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Sample records for low-thrust guidance study

  1. Automated low-thrust guidance for the orbital maneuvering vehicle

    Science.gov (United States)

    Rose, Richard E.; Schmeichel, Harry; Shortwell, Charles P.; Werner, Ronald A.

    1988-01-01

    This paper describes the highly autonomous OMV Guidance Navigation and Control system. Emphasis is placed on a key feature of the design, the low thrust guidance algorithm. The two guidance modes, orbit change guidance and rendezvous guidance, are discussed in detail. It is shown how OMV will automatically transfer from its initial orbit to an arbitrary target orbit and reach a specified rendezvous position relative to the target vehicle.

  2. Shaping low-thrust trajectories with thrust-handling feature

    Science.gov (United States)

    Taheri, Ehsan; Kolmanovsky, Ilya; Atkins, Ella

    2018-02-01

    Shape-based methods are becoming popular in low-thrust trajectory optimization due to their fast computation speeds. In existing shape-based methods constraints are treated at the acceleration level but not at the thrust level. These two constraint types are not equivalent since spacecraft mass decreases over time as fuel is expended. This paper develops a shape-based method based on a Fourier series approximation that is capable of representing trajectories defined in spherical coordinates and that enforces thrust constraints. An objective function can be incorporated to minimize overall mission cost, i.e., achieve minimum ΔV . A representative mission from Earth to Mars is studied. The proposed Fourier series technique is demonstrated capable of generating feasible and near-optimal trajectories. These attributes can facilitate future low-thrust mission designs where different trajectory alternatives must be rapidly constructed and evaluated.

  3. Sensitivity Analysis and Mitigation with Applications to Ballistic and Low-thrust Trajectory Design

    Science.gov (United States)

    Alizadeh, Iman

    determine analytically the maximum divergence directions and also optimal control theory with nonstandard cost functions along with inverse dynamics applied to low-thrust trajectories. Several mission scenarios are shown to demonstrate the applicability of the techniques in the Earth-Moon and the Jupiter-Europa system. In addition, the results provide fundamental insight into design, stability analysis and guidance, navigation and control of low-thrust trajectories to meet challenging mission requirements in support of NASA's vision for space exploration.

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

    Science.gov (United States)

    Maiwald, V.

    2017-09-01

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

  5. Global Optimization of Low-Thrust Interplanetary Trajectories Subject to Operational Constraints

    Science.gov (United States)

    Englander, Jacob Aldo; Vavrina, Matthew; Hinckley, David

    2016-01-01

    Low-thrust electric propulsion provides many advantages for mission to difficult targets-Comets and asteroids-Mercury-Outer planets (with sufficient power supply)Low-thrust electric propulsion is characterized by high power requirements but also very high specific impulse (Isp), leading to very good mass fractions. Low-thrust trajectory design is a very different process from chemical trajectory.

  6. The cislunar low-thrust trajectories via the libration point

    Science.gov (United States)

    Qu, Qingyu; Xu, Ming; Peng, Kun

    2017-05-01

    The low-thrust propulsion will be one of the most important propulsion in the future due to its large specific impulse. Different from traditional low-thrust trajectories (LTTs) yielded by some optimization algorithms, the gradient-based design methodology is investigated for LTTs in this paper with the help of invariant manifolds of LL1 point and Halo orbit near the LL1 point. Their deformations under solar gravitational perturbation are also presented to design LTTs in the restricted four-body model. The perturbed manifolds of LL1 point and its Halo orbit serve as the free-flight phase to reduce the fuel consumptions as much as possible. An open-loop control law is proposed, which is used to guide the spacecraft escaping from Earth or captured by Moon. By using a two-dimensional search strategy, the ON/OFF time of the low-thrust engine in the Earth-escaping and Moon-captured phases can be obtained. The numerical implementations show that the LTTs achieved in this paper are consistent with the one adopted by the SMART-1 mission.

  7. Combined high and low-thrust geostationary orbit insertion with radiation constraint

    Science.gov (United States)

    Macdonald, Malcolm; Owens, Steven Robert

    2018-01-01

    The sequential use of an electric propulsion system is considered in combination with a high-thrust propulsion system for application to the propellant-optimal Geostationary Orbit insertion problem, whilst considering both temporal and radiation flux constraints. Such usage is found to offer a combined propellant mass saving when compared with an equivalent high-thrust only transfer. This propellant mass saving is seen to increase as the allowable transfer duration is increased, and as the thrust from the low-thrust system is increased, assuming constant specific impulse. It was found that the required plane change maneuver is most propellant-efficiently performed by the high-thrust system. The propellant optimal trajectory incurs a significantly increased electron flux when compared to an equivalent high-thrust only transfer. However, the electron flux can be reduced to a similar order of magnitude by increasing the high-thrust propellant consumption, whilst still delivering an improved mass fraction.

  8. Optimization of Low-Thrust Spiral Trajectories by Collocation

    Science.gov (United States)

    Falck, Robert D.; Dankanich, John W.

    2012-01-01

    As NASA examines potential missions in the post space shuttle era, there has been a renewed interest in low-thrust electric propulsion for both crewed and uncrewed missions. While much progress has been made in the field of software for the optimization of low-thrust trajectories, many of the tools utilize higher-fidelity methods which, while excellent, result in extremely high run-times and poor convergence when dealing with planetocentric spiraling trajectories deep within a gravity well. Conversely, faster tools like SEPSPOT provide a reasonable solution but typically fail to account for other forces such as third-body gravitation, aerodynamic drag, solar radiation pressure. SEPSPOT is further constrained by its solution method, which may require a very good guess to yield a converged optimal solution. Here the authors have developed an approach using collocation intended to provide solution times comparable to those given by SEPSPOT while allowing for greater robustness and extensible force models.

  9. Orbital and angular motion construction for low thrust interplanetary flight

    Science.gov (United States)

    Yelnikov, R. V.; Mashtakov, Y. V.; Ovchinnikov, M. Yu.; Tkachev, S. S.

    2016-11-01

    Low thrust interplanetary flight is considered. Firstly, the fuel-optimal control is found. Then the angular motion is synthesized. This motion provides the thruster tracking of the required by optimal control direction. And, finally, reaction wheel control law for tracking this angular motion is proposed and implemented. The numerical example is given and total operation time for thrusters is found. Disturbances from solar pressure, thrust eccentricity, inaccuracy of reaction wheels installation and errors of inertia tensor are taken into account.

  10. Low-Thrust Orbital Transfers in the Two-Body Problem

    Directory of Open Access Journals (Sweden)

    A. A. Sukhanov

    2012-01-01

    Full Text Available Low-thrust transfers between given orbits within the two-body problem are considered; the thrust is assumed power limited. A simple method for obtaining the transfer trajectories based on the linearization of the motion near reference orbits is suggested. Required calculation accuracy can be reached by means of use of a proper number of the reference orbits. The method may be used in the case of a large number of the orbits around the attracting center; no averaging is necessary in this case. The suggested method also is applicable to the cases of partly given final orbit and if there are constraints on the thrust direction. The method gives an optimal solution to the linearized problem which is not optimal for the original nonlinear problem; the difference between the optimal solutions to the original and linearized problems is estimated using a numerical example. Also examples illustrating the method capacities are given.

  11. Trajectory Design in a Combined Low-Thrust Multi-Body Environment

    Data.gov (United States)

    National Aeronautics and Space Administration — Low-thrust propulsion (e.g. electric propulsion, solar sailing, etc.) is a promising new technology that may allow smaller, more efficient spacecraft to participate...

  12. High-velocity low-amplitude manipulation (thrust and athletic performance: a systematic review

    Directory of Open Access Journals (Sweden)

    Mikhail Santos Cerqueira

    Full Text Available Abstract Introduction: The high demand level in sports has encouraged the search for strategies to increase the yield. In this context, manual therapy through high-velocity low-amplitude (thrust has been employed in many sports. Despite the adhesion of manual therapists in clinical practice, there were no systematic reviews on this topic. Objective: To evaluate the effects of thrust on the performance of athletes in relation to the outcomes hand-grip strength, jump height and running speed. Methods: The databases used in the search were MEDLINE / PUBMED, LILACS, CINAHL, PEDro, WEB OF SCIENCE, CENTRAL and SCOPUS, and Randomized controlled trials were included, whose participants were professionals or recreational athletes and had thrust as intervention. The methodological quality of the studies was assessed using the PEDro scale of 10 points. Intervention effects were determined by the mean difference and confidence interval. The data analysis was done in the descriptive form due to the heterogeneity found among studies. Results: Five trials were included with a total of 95 individuals. The methodological quality of studies was low, with an average value of 5.6 on the PEDro scale. It was found two articles for each outcome, but in none of them was presented differences between the experimental and control groups considering the confidence interval. Conclusion: The current evidence is insufficient to determine the use or nonuse the MAVBA in sports in order to improve performance.

  13. Thrusting and back-thrusting as post-emplacement kinematics of the Almora klippe: Insights from Low-temperature thermochronology

    Science.gov (United States)

    Patel, R. C.; Singh, Paramjeet; Lal, Nand

    2015-06-01

    Crystalline klippen over the Lesser Himalayan Sequence (LHS) in the Kumaon and Garhwal regions of NW-Himalaya, are the representative of southern portion of the Main Central Thrust (MCT) hanging wall. These were tectonically transported over the juxtaposed thrust sheets (Berinag, Tons and Ramgarh) of the LHS zone along the MCT. These klippen comprise of NW-SE trending synformal folded thrust sheet bounded by thrusts in the south and north. In the present study, the exhumation histories of two well-known klippen namely Almora and Baijnath, and the Ramgarh thrust sheet, in the Kumaon and Garhwal regions vis-a-vis Himalayan orogeny have been investigated using Apatite Fission Track (AFT) ages. Along a ~ 60 km long orogen perpendicular transect across the Almora klippe and the Ramgarh thrust sheet, 16 AFT cooling ages from the Almora klippe and 2 from the Ramgarh thrust sheet have been found to range from 3.7 ± 0.8 to 13.2 ± 2.7 Ma, and 6.3 ± 0.8 to 7.2 ± 1.0 Ma respectively. From LHS meta-sedimentary rocks only a single AFT age of 3.6 ± 0.8 Ma could be obtained. Three AFT ages from the Baijnath klippe range between 4.7 ± 0.5 and 6.6 ± 0.8 Ma. AFT ages and exhumation rates of different klippen show a dynamic coupling between tectonic and erosion processes in the Kumaon and Garhwal regions of NW-Himalaya. However, the tectonic processes play a dominant role in controlling the exhumation. Thrusting and back thrusting within the Almora klippe and Ramgarh thrust sheet are the post-emplacement kinematics that controlled the exhumation of the Almora klippe. Combining these results with the already published AFT ages from the crystalline klippen and the Higher Himalayan Crystalline (HHC), the kinematics of emplacement of the klippen over the LHS and exhumation pattern across the MCT in the Kumaon and Garhwal regions of NW-Himalaya have been investigated.

  14. Role of wing morphing in thrust generation

    Directory of Open Access Journals (Sweden)

    Mehdi Ghommem

    2014-01-01

    Full Text Available In this paper, we investigate the role of morphing on flight dynamics of two birds by simulating the flow over rigid and morphing wings that have the characteristics of two different birds, namely the Giant Petrel and Dove Prion. The simulation of a flapping rigid wing shows that the root of the wing should be placed at a specific angle of attack in order to generate enough lift to balance the weight of the bird. However, in this case the generated thrust is either very small, or even negative, depending on the wing shape. Further, results show that morphing of the wing enables a significant increase in the thrust and propulsive efficiency. This indicates that the birds actually utilize some sort of active wing twisting and bending to produce enough thrust. This study should facilitate better guidance for the design of flapping air vehicles.

  15. Integrated Targeting and Guidance for Powered Planetary Descent

    Science.gov (United States)

    Azimov, Dilmurat M.; Bishop, Robert H.

    2018-02-01

    This paper presents an on-board guidance and targeting design that enables explicit state and thrust vector control and on-board targeting for planetary descent and landing. These capabilities are developed utilizing a new closed-form solution for the constant thrust arc of the braking phase of the powered descent trajectory. The key elements of proven targeting and guidance architectures, including braking and approach phase quartics, are employed. It is demonstrated that implementation of the proposed solution avoids numerical simulation iterations, thereby facilitating on-board execution of targeting procedures during the descent. It is shown that the shape of the braking phase constant thrust arc is highly dependent on initial mass and propulsion system parameters. The analytic solution process is explicit in terms of targeting and guidance parameters, while remaining generic with respect to planetary body and descent trajectory design. These features increase the feasibility of extending the proposed integrated targeting and guidance design to future cargo and robotic landing missions.

  16. Terminal area automatic navigation, guidance, and control 1: Automatic rollout, turnoff, and taxis

    Science.gov (United States)

    Pines, S.

    1981-01-01

    A study developed for the TCV B-737, designed to apply existing navigation aids plus magnetic leader cable signals and develop breaking and reverse thrust guidance laws to provide for rapid automated rollout, turnoff, and taxi to reduce runway occupation time for a wide variety of landing conditions for conventional commercial-type aircraft, is described. Closed loop guidance laws for braking and reverse thrust are derived for rollout, turnoff, and taxi, as functions of the landing speed, the desired taxi speed and the distance to go. Brake limitations for wet runway conditions and reverse thrust limitations are taken into account to provide decision rules to avoid tire skid and to choose an alternate turnoff point, farther down the runway, to accommodate extreme landing conditions.

  17. Closed Loop Guidance Trade Study for Space Launch System Block-1B Vehicle

    Science.gov (United States)

    Von der Porten, Paul; Ahmad, Naeem; Hawkins, Matt

    2018-01-01

    NASA is currently building the Space Launch System (SLS) Block-1 launch vehicle for the Exploration Mission 1 (EM-1) test flight. The design of the next evolution of SLS, Block-1B, is well underway. The Block-1B vehicle is more capable overall than Block-1; however, the relatively low thrust-to-weight ratio of the Exploration Upper Stage (EUS) presents a challenge to the Powered Explicit Guidance (PEG) algorithm used by Block-1. To handle the long burn durations (on the order of 1000 seconds) of EUS missions, two algorithms were examined. An alternative algorithm, OPGUID, was introduced, while modifications were made to PEG. A trade study was conducted to select the guidance algorithm for future SLS vehicles. The chosen algorithm needs to support a wide variety of mission operations: ascent burns to LEO, apogee raise burns, trans-lunar injection burns, hyperbolic Earth departure burns, and contingency disposal burns using the Reaction Control System (RCS). Additionally, the algorithm must be able to respond to a single engine failure scenario. Each algorithm was scored based on pre-selected criteria, including insertion accuracy, algorithmic complexity and robustness, extensibility for potential future missions, and flight heritage. Monte Carlo analysis was used to select the final algorithm. This paper covers the design criteria, approach, and results of this trade study, showing impacts and considerations when adapting launch vehicle guidance algorithms to a broader breadth of in-space operations.

  18. An Integrated Tool for Low Thrust Optimal Control Orbit Transfers in Interplanetary Trajectories

    Science.gov (United States)

    Dargent, T.; Martinot, V.

    In the last recent years a significant progress has been made in optimal control orbit transfers using low thrust electrical propulsion for interplanetary missions. The system objective is always the same: decrease the transfer duration and increase the useful satellite mass. The optimum control strategy to perform the minimum time to orbit or the minimum fuel consumption requires the use of sophisticated mathematical tools, most of the time dedicated to a specific mission and therefore hardly reusable. To improve this situation and enable Alcatel Space to perform rather quick trajectory design as requested by mission analysis, we have developed a software tool T-3D dedicated to optimal control orbit transfers which integrates various initial and terminal rendezvous conditions - e.g. fixed arrival time for planet encounter - and engine thrust profiles -e.g. thrust law variation with respect to the distance to the Sun -. This single and quite versatile tool allows to perform analyses like minimum consumption for orbit insertions around a planet from an hyperbolic trajectory, interplanetary orbit transfers, low thrust minimum time multiple revolution orbit transfers, etc… From a mathematical point of view, the software relies on the minimum principle formulation to find the necessary conditions of optimality. The satellite dynamics is a two body model and relies of an equinoctial formulation of the Gauss equation. This choice has been made for numerical purpose and to solve more quickly the two point boundaries values problem. In order to handle the classical problem of co-state variables initialization, problems simpler than the actual one can be solved straight forward by the tool and the values of the co-state variables are kept as first guess for a more complex problem. Finally, a synthesis of the test cases is presented to illustrate the capacities of the tool, mixing examples of interplanetary mission, orbit insertion, multiple revolution orbit transfers

  19. Distinguishing thrust sequences in gravity-driven fold and thrust belts

    Science.gov (United States)

    Alsop, G. I.; Weinberger, R.; Marco, S.

    2018-04-01

    Piggyback or foreland-propagating thrust sequences, where younger thrusts develop in the footwalls of existing thrusts, are generally assumed to be the typical order of thrust development in most orogenic settings. However, overstep or 'break-back' sequences, where later thrusts develop above and in the hangingwalls of earlier thrusts, may potentially form during cessation of movement in gravity-driven mass transport deposits (MTDs). In this study, we provide a detailed outcrop-based analysis of such an overstep thrust sequence developed in an MTD in the southern Dead Sea Basin. Evidence that may be used to discriminate overstep thrusting from piggyback thrust sequences within the gravity-driven fold and thrust belt includes upright folds and forethrusts that are cut by younger overlying thrusts. Backthrusts form ideal markers that are also clearly offset and cut by overlying younger forethrusts. Portions of the basal detachment to the thrust system are folded and locally imbricated in footwall synclines below forethrust ramps, and these geometries also support an overstep sequence. However, new 'short-cut' basal detachments develop below these synclines, indicating that movement continued on the basal detachment rather than it being abandoned as in classic overstep sequences. Further evidence for 'synchronous thrusting', where movement on more than one thrust occurs at the same time, is provided by displacement patterns on sequences of thrust ramp imbricates that systematically increases downslope towards the toe of the MTD. Older thrusts that initiate downslope in the broadly overstep sequence continue to move and therefore accrue greater displacements during synchronous thrusting. Our study provides a template to help distinguish different thrust sequences in both orogenic settings and gravity-driven surficial systems, with displacement patterns potentially being imaged in seismic sections across offshore MTDs.

  20. Late Neogene low-angle thrusting on the northwestern margin of the South Carpathians (Poiana Rusca, West Romania)

    Science.gov (United States)

    Oczlon, Martin S.; Onescu, Dan

    2005-12-01

    Mineral exploration drillholes and geoelectric prospecting provide for the first time evidence for thrusting of the South Carpathian Paleozoic basement over northerly adjacent Middle Miocene sediments. Investigations were carried out in two locations, 30 km apart, along the northern margin of the Poiana Rusca Mountains, Romania, southwestern Carpathians. Drill holes in both locations encountered weakly consolidated Middle Miocene clay, sand, and fine gravel below Paleozoic low-grade metamorphic rocks. Intersections from various drill holes demonstrate the presence of low-angle thrusting. Kinematic indicators are so far lacking, but with a thrust direction oriented roughly normal to strike of the Poiana Rusca Mountains, minimum displacement is 1-1.4 km in northwestern or northern direction, respectively. Thrusting occurred most likely during the Late Miocene-Pliocene, whereafter Quaternary regional uplift dissected the thrust plane. In the tectonic framework of Neogene dextral translation of the Tisza-Dacia Block against the southerly adjacent Moesian Platform, transtension appears responsible for Middle Miocene basin formation along the northern margin of the Poiana Rusca region. Proceeding collision of the Tisza-Dacia Block with the East European Craton introduced stronger impingement of the Tisza-Dacia Block against the Moesian Platform, leading to a Late Miocene-Pliocene transpressional regime, in which the northern Poiana Rusca basement was thrust over its adjacent Middle Miocene sediments.

  1. Minimum Propellant Low-Thrust Maneuvers near the Libration Points

    Science.gov (United States)

    Marinescu, A.; Dumitrache, M.

    The impulse technique certainly can bring the vehicle on orbits around the libration points or close to them. The question that aries is, by what means can the vehicle arrive in such cases at the libration points? A first investigation carried out in this paper can give an answer: the use of the technique of low-thrust, which, in addition, can bring the vehicle from the libration points near to or into orbits around these points. This aspect is considered in this present paper where for the applications we have considered the transfer for orbits of the equidistant point L4 and of the collinear point L2, from Earth-moon system. This transfer maneuver can be used to insertion one satellite on libration points orbits. In Earth- moon system the points L 4 and L 5 because an vehicle in on of the equidistant points in quite stable and remains in its vicinity of perturbed, have potential interest for the establishment of transporder satellite for interplanetary tracking. In contrast an vehicle in one of the collinear points is quite instable and it will oscillate along the Earth-moon-axis at increasing amplitude and gradually escape from the libration point. Let use assume that a space vehicle equipped with a low-thrust propulsion is near a libration point L. We consider the planar motion in the restricted frame of the three bodies in the rotating system L, where the Earth-moon distance D=l. The unit of time T is period of the moon's orbit divided by 2 and multiplied by the square root of the quantity one plus the moon/Earth mass ratio, and the unit of mass is the Earth's mass. With these predictions the motion equatios of the vehicle equiped with a low-thrust propulsion installation in the linear approximation near the libration point, have been established. The parameters of the motion at the beginning and the end of these maneuvers are known, the variational problem has been formulated as a Lagrange type problem with fixed extremities. On established the differential

  2. Dielectric Barrier Discharge (DBD) Plasma Actuators Thrust-Measurement Methodology Incorporating New Anti-Thrust Hypothesis

    Science.gov (United States)

    Ashpis, David E.; Laun, Matthew C.

    2014-01-01

    We discuss thrust measurements of Dielectric Barrier Discharge (DBD) plasma actuators devices used for aerodynamic active flow control. After a review of our experience with conventional thrust measurement and significant non-repeatability of the results, we devised a suspended actuator test setup, and now present a methodology of thrust measurements with decreased uncertainty. The methodology consists of frequency scans at constant voltages. The procedure consists of increasing the frequency in a step-wise fashion from several Hz to the maximum frequency of several kHz, followed by frequency decrease back down to the start frequency of several Hz. This sequence is performed first at the highest voltage of interest, then repeated at lower voltages. The data in the descending frequency direction is more consistent and selected for reporting. Sample results show strong dependence of thrust on humidity which also affects the consistency and fluctuations of the measurements. We also observed negative values of thrust or "anti-thrust", at low frequencies between 4 Hz and up to 64 Hz. The anti-thrust is proportional to the mean-squared voltage and is frequency independent. Departures from the parabolic anti-thrust curve are correlated with appearance of visible plasma discharges. We propose the anti-thrust hypothesis. It states that the measured thrust is a sum of plasma thrust and anti-thrust, and assumes that the anti-thrust exists at all frequencies and voltages. The anti-thrust depends on actuator geometry and materials and on the test installation. It enables the separation of the plasma thrust from the measured total thrust. This approach enables more meaningful comparisons between actuators at different installations and laboratories. The dependence on test installation was validated by surrounding the actuator with a large diameter, grounded, metal sleeve.

  3. Anomalous Thrust Production from an RF Test Device Measured on a Low-Thrust Torsion Pendulum

    Science.gov (United States)

    Brady, David; White, Harold G.; March, Paul; Lawrence, James T.; Davies, Frank J.

    2014-01-01

    This paper describes the eight-day August 2013 test campaign designed to investigate and demonstrate viability of using classical magnetoplasmadynamics to obtain a propulsive momentum transfer via the quantum vacuum virtual plasma. This paper will not address the physics of the quantum vacuum plasma thruster, but instead will describe the test integration, test operations, and the results obtained from the test campaign. Approximately 30-50 micro-Newtons of thrust were recorded from an electric propulsion test article consisting primarily of a radio frequency (RF) resonant cavity excited at approximately 935 megahertz. Testing was performed on a low-thrust torsion pendulum that is capable of detecting force at a single-digit micronewton level, within a stainless steel vacuum chamber with the door closed but at ambient atmospheric pressure. Several different test configurations were used, including two different test articles as well as a reversal of the test article orientation. In addition, the test article was replaced by an RF load to verify that the force was not being generated by effects not associated with the test article. The two test articles were designed by Cannae LLC of Doylestown, Pennsylvania. The torsion pendulum was designed, built, and operated by Eagleworks Laboratories at the NASA Johnson Space Center of Houston, Texas. Approximately six days of test integration were required, followed by two days of test operations, during which, technical issues were discovered and resolved. Integration of the two test articles and their supporting equipment was performed in an iterative fashion between the test bench and the vacuum chamber. In other words, the test article was tested on the bench, then moved to the chamber, then moved back as needed to resolve issues. Manual frequency control was required throughout the test. Thrust was observed on both test articles, even though one of the test articles was designed with the expectation that it would not

  4. Numerical and Analytical Study of Optimal Low-Thrust Limited-Power Transfers between Close Circular Coplanar Orbits

    Directory of Open Access Journals (Sweden)

    Sandro da Silva Fernandes

    2007-01-01

    Full Text Available A numerical and analytical study of optimal low-thrust limited-power trajectories for simple transfer (no rendezvous between close circular coplanar orbits in an inverse-square force field is presented. The numerical study is carried out by means of an indirect approach of the optimization problem in which the two-point boundary value problem, obtained from the set of necessary conditions describing the optimal solutions, is solved through a neighboring extremal algorithm based on the solution of the linearized two-point boundary value problem through Riccati transformation. The analytical study is provided by a linear theory which is expressed in terms of nonsingular elements and is determined through the canonical transformation theory. The fuel consumption is taken as the performance criterion and the analysis is carried out considering various radius ratios and transfer durations. The results are compared to the ones provided by a numerical method based on gradient techniques.

  5. Low-Thrust Bipropellant Engine Technology.

    Science.gov (United States)

    1980-08-01

    Non-Destructive Testing OD Outside Diameter xv tr. GLOSSARY (cont.J ODE One Dimensional Equilibrium ODK One Dimensional Kinetics Pc Thrust Chamber...performance (280 sec steady- state, 220 sec pulsing) have not yet been collectively achieved, but should be obtainable with further development activities...even at nozzle area ratios up to 400:1. The influence of nozzle kinetics (i.e., equilibrium versus frozen flow and ODK ) are noted to be a much more

  6. Sacro-iliac joint arthrography in low back pain: feasibility of MRI guidance

    International Nuclear Information System (INIS)

    Ojala, Risto; Klemola, Rauli; Karppinen, Jaro; Sequeiros, Roberto Blanco; Tervonen, Osmo

    2001-01-01

    Objective: Evaluation of the feasibility of MR-guidance in sacro-iliac joint arthrography in patients whose low back pain is suspected to arise from the sacro-iliac joint (SIJ). Methods and patients: Twenty patients with low back pain underwent MR-guided sacro-iliac joint arthrography. Needles made from titanium (size 20 G, MDTech, USA) were used. For image guidance a 0.23T open-configuration C arm magnet (Proview, Marconi Medical Systems, USA) with special interventional hardware and software package (I-Path 200, Marconi Medical Systems) containing an MR compatible in-room console, large-screen (36'') display, optical navigator and accompanying software with dedicated sequences was used. No other image guidance modalities were used. Results: MR-guided SIJ arthrography was successfully performed in all twenty patients without complications. The optimal imaging sequence both for preoperative and intraoperative images was 3D-Gradient Echo sequence. The dispersal of the injected saline and anaesthetic could be determined inside the joint in all cases with heavily T2-weighted fast spin echo sequence. In the present study, 60% of the patients had significant reduction of pain after sacro-iliac joint arthrography and sacro-iliac joint was considered to be the source of patients low back pain in these patients. Conclusion: The present study shows that MR guidance with open configuration low field scanner is an accurate guiding method for sacro-iliac joint arthrography

  7. Search for hadronic events with low thrust and an isolated lepton with the CELLO detector

    International Nuclear Information System (INIS)

    Kroha, H.

    1987-08-01

    Using the CELLO detector at the PETRA e + e - -storage ring, a search for hadronic events with low thrust and an isolated lepton has been carried out. The rate of such events and the thrust distribution of inclusive lepton events show no evidence for a threshold of new sources of inclusive lepton events at the highest PETRA energies. The CELLO data thus do not support the observations of the MARK-J and JADE collaborations of an excess of muon events of this type at √s > 46.3 GeV. (orig.)

  8. A search for hadronic events with low thrust and an isolated lepton

    International Nuclear Information System (INIS)

    Behrend, H.J.; Buerger, J.; Criegee, L.; Dainton, J.B.; Fenner, H.; Field, J.H.; Franke, G.; Meyer, J.; Schroeder, V.; Timm, U.; Winter, G.G.; Zimmermann, W.; Bussey, P.J.; Buttar, C.; Campbell, A.J.; Hendry, D.; McCurrach, G.; Scarr, J.M.; Skillicorn, I.O.; Smith, K.M.; Ahme, J.; Blobel, V.; Feindt, M.; Harjes, J.; Peters, J.H.; Poppe, M.; Spitzer, H.; Boer, W. de; Buschhorn, G.; Grindhammer, G.; Gunderson, B.; Kiesling, C.; Kotthaus, R.; Kroha, H.; Lueers, D.; Oberlack, H.; Schacht, P.; Shooshtari, G.; Wiedenmann, W.; Davier, M.; Grivaz, J.F.; Haissinski, J.; Janot, P.; Journe, V.; Le Diberder, F.; Spadafora, A.; Veillet, J.J.; Cozzika, G.; Ducros, Y.; Lavagne, Y.; Ould Saada, F.; Zacek, J.; Alexander, G.; Bella, G.; Gnat, Y.; Grunhaus, J.; Klatchko, A.; Levy, A.

    1987-01-01

    Using the CELLO detector at the PETRA e + e - storage ring a search for hadronic events with low thrust and an isolated lepton has been carried out. The rate of such events and the thrust distribution of inclusive lepton events show no evidence for a threshold of new sources of inclusive lepton events at the highest PETRA energies. For √s > 46.3 GeV we observe one muon event of the above type, compared to an expectation of 0.8±0.2 events from lower energy data. We do not observe any electron event of this class at the highest PETRA energies. The CELLO data thus do not support the observations of the MARK-J and JADE collaborations of an excess of muon events of the above type at √s > 46.3 GeV. (orig.)

  9. Propeller thrust analysis using Prandtl's lifting line theory, a comparison between the experimental thrust and the thrust predicted by Prandtl's lifting line theory

    Science.gov (United States)

    Kesler, Steven R.

    The lifting line theory was first developed by Prandtl and was used primarily on analysis of airplane wings. Though the theory is about one hundred years old, it is still used in the initial calculations to find the lift of a wing. The question that guided this thesis was, "How close does Prandtl's lifting line theory predict the thrust of a propeller?" In order to answer this question, an experiment was designed that measured the thrust of a propeller for different speeds. The measured thrust was compared to what the theory predicted. In order to do this experiment and analysis, a propeller needed to be used. A walnut wood ultralight propeller was chosen that had a 1.30 meter (51 inches) length from tip to tip. In this thesis, Prandtl's lifting line theory was modified to account for the different incoming velocity depending on the radial position of the airfoil. A modified equation was used to reflect these differences. A working code was developed based on this modified equation. A testing rig was built that allowed the propeller to be rotated at high speeds while measuring the thrust. During testing, the rotational speed of the propeller ranged from 13-43 rotations per second. The thrust from the propeller was measured at different speeds and ranged from 16-33 Newton's. The test data were then compared to the theoretical results obtained from the lifting line code. A plot in Chapter 5 (the results section) shows the theoretical vs. actual thrust for different rotational speeds. The theory over predicted the actual thrust of the propeller. Depending on the rotational speed, the error was: at low speeds 36%, at low to moderate speeds 84%, and at high speeds the error increased to 195%. Different reasons for these errors are discussed.

  10. A Numerical Method to Generate Reference Trajectories for Optimization Methods to Support Low-Thrust Mission Design

    Data.gov (United States)

    National Aeronautics and Space Administration — The recent success of missions employing low thrust propulsion systems has demonstrated the promise this technology holds for a wide array of future applications,...

  11. Modeling low-thrust transfers between periodic orbits about five libration points: Manifolds and hierarchical design

    Science.gov (United States)

    Zeng, Hao; Zhang, Jingrui

    2018-04-01

    The low-thrust version of the fuel-optimal transfers between periodic orbits with different energies in the vicinity of five libration points is exploited deeply in the Circular Restricted Three-Body Problem. Indirect optimization technique incorporated with constraint gradients is employed to further improve the computational efficiency and accuracy of the algorithm. The required optimal thrust magnitude and direction can be determined to create the bridging trajectory that connects the invariant manifolds. A hierarchical design strategy dividing the constraint set is proposed to seek the optimal solution when the problem cannot be solved directly. Meanwhile, the solution procedure and the value ranges of used variables are summarized. To highlight the effectivity of the transfer scheme and aim at different types of libration point orbits, transfer trajectories between some sample orbits, including Lyapunov orbits, planar orbits, halo orbits, axial orbits, vertical orbits and butterfly orbits for collinear and triangular libration points, are investigated with various time of flight. Numerical results show that the fuel consumption varies from a few kilograms to tens of kilograms, related to the locations and the types of mission orbits as well as the corresponding invariant manifold structures, and indicates that the low-thrust transfers may be a beneficial option for the extended science missions around different libration points.

  12. Spacing of Imbricated Thrust Faults and the Strength of Thrust-Belts and Accretionary Wedges

    Science.gov (United States)

    Ito, G.; Regensburger, P. V.; Moore, G. F.

    2017-12-01

    The pattern of imbricated thrust blocks is a prominent characteristic of the large-scale structure of thrust-belts and accretionary wedges around the world. Mechanical models of these systems have a rich history from laboratory analogs, and more recently from computational simulations, most of which, qualitatively reproduce the regular patterns of imbricated thrusts seen in nature. Despite the prevalence of these patterns in nature and in models, our knowledge of what controls the spacing of the thrusts remains immature at best. We tackle this problem using a finite difference, particle-in-cell method that simulates visco-elastic-plastic deformation with a Mohr-Coulomb brittle failure criterion. The model simulates a horizontal base that moves toward a rigid vertical backstop, carrying with it an overlying layer of crust. The crustal layer has a greater frictional strength than the base, is cohesive, and is initially uniform in thickness. As the layer contracts, a series of thrust blocks immerge sequentially and form a wedge having a mean taper consistent with that predicted by a noncohesive, critical Coulomb wedge. The widths of the thrust blocks (or spacing between adjacent thrusts) are greatest at the front of the wedge, tend to decrease with continued contraction, and then tend toward a pseudo-steady, minimum width. Numerous experiments show that the characteristic spacing of thrusts increases with the brittle strength of the wedge material (cohesion + friction) and decreases with increasing basal friction for low (laws that will illuminate the basic physical processes controlling systems, as well as allow researchers to use observations of thrust spacing as an independent constraint on the brittle strength of wedges as well as their bases.

  13. Computational Study of Thrust Generation from Laser-Driven Blast Wave

    International Nuclear Information System (INIS)

    Ohnishi, Naofumi; Ogino, Yousuke

    2008-01-01

    We have performed axisymmetric simulations in order to investigate the thrust generation resulting from the interference between the projectile and the blast wave produced by a pulsed laser. The results obtained by our numerical code well agree for the pressure history and the momentum coupling coefficient with the experimental data. In such analysis, it is found that the approximate impulse estimated only by the pressure history at the projectile base is difficult to predict the actual one. Since the shock wave rapidly attenuates in low fill pressure, and the interaction with the projectile almost finishes in the shroud, a high momentum coupling coefficient can be achieved unlike the case of high fill pressure in which the projectile experiences the subsequent negative thrust

  14. Low-Income Women's Feeding Practices and Perceptions of Dietary Guidance: A Qualitative Study.

    Science.gov (United States)

    Savage, Jennifer S; Neshteruk, Cody D; Balantekin, Katherine N; Birch, Leann L

    2016-12-01

    Objectives Describe themes characterizing feeding behaviors of low-income women participating in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC), and identify the attitudes, beliefs, and sources of information that inform these practices. Methods Formative research was conducted including focus groups and semi-structured individual phone interviews with a total of 68 low-income women participating in WIC. Qualitative data were recorded, transcribed, imported into NVivo 8.0, and analyzed for common themes. Results Mothers reported feeding behaviors inconsistent with guidance from WIC and the American Academy of Pediatrics. Three main themes were identified. First, mothers reported receiving conflicting messaging/advice from medical professionals, WIC nutritionists, and family members, which was confusing. Mothers also reported dissatisfaction with the "one size fits most" approach. Lastly, mothers reported relying on their "instincts" and that "all babies are different" when deciding and rationalizing what feeding guidance to follow. Conclusions Future interventions targeting this high-risk population should consider developing personalized (individualized) messaging, tailored to the needs of each mother-child dyad. Focused efforts are needed to build partnerships between WIC providers and other health care providers to provide more consistent messages about responsive feeding to prevent early obesity.

  15. A microNewton thrust stand for average thrust measurement of pulsed microthruster.

    Science.gov (United States)

    Zhou, Wei-Jing; Hong, Yan-Ji; Chang, Hao

    2013-12-01

    A torsional thrust stand has been developed for the study of the average thrust for microNewton pulsed thrusters. The main body of the thrust stand mainly consists of a torsional balance, a pair of flexural pivots, a capacitive displacement sensor, a calibration assembly, and an eddy current damper. The behavior of the stand was thoroughly studied. The principle of thrust measurement was analyzed. The average thrust is determined as a function of the average equilibrium angle displacement of the balance and the spring stiffness. The thrust stand has a load capacity up to 10 kg, and it can theoretically measure the force up to 609.6 μN with a resolution of 24.4 nN. The static calibrations were performed based on the calibration assembly composed of the multiturn coil and the permanent magnet. The calibration results demonstrated good repeatability (less than 0.68% FSO) and good linearity (less than 0.88% FSO). The assembly of the multiturn coil and the permanent magnet was also used as an exciter to simulate the microthruster to further research the performance of the thrust stand. Three sets of force pulses at 17, 33.5, and 55 Hz with the same amplitude and pulse width were tested. The repeatability error at each frequency was 7.04%, 1.78%, and 5.08%, respectively.

  16. Robust control for constant thrust rendezvous under thrust failure

    Directory of Open Access Journals (Sweden)

    Qi Yongqiang

    2015-04-01

    Full Text Available A robust constant thrust rendezvous approach under thrust failure is proposed based on the relative motion dynamic model. Firstly, the design problem is cast into a convex optimization problem by introducing a Lyapunov function subject to linear matrix inequalities. Secondly, the robust controllers satisfying the requirements can be designed by solving this optimization problem. Then, a new algorithm of constant thrust fitting is proposed through the impulse compensation and the fuel consumption under the theoretical continuous thrust and the actual constant thrust is calculated and compared by using the method proposed in this paper. Finally, the proposed method having the advantage of saving fuel is proved and the actual constant thrust switch control laws are obtained through the isochronous interpolation method, meanwhile, an illustrative example is provided to show the effectiveness of the proposed control design method.

  17. Evaluation of the use of low-cost GPS receivers in the autonomous guidance of agricultural tractors

    Energy Technology Data Exchange (ETDEWEB)

    Alonso-Garcia, S.; Gomez-Gil, J.; Arribas, J. I.

    2011-07-01

    This paper evaluates the use of low-cost global positioning system (GPS) receivers in the autonomous guidance of agricultural tractors. An autonomous guidance system was installed in a 6400 John Deere agricultural tractor. A low cost GPS receiver was used as positioning sensor. Three different control laws were implemented in order to evaluate the autonomous guidance of the tractor with the low-cost receiver. The guidance was experimentally tested with the tracking of straight trajectories and with the step response. The total guidance error was obtained from the receiver accuracy and from the guidance error. For the evaluation of the receivers accuracy, positioning data from several low cost receivers were recorded and analyzed. For the evaluation of the guidance error, tests were performed with each control law at three different speeds. The conclusions obtained were that relative accuracy of low-cost receivers decreases with the time; that for an interval lower than 15 min, the error usually remains below 1 m; that all the control laws have a similar behavior and it is conditioned by the control law adjustment; that automatic guidance with low cost receivers is possible with speeds that went up to 9 km h{sup -}1; and finally, that the total error in the guidance is mainly determined by the receivers accuracy. (Author) 46 refs.

  18. Thrust Measurement of Dielectric Barrier Discharge (DBD) Plasma Actuators: New Anti-Thrust Hypothesis, Frequency Sweeps Methodology, Humidity and Enclosure Effects

    Science.gov (United States)

    Ashpis, David E.; Laun, Matthew C.

    2014-01-01

    We discuss thrust measurements of Dielectric Barrier Discharge (DBD) plasma actuators devices used for aerodynamic active flow control. After a review of our experience with conventional thrust measurement and significant non-repeatability of the results, we devised a suspended actuator test setup, and now present a methodology of thrust measurements with decreased uncertainty. The methodology consists of frequency scans at constant voltages. The procedure consists of increasing the frequency in a step-wise fashion from several Hz to the maximum frequency of several kHz, followed by frequency decrease back down to the start frequency of several Hz. This sequence is performed first at the highest voltage of interest, then repeated at lower voltages. The data in the descending frequency direction is more consistent and selected for reporting. Sample results show strong dependence of thrust on humidity which also affects the consistency and fluctuations of the measurements. We also observed negative values of thrust, or "anti-thrust", at low frequencies between 4 Hz and up to 64 Hz. The anti-thrust is proportional to the mean-squared voltage and is frequency independent. Departures from the parabolic anti-thrust curve are correlated with appearance of visible plasma discharges. We propose the anti-thrust hypothesis. It states that the measured thrust is a sum of plasma thrust and anti-thrust, and assumes that the anti-thrust exists at all frequencies and voltages. The anti-thrust depends on actuator geometry and materials and on the test installation. It enables the separation of the plasma thrust from the measured total thrust. This approach enables more meaningful comparisons between actuators at different installations and laboratories. The dependence on test installation was validated by surrounding the actuator with a grounded large-diameter metal sleeve. Strong dependence on humidity is also shown; the thrust significantly increased with decreasing humidity, e

  19. Emergency Flight Control Using Computer-Controlled Thrust

    Science.gov (United States)

    Burcham, Frank W., Jr.; Fullerton, C. Gordon; Stewart, James F.; Gilyard, Glenn B.; Conley, Joseph A.

    1995-01-01

    Propulsion Controlled Aircraft (PCA) systems are digital electronic control systems undergoing development to provide limited maneuvering ability through variations of individual engine thrusts in multiple-engine airplanes. Provide landing capability when control surfaces inoperable. Incorporated on existing and future airplanes that include digital engine controls, digital flight controls, and digital data buses, adding no weight for additional hardware to airplane. Possible to handle total failure of hydraulic system, depending on how surfaces respond to loss of hydraulic pressure, and broken control cables or linkages. Future airplanes incorporate data from Global Positioning System for guidance to any suitable emergency runway in world.

  20. A Numerical Study of Low-Thrust Limited Power Trajectories between Coplanar Circular Orbits in an Inverse-Square Force Field

    Directory of Open Access Journals (Sweden)

    Sandro da Silva Fernandes

    2012-01-01

    Full Text Available A numerical study of optimal low-thrust limited power trajectories for simple transfer (no rendezvous between circular coplanar orbits in an inverse-square force field is performed by two different classes of algorithms in optimization of trajectories. This study is carried out by means of a direct method based on gradient techniques and by an indirect method based on the second variation theory. The direct approach of the trajectory optimization problem combines the main positive characteristics of two well-known direct methods in optimization of trajectories: the steepest-descent (first-order gradient method and a direct second variation (second-order gradient method. On the other hand, the indirect approach of the trajectory optimization problem involves two different algorithms of the well-known neighboring extremals method. Several radius ratios and transfer durations are considered, and the fuel consumption is taken as the performance criterion. For small-amplitude transfers, the results are compared to the ones provided by a linear analytical theory.

  1. A study of variable thrust, variable specific impulse trajectories for solar system exploration

    Science.gov (United States)

    Sakai, Tadashi

    A study has been performed to determine the advantages and disadvantages of variable thrust and variable Isp (specific impulse) trajectories for solar system exploration. There have been several numerical research efforts for variable thrust, variable Isp, power-limited trajectory optimization problems. All of these results conclude that variable thrust, variable Isp (variable specific impulse, or VSI) engines are superior to constant thrust, constant Isp (constant specific impulse; or CSI) engines. However, most of these research efforts assume a mission from Earth to Mars, and some of them further assume that these planets are circular and coplanar. Hence they still lack the generality. This research has been conducted to answer the following questions: (1) Is a VSI engine always better than a CSI engine or a high thrust engine for any mission to any planet with any time of flight considering lower propellant mass as the sole criterion? (2) If a planetary swing-by is used for a VSI trajectory, is the fuel savings of a VSI swing-by trajectory better than that of a CSI swing-by or high thrust swing-by trajectory? To support this research, an unique, new computer-based interplanetary trajectory calculation program has been created. This program utilizes a calculus of variations algorithm to perform overall optimization of thrust, Isp, and thrust vector direction along a trajectory that minimizes fuel consumption for interplanetary travel. It is assumed that the propulsion system is power-limited, and thus the compromise between thrust and Isp is a variable to be optimized along the flight path. This program is capable of optimizing not only variable thrust trajectories but also constant thrust trajectories in 3-D space using a planetary ephemeris database. It is also capable of conducting planetary swing-bys. Using this program, various Earth-originating trajectories have been investigated and the optimized results have been compared to traditional CSI and high

  2. Management of low back pain with facet joint injections and nerve root blocks under computed tomography guidance. A prospective study

    International Nuclear Information System (INIS)

    Fotiadou, Anastasia; Wojcik, Andrew; Shaju, Antony

    2012-01-01

    The aim of this work was to assess the performance of facet joint and nerve root infiltrations under computed tomography guidance for the management of low back pain and to investigate the complications and patient tolerance. The study was board-certified and informed consent was obtained from all patients. In 1 year, 86 consecutive patients (47 male, 39 female, age range 47-87 years, mean age 63) with low back pain for more than 2 years were included. All patients were clinically examined and had cross-sectional imaging performed before the procedure. Fifty-five facet joint infiltrations and 31 nerve blocks were performed under computed tomography guidance. All patients completed two valid pain questionnaires before and 3 months after the procedures. At the same time, they were clinically examined by the referring Orthopaedic Surgeon. The pain response was assessed by comparing the scores of the questionnaires. The improvement in clinical examination findings was assessed as well. In patients who underwent facet joint infiltrations, long-term pain improvement was achieved in 79% and in those with nerve blocks in 85%. Immediate pain relief was demonstrated in 83% of patients with nerve infiltrations. No complications were observed. All procedures were very well tolerated by patients. Facet joint and nerve infiltrations under computed tomography guidance constitute an accurate and safe method that could be used to relieve low back pain and minimize the risk of disability. (orig.)

  3. Multi-Axis Thrust Measurements of the EO-1 Pulsed Plasma Thruster

    Science.gov (United States)

    Arrington, Lynn A.; Haag, Thomas W.

    1999-01-01

    Pulsed plasma thrusters are low thrust propulsive devices which have a high specific impulse at low power. A pulsed plasma thruster is currently scheduled to fly as an experiment on NASA's Earth Observing-1 satellite mission. The pulsed plasma thruster will be used to replace one of the reaction wheels. As part of the qualification testing of the thruster it is necessary to determine the nominal thrust as a function of charge energy. These data will be used to determine control algorithms. Testing was first completed on a breadboard pulsed plasma thruster to determine nominal or primary axis thrust and associated propellant mass consumption as a function of energy and then later to determine if any significant off-axis thrust component existed. On conclusion that there was a significant off-axis thrust component with the bread-board in the direction of the anode electrode, the test matrix was expanded on the flight hardware to include thrust measurements along all three orthogonal axes. Similar off-axis components were found with the flight unit.

  4. Quality assurance guidance for low-level radioactive waste disposal facility: Final report

    International Nuclear Information System (INIS)

    Pittiglio, C.L. Jr.

    1989-01-01

    This document provides guidance to an applicant on meeting the quality control (QC) requirements for a low-level waste (LLW) disposal facility. The QC requirements are the basis for developing of a quality assurance (QA) program and for the guidance provided herein. The criteria are basic to any QA program. The document specifically establishes QA guidance for the design, construction, and operation of those structures, systems, components, as well as, for site characterization activities necessary to meet the performance objectives and to limit exposure to our release of radioactivity. 7 refs

  5. Thrust reverser design studies for an over-the-wing STOL transport

    Science.gov (United States)

    Ammer, R. C.; Sowers, H. D.

    1977-01-01

    Aerodynamic and acoustics analytical studies were conducted to evaluate three thrust reverser designs for potential use on commercial over-the-wing STOL transports. The concepts were: (1) integral D nozzle/target reverser, (2) integral D nozzle/top arc cascade reverser, and (3) post exit target reverser integral with wing. Aerodynamic flowpaths and kinematic arrangements for each concept were established to provide a 50% thrust reversal capability. Analytical aircraft stopping distance/noise trade studies conducted concurrently with flow path design showed that these high efficiency reverser concepts are employed at substantially reduced power settings to meet noise goals of 100 PNdB on a 152.4 m sideline and still meet 609.6 m landing runway length requirements. From an overall installation standpoint, only the integral D nozzle/target reverser concept was found to penalize nacelle cruise performance; for this concept a larger nacelle diameter was required to match engine cycle effective area demand in reverse thrust.

  6. Accuracy Analysis of Lunar Lander Terminal Guidance Algorithm

    Directory of Open Access Journals (Sweden)

    E. K. Li

    2017-01-01

    Full Text Available This article studies a proposed analytical algorithm of the terminal guidance for the lunar lander. The analytical solution, which forms the basis of the algorithm, was obtained for a constant acceleration trajectory and thrust vector orientation programs that are essentially linear with time. The main feature of the proposed algorithm is a completely analytical solution to provide the lander terminal guidance to the desired spot in 3D space when landing on the atmosphereless body with no numerical procedures. To reach 6 terminal conditions (components of position and velocity vectors at the final time are used 6 guidance law parameters, namely time-to-go, desired value of braking deceleration, initial values of pitch and yaw angles and rates of their change. In accordance with the principle of flexible trajectories, this algorithm assumes the implementation of a regularly updated control program that ensures reaching terminal conditions from the current state that corresponds to the control program update time. The guidance law parameters, which ensure that terminal conditions are reached, are generated as a function of the current phase coordinates of a lander. The article examines an accuracy and reliability of the proposed analytical algorithm that provides the terminal guidance of the lander in 3D space through mathematical modeling of the lander guidance from the circumlunar pre-landing orbit to the desired spot near the lunar surface. A desired terminal position of the lunar lander is specified by the selenographic latitude, longitude and altitude above the lunar surface. The impact of variations in orbital parameters on the terminal guidance accuracy has been studied. By varying the five initial orbit parameters (obliquity, ascending node longitude, argument of periapsis, periapsis height, apoapsis height when the terminal spot is fixed the statistic characteristics of the terminal guidance algorithm error according to the terminal

  7. Spacecraft intercept guidance using zero effort miss steering

    Science.gov (United States)

    Newman, Brett

    The suitability of proportional navigation, or an equivalent zero effort miss formulation, for spacecraft intercepts during midcourse guidance, followed by a ballistic coast to the endgame, is addressed. The problem is formulated in terms of relative motion in a general 3D framework. The proposed guidance law for the commanded thrust vector orientation consists of the sum of two terms: (1) along the line of sight unit direction and (2) along the zero effort miss component perpendicular to the line of sight and proportional to the miss itself and a guidance gain. If the guidance law is to be suitable for longer range targeting applications with significant ballistic coasting after burnout, determination of the zero effort miss must account for the different gravitational accelerations experienced by each vehicle. The proposed miss determination techniques employ approximations for the true differential gravity effect. Theoretical results are applied to a numerical engagement scenario and the resulting performance is evaluated in terms of the miss distances determined from nonlinear simulation.

  8. The effect of inertia force in water lubricated thrust bearings of canned reactor coolant pump

    International Nuclear Information System (INIS)

    Deng Liping

    1994-01-01

    The water lubricated thrust bearings are analyzed. According to characteristic of low viscosity of water the lubricated equation for design and calculation of water lubricated thrust bearings is established. The calculation and analyses show that the effect of inertia force in water lubricated thrust bearings should not be neglected except the conditions of low speed, high angle of inclination and low radius ratio of pad

  9. Nonlinear dynamics of a vectored thrust aircraft

    DEFF Research Database (Denmark)

    Sørensen, C.B; Mosekilde, Erik

    1996-01-01

    With realistic relations for the aerodynamic coefficients, numerical simulations are applied to study the longitudional dynamics of a thrust vectored aircraft. As function of the thrust magnitude and the thrust vectoring angle the equilibrium state exhibits two saddle-node bifurcations and three...

  10. A flow visualization study of single-arm sculling movement emulating cephalopod thrust generation

    Science.gov (United States)

    Kazakidi, Asimina; Gnanamanickam, Ebenezer P.; Tsakiris, Dimitris P.; Ekaterinaris, John A.

    2014-11-01

    In addition to jet propulsion, octopuses use arm-swimming motion as an effective means of generating bursts of thrust, for hunting, defense, or escape. The individual role of their arms, acting as thrust generators during this motion, is still under investigation, in view of an increasing robotic interest for alternative modes of propulsion, inspired by the octopus. Computational studies have revealed that thrust generation is associated with complex vortical flow patterns in the wake of the moving arm, however further experimental validation is required. Using the hydrogen bubble technique, we studied the flow disturbance around a single octopus-like robotic arm, undergoing two-stroke sculling movements in quiescent fluid. Although simplified, sculling profiles have been found to adequately capture the fundamental kinematics of the octopus arm-swimming behavior. In fact, variation of the sculling parameters alters considerably the generation of forward thrust. Flow visualization revealed the generation of complex vortical structures around both rigid and compliant arms. Increased disturbance was evident near the tip, particularly at the transitional phase between recovery and power strokes. These results are in good qualitative agreement with computational and robotic studies. Work funded by the ESF-GSRT HYDRO-ROB Project PE7(281).

  11. A systematic review of thrust manipulation for non-surgical shoulder conditions.

    Science.gov (United States)

    Minkalis, Amy L; Vining, Robert D; Long, Cynthia R; Hawk, Cheryl; de Luca, Katie

    2017-01-01

    Although many conservative management options are available for patients with non-surgical shoulder conditions, there is little evidence of their effectiveness. This review investigated one manual therapy approach, thrust manipulation, as a treatment option. A systematic search was conducted of the electronic databases from inception to March 2016: PubMed, PEDro, ICL, CINAHL, and AMED. Two independent reviewers conducted the screening process to determine article eligibility. Inclusion criteria were manuscripts published in peer-reviewed journals with human participants of any age. The intervention included was thrust, or high-velocity low-amplitude, manipulative therapy directed to the shoulder and/or the regions of the cervical or thoracic spine. Studies investigating secondary shoulder pain or lacking diagnostic confirmation procedures were excluded. Methodological quality was assessed using the PEDro scale and the Cochrane risk-of-bias tool. The initial search rendered 5041 articles. After screening titles and abstracts, 36 articles remained for full-text review. Six articles studying subacromial impingement syndrome met inclusion criteria. Four studies were randomized controlled trials (RCTs) and 2 were uncontrolled clinical studies. Five studies included 1 application of a thoracic spine thrust manipulation and 1 applied 8 treatments incorporating a shoulder joint thrust manipulation. Statistically significant improvements in pain scores were reported in all studies. Three of 4 RCTs compared a thrust manipulation to a sham, and statistical significance in pain reduction was found within the groups but not between them. Clinically meaningful changes in pain were inconsistent; 3 studies reported that scores met minimum clinically important difference, 1 reported scores did not, and 2 were unclear. Four studies found statistically significant improvements in disability; however, 2 were RCTs and did not find statistical significance between the active and sham

  12. High-thrust and low-power operation of a 30-cm-diameter mercury ion thruster

    Science.gov (United States)

    Beattie, J. R.; Kami, S.

    1981-01-01

    An investigation of a 30-cm-diameter mercury ion thruster designed for high-thrust and low-power operation is described. Experimental results are presented which indicate that good performance and long lifetime are achieved by using a boundary magnetic field arrangement to confine the ionizing electrons. Details of advanced ion-optics designs are discussed, and performance measurements obtained with an advanced two-grid ion-optics assembly are presented. Scaling of the state-of-the-art hollow cathode for higher emission-current capability is described, and performance and lifetime measurements are presented for the scaled cathode.

  13. Experimental study on the thrust modulation performance of powdered magnesium and CO2 bipropellant engine

    Science.gov (United States)

    Li, Chao; Hu, Chunbo; Zhu, Xiaofei; Hu, Jiaming; Li, Yue; Hu, Xu

    2018-06-01

    Powdered Mg and CO2 bipropellant engine providing a practical demonstration of in situ resource utilization (ISRU) for Mars Sample Return (MSR) mission seems to be feasible by current investigations. However, essential functions of the engine to satisfy the complicated ballistics requirements such as thrust modulation and multiple pulse have not been established yet. The aim of this experimental study is to evaluate the engine's thrust modulation feasibility and to investigate its thrust modulation characteristics. A powdered Mg and CO2 bipropellant engine construction aiming to achieve thrust modulation ability was proposed. A mass flow rate calibration experiment to evaluate the gas-solid mass flow rate regulating performance was conducted before fire tests. Fire test result shows that the engine achieved successful ignition as well as self-sustaining combustion; Thrust modulation of the engine is feasible, detail thrust estimating result of the test shows that maximum thrust is 135.91 N and the minimum is 5.65 N with a 22.11 thrust modulation ratio, moreover, the transportation period is quick and the thrust modulation ratio is adjustable. At the same time, the powder feed system reaches a two-step flow rate regulating with a modulation ratio of 4.5-5. What' more, caused by the uneven engine working conditions, there is an obvious difference in combustion efficiency value, maximum combustion efficiency of the powdered Mg and CO2 bipropellant engine is 80.20%.

  14. High thrust-to-power ratio micro-cathode arc thruster

    Directory of Open Access Journals (Sweden)

    Joseph Lukas

    2016-02-01

    Full Text Available The Micro-Cathode Arc Thruster (μCAT is an electric propulsion device that ablates solid cathode material, through an electrical vacuum arc discharge, to create plasma and ultimately produce thrust in the μN to mN range. About 90% of the arc discharge current is conducted by electrons, which go toward heating the anode and contribute very little to thrust, with only the remaining 10% going toward thrust in the form of ion current. A preliminary set of experiments were conducted to show that, at the same power level, thrust may increase by utilizing an ablative anode. It was shown that ablative anode particles were found on a collection plate, compared to no particles from a non-ablative anode, while another experiment showed an increase in ion-to-arc current by approximately 40% at low frequencies compared to the non-ablative anode. Utilizing anode ablation leads to an increase in thrust-to-power ratio in the case of the μCAT.

  15. A mechanism of thrust enhancement on a heaving plate due to flexibility at moderately low Reynolds numbers

    Science.gov (United States)

    Lin, Yung-Sheng; Tzeng, Yau-Ting; Chang, Chien-Cheng; Chu, Chin-Chou

    2017-11-01

    A numerical study is conducted to investigate the force mechanisms for a 3D heaving flexible plate from the perspective of a diagnostic force element analysis (Chang 1992). The problem is relevant to a simplified flapping fish-tail with the front edge held fixed in space. The flow is assumed to be laminar with the Reynolds numbers fixed at Re =200 or 500, and the Strouhal number St ranging from 0.1 to 0.6, and the flexure amplitude of the plate a0 for 0.1 to 0.25 (dimensionless). It is shown that heaving, whilst increasing thrust generation, also reduces the frictional drag, yet the flexibility promotes thrust generation at the expense of accruing more frictional drag. In the literature, the thrust exerted on the tail-mimicking plate is largely credited to the vortices in the wake. However, this study performs a regional force analysis to show that the vorticity in the wake region supplies approximately 20-30% of the total thrust, especially in the cases of strong thrust generation. Comparable contributions come also from the regions direct above and below the heaving plate (mainly including the attached vortices) as well as from the two side regions (mainly including the tip vortices) next to the flapping plate. In addition, the potential motion associated with the unsteady flapping and the contribution from the surface vorticity are non-negligible constituent force components. MOST, TAIWAN under Contacts NO. 105-2221-E-002-097-MY3 and NO. 105-2221-E-002 -105 -MY3.

  16. Numerical Modelling and Analysis of Hydrostatic Thrust Air Bearings for High Loading Capacities and Low Air Consumption

    Science.gov (United States)

    Yu, Yunluo; Pu, Guang; Jiang, Kyle

    2017-12-01

    The paper presents a numerical simulation study on hydrostatic thrust air bearings to assess the load capacity, compressed air consumptions, and the dynamic response. Finite Difference Method (FDM) and Finite Volume Method (FVM) are combined to solve the non-linear Reynolds equation to find the pressure distribution of the air bearing gas film and the total loading capacity of the bearing. The influence of design parameters on air film gap characteristics, including the air film thickness, supplied pressure, depth of the groove and external load, are investigated based on the proposed FDM model. The simulation results show that the thrust air bearings with a groove have a higher load capacity and air consumption than without a groove, and the load capacity and air consumption both increase with the depth of the groove. Bearings without the groove are better damped than those with the grooves, and the stability of thrust bearing decreases when the groove depth increases. The stability of the thrust bearings is also affected by their loading.

  17. Low-Cost and Light-Weight Transpiration-Cooled Thrust Chambers, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed effort aims to evaluate the feasibility of using transpiration-cooled Titanium as the primary material in small-scale thrust chambers for in-space...

  18. A Multiconstrained Ascent Guidance Method for Solid Rocket-Powered Launch Vehicles

    Directory of Open Access Journals (Sweden)

    Si-Yuan Chen

    2016-01-01

    Full Text Available This study proposes a multiconstrained ascent guidance method for a solid rocket-powered launch vehicle, which uses a hypersonic glide vehicle (HGV as payload and shuts off by fuel exhaustion. First, pseudospectral method is used to analyze the two-stage launch vehicle ascent trajectory with different rocket ignition modes. Then, constraints, such as terminal height, velocity, flight path angle, and angle of attack, are converted into the constraints within height-time profile according to the second-stage rocket flight characteristics. The closed-loop guidance method is inferred by different spline curves given the different terminal constraints. Afterwards, a thrust bias energy management strategy is proposed to waste the excess energy of the solid rocket. Finally, the proposed method is verified through nominal and dispersion simulations. The simulation results show excellent applicability and robustness of this method, which can provide a valuable reference for the ascent guidance of solid rocket-powered launch vehicles.

  19. A model for helicopter guidance on spiral trajectories

    Science.gov (United States)

    Mendenhall, S.; Slater, G. L.

    1980-01-01

    A point mass model is developed for helicopter guidance on spiral trajectories. A fully coupled set of state equations is developed and perturbation equations suitable for 3-D and 4-D guidance are derived and shown to be amenable to conventional state variable feedback methods. Control variables are chosen to be the magnitude and orientation of the net rotor thrust. Using these variables reference controls for nonlevel accelerating trajectories are easily determined. The effects of constant wind are shown to require significant feedforward correction to some of the reference controls and to the time. Although not easily measured themselves, the controls variables chosen are shown to be easily related to the physical variables available in the cockpit.

  20. Thrust Performance Evaluation of a Turbofan Engine Based on Exergetic Approach and Thrust Management in Aircraft

    Science.gov (United States)

    Yalcin, Enver

    2017-05-01

    The environmental parameters such as temperature and air pressure which are changing depending on altitudes are effective on thrust and fuel consumption of aircraft engines. In flights with long routes, thrust management function in airplane information system has a structure that ensures altitude and performance management. This study focused on thrust changes throughout all flight were examined by taking into consideration their energy and exergy performances for fuel consumption of an aircraft engine used in flight with long route were taken as reference. The energetic and exergetic performance evaluations were made under the various altitude conditions. The thrust changes for different altitude conditions were obtained to be at 86.53 % in descending direction and at 142.58 % in ascending direction while the energy and exergy efficiency changes for the referenced engine were found to be at 80.77 % and 84.45 %, respectively. The results revealed here can be helpful to manage thrust and reduce fuel consumption, but engine performance will be in accordance with operation requirements.

  1. Exoskeletal Engine Concept: Feasibility Studies for Medium and Small Thrust Engines

    Science.gov (United States)

    Halliwell, Ian

    2001-01-01

    The exoskeletal engine concept is one in which the shafts and disks are eliminated and are replaced by rotating casings that support the blades in spanwise compression. Omission of the shafts and disks leads to an open channel at the engine centerline. This has immense potential for reduced jet noise and for the accomodation of an alternative form of thruster for use in a combined cycle. The use of ceramic composite materials has the potential for significantly reduced weight as well as higher working temperatures without cooling air. The exoskeletal configuration is also a natural stepping-stone to complete counter-rotating turbomachinery. Ultimately this will lead to reductions in weight, length, parts count and improved efficiency. The feasibility studies are in three parts. Part I-Systems and Component Requirements addressed the mechanical aspects of components from a functionality perspective. This effort laid the groundwork for preliminary design studies. Although important, it is not felt to be particularly original, and has therefore not been included in the current overview. Part 2-Preliminary Design Studies turned to some of the cycle and performance issues inherent in an exoskeletal configuration and some initial attempts at preliminary design of turbomachinery were described. Twin-spoon and single-spool 25.800-lbf-thrust turbofans were used as reference vehicles in a mid-size commercial subsonic category in addition to a single-spool 5,000-lbf-thrust turbofan that represented a general aviation application. The exoskeletal engine, with its open centerline, has tremendous potential for noise suppression and some preliminary analysis was done which began to quantify the benefits. Part 3-Additional Preliminary Design Studies revisited the design of single-spool 25,800-lbf-thrust turbofan configurations, but in addition to the original FPR = 1.6 and BPR = 5.1 reference engine, two additional configurations used FPR = 2.4 and BPR = 3.0 and FPR = 3.2 and BPR

  2. Coupled Low-thrust Trajectory and System Optimization via Multi-Objective Hybrid Optimal Control

    Science.gov (United States)

    Vavrina, Matthew A.; Englander, Jacob Aldo; Ghosh, Alexander R.

    2015-01-01

    The optimization of low-thrust trajectories is tightly coupled with the spacecraft hardware. Trading trajectory characteristics with system parameters ton identify viable solutions and determine mission sensitivities across discrete hardware configurations is labor intensive. Local independent optimization runs can sample the design space, but a global exploration that resolves the relationships between the system variables across multiple objectives enables a full mapping of the optimal solution space. A multi-objective, hybrid optimal control algorithm is formulated using a multi-objective genetic algorithm as an outer loop systems optimizer around a global trajectory optimizer. The coupled problem is solved simultaneously to generate Pareto-optimal solutions in a single execution. The automated approach is demonstrated on two boulder return missions.

  3. Static investigation of two fluidic thrust-vectoring concepts on a two-dimensional convergent-divergent nozzle

    Science.gov (United States)

    Wing, David J.

    1994-01-01

    A static investigation was conducted in the static test facility of the Langley 16-Foot Transonic Tunnel of two thrust-vectoring concepts which utilize fluidic mechanisms for deflecting the jet of a two-dimensional convergent-divergent nozzle. One concept involved using the Coanda effect to turn a sheet of injected secondary air along a curved sidewall flap and, through entrainment, draw the primary jet in the same direction to produce yaw thrust vectoring. The other concept involved deflecting the primary jet to produce pitch thrust vectoring by injecting secondary air through a transverse slot in the divergent flap, creating an oblique shock in the divergent channel. Utilizing the Coanda effect to produce yaw thrust vectoring was largely unsuccessful. Small vector angles were produced at low primary nozzle pressure ratios, probably because the momentum of the primary jet was low. Significant pitch thrust vector angles were produced by injecting secondary flow through a slot in the divergent flap. Thrust vector angle decreased with increasing nozzle pressure ratio but moderate levels were maintained at the highest nozzle pressure ratio tested. Thrust performance generally increased at low nozzle pressure ratios and decreased near the design pressure ratio with the addition of secondary flow.

  4. Development of threshold guidance: National Low-Level Radioactive Waste Management Program

    International Nuclear Information System (INIS)

    1986-09-01

    The current study has been conducted to provide DOE with a technical basis for the development of threshold guidance. The objective of the study was to develop the necessary background information and recommendations to assist the DOE in implementing the threshold limit concept for the disposal of DOE wastes at DOE facilities. The nature of low-level radioactive waste (LLW) varies greatly in both form and radionuclide content. While some low-level waste streams can contain substantial quantities of radioactive constituents, a potentially significant fraction of low-level waste is contaminated either very slightly or not at all. There is a strong likelihood that managing wastes with extremely low levels of radioactivity as nonradioactive waste would pose no significant safety problems and could result in substantial cost savings relative to its handling as LLW. Since all materials, including waste products, contain some radioactivity, it is necessary to distinguish between those wastes that would require disposal as LLW and those that have sufficiently low levels of radiological content to be managed according to their nonradiological properties. 131 refs., 9 figs., 24 tabs

  5. Guidance of reactor operators and TSC personnel with the severe accident management guidance under shutdown and low power conditions

    International Nuclear Information System (INIS)

    Van Haesendonck, M.F.; Prior, R.P.

    2000-01-01

    The Westinghouse Owners Group Severe Accident Management Guidance (WOG SAMG) was developed between 1991 and 1994. The primary goals for severe accident management that form the basis of the WOG SAMG are to terminate any radioactive releases to the environment; to prevent failure of any containment fission product boundary and to return the plant to a controlled stable condition. The WOG SAMG is primarily a TSC tool for mitigation of low probability core damage events. The philosophy is that control room operators should remain focused on the prevention of core damage, whereas the TSC personnel should concentrate on the mitigation of the severe accident. The symptom based package is built up as a structured process for choosing appropriate actions based on actual plant conditions. No detailed knowledge of severe accident phenomena is required. The scope of the WOG SAMG is limited to severe accidents resulting from initiating events occurring during full power operation. However, a number of studies such as the EdF EPS 1300 Probabilistic Safety Assessment (PSA), the shutdown Probabilistic Risk Assessment (PRA) for Surry, the BERA shutdown PRA for Beznau, the EPRI/ Westinghouse ORAM methodology etc. have shown that the frequency of core damage (a severe accident) during shutdown and low power operation can be of the same order of magnitude as for full power operation. The at-power SAMG is viewed as the resolution of the severe accident issue. Similarly, it is expected that as shutdown PRAs mature, the final resolution of the severe accident issue will lie in SAMG for low power and shutdown operation. Therefore in resolution of this issue, Westinghouse has developed the Shutdown Severe Accident Management Guidance (SSAMG) which gives guidance for both control room and TSC personnel to mitigate a severe accident under shutdown or low power conditions. In the last few years, many LWR plants have been implementing SAMG. In the US, all plants have developed SAMG, and many

  6. Some Calculated Research Results of the Working Process Parameters of the Low Thrust Rocket Engine Operating on Gaseous Oxygen-Hydrogen Fuel

    Science.gov (United States)

    Ryzhkov, V.; Morozov, I.

    2018-01-01

    The paper presents the calculating results of the combustion products parameters in the tract of the low thrust rocket engine with thrust P ∼ 100 N. The article contains the following data: streamlines, distribution of total temperature parameter in the longitudinal section of the engine chamber, static temperature distribution in the cross section of the engine chamber, velocity distribution of the combustion products in the outlet section of the engine nozzle, static temperature near the inner wall of the engine. The presented parameters allow to estimate the efficiency of the mixture formation processes, flow of combustion products in the engine chamber and to estimate the thermal state of the structure.

  7. A Complete First-Order Analytical Solution for Optimal Low-Thrust Limited-Power Transfers Between Coplanar Orbits with Small Eccentricities

    Science.gov (United States)

    Da Silva Fernandes, Sandro; Das Chagas Carvalho, Francisco; Vilhena de Moraes, Rodolpho

    The purpose of this work is to present a complete first order analytical solution, which includes short periodic terms, for the problem of optimal low-thrust limited power trajectories with large amplitude transfers (no rendezvous) between coplanar orbits with small eccentricities in Newtonian central gravity field. The study of these transfers is particularly interesting because the orbits found in practice often have a small eccentricity and the problem of transferring a vehicle from a low earth orbit to a high earth orbit is frequently found. Besides, the analysis has been motivated by the renewed interest in the use of low-thrust propulsion systems in space missions verified in the last two decades. Several researchers have obtained numerical and sometimes analytical solutions for a number of specific initial orbits and specific thrust profiles. Averaging methods are also used in such researches. Firstly, the optimization problem associated to the space transfer problem is formulated as a Mayer problem of optimal control with Cartesian elements - position and velocity vectors - as state variables. After applying the Pontryagin Maximum Principle, successive Mathieu transformations are performed and suitable sets of orbital elements are introduced. The short periodic terms are eliminated from the maximum Hamiltonian function through an infinitesimal canonical transformation built through Hori method - a perturbation canonical method based on Lie series. The new Hamiltonian function, which results from the infinitesimal canonical transformation, describes the extremal trajectories for long duration maneuvers. Closed-form analytical solutions are obtained for the new canonical system by solving the Hamilton-Jacobi equation through the separation of variables technique. By applying the transformation equations of the algorithm of Hori method, a first order analytical solution for the problem is obtained in non-singular orbital elements. For long duration maneuvers

  8. Quality assurance guidance for a low-level radioactive waste disposal facility

    International Nuclear Information System (INIS)

    Pittiglio, C.L. Jr.; Hedges, D.

    1991-04-01

    This document provides guidance to an applicant on meeting the quality control (QC) requirements of 10 CFR 61.12(j) for a low-level radioactive waste (LLRW) disposal facility. The QC requirements, plus audits and managerial controls requirements, establish the need for developing a quality assurance (QA) program and the guidance provided herein. The criteria developed for this document are similar to the criteria developed for Appendix B to Title 10 of the Code of Federal Regulations (10 CFR) Part 50. Although Appendix B is not a regulatory requirement for an LLRW disposal facility, the criteria that were developed for 10 CFR Part 50 are basic to any QA program. This document establishes QA guidance for the design, construction, and operation of those structures, engineered or natural systems, and components whose function is required to meet the performance objectives of Subpart C of 10 CFR Part 61 and to limit exposure to or release of radioactivity. 7 refs

  9. Fuel optimization for low-thrust Earth-Moon transfer via indirect optimal control

    Science.gov (United States)

    Pérez-Palau, Daniel; Epenoy, Richard

    2018-02-01

    The problem of designing low-energy transfers between the Earth and the Moon has attracted recently a major interest from the scientific community. In this paper, an indirect optimal control approach is used to determine minimum-fuel low-thrust transfers between a low Earth orbit and a Lunar orbit in the Sun-Earth-Moon Bicircular Restricted Four-Body Problem. First, the optimal control problem is formulated and its necessary optimality conditions are derived from Pontryagin's Maximum Principle. Then, two different solution methods are proposed to overcome the numerical difficulties arising from the huge sensitivity of the problem's state and costate equations. The first one consists in the use of continuation techniques. The second one is based on a massive exploration of the set of unknown variables appearing in the optimality conditions. The dimension of the search space is reduced by considering adapted variables leading to a reduction of the computational time. The trajectories found are classified in several families according to their shape, transfer duration and fuel expenditure. Finally, an analysis based on the dynamical structure provided by the invariant manifolds of the two underlying Circular Restricted Three-Body Problems, Earth-Moon and Sun-Earth is presented leading to a physical interpretation of the different families of trajectories.

  10. Development of an indirect counterbalanced pendulum optical-lever thrust balance for micro- to millinewton thrust measurement

    International Nuclear Information System (INIS)

    Grubišić, A N; Gabriel, S B

    2010-01-01

    This paper describes the design and testing of an indirect hanging pendulum thrust balance using a laser-optical-lever principle to provide micro- to millinewton thrust measurement for the development of electric propulsion systems. The design philosophy allows the selection of the total thrust range in order to maximize resolution through a counterbalanced pendulum principle, as well as passive magnetic damping in order to allow relatively rapid transient thrust measurement. The balance was designed for the purpose of hollow cathode microthruster characterization, but could be applied to other electric propulsion devices in the thrust range of micro- to millinewtons. An initial thrust characterization of the T5 hollow cathode is presented

  11. Joint Manipulation: Toward a General Theory of High-Velocity, Low-Amplitude Thrust Techniques.

    Science.gov (United States)

    Harwich, Andrew S

    2017-12-01

    The objective of this study was to describe the initial stage of a generalized theory of high-velocity, low-amplitude thrust (HVLAT) techniques for joint manipulation. This study examined the movements described by authors from the fields of osteopathy, chiropractic, and physical therapy to produce joint cavitation in both the metacarpophalangeal (MCP) joint and the cervical spine apophysial joint. This study qualitatively compared the kinetics, the similarities, and the differences between MCP cavitation and cervical facet joint cavitation. A qualitative vector analysis of forces and movements was undertaken by constructing computer-generated, simplified graphical models of the MCP joint and a typical cervical apophysial joint and imposing the motions dictated by the clinical technique. Comparing the path to cavitation of 2 modes of HVLAT for the MCP joint, namely, distraction and hyperflexion, it was found that the hyperflexion method requires an axis of rotation, the hinge axis, which is also required for cervical HVLAT. These results show that there is an analogue of cervical HVLAT in one of the MCP joint HVLATs. The study demonstrated that in a theoretical model, the path to joint cavitation is the same for asymmetric separation of the joint surfaces in the cervical spine and the MCP joints.

  12. Thrust calculation of electric solar wind sail by particle-in-cell simulation

    Energy Technology Data Exchange (ETDEWEB)

    Hoshi, Kento [Kyoto Univ. (Japan). Dept. of Electrical Engineering; Kojima, Hirotsugu; Yamakawa, Hiroshi [Kyoto Univ. (Japan). Research Inst. for Sustainable Humanosphere; Muranaka, Takanobu [Chukyo Univ., Nagoya (Japan). Dept. of Electrical Engineering

    2016-07-01

    In this study, thrust characteristics of an electric solar wind sail were numerically evaluated using full threedimensional particle-in-cell (PIC) simulation. The thrust obtained from the PIC simulation was lower than the thrust estimations obtained in previous studies. The PIC simulation indicated that ambient electrons strongly shield the electrostatic potential of the tether of the sail, and the strong shield effect causes a greater thrust reduction than has been obtained in previous studies. Additionally, previous expressions of the thrust estimation were modified by using the shielded potential structure derived from the present simulation results. The modified thrust estimation agreed very well with the thrust obtained from the PIC simulation.

  13. Thrust calculation of electric solar wind sail by particle-in-cell simulation

    International Nuclear Information System (INIS)

    Hoshi, Kento; Kojima, Hirotsugu; Yamakawa, Hiroshi; Muranaka, Takanobu

    2016-01-01

    In this study, thrust characteristics of an electric solar wind sail were numerically evaluated using full threedimensional particle-in-cell (PIC) simulation. The thrust obtained from the PIC simulation was lower than the thrust estimations obtained in previous studies. The PIC simulation indicated that ambient electrons strongly shield the electrostatic potential of the tether of the sail, and the strong shield effect causes a greater thrust reduction than has been obtained in previous studies. Additionally, previous expressions of the thrust estimation were modified by using the shielded potential structure derived from the present simulation results. The modified thrust estimation agreed very well with the thrust obtained from the PIC simulation.

  14. Encke-Beta Predictor for Orion Burn Targeting and Guidance

    Science.gov (United States)

    Robinson, Shane; Scarritt, Sara; Goodman, John L.

    2016-01-01

    The state vector prediction algorithm selected for Orion on-board targeting and guidance is known as the Encke-Beta method. Encke-Beta uses a universal anomaly (beta) as the independent variable, valid for circular, elliptical, parabolic, and hyperbolic orbits. The variable, related to the change in eccentric anomaly, results in integration steps that cover smaller arcs of the trajectory at or near perigee, when velocity is higher. Some burns in the EM-1 and EM-2 mission plans are much longer than burns executed with the Apollo and Space Shuttle vehicles. Burn length, as well as hyperbolic trajectories, has driven the use of the Encke-Beta numerical predictor by the predictor/corrector guidance algorithm in place of legacy analytic thrust and gravity integrals.

  15. Subacute effects of cervicothoracic spinal thrust/non-thrust in addition to shoulder manual therapy plus exercise intervention in individuals with subacromial impingement syndrome: a prospective, randomized controlled clinical trial pilot study.

    Science.gov (United States)

    Wright, Alexis A; Donaldson, Megan; Wassinger, Craig A; Emerson-Kavchak, Alicia J

    2017-09-01

    To determine the subacute effects of cervicothoracic spinal thrust/non-thrust in addition to shoulder non-thrust plus exercise in patients with subacromial pathology. This was a randomized, single blinded controlled trial pilot study. This trial was registered at ClinicalTrials.gov (NCT01753271) and reported according to Consolidated Standards of Reporting Trials requirements. Patients were randomly assigned to either shoulder treatment plus cervicothoracic spinal thrust/non-thrust or shoulder treatment-only group. Primary outcomes were average pain intensity (Numeric Pain Rating Scale) and physical function (Shoulder Pain and Disability Index) at 2 weeks, 4 weeks, and patient discharge. 18 patients, mean age 43.1(15.8) years satisfied the eligibility criteria and were analyzed for follow-up data. Both groups showed statistically significant improvements in both pain and function at 2 weeks, 4 weeks, and discharge. The between-group differences for changes in pain or physical function were not significant at any time point. The addition of cervicothoracic spinal thrust/non-thrust to the shoulder treatment-only group did not significantly alter improvement in pain or function in patients with subacromial pathology. Both approaches appeared to provide an equally notable benefit. Both groups improved on all outcomes and met the criteria for clinical relevance for both pain and function. 2b.

  16. Thrust distribution for attitude control in a variable thrust propulsion system with four ACS nozzles

    Science.gov (United States)

    Lim, Yeerang; Lee, Wonsuk; Bang, Hyochoong; Lee, Hosung

    2017-04-01

    A thrust distribution approach is proposed in this paper for a variable thrust solid propulsion system with an attitude control system (ACS) that uses a reduced number of nozzles for a three-axis attitude maneuver. Although a conventional variable thrust solid propulsion system needs six ACS nozzles, this paper proposes a thrust system with four ACS nozzles to reduce the complexity and mass of the system. The performance of the new system was analyzed with numerical simulations, and the results show that the performance of the system with four ACS nozzles was similar to the original system while the mass of the whole system was simultaneously reduced. Moreover, a feasibility analysis was performed to determine whether a thrust system with three ACS nozzles is possible.

  17. Early history and reactivation of the rand thrust, southern California

    Science.gov (United States)

    Postlethwaite, Clay E.; Jacobson, Carl E.

    The Rand thrust of the Rand Mountains in the northwestern Mojave Desert separates an upper plate of quartz monzonite and quartzofeldspathic to amphibolitic gneiss from a lower plate of metagraywacke and mafic schist (Rand Schist). The Rand thrust is considered part of the regionally extensive Vincent/Chocolate Mountain thrust system, which is commonly believed to represent a Late Cretaceous subduction zone. The initial direction of dip and sense of movement along the Vincent/Chocolate Mountain thrust are controversial. Microfabrics of mylonites and quartzites from the Rand Mountains were analyzed in an attempt to determine transport direction for this region, but the results are ambiguous. In addition, the southwestern portion of the Rand thrust was found to have been reactivated as a low-angle normal fault after subduction. Reactivation might have occurred shortly after subduction, in which case it could account for the preservation of high-pressure mineral assemblages in the Rand Schist, or it could be related to mid-Tertiary extension in the western United States. In either event, the reactivation might be responsible for the complicated nature of the microfabrics. The Rand Schist exhibits an inverted metamorphic zonation. Isograds in the schist are not significantly truncated by the reactivated segment of the Rand thrust. This indicates that other segments of the Vincent/Chocolate Mountain thrust should be re-evaluated for the possibility of late movement, even if they show an apparently undisturbed inverted metamorphic zonation.

  18. Electromyographic Comparison of Barbell Deadlift, Hex Bar Deadlift, and Hip Thrust Exercises: A Cross-Over Study.

    Science.gov (United States)

    Andersen, Vidar; Fimland, Marius S; Mo, Dag-Andrè; Iversen, Vegard M; Vederhus, Torbjørn; Rockland Hellebø, Lars R; Nordaune, Kristina I; Saeterbakken, Atle H

    2018-03-01

    Andersen, V, Fimland, MS, Mo, D-A, Iversen, VM, Vederhus, T, Rockland Hellebø, LR, Nordaune, KI, and Saeterbakken, AH. Electromyographic comparison of barbell deadlift, hex bar deadlift, and hip thrust exercises: a cross-over study. J Strength Cond Res 32(3): 587-593, 2018-The aim of the study was to compare the muscle activation level of the gluteus maximus, biceps femoris, and erector spinae in the hip thrust, barbell deadlift, and hex bar deadlift; each of which are compound resisted hip extension exercises. After 2 familiarization sessions, 13 resistance-trained men performed a 1 repetition maximum in all 3 exercises in 1 session, in randomized and counterbalanced order. The whole ascending movement (concentric phase), as well as its lower and upper parts (whole movement divided in 2), were analyzed. The hip thrust induced greater activation of the gluteus maximus compared with the hex bar deadlift in the whole (16%, p = 0.025) and the upper part (26%, p = 0.015) of the movement. For the whole movement, the biceps femoris was more activated during barbell deadlift compared with both the hex bar deadlift (28%, p bar deadlift (p = 0.049) compared with hip thrust. Biceps femoris activation in the upper part of the movement was 39% higher for the barbell deadlift compared with the hex bar deadlift (p = 0.001) and 34% higher for the hip thrust compared with the hex bar deadlift (p = 0.002). No differences were displayed for the erector spinae activation (p = 0.312-0.859). In conclusion, the barbell deadlift was clearly superior in activating the biceps femoris compared with the hex bar deadlift and hip thrust, whereas the hip thrust provided the highest gluteus maximus activation.

  19. Axisymmetric thrust-vectoring nozzle performance prediction

    International Nuclear Information System (INIS)

    Wilson, E. A.; Adler, D.; Bar-Yoseph, P.Z

    1998-01-01

    Throat-hinged geometrically variable converging-diverging thrust-vectoring nozzles directly affect the jet flow geometry and rotation angle at the nozzle exit as a function of the nozzle geometry, the nozzle pressure ratio and flight velocity. The consideration of nozzle divergence in the effective-geometric nozzle relation is theoretically considered here for the first time. In this study, an explicit calculation procedure is presented as a function of nozzle geometry at constant nozzle pressure ratio, zero velocity and altitude, and compared with experimental results in a civil thrust-vectoring scenario. This procedure may be used in dynamic thrust-vectoring nozzle design performance predictions or analysis for civil and military nozzles as well as in the definition of initial jet flow conditions in future numerical VSTOL/TV jet performance studies

  20. Analytical studies of blowdown thrust force and dynamic response of pipe at pipe rupture accident

    International Nuclear Information System (INIS)

    Miyazaki, Noriyuki

    1985-01-01

    The motion of a pipe due to blowdown thrust when the pipe broke is called pipe whip. In LWR power plants, by installing restraints, the motion of a pipe when it broke is suppressed, so that the damage does not spread to neighboring equipment by pipe whip. When the pipe whip of a piping system in a LWR power plant is analyzed, blowdown thrust and the dynamic response of a pipe-restraint system are calculated with a computer. The blowdown thrust can be calculated by using such physical quantities as the pressure, flow velocity, density and so on in the system at the time of blowdown, obtained by the thermal-fluid analysis code at LOCA. The dynamic response of a piping-restraint system can be determined by the stress analysis code using finite element method taking the blowdown thrust as an external force acting on the piping. In this study, the validity of the analysis techniques was verified by comparing with the experimental results of the measurement of blowdown thrust and the pipe whip of a piping-restraint system, carried out in the Japan Atomic Energy Research Institute. Also the simplified analysis method to give the maximum strain on a pipe surface is presented. (Kako, I.)

  1. Equivalence ratio and constriction effects on RBCC thrust augmentation

    Science.gov (United States)

    Koupriyanov, M.; Etele, J.

    2011-06-01

    A theoretical analysis of a variable area rocket based combined cycle engine with and without simultaneous mixing and combustion is presented. The flowfield is solved using a steady, quasi-one-dimensional, inviscid control volume formulation with combustion effects included via a generalized equilibrium calculation. Compression augmentation is shown to be sensitive to the equivalence ratio within the primary rocket chamber, where ejector section performance is greatest at both low and high equivalence ratios but near a minimum at stoichiometric conditions. The thrust generated by the RBCC engine compared to that generated by the same rocket in isolation can be increased by as much as 12% at constriction ratios of between 45% and 50%. Thrust augmentation is also shown to vary with equivalence ratio, where for a fixed geometry the maximum thrust is generated at equivalence ratios slightly below unity.

  2. Structural Discordance Between Neogene Detachments and Frontal Sevier Thrusts, Central Mormon Mountains, Southern Nevada

    Science.gov (United States)

    Wernicke, Brian; Walker, J. Douglas; Beaufait, Mark S.

    1985-02-01

    Detailed geologic mapping in the Mormon Mountains of southern Nevada provides significant insight into processes of extensional tectonics developed within older compressional orogens. A newly discovered, WSW-directed low-angle normal fault, the Mormon Peak detachment, juxtaposes the highest levels of the frontal most part of the east-vergent, Mesozoic Sevier thrust belt with autochthonous crystalline basement. Palinspastic analysis suggests that the detachment initially dipped 20-25° to the west and cut discordantly across thrust faults. Nearly complete lateral removal of the hanging wall from the area has exposed a 5 km thick longitudinal cross-section through the thrust belt in the footwall, while highly attenuated remnants of the hanging wall (nowhere more than a few hundred meters thick) structurally veneer the range. The present arched configuration of the detachment resulted in part from progressive "domino-style" rotation of a few degrees while it was active, but is largely due to rotation on younger, structurally lower, basement-penetrating normal faults that initiated at high-angle. The geometry and kinematics of normal faulting in the Mormon Mountains suggest that pre-existing thrust planes are not required for the initiation of low-angle normal faults, and even where closely overlapped by extensional tectonism, need not function as a primary control of detachment geometry. Caution must thus be exercised in interpreting low-angle normal faults of uncertain tectonic heritage such as those seen in the COCORP west-central Utah and BIRP's MOIST deep-reflection profiles. Although thrust fault reactivation has reasonably been shown to be the origin of a very few low-angle normal faults, our results indicate that it may not be as fundamental a component of orogenic architecture as it is now widely perceived to be. We conclude that while in many instances thrust fault reactivation may be both a plausible and attractive hypothesis, it may never be assumed.

  3. Micro thrust and heat generator

    Science.gov (United States)

    Garcia, E.J.

    1998-11-17

    A micro thrust and heat generator have a means for providing a combustion fuel source to an ignition chamber of the micro thrust and heat generator. The fuel is ignited by a ignition means within the micro thrust and heat generator`s ignition chamber where it burns and creates a pressure. A nozzle formed from the combustion chamber extends outward from the combustion chamber and tappers down to a narrow diameter and then opens into a wider diameter where the nozzle then terminates outside of said combustion chamber. The pressure created within the combustion chamber accelerates as it leaves the chamber through the nozzle resulting in pressure and heat escaping from the nozzle to the atmosphere outside the micro thrust and heat generator. The micro thrust and heat generator can be microfabricated from a variety of materials, e.g., of polysilicon, on one wafer using surface micromachining batch fabrication techniques or high aspect ratio micromachining techniques (LIGA). 30 figs.

  4. A new guidance law for a tactical surface-to-surface missile

    Directory of Open Access Journals (Sweden)

    Danilo V. Ćuk

    2012-01-01

    Full Text Available Modern tactical surface-to-surface missiles, equipped with strapdown inertial navigation systems, achieve very good accuracy compared with free-flight rockets. The probable range dispersion mainly depends on instruments errors and longitudinal disturbances such as rocket motor total-impulse deviation as well as differences between the estimated and actual values of the axial force and head wind. This paper gives an extension of the correlated velocity concept for surface-to-surface missiles without a thrust-terminating mechanism. The calculated parameters of the correlated velocity are stored into the memory of an onboard guidance computer. On the basis of the correlated velocity concept, the modified proportional navigation with the adjustment of the time-to-go of the missile to the target was proposed. It is shown that the new guidance law can compensate for the longitudinal disturbances of different levels successfully. The effectiveness of the proposed guidance method was confirmed by means of the calculated probable range and lateral dispersion for the anticipated disturbances in the guidance system.

  5. A Numerical-Analytical Approach Based on Canonical Transformations for Computing Optimal Low-Thrust Transfers

    Science.gov (United States)

    da Silva Fernandes, S.; das Chagas Carvalho, F.; Bateli Romão, J. V.

    2018-04-01

    A numerical-analytical procedure based on infinitesimal canonical transformations is developed for computing optimal time-fixed low-thrust limited power transfers (no rendezvous) between coplanar orbits with small eccentricities in an inverse-square force field. The optimization problem is formulated as a Mayer problem with a set of non-singular orbital elements as state variables. Second order terms in eccentricity are considered in the development of the maximum Hamiltonian describing the optimal trajectories. The two-point boundary value problem of going from an initial orbit to a final orbit is solved by means of a two-stage Newton-Raphson algorithm which uses an infinitesimal canonical transformation. Numerical results are presented for some transfers between circular orbits with moderate radius ratio, including a preliminary analysis of Earth-Mars and Earth-Venus missions.

  6. Vortex flow structures and interactions for the optimum thrust efficiency of a heaving airfoil at different mean angles of attack

    Energy Technology Data Exchange (ETDEWEB)

    Martín-Alcántara, A.; Fernandez-Feria, R. [Universidad de Málaga, Andalucía Tech, E. T. S. Ingeniería Industrial, Dr Ortiz Ramos s/n, 29071 Málaga (Spain); Sanmiguel-Rojas, E. [Área de Mecánica de Fluidos, Universidad de Jaén, Campus de las Lagunillas, 23071 Jaén (Spain)

    2015-07-15

    The thrust efficiency of a two-dimensional heaving airfoil is studied computationally for a low Reynolds number using a vortex force decomposition. The auxiliary potentials that separate the total vortex force into lift and drag (or thrust) are obtained analytically by using an elliptic airfoil. With these auxiliary potentials, the added-mass components of the lift and drag (or thrust) coefficients are also obtained analytically for any heaving motion of the airfoil and for any value of the mean angle of attack α. The contributions of the leading- and trailing-edge vortices to the thrust during their down- and up-stroke evolutions are computed quantitatively with this formulation for different dimensionless frequencies and heave amplitudes (St{sub c} and St{sub a}) and for several values of α. Very different types of flows, periodic, quasi-periodic, and chaotic described as St{sub c}, St{sub a}, and α, are varied. The optimum values of these parameters for maximum thrust efficiency are obtained and explained in terms of the interactions between the vortices and the forces exerted by them on the airfoil. As in previous numerical and experimental studies on flapping flight at low Reynolds numbers, the optimum thrust efficiency is reached for intermediate frequencies (St{sub c} slightly smaller than one) and a heave amplitude corresponding to an advance ratio close to unity. The optimal mean angle of attack found is zero. The corresponding flow is periodic, but it becomes chaotic and with smaller average thrust efficiency as |α| becomes slightly different from zero.

  7. Low-Thrust Out-of-Plane Orbital Station-Keeping Maneuvers for Satellites

    Directory of Open Access Journals (Sweden)

    Vivian M. Gomes

    2012-01-01

    Full Text Available This paper considers the problem of out of plane orbital maneuvers for station keeping of satellites. The main idea is to consider that a satellite is in an orbit around the Earth and that it has its orbit is disturbed by one or more forces. Then, it is necessary to perform a small amplitude orbital correction to return the satellite to its original orbit, to keep it performing its mission. A low thrust propulsion is used to complete this task. It is important to search for solutions that minimize the fuel consumption to increase the lifetime of the satellite. To solve this problem a hybrid optimal control approach is used. The accuracy of the satisfaction of the constraints is considered, in order to try to decrease the fuel expenditure by taking advantage of this freedom. This type of problem presents numerical difficulties and it is necessary to adjust parameters, as well as details of the algorithm, to get convergence. In this versions of the algorithm that works well for planar maneuvers are usually not adequate for the out of plane orbital corrections. In order to illustrate the method, some numerical results are presented.

  8. Mu rhythm desynchronization by tongue thrust observation

    Directory of Open Access Journals (Sweden)

    Kotoe eSakihara

    2015-09-01

    Full Text Available We aimed to investigate the mu rhythm in the sensorimotor area during tongue thrust observation and to obtain an answer to the question as to how subtle non-verbal orofacial movement observation activates the sensorimotor area. Ten healthy volunteers performed finger tap execution, tongue thrust execution, and tongue thrust observation. The electroencephalogram was recorded from 128 electrodes placed on the scalp, and regions of interest were set at sensorimotor areas. The event-related desynchronization (ERD and event-related synchronization (ERS for the mu rhythm (8–13 Hz and beta (13−25 Hz bands were measured. Tongue thrust observation induced mu rhythm ERD, and the ERD was detected at the left hemisphere regardless whether the observed tongue thrust was toward the left or right. Mu rhythm ERD was also recorded during tongue thrust execution. However, temporal analysis revealed that the ERD associated with tongue thrust observation preceded that associated with execution by approximately 2 s. Tongue thrust observation induces mu rhythm ERD in sensorimotor cortex with left hemispheric dominance.

  9. Analysis of thrust/torque signature of MOV

    International Nuclear Information System (INIS)

    Ryu, Ho Geun; Park, Seong Keun; Kim, Dae Woong

    2001-01-01

    For the evaluation of operability of MOV(Motor Operated Valve), the precision prediction of thrust/torque acting on the valve is important. In this paper, the analytical prediction method of thrust/torque was proposed. The design basis stem thrust calculation typically considers the followings: packing thrust, stem rejection load, design basis differential pressure load. In general, test results show that temperature, pressure, fluid type, and differential pressure, independently and combination, all have an effect on the friction factor. The prediction results of thrust/torque are well agreement with dynamic test results

  10. Guidance on the application of quality assurance for characterizing a low-level radioactive waste disposal site

    International Nuclear Information System (INIS)

    Pittiglio, C.L. Jr.; Starmer, R.J.; Hedges, D.

    1990-10-01

    This document provides the Nuclear Regulatory Commission's staff guidance to an applicant on meeting the quality control (QC) requirements of Title 10 of the Code of Federal Regulations, Part 61, Section 61.12 (10 CFR 61.12), for a low-level waste disposal facility. The QC requirements combined with the requirements for managerial controls and audits are the basis for developing a quality assurance (QA) program and for the guidance provided herein. QA guidance is specified for site characterization activities necessary to meet the performance objectives of 10 CFR Part 61 and to limit exposure to or the release of radioactivity. 1 tab

  11. Development of guidance on applications of regulatory requirements for low specific activity materials and surface contaminated objects

    International Nuclear Information System (INIS)

    Pope, R.B.; Easton, E.P.; Shankman, S.F.

    1997-01-01

    In 1985, the International Atomic Energy Agency issued revised regulations for the safe transport of radioactive material. Significant among the changes were major revisions to requirements for Low Specific Activity (LSA) material and Surface Contaminated Objects (SCOs). In preparation for the adoption of these requirements into regulations in the United States, it became apparent that guidance on how to apply these requirements, clarifying technical uncertainties and ensuring proper implementation, would be needed both by the regulators and those regulated. Thus, the US Department of Transportation and the US Nuclear Regulatory Commission, with the assistance of staff from Oak Ridge National Laboratory, are preparing regulatory guidance for LSA material and SCO transport. The guidance will present examples of acceptable methods for demonstrating compliance with the revised rules. Ideas being investigated for inclusion in the pending guidance are discussed in this paper. Under current plans, the guidance will be issued for public comment prior to final issuance of the guidance in 1997

  12. Development of guidance on applications of regulatory requirements for low specific activity materials and surface contaminated objects

    International Nuclear Information System (INIS)

    Pope, R.B.; Easton, E.P.; Shankman, S.F.; Boyle, R.W.

    1997-01-01

    In 1985, the International Atomic Energy Agency issued revised regulations for the safe transport of radioactive material. Significant among the changes were major revisions to requirements for Low Specific Activity (LSA) material and Surface Contaminated Objects (SCOs). In preparation for the adoption of these requirements into regulations in the United States, it became apparent that guidance on how to apply these requirements, clarifying technical uncertainties and ensuring proper implementation, would be needed both by the regulators and those regulated. Thus, the US Department of Transportation and the U.S. Nuclear Regulatory Commission, with the assistance of staff from Oak Ridge National Laboratory, are preparing regulatory guidance for LSA material and SCO transport. The guidance will present examples of acceptable methods for demonstrating compliance with the revised rules. Ideas being investigated for inclusion in the pending guidance are discussed in this paper. Under current plans, the guidance will be issued for public comment prior to final issue of the guidance in 1997. (Author)

  13. Lower extremity thrust and non-thrust joint mobilization for patellofemoral pain syndrome: a case report.

    Science.gov (United States)

    Simpson, Brad G; Simon, Corey B

    2014-05-01

    A 40-year old female presented to physical therapy with a one-year history of insidious right anteromedial and anterolateral knee pain. Additionally, the patient had a history of multiple lateral ankle sprains bilaterally, the last sprain occurring on the right ankle 1 year prior to the onset of knee pain. The patient was evaluated and given a physical therapy diagnosis of patellofemoral pain syndrome (PFPS), with associated talocrural and tibiofemoral joint hypomobility limiting ankle dorsiflexion and knee extension, respectively. Treatment included a high-velocity low amplitude thrust manipulation to the talocrural joint, which helped restore normal ankle dorsiflexion range of motion. The patient also received tibiofemoral joint non-thrust manual therapy to regain normal knee extension mobility prior to implementing further functional progression exercises to her home program (HEP). This case report highlights the importance of a detailed evaluation of knee and ankle joint mobility in patients presenting with anterior knee pain. Further, manual physical therapy to the lower extremity was found to be successful in restoring normal movement patterns and pain-free function in a patient with chronic anterior knee pain.

  14. Duplex geometry: an example from the Moine Thrust Belt

    Science.gov (United States)

    Bowler, S.

    1987-04-01

    The geometry and microstructure of a small duplex formed in one bed from the Moine Thrust Belt of northwest Scotland is reported. The structure is seen in oblique section, within the Cambrian Pipe-rock, in an area of low strain. A range of movement direction indicators are present in the structure. An early grain shape fabric developed close to the roof thrust is taken as the best estimate of the overall movement direction towards 287°. Slickensides in the gouge developed on movement planes within the duplex show varied orientations on a given plane, and are not considered useful indicators of thrust transport direction. Branch lines exposed converge and diverge, suggesting little lateral continuity of the exposed structure. The microstructures present within the structure indicate an increase in localised deformation, and in cataclastic behavior as the duplex evolved. Early layer parallel shear is ubiquitous, giving rise to an elongate grain shape fabric close to bedding surfaces. In early formed horses, a layer-parallel, oblate grain shape fabric, which shows localised slip zones, is overprinted by gouge formation. Later formed horses show only fracturing and gouge development. This sequence is attributed to stick-slip behavior in the propagation or displacement of the original fault, now the floor thrust.

  15. Distributed deformation in the Zagros fold-and-thrust belt: insights from geomorphology

    Science.gov (United States)

    Obaid, Ahmed; Allen, Mark

    2017-04-01

    The Zagros fold-and-thrust belt is part of the active Arabia-Eurasia collision zone, and is an excellent region to study the interactions of tectonics and landscape. In this work we present results of a geomorphic analysis covering the entire range, coupled with more detailed analysis of the Kirkuk Embayment, Iraq. This particular region is a low elevation, low relief region of the Zagros, important for the enormous oil and gas reserves held in late Cenozoic anticlinal traps. Constraints from published earthquake focal mechanisms and hydrocarbon industry sub-surface data are combined with original fieldwork observations in northern Iraq, to produce a new regional cross-section and structural interpretation for the Kirkuk Embayment. We find that overall late Cenozoic shortening across the Embayment is on the order of 5%, representing only a few km. This deformation takes place on a series of anticlines, which are interpreted as overlying steep, planar, basement thrusts. These thrusts are further interpreted as reactivated normal faults, on the basis of (rare) published seismic data. The regional earthquake record confirms the basement involvement, although detachments within the sedimentary succession are also important, especially within the Middle Miocene Fat'ha Formation. Overall, the Zagros is sometimes represented as having a few major thrusts each persistent for 100s of km along the strike of the range. However, these faults are very rarely associated with major structural relief and/or surface fault ruptures during earthquakes. We have analysed the hypsometry of the range and find only gradational changes in the hypsometric integral of drainage basins across strike. This contrasts with regions such as the eastern Tibetan Plateau, where published analysis has revealed abrupt changes, correlating with the surface traces of active thrusts. Our interpretation is that the hypsometry of the Zagros reflects distributed deformation on numerous smaller faults, rather

  16. Friction torque in thrust ball bearings grease lubricated

    Science.gov (United States)

    Ianuş, G.; Dumitraşcu, A. C.; Cârlescu, V.; Olaru, D. N.

    2016-08-01

    The authors investigated experimentally and theoretically the friction torque in a modified thrust ball bearing having only 3 balls operating at low axial load and lubricated with NGLI-00 and NGLI-2 greases. The experiments were made by using spin-down methodology and the results were compared with the theoretical values based on Biboulet&Houpert's rolling friction equations. Also, the results were compared with the theoretical values obtained with SKF friction model adapted for 3 balls. A very good correlation between experiments and Biboulet_&_Houpert's predicted results was obtained for the two greases. Also was observed that the theoretical values for the friction torque calculated with SKF model adapted for a thrust ball bearing having only 3 balls are smaller that the experimental values.

  17. Kinematic evolution of fold and thrust belts. Insights from experimental modeling

    International Nuclear Information System (INIS)

    Ueta, Keiichi

    2011-01-01

    Physical experiments were performed to gain a better understanding on the kinematic evolution of fold and thrust belts. The present study focuses on deformation of sedimentary cover caused by thrust and reverse movements along the basement fault. Our physical models comprise dry quartz sand representing brittle sedimentary rock and viscous silicone polymer representing overpressured mudstone. Computerized X-ray tomography was applied to the experiments to analyze the kinematic evolution of fold and thrust belts. In the sand models, the width of deformation zone above thrust was wider than that above reverse fault, because back thrust developed on the hanging wall of reverse fault. Within the physical models composed of dry sand and silicone polymer, minor folds and thrusts with minor displacement developed on the footwall of the major monoclinal flexure. These results compare well with the geometry and kinematic evolution of the fold and thrust belts in Japan. (author)

  18. Powered Explicit Guidance Modifications and Enhancements for Space Launch System Block-1 and Block-1B Vehicles

    Science.gov (United States)

    Von der Porten, Paul; Ahmad, Naeem; Hawkins, Matt; Fill, Thomas

    2018-01-01

    NASA is currently building the Space Launch System (SLS) Block-1 launch vehicle for the Exploration Mission 1 (EM-1) test flight. NASA is also currently designing the next evolution of SLS, the Block-1B. The Block-1 and Block-1B vehicles will use the Powered Explicit Guidance (PEG) algorithm (of Space Shuttle heritage) for closed loop guidance. To accommodate vehicle capabilities and design for future evolutions of SLS, modifications were made to PEG for Block-1 to handle multi-phase burns, provide PEG updated propulsion information, and react to a core stage engine out. In addition, due to the relatively low thrust-to-weight ratio of the Exploration Upper Stage (EUS) and EUS carrying out Lunar Vicinity and Earth Escape missions, certain enhancements to the Block-1 PEG algorithm are needed to perform Block-1B missions to account for long burn arcs and target translunar and hyperbolic orbits. This paper describes the design and implementation of modifications to the Block-1 PEG algorithm as compared to Space Shuttle. Furthermore, this paper illustrates challenges posed by the Block-1B vehicle and the required PEG enhancements. These improvements make PEG capable for use on the SLS Block-1B vehicle as part of the Guidance, Navigation, and Control (GN&C) System.

  19. Guidance for evidence-informed policies about health systems: rationale for and challenges of guidance development.

    Directory of Open Access Journals (Sweden)

    Xavier Bosch-Capblanch

    Full Text Available In the first paper in a three-part series on health systems guidance, Xavier Bosch-Capblanch and colleagues examine how guidance is currently formulated in low- and middle-income countries, and the challenges to developing such guidance.

  20. Quadcopter thrust optimization with ducted-propeller

    Directory of Open Access Journals (Sweden)

    Kuantama Endrowednes

    2017-01-01

    Full Text Available In relation to quadcopter body frame model, propeller can be categorized into propeller with ducted and without ducted. This study present differences between those two using CFD (Computational Fluid Dynamics method. Both categories utilize two blade-propeller with diameter of 406 (mm. Propeller rotation generates acceleration per time unit on the volume of air. Based on the behavior of generated air velocity, ducted propeller can be modeled into three versions. The generated thrust and performance on each model were calculated to determine the best model. The use of ducted propeller increases the total weight of quadcopter and also total thrust. The influence of this modeling were analyzed in detail with variation of angular velocity propeller from 1000 (rpm to 9000 (rpm. Besides the distance between propeller tip and ducted barrier, the size of ducted is also an important part in thrust optimization and total weight minimization of quadcopter.

  1. Alternative model of thrust-fault propagation

    Science.gov (United States)

    Eisenstadt, Gloria; de Paor, Declan G.

    1987-07-01

    A widely accepted explanation for the geometry of thrust faults is that initial failures occur on deeply buried planes of weak rock and that thrust faults propagate toward the surface along a staircase trajectory. We propose an alternative model that applies Gretener's beam-failure mechanism to a multilayered sequence. Invoking compatibility conditions, which demand that a thrust propagate both upsection and downsection, we suggest that ramps form first, at shallow levels, and are subsequently connected by flat faults. This hypothesis also explains the formation of many minor structures associated with thrusts, such as backthrusts, wedge structures, pop-ups, and duplexes, and provides a unified conceptual framework in which to evaluate field observations.

  2. Exoatmospheric intercepts using zero effort miss steering for midcourse guidance

    Science.gov (United States)

    Newman, Brett

    The suitability of proportional navigation, or an equivalent zero effort miss formulation, for exatmospheric intercepts during midcourse guidance, followed by a ballistic coast to the endgame, is addressed. The problem is formulated in terms of relative motion in a general, three dimensional framework. The proposed guidance law for the commanded thrust vector orientation consists of the sum of two terms: (1) along the line of sight unit direction and (2) along the zero effort miss component perpendicular to the line of sight and proportional to the miss itself and a guidance gain. If the guidance law is to be suitable for longer range targeting applications with significant ballistic coasting after burnout, determination of the zero effort miss must account for the different gravitational accelerations experienced by each vehicle. The proposed miss determination techniques employ approximations for the true differential gravity effect and thus, are less accurate than a direct numerical propagation of the governing equations, but more accurate than a baseline determination, which assumes equal accelerations for both vehicles. Approximations considered are constant, linear, quadratic, and linearized inverse square models. Theoretical results are applied to a numerical engagement scenario and the resulting performance is evaluated in terms of the miss distances determined from nonlinear simulation.

  3. Thrust Control Loop Design for Electric-Powered UAV

    Science.gov (United States)

    Byun, Heejae; Park, Sanghyuk

    2018-04-01

    This paper describes a process of designing a thrust control loop for an electric-powered fixed-wing unmanned aerial vehicle equipped with a propeller and a motor. In particular, the modeling method of the thrust system for thrust control is described in detail and the propeller thrust and torque force are modeled using blade element theory. A relation between current and torque of the motor is obtained using an experimental setup. Another relation between current, voltage and angular velocity is also obtained. The electric motor and the propeller dynamics are combined to model the thrust dynamics. The associated trim and linearization equations are derived. Then, the thrust dynamics are coupled with the flight dynamics to allow a proper design for the thrust loop in the flight control. The proposed method is validated by an application to a testbed UAV through simulations and flight test.

  4. Thrust tectonics in crystalline domains: The origin of a gneiss dome

    Science.gov (United States)

    Greiling, R. O.

    1997-12-01

    Structural geological field work, microscopic and magnetic fabric studies have been applied in order to assess the structural origin of a gneiss dome, based on a regional example from the Neoproterozoic Pan-African Belt of NE Africa, the Wadi Hafafit Culmination (WHC). The culmination is dominated by a number of major shear zones, which form both the boundaries between the gneissic core and surrounding low grade successions as well as those of minor structural units within the gneisses. These shear zones form a linked fault system, which, based on shear criteria, fault-bend fold and overall geometric interrelationships, can be classified as an antiformal stack. The relative age sequence of the shear zones/thrusts with the highest thrust oldest and the lowermost youngest points to a forward-propagating thrust system. This, together with the shear criteria, exclude an origin of the WHC as a metamorphic core complex, where the highest shear zone should be youngest. The geometry of the WHC antiformal stack is documented by maps and sections as well as section balancing and restoration. Microscopic work showed brittle deformation in feldspar and dynamic recrystallization in quartz ribbons. The asymmetry of the fabric confirmed the macroscopically determined shear sense. However, there is one example of an earlier, perhaps extensional shear movement. Mylonitic foliation and transport-parallel lineation have also been determined by magnetic fabric studies. The observations suggest that thrusts may cut across both previously folded crystalline rocks as well as homogeneous granitoid plutonic bodies. According to the regional tectonic picture the large-scale structure of the gneiss dome originated after a phase of (late-orogenic) extensional collapse. It is speculated that during late-orogenic cooling the upper part of the lithosphere was sufficiently strong to allow brittle thrusting whilst the lithosphere as a whole was still weak enough to allow large-scale compressional

  5. Friction and Lubrication of Large Tilting-Pad Thrust Bearings

    Directory of Open Access Journals (Sweden)

    Michał Wasilczuk

    2015-04-01

    Full Text Available Fluid film bearings have been extensively used in the industry because of their unbeatable durability and extremely low friction coefficient, despite a very low coefficient of friction dissipation of energy being noticeable, especially in large bearings. Lubricating systems of large tilting pad thrust bearings utilized in large, vertical shaft hydrogenerators are presented in this paper. A large amount of heat is generated due to viscous shearing of the lubricant large tilting pad thrust bearings, and this requires systems for forced cooling of the lubricant. In the dominant bath lubrication systems, cooling is realized by internal coolers or external cooling systems, with the latter showing some important advantages at the cost of complexity and also, potentially, lower reliability. Substantial losses in the bearings, reaching 1 MW in extreme cases, are a good motivation for the research and development aimed at reducing them. Some possible methods and their potential efficiency, along with some effects already documented, are also described in the paper.

  6. Experimental Performance Study of a High Speed Oil Lubricated Polymer Thrust Bearing

    Directory of Open Access Journals (Sweden)

    Jie Zhou

    2015-01-01

    Full Text Available With the demand for turbomachinery to operate at higher speeds, loads, and power, fluid film bearings that support turbomachinery must be capable of operating in these more demanding applications. Thrust bearings operating at high speeds and loads can experience high surface temperatures and thin fluid film thickness. Typically, babbitt (white metal is the bearing lining material for most turbomachinery bearings but is limited in operating temperature and allowable film thickness. Polymer based materials are alternative materials that can operate at high temperatures and with thin films and have been in use for many decades in high load applications, such as electric submersible pumps (ESP. Test results of polymer lined thrust bearings subjected to modern turbomachinery speeds and loads are presented and compared to babbitt lined bearings of the same design and under similar conditions. The test results show polymer lined thrust bearings can operate at higher bearing unit loads than babbitt.

  7. Izbor faktora rotacije vektora potiska za balističku raketu sa Lambertovim vođenjem / Choice of the rotational factor of the thrust vector for the ballistic missile with Lambert guidance

    Directory of Open Access Journals (Sweden)

    Danilo V. Ćuk

    2008-04-01

    Full Text Available Predmet rada jeste primena Lambertovog vođenja na balističku raketu. Koristeći fundamentalnu jednačinu za upravljački vektor brzine razvijena je formula za određivanje ugla orijentacije vektora potiska u zavisnosti od faktora rotacije njegovog pravca. Izvedena formula zahteva Q-matricu koja povezuje diferencijalnu promenu vektora položaja rakete sa odgovarajućom diferencijalnom promenom korelisane brzine za fiksnu poziciju cilja i konstantno vreme slobodnog leta rakete. Izborom parametra rotacije vektora potiska dobijaju se različiti profili ugaonog položaja rakete i ugla njene brzine u zavisnosti od vremena. Podešavanjem parametra rotacije vektora potiska moguće je ostvariti prekid rada raketnog motora pri nultom napadnom uglu i, na taj način, smanjiti početne poremećaje slobodnog leta rakete. / This paper deals with the application of the Lambert guidance to the ballistic missile. By using the fundamental equation for the velocity-to-be-gained, the demanded command for the thrust angle is developed in terms of the rotational factor of its direction. The developed formula requires the Q-matrix which links a differential change in the missile position vector to the corresponding differential change in the correlated velocity for the fixed target position and the constant time of free flight. The choice of the rotational parameter provides different profiles of the missile attitude and flight path angle with time. By adjusting the rotational parameter for the thrust vector, the cut-off of the rocket engine can occur at zero angle of attack and the initial perturbations during free flight may be thus reduced.

  8. Primary electric propulsion thrust subsystem definition

    Science.gov (United States)

    Masek, T. D.; Ward, J. W.; Kami, S.

    1975-01-01

    A review is presented of the current status of primary propulsion thrust subsystem (TSS) performance, packaging considerations, and certain operational characteristics. Thrust subsystem related work from recent studies by Jet Propulsion Laboratories (JPL), Rockwell and Boeing is discussed. Existing performance for 30-cm thrusters, power processors and TSS is present along with projections for future improvements. Results of analyses to determine (1) magnetic field distributions resulting from an array of thrusters, (2) thruster emitted particle flux distributions from an array of thrusters, and (3) TSS element failure rates are described to indicate the availability of analytical tools for evaluation of TSS designs.

  9. THE RELIGIOUS GUIDANCE FOR PROSTITUTE A Descriptive Study at Palimanan Cirebon

    Directory of Open Access Journals (Sweden)

    Murip Yahya

    2016-02-01

    Full Text Available This study attempts to investigate the implementation of religious guidance for prostitute and its influence to Woman Social Institution Silih Asih in Palimanan, Cirebon. It formulated on four research questions: 1 How is the process of religious guidance in Social Institution Silih Asih; 2 What is the participants’s efforts to achieve the goal of religious guidance; 3 How is the material of religious guidance in Social Institution Silih Asih Palimanan; 4 How is the approach and method of religious guidance applied in Social Institution Silih Asih Palimanan to support and achieve the aim of religious guidance. The study used qualitative-naturalistic, research design with descriptive method. The data were collected through observation, interview, and document analysis. The results of the study show that: 1 there were two stages of religious guidance: identification stage and rehabilitation process; 2 the participants were identified by their age, marital status, education background, parents’ job, and reasons of being prostitute; 3 the materials presented on theoretical and natural materials based on Islam thoughts; 4 the religious guidance used various approaches: experience, habituation, emotional, rational, and holistic.

  10. A users manual for a computer program which calculates time optical geocentric transfers using solar or nuclear electric and high thrust propulsion

    Science.gov (United States)

    Sackett, L. L.; Edelbaum, T. N.; Malchow, H. L.

    1974-01-01

    This manual is a guide for using a computer program which calculates time optimal trajectories for high-and low-thrust geocentric transfers. Either SEP or NEP may be assumed and a one or two impulse, fixed total delta V, initial high thrust phase may be included. Also a single impulse of specified delta V may be included after the low thrust state. The low thrust phase utilizes equinoctial orbital elements to avoid the classical singularities and Kryloff-Boguliuboff averaging to help insure more rapid computation time. The program is written in FORTRAN 4 in double precision for use on an IBM 360 computer. The manual includes a description of the problem treated, input/output information, examples of runs, and source code listings.

  11. Wake vortex properties and thrust production of a harmonically-pitching flexible airfoil at low Reynolds number

    Science.gov (United States)

    Olson, David; Naguib, Ahmed; Koochesfahani, Manoochehr

    2017-11-01

    Many of the natural flyers have deformable wing structures and exhibit complex kinematics in order to produce lift and thrust. Replicating all of these conditions in the laboratory (or in simulations) is extremely difficult, and drawing explicit connections to basic unsteady aerodynamics models and theories is even more complicated. Therefore, simplified wing structure and kinematics are typically used to facilitate drawing out these connections. In this work, measurements are conducted using a rigid and a chordwise-flexible NACA 0009 airfoils when harmonically pitched about the quarter chord point. Molecular tagging velocimetry is used to characterize the wake and estimate the thrust based on the momentum integral equation as function of the reduced frequency and the pitching amplitude. The results obtained using the two different airfoils are compared in order to examine the influence of structural flexibility. Consistent with the literature, chordwise flexibility is found to enhance thrust production and the circulation of the vortices shed into the wake, for a certain range of frequencies and amplitudes. Additional characterizations are undertaken of the wake vortex structure and its scaling. This work was supported by AFOSR Award Number FA9550-10-1-0342.

  12. Cryogenic liquid resettlement activated by impulsive thrust in space-based propulsion system

    Science.gov (United States)

    Hung, R. J.; Shyu, K. L.

    1991-01-01

    The purpose of present study is to investigate the most efficient technique for propellant resettling through the minimization of propellant usage and weight penalties. Comparison between the constant reverse gravity acceleration and impulsive reverse gravity acceleration to be used for the activation of propellant resettlement shows that impulsive reverse gravity thrust is superior to constant reverse gravity thrust for liquid reorientation in a reduced gravity environment. Comparison among impulsive reverse gravity thrust with 0.1, 1.0, and 10 Hz frequencies for liquid-filled level in the range between 30 to 80 percent shows that the selection of a medium frequency of 1.0 Hz impulsive thrust over the other frequency ranges of impulsive thrust is the most proper.

  13. Thrusting and transpressional shearing in the Pan-African nappe southwest El-Sibai core complex, Central Eastern Desert, Egypt

    Science.gov (United States)

    El-Wahed, Mohamed A. Abd.

    2008-01-01

    The Wadi El-Shush area in the Central Eastern Desert (CED) of Egypt is occupied by the Sibai core complex and its surrounding Pan-African nappe complex. The sequence of metamorphic and structural events in the Sibai core complex and the enveloping Pan-African nappe can be summarized as follows: (1) high temperature metamorphism associated with partial melting of amphibolites and development of gneissic and migmatitic rocks, (2) between 740 and 660 Ma, oblique island arc accretion resulted in Pan-African nappe emplacement and the intrusion of syn-tectonic gneissic tonalite at about 680 ± 10 Ma. The NNW-SSE shortening associated with oblique island arc accretion produced low angle NNW-directed thrusts and open folds in volcaniclastic metasediments, schists and isolated serpentinite masses (Pan-African nappe) and created NNE-trending recumbent folds in syn-tectonic granites. The NNW-SSE shortening has produced imbricate structures and thrust duplexes in the Pan-African nappe, (3) NE-ward thrusting which deformed the Pan-African nappe into SW-dipping imbricate slices. The ENE-WSW compression event has created NE-directed thrusts, folded the NNW-directed thrusts and produced NW-trending major and minor folds in the Pan-African nappe. Prograde metamorphism (480-525 °C at 2-4.5 kbar) was synchronous with thrusting events, (4) retrograde metamorphism during sinistral shearing along NNW- to NW-striking strike-slip shear zones (660-580 Ma), marking the external boundaries of the Sibai core complex and related to the Najd Fault System. Sinistral shearing has produced steeply dipping mylonitic foliation and open plunging folds in the NNW- and NE-ward thrust planes. Presence of retrograde metamorphism supports the slow exhumation of Sibai core complex under brittle-ductile low temperature conditions. Arc-accretion caused thrusting, imbrication and crustal thickening, whereas gravitational collapse of a compressed and thickened lithosphere initiated the sinistral movement

  14. Sedimentation of Jurassic fan-delta wedges in the Xiahuayuan basin reflecting thrust-fault movements of the western Yanshan fold-and-thrust belt, China

    Science.gov (United States)

    Lin, Chengfa; Liu, Shaofeng; Zhuang, Qitian; Steel, Ronald J.

    2018-06-01

    Mesozoic thrusting within the Yanshan fold-and-thrust belt of North China resulted in a series of fault-bounded intramontane basins whose infill and evolution remain poorly understood. In particular, the bounding faults and adjacent sediment accumulations along the western segments of the belt are almost unstudied. A sedimentological and provenance analysis of the Lower Jurassic Xiahuayuan Formation and the Upper Jurassic Jiulongshan Formation have been mapped to show two distinctive clastic wedges: an early Jurassic wedge representing a mass-flow-dominated, Gilbert-type fan delta with a classic tripartite architecture, and an late Jurassic shoal-water fan delta without steeply inclined strata. The basinward migration of the fan-delta wedges, together with the analysis of their conglomerate clast compositions, paleocurrent data and detrital zircon U-Pb age spectra, strongly suggest that the northern-bounding Xuanhuan thrust fault controlled their growth during accumulation of the Jiulongshan Formation. Previous studies have suggested that the fan-delta wedge of the Xiahuayuan Formation was also syntectonic, related to movement on the Xuanhua thrust fault. Two stages of thrusting therefore exerted an influence on the formation and evolution of the Xiahuayuan basin during the early-late Jurassic.

  15. Using Engine Thrust for Emergency Flight Control: MD-11 and B-747 Results

    Science.gov (United States)

    Burcham, Frank W., Jr.; Maine, Trindel A.; Burken, John J.; Bull, John

    1998-01-01

    With modern digital control systems, using engine thrust for emergency flight control to supplement or replace failed aircraft normal flight controls has become a practical consideration. The NASA Dryden Flight Research Center has developed a propulsion-controlled aircraft (PCA) system in which computer-controlled engine thrust provides emergency flight control. An F-15 and an MD-11 airplane have been landed without using any flight control surfaces. Preliminary studies have also been conducted that show that engines on only one wing can provide some flight control capability if the lateral center of gravity can be shifted toward the side of the airplane that has the operating engine(s). Simulator tests of several airplanes with no flight control surfaces operating and all engines out on the left wing have all shown positive control capability within the available range of lateral center-of-gravity offset. Propulsion-controlled aircraft systems that can operate without modifications to engine control systems, thus allowing PCA technology to be installed on less capable airplanes or at low cost, are also desirable. Further studies have examined simplified 'PCA Lite' and 'PCA Ultralite' concepts in which thrust control is provided by existing systems such as auto-throttles or a combination of existing systems and manual pilot control.

  16. Advances in Thrust-Based Emergency Control of an Airplane

    Science.gov (United States)

    Creech, Gray; Burken, John J.; Burcham, Bill

    2003-01-01

    Engineers at NASA's Dryden Flight Research Center have received a patent on an emergency flight-control method implemented by a propulsion-controlled aircraft (PCA) system. Utilizing the preexisting auto-throttle and engine-pressure-ratio trim controls of the airplane, the PCA system provides pitch and roll control for landing an airplane safely without using aerodynamic control surfaces that have ceased to function because of a primary-flight-control-system failure. The installation of the PCA does not entail any changes in pre-existing engine hardware or software. [Aspects of the method and system at previous stages of development were reported in Thrust-Control System for Emergency Control of an Airplane (DRC-96-07), NASA Tech Briefs, Vol. 25, No. 3 (March 2001), page 68 and Emergency Landing Using Thrust Control and Shift of Weight (DRC-96-55), NASA Tech Briefs, Vol. 26, No. 5 (May 2002), page 58.]. Aircraft flight-control systems are designed with extensive redundancy to ensure low probabilities of failure. During recent years, however, several airplanes have exhibited major flight-control-system failures, leaving engine thrust as the last mode of flight control. In some of these emergency situations, engine thrusts were successfully modulated by the pilots to maintain flight paths or pitch angles, but in other situations, lateral control was also needed. In the majority of such control-system failures, crashes resulted and over 1,200 people died. The challenge lay in creating a means of sufficient degree of thrust-modulation control to safely fly and land a stricken airplane. A thrust-modulation control system designed for this purpose was flight-tested in a PCA an MD-11 airplane. The results of the flight test showed that without any operational control surfaces, a pilot can land a crippled airplane (U.S. Patent 5,330,131). The installation of the original PCA system entailed modifications not only of the flight-control computer (FCC) of the airplane but

  17. A 10 nN resolution thrust-stand for micro-propulsion devices

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, Subha; Courtney, Daniel G.; Shea, Herbert, E-mail: herbert.shea@epfl.ch [Microsystems for Space Technologies Laboratory (LMTS), Ecole Polytechnique Federale de Lausanne (EPFL), Neuchatel (Switzerland)

    2015-11-15

    We report on the development of a nano-Newton thrust-stand that can measure up to 100 μN thrust from different types of microthrusters with 10 nN resolution. The compact thrust-stand measures the impingement force of the particles emitted from a microthruster onto a suspended plate of size 45 mm × 45 mm and with a natural frequency over 50 Hz. Using a homodyne (lock-in) readout provides strong immunity to facility vibrations, which historically has been a major challenge for nano-Newton thrust-stands. A cold-gas thruster generating up to 50 μN thrust in air was first used to validate the thrust-stand. Better than 10 nN resolution and a minimum detectable thrust of 10 nN were achieved. Thrust from a miniature electrospray propulsion system generating up to 3 μN of thrust was measured with our thrust-stand in vacuum, and the thrust was compared with that computed from beam diagnostics, obtaining agreement within 50 nN to 150 nN. The 10 nN resolution obtained from this thrust-stand matches that from state-of-the-art nano-Newton thrust-stands, which measure thrust directly from the thruster by mounting it on a moving arm (but whose natural frequency is well below 1 Hz). The thrust-stand is the first of its kind to demonstrate less than 3 μN resolution by measuring the impingement force, making it capable of measuring thrust from different types of microthrusters, with the potential of easy upscaling for thrust measurement at much higher levels, simply by replacing the force sensor with other force sensors.

  18. Thrust augmentation for a small turbojet engine

    OpenAIRE

    Hackaday, Gary L.

    1999-01-01

    Approved for public release; distribution is unlimited A Sophia J450 (nine pounds of thrust) gas turbine engine was used first to examine the thrust augmentation generated using an ejector shroud. Experimental results obtained with and without the ejector were compared with performance predicted using an engine code and a one-dimensional ejector analysis. The engine code was revised to incorporate a radial turbine and the correct compressor map. Thrust augmentation of 3-10% was measured an...

  19. Neotectonics and structure of the Himalayan deformation front in the Kashmir Himalaya, India: Implication in defining what controls a blind thrust front in an active fold-thrust belt

    Science.gov (United States)

    Gavillot, Y. G.; Meigs, A.; Yule, J. D.; Rittenour, T. M.; Malik, M. O. A.

    2014-12-01

    Active tectonics of a deformation front constrains the kinematic evolution and structural interaction between the fold-thrust belt and most-recently accreted foreland basin. In Kashmir, the Himalayan Frontal thrust (HFT) is blind, characterized by a broad fold, the Suruin-Mastargh anticline (SMA), and displays no emergent faults cutting either limb. A lack of knowledge of the rate of shortening and structural framework of the SMA hampers quantifying the earthquake potential for the deformation front. Our study utilized the geomorphic expression of dated deformed terraces on the Ujh River in Kashmir. Six terraces are recognized, and three yield OSL ages of 53 ka, 33 ka, and 0.4 ka. Vector fold restoration of long terrace profiles indicates a deformation pattern characterized by regional uplift across the anticlinal axis and back-limb, and by fold limb rotation on the forelimb. Differential uplift across the fold trace suggests localized deformation. Dip data and stratigraphic thicknesses suggest that a duplex structure is emplaced at depth along the basal décollement, folding the overlying roof thrust and Siwalik-Muree strata into a detachment-like fold. Localized faulting at the fold axis explains the asymmetrical fold geometry. Folding of the oldest dated terrace, suggest that rock uplift rates across the SMA range between 2.0-1.8 mm/yr. Assuming a 25° dipping ramp for the blind structure on the basis of dip data constraints, the shortening rate across the SMA ranges between 4.4-3.8 mm/yr since ~53 ka. Of that rate, ~1 mm/yr is likely absorbed by minor faulting in the near field of the fold axis. Given that Himalaya-India convergence is ~18.8-11 mm/yr, internal faults north of the deformation front, such as the Riasi thrust absorbs more of the Himalayan shortening than does the HFT in Kashmir. We attribute a non-emergent thrust at the deformation front to reflect deformation controlled by pre-existing basin architecture in Kashmir, in which the thick succession

  20. Initiation process of a thrust fault revealed by analog experiments

    Science.gov (United States)

    Yamada, Yasuhiro; Dotare, Tatsuya; Adam, Juergen; Hori, Takane; Sakaguchi, Hide

    2016-04-01

    We conducted 2D (cross-sectional) analog experiments with dry sand using a high resolution digital image correlation (DIC) technique to reveal initiation process of a thrust fault in detail, and identified a number of "weak shear bands" and minor uplift prior to the thrust initiation. The observations suggest that the process can be divided into three stages. Stage 1: characterized by a series of abrupt and short-lived weak shear bands at the location where the thrust will be generated later. Before initiation of the fault, the area to be the hanging wall starts to uplift. Stage 2: defined by the generation of the new thrust and its active displacement. The location of the new thrust seems to be constrained by its associated back-thrust, produced at the foot of the surface slope (by the previous thrust). The activity of the previous thrust turns to zero once the new thrust is generated, but the timing of these two events is not the same. Stage 3: characterized by a constant displacement along the (new) thrust. Similar minor shear bands can be seen in the toe area of the Nankai accretionary prism, SW Japan and we can correlate the along-strike variations in seismic profiles to the model results that show the characteristic features in each thrust development stage.

  1. Thrust and jet directional control using the Coanda effect

    Directory of Open Access Journals (Sweden)

    Alexandru DUMITRACHE

    2018-06-01

    Full Text Available The application of the Coandă effect to the directional control of a jet or thrust is presented. Deviation of the thrust force by direct flow can be achieved by using the Coandă effect to change the angle of the primary jet engine exhaust nozzle. Major interest in the study of this phenomenon is caused by the possibility of using this effect for aircrafts with short take-off and landing, for thrust vectoring. The numerical investigations are performed using a RANS solver with an adequate turbulence model, showing a change of the jet direction. Thus, the conditions and the limits within which one can benefit from the advantages of Coandă-type flows are determined.

  2. Nanonewton thrust measurement of photon pressure propulsion using semiconductor laser

    Science.gov (United States)

    Iwami, K.; Akazawa, Taku; Ohtsuka, Tomohiro; Nishida, Hiroyuki; Umeda, Norihiro

    2011-09-01

    To evaluate the thrust produced by photon pressure emitted from a 100 W class continuous-wave semiconductor laser, a torsion-balance precise thrust stand is designed and tested. Photon emission propulsion using semiconductor light sources attract interests as a possible candidate for deep-space propellant-less propulsion and attitude control system. However, the thrust produced by photon emission as large as several ten nanonewtons requires precise thrust stand. A resonant method is adopted to enhance the sensitivity of the biflier torsional-spring thrust stand. The torsional spring constant and the resonant of the stand is 1.245 × 10-3 Nm/rad and 0.118 Hz, respectively. The experimental results showed good agreement with the theoretical estimation. The thrust efficiency for photon propulsion was also defined. A maximum thrust of 499 nN was produced by the laser with 208 W input power (75 W of optical output) corresponding to a thrust efficiency of 36.7%. The minimum detectable thrust of the stand was estimated to be 2.62 nN under oscillation at a frequency close to resonance.

  3. Thrust evaluation of magneto plasma sail that obtains an electromagnetic thrust from the solar wind

    International Nuclear Information System (INIS)

    Kajimura, Yoshihiro; Funaki, Ikkoh; Usui, Hideyuki; Yamakawa, Hiroshi

    2011-01-01

    Magneto Plasma Sail (MPS) is a propulsion system used in space, which generates its force by the interaction between the solar wind and an inflated magnetic field via a plasma injection. The quantitative evaluation of the thrust increment generated by injecting a plasma jet with a β in less than unity was conducted by three-dimensional hybrid particle-in-cell (PIC) simulations in an ion inertia scale. The injected plasma β in is 0.02 and the ratio of Larmor radius of injected ion to the representative length of the magnetic field is 0.5 at the injection point. In this situation, the obtained thrust of the MPS is 1.6 mN compared with the 0.2 mN of the thrust obtained by the pure magnetic sail since the induced current region on magnetosphere expanded by the magnetic inflation. (author)

  4. Transient analysis of blowdown thrust force under PWR LOCA

    International Nuclear Information System (INIS)

    Yano, Toshikazu; Miyazaki, Noriyuki; Isozaki, Toshikuni

    1982-10-01

    The analytical results of blowdown characteristics and thrust forces were compared with the experiments, which were performed as pipe whip and jet discharge tests under the PWR LOCA conditions. The blowdown thrust forces obtained by Navier-Stokes momentum equation about a single-phase, homogeneous and separated two-phase flow, assuming critical pressure at the exit if a critical flow condition was satisfied. The following results are obtained. (1) The node-junction method is useful for both the analyses of the blowdown thrust force and of the water hammer phenomena. (2) The Henry-Fauske model for subcooled critical flow is effective for the analysis of the maximum thrust force under the PWR LOCA conditions. The jet thrust parameter of the analysis and experiment is equal to 1.08. (3) The thrust parameter of saturated blowdown has the same one with the value under pressurized condition when the stagnant pressure is chosen as the saturated one. (4) The dominant terms of the blowdown thrust force in the momentum equation are the pressure and momentum terms except that the acceleration term has large contribution only just after the break. (5) The blowdown thrust force in the analysis greatly depends on the selection of the exit pressure. (author)

  5. Aircraft Engine Thrust Estimator Design Based on GSA-LSSVM

    Science.gov (United States)

    Sheng, Hanlin; Zhang, Tianhong

    2017-08-01

    In view of the necessity of highly precise and reliable thrust estimator to achieve direct thrust control of aircraft engine, based on support vector regression (SVR), as well as least square support vector machine (LSSVM) and a new optimization algorithm - gravitational search algorithm (GSA), by performing integrated modelling and parameter optimization, a GSA-LSSVM-based thrust estimator design solution is proposed. The results show that compared to particle swarm optimization (PSO) algorithm, GSA can find unknown optimization parameter better and enables the model developed with better prediction and generalization ability. The model can better predict aircraft engine thrust and thus fulfills the need of direct thrust control of aircraft engine.

  6. Thrust performance, propellant ionization, and thruster erosion of an external discharge plasma thruster

    Science.gov (United States)

    Karadag, Burak; Cho, Shinatora; Funaki, Ikkoh

    2018-04-01

    It is quite a challenge to design low power Hall thrusters with a long lifetime and high efficiency because of the large surface area to volume ratio and physical limits to the magnetic circuit miniaturization. As a potential solution to this problem, we experimentally investigated the external discharge plasma thruster (XPT). The XPT produces and sustains a plasma discharge completely in the open space outside of the thruster structure through a magnetic mirror configuration. It eliminates the very fundamental component of Hall thrusters, discharge channel side walls, and its magnetic circuit consists solely of a pair of hollow cylindrical permanent magnets. Thrust, low frequency discharge current oscillation, ion beam current, and plasma property measurements were conducted to characterize the manufactured prototype thruster for the proof of concept. The thrust performance, propellant ionization, and thruster erosion were discussed. Thrust generated by the XPT was on par with conventional Hall thrusters [stationary plasma thruster (SPT) or thruster with anode layer] at the same power level (˜11 mN at 250 W with 25% anode efficiency without any optimization), and discharge current had SPT-level stability (Δ design and provide a successful proof of concept experiment of the XPT.

  7. Thrust generation and wake structure for flow across a pitching ...

    Indian Academy of Sciences (India)

    ... condition for the generation of thrust. The vortex strength is found to be invariant of the pitching frequency. Certain differences from the reported results are noted, which may be because of difference in the airfoil shape. These results can help improve understanding of the flow behavior as the low Reynolds number range ...

  8. A double pendulum plasma thrust balance and thrust measurement at a tandem mirror exhaust

    International Nuclear Information System (INIS)

    Yang, T.F.; Liu, P.; Chang-Diaz, F.R.; Lander, H.; Childs, R.A.; Becker, H.D.; Fairfax, S.A.

    1995-01-01

    For the purpose of measuring the plasma momentum flux in a plasma system, a highly sensitive and precision balance has been developed. It can measure a force, an impulse, or thrust as low as 0.1 mN free of mechanical noise, electrical and magnetic pickups. The double pendulum system consists of two parallel conducting plates. One or both of the plates can be suspended by needles. The needle suspended plate (or plates) can swing freely with negligible friction because of the sharp points of the needles. When one of the plates is impacted by an impulse it will swing relatively to the fixed plate or other movable plate. The capacitance between the plates changes as a result of such a motion. The change of capacitance as a function of time is recorded as an oscillating voltage signal. The amplitude of such a voltage signal is proportional to the impacting force or impulse. The proportional factor can be calibrated. The forces can thus be read out from the recorded value of the voltage. The equation of motion for the pendulum system has been solved analytically. The circuit equation for the electronic measurement system has been formulated and solved numerically. Using this balance the thrust at the exhaust of a Tandem Mirror plasma thruster has been measured. The analytical solution of the overall characteristics agrees greatly with the measurement. copyright 1995 American Institute of Physics

  9. Hydrodynamic aspects of thrust generation in gymnotiform swimming

    Science.gov (United States)

    Shirgaonkar, Anup A.; Curet, Oscar M.; Patankar, Neelesh A.; Maciver, Malcolm A.

    2008-11-01

    The primary propulsor in gymnotiform swimmers is a fin running along most of the ventral midline of the fish. The fish propagates traveling waves along this ribbon fin to generate thrust. This unique mode of thrust generation gives these weakly electric fish great maneuverability cluttered spaces. To understand the mechanical basis of gymnotiform propulsion, we investigated the hydrodynamics of a model ribbon-fin of an adult black ghost knifefish using high-resolution numerical experiments. We found that the principal mechanism of thrust generation is a central jet imparting momentum to the fluid with associated vortex rings near the free edge of the fin. The high-fidelity simulations also reveal secondary vortex rings potentially useful in rapid sideways maneuvers. We obtained the scaling of thrust with respect to the traveling wave kinematic parameters. Using a fin-plate model for a fish, we also discuss improvements to Lighthill's inviscid theory for gymnotiform and balistiform modes in terms of thrust magnitude, viscous drag on the body, and momentum enhancement.

  10. Measuring Model Rocket Engine Thrust Curves

    Science.gov (United States)

    Penn, Kim; Slaton, William V.

    2010-01-01

    This paper describes a method and setup to quickly and easily measure a model rocket engine's thrust curve using a computer data logger and force probe. Horst describes using Vernier's LabPro and force probe to measure the rocket engine's thrust curve; however, the method of attaching the rocket to the force probe is not discussed. We show how a…

  11. Identifying representative symbology for low visibility operations/surface movement guidance and control system (LVO/SMGCS) paper charts

    Science.gov (United States)

    2015-05-04

    The Volpe Center developed a questionnaire to examine the representativeness of symbol shapes and the usefulness of information depicted on Low Visibility Operations/Surface Movement Guidance and Control System (LVO/SMGCS) paper charts. One-hundred f...

  12. IPMC-driven thrust generation: a new conceptual design (Conference Presentation)

    Science.gov (United States)

    Olsen, Zakai; Kim, Kwang Jin

    2017-04-01

    Ionic Polymer-Metal Composites (IPMC) are highly functional actuators that find many uses in the field of soft robotics due to their low actuation voltage and ability to operate in aquatic environments. The actuation of an IPMC relies on the swelling of the negatively charged side when a potential is applied, due to the free-moving cations and water molecules migrating to that half. While this bending type actuation can be utilized to perform many tasks, it is ill suited for the primary propulsion mechanism in certain soft robotic applications. Here, a new conceptual design is presented which utilizes the bending of IPMC materials to achieve complex actuation motion in an attempt to generate a non-zero net thrust for propulsion of soft robots. The design capitalizes on advances in the manufacturing processes of electroactive polymer materials, which now allow for more complex shapes and thus new and unique modes of actuation. By utilizing the consistent bending deformation of IPMC actuators, in conjunction with carefully considered geometry, an IPMC driven body may serve as a primary mode of propulsion through a positive net thrust generation. This work consists of the initial feasibility study, concept testing, and optimization for such an actuator through computer modeling and simulation. COMSOL will be used for the finite element analysis to design the most efficient and optimized design for a positive net thrust generation. Such an IPMC design may find a great deal of applications, and the potential of future integration into other soft robotic systems is considered.

  13. Using U-Th-Pb petrochronology to determine rates of ductile thrusting: Time windows into the Main Central Thrust, Sikkim Himalaya

    Science.gov (United States)

    Mottram, Catherine M.; Parrish, Randall R.; Regis, Daniele; Warren, Clare J.; Argles, Tom W.; Harris, Nigel B. W.; Roberts, Nick M. W.

    2015-07-01

    Quantitative constraints on the rates of tectonic processes underpin our understanding of the mechanisms that form mountains. In the Sikkim Himalaya, late structural doming has revealed time-transgressive evidence of metamorphism and thrusting that permit calculation of the minimum rate of movement on a major ductile fault zone, the Main Central Thrust (MCT), by a novel methodology. U-Th-Pb monazite ages, compositions, and metamorphic pressure-temperature determinations from rocks directly beneath the MCT reveal that samples from 50 km along the transport direction of the thrust experienced similar prograde, peak, and retrograde metamorphic conditions at different times. In the southern, frontal edge of the thrust zone, the rocks were buried to conditions of 550°C and 0.8 GPa between 21 and 18 Ma along the prograde path. Peak metamorphic conditions of 650°C and 0.8-1.0 GPa were subsequently reached as this footwall material was underplated to the hanging wall at 17-14 Ma. This same process occurred at analogous metamorphic conditions between 18-16 Ma and 14.5-13 Ma in the midsection of the thrust zone and between 13 Ma and 12 Ma in the northern, rear edge of the thrust zone. Northward younging muscovite 40Ar/39Ar ages are consistently 4 Ma younger than the youngest monazite ages for equivalent samples. By combining the geochronological data with the >50 km minimum distance separating samples along the transport axis, a minimum average thrusting rate of 10 ± 3 mm yr-1 can be calculated. This provides a minimum constraint on the amount of Miocene India-Asia convergence that was accommodated along the MCT.

  14. The Research Status and Progress of Heavy/Large Hydrostatic Thrust Bearing

    Directory of Open Access Journals (Sweden)

    Xibing Li

    2014-03-01

    Full Text Available How to improve the rotation speed of heavy/large CNC vertical lathe, the machining efficiency, and machining precision is one of the key issues which need to be solved urgently. Hydrostatic thrust bearing is the key part to the heavy/large CNC vertical lathe; its performance directly affects the machining quality and operation efficiency. This paper analyses the latest research results from the perspective of the mechanical properties of hydrostatic thrust bearing, oil film lubrication, static pressure bearing thermal deformation, and the high efficiency refrigeration and evaluates the future scientific research direction in this area. Analysis shows that with the development of hydrostatic thrust bearing to the high speed, high precision, high efficiency, high stability, high multifunction, and high power, the study of hydrostatic thrust bearing will focus on the optimal design of the oil chamber to produce the least amount of heat, how to control the thermal deformation of hydrostatic thrust bearing, and the high efficiency refrigeration to ensure the machining accuracy of CNC equipment.

  15. Analysis of Fault Spacing in Thrust-Belt Wedges Using Numerical Modeling

    Science.gov (United States)

    Regensburger, P. V.; Ito, G.

    2017-12-01

    Numerical modeling is invaluable in studying the mechanical processes governing the evolution of geologic features such as thrust-belt wedges. The mechanisms controlling thrust fault spacing in wedges is not well understood. Our numerical model treats the thrust belt as a visco-elastic-plastic continuum and uses a finite-difference, marker-in-cell method to solve for conservation of mass and momentum. From these conservation laws, stress is calculated and Byerlee's law is used to determine the shear stress required for a fault to form. Each model consists of a layer of crust, initially 3-km-thick, carried on top of a basal décollement, which moves at a constant speed towards a rigid backstop. A series of models were run with varied material properties, focusing on the angle of basal friction at the décollement, the angle of friction within the crust, and the cohesion of the crust. We investigate how these properties affected the spacing between thrusts that have the most time-integrated history of slip and therefore have the greatest effect on the large-scale undulations in surface topography. The surface position of these faults, which extend through most of the crustal layer, are identifiable as local maxima in positive curvature of surface topography. Tracking the temporal evolution of faults, we find that thrust blocks are widest when they first form at the front of the wedge and then they tend to contract over time as more crustal material is carried to the wedge. Within each model, thrust blocks form with similar initial widths, but individual thrust blocks develop differently and may approach an asymptotic width over time. The median of thrust block widths across the whole wedge tends to decrease with time. Median fault spacing shows a positive correlation with both wedge cohesion and internal friction. In contrast, median fault spacing exhibits a negative correlation at small angles of basal friction (laws that can be used to predict fault spacing in

  16. Track 2 sites: Guidance for assessing low probability hazard sites at the INEL

    International Nuclear Information System (INIS)

    1994-01-01

    This document presents guidance for assessment of Track 2 low probability hazard sites (LPHS) at the Idaho National Engineering Laboratory (INEL). The Track 2 classification was developed specifically for the INEL to streamline the implementation of Comprehensive Environmental Response, Compensation, and Liability Act. Track 2 LPHSs are described as sites where insufficient data are available to make a decision concerning the risk level or to select or design a remedy. As such, these types of sites are not described in the National Contingency Plan or existing regulatory guidance. The goal of the Track 2 process is to evaluate LPHSs using existing qualitative and quantitative data to minimize the collection of new environmental data. To this end, this document presents a structured format consisting of a series of questions and tables. A qualitative risk assessment is used. The process is iterative, and addresses an LPHS from multiple perspectives (i.e., historical, empirical, process) in an effort to generate a reproducible and defensible method. This rigorous approach follows the data quality objective process and establishes a well organized, logical approach to consolidate and assess existing data, and set decision criteria. If necessary, the process allows for the design of a sampling and analysis strategy to obtain new environmental data of appropriate quality to support decisions for each LPHS. Finally, the guidance expedites consensus between regulatory parties by emphasizing a team approach to Track 2 investigations

  17. Radial loads and axial thrusts on centrifugal pumps

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    The proceedings of a seminar organised by the Power Industries Division of the IMechE are presented in this text. Complete contents: Review of parameters influencing hydraulic forces on centrifugal impellers; The effect of fluid forces at various operation conditions on the vibrations of vertical turbine pumps; A review of the pump rotor axial equilibrium problem - some case studies; Dynamic hydraulic loading on a centrifugal pump impeller; Experimental research on axial thrust loads of double suction centrifugal pumps; A comparison of pressure distribution and radial loads on centrifugal pumps; A theoretical and experimental investigation of axial thrusts within a multi-stage centrifugal pump

  18. Thrust sensing for small UAVs

    Science.gov (United States)

    Marchman, Christopher Scott

    Unmanned aerial vehicles (UAVs) have become prevalent in both military and civilian applications. UAVs have many size categories from large-scale aircraft to micro air vehicles. The performance, health, and efficiency for UAVs of smaller sizes can be difficult to assess and few associated instrumentation systems have been developed. Thrust measurements on the ground can characterize systems especially when combined with simultaneous motor power measurements. This thesis demonstrates the use of strain measurements to measure the thrust produced by motor/propeller combinations for such small UAVs. A full-bridge Wheatstone circuit and electrical resistance strain gauges were used in conjunction with constant-stress cantilever beams for static tests and dynamic wind tunnel tests. An associated instrumentation module monitored power from the electric motor. Monitoring the thrust data over time can provide insights into optimal propeller and motor selection and early detection of problems such as component failure. The approach provides a system for laboratory or field measurements that can be scaled for a wide range of small UAVs.

  19. Thrust Augmented Nozzle for a Hybrid Rocket with a Helical Fuel Port

    Science.gov (United States)

    Marshall, Joel H.

    A thrust augmented nozzle for hybrid rocket systems is investigated. The design lever-ages 3-D additive manufacturing to embed a helical fuel port into the thrust chamber of a hybrid rocket burning gaseous oxygen and ABS plastic as propellants. The helical port significantly increases how quickly the fuel burns, resulting in a fuel-rich exhaust exiting the nozzle. When a secondary gaseous oxygen flow is injected into the nozzle downstream of the throat, all of the remaining unburned fuel in the plume spontaneously ignites. This secondary reaction produces additional high pressure gases that are captured by the nozzle and significantly increases the motor's performance. Secondary injection and combustion allows a high expansion ratio (area of the nozzle exit divided by area of the throat) to be effective at low altitudes where there would normally be significantly flow separation and possibly an embedded shock wave due. The result is a 15 percent increase in produced thrust level with no loss in engine efficiency due to secondary injection. Core flow efficiency was increased significantly. Control tests performed using cylindrical fuel ports with secondary injection, and helical fuel ports without secondary injection did not exhibit this performance increase. Clearly, both the fuel-rich plume and secondary injection are essential features allowing the hybrid thrust augmentation to occur. Techniques for better design optimization are discussed.

  20. Thrust characteristics of a series of convergent-divergent exhaust nozzles at subsonic and supersonic flight speeds

    Science.gov (United States)

    Fradenburgh, Evan A; Gorton, Gerald C; Beke, Andrew

    1954-01-01

    An experimental investigation of a series of four convergent-divergent exhaust nozzles was conducted in the Lewis 8-by-6 foot supersonic wind tunnel at Mach numbers of 0.1, 0.6, 1.6, and 2.0 over a range of nozzle pressure ratios. The thrust characteristics of these nozzles were determined by a pressure-integration technique. From a thrust standpoint, a nozzle designed to give uniform parallel flow at the exit had no advantage over the simple geometric design with conical convergent and divergent sections. The rapid-divergent nozzles might be competitive with the more gradual-divergent nozzles since the relatively short length of these nozzles would be advantageous from a weight standpoint and might result in smaller thrust losses due to friction. The thrusts, with friction losses neglected, were predicted satisfactorily by one-dimensional theory for the nozzles with relatively gradual divergence. The thrusts of the rapid-divergent designs were several percentages below the theoretical values at the design pressure ratio or above, while at low pressure ratios there was a considerable effect of free-stream Mach number, with thrusts considerably above theoretical values at subsonic speeds and somewhat above theoretical values at supersonic speeds. This Mach numb effect appeared to be related to the variation of the model base pressure with free-stream Mach number.

  1. Dynamic Imbalance Would Counter Offcenter Thrust

    Science.gov (United States)

    Mccanna, Jason

    1994-01-01

    Dynamic imbalance generated by offcenter thrust on rotating body eliminated by shifting some of mass of body to generate opposing dynamic imbalance. Technique proposed originally for spacecraft including massive crew module connected via long, lightweight intermediate structure to massive engine module, such that artificial gravitation in crew module generated by rotating spacecraft around axis parallel to thrust generated by engine. Also applicable to dynamic balancing of rotating terrestrial equipment to which offcenter forces applied.

  2. Reliability and validity of a tool to measure the severity of tongue thrust in children: the Tongue Thrust Rating Scale.

    Science.gov (United States)

    Serel Arslan, S; Demir, N; Karaduman, A A

    2017-02-01

    This study aimed to develop a scale called Tongue Thrust Rating Scale (TTRS), which categorised tongue thrust in children in terms of its severity during swallowing, and to investigate its validity and reliability. The study describes the developmental phase of the TTRS and presented its content and criterion-based validity and interobserver and intra-observer reliability. For content validation, seven experts assessed the steps in the scale over two Delphi rounds. Two physical therapists evaluated videos of 50 children with cerebral palsy (mean age, 57·9 ± 16·8 months), using the TTRS to test criterion-based validity, interobserver and intra-observer reliability. The Karaduman Chewing Performance Scale (KCPS) and Drooling Severity and Frequency Scale (DSFS) were used for criterion-based validity. All the TTRS steps were deemed necessary. The content validity index was 0·857. A very strong positive correlation was found between two examinations by one physical therapist, which indicated intra-observer reliability (r = 0·938, P reliability (r = 0·892, P validity of the TTRS. The TTRS is a valid, reliable and clinically easy-to-use functional instrument to document the severity of tongue thrust in children. © 2016 John Wiley & Sons Ltd.

  3. Thermal–Hydrodynamic Behaviour of Coated Pivoted Pad Thrust Bearings: Comparison between Babbitt, PTFE and DLC

    OpenAIRE

    Konstantinos Katsaros; Dimitrios A. Bompos; Pantelis G. Nikolakopoulos; Stephanos Theodossiades

    2018-01-01

    The hydrodynamic lubrication and thermal analysis of tilting pad thrust bearings has been a major subject for many studies in the field of tribology. There is only a limited number of studies regarding thrust bearings with coated surfaces. The purpose of this study is to build a parametric, iterative algorithm in order to perform a complete thermal and hydrodynamic lubrication analysis for pivoted pad thrust bearings with coatings. The analytical model is mainly based on the energy, continuit...

  4. 76 FR 20992 - Guidance for Industry and Food and Drug Administration Staff; Class II Special Controls Guidance...

    Science.gov (United States)

    2011-04-14

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2011-D-0189] Guidance for Industry and Food and Drug Administration Staff; Class II Special Controls Guidance Document: Low Level Laser System for Aesthetic Use; Availability AGENCY: Food and Drug Administration, HHS...

  5. Detachments in Shale: Controlling Characteristics on Fold-Thrust Belt Style

    Science.gov (United States)

    Hansberry, Rowan; King, Ros; Collins, Alan; Morley, Chris

    2013-04-01

    (e.g. Platt, 1986; Bilotti and Shaw, 2005; Morley, 2007). Therefore, through a mixture of field observations, sample analysis and theoretical analysis it will be possible to determine a full range of shale detachment parameters and their impact on the structural style of fold-thrust belts across a variety of settings. Recent work in Muak Lek, central Thailand has focused on a structural investigation of fold-thrust belt deformation of a passive margin sequence as a result of continent-continent collision during the Triassic Indosinian Orogeny. Exceptional outcropping of the detachment lithology is accessible in the Siam City Cement quarry allowing construction of sections detailing the deformational style across the detachment itself. The detachment forms complex, 3-dimensional duplex-like structures creating egg-carton geometries enveloping foliation surfaces in the zones of most intense strain. Up section strain decreases to discrete thrust imbricates of decametre scale. Samples of limestone and secondary calcite were collected through the sections for oxygen stable isotopes analysis which show a distinct pattern of isotopic fractionation across the main thrust and into the detachment. Results from this study give insights into the nature of shale detachments and the control on fold-thrust belt development.

  6. Measurement of Impulsive Thrust from a Closed Radio Frequency Cavity in Vacuum

    Science.gov (United States)

    White, Harold; March, Paul; Lawrence, James; Vera, Jerry; Sylvester, Andre; Brady, David; Bailey, Paul

    2016-01-01

    A vacuum test campaign evaluating the impulsive thrust performance of a tapered RF test article excited in the TM212 mode at 1,937 megahertz (MHz) has been completed. The test campaign consisted of a forward thrust phase and reverse thrust phase at less than 8 x 10(exp -6) Torr vacuum with power scans at 40 watts, 60 watts, and 80 watts. The test campaign included a null thrust test effort to identify any mundane sources of impulsive thrust, however none were identified. Thrust data from forward, reverse, and null suggests that the system is consistently performing with a thrust to power ratio of 1.2 +/- 0.1 mN/kW.

  7. 14 CFR 25.904 - Automatic takeoff thrust control system (ATTCS).

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Automatic takeoff thrust control system... Automatic takeoff thrust control system (ATTCS). Each applicant seeking approval for installation of an engine power control system that automatically resets the power or thrust on the operating engine(s) when...

  8. Comparison of Low-Thrust Control Laws for Application in Planetocentric Space

    Science.gov (United States)

    Falck, Robert D.; Sjauw, Waldy K.; Smith, David A.

    2014-01-01

    Recent interest at NASA for the application of solar electric propulsion for the transfer of significant payloads in cislunar space has led to the development of high-fidelity simulations of such missions. With such transfers involving transfer times on the order of months, simulation time can be significant. In the past, the examination of such missions typically began with the use of lower-fidelity trajectory optimization tools such as SEPSPOT to develop and tune guidance laws which delivered optimal or near- optimal trajectories, where optimal is generally defined as minimizing propellant expenditure or time of flight. The transfer of these solutions to a high-fidelity simulation is typically an iterative process whereby the initial solution may nearly, but not precisely, meet mission objectives. Further tuning of the guidance algorithm is typically necessary when accounting for high-fidelity perturbations such as those due to more detailed gravity models, secondary-body effects, solar radiation pressure, etc. While trajectory optimization is a useful method for determining optimal performance metrics, algorithms which deliver nearly optimal performance with minimal tuning are an attractive alternative.

  9. Dynamic Model for Thrust Generation of Marine Propellers

    DEFF Research Database (Denmark)

    Blanke, Mogens; Lindegaard, Karl-Petter; Fossen, Thor I.

    2000-01-01

    Mathematical models of propeller thrust and torque are traditionally based on steady state thrust and torque characteristics obtained in model basin or cavitation tunnel tests. Experimental results showed that these quasi steady state models do not accurately describe the transient phenomena in a...

  10. Frontal compression along the Apennines thrust system: The Emilia 2012 example from seismicity to crustal structure

    Science.gov (United States)

    Chiarabba, Claudio; De Gori, Pasquale; Improta, Luigi; Lucente, Francesco Pio; Moretti, Milena; Govoni, Aladino; Di Bona, Massimo; Margheriti, Lucia; Marchetti, Alessandro; Nardi, Anna

    2014-12-01

    The evolution of the Apennines thrust-and-fold belt is related to heterogeneous process of subduction and continental delamination that generates extension within the mountain range and compression on the outer front of the Adria lithosphere. While normal faulting earthquakes diffusely occur along the mountain chain, the sparse and poor seismicity in the compressional front does not permit to resolve the ambiguity that still exists about which structure accommodates the few mm/yr of convergence observed by geodetic data. In this study, we illustrate the 2012 Emilia seismic sequence that is the most significant series of moderate-to-large earthquakes developed during the past decades on the compressional front of the Apennines. Accurately located aftershocks, along with P-wave and Vp/Vs tomographic models, clearly reveal the geometry of the thrust system, buried beneath the Quaternary sediments of the Po Valley. The seismic sequence ruptured two distinct adjacent thrust faults, whose different dip, steep or flat, accounts for the development of the arc-like shape of the compressional front. The first shock of May 20 (Mw 6.0) developed on the middle Ferrara thrust that has a southward dip of about 30°. The second shock of May 29 (Mw 5.8) ruptured the Mirandola thrust that we define as a steep dipping (50-60°) pre-existing (Permo-Triassic) basement normal fault inverted during compression. The overall geometry of the fault system is controlled by heterogeneity of the basement inherited from the older extension. We also observe that the rupture directivity during the two main-shocks and the aftershocks concentration correlate with low Poisson ratio volumes, probably indicating that portions of the fault have experienced intense micro-damage.

  11. Neogene deformation of thrust-top Rzeszów Basin (Outer Carpathians, Poland)

    Science.gov (United States)

    Uroda, Joanna

    2015-04-01

    The Rzeszów Basin is a 220 km2 basin located in the frontal part of Polish Outer Carpathians fold-and-thrust belt. Its sedimentary succession consist of ca. 600 m- thick Miocene evaporates, litoral and marine sediments. This basin developed between Babica-Kąkolówka anticline and frontal thrust of Carpathian Orogen. Rzeszów thrust-top basin is a part of Carpathian foreland basin system- wedge-top depozone. The sediments of wedge -top depozone were syntectonic deformed, what is valuable tool to understand kinematic history of the orogen. Analysis of field and 3D seismic reflection data showed the internal structure of the basin. Seismic data reveal the presence of fault-bend-folds in the basement of Rzeszów basin. The architecture of the basin - the presence of fault-releated folds - suggest that the sediments were deformed in last compressing phase of Carpathian Orogen deformation. Evolution of Rzeszów Basin is compared with Bonini et.al. (1999) model of thrust-top basin whose development is controlled by the kinematics of two competing thrust anticlines. Analysis of seismic and well data in Rzeszów basin suggest that growth sediments are thicker in south part of the basin. During the thrusting the passive rotation of the internal thrust had taken place, what influence the basin fill architecture and depocentre migration opposite to thrust propagation. Acknowledgments This study was supported by grant No 2012/07/N/ST10/03221 of the Polish National Centre of Science "Tectonic activity of the Skole Nappe based on analysis of changes in the vertical profile and depocentre migration of Neogene sediments in Rzeszów-Strzyżów area (Outer Carpathians)". Seismic data by courtesy of the Polish Gas and Oil Company. References Bonini M., Moratti G., Sani F., 1999, Evolution and depocentre migration in thrust-top basins: inferences from the Messinian Velona Basin (Northern Apennines, Italy), Tectonophysics 304, 95-108.

  12. A Time-Regularized, Multiple Gravity-Assist Low-Thrust, Bounded-Impulse Model for Trajectory Optimization

    Science.gov (United States)

    Ellison, Donald H.; Englander, Jacob A.; Conway, Bruce A.

    2017-01-01

    The multiple gravity assist low-thrust (MGALT) trajectory model combines the medium-fidelity Sims-Flanagan bounded-impulse transcription with a patched-conics flyby model and is an important tool for preliminary trajectory design. While this model features fast state propagation via Keplers equation and provides a pleasingly accurate estimation of the total mass budget for the eventual flight suitable integrated trajectory it does suffer from one major drawback, namely its temporal spacing of the control nodes. We introduce a variant of the MGALT transcription that utilizes the generalized anomaly from the universal formulation of Keplers equation as a decision variable in addition to the trajectory phase propagation time. This results in two improvements over the traditional model. The first is that the maneuver locations are equally spaced in generalized anomaly about the orbit rather than time. The second is that the Kepler propagator now has the generalized anomaly as its independent variable instead of time and thus becomes an iteration-free propagation method. The new algorithm is outlined, including the impact that this has on the computation of Jacobian entries for numerical optimization, and a motivating application problem is presented that illustrates the improvements that this model has over the traditional MGALT transcription.

  13. Lateral Vibration of Hydroelectric Generating Set with Different Supporting Condition of Thrust Pad

    Directory of Open Access Journals (Sweden)

    Xiaohui Si

    2011-01-01

    Full Text Available The variations of the supporting condition, which change the stiffness of tilting pad thrust bearing, may alter the dynamic behavior of the rotor system. The effects of supporting condition of thrust pad on the lateral vibration of a hydroelectric generating set are investigated in this paper. The action of a thrust bearing is described as moments acting on the thrust collar, and the tilting stiffness coefficients of thrust bearing are calculated. A model based on typical beam finite element method is established to calculate the dynamic response, and the effects of supporting conditions such as elastic oil tank support, different heights of the thrust pads with rigid support are discussed. The results reveal that the influence of thrust bearing is small when the elastic oil tanks work normally. When the supporting conditions turn to be rigid due to the oil leakage, the differences of thrust pad heights have evident influence on the load distribution of the thrust pads; while the effects on the tilting stiffness of the thrust bearing and the amplitude of the lateral shaft vibration is small when the maximum load on thrust pads is smaller than the allowable value.

  14. Thrust Vectoring of a Continuous Rotating Detonation Engine by Changing the Local Injection Pressure

    International Nuclear Information System (INIS)

    Liu Shi-Jie; Lin Zhi-Yong; Sun Ming-Bo; Liu Wei-Dong

    2011-01-01

    The thrust vectoring ability of a continuous rotating detonation engine is numerically investigated, which is realized via increasing local injection stagnation pressure of half of the simulation domain compared to the other half. Under the homogeneous injection condition, both the flow-field structure and the detonation wave propagation process are analyzed. Due to the same injection condition along the inlet boundary, the outlines of fresh gas zones at different moments are similar to each other. The main flow-field features under thrust vectoring cases are similar to that under the baseline condition. However, due to the heterogeneous injection system, both the height of the fresh gas zone and the pressure value of the fresh gas in the high injection pressure zone are larger than that in the low injection pressure zone. Thus the average pressure in half of the engine is larger than that in the other half and the thrust vectoring adjustment is realized. (fundamental areas of phenomenology(including applications))

  15. Analyzing structural variations along strike in a deep-water thrust belt

    Science.gov (United States)

    Totake, Yukitsugu; Butler, Robert W. H.; Bond, Clare E.; Aziz, Aznan

    2018-03-01

    We characterize a deep-water fold-thrust arrays imaged by a high-resolution 3D seismic dataset in the offshore NW Borneo, Malaysia, to understand the kinematics behind spatial arrangement of structural variations throughout the fold-thrust system. The seismic volume used covers two sub-parallel fold trains associated with a series of fore-thrusts and back-thrusts. We measured fault heave, shortening value, fold geometries (forelimb dip, interlimb angle and crest depth) along strike in individual fold trains. Heave plot on strike projection allows to identify individual thrust segments showing semi-elliptical to triangular to bimodal patterns, and linkages of these segments. The linkage sites are marked by local minima in cumulative heave. These local heave minima are compensated by additional structures, such as small imbricate thrusts and tight folds indicated by large forelimb dip and small interlimb angle. Complementary profiles of the shortening amount for the two fold trains result in smoother gradient of total shortening across the structures. We interpret this reflects kinematic interaction between two fold-thrust trains. This type of along-strike variation analysis provides comprehensive understanding of a fold-thrust system and may provide an interpretative strategy for inferring the presence of complex multiple faults in less well-imaged parts of seismic volumes.

  16. Virtual Ultrasound Guidance for Inexperienced Operators

    Science.gov (United States)

    Caine, Timothy; Martin, David

    2012-01-01

    Medical ultrasound or echocardiographic studies are highly operator-dependent and generally require lengthy training and internship to perfect. To obtain quality echocardiographic images in remote environments, such as on-orbit, remote guidance of studies has been employed. This technique involves minimal training for the user, coupled with remote guidance from an expert. When real-time communication or expert guidance is not available, a more autonomous system of guiding an inexperienced operator through an ultrasound study is needed. One example would be missions beyond low Earth orbit in which the time delay inherent with communication will make remote guidance impractical. The Virtual Ultrasound Guidance system is a combination of hardware and software. The hardware portion includes, but is not limited to, video glasses that allow hands-free, full-screen viewing. The glasses also allow the operator a substantial field of view below the glasses to view and operate the ultrasound system. The software is a comprehensive video program designed to guide an inexperienced operator through a detailed ultrasound or echocardiographic study without extensive training or guidance from the ground. The program contains a detailed description using video and audio to demonstrate equipment controls, ergonomics of scanning, study protocol, and scanning guidance, including recovery from sub-optimal images. The components used in the initial validation of the system include an Apple iPod Classic third-generation as the video source, and Myvue video glasses. Initially, the program prompts the operator to power-up the ultrasound and position the patient. The operator would put on the video glasses and attach them to the video source. After turning on both devices and the ultrasound system, the audio-video guidance would then instruct on patient positioning and scanning techniques. A detailed scanning protocol follows with descriptions and reference video of each view along with

  17. Space shuttle orbit maneuvering engine reusable thrust chamber program

    Science.gov (United States)

    Senneff, J. M.

    1975-01-01

    Reusable thrust chamber and injector concepts were evaluated for the space shuttle orbit maneuvering engine (OME). Parametric engine calculations were carried out by computer program for N2O4/amine, LOX/amine and LOX/hydrocarbon propellant combinations for engines incorporating regenerative cooled and insulated columbium thrust chambers. The calculation methods are described including the fuel vortex film cooling method of combustion gas temperature control, and performance prediction. A method of acceptance of a regeneratively cooled heat rejection reduction using a silicone oil additive was also demonstrated by heated tube heat transfer testing. Regeneratively cooled thrust chamber operation was also demonstrated where the injector was characterized for the OME application with a channel wall regenerative thrust chamber. Bomb stability testing of the demonstration chambers/injectors demonstrated recovery for the nominal design of acoustic cavities. Cavity geometry changes were also evaluated to assess their damping margin. Performance and combustion stability was demonstrated of the originally developed 10 inch diameter combustion pattern operating in an 8 inch diameter thrust chamber.

  18. pedagogical guidance for south african consumer studies education

    African Journals Online (AJOL)

    user

    preferred teaching-learning strategies utilised internationally in subjects related to Consumer. ISSN 0378-5254 Journal of Family Ecology and Consumer Sciences, Vol 42, 2014. 48. Pedagogical guidance for South African Consumer Studies education. 1 The seven theory content topics contained in the Consumer Studies ...

  19. 2-D traveltime and waveform inversion for improved seismic imaging: Naga Thrust and Fold Belt, India

    Science.gov (United States)

    Jaiswal, Priyank; Zelt, Colin A.; Bally, Albert W.; Dasgupta, Rahul

    2008-05-01

    Exploration along the Naga Thrust and Fold Belt in the Assam province of Northeast India encounters geological as well as logistic challenges. Drilling for hydrocarbons, traditionally guided by surface manifestations of the Naga thrust fault, faces additional challenges in the northeast where the thrust fault gradually deepens leaving subtle surface expressions. In such an area, multichannel 2-D seismic data were collected along a line perpendicular to the trend of the thrust belt. The data have a moderate signal-to-noise ratio and suffer from ground roll and other acquisition-related noise. In addition to data quality, the complex geology of the thrust belt limits the ability of conventional seismic processing to yield a reliable velocity model which in turn leads to poor subsurface image. In this paper, we demonstrate the application of traveltime and waveform inversion as supplements to conventional seismic imaging and interpretation processes. Both traveltime and waveform inversion utilize the first arrivals that are typically discarded during conventional seismic processing. As a first step, a smooth velocity model with long wavelength characteristics of the subsurface is estimated through inversion of the first-arrival traveltimes. This velocity model is then used to obtain a Kirchhoff pre-stack depth-migrated image which in turn is used for the interpretation of the fault. Waveform inversion is applied to the central part of the seismic line to a depth of ~1 km where the quality of the migrated image is poor. Waveform inversion is performed in the frequency domain over a series of iterations, proceeding from low to high frequency (11-19 Hz) using the velocity model from traveltime inversion as the starting model. In the end, the pre-stack depth-migrated image and the waveform inversion model are jointly interpreted. This study demonstrates that a combination of traveltime and waveform inversion with Kirchhoff pre-stack depth migration is a promising approach

  20. Why style matters - uncertainty and structural interpretation in thrust belts.

    Science.gov (United States)

    Butler, Rob; Bond, Clare; Watkins, Hannah

    2016-04-01

    lithified systems will be drawn from the foothills of the Colombian Andes and the Papuan fold-belt. These show major forelimb structures with segmented steep-limbs containing substantial oil-columns, suggesting forelimb complexity in lithified sections maybe more common than predicted by idealised models. As with individual fold-thrust structures, regional cross-sections are commonly open to multiple interpretations. To date the over-reliance on comparative approaches with a narrow range of published studies (e.g. Canadian cordilleran foothills) has biased global interpretations of thrust systems. Perhaps the most significant issues relate to establishing a depth to detachment - specifically the involvement of basement at depth - especially the role of pre-existing (rift-originated) faults and their inversion. Not only do these choices impact on the local interpretation, the inferred shortening values, obtained by comparing restored section-lengths, can be radically different. Further issues arise for emergent, syn-depositional thrust systems where sedimentation prohibits flat-on-flat thrusting in favour of continuously ramping thrust trajectories. Inappropriate adoption of geometries gathered from buried (duplex) systems can create geometric interpretations that are tectono-stratigraphically invalid. This presentation illustrates these topics using a variety of thrust systems with the aim of promoting discussion on developing better interpretative strategies than those adopted hitherto.

  1. OFFICE OF SCIENCE AND TECHNOLOGY AND INTERNATIONAL, NATURAL BARRIERS THRUST OVERVIEW

    International Nuclear Information System (INIS)

    B. Bodvarsson; Y. Tsang

    2006-01-01

    The Natural Barriers Thrust supports scientific studies of the natural system at the proposed repository site of Yucca Mountain. It stresses the realistic representation of the natural system with respect to processes and parameters, by means of laboratory, field, and modeling studies. It has the objectives to demonstrate that the natural barriers can make large contributions to repository performance, supporting the multiple-barrier concept for geological disposal of high-level radioactive waste; and to reduce the overall cost of repository development by elimination of unnecessary engineered components, given the demonstrated natural barriers performance. In this overview we enumerate the research projects within the Natural Barriers Thrust grouped under five elements: (1) Drift Seepage, (2) In-drift Environment, (3) Drift Shadow, (4) Unsaturated Zone Flow and Transport, and (5) Saturated Zone Flow and Transport. The long-term strategic plan of the Natural Barriers Thrust and some key results are also briefly described

  2. Thrust generation by a heaving flexible foil: Resonance, nonlinearities, and optimality

    Science.gov (United States)

    Paraz, Florine; Schouveiler, Lionel; Eloy, Christophe

    2016-01-01

    Flexibility of marine animal fins has been thought to enhance swimming performance. However, despite numerous experimental and numerical studies on flapping flexible foils, there is still no clear understanding of the effect of flexibility and flapping amplitude on thrust generation and swimming efficiency. Here, to address this question, we combine experiments on a model system and a weakly nonlinear analysis. Experiments consist in immersing a flexible rectangular plate in a uniform flow and forcing this plate into a heaving motion at its leading edge. A complementary theoretical model is developed assuming a two-dimensional inviscid problem. In this model, nonlinear effects are taken into account by considering a transverse resistive drag. Under these hypotheses, a modal decomposition of the system motion allows us to predict the plate response amplitude and the generated thrust, as a function of the forcing amplitude and frequency. We show that this model can correctly predict the experimental data on plate kinematic response and thrust generation, as well as other data found in the literature. We also discuss the question of efficiency in the context of bio-inspired propulsion. Using the proposed model, we show that the optimal propeller for a given thrust and a given swimming speed is achieved when the actuating frequency is tuned to a resonance of the system, and when the optimal forcing amplitude scales as the square root of the required thrust.

  3. Aircraft Horizontal Thrust Measurement Facility

    Data.gov (United States)

    Federal Laboratory Consortium — This facility is designed to support the DoD mission by providing unique air vehicle installed engine performance (thrust output) measurements. This system consists...

  4. Highly effective photonic cue for repulsive axonal guidance.

    Directory of Open Access Journals (Sweden)

    Bryan J Black

    Full Text Available In vivo nerve repair requires not only the ability to regenerate damaged axons, but most importantly, the ability to guide developing or regenerating axons along paths that will result in functional connections. Furthermore, basic studies in neuroscience and neuro-electronic interface design require the ability to construct in vitro neural circuitry. Both these applications require the development of a noninvasive, highly effective tool for axonal growth-cone guidance. To date, a myriad of technologies have been introduced based on chemical, electrical, mechanical, and hybrid approaches (such as electro-chemical, optofluidic flow and photo-chemical methods. These methods are either lacking in desired spatial and temporal selectivity or require the introduction of invasive external factors. Within the last fifteen years however, several attractive guidance cues have been developed using purely light based cues to achieve axonal guidance. Here, we report a novel, purely optical repulsive guidance technique that uses low power, near infrared light, and demonstrates the guidance of primary goldfish retinal ganglion cell axons through turns of up to 120 degrees and over distances of ∼90 µm.

  5. A Determinate Model of Thrust-Augmenting Ejectors

    Science.gov (United States)

    Whitley, N.; Krothapalli, A.; van Dommelen, L.

    1996-01-01

    A theoretical analysis of the compressible flow through a constant-area jet-engine ejector in which a primary jet mixes with ambient fluid from a uniform free stream is pursued. The problem is reduced to a determinate mathematical one by prescribing the ratios of stagnation properties between the primary and secondary flows. For some selections of properties and parameters more than one solution is possible and the meaning of these solutions is discussed by means of asymptotic expansions. Our results further show that while under stationary conditions the thrust-augmentation ratio assumes a value of 2 in the large area-ratio limit, for a free-stream Mach number greater than 0.6 very little thrust augmentation is left. Due to the assumptions made, the analysis provides idealized values for the thrust-augmentation ratio and the mass flux entrainment factor.

  6. Thrust Stand for Vertically Oriented Electric Propulsion Performance Evaluation

    Science.gov (United States)

    Moeller, Trevor; Polzin, Kurt A.

    2010-01-01

    A variation of a hanging pendulum thrust stand capable of measuring the performance of an electric thruster operating in the vertical orientation is presented. The vertical orientation of the thruster dictates that the thruster must be horizontally offset from the pendulum pivot arm, necessitating the use of a counterweight system to provide a neutrally-stable system. Motion of the pendulum arm is transferred through a balance mechanism to a secondary arm on which deflection is measured. A non-contact light-based transducer is used to measure displacement of the secondary beam. The members experience very little friction, rotating on twisting torsional pivots with oscillatory motion attenuated by a passive, eddy current damper. Displacement is calibrated using an in situ thrust calibration system. Thermal management and self-leveling systems are incorporated to mitigate thermal and mechanical drifts. Gravitational restoring force and torsional spring constants associated with flexure pivots provide restoring moments. An analysis of the design indicates that the thrust measurement range spans roughly four decades, with the stand capable of measuring thrust up to 12 N for a 200 kg thruster and up to approximately 800 mN for a 10 kg thruster. Data obtained from calibration tests performed using a 26.8 lbm simulated thruster indicated a resolution of 1 mN on 100 mN-level thrusts, while those tests conducted on 200 lbm thruster yielded a resolution of roughly 2.5 micro at thrust levels of 0.5 N and greater.

  7. Thrust stand for vertically oriented electric propulsion performance evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, Trevor [University of Tennessee Space Institute, Tullahoma, Tennessee 37388 (United States); Polzin, Kurt A. [NASA, Marshall Space Flight Center, Huntsville, Alabama 35812 (United States)

    2010-11-15

    A variation of a hanging pendulum thrust stand capable of measuring the performance of an electric thruster operating in the vertical orientation is presented. The vertical orientation of the thruster dictates that the thruster must be horizontally offset from the pendulum pivot arm, necessitating the use of a counterweight system to provide a neutrally stable system. Motion of the pendulum arm is transferred through a balance mechanism to a secondary arm on which deflection is measured. A noncontact light-based transducer is used to measure displacement of the secondary beam. The members experience very little friction, rotating on twisting torsional pivots with oscillatory motion attenuated by a passive, eddy-current damper. Displacement is calibrated using an in situ thrust calibration system. Thermal management and self-leveling systems are incorporated to mitigate thermal and mechanical drifts. Gravitational force and torsional spring constants associated with flexure pivots provide restoring moments. An analysis of the design indicates that the thrust measurement range spans roughly four decades, with the stand capable of measuring thrust up to 12 N for a 200 kg thruster and up to approximately 800 mN for a 10 kg thruster. Data obtained from calibration tests performed using a 26.8 lbm simulated thruster indicated a resolution of 1 mN on 100 mN level thrusts, while those tests conducted on a 200 lbm thruster yielded a resolution of roughly 2.5 mN at thrust levels of 0.5 N and greater.

  8. Thrust stand for vertically oriented electric propulsion performance evaluation

    International Nuclear Information System (INIS)

    Moeller, Trevor; Polzin, Kurt A.

    2010-01-01

    A variation of a hanging pendulum thrust stand capable of measuring the performance of an electric thruster operating in the vertical orientation is presented. The vertical orientation of the thruster dictates that the thruster must be horizontally offset from the pendulum pivot arm, necessitating the use of a counterweight system to provide a neutrally stable system. Motion of the pendulum arm is transferred through a balance mechanism to a secondary arm on which deflection is measured. A noncontact light-based transducer is used to measure displacement of the secondary beam. The members experience very little friction, rotating on twisting torsional pivots with oscillatory motion attenuated by a passive, eddy-current damper. Displacement is calibrated using an in situ thrust calibration system. Thermal management and self-leveling systems are incorporated to mitigate thermal and mechanical drifts. Gravitational force and torsional spring constants associated with flexure pivots provide restoring moments. An analysis of the design indicates that the thrust measurement range spans roughly four decades, with the stand capable of measuring thrust up to 12 N for a 200 kg thruster and up to approximately 800 mN for a 10 kg thruster. Data obtained from calibration tests performed using a 26.8 lbm simulated thruster indicated a resolution of 1 mN on 100 mN level thrusts, while those tests conducted on a 200 lbm thruster yielded a resolution of roughly 2.5 mN at thrust levels of 0.5 N and greater.

  9. Small Low Mass Advanced PBR's for Propulsion

    Science.gov (United States)

    Powell, J. R.; Todosow, M.; Ludewig, H.

    1994-07-01

    The advanced Particle Bed Reactor (PBR) to be described in this paper is characterized by relatively low power, and low cost, while still maintaining competition values for thrust/weight, specific impulse and operating times. The mission parameter which this reactor attempts to satisfy are: Thrust (N) = 6.8 (4); Specific Impulse (S) = 875; Total Full Thrust Time (S) = 1500; Thrust/Weight (unshielded) = 20 These requirements imply the following reactor design goals: Power (MW) = 400; Mixed Mean Outlet Temperature (K) = 3000; Chamber Pressure (Mpa) = 7 The following discussion will cover concept feasibility analyses, mass estimates, and a conclusion.

  10. The paradox of vertical σ2 in foreland fold and thrust belts

    Science.gov (United States)

    Tavani, Stefano

    2014-05-01

    Occurrence of aesthetically appealing thrust systems and associated large scale anticlines, in both active and fossil foreland fold and thrust belts, is commonly interpreted as an evidence for Andersonian compressional framework. Indeed, these structures would testify for a roughly vertical σ3. Such a correlation between thrusts occurrence and stress field orientation, however, frequently fails to explain denser observations at a smaller scale. The syn-orogenic deformation meso-structures hosted in exposed km-scale thrust-related folds, in fact, frequently and paradoxically witness for a syn-thrusting strike-slip stress configuration, with a near-vertical σ2 and a sub-horizontal σ3. This apparent widespread inconsistency between syn-orogenic meso-structures and stress field orientation is here named "the σ2 paradox". A possible explanation for such a paradox is provided by inherited extensional deformation structures commonly developed prior to thrusting, in the flexural foreland basins located ahead of fold and thrust belts. Thrust nucleation and propagation is facilitated and driven by the positive inversion of the extensional inheritances, and their subsequent linkage. This process eventually leads to the development of large reverse fault zones and can occur both in compressive and strike-slip stress configurations.

  11. Electromagnetic calibration system for sub-micronewton torsional thrust stand

    Science.gov (United States)

    Lam, J. K.; Koay, S. C.; Cheah, K. H.

    2017-12-01

    It is critical for a micropropulsion system to be evaluated. Thrust stands are widely recognised as the instrument to complete such tasks. This paper presents the development of an alternative electromagnetic calibration technique for thrust stands. Utilising the commercially made voice coils and permanent magnets, the proposed system is able to generate repeatable and also consistent steady-state calibration forces at over four orders of magnitude (30 - 23000 μN). The system is then used to calibrate a custom-designed torsional thrust stand, where its inherent ability in ease of setup is well demonstrated.

  12. Bulk-Flow Analysis of Hybrid Thrust Bearings for Advanced Cryogenic Turbopumps

    Science.gov (United States)

    SanAndres, Luis

    1998-01-01

    A bulk-flow analysis and computer program for prediction of the static load performance and dynamic force coefficients of angled injection, orifice-compensated hydrostatic/hydrodynamic thrust bearings have been completed. The product of the research is an efficient computational tool for the design of high-speed thrust bearings for cryogenic fluid turbopumps. The study addresses the needs of a growing technology that requires of reliable fluid film bearings to provide the maximum operating life with optimum controllable rotordynamic characteristics at the lowest cost. The motion of a cryogenic fluid on the thin film lands of a thrust bearing is governed by a set of bulk-flow mass and momentum conservation and energy transport equations. Mass flow conservation and a simple model for momentum transport within the hydrostatic bearing recesses are also accounted for. The bulk-flow model includes flow turbulence with fluid inertia advection, Coriolis and centrifugal acceleration effects on the bearing recesses and film lands. The cryogenic fluid properties are obtained from realistic thermophysical equations of state. Turbulent bulk-flow shear parameters are based on Hirs' model with Moody's friction factor equations allowing a simple simulation for machined bearing surface roughness. A perturbation analysis leads to zeroth-order nonlinear equations governing the fluid flow for the thrust bearing operating at a static equilibrium position, and first-order linear equations describing the perturbed fluid flow for small amplitude shaft motions in the axial direction. Numerical solution to the zeroth-order flow field equations renders the bearing flow rate, thrust load, drag torque and power dissipation. Solution to the first-order equations determines the axial stiffness, damping and inertia force coefficients. The computational method uses well established algorithms and generic subprograms available from prior developments. The Fortran9O computer program hydrothrust runs

  13. Experimental Determination of Exhaust Gas Thrust, Special Report

    Science.gov (United States)

    Pinkel, Benjamin; Voss, Fred

    1940-01-01

    This investigation presents the results of tests made on a radial engine to determine the thrust that can be obtained from the exhaust gas when discharged from separate stacks and when discharged from the collector ring with various discharge nozzles. The engine was provided with a propeller to absorb the power and was mounted on a test stand equipped with scales for measuring the thrust and engine torque. The results indicate that at full open throttle at sea level, for the engine tested, a gain in thrust horsepower of 18 percent using separate stacks, and 9.5 percent using a collector ring and discharge nozzle, can be expected at an air speed of 550 miles per hour.

  14. Guidance and Control Architecture Design and Demonstration for Low Ballistic Coefficient Atmospheric Entry

    Science.gov (United States)

    Swei, Sean

    2014-01-01

    We propose to develop a robust guidance and control system for the ADEPT (Adaptable Deployable Entry and Placement Technology) entry vehicle. A control-centric model of ADEPT will be developed to quantify the performance of candidate guidance and control architectures for both aerocapture and precision landing missions. The evaluation will be based on recent breakthroughs in constrained controllability/reachability analysis of control systems and constrained-based energy-minimum trajectory optimization for guidance development operating in complex environments.

  15. Electronics Engineering Department Thrust Area report FY'84

    International Nuclear Information System (INIS)

    Minichino, C.; Phelps, P.L.

    1984-01-01

    This report describes the work of the Electronics Engineering Department Thrust Areas for FY'84: diagnostics and microelectronic engineering; signal and control engineering; microwave and pulsed power engineering; computer-aided engineering; engineering modeling and simulation; and systems engineering. For each Thrust Area, an overview and a description of the goals and achievements of each project is provided

  16. Study on a high thrust force bi-double-sided permanent magnet linear synchronous motor

    Directory of Open Access Journals (Sweden)

    Liang Tong

    2016-03-01

    Full Text Available A high thrust force bi-double-sided permanent magnet linear synchronous motor used in gantry-type five-axis machining center is designed and its performance was tested in this article. This motor is the subproject of Chinese National Science and Technology Major Project named as “development of domestic large thrust linear motor used in high-speed gantry-type five-axis machining center project” jointly participated by enterprises and universities. According to the requirement of the application environment and motor performance parameters, the linear motor’s basic dimensions, form of windings, and magnet arrangement are preliminarily specified through theoretical analysis and calculation. To verify the correctness of the result of the calculation, the finite element model of the motor is established. The static and dynamic characteristics of the motor are studied and analyzed through the finite element method, and the initial scheme is revised. The prototype of the motor is manufactured based on the final revised structure parameters, and the performance of the motor is fully tested using the evaluation platform for direct-drive motor component. Experimental test results meet the design requirements and show the effectiveness of design method and process.

  17. Cenozoic structural evolution, thermal history, and erosion of the Ukrainian Carpathians fold-thrust belt

    Science.gov (United States)

    Nakapelyukh, Mykhaylo; Bubniak, Ihor; Bubniak, Andriy; Jonckheere, Raymond; Ratschbacher, Lothar

    2018-01-01

    The Carpathians are part of the Alpine-Carpathian-Dinaridic orogen surrounding the Pannonian basin. Their Ukrainian part constitutes an ancient subduction-accretion complex that evolved into a foreland fold-thrust belt with a shortening history that was perpendicular to the orogenic strike. Herein, we constrain the evolution of the Ukrainian part of the Carpathian fold-thrust belt by apatite fission-track dating of sedimentary and volcanic samples and cross-section balancing and restoration. The apatite fission-track ages are uniform in the inner―southwestern part of the fold-thrust belt, implying post-shortening erosion since 12-10 Ma. The ages in the leading and trailing edges record provenance, i.e., sources in the Trans-European suture zone and the Inner Carpathians, respectively, and show that these parts of the fold-thrust were not heated to more than 100 °C. Syn-orogenic strata show sediment recycling: in the interior of the fold-thrust belt―the most thickened and most deeply eroded nappes―the apatite ages were reset, eroded, and redeposited in the syn-orogenic strata closer to the fore- and hinterland; the lag times are only a few million years. Two balanced cross sections, one constructed for this study and based on field and subsurface data, reveal an architecture characterized by nappe stacks separated by high-displacement thrusts; they record 340-390 km shortening. A kinematic forward model highlights the fold-thrust belt evolution from the pre-contractional configuration over the intermediate geometries during folding and thrusting and the post-shortening, erosional-unloading configuration at 12-10 Ma to the present-day geometry. Average shortening rates between 32-20 Ma and 20-12 Ma amounted to 13 and 21 km/Ma, respectively, implying a two-phased deformation of the Ukrainian fold-thrust belt.

  18. Lateral Vibration of Hydroelectric Generating Set with Different Supporting Condition of Thrust Pad

    OpenAIRE

    Si, Xiaohui; Lu, Wenxiu; Chu, Fulei

    2011-01-01

    The variations of the supporting condition, which change the stiffness of tilting pad thrust bearing, may alter the dynamic behavior of the rotor system. The effects of supporting condition of thrust pad on the lateral vibration of a hydroelectric generating set are investigated in this paper. The action of a thrust bearing is described as moments acting on the thrust collar, and the tilting stiffness coefficients of thrust bearing are calculated. A model based on typical beam finite element ...

  19. Pole-shape optimization of permanent-magnet linear synchronous motor for reduction of thrust ripple

    Energy Technology Data Exchange (ETDEWEB)

    Tavana, Nariman Roshandel, E-mail: nroshandel@ee.iust.ac.i [Department of Electrical Engineering, Iran University of Science and Technology, Narmak, Tehran 16846-13114 (Iran, Islamic Republic of); Shoulaie, Abbas, E-mail: shoulaie@iust.ac.i [Department of Electrical Engineering, Iran University of Science and Technology, Narmak, Tehran 16846-13114 (Iran, Islamic Republic of)

    2011-01-15

    In this paper, we have used magnet arc shaping technique in order to improve the performance of permanent-magnet linear synchronous motor (PMLSM). At first, a detailed analytical modeling based on Maxwell equations is presented for the analysis and design of PMLSM with the arc-shaped magnetic poles (ASMPs). Then the accuracy of presented method is verified by finite-element method. Very close agreement between the analytical and finite-element results shows the effectiveness of the proposed method. Finally, a magnet shape design is carried out based on the analytical method to enhance the motor developed thrust. Pertinent evaluations on the optimal design performance demonstrate that shape optimization leads to a design with extra low thrust ripple.

  20. Pole-shape optimization of permanent-magnet linear synchronous motor for reduction of thrust ripple

    International Nuclear Information System (INIS)

    Tavana, Nariman Roshandel; Shoulaie, Abbas

    2011-01-01

    In this paper, we have used magnet arc shaping technique in order to improve the performance of permanent-magnet linear synchronous motor (PMLSM). At first, a detailed analytical modeling based on Maxwell equations is presented for the analysis and design of PMLSM with the arc-shaped magnetic poles (ASMPs). Then the accuracy of presented method is verified by finite-element method. Very close agreement between the analytical and finite-element results shows the effectiveness of the proposed method. Finally, a magnet shape design is carried out based on the analytical method to enhance the motor developed thrust. Pertinent evaluations on the optimal design performance demonstrate that shape optimization leads to a design with extra low thrust ripple.

  1. Postseismic afterslip 30 years after the 1978 Tabas-e-Golshan (Iran) earthquake: observations and implications for the geological evolution of thrust belts

    Science.gov (United States)

    Copley, Alex

    2014-05-01

    This paper presents InSAR observations of postseismic afterslip occurring up to 30 yr after the Mw7.3 1978 Tabas-e-Golshan thrust-faulting earthquake in eastern Iran. Comparison of the surface motion from 1996 to 1999 with that from 2003 to 2010, along with information provided by the Quaternary-averaged slip rates of faults in the region, suggests that the imaged slip is transient and decaying through time. Models of the surface deformation field imply slip on faults dipping at 55 ± 10°, reaching from the surface to depths of 4-5 km, and slipping at 5 ± 1 mm yr-1. These faults outcrop on the margins of low anticlinal hills composed of actively uplifting Neogene deposits. When compared with the previously studied main shock focal parameters (slip on a plane dipping at 16 ± 5° with a centroid depth of ˜9 km), and the aftershock distribution (a band at ˜6-14 km), the InSAR results imply postseismic slip on a high-angle thrust ramp connecting the surface anticlines to the coseismic low-angle fault plane at depth. In one location, both a thrust ramp and also a backthrust are postseismically active. The InSAR observations demonstrate the role of postseismic afterslip in the growth of these commonly observed thrust belt geometries, and highlight that deformation throughout the seismic cycle can contribute to the geological evolution of regions of active faulting.

  2. Polyphase tertiary fold-and-thrust tectonics in the Belluno Dolomites: new mapping, kinematic analysis, and 3D modelling

    Science.gov (United States)

    Chistolini, Filippo; Bistacchi, Andrea; Massironi, Matteo; Consonni, Davide; Cortinovis, Silvia

    2014-05-01

    The Belluno Dolomites are comprised in the eastern sector of the Southern Alps, which corresponds to the fold-and-thrust belt at the retro-wedge of the Alpine collisional orogen. They are characterized by a complex and polyphase fold-and-thrust tectonics, highlighted by multiple thrust sheets and thrust-related folding. We have studied this tectonics in the Vajont area where a sequence of Jurassic, Cretaceous and Tertiary units have been involved in multiple deformations. The onset of contractional tectonics in this part of the Alps is constrained to be Tertiary (likely Post-Eocene) by structural relationships with the Erto Flysch, whilst in the Mesozoic tectonics was extensional. We have recognized two contractional deformation phases (D1 and D2 in the following), of which only the second was mentioned in previous studies of the area and attributed to the Miocene Neoalpine event. D1 and D2 are characterized by roughly top-to-WSW (possibly Dinaric) and top-to-S (Alpine) transport directions respectively, implying a 90° rotation of the regional-scale shortening axis, and resulting in complex thrust and fold interference and reactivation patterns. Geological mapping and detailed outcrop-scale kinematic analysis allowed us to characterize the kinematics and chronology of deformations. Particularly, relative chronology was unravelled thanks to (1) diagnostic fold interference patterns and (2) crosscutting relationships between thrust faults and thrust-related folds. A km-scale D1 syncline, filled with the Eocene Erto Flysch and "decapitated" by a D2 thrust fault, provides the best map-scale example of crosscutting relationships allowing to reconstruct the faulting history. Due to the strong competence contrast between Jurassic carbonates and Tertiary flysch, in this syncline spectacular duplexes were also developed during D2. In order to quantitatively characterize the complex interference pattern resulting from two orthogonal thrusting and folding events, we

  3. Amplitude Effects on Thrust Production for Undulatory Swimmers

    Science.gov (United States)

    Gater, Brittany; Bayandor, Javid

    2017-11-01

    Biological systems offer novel and efficient solutions to many engineering applications, including marine propulsion. It is of interest to determine how fish interact with the water around them, and how best to utilize the potential their methods offer. A stingray-like fin was chosen for analysis due to the maneuverability and versatility of stingrays. The stingray fin was modeled in 2D as a sinusoidal wave with an amplitude increasing from zero at the leading edge to a maximum at the trailing edge. Using this model, a parametric study was performed to examine the effects of the fin on surrounding water in CFD simulations. The results were analyzed both qualitatively, in terms of the pressure contours on the fin and vorticity in the trailing wake, and quantitatively, in terms of the resultant forces on the fin. The amplitude was found to have no effect on the average thrust during steady swimming, when the wave speed on the fin was approximately equal to the swimming speed. However, amplitude was shown to have a significant effect on thrust production when the fin was accelerating. This finding suggests that for undulatory swimmers, amplitude is less useful for controlling swimming speed, but can be used to great effect for augmenting thrust during acceleration.

  4. Thrust Area Report, Engineering Research, Development and Technology

    Energy Technology Data Exchange (ETDEWEB)

    Langland, R. T.

    1997-02-01

    The mission of the Engineering Research, Development, and Technology Program at Lawrence Livermore National Laboratory (LLNL) is to develop the knowledge base, process technologies, specialized equipment, tools and facilities to support current and future LLNL programs. Engineering`s efforts are guided by a strategy that results in dual benefit: first, in support of Department of Energy missions, such as national security through nuclear deterrence; and second, in enhancing the nation`s economic competitiveness through our collaboration with U.S. industry in pursuit of the most cost- effective engineering solutions to LLNL programs. To accomplish this mission, the Engineering Research, Development, and Technology Program has two important goals: (1) identify key technologies relevant to LLNL programs where we can establish unique competencies, and (2) conduct high-quality research and development to enhance our capabilities and establish ourselves as the world leaders in these technologies. To focus Engineering`s efforts technology {ital thrust areas} are identified and technical leaders are selected for each area. The thrust areas are comprised of integrated engineering activities, staffed by personnel from the nine electronics and mechanical engineering divisions, and from other LLNL organizations. This annual report, organized by thrust area, describes Engineering`s activities for fiscal year 1996. The report provides timely summaries of objectives, methods, and key results from eight thrust areas: Computational Electronics and Electromagnetics; Computational Mechanics; Microtechnology; Manufacturing Technology; Materials Science and Engineering; Power Conversion Technologies; Nondestructive Evaluation; and Information Engineering. Readers desiring more information are encouraged to contact the individual thrust area leaders or authors. 198 refs., 206 figs., 16 tabs.

  5. Experimental measurement of dolphin thrust generated during a tail stand using DPIV

    Science.gov (United States)

    Wei, Timothy; Fish, Frank; Williams, Terrie; Wu, Vicki; Sherman, Erica; Misfeldt, Mitchel; Ringenberg, Hunter; Rogers, Dylan

    2016-11-01

    The thrust generated by dolphins doing tail stands was measured using DPIV. The technique entailed measuring vortex strength associated with the tail motion and correlating it to above water video sequences showing the amount of the dolphin's body that was being lifted out of the water. The underlying drivers for this research included: i) understanding the physiology, hydrodynamics and efficiency of dolphin locomotion, ii) developing non-invasive measurement techniques for studying marine swimming and iii) quantifying the actual propulsive capabilities of these animals. Two different bottlenose dolphins at the Long Marine Lab at UC-Santa Cruz were used as test subjects. Application of the Kutta-Joukowski Theorem on measured vortex circulations yielded thrust values that were well correlated with estimates of dolphin body weight being supported above water. This demonstrates that the tail motion can be interpreted as a flapping hydrofoil that can generate a sustained thrust roughly equal to the dolphin's weight. Videos of DPIV measurements overlaid with the dolphins will be presented along with thrust/weight data.

  6. Occlusal consequence of using average condylar guidance settings: An in vitro study.

    Science.gov (United States)

    Lee, Wonsup; Lim, Young-Jun; Kim, Myung-Joo; Kwon, Ho-Beom

    2017-04-01

    A simplified mounting technique that adopts an average condylar guidance has been advocated. Despite this, the experimental explanation of how average settings differ from individual condylar guidance remains unclear. The purpose of this in vitro study was to examine potential occlusal error by using average condylar guidance settings during nonworking side movement of the articulator. Three-dimensional positions of the nonworking side maxillary first molar at various condylar and incisal settings were traced using a laser displacement sensor attached to the motorized stages with biaxial freedom of movement. To examine clinically relevant occlusal consequences of condylar guidance setting errors, the vertical occlusal error was defined as the vertical-axis positional difference between the average setting trace and the other condylar guidance setting trace. In addition, the respective contribution of the condylar and incisal guidance to the position of the maxillary first molar area was analyzed by multiple regression analysis using the resultant coordinate data. Alteration from individual to average settings led to a positional difference in the maxillary first molar nonworking side movement. When the individual setting was lower than average, vertical occlusal error occurred, which might cause occlusal interference. The vertical occlusal error ranged from -2964 to 1711 μm. In addition, the occlusal effect of incisal guidance was measured as a partial regression coefficient of 0.882, which exceeded the effect of condylar guidance, 0.431. Potential occlusal error as a result of adopting an average condylar guidance setting was observed. The occlusal effect of incisal guidance doubled the effect of condylar guidance. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  7. Remedial Investigation/Feasibility Study (RI/FS) process, elements and techniques guidance

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-01

    This manual provides detailed guidance on Remedial Investigation/Feasibility Studies (RI/FSs) conducted pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) at Department of Energy (DOE) facilities. The purpose of the RI/FS, to assess the risk posed by a hazardous waste site and to determine the best way to reduce that risk, and its structure (site characterization, risk assessment, screening and detailed analysis of alternatives, etc.) is defined in the National Oil and Hazardous Substances Pollution Contingency Plan (NCP) and further explained in the Environmental Protection Agency`s (EPA`s) Guidance for Conducting Remedial Investigations and Feasibility Studies Under CERCLA (Interim Final) 540/G-89/004, OSWER Directive 9355.3-01, October 1988. Though issued in 1988, the EPA guidance remains an excellent source of information on the conduct and structure of an RI/FS. This document makes use of supplemental RI/FS-related guidance that EPA has developed since its initial document was issued in 1988, incorporates practical lessons learned in more than 12 years of experience in CERCLA hazardous site remediation, and drawing on those lessons, introduces the Streamlined Approach For Environmental Restoration (SAFER), developed by DOE as a way to proceed quickly and efficiently through the RI/FS process at DOE facilities. Thus as its title implies, this guidance is intended to describe in detail the process and component elements of an RI/FS, as well as techniques to manage the RI/FS effectively.

  8. Track 2 sites: Guidance for assessing low probability hazard sites at the INEL. Revision 6

    Energy Technology Data Exchange (ETDEWEB)

    1994-01-01

    This document presents guidance for assessment of Track 2 low probability hazard sites (LPHS) at the Idaho National Engineering Laboratory (INEL). The Track 2 classification was developed specifically for the INEL to streamline the implementation of Comprehensive Environmental Response, Compensation, and Liability Act. Track 2 LPHSs are described as sites where insufficient data are available to make a decision concerning the risk level or to select or design a remedy. As such, these types of sites are not described in the National Contingency Plan or existing regulatory guidance. The goal of the Track 2 process is to evaluate LPHSs using existing qualitative and quantitative data to minimize the collection of new environmental data. To this end, this document presents a structured format consisting of a series of questions and tables. A qualitative risk assessment is used. The process is iterative, and addresses an LPHS from multiple perspectives (i.e., historical, empirical, process) in an effort to generate a reproducible and defensible method. This rigorous approach follows the data quality objective process and establishes a well organized, logical approach to consolidate and assess existing data, and set decision criteria. If necessary, the process allows for the design of a sampling and analysis strategy to obtain new environmental data of appropriate quality to support decisions for each LPHS. Finally, the guidance expedites consensus between regulatory parties by emphasizing a team approach to Track 2 investigations.

  9. Crustal scale geometry of the Zagros fold–thrust belt, Iran

    OpenAIRE

    McQuarrie, Nadine

    2004-01-01

    Balanced cross-sections across the Zagros fold–thrust belt in Iran are used to analyze the geometry of deformation within the sedimentary cover rocks, and to test the hypothesis of basement involved thrusting throughout the fold–thrust belt. Although the Zagros deformation front is a relatively rectilinear feature, the sinuous map-view morphology of the mountain front is a result of a 6 km structural step in the regional elevation of the Asmari Limestone that produces a pronounced step in top...

  10. Pliocene episodic exhumation and the significance of the Munsiari thrust in the northwestern Himalaya

    Science.gov (United States)

    Stübner, Konstanze; Grujic, Djordje; Dunkl, István; Thiede, Rasmus; Eugster, Patricia

    2018-01-01

    The Himalayan thrust belt comprises three in-sequence foreland-propagating orogen-scale faults, the Main Central thrust, the Main Boundary thrust, and the Main Frontal thrust. Recently, the Munsiari-Ramgarh-Shumar thrust system has been recognized as an additional, potentially orogen-scale shear zone in the proximal footwall of the Main Central thrust. The timing of the Munsiari, Ramgarh, and Shumar thrusts and their role in Himalayan tectonics are disputed. We present 31 new zircon (U-Th)/He ages from a profile across the central Himachal Himalaya in the Beas River area. Within a ∼40 km wide belt northeast of the Kullu-Larji-Rampur window, ages ranging from 2.4 ± 0.4 Ma to 5.4 ± 0.9 Ma constrain a distinct episode of rapid Pliocene to Present exhumation; north and south of this belt, zircon (U-Th)/He ages are older (7.0 ± 0.7 Ma to 42.2 ± 2.1 Ma). We attribute the Pliocene rapid exhumation episode to basal accretion to the Himalayan thrust belt and duplex formation in the Lesser Himalayan sequence including initiation of the Munsiari thrust. Pecube thermokinematic modelling suggests exhumation rates of ∼2-3 mm/yr from 4-7 to 0 Ma above the duplex contrasting with lower (middle-late Miocene exhumation rates. The Munsiari thrust terminates laterally in central Himachal Pradesh. In the NW Indian Himalaya, the Main Central thrust zone comprises the sheared basal sections of the Greater Himalayan sequence and the mylonitic 'Bajaura nappe' of Lesser Himalayan affinity. We correlate the Bajaura unit with the Ramgarh thrust sheet in Nepal based on similar lithologies and the middle Miocene age of deformation. The Munsiari thrust in the central Himachal Himalaya is several Myr younger than deformation in the Bajaura and Ramgarh thrust sheets. Our results illustrate the complex and segmented nature of the Munsiari-Ramgarh-Shumar thrust system.

  11. Thermal–Hydrodynamic Behaviour of Coated Pivoted Pad Thrust Bearings: Comparison between Babbitt, PTFE and DLC

    Directory of Open Access Journals (Sweden)

    Konstantinos Katsaros

    2018-05-01

    Full Text Available The hydrodynamic lubrication and thermal analysis of tilting pad thrust bearings has been a major subject for many studies in the field of tribology. There is only a limited number of studies regarding thrust bearings with coated surfaces. The purpose of this study is to build a parametric, iterative algorithm in order to perform a complete thermal and hydrodynamic lubrication analysis for pivoted pad thrust bearings with coatings. The analytical model is mainly based on the energy, continuity and Navier–Stokes equations, which are solved numerically with the Semi-Implicit Method for Pressure Linked Equations Consistent (SIMPLEC method. The analysis focuses on a single pivoted pad of the thrust bearing. The thermal properties of the coating material are taken into account and the resulting thermal and flow fields are solved. The basic hydrodynamic and tribological characteristics are calculated for an uncoated, a Babbitt coated, a PTFE coated and a diamond like carbon (DLC coated pivoted pad thrust bearing. The pressure and the film thickness distribution, as well as the load capacity and the frictional forces, are determined for several pad positions and velocities of the rotor. A mineral oil lubricant is used to estimate the shear thinning or thickening effects on the pad tribological performance. The results indicate that pads coated with PTFE and DLC show lower friction forces compared to the common steel and Babbitt applications. At the same time, the DLC coating seems to affect the bearing’s flow and thermal fields less than the PTFE, making it more suitable for thrust bearings applications.

  12. 76 FR 82306 - Draft Guidance for Industry on Use of Histology in Biomarker Qualification Studies; Availability

    Science.gov (United States)

    2011-12-30

    ...] Draft Guidance for Industry on Use of Histology in Biomarker Qualification Studies; Availability AGENCY... announcing the availability of a draft guidance for industry entitled ``Use of Histology in Biomarker... studies for which histology is a reference standard. This guidance discusses the processes that should be...

  13. 14 CFR 23.934 - Turbojet and turbofan engine thrust reverser systems tests.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Turbojet and turbofan engine thrust... CATEGORY AIRPLANES Powerplant General § 23.934 Turbojet and turbofan engine thrust reverser systems tests. Thrust reverser systems of turbojet or turbofan engines must meet the requirements of § 33.97 of this...

  14. Peak thrust operation of linear induction machines from parameter identification

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Z.; Eastham, T.R.; Dawson, G.E. [Queen`s Univ., Kingston, Ontario (Canada). Dept. of Electrical and Computer Engineering

    1995-12-31

    Various control strategies are being used to achieve high performance operation of linear drives. To maintain minimum volume and weight of the power supply unit on board the transportation vehicle, peak thrust per unit current operation is a desirable objective. True peak thrust per unit current through slip control is difficult to achieve because the parameters of linear induction machines vary during normal operation. This paper first develops a peak thrust per unit current control law based on the per-phase equivalent circuit for linear induction machines. The algorithm for identification of the variable parameters in induction machines is then presented. Application to an operational linear induction machine (LIM) demonstrates the utility of this algorithm. The control strategy is then simulated, based on an operational transit LIM, to show the capability of achieving true peak thrust operation for linear induction machines.

  15. Development of the water-lubricated thrust bearing of the hydraulic turbine generator

    International Nuclear Information System (INIS)

    Inoue, K; Deguchi, K; Okude, K; Fujimoto, R

    2012-01-01

    In hydropower plant, a large quantities of turbine oil is used as machine control pressure oil and lubricating oil. If the oil leak out from hydropower plant, it flows into a river. And such oil spill has an adverse effect on natural environment because the oil does not degrade easily. Therefore the KANSAI and Hitachi Mitsubishi Hydro developed the water-lubricated thrust bearing for vertical type hydraulic turbine generator. The water-lubricated bearing has advantages in risk avoidance of river pollution because it does not need oil. For proceeding the development of the water-lubricated thrust bearing, we studied following items. The first is the examination of the trial products of water lubricating liquid. The second is the study of bearing structure which can satisfy bearing performance such as temperature characteristic and so on. The third is the mock-up testing for actual application in the future. As a result, it was found that the water-lubricated thrust bearing was technically applicable to actual equipments.

  16. A Study on the Influence of Teacher's Verbal Guidance on Pupil's Emotional Functions

    OpenAIRE

    後藤, 靖宏

    2006-01-01

    How do the pupils accept teachers' words of guidance? The purpose of this paper is to study the influence of teachers' verbal guidance on pupil's consciousness ( of emotions and enthusiasm). Although speech (language) is the fastest method of communication between people, it is not the only means of communication. We usually have two means of communication in human interaction, that is verbal communication and nonverbal communication. This is the same with pupil or student guidance. Nonverbal...

  17. State of Data Guidance in Journal Policies: A Case Study in Oncology

    Directory of Open Access Journals (Sweden)

    Deborah H. Charbonneau

    2015-06-01

    Full Text Available This article reports the results of a study examining the state of data guidance provided to authors by 50 oncology journals. The purpose of the study was the identification of data practices addressed in the journals’ policies. While a number of studies have examined data sharing practices among researchers, little is known about how journals address data sharing. Thus, what was discovered through this study has practical implications for journal publishers, editors, and researchers. The findings indicate that journal publishers should provide more meaningful and comprehensive data guidance to prospective authors. More specifically, journal policies requiring data sharing, should direct researchers to relevant data repositories, and offer better metadata consultation to strengthen existing journal policies. By providing adequate guidance for authors, and helping investigators to meet data sharing mandates, scholarly journal publishers can play a vital role in advancing access to research data.

  18. Development of a dilatant damage zone along a thrust relay in a low-porosity quartz arenite

    Science.gov (United States)

    Cook, Jennie E.; Dunne, William M.; Onasch, Charles M.

    2006-05-01

    A damage zone along a backthrust fault system in well-cemented quartz arenite in the Alleghanian foreland thrust system consists of a network of NW-dipping thrusts that are linked by multiple higher-order faults and bound a zone of intense extensional fractures and breccias. The damage zone developed at an extensional step-over between two independent, laterally propagating backthrusts. The zone is unusual because it preserves porous brittle fabrics despite formation at >5 km depth. The presence of pervasive, late-stage fault-normal joints in a fault-bounded horse in the northwestern damage zone indicates formation between two near-frictionless faults. This decrease in frictional resistance was likely a result of increased fluid pressure. In addition to physical effects, chemical effects of fluid also influenced damage zone development. Quartz cements, fluid inclusion data, and Fourier Transform Infrared analysis indicate that both aqueous and methane-rich fluids were present within the damage zone at different times. The backthrust network likely acted as a fluid conduit system, bringing methane-rich fluids up from the underlying unit and displacing resident aqueous fluids. The presence of methane not only enhanced the effects of fluid pressure, which facilitated brittle fracturing, but inhibited formation of later-stage quartz cements, thereby preserving open fractures and porous breccias.

  19. A Study of Interactions Between Thrust and Strike-slip Faults

    Directory of Open Access Journals (Sweden)

    Jeng-Cheng Wang

    2013-01-01

    Full Text Available A 3-D finite difference method is applied in this study to investigate a spontaneous rupture within a fault system which includes a primary thrust fault and two strike-slip sub-faults. With the occurrence of a rupture on a fault, the rupture condition follows Coulomb¡¦s friction law wherein the stress-slip obeys the slip-weakening fracture criteria. To overcome the geometrical complexity of such a system, a finite difference method is encoded in two different coordinate systems; then, the calculated displacements are connected between the two systems using a 2-D interpolation technique. The rupture is initiated at the center of the main fault under the compression of regional tectonic stresses and then propagates to the boundaries whereby the main fault rupture triggers two strike-slip sub-faults. Simulation results suggest that the triggering of two sub-faults is attributed to two primary factors, regional tectonic stresses and the relative distances between the two sub-faults and the main fault.

  20. MHD thrust vectoring of a rocket engine

    Science.gov (United States)

    Labaune, Julien; Packan, Denis; Tholin, Fabien; Chemartin, Laurent; Stillace, Thierry; Masson, Frederic

    2016-09-01

    In this work, the possibility to use MagnetoHydroDynamics (MHD) to vectorize the thrust of a solid propellant rocket engine exhaust is investigated. Using a magnetic field for vectoring offers a mass gain and a reusability advantage compared to standard gimbaled, elastomer-joint systems. Analytical and numerical models were used to evaluate the flow deviation with a 1 Tesla magnetic field inside the nozzle. The fluid flow in the resistive MHD approximation is calculated using the KRONOS code from ONERA, coupling the hypersonic CFD platform CEDRE and the electrical code SATURNE from EDF. A critical parameter of these simulations is the electrical conductivity, which was evaluated using a set of equilibrium calculations with 25 species. Two models were used: local thermodynamic equilibrium and frozen flow. In both cases, chlorine captures a large fraction of free electrons, limiting the electrical conductivity to a value inadequate for thrust vectoring applications. However, when using chlorine-free propergols with 1% in mass of alkali, an MHD thrust vectoring of several degrees was obtained.

  1. Development of GE90 engine with largest thrust. GE90 engine no kaihatsu jokyo

    Energy Technology Data Exchange (ETDEWEB)

    Aono, H [Ishikawajima-Harima Heavy Industries, Co. Ltd., Tokyo (Japan)

    1994-05-01

    The present paper explained the turbofan engine GE90 which is being developed by General Electric Co., USA. That engine is to meet the thrust (takeoff thrust) of 300 to 530kN as required for the new-generation wide-fuselage civil transport plane which is being designed for its planned operation in the 1990's. In April, 1991, the world's strongest thrust of 480kN was achieved with engine elements also confirmed through element test. Thereafter, the engine underwent a flying test on board of Boeing 747 to materialize the planned operation in 1995. Made to be 9 in by-pass ratio and about 40 in overall pressure ratio, the GE90 was given the concept that advantage could be secured in both propulsive efficiency and thermal efficiency. That concept could be materialized by the development of composite fan blade technology and energy-efficient technology which were both demonstrated with an unducted fan. In spite of its pressure ratio of 22, the GE90's high pressure compressor demonstrates its polytropic efficiency which is equal to that of the low pressure ratio compressor. 3 refs., 19 figs., 1 tab.

  2. Varying frontal thrust spacing in mono-vergent wedges: An insight ...

    Indian Academy of Sciences (India)

    Corresponding author. e-mail: bose.santanu@gmail.com. Sandbox experiments are used to study frontal thrust fault spacing, which is a .... characterized by systematically arranged foreland ...... Sengupta S (London: Chapman and Hall), pp.

  3. Guidance document for prepermit bioassay testing of low-level radioactive waste

    International Nuclear Information System (INIS)

    Anderson, S.L.; Harrison, F.L.

    1990-11-01

    In response to the mandate of Public Law 92-532, the Marine Protection, Research, and Sanctuaries Act (MPRSA) of 1972, as amended, the Environmental Protection Agency (EPA) has developed a program to promulgate regulations and criteria to control the ocean disposal of radioactive wastes. The EPA seeks to understand the mechanisms for biological response of marine organisms to the low levels of radioactivity that may arise from the release of these wastes as a result of ocean-disposal practices. Such information will play an important role in determining the adequacy of environmental assessments provided to the EPA in support of any disposal permit application. Although the EPA requires packaging of low-level radioactive waste to prevent release during radiodecay of the materials, some release of radioactive material into the deep-sea environment may occur when a package deteriorates. Therefore, methods for evaluating the impact on biota are being evaluated. Mortality and phenotypic responses are not anticipated at the expected low environmental levels that might occur if radioactive materials were released from the low-level waste packages. Therefore, traditional bioassay systems are unsuitable for assessing sublethal effects on biota in the marine environment. The EPA Office of Radiation Programs (ORP) has had an ongoing program to examine sublethal responses to radiation at the cellular level, using cytogenetic end points. This technical guidance report represents prepermit bioassay procedures that potentially may be applicable to the assessment of effects from a mixture of radionuclides that could be released from a point source at the ocean bottom. Methodologies along with rationale and a discussion of uncertainty are presented for the sediment benthic bioassay protocols identified in this report

  4. Guidance document for prepermit bioassay testing of low-level radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, S.L.; Harrison, F.L.

    1990-11-01

    In response to the mandate of Public Law 92-532, the Marine Protection, Research, and Sanctuaries Act (MPRSA) of 1972, as amended, the Environmental Protection Agency (EPA) has developed a program to promulgate regulations and criteria to control the ocean disposal of radioactive wastes. The EPA seeks to understand the mechanisms for biological response of marine organisms to the low levels of radioactivity that may arise from the release of these wastes as a result of ocean-disposal practices. Such information will play an important role in determining the adequacy of environmental assessments provided to the EPA in support of any disposal permit application. Although the EPA requires packaging of low-level radioactive waste to prevent release during radiodecay of the materials, some release of radioactive material into the deep-sea environment may occur when a package deteriorates. Therefore, methods for evaluating the impact on biota are being evaluated. Mortality and phenotypic responses are not anticipated at the expected low environmental levels that might occur if radioactive materials were released from the low-level waste packages. Therefore, traditional bioassay systems are unsuitable for assessing sublethal effects on biota in the marine environment. The EPA Office of Radiation Programs (ORP) has had an ongoing program to examine sublethal responses to radiation at the cellular level, using cytogenetic end points. This technical guidance report represents prepermit bioassay procedures that potentially may be applicable to the assessment of effects from a mixture of radionuclides that could be released from a point source at the ocean bottom. Methodologies along with rationale and a discussion of uncertainty are presented for the sediment benthic bioassay protocols identified in this report.

  5. Changes in shoulder pain and disability after thrust manipulation in subjects presenting with second and third rib syndrome.

    Science.gov (United States)

    Dunning, James; Mourad, Firas; Giovannico, Giuseppe; Maselli, Filippo; Perreault, Thomas; Fernández-de-Las-Peñas, César

    2015-01-01

    The purpose of this preliminary study was to investigate changes in shoulder pain, disability, and perceived level of recovery after 2 sessions of upper thoracic and upper rib high-velocity low-amplitude (HVLA) thrust manipulation in patients with shoulder pain secondary to second and third rib syndrome. This exploratory study evaluated 10 consecutive individuals with shoulder pain, with or without brachial pain, and a negative Neer impingement test, who completed the Shoulder Pain and Disability Index (SPADI), the numeric pain rating scale (NPRS), and the global rating of change. Patients received 2 sessions of HVLA thrust manipulation targeting the upper thoracic spine bilaterally and the second and third ribs on the symptomatic side. Outcome measures were completed after the first treatment session, at 48 hours, 1 month, and 3 months. Patients showed a significant decrease in SPADI (F = 59.997; P = .001) and significant decrease in resting shoulder NPRS (F = 63.439; P = .001). For both NPRS and SPADI, there were significant differences between the pretreatment scores and each of the postintervention scores through 3-month follow-up (P pain secondary to second and third rib syndrome who received upper thoracic and upper rib HVLA thrust manipulations showed significant reductions in pain and disability and improvement in perceived level of recovery. Copyright © 2015 National University of Health Sciences. Published by Elsevier Inc. All rights reserved.

  6. Guidance for Identifying, Selecting and Evaluating Open Literature Studies

    Science.gov (United States)

    This guidance for Office of Pesticide Program staff will assist in their evaluation of open literature studies of pesticides. It also describes how we identify, select, and ensure that data we use in risk assessments is of sufficient scientific quality.

  7. Computer Tomography Analysis of Fastrac Composite Thrust Chamber Assemblies

    Science.gov (United States)

    Beshears, Ronald D.

    2000-01-01

    Computed tomography (CT) inspection has been integrated into the production process for NASA's Fastrac composite thrust chamber assemblies (TCAs). CT has been proven to be uniquely qualified to detect the known critical flaw for these nozzles, liner cracks that are adjacent to debonds between the liner and overwrap. CT is also being used as a process monitoring tool through analysis of low density indications in the nozzle overwraps. 3d reconstruction of CT images to produce models of flawed areas is being used to give program engineers better insight into the location and nature of nozzle flaws.

  8. Complex thrusting at the toe of the Nankai accretionary prism, NanTroSEIZE Kumano transect

    Science.gov (United States)

    Moore, G. F.; Park, J.; Kodaira, S.; Kaneda, Y.

    2009-12-01

    Seismic reflection data collected over the past 10 years by the Institute for Research on Earth Evolution (IFREE) of Japan Agency for Marine Earth Science and Technology (JAMSTEC) image a zone of complex thrusting at the toe of the Nankai accretionary prism south of Kii Peninsula, Honshu, Japan. The frontal part of the Nankai prism west of Shionomisaki Canyon (SC) at ~136° E, including the Muroto and Ashizuri Transects off Shikoku, is generally formed of imbricate thrusts with spacing of ~ 1-3 km that dip ~25-35° landward and sole into a prominent décollement. Out-of-sequence thrusts (OOSTs) are usually restricted to the landward margin of this imbricate thrust zone. East of SC, in the Kumano Transect area, the imbricate thrust zone is bounded on its seaward edge by a frontal thrust block that is ~5-6 km wide and consists of several OOSTs. The frontal thrust dips ~5-10° under this ~2-4 km thick block, emplacing this thrust sheet over the trench floor. The number and character of thrusts within the frontal thrust block vary laterally along strike. The 2006 Kumano 3D seismic data set images details of one segment of this complex frontal thrust block. Out-of-sequence faulting has led to underplating of several smaller thrust slices and movement along oblique ramps has led to a complex pattern of faulting that cannot be recognized in even closely-spaced 2D seismic lines. The frontal thrust block is further modified by subduction of seamounts and ridges that have caused large slumps of material from the block.

  9. Upper cervical and upper thoracic thrust manipulation versus nonthrust mobilization in patients with mechanical neck pain: a multicenter randomized clinical trial.

    Science.gov (United States)

    Dunning, James R; Cleland, Joshua A; Waldrop, Mark A; Arnot, Cathy F; Young, Ian A; Turner, Michael; Sigurdsson, Gisli

    2012-01-01

    Randomized clinical trial. To compare the short-term effects of upper cervical and upper thoracic high-velocity low-amplitude (HVLA) thrust manipulation to nonthrust mobilization in patients with neck pain. Although upper cervical and upper thoracic HVLA thrust manipulation and nonthrust mobilization are common interventions for the management of neck pain, no studies have directly compared the effects of both upper cervical and upper thoracic HVLA thrust manipulation to nonthrust mobilization in patients with neck pain. Patients completed the Neck Disability Index, the numeric pain rating scale, the flexion-rotation test for measurement of C1-2 passive rotation range of motion, and the craniocervical flexion test for measurement of deep cervical flexor motor performance. Following the baseline evaluation, patients were randomized to receive either HVLA thrust manipulation or nonthrust mobilization to the upper cervical (C1-2) and upper thoracic (T1-2) spines. Patients were reexamined 48-hours after the initial examination and again completed the outcome measures. The effects of treatment on disability, pain, C1-2 passive rotation range of motion, and motor performance of the deep cervical flexors were examined with a 2-by-2 mixed-model analysis of variance (ANOVA). One hundred seven patients satisfied the eligibility criteria, agreed to participate, and were randomized into the HVLA thrust manipulation (n = 56) and nonthrust mobilization (n = 51) groups. The 2-by-2 ANOVA demonstrated that patients with mechanical neck pain who received the combination of upper cervical and upper thoracic HVLA thrust manipulation experienced significantly (Ppain (58.5%) than those of the nonthrust mobilization group (12.8% and 12.6%, respectively) following treatment. In addition, the HVLA thrust manipulation group had significantly (Pcervical flexor muscles as compared to the group that received nonthrust mobilization. The number needed to treat to avoid an unsuccessful outcome

  10. Developing stochastic model of thrust and flight dynamics for small UAVs

    Science.gov (United States)

    Tjhai, Chandra

    This thesis presents a stochastic thrust model and aerodynamic model for small propeller driven UAVs whose power plant is a small electric motor. First a model which relates thrust generated by a small propeller driven electric motor as a function of throttle setting and commanded engine RPM is developed. A perturbation of this model is then used to relate the uncertainty in throttle and engine RPM commanded to the error in the predicted thrust. Such a stochastic model is indispensable in the design of state estimation and control systems for UAVs where the performance requirements of the systems are specied in stochastic terms. It is shown that thrust prediction models for small UAVs are not a simple, explicit functions relating throttle input and RPM command to thrust generated. Rather they are non-linear, iterative procedures which depend on a geometric description of the propeller and mathematical model of the motor. A detailed derivation of the iterative procedure is presented and the impact of errors which arise from inaccurate propeller and motor descriptions are discussed. Validation results from a series of wind tunnel tests are presented. The results show a favorable statistical agreement between the thrust uncertainty predicted by the model and the errors measured in the wind tunnel. The uncertainty model of aircraft aerodynamic coefficients developed based on wind tunnel experiment will be discussed at the end of this thesis.

  11. Control on frontal thrust progression by the mechanically weak Gondwana horizon in the Darjeeling-Sikkim Himalaya

    Science.gov (United States)

    Ghosh, Subhajit; Bose, Santanu; Mandal, Nibir; Das, Animesh

    2018-03-01

    This study integrates field evidence with laboratory experiments to show the mechanical effects of a lithologically contrasting stratigraphic sequence on the development of frontal thrusts: Main Boundary Thrust (MBT) and Daling Thrust (DT) in the Darjeeling-Sikkim Himalaya (DSH). We carried out field investigations mainly along two river sections in the DSH: Tista-Kalijhora and Mahanadi, covering an orogen-parallel stretch of 20 km. Our field observations suggest that the coal-shale dominated Gondwana sequence (sandwiched between the Daling Group in the north and Siwaliks in the south) has acted as a mechanically weak horizon to localize the MBT and DT. We simulated a similar mechanical setting in scaled model experiments to validate our field interpretation. In experiments, such a weak horizon at a shallow depth perturbs the sequential thrust progression, and causes a thrust to localize in the vicinity of the weak zone, splaying from the basal detachment. We correlate this weak-zone-controlled thrust with the DT, which accommodates a large shortening prior to activation of the weak zone as a new detachment with ongoing horizontal shortening. The entire shortening in the model is then transferred to this shallow detachment to produce a new sequence of thrust splays. Extrapolating this model result to the natural prototype, we show that the mechanically weak Gondwana Sequence has caused localization of the DT and MBT in the mountain front of DSH.

  12. Paleozoic-involving thrust array in the central Sierras Interiores (South Pyrenean Zone, Central Pyrenees): regional implications

    Science.gov (United States)

    Rodriguez, L.; Cuevas, J.; Tubía, J. M.

    2012-04-01

    This work deals with the structural evolution of the Sierras Interiores between the Tena and Aragon valleys. The Sierras Interiores is a WNW-trending mountain range that bounds the South Pyrenean Zone to the north and that is characterized by a thrust-fold system with a strong lithological control that places preferably decollements in Triassic evaporites. In the studied area of the Sierras Interiores Cenomanian limestones cover discordantly the Paleozoic rocks of the Axial Zone because there is a stratigraphic lacuna developed from Triassic to Late Cretaceous times. A simple lithostratigraphy of the study area is made up of Late Cenomanian to Early Campanian limestones with grey colour and massive aspect in landscape (170 m, Lower calcareous section), Campanian to Maastrichtian brown coloured sandstones (400-600 m, Marboré sandstones) and, finally, Paleocene light-coloured massive limestones (130-230 m), that often generate the higher topographic levels of the Sierras Interiores due to their greater resistance to erosion. Above the sedimentary sequence of the Sierras Interiores, the Jaca Basin flysch succession crops out discordantly. Based on a detailed mapping of the studied area of the Sierras Interiores, together with well and structural data of the Jaca Basin (Lanaja, 1987; Rodríguez and Cuevas, 2008) we have constructed a 12 km long NS cross section, approximately parallel to the movement direction deduced for this region (Rodríguez et al., 2011). The main structure is a thrust array made up of at least four Paleozoic-involving thrusts (the deeper thrust system) of similar thickness in a probably piggyback sequence, some of which are blind thrusts that generate fold-propagation-folds in upper levels. The higher thrust of the thrust array crops out duplicating the lower calcareous section all over the Sierras Interiores. The emplacement of the deeper thrust system generated the tightness of previous structures: south directed piggyback duplexes (the upper

  13. Measuring Integrated Socioemotional Guidance at School: Factor Structure and Reliability of the Socioemotional Guidance Questionnaire (SEG-Q)

    Science.gov (United States)

    Jacobs, Karen; Struyf, Elke

    2013-01-01

    Socioemotional guidance of students has recently become an integral part of education, however no instrument exists to measure integrated socioemotional guidance. This study therefore examines the factor structure and reliability of the Socioemotional Guidance Questionnaire. Psychometric properties of the Socioemotional Guidance Questionnaire and…

  14. Significant strain accumulation between the deformation front and landward out-of-sequence thrusts in accretionary wedge of SW Taiwan revealed by cGPS and SAR interferometry

    Science.gov (United States)

    Tsai, M. C.

    2017-12-01

    High strain accumulation across the fold-and-thrust belt in Southwestern Taiwan are revealed by the Continuous GPS (cGPS) and SAR interferometry. This high strain is generally accommodated by the major active structures in fold-and-thrust belt of western Foothills in SW Taiwan connected to the accretionary wedge in the incipient are-continent collision zone. The active structures across the high strain accumulation include the deformation front around the Tainan Tableland, the Hochiali, Hsiaokangshan, Fangshan and Chishan faults. Among these active structures, the deformation pattern revealed from cGPS and SAR interferometry suggest that the Fangshan transfer fault may be a left-lateral fault zone with thrust component accommodating the westward differential motion of thrust sheets on both side of the fault. In addition, the Chishan fault connected to the splay fault bordering the lower-slope and upper-slope of the accretionary wedge which could be the major seismogenic fault and an out-of-sequence thrust fault in SW Taiwan. The big earthquakes resulted from the reactivation of out-of-sequence thrusts have been observed along the Nankai accretionary wedge, thus the assessment of the major seismogenic structures by strain accumulation between the frontal décollement and out-of-sequence thrusts is a crucial topic. According to the background seismicity, the low seismicity and mid-crust to mantle events are observed inland and the lower- and upper- slope domain offshore SW Taiwan, which rheologically implies the upper crust of the accretionary wedge is more or less aseimic. This result may suggest that the excess fluid pressure from the accretionary wedge not only has significantly weakened the prism materials as well as major fault zone, but also makes the accretionary wedge landward extension, which is why the low seismicity is observed in SW Taiwan area. Key words: Continuous GPS, SAR interferometry, strain rate, out-of-sequence thrust.

  15. Study on the Reduced Traffic Congestion Method Based on Dynamic Guidance Information

    Science.gov (United States)

    Li, Shu-Bin; Wang, Guang-Min; Wang, Tao; Ren, Hua-Ling; Zhang, Lin

    2018-05-01

    This paper studies how to generate the reasonable information of travelers’ decision in real network. This problem is very complex because the travelers’ decision is constrained by different human behavior. The network conditions can be predicted by using the advanced dynamic OD (Origin-Destination, OD) estimation techniques. Based on the improved mesoscopic traffic model, the predictable dynamic traffic guidance information can be obtained accurately. A consistency algorithm is designed to investigate the travelers’ decision by simulating the dynamic response to guidance information. The simulation results show that the proposed method can provide the best guidance information. Further, a case study is conducted to verify the theoretical results and to draw managerial insights into the potential of dynamic guidance strategy in improving traffic performance. Supported by National Natural Science Foundation of China under Grant Nos. 71471104, 71771019, 71571109, and 71471167; The University Science and Technology Program Funding Projects of Shandong Province under Grant No. J17KA211; The Project of Public Security Department of Shandong Province under Grant No. GATHT2015-236; The Major Social and Livelihood Special Project of Jinan under Grant No. 20150905

  16. Width of surface rupture zone for thrust earthquakes: implications for earthquake fault zoning

    Science.gov (United States)

    Boncio, Paolo; Liberi, Francesca; Caldarella, Martina; Nurminen, Fiia-Charlotta

    2018-01-01

    The criteria for zoning the surface fault rupture hazard (SFRH) along thrust faults are defined by analysing the characteristics of the areas of coseismic surface faulting in thrust earthquakes. Normal and strike-slip faults have been deeply studied by other authors concerning the SFRH, while thrust faults have not been studied with comparable attention. Surface faulting data were compiled for 11 well-studied historic thrust earthquakes occurred globally (5.4 ≤ M ≤ 7.9). Several different types of coseismic fault scarps characterize the analysed earthquakes, depending on the topography, fault geometry and near-surface materials (simple and hanging wall collapse scarps, pressure ridges, fold scarps and thrust or pressure ridges with bending-moment or flexural-slip fault ruptures due to large-scale folding). For all the earthquakes, the distance of distributed ruptures from the principal fault rupture (r) and the width of the rupture zone (WRZ) were compiled directly from the literature or measured systematically in GIS-georeferenced published maps. Overall, surface ruptures can occur up to large distances from the main fault ( ˜ 2150 m on the footwall and ˜ 3100 m on the hanging wall). Most of the ruptures occur on the hanging wall, preferentially in the vicinity of the principal fault trace ( > ˜ 50 % at distances guidelines). In the absence of such a very detailed study (basic SM, i.e. Level 1 SM of Italian guidelines) a width of ˜ 840 m (90 % probability from "simple thrust" database of distributed ruptures, excluding B-M, F-S and Sy fault ruptures) is suggested to be sufficiently precautionary. For more detailed SM, where the fault is carefully mapped, one must consider that the highest SFRH is concentrated in a narrow zone, ˜ 60 m in width, that should be considered as a fault avoidance zone (more than one-third of the distributed ruptures are expected to occur within this zone). The fault rupture hazard zones should be asymmetric compared to the trace

  17. Quadcopter Attitude and Thrust Simulation Based on Simulink Platform

    Directory of Open Access Journals (Sweden)

    Endrowednes Kuantama

    2015-12-01

    Full Text Available Orientation of quadcopter axes relative to reference line direction of motion will result in attitude and every movement is controlled regulated by each rotor’s thrust. Mathematical equation based on Euler formula and 3D simulation using Matlab/Simulink software platform are used to model quadcopter movement. Change of attitude, position and thrust of each rotor can be seen through this simulation movement.

  18. Non-cable vehicle guidance

    Energy Technology Data Exchange (ETDEWEB)

    Daugela, G.C.; Willott, A.M.; Chopiuk, R.G.; Thornton, S.E.

    1988-06-01

    The purpose is to determine the most promising driverless mine vehicle guidance systems that are not dependent on buried cables, and to plan their development. The project is presented in two phases: a preliminary study and literature review to determine whether suitable technologies exist to justify further work; and an in-depth assessment and selection of technologies for vehicle guidance. A large number of guidance elements are involved in a completely automated vehicle. The technologies that hold the best potential for development of guidance systems for mine vehicles are ultrasonics, radar, lasers, dead reckoning, and guidance algorithms. The best approach to adaptation of these technologies is on a step by step basis. Guidance modules that are complete in themselves and are designed to be integrated with other modules can provide short term benefits. Two modules are selected for development: the dragline operations monitor and automated machine control for optimized mining (AMCOM). 99 refs., 20 figs., 40 tabs.

  19. Single-stage-to-orbit performance enhancement from take-off thrust augmentation

    Science.gov (United States)

    Galati, Terence; Elkins, Travis

    1997-01-01

    Thrust augmentation offers the Single Stage to Orbit (SSTO) space launch vehicle improved payload capability while reducing vehicle weight and cost. Optimization of vehicle configuration and flight profile are studied. Using a 612,000 kg Gross Lift Off Weight (GLOW) SSTO with three Castor® strap-on motors, payloads in excess of 18,000 kg to Low Earth Orbit (LEO) are achievable. Emphasis is placed on finding vehicle optimums in the 9,000 kg payload range to capture over 80% of commercial payloads. Strap-on boosters allow a small SSTO vehicle to fly with a mass fraction of only 0.88 and LOX/H2 engines operating at 445 sec vacuum specific impulse. Payload sensitivity due to variations of mass fraction, Isp and pitch rate are quantified.

  20. Orogenic plateau growth: Expansion of the Turkish-Iranian Plateau across the Zagros fold-and-thrust belt

    Science.gov (United States)

    Allen, M. B.; Saville, C.; Blanc, E. J.-P.; Talebian, M.; Nissen, E.

    2013-03-01

    This paper shows how the Turkish-Iranian Plateau grows laterally by incrementally incorporating adjacent parts of the Zagros fold-and-thrust belt. The limit of significant, seismogenic, thrusting in the Zagros (Mw > 5) occurs close to the regional 1250 m elevation contour. The seismicity cutoff is not a significant bedrock geology boundary. Elevations increase northward, toward regional plateau elevations of 2 km, implying that another process produced the extra elevation. Between the seismogenic limit of thrusting and the suture, this process is a plausibly ductile thickening of the basement, suggesting depth-dependent strain during compression. Similar depth-dependant crustal strain may explain why the Tibetan plateau has regional elevations 1500 m greater than the elevation limit of seismogenic thrusting at its margins. We estimate 68 km shortening across the Zagros Simply Folded Belt in the Fars region, and 120 km total shortening of the Arabian plate. The Dezful Embayment is a low strain zone in the western Zagros. Deformation is more intense to its northeast, in the Bakhtyari Culmination. The orogenic taper (across strike topographic gradient) across the Dezful Embayment is 0.0004, and across the Bakhtyari Culmination, 0.022. Lateral plateau growth is more pronounced farther east (Fars), where a more uniform structure has a taper of 0.010 up to elevations of 1750 m. A >100 km wide region of the Zagros further northeast has a taper of 0.002 and is effectively part of the Turkish-Iranian Plateau. Internal drainage enhances plateau development but is not a pre-requisite. Aspects of the seismicity, structure, and geomorphology of the Zagros do not support critical taper models for fold-and-thrust belts.

  1. Thermal barrier coatings (TBC's) for high heat flux thrust chambers

    Science.gov (United States)

    Bradley, Christopher M.

    -section components has become critical, but at the same time the service conditions have put our best alloy systems to their limits. As a result, implementation of cooling holes and thermal barrier coatings are new advances in hot-section technologies now looked at for modifications to reach higher temperature applications. Current thermal barrier coatings used in today's turbine applications is known as 8%yttria-stabilized zirconia (YSZ) and there are no coatings for current thrust chambers. Current research is looking at the applicability of 8%yttria-stabilized hafnia (YSH) for turbine applications and the implementation of 8%YSZ onto thrust chambers. This study intends to determine if the use of thermal barrier coatings are applicable for high heat flux thrust chambers using industrial YSZ will be advantageous for improvements in efficiency, thrust and longer service life by allowing the thrust chambers to be used more than once.

  2. Comparison of Thrust Characteristics in Pencil Sized Cylinder-type Linear Motors with Different Magnet Arrays

    OpenAIRE

    Nakaiwa, K; Yamada, A; Tashiro, K; Wakiwaka, H

    2009-01-01

    From a strong demand on the miniaturization of a chip mounter or a semiconductor device, the thrust improvement considering the magnets arrangement is studied. We accept a core stator with a Halbach type magnet array for a current linear motor. The thrust characteristics are compared with two kinds of mover, a NS magnet array and a Halbach magnet array.

  3. Space shuttle maneuvering engine reusable thrust chamber program. Task 11: Low epsilon stability test report data dump

    Science.gov (United States)

    Pauckert, R. P.

    1974-01-01

    The stability characteristics of the like-doublet injector were defined over the range of OME chamber pressures and mixture ratios. This was accomplished by bomb testing the injector and cavity configurations in solid wall thrust chamber hardware typical of a flight contour with fuel heated to regenerative chamber outlet temperatures. It was found that stability in the 2600-2800 Hz region depends upon injector hydraulics and on chamber acoustics.

  4. Seafloor expression and shallow structure of a fold-and-thrust system, Isfjorden, west Spitsbergen

    Directory of Open Access Journals (Sweden)

    Maria Blinova

    2012-09-01

    Full Text Available A detailed map of the structure of the west Spitsbergen fold-and-thrust belt in the Isfjorden area, Spitsbergen, is presented. The map was constructed from a dense grid of two-dimensional multichannel reflection seismic and bathymetric data. Joint interpretation of two data sets allowed a comparison of tectonic structures detected along the uppermost parts of the seismic sections and those reflected in the morphology of the seafloor. Three major, predominantly north-west–south-east striking faults were identified. The westernmost fault (T1 is a hinterland-directed (most likely out of sequence thrust, while the central and easternmost faults (T2 and T3 are foreland-directed (in-sequence thrusts. The thrusts divide Isfjorden into three subareas. Subarea 1 is bounded by thrust faults T1 and T2 and comprises Tertiary rocks surrounded by Jurassic–Cretaceous strata. The structural signature of Subarea 1 is that of a system of hinterland- and foreland-directed thrust faults, resulting in a seafloor relief characterized by parallel ridges and troughs. Subarea 2 is limited by thrust faults T2 and T3 and shows Jurassic–Cretaceous outcrops on the seafloor. Subarea 3 is situated east of the main thrust fault T3 and mainly involves outcrops of Triassic–Jurassic rocks. Together, Subareas 2 and 3 are dominated by foreland-directed, north-west–south-east and NNW–SSE-striking thrusts that are hardly detectable in bathymetric data.

  5. Resistive thrust production can be as crucial as added mass mechanisms for inertial undulatory swimmers

    Science.gov (United States)

    Piñeirua, M.; Godoy-Diana, R.; Thiria, B.

    2015-08-01

    In this Rapid Communication, we address a crucial point regarding the description of moderate to high Reynolds numbers aquatic swimmers. For decades, swimming animals have been classified in two different families of propulsive mechanisms based on the Reynolds number: the resistive swimmers, using local friction to produce the necessary thrust force for locomotion at low Reynolds number, and the reactive swimmers, lying in the high Reynolds range, and using added mass acceleration (described by perfect fluid theory). However, inertial swimmers are also systems that dissipate energy, due to their finite size, therefore involving strong resistive contributions, even for high Reynolds numbers. Using a complete model for the hydrodynamic forces, involving both reactive and resistive contributions, we revisit here the physical mechanisms responsible for the thrust production of such swimmers. We show, for instance, that the resistive part of the force balance is as crucial as added mass effects in the modeling of the thrust force, especially for elongated species. The conclusions brought by this work may have significant contributions to the understanding of complex swimming mechanisms, especially for the future design of artificial swimmers.

  6. Analysis of oil lubricated, fluid film, thrust bearings with allowance for temperature dependent viscosity

    Science.gov (United States)

    Pan, C. H. T.; Malanoski, S. B.

    1972-01-01

    A preliminary design study was performed to seek a fluid-film thrust bearing design intended to be part of a high-speed, hybrid (rolling element/fluid film) bearing configuration. The base line used is a design previously tested. To improve the accuracy of theoretical predictions of load capacity, flow rate, and friction power loss, an analytical procedure was developed to include curvature effects inherent in thrust bearings and to allow for the temperature rise in the fluid due to viscous heating. Also, a narrow-groove approximation in the treatment of the temperature field was formulated to apply the procedure to the Whipple thrust bearing. A comparative trade-off study was carried out assuming isothermal films; its results showed the shrouded-step design to be superior to the Whipple design for the intended application. An extensive parametric study was performed, employing isoviscous calculations, to determine the optimized design, which was subsequently recalculated allowing for temperature effects.

  7. Guidance on assessing the methodological and reporting quality of toxicologically relevant studies: A scoping review.

    Science.gov (United States)

    Samuel, Gbeminiyi O; Hoffmann, Sebastian; Wright, Robert A; Lalu, Manoj Mathew; Patlewicz, Grace; Becker, Richard A; DeGeorge, George L; Fergusson, Dean; Hartung, Thomas; Lewis, R Jeffrey; Stephens, Martin L

    2016-01-01

    Assessments of methodological and reporting quality are critical to adequately judging the credibility of a study's conclusions and to gauging its potential reproducibility. To aid those seeking to assess the methodological or reporting quality of studies relevant to toxicology, we conducted a scoping review of the available guidance with respect to four types of studies: in vivo and in vitro, (quantitative) structure-activity relationships ([Q]SARs), physico-chemical, and human observational studies. Our aims were to identify the available guidance in this diverse literature, briefly summarize each document, and distill the common elements of these documents for each study type. In general, we found considerable guidance for in vivo and human studies, but only one paper addressed in vitro studies exclusively. The guidance for (Q)SAR studies and physico-chemical studies was scant but authoritative. There was substantial overlap across guidance documents in the proposed criteria for both methodological and reporting quality. Some guidance documents address toxicology research directly, whereas others address preclinical research generally or clinical research and therefore may not be fully applicable to the toxicology context without some translation. Another challenge is the degree to which assessments of methodological quality in toxicology should focus on risk of bias - as in clinical medicine and healthcare - or be broadened to include other quality measures, such as confirming the identity of test substances prior to exposure. Our review is intended primarily for those in toxicology and risk assessment seeking an entry point into the extensive and diverse literature on methodological and reporting quality applicable to their work. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  8. Multi-step optimization strategy for fuel-optimal orbital transfer of low-thrust spacecraft

    Science.gov (United States)

    Rasotto, M.; Armellin, R.; Di Lizia, P.

    2016-03-01

    An effective method for the design of fuel-optimal transfers in two- and three-body dynamics is presented. The optimal control problem is formulated using calculus of variation and primer vector theory. This leads to a multi-point boundary value problem (MPBVP), characterized by complex inner constraints and a discontinuous thrust profile. The first issue is addressed by embedding the MPBVP in a parametric optimization problem, thus allowing a simplification of the set of transversality constraints. The second problem is solved by representing the discontinuous control function by a smooth function depending on a continuation parameter. The resulting trajectory optimization method can deal with different intermediate conditions, and no a priori knowledge of the control structure is required. Test cases in both the two- and three-body dynamics show the capability of the method in solving complex trajectory design problems.

  9. Seamless Guidance System Combining GPS, BLE Beacon, and NFC Technologies

    Directory of Open Access Journals (Sweden)

    Rung-Shiang Cheng

    2016-01-01

    Full Text Available Users rely increasingly on Location-Based Services (LBS and automated navigation/guidance systems nowadays. However, while such services are easily implemented in outdoor environments using Global Positioning System (GPS technology, a requirement still exists for accurate localization and guidance schemes in indoor settings. Accordingly, the present study proposes a system based on GPS, Bluetooth Low Energy (BLE beacons, and Near Field Communication (NFC technology. Through establishing graphic information and the design of algorithm, this study develops a guidance system for indoors and outdoors on smart phones, wishing to give user perfect smart life through this system. The proposed system is implemented on a smart phone and evaluated on a student campus environment. The experimental results confirm the ability of the proposed app to switch automatically from an outdoor mode to an indoor mode and to guide the user to requested target destination via the shortest possible route.

  10. Structural optimization of the Halbach array PM rim thrust motor

    Science.gov (United States)

    Cao, Haichuan; Chen, Weihu

    2018-05-01

    The Rim-driven Thruster (RDT) integrates the thrust motor and the propeller, which can effectively reduce the space occupied by the propulsion system, improve the propulsion efficiency, and thus has important research value and broad market prospects. The Halbach Permanent Magnet Rim Thrust Motor (HPMRTM) can improve the torque density of the propulsion motor by utilizing the unilateral magnetic field of the Halbach array. In this paper, the numerical method is used to study the electromagnetic performance of the motor under different Halbach array parameters. The relationship between motor parameters such as air-gap flux density, electromagnetic torque and Halbach array parameters is obtained, and then the motor structure is optimized. By comparing with Common Permanent Magnet RTM, the advantages of HPMRTM are verified.

  11. Test Results for a Non-toxic, Dual Thrust Reaction Control Engine

    Science.gov (United States)

    Robinson, Philip J.; Veith, Eric M.; Turpin, Alicia A.

    2005-01-01

    A non-toxic, dual thrust reaction control engine (RCE) was successfully tested over a broad range of operating conditions at the Aerojet Sacramento facility. The RCE utilized LOX/Ethanol propellants; and was tested in steady state and pulsing modes at 25-lbf thrust (vernier) and at 870-lbf thrust (primary). Steady state vernier tests vaned chamber pressure (Pc) from 0.78 to 5.96 psia, and mixture ratio (MR) from 0.73 to 1.82, while primary steady state tests vaned Pc from 103 to 179 psia and MR from 1.33 to 1.76. Pulsing tests explored EPW from 0.080 to 10 seconds and DC from 5 to 50 percent at both thrust levels. Vernier testing accumulated a total of 6,670 seconds of firing time, and 7,215 pulses, and primary testing accumulated a total of 2,060 seconds of firing time and 3,646 pulses.

  12. Implications of heterogeneous fracture distribution on reservoir quality; an analogue from the Torridon Group sandstone, Moine Thrust Belt, NW Scotland

    Science.gov (United States)

    Watkins, Hannah; Healy, David; Bond, Clare E.; Butler, Robert W. H.

    2018-03-01

    Understanding fracture network variation is fundamental in characterising fractured reservoirs. Simple relationships between fractures, stress and strain are commonly assumed in fold-thrust structures, inferring relatively homogeneous fracture patterns. In reality fractures are more complex, commonly appearing as heterogeneous networks at outcrop. We use the Achnashellach Culmination (NW Scotland) as an outcrop analogue to a folded tight sandstone reservoir in a thrust belt. We present fracture data is collected from four fold-thrust structures to determine how fracture connectivity, orientation, permeability anisotropy and fill vary at different structural positions. We use a 3D model of the field area, constructed using field observations and bedding data, and geomechanically restored using Move software, to determine how factors such as fold curvature and strain influence fracture variation. Fracture patterns in the Torridon Group are consistent and predictable in high strain forelimbs, however in low strain backlimbs fracture patterns are inconsistent. Heterogeneities in fracture connectivity and orientation in low strain regions do not correspond to fluctuations in strain or fold curvature. We infer that where strain is low, other factors such as lithology have a greater control on fracture formation. Despite unpredictable fracture attributes in low strain regions, fractured reservoir quality would be highest here because fractures in high strain forelimbs are infilled with quartz. Heterogeneities in fracture attribute data on fold backlimbs mean that fractured reservoir quality and reservoir potential is difficult to predict.

  13. The Nucleation and Propagation of Thrust Ramps: Insights from Quantitative Analysis of Frictional Analog (Sandbox) Models

    Science.gov (United States)

    Sen, P.; Haq, S. S.; Marshak, S.

    2012-12-01

    Particle Imaging Velocimetry (PIV) provides a unique opportunity to analyze deformation in sandbox analog models at a scale that allows documentation of movement within and around individual shear structures. We employed PIV analysis to quantify deformation in sandbox experiments designed to simulate the initiation of thrust ramps developed during crustal shortening (i.e., contractional deformation). Our intent was to answer a long-standing question: Do ramps initiate at the tip of a detachment, or do they initiate in the interior of a deforming layer and propagate up-dip and down-dip until they link to the detachment at a location to the hinterland of the detachment's tip line? Most geometric studies of ramp-flat geometries in fold-thrust belts assume that ramps propagate up-dip from the tip of the detachment, and grow only in one direction. Field studies, in contrast, reveal that layer-parallel shortening structures develop to the foreland of the last ramp to form, suggesting that ramps initiate in a thrust sheet that has already undergone displacement above a detachment. Published sandbox models, using color-sand marker layers, support this idea. To test this idea further, we set up a model using a 3 m-long by 0.31-m wide glass-walled sandbox with a rigid backstop. The sand layer was sifted onto a sheet of mylar that could be pulled beneath the rigid backstop. Sand used in our experiments consisted of <250 μm-diameter grains. We carried out multiple runs using 4 cm, 5 cm and 6 cm-thick layers. Images were acquired over 1 mm displacement intervals using an 18 mega-pixel camera. By moving the camera at specific steps during the experiment, we sampled the development of several thrust ramps. The images taken during experimental runs were analyzed with a MATLAB-based program called 'PIV LAB' that utilizes an image cross-correlation subroutine to determine displacement fields of the sand particles. Our results demonstrate that: (1) thrust ramps initiate within the

  14. Lessons for Interstellar Travel from the Guidance and Control Design of the Near Earth Asteroid Scout Solar Sail Mission

    Science.gov (United States)

    Diedrich, Benjamin; Heaton, Andrew

    2017-01-01

    NASA is developing the Near Earth Asteroid (NEA) Scout mission that will use a solar sail to travel to an asteroid where it will perform a slow flyby to acquire science imagery. A guidance and control system was developed to meet the science and trajectory requirements. The NEA Scout design process can be applied to an interstellar or precursor mission that uses a beam propelled sail. The scientific objectives are met by accurately targeting the destination trajectory position and velocity. The destination is targeted by understanding the force on the sail from the beam (or sunlight in the case of NEA Scout) over the duration of the thrust maneuver. The propulsive maneuver is maintained by accurate understanding of the torque on the sail, which is a function of sail shape, optical properties, and mass properties, all of which apply to NEA Scout and beam propelled sails. NEA Scout uses active control of the sail attitude while trimming the solar torque, which could be used on a beamed propulsion sail if necessary. The biggest difference is that NEA Scout can correct for uncertainties in sail thrust modeling, spacecraft orbit, and target orbit throughout the flight to the target, while beamed propulsion needs accurate operation for the short duration of the beamed propulsion maneuver, making accurate understanding of the sail thrust and orbits much more critical.

  15. Back-thrusting in Lesser Himalaya: Evidences from magnetic fabric ...

    Indian Academy of Sciences (India)

    Back-thrusting in Lesser Himalaya: Evidences from magnetic fabric studies in parts of Almora crystalline zone, Kumaun Lesser Himalaya. Amar Agarwal, K K Agarwal, R Bali, Chandra Prakash and Gaurav Joshi. Supplementary data. Table S1. AMS data, representing mean of values from cores (N) collected from each site ...

  16. Late thrusting extensional collapse at the mountain front of the northern Apennines (Italy)

    Science.gov (United States)

    Tavani, Stefano; Storti, Fabrizio; Bausã, Jordi; MuñOz, Josep A.

    2012-08-01

    Thrust-related anticlines exposed at the mountain front of the Cenozoic Appenninic thrust-and-fold belt share the presence of hinterlandward dipping extensional fault zones running parallel to the hosting anticlines. These fault zones downthrow the crests and the backlimbs with displacements lower than, but comparable to, the uplift of the hosting anticline. Contrasting information feeds a debate about the relative timing between thrust-related folding and beginning of extensional faulting, since several extensional episodes, spanning from early Jurassic to Quaternary, are documented in the central and northern Apennines. Mesostructural data were collected in the frontal anticline of the Sibillini thrust sheet, the mountain front in the Umbria-Marche sector of the northern Apennines, with the aim of fully constraining the stress history recorded in the deformed multilayer. Compressional structures developed during thrust propagation and fold growth, mostly locating in the fold limbs. Extensional elements striking about perpendicular to the shortening direction developed during two distinct episodes: before fold growth, when the area deformed by outer-arc extension in the peripheral bulge, and during a late to post thrusting stage. Most of the the extensional deformation occurred during the second stage, when the syn-thrusting erosional exhumation of the structures caused the development of pervasive longitudinal extensional fracturing in the crestal sector of the growing anticline, which anticipated the subsequent widespread Quaternary extensional tectonics.

  17. Quality Assurance in University Guidance Services

    Science.gov (United States)

    Simon, Alexandra

    2014-01-01

    In Europe there is no common quality assurance framework for the delivery of guidance in higher education. Using a case study approach in four university career guidance services in England, France and Spain, this article aims to study how quality is implemented in university career guidance services in terms of strategy, standards and models,…

  18. Engineering research, development and technology: Thrust area report FY 91

    International Nuclear Information System (INIS)

    1991-01-01

    The mission of the Engineering Research, Development, and Technology Program at Lawrence, Livermore National Laboratory (LLNL) is to develop the technical staff and the technology needed to support current and future LLNL programs. To accomplish this mission, the Engineering Research, Development, and Technology Program has two important goals: (1) to identify key technologies and (2) conduct high quality work to enhance our capabilities in these key technologies. To help focus our efforts, we identify technology thrust areas and select technical leaders for each area. The thrust areas are integrated engineering activities and, rather than being based on individual disciplines, they are staffed by personnel from Electronics Engineering, Mechanical Engineering, and other LLNL organizations, as appropriate. The thrust area leaders are expected to establish strong links to LLNL program leaders and to industry; to use outside and inside experts to review the quality and direction of the work; to use university contacts to supplement and complement their efforts; and to be certain that we are not duplicating the work of others. The thrust area leader is also responsible for carrying out the work that follows from the Engineering Research, Development, and Technology Program so that the results can be applied as early as possible to the needs of LLNL programs. This annual report, organized by thrust area, describes activities conducted within the Program for the fiscal year, 1991. Its intent is to provide timely summaries of objectives, theories, methods, and results

  19. The thrust belts of Western North America

    Energy Technology Data Exchange (ETDEWEB)

    Moulton, F.C.

    1993-08-01

    Most of the Basin and Range physiographic province of western North America is now believed to be part of the overthrust. The more obvious overthrust belt along the eastern edge of the Basin and Range Province is named the Sevier orogenic belt, where older rocks are observed thrust onto younger rocks. More detailed surface geological mapping, plus deep multiple-fold geophysical work and many oil and gas wildcat wells, have confirmed an east-vergent shortened and stacked sequence is present in many places in the Basin and Range. This western compressive deformed area in east central Nevada is now named the Elko orogenic belt by the U.S. Geological Survey. This older compressed Elko orogenic belt started forming approximately 250 m.y. ago when the North American plate started to move west as the Pangaea supercontinent started to fragment. The North American plate moved west under the sediments of the Miogeocline that were also moving west. Surface-formed highlands and oceanic island arcs on the west edge of the North American plate restricted the westward movement of the sediments in the Miogeocline, causing east-vergent ramp thrusts to form above the westward-moving North American plate. The flat, eastward-up-cutting thrust assemblages moved on the detachment surfaces.

  20. Dissecting Attending Surgeons' Operating Room Guidance: Factors That Affect Guidance Decision Making.

    Science.gov (United States)

    Chen, Xiaodong Phoenix; Williams, Reed G; Smink, Douglas S

    2015-01-01

    The amount of guidance provided by the attending surgeon in the operating room (OR) is a key element in developing residents' autonomy. The purpose of this study is to explore factors that affect attending surgeons' decision making regarding OR guidance provided to the resident. We used video-stimulated recall interviews (VSRI) throughout this 2-phase study. In Phase 1, 3 attending surgeons were invited to review separately 30 to 45 minute video segments of their prerecorded surgical operations to explore factors that influenced their OR guidance decision making. In Phase 2, 3 attending surgeons were observed and documented in the OR (4 operations, 341min). Each operating surgeon reviewed their videotaped surgical performance within 5 days of the operation to reflect on factors that affected their decision making during the targeted guidance events. All VSRI were recorded. Thematic analysis and manual coding were used to synthesize and analyze data from VSRI transcripts, OR observation documents, and field notes. A total of 255 minutes of VSRI involving 6 surgeons and 7 surgical operations from 5 different procedures were conducted. A total of 13 guidance decision-making influence factors from 4 categories were identified (Cohen's κ = 0.674): Setting (case schedule and patient morbidity), content (procedure attributes and case progress), resident (current competency level, trustworthiness, self-confidence, and personal traits), and attending surgeon (level of experience, level of comfort, preferred surgical technique, OR training philosophy, and responsibility as surgeon). A total of 5 factors (case schedule, patient morbidity, procedure attributes, resident current competency level, and trustworthiness) influenced attending surgeons' pre-OR guidance plans. "OR training philosophy" and "responsibility as surgeon" were anchor factors that affected attending surgeons' OR guidance decision-making patterns. Surgeons' OR guidance decision making is a dynamic process

  1. Vocational guidance in social volunteering

    Directory of Open Access Journals (Sweden)

    Nikolay S. Pryazhnikov

    2017-03-01

    Full Text Available The paper discusses the possibilities and limitations of vocational guidance in the social volunteering system. The essence of volunteer work is closely related with assistance to desperate people in searching for the meaning of living, often coinciding with labour activity that are deemed in terms of “the main matter of life” and “the leading activity”. For adolescents, it is the choice of career, and for adults, it is the work proper (i.e. an essential condition for personal self-realization. The problem of “forced volunteering” for experts in vocational guidance also means that they often have to work voluntarily and unselfishly outside the official guidelines. To clarify the terms «volunteer» and «a person in desperate need of help» the study used the method of analyzing the documents, e.g. the Regulations on Social Volunteering, the generalization of psychological sources, the initial survey of university students as active supporters of the volunteer movement, On the essence of volunteering and the place of career guidance in selfless social work. Vocational guidance is not excluded from the general system of volunteerism, but has an insufficiently defined status and low popularity among participants in social volunteering. Also, the problem of «forced volunteering» of experts in career counseling, which often requires voluntary and unselfish performance of quality work outside the framework of official instructions, is also indicated. Simultaneously, positive aspects of such disinterested career initiatives are noted, in particular, less control by the official inspectors (or customers and, accordingly, greater freedom of creativity than when someone else does the work.

  2. Studying Wind Energy/Bird Interactions: A Guidance Document

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, R. [California Energy Commission (US); Morrison, M. [California State Univ., Sacramento, CA (US); Sinclair, K. [Dept. of Energy/National Renewable Energy Lab. (US); Strickland, D. [WEST, Inc. (US)

    1999-12-01

    This guidance document is a product of the Avian Subcommittee of the National Wind Coordinating Committee (NWCC). The NWCC was formed to better understand and promote responsible, credible, and comparable avian/wind energy interaction studies. Bird mortality is a concern and wind power is a potential clean and green source of electricity, making study of wind energy/bird interactions essential. This document provides an overview for regulators and stakeholders concerned with wind energy/bird interactions, as well as a more technical discussion of the basic concepts and tools for studying such interactions.

  3. EFFECTS OF SMALL THRUST ON THE MOTION OF AN ARTIFICIAL EARTH SATELLITE

    OpenAIRE

    TAKEUCHI, Sumio; 武内, 澄夫

    1982-01-01

    Perturbative effects of small thrust on the motion of an artificial earth satellite are investigated. The Lagrange planetary equations in Gaussian form are applied to determine the variations of the orbital elements. Also, equations of motion expressed in terms of different components of the thrust acceleration are used. It is assumed that the small thrust acceleration is a function of time and expressible as a linear combination of a polynomial and a composite set of all sines and cosines. B...

  4. Experimental test of static and dynamic characteristics of tilting-pad thrust bearings

    OpenAIRE

    Annan Guo; Xiaojing Wang; Jian Jin; Diann Y Hua; Zikai Hua

    2015-01-01

    The axial vibration in turbine machine has attracted more and more interest. Tilting-pad thrust bearings are widely used in turbine machines to support the axial load. The dynamic properties generated by oil film of the thrust pad have important effects on the axial vibration of the rotor-bearing system. It is necessary to develop the method to test the dynamic characteristics of thrust bearings. A new rig has been developed. The facility allows a complete set of bearing operating parameters ...

  5. Thrust initiation and its control on tectonic wedge geometry: An insight from physical and numerical models

    Science.gov (United States)

    Bose, Santanu; Mandal, Nibir; Saha, Puspendu; Sarkar, Shamik; Lithgow-Bertelloni, Carolina

    2014-10-01

    We performed a series of sandbox experiments to investigate the initiation of thrust ramping in tectonic wedges on a mechanically continuous basal decollement. The experiments show that the decollement slope (β) is the key factor in controlling the location of thrust initiation with respect to the backstop (i.e. tectonic suture line). For β = 0, the ramping begins right at the backstop, followed by sequential thrusting in the frontal direction, leading to a typical mono-vergent wedge. In contrast, the ramp initiates away from the backstop as β > 0. Under this boundary condition an event of sequential back thrusting takes place prior to the onset of frontal thrust progression. These two-coupled processes eventually give rise to a bi-vergent geometry of the thrust wedge. Using the Drucker-Prager failure criterion in finite element (FE) models, we show the location of stress intensification to render a mechanical basis for the thrust initiation away from the backstop if β > 0. Our physical and FE model results explain why the Main Central Thrust (MCT) is located far away from the Indo-Tibetan plate contact (ITSZ) in the Himalayan fold-and-thrust belts.

  6. Effect of flashlight guidance on manual ventilation performance in cardiopulmonary resuscitation: A randomized controlled simulation study.

    Science.gov (United States)

    Kim, Ji Hoon; Beom, Jin Ho; You, Je Sung; Cho, Junho; Min, In Kyung; Chung, Hyun Soo

    2018-01-01

    Several auditory-based feedback devices have been developed to improve the quality of ventilation performance during cardiopulmonary resuscitation (CPR), but their effectiveness has not been proven in actual CPR situations. In the present study, we investigated the effectiveness of visual flashlight guidance in maintaining high-quality ventilation performance. We conducted a simulation-based, randomized, parallel trial including 121 senior medical students. All participants were randomized to perform ventilation during 2 minutes of CPR with or without flashlight guidance. For each participant, we measured mean ventilation rate as a primary outcome and ventilation volume, inspiration velocity, and ventilation interval as secondary outcomes using a computerized device system. Mean ventilation rate did not significantly differ between flashlight guidance and control groups (P = 0.159), but participants in the flashlight guidance group exhibited significantly less variation in ventilation rate than participants in the control group (Pguidance group. Our results demonstrate that flashlight guidance is effective in maintaining a constant ventilation rate and interval. If confirmed by further studies in clinical practice, flashlight guidance could be expected to improve the quality of ventilation performed during CPR.

  7. Beryllium satellite thrust cone design, manufacture and test

    International Nuclear Information System (INIS)

    Schneiter, H.; Chandler, D.

    1977-01-01

    Pre-formed beryllium sheet material has been used in the design, manufacturing and test of a satellite thrust cone structure. Adhesive bonding was used for attachment of aluminium flanges and conical segment lap strips. Difficulties in beryllium structure design such as incompatibilities with aluminium and handling problems are discussed. Testing to optimize beryllium-beryllium and beryllium-aluminium adhesive bonds is described. The completed thrust cone assembly has been subjected to static load testing and the results are presented. A summary of the relative merits of the use of beryllium in satellite structures is given with recommendations for future users. (author)

  8. Cyclic hot firing results of tungsten-wire-reinforced, copper-lined thrust chambers

    Science.gov (United States)

    Kazaroff, John M.; Jankovsky, Robert S.

    1990-01-01

    An advanced thrust liner material for potential long life reusable rocket engines is described. This liner material was produced with the intent of improving the reusable life of high pressure thrust chambers by strengthening the chamber in the hoop direction, thus avoiding the longitudinal cracking due to low cycle fatigue that is observed in conventional homogeneous copper chambers, but yet not reducing the high thermal conductivity that is essential when operating with high heat fluxes. The liner material produced was a tungsten wire reinforced copper composite. Incorporating this composite into two hydrogen-oxygen test rocket chambers was done so that its performance as a reusable liner material could be evaluated. Testing results showed that both chambers failed prematurely, but the crack sites were perpendicular to the normal direction of cracking indicating a degree of success in containing the tremendous thermal strain associated with high temperature rocket engines. The failures, in all cases, were associated with drilled instrumentation ports and no other damages or deformations were found elsewhere in the composite liners.

  9. North Aegean core complexes, the gravity spreading of a thrust wedge

    NARCIS (Netherlands)

    Kydonakis, Konstantinos; Brun, Jean Pierre; Sokoutis, Dimitrios

    2015-01-01

    The North Aegean core complexes developed in middle Eocene soon after the end of continental block convergence and piling up of the Hellenic Thrust Wedge. They formed during back-arc extension, driven by the Hellenic slab rollback, at the back of the thrust wedge. A series of scaled laboratory

  10. MATERIALS PERFORMANCE TARGETED THRUST FY 2004 PROJECTS

    International Nuclear Information System (INIS)

    DOE

    2005-01-01

    The Yucca Mountain site was recommended by the President to be a geological repository for commercial spent nuclear fuel and high-level radioactive waste. The multi-barrier approach was adopted for assessing and predicting system behavior, including both natural barriers and engineered barriers. A major component of the long-term strategy for safe disposal of nuclear waste is first to completely isolate the radionuclides in waste packages for long times and then to greatly retard the egress and transport of radionuclides from penetrated packages. The goal of the Materials Performance Targeted Thrust program is to further enhance the understanding of the role of engineered barriers in waste isolation. In addition, the Thrust will explore technical enhancements and seek to offer improvements in materials costs and reliability

  11. NATURAL BARRIERS TARGETED THRUST FY 2004 PROJECTS

    International Nuclear Information System (INIS)

    NA

    2005-01-01

    This booklet contains project descriptions of work performed by the Department of Energy (DOE), Office of Civilian Radioactive Waste Management (OCRWM), Office of Science and Technology and International's (OSTandI) Natural Barriers Targeted Thrust during Fiscal Year (FY) 2004. The Natural Barriers Targeted Thrust is part of OSTandI's Science and Technology Program which supports the OCRWM mission to manage and dispose of high-level radioactive waste and spent nuclear fuel in a manner that protects health, safety, and the environment; enhances national and energy security; and merits public confidence. In general, the projects described will continue beyond FY 2004 assuming that the technical work remains relevant to the proposed Yucca Mountain Repository and sufficient funding is made available to the Science and Technology Program

  12. Smartphone Video Guidance Sensor for Small Satellites

    Data.gov (United States)

    National Aeronautics and Space Administration — Smartphone Video Guidance Sensor(SVGS) for Small Satellites will provide a low-cost,integrated rendezvous & proximity operations sensor system to allow an...

  13. One-equation modeling and validation of dielectric barrier discharge plasma actuator thrust

    International Nuclear Information System (INIS)

    Yoon, Jae-San; Han, Jae-Hung

    2014-01-01

    Dielectric barrier discharge (DBD) plasma actuators with an asymmetric electrode configuration can generate a wall-bounded jet without mechanical moving parts, which require considerable modifications of existing aeronautical objects and which incur high maintenance costs. Despite this potential, one factor preventing the wider application of such actuators is the lack of a reliable actuator model. It is difficult to develop such a model because calculating the ion-electric field and fluid interaction consume a high amount calculation effort during the numerical analysis. Thus, the authors proposed a semi-empirical model which predicted the thrust of plasma actuators with a simple equation. It gave a numeric thrust value, and we implemented the value on a computational fluid dynamics (CFD) solver to describe the two-dimensional flow field induced by the actuator. However, the model had a narrow validation range, depending on the empirical formula, and it did not fully consider environment variables. This study presents an improved model by replacing the empirical formulae in the previous model with physical equations that take into account physical phenomena and environmental variables. During this process, additional operation parameters, such as pressure, temperature and ac waveforms, are newly taken to predict the thrust performance of the actuators with a wider range of existing parameters, the thickness of the dielectric barrier, the exposed electrode, the dielectric constant, the ac frequency and the voltage amplitude. Thrust prediction curves from the model are compared to those of earlier experimental results, showing that the average error is less than 5% for more than one hundred instances of data. As in the earlier work, the predicted thrust value is implemented on a CFD solver, and two-dimensional wall-jet velocity profiles induced by the actuator are compared to the previous experimental results. (paper)

  14. 14 CFR Appendix I to Part 25 - Installation of an Automatic Takeoff Thrust Control System (ATTCS)

    Science.gov (United States)

    2010-01-01

    ... Appendix I to Part 25—Installation of an Automatic Takeoff Thrust Control System (ATTCS) I25.1General. (a... crew to increase thrust or power. I25.2Definitions. (a) Automatic Takeoff Thrust Control System (ATTCS... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Installation of an Automatic Takeoff Thrust...

  15. a Revision to the Tectonics of the Flores Back-Arc Thrust Zone, Indonesia?

    Science.gov (United States)

    Tikku, A. A.

    2011-12-01

    The Flores and Bali Basins are continental basins in the Flores back-arc thrust zone associated with Eocene subduction of the Indo-Australian plate beneath the Sunda plate followed by Miocene to present-day inversion/thrusting. The basins are east of Java and north of the islands of Bali, Lombok, Sumbawa and Flores in the East Java Sea area of Indonesia. The tectonic interpretation of these basins is based on seismic, bathymetry and gravity data and is also supported by present-day GPS measurements that demonstrate subduction is no longer active across the Flores thrust zone. Current thinking about the area is that the Flores Basin (on the east end of the thrust zone) had the most extension in the back-arc thrust and may be a proto-oceanic basin, though the option of a purely continental extensional basin can not be ruled out. The Bali Basin (on the west end of the thrust zone) is thought to be shallower and have experienced less continental thinning and extension than the Flores Basin. Depth to basement estimates from recently collected marine magnetic data indicate the depth of the Bali Basin may be comparable to the depth of the Flores Basin. Analysis of the marine magnetic data and potential implications of relative plate motions will be presented.

  16. Control-Volume Analysis Of Thrust-Augmenting Ejectors

    Science.gov (United States)

    Drummond, Colin K.

    1990-01-01

    New method of analysis of transient flow in thrust-augmenting ejector based on control-volume formulation of governing equations. Considered as potential elements of propulsion subsystems of short-takeoff/vertical-landing airplanes.

  17. Another Look at Rocket Thrust

    Science.gov (United States)

    Hester, Brooke; Burris, Jennifer

    2012-01-01

    Rocket propulsion is often introduced as an example of Newton's third law. The rocket exerts a force on the exhaust gas being ejected; the gas exerts an equal and opposite force--the thrust--on the rocket. Equivalently, in the absence of a net external force, the total momentum of the system, rocket plus ejected gas, remains constant. The law of…

  18. Palaeomagnetic evidence for post-thrusting tectonic rotation in the Southeast Pyrenees, Spain

    Science.gov (United States)

    Keller, P.; Lowrie, W.; Gehring, A. U.

    1994-12-01

    The structural framework of the Southeast Pyrenees led to two conflicting interpretations—thrust tectonics vs. wrench tectonics—to explain the geometry of this mountain range. In the present study palaeomagnetic data are presented in an attempt to resolve this conflict. The data reveal different magnetisation directions that indicate tectonic rotations about vertical axes. By means of a regionally homogeneous pattern of rotation, three tectonic units could be distinguished in the Southeast Pyrenees. The Internal Unit in the north reveals no rotation since the Permian. The External Unit to the south shows anticlockwise rotation of 25°, younger than the Early Oligocene. The Pedraforca Unit, placed on the External Unit, shows 57° clockwise rotation which can be assigned to the Neogene. The anticlockwise rotation of the External Unit can be explained by differential compression during the last phase of Pyrenean thrusting, whereas the clockwise rotation of the Pedraforca Unit can be interpreted by post-thrusting tectonics. The rotation pattern of the Southeast Pyrenees provides evidence for both Cretaceous to Paleogene N-S compression and Neogene right-lateral wrench tectonics.

  19. Research on axial thrust of the waterjet pump based on CFD under cavitation conditions

    International Nuclear Information System (INIS)

    Shen, Z H; Pan, Z Y

    2015-01-01

    Based on RANS equations, performance of a contra-rotating axial-flow waterjet pump without hydrodynamic cavitation state had been obtained combined with shear stress transport turbulence model. Its cavitation hydrodynamic performance was calculated and analysed with mixture homogeneous flow cavitation model based on Rayleigh-Plesset equations. The results shows that the cavitation causes axial thrust of waterjet pump to drop. Furthermore, axial thrust and head cavitation characteristic curve is similar. However, the drop point of the axial thrust is postponed by 5.1% comparing with one of head, and the critical point of the axial thrust is postponed by 2.6%

  20. Research on axial thrust of the waterjet pump based on CFD under cavitation conditions

    Science.gov (United States)

    Shen, Z. H.; Pan, Z. Y.

    2015-01-01

    Based on RANS equations, performance of a contra-rotating axial-flow waterjet pump without hydrodynamic cavitation state had been obtained combined with shear stress transport turbulence model. Its cavitation hydrodynamic performance was calculated and analysed with mixture homogeneous flow cavitation model based on Rayleigh-Plesset equations. The results shows that the cavitation causes axial thrust of waterjet pump to drop. Furthermore, axial thrust and head cavitation characteristic curve is similar. However, the drop point of the axial thrust is postponed by 5.1% comparing with one of head, and the critical point of the axial thrust is postponed by 2.6%.

  1. Structural characteristics around the frontal thrust along the Nankai Trough revealed by bathymetric and seismic reflection survey

    Science.gov (United States)

    Yamashita, M.; Nakanishi, A.; Moore, G. F.; Kodaira, S.; Nakamura, Y.; Miura, S.; Kaneda, Y.

    2016-12-01

    evaluate the initiation and evolution of frontal thrust at the toe of Nankai trough axis. This study is part of "Research project for compound disaster mitigation on the great earthquakes and tsunamis around the Nankai Trough region" funded by the Ministry of Education, Culture, Sports, Science, and Technology of Japan.

  2. Bivergent thrust wedges surrounding oceanic island arcs: Insight from observations and sandbox models of the northeastern caribbean plate

    Science.gov (United States)

    ten Brink, Uri S.; Marshak, S.; Granja, Bruna J.L.

    2009-01-01

    At several localities around the world, thrust belts have developed on both sides of oceanic island arcs (e.g., Java-Timor, Panama, Vanuatu, and the northeastern Caribbean). In these localities, the overall vergence of the backarc thrust belt is opposite to that of the forearc thrust belt. For example, in the northeastern Caribbean, a north-verging accretionary prism lies to the north of the Eastern Greater Antilles arc (Hispaniola and Puerto Rico), whereas a south-verging thrust belt called the Muertos thrust belt lies to the south. Researchers have attributed such bivergent geometry to several processes, including: reversal of subduction polarity; subduction-driven mantle flow; stress transmission across the arc; gravitational spreading of the arc; and magmatic inflation within the arc. New observations of deformational features in the Muertos thrust belt and of fault geometries produced in sandbox kinematic models, along with examination of published studies of island arcs, lead to the conclusion that the bivergence of thrusting in island arcs can develop without reversal of subduction polarity, without subarc mantle flow, and without magmatic inflation. We suggest that the Eastern Greater Antilles arc and comparable arcs are simply crustalscale bivergent (or "doubly vergent") thrust wedges formed during unidirectional subduction. Sandbox kinematic modeling suggests, in addition, that a broad retrowedge containing an imbricate fan of thrusts develops only where the arc behaves relatively rigidly. In such cases, the arc acts as a backstop that transmits compressive stress into the backarc region. Further, modeling shows that when arcs behave as rigid blocks, the strike-slip component of oblique convergence is accommodated entirely within the prowedge and the arc-the retrowedge hosts only dip-slip faulting ("frontal thrusting"). The existence of large retrowedges and the distribution of faulting in an island arc may, therefore, be evidence that the arc is

  3. Automatic control of a primary electric thrust subsystem

    Science.gov (United States)

    Macie, T. W.; Macmedan, M. L.

    1975-01-01

    A concept for automatic control of the thrust subsystem has been developed by JPL and participating NASA Centers. This paper reports on progress in implementing the concept at JPL. Control of the Thrust Subsystem (TSS) is performed by the spacecraft computer command subsystem, and telemetry data is extracted by the spacecraft flight data subsystem. The Data and Control Interface Unit, an element of the TSS, provides the interface with the individual elements of the TSS. The control philosophy and implementation guidelines are presented. Control requirements are listed, and the control mechanism, including the serial digital data intercommunication system, is outlined. The paper summarizes progress to Fall 1974.

  4. Field Tests on Hydrodynamic and Hybrid Operation of a Bidirectional Thrust Bearing of a Pump-Turbine

    Directory of Open Access Journals (Sweden)

    Michał Wasilczuk

    2017-12-01

    Full Text Available In vertical shaft pump turbines operating in pumped storage power plants an important role is played by a thrust bearing. Due to the bidirectional character of operation, thrust bearing tilting pads have to be supported symmetrically, which is known to be unfavourable from the point of view of their performance. Large thrust bearings have to be carefully designed so as to minimise excessive thermo-elastic pad deformations. The research into fluid film thrust bearings has been quite extensive over the years, comprising theoretical studies of bearing properties with the use of more and more sophisticated calculation codes. On the other hand, the availability of experimental field data on bearing operation is limited, for obvious reasons. In this paper the authors present part of the results of extensive field tests of a large bearing of a pump-turbine they have conducted in a pumped storage power plant. Hopefully this data will be of interest to other researchers to compare theoretical predictions to measurement data.

  5. 77 FR 9948 - International Conference on Harmonisation; Guidance on E7 Studies in Support of Special...

    Science.gov (United States)

    2012-02-21

    ...] International Conference on Harmonisation; Guidance on E7 Studies in Support of Special Populations; Geriatrics... Food and Drug Administration (FDA) is announcing the availability of a guidance entitled ``E7 Studies... under the auspices of the International Conference on Harmonisation of Technical Requirements for...

  6. A Formal Investigation of the Organization of Guidance Behavior: Implications for Humans and Autonomous Guidance

    Science.gov (United States)

    Kong, Zhaodan

    Guidance behavior generated either by artificial agents or humans has been actively studied in the fields of both robotics and cognitive science. The goals of these two fields are different. The former is the automatic generation of appropriate or even optimal behavior, while the latter is the understanding of the underlying mechanism. Their challenges, though, are closely related, the most important one being the lack of a unified, formal and grounded framework where the guidance behavior can be modeled and studied. This dissertation presents such a framework. In this framework, guidance behavior is analyzed as the closed-loop dynamics of the whole agent-environment system. The resulting dynamics give rise to interaction patterns. The central points of this dissertation are that: first of all, these patterns, which can be explained in terms of symmetries that are inherent to the guidance behavior, provide building blocks for the organization of behavior; second, the existence of these patterns and humans' organization of their guidance behavior based on these patterns are the reasons that humans can generate successful behavior in spite of all the complexities involved in the planning and control. This dissertation first gives an overview of the challenges existing in both scientific endeavors, such as human and animal spatial behavior study, and engineering endeavors, such as autonomous guidance system design. It then lays out the foundation for our formal framework, which states that guidance behavior should be interpreted as the collection of the closed-loop dynamics resulting from the agent's interaction with the environment. The following, illustrated by examples of three different UAVs, shows that the study of the closed-loop dynamics should not be done without the consideration of vehicle dynamics, as is the common practice in some of the studies in both autonomous guidance and human behavior analysis. The framework, the core concepts of which are

  7. Thrust Reduction of Magnetic Levitation Vehicle Driven by Long Stator Linear Synchronous Motor

    Directory of Open Access Journals (Sweden)

    Wan-Tsun Tseng

    2013-01-01

    Full Text Available The propulsion technology of long stator linear synchronous motors is used to drive high-speed maglev trains. The linear synchronous motor stator is divided into sections placed on guideway. The electric power supplies to stator sections in which the train just passes in change-step mode for long-distance operation. However, a thrust drop will be caused by change-step machinery for driving magnetic vehicle. According to the train speed and vehicle data, the change-step mode has three types of operation, namely premature commutation, simultaneous commutation, and late commutation. Each type of operation has a different thrust drop which can be affected by several parameters such as jerk, running speed, motor section length, and vehicle data. This paper focuses on determining the thrust drop of the change-step mode. The study results of this paper can be used to improve the operation system of high-speed maglev trains.

  8. Growth of the Zagros Fold-Thrust Belt and Foreland Basin, Northern Iraq, Kurdistan

    Science.gov (United States)

    Koshnaw, Renas; Horton, Brian; Stockli, Daniel; Barber, Douglas; Ghalib, Hafidh; Dara, Rebwar

    2016-04-01

    The Zagros orogenic belt in the Middle Eastern segment of the Alpine-Himalayan system is among the youngest seismically active continental collision zones on Earth. However, due to diachronous and incremental collision, the precise ages and kinematics of shortening and deposition remain poorly understood. The Kurdistan region of the Zagros fold-thrust belt and foreland basin contains well-preserved Neogene wedge-top and foredeep deposits that include clastic nonmarine fill of the Upper Fars, Lower Bakhtiari, and Upper Bakhtiari Formations. These deposits record significant information about orogenic growth, fold-thrust dynamics, and advance of the deformation front. Thermochronologic and geochronologic data from thrust sheets and stratigraphic archives combined with local earthquake data provide a unique opportunity to address the linkages between surface and subsurface geologic relationships. This research seeks to constrain the timing and geometry of exhumation and deformation by addressing two key questions: (1) Did the northwestern Zagros fold-thrust belt evolve from initial thin-skinned shortening to later thick-skinned deformation or vice-versa? (2) Did the fold-thrust belt advance steadily under critical/supercritical wedge conditions involving in-sequence thrusting or propagate intermittently under subcritical conditions with out-of-sequence deformation? From north to south, apatite (U-Th)/He ages from the Main Zagros Thrust, the Mountain Front Flexure (MFF), and additional frontal thrusts suggest rapid exhumation by ~10 Ma, ~5 Ma, and ~8 Ma respectively. Field observations and seismic sections indicate progressive tilting and development of growth strata within the Lower Bakhtiari Formation adjacent to the frontal thrusts and within the Upper Bakhtiari Formation near the MFF. In the Kurdistan region of Iraq, a regional balanced cross section constrained by new thermochronometric results, proprietary seismic reflection profiles, and earthquake hypocenters

  9. Advanced Active-Magnetic-Bearing Thrust-Measurement System

    Science.gov (United States)

    Imlach, Joseph; Kasarda, Mary; Blumber, Eric

    2008-01-01

    An advanced thrust-measurement system utilizes active magnetic bearings to both (1) levitate a floating frame in all six degrees of freedom and (2) measure the levitation forces between the floating frame and a grounded frame. This system was developed for original use in measuring the thrust exerted by a rocket engine mounted on the floating frame, but can just as well be used in other force-measurement applications. This system offers several advantages over prior thrust-measurement systems based on mechanical support by flexures and/or load cells: The system includes multiple active magnetic bearings for each degree of freedom, so that by selective use of one, some, or all of these bearings, it is possible to test a given article over a wide force range in the same fixture, eliminating the need to transfer the article to different test fixtures to obtain the benefit of full-scale accuracy of different force-measurement devices for different force ranges. Like other active magnetic bearings, the active magnetic bearings of this system include closed-loop control subsystems, through which the stiffness and damping characteristics of the magnetic bearings can be modified electronically. The design of the system minimizes or eliminates cross-axis force-measurement errors. The active magnetic bearings are configured to provide support against movement along all three orthogonal Cartesian axes, and such that the support along a given axis does not produce force along any other axis. Moreover, by eliminating the need for such mechanical connections as flexures used in prior thrust-measurement systems, magnetic levitation of the floating frame eliminates what would otherwise be major sources of cross-axis forces and the associated measurement errors. Overall, relative to prior mechanical-support thrust-measurement systems, this system offers greater versatility for adaptation to a variety of test conditions and requirements. The basic idea of most prior active

  10. Fusion guidance in endovascular peripheral artery interventions: a feasibility study.

    Science.gov (United States)

    Sailer, Anna M; de Haan, Michiel W; de Graaf, Rick; van Zwam, Willem H; Schurink, Geert Willem H; Nelemans, Patricia J; Wildberger, Joachim E; Das, Marco

    2015-04-01

    This study was designed to evaluate the feasibility of endovascular guidance by means of live fluoroscopy fusion with magnetic resonance angiography (MRA) and computed tomography angiography (CTA). Fusion guidance was evaluated in 20 endovascular peripheral artery interventions in 17 patients. Fifteen patients had received preinterventional diagnostic MRA and two patients had undergone CTA. Time for fluoroscopy with MRA/CTA coregistration was recorded. Feasibility of fusion guidance was evaluated according to the following criteria: for every procedure the executing interventional radiologists recorded whether 3D road-mapping provided added value (yes vs. no) and whether PTA and/or stenting could be performed relying on the fusion road-map without need for diagnostic contrast-enhanced angiogram series (CEAS) (yes vs. no). Precision of the fusion road-map was evaluated by recording maximum differences between the position of the vasculature on the virtual CTA/MRA images and conventional angiography. Average time needed for image coregistration was 5 ± 2 min. Three-dimensional road-map added value was experienced in 15 procedures in 12 patients. In half of the patients (8/17), intervention was performed relying on the fusion road-map only, without diagnostic CEAS. In two patients, MRA roadmap showed a false-positive lesion. Excluding three patients with inordinate movements, mean difference in position of vasculature on angiography and MRA/CTA road-map was 1.86 ± 0.95 mm, implying that approximately 95 % of differences were between 0 and 3.72 mm (2 ± 1.96 standard deviation). Fluoroscopy with MRA/CTA fusion guidance for peripheral artery interventions is feasible. By reducing the number of CEAS, this technology may contribute to enhance procedural safety.

  11. NATURAL BARRIERS TARGETED THRUST FY 2004 PROJECTS

    Energy Technology Data Exchange (ETDEWEB)

    NA

    2005-07-27

    This booklet contains project descriptions of work performed by the Department of Energy (DOE), Office of Civilian Radioactive Waste Management (OCRWM), Office of Science and Technology and International's (OST&I) Natural Barriers Targeted Thrust during Fiscal Year (FY) 2004. The Natural Barriers Targeted Thrust is part of OST&I's Science and Technology Program which supports the OCRWM mission to manage and dispose of high-level radioactive waste and spent nuclear fuel in a manner that protects health, safety, and the environment; enhances national and energy security; and merits public confidence. In general, the projects described will continue beyond FY 2004 assuming that the technical work remains relevant to the proposed Yucca Mountain Repository and sufficient funding is made available to the Science and Technology Program.

  12. A Simple Method to Measure Nematodes' Propulsive Thrust and the Nematode Ratchet.

    Science.gov (United States)

    Bau, Haim; Yuan, Jinzhou; Raizen, David

    2015-11-01

    Since the propulsive thrust of micro organisms provides a more sensitive indicator of the animal's health and response to drugs than motility, a simple, high throughput, direct measurement of the thrust is desired. Taking advantage of the nematode C. elegans being heavier than water, we devised a simple method to determine the propulsive thrust of the animals by monitoring their velocity when swimming along an inclined plane. We find that the swimming velocity is a linear function of the sin of the inclination angle. This method allows us to determine, among other things, the animas' propulsive thrust as a function of genotype, drugs, and age. Furthermore, taking advantage of the animals' inability to swim over a stiff incline, we constructed a sawteeth ratchet-like track that restricts the animals to swim in a predetermined direction. This research was supported, in part, by NIH NIA Grant 5R03AG042690-02.

  13. Metaheuristic and Machine Learning Models for TFE-731-2, PW4056, and JT8D-9 Cruise Thrust

    Science.gov (United States)

    Baklacioglu, Tolga

    2017-08-01

    The requirement for an accurate engine thrust model has a major antecedence in airline fuel saving programs, assessment of environmental effects of fuel consumption, emissions reduction studies, and air traffic management applications. In this study, utilizing engine manufacturers' real data, a metaheuristic model based on genetic algorithms (GAs) and a machine learning model based on neural networks (NNs) trained with Levenberg-Marquardt (LM), delta-bar-delta (DBD), and conjugate gradient (CG) algorithms were accomplished to incorporate the effect of both flight altitude and Mach number in the estimation of thrust. For the GA model, the analysis of population size impact on the model's accuracy and effect of number of data on model coefficients were also performed. For the NN model, design of optimum topology was searched for one- and two-hidden-layer networks. Predicted thrust values presented a close agreement with real thrust data for both models, among which LM trained NNs gave the best accuracies.

  14. Investigation on Thrust and Moment Coefficients of a Centrifugal Turbomachine

    Directory of Open Access Journals (Sweden)

    Bo Hu

    2018-04-01

    Full Text Available In radial pumps and turbines, the centrifugal through-flow in both the front and the back chambers is quite common. It strongly impacts the core swirl ratio, pressure distribution, axial thrust and frictional torque. In order to investigate these relationships experimentally, a test rig was designed at the University of Duisburg-Essen and described in this paper. Based on both the experimental and numerical results, correlations are determined to predict the impacts of the centrifugal through-flow on the core swirl ratio, the thrust coefficient and the moment coefficient. Two correlations respectively are determined to associate the core swirl ratio with the local through-flow coefficient for both Batchelor type flow and Stewartson type flow. The correlations describing the thrust coefficient and the moment coefficient in a rotor-stator cavity with centripetal through-flow (Hu et al., 2017 are modified for the case of centrifugal through-flow. The Daily and Nece diagram distinguishing between different flow regimes in rotor-stator cavities is extended with a through-flow coordinate into 3D. The achieved results provide a comprehensive data base which is intended to support the calculation of axial thrust and moment coefficients during the design process of radial pumps and turbines in a more accurate manner.

  15. Separability of drag and thrust in undulatory animals and machines

    Science.gov (United States)

    Bale, Rahul; Shirgaonkar, Anup A.; Neveln, Izaak D.; Bhalla, Amneet Pal Singh; Maciver, Malcolm A.; Patankar, Neelesh A.

    2014-12-01

    For nearly a century, researchers have tried to understand the swimming of aquatic animals in terms of a balance between the forward thrust from swimming movements and drag on the body. Prior approaches have failed to provide a separation of these two forces for undulatory swimmers such as lamprey and eels, where most parts of the body are simultaneously generating drag and thrust. We nonetheless show that this separation is possible, and delineate its fundamental basis in undulatory swimmers. Our approach unifies a vast diversity of undulatory aquatic animals (anguilliform, sub-carangiform, gymnotiform, bal-istiform, rajiform) and provides design principles for highly agile bioinspired underwater vehicles. This approach has practical utility within biology as well as engineering. It is a predictive tool for use in understanding the role of the mechanics of movement in the evolutionary emergence of morphological features relating to locomotion. For example, we demonstrate that the drag-thrust separation framework helps to predict the observed height of the ribbon fin of electric knifefish, a diverse group of neotropical fish which are an important model system in sensory neurobiology. We also show how drag-thrust separation leads to models that can predict the swimming velocity of an organism or a robotic vehicle.

  16. Underwater thrust and power generation using flexible piezoelectric composites: an experimental investigation toward self-powered swimmer-sensor platforms

    International Nuclear Information System (INIS)

    Erturk, Alper; Delporte, Ghislain

    2011-01-01

    Fiber-based flexible piezoelectric composites offer several advantages to use in energy harvesting and biomimetic locomotion. These advantages include ease of application, high power density, effective bending actuation, silent operation over a range of frequencies, and light weight. Piezoelectric materials exhibit the well-known direct and converse piezoelectric effects. The direct piezoelectric effect has received growing attention for low-power generation to use in wireless electronic applications while the converse piezoelectric effect constitutes an alternative to replace the conventional actuators used in biomimetic locomotion. In this paper, underwater thrust and electricity generation are investigated experimentally by focusing on biomimetic structures with macro-fiber composite piezoelectrics. Fish-like bimorph configurations with and without a passive caudal fin (tail) are fabricated and compared. The favorable effect of having a passive caudal fin on the frequency bandwidth is reported. The presence of a passive caudal fin is observed to bring the second bending mode close to the first one, yielding a wideband behavior in thrust generation. The same smart fish configuration is tested for underwater piezoelectric power generation in response to harmonic excitation from its head. Resonant piezohydroelastic actuation is reported to generate milli-newton level hydrodynamic thrust using milli-watt level actuation power input. The average actuation power requirement for generating a mean thrust of 19 mN at 6 Hz using a 10 g piezoelastic fish with a caudal fin is measured as 120 mW. This work also discusses the feasibility of thrust generation using the harvested energy toward enabling self-powered swimmer-sensor platforms with comparisons based on the capacity levels of structural thin-film battery layers as well as harvested solar and vibrational energy

  17. Thrust and torque characteristics based on a new cutter-head load model

    Science.gov (United States)

    Liu, Jianqin; Ren, Jiabao; Guo, Wei

    2015-07-01

    Full face rock tunnel boring machine(TBM) has been widely used in hard rock tunnels, however, there are few published theory about cutter-head design, and the design criteria of cutter-head under complex geological is not clear yet. To deal with the complex relationship among geological parameters, cutter parameters, and operating parameters during tunneling processes, a cutter-head load model is established by using CSM(Colorado school of mines) prediction model. Force distribution on cutter-head under a certain geology is calculated with the new established load model, and result shows that inner cutters bear more force than outer cutters, combining with disc cutters abrasion; a general principle of disc cutters' layout design is proposed. Within the model, the relationship among rock uniaxial compressive strength(UCS), penetration and thrust on cutter-head are analyzed, and the results shows that with increasing penetration, cutter thrust increases, but the growth rate slows and higher penetration makes lower special energy(SE). Finally, a fitting mathematical model of ZT(ratio of cutter-head torque and thrust) and penetration is established, and verified by TB880E, which can be used to direct how to set thrust and torque on cutter-head. When penetration is small, the cutter-head thrust is the main limiting factor in tunneling; when the penetration is large, cutter-head torque is the major limiting factor in tunneling. Based on the new cutter-head load model, thrust and torque characteristics of TBM further are researched and a new way for cutter-head layout design and TBM tunneling operations is proposed.

  18. 76 FR 59142 - Guidance for Industry on Reproductive and Developmental Toxicities-Integrating Study Results To...

    Science.gov (United States)

    2011-09-23

    ... of study results to assess concerns about human reproductive and developmental toxicities. It does... assist that office in processing your requests. See the SUPPLEMENTARY INFORMATION section for electronic access to the guidance document. Submit electronic comments on the guidance to http://www.regulations.gov...

  19. Engineering Research and Development and Technology thrust area report FY92

    Energy Technology Data Exchange (ETDEWEB)

    Langland, R.T.; Minichino, C. [eds.

    1993-03-01

    The mission of the Engineering Research, Development, and Technology Program at Lawrence Livermore National Laboratory (LLNL) is to develop the technical staff and the technology needed to support current and future LLNL programs. To accomplish this mission, the Engineering Research, Development, and Technology Program has two important goals: (1) to identify key technologies and (2) to conduct high-quality work to enhance our capabilities in these key technologies. To help focus our efforts, we identify technology thrust areas and select technical leaders for each area. The thrust areas are integrated engineering activities and, rather than being based on individual disciplines, they are staffed by personnel from Electronics Engineering, Mechanical Engineering, and other LLNL organizations, as appropriate. The thrust area leaders are expected to establish strong links to LLNL program leaders and to industry; to use outside and inside experts to review the quality and direction of the work; to use university contacts to supplement and complement their efforts; and to be certain that we are not duplicating the work of others. This annual report, organized by thrust area, describes activities conducted within the Program for the fiscal year 1992. Its intent is to provide timely summaries of objectives, theories, methods, and results. The nine thrust areas for this fiscal year are: Computational Electronics and Electromagnetics; Computational Mechanics; Diagnostics and Microelectronics; Emerging Technologies; Fabrication Technology; Materials Science and Engineering; Microwave and Pulsed Power; Nondestructive Evaluation; and Remote Sensing and Imaging, and Signal Engineering.

  20. Engineering Research and Development and Technology thrust area report FY92

    International Nuclear Information System (INIS)

    Langland, R.T.; Minichino, C.

    1993-03-01

    The mission of the Engineering Research, Development, and Technology Program at Lawrence Livermore National Laboratory (LLNL) is to develop the technical staff and the technology needed to support current and future LLNL programs. To accomplish this mission, the Engineering Research, Development, and Technology Program has two important goals: (1) to identify key technologies and (2) to conduct high-quality work to enhance our capabilities in these key technologies. To help focus our efforts, we identify technology thrust areas and select technical leaders for each area. The thrust areas are integrated engineering activities and, rather than being based on individual disciplines, they are staffed by personnel from Electronics Engineering, Mechanical Engineering, and other LLNL organizations, as appropriate. The thrust area leaders are expected to establish strong links to LLNL program leaders and to industry; to use outside and inside experts to review the quality and direction of the work; to use university contacts to supplement and complement their efforts; and to be certain that we are not duplicating the work of others. This annual report, organized by thrust area, describes activities conducted within the Program for the fiscal year 1992. Its intent is to provide timely summaries of objectives, theories, methods, and results. The nine thrust areas for this fiscal year are: Computational Electronics and Electromagnetics; Computational Mechanics; Diagnostics and Microelectronics; Emerging Technologies; Fabrication Technology; Materials Science and Engineering; Microwave and Pulsed Power; Nondestructive Evaluation; and Remote Sensing and Imaging, and Signal Engineering

  1. Experimental study on combustion modes and thrust performance of a staged-combustor of the scramjet with dual-strut

    Science.gov (United States)

    Yang, Qingchun; Chetehouna, Khaled; Gascoin, Nicolas; Bao, Wen

    2016-05-01

    To enable the scramjet operate in a wider flight Mach number, a staged-combustor with dual-strut is introduced to hold more heat release at low flight Mach conditions. The behavior of mode transition was examined using a direct-connect model scramjet experiment along with pressure measurements. The typical operating modes of the staged-combustor are analyzed. Fuel injection scheme has a significant effect on the combustor operating modes, particularly for the supersonic combustion mode. Thrust performances of the combustor with different combustion modes and fuel distributions are reported in this paper. The first-staged strut injection has a better engine performance in the operation of subsonic combustion mode. On the contrast, the second-staged strut injection has a better engine performance in the operation of supersonic combustion mode.

  2. 77 FR 9946 - Draft Guidance for Industry on Drug Interaction Studies-Study Design, Data Analysis, Implications...

    Science.gov (United States)

    2012-02-21

    ... industry entitled ``Drug Interaction Studies--Study Design, Data Analysis, Implications for Dosing, and... data analysis in the context of identifying potential drug interactions. The guidance also addresses... Studies--Study Design, Data Analysis, and Implications for Dosing and Labeling.'' Comments were received...

  3. Contextual cueing improves attentional guidance, even when guidance is supposedly optimal.

    Science.gov (United States)

    Harris, Anthony M; Remington, Roger W

    2017-05-01

    Visual search through previously encountered contexts typically produces reduced reaction times compared with search through novel contexts. This contextual cueing benefit is well established, but there is debate regarding its underlying mechanisms. Eye-tracking studies have consistently shown reduced number of fixations with repetition, supporting improvements in attentional guidance as the source of contextual cueing. However, contextual cueing benefits have been shown in conditions in which attentional guidance should already be optimal-namely, when attention is captured to the target location by an abrupt onset, or under pop-out conditions. These results have been used to argue for a response-related account of contextual cueing. Here, we combine eye tracking with response time to examine the mechanisms behind contextual cueing in spatially cued and pop-out conditions. Three experiments find consistent response time benefits with repetition, which appear to be driven almost entirely by a reduction in number of fixations, supporting improved attentional guidance as the mechanism behind contextual cueing. No differences were observed in the time between fixating the target and responding-our proxy for response related processes. Furthermore, the correlation between contextual cueing magnitude and the reduction in number of fixations on repeated contexts approaches 1. These results argue strongly that attentional guidance is facilitated by familiar search contexts, even when guidance is near-optimal. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  4. Experimental test of static and dynamic characteristics of tilting-pad thrust bearings

    Directory of Open Access Journals (Sweden)

    Annan Guo

    2015-07-01

    Full Text Available The axial vibration in turbine machine has attracted more and more interest. Tilting-pad thrust bearings are widely used in turbine machines to support the axial load. The dynamic properties generated by oil film of the thrust pad have important effects on the axial vibration of the rotor-bearing system. It is necessary to develop the method to test the dynamic characteristics of thrust bearings. A new rig has been developed. The facility allows a complete set of bearing operating parameters to be measured. Parameters measured include oil temperatures, oil-film thickness, and pressure. The static load and dynamic load can be added on the thrust bearing in the vertical direction at the same time. The relative and absolute displacement vibrations of the test experimental bearing with the changes of dynamic force are measured, and the dynamic characteristics of the test bearing are obtained. The experimental results show clearly that the operating conditions influence largely on the pad static and dynamic characteristics.

  5. Semantic guidance of eye movements in real-world scenes

    OpenAIRE

    Hwang, Alex D.; Wang, Hsueh-Cheng; Pomplun, Marc

    2011-01-01

    The perception of objects in our visual world is influenced by not only their low-level visual features such as shape and color, but also their high-level features such as meaning and semantic relations among them. While it has been shown that low-level features in real-world scenes guide eye movements during scene inspection and search, the influence of semantic similarity among scene objects on eye movements in such situations has not been investigated. Here we study guidance of eye movemen...

  6. Morphotectonics of the central Muertos thrust belt and Muertos Trough (northeastern Caribbean)

    Science.gov (United States)

    Granja, Bruna J.L.; ten Brink, Uri S.; Carbó-Gorosabel, Andrés; Muñoz-Martín, A.; Gomez, Ballesteros M.

    2009-01-01

    Multibeam bathymetry data acquired during the 2005 Spanish R/V Hesp??rides cruise and reprocessed multichannel seismic profiles provide the basis for the analysis of the morphology and deformation in the central Muertos Trough and Muertos thrust belt. The Muertos Trough is an elongated basin developed where the Venezuelan Basin crust is thrusted under the Muertos fold-and-thrust belt. Structural variations along the Muertos Trough are suggested to be a consequence of the overburden of the asymmetrical thrust belt and by the variable nature of the Venezuelan Basin crust along the margin. The insular slope can be divided into three east-west trending slope provinces with high lateral variability which correspond to different accretion stages: 1) The lower slope is composed of an active sequence of imbricate thrust slices and closed fold axes, which form short and narrow accretionary ridges and elongated slope basins; 2) The middle slope shows a less active imbricate structure resulting in lower superficial deformation and bigger slope basins; 3) The upper slope comprises the talus region and extended terraces burying an island arc basement and an inactive imbricate structure. The talus region is characterized by a dense drainage network that transports turbidite flows from the islands and their surrounding carbonate platform areas to the slope basins and sometimes to the trough. In the survey area the accommodation of the ongoing east-west differential motion between the Hispaniola and the Puerto Rico-Virgin Islands blocks takes place by means of diffuse deformation. The asymmetrical development of the thrust belt is not related to the geological conditions in the foreland, but rather may be caused by variations in the geometry and movement of the backstop. The map-view curves of the thrust belt and the symmetry of the recesses suggest a main north-south convergence along the Muertos margin. The western end of the Investigator Fault Zone comprises a broad band of

  7. A calibration mechanism based on the principles of the Michelson interferometer micro-thrust test device

    Science.gov (United States)

    Yan, Biao; Wang, Hai; Yang, Chunlai; Wen, Li

    2017-08-01

    A micro-thrust test system based on Michelson interferometer was proposed and tested. The relationship between thrust and output voltage of the calibration component in the system was calculated and verified with numerical modeling. The fitting function of the calibration component was obtained, which will be tested during future thrust test experiments.

  8. Guidance levels, achievable doses and expectation levels

    International Nuclear Information System (INIS)

    Li, Lianbo; Meng, Bing

    2002-01-01

    The National Radiological Protection Board (NRPB), the International Atomic Energy Agency (IAEA) and the Commission of the European Communities (CEC) published their guidance levels and reference doses for typical X-ray examination and nuclear medicine in their documents in 1993, 1994 and 1996 respectively. From then on, the concept of guidance levels or reference doses have been applied to different examinations in the field of radiology and proved to be effective for reduction of patient doses. But the guidance levels or reference doses are likely to have some shortcomings and can do little to make further reduction of patient dose in the radiology departments where patient dose are already below them. For this reason, the National Radiological Protection Board (NRPB) proposed a concept named achievable doses which are based on the mean dose observed for a selected sample of radiology departments. This paper will review and discuss the concept of guidance levels and achievable doses, and propose a new concept referred to as Expectation Levels that will encourage the radiology departments where patient dose are already below the guidance levels to keep patient dose as low as reasonably achievable. Some examples of the expectation levels based on the data published by a few countries are also illustrated in this paper

  9. High Thrust-to-Power Annular Engine Technology

    Science.gov (United States)

    Patterson, Michael J.; Thomas, Robert E.; Crofton, Mark W.; Young, Jason A.; Foster, John E.

    2015-01-01

    Gridded ion engines have the highest efficiency and total impulse of any mature electric propulsion technology, and have been successfully implemented for primary propulsion in both geocentric and heliocentric environments with excellent ground/in-space correlation of performance. However, they have not been optimized to maximize thrust-to-power, an important parameter for Earth orbit transfer applications. This publication discusses technology development work intended to maximize this parameter. These activities include investigating the capabilities of a non-conventional design approach, the annular engine, which has the potential of exceeding the thrust-to-power of other EP technologies. This publication discusses the status of this work, including the fabrication and initial tests of a large-area annular engine. This work is being conducted in collaboration among NASA Glenn Research Center, The Aerospace Corporation, and the University of Michigan.

  10. Effect of Cutting Parameters on Thrust Force and Surface Roughness in Drilling of Al-2219/B4C/Gr Metal Matrix Composites

    Science.gov (United States)

    Ravindranath, V. M.; Basavarajappa, G. S. Shiva Shankar S.; Suresh, R.

    2016-09-01

    In aluminium matrix composites, reinforcement of hard ceramic particle present inside the matrix which causes tool wear, high cutting forces and poor surface finish during machining. This paper focuses on effect of cutting parameters on thrust force, surface roughness and burr height during drilling of MMCs. In the present work, discuss the influence of spindle speed and feed rate on drilling the pure base alloy (Al-2219), mono composite (Al- 2219+8% B4C) and hybrid composite (Al-2219+8%B4C+3%Gr). The composites were fabricated using liquid metallurgy route. The drilling experiments were conducted by CNC machine with TiN coated HSS tool, M42 (Cobalt grade) and carbide tools at various spindle speeds and feed rates. The thrust force, surface roughness and burr height of the drilled hole were investigated in mono composite and hybrid composite containing graphite particles, the experimental results show that the feed rate has more influence on thrust force and surface roughness. Lesser thrust force and discontinuous chips were produced during machining of hybrid composites when compared with mono and base alloy during drilling process. It is due to solid lubricant property of graphite which reduces the lesser thrust force, burr height and lower surface roughness. When machining with Carbide tool at low feed and high speeds good surface finish was obtained compared to other two types of cutting tool materials.

  11. On the Possibilities of Decreasing Power Loss in Large Tilting Pad Thrust Bearings

    OpenAIRE

    Wasilczuk, Michal; Rotta, Grzegorz

    2013-01-01

    Different systems of direct oil supply have been developed in order to facilitate efficient introduction of fresh lubricant to the oil gap and reduction of churning power loss in tilting pad thrust bearings. Up to now there is no documented application of the supply groove in large thrust bearings used in water power plants. The results of modeling lubricant flow in the lubricating groove of a thrust bearing pad will be presented in the paper. CFD software was used to carry out fluid film cal...

  12. Kinematics of swimming and thrust production during powerstroking bouts of the swim frenzy in green turtle hatchlings

    Directory of Open Access Journals (Sweden)

    David T. Booth

    2014-09-01

    Full Text Available Hatchling sea turtles emerge from nests, crawl down the beach and enter the sea where they typically enter a stereotypical hyperactive swimming frenzy. During this swim the front flippers are moved up and down in a flapping motion and are the primary source of thrust production. I used high-speed video linked with simultaneous measurement of thrust production in tethered hatchlings, along with high-speed video of free swimming hatchlings swimming at different water speeds in a swim flume to investigate the links between kinematics of front flipper movement, thrust production and swimming speed. In particular I tested the hypotheses that (1 increased swimming speed is achieved through an increased stroke rate; (2 force produced per stroke is proportional to stroke amplitude, (3 that forward thrust is produced during both the down and up phases of stroking; and (4 that peak thrust is produced towards the end of the downstroke cycle. Front flipper stroke rate was independent of water speed refuting the hypothesis that swimming speed is increased by increasing stroke rate. Instead differences in swimming speed were caused by a combination of varying flipper amplitude and the proportion of time spent powerstroking. Peak thrust produced per stroke varied within and between bouts of powerstroking, and these peaks in thrust were correlated with both flipper amplitude and flipper angular momentum during the downstroke supporting the hypothesis that stroke force is a function of stroke amplitude. Two distinct thrust production patterns were identified, monophasic in which a single peak in thrust was recorded during the later stages of the downstroke, and biphasic in which a small peak in thrust was recorded at the very end of the upstroke and this followed by a large peak in thrust during the later stages of the downstroke. The biphasic cycle occurs in ∼20% of hatchlings when they first started swimming, but disappeared after one to two hours of

  13. Fusion Guidance in Endovascular Peripheral Artery Interventions: A Feasibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Sailer, Anna M., E-mail: anni.sailer@mumc.nl; Haan, Michiel W. de, E-mail: m.de.haan@mumc.nl; Graaf, Rick de, E-mail: r.de.graaf@mumc.nl; Zwam, Willem H. van, E-mail: w.van.zwam@mumc.nl [Maastricht University Medical Center, Department of Radiology (Netherlands); Schurink, Geert Willem H., E-mail: gwh.schurink@mumc.nl [Maastricht University Medical Center, Department of Surgery (Netherlands); Nelemans, Patricia J., E-mail: patty.nelemans@maastrichtuniversity.nl [Maastricht University Medical Centre, Department of Epidemiology (Netherlands); Wildberger, Joachim E., E-mail: j.wildberger@mumc.nl; Das, Marco, E-mail: m.das@mumc.nl [Maastricht University Medical Center, Department of Radiology (Netherlands)

    2015-04-15

    PurposeThis study was designed to evaluate the feasibility of endovascular guidance by means of live fluoroscopy fusion with magnetic resonance angiography (MRA) and computed tomography angiography (CTA).MethodsFusion guidance was evaluated in 20 endovascular peripheral artery interventions in 17 patients. Fifteen patients had received preinterventional diagnostic MRA and two patients had undergone CTA. Time for fluoroscopy with MRA/CTA coregistration was recorded. Feasibility of fusion guidance was evaluated according to the following criteria: for every procedure the executing interventional radiologists recorded whether 3D road-mapping provided added value (yes vs. no) and whether PTA and/or stenting could be performed relying on the fusion road-map without need for diagnostic contrast-enhanced angiogram series (CEAS) (yes vs. no). Precision of the fusion road-map was evaluated by recording maximum differences between the position of the vasculature on the virtual CTA/MRA images and conventional angiography.ResultsAverage time needed for image coregistration was 5 ± 2 min. Three-dimensional road-map added value was experienced in 15 procedures in 12 patients. In half of the patients (8/17), intervention was performed relying on the fusion road-map only, without diagnostic CEAS. In two patients, MRA roadmap showed a false-positive lesion. Excluding three patients with inordinate movements, mean difference in position of vasculature on angiography and MRA/CTA road-map was 1.86 ± 0.95 mm, implying that approximately 95 % of differences were between 0 and 3.72 mm (2 ± 1.96 standard deviation).ConclusionsFluoroscopy with MRA/CTA fusion guidance for peripheral artery interventions is feasible. By reducing the number of CEAS, this technology may contribute to enhance procedural safety.

  14. Fusion Guidance in Endovascular Peripheral Artery Interventions: A Feasibility Study

    International Nuclear Information System (INIS)

    Sailer, Anna M.; Haan, Michiel W. de; Graaf, Rick de; Zwam, Willem H. van; Schurink, Geert Willem H.; Nelemans, Patricia J.; Wildberger, Joachim E.; Das, Marco

    2015-01-01

    PurposeThis study was designed to evaluate the feasibility of endovascular guidance by means of live fluoroscopy fusion with magnetic resonance angiography (MRA) and computed tomography angiography (CTA).MethodsFusion guidance was evaluated in 20 endovascular peripheral artery interventions in 17 patients. Fifteen patients had received preinterventional diagnostic MRA and two patients had undergone CTA. Time for fluoroscopy with MRA/CTA coregistration was recorded. Feasibility of fusion guidance was evaluated according to the following criteria: for every procedure the executing interventional radiologists recorded whether 3D road-mapping provided added value (yes vs. no) and whether PTA and/or stenting could be performed relying on the fusion road-map without need for diagnostic contrast-enhanced angiogram series (CEAS) (yes vs. no). Precision of the fusion road-map was evaluated by recording maximum differences between the position of the vasculature on the virtual CTA/MRA images and conventional angiography.ResultsAverage time needed for image coregistration was 5 ± 2 min. Three-dimensional road-map added value was experienced in 15 procedures in 12 patients. In half of the patients (8/17), intervention was performed relying on the fusion road-map only, without diagnostic CEAS. In two patients, MRA roadmap showed a false-positive lesion. Excluding three patients with inordinate movements, mean difference in position of vasculature on angiography and MRA/CTA road-map was 1.86 ± 0.95 mm, implying that approximately 95 % of differences were between 0 and 3.72 mm (2 ± 1.96 standard deviation).ConclusionsFluoroscopy with MRA/CTA fusion guidance for peripheral artery interventions is feasible. By reducing the number of CEAS, this technology may contribute to enhance procedural safety

  15. Effect of outer wing separation on lift and thrust generation in a flapping wing system

    International Nuclear Information System (INIS)

    Mahardika, Nanang; Viet, Nguyen Quoc; Park, Hoon Cheol

    2011-01-01

    We explore the implementation of wing feather separation and lead-lagging motion to a flapping wing. A biomimetic flapping wing system with separated outer wings is designed and demonstrated. The artificial wing feather separation is implemented in the biomimetic wing by dividing the wing into inner and outer wings. The features of flapping, lead-lagging, and outer wing separation of the flapping wing system are captured by a high-speed camera for evaluation. The performance of the flapping wing system with separated outer wings is compared to that of a flapping wing system with closed outer wings in terms of forward force and downward force production. For a low flapping frequency ranging from 2.47 to 3.90 Hz, the proposed biomimetic flapping wing system shows a higher thrust and lift generation capability as demonstrated by a series of experiments. For 1.6 V application (lower frequency operation), the flapping wing system with separated wings could generate about 56% higher forward force and about 61% less downward force compared to that with closed wings, which is enough to demonstrate larger thrust and lift production capability of the separated outer wings. The experiments show that the outer parts of the separated wings are able to deform, resulting in a smaller amount of drag production during the upstroke, while still producing relatively greater lift and thrust during the downstroke.

  16. Robotic Pectoral Fin Thrust Vectoring Using Weighted Gait Combinations

    Directory of Open Access Journals (Sweden)

    John S. Palmisano

    2012-01-01

    Full Text Available A method was devised to vector propulsion of a robotic pectoral fin by means of actively controlling fin surface curvature. Separate flapping fin gaits were designed to maximize thrust for each of three different thrust vectors: forward, reverse, and lift. By using weighted combinations of these three pre-determined main gaits, new intermediate hybrid gaits for any desired propulsion vector can be created with smooth transitioning between these gaits. This weighted gait combination (WGC method is applicable to other difficult-to-model actuators. Both 3D unsteady computational fluid dynamics (CFD and experimental results are presented.

  17. Career guidance in communities

    DEFF Research Database (Denmark)

    Thomsen, Rie

    for the development of a critically reflexive career guidance practice. The considerations are organised around seven elements. 1. Creating opportunity, structure and access 2. Entering a community and increasing visibility 3. Providing guidance in communities 4. Exploring potentials in guidance situations 5...... in career guidance practices as well as in the lives of the people in the communities. This paper falls into two parts: The first part considers the collective as the starting point for the development of meaningful career guidance activities. Based on previous research on career guidance in communities......The aim of this paper is to inspire practitioners and professionals to leave their offices to bring career guidance into communities that might not identify with career guidance in the first instance. By making the effort to engage with communities, practitioners may bring about a critical change...

  18. Comparing the New Madrid Seismic Zone with the Osning Thrust: implications for GIA-induced intraplate tectonics in northern Germany

    Science.gov (United States)

    Brandes, Christian; Steffen, Holger; Wu, Patrick; Tanner, David; Winsemann, Jutta

    2013-04-01

    Continental intraplate tectonics is a widespread phenomenon that causes significant earthquakes. These earthquakes even occur in areas that are characterized by low strain rates and there are often long intervals between the individual seismic events (Gangopadhyay & Talwani, 2003) that result in a hazard potential. To better understand the controlling factors of intraplate plate earthquakes in northern Germany, we compare the Osning Thrust with the intensively-studied New Madrid Seismic Zone in the Midwest USA. Both areas share major similarities such as a failed rift-basin setting, the presence of intrusive magmatic bodies in the subsurface, tectonic reactivation during the Late Cretaceous, paleo- and historic seismicity and comparable fault parameters. In addition, both areas have a very similar Late Pleistocene deglaciation history. New Madrid was c. 340 km south of the Laurentide ice sheet and ice retreat started around 21 ka and was completed by 8.5 ka (Grollimund & Zoback, 2001). The Osning Thrust was c. 310 km south of the Scandinavian ice sheet and deglaciation began at 24 ka. Both areas show historic seismicity in a similar time frame (New Madrid Seismic Zone: 1811-1812, Johnston & Schweig, 1996); Osning Thrust: 1612 and 1767, Grünthal & Bosse, 1997). We use numerical simulations to identify the timing of potentially GIA-induced fault activity, which are based on the fault stability margin concept of Wu & Hasegawa (1996). From our modelling results it is evident that the fault stability margin changed to negative between 16 and 13 ka for the Osning Thrust, which matches the OSL data of fault-related growth strata (Brandes et al., 2012). For the New Madrid Seismic Zone, the fault stability margin becomes zero between 2.5 ka BP (before 1812) to about 2 ka after the 1812 event, depending on the parameters of the model. This indicates that for both seismic zones, seismicity due to deglaciation was and still is very likely. From this study it can be derived

  19. Dynamic recrystallization mechanisms and their transition in the Daling Thrust (DT) zone, Darjeeling-Sikkim Himalaya

    Science.gov (United States)

    Ghosh, Subhajit; Bose, Santanu; Mandal, Nibir; Dasgupta, Sujoy

    2016-04-01

    The Daling Thrust (DT) delineates a zone of intense shear localization in the Lesser Himalayan Sequence (LHS) of the Darjeeling-Sikkim Himalaya. From microstructural studies of deformed quartzite samples, we show a transition in the dynamic recrystallization mechanism with increasing distance from the DT, dominated by grain boundary bulging (BLG) recrystallization closest to the DT, and progressively replaced by sub-grain rotation (SGR) recrystallization away from the thrust. The transition is marked by a characteristic variation in the fractal dimension (D) of grain boundaries, estimated from the area-perimeter method. For the BLG regime, D ≈ 1.046, which decreases significantly to a value as low as 1.025 for the SGR regime. Using the available thermal data for BLG and SGR recrystallization, we infer increasing deformation temperatures away from the DT in the hanging wall. Based on the quartz piezometer our estimates reveal strong variations in the flow stress (59.00 MPa to 16.00 MPa) over a distance of 1.2 km from the DT. Deformation mechanism maps constructed for different temperatures indicate that the strain rates (10- 12 S- 1 to 10- 14 S- 1) comply with the geologically possible range. Finally, we present a mechanical model to provide a possible explanation for the cause of stress intensification along the DT.

  20. LEVEL SOCIAL SELF CONCEPT AND IMPLICATION IN GUIDANCE AND COUNSELING

    Directory of Open Access Journals (Sweden)

    Widya Kartika Sari

    2016-12-01

    Full Text Available Teenager consider themselves based on the perception others and one of the element which affecting the maturation in self concept is how the assessment and social environment revenue toward it self .This study purpose to describe the self concept of teens and the implications in guidance and counseling .The research type descriptive quantitative methods. The Research was done to teenagers of simple  orphanage in  bengkulu with a population about 103 teenagers .The total of the  research about 82 survey youth to the sample used purposive sampling techniqul  instrument was used  the closed of  scale likert model  with validity 0.873 , reliability ( 0,931 self concept .The findings of this research shows that: ( 1 self concept as of teens tend to be low category. (2  implications finding for service counseling guidance the basic of arranging the guidance counseling program service which can formed  and improved the self concept of teens positively.

  1. Guidance and control, 1993; Annual Rocky Mountain Guidance and Control Conference, 16th, Keystone, CO, Feb. 6-10, 1993

    Science.gov (United States)

    Culp, Robert D.; Bickley, George

    Papers from the sixteenth annual American Astronautical Society Rocky Mountain Guidance and Control Conference are presented. The topics covered include the following: advances in guidance, navigation, and control; control system videos; guidance, navigation and control embedded flight control systems; recent experiences; guidance and control storyboard displays; and applications of modern control, featuring the Hubble Space Telescope (HST) performance enhancement study. For individual titles, see A95-80390 through A95-80436.

  2. Hydrodynamic thrust generation and power consumption investigations for piezoelectric fins with different aspect ratios

    Science.gov (United States)

    Shahab, S.; Tan, D.; Erturk, A.

    2015-12-01

    Bio-inspired hydrodynamic thrust generation using piezoelectric transduction has recently been explored using Macro-Fiber Composite (MFC) actuators. The MFC technology strikes a balance between the actuation force and structural deformation levels for effective swimming performance, and additionally offers geometric scalability, silent operation, and ease of fabrication. Recently we have shown that mean thrust levels comparable to biological fish of similar size can be achieved using MFC fins. The present work investigates the effect of length-to-width (L/b) aspect ratio on the hydrodynamic thrust generation performance of MFC cantilever fins by accounting for the power consumption level. It is known that the hydrodynamic inertia and drag coefficients are controlled by the aspect ratio especially for L/bdrag coefficients from the vibration response to harmonic actuation for the first bending mode. Experiments are then conducted for various actuation voltage levels to quantify the mean thrust resultant and power consumption levels for different aspect ratios. Variation of the thrust coefficient of the MFC bimorph fins with changing aspect ratio is also semi-empirically modeled and presented.

  3. Breathing guidance in radiation oncology and radiology: A systematic review of patient and healthy volunteer studies

    International Nuclear Information System (INIS)

    Pollock, Sean; Keall, Paul; Keall, Robyn

    2015-01-01

    Purpose: The advent of image-guided radiation therapy has led to dramatic improvements in the accuracy of treatment delivery in radiotherapy. Such advancements have highlighted the deleterious impact tumor motion can have on both image quality and radiation treatment delivery. One approach to reducing tumor motion irregularities is the use of breathing guidance systems during imaging and treatment. These systems aim to facilitate regular respiratory motion which in turn improves image quality and radiation treatment accuracy. A review of such research has yet to be performed; it was therefore their aim to perform a systematic review of breathing guidance interventions within the fields of radiation oncology and radiology. Methods: From August 1–14, 2014, the following online databases were searched: Medline, Embase, PubMed, and Web of Science. Results of these searches were filtered in accordance to a set of eligibility criteria. The search, filtration, and analysis of articles were conducted in accordance with preferred reporting items for systematic reviews and meta-analyses. Reference lists of included articles, and repeat authors of included articles, were hand-searched. Results: The systematic search yielded a total of 480 articles, which were filtered down to 27 relevant articles in accordance to the eligibility criteria. These 27 articles detailed the intervention of breathing guidance strategies in controlled studies assessing its impact on such outcomes as breathing regularity, image quality, target coverage, and treatment margins, recruiting either healthy adult volunteers or patients with thoracic or abdominal lesions. In 21/27 studies, significant (p < 0.05) improvements from the use of breathing guidance were observed. Conclusions: There is a trend toward the number of breathing guidance studies increasing with time, indicating a growing clinical interest. The results found here indicate that further clinical studies are warranted that quantify the

  4. Breathing guidance in radiation oncology and radiology: A systematic review of patient and healthy volunteer studies

    Energy Technology Data Exchange (ETDEWEB)

    Pollock, Sean, E-mail: sean.pollock@sydney.edu.au; Keall, Paul [Radiation Physics Laboratory, University of Sydney, Sydney 2050 (Australia); Keall, Robyn [Central School of Medicine, University of Sydney, Sydney 2050, Australia and Hammond Care, Palliative Care and Supportive Care Service, Greenwich 2065 (Australia)

    2015-09-15

    Purpose: The advent of image-guided radiation therapy has led to dramatic improvements in the accuracy of treatment delivery in radiotherapy. Such advancements have highlighted the deleterious impact tumor motion can have on both image quality and radiation treatment delivery. One approach to reducing tumor motion irregularities is the use of breathing guidance systems during imaging and treatment. These systems aim to facilitate regular respiratory motion which in turn improves image quality and radiation treatment accuracy. A review of such research has yet to be performed; it was therefore their aim to perform a systematic review of breathing guidance interventions within the fields of radiation oncology and radiology. Methods: From August 1–14, 2014, the following online databases were searched: Medline, Embase, PubMed, and Web of Science. Results of these searches were filtered in accordance to a set of eligibility criteria. The search, filtration, and analysis of articles were conducted in accordance with preferred reporting items for systematic reviews and meta-analyses. Reference lists of included articles, and repeat authors of included articles, were hand-searched. Results: The systematic search yielded a total of 480 articles, which were filtered down to 27 relevant articles in accordance to the eligibility criteria. These 27 articles detailed the intervention of breathing guidance strategies in controlled studies assessing its impact on such outcomes as breathing regularity, image quality, target coverage, and treatment margins, recruiting either healthy adult volunteers or patients with thoracic or abdominal lesions. In 21/27 studies, significant (p < 0.05) improvements from the use of breathing guidance were observed. Conclusions: There is a trend toward the number of breathing guidance studies increasing with time, indicating a growing clinical interest. The results found here indicate that further clinical studies are warranted that quantify the

  5. Pilot Study of a New Nonradioactive Surgical Guidance Technology for Locating Nonpalpable Breast Lesions.

    Science.gov (United States)

    Cox, Charles E; Garcia-Henriquez, Norbert; Glancy, M Jordan; Whitworth, Pat; Cox, John M; Themar-Geck, Melissa; Prati, Ronald; Jung, Michelle; Russell, Scott; Appleton, Kristie; King, Jeff; Shivers, Steven C

    2016-06-01

    The current technique for locating nonpalpable breast lesions is wire localization (WL). Radioactive seed localization and intraoperative ultrasound were developed to improve difficulties with WL. The SAVI SCOUT surgical guidance system was developed to improve these methods. The SCOUT system is a non-radioactive, FDA-cleared medical device that uses electromagnetic wave technology to provide real-time guidance during excisional breast procedures. Consenting patients underwent localization and excision using an implantable electromagnetic wave reflective device (reflector) and a detector handpiece with a console. Using image guidance, the reflector was placed up to 7 days before the surgical procedure. The primary end points of the study were successful reflector placement, localization, and retrieval. The secondary end points were percentage of clear margins, reexcision rates, days of placement before excision, and physician comparison with WL. This study analyzed 50 patients. The reflectors were placed under mammographic guidance (n = 18, 36 %) or ultrasound guidance (n = 32, 64 %). Of the 50 patients, 10 (20 %) underwent excisional biopsy and 40 (80 %) had a lumpectomy. The lesion and reflector were successfully removed in all 50 patients, and no adverse events occurred. Of the 41 patients who had in situ and/or invasive carcinoma identified, 38 (93 %) had clear margins and 3 (7 %) were recommended for reexcision. These data suggest that the SCOUT system is safe and effective for guiding the excision of nonpalpable breast lesions and a viable alternative to standard localization options. A larger prospective, multi-institution trial of SCOUT currently is underway to validate these findings.

  6. Camera Layout Design for the Upper Stage Thrust Cone

    Science.gov (United States)

    Wooten, Tevin; Fowler, Bart

    2010-01-01

    Engineers in the Integrated Design and Analysis Division (EV30) use a variety of different tools to aid in the design and analysis of the Ares I vehicle. One primary tool in use is Pro-Engineer. Pro-Engineer is a computer-aided design (CAD) software that allows designers to create computer generated structural models of vehicle structures. For the Upper State thrust cone, Pro-Engineer was used to assist in the design of a layout for two camera housings. These cameras observe the separation between the first and second stage of the Ares I vehicle. For the Ares I-X, one standard speed camera was used. The Ares I design calls for two separate housings, three cameras, and a lighting system. With previous design concepts and verification strategies in mind, a new layout for the two camera design concept was developed with members of the EV32 team. With the new design, Pro-Engineer was used to draw the layout to observe how the two camera housings fit with the thrust cone assembly. Future analysis of the camera housing design will verify the stability and clearance of the camera with other hardware present on the thrust cone.

  7. Guidance For The Proper Characterization And Classification Of Low Specific Activity Materials And Surface Contaminated Objects For Disposal

    International Nuclear Information System (INIS)

    Portsmouth, J.H.; Blackford, L.T.

    2012-01-01

    Regulatory concerns over the proper characterization of certain waste streams led CH2M HILL Plateau Remediation Company (CHPRC) to develop written guidance for personnel involved in Decontamination and Decommissioning (D and D) activities, facility management and Waste Management Representatives (WMRs) involved in the designation of wastes for disposal on and off the Hanford Site. It is essential that these waste streams regularly encountered in D and D operations are properly designated, characterized and classified prior to shipment to a Treatment, Storage or Disposal Facility (TSDF). Shipments of waste determined by the classification process as Low Specific Activity (LSA) or Surface Contaminated Objects (SCO) must also be compliant with all applicable U.S. Department of Transportation (DOE) regulations as well as Department of Energy (DOE) orders. The compliant shipment of these waste commodities is critical to the Hanford Central Plateau cleanup mission. Due to previous problems and concerns from DOE assessments, CHPRC internal critiques as well as DOT, a management decision was made to develop written guidance and procedures to assist CHPRC shippers and facility personnel in the proper classification of D and D waste materials as either LSA or SCO. The guidance provides a uniform methodology for the collection and documentation required to effectively characterize, classify and identify candidate materials for shipping operations. A primary focus is to ensure that waste materials generated from D and D and facility operations are compliant with the DOT regulations when packaged for shipment. At times this can be difficult as the current DOT regulations relative to the shipment of LSA and SCO materials are often not clear to waste generators. Guidance is often sought from NUREG 1608/RAMREG-003 (3): a guidance document that was jointly developed by the DOT and the Nuclear Regulatory Commission (NRC) and published in 1998. However, NUREG 1608 (3) is now thirteen

  8. A comparative study to evaluate the discrepancy in condylar guidance values between two commercially available arcon and non-arcon articulators: A clinical study

    Directory of Open Access Journals (Sweden)

    Mukesh Kumar Goyal

    2011-01-01

    Full Text Available Aim: The purpose of this study was comparative evaluation of sagittal condylar values of arcon and non-arcon articulators with cephalometric readings and to determine the amount of discrepancy in sagittal condylar guidance values between arcon and non-arcon articulators using same protrusive record. Materials and Methods: Twenty subjects in the age group of 19-35 years, free from temporomandibular joint dysfunction, and occlusal disharmony, with healthy dentition participated in the study. Hanau H2 (non-arcon type and Hanau Wide-Vue (arcon type articulators were programmed for sagittal condylar guidance values using the same protrusive record made in polysiloxane bite registration material with edge to edge degree of protrusion. The resultant values for both the articulators on either side were compared with values obtained from tracing of digital lateral cephalogram using Kodak Dental imaging Window software 6.6.3.0-C program. The tabulated data were subjected to statistical analysis, ANOVA (Fishers ′F′ test for group comparison, Tukey′s HSD test for inter-comparison, student′s unpaired ′t′ test for intra-group comparison, and level of significance (P was calculated using the same. Results: The mean sagittal condylar guidance values of the three different groups were found to be very highly significant (P=0.001 and highly significant (P=0.002 on the right and left sides respectively. There was a very highly significant difference (P=0.001 and highly significant difference (P=0.003 between the arcon and non-arcon group on the right and left side respectively. No significant difference was found between the arcon and cephalometric group (P=0.284 right, P=0.853 left and a statistically significant difference was found between the non-arcon and cephalometric group (P=0.049 right, P=0.015 left. On intragroup comparison there was no statistically significant difference in sagittal condylar values on the right and left sides. Conclusion

  9. Guidance Counsellor Strategies for Handling Bullying

    Science.gov (United States)

    Power-Elliott, Michleen; Harris, Gregory E.

    2012-01-01

    The purpose of this exploratory-descriptive study was to examine how guidance counsellors in the province of Newfoundland and Labrador would handle a specific verbal-relational bullying incident. Also of interest was guidance counsellor involvement and training in bullying programmes and Positive Behaviour Supports. Data for this study was…

  10. Experimental demonstration of ion extraction from magnetic thrust chamber for laser fusion rocket

    Science.gov (United States)

    Saito, Naoya; Yamamoto, Naoji; Morita, Taichi; Edamoto, Masafumi; Nakashima, Hideki; Fujioka, Shinsuke; Yogo, Akifumi; Nishimura, Hiroaki; Sunahara, Atsushi; Mori, Yoshitaka; Johzaki, Tomoyuki

    2018-05-01

    A magnetic thrust chamber is an important system of a laser fusion rocket, in which the plasma kinetic energy is converted into vehicle thrust by a magnetic field. To investigate the plasma extraction from the system, the ions in a plasma are diagnosed outside the system by charge collectors. The results clearly show that the ion extraction does not strongly depend on the magnetic field strength when the energy ratio of magnetic field to plasma is greater than 4.3, and the magnetic field pushes back the plasma to generate a thrust, as previously suggested by numerical simulation and experiments.

  11. Thrust Augmentation by Airframe-Integrated Linear-Spike Nozzle Concept for High-Speed Aircraft

    Directory of Open Access Journals (Sweden)

    Hidemi Takahashi

    2018-02-01

    Full Text Available The airframe-integrated linear-spike nozzle concept applied to an external nozzle for high-speed aircraft was evaluated with regard to the thrust augmentation capability and the trim balance. The main focus was on the vehicle aftbody. The baseline airframe geometry was first premised to be a hypersonic waverider design. The baseline aftbody case had an external nozzle comprised of a simple divergent nozzle and was hypothetically replaced with linear-spike external nozzle configurations. Performance evaluation was mainly conducted by considering the nozzle thrust generated by the pressure distribution on the external nozzle surface at the aftbody portion calculated by computer simulation at a given cruise condition with zero angle of attack. The thrust performance showed that the proposed linear-spike external nozzle concept was beneficial in thrust enhancement compared to the baseline geometry because the design of the proposed concept had a compression wall for the exhaust flow, which resulted in increasing the wall pressure. The configuration with the boattail and the angled inner nozzle exhibited further improvement in thrust performance. The trim balance evaluation showed that the aerodynamic center location appeared as acceptable. Thus, benefits were obtained by employing the airframe-integrated linear-spike external nozzle concept.

  12. Engineering Research, Development and Technology, FY95: Thrust area report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-02-01

    The mission of the Engineering Research, Development, and Technology Program at Lawrence Livermore National Laboratory (LLNL) is to develop the knowledge base, process technologies, specialized equipment, tools and facilities to support current and future LLNL programs. Engineering`s efforts are guided by a strategy that results in dual benefit: first, in support of Department of Energy missions, such as national security through nuclear deterrence; and second, in enhancing the nation`s economic competitiveness through their collaboration with US industry in pursuit of the most cost-effective engineering solutions to LLNL programs. To accomplish this mission, the Engineering Research, Development, and Technology Program has two important goals: (1) identify key technologies relevant to LLNL programs where they can establish unique competencies, and (2) conduct high-quality research and development to enhance their capabilities and establish themselves as the world leaders in these technologies. To focus Engineering`s efforts, technology thrust areas are identified and technical leaders are selected for each area. The thrust areas are comprised of integrated engineering activities, staffed by personnel from the nine electronics and mechanical engineering divisions, and from other LLNL organizations. This annual report, organized by thrust area, describes Engineering`s activities for fiscal year 1995. The report provides timely summaries of objectives methods, and key results from eight thrust areas: computational electronics and electromagnetics; computational mechanics; microtechnology; manufacturing technology; materials science and engineering; power conversion technologies; nondestructive evaluation; and information engineering.

  13. F-15B ACTIVE with thrust vectoring nozzles on test stand

    Science.gov (United States)

    1995-01-01

    This November 13, 1995, photograph of the F-15 Advanced Controls Technology for Integrated Vehicles (ACTIVE) at NASA's Dryden Flight Research Center, Edwards, California, shows the thrust stand being used for ground testing of a new thrust-vectoring concept involving two new Pratt & Whitney nozzles that can turn up to 20 degrees in any direction. These nozzles give the aircraft thrust control in the pitch (up and down) and yaw (left and right) directions. This will reduce drag and increase fuel economy or range as compared with conventional aerodynamic controls, which increase the retarding forces (drag) acting upon the aircraft. These tests could lead to significant performance increases for military and commercial aircraft. The research program is the product of a collaborative effort by NASA, the Air Force's Wright Laboratory, Pratt & Whitney, and McDonnell Douglas Aerospace.

  14. Linkages between orogenic plateau build-up, fold-thrust shortening, and foreland basin evolution in the Zagros (NW Iran)

    Science.gov (United States)

    Barber, D. E.; Stockli, D. F.

    2017-12-01

    The Iranian Plateau (IP) is a thickened, low-relief morphotectonic province of diffuse deformation that formed due to Arabia-Eurasia collision and may serve as a younger analogue for the Tibetan Plateau. Despite detailed geophysical characterization of the IP, its deformation history and relationship to the Zagros fold-thrust belt and its foreland basin evolution remains unresolved. Low-temperature thermochronometry and provenance data from a transect across the internal and external Zagros track growth of the IP and delineate multiphase interaction between upper- and lower-plate processes during closure of the Neotethys and Arabia-Eurasia suturing. Inversion of zircon (U-Th)/He and fission-track data from plutonic and metamorphic basement rocks in the Sanandaj-Sirjan Zone (SSZ) of the IP reveals an initial stage of low-rate exhumation from 36-25 Ma, simultaneous with the onset of tectonic subsidence and marine incursion in the Zagros foreland basin. Overlapping apatite fission-track and (U-Th)/He ages indicate sharp acceleration in SSZ exhumation rates between 20-15 Ma, coincident with rejuvenation of foreland basin subsidence and an influx of Eurasian-derived sediments into the Zagros foreland deposited above an Oligocene unconformity. The mid-Miocene marks a transition in focused exhumation from the SSZ to Arabian lower-plate. Apatite (U-Th)/He ages suggest in-sequence fold-thrust propagation from the High Zagros to simply folded belt from 10 Ma to recent, which is reflected in the foreland by a shift in provenance to dominantly recycled Arabian-derived detritus and clastic facies progradation. Integrated thermochronometric and provenance data document a two-phase outward expansion of the Iranian Plateau and Zagros fold-thrust belt, tightly coupled to distinct phases of basin evolution and provenance shifts in the Zagros foreland. We associate multiple deformation and basin episodes with protracted collisional processes, from subduction of attenuated Arabian

  15. Nurses' provision of parental guidance regarding school-aged children's postoperative pain management: a descriptive correlational study.

    Science.gov (United States)

    He, Hong-Gu; Klainin-Yobas, Piyanee; Ang, Emily Neo Kim; Sinnappan, Rajammal; Pölkki, Tarja; Wang, Wenru

    2015-02-01

    Involving parents in children's pain management is essential to achieve optimal outcomes. Parents need to be equipped with sufficient knowledge and information. Only a limited number of studies have explored nurses' provision of parental guidance regarding the use of nonpharmacologic methods in children's pain management. This study aimed to examine nurses' perceptions of providing preparatory information and nonpharmacologic methods to parents, and how their demographics and perceived knowledge adequacy of these methods influence this guidance. A descriptive correlational study using questionnaire surveys was conducted to collect data from a convenience sample of 134 registered nurses working in seven pediatric wards of two public hospitals in Singapore. Descriptive statistics, independent-samples t test, and multiple linear regression were used to analyze the data. Most nurses provided various types of cognitive information to parents related to their children's surgery, whereas information about children's feelings was less often provided. Most nurses provided guidance to parents on positioning, breathing technique, comforting/reassurance, helping with activities of daily living, relaxation, and creating a comfortable environment. Nurses' provision of parental guidance on preparatory information and nonpharmacologic methods was significantly different between subgroups of age, education, parent or not, and perceived knowledge adequacy of nonpharmacologic methods. Nurses' perceived knowledge adequacy was the main factor influencing their provision of parental guidance. More attention should be paid to nurses who are younger, have less working experience, and are not parents. There is a need to educate nurses about nonpharmacologic pain relief methods to optimize their provision of parental guidance. Copyright © 2015 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.

  16. Tail thrust of bluefish Pomatomus saltatrix at different buoyancies, speeds, and swimming angles.

    Science.gov (United States)

    Ogilvy, C S; DuBois, A B

    1982-06-01

    1. The tail thrust of bluefish Pomatomus saltatrix was measured using a body accelerometer at different water speeds, buoyancies, and angles of water flow to determine the contribution of tail thrust in overcoming parasitic drag, induced drag, and weight directed along the track. The lengths and weights of the fish averaged 0.52 m and 1.50 kg respectively. 2. The tail thrust overcoming parasitic drag in Newtons, as measured during neutral buoyancy, was: 0.51 x speed + 0.15, with a standard error of estimate of 0.09 N. 3. When buoyancy was altered by the introduction or removal of air from a balloon implanted in the swim bladder, the tail thrust was altered by an amount of the same order as the value calculated for the induced drag of the pectoral fins. 4. The component of weight directed backward along the track was the weight in water multiplied by the sine of the angle of the swimming tunnel relative to horizontal. When this force was added to the calculated induced drag and tail thrust measured at neutral buoyancy, the rearward force equal to the tail thrust, at 45 ml negative buoyancy, 0.5 m s-1, and 15 degrees head up, was 0.12 N due to weight + 0.05 N due to induced drag + 0.40 N due to parasitic drag = 0.57 N total rearward force. 5. The conditions required for gliding were not achieved in our bluefish because the drag exceeded the component of the weight in water directed forward along the track at speeds above the stalling speed of the pectoral fins.

  17. Shock unsteadiness in a thrust optimized parabolic nozzle

    Science.gov (United States)

    Verma, S. B.

    2009-07-01

    This paper discusses the nature of shock unsteadiness, in an overexpanded thrust optimized parabolic nozzle, prevalent in various flow separation modes experienced during start up {(δ P0 /δ t > 0)} and shut down {(δ P0/δ t The results are based on simultaneously acquired data from real-time wall pressure measurements using Kulite pressure transducers, high-speed schlieren (2 kHz) of the exhaust flow-field and from strain-gauges installed on the nozzle bending tube. Shock unsteadiness in the separation region is seen to increase significantly just before the onset of each flow transition, even during steady nozzle operation. The intensity of this measure ( rms level) is seen to be strongly influenced by relative locations of normal and overexpansion shock, the decrease in radial size of re-circulation zone in the back-flow region, and finally, the local nozzle wall contour. During restricted shock separation, the pressure fluctuations in separation region exhibit periodic characteristics rather than the usually observed characteristics of intermittent separation. The possible physical mechanisms responsible for the generation of flow unsteadiness in various separation modes are discussed. The results are from an experimental study conducted in P6.2 cold-gas subscale test facility using a thrust optimized parabolic nozzle of area-ratio 30.

  18. A six degree-of-freedom thrust sensor for a labscale hybrid rocket

    Science.gov (United States)

    Wright, Ann M.; Wright, Andrew B.; Born, Traig; Strickland, Ryan

    2013-12-01

    A six degree-of-freedom thrust sensor was designed, constructed, calibrated, and tested using the labscale hybrid rocket at the University of Arkansas at Little Rock. The system consisted of six independent legs: one parallel to the axis of symmetry of the rocket for main thrust measurement, two vertical legs near the nozzle end of the rocket, one vertical leg near the oxygen input end of the rocket, and two separated horizontal legs near the nozzle end. Each leg was composed of a rotational bearing, a load cell, and a universal joint above and below the load cell. The leg was designed to create point contact along only one direction and minimize the non-axial forces applied to the load cell. With this system, force in each direction and moments for roll, pitch, and yaw can be measured. The system was calibrated and tested using a labscale hybrid rocket using gaseous oxygen and hydroxyl-terminated polybutadiene solid fuel. The thrust stand proved to be stable during calibration tests. Thrust force vector components and roll, pitch, and yaw moments were calculated for test firings with an oxygen mass flow rate range of 0.0174-0.0348 kg s-1.

  19. Determining heterogeneous deformation for granitic rocks in the northern thrust in Wadi Mubarak belt, Eastern Desert, Egypt

    Science.gov (United States)

    Kassem, Osama M. K.

    2011-05-01

    Finite-strain was studied in the mylonitic granitic and metasedimentary rocks in the northern thrust in Wadi Mubarak belt to show a relationship to nappe contacts between the old granitic and metavolcano-sedimentary rocks and to shed light on the heterogeneous deformation for the northern thrust in Wadi Mubarak belt. We used the Rf/ϕ and Fry methods on feldspar porphyroclasts, quartz and mafic grains from 7 old granitic and 7 metasedimentary samples in the northern thrust in Wadi Mubarak belt. The finite-strain data shows that old granitic rocks were moderate to highly deformed and axial ratios in the XZ section range from 3.05 to 7.10 for granitic and metasedimentary rocks. The long axes (X) of the finite-strain ellipsoids trend W/WNW and E/ENE in the northern thrust in Wadi Mubarak belt. Furthermore, the short axes (Z) are subvertical associated with a subhorizontal foliation. The value of strain magnitudes mainly constants towards the tectonic contacts between the mylonitic granite and metavolcano-sedimentary rocks. The data indicate oblate strain symmetry (flattening strain) in the mylonitic granite rocks. It is suggested that the accumulation of finite strain was formed before or/and during nappe contacts. The penetrative subhorizontal foliation is subparallel to the tectonic contacts with the overlying nappes and foliation was formed during nappe thrusting.

  20. Analysis and simulation on two types of thrust reversers in an aircraft engine

    Directory of Open Access Journals (Sweden)

    Tian Feng

    2017-01-01

    Full Text Available With rapid development of new composite material and manufacturing, innovative engineering solutions are supplied to the advanced nacelle, such as integrated propulsion system(IPS, carbon-fiber composite inner skin by single-piece molding process,which offers a reduction in fuel burn and less noise produced by engines. The advanced nacelle has an O-duct thrust reverser demonstrator whose composite structure is in the form of an “O” as opposed to the traditional “D-duct”. A comparative study is to be conducted to investigate the differences between the latest O-duct and conventional D-duct in numerical approaches. To focus on the quantitative analysis of thrust reverser’s operation, this paper mainly uses CATIA/Digital Mock Up(DMU to simulate under deployment and stowed conditions of two different thrust reverser. After comparing the structural weight, the design models of blocker door are built for kinematic analysis of relevant mechanism and simulation. The results show that simplified design and elimination of multiple interfaces generates weight saving, O-duct improves airflows within the engine, meanwhile D-duct has excellent cost effective and maintainability.

  1. Thermotectonic history of the Marañón Fold-Thrust Belt, Peru: Insights into mineralisation in an evolving orogen

    Science.gov (United States)

    Scherrenberg, Arne F.; Kohn, Barry P.; Holcombe, Rodney J.; Rosenbaum, Gideon

    2016-01-01

    Fold-thrust belts along convergent margins around the world host major ore deposits. The origin of such ore deposits is commonly episodic and so are the temporal and spatial variations in deformation styles in these fold-thrust belts. Here we focus on the Marañón Fold-Thrust Belt (MFTB) of the Peruvian Andes, and demonstrate a link between the spatio-temporal distribution of ore deposits and thick-skinned tectonics. We present low-temperature thermochronology results from the MFTB that document the uplift/exhumation history and timing of thick-skinned tectonics and vergence reversal. Our results suggest that the thermal history of the MFTB involved two discrete intervals of opposed-vergence, large-scale crustal deformation since the Late Cretaceous. An early interval, at 80-20 Ma, was associated with folding and east-vergent thin-skinned tectonics, and was followed by west-vergent thick-skinned deformation at 20-0 Ma. Furthermore, our findings suggest that thick-skinned contraction was coincident with increased focusing of mineralising fluids and ore deposition in the MFTB during the early Miocene, and in the mid-Miocene both mineralisation and deformation were enhanced by subduction of the Nazca Ridge underneath the South American Plate.

  2. Flat-ramp vs. convex-concave thrust geometries in a deformable hanging wall: new insights from analogue modeling experiments

    Science.gov (United States)

    Almeida, Pedro; Tomas, Ricardo; Rosas, Filipe; Duarte, Joao; Terrinha, Pedro

    2015-04-01

    Different modes of strain accommodation affecting a deformable hanging-wall in a flat-ramp-flat thrust system were previously addressed through several (sandbox) analog modeling studies, focusing on the influence of different variables, such as: a) thrust ramp dip angle and friction (Bonini et al, 2000); b) prescribed thickness of the hanging-wall (Koy and Maillot, 2007); and c) sin-thrust erosion (compensating for topographic thrust edification, e.g. Persson and Sokoutis, 2002). In the present work we reproduce the same experimental procedure to investigate the influence of two different parameters on hanging-wall deformation: 1) the geometry of the thrusting surface; and 2) the absence of a velocity discontinuity (VD) that is always present in previous similar analogue modeling studies. Considering the first variable we use two end member ramp geometries, flat-ramp-flat and convex-concave, to understand the control exerted by the abrupt ramp edges in the hanging-wall stress-strain distribution, comparing the obtain results with the situation in which such edge singularities are absent (convex-concave thrust ramp). Considering the second investigated parameter, our motivation was the recognition that the VD found in the different analogue modeling settings simply does not exist in nature, despite the fact that it has a major influence on strain accommodation in the deformable hanging-wall. We thus eliminate such apparatus artifact from our models and compare the obtained results with the previous ones. Our preliminary results suggest that both investigated variables play a non-negligible role on the structural style characterizing the hanging-wall deformation of convergent tectonic settings were such thrust-ramp systems were recognized. Acknowledgments This work was sponsored by the Fundação para a Ciência e a Tecnologia (FCT) through project MODELINK EXPL/GEO-GEO/0714/2013. Pedro Almeida wants to thank to FCT for the Ph.D. grant (SFRH/BD/52556/2014) under the

  3. The Competitive Influences of Perceptual Load and Working Memory Guidance on Selective Attention.

    Directory of Open Access Journals (Sweden)

    Jinfeng Tan

    Full Text Available The perceptual load theory in selective attention literature proposes that the interference from task-irrelevant distractor is eliminated when perceptual capacity is fully consumed by task-relevant information. However, the biased competition model suggests that the contents of working memory (WM can guide attentional selection automatically, even when this guidance is detrimental to visual search. An intriguing but unsolved question is what will happen when selective attention is influenced by both perceptual load and WM guidance. To study this issue, behavioral performances and event-related potentials (ERPs were recorded when participants were presented with a cue to either identify or hold in memory and had to perform a visual search task subsequently, under conditions of low or high perceptual load. Behavioural data showed that high perceptual load eliminated the attentional capture by WM. The ERP results revealed an obvious WM guidance effect in P1 component with invalid trials eliciting larger P1 than neutral trials, regardless of the level of perceptual load. The interaction between perceptual load and WM guidance was significant for the posterior N1 component. The memory guidance effect on N1 was eliminated by high perceptual load. Standardized Low Resolution Electrical Tomography Analysis (sLORETA showed that the WM guidance effect and the perceptual load effect on attention can be localized into the occipital area and parietal lobe, respectively. Merely identifying the cue produced no effect on the P1 or N1 component. These results suggest that in selective attention, the information held in WM could capture attention at the early stage of visual processing in the occipital cortex. Interestingly, this initial capture of attention by WM could be modulated by the level of perceptual load and the parietal lobe mediates target selection at the discrimination stage.

  4. The Competitive Influences of Perceptual Load and Working Memory Guidance on Selective Attention.

    Science.gov (United States)

    Tan, Jinfeng; Zhao, Yuanfang; Wang, Lijun; Tian, Xia; Cui, Yan; Yang, Qian; Pan, Weigang; Zhao, Xiaoyue; Chen, Antao

    2015-01-01

    The perceptual load theory in selective attention literature proposes that the interference from task-irrelevant distractor is eliminated when perceptual capacity is fully consumed by task-relevant information. However, the biased competition model suggests that the contents of working memory (WM) can guide attentional selection automatically, even when this guidance is detrimental to visual search. An intriguing but unsolved question is what will happen when selective attention is influenced by both perceptual load and WM guidance. To study this issue, behavioral performances and event-related potentials (ERPs) were recorded when participants were presented with a cue to either identify or hold in memory and had to perform a visual search task subsequently, under conditions of low or high perceptual load. Behavioural data showed that high perceptual load eliminated the attentional capture by WM. The ERP results revealed an obvious WM guidance effect in P1 component with invalid trials eliciting larger P1 than neutral trials, regardless of the level of perceptual load. The interaction between perceptual load and WM guidance was significant for the posterior N1 component. The memory guidance effect on N1 was eliminated by high perceptual load. Standardized Low Resolution Electrical Tomography Analysis (sLORETA) showed that the WM guidance effect and the perceptual load effect on attention can be localized into the occipital area and parietal lobe, respectively. Merely identifying the cue produced no effect on the P1 or N1 component. These results suggest that in selective attention, the information held in WM could capture attention at the early stage of visual processing in the occipital cortex. Interestingly, this initial capture of attention by WM could be modulated by the level of perceptual load and the parietal lobe mediates target selection at the discrimination stage.

  5. Analysis of the gas-lubricated flat-sector-pad thrust bearing

    Science.gov (United States)

    Etsion, I.

    1976-01-01

    A flat sector-shaped pad geometry for a gas-lubricated thrust bearing is analyzed considering both the pitch and roll of the pad. It is shown that maximum load capacity is achieved when the pad is tilted so as to create uniform minimum film thickness along the pad trailing edge. Performance characteristics for various geometries and operating conditions of gas thrust bearings are presented in the form of design curves, and a comparison is made with the rectangular slider approximation. It is found that this approximation is unsafe for practical design, since it always overestimates load capacity.

  6. Guidance for closure of existing DOE LLW disposal sites

    International Nuclear Information System (INIS)

    Blanchfield, L.

    1987-01-01

    During FY 1986, a closure guidance document was developed. The purpose of this document is to provide guidance in support of DOE Order 5820.2 to site operating contractors for the stabilization and closure of existing low-level waste (LLW) shallow land disposal sites at US Department of Energy (DOE) facilities. Guidance is provided to aid operators in placing existing LLW sites in a closed conditions, i.e., a condition in which a nonoperational site meets postclosure performance requirements and can be shown, within a high degree of confidence, to perform as anticipated in the future, under the most cost-effective maintenance approach. Guidance is based on the philosophy that closure should be planned and performed using a systems approach. Plans for FY 1987 call for revision of the document to incorporate more information on closure of LLW sites also containing radioactive mixed waste and/or transuranic waste. 4 references, 3 figures, 2 tables

  7. Active Thrust on an Inclined Retaining Wall with Inclined Cohesionless Backfill due to Surcharge Effect

    OpenAIRE

    Dewaikar, D. M.; Pandey, S. R.; Dixit, Jagabandhu

    2012-01-01

    A method based on the application of Kötter’s equation is proposed for the complete analysis of active thrust on an inclined wall with inclined cohesionless backfill under surcharge effect. Coulomb’s failure mechanism is considered in the analysis. The point of application of active thrust is determined from the condition of moment equilibrium. The coefficient of active pressure and the point of application of the active thrust are computed and presented in nondimensional form. One distinguis...

  8. Effects of Flat Slab Subduction on Andean Thrust Kinematics and Foreland Basin Evolution in Western Argentina

    Science.gov (United States)

    Horton, B. K.; Fuentes, F.; McKenzie, N. R.; Constenius, K. N.; Alvarado, P. M.

    2014-12-01

    Debate persists over the effects of flat-slab subduction on the kinematics of overriding plate deformation and the evolution of retroarc sedimentary basins. In western Argentina, major spatial and temporal variations in the geometry of the subducting Nazca slab since ~15 Ma provide opportunities to evaluate the late Cenozoic response of the Andean fold-thrust belt and foreland basin to subhorizontal subduction. Preliminary results from several structural and sedimentary transects spanning the frontal thrust belt and foreland basin system between 31°S and 35°S reveal Oligocene-middle Miocene hinterland exhumation during normal-slab subduction followed thereafter by progressive slab shallowing with initial rapid cratonward propagation of ramp-flat thrust structures (prior to basement-involved foreland uplifts) and accompanying wholesale exhumation and recycling of the early Andean foreland basin (rather than regional dynamic subsidence). Detrital zircon U-Pb geochronologic data prove instrumental for revealing shifts in thrust-belt exhumation, defining depositional ages within the foreland basin, and constraining the timing of activity along frontal thrust structures. In both the San Juan (31-32°S) and Malargüe (34-35°S) segments of the fold-thrust belt, geochronological results for volcaniclastic sandstones and syndeformational growth strata are consistent with a major eastward advance in shortening at 12-9 Ma. This episode of rapid thrust propagation precedes the reported timing of Sierras Pampeanas basement-involved foreland uplifts and encompasses modern regions of both normal- and flat-slab subduction, suggesting that processes other than slab dip (such as inherited crustal architecture, critical wedge dynamics, and arc magmatism) are additional regulators of thrust-belt kinematics and foreland basin evolution.

  9. Horizontal faults as potential aquifers in the department of Florida. Part One: Thrust-fault Paleoproterozoic Castro Creek

    International Nuclear Information System (INIS)

    Bossi, J.; Caggiano, R.; Pineyro, D.

    2011-01-01

    Since 1996 Bossi and Pineyro proposed the posibility of subhorizontal contacts between Piedra Alta geological units with very different metamorphic grade and lithological associations. The idea was discarded in an itinerant workshop because of lacking of mylonites in the proposed planes containing pegmatites and/or muscovite granites of very low dipping. The possibility that peraluminous magma acted as a lubricant and allow significant movements without great efforts led to rework the topic, utilizing 850 observations of the Vulcanitas Arqueanas Project and 750 observations of the Terreno Piedra Alta Project Georeferenced observations were located on 1:50,000 topographic maps and areas with higher density were aerophotointerpreted at 1:40,000 scale and geologically surveyed at different scales.The thrust-fault of Florida granite belt over San Jose belt was confirmed, and a new thrust-fault was found in the Arroyo Castro valley with 2% dipping to the north

  10. Dose Matters: FDA's Guidance on Children's X-rays

    Science.gov (United States)

    ... Consumer Updates Dose Matters: FDA's Guidance on Children's X-rays Share Tweet Linkedin Pin it More sharing options ... exposure during medical procedures. The level of ionizing radiation from X-ray imaging is generally very low, but can ...

  11. Lubrication analysis of the thrust bearing in the main coolant pump of SMART

    International Nuclear Information System (INIS)

    Lee, J. S.; Park, J. S.; Kim, J. H.; Hur, H.; Kim, J. I.

    2001-01-01

    Thrust bearing and journal bearings are installed in the main coolant pump for SMART to support the rotating shaft with proper lubrication. The canned motor type main coolant pumps are arranged vertically on the reactor vessel and especially the MCP bearings are lubricated with water without external lubricating oil supply. Because axial load capacity of the thrust bearing can hardly meet requirement to acquire hydrodynamic or fluid film lubrication state, self-lubrication characteristics of silicon graphite meterials would be needed. Lubricational analysis method for thrust bearing for the main coolant pump of SMART is proposed, and lubricational characteristics of the bearing generated by solving the Reynolds equation are examined in this paper

  12. 75 FR 3471 - International Conference on Harmonisation; Guidance on M3(R2) Nonclinical Safety Studies for the...

    Science.gov (United States)

    2010-01-21

    ...] International Conference on Harmonisation; Guidance on M3(R2) Nonclinical Safety Studies for the Conduct of... the availability of a guidance entitled ``M3(R2) Nonclinical Safety Studies for the Conduct of Human... auspices of the International Conference on Harmonisation of Technical Requirements for Registration of...

  13. The Thermal State Computational Research of the Low-Thrust Oxygen-Methane Gaseous-Propellant Rocket Engine in the Pulse Mode of Operation

    Directory of Open Access Journals (Sweden)

    O. A. Vorozheeva

    2014-01-01

    Full Text Available Currently promising development direction of space propulsion engineering is to use, as spacecraft controls, low-thrust rocket engines (RDTM on clean fuels, such as oxygen-methane. Modern RDTM are characterized by a lack regenerative cooling and pulse mode of operation, during which there is accumulation of heat energy to lead to the high thermal stress of RDTM structural elements. To get an idea about the thermal state of its elements, which further will reduce the number of fire tests is therefore necessary in the development phase of a new product. Accordingly, the aim of this work is the mathematical modeling and computational study of the thermal state of gaseous oxygen-methane propellant RDMT operating in pulse mode.In this paper we consider a model RDTM working on gaseous propellants oxygen-methane in pulse mode.To calculate the temperature field of the chamber wall of model RDMT under consideration is used the mathematical model of non-stationary heat conduction in a two-dimensional axisymmetric formulation that takes into account both the axial heat leakages and the nonstationary processes occurring inside the chamber during pulse operation of RDMT.As a result of numerical study of the thermal state of model RDMT, are obtained the temperature fields during engine operation based on convective, conductive, and radiative mechanisms of heat transfer from the combustion products to the wall.It is shown that the elements of flanges of combustion chamber of model RDMT act as heat sinks structural elements. Temperatures in the wall of the combustion chamber during the engine mode of operation are considered relatively low.Raised temperatures can also occur in the mixing head in the feeding area of the oxidant into the combustion chamber.During engine operation in the area forming the critical section, there is an intensive heating of a wall, which can result in its melting, which in turn will increase the minimum nozzle throat area and hence

  14. Emergency Flight Control Using Only Engine Thrust and Lateral Center-of-Gravity Offset: A First Look

    Science.gov (United States)

    Burcham, Frank W., Jr.; Burken, John; Maine, Trindel A.; Bull, John

    1997-01-01

    Normally, the damage that results in a total loss of the primary flight controls of a jet transport airplane, including all engines on one side, would be catastrophic. In response, NASA Dryden has conceived an emergency flight control system that uses only the thrust of a wing-mounted engine along with a lateral center-of-gravity (CGY) offset from fuel transfer. Initial analysis and simulation studies indicate that such a system works, and recent high-fidelity simulation tests on the MD-11 and B-747 suggest that the system provides enough control for a survivable landing. This paper discusses principles of flight control using only a wing engine thrust and CGY offset, along with the amount of CGY offset capability of some transport airplanes. The paper also presents simulation results of the throttle-only control capability and closed-loop control of ground track using computer-controlled thrust.

  15. Optimal design of Tilting-Pad Thrust Bearings with High Pressure Injection Pockets

    DEFF Research Database (Denmark)

    Heinrichson, Niels; Santos, Ilmar

    2006-01-01

    A thermo-elasto-hydrodynamic(TEHD) model based on the Reynolds equation has been used to study the effect of oil injection pockets on the performance of tilting pad thrust bearings. The optimal position of the pivot both with respect to load carrying capacity and minimal power consumption is seen...

  16. Neandertal humeri may reflect adaptation to scraping tasks, but not spear thrusting.

    Directory of Open Access Journals (Sweden)

    Colin N Shaw

    Full Text Available Unique compared with recent and prehistoric Homo sapiens, Neandertal humeri are characterised by a pronounced right-dominant bilateral strength asymmetry and an anteroposteriorly strengthened diaphyseal shape. Remodeling in response to asymmetric forces imposed during regular underhanded spear thrusting is the most influential explanatory hypothesis. The core tenet of the "Spear Thrusting Hypothesis", that underhand thrusting requires greater muscle activity on the right side of the body compared to the left, remains untested. It is unclear whether alternative subsistence behaviours, such as hide processing, might better explain this morphology. To test this, electromyography was used to measure muscle activity at the primary movers of the humerus (pectoralis major (PM, anterior (AD and posterior deltoid (PD during three distinct spear-thrusting tasks and four separate scraping tasks. Contrary to predictions, maximum muscle activity (MAX and total muscle activity (TOT were significantly higher (all values, p<.05 at the left (non-dominant AD, PD and PM compared to the right side of the body during spear thrusting tasks. Thus, the muscle activity required during underhanded spearing tasks does not lend itself to explaining the pronounced right dominant strength asymmetry found in Neandertal humeri. In contrast, during the performance of all three unimanual scraping tasks, right side MAX and TOT were significantly greater at the AD (all values, p<.01 and PM (all values, p<.02 compared to the left. The consistency of the results provides evidence that scraping activities, such as hide preparation, may be a key behaviour in determining the unusual pattern of Neandertal arm morphology. Overall, these results yield important insight into the Neandertal behavioural repertoire that aided survival throughout Pleistocene Eurasia.

  17. Flow measurement and thrust estimation of a vibrating ionic polymer metal composite

    International Nuclear Information System (INIS)

    Chae, Woojin; Cha, Youngsu; Peterson, Sean D; Porfiri, Maurizio

    2015-01-01

    Ionic polymer metal composites (IPMCs) are an emerging class of soft active materials that are finding growing application as underwater propulsors for miniature biomimetic swimmers. Understanding the hydrodynamics generated by an IPMC vibrating under water is central to the design of such biomimetic swimmers. In this paper, we propose the use of time-resolved particle image velocimetry to detail the fluid kinematics and kinetics in the vicinity of an IPMC vibrating along its fundamental structural mode. The reconstructed pressure field is ultimately used to estimate the thrust produced by the IPMC. The vibration frequency is systematically varied to elucidate the role of the Reynolds number on the flow physics and the thrust production. Experimental results indicate the formation and shedding of vortical structures from the IPMC tip during its vibration. Vorticity shedding is sustained by the pressure gradients along each side of the IPMC, which are most severe in the vicinity of the tip. The mean thrust is found to robustly increase with the Reynolds number, closely following a power law that has been derived from direct three-dimensional numerical simulations. A reduced order distributed model is proposed to describe IPMC underwater vibration and estimate thrust production, offering insight into the physics of underwater propulsion and aiding in the design of IPMC-based propulsors. (paper)

  18. A six degree-of-freedom thrust sensor for a labscale hybrid rocket

    International Nuclear Information System (INIS)

    Wright, Ann M; Born, Traig; Strickland, Ryan; Wright, Andrew B

    2013-01-01

    A six degree-of-freedom thrust sensor was designed, constructed, calibrated, and tested using the labscale hybrid rocket at the University of Arkansas at Little Rock. The system consisted of six independent legs: one parallel to the axis of symmetry of the rocket for main thrust measurement, two vertical legs near the nozzle end of the rocket, one vertical leg near the oxygen input end of the rocket, and two separated horizontal legs near the nozzle end. Each leg was composed of a rotational bearing, a load cell, and a universal joint above and below the load cell. The leg was designed to create point contact along only one direction and minimize the non-axial forces applied to the load cell. With this system, force in each direction and moments for roll, pitch, and yaw can be measured. The system was calibrated and tested using a labscale hybrid rocket using gaseous oxygen and hydroxyl-terminated polybutadiene solid fuel. The thrust stand proved to be stable during calibration tests. Thrust force vector components and roll, pitch, and yaw moments were calculated for test firings with an oxygen mass flow rate range of 0.0174–0.0348 kg s −1 . (paper)

  19. Review of soil contamination guidance

    International Nuclear Information System (INIS)

    Mueller, M.A.; Kennedy, W.E. Jr.; Soldat, J.K.

    1981-08-01

    A review of existing and proposed radioactive soil contamination standards and guidance was conducted for United Nuclear Corporation (UNC), Office of Surplus Facilities Management. Information was obtained from both government agencies and other sources during a literature survey. The more applicable standards were reviewed, evaluated, and summarized. Information pertaining to soil contamination for both facility operation and facility decommissioning was obtained from a variety of sources. These sources included: the Code of Federal Regulations, regulatory guides, the Federal Register, topical reports written by various government agencies, topical reports written by national laboratories, and publications from the American National Standards Institute (ANSI). It was difficult to directly compare the standards and guidance obtained from these sources since each was intended for a specific situation and different units or bases were used. However, most of the information reviewed was consistent with the philosophy of maintaining exposures at levels as low as reasonably achievable

  20. Width of surface rupture zone for thrust earthquakes: implications for earthquake fault zoning

    Directory of Open Access Journals (Sweden)

    P. Boncio

    2018-01-01

    Full Text Available The criteria for zoning the surface fault rupture hazard (SFRH along thrust faults are defined by analysing the characteristics of the areas of coseismic surface faulting in thrust earthquakes. Normal and strike–slip faults have been deeply studied by other authors concerning the SFRH, while thrust faults have not been studied with comparable attention. Surface faulting data were compiled for 11 well-studied historic thrust earthquakes occurred globally (5.4 ≤ M ≤ 7.9. Several different types of coseismic fault scarps characterize the analysed earthquakes, depending on the topography, fault geometry and near-surface materials (simple and hanging wall collapse scarps, pressure ridges, fold scarps and thrust or pressure ridges with bending-moment or flexural-slip fault ruptures due to large-scale folding. For all the earthquakes, the distance of distributed ruptures from the principal fault rupture (r and the width of the rupture zone (WRZ were compiled directly from the literature or measured systematically in GIS-georeferenced published maps. Overall, surface ruptures can occur up to large distances from the main fault ( ∼ 2150 m on the footwall and  ∼  3100 m on the hanging wall. Most of the ruptures occur on the hanging wall, preferentially in the vicinity of the principal fault trace ( >   ∼  50 % at distances  <   ∼  250 m. The widest WRZ are recorded where sympathetic slip (Sy on distant faults occurs, and/or where bending-moment (B-M or flexural-slip (F-S fault ruptures, associated with large-scale folds (hundreds of metres to kilometres in wavelength, are present. A positive relation between the earthquake magnitude and the total WRZ is evident, while a clear correlation between the vertical displacement on the principal fault and the total WRZ is not found. The distribution of surface ruptures is fitted with probability density functions, in order to define a criterion to

  1. Late Miocene-Early Pliocene reactivation of the Main Boundary Thrust: Evidence from the seismites in southeastern Kumaun Himalaya, India

    Science.gov (United States)

    Mishra, Anurag; Srivastava, Deepak C.; Shah, Jyoti

    2013-05-01

    Tectonic history of the Himalaya is punctuated by successive development of the faults that run along the boundaries between different lithotectonic terrains. The Main Boundary Fault, defining the southern limit of the Lesser Himalayan terrain, is tectonically most active. A review of published literature reveals that the nature and age of reactivation events on the Main Boundary Fault is one of the poorly understood aspects of the Himalayan orogen. By systematic outcrop mapping of the seismites, this study identifies a Late Miocene-Early Pliocene reactivation on the Main Boundary Thrust in southeast Kumaun Himalaya. Relatively friable and cohesionless Neogene sedimentary sequences host abundant soft-sediment deformation structures in the vicinity of the Main Boundary Thrust. Among a large variety of structures, deformed cross-beds, liquefaction pockets, slump folds, convolute laminations, sand dykes, mushroom structures, fluid escape structures, flame and load structures and synsedimentary faults are common. The morphological attributes, the structural association and the distribution pattern of the soft-sediment deformation structures with respect to the Main Boundary Fault strongly suggest their development by seismically triggered liquefaction and fluidization. Available magnetostratigraphic age data imply that the seismites were developed during a Late Miocene-Early Pliocene slip on the Main Boundary Thrust. The hypocenter of the main seismic event may lie on the Main Boundary Thrust or to the north of the study area on an unknown fault or the Basal Detachment Thrust.

  2. A qualitative study in parental perceptions and understanding of SIDS-reduction guidance in a UK bi-cultural urban community.

    Science.gov (United States)

    Crane, Denise; Ball, Helen L

    2016-01-30

    Differences in both Sudden Infant Death Syndrome (SIDS) rates and infant care practices between white British and South Asians in UK are well known, but research has not yet examined how these two groups understand and implement SIDS-reduction guidance. This study aimed to discover how white British and Pakistani mothers in Bradford recall, understand and interpret SIDS-reduction guidance, and to explore whether and how they implement this guidance in caring for their infants. In-depth narrative interviews with 46 mothers (25 white British origin and 21 Pakistani origin) of 8-12 week old infants recruited from the pool of participants enrolled in the 'Born in Bradford' (BiB) cohort study. All mothers were aware of UK SIDS-reduction guidance from leaflets presented to them during antenatal or postnatal interactions with health care providers. Pakistani mothers tended to dismiss the guidance in toto as being irrelevant to their cultural practices; white British mothers dismissed, adapted and adopted aspects of the guidance to suit their preferred parenting decisions and personal circumstances. Many mothers misunderstood or misinterpreted the guidance given and explained their infant care behaviour according to their social and cultural circumstances. Current SIDS reduction information in the UK does not meet the needs of immigrant families, and is easily misinterpreted or misunderstood by mothers from all sections of the community. Tailored information acknowledging cultural differences in infant care practices is vital, as is greater discussion with all mothers about the reasons for SIDS reduction guidance.

  3. Graphic Turbulence Guidance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Forecast turbulence hazards identified by the Graphical Turbulence Guidance algorithm. The Graphical Turbulence Guidance product depicts mid-level and upper-level...

  4. Energy Efficient Engine program advanced turbofan nacelle definition study

    Science.gov (United States)

    Howe, David C.; Wynosky, T. A.

    1985-01-01

    Advanced, low drag, nacelle configurations were defined for some of the more promising propulsion systems identified in the earlier Benefit/Cost Study, to assess the benefits associated with these advanced technology nacelles and formulate programs for developing these nacelles and low volume thrust reversers/spoilers to a state of technology readiness in the early 1990's. The study results established the design feasibility of advanced technology, slim line nacelles applicable to advanced technology, high bypass ratio turbofan engines. Design feasibility was also established for two low volume thrust reverse/spoiler concepts that meet or exceed the required effectiveness for these engines. These nacelle and thrust reverse/spoiler designs were shown to be applicable in engines with takeoff thrust sizes ranging from 24,000 to 60,000 pounds. The reduced weight, drag, and cost of the advanced technology nacelle installations relative to current technology nacelles offer a mission fuel burn savings ranging from 3.0 to 4.5 percent and direct operating cost plus interest improvements from 1.6 to 2.2 percent.

  5. Stress Transfer Processes during Great Plate Boundary Thrusting Events: A Study from the Andaman and Nicobar Segments

    Science.gov (United States)

    Andrade, V.; Rajendran, K.

    2010-12-01

    The response of subduction zones to large earthquakes varies along their strike, both during the interseismic and post-seismic periods. The December 26, 2004 earthquake nucleated at 3° N latitude and its rupture propagated northward, along the Andaman-Sumatra subduction zone, terminating at 15°N. Rupture speed was estimated at about 2.0 km per second in the northern part under the Andaman region and 2.5 - 2.7 km per second under southern Nicobar and North Sumatra. We have examined the pre and post-2004 seismicity to understand the stress transfer processes within the subducting plate, in the Andaman (10° - 15° N ) and Nicobar (5° - 10° N) segments. The seismicity pattern in these segments shows distinctive characteristics associated with the outer rise, accretionary prism and the spreading ridge, all of which are relatively better developed in the Andaman segment. The Ninety East ridge and the Sumatra Fault System are significant tectonic features in the Nicobar segment. The pre-2004 seismicity in both these segments conform to the steady-state conditions wherein large earthquakes are fewer and compressive stresses dominate along the plate interface. Among the pre-2004 great earthquakes are the 1881 Nicobar and 1941 Andaman events. The former is considered to be a shallow thrust event that generated a small tsunami. Studies in other subduction zones suggest that large outer-rise tensional events follow great plate boundary breaking earthquakes due to the the up-dip transfer of stresses within the subducting plate. The seismicity of the Andaman segment (1977-2004) concurs with the steady-state stress conditions where earthquakes occur dominantly by thrust faulting. The post-2004 seismicity shows up-dip migration along the plate interface, with dominance of shallow normal faulting, including a few outer rise events and some deeper (> 100 km) strike-slip faulting events within the subducting plate. The September 13, 2002, Mw 6.5 thrust faulting earthquake at

  6. Ecological risk assessment guidance for preparation of remedial investigation/feasibility study work plans

    International Nuclear Information System (INIS)

    Pentecost, E.D.; Vinikour, W.S.

    1993-08-01

    This guidance document (1) provides instructions on preparing the components of an ecological work plan to complement the overall site remedial assessment investigation/feasibility study (RI/FS) work plan and (2) directs the user on how to implement ecological tasks identified in the plan. Under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), as amended by the Superfired Amendments and Reauthorization Act of 1986 (SARA), an RI/FS work plan win have to be developed as part of the site-remediation scoping the process. Specific guidance on the RI/FS process and the preparation of work plans has been developed by the US Environmental Protection Agency (EPA 1988a). This document provides guidance to US Department of Energy (DOE) staff and contractor personnel for incorporation of ecological information into environmental remediation planning and decision making at CERCLA sites. An overview analysis of early ecological risk assessment methods (i.e., in the 1980s) at Superfund sites was conducted by the EPA (1989a). That review provided a perspective of attention given to ecological issues in some of the first RI/FS studies. By itself, that reference is of somewhat limited value; it does, however, establish a basis for comparison of past practices in ecological risk with current, more refined methods

  7. Experimental evidence that thrust earthquake ruptures might open faults.

    Science.gov (United States)

    Gabuchian, Vahe; Rosakis, Ares J; Bhat, Harsha S; Madariaga, Raúl; Kanamori, Hiroo

    2017-05-18

    Many of Earth's great earthquakes occur on thrust faults. These earthquakes predominantly occur within subduction zones, such as the 2011 moment magnitude 9.0 eathquake in Tohoku-Oki, Japan, or along large collision zones, such as the 1999 moment magnitude 7.7 earthquake in Chi-Chi, Taiwan. Notably, these two earthquakes had a maximum slip that was very close to the surface. This contributed to the destructive tsunami that occurred during the Tohoku-Oki event and to the large amount of structural damage caused by the Chi-Chi event. The mechanism that results in such large slip near the surface is poorly understood as shallow parts of thrust faults are considered to be frictionally stable. Here we use earthquake rupture experiments to reveal the existence of a torquing mechanism of thrust fault ruptures near the free surface that causes them to unclamp and slip large distances. Complementary numerical modelling of the experiments confirms that the hanging-wall wedge undergoes pronounced rotation in one direction as the earthquake rupture approaches the free surface, and this torque is released as soon as the rupture breaks the free surface, resulting in the unclamping and violent 'flapping' of the hanging-wall wedge. Our results imply that the shallow extent of the seismogenic zone of a subducting interface is not fixed and can extend up to the trench during great earthquakes through a torquing mechanism.

  8. Guidance for Reviewing OCSPP 850.2100 Avian Oral Toxicity Studies Conducted with Passerine Birds

    Science.gov (United States)

    Guidance based on comparison of results from the TG223 validation studies to results from avian acute oral studies previously submitted to EPA for two test chemicals following EPA's 850.2100 (public draft) guidelines.

  9. Influence of jet thrust on penetrator penetration when studying the structure of space object blanket

    Directory of Open Access Journals (Sweden)

    N. A. Fedorova

    2014-01-01

    Full Text Available The article presents the calculation-and-theory-based research results to examine the possibility for using the jet thrust impulse to increase a penetration depth of high-velocity penetrator modules. Such devices can be used for studies of Earth surface layer composition, and in the nearest future for other Solar system bodies too. Research equipment (sensors and different instruments is housed inside a metal body of the penetrator with a sharpened nose that decreases drag force in soil. It was assumed, that this penetrator is additionally equipped with the pulse jet engine, which is fired at a certain stage of penetrator motion into target.The penetrator is considered as a rigid body of variable mass, which is subjected to drag force and reactive force applied at the moment the engine fires. A drag force was represented with a binomial empirical law, and penetrator nose part was considered to be conical. The jet thrust force was supposed to be constant during its application time. It was in accordance with assumption that mass flow and flow rate of solid propellant combustion products were constant. The amount of propellant in the penetrator was characterized by Tsiolkovsky number Z, which specifies the ratio between the fuel mass and the penetrator structure mass with no fuel.The system of equations to describe the penetrator dynamics was given in dimensionless form using the values aligned with penetration of an equivalent inert penetrator as the time and penetration depth scales. Penetration dynamics of penetrator represented in this form allowed to eliminate the influence of penetrator initial mass and its cross-section diameter on the solution results. The lack of such dependency is convenient for comparing the calculation results since they hold for penetrators of various initial masses and cross-sections.To calculate the penetration a lunar regolith was taken as a soil material. Calculations were carried out for initial velocities of

  10. The Study of a Super Low Altitude Satellite

    Science.gov (United States)

    Noda, Atsushi; Homma, Masanori; Utashima, Masayoshi

    This paper reports the result of a study for super low altitude satellite. The altitude of this satellite's orbit is lower than ever. The altitude of a conventional earth observing satellite is generally around from 600km to 900km. The lowest altitude of earth observing satellite launched in Japan was 350km; the Tropical Rainfall Measuring Mission (TRMM). By comparison, the satellite reported in this paper is much lower than that and it is planned to orbit below 200km. Furthermore, the duration of the flight planned is more than two years. Any satellite in the world has not achieved to keep such a low altitude that long term. The satellite in such a low orbit drops quickly because of the strong air drag. Our satellite will cancel the air drag effect by ion engine thrust. To realize this idea, a drag-free system will be applied. This usually leads a complicated and expensive satellite system. We, however, succeeded in finding a robust control law for a simple system even under the unpredictable change of air drag. When the altitude of the satellite is lowered successfully, the spatial resolution of an optical sensor can be highly improved. If a SAR is equipped with the satellite, it enables the drastic reduction of electric power consumption and the fabulous spatial resolution improvement at the same time.

  11. Performance study on a low-temperature absorption–compression cascade refrigeration system driven by low-grade heat

    International Nuclear Information System (INIS)

    Xu, Yingjie; Chen, Guangming; Wang, Qin; Han, Xiaohong; Jiang, Ning; Deng, Shiming

    2016-01-01

    Highlights: • An absorption–compression system for low-temperature is developed and analyzed. • Cooling capacity, compression power, and discharge temperature are all improved. • At −170 °C, giving 200 W low-grade cooling capacity, COP increases by 28.6%. • Simulation results are verified experimentally, showing good agreement. - Abstract: This paper presents a performance study on a low-temperature absorption–compression cascade refrigeration system (LACRS), which consists of an absorption subsystem (AS) and a vapor compression auto-cascade subsystem (CS). In the system, low-grade heat of AS is used to subcool the CS, which can obtain cold energy at −170 °C. A simulation study is carried out to investigate the effects of evaporating temperature and low-grade cooling capacity on system performance. The study results show that as low-grade cooling capacity from the AS is provided to the CS, high-grade cooling capacity increases, compressor power consumption decreases, and the COP of the CS therefore increases. Comparing with compression auto-cascade cycle, the largest COP improvement of LACRS is about 38%. The model is verified by experimental data. An additional high-grade cooling capacity is obtained experimentally at −170 °C. The study results presented in this paper not only demonstrate the excellent performance of the LACRS, but also provide important guidance to further system design, and practical application.

  12. Laser guidance of mesoscale particles

    Science.gov (United States)

    Underdown, Frank Hartman, Jr.

    Mesoscale particles are guided and trapped in hollow optical fibers using radiation pressure forces. Laser light from a 0.4W, 780nm diode laser is guided in a low- loss fiber mode and used to generate the guidance forces. Laser scattering and absorption forces propels particles along the fiber and polarization gradient forces attract them to the fiber's axial center. Using two counter propagating laser beams, inside the fiber, particles can be trapped in three dimensions. Measuring the spring constant of the trap gives the gradient force. This dissertation describes Rayleigh and Mie scattering models for calculating guidance forces. Calculated forces as a function of particle size and composition (i.e. dielectric, semiconductor, and metals) will be presented. For example, under typical experimental conditions 100nm Au particles are guided by a 2 × 10-14 N propulsive force in a water filled fiber. In comparison, the measured force, obtained from the particle's velocity and Stokes' law, is 7.98 × 10-14 N.

  13. Erosion influences the seismicity of active thrust faults.

    Science.gov (United States)

    Steer, Philippe; Simoes, Martine; Cattin, Rodolphe; Shyu, J Bruce H

    2014-11-21

    Assessing seismic hazards remains one of the most challenging scientific issues in Earth sciences. Deep tectonic processes are classically considered as the only persistent mechanism driving the stress loading of active faults over a seismic cycle. Here we show via a mechanical model that erosion also significantly influences the stress loading of thrust faults at the timescale of a seismic cycle. Indeed, erosion rates of about ~0.1-20 mm yr(-1), as documented in Taiwan and in other active compressional orogens, can raise the Coulomb stress by ~0.1-10 bar on the nearby thrust faults over the inter-seismic phase. Mass transfers induced by surface processes in general, during continuous or short-lived and intense events, represent a prominent mechanism for inter-seismic stress loading of faults near the surface. Such stresses are probably sufficient to trigger shallow seismicity or promote the rupture of deep continental earthquakes up to the surface.

  14. Aspects of the structural and late thermal evolution of the Redbank Thrust system, central Australia: constraints from the Speares Metamorphics

    International Nuclear Information System (INIS)

    Biermeier, C.; Wiesinger, M.; Stuewe, K.; Foster, D.A.

    2003-01-01

    We present new data on the field geology and late thermal evolution of the Redbank Thrust system in the Arunta Block of central Australia. Geochronological and field data from the Speares Meta-morphics are also used to relate the thermal evolution of the Redbank Thrust system to the structural evolution of the region. We show that several stages in the evolution might be discerned. An originally sedimentary sequence was intruded by mafic intrusions and then deformed during partial melting to form the principal foliation observed in the region (D1). This sequence was then folded during D2 into upright folds with north- to northeast-plunging fold axes. These events are likely to correlate with the Strangways and/or Argilke and Chewings Orogenies known from previous studies. Subsequently, the Redbank Thrust was initiated during D3. This event is recognised by deflection of the host rocks into the shear zone and might therefore have been associated with a component of strike-slip motion. It occurred probably at or before 1500-1400 Ma. Subsequent north-over-south thrust motion in the Redbank Thrust formed the intense mylonitic fabric and folded the mylonitic fabric during D4 into asymmetric folds with shallow fold axes. New 40 Ar/ 39 Ar K-feldspar ages from three samples collected from variably deformed branches of the Redbank Thrust and undeformed rocks in the Speares Metamorphics suggest that most parts of the Redbank Thrust system cooled relatively slowly after metamorphism and deformation in the Mesoproterozoic so that the D4 thrusting might have been very long-lived. Minimum ages of the K-feldspar age spectra show that the entire region cooled below 200 deg C by approximately 300 Ma. Apatite fission track ages from nine samples show that cooling through the apatite partial annealing zone occurred during Cretaceous time (ca 150-70 Ma) and modelled cooling histories are consistent with the cooling rates obtained from the K-feldspar data. They indicate that final

  15. Numerical Simulation and Experimental Study on the Gas-Solid Coupling of the Aerostatic Thrust Bearing with Elastic Equalizing Pressure Groove

    Directory of Open Access Journals (Sweden)

    Zhao Xiao-long

    2017-01-01

    Full Text Available Aiming at the problem of low stiffness of aerostatic bearing, according to the principle of gas-solid coupling, this paper designs a kind of aerostatic thrust bearing with elastic equalizing pressure groove (EEPG and investigates the effect of elastic equalizing pressure groove (EEPG on the stiffness of aerostatic bearing. According to the physical model of the bearing, one deduces the deformation control equation of the elastic equalizing pressure groove and the control equation of gas lubrication, using finite difference method to derive the control equations and coupling calculation. The bearing capacity and stiffness of aerostatic bearing with EEPG in different gas film clearance are obtained. The calculation results show that the stiffness increased by 59%. The results of numerical calculation and experimental results have good consistency, proving the gas-solid coupling method can improve the bearing stiffness.

  16. Evaluation of Hanau's formula in determination of lateral condylar guidance: A clinical research study

    Science.gov (United States)

    Bhawsar, Sanjay Vasant; Marathe, Ashlesha Subhash; Ansari, Sadekh Abdul

    2015-01-01

    Statement of Problem: The accuracy and reliability of the methods used for programming the semi-adjustable articulators determine the accuracy in occlusion. The current recommended average settings using the Hanau's formula commonly used by clinicians is questionable, and thus reassessment is needed. This study was carried out to evaluate and compare the lateral condylar guidance: (1) Using the Hanau's formula and the computerized jaw tracking device (Kinesiograph). (2) On the right and left sides using both these methods. Materials and Methods: A total of 20 completely edentulous patients (14 male and 6 females) within 40–60 years of age were selected. Jaw relation was recorded followed by face bow transfer. Extraoral Gothic arch tracing was recorded; three protrusive records were obtained and condylar guidance was calculated. Lateral condylar guidance was then calculated using Hanau's formula, followed by the computerized jaw tracking device. A comparative evaluation was done of the obtained values. The same investigator worked with each of the study participants for the purpose of standardization. Results: The lateral condylar guidance values obtained using the Hanau's formula ranged from 14 to 17° while those obtained using the computerized K7 jaw tracking device ranged from 8 to 40°. Bennett angle values, obtained using the jaw tracking device and Hanau's formula showed statistically significant differences (P 0.05). Conclusion: Based on the results, dentist and dental technicians should consider reassessing the current recommended average settings and use of the Hanau's formula for programming the semi-adjustable articulators. PMID:26929535

  17. Flight Trajectory Planning for Fixed-Wing Aircraft in Loss of Thrust Emergencies

    OpenAIRE

    Paul, Saswata; Hole, Frederick; Zytek, Alexandra; Varela, Carlos A.

    2017-01-01

    Loss of thrust emergencies-e.g., induced by bird/drone strikes or fuel exhaustion-create the need for dynamic data-driven flight trajectory planning to advise pilots or control UAVs. While total loss of thrust trajectories to nearby airports can be pre-computed for all initial points in a 3D flight plan, dynamic aspects such as partial power and airplane surface damage must be considered for accuracy. In this paper, we propose a new Dynamic Data-Driven Avionics Software (DDDAS) approach which...

  18. Cervicothoracic junction thrust manipulation in the multimodal management of a patient with temporomandibular disorder.

    Science.gov (United States)

    Jayaseelan, Dhinu J; Tow, Nancy S

    2016-05-01

    Temporomandibular disorder (TMD) is a common condition that can be difficult to manage in physical therapy. A number of interventions, such as manual therapy, therapeutic exercise, and patient education have typically been used in some combination. However, the evidence regarding thrust manipulation of not only the local but also adjacent segments is sparse. Specifically, the use of cervicothoracic (CT) junction thrust manipulation has not previously been described in the management of individuals with TMD. In this case report, CT junction thrust manipulation, in addition to locally directed manual therapy, exercise, and postural education, was associated with immediate improvements in neck and jaw symptoms and function in a complex patient with TMD. The patient was seen for seven visits over the course of 2 months and demonstrated clinically significant changes in the neck disability index (NDI), the numeric rating of pain scale (NPRS), and the global rating of change (GROC) scale. The purpose of this report is to describe the successful physical therapy management of a patient with TMD utilizing manual therapy, including CT junction thrust manipulation, education, and exercise.

  19. A static investigation of the thrust vectoring system of the F/A-18 high-alpha research vehicle

    Science.gov (United States)

    Mason, Mary L.; Capone, Francis J.; Asbury, Scott C.

    1992-01-01

    A static (wind-off) test was conducted in the static test facility of the Langley 16-foot Transonic Tunnel to evaluate the vectoring capability and isolated nozzle performance of the proposed thrust vectoring system of the F/A-18 high alpha research vehicle (HARV). The thrust vectoring system consisted of three asymmetrically spaced vanes installed externally on a single test nozzle. Two nozzle configurations were tested: A maximum afterburner-power nozzle and a military-power nozzle. Vane size and vane actuation geometry were investigated, and an extensive matrix of vane deflection angles was tested. The nozzle pressure ratios ranged from two to six. The results indicate that the three vane system can successfully generate multiaxis (pitch and yaw) thrust vectoring. However, large resultant vector angles incurred large thrust losses. Resultant vector angles were always lower than the vane deflection angles. The maximum thrust vectoring angles achieved for the military-power nozzle were larger than the angles achieved for the maximum afterburner-power nozzle.

  20. Complex fold and thrust belt structural styles: Examples from the Greater Juha area of the Papuan Fold and Thrust Belt, Papua New Guinea

    Science.gov (United States)

    Mahoney, Luke; Hill, Kevin; McLaren, Sandra; Hanani, Amanda

    2017-07-01

    The remote and inhospitable Papuan Fold Belt in Papua New Guinea is one of the youngest yet least well-documented fold and thrust belts on Earth. Within the frontal Greater Juha area we have carried out >100 km of geological traverses and associated analyses that have added significantly to the contemporary geological and geophysical dataset. Our structural analysis provides evidence of major inversion, detachment and triangle zone faults within the uplifted Eastern Muller Ranges. We have used the dataset to develop a quasi-3D model for the Greater Juha area, with associated cross-sections revealing that the exposed Cenozoic Darai Limestone is well-constrained with very low shortening of 12.6-21.4% yet structures are elevated up to 7 km above regional. We suggest the inversion of pre-existing rift architecture is the primary influence on the evolution of the area and that structures link to the surface via triangle zones and detachment faults within the incompetent Mesozoic passive-margin sedimentary sequence underlying competent Darai Limestone. Arc-normal oriented structures, dominantly oblique dextral, up-to-the-southeast, are pervasive across a range of scales and are here interpreted to relate at depth to weakened pre-existing basement cross-structures. It is proposed that Palaeozoic basement fabric controlled the structural framework of the basin during Early Mesozoic rifting forming regional-scale accommodation zones and related local-scale transfer structures that are now expressed as regional-scale arc-normal lineaments and local-scale arc-normal structures, respectively. Transfer structures, including complexly breached relay ramps, utilise northeast-southwest striking weaknesses associated with the basement fabric, as a mechanism for accommodating displacement along major northwest-southeast striking normal faults. These structures have subsequently been inverted to form arc-normal oriented zones of tear faulting that accommodate laterally variable

  1. Measurements versus Predictions for a Hybrid (Hydrostatic Plus Hydrodynamic) Thrust Bearing for a Range of Orifice Diameters

    Science.gov (United States)

    2010-05-01

    Type of Lubrication for a Tilting Pad Thrust Bearing ,” ASME Journal of Lubrication Technology, 96 Ser F (1), pp. 22-27. [9] Gregory, R.S., 1974...1986, “Measurements of Maximum Temperature in Tilting - Pad Thrust Bearings ,” Technical Preprints - Presented at the ASLE 41st Annual Meeting. (ASLE...Safar [7] provides a modified Reynolds number analysis on hydrostatic thrust bearing performance parameters including the effects of tilt . Finally, San

  2. Key performance indicators for the assessment of pediatric pharmacotherapeutic guidance.

    Science.gov (United States)

    Barrett, Jeffrey S; Patel, Dimple; Jayaraman, Bhuvana; Narayan, Mahesh; Zuppa, Athena

    2008-07-01

    Given the paucity of actual guidance provided for managing pediatric drug therapy, prescribing caregivers must be able to draw on the limited published information in pediatrics and/or guidance provided in adults with some account for expected pediatric response. Guidance for managing drug therapy in children is clearly desirable. Our objectives were to construct key performance indicators (KPIs) for pediatric pharmacotherapy guidance to identify drugs where pharmacotherapy guidance would be most beneficial. A pilot survey to assess variation in caregiver appreciation for pediatric dosing guidance has also been constructed to provide a complementary subjective assessment. Three KPI categories, drug utilization (based on hospital admission and billing data collected from 2001 through 2006), medical need, and guidance outcome value along with a KPI composite score have been proposed. Low scores are favored with respect to prioritization for pharmacotherapy guidance. The pilot survey consisted of 15 questions to assess 1) physician knowledge regarding dosing guidance, 2) attitudes toward dose modification and patient individualization, 3) the accessibility, ease of use and appropriateness of existing data stores, and 4) frequency of dosing modification, consultation of dosing compendiums and estimate of success rate in dosing guidance. Pilot results suggest that dosing guidance is generally viewed as important and that the existing resources are insufficient to guide recommendations for all drugs. While the majority of respondents check more than one resource less than 25% of the time, at least 25% of the respondents check more than one resource 25-50% of the time. The majority viewed the relevance of dosing guidance very important to the management of drug therapy. The questionnaire is being extended to the primary care centers, the Kids First Network and specialty care centers. Results will guide the development of decision support systems (DSS) that provide patient

  3. A model for teaching and learning spinal thrust manipulation and its effect on participant confidence in technique performance.

    Science.gov (United States)

    Wise, Christopher H; Schenk, Ronald J; Lattanzi, Jill Black

    2016-07-01

    Despite emerging evidence to support the use of high velocity thrust manipulation in the management of lumbar spinal conditions, utilization of thrust manipulation among clinicians remains relatively low. One reason for the underutilization of these procedures may be related to disparity in training in the performance of these techniques at the professional and post professional levels. To assess the effect of using a new model of active learning on participant confidence in the performance of spinal thrust manipulation and the implications for its use in the professional and post-professional training of physical therapists. A cohort of 15 DPT students in their final semester of entry-level professional training participated in an active training session emphasizing a sequential partial task practice (SPTP) strategy in which participants engaged in partial task practice over several repetitions with different partners. Participants' level of confidence in the performance of these techniques was determined through comparison of pre- and post-training session surveys and a post-session open-ended interview. The increase in scores across all items of the individual pre- and post-session surveys suggests that this model was effective in changing overall participant perception regarding the effectiveness and safety of these techniques and in increasing student confidence in their performance. Interviews revealed that participants greatly preferred the SPTP strategy, which enhanced their confidence in technique performance. Results indicate that this new model of psychomotor training may be effective at improving confidence in the performance of spinal thrust manipulation and, subsequently, may be useful for encouraging the future use of these techniques in the care of individuals with impairments of the spine. Inasmuch, this method of instruction may be useful for training of physical therapists at both the professional and post-professional levels.

  4. The kinematic evolution of the Serra Central Salient, Eastern Brazil: A Neoproterozoic progressive arc in northern Espinhaço fold-thrust belt

    Science.gov (United States)

    Bersan, Samuel Moreira; Danderfer, André; Lagoeiro, Leonardo; Costa, Alice Fernanda de Oliveira

    2017-12-01

    Convex-to-the-foreland map-view curves are common features in fold-thrust belts around cratonic areas. These features are easily identifiable in belts composed of supracrustal rocks but have been rarely described in rocks from relatively deeper crustal levels where plastic deformation mechanisms stand out. Several local salients have been described in Neoproterozoic marginal fold-thrust belts around the São Francisco craton. In the northern part of the Espinhaço fold-thrust belt, which borders the eastern portion of the São Francisco craton, both Archean-Paleoproterozoic basement rocks and Proterozoic cover rocks are involved in the so-called Serra Central salient. A combination of conventional structural analysis and microstructural and paleostress studies were conducted to characterize the kinematic and the overall architecture and processes involved in the generation of this salient. The results allowed us to determine that the deformation along the Serra Central salient occur under low-grade metamorphic conditions and was related to a gently oblique convergence with westward mass transport that developed in a confined flow, controlled by two transverse bounding shear zones. We propose that the Serra Central salient nucleates as a basin-controlled primary arc that evolves to a progressive arc with secondary vertical axis rotation. This secondary rotation, well-illustrated by the presence of two almost orthogonal families of folds, was dominantly controlled by buttress effect exert by a basement high located in the foreland of the Serra Central salient.

  5. Guidance and methods for satisfying low specific activity material and surface contaminated object regulatory requirements

    International Nuclear Information System (INIS)

    Pope, R.B.; Shappert, L.B.; Michelhaugh, R.D.; Boyle, R.W.; Easton, E.P.; Coodk, J.R.

    1998-01-01

    The U.S. Department of Transportation (DOT) and the U.S. Nuclear Regulatory Commission (NRC) have prepared a comprehensive set of draft guidance for shippers and inspectors to use when applying the newly imposed regulatory requirements for low specific activity (LSA) material and surface contaminated objects (SCOs). These requirements represent significant departures in some areas from the manner in which these materials and objects were regulated by the earlier versions of the regulations. The proper interpretation and application of the regulatory criteria can require a fairly complex set of decisions be made. To assist those trying these regulatory requirements, a detailed set of logic-flow diagrams representing decisions related to multiple factors were prepared and included in the draft report for comment on Categorizing and Transporting Low Specific Activity Materials and Surface Contaminated Objects, (DOT/NRC, 1997). These logic-flow diagrams, as developed, are specific to the U.S. regulations, but were readily adaptable to the IAEA regulations. The diagrams have been modified accordingly and tied directly to specific paragraphs in IAEA Safety Series No. 6. This paper provides the logic-flow diagrams adapted in the IAEA regulations, and demonstrated how these diagrams can be used to assist consignors and inspectors in assessing compliance of shipments with the LSA material and SCO regulatory requirements. (authors)

  6. Feasibility Study of Needle Placement in Percutaneous Vertebroplasty: Cone-Beam Computed Tomography Guidance Versus Conventional Fluoroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Braak, Sicco J., E-mail: sjbraak@gmail.com [St. Antonius Hospital, Department of Radiology (Netherlands); Zuurmond, Kirsten, E-mail: kirsten.zuurmond@philips.com; Aerts, Hans C. J., E-mail: hans.cj.aerts@philips.com [Philips Medical, Department of Clinical Development (Netherlands); Leersum, Marc van, E-mail: m.van.leersum@antoniusziekenhuis.nl; Overtoom, Timotheus T. Th., E-mail: overtm@knoware.nl; Heesewijk, Johannes P. M. van, E-mail: j.heesewijk@antoniusziekenhuis.nl; Strijen, Marco J. L. van, E-mail: m.van.strijen@antoniusziekenhuis.nl [St. Antonius Hospital, Department of Radiology (Netherlands)

    2013-08-01

    ObjectiveTo investigate the accuracy, procedure time, fluoroscopy time, and dose area product (DAP) of needle placement during percutaneous vertebroplasty (PVP) using cone-beam computed tomography (CBCT) guidance versus fluoroscopy.Materials and MethodsOn 4 spine phantoms with 11 vertebrae (Th7-L5), 4 interventional radiologists (2 experienced with CBCT guidance and two inexperienced) punctured all vertebrae in a bipedicular fashion. Each side was randomization to either CBCT guidance or fluoroscopy. CBCT guidance is a sophisticated needle guidance technique using CBCT, navigation software, and real-time fluoroscopy. The placement of the needle had to be to a specific target point. After the procedure, CBCT was performed to determine the accuracy, procedure time, fluoroscopy time, and DAP. Analysis of the difference between methods and experience level was performed.ResultsMean accuracy using CBCT guidance (2.61 mm) was significantly better compared with fluoroscopy (5.86 mm) (p < 0.0001). Procedure time was in favor of fluoroscopy (7.39 vs. 10.13 min; p = 0.001). Fluoroscopy time during CBCT guidance was lower, but this difference is not significant (71.3 vs. 95.8 s; p = 0.056). DAP values for CBCT guidance and fluoroscopy were 514 and 174 mGy cm{sup 2}, respectively (p < 0.0001). There was a significant difference in favor of experienced CBCT guidance users regarding accuracy for both methods, procedure time of CBCT guidance, and added DAP values for fluoroscopy.ConclusionCBCT guidance allows users to perform PVP more accurately at the cost of higher patient dose and longer procedure time. Because procedural complications (e.g., cement leakage) are related to the accuracy of the needle placement, improvements in accuracy are clinically relevant. Training in CBCT guidance is essential to achieve greater accuracy and decrease procedure time/dose values.

  7. Global guidance on environmental life cycle impact assessment indicators: Progress and case study

    DEFF Research Database (Denmark)

    Frischknecht, Rolf; Fantke, Peter; Tschümperlin, Laura

    2016-01-01

    Purpose The life cycle impact assessment (LCIA) guidance flagship project of the United Nations Environment Programme (UNEP)/Society of Environmental Toxicology and Chemistry (SETAC) Life Cycle Initiative aims at providing global guidance and building scientific consensus on environmental LCIA in...

  8. Real-time tomosynthesis for radiation therapy guidance.

    Science.gov (United States)

    Hsieh, Scott S; Ng, Lydia W

    2017-11-01

    Fluoroscopy has been a tool of choice for monitoring treatments or interventions because of its extremely fast imaging times. However, the contrast obtained in fluoroscopy may be insufficient for certain clinical applications. In stereotactic ablative radiation therapy of the lung, fluoroscopy often lacks sufficient contrast for gating treatment. The purpose of this work is to describe and assess a real-time tomosynthesis design that can produce sufficient contrast for guidance of lung tumor treatment within a small field of view. Previous tomosynthesis designs in radiation oncology have temporal resolution on the order of seconds. The proposed system design uses parallel acquisition of multiple frames by simultaneously illuminating the field of view with multiple sources, enabling a temporal resolution of up to 30 frames per second. For a small field of view, a single flat-panel detector could be used if different sectors of the detector are assigned to specific sources. Simulated images were generated by forward projection of existing clinical datasets. The authors varied the number of tubes and the power of each tube in order to determine the impact on tumor visualization. Visualization of the tumor was much clearer in tomosynthesis than in fluoroscopy. Contrast generally improved with the number of sources used, and a minimum of four sources should be used. The high contrast of the lung allows very low system power, and in most cases, less than 1 mA was needed. More power is required in the lateral direction than the AP direction. The proposed system produces images adequate for real-time guidance of radiation therapy. The additional hardware requirements are modest, and the system is capable of imaging at high frame rates and low dose. Further development, including a prototype system and a dosimetry study, is needed to further evaluate the feasibility of this device for radiation therapy guidance. © 2017 American Association of Physicists in Medicine.

  9. The temporal dynamics of visual working memory guidance of selective attention

    Directory of Open Access Journals (Sweden)

    Jinfeng eTan

    2014-09-01

    Full Text Available The biased competition model proposes that there is top-down directing of attention to a stimulus matching the contents of working memory (WM, even when the maintenance of a WM representation is detrimental to target relevant performance. Despite many studies elucidating that spatial WM guidance can be present early in the visual processing system, whether visual WM guidance also influences perceptual selection remains poorly understood. Here, we investigated the electrophysiological correlates of early guidance of attention by WM in humans. Participants were required to perform a visual search task while concurrently maintaining object representations in their visual working memory. Behavioral results showed that response times (RTs were longer when the distractor in the visual search task was held in WM. The earliest WM guidance effect was observed in the P1 component (90-130 ms, with match trials eliciting larger P1 amplitude than mismatch trials. A similar result was also found in the N1 component (160-200 ms. These P1 and N1 effects could not be attributed to bottom-up perceptual priming from the presentation of a memory cue, because there was no significant difference in early ERP component when the cue was merely perceptually identified but not actively held in working memory. Standardized Low Resolution Electrical Tomography Analysis (sLORETA showed that the early WM guidance occurred in the occipital lobe and the N1-related activation occurred in the parietal gyrus. Time-frequency data suggested that alpha-band event-related spectral perturbation (ERSP magnitudes increased under the match condition compared with the mismatch condition. In conclusion, the present study suggests that the reappearance of a stimulus held in WM enhanced activity in the occipital area. Subsequently, this initial capture of attention by WM could be inhibited by competing visual inputs through attention re-orientation, reflecting by the alpha-band rhythm.

  10. Improved Rhenium Thrust Chambers for In-Space Propulsion, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Radiation-cooled, bipropellant thrust chambers are being considered for the ascent/descent engines and reaction control systems for NASA missions such as Mars Sample...

  11. A flight management algorithm and guidance for fuel-conservative descents in a time-based metered air traffic environment: Development and flight test results

    Science.gov (United States)

    Knox, C. E.

    1984-01-01

    A simple airborne flight management descent algorithm designed to define a flight profile subject to the constraints of using idle thrust, a clean airplane configuration (landing gear up, flaps zero, and speed brakes retracted), and fixed-time end conditions was developed and flight tested in the NASA TSRV B-737 research airplane. The research test flights, conducted in the Denver ARTCC automated time-based metering LFM/PD ATC environment, demonstrated that time guidance and control in the cockpit was acceptable to the pilots and ATC controllers and resulted in arrival of the airplane over the metering fix with standard deviations in airspeed error of 6.5 knots, in altitude error of 23.7 m (77.8 ft), and in arrival time accuracy of 12 sec. These accuracies indicated a good representation of airplane performance and wind modeling. Fuel savings will be obtained on a fleet-wide basis through a reduction of the time error dispersions at the metering fix and on a single-airplane basis by presenting the pilot with guidance for a fuel-efficient descent.

  12. Dating of movements along thrusts and faults in the Himalaya

    International Nuclear Information System (INIS)

    Saini, H.S.

    1982-01-01

    Radiometric dating of movements along the MCT (Vaikrita Thrust), two local but deep seated thrust and the Sumdoh Fault Zone bordering the Kinnar Kailas Granite in the Baspa and Satluj valleys, NE Himachal Himalaya, has been attempted for the first time by fission track method. Garnet and apatite fission track ages suggest the age of the latest phase of movements around 14 and 7 m.y. respectively along the MCT and Sumdoh Fault. The vertical uplift rates along them were 1.1mm/year from 14 to 7 m.y. and 0.6 mm/year from 7 m.y. to recent geologic past respectively, as against the value 0.036 mm/year during the period from 210 to 17 m.y. in the undisturbed area. (author)

  13. Optimization of residual heat removal pump axial thrust and axial bearing

    International Nuclear Information System (INIS)

    Schubert, F.

    1996-01-01

    The residual heat removal (RHR) pumps of German 1300 megawatt pressurized-water reactor (PWR) power plants are of the single stage end suction type with volute casing or with diffuser and forged circular casing. Due to the service conditions the pumps have to cover the full capacity range as well as a big variation in suction static pressure. This results in a big difference in the axial thrust that has to be borne by the axial bearing. Because these pumps are designed to operate without auxiliary systems (things that do not exist can not fail), they are equipped with antifriction bearings and sump oil lubrication. To minimize the heat production within the bearing casing, a number of PWR plants have pumps with combined axial/radial bearings of the ball type. Due to the fact that the maximum axial thrust caused by static pressure and hydrodynamic forces on the impeller is too big to be borne by that type of axial bearing, the impellers were designed to produce a hydrodynamic axial force that counteracts the static axial force. Thus, the resulting axial thrust may change direction when the static pressure varies

  14. Optimization of residual heat removal pump axial thrust and axial bearing

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, F.

    1996-12-01

    The residual heat removal (RHR) pumps of German 1300 megawatt pressurized-water reactor (PWR) power plants are of the single stage end suction type with volute casing or with diffuser and forged circular casing. Due to the service conditions the pumps have to cover the full capacity range as well as a big variation in suction static pressure. This results in a big difference in the axial thrust that has to be borne by the axial bearing. Because these pumps are designed to operate without auxiliary systems (things that do not exist can not fail), they are equipped with antifriction bearings and sump oil lubrication. To minimize the heat production within the bearing casing, a number of PWR plants have pumps with combined axial/radial bearings of the ball type. Due to the fact that the maximum axial thrust caused by static pressure and hydrodynamic forces on the impeller is too big to be borne by that type of axial bearing, the impellers were designed to produce a hydrodynamic axial force that counteracts the static axial force. Thus, the resulting axial thrust may change direction when the static pressure varies.

  15. An Investigation of the Guidance Counselling Needs of Adults with Dyslexia in the Adult Educational Guidance Initiative (AEGI)

    Science.gov (United States)

    Elftorp, Petra; Hearne, Lucy

    2014-01-01

    The experiences of adult learners with dyslexia is an under-researched area in Ireland at present. This article will discuss the findings from phase one of a mixed methods research study, which is investigating the guidance counselling needs of clients with dyslexia within the Adult Education Guidance Initiative (AEGI). The research is underpinned…

  16. Optimal Thrust Vectoring for an Annular Aerospike Nozzle, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Recent success of an annular aerospike flight test by NASA Dryden has prompted keen interest in providing thrust vector capability to the annular aerospike nozzle...

  17. Regulatory Guidance for Lightning Protection in Nuclear Power Plants

    International Nuclear Information System (INIS)

    Kisner, Roger A.; Wilgen, John B.; Ewing, Paul D.; Korsah, Kofi; Antonescu, Christina E.

    2006-01-01

    Oak Ridge National Laboratory (ORNL) was engaged by the U.S. Nuclear Regulatory Commission (NRC) Office of Nuclear Regulatory Research (RES) to develop the technical basis for regulatory guidance to address design and implementation practices for lightning protection systems in nuclear power plants (NPPs). Lightning protection is becoming increasingly important with the advent of digital and low-voltage analog systems in NPPs. These systems have the potential to be more vulnerable than older analog systems to the resulting power surges and electromagnetic interference (EMI) when lightning strikes facilities or power lines. This paper discusses the technical basis for guidance to licensees and applicants covered in Regulatory Guide (RG) 1.204, Guidelines for Lightning Protection of Nuclear Power Plants, issued August 2005. RG 1.204 describes guidance for practices that are acceptable to the NRC staff for protecting nuclear power structures and systems from direct lightning strikes and the resulting secondary effects.

  18. Soil Vapor Extraction System Optimization, Transition, and Closure Guidance

    Energy Technology Data Exchange (ETDEWEB)

    Truex, Michael J.; Becker, Dave; Simon, Michelle A.; Oostrom, Martinus; Rice, Amy K.; Johnson, Christian D.

    2013-02-08

    Soil vapor extraction (SVE) is a prevalent remediation approach for volatile contaminants in the vadose zone. A diminishing rate of contaminant extraction over time is typically observed due to 1) diminishing contaminant mass, and/or 2) slow rates of removal for contamination in low-permeability zones. After a SVE system begins to show indications of diminishing contaminant removal rate, SVE performance needs to be evaluated to determine whether the system should be optimized, terminated, or transitioned to another technology to replace or augment SVE. This guidance specifically addresses the elements of this type of performance assessment. While not specifically presented, the approach and analyses in this guidance could also be applied at the onset of remediation selection for a site as a way to evaluate current or future impacts to groundwater from vadose zone contamination. The guidance presented here builds from existing guidance for SVE design, operation, optimization, and closure from the U.S. Environmental Protection Agency, U.S. Army Corps of Engineers, and the Air Force Center for Engineering and the Environment. The purpose of the material herein is to clarify and focus on the specific actions and decisions related to SVE optimization, transition, and/or closure.

  19. Raising the Profile of Career Guidance: Educational and Vocational Guidance Practitioner

    Science.gov (United States)

    Hiebert, Bryan

    2009-01-01

    In 2007 the International Association for Educational and Vocational Guidance (IAEVG) launched the Educational and Vocational Guidance Practitioner credential (EVGP) as one means of formally acknowledging the knowledge, skills, and personal attributes that practitioners need in order to provide quality career development services to clients. This…

  20. Math modeling for helicopter simulation of low speed, low altitude and steeply descending flight

    Science.gov (United States)

    Sheridan, P. F.; Robinson, C.; Shaw, J.; White, F.

    1982-01-01

    A math model was formulated to represent some of the aerodynamic effects of low speed, low altitude, and steeply descending flight. The formulation is intended to be consistent with the single rotor real time simulation model at NASA Ames Research Center. The effect of low speed, low altitude flight on main rotor downwash was obtained by assuming a uniform plus first harmonic inflow model and then by using wind tunnel data in the form of hub loads to solve for the inflow coefficients. The result was a set of tables for steady and first harmonic inflow coefficients as functions of ground proximity, angle of attack, and airspeed. The aerodynamics associated with steep descending flight in the vortex ring state were modeled by replacing the steady induced downwash derived from momentum theory with an experimentally derived value and by including a thrust fluctuations effect due to vortex shedding. Tables of the induced downwash and the magnitude of the thrust fluctuations were created as functions of angle of attack and airspeed.

  1. Dynamic Eco-Driving Speed Guidance at Signalized Intersections: Multivehicle Driving Simulator Based Experimental Study

    Directory of Open Access Journals (Sweden)

    Peng Chen

    2018-01-01

    Full Text Available Variations in vehicle fuel consumption and gas emissions are usually associated with changes in cruise speed and the aggressiveness of drivers’ acceleration/deceleration, especially at traffic signals. In an attempt to enhance vehicle fuel efficiency on arterials, this study developed a dynamic eco-driving speed guidance strategy (DESGS using real-time signal timing and vehicle positioning information in a connected vehicle (CV environment. DESGS mainly aims to optimize the fuel/emission speed profiles for vehicles approaching signalized intersections. An optimization-based rolling horizon and a dynamic programming approach were proposed to track the optimal guided velocity for individual vehicles along the travel segment. In addition, a vehicle specific power (VSP based approach was integrated into DESGS to estimate the fuel consumption and CO2 emissions. To evaluate the effectiveness of the overall strategy, 15 experienced drivers were recruited to participate in interactive speed guidance experiments using multivehicle driving simulators. It was found that compared to vehicles without speed guidance, those with DESGS had a significantly reduced number of stops and approximately 25% less fuel consumption and CO2 emissions.

  2. Non-Toxic Dual Thrust Reaction Control Engine Development for On-Orbit APS Applications

    Science.gov (United States)

    Robinson, Philip J.; Veith, Eric M.

    2003-01-01

    A non-toxic dual thrust proof-of-concept demonstration engine was successfully tested at the Aerojet Sacramento facility under a technology contract sponsored by the National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC). The goals of the NASA MSFC contract (NAS8-01109) were to develop and expand the technical maturity of a non-toxic, on-orbit auxiliary propulsion system (APS) thruster under the Next Generation Launch Technology (NGLT) program. The demonstration engine utilized the existing Kistler K-1 870 lbf LOX/Ethanol orbital maneuvering engine ( O m ) coupled with some special test equipment (STE) that enabled engine operation at 870 lbf in the primary mode and 25 lbf in the vernier mode. Ambient testing in primary mode varied mixture ratio (MR) from 1.28 to 1.71 and chamber pressure (P(c) from 110 to 181 psia, and evaluated electrical pulse widths (EPW) of 0.080, 0.100 and 0.250 seconds. Altitude testing in vernier mode explored igniter and thruster pulsing characteristics, long duration steady state operation (greater than 420 sec) and the impact of varying the percent fuel film cooling on vernier performance and chamber thermal response at low PC (4 psia). Data produced from the testing provided calibration of the performance and thermal models used in the design of the next version of the dual thrust Reaction Control Engine (RCE).

  3. A particle bed reactor based NTP in the 112,500 N thrust class

    International Nuclear Information System (INIS)

    Ludewig, H.; Powell, J.R.; Lazareth, O.W. Jr.; Todosow, M.

    1993-01-01

    This paper discusses the application of a Particle Bed Reactor (PBR) to a 112,500 N thrust Nuclear Thermal Propulsion (NTP) Engine. The method of analysis is described, followed by a presentation of the results. It is concluded that the PBR would result in a very competitive NTP engine. In addition, due to the high power densities possible with a PBR, high thrust/weight ratios are possible. This conclusion can be used to satisfy a variety of mission goals

  4. A particle bed reactor based NTP in the 112,500 N thrust class

    Science.gov (United States)

    Ludewig, Hans; Powell, James R.; Lazareth, Otto W.; Todosow, Michael

    1993-01-01

    This paper discusses the application of a Particle Bed Reactor (PBR) to a 112,500 N thrust Nuclear Thermal Propulsion (NTP) Engine. The method of analysis is described, followed by a presentation of the results. It is concluded that the PBR would result in a very competitive NTP engine. In addition, due to the high power densities possible with a PBR, high thrust/weight ratios are possible. This conclusion can be used to satisfy a variety of mission goals.

  5. Electrical resistivity structures and tectonic implications of Main Karakorum Thrust (MKT) in the western Himalayas: NNE Pakistan

    Science.gov (United States)

    Shah, Syed Tallataf Hussain; Zhao, Junmeng; Xiao, Qibin; Bhatti, Zahid Imran; Khan, Nangyal Ghani; Zhang, Heng; Deng, Gong; Liu, Hongbing

    2018-06-01

    We discovered a conductive zone along Main Karakoram Thrust which could be an indication of flat subduction of Kohistan island arc beneath the Eurasian plate. Kohistan island arc collided with the Karakoram Block of the Eurasian Plate in the Early Cretaceous. However, according to findings of many researchers, the subduction ceased about 75 Ma ago. The presence of the conductive zone is an indication of current magmatism or hydrothermal fluids. Maximum low-frequency band data from Fourteen sites with recording periods of 10-2-103 s was acquired along a profile crossing MKT. Our results reveal the existence of multiple low resistivity zones beneath the region extending from shallow to the depths of more than 100 km. These low-resistivity zones might be a signature of the ongoing magmatic activities or hydrothermal fluids along the Shyok Suture Zone. In addition, we discovered another large conductive body towards the south of the study area which could be a result of uprising magmatic plumes generated by the subducting Indian plate along the Indian suture zone and their entrapment in the overlying Kohistan block.

  6. Guidance Law Design for a Class of Dual-Spin Mortars

    Directory of Open Access Journals (Sweden)

    Qing-wei Guo

    2015-01-01

    Full Text Available To minimize the cost and maximize the ease of use, a class of dual-spin mortars is designed which only rely on GPS receiver and geomagnetic measurements. However, there are some problems to be solved when the range is small, such as low correction authority and trajectory bending. Guidance law design for this mortar is detailed. Different guidance laws were designed for the ascending and descending segments, respectively. By taking variable parameter guidance law in the vertical plane and using compensation in the lateral plane, the problems mentioned above were resolved. Roll angle resolving algorithms with geomagnetic measurements were demonstrated and the experiment results proved to be effective. In order to verify the effectiveness, Seven-Degrees-of-Freedom (7-DOF rigid ballistic model were established and hardware in the loop simulation was introduced. After the transform function of the actuator was obtained, the control model of the shell was improved. The results of the Monte Carlo simulation demonstrate that the guidance law is suitable and the mortar can be effectively controlled.

  7. Effects of Cavity on the Performance of Dual Throat Nozzle During the Thrust-Vectoring Starting Transient Process.

    Science.gov (United States)

    Gu, Rui; Xu, Jinglei

    2014-01-01

    The dual throat nozzle (DTN) technique is capable to achieve higher thrust-vectoring efficiencies than other fluidic techniques, without compromising thrust efficiency significantly during vectoring operation. The excellent performance of the DTN is mainly due to the concaved cavity. In this paper, two DTNs of different scales have been investigated by unsteady numerical simulations to compare the parameter variations and study the effects of cavity during the vector starting process. The results remind us that during the vector starting process, dynamic loads may be generated, which is a potentially challenging problem for the aircraft trim and control.

  8. Quality assurance and quality control in mammography: a review of available guidance worldwide.

    Science.gov (United States)

    Reis, Cláudia; Pascoal, Ana; Sakellaris, Taxiarchis; Koutalonis, Manthos

    2013-10-01

    Review available guidance for quality assurance (QA) in mammography and discuss its contribution to harmonise practices worldwide. Literature search was performed on different sources to identify guidance documents for QA in mammography available worldwide in international bodies, healthcare providers, professional/scientific associations. The guidance documents identified were reviewed and a selection was compared for type of guidance (clinical/technical), technology and proposed QA methodologies focusing on dose and image quality (IQ) performance assessment. Fourteen protocols (targeted at conventional and digital mammography) were reviewed. All included recommendations for testing acquisition, processing and display systems associated with mammographic equipment. All guidance reviewed highlighted the importance of dose assessment and testing the Automatic Exposure Control (AEC) system. Recommended tests for assessment of IQ showed variations in the proposed methodologies. Recommended testing focused on assessment of low-contrast detection, spatial resolution and noise. QC of image display is recommended following the American Association of Physicists in Medicine guidelines. The existing QA guidance for mammography is derived from key documents (American College of Radiology and European Union guidelines) and proposes similar tests despite the variations in detail and methodologies. Studies reported on QA data should provide detail on experimental technique to allow robust data comparison. Countries aiming to implement a mammography/QA program may select/prioritise the tests depending on available technology and resources. •An effective QA program should be practical to implement in a clinical setting. •QA should address the various stages of the imaging chain: acquisition, processing and display. •AEC system QC testing is simple to implement and provides information on equipment performance.

  9. Growth stratal records of instantaneous and progressive limb rotation in the Precordillera thrust belt and Bermejo basin, Argentina

    Science.gov (United States)

    Zapata, TomáS. R.; Allmendinger, Richard W.

    1996-10-01

    Analysis of synorogenic deposits preserved near the thrust front zone of the Precordillera fold and thrust belt and in the Bermejo foreland basin in central Argentina documents the evolution of deformation during the last 5 Myr as well as the thrust system kinematics. Seismic lines across the area display examples of progressive and instantaneous limb rotations. The easternmost thrust plate of the Central Precordillera, the Niquivil thrust, experienced episodic motion in two main stages: a first thrust movement as a fault-propagation fold and a second movement as a high-angle anticlinal breakthrough fault after a period of quiescence. Growth strata deposited in the La Pareja intermontane basin and the Las Salinas and Bermejo anticline recorded continuous growth of Eastern Precordilleran structures beginning at ˜2.7 Ma, with uplift rates of ˜0.3 mm/yr for the Niquivil anticline, 1.08 mm/yr for the Las Salinas anticline, and between ˜0.6 and 0.38 mm/yr during the last ˜2 Myr for the Bermejo anticline. Once the Eastern Precordillera began to grow, the propagation of the Niquivil thrust stopped, restricting the deformation to the young Vallecito out-of sequence thrust. The complex geometry of growth strata deposited on the back limb of the Las Salinas anticline can be explained by using a model of a two-step fault propagation fold with constant layer thickness. The Bermejo anticline of the Eastern Precordillera is formed by the simultaneous propagation of a shallow fault, responsible for the fold shape, and a deep fault that produced vertical uplift. A growth triangle that documents instantaneous forelimb rotation for a fault-propagation fold is recorded for the first time in a published seismic line.

  10. Mobile DNA and the TE-Thrust hypothesis: supporting evidence from the primates

    Directory of Open Access Journals (Sweden)

    Oliver Keith R

    2011-05-01

    Full Text Available Abstract Transposable elements (TEs are increasingly being recognized as powerful facilitators of evolution. We propose the TE-Thrust hypothesis to encompass TE-facilitated processes by which genomes self-engineer coding, regulatory, karyotypic or other genetic changes. Although TEs are occasionally harmful to some individuals, genomic dynamism caused by TEs can be very beneficial to lineages. This can result in differential survival and differential fecundity of lineages. Lineages with an abundant and suitable repertoire of TEs have enhanced evolutionary potential and, if all else is equal, tend to be fecund, resulting in species-rich adaptive radiations, and/or they tend to undergo major evolutionary transitions. Many other mechanisms of genomic change are also important in evolution, and whether the evolutionary potential of TE-Thrust is realized is heavily dependent on environmental and ecological factors. The large contribution of TEs to evolutionary innovation is particularly well documented in the primate lineage. In this paper, we review numerous cases of beneficial TE-caused modifications to the genomes of higher primates, which strongly support our TE-Thrust hypothesis.

  11. Guidance concepts for time-based flight operations

    Science.gov (United States)

    Vicroy, Dan D.

    1990-01-01

    Airport congestion and the associated delays are severe in today's airspace system and are expected to increase. NASA and the FAA is investigating various methods of alleviating this problem through new technology and operational procedures. One concept for improving airspace productivity is time-based control of aircraft. Research to date has focused primarily on the development of time-based flight management systems and Air Traffic Control operational procedures. Flight operations may, however, require special onboard guidance in order to satisfy the Air Traffic Control imposed time constraints. The results are presented of a simulation study aimed at evaluating several time-based guidance concepts in terms of tracking performance, pilot workload, and subjective preference. The guidance concepts tested varied in complexity from simple digital time-error feedback to an advanced time-referenced-energy guidance scheme.

  12. Structures and morphotectonic evolution of the frontal fold–thrust ...

    Indian Academy of Sciences (India)

    52

    MBT) at N. 57 ... The Indian lithospheric plate flexed and subsided presumably by in-. 81 ... Kimin Formation that are parts of hanging wall flat of the HFT, and (ii) MBT and Tipi Thrust: at ... least 6 km of crustal layer (Lang and Huntington 2014).

  13. Graphical Turbulence Guidance - Composite

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Forecast turbulence hazards identified by the Graphical Turbulence Guidance algorithm. The Graphical Turbulence Guidance product depicts mid-level and upper-level...

  14. 78 FR 48175 - Retrospective Review of Draft Guidance Documents Issued Before 2010; Withdrawal of Guidances

    Science.gov (United States)

    2013-08-07

    ... guidances (number 19 through 22), contact the Office of Pharmaceutical Science in CDER. 23. ``Qualifying for... to the pharmaceutical industry. In most cases, FDA has developed other guidances and resources to... guidances: 1. ``Manufacturing, Processing, or Holding Active Pharmaceutical Ingredients''--issued April 1998...

  15. Correlation of the Condylar Guidance Obtained by Protrusive Interocclusal Record and Panoramic Radiographs in Completely Edentulous Patients: An in Vivo Study

    Directory of Open Access Journals (Sweden)

    Khyati Shah

    2014-01-01

    Results: The results showed statistically significant difference between the condylar guidance values obtained from Orthopantomograph (Radiograph and the condylar guidance values obtained at the stage of jaw relation. Conclusion: Within the limitations of the study, it can be concluded that the condylar guidance values obtained from the Radiographs were higher than those obtained at the stage of jaw relation recording stage.

  16. 75 FR 69089 - Guidance for Industry and Food and Drug Administration Staff; Class II Special Controls Guidance...

    Science.gov (United States)

    2010-11-10

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2010-D-0514] Guidance for Industry and Food and Drug Administration Staff; Class II Special Controls Guidance Document... Administration (FDA) is announcing the availability of the guidance entitled ``Class II Special Controls Guidance...

  17. 76 FR 29251 - Guidance for Industry and Food and Drug Administration Staff; Class II Special Controls; Guidance...

    Science.gov (United States)

    2011-05-20

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2006-D-0094] Guidance for Industry and Food and Drug Administration Staff; Class II Special Controls; Guidance Document... of the guidance entitled ``Guidance for Industry and Food and Drug Administration Staff; Class II...

  18. Lithologic Controls on Structure Highlight the Role of Fluids in Failure of a Franciscan Complex Accretionary Prism Thrust Fault

    Science.gov (United States)

    Bartram, H.; Tobin, H. J.; Goodwin, L. B.

    2015-12-01

    Plate-bounding subduction zone thrust systems are the source of major earthquakes and tsunamis, but their mechanics and internal structure remain poorly understood and relatively little-studied compared to faults in continental crust. Exposures in exhumed accretionary wedges present an opportunity to study seismogenic subduction thrusts in detail. In the Marin Headlands, a series of thrusts imbricates mechanically distinct lithologic units of the Mesozoic Franciscan Complex including pillow basalt, radiolarian chert, black mudstone, and turbidites. We examine variations in distribution and character of structure and vein occurrence in two exposures of the Rodeo Cove thrust, a fossil plate boundary exposed in the Marin Headlands. We observe a lithologic control on the degree and nature of fault localization. At Black Sand Beach, deformation is localized in broad fault cores of sheared black mudstone. Altered basalts, thrust over greywacke, mudstone, and chert, retain their coherence and pillow structures. Veins are only locally present. In contrast, mudstone is virtually absent from the exposure 2 km away at Rodeo Beach. At this location, deformation is concentrated in the altered basalts, which display evidence of extensive vein-rock interaction. Altered basalts exhibit a pervasive foliation, which is locally disrupted by both foliation-parallel and cross-cutting carbonate-filled veins and carbonate cemented breccia. Veins are voluminous (~50%) at this location. All the structures are cut by anastomosing brittle shear zones of foliated cataclasite or gouge. Analyses of vein chemistry will allow us to compare the sources of fluids that precipitated the common vein sets at Rodeo Beach to the locally developed veins at Black Sand Beach. These observations lead us to hypothesize that in the absence of a mechanically weak lithology, elevated pore fluid pressure is required for shear failure. If so, the vein-rich altered basalt at Rodeo Beach may record failure of an

  19. RESEARCH OF THE HIGH HARMONICS INDIVIDUAL BLADE CONTROL EFFECT ON VIBRATIONS CAUSED BY THE HELICOPTER MAIN ROTOR THRUST

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available The paper presents numerical results analysis of main rotor vibration due to helicopter main rotor thrust pulsation.The calculation method, the object of research and numerical research results with the aim to reduce the amplitude of the vibrations transmitted to the hub from the helicopters main rotor by the individual blade control in azimuth by the installation angle of blades cyclic changes are set out in the article. The individual blades control law for a five-blade main rotor based on the blade frequencies is made. It allows reducing the vibration from thrust. Research takes into account the main rotor including and excluding the blade flapping motion. The minimal vibrations regime is identified.Numerical study of variable loads caused by unsteady flow around the main rotor blades at high relative speeds of flight, which transmitted to the rotor hub, is made. The scheme of a thin lifting surface and the rotor vortex theory are used for simulation of the aerodynamic loads on blades. Non - uniform loads caused by the thrust, decomposed on the blade harmonic and its overtones. The largest values of deviation from the mean amplitude thrust are received. The analysis of variable loads with a traditional control system is made. Algorithms of higher harmonics individual blade control capable of reducing the thrust pulsation under the average value of thrust are developed.Numerical research shows that individual blade control of high harmonics reduces variable loads. The necessary change in the blade installation is about ± 0,2 degree that corresponds to the maximum displacement of the additional con- trol stick is about 1 mm.To receive the overall picture is necessary to consider all six components of forces and moments. Control law with own constants will obtained for each of them. It is supposed, that each of six individual blade control laws have an impact on other components. Thus, the problem reduces to the optimization issue. The

  20. A Thrust Allocation Method for Efficient Dynamic Positioning of a Semisubmersible Drilling Rig Based on the Hybrid Optimization Algorithm

    Directory of Open Access Journals (Sweden)

    Luman Zhao

    2015-01-01

    Full Text Available A thrust allocation method was proposed based on a hybrid optimization algorithm to efficiently and dynamically position a semisubmersible drilling rig. That is, the thrust allocation was optimized to produce the generalized forces and moment required while at the same time minimizing the total power consumption under the premise that forbidden zones should be taken into account. An optimization problem was mathematically formulated to provide the optimal thrust allocation by introducing the corresponding design variables, objective function, and constraints. A hybrid optimization algorithm consisting of a genetic algorithm and a sequential quadratic programming (SQP algorithm was selected and used to solve this problem. The proposed method was evaluated by applying it to a thrust allocation problem for a semisubmersible drilling rig. The results indicate that the proposed method can be used as part of a cost-effective strategy for thrust allocation of the rig.

  1. Health and thermal comfort: From WHO guidance to housing strategies

    International Nuclear Information System (INIS)

    Ormandy, David; Ezratty, Véronique

    2012-01-01

    There are many references to the WHO guidance on thermal comfort in housing, but not to the original source material. Based on archive material, this paper gives the evidential basis for the WHO guidance. It then reports on evidence that some groups may be more susceptible to high or low indoor temperatures than others. It examines different methods for measuring thermal comfort, such as air temperature measurement, assessing residents' perception, and predicting satisfaction. Resident's perception was used effectively in the WHO LARES project, showing that self-reported poor health was significantly associated with poor thermal comfort. Tools to inform strategies directed at dealing with cold homes and fuel poverty are considered, including Energy Performance Certificates, Fuel Poverty Indicators, and the English Housing Health and Safety Rating System. Conclusions from a WHO Workshop on Housing, Energy and Thermal Comfort are also summarised. The WHO view of thermal comfort, which is driven by protecting health from both high and low indoor temperatures, should be recognised in energy efficiency, fuel poverty and climate change strategies. While this is a major challenge, it could provide both health gains for individuals, and economic benefits for society. - Highlights: ► WHO guidance on thermal comfort is directed to protecting health in the home environment. ► In particular, the WHO guidance aims to protect the health of the most susceptible and fragile. ► Housing energy efficiency strategies protect health, and attack inequities. ► Housing energy efficiency strategies also have economic benefits for society.

  2. Low Loss Single-Mode Porous-Core Kagome Photonic Crystal Fiber for THz Wave Guidance

    DEFF Research Database (Denmark)

    Hasanuzzaman, G. K. M.; Habib, Selim; Abdur Razzak, S. M.

    2015-01-01

    A novel porous-core kagome lattice photonic crystal fiber (PCF) is designed and analyzed in this paper for terahertz (THz) wave guidance. Using finite element method (FEM), properties of the proposed kagome lattice PCF are simulated in details including the effective material loss (EML), confinem...

  3. Flapping tail membrane in bats produces potentially important thrust during horizontal takeoffs and very slow flight.

    Directory of Open Access Journals (Sweden)

    Rick A Adams

    Full Text Available Historically, studies concerning bat flight have focused primarily on the wings. By analyzing high-speed video taken on 48 individuals of five species of vespertilionid bats, we show that the capacity to flap the tail-membrane (uropatagium in order to generate thrust and lift during takeoffs and minimal-speed flight (<1 m (s-1 was largely underestimated. Indeed, bats flapped the tail-membrane by extensive dorso-ventral fanning motions covering as much as 135 degrees of arc consistent with thrust generation by air displacement. The degree of dorsal extension of the tail-membrane, and thus the potential amount of thrust generated during platform launches, was significantly correlated with body mass (P = 0.02. Adduction of the hind limbs during upstrokes collapsed the tail-membrane thereby reducing its surface area and minimizing negative lift forces. Abduction of the hind limbs during the downstroke fully expanded the tail-membrane as it was swept ventrally. The flapping kinematics of the tail-membrane is thus consistent with expectations for an airfoil. Timing offsets between the wings and tail-membrane during downstrokes was as much as 50%, suggesting that the tail-membrane was providing thrust and perhaps lift when the wings were retracting through the upstoke phase of the wing-beat cycle. The extent to which the tail-membrane was used during takeoffs differed significantly among four vespertilionid species (P = 0.01 and aligned with predictions derived from bat ecomorphology. The extensive fanning motion of the tail membrane by vespertilionid bats has not been reported for other flying vertebrates.

  4. RGM is a repulsive guidance molecule for retinal axons

    DEFF Research Database (Denmark)

    Monnier, Philippe P; Sierra, Ana; Macchi, Paolo

    2002-01-01

    with known guidance cues, and its messenger RNA is distributed in a gradient with increasing concentration from the anterior to posterior pole of the embryonic tectum. Recombinant RGM at low nanomolar concentration induces collapse of temporal but not of nasal growth cones and guides temporal retinal axons...

  5. Design of a mixer for the thrust-vectoring system on the high-alpha research vehicle

    Science.gov (United States)

    Pahle, Joseph W.; Bundick, W. Thomas; Yeager, Jessie C.; Beissner, Fred L., Jr.

    1996-01-01

    One of the advanced control concepts being investigated on the High-Alpha Research Vehicle (HARV) is multi-axis thrust vectoring using an experimental thrust-vectoring (TV) system consisting of three hydraulically actuated vanes per engine. A mixer is used to translate the pitch-, roll-, and yaw-TV commands into the appropriate TV-vane commands for distribution to the vane actuators. A computer-aided optimization process was developed to perform the inversion of the thrust-vectoring effectiveness data for use by the mixer in performing this command translation. Using this process a new mixer was designed for the HARV and evaluated in simulation and flight. An important element of the Mixer is the priority logic, which determines priority among the pitch-, roll-, and yaw-TV commands.

  6. Engineering research, development and technology. Thrust area report, FY93

    Energy Technology Data Exchange (ETDEWEB)

    1994-05-01

    The mission of the Engineering Research, Development, and Technology Program at Lawrence Livermore National Laboratory (LLNL) is to develop the technical staff, tools, and facilities needed to support current and future LLNL programs. The efforts are guided by a dual-benefit research and development strategy that supports Department of Energy missions, such as national security through nuclear deterrence and economic competitiveness through partnerships with U.S. industry. This annual report, organized by thrust area, describes the activities for the fiscal year 1993. The report provides timely summaries of objectives, methods, and results from nine thrust areas for this fiscal year: Computational Electronics and Electromagnetics; Computational Mechanics; Diagnostics and Microelectronics; Fabrication Technology; Materials Science and Engineering; Power Conversion Technologies; Nondestructive Evaluation; Remote Sensing, Imaging, and Signal Engineering; and Emerging Technologies. Separate abstracts were prepared for 47 papers in this report.

  7. The complete two-loop integrated jet thrust distribution in soft-collinear effective theory

    International Nuclear Information System (INIS)

    Manteuffel, Andreas von; Schabinger, Robert M.; Zhu, Hua Xing

    2014-01-01

    In this work, we complete the calculation of the soft part of the two-loop integrated jet thrust distribution in e + e − annihilation. This jet mass observable is based on the thrust cone jet algorithm, which involves a veto scale for out-of-jet radiation. The previously uncomputed part of our result depends in a complicated way on the jet cone size, r, and at intermediate stages of the calculation we actually encounter a new class of multiple polylogarithms. We employ an extension of the coproduct calculus to systematically exploit functional relations and represent our results concisely. In contrast to the individual contributions, the sum of all global terms can be expressed in terms of classical polylogarithms. Our explicit two-loop calculation enables us to clarify the small r picture discussed in earlier work. In particular, we show that the resummation of the logarithms of r that appear in the previously uncomputed part of the two-loop integrated jet thrust distribution is inextricably linked to the resummation of the non-global logarithms. Furthermore, we find that the logarithms of r which cannot be absorbed into the non-global logarithms in the way advocated in earlier work have coefficients fixed by the two-loop cusp anomalous dimension. We also show that in many cases one can straightforwardly predict potentially large logarithmic contributions to the integrated jet thrust distribution at L loops by making use of analogous contributions to the simpler integrated hemisphere soft function

  8. Guidance on Conducting and REporting DElphi Studies (CREDES) in palliative care: Recommendations based on a methodological systematic review.

    Science.gov (United States)

    Jünger, Saskia; Payne, Sheila A; Brine, Jenny; Radbruch, Lukas; Brearley, Sarah G

    2017-09-01

    The Delphi technique is widely used for the development of guidance in palliative care, having impact on decisions with relevance for patient care. To systematically examine the application of the Delphi technique for the development of best practice guidelines in palliative care. A methodological systematic review was undertaken using the databases PubMed, CINAHL, Web of Science, Academic Search Complete and EMBASE. Original articles (English language) were included when reporting on empirical studies that had used the Delphi technique to develop guidance for good clinical practice in palliative care. Data extraction included a quality appraisal on the rigour in conduct of the studies and the quality of reporting. A total of 30 empirical studies (1997-2015) were considered for full-text analysis. Considerable differences were identified regarding the rigour of the design and the reporting of essential process and outcome parameters. Furthermore, discrepancies regarding the use of terms for describing the method were observed, for example, concerning the understanding of a 'round' or a 'modified Delphi study'. Substantial variation was found concerning the quality of the study conduct and the transparency of reporting of Delphi studies used for the development of best practice guidance in palliative care. Since credibility of the resulting recommendations depends on the rigorous use of the Delphi technique, there is a need for consistency and quality both in the conduct and reporting of studies. To allow a critical appraisal of the methodology and the resulting guidance, a reporting standard for Conducting and REporting of DElphi Studies (CREDES) is proposed.

  9. Applying the anisotropy of magnetic susceptibility technique to the study of the tectonic evolution of the West Spitsbergen Fold-and-Thrust Belt

    Directory of Open Access Journals (Sweden)

    Katarzyna Dudzisz

    2016-12-01

    Full Text Available We demonstrate the use of the anisotropy of magnetic susceptibility (AMS method to determine the orientation of the principal tectonic strain directions developed during the formation of the West Spitsbergen Fold-and-Thrust Belt (WSFTB. The AMS measurements and extensive rock-magnetic studies of the Lower Triassic rocks reported here were focused on the recognition of the magnetic fabric, the identification of ferromagnetic minerals and an estimation of the influence of ferro- and paramagnetic minerals on magnetic susceptibility. At most sites, the paramagnetic minerals controlled the magnetic susceptibility, and at only one site the impact of ferromagnetic minerals was higher. The AMS technique documented the presence of different types of magnetic fabrics within the sampled sites. At two sites, a normal (Kmin perpendicular to the bedding magnetic fabric of sedimentary origin was detected. This was associated with a good clustering of the maximum AMS axes imposed by tectonic strain. The Kmax magnetic lineation directions obtained here parallel the general NNW–SSE trend of the WSFTB fold axial traces and thrust fronts. The two other investigated sites possessed mixed and inverted fabrics, the latter of which appear to reflect the presence of iron-bearing carbonates.

  10. Numerical research on rotating speed influence and flow state distribution of water-lubricated thrust bearing

    International Nuclear Information System (INIS)

    Deng Xiao; Deng Liping; Huang Wei

    2015-01-01

    Water-lubricated thrust bearing is one of the key parts in canned motor pump, for example, the RCP in AP1000, and it functions to balance axial loads. A calculation model which can handle all flow state lubrication performance for water-lubricated thrust bearing has been presented. The model first includes laminar and turbulent Reynolds' equation. Then to get continuous viscosity coefficients cross critical Reynolds number, a transition zone which ranges based on engineering experience is put up, through which Hermite interpolation is employed. The model is numerically solved in finite difference method with uniform grids. To accelerate the calculation process, multigrid method and line relaxation is adopted within the iteration procedure. A medium sized water-lubricated tilting pad thrust bearing is exampled to verify the calculation model. Results suggest that as rotating speed enlarges, lubrication state distribution of the thrust bearing gradually tends to turbulent lubrication from the intersection corner of pad outer diameter and pad inlet to the opposite, minimum water film thickness increases approximately linearly, maximum water film pressure has little change, meanwhile the friction power grows nearly in exponential law which could result in bad effect by yielding much more heat. (author)

  11. Integrating mechanisms of visual guidance in naturalistic language production.

    Science.gov (United States)

    Coco, Moreno I; Keller, Frank

    2015-05-01

    Situated language production requires the integration of visual attention and linguistic processing. Previous work has not conclusively disentangled the role of perceptual scene information and structural sentence information in guiding visual attention. In this paper, we present an eye-tracking study that demonstrates that three types of guidance, perceptual, conceptual, and structural, interact to control visual attention. In a cued language production experiment, we manipulate perceptual (scene clutter) and conceptual guidance (cue animacy) and measure structural guidance (syntactic complexity of the utterance). Analysis of the time course of language production, before and during speech, reveals that all three forms of guidance affect the complexity of visual responses, quantified in terms of the entropy of attentional landscapes and the turbulence of scan patterns, especially during speech. We find that perceptual and conceptual guidance mediate the distribution of attention in the scene, whereas structural guidance closely relates to scan pattern complexity. Furthermore, the eye-voice span of the cued object and its perceptual competitor are similar; its latency mediated by both perceptual and structural guidance. These results rule out a strict interpretation of structural guidance as the single dominant form of visual guidance in situated language production. Rather, the phase of the task and the associated demands of cross-modal cognitive processing determine the mechanisms that guide attention.

  12. Interaction of the Zagros Fold-Thrust Belt and the Arabian-type, deep-seated folds in the Abadan Plain and the Dezful Embayment, SW Iran

    Energy Technology Data Exchange (ETDEWEB)

    Fard, Iraj Abdollahie [National Iranian Oil Co., Exploration Directorate, Tehran (Iran); Braathen, Alvar [Bergen Univ., Centre for Integrated Petroleum Research, Bergen (Norway); Mokhtari, Mohamad [International Institute of Earthquake Engineering and Seismology, Tehran (Iran); Alavi, Seyed Ahmad [Shahid Beheshti Univ., Earth Sciences Faculty, Tehran (Iran)

    2006-07-01

    The Dezful Embayment and Abadan Plain (SW Iran) contain major parts of the remaining Iranian oil reserves. These oil provinces are characterized by two types of structural closure: very gentle N-S- to NE-SW-trending basement-cored anticlines (Arabian-type highs) in the SE; and open to tight, NW-SE-trending thrust-related folds in the NE (Zagros Fold-Thrust Belt; ZFTB). Most deep-seated anticlines are upright and symmetrical in Cretaceous and older units. In some cases they reveal steep faults in their core which, in the light of regional observations, suggest that the basement is involved in the faulting. Untested plays around these anticlines include reefal build-ups, debris flows, truncated sedimentary sections and onlapping clastic units. The ZFTB shows a classic structural style, with overall shortening reflected in thrust displacement declining from the Dezful Embayment towards the frontal zone in the Abadan Plain. The Early Cambrian Hormuz Salt represents the fundamental sole for the fold-thrust belt and locates major fault-propagation folds in the southwestern Dezful Embayment. These folds represent the main petroleum target of the area. Another important unit is the Mid-Miocene Gachsaran Formation. This detachment reveals both in-sequence and out-of-sequence thrusting. Interaction of deep-seated anticlines and fold-thrust structures results in thrust imbrications and formation of duplexes within the Gachsaran Formation when thrusts abut deep-seated anticlines. Above the crest of the anticlines, thrusts are forced up-section into syn-tectonic deposits, whereas the forelimb reveals out-of-the-syncline thrusts. Several petroleum plays are identified in such zones of structural interaction, including anticlines above buttress-related duplexes, out-of-sequence imbricate thrust fans with associated folds above major anticlines, truncation of footwall layers below potentially sealing thrusts, and sub-thrust anticlines. (Author)

  13. Numerical analysis of all flow state lubrication performance of water-lubricated thrust bearing

    International Nuclear Information System (INIS)

    Deng Xiao; Deng Liping; Huang Wei; Liu Lizhi; Zhao Xuecen; Liu Songya

    2015-01-01

    A model enabling all different flow state lubrication performance simulation and analysis for water-lubricated thrust bearing is presented, considering the temperature influence and elastic deformation. Lubrication state in the model is changed directly from laminar lubrication to turbulent lubrication once Reynolds number exceeds the critical Reynolds number. The model is numerically solved and results show that temperature variation is too little to influence the lubrication performance; the elastic deformation can slightly reduce the load carrying capacity of the thrust bearing; and the turbulent lubrication can remarkably improve the load carrying capacity. (authors)

  14. Improvement in thrust force estimation of solenoid valve considering minor hysteresis loop

    Directory of Open Access Journals (Sweden)

    Myung-Hwan Yoon

    2017-05-01

    Full Text Available Solenoid valve is a very important hydraulic actuator for an automatic transmission in terms of shift quality. The same form of pressure for the clutch and the input current are required for an ideal control. However, the gap between a pressure and a current can occur which brings a delay in a transmission and a decrease in quality. This problem is caused by hysteresis phenomenon. As the ascending or descending magnetic field is applied to the solenoid, different thrust forces are generated. This paper suggests the calculation method of the thrust force considering the hysteresis phenomenon and consequently the accurate force can be obtained. Such hysteresis occurs in ferromagnetic materials, however the hysteresis phenomenon includes a minor hysteresis loop which begins with an initial magnetization curve and is generated by DC biased field density. As the core of the solenoid is ferromagnetic material, an accurate thrust force is obtained by applying the minor hysteresis loop compared to the force calculated by considering only the initial magnetization curve. An analytical background and the detailed explanation of measuring the minor hysteresis loop are presented. Furthermore experimental results and finite element analysis results are compared for the verification.

  15. Trajectory control with continuous thrust applied to a rendezvous maneuver

    International Nuclear Information System (INIS)

    Santos, W G; Rocco, E M

    2013-01-01

    A rendezvous mission can be divided into the following phases: launch, phasing, far range rendezvous, close range rendezvous and mating (docking or berthing). This paper aims to present a close range rendezvous with closed loop controlled straight line trajectory. The approaching is executed on V-bar axis. A PID controller and continuous thrust are used to eliminate the residual errors in the trajectory. A comparative study about the linear and nonlinear dynamics is performed and the results showed that the linear equations become inaccurate insofar as the chaser moves away from the target

  16. Strapdown Homing Guidance System Design for Some Ammunition

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The strapdown homing guidance system for some ammunition was mainly studied. A strong tracking Kalman filter was designed for the strapdown homing guidance system using the information measured by the strapdown homing seeker to estimate relative movement variables between the ammunition and target. Then the optimal proportional law, which using the estimated information, guided the ammunition. Simulation results show that the designed strapdown homing guidance system with strong tracking Kalman filter can attack the maneuvering target effectively, and satisfy the performance index for the guided ammunition system.

  17. Semantic guidance of eye movements in real-world scenes.

    Science.gov (United States)

    Hwang, Alex D; Wang, Hsueh-Cheng; Pomplun, Marc

    2011-05-25

    The perception of objects in our visual world is influenced by not only their low-level visual features such as shape and color, but also their high-level features such as meaning and semantic relations among them. While it has been shown that low-level features in real-world scenes guide eye movements during scene inspection and search, the influence of semantic similarity among scene objects on eye movements in such situations has not been investigated. Here we study guidance of eye movements by semantic similarity among objects during real-world scene inspection and search. By selecting scenes from the LabelMe object-annotated image database and applying latent semantic analysis (LSA) to the object labels, we generated semantic saliency maps of real-world scenes based on the semantic similarity of scene objects to the currently fixated object or the search target. An ROC analysis of these maps as predictors of subjects' gaze transitions between objects during scene inspection revealed a preference for transitions to objects that were semantically similar to the currently inspected one. Furthermore, during the course of a scene search, subjects' eye movements were progressively guided toward objects that were semantically similar to the search target. These findings demonstrate substantial semantic guidance of eye movements in real-world scenes and show its importance for understanding real-world attentional control. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Measurement and analysis of thrust force in drilling sisal-glass fiber reinforced polymer composites

    Science.gov (United States)

    Ramesh, M.; Gopinath, A.

    2017-05-01

    Drilling of composite materials is difficult when compared to the conventional materials because of its in-homogeneous nature. The force developed during drilling play a major role in the surface quality of the hole and minimizing the damages around the surface. This paper focuses the effect of drilling parameters on thrust force in drilling of sisal-glass fiber reinforced polymer composite laminates. The quadratic response models are developed by using response surface methodology (RSM) to predict the influence of cutting parameters on thrust force. The adequacy of the models is checked by using the analysis of variance (ANOVA). A scanning electron microscope (SEM) analysis is carried out to analyze the quality of the drilled surface. From the results, it is found that, the feed rate is the most influencing parameter followed by spindle speed and the drill diameter is the least influencing parameter on the thrust force.

  19. An Assessment of the Implementation of Guidance and Counselling ...

    African Journals Online (AJOL)

    This paper is based on a research study carried out by the author in 2003. The study assessed how Guidance and Counselling Programmes were being implemented in Gweru urban secondary schools at Ordinary level. The assessment focused on such key elements in Guidance and Counselling as time allocation, ...

  20. The temporal dynamics of visual working memory guidance of selective attention.

    Science.gov (United States)

    Tan, Jinfeng; Zhao, Yuanfang; Wu, Shanshan; Wang, Lijun; Hitchman, Glenn; Tian, Xia; Li, Ming; Hu, Li; Chen, Antao

    2014-01-01

    The biased competition model proposes that there is top-down directing of attention to a stimulus matching the contents of working memory (WM), even when the maintenance of a WM representation is detrimental to target relevant performance. Despite many studies elucidating that spatial WM guidance can be present early in the visual processing system, whether visual WM guidance also influences perceptual selection remains poorly understood. Here, we investigated the electrophysiological correlates of early guidance of attention by WM in humans. Participants were required to perform a visual search task while concurrently maintaining object representations in their visual WM. Behavioral results showed that response times (RTs) were longer when the distractor in the visual search task was held in WM. The earliest WM guidance effect was observed in the P1 component (90-130 ms), with match trials eliciting larger P1 amplitude than mismatch trials. A similar result was also found in the N1 component (160-200 ms). These P1 and N1 effects could not be attributed to bottom-up perceptual priming from the presentation of a memory cue, because there was no significant difference in early event-related potential (ERP) component when the cue was merely perceptually identified but not actively held in WM. Standardized Low Resolution Electrical Tomography Analysis (sLORETA) showed that the early WM guidance occurred in the occipital lobe and the N1-related activation occurred in the parietal gyrus. Time-frequency data suggested that alpha-band event-related spectral perturbation (ERSP) magnitudes increased under the match condition compared with the mismatch condition only when the cue was held in WM. In conclusion, the present study suggests that the reappearance of a stimulus held in WM enhanced activity in the occipital area. Subsequently, this initial capture of attention by WM could be inhibited by competing visual inputs through attention re-orientation, reflecting by the

  1. Human-Robot Interaction: Does Robotic Guidance Force Affect Gait-Related Brain Dynamics during Robot-Assisted Treadmill Walking?

    Directory of Open Access Journals (Sweden)

    Kristel Knaepen

    Full Text Available In order to determine optimal training parameters for robot-assisted treadmill walking, it is essential to understand how a robotic device interacts with its wearer, and thus, how parameter settings of the device affect locomotor control. The aim of this study was to assess the effect of different levels of guidance force during robot-assisted treadmill walking on cortical activity. Eighteen healthy subjects walked at 2 km.h-1 on a treadmill with and without assistance of the Lokomat robotic gait orthosis. Event-related spectral perturbations and changes in power spectral density were investigated during unassisted treadmill walking as well as during robot-assisted treadmill walking at 30%, 60% and 100% guidance force (with 0% body weight support. Clustering of independent components revealed three clusters of activity in the sensorimotor cortex during treadmill walking and robot-assisted treadmill walking in healthy subjects. These clusters demonstrated gait-related spectral modulations in the mu, beta and low gamma bands over the sensorimotor cortex related to specific phases of the gait cycle. Moreover, mu and beta rhythms were suppressed in the right primary sensory cortex during treadmill walking compared to robot-assisted treadmill walking with 100% guidance force, indicating significantly larger involvement of the sensorimotor area during treadmill walking compared to robot-assisted treadmill walking. Only marginal differences in the spectral power of the mu, beta and low gamma bands could be identified between robot-assisted treadmill walking with different levels of guidance force. From these results it can be concluded that a high level of guidance force (i.e., 100% guidance force and thus a less active participation during locomotion should be avoided during robot-assisted treadmill walking. This will optimize the involvement of the sensorimotor cortex which is known to be crucial for motor learning.

  2. Human-Robot Interaction: Does Robotic Guidance Force Affect Gait-Related Brain Dynamics during Robot-Assisted Treadmill Walking?

    Science.gov (United States)

    Knaepen, Kristel; Mierau, Andreas; Swinnen, Eva; Fernandez Tellez, Helio; Michielsen, Marc; Kerckhofs, Eric; Lefeber, Dirk; Meeusen, Romain

    2015-01-01

    In order to determine optimal training parameters for robot-assisted treadmill walking, it is essential to understand how a robotic device interacts with its wearer, and thus, how parameter settings of the device affect locomotor control. The aim of this study was to assess the effect of different levels of guidance force during robot-assisted treadmill walking on cortical activity. Eighteen healthy subjects walked at 2 km.h-1 on a treadmill with and without assistance of the Lokomat robotic gait orthosis. Event-related spectral perturbations and changes in power spectral density were investigated during unassisted treadmill walking as well as during robot-assisted treadmill walking at 30%, 60% and 100% guidance force (with 0% body weight support). Clustering of independent components revealed three clusters of activity in the sensorimotor cortex during treadmill walking and robot-assisted treadmill walking in healthy subjects. These clusters demonstrated gait-related spectral modulations in the mu, beta and low gamma bands over the sensorimotor cortex related to specific phases of the gait cycle. Moreover, mu and beta rhythms were suppressed in the right primary sensory cortex during treadmill walking compared to robot-assisted treadmill walking with 100% guidance force, indicating significantly larger involvement of the sensorimotor area during treadmill walking compared to robot-assisted treadmill walking. Only marginal differences in the spectral power of the mu, beta and low gamma bands could be identified between robot-assisted treadmill walking with different levels of guidance force. From these results it can be concluded that a high level of guidance force (i.e., 100% guidance force) and thus a less active participation during locomotion should be avoided during robot-assisted treadmill walking. This will optimize the involvement of the sensorimotor cortex which is known to be crucial for motor learning.

  3. Earthquakes, gravity, and the origin of the Bali Basin: An example of a Nascent Continental Fold-and-Thrust Belt

    Science.gov (United States)

    McCaffrey, Robert; Nabelek, John

    1987-01-01

    We infer from the bathymetry and gravity field and from the source mechanisms and depths of the eight largest earthquakes in the Bali region that the Bali Basin is a downwarp in the crust of the Sunda Shelf produced and maintained by thrusting along the Flores back arc thrust zone. Earthquake source mechanisms and focal depths are inferred from the inversion of long-period P and SH waves for all events and short-period P waves for two of the events. Centroidal depths that give the best fit to the seismograms range from 10 to 18 km, but uncertainties in depth allow a range from 7 to 24 km. The P wave nodal planes that dip south at 13° to 35° (±7°) strike roughly parallel to the volcanic arc and are consistent with thrusting of crust of the Bali Basin beneath it. The positions of the earthquakes with respect to crustal features inferred from seismic and gravity data suggest that the earthquakes occur in the basement along the western end of the Flores thrust zone. The slip direction for the back arc thrust zone inferred from the orientation of the earthquake slip vectors indicates that the thrusting in the Bali Basin is probably part of the overall plate convergence, as it roughly coincides with the convergence direction between the Sunda arc and the Indian Ocean plate. Summation of seismic moments of earthquakes between 1960 and 1985 suggests a minimum rate of convergence across the thrust zone of 4 ± 2 mm/a. The presence of back arc thrusting suggests that some coupling between the Indian Ocean plate and the Sunda arc occurs but mechanisms such as continental collision or a shallow subduction of the Indian Ocean plate probably can be ruled out. The present tectonic setting and structure of the Bali Basin is comparable to the early forelands of the Andes or western North America in that a fold-and-thrust belt is forming on the continental side of an arc-trench system at which oceanic lithosphere is being subducted. The Bali Basin is flanked by the Tertiary Java

  4. An approach to evaluate capacitance, capacitive reactance and resistance of pivoted pads of a thrust bearing

    Science.gov (United States)

    Prashad, Har

    1992-07-01

    A theoretical approach is developed for determining the capacitance and active resistance between the interacting surfaces of pivoted pads and thrust collar, under different conditions of operation. It is shown that resistance and capacitive reactance of a thrust bearing decrease with the number of pads times the values of these parameters for an individual pad, and that capacitance increases with the number of pads times the capacitance of an individual pad. The analysis presented has a potential to diagnose the behavior of pivoted pad thrust bearings with the angle of tilt and the ratio of film thickness at the leading to trailing edge, by determining the variation of capacitance, resistance, and capacitive reactance.

  5. Factors affecting guidance and counseling programme in primary ...

    African Journals Online (AJOL)

    The objective of this study was to establish the factors that affect guidance and counseling in primary schools. Guidance and counseling seems not to be adequately helping pupils with physical and psychological problems in Nairobi province of Kenya. Many primary schools are faced with indiscipline and poor performance ...

  6. Trajectory reshaping based guidance with impact time and angle constraints

    Directory of Open Access Journals (Sweden)

    Zhao Yao

    2016-08-01

    Full Text Available This study presents a novel impact time and angle constrained guidance law for homing missiles. The guidance law is first developed with the prior-assumption of a stationary target, which is followed by the practical extension to a maneuvering target scenario. To derive the closed-form guidance law, the trajectory reshaping technique is utilized and it results in defining a specific polynomial function with two unknown coefficients. These coefficients are determined to satisfy the impact time and angle constraints as well as the zero miss distance. Furthermore, the proposed guidance law has three additional guidance gains as design parameters which make it possible to adjust the guided trajectory according to the operational conditions and missile’s capability. Numerical simulations are presented to validate the effectiveness of the proposed guidance law.

  7. 78 FR 12759 - Draft Guidance for Industry on Attachment to Guidance on Antiviral Product Development-Conducting...

    Science.gov (United States)

    2013-02-25

    ...; formerly 2005D-0183] Draft Guidance for Industry on Attachment to Guidance on Antiviral Product Development... guidance to the Division of Drug Information, Center for Drug Evaluation and Research, Food and Drug... 20852. FOR FURTHER INFORMATION CONTACT: Lisa K. Naeger, Center for Drug Evaluation and Research, Food...

  8. Analysis of gas turbine engines using water and oxygen injection to achieve high Mach numbers and high thrust

    Science.gov (United States)

    Henneberry, Hugh M.; Snyder, Christopher A.

    1993-01-01

    An analysis of gas turbine engines using water and oxygen injection to enhance performance by increasing Mach number capability and by increasing thrust is described. The liquids are injected, either separately or together, into the subsonic diffuser ahead of the engine compressor. A turbojet engine and a mixed-flow turbofan engine (MFTF) are examined, and in pursuit of maximum thrust, both engines are fitted with afterburners. The results indicate that water injection alone can extend the performance envelope of both engine types by one and one-half Mach numbers at which point water-air ratios reach 17 or 18 percent and liquid specific impulse is reduced to some 390 to 470 seconds, a level about equal to the impulse of a high energy rocket engine. The envelope can be further extended, but only with increasing sacrifices in liquid specific impulse. Oxygen-airflow ratios as high as 15 percent were investigated for increasing thrust. Using 15 percent oxygen in combination with water injection at high supersonic Mach numbers resulted in thrust augmentation as high as 76 percent without any significant decrease in liquid specific impulse. The stoichiometric afterburner exit temperature increased with increasing oxygen flow, reaching 4822 deg R in the turbojet engine at a Mach number of 3.5. At the transonic Mach number of 0.95 where no water injection is needed, an oxygen-air ratio of 15 percent increased thrust by some 55 percent in both engines, along with a decrease in liquid specific impulse of 62 percent. Afterburner temperature was approximately 4700 deg R at this high thrust condition. Water and/or oxygen injection are simple and straightforward strategies to improve engine performance and they will add little to engine weight. However, if large Mach number and thrust increases are required, liquid flows become significant, so that operation at these conditions will necessarily be of short duration.

  9. Tsunami simulations of mega-thrust earthquakes in the Nankai–Tonankai Trough (Japan) based on stochastic rupture scenarios

    KAUST Repository

    Goda, Katsuichiro; Yasuda, Tomohiro; Mai, Paul Martin; Maruyama, Takuma; Mori, Nobuhito

    2017-01-01

    In this study, earthquake rupture models for future mega-thrust earthquakes in the Nankai–Tonankai subduction zone are developed by incorporating the main characteristics of inverted source models of the 2011 Tohoku earthquake. These scenario

  10. Consideration of health inequalities in systematic reviews: a mapping review of guidance.

    Science.gov (United States)

    Maden, Michelle

    2016-11-28

    Given that we know that interventions shown to be effective in improving the health of a population may actually widen the health inequalities gap while others reduce it, it is imperative that all systematic reviewers consider how the findings of their reviews may impact (reduce or increase) on the health inequality gap. This study reviewed existing guidance on incorporating considerations of health inequalities in systematic reviews in order to examine the extent to which they can help reviewers to incorporate such issues. A mapping review was undertaken to identify guidance documents that purported to inform reviewers on whether and how to incorporate considerations of health inequalities. Searches were undertaken in Medline, CINAHL and The Cochrane Library Methodology Register. Review guidance manuals prepared by international organisations engaged in undertaking systematic reviews, and their associated websites were scanned. Studies were included if they provided an overview or discussed the development and testing of guidance for dealing with the incorporation of considerations of health inequalities in evidence synthesis. Results are summarised in narrative and tabular forms. Twenty guidance documents published between 2009 and 2016 were included. Guidance has been produced to inform considerations of health inequalities at different stages of the systematic review process. The Campbell and Cochrane Equity Group have been instrumental in developing and promoting such guidance. Definitions of health inequalities and guidance differed across the included studies. All but one guidance document were transparent in their method of production. Formal methods of evaluation were reported for six guidance documents. Most of the guidance was operationalised in the form of examples taken from published systematic reviews. The number of guidance items to operationalise ranges from 3 up to 26 with a considerable overlap noted. Adhering to the guidance will require more

  11. Condylar guidance: correlation between protrusive interocclusal record and panoramic radiographic image: a pilot study.

    Science.gov (United States)

    Tannamala, Pavan Kumar; Pulagam, Mahesh; Pottem, Srinivas R; Swapna, B

    2012-04-01

    The purpose of this study was to compare the sagittal condylar angles set in the Hanau articulator by use of a method of obtaining an intraoral protrusive record to those angles found using a panoramic radiographic image. Ten patients, free of signs and symptoms of temporomandibular disorder and with intact dentition were selected. The dental stone casts of the subjects were mounted on a Hanau articulator with a springbow and poly(vinyl siloxane) interocclusal records. For all patients, the protrusive records were obtained when the mandible moved forward by approximately 6 mm. All procedures for recording, mounting, and setting were done in the same session. The condylar guidance angles obtained were tabulated. A panoramic radiographic image of each patient was made with the Frankfurt horizontal plane parallel to the floor of the mouth. Tracings of the radiographic images were made. The horizontal reference line was marked by joining the orbitale and porion. The most superior and most inferior points of the curvatures were identified. These two lines were connected by a straight line representing the mean curvature line. Angles made by the intersection of the mean curvature line and the horizontal reference line were measured. The results were subjected to statistical analysis with a significance level of p record method. The mean condylar guidance angle between the right and left side by both the methods was not statistically significant. The comparison of mean condylar guidance angles between the right side of the protrusive record method and the right side of the panoramic radiographic method and the left side of the protrusive record method and the left side of the panoramic radiographic method (p= 0.071 and p= 0.057, respectively) were not statistically significant. Within the limitations of this study, it was concluded that the protrusive condylar guidance angles obtained by panoramic radiograph may be used in programming semi-adjustable articulators. © 2012

  12. Comparison Between Predictions and Measurements of Performance Characteristics for an Eight Pocket Hybrid (Combination Hydrostatic and Hydrodynamic) Thrust Bearing

    Science.gov (United States)

    2008-12-03

    STB stainless steel housing. Drive End Thrust Collar Free End Splash Guard Slave Thrust Bearing Face STB Flange Figure 12: Exploded view of slave...Bulk Flow Analysis of Hybrid Thrust Bearing for Process Fluid Applications.” ASME Trans., Journal of Tribology , January, Vol. 122 (1), pp. 170-180...ASME Journal of Tribology , Vol. 123, pp. 768-776 [5] San Andrés, L., (2006), “MEEN 626 Notes 2 Derivation of the Classical Reynolds Equation for

  13. Stem thrust prediction model for W-K-M double wedge parallel expanding gate valves

    Energy Technology Data Exchange (ETDEWEB)

    Eldiwany, B.; Alvarez, P.D. [Kalsi Engineering Inc., Sugar Land, TX (United States); Wolfe, K. [Electric Power Research Institute, Palo Alto, CA (United States)

    1996-12-01

    An analytical model for determining the required valve stem thrust during opening and closing strokes of W-K-M parallel expanding gate valves was developed as part of the EPRI Motor-Operated Valve Performance Prediction Methodology (EPRI MOV PPM) Program. The model was validated against measured stem thrust data obtained from in-situ testing of three W-K-M valves. Model predictions show favorable, bounding agreement with the measured data for valves with Stellite 6 hardfacing on the disks and seat rings for water flow in the preferred flow direction (gate downstream). The maximum required thrust to open and to close the valve (excluding wedging and unwedging forces) occurs at a slightly open position and not at the fully closed position. In the nonpreferred flow direction, the model shows that premature wedging can occur during {Delta}P closure strokes even when the coefficients of friction at different sliding surfaces are within the typical range. This paper summarizes the model description and comparison against test data.

  14. Stem thrust prediction model for W-K-M double wedge parallel expanding gate valves

    International Nuclear Information System (INIS)

    Eldiwany, B.; Alvarez, P.D.; Wolfe, K.

    1996-01-01

    An analytical model for determining the required valve stem thrust during opening and closing strokes of W-K-M parallel expanding gate valves was developed as part of the EPRI Motor-Operated Valve Performance Prediction Methodology (EPRI MOV PPM) Program. The model was validated against measured stem thrust data obtained from in-situ testing of three W-K-M valves. Model predictions show favorable, bounding agreement with the measured data for valves with Stellite 6 hardfacing on the disks and seat rings for water flow in the preferred flow direction (gate downstream). The maximum required thrust to open and to close the valve (excluding wedging and unwedging forces) occurs at a slightly open position and not at the fully closed position. In the nonpreferred flow direction, the model shows that premature wedging can occur during ΔP closure strokes even when the coefficients of friction at different sliding surfaces are within the typical range. This paper summarizes the model description and comparison against test data

  15. Computer-based written emotional disclosure: the effects of advance or real-time guidance and moderation by Big 5 personality traits.

    Science.gov (United States)

    Beyer, Jonathan A; Lumley, Mark A; Latsch, Deborah V; Oberleitner, Lindsay M S; Carty, Jennifer N; Radcliffe, Alison M

    2014-01-01

    Standard written emotional disclosure (WED) about stress, which is private and unguided, yields small health benefits. The effect of providing individualized guidance to writers may enhance WED, but has not been tested. This trial of computer-based WED compared two novel therapist-guided forms of WED - advance guidance (before sessions) and real-time guidance (during sessions, through instant messaging) - to both standard WED and control writing; it also tested Big 5 personality traits as moderators of guided WED. Young adult participants (n = 163) with unresolved stressful experiences were randomized to conditions, had three, 30-min computer-based writing sessions, and were reassessed six weeks later. Contrary to hypotheses, real-time guidance WED had poorer outcomes than the other conditions on several measures, and advance guidance WED also showed some poorer outcomes. Moderator analyses revealed that participants with low baseline agreeableness, low extraversion, or high conscientiousness had relatively poor responses to guidance. We conclude that providing guidance for WED, especially in real-time, may interfere with emotional processing of unresolved stress, particularly for people whose personalities have poor fit with this interactive form of WED.

  16. Fine Guidance Sensing for Coronagraphic Observatories

    Science.gov (United States)

    Brugarolas, Paul; Alexander, James W.; Trauger, John T.; Moody, Dwight C.

    2011-01-01

    Three options have been developed for Fine Guidance Sensing (FGS) for coronagraphic observatories using a Fine Guidance Camera within a coronagraphic instrument. Coronagraphic observatories require very fine precision pointing in order to image faint objects at very small distances from a target star. The Fine Guidance Camera measures the direction to the target star. The first option, referred to as Spot, was to collect all of the light reflected from a coronagraph occulter onto a focal plane, producing an Airy-type point spread function (PSF). This would allow almost all of the starlight from the central star to be used for centroiding. The second approach, referred to as Punctured Disk, collects the light that bypasses a central obscuration, producing a PSF with a punctured central disk. The final approach, referred to as Lyot, collects light after passing through the occulter at the Lyot stop. The study includes generation of representative images for each option by the science team, followed by an engineering evaluation of a centroiding or a photometric algorithm for each option. After the alignment of the coronagraph to the fine guidance system, a "nulling" point on the FGS focal point is determined by calibration. This alignment is implemented by a fine alignment mechanism that is part of the fine guidance camera selection mirror. If the star images meet the modeling assumptions, and the star "centroid" can be driven to that nulling point, the contrast for the coronagraph will be maximized.

  17. Simple Sensitivity Analysis for Orion Guidance Navigation and Control

    Science.gov (United States)

    Pressburger, Tom; Hoelscher, Brian; Martin, Rodney; Sricharan, Kumar

    2013-01-01

    The performance of Orion flight software, especially its GNC software, is being analyzed by running Monte Carlo simulations of Orion spacecraft flights. The simulated performance is analyzed for conformance with flight requirements, expressed as performance constraints. Flight requirements include guidance (e.g. touchdown distance from target) and control (e.g., control saturation) as well as performance (e.g., heat load constraints). The Monte Carlo simulations disperse hundreds of simulation input variables, for everything from mass properties to date of launch. We describe in this paper a sensitivity analysis tool ("Critical Factors Tool" or CFT) developed to find the input variables or pairs of variables which by themselves significantly influence satisfaction of requirements or significantly affect key performance metrics (e.g., touchdown distance from target). Knowing these factors can inform robustness analysis, can inform where engineering resources are most needed, and could even affect operations. The contributions of this paper include the introduction of novel sensitivity measures, such as estimating success probability, and a technique for determining whether pairs of factors are interacting dependently or independently. The tool found that input variables such as moments, mass, thrust dispersions, and date of launch were found to be significant factors for success of various requirements. Examples are shown in this paper as well as a summary and physics discussion of EFT-1 driving factors that the tool found.

  18. Vehicle speed guidance strategy at signalized intersection based on cooperative vehicle infrastructure system

    Directory of Open Access Journals (Sweden)

    Fengyuan JIA

    2017-10-01

    Full Text Available In order to reduce stopping time of vehicle at a signalized intersection, aiming at the difficulty, even the impossibility to obtain real-time queue length of intersection in third and fourth-tier cities in China sometimes, a speed guidance strategy based on cooperative vehicle infrastructure system is put forward and studied. For validating the strategy, the traffic signal timing data of the intersection at Hengshan Road and North Fengming Lake Road in Wuhu is collected by a vehicular traffic signal reminder system which is designed. The simulation experiments using the acquired data are done by software VISSIM. The simulation results demonstrate that the strategy under high and low traffic flow can effectively decrease the link travel-time, reducing average ratio is 9.2 % and 13.0 %, respectively, and the effect under low traffic flow is better than that under high traffic flow. The strategy improves efficiency of traffic at a signalized intersection and provides an idea for the application of vehicle speed guidance based on cooperative vehicle infrastructure system.

  19. Recent Mega-Thrust Tsunamigenic Earthquakes and PTHA

    Science.gov (United States)

    Lorito, S.

    2013-05-01

    The occurrence of several mega-thrust tsunamigenic earthquakes in the last decade, including but not limited to the 2004 Sumatra-Andaman, the 2010 Maule, and 2011 Tohoku earthquakes, has been a dramatic reminder of the limitations in our capability of assessing earthquake and tsunami hazard and risk. However, the increasingly high-quality geophysical observational networks allowed the retrieval of most accurate than ever models of the rupture process of mega-thrust earthquakes, thus paving the way for future improved hazard assessments. Probabilistic Tsunami Hazard Analysis (PTHA) methodology, in particular, is less mature than its seismic counterpart, PSHA. Worldwide recent research efforts of the tsunami science community allowed to start filling this gap, and to define some best practices that are being progressively employed in PTHA for different regions and coasts at threat. In the first part of my talk, I will briefly review some rupture models of recent mega-thrust earthquakes, and highlight some of their surprising features that likely result in bigger error bars associated to PTHA results. More specifically, recent events of unexpected size at a given location, and with unexpected rupture process features, posed first-order open questions which prevent the definition of an heterogeneous rupture probability along a subduction zone, despite of several recent promising results on the subduction zone seismic cycle. In the second part of the talk, I will dig a bit more into a specific ongoing effort for improving PTHA methods, in particular as regards epistemic and aleatory uncertainties determination, and the computational PTHA feasibility when considering the full assumed source variability. Only logic trees are usually explicated in PTHA studies, accounting for different possible assumptions on the source zone properties and behavior. The selection of the earthquakes to be actually modelled is then in general made on a qualitative basis or remains implicit

  20. On the lag time between internal strain and basement involved thrust induced exhumation: The case of the Colombian Eastern Cordillera

    Science.gov (United States)

    Mora, Andrès; Blanco, Vladimir; Naranjo, Julian; Sanchez, Nelson; Ketcham, Richard A.; Rubiano, Jorge; Stockli, Daniel F.; Quintero, Isaid; Nemčok, Michal; Horton, Brian K.; Davila, Hamblet

    2013-07-01

    Thrust sheets accumulate internal strain before they start moving along discrete fault planes. However, there are no previous studies evaluating the time difference between initiation of strain and fault displacement. In this paper we use observations from the Eastern Cordillera of Colombia to evaluate this interval. We utilize multiple thermochronometers and paleothermometers to refine the timing of deformation. Based on these new data we build time-temperature path estimates that together with geometric outcrop-based structural analysis and fluid inclusions allow us to assign relative timing to features associated with strain, such as cleavage, veins and certain types of fractures, and compare that with the timing of thrusting. We find that cleavage was only formed close to maximum paleotemperatures, almost coeval with the onset of thrust-induced denudation by the Late Oligocene. The corresponding structural level of fold-related veins suggest that they were formed later but still when the country rocks were at temperatures higher than 160 °C, mostly during the Early Miocene and still coexisted with the latest stages of cleavage formation. Our data show that the main period of strain hardening was short (probably a few million years) and occurred before first-order basement thrusting was dominant, but was associated with second-order folding.

  1. Strain indicators and magnetic fabric in intraplate fault zones: Case study of Daroca thrust, Iberian Chain, Spain

    Science.gov (United States)

    Casas-Sainz, A. M.; Gil-Imaz, A.; Simón, J. L.; Izquierdo-Llavall, E.; Aldega, L.; Román-Berdiel, T.; Osácar, M. C.; Pueyo-Anchuela, Ó.; Ansón, M.; García-Lasanta, C.; Corrado, S.; Invernizzi, C.; Caricchi, C.

    2018-04-01

    Anisotropy of magnetic susceptibility (AMS) has been applied to the study of shallow fault zones, although interpretation of the results requires establishing clear relationships between petrofabric and magnetic features, magnetic behaviour of fault rocks, and an extensive knowledge of P-T conditions. In this work, we demonstrate that magnetic methods can be applied to the study of heterogeneous fault zones, provided that a series of requisites are met. A major fault zone within the Iberian plate (Daroca thrust), showing transpressional movements during Cenozoic time was chosen for this purpose, because of the exceptional outcrops of fault gouge and microbreccia and its relevance within the context of the northeastern Iberian Plate. Magnetic fabrics were analysed and the results were compared with foliation and S-C structures measured within the fault zone. Clay mineral assemblages suggest maximum burial depths shallower than 2 km (kinematic indicators are consistent with a reverse movement for most of the fault zone.

  2. Becoming a Guidance Counsellor in Ontario: Formative Influences from Counsellors' Perspective

    Science.gov (United States)

    Nadon, Daniel; Samson, André; Gazzola, Nicola; Thériault, Anne

    2016-01-01

    Contrary to guidance counsellors elsewhere in North America who hold a master's degree, career and guidance counselling services in secondary schools in Ontario are delivered by teachers who have completed additional undergraduate studies. Guidance counsellors are pivotal components of the school as they complete tasks that promote students'…

  3. Quality in career guidance: The Danish case

    DEFF Research Database (Denmark)

    Plant, Peter

    2011-01-01

    Quality assurance systems are introduced in career guidance to monitor, control and develop guidance interventions. The Danish case represents at centrally driven, top-down approach......Quality assurance systems are introduced in career guidance to monitor, control and develop guidance interventions. The Danish case represents at centrally driven, top-down approach...

  4. Effect of basement structure and salt tectonics on deformation styles along strike: An example from the Kuqa fold-thrust belt, West China

    Science.gov (United States)

    Neng, Yuan; Xie, Huiwen; Yin, Hongwei; Li, Yong; Wang, Wei

    2018-04-01

    The Kuqa fold-thrust belt (KFTB) has a complex thrust-system geometry and comprises basement-involved thrusts, décollement thrusts, triangle zones, strike-slip faults, transpressional faults, and pop-up structures. These structures, combined with the effects of Paleogene salt tectonics and Paleozoic basement uplift form a complex structural zone trending E-W. Interpretation and comprehensive analysis of recent high-quality seismic data, field observations, boreholes, and gravity data covering the KFTB has been performed to understand the characteristics and mechanisms of the deformation styles along strike. Regional sections, fold-thrust system maps of the surface and the sub-salt layer, salt and basement structure distribution maps have been created, and a comprehensive analysis of thrust systems performed. The results indicate that the thrust-fold system in Paleogene salt range can be divided into five segments from east to west: the Kela-3, Keshen, Dabei, Bozi, and Awate segments. In the easternmost and westernmost parts of the Paleogene salt range, strike-slip faulting and basement-involved thrusting are the dominant deformation styles, as basement uplift and the limits of the Cenozoic evaporite deposit are the main controls on deformation. Salt-core detachment fold-thrust systems coincide with areas of salt tectonics, and pop-up, imbricate, and duplex structures are associated with the main thrust faults in the sub-salt layer. Distribution maps of thrust systems, basement structures, and salt tectonics show that Paleozoic basement uplift controlled the Paleozoic foreland basin morphology and the distribution of Cenozoic salt in the KFTB, and thus had a strong influence on the segmented structural deformation and evolution of the fold-thrust belt. Three types of transfer zone are identified, based on the characteristics of the salt layer and basement uplift, and the effects of these zones on the fault systems are evaluated. Basement uplift and the boundary of

  5. Balloon sheaths for gastrointestinal guidance and access: a preliminary phantom study

    International Nuclear Information System (INIS)

    He, Xu; Shin, Ji Hoon; Kim, Hyo Cheol; Woo, Cheol Woong; Woo, Sung Ha; Choi, Won Chan; Kim, Jong Gyu; Lim, Jin Oh; Kim, Tae Hyung; Yoon, Chang Jin; Song, Ho Young; Kang, Wee Chang

    2005-01-01

    We wanted to evaluate the feasibility and usefulness of a newly designed balloon sheath for gastrointestinal guidance and access by conducting a phantom study. The newly designed balloon sheath consisted of an introducer sheath and a supporting balloon. A coil catheter was advanced over a guide wire into two gastroduodenal phantoms (one was with stricture and one was without stricture); group I was without a balloon sheath, group II was with a deflated balloon sheath, and groups III and IV were with an inflated balloon and with the balloon in the fundus and body, respectively. Each test was performed for 2 minutes and it was repeated 10 times in each group by two researchers, and the positions reached by the catheter tip were recorded. Both researchers had better performances with both phantoms in order of group IV, III, II and I. In group IV, both researchers advanced the catheter tip through the fourth duodenal segment in both the phantoms. In group I, however, the catheter tip never reached the third duodenal segment in both the phantoms by both the researchers. The numeric values for the four study groups were significantly different for both the phantoms (ρ < 0.001). A significant difference was also found between group III and IV for both phantoms (ρ < 0.001). The balloon sheath seems to be feasible for clinical use, and it has good clinical potential for gastrointestinal guidance and access, particularly when the inflated balloon is placed in the gastric body

  6. 77 FR 34390 - Draft Guidance for Industry: Amendment to “Guidance for Industry: Revised Preventive Measures To...

    Science.gov (United States)

    2012-06-11

    ... recommendations for plasma-derived products, including albumin and products containing plasma-derived albumin, in..., submit either electronic or written comments on the draft guidance by September 10, 2012. ADDRESSES... electronic access to the draft guidance document. Submit electronic comments on the draft guidance to http...

  7. 75 FR 54637 - Guidance for Industry and Food and Drug Administration Staff; Class II Special Controls Guidance...

    Science.gov (United States)

    2010-09-08

    ... conferencing and electronic submissions, Mammography Matters, and other device-oriented information. The CDRH... approval) into class II (special controls). DATES: Submit written or electronic comments on this guidance... electronic access to the guidance. Submit electronic comments on the guidance to http://www.regulations.gov...

  8. On the paleoseismic evidence of the 1803 earthquake rupture (or lack of it) along the frontal thrust of the Kumaun Himalaya

    Science.gov (United States)

    Rajendran, C. P.; John, Biju; Anandasabari, K.; Sanwal, Jaishri; Rajendran, Kusala; Kumar, Pankaj; Chopra, Sundeep

    2018-01-01

    The foothills of the Himalaya bordered by the Main Frontal Thrust (MFT) continue to be a locus of paleoseismological studies. One of such recent studies of trench stratigraphy near the central (Indian) Himalayan foothills (Malik et al., (2016) has reported multiple ruptures dated at 467-570, 1294-1587 and 1750-1932 CE. The last offset has been attributed to the Uttarkashi earthquake of 1803 and the penultimate faulting, with lesser confidence to an earthquake in 1505 CE. We tested these claims by logging an adjacent section on a shared scarp, and the new trench site, however, revealed a stratigraphic configuration partially in variance with from what has been reported in the earlier study. Our findings do not support the previous interpretation of the trench stratigraphy that suggested multiple displacements cutting across a varied set of deformed stratigraphic units leading up to the 1803 rupture. The current interpretation posits a single episode of a low-angle displacement at this site occurred between 1266 CE and 1636. Our results suggest a single medieval earthquake, conforming to what was reported from the previously studied neighboring sites to the east and west. The present study while reiterating a great medieval earthquake questions the assumption that the 1803 earthquake ruptured the MFT. Although a décollement earthquake, the 1803 rupture may have been arrested midway on the basal flat, and fell short of reaching the MFT, somewhat comparable to a suite of blind thrust earthquakes like the1905 Kangra and the 1833 Nepal earthquakes.

  9. Automated Escape Guidance Algorithms for An Escape Vehicle

    Science.gov (United States)

    Flanary, Ronald; Hammen, David; Ito, Daigoro; Rabalais, Bruce; Rishikof, Brian; Siebold, Karl

    2002-01-01

    An escape vehicle was designed to provide an emergency evacuation for crew members living on a space station. For maximum escape capability, the escape vehicle needs to have the ability to safely evacuate a station in a contingency scenario such as an uncontrolled (e.g., tumbling) station. This emergency escape sequence will typically be divided into three events: The fust separation event (SEP1), the navigation reconstruction event, and the second separation event (SEP2). SEP1 is responsible for taking the spacecraft from its docking port to a distance greater than the maximum radius of the rotating station. The navigation reconstruction event takes place prior to the SEP2 event and establishes the orbital state to within the tolerance limits necessary for SEP2. The SEP2 event calculates and performs an avoidance burn to prevent station recontact during the next several orbits. This paper presents the tools and results for the whole separation sequence with an emphasis on the two separation events. The fust challenge includes collision avoidance during the escape sequence while the station is in an uncontrolled rotational state, with rotation rates of up to 2 degrees per second. The task of avoiding a collision may require the use of the Vehicle's de-orbit propulsion system for maximum thrust and minimum dwell time within the vicinity of the station vicinity. The thrust of the propulsion system is in a single direction, and can be controlled only by the attitude of the spacecraft. Escape algorithms based on a look-up table or analytical guidance can be implemented since the rotation rate and the angular momentum vector can be sensed onboard and a-priori knowledge of the position and relative orientation are available. In addition, crew intervention has been provided for in the event of unforeseen obstacles in the escape path. The purpose of the SEP2 burn is to avoid re-contact with the station over an extended period of time. Performing this maneuver properly

  10. Structure and tectonics of the Main Himalayan Thrust and associated faults from recent earthquake and seismic imaging studies using the NAMASTE array

    Science.gov (United States)

    Karplus, M. S.; Pant, M.; Velasco, A. A.; Nabelek, J.; Kuna, V. M.; Sapkota, S. N.; Ghosh, A.; Mendoza, M.; Adhikari, L. B.; Klemperer, S. L.

    2017-12-01

    The India-Eurasia collision zone presents a significant earthquake hazard, as demonstrated by the recent, devastating April 25, 2015 M=7.8 Gorkha earthquake and the following May 12, 2015 M=7.3 earthquake. Important questions remain, including distinguishing possible geometries of the Main Himalayan Thrust (MHT), the role of other regional faults, the crustal composition and role of fluids in faulting, and the details of the rupture process, including structural causes and locations of rupture segmentation both along-strike and down-dip. These recent earthquakes and their aftershocks provide a unique opportunity to learn more about this collision zone. In June 2015, funded by NSF, we deployed the Nepal Array Measuring Aftershock Seismicity Trailing Earthquake (NAMASTE) array of 46 seismic stations distributed across eastern and central Nepal, spanning the region with most of the aftershocks. This array remained in place for 11 months from June 2015 to May 2016. We combine new results from this aftershock network in Nepal with previous geophysical and geological studies across the Himalaya to derive a new understanding of the tectonics of the Himalaya and southern Tibet in Nepal and surrounding countries. We focus on structure and composition of the Main Himalayan Thrust and compare this continent-continent subduction megathrust with megathrusts in other subduction zones.

  11. Lifelong guidance: How guidance and counselling support lifelong learning in the contrasting contexts of China and Denmark

    Science.gov (United States)

    Zhang, Zhixin

    2016-10-01

    Due to the effects of globalisation and rapid technological development, traditional linear life course patterns of the past are gradually disappearing, and this affects education and learning systems as well as labour markets. Individuals are forced to develop lifestyles and survival strategies to manage job insecurity and make their skills and interests meet labour market needs. In modern attempts to develop and implement institutional provision for lifelong learning, guidance and counselling play an important role. The current Danish guidance system is well-organised, highly structured and professionalised. By contrast, Chinese guidance is still fragmented and "sectorisational". This paper explores whether elements of the highly structured and professionalised Danish guidance system and practice might be applicable to the Chinese context. The author begins by outlining international and national factors which are affecting citizens' life and career planning. She then presents and discusses the evolution of guidance and the different elements of provision in each of the two countries. Next, She compares the concepts and goals of "lifelong guidance" in Denmark and China, pointing out their similarities and differences and their respective strengths and weaknesses. The paper concludes with some suggestions for the further development of guidance in China.

  12. Video-Guidance Design for the DART Rendezvous Mission

    Science.gov (United States)

    Ruth, Michael; Tracy, Chisholm

    2004-01-01

    NASA's Demonstration of Autonomous Rendezvous Technology (DART) mission will validate a number of different guidance technologies, including state-differenced GPS transfers and close-approach video guidance. The video guidance for DART will employ NASA/Marshall s Advanced Video Guidance Sensor (AVGS). This paper focuses on the terminal phase of the DART mission that includes close-approach maneuvers under AVGS guidance. The closed-loop video guidance design for DART is driven by a number of competing requirements, including a need for maximizing tracking bandwidths while coping with measurement noise and the need to minimize RCS firings. A range of different strategies for attitude control and docking guidance have been considered for the DART mission, and design decisions are driven by a goal of minimizing both the design complexity and the effects of video guidance lags. The DART design employs an indirect docking approach, in which the guidance position targets are defined using relative attitude information. Flight simulation results have proven the effectiveness of the video guidance design.

  13. Threshold guidance update

    International Nuclear Information System (INIS)

    Wickham, L.E.

    1986-01-01

    The Department of Energy (DOE) is developing the concept of threshold quantities for use in determining which waste materials must be handled as radioactive waste and which may be disposed of as nonradioactive waste at its sites. Waste above this concentration level would be managed as radioactive or mixed waste (if hazardous chemicals are present); waste below this level would be handled as sanitary waste. Last years' activities (1984) included the development of a threshold guidance dose, the development of threshold concentrations corresponding to the guidance dose, the development of supporting documentation, review by a technical peer review committee, and review by the DOE community. As a result of the comments, areas have been identified for more extensive analysis, including an alternative basis for selection of the guidance dose and the development of quality assurance guidelines. Development of quality assurance guidelines will provide a reasonable basis for determining that a given waste stream qualifies as a threshold waste stream and can then be the basis for a more extensive cost-benefit analysis. The threshold guidance and supporting documentation will be revised, based on the comments received. The revised documents will be provided to DOE by early November. DOE-HQ has indicated that the revised documents will be available for review by DOE field offices and their contractors

  14. Regulatory guidance document

    International Nuclear Information System (INIS)

    1994-05-01

    The Office of Civilian Radioactive Waste Management (OCRWM) Program Management System Manual requires preparation of the OCRWM Regulatory Guidance Document (RGD) that addresses licensing, environmental compliance, and safety and health compliance. The document provides: regulatory compliance policy; guidance to OCRWM organizational elements to ensure a consistent approach when complying with regulatory requirements; strategies to achieve policy objectives; organizational responsibilities for regulatory compliance; guidance with regard to Program compliance oversight; and guidance on the contents of a project-level Regulatory Compliance Plan. The scope of the RGD includes site suitability evaluation, licensing, environmental compliance, and safety and health compliance, in accordance with the direction provided by Section 4.6.3 of the PMS Manual. Site suitability evaluation and regulatory compliance during site characterization are significant activities, particularly with regard to the YW MSA. OCRWM's evaluation of whether the Yucca Mountain site is suitable for repository development must precede its submittal of a license application to the Nuclear Regulatory Commission (NRC). Accordingly, site suitability evaluation is discussed in Chapter 4, and the general statements of policy regarding site suitability evaluation are discussed in Section 2.1. Although much of the data and analyses may initially be similar, the licensing process is discussed separately in Chapter 5. Environmental compliance is discussed in Chapter 6. Safety and Health compliance is discussed in Chapter 7

  15. The Influence of Injection Pockets on the Performance of Tilting-Pad Thrust Bearings: Part II – Comparison Between Theory and Experiment

    DEFF Research Database (Denmark)

    Heinrichson, Niels; Santos, Ilmar

    2006-01-01

    This is Part II of a two-part series of papers describing the effects of high pressure injection pockets on the operating conditions of tilting-pad thrust bearings. Measurements of the distribution of pressure and oil film thickness are presented for tilting-pad thrust bearing pads of approximately...... 100 cm2 surface area. Two pads are measured in a laboratory test-rig at loads of approximately 0.5, 1.5 and 4.0 MPa and velocities of up to 33 m/s. One pad has a plain surface. The other pad has a conical injection pocket at the pivot point and a leading edge taper. The measurements are compared...... to theoretical values obtained using a three dimensional thermo-elasto-hydrodynamic (TEHD) numerical model. At low and intermediate loads the theoretical pressure distribution corresponds well to the measured values for both pads although the influence of the pocket is slightly underestimated. At high loads...

  16. West-directed thrusting south of the eastern Himalayan syntaxis indicates clockwise crustal flow at the indenter corner during the India-Asia collision

    Science.gov (United States)

    Haproff, Peter J.; Zuza, Andrew V.; Yin, An

    2018-01-01

    Whether continental deformation is accommodated by microplate motion or continuum flow is a central issue regarding the nature of Cenozoic deformation surrounding the eastern Himalayan syntaxis. The microplate model predicts southeastward extrusion of rigid blocks along widely-spaced strike-slip faults, whereas the crustal-flow model requires clockwise crustal rotation along closely-spaced, semi-circular right-slip faults around the eastern Himalayan syntaxis. Although global positioning system (GPS) data support the crustal-flow model, the surface velocity field provides no information on the evolution of the India-Asia orogenic system at million-year scales. In this work, we present the results of systematic geologic mapping across the northernmost segment of the Indo-Burma Ranges, located directly southeast of the eastern Himalayan syntaxis. Early research inferred the area to have experienced either right-slip faulting accommodating northward indentation of India or thrusting due to the eastward continuation of the Himalayan orogen in the Cenozoic. Our mapping supports the presence of dip-slip thrust faults, rather than strike-slip faults. Specifically, the northern Indo-Burma Ranges exposes south- to west-directed ductile thrust shear zones in the hinterland and brittle fault zones in the foreland. The trends of ductile stretching lineations within thrust shear zones and thrust sheets rotate clockwise from the northeast direction in the northern part of the study area to the east direction in the southern part of the study area. This clockwise deflection pattern of lineations around the eastern Himalayan syntaxis mirrors the clockwise crustal-rotation pattern as suggested by the crustal-flow model and contemporary GPS velocity field. However, our finding is inconsistent with discrete strike-slip deformation in the area and the microplate model.

  17. Simulation of Thrust-Vectored Aircraft Maneuvers on a Human Centrifuge: Model Validation and Design for the Dynamic Environment Simulator

    National Research Council Canada - National Science Library

    van

    1998-01-01

    .... The F-22 will be the first production thrust vectored aircraft in aviation history. Because of its pitch axis thrust vector control, the F-22 can pitch at high rates of angular velocity as it flies...

  18. Northward laramide thrusting in the quitovac region, northwestern sonora, mexico: Implications for the juxtaposition of paleoproterozoic basement blocks and the mojave-sonora megashear hypothesis

    Science.gov (United States)

    Iriondo, Alexander; Martínez-Torres, Luis M.; Kunk, Michael J.; Atkinson, William W.; Premo, Wayne R.; McIntosh, William C.

    2005-01-01

    Restoration of 12%–30% Basin and Range extension allows direct interpretation of ductile fabrics associated with a stack of Laramide thrust faults in the Quitovac region in northwestern Sonora. The inferred direction of displacement of these thrusts varies gradually from N63°W to N23°E and is interpreted to represent a clockwise rotation of the direction of Laramide thrusting through time. The thrust faults represent a piggy-back sequence of thrusting propagating north, toward the foreland. The average direction and sense of displacement of the thrusts is N18°W, and the cumulative 45 km of estimated northward-directed displacement corresponds to ∼86% of shortening.Based on geochronological constraints, onset of thrusting in Quitovac occurred sometime between 75 and 61 Ma, whereas cessation occurred at ca. 39 Ma. The presence of Paleocene-Eocene orogenic gold mineralization, spatially associated with thrusting, strengthens our idea that compressional tectonism associated with the Laramide orogeny is a very important and widespread dynamometamorphic event in the region.Similarities in age, kinematics, and structural stratigraphy indicate that the thrusting in the Quitovac region may be equivalent to the Laramide Quitobaquito Thrust in southwestern Arizona. In both areas, thrust faults juxtapose the Paleoproterozoic Caborca and “North America” basement blocks. This juxtaposition was previously proposed as exclusively related to movements along the hypothetical Upper Jurassic Mojave-Sonora megashear. The Laramide northward displacements and clockwise rotations recorded in the Caborca block rocks in Quitovac contradict the southward displacements (∼800 km) and counterclockwise rotations inherent in the left-lateral Upper Jurassic Mojave-Sonora megashear hypothesis. We conclude that if this megashear exists in northwestern Sonora, its trace should be to the southwest of the Quitovac region.

  19. Electronegative Gas Thruster - Direct Thrust Measurement Project

    Science.gov (United States)

    Dankanich, John (Principal Investigator); Aanesland, Ane; Polzin, Kurt; Walker, Mitchell

    2015-01-01

    This effort is an international collaboration and academic partnership to mature an innovative electric propulsion (EP) thruster concept to TRL 3 through direct thrust measurement. The initial target application is for Small Satellites, but can be extended to higher power. The Plasma propulsion with Electronegative GASES (PEGASES) concept simplifies ion thruster operation, eliminates a neutralizer requirement and should yield longer life capabilities and lower cost implementation over conventional gridded ion engines. The basic proof-of concept has been demonstrated and matured to TRL 2 over the past several years by researchers at the Laboratoire de Physique des Plasma in France. Due to the low maturity of the innovation, there are currently no domestic investments in electronegative gas thrusters anywhere within NASA, industry or academia. The end product of this Center Innovation Fund (CIF) project will be a validation of the proof-of-concept, maturation to TRL 3 and technology assessment report to summarize the potential for the PEGASES concept to supplant the incumbent technology. Information exchange with the foreign national will be one-way with the exception of the test results. Those test results will first go through a standard public release ITAR/export control review, and the results will be presented in a public technical forum, and the results will be presented in a public technical forum.

  20. Electric sail elliptic displaced orbits with advanced thrust model

    Science.gov (United States)

    Niccolai, Lorenzo; Quarta, Alessandro A.; Mengali, Giovanni

    2017-09-01

    This paper analyzes the performance of an Electric Solar Wind Sail for generating and maintaining an elliptic, heliocentric, displaced non-Keplerian orbit. In this sense, this paper extends and completes recent studies regarding the performances of an Electric Solar Wind Sail that covers a circular, heliocentric, displaced orbit of given characteristics. The paper presents the general equations that describe the elliptic orbit maintenance in terms of both spacecraft attitude and performance requirements, when a refined thrust model (recently proposed for the preliminary mission design) is taken into account. In particular, the paper also discusses some practical applications on particular mission scenarios in which an analytic solution of the governing equations has been found.

  1. Structure-based thresholds of toxicological concern-guidance for application to substances present at low levels in the diet

    International Nuclear Information System (INIS)

    Renwick, A.G.

    2005-01-01

    Health-based guidance values, such as the ADI, use chemical-specific data to determine the highest intake that would be without significant adverse health effects. A threshold of toxicological concern (TTC) is a level of intake predicted to be without adverse effects based on the toxicity of structurally related compounds. The main advantage of the use of TTCs is that the risk of low exposures can be evaluated without the need for chemical-specific animal toxicity data. TTCs have been used for many years for screening the safety of packaging migrants by the FDA in the USA, and of flavoring substances, by the JECFA. A recent reassessment of the use of TTCs, organized by ILSI Europe, has developed a decision tree which allows a systematic approach to the evaluation of low levels of diverse chemicals in food. The decision tree incorporates a series of increasing TTC values into a step-wise approach. Potentially genotoxic carcinogens are considered first, based on the presence of known structural alerts. Aflatoxin-like, azoxy- and nitroso-compounds are removed from consideration because they are the most potent, and a practical TTC could not be established. Other compounds with structural alerts for genotoxicity are allocated a TTC of 0.15 μg/person per day. Compounds without structural alerts for genotoxicity are evaluated based on chemical structure and intake using a series of TTC values derived by the application of a 100-fold uncertainty factor to the 5th percentile of the distribution of NOAELs from chronic studies on compounds sharing similar structural characteristics

  2. Contextual Cueing Improves Attentional Guidance, Even When Guidance Is Supposedly Optimal

    OpenAIRE

    Harris, A. M.; Remington, R. W.

    2017-01-01

    Visual search through previously encountered contexts typically produces reduced reaction times compared with search through novel contexts. This contextual cueing benefit is well established, but there is debate regarding its underlying mechanisms. Eye-tracking studies have consistently shown reduced number of fixations with repetition, supporting improvements in attentional guidance as the source of contextual cueing. However, contextual cueing benefits have been shown in conditions in whic...

  3. ONE OF THE MAIN NEOTECTONIC STRUCTURES IN THE NW CENTRAL ANATOLIA: BEYPAZARI BLIND THRUST ZONE AND RELATED FAULT-PROPAGATION FOLDS

    Directory of Open Access Journals (Sweden)

    Gürol SEYİTOĞLU

    2016-12-01

    Full Text Available This paper suggests that the structure known as "Beypazarı flexure / monocline" in the Turkish geology literature should be named as "Beypazarı fault-propagation folds". Beypazarı, Kilci and Başören blind thrusts together with Erenler back thrust constitute the Beypazarı Blind Thrust Zone which is an active neotectonic structure as indicated by earthquake activity. NW-SE contraction created by the interaction between the North Anatolian Fault Zone, the Kırıkkale-Erbaa Fault Zone and the Eskişehir Fault Zone produced the Eldivan-Elmadağ Pinched Crustal Wedge, the Abdüsselam Pinched Crustal Wedge and the Beypazarı Blind Thrust Zone. These structures take up the internal deformation of the Anatolian Plate.

  4. Development of Safety Review Guidance for Research and Training Reactors

    International Nuclear Information System (INIS)

    Oh, Kju-Myeng; Shin, Dae-Soo; Ahn, Sang-Kyu; Lee, Hoon-Joo

    2007-01-01

    The KINS already issued the safety review guidance for pressurized LWRs. But the safety review guidance for research and training reactors were not developed. So, the technical standard including safety review guidance for domestic research and training reactors has been applied mutates mutandis to those of nuclear power plants. It is often difficult for the staff to effectively perform the safety review of applications for the permit by the licensee, based on peculiar safety review guidance. The NRC and NSC provide the safety review guidance for test and research reactors and European countries refer to IAEA safety requirements and guides. The safety review guide (SRG) of research and training reactors was developed considering descriptions of the NUREG- 1537 Part 2, previous experiences of safety review and domestic regulations for related facilities. This study provided the safety review guidance for research and training reactors and surveyed the difference of major acceptance criteria or characteristics between the SRG of pressurized light water reactor and research and training reactors

  5. Design of guidance laws for lunar pinpoint soft landing

    NARCIS (Netherlands)

    Guo, J.; Han, C.

    2009-01-01

    Future lunar missions ask for the capability to perform precise Guidance, Navigation and Control (GNC) to the selected landing sites on the lunar surface. This paper studies the guidance issues for the lunar pinpoint soft landing problem. The primary contribution of this paper is the design of

  6. Late Cenozoic basin evolution and fold-thrust deformation in the southern Central Andes: Initial constraints from synorogenic deposits of the Precordillera, Argentina

    Science.gov (United States)

    Levina, M.; Horton, B. K.; Fuentes, F.; Stockli, D. F.

    2012-12-01

    In the Precordillera region of the Argentine Andes, Cenozoic shortening associated with flattening of the Pampean segment of the subducting Nazca plate has resulted in a series of thin skinned fold-thrust systems that partitioned and uplifted Cenozoic foreland basin deposits. The kinematic and temporal evolution of the Andean Precordillera can be approached through detailed analyses of the sedimentary fill now preserved in intermontane regions and the bedrock low-temperature thermochronology of the fold-thrust belt. In this project, we focus on Neogene foreland basin fill exposed in the central and eastern Precordillera along the San Juan River (Quebrada Albarracín and Pachaco regions), on the western flank of the Sierra Talacasto, and in the Loma de las Tapias area near the Ullum dam. The sedimentary successions exposed in these regions record the hinterland development of the Frontal Cordillera (detrital zircon provenance and composition of sandstone and conglomeratic units), regional volcanism (pyroclastic flows and tuffaceous sandstone units), and initial construction of the Precordillera (fault cutoff relationships, growth strata, and paleocurrent changes). We investigate the development and subsequent partitioning and deformation of these synorogenic sections using sediment provenance (detrital zircon U-Pb geochronology, conglomerate clast counts, sandstone petrography, and paleocurrent measurements), facies analysis of measured stratigraphic successions, and initial apatite (U-Th)/He cooling histories to constrain the age of uplift-induced exhumation of successive thrust sheets in the Andean Precordillera.

  7. Static thrust-vectoring performance of nonaxisymmetric convergent-divergent nozzles with post-exit yaw vanes. M.S. Thesis - George Washington Univ., Aug. 1988

    Science.gov (United States)

    Foley, Robert J.; Pendergraft, Odis C., Jr.

    1991-01-01

    A static (wind-off) test was conducted in the Static Test Facility of the 16-ft transonic tunnel to determine the performance and turning effectiveness of post-exit yaw vanes installed on two-dimensional convergent-divergent nozzles. One nozzle design that was previously tested was used as a baseline, simulating dry power and afterburning power nozzles at both 0 and 20 degree pitch vectoring conditions. Vanes were installed on these four nozzle configurations to study the effects of vane deflection angle, longitudinal and lateral location, size, and camber. All vanes were hinged at the nozzle sidewall exit, and in addition, some were also hinged at the vane quarter chord (double-hinged). The vane concepts tested generally produced yaw thrust vectoring angles much less than the geometric vane angles, for (up to 8 percent) resultant thrust losses. When the nozzles were pitch vectored, yawing effectiveness decreased as the vanes were moved downstream. Thrust penalties and yawing effectiveness both decreased rapidly as the vanes were moved outboard (laterally). Vane length and height changes increased yawing effectiveness and thrust ratio losses, while using vane camber, and double-hinged vanes increased resultant yaw angles by 50 to 100 percent.

  8. Constraints on inner forearc deformation from balanced cross sections, Fila Costeña thrust belt, Costa Rica

    Science.gov (United States)

    Sitchler, Jason C.; Fisher, Donald M.; Gardner, Thomas W.; Protti, Marino

    2007-12-01

    The Fila Costeña thrust belt in the forearc of Costa Rica is accommodating a significant portion of the convergence of the Cocos plate and Panama microplate. Geologic mapping of the thrust belt depicts a duplex with three horses that incorporate Eocene limestones and Oligocene to early Miocene clastics inboard of the subducting Cocos Ridge axis. By constructing a cross section at this location along a NE-SW trending transect perpendicular to the thrust belt, we constrain a shortening rate of approximately 40 mm/a and propose that as much as 50% of the total plate convergence rate is taken up in the inner forearc. The Eocene limestones at the base of the thrust sheets pinch out in both directions away from the onland projection of the Cocos Ridge axis owing to decrease in slip on faults and a lateral ramp in the basal décollement. The thrust belt terminates near the Panama border at the onland projection of the subducting Panama Fracture Zone. These observations suggest that shortening is propagating to the east with the migration of the Panama triple junction and the onset of shallow subduction of the thickened edge of the Cocos plate. The absence of similar features in the Nicaraguan forearc, where the subducting crust is older, subducts more steeply, and lacks incoming ridges and seamounts, indicates that deformation of the forearc basin in Costa Rica reflects greater coupling between the converging plates inboard of the Cocos Ridge.

  9. Kink bands in thrust regime: Examples from Srinagar–Garhwal area ...

    Indian Academy of Sciences (India)

    Srinagar–Garhwal; kink bands; paleostress; shearing along kink planes; Himalaya; North Almora Thrust. J. Earth Syst. Sci. 120, No. 5, October 2011, pp. 939–948 ..... The α>β geometry observed in kink bands suggest towards shearing as a common phenomenon along the kink planes. (Anderson 1964). Since considerable ...

  10. Providing Career Guidance for Young Women.

    Science.gov (United States)

    Colby, Pamela G.

    This module is directed at personnel working or planning to work in the areas of guidance, counseling, placement and follow-through in junior and senior high school settings, grades 7-12. The module topic is career guidance for young women of junior and senior high school age, aand the focus will be on providing nonbiased career guidance which…

  11. Measurement of the longitudinal cross-section using the direction of the thrust axis in hadronic events at LEP

    CERN Document Server

    Abbiendi, G.; Alexander, G.; Allison, John; Altekamp, N.; Anderson, K.J.; Anderson, S.; Arcelli, S.; Asai, S.; Ashby, S.F.; Axen, D.; Azuelos, G.; Ball, A.H.; Barberio, E.; Barlow, Roger J.; Bartoldus, R.; Batley, J.R.; Baumann, S.; Bechtluft, J.; Behnke, T.; Bell, Kenneth Watson; Bella, G.; Bellerive, A.; Bentvelsen, S.; Bethke, S.; Betts, S.; Biebel, O.; Biguzzi, A.; Bird, S.D.; Blobel, V.; Bloodworth, I.J.; Bobinski, M.; Bock, P.; Bohme, J.; Bonacorsi, D.; Boutemeur, M.; Braibant, S.; Bright-Thomas, P.; Brigliadori, L.; Brown, Robert M.; Burckhart, H.J.; Burgard, C.; Burgin, R.; Capiluppi, P.; Carnegie, R.K.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, David G.; Chrisman, D.; Ciocca, C.; Clarke, P.E.L.; Clay, E.; Cohen, I.; Conboy, J.E.; Cooke, O.C.; Couyoumtzelis, C.; Coxe, R.L.; Cuffiani, M.; Dado, S.; Dallavalle, G.Marco; Davis, R.; De Jong, S.; del Pozo, L.A.; De Roeck, A.; Desch, K.; Dienes, B.; Dixit, M.S.; Dubbert, J.; Duchovni, E.; Duckeck, G.; Duerdoth, I.P.; Eatough, D.; Estabrooks, P.G.; Etzion, E.; Evans, H.G.; Fabbri, F.; Fanti, M.; Faust, A.A.; Fiedler, F.; Fierro, M.; Fleck, I.; Folman, R.; Furtjes, A.; Futyan, D.I.; Gagnon, P.; Gary, J.W.; Gascon, J.; Gascon-Shotkin, S.M.; Gaycken, G.; Geich-Gimbel, C.; Giacomelli, G.; Giacomelli, P.; Gibson, V.; Gibson, W.R.; Gingrich, D.M.; Glenzinski, D.; Goldberg, J.; Gorn, W.; Grandi, C.; Gross, E.; Grunhaus, J.; Gruwe, M.; Hanson, G.G.; Hansroul, M.; Hapke, M.; Harder, K.; Hargrove, C.K.; Hartmann, C.; Hauschild, M.; Hawkes, C.M.; Hawkings, R.; Hemingway, R.J.; Herndon, M.; Herten, G.; Heuer, R.D.; Hildreth, M.D.; Hill, J.C.; Hillier, S.J.; Hobson, P.R.; Hocker, James Andrew; Homer, R.J.; Honma, A.K.; Horvath, D.; Hossain, K.R.; Howard, R.; Huntemeyer, P.; Hutchcroft, D.E.; Igo-Kemenes, P.; Imrie, D.C.; Ishii, K.; Jacob, F.R.; Jawahery, A.; Jeremie, H.; Jimack, M.; Jones, C.R.; Jovanovic, P.; Junk, T.R.; Karlen, D.; Kartvelishvili, V.; Kawagoe, K.; Kawamoto, T.; Kayal, P.I.; Keeler, R.K.; Kellogg, R.G.; Kennedy, B.W.; Klier, A.; Kluth, S.; Kobayashi, T.; Kobel, M.; Koetke, D.S.; Kokott, T.P.; Kolrep, M.; Komamiya, S.; Kowalewski, Robert V.; Kress, T.; Krieger, P.; von Krogh, J.; Kuhl, T.; Kyberd, P.; Lafferty, G.D.; Lanske, D.; Lauber, J.; Lautenschlager, S.R.; Lawson, I.; Layter, J.G.; Lazic, D.; Lee, A.M.; Lellouch, D.; Letts, J.; Levinson, L.; Liebisch, R.; List, B.; Littlewood, C.; Lloyd, A.W.; Lloyd, S.L.; Loebinger, F.K.; Long, G.D.; Losty, M.J.; Ludwig, J.; Lui, D.; Macchiolo, A.; Macpherson, A.; Mader, W.; Mannelli, M.; Marcellini, S.; Markopoulos, C.; Martin, A.J.; Martin, J.P.; Martinez, G.; Mashimo, T.; Mattig, Peter; McDonald, W.John; McKenna, J.; Mckigney, E.A.; McMahon, T.J.; McPherson, R.A.; Meijers, F.; Menke, S.; Merritt, F.S.; Mes, H.; Meyer, J.; Michelini, A.; Mihara, S.; Mikenberg, G.; Miller, D.J.; Mir, R.; Mohr, W.; Montanari, A.; Mori, T.; Nagai, K.; Nakamura, I.; Neal, H.A.; Nellen, B.; Nisius, R.; O'Neale, S.W.; Oakham, F.G.; Odorici, F.; Ogren, H.O.; Oreglia, M.J.; Orito, S.; Palinkas, J.; Pasztor, G.; Pater, J.R.; Patrick, G.N.; Patt, J.; Perez-Ochoa, R.; Petzold, S.; Pfeifenschneider, P.; Pilcher, J.E.; Pinfold, J.; Plane, David E.; Poffenberger, P.; Polok, J.; Przybycien, M.; Rembser, C.; Rick, H.; Robertson, S.; Robins, S.A.; Rodning, N.; Roney, J.M.; Roscoe, K.; Rossi, A.M.; Rozen, Y.; Runge, K.; Runolfsson, O.; Rust, D.R.; Sachs, K.; Saeki, T.; Sahr, O.; Sang, W.M.; Sarkisian, E.K.G.; Sbarra, C.; Schaile, A.D.; Schaile, O.; Scharf, F.; Scharff-Hansen, P.; Schieck, J.; Schmitt, B.; Schmitt, S.; Schoning, A.; Schroder, Matthias; Schumacher, M.; Schwick, C.; Scott, W.G.; Seuster, R.; Shears, T.G.; Shen, B.C.; Shepherd-Themistocleous, C.H.; Sherwood, P.; Siroli, G.P.; Sittler, A.; Skuja, A.; Smith, A.M.; Snow, G.A.; Sobie, R.; Soldner-Rembold, S.; Sproston, M.; Stahl, A.; Stephens, K.; Steuerer, J.; Stoll, K.; Strom, David M.; Strohmer, R.; Surrow, B.; Talbot, S.D.; Tanaka, S.; Taras, P.; Tarem, S.; Teuscher, R.; Thiergen, M.; Thomson, M.A.; von Torne, E.; Torrence, E.; Towers, S.; Trigger, I.; Trocsanyi, Z.; Tsur, E.; Turcot, A.S.; Turner-Watson, M.F.; Van Kooten, Rick J.; Vannerem, P.; Verzocchi, M.; Voss, H.; Wackerle, F.; Wagner, A.; Ward, C.P.; Ward, D.R.; Watkins, P.M.; Watson, A.T.; Watson, N.K.; Wells, P.S.; Wermes, N.; White, J.S.; Wilson, G.W.; Wilson, J.A.; Wyatt, T.R.; Yamashita, S.; Yekutieli, G.; Zacek, V.; Zer-Zion, D.

    1998-01-01

    In the process e+e- to hadrons, one of the effects of gluon emission is to modify the 1+cos(theta)**2 form of the angular distribution of the thrust axis, an effect which may be quantified by the longitudinal cross-section. Using the OPAL detector at LEP, we have determined the longitudinal to total cross-section ratio to be 0.0127+-0.0016+-0.0013 at the parton level, in good agreement with the expectation of QCD computed to Order(alpha_s**2) Comparisions at the hadron level with Monte Carlo models are presented. The dependence of the longitudinal cross-section on the value of thrust has also been studied, and provides a new test of QCD.

  12. 78 FR 73199 - Draft Guidance for Industry on Bioequivalence Studies With Pharmacokinetic Endpoints for Drugs...

    Science.gov (United States)

    2013-12-05

    ... exposure measures is suitable for documenting BE (e.g., transdermal delivery systems and certain rectal and... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2013-D-1464] Draft Guidance for Industry on Bioequivalence Studies With Pharmacokinetic Endpoints for Drugs Submitted...

  13. ICRP guidance on radioactive waste disposal

    International Nuclear Information System (INIS)

    Cooper, J.R.

    2002-01-01

    The International Commission on Radiological Protection (ICRP) issued recommendations for a system of radiological protection in 1991 as the 1990 Recommendations. Guidance on the application of these recommendations in the general area of waste disposal was issued in 1997 as Publication 77 and guidance specific to disposal of solid long-lived radioactive waste was issued as Publication 81. This paper summarises ICRP guidance in radiological protection requirements for waste disposal concentrating on the ones of relevance to the geological disposal of solid radioactive waste. Suggestions are made for areas where further work is required to apply the ICRP guidance. (author)

  14. An Evaluation of Unemployment Reduction in Akwa Ibom State using Career Guidance and Counselling

    OpenAIRE

    Nsikak-Abasi Udofia; Eno Daniel Inyang

    2013-01-01

    This study was carried out to examine the possibility of reducing unemployment in Akwa Ibom State using career guidance and counselling interventions. To guide the study, four research questions and four null hypotheses were formulated. Variables such as educational guidance, vocational, personality trait guidance and sociological guidance were used in the investigation. A survey design was used in studying a population of 6509 senior secondary two students in 58 public secondary schools that...

  15. Evaluation Of Career Guidance Program In Vocational High School

    Directory of Open Access Journals (Sweden)

    Martaningsih Sri Tutur

    2018-01-01

    This review of career guidance program evaluation is conducted qualitatively through surveys, interviews and leiterature studies to provide an overview of evaluation program and its relevance to the necessity. Understanding the quality, weaknesses, obstacles to service implementation, and potential utilization are expected to improve career guidance effectiveness services in vocational high school. An evaluation on the overall career guidance program, will provide feedback for ongoing improvement. Various evaluation models are available, it needs to be selected about the relevance to the career counseling program characteristics, so that evaluation feedback is more optimal.

  16. The Chevron Foil Thrust Bearing: Improved Performance Through Passive Thermal Management and Effective Lubricant Mixing

    Science.gov (United States)

    Bruckner, Robert

    2013-01-01

    An improved foil thrust bearing is described that eliminates or reduces the need for forced cooling of the bearing foils while at the same time improves the load capacity of the bearing, enhances damping, provides overload tolerance, and eliminates the high speed load capacity drop-off that plagues the current state of the art. The performance improvement demonstrated by the chevron foil thrust bearing stems from a novel trailing edge shape that splays the hot lubricant in the thin film radially, thus preventing hot lubricant carry-over into the ensuing bearing sector. Additionally, the chevron shaped trailing edge induces vortical mixing of the hot lubricant with the gas that is naturally resident within the inter-pad region of a foil thrust bearing. The elimination of hot gas carry-over in combination with the enhanced mixing has enabled a completely passive thermally managed foil bearing design. Laboratory testing at NASA has confirmed the original analysis and reduced this concept to practice.

  17. Guidance at the educational marketplace

    DEFF Research Database (Denmark)

    Lystbæk, Christian Tang

    in educational policies and institutions. As educational systems have expanded and, further, have been restructured with the expansion of choice opportunities since the 1980s, guidance has become prioritized as a form of counseling or coaching, which can support students. Thus, guidance has become an important...... `agent´ on the educational "market´, assisting (potential) students into and around the `marketplace´. Consequently, guidance is also an important `agent´ for educational institutions that increasingly use marketing strategies to promote themselves on the market to attract and hold on to their “customers......” in order for the institutions to increase their ´market value´, `sales” and “turnover”. Thus, the expansion of guidance is nurtured by the expansion of the logic of marketization and consumerism. Drawing on Foucauldian perspectives in educational research, which highlight the expansion of powerful...

  18. Dual Mode Low Power Hall Thruster, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Sample and return missions desire and missions like Saturn Observer require a low power Hall thruster that can operate at high thrust to power as well as high...

  19. Dynamic Characteristics of Rotors on Passive and Active Thrust Fluid-film Bearings with Fixed Pads

    Directory of Open Access Journals (Sweden)

    Babin Alexander

    2018-01-01

    Full Text Available Application of fluid-film bearings in rotor machines in many cases could have no alternative due to obvious advantages when compared to roller element bearings. Integration of information technology in mechanical engineering resulting in emergence of a new field of research – mechatronic bearings which allowed tracking condition of the most important parts of a machine and adjusting operational parameters of the system. Application of servo valves to control the flow rate through a fluid-film bearing is the most universal and simple way of rotor’s position control due to relative simplicity of modelling and absence of need to radically change the design of conventional hydrodynamic bearings. In the present paper numerical simulations of passive (conventional as opposed to mechatronic and active hybrid thrust fluid-film bearings with a central feeding chamber are presented, that are parts of a mechatronic rotor-bearing node. Numerical model of an active thrust bearing is based on solution of equations of hydrodynamics, rotor dynamics and an additional model of a servo valve. Various types of control have been investigated: P, PI and PID control, and the dynamic behaviour of a system has been estimated under various loads, namely static, periodic and impulse. A design of a test rig has been proposed to study passive and active thrust fluid-film bearings aimed at, among other, validation of numerical results of active bearings simulation.

  20. Regulatory guidance for license renewal

    International Nuclear Information System (INIS)

    Thoma, John A.

    1991-01-01

    The proposed 10 CFR Part 54 rule proceduralizes the process for license renewal by identifying both the administrative and technical requirements for a renewal application. To amplify and support this regulation, written guidance has been provided in the form of a draft Regulatory Guide (DG 1009) and a draft Standard Review Plan for License Renewal (NUREG 1299). This guidance is scheduled to be finalized in 1992. Similar guidance will be provided for the proposed revisions to 10 CFR Part 51 concerning the environmental aspects of license renewal. (author)

  1. Conceptual Engine System Design for NERVA derived 66.7KN and 111.2KN Thrust Nuclear Thermal Rockets

    International Nuclear Information System (INIS)

    Fittje, James E.; Buehrle, Robert J.

    2006-01-01

    The Nuclear Thermal Rocket concept is being evaluated as an advanced propulsion concept for missions to the moon and Mars. A tremendous effort was undertaken during the 1960's and 1970's to develop and test NERVA derived Nuclear Thermal Rockets in the 111.2 KN to 1112 KN pound thrust class. NASA GRC is leveraging this past NTR investment in their vehicle concepts and mission analysis studies, and has been evaluating NERVA derived engines in the 66.7 KN to the 111.2 KN thrust range. The liquid hydrogen propellant feed system, including the turbopumps, is an essential component of the overall operation of this system. The NASA GRC team is evaluating numerous propellant feed system designs with both single and twin turbopumps. The Nuclear Engine System Simulation code is being exercised to analyze thermodynamic cycle points for these selected concepts. This paper will present propellant feed system concepts and the corresponding thermodynamic cycle points for 66.7 KN and 111.2 KN thrust NTR engine systems. A pump out condition for a twin turbopump concept will also be evaluated, and the NESS code will be assessed against the Small Nuclear Rocket Engine preliminary thermodynamic data

  2. The Use of Vocational Guidance E-Systems in Colleges of Technology, Saudi Arabia

    Science.gov (United States)

    Alsaidan, Saad; Zhang, Li

    2018-01-01

    This study aimed to explore how much interest do technical colleges students have in vocational guidance E-Systems and to detect the most important E-Systems of vocational guidance that they use. The researcher collected data, through questionnaires, from 311 students in their fourth, fifth, or sixth semesters in the colleges of technology in Saudi Arabia. The data were analysed using the chi square test, factor analysis, and descriptive analysis. This study shows the importance in the integration of the E-Systems to vocational guidance. The model includes: the use of e-vocational consulting programs, e-extracurricular programs, e-vocational activities, informational systems, and e-exams for vocational tendency, which were rarely studied before. The results indicated that the college student is highly motivated by vocational guidance using the E-system, unlike the traditional methods of vocational guidance, and young students are motivated by the E-system when it is used in vocational guidance. The study conclude that the integration of the E-system has significantly contributed to vocational guidance. The study recommends that the e-system be implemented to all areas of decision-making. Practitioners should Interact with students through the E-Systems and arrive at decisions that are good for educational growth.

  3. Mechatronic track guidance on disturbed track: the trade-off between actuator performance and wheel wear

    Science.gov (United States)

    Kurzeck, Bernhard; Heckmann, Andreas; Wesseler, Christoph; Rapp, Matthias

    2014-05-01

    Future high-speed trains are the main focus of the DLR research project Next Generation Train. One central point of the research activities is the development of mechatronic track guidance for the two-axle intermediate wagons with steerable, individually powered, independently rotating wheels. The traction motors hereby fulfil two functions; they concurrently are traction drives and steering actuators. In this paper, the influence of the track properties - line layout and track irregularities - on the performance requirements for the guidance actuator is investigated using multi-body models in SIMPACK®. In order to compromise on the design conflict between low wheel wear and low steering torque, the control parameters of the mechatronic track guidance are optimised using the DLR in-house software MOPS. Besides the track irregularities especially the increasing inclination at transition curves defines high actuator requirements due to gyroscopic effects at high speed. After introducing a limiter for the actuating variables into the control system, a good performance is achieved.

  4. Energy from sea wave thrust and flow of water

    International Nuclear Information System (INIS)

    Sarkar, S.R.

    1996-01-01

    The area adjacent to the tidal rivers, irrigational canal, drain and also the seashore may be energized harnessing the energy from the flow/wave thrust by simply converting it into unidirectional rotating force to drive the generator for power generation. The existing plants are big in size and also fixed in place. A plant which will be a small/portable type is described. 7 refs., figs

  5. Study of the Use of a Terminal Controller Technique for Reentry Guidance of a Capsule-Type Vehicle

    Science.gov (United States)

    Foudriat, Edwin C.

    1961-01-01

    A study has been made of the use o f a terminal controller technique i n the guidance of a high-drag, variable-lift reentry vehicle to a desired landing point. The technique uses linearized equations of motion attained by the perturbation of the dependent variables from those of a reference trajectory. The guidance system continuously predicts the terminal range error and uses this error to control the angle of attack of the vehicle in an on-off manner until the predicted range error is within +-O.1 degrees of the required arc or +-6.9 miles.

  6. Development trend of low bypass ratio turbofan engines. Tei baipasu hi tabo fan engine no kaihatsu doko

    Energy Technology Data Exchange (ETDEWEB)

    Yashima, S [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

    1994-03-10

    As a turbojet engine gets a thrust by blowing out the exhaust of a gas generator, for decreasing the fuel consumption ratio is more advantageous when a bypass air quantity is made as much as possible. Therefore in the subsonic speed passenger aircrafts putting an economy in the first place, the high bypass ratio turbofan engines are used. Even in case of the subsonic speed aircrafts, in addition, for the trainer airplanes and fighters, a type to be built in the engines in the fuselages, the low bypass ratio engines with small front areas are used. When a turbofan engine with a low bypass ratio is picked up, therefore recently, it is general that a military engine with a bypass ratio under 1 (about 0.5 is frequent) is pointed, as for a development trend also from a viewpoint of the performance improvement as a military engine, an improvement of the thrust-weight ratio and specific thrust are attached importance to. In this paper, these performance parameters, a trend to make them lighter weight, and the elementary technologies peculiar to a low bypass ratio engine are described, and moreover the study and development state in Europe, America and Japan are put in order. 8 refs., 14 figs., 2 tabs.

  7. Students' perception of guidance and counselling services offered in ...

    African Journals Online (AJOL)

    Many students of tertiary institutions including Colleges of Education are young adults who feel more concerned about getting a job, making a home and continuing higher education. These concerns require proper guidance The general purpose of this study therefore was to find out the perception of students on guidance ...

  8. Towards a new approach to model guidance laws

    International Nuclear Information System (INIS)

    Borne, P.; Duflos, E.; Vanheeghe, P.

    1994-01-01

    Proportional navigation laws have been widely used and studied. Nevertheless very few publications explain rigorously the origin of all these laws. For researchers who are starting to work on guidance laws, a feeling of confusion can result. For others, this lack of explanation can be, for example, the source of the difficulties to make the true proportional navigation become equivalent to the pure proportional navigation. The authors propose here a way to model guidance laws in order to fill this lack of explanation. The first consequence is a better exploration of the kinematic behaviors arising during the guidance process. The second consequence is the definition of a new 3D guidance law which can be seen as a generalization of the true proportional navigation. Moreover, this generalization allow this last law to become equivalent to the pure proportional navigation in terms of initial conditions which allow the object to reach its target

  9. The axonal guidance receptor neogenin promotes acute inflammation.

    Directory of Open Access Journals (Sweden)

    Klemens König

    Full Text Available Neuronal guidance proteins (NGP were originally described in the context of axonal growth and migration. Yet recent work has demonstrated that NGPs also serve as guidance cues for immune competent cells. A crucial target receptor for NGPs during embryonic development is the neogenin receptor, however its role during acute inflammation is unknown. We report here that neogenin is abundantly expressed outside the nervous system and that animals with endogenous repression of neogenin (Neo1(-/- demonstrate attenuated changes of acute inflammation. Studies using functional inhibition of neogenin resulted in a significant attenuation of inflammatory peritonitis. In studies employing bone marrow chimeric animals we found the hematopoietic presence of Neo1(-/- to be responsible for the attenuated inflammatory response. Taken together our studies suggest that the guidance receptor neogenin holds crucial importance for the propagation of an acute inflammatory response and further define mechanisms shared between the nervous and the immune system.

  10. Constituent aspects of workplace guidance in secondary VET

    NARCIS (Netherlands)

    Swager, Robert; Klarus, Ruud; Van Merriënboer, Jeroen; Nieuwenhuis, Loek

    2018-01-01

    Purpose – This paper aims to present an integrated model of workplace guidance to enhance awareness of what constitutes good guidance, to improve workplace guidance practices in vocational education and training. Design/methodology/approach – To identify constituent aspects of workplace guidance,

  11. Lift, drag, and guidance forces on alternating polarity magnets, using loop guideways

    International Nuclear Information System (INIS)

    Lindenbaum, S.D.; Lee, M.S.

    1975-01-01

    Exact solutions of track current, lift force, and drag force, together with their velocity dependence, have been computed for a vehicle carrying a finite number of fixed current alternating polarity superconducting magnets, suspended at various heights over structured track guideways of the single- and double-loop (''null'') types. Results for the double-loop case are compared with those of a previously reported approximate analysis. The analytical method is then applied to a study of a low-drag guidance loop guideway which is integrable with lift loop guideways utilizing a common set of vehicle magnets. Solutions are obtained for guidance track restoring forces, lateral destabilization forces, and lift force degradation as functions of lateral displacement from symmetry. The dependence of lift, drag, and lift-to-drag on track loop parameters is studied and the linear dependence of lift-to-drag on loop time constant confirmed. The contribution to the forces made by successive addition of alternating polarity magnets is calculated and the marked reduction in lift force pulsation noted

  12. General RMP Guidance - Appendix D: OSHA Guidance on PSM

    Science.gov (United States)

    OSHA's Process Safety Management (PSM) Guidance on providing complete and accurate written information concerning process chemicals, process technology, and process equipment; including process hazard analysis and material safety data sheets.

  13. Amending the Characterization of Guidance in Visual Analytics

    OpenAIRE

    Ceneda, Davide; Gschwandtner, Theresia; May, Thorsten; Miksch, Silvia; Schulz, Hans-Jörg; Streit, Marc; Tominski, Christian

    2017-01-01

    At VAST 2016, a characterization of guidance has been presented. It includes a definition of guidance and a model of guidance based on van Wijk's model of visualization. This note amends the original characterization of guidance in two aspects. First, we provide a clarification of what guidance actually is (and is not). Second, we insert into the model a conceptually relevant link that was missing in the original version.

  14. Neutral-depletion-induced axially asymmetric density in a helicon source and imparted thrust

    Science.gov (United States)

    Takahashi, Kazunori; Takao, Yoshinori; Ando, Akira

    2016-02-01

    The high plasma density downstream of the source is observed to be sustained only for a few hundreds of microsecond at the initial phase of the discharge, when pulsing the radiofrequency power of a helicon plasma thruster. Measured relative density of argon neutrals inside the source implies that the neutrals are significantly depleted there. A position giving a maximum plasma density temporally moves to the upstream side of the source due to the neutral depletion and then the exhausted plasma density significantly decreases. The direct thrust measurement demonstrates that the higher thrust-to-power ratio is obtained by using only the initial phase of the high density plasma, compared with the steady-state operation.

  15. Levodopa increases oxidative stress and repulsive guidance molecule A levels: a pilot study in patients with Parkinson's disease.

    Science.gov (United States)

    Müller, Thomas; Trommer, Isabel; Muhlack, Siegfried; Mueller, Bernhard K

    2016-04-01

    Exposure to free radicals influences synthesis, degradation and function of proteins, such as repulsive guidance molecule A. Decay of this protein is essential for neuronal maintenance and recovery. Levodopa elevates oxidative stress. Therefore levodopa may impact repulsive guidance molecule A metabolism. Objectives were to investigate plasma concentrations of repulsive guidance molecule A, levodopa, cysteine and cysteinyl-glycine before and 1 h after levodopa application in patients with Parkinson's disease. Cysteine and cysteinyl-glycine as biomarkers for oxidative stress exposure decreased, repulsive guidance molecule A and levodopa rose. Repulsive guidance molecule A remained unchanged in levodopa naïve patients, but particularly went up in patients on a prior chronic levodopa regimen. Decay of cysteine specifically cysteinyl-glycine results from an elevated glutathione generation with rising cysteine consumption respectively from the alternative glutathione transformation to its oxidized form glutathione disulfide after free radical scavenging. Repulsive guidance molecule A rise may inhibit physiologic mechanisms for neuronal survival.

  16. Thrust and torque vector characteristics of axially-symmetric E-sail

    Science.gov (United States)

    Bassetto, Marco; Mengali, Giovanni; Quarta, Alessandro A.

    2018-05-01

    The Electric Solar Wind Sail is an innovative propulsion system concept that gains propulsive acceleration from the interaction with charged particles released by the Sun. The aim of this paper is to obtain analytical expressions for the thrust and torque vectors of a spinning sail of given shape. Under the only assumption that each tether belongs to a plane containing the spacecraft spin axis, a general analytical relation is found for the thrust and torque vectors as a function of the spacecraft attitude relative to an orbital reference frame. The results are then applied to the noteworthy situation of a Sun-facing sail, that is, when the spacecraft spin axis is aligned with the Sun-spacecraft line, which approximatively coincides with the solar wind direction. In that case, the paper discusses the equilibrium shape of the generic conducting tether as a function of the sail geometry and the spin rate, using both a numerical and an analytical (approximate) approach. As a result, the structural characteristics of the conducting tether are related to the spacecraft geometric parameters.

  17. Inverse Analysis and Modeling for Tunneling Thrust on Shield Machine

    Directory of Open Access Journals (Sweden)

    Qian Zhang

    2013-01-01

    Full Text Available With the rapid development of sensor and detection technologies, measured data analysis plays an increasingly important role in the design and control of heavy engineering equipment. The paper proposed a method for inverse analysis and modeling based on mass on-site measured data, in which dimensional analysis and data mining techniques were combined. The method was applied to the modeling of the tunneling thrust on shield machines and an explicit expression for thrust prediction was established. Combined with on-site data from a tunneling project in China, the inverse identification of model coefficients was carried out using the multiple regression method. The model residual was analyzed by statistical methods. By comparing the on-site data and the model predicted results in the other two projects with different tunneling conditions, the feasibility of the model was discussed. The work may provide a scientific basis for the rational design and control of shield tunneling machines and also a new way for mass on-site data analysis of complex engineering systems with nonlinear, multivariable, time-varying characteristics.

  18. Thrust augmentation in tandem flapping foils by foil-wake interaction

    Science.gov (United States)

    Anderson, Erik; Lauder, George

    2006-11-01

    Propulsion by pitching and heaving airfoils and hydrofoils has been a focus of much research in the field of biologically inspired propulsion. Organisms that use this sort of propulsion are self-propelled, so it is difficult to use standard experimental metrics such as thrust and drag to characterize performance. We have constructed a flapping foil robot mounted in a flume on air-bearings that allows for the determination of self-propelled speed as a metric of performance. We have used a pair of these robots to examine the impact of an upstream flapping foil on a downstream flapping foil as might apply to tandem fins of a swimming organism or in-line swimming of schooling organisms. Self-propelled speed and a force transducer confirmed significant thrust augmentation for particular foil-to-foil spacings, phase differences, and flapping frequencies. Flow visualization shows the mechanism to be related to the effective angle of attack of the downstream foil due to the structure of the wake of the upstream foil. This confirms recent computational work and the hypotheses by early investigators of fish fluid dynamics.

  19. On the Design of Tilting-Pad Thrust Bearings

    OpenAIRE

    Heinrichson, Niels; Santos, Ilmar

    2007-01-01

    Pockets are often machined in the surfaces of tilting-pad thrust bearings to allow for hydrostatic jacking in the start-up phase. Pockets and other recesses in the surfaces of bearing pads influence the pressure distribution and thereby the position of the pivot resulting in the most advantageous pad convergence ratio. In this thesis, a theoretical approach is applied in the attempt to quantify the influence of recesses in the pad surfaces. The recesses may be relatively deep and enclosed as ...

  20. Optimal guidance law in quantum mechanics

    International Nuclear Information System (INIS)

    Yang, Ciann-Dong; Cheng, Lieh-Lieh

    2013-01-01

    Following de Broglie’s idea of a pilot wave, this paper treats quantum mechanics as a problem of stochastic optimal guidance law design. The guidance scenario considered in the quantum world is that an electron is the flight vehicle to be guided and its accompanying pilot wave is the guidance law to be designed so as to guide the electron to a random target driven by the Wiener process, while minimizing a cost-to-go function. After solving the stochastic optimal guidance problem by differential dynamic programming, we point out that the optimal pilot wave guiding the particle’s motion is just the wavefunction Ψ(t,x), a solution to the Schrödinger equation; meanwhile, the closed-loop guidance system forms a complex state–space dynamics for Ψ(t,x), from which quantum operators emerge naturally. Quantum trajectories under the action of the optimal guidance law are solved and their statistical distribution is shown to coincide with the prediction of the probability density function Ψ ∗ Ψ. -- Highlights: •Treating quantum mechanics as a pursuit-evasion game. •Reveal an interesting analogy between guided flight motion and guided quantum motion. •Solve optimal quantum guidance problem by dynamic programming. •Gives a formal proof of de Broglie–Bohm’s idea of a pilot wave. •The optimal pilot wave is shown to be a wavefunction solved from Schrödinger equation