (OML) for enhanced aerodynamic control. A key component of this TPS is the nose assembly, which is one the most loaded part during re-entry. The paper describes the analysis activities that led to the qualification of the nose assembly, through two activities: Dynamical behavior of the nose. Thermal behavior of the nose For both cases, the paper shows how FE models, compared with tests results, led to the understanding and simulation of the nose assembly behavior, allowing HERAKLES to confirm the design margins before flight.

  16. Incarcerated Veterans Outreach Program.

    PubMed

    Schaffer, Bradley J

    2016-01-01

    The objective of this study is to identify and facilitate re-entry services for military veterans in the Criminal Justice System through the Incarcerated Veteran Outreach Program. Veterans are explored as a subgroup of the general inmate jail populations in southern Ohio based upon veteran's status, military discharges, service-related injuries, treatment needs, pre-release planning, and re-entry services. Veterans reported having psycho-social problems, diverse levels of criminality, criminogenic needs, and significant episodes of homelessness. A sample of 399 incarcerated veterans in state prison, county jails, and community corrections setting were identified and completed the psycho-social pre-release assessment. Their average age was 44.6; they were more likely to be White males, divorced, most honorably discharged, and were represented in the following eras: 34% Vietnam, 35% post-Vietnam, 26% Persian Gulf War, and 5% Operation Iraqi Freedom/Operation Enduring Freedom. The findings encourage the development of a re-entry outreach model and strategies to prevent episodes of criminal recidivism. PMID:25975930

  17. Social reintegration of traumatic brain-injured: the French experience.

    PubMed

    Truelle, J-L; Wild, K Von; Onillon, M; Montreuil, M

    2010-01-01

    Traumatic Brain Injury (TBI) may lead to specific handicap, often hidden, mainly due to cognitive and behavioural sequelae. Social re-entry is a long-term, fluctuant and precarious process. The French experience will be illustrated by 6 initiatives answering to 6 challenges to do with TBI specificities:1. bridging the gap, between initial rehabilitation and community re-entry, via transitional units dealing with assessment, retraining, social/vocational orientation and follow-up. Today, there are 30 such units based on multidisciplinary teams.2. assessing recovery by TBI-specific and validated evaluation tools: EBIS holistic document, BNI Screening of higher cerebral functions, Glasgow outcome extended, and QOLIBRI, a TBI-specific quality of life tool.3. promoting specific re-entry programmes founded on limited medication, ecological neuro-psychological rehabilitation, exchange groups and workshops, violence prevention, continuity of care, environmental structuration, and "resocialisation".4. taking into account the "head injured family"5. facilitating recovery after sports-related concussion6. facing medico-legal consequences and compensation: In that perspective, we developed guidelines for TBI-specific expert appraisal, including mandatory neuro-psychological assessment, family interview and an annual forum gathering lawyers and health professionals. PMID:22028740

  18. Demisable Reaction-Wheel Assembly

    NASA Technical Reports Server (NTRS)

    Roder, Russell; Ahronovich, Eliezer; Davis, Milton C., III

    2008-01-01

    A document discusses the concept of a demisable motor-drive-and-flywheel assembly [reaction-wheel assembly (RWA)] used in controlling the attitude of a spacecraft. Demisable as used here does not have its traditional legal meaning; instead, it signifies susceptible to melting, vaporizing, and/or otherwise disintegrating during re-entry of the spacecraft into the atmosphere of the Earth so as not to pose a hazard to anyone or anything on the ground. Prior RWAs include parts made of metals (e.g., iron, steel, and titanium) that melt at high temperatures and include structures of generally closed character that shield some parts (e.g., magnets) against re-entry heating. In a demisable RWA, the flywheel would be made of aluminum, which melts at a lower temperature. The flywheel web would not be a solid disk but would have a more open, nearly-spoke-like structure so that it would disintegrate more rapidly; hence, the flywheel rim would separate more rapidly so that parts shielded by the rim would be exposed sooner to re-entry heating. In addition, clearances between the flywheel and other components would be made greater, imparting a more open character and thus increasing the exposure of those components.

  19. Occupational competence and its relationship to emotional health in injured workers in return to work programs: a Malaysian study.

    PubMed

    Murad, Mohd Suleiman; O'brien, Lisa; Farnworth, Louise; Chien, Chi-Wen

    2013-03-01

    Workers with musculoskeletal disorders undertaking Malaysia's return to work (RTW) programmes may experience challenges in occupational competence (OC) and negative emotional states (NES). This study aimed to measure and examines the OC and NES of the workers by comparing specific comparison groups and groups of different phases. A total of 76 participants were recruited from a national RTW programme and categorized into three groups based on different RTW phases: off-work (n = 22), re-entry (n = 31), and maintenance (n = 23). Self-report questionnaires consisted of the Occupational Self Assessment version 2.2 and the Depression, Anxiety and Stress Scale-21. Results showed that injured workers exhibited significantly lower OC in comparison with an international group with various disabilities. In contrast, there was significantly higher NES when compared with Malaysia's general population. Significant differences in OC and NES were also found between workers in the three RTW phases. In particular, OC and NES in the off-work and re-entry phases were significantly lower (OC) and higher (NES) than in the maintenance phase. Furthermore, there was a moderate, negative correlation between OC and NES in the off-work and re-entry phase groups. This indicated that low levels of perceived OC were associated with higher levels of NES.

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

    NASA Astrophysics Data System (ADS)

    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

  1. ESTIMATING THE BENEFIT OF TRMM TROPICAL CYCLONE DATA IN SAVING LIVES

    NASA Technical Reports Server (NTRS)

    Adler, Robert F.

    2005-01-01

    The Tropical Rainfall Measuring Mission (TRMM) is a joint NASA/JAXA research mission launched in late 1997 to improve our knowledge of tropical rainfall processes and climatology (Kummerow et ai., 2000; Adler et ai., 2003). In addition to being a highly successful research mission, its data are available in real time and operational weather agencies in the U.S. and internationally are using TRMM data and images to monitor and forecast hazardous weather (tropical cyclones, floods, etc.). For example, in 2004 TRMM data were used 669 times for determining tropical cyclone location fixes (National Research Council, 2004). TRMM flies at a relatively low altitude, 400 km, and requires orbit adjustment maneuvers to maintain altitude against the small drag of the atmosphere. There is enough fuel used for these maneuvers remaining on TRMM for the satellite to continue flying until 2011-12. However, most of the remaining fuel may be used to perform a controlled re-entry of the satellite into the Pacific Ocean. The fuel threshold for this operation will be reached in the summer of 2005, although the maneuver would actually occur in late 2006 or 2007. The full science mission would end in 2005 under the controlled re-entry option. This re-entry option is related to the estimated probability of injury (1/5,000) that might occur during an uncontrolled re-entry of the satellite. If the estimated probability of injury exceeds 1/10,000 a satellite is a candidate for a possible controlled re-entry. In the TRMM case the NASA Safety Office examined the related issues and concluded that, although TRMM exceeded the formal threshold, the use of TRMM data in the monitoring and forecasting of hazardous weather gave a public safety benefit that compensated for TRMM slightly exceeding the orbital debris threshold (Martin, 2002). This conclusion was based in part on results of an independent panel during a workshop on benefits of TRMM data in concluded that the benefit of TRMM data in saving

  2. Base Flow Investigation of the Apollo AS-202 Command Module. Chapter 6

    NASA Technical Reports Server (NTRS)

    Walpot, Louis M. G.; Wright, Michael J.; Noeding, Peter; Schrijer, Ferry

    2011-01-01

    In recent years, both Europe and the US are developing hypersonic research and operational vehicles. These include (re)entry capsules (both ballistic and lifting) and lifting bodies such as ExoMars, EXPERT, ARV, CEV and IXV. The research programs are meant to enable technology and engineering capabilities to support during the next decade the development of affordable (possibly reusable) space transportation systems as well as hypersonic weapons systems for time critical targets. These programs have a broad range of goals, ranging from the qualification of thermal protection systems, the assessment of RCS performances, the development of GNC algorithms, to the full demonstration of the performance and operability of the integrated vehicles. Since the aerothermodynamic characteristics influence nearly all elements of the vehicle design, the accurate prediction of the aerothermal environment is a prerequisite for the design of efficient hypersonic systems. Significant uncertainties in the prediction of the hypersonic aerodynamic and the aerothermal loads can lead to conservative margins in the design of the vehicle including its Outer Mould Line (OML), thermal protection system, structure, and required control system robustness. The current level of aerothermal prediction uncertainties results therefore in reduced vehicle performances (e.g., sub-optimal payload to mass ratio, increased operational constraints). On the other hand, present computational capabilities enable the simulation of three dimensional flow fields with complex thermo-chemical models over complete trajectories and ease the validation of these tools by, e.g., reconstruction of detailed wind tunnel tests performed under identified and controlled conditions (flow properties and vehicle attitude in particular). These controlled conditions are typically difficult to achieve when performing in flight measurements which in turn results in large associated measurement uncertainties. Similar problems arise

  3. RITD – Wind tunnel testing

    NASA Astrophysics Data System (ADS)

    Haukka, Harri; Harri, Ari-Matti; Aleksashkin, Sergei; Koryanov, Valeri; Schmidt, Walter; Heilimo, Jyri; Finchenko, Valeri; Martynov, Maxim; Ponomarenko, Andrey; Kazakovtsev, Victor; Arruego, Ignazio

    2015-04-01

    An atmospheric re-entry and descent and landing system (EDLS) concept based on inflatable hypersonic decelerator techniques is highly promising for the Earth re-entry missions. We developed such EDLS for the Earth re-entry utilizing a concept that was originally developed for Mars. This EU-funded project is called RITD - Re-entry: Inflatable Technology Development - and it was to assess the bene¬fits 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 develope 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. The RITD entry and descent system utilizes an inflatable hypersonic decelerator. Development of such system requires a combination of wind tunnel tests and numerical simulations. This included wind tunnel tests both in transsonic and subsonic regimes. The principal aim of the wind tunnel tests was the determination of the RITD damping factors in the Earth atmosphere and recalculation of the results for the case of the vehicle descent in the Mars atmosphere. The RITD mock-up model used in the tests was in scale of 1:15 of the real-size vehicle as the dimensions were (midsection) diameter of 74.2 mm and length of 42 mm. For wind tunnel testing purposes the frontal part of the mock-up model body was manufactured by using a PolyJet 3D printing technology based on the light curing of liquid resin. The tail part of the mock-up model body was manufactured of M1 grade copper. The structure of the mock-up model placed th center of gravity in the same position as that of the real-size RITD. The wind tunnel test program included the defining of the damping factor at seven values of Mach numbers 0.85; 0.95; 1.10; 1.20; 1.25; 1.30 and 1.55 with the angle of attack ranging from 0 degree to 40 degrees with the step of 5 degrees. The damping characteristics of

  4. Collisional radiative coarse-grain model for ionization in air

    NASA Astrophysics Data System (ADS)

    Panesi, Marco; Lani, Andrea

    2013-05-01

    We present a reduced kinetic mechanism for the modeling of the behavior of the electronic states of the atomic species in air mixtures. The model is built by lumping the electronically excited states of the atomic species and by performing Maxwell-Boltzmann averages of the rate constants describing the elementary kinetic processes of the individual states within each group. The necessary reaction rate coefficients are taken from the model compiled by Bultel et al. ["Collisional-radiative model in air for earth re-entry problems," Phys. Plasmas 13, 043502 (2006), 10.1063/1.2194827]. The reduced number of pseudo-states considered leads to a significant reduction of the computational cost, thus enabling the application of the state of the art collisional radiative models to bi-dimensional and three-dimensional problems. The internal states of the molecular species are assumed to be in equilibrium. The rotational energy mode is assumed to quickly equilibrate with the translational energy mode at the kinetic temperature of the heavy species as opposed to the electronic and the vibrational modes, assumed to be in Maxwell-Boltzmann equilibrium at a common temperature TV. In a first step we validate the model by using simple zero- and one-dimensional test cases for which the full kinetic mechanism can be run efficiently. Finally, the reduced kinetic model is used to analyze the strong non-equilibrium flow surrounding the FIRE II flight experiment during the early part of its re-entry trajectory. It is found that the reduced kinetic mechanism is capable of reproducing the ionizational non-equilibrium phenomena, responsible for the drastic reduction of the radiative heat loads on the space capsules during the re-entry phase.

  5. A microRNA network regulates proliferative timing and extracellular matrix synthesis during cellular quiescence in fibroblasts

    PubMed Central

    2012-01-01

    Background Although quiescence (reversible cell cycle arrest) is a key part in the life history and fate of many mammalian cell types, the mechanisms of gene regulation in quiescent cells are poorly understood. We sought to clarify the role of microRNAs as regulators of the cellular functions of quiescent human fibroblasts. Results Using microarrays, we discovered that the expression of the majority of profiled microRNAs differed between proliferating and quiescent fibroblasts. Fibroblasts induced into quiescence by contact inhibition or serum starvation had similar microRNA profiles, indicating common changes induced by distinct quiescence signals. By analyzing the gene expression patterns of microRNA target genes with quiescence, we discovered a strong regulatory function for miR-29, which is downregulated with quiescence. Using microarrays and immunoblotting, we confirmed that miR-29 targets genes encoding collagen and other extracellular matrix proteins and that those target genes are induced in quiescence. In addition, overexpression of miR-29 resulted in more rapid cell cycle re-entry from quiescence. We also found that let-7 and miR-125 were upregulated in quiescent cells. Overexpression of either one alone resulted in slower cell cycle re-entry from quiescence, while the combination of both together slowed cell cycle re-entry even further. Conclusions microRNAs regulate key aspects of fibroblast quiescence including the proliferative state of the cells as well as their gene expression profiles, in particular, the induction of extracellular matrix proteins in quiescent fibroblasts. PMID:23259597

  6. Use of Chemical Pesticides in Ethiopia: A Cross-Sectional Comparative Study on Knowledge, Attitude and Practice of Farmers and Farm Workers in Three Farming Systems.

    PubMed

    Negatu, Beyene; Kromhout, Hans; Mekonnen, Yalemtshay; Vermeulen, Roel

    2016-06-01

    Chemical pesticides, regardless of their inherent hazard, are used intensively in the fast changing agricultural sector of Ethiopia. We conducted a cross-sectional pesticide Knowledge, Attitude and Practice (KAP) survey among 601 farmers and farm workers (applicators and re-entry workers) in three farming systems [large-scale closed greenhouses (LSGH), large-scale open farms (LSOF), and small-scale irrigated farms (SSIF)]. Main observations were that 85% of workers did not attain any pesticide-related training, 81% were not aware of modern alternatives for chemical pesticides, 10% used a full set of personal protective equipment, and 62% did not usually bath or shower after work. Among applicators pesticide training attendance was highest in LSGH (35%) and was lowest in SSIF (4%). None of the female re-entry farm workers had received pesticide-related training. Personal protective equipment use was twice as high among pesticide applicators as among re-entry workers (13 versus 7%), while none of the small-scale farm workers used personal protection equipment. Stockpiling and burial of empty pesticide containers and discarding empty pesticide containers in farming fields were reported in both LSOF and by 75% of the farm workers in SSIF. Considerable increment in chemical pesticide usage intensity, illegitimate usages of DDT and Endosulfan on food crops and direct import of pesticides without the formal Ethiopian registration process were also indicated. These results point out a general lack of training and knowledge regarding the safe use of pesticides in all farming systems but especially among small-scale farmers. This in combination with the increase in chemical pesticide usage in the past decade likely results in occupational and environmental health risks. Improved KAP that account for institutional difference among various farming systems and enforcement of regulatory measures including the available occupational and environmental proclamations in Ethiopia are

  7. Prediction of STS-107 Hypervelocity Flow Fields about the Shuttle Orbiter with Various Wing Leading Edge Damage

    NASA Technical Reports Server (NTRS)

    Pulsonetti, Maria V.; Thompson, Richard A.; Alter, Stephen J.

    2004-01-01

    Computations were performed for damaged configurations of the Shuttle Orbiter in support of the STS-107 Columbia accident investigation. Two configurations with missing wing leading-edge reinforced carbon-carbon (RCC) panels were evaluated at conditions just prior to the peak heating trajectory point. The initial configuration modeled the Orbiter with an approximate missing RCC panel 6 to determine whether this damage could result in anomalous temperatures measured during the STS-107 reentry. This missing RCC panel 6 computation was found to produce heating augmentation factors of 5 times the nominal heating rates on the side fuselage with lesser heat increases on the front of the OMS pod. This is consistent with the thermocouple and resistance temperature detector sensors from the STS-107 re-entry which observed off nominal high early in the re-entry trajectory. A second damaged configuration modeled the Orbiter with missing RCC panel 9 and included ingestion of the flow into the outboard RCC channel. This computation lowered the level (only 2 times nominal) and moved the location of the heating augmentation on the leeside fuselage relative to the missing RCC panel 6 configuration. The lesser heating augmentation for missing RCC panel 9 was confined near the wing fuselage juncture. Near nominal heating was predicted on the remainder of the side fuselage with some lower than nominal heating on the front surface of the OMS pod. These results for missing RCC panel 9 are consistent with data from the STS-107 re-entry where the heating augmentation was observed to move off the side fuselage and OMS pod sensors at later times in the trajectory. As this solution requires supersonic mass ingestion into the RCC channel, it is probably not an appropriate model prior to penetration of the flow through the spar into the wing structure. It may, however, be representative of the conditions at later times and could account for the movement of the heating signature on the side

  8. Disposal strategy for the geosynchronous orbits of the Beidou Navigation Satellite System

    NASA Astrophysics Data System (ADS)

    Tang, Jingshi; Liu, Lin

    Beidou Navigation Satellite System (BDS) is China's navigation satelite system. It is now operational for navigation service in China and Asia-Pacific region and is due to be fully operational as a global navigation system by 2020. Unlike other navigation satellite systems, BDS consists of both 12-hour medium Earth orbit and 24-hour geosynchronous orbit. To sustain a safe environment for the navigation satellites, the end-of-life satellites must be disposed appropriately so they do not pose potential dangers to the operational satellites. There are currently two strategies for the disposal orbit. One is to put the disposed satellite in a graveyard orbit that has a safe distance from the operational satellites. It is often applied in geosynchronous orbits and such graveyard orbit can always maintain a safe distance even for a few centuries. This strategy is also currently adopted by GPS, yet recent researches show a re-entry orbit can sometimes be a better alternative. The interaction of Earth oblateness and lunisolar gravitation can lead to a rapid increase in the orbit eccentricity such that by proper design the disposed GPS satellite can be cleared out by re-entry into the atmosphere. In this work we focus on the disposal strategy for BDS geosynchronous orbit, which consists of the equatorial stationary orbit (GEO) and the inclined orbit (IGSO). We show that these two orbits are essentially in two different dynamical environments and evolve quite distinctly over a long period of time. Taking advantage of the dynamic nature, we apply the graveyard orbit and the re-entry orbit to GEO and IGSO respectively and propose appropriate disposal strategies accordingly.

  9. Repression of DNA replication licensing in quiescence is independent of geminin and may define the cell cycle state of progenitor cells

    SciTech Connect

    Kingsbury, Sarah R.; Loddo, Marco; Fanshawe, Thomas; Obermann, Ellen C.; Prevost, A. Toby; Stoeber, Kai . E-mail: k.stoeber@ucl.ac.uk; Williams, Gareth H.

    2005-09-10

    The DNA replication (or origin) licensing machinery ensures precise duplication of the genome and contributes to the regulation of proliferative capacity in metazoa. Using an in vitro fibroblast model system coupled to a cell-free DNA replication assay, we have studied regulation of the origin licensing pathway during exit from and re-entry into the mitotic cell cycle. We show that in the quiescent state (G0) loss of proliferative capacity is achieved in part through down-regulation of the replication licensing factors Cdc6 and Mcm2-7. The origin licensing repressor geminin is absent in quiescent fibroblasts, suggesting that this powerful inhibitor of the licensing machinery is not required to suppress proliferative capacity in G0. Geminin expression is induced at a late stage in the G0-S transition post pre-RC assembly. Ectopic geminin can block re-acquisition of DNA replication competence during re-entry into the cell cycle, indicating that geminin levels must be tightly down-regulated for escape from G0. Analysis of geminin levels in thyroid shows that geminin expression is suppressed in anatomical compartments/tissues harbouring quiescent cells, confirming our in vitro data. Spatio-temporal control of geminin expression may therefore be of particular relevance for multi-potential stem cells which cycle infrequently. In support of this hypothesis, we have identified a unique population of cells in the putative stem cell niche of intestinal epithelium that are unlicensed and lack geminin expression, a prerequisite for successful re-entry into cycle. Our data argue that the prolonged cell cycle times observed for intestinal stem cells could be due to exit of progenitor cells from cycle into an unlicensed 'out-of-cycle' state, a powerful mechanism by which rapidly proliferating tissues may resist genotoxic insult.

  10. Potential applications of skip SMV with thrust engine

    NASA Astrophysics Data System (ADS)

    Wang, Weilin; Savvaris, Al

    2016-11-01

    This paper investigates the potential applications of Space Maneuver Vehicles (SMV) with skip trajectory. Due to soaring space operations over the past decades, the risk of space debris has considerably increased such as collision risks with space asset, human property on ground and even aviation. Many active debris removal methods have been investigated and in this paper, a debris remediation method is first proposed based on skip SMV. The key point is to perform controlled re-entry. These vehicles are expected to achieve a trans-atmospheric maneuver with thrust engine. If debris is released at altitude below 80 km, debris could be captured by the atmosphere drag force and re-entry interface prediction accuracy is improved. Moreover if the debris is released in a cargo at a much lower altitude, this technique protects high value space asset from break up by the atmosphere and improves landing accuracy. To demonstrate the feasibility of this concept, the present paper presents the simulation results for two specific mission profiles: (1) descent to predetermined altitude; (2) descent to predetermined point (altitude, longitude and latitude). The evolutionary collocation method is adopted for skip trajectory optimization due to its global optimality and high-accuracy. This method is actually a two-step optimization approach based on the heuristic algorithm and the collocation method. The optimal-control problem is transformed into a nonlinear programming problem (NLP) which can be efficiently and accurately solved by the sequential quadratic programming (SQP) procedure. However, such a method is sensitive to initial values. To reduce the sensitivity problem, genetic algorithm (GA) is adopted to refine the grids and provide near optimum initial values. By comparing the simulation data from different scenarios, it is found that skip SMV is feasible in active debris removal and the evolutionary collocation method gives a truthful re-entry trajectory that satisfies the

  11. Experimental Study Of SHEFEX II Hypersonic Aerodynamics And Canard Efficiency In H2K

    NASA Astrophysics Data System (ADS)

    Neeb, D.; Gulhan, A.

    2011-05-01

    One main objective of the DLR SHEFEX programme is to prove that sharp edged vehicles are capable of performing a re-entry into earth atmosphere by using a simple thermal protection system consisting of flat ceramic tiles. In comparison to blunt nose configurations like the Space shuttle, which are normally used for re-entry configurations, the SHEFEX TPS design is able to significantly reduce the costs and complexity of TPS structures and simultaneously increase the aerodynamic performance of the flight vehicle [1], [2]. To study its characteristics and perform several defined in-flight experiments during re-entry, the vehicle’s attitude will be controlled actively by canards [3]. In the framework of the SHEFEX II project an experimental investigation has been conducted in the hypersonic wind tunnel H2K to characterize the aerodynamic performance of the vehicle in hypersonic flow regime. The model has a modular design to enable the study of a variety of different influencing parameters. Its 4 circumferential canards have been made independently adjustable to account for the simulation of different manoeuvre conditions. To study the control behaviour of the vehicle and validate CFD data, a variation of canard deflections, angle of attack and angle of sideslip have been applied. Tests have been carried out at Mach 7 and 8.7 with a Reynolds number sensitivity study at the lower Mach number. The model was equipped with a six component internal balance to realize accurate coefficient measurements. The flow topology has been analyzed using Schlieren images. Beside general aerodynamic performance and canard efficiencies, flow phenomena like shock impingement on the canards could be determined by Schlieren images as well as by the derived coefficients.

  12. CubeSat Material Limits for Design for Demise

    NASA Technical Reports Server (NTRS)

    Kelley, R. L.; Jarkey, D. R.

    2014-01-01

    The CubeSat form factor of nano-satellite (a satellite with a mass between one and ten kilograms) has grown in popularity due to their ease of construction and low development and launch costs. In particular, their use as student led payload design projects has increased due to the growing number of launch opportunities. CubeSats are often deployed as secondary or tertiary payloads on most US launch vehicles or they may be deployed from the ISS. The focus of this study will be on CubeSats launched from the ISS. From a space safety standpoint, the development and deployment processes for CubeSats differ significantly from that of most satellites. For large satellites, extensive design reviews and documentation are completed, including assessing requirements associated with re-entry survivability. Typical CubeSat missions selected for ISS deployment have a less rigorous review process that may not evaluate aspects beyond overall design feasibility. CubeSat design teams often do not have the resources to ensure their design is compliant with re-entry risk requirements. A study was conducted to examine methods to easily identify the maximum amount of a given material that can be used in the construction of a CubeSats without posing harm to persons on the ground. The results demonstrate that there is not a general equation or relationship that can be used for all materials; instead a limiting value must be defined for each unique material. In addition, the specific limits found for a number of generic materials that have been previously used as benchmarking materials for re-entry survivability analysis tool comparison will be discussed.

  13. New methods to detect particle velocity and mass flux in arc-heated ablation/erosion facilities

    NASA Technical Reports Server (NTRS)

    Brayton, D. B.; Bomar, B. W.; Seibel, B. L.; Elrod, P. D.

    1980-01-01

    Arc-heated flow facilities with injected particles are used to simulate the erosive and ablative/erosive environments encountered by spacecraft re-entry through fog, clouds, thermo-nuclear explosions, etc. Two newly developed particle diagnostic techniques used to calibrate these facilities are discussed. One technique measures particle velocity and is based on the detection of thermal radiation and/or chemiluminescence from the hot seed particles in a model ablation/erosion facility. The second technique measures a local particle rate, which is proportional to local particle mass flux, in a dust erosion facility by photodetecting and counting the interruptions of a focused laser beam by individual particles.

  14. Orion Multi-Purpose Crew Vehicle (MPCV) Capsule Parachute Assembly System (CPAS) Wake Deficit Wind Tunnel Testing

    NASA Technical Reports Server (NTRS)

    Ross, James C.; Schuster, David M.

    2014-01-01

    During descent after re-entry into the Earth's atmosphere, the Orion CM deploys its drogue parachutes at approximately Mach 0.7. Accurately predicting the dynamic pressure experienced by the drogue parachutes at deployment is critical to properly designing the parachutes. This NASA Engineering and Safety Center assessment was designed to provide a complete set of flowfield measurements on and around an idealized Orion Crew Module shape with the most appropriate wind tunnel simulation of the Orion flight conditions prior to parachute deployment. This document contains the details of testing and the outcome of the assessment.

  15. Paroxysmal Supraventricular Tachycardia: Pathophysiology, Diagnosis, and Management.

    PubMed

    Al-Zaiti, Salah S; Magdic, Kathy S

    2016-09-01

    Paroxysmal supraventricular tachycardia (PSVT) is a well-known and thoroughly studied clinical syndrome, characterized by regular tachycardia rhythm with sudden onset and abrupt termination. Most patients present with palpitations and dizziness, and their electrocardiogram demonstrates a narrow QRS complex and regular tachycardia with hidden or inverted P waves. PSVT is caused by re-entry due to the presence of inhomogeneous, accessory, or concealed conducting pathways. Hemodynamically stable patients are treated by vagal maneuvers, intravenous adenosine, diltiazem, or verapamil, hemodynamically unstable patients are treated by cardioversion. Patients with symptomatic and recurrent PSVT can be treated with long-term drug treatment or catheter ablation.

  16. Waves in space plasma dipole antenna subsystem

    NASA Technical Reports Server (NTRS)

    Thomson, Mark

    1993-01-01

    The Waves In Space Plasma (WISP) flight experiment requires a 50-meter-long deployable dipole antenna subsystem (DASS) to radiate radio frequencies from the STS Orbiter cargo bay. The transmissions are to excite outer ionospheric plasma between the dipole and a free-flying receiver (Spartan) for scientific purposes. This report describes the singular DASS design requirements and how the resulting design satisfies them. A jettison latch is described in some detail. The latch releases the antenna in case of any problems which might prevent the bay doors from closing for re-entry and landing of the Orbiter.

  17. Embryonic Stem Cell-Derived Microvesicles: Could They be Used for Retinal Regeneration?

    PubMed

    Farber, Debora B; Katsman, Diana

    2016-01-01

    Mouse embryonic stem cells (mESCs) release into the medium in which they are cultured heterogeneous populations of microvesicles (mESMVs), important components of cell-cell communication, that transfer their contents not only to other stem cells but also to cells of other origins. The purpose of these studies was to demonstrate that ESMVs could be the signals that lead the retinal progenitor Müller cells to de-differentiate and re-entry the cell cycle, followed by differentiation along retinal lineages. Indeed, we found that ESMVs induce these processes and change Müller cells' microenvironment towards a more permissive state for tissue regeneration.

  18. Matched asymptotic solutions for a hypervelocity atmospheric entry vehicle

    NASA Astrophysics Data System (ADS)

    O'Neill, Chris F.; McInnes, Colin R.

    1993-10-01

    The trajectories of unguided hypervelocity atmospheric entry vehicles are investigated analytically using the method of matched asymptotic expansions. Ballistic entry into the atmosphere of a spherical, non-rotating planet is solved for using both constant and velocity dependent drag coefficient models. The analytical solutions are used to predict a variety of re-entry parameters and comparisons are made with a variable drag coefficient numerical simulation. The derived relations represent a quick method of obtaining accurate trajectory data without the need for numerical computation and as such appear suitable for onboard guidance purposes.

  19. KSC-04PD-1428

    NASA Technical Reports Server (NTRS)

    2004-01-01

    KENNEDY SPACE CENTER, FLA. Workers in the Orbiter Processing Facility complete the installation of the Reinforced Carbon- Carbon panel on Discovery. The chin panel is the smile-shaped section of RCC directly below the nose cap that provides a thermal barrier during re-entry. The nose cap, with chin panel, was removed from the vehicle in the summer of 2003 and returned to the vendor, where it underwent numerous forms of Non- Destructive Evaluation. These tests included X-ray, ultrasound and eddy current to ensure its structural integrity prior to reinstallation. Discovery is designated as the Return to Flight vehicle for mission STS-114, no earlier than March 2005.

  20. Alzheimer’s Disease Pathologic Cascades: Who Comes First, What Drives What

    PubMed Central

    Swerdlow, Russell H.

    2013-01-01

    This review discusses known and speculated relationships between Alzheimer’s disease (AD) biochemical, molecular, and histologic phenomena. In the AD brain, various pathologies including neuritic plaques, neurofibrillary tangles, synaptic loss, oxidative stress, cell cycle re-entry, and mitochondrial changes have all been described. In an attempt to explain what exactly goes wrong in the AD brain various investigators have proposed different heuristic and hierarchical schemes. It is important to accurately define the AD pathology hierarchy because treatments targeting the true apex of its pathologic cascade arguably have the best chance of preventing, mitigating, or even curing this disease. PMID:21913048

  1. Differential profile and treatment development of drug-addicted patients depending on violent behaviours and/or criminal acts.

    PubMed

    López-Goñi, José J; Fernández-Montalvo, Javier; Arteaga, Alfonso; Cacho, Raúl

    2015-01-01

    This study explored the prevalence of violent and/or criminal behaviors in drug-addicted patients. A sample of 252 drug-addicted patients who sought treatment was assessed. Information was collected on violent behaviors, criminal acts, socio-demographic factors, consumption factors, psychopathological factors, and personality variables. The sample was divided into 4 groups according to the presence of violence and/or criminal behaviors. There were significant differences between the groups on some variables. In general, patients associated with both violence and criminal behaviors showed a greater severity in drug consumption and maladjustment variables, as well as a higher rate of treatment dropout and re-entry.

  2. Differential profile and treatment development of drug-addicted patients depending on violent behaviours and/or criminal acts.

    PubMed

    López-Goñi, José J; Fernández-Montalvo, Javier; Arteaga, Alfonso; Cacho, Raúl

    2015-01-01

    This study explored the prevalence of violent and/or criminal behaviors in drug-addicted patients. A sample of 252 drug-addicted patients who sought treatment was assessed. Information was collected on violent behaviors, criminal acts, socio-demographic factors, consumption factors, psychopathological factors, and personality variables. The sample was divided into 4 groups according to the presence of violence and/or criminal behaviors. There were significant differences between the groups on some variables. In general, patients associated with both violence and criminal behaviors showed a greater severity in drug consumption and maladjustment variables, as well as a higher rate of treatment dropout and re-entry. PMID:25774971

  3. Exploration of Impinging Water Spray Heat Transfer at System Pressures Near the Triple Point

    NASA Technical Reports Server (NTRS)

    Golliher, Eric L.; Yao, Shi-Chune

    2013-01-01

    The heat transfer of a water spray impinging upon a surface in a very low pressure environment is of interest to cooling of space vehicles during launch and re-entry, and to industrial processes where flash evaporation occurs. At very low pressure, the process occurs near the triple point of water, and there exists a transient multiphase transport problem of ice, water and water vapor. At the impingement location, there are three heat transfer mechanisms: evaporation, freezing and sublimation. A preliminary heat transfer model was developed to explore the interaction of these mechanisms at the surface and within the spray.

  4. Polyimide Boosts High-Temperature Performance

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Maverick Corporation, of Blue Ash, Ohio, licensed DMBZ-15 polyimide technology from Glenn Research Center. This ultrahigh-temperature material provides substantial weight savings and reduced machining costs compared to the same component made with more traditional metallic materials. DMBZ-15 has a wide range of applications from aerospace (aircraft engine and airframe components, space transportation systems, and missiles) to non-aerospace (oil drilling, rolling mill), and is particularly well-suited to use as face sheets with honey cones or thermal protection systems for reusable launch vehicles, which encounter elevated temperatures during launch and re-entry.

  5. Sustained Ventricular Tachycardia in Apparently Normal Hearts: Ablation Should Be the First Step in Management.

    PubMed

    Moss, Joshua D; Tung, Roderick

    2016-09-01

    Patients without structural heart disease tend to have fewer morphologies of ventricular tachycardia, with automaticity and triggered activity a more common mechanism than re-entry associated with extremely low risk of sudden death. Ablation can be curative in patients with a single morphology of ventricular tachycardia that is focal in origin, particularly in patients without overt structural heart disease. There are limited data in secondary prevention implantable cardioverter defibrillator literature to support the routine implementation of implantable cardioverter defibrillator in normal hearts. Antiarrhythmic drugs have not been shown to reduce all-cause mortality in patients with and without structural heart disease. PMID:27521095

  6. KSC-03PD-0828

    NASA Technical Reports Server (NTRS)

    2003-01-01

    KENNEDY SPACE CENTER, FLA. - The Orbiter Experiment Support System (OEX) recorder from Columbia, in protective covering, sits on the pavement after its arrival at KSC aboard a T-38 jet aircraft. Search teams near Hemphill, Texas, recovered the recorder, which stores sensor information about temperature, aerodynamic pressure, vibrations and other data from dozens of sensor locations on the orbiter, operating only during launch and re-entry. The OEX uses magnetic tape to record data that is not sent to the ground by telemetry.

  7. 10.2 Thermal-Structural Testing

    NASA Technical Reports Server (NTRS)

    Hudson, Larry D.

    2008-01-01

    Objective: Test a C/SiC Ruddervator Subcomponent under relevant thermal, mechanical & dynamic loading a) Thermal-structural mission cycling for re-entry and hypersonic cruise conditions; b) High-temperature modal survey to study the effect of heating on mode shapes, natural frequencies and damping. Supports NASA ARMD Hypersonics Material & Structures Program. Partners: NASA Dryden / Langley / Glenn, Lockheed-Martin, Materials Research & Design, GE CCP Test Phases - Phase 1: Acoustic-Vibration Testing (LaRC) completed - Phase 2: Thermal-Mechanical Testing (DFRC) in assembly - Phase 3: Mechanical Testing (DFRC) in assembly

  8. The 15 kW sub e (nominal) solar thermal electric power conversion concept definition study: Steam Rankine turbine system

    NASA Technical Reports Server (NTRS)

    Bland, T. J.

    1979-01-01

    A study to define the performance and cost characteristics of a solar powered, steam Rankine turbine system located at the focal point of a solar concentrator is presented. A two stage re-entry turbine with reheat between stages, which has an efficiency of 27% at a turbine inlet temperature of 732 C was used. System efficiency was defined as 60 Hertz electrical output divided by absorbed thermal input in the working fluid. Mass production costs were found to be approximately 364 dollars/KW.

  9. Modeling of transient heat pipe operation

    NASA Technical Reports Server (NTRS)

    Colwell, G. T.; Hartley, J. G.

    1985-01-01

    The overall goal is to gain a better understanding of the transient behavior of heat pipes operating under both normal and adverse conditions. Normal operation refers to cases where the capillary structure remains fully wetted. Adverse operation occurs when drying, re-wetting, choking, noncontinuum flow, freezing, thawing etc., occur within the heat pipe. The work was redirected towards developing the capability to predict operational behavior of liquid metal heat pipes used for cooling aerodynamic structures. Of particular interest is the startup of such heat pipes from an initially frozen state such as might occur during re-entry of a space vehicle into the Earth's atmosphere or during flight of hypersonic aircraft.

  10. Engineering Support of Microgravity Life Science Research: Development of an Avian Development Facility

    NASA Technical Reports Server (NTRS)

    Vellinger, J.; Deuser, M.; Hullinger, R.

    1995-01-01

    The Avian Development Facility (ADF) is designed to provide a 'window' for the study of embryogenesis in space. It allows researchers to determine and then to mitigate or nullify the forces of altered gravity upon embryos when leaving and re-entering the Earth's gravity. The ADF design will allow investigations to begin their incubation after their experiments have achieved orbit, and shut down the experiment and fix specimens before leaving orbit. In effect, the ADF makes every attempt to minimize launch and re-entry effects in order to isolate and preserve the effects of the experimental variable(s) of the space environment.

  11. Technologies involved in configuring an advanced earth-to-orbit transport for low structural mass

    NASA Technical Reports Server (NTRS)

    Macconochie, I. O.; Klich, P. J.

    1980-01-01

    A tradeoff study for a single-stage, earth-to-orbit transport spacecraft configured with low structural mass as the prime objective is presented. Among the major design elements affecting vehicle mass are: maneuverability and re-entry heating, the compatibility of an irregular cargo bay geometry to future mission requirements, the fabrication and assembly of large honeycomb structure fuselage sections, and the development of LOX/LH2 engine extendable nozzles and dual-propulsion schemes. It is shown that vehicle geometry and materials and structural technologies will be the critical areas in the development of such a system.

  12. Aerospace gerontology

    NASA Technical Reports Server (NTRS)

    Comfort, A.

    1982-01-01

    The relevancy of gerontology and geriatrics to the discipline of aerospace medicine is examined. It is noted that since the shuttle program gives the facility to fly passengers, including specially qualified older persons, it is essential to examine response to acceleration, weightlessness, and re-entry over the whole adult lifespan, not only its second quartile. The physiological responses of the older person to weightlessness and the return to Earth gravity are reviewed. The importance of the use of the weightless environment to solve critical problems in the fields of fundamental gerontology and geriatrics is also stressed.

  13. Productivity improvement by frontier horizontal drilling in Italy

    SciTech Connect

    Schenato, A.

    1995-12-31

    Italian domestic activity on horizontal wells has been specially addressed to carbonate reservoir and specifically targeted to re-entry in existing wells. The speech will focus on the specific experience matured in frontier applications in Italy, from 1989 with the short radius drain holes in Sicily, throughout world record deep water short radius in the southern part of Adriatic sea and depth world record medium radius in a HP/HT reservoir in the Po Valley. Production results will be reported as well as the achieved technological aspects.

  14. Planetary Mission Entry Vehicles Quick Reference Guide. Version 3.0

    NASA Technical Reports Server (NTRS)

    Davies, Carol; Arcadi, Marla

    2006-01-01

    This is Version 3.0 of the planetary mission entry vehicle document. Three new missions, Re-entry F, Hayabusa, and ARD have been added to t he previously published edition (Version 2.1). In addition, the Huyge ns mission has been significantly updated and some Apollo data correc ted. Due to the changing nature of planetary vehicles during the desi gn, manufacture and mission phases, and to the variables involved in measurement and computation, please be aware that the data provided h erein cannot be guaranteed. Contact Carol Davies at cdavies@mail.arc. nasa.gov to correct or update the current data, or to suggest other missions.

  15. An Overview of Demise Calculations, Conceptual Design Studies, and Hydrazine Compatibility Testing for the GPM Core Spacecraft Propellant Tank

    NASA Technical Reports Server (NTRS)

    Estes, Robert H.; Moore, N. R.

    2007-01-01

    NASA's Global Precipitation Measurement (GPM) mission is an ongoing Goddard Space Flight Center (GSFC) project whose basic objective is to improve global precipitation measurements. It has been decided that the GPM spacecraft is to be a "design for demise" spacecraft. This requirement resulted in the need for a propellant tank that would also demise or ablate to an appropriate degree upon re-entry. This paper will describe GSFC-performed spacecraft and tankage demise analyses, vendor conceptual design studies, and vendor performed hydrazine compatibility and wettability tests performed on 6061 and 2219 aluminum alloys.

  16. Redefining single-parent families: cohabitation and changing family reality.

    PubMed

    Bumpass, L L; Raley, R K

    1995-02-01

    This paper explores the implications, for the measured prevalence and duration of mother-only families, of marked changes in nonmarital fertility, unmarried cohabitation, and homeleaving and re-entry. Throughout, estimates are compared on the basis of marital definitions and definitions including cohabitation. The duration of the first single-parent spell appears to have increased under the marital definition, but declines substantially when cohabitations are taken into account. A substantial proportion of single mothers have spent some time as single parents while in their parents' household. Hence we argue that definitions of single-parent families must be based on living arrangements rather than on the parents' marital status. PMID:7774733

  17. Paroxysmal Supraventricular Tachycardia: Pathophysiology, Diagnosis, and Management.

    PubMed

    Al-Zaiti, Salah S; Magdic, Kathy S

    2016-09-01

    Paroxysmal supraventricular tachycardia (PSVT) is a well-known and thoroughly studied clinical syndrome, characterized by regular tachycardia rhythm with sudden onset and abrupt termination. Most patients present with palpitations and dizziness, and their electrocardiogram demonstrates a narrow QRS complex and regular tachycardia with hidden or inverted P waves. PSVT is caused by re-entry due to the presence of inhomogeneous, accessory, or concealed conducting pathways. Hemodynamically stable patients are treated by vagal maneuvers, intravenous adenosine, diltiazem, or verapamil, hemodynamically unstable patients are treated by cardioversion. Patients with symptomatic and recurrent PSVT can be treated with long-term drug treatment or catheter ablation. PMID:27484659

  18. STS-87 Mission Specialist Doi in white room

    NASA Technical Reports Server (NTRS)

    1997-01-01

    STS-87 Mission Specialist Takao Doi, Ph.D., of the National Space Development Agency of Japan, is assisted with his ascent and re- entry flight suit by Dave Law, USA mechanical technician, in the white room at Launch Pad 39B as Dr. Doi prepares to enter the Space Shuttle orbiter Columbia on launch day. At right wearing glasses is Danny Wyatt, NASA quality assurance specialist. STS-87 is the fourth flight of the United States Microgravity Payload and Spartan-201. The 16-day mission will include a spacewalk by Dr. Doi and Mission Specialist Winston Scott.

  19. STS-87 Mission Specialist Scott in white room

    NASA Technical Reports Server (NTRS)

    1997-01-01

    STS-87 Mission Specialist Winston Scott is assisted with his ascent and re-entry flight suit in the white room at Launch Pad 39B by Danny Wyatt, NASA quality assurance specialist. STS-87 is the fourth flight of the United States Microgravity Payload and Spartan-201. Scott is scheduled to perform an extravehicular activity spacewalk with Mission Specialist Takao Doi, Ph.D., of the National Space Development Agency of Japan, during STS-87. Scott also performed a spacewalk on the STS-72 mission.

  20. Sensorimotor Adaptation Following Exposure to Ambiguous Inertial Motion Cues

    NASA Technical Reports Server (NTRS)

    Wood, S. J.; Clement, G. R.; Rupert, A. H.; Reschke, M. F.; Harm, D. L.; Guedry, F. E.

    2007-01-01

    The central nervous system must resolve the ambiguity of inertial motion sensory cues in order to derive accurate spatial orientation awareness. Adaptive changes in how inertial cues from the otolith system are integrated with other sensory information lead to perceptual and postural disturbances upon return to Earth s gravity. The primary goals of this ground-based research investigation are to explore physiological mechanisms and operational implications of tilt-translation disturbances during and following re-entry, and to evaluate a tactile prosthesis as a countermeasure for improving control of whole-body orientation during tilt and translation motion.

  1. 2001 Flight Mechanics Symposium

    NASA Technical Reports Server (NTRS)

    Lynch, John P. (Editor)

    2001-01-01

    This conference publication includes papers and abstracts presented at the Flight Mechanics Symposium held on June 19-21, 2001. Sponsored by the Guidance, Navigation and Control Center of Goddard Space Flight Center, this symposium featured technical papers on a wide range of issues related to attitude/orbit determination, prediction and control; attitude simulation; attitude sensor calibration; theoretical foundation of attitude computation; dynamics model improvements; autonomous navigation; constellation design and formation flying; estimation theory and computational techniques; Earth environment mission analysis and design; and, spacecraft re-entry mission design and operations.

  2. Analysis of low-density effects in suborbital flight of FAST20XX

    NASA Astrophysics Data System (ADS)

    Votta, Raffaele; Marini, Marco; Morsa, Luigi; Fels, Giorgio; Zuppardi, Gennaro; Schwanekamp, Tobias; Sippel, Martin

    2012-11-01

    The paper studies the high altitude effects to the future hypersonic/suborbital re-entry vehicle SpaceLiner developed in the framework of EC-funded FAST20XX project. Bridging functions have been developed and validated by means of DSMC calculations. The effects of rarefaction on global longitudinal aerodynamics of SpaceLiner in the range of altitude 65÷85 km have been pointed out by comparing to the aerodatabase in continuum regime conditions. DSMC computation has been done in the higher SpaceLiner altitude point confirming the bridging function results and providing heat transfer estimations.

  3. Policy advocacy and leadership training for formerly incarcerated women: an empowerment evaluation of ReConnect, a program of the Women in Prison Project, Correctional Association of New York.

    PubMed

    Pinto, R M; Rahman, R; Williams, A

    2014-12-01

    There is limited knowledge on re-entry initiatives for formerly incarcerated women specifically on building women's advocacy and leadership skills. Our research highlights an empowerment evaluation on ReConnect, a 12-session; innovative advocacy and leadership development program rooted in an integrated framework of empowerment, and transformational leadership theories. Using thematic analysis, we coded three focus groups with 24 graduates, for themes that matched our framework's concepts. ReConnect graduates reported being empowered by the information they received on parental rights, housing, and employment. Participants agreed that ReConnect improved their communication skills, preparing them to advocate for themselves and community members. PMID:25156631

  4. Advanced Ablative Insulators and Methods of Making Them

    NASA Technical Reports Server (NTRS)

    Congdon, William M.

    2005-01-01

    Advanced ablative (more specifically, charring) materials that provide temporary protection against high temperatures, and advanced methods of designing and manufacturing insulators based on these materials, are undergoing development. These materials and methods were conceived in an effort to replace the traditional thermal-protection systems (TPSs) of re-entry spacecraft with robust, lightweight, better-performing TPSs that can be designed and manufactured more rapidly and at lower cost. These materials and methods could also be used to make improved TPSs for general aerospace, military, and industrial applications.

  5. Toughened uni-piece, fibrous, reinforced, oxidization-resistant composite

    NASA Technical Reports Server (NTRS)

    Stewart, David A. (Inventor); Leiser, Daniel B. (Inventor)

    2008-01-01

    A composite thermal protection structure, for applications such as atmospheric re-entry vehicles, that can withstand temperatures as high as 3600.degree F. The structure includes an exposed surface cap having a specially formulated coating, an insulator base adjacent to the cap with another specially formulated coating, and one or more pins that extend from the cap through the insulator base to tie the cap and base together, through ceramic bonding and mechanical attachment. The cap and insulator base have corresponding depressions and projections that mate and allow for differences in thermal expansion of the cap and base.

  6. Turbulent Supersonic/Hypersonic Heating Correlations for Open and Closed Cavities

    NASA Technical Reports Server (NTRS)

    Everhart, Joel L.; Greene, Francis A.

    2009-01-01

    Supersonic/hypersonic laminar heating correlations that were developed for damage assessment analysis of atmospheric re-entry vehicles have been modified and extended to cover fully-turbulent conditions over rectangular cavity geometries that are aligned with the local velocity. Turbulent boundary layer properties were computationally determined and used to develop the cavity geometry parametrics and to correlate experimental closed cavity heating data to yield new relationships for the floor-averaged and centerline endwall peakheating augmentation. With the form of the closed-cavity correlations established, historical data were used to develop new correlations for turbulent open-cavity heating.

  7. Turbulent Supersonic/Hypersonic Heating Correlations for Open and Closed Cavities

    NASA Technical Reports Server (NTRS)

    Everhart, Joel L.; Greene, Francis A.

    2009-01-01

    Supersonic/hypersonic laminar heating correlations that were developed for damage assessment analysis of atmospheric re-entry vehicles have been modified and extended to cover fully-turbulent conditions over rectangular cavity geometries that are aligned with the local velocity. Turbulent boundary layer properties were computationally determined and used to develop the cavity geometry parametrics and to correlate experimental closed cavity heating data to yield new relationships for the floor-averaged and centerline endwall peak-heating augmentation. With the form of the closed-cavity correlations established, historical data were used to develop new correlations for turbulent open-cavity heating.

  8. Vestibular reactions to spaceflight: human factors issues.

    PubMed

    Young, L R

    2000-09-01

    Vestibular function, along with other sensory systems influencing spatial orientation, can have a profound influence on the ability of astronauts to function effectively. Beyond the well-known problems of space motion sickness, vestibular effects can influence astronaut well-being and performance during all phases of a space mission. This paper discusses some of the major vestibular reactions affecting human factors encountered in all space missions, and covers them chronologically in the following sequence: launch, early on-orbit, late on-orbit, EVA, artificial gravity, re-entry, and post-landing.

  9. Fire retardancy using applied materials

    NASA Technical Reports Server (NTRS)

    Feldman, R.

    1971-01-01

    An example of advanced technology transfer from the Little Joe, Surveyor, Comsat, re-entry and Apollo age to everyday fire protection needs is presented. Utilizing the principle of sublimation cooling for thermostatic temperature control, the material meets a wide range of fire retardancy and heat transmission control requirements. Properties vary from flexible tape for conduits and electrical cables to rigid coatings for column protection, with a broad spectrum of sublimation temperatures available. The material can be applied in the field or in the factory, utilizing mass production techniques, yielding a product that is reliable, effective, widely available and low in cost.

  10. NASN position statement: Concussions--the role of the school nurse.

    PubMed

    Diaz, Anne L; Wyckoff, Leah J

    2013-03-01

    It is the position of the National Association of School Nurses that the registered professional school nurse (hereinafter referred to as school nurse) is an essential member of the team addressing concussions. As the school-based clinical professional on the team, the school nurse has the knowledge and skills to provide concussion prevention education to parents, students, and staff; identify suspected concussions; and help guide the student's post-concussion graduated academic and activity re-entry process. The school nurse collaborates with the team of stakeholders including health care providers, school staff, athletic trainers, and parents.

  11. Policy advocacy and leadership training for formerly incarcerated women: an empowerment evaluation of ReConnect, a program of the Women in Prison Project, Correctional Association of New York.

    PubMed

    Pinto, R M; Rahman, R; Williams, A

    2014-12-01

    There is limited knowledge on re-entry initiatives for formerly incarcerated women specifically on building women's advocacy and leadership skills. Our research highlights an empowerment evaluation on ReConnect, a 12-session; innovative advocacy and leadership development program rooted in an integrated framework of empowerment, and transformational leadership theories. Using thematic analysis, we coded three focus groups with 24 graduates, for themes that matched our framework's concepts. ReConnect graduates reported being empowered by the information they received on parental rights, housing, and employment. Participants agreed that ReConnect improved their communication skills, preparing them to advocate for themselves and community members.

  12. Manned geosynchronous mission requirements and systems analysis study. Volume 1: Executive summary

    NASA Technical Reports Server (NTRS)

    Boyland, R. E.; Sherman, S. W.; Morfin, H. W.

    1979-01-01

    The crew capsule of the MOTV was studied with emphasis on crew accommodations, crew capsule functional requirements, subsystem interface definition between crew module and propulsion module, and man rating requirements. Competing mission modes were studied covering a wide range of propulsion concepts. These included one stage, one and one half stage, and two stage concepts using either the standard STS or an augmented STS. Several deorbit concepts were considered, including all propulsive modes, direct re-entry, and aeromaneuvering skip in skip out in the upper reaches of Earth's atmosphere. A five year plan covering costs, schedules, and critical technology issues is discussed.

  13. STS-114: Discovery Post Landing Press Briefing from JSC

    NASA Technical Reports Server (NTRS)

    2005-01-01

    LeRoy Cain, STS-114 Ascent/Entry Flight Director, takes a solo stand with the Press in this briefing. He noted that the successful flight and return of Discovery is another important milestone, a fresh start, and a new beginning as part of NASA's commitment to the President's vision of man's return to the Moon, Mars and beyond. From this successful test flight, NASA will have a lot of learning and hard work to do in preparation for the next flight. Weather factors, safe landing, touch down, communications, re-entry, the Columbia, were some topics covered with the News media.

  14. Perspectives of SiC-Based Ceramic Composites and Their Applications to Fusion Reactors 6.Recent Research Activities regarding SiC-Based Ceramic Composites for Aerospace Applications

    NASA Astrophysics Data System (ADS)

    Ogasawara, Toshio

    In this article, the present and future prospects of the research and development regarding continuous SiC fiber reinforced ceramic matrix composites (CMCs) for aerospace applications are reviewed. These activities in Japan are described in term of their major applications, i.e. turbo fan engine components for aircrafts, rocket propulsion components, thermal protection system for future re-entry vehicles, thruster for satellites. It is suggested that high performance, affordable processing cost, and excellent reliability will be important factors in the practical use of CMCs in the future.

  15. A prediction method for flow in the Shuttle tile strain isolation pad

    NASA Astrophysics Data System (ADS)

    Lawing, Pierce L.

    1987-06-01

    The Shuttle Orbiter thermal protection system uses a Strain Isolation Pad (SIP) between the tile and the Orbiter. This paper presents experimental measurements of the pressure drop and associated flow rate through a sample of the SIP material. Included are data for a range of air densities representative of Shuttle ascent and re-entry trajectories. Also presented are new theoretical and correlative methods which predict the experimental data. These methods will help in predicting venting characteristics of tile assemblies during ascent, and hot gas leak under the tiles during descent. The predictive philosophy developed is useful in the study of fibrous and porous media fluid mechanics.

  16. STS-89 Mission Specialist Michael Anderson is assisted with his flight suit in the white room

    NASA Technical Reports Server (NTRS)

    1998-01-01

    STS-89 Mission Specialist Michael Anderson is assisted with his ascent and re-entry flight suit in the white room at Launch Pad 39A before entering Space Shuttle Endeavour for launch. The STS- 89 mission will be the eighth docking of the Space Shuttle with the Russian Space Station Mir. After docking, Mission Specialist Andrew Thomas, Ph.D., will transfer to the space station, succeeding David Wolf, M.D., who will return to Earth aboard Endeavour. Dr. Thomas will live and work on Mir until June. STS- 89 is scheduled for a Jan. 22 liftoff at 9:48 p.m.

  17. NASA Astrophysics Data System (ADS)

    Forbes, Jeffrey M.; Zhang, Xiaoli; Zhang, Jesse; Doornbos, Eelco; Bruinsma, Sean L.

    2013-12-01

    A major discovery of the last decade is that tropospherically-generated solar and lunar tides extend well into the ionosphere-thermosphere (IT) system, and drive ionosphere and neutral density variability pertinent to the operation of communications and navigation systems, and orbital and re-entry predictions. This paper describes how density and wind measurements from accelerometers on CHAMP, GRACE and GOCE are used to elucidate this vertical coupling that occurs in the atmosphere. A few new results are provided for GOCE, and some insights into how Swarm will contribute are described as well.

  18. Effective Thermal Conductivity of High Temperature Insulations for Reusable Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Daryabeigi, Kamran

    1999-01-01

    An experimental apparatus was designed to measure the effective thermal conductivity of various high temperature insulations subject to large temperature gradients representative of typical launch vehicle re-entry aerodynamic heating conditions. The insulation sample cold side was maintained around room temperature, while the hot side was heated to temperatures as high as 1800 degrees Fahrenheit. The environmental pressure was varied from 0.0001 to 760 torr. All the measurements were performed in a dry gaseous nitrogen environment. The effective thermal conductivity of Saffil, Q-Fiber felt, Cerachrome, and three multi-layer insulation configurations were measured.

  19. High efficiency tantalum-based ceramic composite structures

    NASA Technical Reports Server (NTRS)

    Stewart, David A. (Inventor); Leiser, Daniel B. (Inventor); DiFiore, Robert R. (Inventor); Katvala, Victor W. (Inventor)

    2010-01-01

    Tantalum-based ceramics are suitable for use in thermal protection systems. These composite structures have high efficiency surfaces (low catalytic efficiency and high emittance), thereby reducing heat flux to a spacecraft during planetary re-entry. These ceramics contain tantalum disilicide, molybdenum disilicide and borosilicate glass. The components are milled, along with a processing aid, then applied to a surface of a porous substrate, such as a fibrous silica or carbon substrate. Following application, the coating is then sintered on the substrate. The composite structure is substantially impervious to hot gas penetration and capable of surviving high heat fluxes at temperatures approaching 3000.degree. F. and above.

  20. Background-Oriented Schlieren for Large-Scale and High-Speed Aerodynamic Phenomena

    NASA Technical Reports Server (NTRS)

    Mizukaki, Toshiharu; Borg, Stephen; Danehy, Paul M.; Murman, Scott M.; Matsumura, Tomoharu; Wakabayashi, Kunihiko; Nakayama, Yoshio

    2015-01-01

    Visualization of the flow field around a generic re-entry capsule in subsonic flow and shock wave visualization with cylindrical explosives have been conducted to demonstrate sensitivity and applicability of background-oriented schlieren (BOS) for field experiments. The wind tunnel experiment suggests that BOS with a fine-pixel imaging device has a density change detection sensitivity on the order of 10(sup -5) in subsonic flow. In a laboratory setup, the structure of the shock waves generated by explosives have been successfully reconstructed by a computed tomography method combined with BOS.

  1. Insulation Material

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Manufactured by Hitco Materials Division of Armco, Inc. a ceramic fiber insulation material known as Refrasil has been used extensively as a heat-absorbing ablative reinforcement for such space systems as rocket motor nozzles, combustion chambers, and re-entry shields. Refrasil fibers are highly porous and do not melt or vaporize until fibers exceed 3,100 degrees Fahrenheit. Due to these and other properties, Refrasil has found utility in a number of industrial high temperature applications where glass, asbestos and other materials fail. Hitco used this insulation to assist Richardson Co., Inc. in the manufacturing of hard rubber and plastic molded battery cases.

  2. Evidence for Day-to-Night Ion Transport at Low Solar Activity in the Venus Pre-Dawn Ionosphere

    NASA Technical Reports Server (NTRS)

    Brannon, J. F.; Fox, J. L.; Porter, H. S.

    1993-01-01

    Periapsis of the Pioneer Venus spacecraft dropped below 180 km on August 28, 1992 near midnight, and 42 orbits of low altitude data at moderately low solar activity in the pre-dawn sector were obtained before contact was lost to the spacecraft in October, 1992. Through a combination of analysis of data from the PV orbiter ion mass spectrometer (OIMS) and modeling, we consider here what can be learned about the relative importance of plasma transport from the dayside and electron precipitation in maintaining the nightside ionosphere during the re-entry period. In particular, we examine here the atomic ion density profiles. We compute the average peak density of O(+) as a function of solar zenith angle and determine what fluxes of atomic ions or precipitating electrons would be necessary to produce those values. We then compare model calculations of the ion densities to those observed during the re-entry period. We find that the low solar activity nightside ionosphere shows evidence of significant day-to-night plasma transport.

  3. Evidence for Day-to-Night Ion Transport at Low Solar Activity in the Venus Pre-Dawn Ionosphere

    NASA Technical Reports Server (NTRS)

    Brannon, J. F.; Fox, J. L.; Porter, H. S.

    1993-01-01

    Periapsis of the Pioneer Venus spacecraft 2 dropped below 180 km on August 28, 1992 near midnight, and 42 orbits of low altitude data at moderately low solar activity in the pre-dawn sector were obtained before contact was lost to the spacecraft in October, 1992. Through a combination of analysis of data from the PV orbiter ion mass spectrometer (OIMS) and modeling, we consider here what can be learned about the relative importance of plasma transport from the dayside and electron precipitation in maintaining the nightside ionosphere during the re-entry period. In particular, we examine here the atomic ion density profiles. We compute the average peak density of O(+) as a function of solar zenith angle and determine what fluxes of atomic ions or precipitating electrons would he necessary to produce those values. We then compare model calculations of the ion densities to those observed during the re-entry period. We find that the low solar activity nightside ionosphere shows evidence of significant day-to-night plasma transport.

  4. Evidence for day-to-night ion transport at low solar activity in the Venus pre-dawn ionosphere

    NASA Technical Reports Server (NTRS)

    Brannon, J. F.; Fox, J. L.; Porter, H. S.

    1993-01-01

    Periapsis of the Pioneer Venus (PV) spacecraft dropped below 180 km on August 28, 1992 near midnight, and 42 orbits of low altitude data at moderately low solar activity in the pre-dawn sector were obtained before contact was lost to the spacecraft in October, 1992. Through a combination of analysis of data from the PV orbiter ion mass spectrometer (OIMS) and modeling, we consider here what can be learned about the relative importance of plasma transport from the dayside and electron precipitation in maintaining the nightside ionosphere during the re-entry period. In particular, we examine here the atomic ion density profiles. We compute the average peak density of O(+) as a function of solar zenith angle and determine what fluxes of atomic ions or precipitating electrons would be necessary to produce those values. We then compare model calculations of the ion densities to those observed during the re-entry period. We find that the low solar activity nightside ionosphere shows evidence of significant day-to-night plasma transport.

  5. Animal life support transporters for Shuttle/Spacelab

    NASA Technical Reports Server (NTRS)

    Berry, W. E.; Hunt, S. R.

    1978-01-01

    Two transporter devices have been developed by the NASA Ames Research Center, primarily for the purpose of stowing small vertebrates and primates in the mid-deck avionics bay of the Shuttle during launch and re-entry. These animals will be used in Life Science Spacelab experiments. Stowage in the mid-deck area will reduce animal exposure to the high noise levels existing in Spacelab during launch; further, the possible exposure of the animals to high temperatures in Spacelab during re-entry and post-landing will be eliminated. The transporters will provide experimenters more timely access to their animals during experiment-critical, pre-launch, and post-landing periods. Rechargeable batteries in the transporters will provide life support system functions for the animals during periods of transfer and during mission phases in which power is temporarily unavailable. The transporters have been successfully designed, fabricated, and tested. Integrated testing of the transporters was performed in the Space Mission Development III (SMD III) Simulation at the NASA Johnson Space Center.

  6. Investigation of Post-Flight Solid Rocket Booster Thermal Protection System

    NASA Technical Reports Server (NTRS)

    Nelson, Linda A.

    2006-01-01

    After every Shuttle mission, the Solid Rocket Boosters (SRBs) are recovered and observed for missing material. Most of the SRB is covered with a cork-based thermal protection material (MCC-l). After the most recent shuttle mission, STS-114, the forward section of the booster appeared to have been impacted during flight. The darkened fracture surfaces indicated that this might have occurred early in flight. The scope of the analysis included microscopic observations to assess the degree of heat effects and locate evidence of the impact source as well as chemical analysis of the fracture surfaces and recovered foreign material using Fourier Transform Infrared Spectroscopy and Scanning Electron Microscopy/Energy Dispersive Spectroscopy. The amount of heat effects and presence of soot products on the fracture surface indicated that the material was impacted prior to SRB re-entry into the atmosphere. Fragments of graphite fibers found on these fracture surfaces were traced to slag inside the Solid Rocket Motor (SRM) that forms during flight as the propellant is spent and is ejected throughout the descent of the SRB after separation. The direction of the impact mark matches with the likely trajectory of SRBs tumbling prior to re-entry.

  7. Inviscid Limit for Damped and Driven Incompressible Navier-Stokes Equations in mathbb R^2

    NASA Astrophysics Data System (ADS)

    Ramanah, D.; Raghunath, S.; Mee, D. J.; Rösgen, T.; Jacobs, P. A.

    2007-08-01

    Experiments to demonstrate the use of the background-oriented schlieren (BOS) technique in hypersonic impulse facilities are reported. BOS uses a simple optical set-up consisting of a structured background pattern, an electronic camera with a high shutter speed and a high intensity light source. The visualization technique is demonstrated in a small reflected shock tunnel with a Mach 4 conical nozzle, nozzle supply pressure of 2.2 MPa and nozzle supply enthalpy of 1.8 MJ/kg. A 20° sharp circular cone and a model of the MUSES-C re-entry body were tested. Images captured were processed using PIV-style image analysis to visualize variations in the density field. The shock angle on the cone measured from the BOS images agreed with theoretical calculations to within 0.5°. Shock standoff distances could be measured from the BOS image for the re-entry body. Preliminary experiments are also reported in higher enthalpy facilities where flow luminosity can interfere with imaging of the background pattern.

  8. Convective Heating Predictions of Apollo IV Flight Data

    NASA Technical Reports Server (NTRS)

    White, Molly E.

    2012-01-01

    It has been more than 50 years since NASA engineers have attempted to design a manned space vehicle with the capability to return from beyond low Earth orbit. In this interval, our methodologies for designing the thermal protection system (TPS) to protect humans from the extremely high temperatures of re-entry have changed significantly. With these considerations in mind, we return to the Apollo IV (AS-501) flight data. This incredible data set allows us to assess the current tools and methodologies being used to design Orion MPCV. In particular, our ability to predict the aftbody separated region convective heating environments for MPCV is critical. The design uses reusable TPS in this area, whereas Apollo designers used ablative TPS which can withstand much more severe environments. This presentation will revisit the flight data, summarize the assumptions going into the analysis, present the results and draw conclusions regarding how accurately we can currently predict the heating in the aftbody separated region of a re-entry capsule.

  9. Colon perforation during percutaneous nephrolithotomy and fistula closure with Spongostan following conservative therapy.

    PubMed

    Ün, Sıtkı; Çakır, Volkan; Köse, Osman; Türk, Hakan; Yılmaz, Yüksel

    2015-01-01

    Percutaneous nephrolithotomy (PCNL) is the first-line treatment for kidney stones. Colon perforation is a rare, but dangerous, complication. Colonic perforation might be very serious if it is not found early. After an unsuccessful extracorporeal shockwave lithotripsy, a 45-year-old female underwent a left-sided PCNL for two 1-cm kidney stones in the left kidney upper pole calyx. During dilatation, a colon perforation was suspected. The procedure was finished by inserting a 14Fr re-entry catheter into the colon. On postoperative day 5, a fluoroscopy was performed by injecting contrast dye through the re-entry catheter, which showed a fistula formation between skin and colon. The catheter was removed completely. A 16Fr external drainage catheter was inserted over the guide-wire through the fistula tract. The fistula was closed by introducing prepared absorbable hemostatic gelatin powder (Spongostan) particles into the fistula tract through the catheter. Fistula tracks can be closed early by injecting absorbable Spongostan particles into the colonic fistula tract, thereby reducing inpatient time and increasing patient comfort.

  10. CNES Software Set for the French Space Operations Act

    NASA Astrophysics Data System (ADS)

    Fuentes, N.

    2012-01-01

    To fulfill its mission of compliance checked within the framework of the FSOA, French Space Operations Act (referred to as the Loi sur les Opérations Spatiales or LOS in French), including in particular the monitoring of safety requirements for people and property, CNES has developed a set of consistent and complementary tools for all space operations under French responsibility: -ACRL for Risk Analysis of collision with a manned vehicle at launch; - DEBRISK for analyzing survivability of fragments of a space object during re-entry; -ELECTRA ORESTE for estimating human risk during launch and controlled or uncontrolled re-entry; -STELA to ensure that requirements are applied concerning: the removal of spacecraft or launch vehicle orbital stages from the protected regions after end-of-mission in low earth or geostationary orbit. This article gives an overview of the software set available at CNES control offices to study the issues of risk analysis provided by operators. For each tool, the article outlines the requirements verified: main choice modelling, space mechanics, aerodynamics, demographics, probabilistic estimation, etc., in addition to current distribution, documentation, related publications and prospects.

  11. Use of an Eight-arm Radial Water Maze to Assess Working and Reference Memory Following Neonatal Brain Injury

    PubMed Central

    Penley, Stephanie C.; Gaudet, Cynthia M.; Threlkeld, Steven W.

    2013-01-01

    Working and reference memory are commonly assessed using the land based radial arm maze. However, this paradigm requires pretraining, food deprivation, and may introduce scent cue confounds. The eight-arm radial water maze is designed to evaluate reference and working memory performance simultaneously by requiring subjects to use extra-maze cues to locate escape platforms and remedies the limitations observed in land based radial arm maze designs. Specifically, subjects are required to avoid the arms previously used for escape during each testing day (working memory) as well as avoid the fixed arms, which never contain escape platforms (reference memory). Re-entries into arms that have already been used for escape during a testing session (and thus the escape platform has been removed) and re-entries into reference memory arms are indicative of working memory deficits. Alternatively, first entries into reference memory arms are indicative of reference memory deficits. We used this maze to compare performance of rats with neonatal brain injury and sham controls following induction of hypoxia-ischemia and show significant deficits in both working and reference memory after eleven days of testing. This protocol could be easily modified to examine many other models of learning impairment. PMID:24335781

  12. Catheter Ablation of Multiple Accessory Pathways in Duchenne Muscular Dystrophy

    PubMed Central

    Stöllberger, Claudia; Steger, Christine; Gatterer, Edmund

    2013-01-01

    A 23-year-old male with Duchenne muscular dystrophy (DMD) experienced self-limiting palpitations at age 19 years for the first time. Palpitations recurred not earlier than at age 23 years, and were attributed to narrow complex tachycardia, which could be terminated with adenosine. Since electrocardiography showed a delta-wave, Wolff-Parkinson-White (WPW) syndrome was diagnosed, ajmaline prescribed and radio-frequency catheter ablation of three accessory pathways carried out one week later. One day after ablation, however, a relapse of the supraventricular tachycardia occurred and was terminated with ajmaline. Re-entry tachycardia occurred a second time six days after ablation, and as before, it was stopped only with ajmaline. Despite administration of verapamil to prevent tachycardia, it occurred a third time four months after ablation. This case shows that cardiac involvement in DMD may manifest also as WPW-syndrome. In these patients, repeated radio-frequency catheter ablation of accessory pathways may be necessary to completely block the re-entry mechanism. PMID:23508228

  13. Treatment of mandibular class II furcation defects by the use of amelogenins and autologous bone. Two case reports.

    PubMed

    Aimetti, M; Pigella, E; Romano, F; Debernardi, C

    2005-10-01

    The aim of this preliminary study was to evaluate the clinical effectiveness of the association of amelogenins and autologous bone graft in the management of mandibular class II furcation defects. This randomized case-controlled study was conducted on 2 patients who presented 2 contralateral mandibular buccal class II furcation lesions. One defect was treated by amelogenins and autologous bone graft (test site) and the other one by open flap debridement (control site). At baseline and at 12 months postoperatively, the full-mouth plaque score (FMPS) and the full-mouth bleeding score (FMBS), the probing depth (PD), the clinical attachment level (CAL) and the recession (REC) were recorded and a periapical radiograph of the selected area was taken. In addition, at 12 months a surgical re-entry was performed. Test sites had a greater horizontal PD reduction and radiographic bone filling compared to control sites. None of the treated sites achieved complete furcation closure. At the time of re-entry, furcations treated by amelogenins were partially filled by newly formed not soundable hard tissue, while furcations treated by conventional flap surgery were filled by epithelial and connective tissue. These findings suggest that the treatment of mandibular class II furcations by amelogenins and autologous bone graft may result in a significant clinical improvement. Further long-term studies conducted on a larger sample size are therefore needed to confirm our results. PMID:16224378

  14. G1 phase regulation, area-specific cell cycle control, and cytoarchitectonics in the primate cortex

    PubMed Central

    Lukaszewicz, Agnès; Savatier, Pierre; Cortay, Véronique; Giroud, Pascale; Huissoud, Cyril; Berland, Michel; Kennedy, Henry; Dehay, Colette

    2005-01-01

    We have investigated the cell-cycle related mechanisms that lead to the emergence of the primate areas 17 and 18. These areas are characterized by striking differences in cytoarchitectonics and neuron number. We show in vivo that (i) area 17 precursors of supragranular neurons exhibit a shorter cell-cycle duration, a reduced G1 phase and a higher rate of cell-cycle re-entry than area 18 precursors (ii) area-specific levels of expression of Cyclin E (high in area 17, low in area 18) and p27Kip1 (low in area 17, high in area 18) (iii) Ex vivo up and down modulation of Cyclin E and p27Kip1 show that both regulators influence cell-cycle kinetics by modifying rates of cell-cycle progression and cell-cycle re-entry (iv) Modeling the areal differences in cell-cycle parameters suggests that they contribute to areal differences in numbers of precursors and neuron production. PMID:16055060

  15. Advanced Seal Sessions I and II

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M.; Dunlap, Patrick H.; Sarawate, Neelesh

    2013-01-01

    As aircraft operators continue to seek higher fuel efficiency, lower emissions, and longer on-wing performance, turbine engine designers are scrutinizing all components for areas of improvement. To achieve overall goals, turbine pressure ratios and by-pass ratios continue to climb. Also, designers are seeking to minimize parasitic and cooling flows to extract the most useful work out of the flow stream, placing a renewed interest on seal technology and secondary flow path management. In the area of future manned spacecraft, advancements are being examined for both habitat seals and re-entry thermal protection system thermal barrierseals. For long duration space craft, designers are continuing to look for savings in parasitic losses to reduce the amount of cabin re-supply air that needs to be brought along. This is placing greater demands on seal designs and materials to exhibit low leakage and be resistant to space environments. For future missions to and from distant planets, the re-entry heating will be higher than for low-earth orbit or lunar return motivating advanced thermal barrier development. This presentation will provide an overview of the seal challenges and opportunities in these diverse areas.

  16. Loss of Polo ameliorates APP-induced Alzheimer’s disease-like symptoms in Drosophila

    PubMed Central

    Peng, Fei; Zhao, Yu; Huang, Xirui; Chen, Changyan; Sun, Lili; Zhuang, Luming; Xue, Lei

    2015-01-01

    The amyloid precursor protein (APP) has been implicated in the pathogenesis of Alzheimer’s disease (AD). Despite extensive studies, little is known about the regulation of APP’s functions in vivo. Here we report that expression of human APP in Drosophila, in the same temporal-spatial pattern as its homolog APPL, induced morphological defects in wings and larval NMJ, larva and adult locomotion dysfunctions, male choice disorder and lifespan shortening. To identify additional genes that modulate APP functions, we performed a genetic screen and found that loss of Polo, a key regulator of cell cycle, partially suppressed APP-induced morphological and behavioral defects in larval and adult stages. Finally, we showed that eye-specific expression of APP induced retina degeneration and cell cycle re-entry, both phenotypes were mildly ameliorated by loss of Polo. These results suggest Polo is an important in vivo regulator of the pathological functions of APP, and provide insight into the role of cell cycle re-entry in AD pathogenesis. PMID:26597721

  17. Thermostructural Evaluation of Joggle Region on the Shuttle Orbiter's Wing Leading Edge

    NASA Technical Reports Server (NTRS)

    Walker, Sandra P.; Warren, Jerry E.

    2012-01-01

    An investigation was initiated to determine the cause of coating spallation occurring on the Shuttle Orbiter's wing leading edge panels in the slip-side joggle region. The coating spallation events were observed, post flight, on differing panels on different missions. As part of the investigation, the high re-entry heating occurring on the joggles was considered here as a possible cause. Thus, a thermostructural evaluation was conducted to determine the detailed state-of-stress in the joggle region during re-entry and the feasibility of a laboratory test on a local joggle specimen to replicate this state-of-stress. A detailed three-dimensional finite element model of a panel slip-side joggle region was developed. Parametric and sensitivity studies revealed significant stresses occur in the joggle during peak heating. A critical interlaminar normal stress concentration was predicted in the substrate at the coating interface and was confined to the curved joggle region. Specifically, the high interlaminar normal stress is identified to be the cause for the occurrence of failure in the form of local subsurface material separation occurring in the slip-side joggle. The predicted critical stresses are coincident with material separations that had been observed with microscopy in joggle specimens obtained from flight panels.

  18. Investigation of configuration effects on entry heating distributions at Mach no. equal 8.0 (OH41). [for wind tunnel model of space shuttle orbiter

    NASA Technical Reports Server (NTRS)

    Gorowitz, H.; White, R.; Derrico, A.

    1973-01-01

    Aerodynamic heating data were obtained on 0.006 scale models of four Rockwell International SSV double delta wing Orbiters in the Mach 8 variable density tunnel. A model of two previously tested Rockwell International Orbiters which are identified in the Configuration Description of this report were also tested. Orbiter surfaces were thermally mapped from the laminar through turbulent flight regimes during re-entry. Various modifications were made to model lower surfaces to determine the cause of transition in the vicinity of 3.0 million Reynolds number per foot. Re-entry data were acquired for angles of attack from 25 through 35 degrees at nominal Reynolds numbers per foot of 1.0, 2.0, 2.3, 2.5, 3.0, 3.5, 4.5 and 6.0 million utilizing the phase change paint technique. Launch data were acquired on the model upper surfaces for angles of attack of 0 and -5 degrees at nominal Reynolds numbers per foot of 3.0 and 6.0 million. A total of 70 orbiter heating runs and 6 material sample sphere runs were completed.

  19. Homelessness in a national sample of incarcerated veterans in state and federal prisons.

    PubMed

    Tsai, Jack; Rosenheck, Robert A; Kasprow, Wesley J; McGuire, James F

    2014-05-01

    The Veterans Health Administration (VHA) has been increasing efforts to reach out to assist incarcerated veterans. While previous studies have shown strong associations between incarceration and homelessness, few studies have examined distinctive characteristics of incarcerated homeless and non-homeless veterans. National administrative data on 30,348 incarcerated veterans served by the Health Care for Re-entry Veterans (HCRV) program were analyzed. Incarcerated veterans were classified into four groups based on their history of past homelessness: not homeless, transiently homeless, episodically homeless, and chronically homeless. Multinomial logistic regression was used to compare groups on sociodemographic characteristics, criminal justice status, clinical status, and their interest in using VHA services. Of the sample, 70 % were classified as not homeless, 8 % as transiently homeless, 11 % as episodically homeless, and 11 % as chronically homeless. Thus, 30 % of the sample had a homeless history, which is five times the 6 % rate of past homelessness among adult men in the general population. Compared to non-homeless incarcerated veterans, all three homeless groups reported significantly more mental health problems, more substance abuse, more times arrested in their lifetime, more likely to be incarcerated for a non-violent offense, and were more interested in receiving VHA services after release from prison. Together, these findings suggest re-entry programs, like HCRV, can address relevant mental health-related service needs, especially among formerly homeless veterans and veterans in need of services are receptive to the offer of assistance. PMID:23512110

  20. The effect of solar forcing induced atmospheric perturbations on LEO satellites' nominal aerodynamic drag

    NASA Astrophysics Data System (ADS)

    Nwankwo, Victor U. J.; Chakrabarti, Sandip Kumar; Weigel, Robert

    2016-07-01

    Atmospheric drag is the strongest force perturbing the motion of satellites in low Earth orbits LEO, and could cause re-entry of satellites, difficulty in identifying and tracking of the satellites and other space objects, manuvering and prediction of lifetime and re-entry. Solar activities influence the temperature, density and composition of the upper atmosphere. These effects thus strongly depend on the phase of a solar cycle. The frequency of intense flares and storms increase during solar maximum. Heating up of the atmosphere causes its expansion eventually leading to accelerated drag of orbiting satellites, especially those in LEO. In this paper, we present the model of the atmospheric drag effect on the trajectory of hypothetical LEO satellites of different ballistic coefficients. We investigate long-term trend of atmospheric drag on LEO satellites due to solar forcing induced atmospheric perturbations and heating at different phases of the solar cycle, and during interval of strong geomagnetic disturbances or storms. We show the dependence of orbital decay on severity of both the solar cycle and phase, and the extent of geomagnetic perturbations. The result of the model compares well with the observed decay profile of existing LEO satellites and provides a better understanding of the issue of the orbital decay. Our result may also be useful for selection of launch window of satellites for an extended lifetime in the orbit.

  1. Post-Flight Analysis of the Guidance, Navigation, and Control Performance During Orion Exploration Flight Test 1

    NASA Technical Reports Server (NTRS)

    Barth, Andrew; Mamich, Harvey; Hoelscher, Brian

    2015-01-01

    The first test flight of the Orion Multi-Purpose Crew Vehicle presented additional challenges for guidance, navigation and control as compared to a typical re-entry from the International Space Station or other Low Earth Orbit. An elevated re-entry velocity and steeper flight path angle were chosen to achieve aero-thermal flight test objectives. New IMU's, a GPS receiver, and baro altimeters were flight qualified to provide the redundant navigation needed for human space flight. The guidance and control systems must manage the vehicle lift vector in order to deliver the vehicle to a precision, coastal, water landing, while operating within aerodynamic load, reaction control system, and propellant constraints. Extensive pre-flight six degree-of-freedom analysis was performed that showed mission success for the nominal mission as well as in the presence of sensor and effector failures. Post-flight reconstruction analysis of the test flight is presented in this paper to show whether that all performance metrics were met and establish how well the pre-flight analysis predicted the in-flight performance.

  2. Evidence for day-to-night ion transport at low solar activity in the Venus pre-dawn ionosphere

    NASA Astrophysics Data System (ADS)

    Brannon, J. F.; Fox, J. L.; Porter, H. S.

    1993-12-01

    Periapsis of the Pioneer Venus (PV) spacecraft dropped below 180 km on August 28, 1992 near midnight, and 42 orbits of low altitude data at moderately low solar activity in the pre-dawn sector were obtained before contact was lost to the spacecraft in October, 1992. Through a combination of analysis of data from the PV orbiter ion mass spectrometer (OIMS) and modeling, we consider here what can be learned about the relative importance of plasma transport from the dayside and electron precipitation in maintaining the nightside ionosphere during the re-entry period. In particular, we examine here the atomic ion density profiles. We compute the average peak density of O(+) as a function of solar zenith angle and determine what fluxes of atomic ions or precipitating electrons would be necessary to produce those values. We then compare model calculations of the ion densities to those observed during the re-entry period. We find that the low solar activity nightside ionosphere shows evidence of significant day-to-night plasma transport.

  3. STS-114: Discovery Post MMT Briefing

    NASA Technical Reports Server (NTRS)

    2005-01-01

    On flight day 13, Leroy Cain, STS-114 Ascent/Entry Flight Director, discusses the condition of the Space Shuttle Discovery, and the weather outlook for landing. He answers questions from the news media about his feelings about re-entry since the Columbia tragedy, possible new information during re-entry, critical moments in the Mission Control Room during landing, and differences between night landing and day landing. Footage of the Mission Control Room and a talk with Soichi Noguchi in orbit is shown. Also, footage of the truss structure of the International Space Station, Destiny Laboratory, crew cabin of Discovery, and the Orbiter Docking System linked up to forward docking port on Discovery is shown. Eileen Collins and Wendy Lawrence are shown in the flight deck of Discovery. Charles Camarda is also shown in the mid-deck. Downlink television from Discovery shows spacewalk choreographer Andy Thomas with Stephen Robinson and Soichi Noguchi preparing for depressurization and pre-breathing activities that will lead to the opening of the hatch. The installation of a replacement GPS antenna, images of the port wing of Discovery and Canadarm moving with the Orbital Boom Sensor System (OBSS) extension is shown.

  4. Mechanical testing of ultra-high temperature ceramics at 1500°C in air - Development of an experimental facility and test method

    NASA Astrophysics Data System (ADS)

    Winder, Sheena L.

    2015-10-01

    With a melting point in excess of 3000°C and a high density, ultra-high temperature ceramics (UHTCs) are a candidate material for hypersonic flight vehicles, atmospheric re-entry vehicles, and rocket propulsion systems. When ceramics are under consideration as a structural material, creep is an important design criterion and a life-limiting condition. However, the characterization of mechanical behavior at temperatures in excess of 1300°C has many challenges to overcome. Of utmost importance is the selection of materials for test fixtures. Materials selected must maintain their structural integrity, not cause chemical degradation of the test material, and not interfere with the acquisition of data at required temperatures in extreme environments over long durations. In this work, the thermo-chemical compatibility of hafnium diboride (HfB 2) UHTC with other high temperature materials was investigated. The findings enabled the development and construction of a mechanical testing facility capable of reaching 1700°C in air. Platinum foil proved unstable in the presence of HfB2 at 1500°C, while yttrium aluminum garnet and alumina were demonstrated to successfully perform as test fixture materials inside the test chamber. The results of this research represent a significant contribution towards the use of UHTCs in extreme environments associated with hypersonic flight and atmospheric re-entry.

  5. Genome-wide screen identifies novel machineries required for both ciliogenesis and cell cycle arrest upon serum starvation.

    PubMed

    Kim, Ji Hyun; Ki, Soo Mi; Joung, Je-Gun; Scott, Eric; Heynen-Genel, Susanne; Aza-Blanc, Pedro; Kwon, Chang Hyuk; Kim, Joon; Gleeson, Joseph G; Lee, Ji Eun

    2016-06-01

    Biogenesis of the primary cilium, a cellular organelle mediating various signaling pathways, is generally coordinated with cell cycle exit/re-entry. Although the dynamic cell cycle-associated profile of the primary cilium has been largely accepted, the mechanism governing the link between ciliogenesis and cell cycle progression has been poorly understood. Using a human genome-wide RNAi screen, we identify genes encoding subunits of the spliceosome and proteasome as novel regulators of ciliogenesis. We demonstrate that 1) the mRNA processing-related hits are essential for RNA expression of molecules acting in cilia disassembly, such as AURKA and PLK1, and 2) the ubiquitin-proteasome systems (UPS)-involved hits are necessary for proteolysis of molecules acting in cilia assembly, such as IFT88 and CPAP. In particular, we show that these screen hit-associated mechanisms are crucial for both cilia assembly and cell cycle arrest in response to serum withdrawal. Finally, our data suggest that the mRNA processing mechanism may modulate the UPS-dependent decay of cilia assembly regulators to control ciliary resorption-coupled cell cycle re-entry. PMID:27033521

  6. Chelyabinsk, Zond IV, and a possible first-century fireball of historical importance

    NASA Astrophysics Data System (ADS)

    Hartmann, William K.

    2015-03-01

    The well-recorded Chelyabinsk event, the Tunguska event, and the re-entry of the Zond IV vehicle offer opportunities to compare reactions of modern eyewitnesses to eyewitness accounts of possible ancient fireball events. The first-century book, Acts of the Apostles, gives three separate descriptions of a bright light "from heaven," which occurred probably in the 30s (C.E.) near Damascus, Syria. The details offer a strikingly good match to a Chelyabinsk-class or Tunguska-class fireball. Among the most impressive, unexpected consistencies with modern knowledge is the first-century description of symptoms of temporary blindness caused by exposure to intense radiation, matching a condition now known as photokeratitis. An analysis of the re-entry of debris from the Russian Zond IV over the eastern United States in 1968 shows how actual perceived phenomena in an unfamiliar natural celestial apparition are often conceived by the observer in terms of current cultural conceptions, and it is suggested that this happened also in the first-century case.

  7. Developing Health-Based Pre-Planning Clearance Goals for Airport Remediation Following Chemical Terrorist Attack: Introduction and Key Assessment Considerations

    PubMed Central

    Watson, Annetta; Hall, Linda; Raber, Ellen; Hauschild, Veronique D.; Dolislager, Fredrick; Love, Adam H.; Hanna, M. Leslie

    2011-01-01

    In the event of a chemical terrorist attack on a transportation hub, post-event remediation and restoration activities necessary to attain unrestricted facility reuse and re-entry could require hours to multiple days. While restoration timeframes are dependent on numerous variables, a primary controlling factor is the level of pre-planning and decision-making completed prior to chemical terrorist release. What follows is the first of a two-part analysis identifying key considerations, critical information, and decision criteria to facilitate post-attack and post-decontamination consequence management activities. A conceptual site model and human health-based exposure guidelines are developed and reported as an aid to site-specific pre-planning in the current absence of U.S. state or Federal values designated as compound-specific remediation or re-entry concentrations, and to safely expedite facility recovery to full operational status. Chemicals of concern include chemical warfare nerve and vesicant agents and the toxic industrial compounds phosgene, hydrogen cyanide, and cyanogen chloride. This work has been performed as a national case study conducted in partnership with the Los Angeles International Airport and The Bradley International Terminal. All recommended guidelines have been selected for consistency with airport scenario release parameters of a one-time, short-duration, finite airborne release from a single source followed by compound-specific decontamination. PMID:21390292

  8. Mice Drawer System: a Long Duration Animal Experiment on the International Space Station

    NASA Astrophysics Data System (ADS)

    Cotronei, Vittorio; Liu, Yi; Pignataro, Salvatore

    Mice represent one of the most important animal models for biomedical research. In the past decade mice have been used as surrogates to understand physiological adaption and its under-lying mechanisms to orbital spaceflight. A breakthrough in this field has been achieved with the launch of MDS experiment inside Shuttle Discovery (mission STS-128) on August 28, 2009 at 23:58 EST, and its re-entry to earth by Shuttle Atlantis (mission STS-129) on November 27 2009 at 9:47 EST, marking this as the first long duration animal experiment on the Interna-tional Space Station (ISS). This presentation will provide the life history and milestones starting from the project brainstorm to the post-ground activities of the recent MDS payload mission. The Italian Space Agency (ASI) initiated and coordinated this multi-disciplinary project by focusing on five areas: the development of a multi-purpose automated payload by industry; bio-compatibility tests of subsystems throughout various critical phases of the payload development by researchers, development of a ground segment to interface with NASA Payload Operations Center and three different geographically distributed Italian Operations Centers; establishment of an international tissue sharing program; specialized bio-specimen intercontinental shipment. With close collaboration with NASA, activities such as pre-flight payload acceptance, animal preparation, in-flight crew intervention and re-entry animal recovery were smoothly and swiftly accomplished.

  9. Topological Constraints on Chain-Folding Structure of Semicrystalline Polymer as Studied by 13C-13C Double Quantum NMR

    NASA Astrophysics Data System (ADS)

    Hong, Youlee; Miyoshi, Toshikazu

    Chain-folding process is a prominent feature of long polymer chains during crystallization. Over the last half century, much effort has been paid to reveal the chain trajectory. Even though various chain-folding models as well as theories of crystallization at molecule levels have been proposed, they could be not reconciled due to the limited experimental evidences. Recent development of double quantum NMR with selective isotope labeling identified the chain-trajectory of 13C labeled isotactic poly(1-butene). The systematic experiments covered a wide range of parameters, i.e. kinetics, concentration, and molecular weight (Mw) . It was demonstrated that i) adjacent re-entry site was invariant as a function of crystallization temperature (Tc) , concentration, andMw, ii) long-range order of adjacent re-entry sequence is independence of kinetics at a given concentration while it decreased with increasing the polymer concentration at a given Tc due to the increased interruption between the chains, and iii) high Mw chains led to the multilayer folded structures in single crystals, but the melt state induced the identical short adjacent sequences of long and short polymer over a wide range of Tc due to the entanglements. The behaviors indicated that the topological restriction plays significant roles in the chain-folding process rather than the kinetics. The proposed framework to control the chain-folding structure presents a new perspective into the chain organization by either the intra- or inter-chain interaction. National Science Foundation Grants DMR-1105829 and 1408855.

  10. Coiled tubing drilling: Real time MWD with dedicated powers to the BHA

    SciTech Connect

    Leismer, D.; Williams, B.; Pursell, J.

    1996-12-31

    This paper describes and analyzes the development and ongoing field trials of a Real Time MWD Coiled Tubing Drilling System. The new system holds great promise for advancing the state of coiled tubing drilling for certain applications. The system is designed for through-tubing, short radius re-entry and drilling highly deviated wells as horizontal laterals to a geologic target with minimum wellbore tortuosity. Currently, 4-1/2-in production tubing is the smallest re-entry candidate. Real time MWD and Bottom Hole Assembly (BHA) control is achieved by the use of a combination hydraulic and electric umbilical internal to the coiled tubing (CT), allowing continuous data collection and selective surface control of the BHA components. This communication line allows orientation in 10{degree} increments (or less) while drilling, applies weight-on-bit and operates a reusable circulating valve. In addition, the umbilical provides real-time monitoring of weight-on-bit, circulating pressures of the drilling fluid internal and external to the BHA, dedicated hydraulic system bottom hole pressure, downhole temperature and survey data from logging equipment.

  11. Use of an eight-arm radial water maze to assess working and reference memory following neonatal brain injury.

    PubMed

    Penley, Stephanie C; Gaudet, Cynthia M; Threlkeld, Steven W

    2013-12-04

    Working and reference memory are commonly assessed using the land based radial arm maze. However, this paradigm requires pretraining, food deprivation, and may introduce scent cue confounds. The eight-arm radial water maze is designed to evaluate reference and working memory performance simultaneously by requiring subjects to use extra-maze cues to locate escape platforms and remedies the limitations observed in land based radial arm maze designs. Specifically, subjects are required to avoid the arms previously used for escape during each testing day (working memory) as well as avoid the fixed arms, which never contain escape platforms (reference memory). Re-entries into arms that have already been used for escape during a testing session (and thus the escape platform has been removed) and re-entries into reference memory arms are indicative of working memory deficits. Alternatively, first entries into reference memory arms are indicative of reference memory deficits. We used this maze to compare performance of rats with neonatal brain injury and sham controls following induction of hypoxia-ischemia and show significant deficits in both working and reference memory after eleven days of testing. This protocol could be easily modified to examine many other models of learning impairment.

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

    NASA Technical Reports Server (NTRS)

    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.

  13. H. Julian Allen

    NASA Technical Reports Server (NTRS)

    1957-01-01

    H. Julian Allen stands beside the observation window of the 8 x 7 foot test section of the NACA Ames Unitary Plan Wind Tunnel. H. Julian Allen is best known for his 'Blunt Body Theory' of aerodynamics, a design technique for alleviating the severe re-entry heating problem which was then delaying the development of ballistic missiles. His findings revolutionized the fundamental design of ballistic missle re-entry shapes. Subsequently, applied research led to applications of the 'blunt' shape to ballistic missles and spacecraft which were intended to re-enter the Earth's atmosphere. This application led to the design of ablative heat shields that protected the Mercury, Gemini and Apollo astronauts as their space capsules re- entered the Earth's atmosphere. 'Harvey' Allen as he was called by most, was not only a brilliant scientist and aeronautical engineer but was also admired for his kindness, thoughtfulness and sense of humor. Among his many other accomplishments, Harvey Allen served as Center Director of the NASA Ames Research Center from 1965 to 1969. He died of a heart attack on January 29, 1977 at the age of 66.

  14. H. Julian Allen with Blunt Body Theory

    NASA Technical Reports Server (NTRS)

    1957-01-01

    H. Julian Allen is best known for his 'Blunt Body Theory' of aerodynamics, a design technique for alleviating the severe re-entry heating problem which was then delaying the development of ballistic missiles. His findings revolutionized the fundamental design of ballistic missle re-entry shapes. Subsequently, applied research led to applications of the 'blunt' shape to ballistic missles and spacecraft which were intended to re-enter the Earth's atmosphere. This application led to the design of ablative heat shields that protected the Mercury, Gemini and Apollo astronauts as their space capsules re- entered the Earth's atmosphere. 'Harvey' Allen as he was called by most, was not only a brilliant scientist and aeronautical engineer but was also admired for his kindness, thoughtfulness and sense of humor. Among his many other accomplishments, Harvey Allen served as Center Director of the NASA Ames Research Center from 1965 to 1969. He died of a heart attack on January 29, 1977 at the age of 66.

  15. Observations of Shock Diffusion and Interactions in Supersonic Freestreams with Counterflowing Jets

    NASA Technical Reports Server (NTRS)

    Daso, Endwell O.; Pritchett, Victor E.; Wang, Ten-See; Blankson, Isiah M.; Auslender, Aaron H.

    2006-01-01

    One of the technical challenges in long-duration space exploration and interplanetary missions is controlled entry and re-entry into planetary and Earth atmospheres, which requires the dissipation of considerable kinetic energy as the spacecraft decelerates and penetrates the atmosphere. Efficient heat load management of stagnation points and acreage heating remains a technological challenge and poses significant risk, particularly for human missions. An innovative approach using active flow control concept is proposed to significantly modify the external flow field about the spacecraft in planetary atmospheric entry and re-entry in order to mitigate the harsh aerothermal environments, and significantly weaken and disperse the shock-wave system to reduce aerothermal loads and wave drag, as well as improving aerodynamic performance. To explore the potential benefits of this approach, we conducted fundamental experiments in a trisonic blow down wind tunnel to investigate the effects of counterflowing sonic and supersonic jets against supersonic freestreams to gain a better understanding of the flow physics of the interactions of the opposing flows and the resulting shock structure.

  16. Rarefield-Flow Shuttle Aerodynamics Flight Model

    NASA Technical Reports Server (NTRS)

    Blanchard, Robert C.; Larman, Kevin T.; Moats, Christina D.

    1994-01-01

    A model of the Shuttle Orbiter rarefied-flow aerodynamic force coefficients has been derived from the ratio of flight acceleration measurements. The in-situ, low-frequency (less than 1Hz), low-level (approximately 1 x 10(exp -6) g) acceleration measurements are made during atmospheric re-entry. The experiment equipment designed and used for this task is the High Resolution Accelerometer Package (HiRAP), one of the sensor packages in the Orbiter Experiments Program. To date, 12 HiRAP re-entry mission data sets spanning a period of about 10 years have been processed. The HiRAP-derived aerodynamics model is described in detail. The model includes normal and axial hypersonic continuum coefficient equations as function of angle of attack, body-flap deflection, and elevon deflection. Normal and axial free molecule flow coefficient equations as a function of angle of attack are also presented, along with flight-derived rarefied-flow transition bridging formulae. Comparisons are made between the aerodynamics model, data from the latest Orbiter Operational Aerodynamic Design Data Book, applicable computer simulations, and wind-tunnel data.

  17. The Anaphase-Promoting Complex/Cyclosome Is Essential for Entry into Meiotic M-Phase.

    PubMed

    Malhotra, Saurav; Vinod, Palakkad Krishnanunni; Mansfeld, Jörg; Stemmann, Olaf; Mayer, Thomas U

    2016-01-11

    Vertebrate immature oocytes are arrested at prophase of meiosis I (MI). Hormonal stimulation breaks this prophase-I arrest and induces re-entry into MI. The mechanism underlying meiotic resumption remains largely elusive. Here, we demonstrate that the anaphase-promoting complex/cyclosome (APC/C) in complex with Cdh1 has an unexpected function in meiosis in that it is essential for meiotic resumption. We identify the catalytic subunit of protein phosphatase 6 (PP6c) as the critical substrate whose APC/C(Cdh1)-mediated destruction is a prerequisite for the re-entry of immature Xenopus laevis oocytes into MI. Preventing PP6c destruction impairs activating autophosphorylation of Aurora A, a cell-cycle kinase critical for meiotic translation. Restoring meiotic translation rescues the meiotic resumption defect of Cdh1-depleted oocytes. Thus, our studies discover that the essential function of the APC/C in triggering cell-cycle transitions is not limited to M-phase exit but also applies to entry into meiotic M-phase, and identify a crucial APC/C-PP6c-Aurora A axis in the resumption of female meiosis.

  18. SHEFEX II Flight Instrumentation And Preparation Of Post Flight Analysis

    NASA Astrophysics Data System (ADS)

    Thiele, Thomas; Siebe, Frank; Gulhan, Ali

    2011-05-01

    A main disadvantage of modern TPS systems for re- entry vehicles is the expensive manufacturing and maintenance process due to the complex geometry of these blunt nose configurations. To reduce the costs and to improve the aerodynamic performance the German Aerospace Center (DLR) is following a different approach using TPS structures consisting of flat ceramic tiles. To test these new sharp edged TPS structures the SHEFEX I flight experiment was designed and successfully performed by DLR in 2005. To further improve the reliability of the sharp edged TPS design at even higher Mach numbers, a second flight experiment SHEFEX II will be performed in September 2011. In comparison to SHEFEX I the second flight experiment has a fully symmetrical shape and will reach a maximum Mach number of about 11. Furthermore the vehicle has an active steering system using four canards to control the flight attitude during re-entry, e.g. roll angle, angle of attack and sideslip. After a successful flight the evaluation of the flight data will be performed using a combination of numerical and experimental tools. The data will be used for the improvement of the present numerical analysis tools and to get a better understanding of the aerothermal behaviour of sharp TPS structures. This paper presents the flight instrumentation of the SHEFEX II TPS. In addition the concept of the post flight analysis is presented.

  19. Relationship influence and health risk behavior among re-entering women offenders

    PubMed Central

    Frisman, Linda; Lin, Hsui-Ju; Leukefeld, Carl; Oser, Carrie; Havens, Jennifer R.; Prendergast, Michael; Surratt, Hilary L.; Clarke, Jennifer

    2011-01-01

    Background Studies have shown that relationships can influence health risk behaviors such as drug use among women offenders. This study takes an exploratory look at the positive and negative influences of parents, peers, and partners for women prisoners to better understand their health risk behavior for HIV, including risky sex and drug use. Methods The current study includes secondary analysis of cross-sectional data from women offenders enrolled in three protocols of the National Institute on Drug Abuse (NIDA) funded Criminal Justice Drug Abuse Treatment Studies (CJDATS) cooperative agreement. Baseline interviews were completed with incarcerated women preparing for community re-entry and focused on behaviors during the 6 months prior to incarceration. Relationship influences during the 6 months before prison were categorized as “positive” or “negative” for the women offenders. Findings Multivariate regression models suggested that positive parental influence was significantly associated with reduced HIV risk and reduced drug use in the 6 months prior to incarceration. However, negative peer influence increased drug use including both risky needle behavior and any drug use in the 6 months prior to incarceration. Conclusions These data suggest that, while relationships are generally important to women, particular types of relationship influences may be related to risky behavior. Implications for targeting re-entry interventions for women offenders are discussed. PMID:21315617

  20. Developing health-based pre-planning clearance goals for airport remediation following chemical terrorist attack: Introduction and key assessment considerations

    SciTech Connect

    Watson, Annetta Paule; Raber, Ellen; Dolislager, Frederick; Hauschild, Veronique; Hall, Dr. Linda; Love, Dr. Adam

    2011-01-01

    In the event of a chemical terrorist attack on a transportation hub, post-event remediation and restoration activities necessary to attain unrestricted facility re-use and re-entry could require hours to multiple days. While restoration timeframes are dependent on numerous variables, a primary controlling factor is the level of pre-planning and decision-making completed prior to chemical terrorist release. What follows is the first of a two-part analysis identifying key considerations, critical information, and decision criteria to facilitate post-attack and post-decontamination consequence management activities. A conceptual site model and human health-based exposure guidelines are developed and reported as an aid to site-specific pre-planning in the current absence of U.S. state or Federal values designated as compound-specific remediation or re-entry concentrations, and to safely expedite facility recovery to full operational status. Chemicals of concern include chemical warfare nerve and vesicant agents and the toxic industrial compounds phosgene, hydrogen cyanide, and cyanogen chloride. This work has been performed as a national case study conducted in partnership with the Los Angeles International Airport and The Bradley International Terminal. All recommended guidelines have been selected for consistency with airport scenario release parameters of a one-time, short-duration, finite airborne release from a single source followed by compound-specific decontamination.

  1. A source of hope for at-risk youth. A hospital's community outreach efforts provide an alternative for troubled teens.

    PubMed

    Roundy, L

    1994-05-01

    In 1990 St. Bernardine Medical Center, San Bernardino, CA, initiated a mission project to reach out to youth and families in the hospital's service area. Increased unemployment, escalating crime, and a failing social structure had left many San Bernardino residents with few resources for breaking out of a cycle of crime and poverty fostered by their environment. Responding to the results of a community needs assessment, St. Bernardine mission project planners decided the project's first program should target at-risk youth. Collaborating with the San Bernardino County Probation Department, St. Bernardine began offering a variety of services to youth in the probation department's Regional Youth Educational Facility, which houses boys between the ages of 16 and 18, and the Kuiper Youth Center, which houses girls between 11 and 18 years old. Realizing that a truly effective program would have to maintain contact with youth after they left these facilities, St. Bernardine expanded its outreach efforts to include at-risk families as well. The mission project's 12-week Parenting Re-entry Program builds parenting skills by addressing a variety of topics, including values clarification, communication skills, and positive reentry into the community. In addition to the Parenting Re-entry Program, St. Bernardine, through its Family Focus Center, offers counseling services, an information referral library, and a Teen Focus Component that features evening basketball, a drama club, and other healthy alternatives for teens.

  2. German Contribution to the X-38 CRV Demonstrator in the Field of Guidance, Navigation and Control (GNC)

    NASA Astrophysics Data System (ADS)

    Soppa, Uwe; Görlach, Thomas; Roenneke, Axel Justus

    2002-01-01

    As a solution to meet a safety requirement to the future full scale space station infrastructure, the Crew Return/Rescue Vehicle (CRV) was supposed to supply the return capability for the complete ISS crew of 7 astronauts back to earth in case of an emergency. A prototype of such a vehicle named X-38 has been developed and built by NASA with European partnership (ESA, DLR). An series of aerial demonstrators (V13x) for tests of the subsonic TAEM phase and the parafoil descent and landing system has been flown by NASA from 1998 to 2001. A full scale unmanned space flight demonstrator (V201) has been built at JSC Houston and although the project has been stopped for budgetary reasons in 2002, it will hopefully still be flown in near future. The X-38 is a lifting body with hypersonic lift to drag ratio about 0.9. In comparison to the Space Shuttle Orbiter, this design provides less aerodynamic maneuvrability and a different actuator layout (divided body flap and winglet rudders instead as combined aileron and elevon in addition to thrust- ers for the early re-entry phase). Hence, the guidance and control concepts used onboard the shuttle orbiter had to be adapted and further developed for the application on the new vehicle. In the frame of the European share of the X-38 project and also of the German TETRA (TEchnol- ogy for future space TRAnsportation) project different GNC related contributions have been made: First, the primary flight control software for the autonomous guidance and control of the X-38 para- foil descent and landing phase has been developed, integrated and successfully flown on multiple vehicles and missions during the aerial drop test campaign conducted by NASA. Second, a real time X-38 vehicle simulator was provided to NASA which has also been used for the validation of a European re-entry guidance and control software (see below). According to the NASA verification and validation plan this simulator is supposed to be used as an independent vali

  3. Atrial proarrhythmia due to increased inward rectifier current (I(K1)) arising from KCNJ2 mutation--a simulation study.

    PubMed

    Kharche, Sanjay; Garratt, Clifford J; Boyett, Mark R; Inada, Shin; Holden, Arun V; Hancox, Jules C; Zhang, Henggui

    2008-01-01

    Atrial fibrillation (AF) has been linked to increased inward rectifier potassium current, I(K1), either due to AF-induced electrical remodelling, or from functional changes due to the Kir2.1 V93I mutation. The aim of this simulation study was to identify at cell and tissue levels' mechanisms by which increased I(K1) facilitates and perpetuates AF. The Courtemanche et al. human atrial cell action potential (AP) model was modified to incorporate reported changes in I(K1) induced by the Kir2.1 V93I mutation in both heterozygous (Het) and homozygous (Hom) mutant forms. The modified models for wild type (WT), Het and Hom conditions were incorporated into homogeneous 1D, 2D and 3D tissue models. Restitution curves of AP duration (APD), effective refractory period (ERP) and conduction velocity (CV) were computed and both the temporal and the spatial vulnerability of atrial tissue to re-entry were measured. The lifespan and tip meandering pattern of re-entry were also characterised. For comparison, parallel simulations were performed by incorporating into the Courtmanche et al. model a linear increase in maximal I(K1) conductance. It was found that the gain-in-function of V93I 'mutant'I(K1) led to abbreviated atrial APs and flattened APD, ERP and CV restitution curves. It also hyperpolarised atrial resting membrane potential and slowed down intra-atrial conduction. V93I 'mutant'I(K1) reduced the tissue's temporal vulnerability but increased spatial vulnerability to initiate and sustain re-entry, resulting in an increased overall susceptibility of atrial tissue to arrhythmogenesis. In the 2D model, spiral waves self-terminated for WT (lifespan < 3.3 s) tissue, but persisted in Het and Hom tissues for the whole simulation period (lifespan > 10 s). The tip of the spiral wave meandered more in WT tissue than in Het and Hom tissues. Increased I(K1) due to augmented maximal conductance produced similar results to those of Het and Hom Kir2.1 V93I mutant conditions. In the 3D

  4. Ceramic Thermal Protection Materials - How Far Can We Go? (Part II)

    NASA Astrophysics Data System (ADS)

    Hilfer, G.

    2002-01-01

    A space vehicle re-entering the earth's atmosphere is exposed to severe environmental conditions. In particular, certain surface areas of the vehicle such as the stagnation point area or exposed control surfaces have to withstand extraordinary thermal and oxidative loads. These loads that have to be taken by a thermal protection system (TPS) are driven mainly by the geometry of the vehicle, its mass and its re-entry path. As a consequence, small vehicles like the X-38 demonstrator of a re-usable crew return vehicle (CRV) need TPS components capable of withstanding temperatures of 1800°C accompanied by severe aerodynamic and chemical loads. Currently, the only promising materials having the potential of re-usability in such an environment are Si-based ceramics and related derivatives such as C-C/SiC. These materials have an extended oxidation regime leading to the formation of an oxidation-inhibiting SiO2-layer. Nevertheless, a number of parameters may turn this so-called passive oxidation mode into a different oxidation mode which can be characterized by the release of gaseous SiO. This is the so-called active oxidation mode which induces massive degradation of the material. Based on a long-term experimental and theoretical investigation performed on the constituents of SiC and its most important derivatives and oxidation products, a mechanism was proposed describing the relevant parameters which govern the transition from passive to active oxidation of SiC in a re-entry type environment. The crucial reaction process related to this transition was found to be the interaction of SiO and SiO2 with atomic and molecular oxygen, i.e. In a previous publication this mechanism was derived by a thorough study of a large number of related elementary reaction steps and the analysis of experimental findings [1]. In the course of the investigation, however, many other results have been obtained which could not be published within the frame of the above publication. Therefore

  5. Orbiter Return-To-Flight Entry Aeroheating

    NASA Technical Reports Server (NTRS)

    Campbell, Charles H.; Anderson, Brian; Bourland, Gary; Bouslog, Stan; Cassady, Amy; Horvath, Tom; Berry, Scott A.; Gnoffo, Peter; Wood, Bill; Reuther, James; Driver, Dave; Chao, Dennis

    2006-01-01

    The Columbia accident on February 1, 2003 began an unprecedented level of effort within the hypersonic aerothermodynamic community to support the Space Shuttle Program. During the approximately six month time frame of the primary Columbia Accident Investigation Board activity, many technical disciplines were involved in a concerted effort to reconstruct the last moments of the Columbia and her crew, and understand the critical events that led to that loss. Significant contributions to the CAIB activity were made by the hypersonic aerothermodynamic community(REF CAIB) in understanding the re-entry environments that led to the propagation of an ascent foam induced wing leading edge damage to a subsequent breech of the wing spar of Columbia, and the subsequent breakup of the vehicle. A core of the NASA hypersonic aerothermodynamics team that was involved in the CAIB investigation has been combined with the United Space Alliance and Boeing Orbiter engineering team in order to position the Space Shuttle Program with a process to perform in-flight Thermal Protection System damage assessments. This damage assessment process is now part of the baselined plan for Shuttle support, and is a direct out-growth of the Columbia accident and NASAs response. Multiple re-entry aeroheating tools are involved in this damage assessment process, many of which have been developed during the Return To Flight activity. In addition, because these aeroheating tools are part of an overall damage assessment process that also involves the thermal and stress analyses community, in addition to a much broader mission support team, an integrated process for performing the damage assessment activities has been developed by the Space Shuttle Program and the Orbiter engineering community. Several subsets of activity in the Orbiter aeroheating communities support to the Return To Flight effort have been described in previous publications (CFD?, Cavity Heating? Any BLT? Grid Generation?). This work will

  6. Synthesis and analysis of Mo-Si-B based coatings for high temperature oxidation protection of ceramic materials

    NASA Astrophysics Data System (ADS)

    Ritt, Patrick J.

    The use of Ni-based superalloys in turbine engines has all but been exhausted, with operating temperatures nearing the melting point of these materials. The use of ceramics in turbine engines, particularly ceramic matrix composites such as SiC/C and SiC/SiC, is of interest due to their low density and attractive mechanical properties at elevated temperatures. The same materials are also in consideration for leading edges on hypersonic vehicles. However, SiC-based composites degrade in high temperature environments with low partial pressures of oxygen due to active oxidation, as well as high temperature environments containing water or sand. The need for a protective external coating for SiC-based composites in service is obvious. To date, no coating investigated for SiC/C or SiC/SiC has been proven to be resistant to oxidation and corrosion at intermediate and high temperatures, as well as in environments deficient in oxygen. The Mo-Si-B coating shows great promise in this area, having been proven resistant to attack from oxidation at extreme temperatures, from water vapor and from calcia-magnesia-aluminosilicate (CMAS). The adaptation of the Mo-Si-B coating for ceramic materials is presented in detail here. Evaluation of the coating under a range of oxidation conditions as well as simulated re-entry conditions confirms the efficacy of the Mo-Si-B based coating as protection from catastrophic failure. The key to the oxidation and corrosion resistance is a robust external aluminoborosilica glass layer that forms and flows quickly to cover the substrate, even under the extreme simulated re-entry conditions. Suppression of active oxidation of SiC, which may occur during atmospheric re-entry and hypersonic flight trajectories, has also been examined. In order to adapt the Mo-Si-B based coating to low partial pressures of oxygen and elevated temperatures, controlled amounts of Al were added to the Mo-Si-B based coating. The resulting coating decreased the inward

  7. X-38 Full Scale TPS Flight Qualification

    NASA Astrophysics Data System (ADS)

    Hilfer, G.

    2002-01-01

    The X-38 of NASA which is an experimental vehicle to prove crucial technologies of a future Crew Return Vehicle (CRV) for the International Space Station (ISS) will be equipped with a large number of newly developed components and systems. In particular, the thermal protection system of the most severely loaded surface areas such as the nose cap and the control surfaces represent a promising approach with respect to thermal endurance and re-usability aspects. The foremost nose section, the body flaps and a wing leading edge segment are all made from SiC-based fiber ceramics. Moreover, the body flap is an entire hot structure. The Nose Skirt Assembly and the Body Flap were developed and manufactured by German industry (MAN Technologie, DLR and ASTRIUM) within the frame of the national TETRA program. The Leading Edge Unit was developed and manufactured by MAN Technologie within the ESA-ARTP. As another effort within the TETRA program aimed at extending the national competence range, IABG developed and built a high-temperature test facility enabling full-scale flight qualification of thermal protection components. The main purpose of this facility was to allow application of all relevant load categories encountered during re-entry flight, i.e. thermal, mechanical and oxidative loads. The facility is in service since April 1999. Within the scope of the X-38 qualification tests the flexibility of the test facility could be demonstrated. Three full scale thermal protection components of X-38 which were very different in size, shape and test requirements were successfully flight qualified in the years 1999 - 2001. For all of the three components, namely the Leading Edge Unit, the Nose Skirt Assembly and the Body Flap, the time- dependent and locally variable temperature profiles of the re-entry flight had to be simulated in order to verify the structural integrity under thermal loads. Within these tests a superposition of the thermal loads with oxidative loads, with the

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

    NASA Astrophysics Data System (ADS)

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

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

  9. System definition study of deployable, non-metallic space structures

    NASA Astrophysics Data System (ADS)

    Stimler, F. J.

    1984-06-01

    The state of the art for nonmetallic materials and fabrication techniques suitable for future space structures are summarized. Typical subsystems and systems of interest to the space community that are reviewed include: (1) inflatable/rigidized space hanger; (2) flexible/storable acoustic barrier; (3) deployable fabric bulkhead in a space habitat; (4) extendible tunnel for soft docking; (5) deployable space recovery/re-entry systems for personnel or materials; (6) a manned habitat for a space station; (7) storage enclosures external to the space station habitat; (8) attachable work stations; and (9) safe haven structures. Performance parameters examined include micrometeoroid protection; leakage rate prediction and control; rigidization of flexible structures in the space environment; flammability and offgassing; lifetime for nonmetallic materials; crack propagation prevention; and the effects of atomic oxygen and space debris. An expandable airlock for shuttle flight experiments and potential tethered experiments from shuttle are discussed.

  10. Investigation of the Geokinetics horizontal in situ oil shale retorting process. Quarterly report, January-March 1980

    SciTech Connect

    Hutchinson, D.L.

    1980-05-01

    Retort No. 18 produced 3479 barrels of oil during the quarter for a total of 4528 barrels to date. Chromatographic analyses of Retort No. 18 shale oil by the GKI analytical laboratory indicated variation in the oil from the wells near the air-in end and from the air-out end of the retort. Shale oil has been blended with Altamont crude (the Roosevelt refinery's normal feedstock); the distillation, API gravity, pour point, flash point, Naptha and Cat Gas were not affected by the shale oil. The diesel off the crude unit changed from water white to yellow, however, and a fine grayish-brown precipitate formed. Re-entry drilling was performed on Retorts No. 21, No. 22, and No. 23 during the quarter; tracer tests were run by Sandia Laboratories on Retorts No. 19, No. 21, No. 22, and No. 23. Blasthole drilling began on Retort No. 25.

  11. Toughened uni-piece, fibrous, reinforced, oxidization-resistant composite

    NASA Technical Reports Server (NTRS)

    Stewart, David A. (Inventor); Leiser, Daniel B. (Inventor)

    2008-01-01

    A composite thermal protection structure, for applications such as atmospheric re-entry vehicles, that can withstand temperatures as high as 3600.degree. F. The structure includes an exposed surface cap having a specially formulated coating, an insulator base adjacent to the cap with another specially formulated coating, and one or more pins that extend from the cap through the insulator base to tie the cap and base together, through ceramic bonding and mechanical attachment. The cap and insulator base have corresponding depressions and projections that mate and allow for differences in thermal expansion of the cap and base. A thin coating of a reaction cured glass formulation is optionally provided on the structure to allow reduce oxidization and/or to reduce catalytic efficiency.

  12. Finishing and proof testing of windows for manned space craft

    NASA Astrophysics Data System (ADS)

    Miska, Herbert A.

    1993-12-01

    The development of the Space Shuttle Orbiter in the early 1970s marked the first time that a fracture mechanics approach was taken to the design of the window systems of a manned space craft. Earlier vehicles were never subjected to repeated launch and re-entry and therefore fatigue or slow crack growth were not major concerns. The design and proof test methodology evolved at that time continues to be applied in the development of the window systems for the Space Station Freedom. A combination of fixed abrasive grinding, lapping, and chemical machining is employed on the fused silica window panes to insure that sub- surface damage is carefully controlled and minimized. All panes are proof tested under controlled atmospheric conditions which preclude crack growth during the test. This paper also covers some of the history of space craft window design, the rationale for the material choices as well as a review of the finishing and test methods employed.

  13. Probabilistic Structural Health Monitoring of the Orbiter Wing Leading Edge

    NASA Technical Reports Server (NTRS)

    Yap, Keng C.; Macias, Jesus; Kaouk, Mohamed; Gafka, Tammy L.; Kerr, Justin H.

    2011-01-01

    A structural health monitoring (SHM) system can contribute to the risk management of a structure operating under hazardous conditions. An example is the Wing Leading Edge Impact Detection System (WLEIDS) that monitors the debris hazards to the Space Shuttle Orbiter s Reinforced Carbon-Carbon (RCC) panels. Since Return-to-Flight (RTF) after the Columbia accident, WLEIDS was developed and subsequently deployed on board the Orbiter to detect ascent and on-orbit debris impacts, so as to support the assessment of wing leading edge structural integrity prior to Orbiter re-entry. As SHM is inherently an inverse problem, the analyses involved, including those performed for WLEIDS, tend to be associated with significant uncertainty. The use of probabilistic approaches to handle the uncertainty has resulted in the successful implementation of many development and application milestones.

  14. Provider perspectives regarding the health care needs of a key population: HIV-infected prisoners after incarceration.

    PubMed

    Sidibe, Turquoise; Golin, Carol; Turner, Kea; Fray, Niasha; Fogel, Cathie; Flynn, Patrick; Gould, Michele; Knight, Kevin; Wohl, David

    2015-01-01

    During incarceration, many HIV-infected prisoners receive care and are adherent to medication. However, following release, many have difficulty engaging in HIV care and remaining on antiretroviral therapy. Community-based service providers for HIV-infected releasees have a deep understanding of the health needs and challenges these individuals face on community re-entry. We conducted in-depth qualitative interviews with 38 health care and service professionals in two southern U.S. states regarding the barriers releasees faced in meeting their health needs, including HIV care and treatment post release. Individual, community, and organization-level barriers to HIV care and treatment adherence post release were identified, and offered unique insight into the ways that these multilevel obstacles affect HIV-infected former prisoners' abilities to engage in care and access necessary social services. Provider perspectives should be considered when designing interventions to support HIV care after release.

  15. Space Shuttle Model In The 16 Foot Transonic Tunnel

    NASA Technical Reports Server (NTRS)

    1978-01-01

    What may appear at first glance to be a swimming shark is a wind tunnel model of the Space Shuttle Orbiter, being tested at NASA's Langley Research Center in Hampton,VA. The Orbiter model is 5.5 feet long (1/20th of the real Orbiter's length) and has remotely operated control surfaces. Inside Langley's 16 foot Transonic Wind Tunnel, the model simulated Orbiter re-entry into the Earth's atmosphere, when it must fly through the transonic speed range (the range that crosses the sound barrier). Information on Orbiter stability and control, collected and analyzed during the tests, were integrated with other data to become part of computerized flight simulation programs.

  16. Testing of a Wireless Sensor System for Instrumented Thermal Protection Systems

    NASA Technical Reports Server (NTRS)

    Kummer, Allen T.; Weir, Erik D.; Morris, Trey J.; Friedenberger, Corey W.; Singh, Aseem; Capuro, Robert M.; Bilen, Sven G.; Fu, Johnny; Swanson, Gregory T.; Hash, David B.

    2011-01-01

    Funded by NASA's Constellation Universities Institutes Project (CUIP), we have been developing and testing a system to wirelessly power and collect data from sensors on space platforms in general and, in particular, the harsh environment of spacecraft re-entry. The elimination of wires and associated failures such as chafing, sparking, ageing, and connector issues can increase reliability and design flexibility while reducing costs. These factors present an appealing case for the pursuit of wireless solutions for harsh environments, particularly for their use in space and on spacecraft. We have designed and built a prototype wireless sensor system. The system, with capabilities similar to that of a wired sensor system, was tested in NASA Ames Research Center s Aerodynamic Heating Facility and Interaction Heating Facility. This paper discusses the overall development effort, testing results, as well as future directions.

  17. A computational intelligence approach to the Mars Precision Landing problem

    NASA Astrophysics Data System (ADS)

    Birge, Brian Kent, III

    Various proposed Mars missions, such as the Mars Sample Return Mission (MRSR) and the Mars Smart Lander (MSL), require precise re-entry terminal position and velocity states. This is to achieve mission objectives including rendezvous with a previous landed mission, or reaching a particular geographic landmark. The current state of the art footprint is in the magnitude of kilometers. For this research a Mars Precision Landing is achieved with a landed footprint of no more than 100 meters, for a set of initial entry conditions representing worst guess dispersions. Obstacles to reducing the landed footprint include trajectory dispersions due to initial atmospheric entry conditions (entry angle, parachute deployment height, etc.), environment (wind, atmospheric density, etc.), parachute deployment dynamics, unavoidable injection error (propagated error from launch on), etc. Weather and atmospheric models have been developed. Three descent scenarios have been examined. First, terminal re-entry is achieved via a ballistic parachute with concurrent thrusting events while on the parachute, followed by a gravity turn. Second, terminal re-entry is achieved via a ballistic parachute followed by gravity turn to hover and then thrust vector to desired location. Third, a guided parafoil approach followed by vectored thrusting to reach terminal velocity is examined. The guided parafoil is determined to be the best architecture. The purpose of this study is to examine the feasibility of using a computational intelligence strategy to facilitate precision planetary re-entry, specifically to take an approach that is somewhat more intuitive and less rigid, and see where it leads. The test problems used for all research are variations on proposed Mars landing mission scenarios developed by NASA. A relatively recent method of evolutionary computation is Particle Swarm Optimization (PSO), which can be considered to be in the same general class as Genetic Algorithms. An improvement over

  18. Thermal protection system ablation sensor

    NASA Technical Reports Server (NTRS)

    Gorbunov, Sergey (Inventor); Martinez, Edward R. (Inventor); Scott, James B. (Inventor); Oishi, Tomomi (Inventor); Fu, Johnny (Inventor); Mach, Joseph G. (Inventor); Santos, Jose B. (Inventor)

    2011-01-01

    An isotherm sensor tracks space vehicle temperatures by a thermal protection system (TPS) material during vehicle re-entry as a function of time, and surface recession through calibration, calculation, analysis and exposed surface modeling. Sensor design includes: two resistive conductors, wound around a tube, with a first end of each conductor connected to a constant current source, and second ends electrically insulated from each other by a selected material that becomes an electrically conductive char at higher temperatures to thereby complete an electrical circuit. The sensor conductors become shorter as ablation proceeds and reduced resistance in the completed electrical circuit (proportional to conductor length) is continually monitored, using measured end-to-end voltage change or current in the circuit. Thermocouple and/or piezoelectric measurements provide consistency checks on local temperatures.

  19. Testing geopressured geothermal reservoirs in existing wells. Wells of Opportunity Program final contract report, 1980-1981

    SciTech Connect

    Not Available

    1982-01-01

    The geopressured-geothermal candidates for the Wells of Opportunity program were located by the screening of published information on oil industry activity and through direct contact with the oil and gas operators. This process resulted in the recommendation to the DOE of 33 candidate wells for the program. Seven of the 33 recommended wells were accepted for testing. Of these seven wells, six were actually tested. The first well, the No. 1 Kennedy, was acquired but not tested. The seventh well, the No. 1 Godchaux, was abandoned due to mechanical problems during re-entry. The well search activities, which culminated in the acceptance by the DOE of 7 recommended wells, were substantial. A total of 90,270 well reports were reviewed, leading to 1990 wells selected for thorough geological analysis. All of the reservoirs tested in this program have been restricted by one or more faults or permeability barriers. A comprehensive discussion of test results is presented.

  20. KSC-04PD-1424

    NASA Technical Reports Server (NTRS)

    2004-01-01

    KENNEDY SPACE CENTER, FLA. Workers in the Orbiter Processing Facility lift the Reinforced Carbon-Carbon (RCC) chin panel to install on Discovery. The chin panel is the smile-shaped section of RCC directly below the nose cap that provides a thermal barrier during re-entry. The nose cap, with chin panel, was removed from the vehicle in the summer of 2003 and returned to the vendor, where it underwent numerous forms of Non-Destructive Evaluation. These tests included X-ray, ultrasound and eddy current to ensure its structural integrity prior to reinstallation. Discovery is designated as the Return to Flight vehicle for mission STS-114, no earlier than March 2005.

  1. KSC-04PD-1427

    NASA Technical Reports Server (NTRS)

    2004-01-01

    KENNEDY SPACE CENTER, FLA. Workers in the Orbiter Processing Facility check the placement of the Reinforced Carbon-Carbon chin panel on Discovery. The chin panel is the smile-shaped section of RCC directly below the nose cap that provides a thermal barrier during re-entry. The nose cap, with chin panel, was removed from the vehicle in the summer of 2003 and returned to the vendor, where it underwent numerous forms of Non-Destructive Evaluation. These tests included X-ray, ultrasound and eddy current to ensure its structural integrity prior to reinstallation. Discovery is designated as the Return to Flight vehicle for mission STS-114, no earlier than March 2005.

  2. KSC-04PD-1423

    NASA Technical Reports Server (NTRS)

    2004-01-01

    KENNEDY SPACE CENTER, FLA. Workers in the Orbiter Processing Facility prepare the Reinforced Carbon-Carbon (RCC) chin panel to install on Discovery. The chin panel is the smile-shaped section of RCC directly below the nose cap that provides a thermal barrier during re-entry. The nose cap, with chin panel, was removed from the vehicle in the summer of 2003 and returned to the vendor, where it underwent numerous forms of Non-Destructive Evaluation. These tests included X-ray, ultrasound and eddy current to ensure its structural integrity prior to reinstallation. Discovery is designated as the Return to Flight vehicle for mission STS-114, no earlier than March 2005.

  3. KSC-04PD-1425

    NASA Technical Reports Server (NTRS)

    2004-01-01

    KENNEDY SPACE CENTER, FLA. Workers in the Orbiter Processing Facility lift the Reinforced Carbon-Carbon (RCC) chin panel into place on Discovery. The chin panel is the smile-shaped section of RCC directly below the nose cap that provides a thermal barrier during re-entry. The nose cap, with chin panel, was removed from the vehicle in the summer of 2003 and returned to the vendor, where it underwent numerous forms of Non-Destructive Evaluation. These tests included X-ray, ultrasound and eddy current to ensure its structural integrity prior to reinstallation. Discovery is designated as the Return to Flight vehicle for mission STS-114, no earlier than March 2005.

  4. KSC-04PD-1426

    NASA Technical Reports Server (NTRS)

    2004-01-01

    KENNEDY SPACE CENTER, FLA. Workers in the Orbiter Processing Facility check the placement of the Reinforced Carbon-Carbon (RCC) chin panel on Discovery. . The chin panel is the smile- shaped section of RCC directly below the nose cap that provides a thermal barrier during re-entry. The nose cap, with chin panel, was removed from the vehicle in the summer of 2003 and returned to the vendor, where it underwent numerous forms of Non- Destructive Evaluation. These tests included X-ray, ultrasound and eddy current to ensure its structural integrity prior to reinstallation. Discovery is designated as the Return to Flight vehicle for mission STS-114, no earlier than March 2005.

  5. Understanding the Columbia Space Shuttle Accident

    SciTech Connect

    Osheroff, Doug

    2004-06-16

    On February 1, 2003, the NASA space shuttle Columbia broke apart during re-entry over East Texas at an altitude of 200,000 feet and a velocity of approximately 12,000 mph. All aboard perished. Prof. Osheroff was a member of the board that investigated the origins of this accident, both physical and organizational. In his talk he will describe how the board was able to determine with almost absolute certainty the physical cause of the accident. In addition, Prof. Osherhoff will discuss its organizational and cultural causes, which are rooted deep in the culture of the human spaceflight program. Why did NASA continue to fly the shuttle system despite the persistent failure of a vital sub-system that it should have known did indeed pose a safety risk on every flight? Finally, Prof. Osherhoff will touch on the future role humans are likely to play in the exploration of space.

  6. Direct Monte Carlo Simulations of the Intermediate Experimental Vehicle at Early Stages of Reentry

    NASA Astrophysics Data System (ADS)

    Banyai, T.; Torres, E.; Kashkovsky, A. V.; Vashchenkov, P. V.; Ivanov, M. S.; Rambaud, P.

    2011-05-01

    Within the European Space Agency (ESA) framework program FLPP Next Generation Launcher (NGL) preparatory activities on System, In-Flight Experimentation and Aerothermodynamics Period 1, Step 2, von Karman Institute (VKI) has to perform ground testing and numerical simulations to contribute to the aerothermodynamic database of the Intermediate eXperimental Vehicle (IXV) along its trajectory during re-entry. The present article summarizes the part of these activities in relation with the evaluation of the aerodynamic properties in the early stages of reentry. Due to the rarefied nature of the higher atmosphere, the computations were carried out by means of Direct Simulation of Monte Carlo (DSMC) method. The aim of this work was to a., validate the methodology used at VKI, b., perform computations at several points along the trajectory and c., assess the feasibility of joint simulation of rarefied flow and thrusters.

  7. Aerodynamic and aerothermodynamic trade-off analysis of a small hypersonic flying test bed

    NASA Astrophysics Data System (ADS)

    Pezzella, Giuseppe

    2011-08-01

    This paper deals with the aerodynamic and aerothermodynamic trade-off analysis aiming to design a small hypersonic flying test bed with a relatively simple vehicle architecture. Such vehicle will have to be launched with a sounding rocket and shall re-enter the Earth atmosphere allowing to perform several experiments on critical re-entry technologies such as boundary-layer transition and shock-shock interaction phenomena. The flight shall be conducted at hypersonic Mach number, in the range 6-8 at moderate angles of attack. In the paper some design analyses are shown as, for example, the longitudinal and lateral-directional stability analysis. A preliminary optimization of the configuration has been also done to improve the aerodynamic performance and stability of the vehicle. Several design results, based both on engineering approach and computational fluid dynamics, are reported and discussed in the paper. The aerodynamic model of vehicle is also provided.

  8. Communication: Equilibrium rate coefficients from atomistic simulations: The O((3)P) + NO((2)Π) → O2(X(3)Σg(-)) + N((4)S) reaction at temperatures relevant to the hypersonic flight regime.

    PubMed

    Castro-Palacio, Juan Carlos; Bemish, Raymond J; Meuwly, Markus

    2015-03-01

    The O((3)P) + NO((2)Π) → O2(X(3)Σg(-)) + N((4)S) reaction is among the N- and O- involving reactions that dominate the energetics of the reactive air flow around spacecraft during hypersonic atmospheric re-entry. In this regime, the temperature in the bow shock typically ranges from 1000 to 20,000 K. The forward and reverse rate coefficients for this reaction derived directly from trajectory calculations over this range of temperature are reported in this letter. Results compare well with the established equilibrium constants for the same reaction from thermodynamic quantities derived from spectroscopy in the gas phase which paves the way for large-scale in silico investigations of equilibrium rates under extreme conditions.

  9. [Stent Grafting for Aortic Dissection].

    PubMed

    Uchida, Naomichi

    2016-07-01

    The purpose of stent graft for aortic dissection is to terminate antegrade blood flow into the false lumen through primary entry. Early intervention for primary entry makes excellent aortic remodeling and emergent stent grafting for complicated acute type B aortic dissection is supported as a class I. On the other hand stent grafting for chronic aortic dissection is controversial. Early stent grafting is considered with in 6 months after on-set if the diameter of the descending aorta is more than 40 mm. Additional interventions for residual false lumen on the downstream aorta are still required. Stent graft for re-entry, candy-plug technique, and double stenting, other effective re-interventions were reported. Best treatment on the basis of each anatomical and physical characteristics should be selected in each institution. Frozen elephant trunk is alternative procedure for aortic dissection without the need to take account of proximal anatomical limitation and effective for acute type A aortic dissection. PMID:27440026

  10. KSC-03PD-0328

    NASA Technical Reports Server (NTRS)

    2003-01-01

    KENNEDY SPACE CENTER, FLA. -- In the Thermal Protection System Facility, NASA Administrator Sean O'Keefe (center) looks at a Dome Heat Shield blanket that is used for Shuttle engines. From left is Glen Mahone, acting director for NASA Public Affairs, Jim Kennedy, deputy director of Kennedy Space Center, O'Keefe, Lee Zook, project leader, and Chuck Fontana, associate program manager, Integrated Logistics. O'Keefe is visiting the site to learn more about the TPS products and process in protecting orbiters from the intense heat of launch and re-entry. TPS tiles have been discussed in the investigation into the Columbia tragedy that destroyed the orbiter and claimed the lives of seven astronauts.

  11. Analysis of internal ablation for the thermal control of aerospace vehicles

    NASA Technical Reports Server (NTRS)

    Camberos, Jose A.; Roberts, Leonard

    1989-01-01

    A new method of thermal protection for transatmospheric vehicles is introduced. The method involves the combination of radiation, ablation and transpiration cooling. By placing an ablating material behind a fixed-shape, porous outer shield, the effectiveness of transpiration cooling is made possible while retaining the simplicity of a passive mechanism. A simplified one-dimensional approach is used to derive the governing equations. Reduction of these equations to non-dimensional form yields two parameters which characterize the thermal protection effectiveness of the shield and ablator combination for a given trajectory. The non-dimensional equations are solved numerically for a sample trajectory corresponding to glide re-entry. Four typical ablators are tested and compared with results obtained by using the thermal properties of water. For the present level of analysis, the numerical computations adequately support the analytical model.

  12. Triggers and Anatomical Substrates in the Genesis and Perpetuation of Atrial Fibrillation

    PubMed Central

    Sánchez-Quintana, Damián; López-Mínguez, José Ramón; Pizarro, Gonzalo; Murillo, Margarita; Cabrera, José Angel

    2012-01-01

    The definition of atrial fibrillation (AF) as a functional electrical disorder does not reflect the significant underlying structural abnormalities. Atrial and Pulmonary Vein (PV) muscle sleeve microstructural remodeling is present, and establishes a vulnerable substrate for AF maintenance. In spite of an incomplete understanding of the anatomo-functional basis for AF, current evidence demonstrates that this arrhythmia usually requires a trigger for initiation and a vulnerable electrophysiological and/or anatomical substrate for maintenance. It is still unclear whether the trigger mechanisms include focal enhanced automaticity, triggered activity and/or micro re-entry from myocardial tissue. Initiation of AF can be favored by both parasympathetic and sympathetic stimulation, which also seem to play a role in maintaining AF. Finally, evolving clinical evidence demonstrates that inflammation is associated with new-onset and recurrent AF through a mechanism that possibly involves cellular degeneration, apoptosis, and subsequent atrial fibrosis. PMID:22920484

  13. Hypersonic Flow Computations on Unstructured Meshes

    NASA Technical Reports Server (NTRS)

    Bibb, K. L.; Riley, C. J.; Peraire, J.

    1997-01-01

    A method for computing inviscid hypersonic flow over complex configurations using unstructured meshes is presented. The unstructured grid solver uses an edge{based finite{volume formulation. Fluxes are computed using a flux vector splitting scheme that is capable of representing constant enthalpy solutions. Second{order accuracy in smooth flow regions is obtained by linearly reconstructing the solution, and stability near discontinuities is maintained by locally forcing the scheme to reduce to first-order accuracy. The implementation of the algorithm to parallel computers is described. Computations using the proposed method are presented for a sphere-cone configuration at Mach numbers of 5.25 and 10.6, and a complex hypersonic re-entry vehicle at Mach numbers of 4.5 and 9.8. Results are compared to experimental data and computations made with established structured grid methods. The use of the solver as a screening tool for rapid aerodynamic assessment of proposed vehicles is described.

  14. CHOA concussion consensus: establishing a uniform policy for academic accommodations.

    PubMed

    Popoli, David Michael; Burns, Thomas G; Meehan, William P; Reisner, Andrew

    2014-03-01

    Concussion research generally centers on physical challenges, though aspects such as social functioning and returning to school also warrant attention in pediatric populations. Restoring academic performance postconcussion remains a challenge. Here we provide recommendations addressing a uniform policy for pediatric concussion patients in academic institutions. Tools that may minimize difficulty with academic re-entry include independent educational evaluations, individualized educational programs (IEPs), student support teams (SSTs), letters of academic accommodation, time off, and 504 Plans. Recognition and treatment is crucial for symptom relief and prevention of functional disruption, as is specialist referral during the acute window. We recommend early intervention with a letter of academic accommodation and SST and suggest that 504 Plans and IEPs be reserved for protracted or medically complicated cases. Students with concussion should be observed for anxiety and depression because these symptoms can lead to prolonged recovery, decreased quality of life, and other social challenges.

  15. Immune System Dysregulation, Viral Reactivation and Stress During Short-Duration Spaceflight

    NASA Technical Reports Server (NTRS)

    Pierson, Duane; Sams, Clarence; Crucian, Brian; Mehta, Satish; Stowe, Raymond; Uchakin, Peter; Quiriarte, Heather

    2010-01-01

    The objective of this NASA Short-Duration Bioastronautics Investigation (SDBI) was to assess spaceflight-associated immune dysregulation. Many previous studies have investigated this phenomenon post-flight, and found altered distribution and function of the peripheral leukocyte populations. Alterations in cytokine production profiles have also been reported. Unfortunately, post-flight data may be altered by the stress associated with high-G re-entry and readaptation to unit gravity following deconditioning. Therefore, the current study collected blood and saliva samples from crewmembers immediately before landing, and returned those samples to Earth for terrestrial analysis. Assays include peripheral comprehensive immunophenotype, T cell function, cytokine profiles, viral-specific immunity, latent viral reactivation (EBV, CMV, VZV), and stress hormone measurements. A total of 18 short duration crewmembers completed the study and the final data will be presented.

  16. An emerging molecular and cellular framework for memory processing by the hippocampus.

    PubMed

    Wittenberg, Gayle M; Tsien, Joe Z

    2002-10-01

    The hippocampus plays a central role in memory consolidation, a process for converting short-term memory into cortically stored, long-lasting memory in the mammalian brain. Here, we review recent data and discuss the 'synaptic re-entry reinforcement' (SRR) hypothesis, which can account for the role of the hippocampus in memory consolidation at both the molecular and systems levels. The central idea of the SRR hypothesis is that reactivation of neural ensembles in the hippocampus during the consolidation period results in multiple rounds of NMDA-receptor-dependent synaptic reinforcement of the hippocampal memory traces created during initial learning. In addition, such reactivation and reinforcement processes permit the hippocampus to act as a 'coincidence regenerator', providing coordinated input that drives the coherent reactivation of cortical neurons, resulting in the progressive strengthening of cortical memory traces through reactivation of cortical NMDA receptors. PMID:12220877

  17. Space shuttle guidance, navigation, and control design equations. Volume 3: Guidance

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Space shuttle guidance, navigation, and control design equations are presented. The space-shuttle mission includes three relatively distinct guidance phases which are discussed; atmospheric boost, which is characterized by an adaptive guidance law; extra-atmospheric activities; and re-entry activities, where aerodynamic surfaces are the principal effectors. Guidance tasks include pre-maneuver targeting and powered flight guidance, where powered flight is defined to include the application of aerodynamic forces as well as thruster forces. A flow chart which follows guidance activities throughout the mission from the pre-launch phase through touchdown is presented. The main guidance programs and subroutines used in each phase of a typical rendezvous mission are listed. Detailed software requirements are also presented.

  18. Results from Navigator GPS Flight Testing for the Magnetospheric MultiScale Mission

    NASA Technical Reports Server (NTRS)

    Lulich, Tyler D.; Bamford, William A.; Wintermitz, Luke M. B.; Price, Samuel R.

    2012-01-01

    The recent delivery of the first Goddard Space Flight Center (GSFC) Navigator Global Positioning System (GPS) receivers to the Magnetospheric MultiScale (MMS) mission spacecraft is a high water mark crowning a decade of research and development in high-altitude space-based GPS. Preceding MMS delivery, the engineering team had developed receivers to support multiple missions and mission studies, such as Low Earth Orbit (LEO) navigation for the Global Precipitation Mission (GPM), above the constellation navigation for the Geostationary Operational Environmental Satellite (GOES) proof-of-concept studies, cis-Lunar navigation with rapid re-acquisition during re-entry for the Orion Project and an orbital demonstration on the Space Shuttle during the Hubble Servicing Mission (HSM-4).

  19. Particle kinetic simulation of high altitude hypervelocity flight

    NASA Technical Reports Server (NTRS)

    Heinemann, Klaus; Boyd, Iain D.; Haas, Brian L.

    1993-01-01

    In this grant period, the focus has been on the effects of thermo-chemical nonequilibrium in low-density gases, and on interactions between such gases and solid surfaces. Such conditions apply to hypersonic flows of re-entry vehicles, and to the expansion plumes of small rockets. Due to the nonequilibrium nature of these flows, a particle approach has been adopted. The method continues to undergo refinement and application to typical flows of interest. A number of studies have been performed for flows in thermo-chemical nonequilibrium. The effects of vibrational nonequilibrium on the rate of dissociation were studied for diatomic nitrogen. It was found that a new model reproduced the nonequilibrium behavior observed experimentally.

  20. Experimental investigation of supersonic low pressure air plasma flows obtained with different arc-jet operating conditions

    NASA Astrophysics Data System (ADS)

    Lago, Viviana; Ndiaye, Abdoul-Aziz

    2012-11-01

    A stationary arc-jet plasma flow at low pressure is used to simulate some properties of the gas flow surrounding a vehicle during its entry into celestial body's atmospheres. This paper presents an experimental study concerning plasmas simulating a re-entry into our planet. Optical measurements have been carried out for several operating plasma conditions in the free stream, and in the shock layer formed in front of a flat cylindrical plate, placed in the plasma jet. The analysis of the spectral radiation enabled the identification of the emitting species, the determination of the rotational and vibrational temperatures in the free-stream and in the shock layer and the determination of the distance of the shock to the flat plate face. Some plasma fluid parameters like, stagnation pressure, specific enthalpy and heat flux have been determined experimentally along the plasma-jet axis.

  1. CFD Modeling of Thermally and Chemically Nonequilibrium Flows in Discharge Channel and in Subsonic Plasmatron Jets Around of the Flat-Face Model

    NASA Astrophysics Data System (ADS)

    Sakharov, V. I.; Kolesnikov, A. F.; Gordeev, A. N.; Vérant, J.-L.

    2009-01-01

    Numerical simulation of subsonic ICP flow and exhausted air and CO2 - plasma jets around of the flat- face model with SiC coating were performed for IPG-4 (IPM RAS) facility test regimes simulating of re-entry heating of the Pre-X space vehicle (Earth) and MSRO - Mars Sample Return Orbiter (Mars). The calculation of the body heat flux maps was based on numerical solution of one-dimensional equations of laminar thermally and chemically nonequilibrium multi components boundary layer with finite thickness. The necessary flow data at the outer edge of the boundary layer were taken from results of Navier-Stokes calculations. The result obtained in the framework of macroscopic approach shows that the SiC samples are a low catalytic material in regards with the specified operating conditions for Pre-X and for MSRO.

  2. Comparative analysis of ear-hole closure identifies epimorphic regeneration as a discrete trait in mammals.

    PubMed

    Gawriluk, Thomas R; Simkin, Jennifer; Thompson, Katherine L; Biswas, Shishir K; Clare-Salzler, Zak; Kimani, John M; Kiama, Stephen G; Smith, Jeramiah J; Ezenwa, Vanessa O; Seifert, Ashley W

    2016-01-01

    Why mammals have poor regenerative ability has remained a long-standing question in biology. In regenerating vertebrates, injury can induce a process known as epimorphic regeneration to replace damaged structures. Using a 4-mm ear punch assay across multiple mammalian species, here we show that several Acomys spp. (spiny mice) and Oryctolagus cuniculus completely regenerate tissue, whereas other rodents including MRL/MpJ 'healer' mice heal similar injuries by scarring. We demonstrate ear-hole closure is independent of ear size, and closure rate can be modelled with a cubic function. Cellular and genetic analyses reveal that injury induces blastema formation in Acomys cahirinus. Despite cell cycle re-entry in Mus musculus and A. cahirinus, efficient cell cycle progression and proliferation only occurs in spiny mice. Together, our data unite blastema-mediated regeneration in spiny mice with regeneration in other vertebrates such as salamanders, newts and zebrafish, where all healthy adults regenerate in response to injury. PMID:27109826

  3. Exploration Flight Test 1 Afterbody Aerothermal Environment Reconstruction

    NASA Technical Reports Server (NTRS)

    Hyatt, Andrew J.; Oliver, Brandon; Amar, Adam; Lessard, Victor

    2016-01-01

    The Exploration Flight Test 1 vehicle included roughly 100 near surface thermocouples on the after body of the vehicle. The temperature traces at each of these instruments have been used to perform inverse environment reconstruction to determine the aerothermal environment experienced during re-entry of the vehicle. This paper provides an overview of the reconstructed environments and identifies critical aspects of the environment. These critical aspects include transition and reaction control system jet influence. A blind test of the process and reconstruction tool was also performed to build confidence in the reconstructed environments. Finally, an uncertainty quantification analysis was also performed to identify the impact of each of the uncertainties on the reconstructed environments.

  4. Correctional Management and Treatment of Autism Spectrum Disorder.

    PubMed

    Michna, Isabella; Trestman, Robert

    2016-06-01

    Over the past two decades, the recognition and diagnosis of autism spectrum disorders (ASDs) has grown. One result is the parallel recognition of a substantial prevalence of individuals with ASD who, because of life-long social and emotional deficits, have become involved with the criminal justice system (CJS). It is generally acknowledged that many CJS professionals who encounter individuals with ASD are ill equipped to treat or advocate for them. Currently, there is no universal training on ASD for CJS professionals, nor are there service standards for individuals with ASD during incarceration, to support their community re-entry and reduce recidivism. In this article, we review the background and context for management and treatment during incarceration for individuals with ASD. PMID:27236182

  5. Non-random subcellular distribution of variant EKLF in erythroid cells

    PubMed Central

    Quadrini, Karen J.; Gruzglin, Eugenia; Bieker, James J.

    2008-01-01

    EKLF protein plays a prominent role during erythroid development as a nuclear transcription factor. Not surprisingly, exogenous EKLF quickly localizes to the nucleus. However, using two different assays we have unexpectedly found that a substantial proportion of endogenous EKLF resides in the cytoplasm at steady state in all erythroid cells examined. While EKLF localization does not appear to change during either erythroid development or terminal differentiation, we find that the protein displays subtle yet distinct biochemical and functional differences depending on which subcellular compartment it is isolated from, with PEST sequences possibly playing a role in these differences. Localization is unaffected by inhibition of CRM1 activity and the two populations are not differentiated by stability. Heterokaryon assays demonstrate that EKLF is able to shuttle out of the nucleus although its nuclear re-entry is rapid. These studies suggest there is an unexplored role for EKLF in the cytoplasm that is separate from its well-characterized nuclear function. PMID:18329016

  6. KSC-05PD-0121

    NASA Technical Reports Server (NTRS)

    2005-01-01

    KENNEDY SPACE CENTER, FLA. Matt Scott, with United Space Alliance, lifts the final Reinforced Carbon-Carbon (RCC) panel into position for installation on orbiter Discoverys left wing. The leading edges of each of an orbiters wings have 22 RCC panels. They are light gray and made entirely of carbon composite material, which protect the orbiter during re-entry. The molded components are approximately 0.25- to 0.5-inch thick and capable of withstanding temperatures up to 3,220 degrees F. Following the Columbia accident in February 2002, which was caused by a breach in an RCC panel that allowed hot gases into the vehicle, each panel on Discovery was removed and thoroughly inspected before final reinstallation. Discovery is the designated orbiter to fly on the Return to Flight mission STS-114, the first Space Shuttle to launch since the accident. The launch window for the mission is May 12 to June 3, 2005.

  7. Relative Navigation Determination in the Capture of Non-Cooperative Targets

    NASA Astrophysics Data System (ADS)

    Gomez, Harvey; Boge, Toralf

    2013-08-01

    The active removal of space debris has great interest nowadays because of recent events of space collisions in LEO and unexpected object re-entry. There have been some test flights, e.g. ETS-VII [1] and Orbital Express [2], for on-orbit satellite servicing and autonomous rendezvous and docking, with the advantage of being cooperative targets, which gives aid for attitude and position determination by the chaser. In case of space debris, no cooperative information is given and the chaser satellite must extract accurate information about the behaviour of the tumbling debris. For this, specific sensors will be used during each phase of the rendezvous approach in order to ensure a secure and safe mission during the complete process. The purpose of this paper is to describe the use of possible sensors for autonomous rendezvous to space debris, i.e. non-cooperative targets.

  8. Steady State Transportation Cooling in Porous Media Under Local, Non-Thermal Equilibrium Fluid Flow

    NASA Technical Reports Server (NTRS)

    Rodriquez, Alvaro Che

    2002-01-01

    An analytical solution to the steady-state fluid temperature for 1-D (one dimensional) transpiration cooling has been derived. Transpiration cooling has potential use in the aerospace industry for protection against high heating environments for re-entry vehicles. Literature for analytical treatments of transpiration cooling has been largely confined to the assumption of thermal equilibrium between the porous matrix and fluid. In the present analysis, the fundamental fluid and matrix equations are coupled through a volumetric heat transfer coefficient and investigated in non-thermal equilibrium. The effects of varying the thermal conductivity of the solid matrix and the heat transfer coefficient are investigated. The results are also compared to existing experimental data.

  9. STS-76 Post Flight Press Conference

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The flight crew of the STS-76 Space Shuttle Orbiter Atlantis; Cmdr. Kevin P. Chilton, Pilot Richard A. Searfoss, and Mission Specialists Linda M. Godwin, Michael R. Clifford, and Ronald M. Sega present an overview of their mission. Highlights STS-76 include the first spacewalk by U.S. astronauts while the shuttle is attached to the Russian Space Station Mir, and the transfer of Shannon W. Lucid to the Mir-21 crew, the first American woman to serve as a Mir station researcher. She will remain aboard the orbiting station until Atlantis again docks with Mir in early August. Video footage includes the following: prelaunch and launch activities; shuttle launch; in-orbit rendezous; in-orbit docking between Mir and the orbiter; general crew activities; tranfer of supplies; Godwin and Clifford's EVA; undocking maneuvers; and the re-entry and landing of the orbiter.

  10. Pulmonary vein triggers, focal sources, rotors and atrial cardiomyopathy: implications for the choice of the most effective ablation therapy.

    PubMed

    Pison, L; Tilz, R; Jalife, J; Haïssaguerre, M

    2016-05-01

    Understanding of the pathophysiological mechanism(s) underlying atrial fibrillation (AF) is the foundation on which current ablation strategies are built. In the vast majority of patients with paroxysmal AF, the ablation procedure should target the pulmonary veins. In patients with nonparoxysmal AF, however, pulmonary vein isolation alone seems to be insufficient to prevent the arrhythmia. Several recent clinical trials have investigated the concept that rotors (re-entry based on a meandering central core from which spiral waves emanate) might be the mechanism responsible for sustaining AF. Ablation of these localized AF sources is an important step towards substrate-driven procedures in persistent AF. Hybrid AF ablation procedures, based on the integration of endocardial transcatheter and epicardial off-pump surgical techniques, have been introduced to overcome their mutual shortcomings. The long-term results are encouraging, especially in currently challenging settings such as nonparoxysmal AF and failed endocardial catheter ablation procedures. PMID:26991806

  11. Evaluation of metal matrix composites

    NASA Technical Reports Server (NTRS)

    Okelly, K. P.

    1971-01-01

    The results of an evaluation of candidate metal-matrix composite materials for shuttle space radiators mounted to external structure are presented. The evaluation was specifically applicable to considerations of the manufacturing and properties of a potential space radiator. Two candidates, boron/aluminum and graphite/aluminum were obtained or made in various forms and tested in sufficient depth to allow selection of one of the two for future scale-up programs. The effort accomplished on this program verified that aluminum reinforced with boron was within the state-of-the-art in industry and possessed properties usable in the external skin areas available for shuttle radiators where re-entry temperatures will not exceed 800 F. It further demonstrated that graphite/aluminum has an apparently attractive future for space applications but requires extension development prior to scale-up.

  12. Sensorimotor Adaptations Following Exposure to Ambiguous Inertial Motion Cues

    NASA Technical Reports Server (NTRS)

    Wood, S. J.; Harm, D. L.; Reschke, M. F.; Rupert, A. H.; Clement, G. R.

    2009-01-01

    The central nervous system must resolve the ambiguity of inertial motion sensory cues in order to derive accurate spatial orientation awareness. We hypothesize that multi-sensory integration will be adaptively optimized in altered gravity environments based on the dynamics of other sensory information available, with greater changes in otolith-mediated responses in the mid-frequency range where there is a crossover of tilt and translation responses. The primary goals of this ground-based research investigation are to explore physiological mechanisms and operational implications of tilt-translation disturbances during and following re-entry, and to evaluate a tactile prosthesis as a countermeasure for improving control of whole-body orientation.

  13. Space Tug Aerobraking Study. Volume 2: Technical

    NASA Technical Reports Server (NTRS)

    Corso, C. J.; Eyer, C. L.

    1972-01-01

    The feasibility and practicality of employing an aerobraking trajectory for return of the reusable Space Tug from geosynchronous and other high energy missions was investigated. The aerobraking return trajectory modes from high orbits employ transfer ellipses which have low perigee altitudes wherein the earth's sensible atmosphere provides drag to reduce the Tug descent delta velocity requirements and thus decrease the required return trip propulsive energy. An aerobraked Space Tug, sized to the Space Shuttle payload capability and dimensional constraints, can accomplish 95 percent of the geosynchronous missions with a single Shuttle/Tug launch per mission. Aerodynamics, aerothermodynamics, trajectory, quidance and control, configuration concepts, materials, weights and performance parameters were identified. Sensitivities to trajectory uncertainties, atmospheric anomalies and re-entry environments were determined. New technology requirements and future studies required to further enhance the aerobraking potential were identified.

  14. Numerical Simulations of High-Altitude Aerothermodynamics of a Promising Spacecraft Model

    NASA Astrophysics Data System (ADS)

    Vashchenkov, P.; Ivanov, M.; Krylov, A.

    2011-05-01

    The paper describes a numerical study of aerodynamic characteristics of a re-entry vehicle in the range of altitudes from 120 to 60 km. The computations are performed by the DSMC method with the use of the SMILE software system and by the local bridging method with the use of the RuSat software system. Some computations are performed in an axisymmetric formulation, which makes it possible to estimate the real gas effects (nonequilibrium of internal energy, dissociation of the gas, etc.) on the efficiency of control surfaces. A comparison of results obtained by the local bridging method and the DSMC method allow estimation of the errors of aerodynamic characteristics obtained by the local bridging method.

  15. An object-oriented implementation of a parallel Monte Carlo code for radiation transport

    NASA Astrophysics Data System (ADS)

    Santos, Pedro Duarte; Lani, Andrea

    2016-05-01

    This paper describes the main features of a state-of-the-art Monte Carlo solver for radiation transport which has been implemented within COOLFluiD, a world-class open source object-oriented platform for scientific simulations. The Monte Carlo code makes use of efficient ray tracing algorithms (for 2D, axisymmetric and 3D arbitrary unstructured meshes) which are described in detail. The solver accuracy is first verified in testcases for which analytical solutions are available, then validated for a space re-entry flight experiment (i.e. FIRE II) for which comparisons against both experiments and reference numerical solutions are provided. Through the flexible design of the physical models, ray tracing and parallelization strategy (fully reusing the mesh decomposition inherited by the fluid simulator), the implementation was made efficient and reusable.

  16. Tandem spheres in hypersonic flow

    SciTech Connect

    Laurence, Stuart J; Deiterding, Ralf; Hornung, Hans G

    2009-01-01

    The problem of determining the forces acting on a secondary body when it is travelling at some point within the shocked region created by a hypersonic primary body is of interest in such situations as store or stage separation, re-entry of multiple vehicles, and atmospheric meteoroid fragmentation. The current work is concerned with a special case of this problem, namely that in which both bodies are spheres and are stationary with respect to one another. We first present an approximate analytical model of the problem; subsequently, numerical simulations are described and results are compared with those from the analytical model. Finally, results are presented from a series of experiments in the T5 hypervelocity shock tunnel in which a newly-developed force-measurement technique was employed.

  17. The design and realisation of the IXV Mission Analysis and Flight Mechanics

    NASA Astrophysics Data System (ADS)

    Haya-Ramos, Rodrigo; Blanco, Gonzalo; Pontijas, Irene; Bonetti, Davide; Freixa, Jordi; Parigini, Cristina; Bassano, Edmondo; Carducci, Riccardo; Sudars, Martins; Denaro, Angelo; Angelini, Roberto; Mancuso, Salvatore

    2016-07-01

    The Intermediate eXperimental Vehicle (IXV) is a suborbital re-entry demonstrator successfully launched in February 2015 focusing on the in-flight demonstration of a lifting body system with active aerodynamic control surfaces. This paper presents an overview of the Mission Analysis and Flight Mechanics of the IXV vehicle, which comprises computation of the End-to-End (launch to splashdown) design trajectories, characterisation of the Entry Corridor, assessment of the Mission Performances through Monte Carlo campaigns, contribution to the aerodynamic database, analysis of the Visibility and link budget from Ground Stations and GPS, support to safety analyses (off nominal footprints), specification of the Centre of Gravity box, selection of the Angle of Attack trim line to be flown and characterisation of the Flying Qualities performances. An initial analysis and comparison with the raw flight data obtained during the flight will be discussed and first lessons learned derived.

  18. Elderly prisoners: a growing and forgotten group within correctional systems vulnerable to elder abuse.

    PubMed

    Stojkovic, Stan

    2007-01-01

    There are over 2.1 million people incarcerated in the nation's jails and prisons. Additionally, close to 600,000 prisoners are released annually into communities across the country. Many prisoners and those released from prisons are elderly. The purpose of this article is to examine the systemic abuse and neglect experienced by elderly prisoners while they are incarcerated and when they are released from prison. Most correctional systems have inadequate resources, processes, and personnel to manage the elderly population inside and outside of prisons. In addition to providing a definition of "elderly prisoner," two specific problems-prison health care and prisoner re-entry-are examined in the article. The article concludes with recommendations for both policy and research on how best we can further understand and address the multiple needs and concerns faced by elderly prisoners. PMID:18160383

  19. IRVE-II Post-Flight Trajectory Reconstruction

    NASA Technical Reports Server (NTRS)

    O'Keefe, Stephen A.; Bose, David M.

    2010-01-01

    NASA s Inflatable Re-entry Vehicle Experiment (IRVE) II successfully demonstrated an inflatable aerodynamic decelerator after being launched aboard a sounding rocket from Wallops Flight Facility (WFF). Preliminary day of flight data compared well with pre-flight Monte Carlo analysis, and a more complete trajectory reconstruction performed with an Extended Kalman Filter (EKF) approach followed. The reconstructed trajectory and comparisons to an attitude solution provided by NASA Sounding Rocket Operations Contract (NSROC) personnel at WFF are presented. Additional comparisons are made between the reconstructed trajectory and pre and post-flight Monte Carlo trajectory predictions. Alternative observations of the trajectory are summarized which leverage flight accelerometer measurements, the pre-flight aerodynamic database, and on-board flight video. Finally, analysis of the payload separation and aeroshell deployment events are presented. The flight trajectory is reconstructed to fidelity sufficient to assess overall project objectives related to flight dynamics and overall, IRVE-II flight dynamics are in line with expectations

  20. The evolution of case management for service members injured in Iraq and Afghanistan.

    PubMed

    Kelley, Patricia Watts; Kenny, Deborah J; Gordon, Deborah R; Benner, Patricia

    2015-03-01

    In this article we describe the nursing care needs of wounded service members (WSMs) from the wars in Iraq and Afghanistan and the evolving role of the nurse case manager (CM). New types of injuries, in-field treatment, immediate transport to multiple care centers, and new technologies have created a new patient population of WSMs that requires new types of nursing care and knowledge. We interviewed 235 nurses, including CMs from nine military treatment facilities (MTFs) and the Veterans Administration (VA), on actual patient care experiences and new knowledge development, and 67 WSMs about their experiences of care. New military and VA nurse case management roles are essential for the effective functioning of the evolving, highly specialized, and transport-based health care system. Working effectively with WSMs required that the CM role be expanded beyond health care management to include family support, re-entry, and life coaching for the extremely altered life circumstances of WSMs.