WorldWideScience

Sample records for dynamics boom splash

  1. Splash Dynamics of Falling Surfactant-Laden Droplets

    Science.gov (United States)

    Sulaiman, Nur; Buitrago, Lewis; Pereyra, Eduardo

    2017-11-01

    Splashing dynamics is a common issue in oil and gas separation technology. In this study, droplet impact of various surfactant concentrations onto solid and liquid surfaces is studied experimentally using a high-speed imaging analysis. Although this area has been widely studied in the past, there is still not a good understanding of the role of surfactant over droplet impact and characterization of resulting splash dynamics. The experiments are conducted using tap water laden with anionic surfactant. The effects of system parameters on a single droplet impingement such as surfactant concentration (no surfactant, below, at and above critical micelle concentration), parent drop diameter (2-5mm), impact velocity and type of impact surface (thin and deep pool) are investigated. Image analysis technique is shown to be an effective technique for identification of coalescence to splashing transition. In addition, daughter droplets size distributions are analyzed qualitatively in the events of splashing. As expected, it is observed that the formation of secondary droplets is affected by the surfactant concentration. A summary of findings will be discussed.

  2. Dynamic Analysis of The Intelligent Sprayer Boom

    DEFF Research Database (Denmark)

    Wiggers, Sine Leergaard; Maagaard, Jørgen; Terp, Christian Istjord

    called “The intelligent sprayer boom”. For the sprayer boom the primary challenge is to hit the weeds with precision from a movable platform. Since the sprayer boom is mounted on a tractor the system will react to bumps in the field. The intelligent sprayer boom has an integrated camera technology......As part of the 3 year project “The intelligent Sprayer Boom”, financed by The Danish National Advanced Technology Foundation, the dynamics of the sprayer boom is to be analysed. In order to minimize the amount of herbicides used to kill the weeds in agriculture a new sprayer boom is being developed...

  3. The shape and dynamics of the generation of the splash forms in single-phase systems after drop hitting

    Science.gov (United States)

    Sochan, Agata; Beczek, Michał; Mazur, Rafał; RyŻak, Magdalena; Bieganowski, Andrzej

    2018-02-01

    The splash phenomenon is being increasingly explored with the use of modern measurement tools, including the high-speed cameras. Recording images at a rate of several thousand frames per second facilitates parameterization and description of the dynamics of splash phases. This paper describes the impact of a single drop of a liquid falling on the surface of the same liquid. Three single-phase liquid systems, i.e., water, petrol, and diesel fuel, were examined. The falling drops were characterized by different kinetic energy values depending on the height of the fall, which ranged from 0.1 to 7.0 m. Four forms, i.e., waves, crowns, semi-closed domes, and domes, were distinguished depending on the drop energy. The analysis of the recorded images facilitated determination of the static and dynamic parameters of each form, e.g., the maximum height of each splash form, the width of the splash form at its maximum height, and the rate of growth of the splash form. We, Re, Fr, and K numbers were determined for all analyzed liquid systems. On the basis of the obtained values of dimensionless numbers, the areas of occurrence of characteristic splash forms were separated.

  4. Origin and dynamics of vortex rings in drop splashing.

    Science.gov (United States)

    Lee, Ji San; Park, Su Ji; Lee, Jun Ho; Weon, Byung Mook; Fezzaa, Kamel; Je, Jung Ho

    2015-09-04

    A vortex is a flow phenomenon that is very commonly observed in nature. More than a century, a vortex ring that forms during drop splashing has caught the attention of many scientists due to its importance in understanding fluid mixing and mass transport processes. However, the origin of the vortices and their dynamics remain unclear, mostly due to the lack of appropriate visualization methods. Here, with ultrafast X-ray phase-contrast imaging, we show that the formation of vortex rings originates from the energy transfer by capillary waves generated at the moment of the drop impact. Interestingly, we find a row of vortex rings along the drop wall, as demonstrated by a phase diagram established here, with different power-law dependencies of the angular velocities on the Reynolds number. These results provide important insight that allows understanding and modelling any type of vortex rings in nature, beyond just vortex rings during drop splashing.

  5. Splash Dynamics of Watercolors on Dry, Wet, and Cooled Surfaces

    Science.gov (United States)

    Baron, David; Vaidya, Ashwin; Su, Haiyan

    2015-11-01

    In his classic study in 1908, A.M. Worthington gave a thorough account of splashes and their formation through visualization experiments. In more recent times, there has been renewed interest in this subject, and much of the underlying physics behind Worthington's experiments has now been clarified. One specific set of such recent studies, which motivates this paper, concerns the fluid dynamics behind Jackson Pollock's drip paintings. The physical processes and the mathematical structures hidden in his works have received serious attention and made the scientific pursuit of art a compelling area of exploration. Our work explores the interaction of watercolors with watercolor paper. Specifically, we conduct experiments to analyze the settling patterns of droplets of watercolor paint on wet and frozen paper. Variations in paint viscosity, paper roughness, paper temperature, and the height of a released droplet are examined from time of impact, through its transient stages, until its final, dry state. Observable phenomena such as paint splashing, spreading, fingering, branching, rheological deposition, and fractal patterns are studied in detail and classified in terms of the control parameters.

  6. The making of a splash

    KAUST Repository

    Thoroddsen, Sigurdur T.

    2011-12-20

    The splash resulting from the impact of a drop onto a pool is a particularly beautiful manifestation of a canonical problem, where a mass of fluid breaks up into smaller pieces. Despite over a century of experimental study, the splashing mechanics have eluded full description, the details often being obscured by the very rapid motions and small length scales involved. Zhang et al. (J. Fluid Mech., vol. 690, 2012, pp. 515) introduce a powerful new tool to the experimental arsenal, when they apply X-ray imaging to study the fine ejecta sheets which emerge during the earliest contact of the drop. Their images reveal hidden details and complex underlying dynamics, which will directly affect the size and velocity of the splashing droplets. © 2011 Cambridge University Press.

  7. Dynamic simulation of a planar flexible boom for tokamak in-vessel operations

    International Nuclear Information System (INIS)

    Ambrosino, G.; Celentano, G.; Garofalo, F.; Maisonnier, D.

    1991-01-01

    In this paper we present a dynamic model for the analysis of the vibrations of a planar articulated flexible boom to be used for tokamak in-vessel maintenance operations. The peculiarity of the mechanical structure of the boom enables us to consider separately the oscillations in the horizontal and vertical planes so that two separate models can be constructed for describing these phenomena. The results of simulations based on booms like that proposed for NET in-vessel operations are presented. (orig.)

  8. The crown splash

    Science.gov (United States)

    Deegan, Robert; Brunet, Philippe; Eggers, Jens

    2008-11-01

    The impact of a drop onto a liquid layer and the subsequent splash has important implications for diverse physical processes such as air-sea gas transfer, cooling, and combustion. In the crown splash parameter regime, the splash pattern is highly regular. We focus on this case as a model for the mechanism that leads to secondary droplets, and thus explain the drop size distribution resulting from the splash. We show that the mean number of secondary droplets is determined by the most unstable wavelength of the Rayleigh-Plateau instability. Variations from this mean are governed by the width of the spectrum. Our results for the crown splash will provide the basis for understanding more complicated splashes.

  9. Method of Obtaining High Resolution Intrinsic Wire Boom Damping Parameters for Multi-Body Dynamics Simulations

    Science.gov (United States)

    Yew, Alvin G.; Chai, Dean J.; Olney, David J.

    2010-01-01

    The goal of NASA's Magnetospheric MultiScale (MMS) mission is to understand magnetic reconnection with sensor measurements from four spinning satellites flown in a tight tetrahedron formation. Four of the six electric field sensors on each satellite are located at the end of 60- meter wire booms to increase measurement sensitivity in the spin plane and to minimize motion coupling from perturbations on the main body. A propulsion burn however, might induce boom oscillations that could impact science measurements if oscillations do not damp to values on the order of 0.1 degree in a timely fashion. Large damping time constants could also adversely affect flight dynamics and attitude control performance. In this paper, we will discuss the implementation of a high resolution method for calculating the boom's intrinsic damping, which was used in multi-body dynamics simulations. In summary, experimental data was obtained with a scaled-down boom, which was suspended as a pendulum in vacuum. Optical techniques were designed to accurately measure the natural decay of angular position and subsequently, data processing algorithms resulted in excellent spatial and temporal resolutions. This method was repeated in a parametric study for various lengths, root tensions and vacuum levels. For all data sets, regression models for damping were applied, including: nonlinear viscous, frequency-independent hysteretic, coulomb and some combination of them. Our data analysis and dynamics models have shown that the intrinsic damping for the baseline boom is insufficient, thereby forcing project management to explore mitigation strategies.

  10. Thermal shock induced dynamics of a spacecraft with a flexible deploying boom

    Science.gov (United States)

    Shen, Zhenxing; Li, Huijian; Liu, Xiaoning; Hu, Gengkai

    2017-12-01

    The dynamics in the process of deployment of a flexible extendible boom as a deployable structure on the spacecraft is studied. For determining the thermally induced vibrations of the boom subjected to an incident solar heat flux, an axially moving thermal-dynamic beam element based on the absolute nodal coordinate formulation which is able to precisely describe the large displacement, rotation and deformation of flexible body is presented. For the elastic forces formulation of variable-length beam element, the enhanced continuum mechanics approach is adopted, which can eliminate the Poisson locking effect, and take into account the tension-bending-torsion coupling deformations. The main body of the spacecraft, modeled as a rigid body, is described using the natural coordinates method. In the derived nonlinear thermal-dynamic equations of rigid-flexible multibody system, the mass matrix is time-variant, and a pseudo damping matrix which is without actual energy dissipation, and a heat conduction matrix which is relative to the moving speed and the number of beam element are arisen. Numerical results give the dynamic and thermal responses of the nonrotating and spinning spacecraft, respectively, and show that thermal shock has a significant influence on the dynamics of spacecraft.

  11. Standardization of splash device

    Science.gov (United States)

    Fernández Raga, María; Peters, Piet

    2017-04-01

    The erosion is a complex process that has been studied extensively by numerous researchers, requiring a prolongued time effort and a large economic investment. To be effective, the measurements of erosion should be precise, controlled and replicable, and to assure efectiveness, measurement devices of erosion should be properly designed, constructed, well calibrated and also they should be operated by a trained person (Stroosnijder, 2005). Because researchers try to improve old devices, the equipment is constantly being redesigned, making the measurements not comparable and furthermore, producing a lack of available standarized device. The lack of standardization of erosion equipment is more obvious in the case of the local splash erosion, where the nature of the process makes very difficult to isolate its effects. In this article we compare the results obtained from five of the most common splash erosion devices (selected from more than 16 different currently types), under the same rain conditions, with the objective of facilitate the standardization of the method that will be more easy to build, minimizing the error. A set of six splash devices were setted in well known positions under simulated rain, to measured the differences, among devices and the accuracy of the data recovered after 10 minutes of rainfall simulation under different intensities (from 60 to 130 mm/h). The rainfall simulator of Wageningen was used, using sand as splash erosion source. Differences in the infiltration were also measured, and a calibration of sizes and speeds of the raindrops was done using the photography method (Hamidreza-Sadeghi et al., 2013). The splash devices selected for this study were unbounded splash devices (like the funnel, the cup (Fernandez-Raga et al., 2010) and the splash flume (Jomaa et al., 2010)), and bounded devices that allow the calculation of splash rate, (like the new cup (Scholten et al., 2011) and the Morgan tray). The behaviour of different splash devices

  12. Two mechanisms of droplet splashing on a solid substrate

    KAUST Repository

    Jian, Zhen

    2017-11-29

    We investigate droplet impact on a solid substrate in order to understand the influence of the gas in the splashing dynamics. We use numerical simulations where both the liquid and the gas phases are considered incompressible in order to focus on the gas inertial and viscous contributions. We first confirm that the dominant gas effect on the dynamics is due to its viscosity through the cushioning of the gas layer beneath the droplet. We then describe an additional inertial effect that is directly related to the gas density. The two different splashing mechanisms initially suggested theoretically are observed numerically, depending on whether a jet is created before or after the impacting droplet wets the substrate. Finally, we provide a phase diagram of the drop impact outputs as the gas viscosity and density vary, emphasizing the dominant effect of the gas viscosity with a small correction due to the gas density. Our results also suggest that gas inertia influences the splashing formation through a Kelvin–Helmholtz-like instability of the surface of the impacting droplet, in agreement with former theoretical works.

  13. SPLASH'13 workshops summary

    DEFF Research Database (Denmark)

    Balzer, S.; Schultz, U. P.

    2013-01-01

    Following its long-standing tradition, SPLASH 2013 will host 19 high-quality workshops, allowing their participants to meet and discuss research questions with peers, to mature new and exciting ideas, and to build up communities and start new collaborations. SPLASH workshops complement the main t...

  14. Splash-cup plants accelerate raindrops to disperse seeds

    Science.gov (United States)

    Amador, Guillermo J.; Yamada, Yasukuni; McCurley, Matthew; Hu, David L.

    2013-01-01

    The conical flowers of splash-cup plants Chrysosplenium and Mazus catch raindrops opportunistically, exploiting the subsequent splash to disperse their seeds. In this combined experimental and theoretical study, we elucidate their mechanism for maximizing dispersal distance. We fabricate conical plant mimics using three-dimensional printing, and use high-speed video to visualize splash profiles and seed travel distance. Drop impacts that strike the cup off-centre achieve the largest dispersal distances of up to 1 m. Such distances are achieved because splash speeds are three to five times faster than incoming drop speeds, and so faster than the traditionally studied splashes occurring upon horizontal surfaces. This anomalous splash speed is because of the superposition of two components of momentum, one associated with a component of the drop's motion parallel to the splash-cup surface, and the other associated with film spreading induced by impact with the splash-cup. Our model incorporating these effects predicts the observed dispersal distance within 6–18% error. According to our experiments, the optimal cone angle for the splash-cup is 40°, a value consistent with the average of five species of splash-cup plants. This optimal angle arises from the competing effects of velocity amplification and projectile launching angle. PMID:23235266

  15. The making of a splash

    KAUST Repository

    Thoroddsen, Sigurdur T

    2011-01-01

    The splash resulting from the impact of a drop onto a pool is a particularly beautiful manifestation of a canonical problem, where a mass of fluid breaks up into smaller pieces. Despite over a century of experimental study, the splashing mechanics

  16. Modification of booming level for higher correlation with booming sensation; Booming level no koseidoka

    Energy Technology Data Exchange (ETDEWEB)

    Hatano, S; Hashimoto, T [Seikei University, Tokyo (Japan)

    1997-10-01

    In our previous study, we proposed a objective measure, i.e., Booming Level for quantifying booming sensation caused by car interior noise. In this paper, Booming Level was modified with its weighting function and within the process of calculation 1/3 octave band level was modified for the best match with subjective result. These modifications were conducted through a subjective experiment rating booming sensation with sounds having much lower frequency contents below 63Hz. With this modified Booming Level, we have obtained higher correlation for rating booming sensation with sounds having prominent low frequency components. 1 ref., 10 figs.

  17. LASER APPLICATIONS AND OTHER TOPICS IN QUANTUM ELECTRONICS: Dynamics of splashing of molten metals during irradiation with single CO2 laser pulses

    Science.gov (United States)

    Arutyunyan, R. V.; Baranov, V. Yu; Bol'shov, Leonid A.; Dolgov, V. A.; Malyuta, D. D.; Mezhevov, V. S.; Semak, V. V.

    1988-03-01

    An experimental investigation was made of the dynamics of the loss of the melt as a result of interaction with single-mode CO2 laser radiation pulses of 5-35 μs duration. The dynamics of splashing of the melt during irradiation with short pulses characterized by a Gaussian intensity distribution differed from that predicted by models in which the distribution of the vapor pressure was assumed to be radially homogeneous.

  18. A benchmark study for the crown-type splashing dynamics of one- and two-component droplet wall-film interactions

    Science.gov (United States)

    Geppert, A.; Terzis, A.; Lamanna, G.; Marengo, M.; Weigand, B.

    2017-12-01

    The present paper investigates experimentally the impact dynamics of crown-type splashing for miscible two- and one-component droplet wall-film interactions over a range of Weber numbers and dimensionless film thicknesses. The splashing outcome is parametrised in terms of a set of quantifiable parameters, such as crown height, top and base diameter, wall inclination, number of fingers, and secondary droplet properties. The results show that the outcome of a splashing event is not affected by the choice of similar or dissimilar fluids, provided the dimensionless film thickness is larger than 0.1. Below this threshold, distinctive features of two-component interactions appear, such as hole formation and crown bottom breakdown. The observation of different crown shapes (e.g. V-shaped, cylindrical, and truncated-cone) confirms that vorticity production induces changes in the crown wall inclination, thus affecting the evolution of the crown height and top diameter. The evolution of the crown base diameter, instead, is mainly dependent on the relative importance of liquid inertia and viscous losses in the wall-film. The maximum number of liquid fingers decreases with increasing wall, film thickness, due to the enhanced attenuation of the effect of surface properties on the fingering process. The formation of secondary droplets is also affected by changes in the crown wall inclination. In particular, for truncated-cone shapes the occurrence of crown rim contraction induces a large scatter in the secondary droplet properties. Consequently, empirical models for the maximum number and mean diameter of the secondary droplets are derived for V-shaped crowns, as observed for the hexadecane-Hyspin interactions.

  19. MODEL CORRELATION STUDY OF A RETRACTABLE BOOM FOR A SOLAR SAIL SPACECRAFT

    Science.gov (United States)

    Adetona, O.; Keel, L. H.; Oakley, J. D.; Kappus, K.; Whorton, M. S.; Kim, Y. K.; Rakpczy, J. M.

    2005-01-01

    To realize design concepts, predict dynamic behavior and develop appropriate control strategies for high performance operation of a solar-sail spacecraft, we developed a simple analytical model that represents dynamic behavior of spacecraft with various sizes. Since motion of the vehicle is dominated by retractable booms that support the structure, our study concentrates on developing and validating a dynamic model of a long retractable boom. Extensive tests with various configurations were conducted for the 30 Meter, light-weight, retractable, lattice boom at NASA MSFC that is structurally and dynamically similar to those of a solar-sail spacecraft currently under construction. Experimental data were then compared with the corresponding response of the analytical model. Though mixed results were obtained, the analytical model emulates several key characteristics of the boom. The paper concludes with a detailed discussion of issues observed during the study.

  20. Managing Credit Booms and Busts : A Pigouvian Taxation Approach

    NARCIS (Netherlands)

    Jeanne, O.; Korinek, A.

    2010-01-01

    We study a dynamic model in which the interaction between debt ac- cumulation and asset prices magni es credit booms and busts. We find that borrowers do not internalize these feedback e¤ects and therefore suf- fer from excessively large booms and busts in both credit flows and asset prices. We show

  1. Measuring splash erosion potential under vegetation using sand-filled splash cups

    Science.gov (United States)

    Geißler, C.; Scholten, T.; Kühn, P.

    2009-04-01

    In soil erosion research it is widely accepted that vegetation is not only protecting the soil from the erosive power of rainfall. Under specific circumstances (like they occur e.g. in forests) vegetation can enhance the erosive power of rainfall by modifying its properties (esp. drop size distribution, kinetic energy). The adjacent processes are very complex and variable in time and space and depend on numerous variables (e.g. rainfall intensity, drop size distribution, drop fall velocity, height of the canopy, density of the canopy, crown and leaf traits, LAI). In the last decades a large number of studies focused this process-system using different methods and came to often different results (Brandt 1989; Calder 2001; Foot & Morgan 2005; Hall & Calder 1993; Mosley 1982; Nanko et al. 2006; Park & Cameron 2008; Vis 1986). The main objective of our field experiments in subtropical China is to quantify the modification of precipitation by its pass through the canopy layer for six different tree species, three different successional stages and three different biodiversity classes. For this, new splash cups were developed based on the archetype of Ellison (1947). In contrast to previous studies with splash cups (Vis 1986) or other forms of splash cups (Kinnell 1974; Morgan 1981) we measured the unit sand remaining inside the cup after single natural rainfall events. The new splash cups contain of a PE-flask to which a carrier system has been attached. In this carrier system a cup filled with unit sand of 125-200 µm particle size is inserted. At the bottom of the cup a silk cover is attached to avoid the loss of sand and to guarantee free drainage of water from the cup to the carrier and vice versa. Cup and PE-flask are hydraulically connected by a cotton wick to assure constant moisture content throughout the time of measuring. Additionally, vents in the carrier system ensure that the pressure arising from the insertion of the cup doesn't lead to a loss of sand. The

  2. Splash Safety During Dermatologic Procedures Among US Dermatology Residents.

    Science.gov (United States)

    Korta, Dorota Z; Chapman, Lance W; Lee, Patrick K; Linden, Kenneth G

    2017-07-01

    Dermatologists are at potential risk of acquiring infections from contamination of the mucous membranes by blood and body fluids. However, there are little data on splash safety during procedural dermatology. To determine dermatology resident perceptions about splash risk during dermatologic procedures and to quantify the rate of protective equipment use. An anonymous on-line survey was sent to 108 United States ACGME-approved dermatology residency programs assessing frequency of facial protection during dermatologic procedures, personal history of splash injury, and, if applicable, reasons for not always wearing facial protection. A total of 153 dermatology residents responded. Rates of facial protection varied by procedure, with the highest rates during surgery and the lowest during local anesthetic injection. Over 54% of respondents reported suffering facial splash while not wearing facial protection during a procedure. In contrast, 88.9% of respondents correctly answered that there is a small risk of acquiring infection from mucosal splash. Residency program recommendations for facial protection seem to vary by procedure. The authors' results demonstrate that although facial splash is a common injury, facial protection rates and protective recommendations vary significantly by procedure. These data support the recommendation for enhanced facial protection guidelines during procedural dermatology.

  3. State of the art of sonic boom modeling

    Science.gov (United States)

    Plotkin, Kenneth J.

    2002-01-01

    Based on fundamental theory developed through the 1950s and 1960s, sonic boom modeling has evolved into practical tools. Over the past decade, there have been requirements for design tools for an advanced supersonic transport, and for tools for environmental assessment of various military and aerospace activities. This has resulted in a number of advances in the understanding of the physics of sonic booms, including shock wave rise times, propagation through turbulence, and blending sonic boom theory with modern computational fluid dynamics (CFD) aerodynamic design methods. This article reviews the early fundamental theory, recent advances in theory, and the application of these advances to practical models.

  4. Boundary-layer effects in droplet splashing

    Science.gov (United States)

    Riboux, Guillaume; Gordillo, Jose Manuel

    2017-11-01

    A drop falling onto a solid substrate will disintegrate into smaller parts when its impact velocity exceeds the so called critical velocity for splashing. Under these circumstances, the very thin liquid sheet ejected tangentially to the solid after the drop touches the substrate, lifts off as a consequence of the aerodynamic forces exerted on it and finally breaks into smaller droplets, violently ejected radially outwards, provoking the splash. Here, the tangential deceleration experienced by the fluid entering the thin liquid sheet is investigated making use of boundary layer theory. The velocity component tangent to the solid, computed using potential flow theory provides the far field boundary condition as well as the pressure gradient for the boundary layer equations. The structure of the flow permits to find a self similar solution of the boundary layer equations. This solution is then used to calculate the boundary layer thickness at the root of the lamella as well as the shear stress at the wall. The splash model presented in, which is slightly modified to account for the results obtained from the boundary layer analysis, provides a very good agreement between the measurements and the predicted values of the critical velocity for the splash.

  5. Booming Sand Dunes

    Science.gov (United States)

    Vriend, Nathalie

    "Booming" sand dunes are able to produce low-frequency sound that resembles a pure note from a music instrument. The sound has a dominant audible frequency (70-105 Hz) and several higher harmonics and may be heard from far distances away. A natural or induced avalanche from a slip face of the booming dune triggers the emission that may last for several minutes. There are various references in travel literature to the phenomenon, but to date no scientific explanation covered all field observations. This thesis introduces a new physical model that describes the phenomenon of booming dunes. The waveguide model explains the selection of the booming frequency and the amplification of the sound in terms of constructive interference in a confined geometry. The frequency of the booming is a direct function of the dimensions and velocities in the waveguide. The higher harmonics are related to the higher modes of propagation in the waveguide. The experimental validation includes quantitative field research at the booming dunes of the Mojave Desert and Death Valley National Park. Microphone and geophone recordings of the acoustic and seismic emission show a variation of booming frequency in space and time. The analysis of the sensor data quantifies wave propagation characteristics such as speed, dispersion, and nonlinear effects and allows the distinction between the source mechanism of the booming and the booming itself. The migration of sand dunes results from a complicated interplay between dune building, wind regime, and precipitation. The morphological and morphodynamical characteristics of two field locations are analyzed with various geophysical techniques. Ground-penetrating radar images the subsurface structure of the dunes and reveal a natural, internal layering that is directly related to the history of dune migration. The seismic velocity increases abruptly with depth and gradually increases with downhill position due to compaction. Sand sampling shows local

  6. Wavelength selection in the crown splash

    Science.gov (United States)

    Zhang, Li V.; Brunet, Philippe; Eggers, Jens; Deegan, Robert D.

    2010-12-01

    The impact of a drop onto a liquid layer produces a splash that results from the ejection and dissolution of one or more liquid sheets, which expand radially from the point of impact. In the crown splash parameter regime, secondary droplets appear at fairly regularly spaced intervals along the rim of the sheet. By performing many experiments for the same parameter values, we measure the spectrum of small-amplitude perturbations growing on the rim. We show that for a range of parameters in the crown splash regime, the generation of secondary droplets results from a Rayleigh-Plateau instability of the rim, whose shape is almost cylindrical. In our theoretical calculation, we include the time dependence of the base state. The remaining irregularity of the pattern is explained by the finite width of the Rayleigh-Plateau dispersion relation. Alternative mechanisms, such as the Rayleigh-Taylor instability, can be excluded for the experimental parameters of our study.

  7. Drop splashing: the role of surface wettability and liquid viscosity

    Science.gov (United States)

    Almohammadi, Hamed; Amirfazli, Alidad; -Team

    2017-11-01

    There are seemingly contradictory results in the literature about the role of surface wettability and drop viscosity for the splashing behavior of a drop impacting onto a surface. Motivated by such issues, we conducted a systematic experimental study where splashing behavior for a wide range of the liquid viscosity (1-100 cSt) and surface wettability (hydrophilic to hydrophobic) are examined. The experiments were performed for the liquids with both low and high surface tensions ( 20 and 72 mN/m). We found that the wettability affects the splashing threshold at high or low contact angle values. At the same drop velocity, an increase of the viscosity (up to 4 cSt) promotes the splashing; while, beyond such value, any increase in viscosity shows the opposite effect. It is also found that at a particular combination of liquid surface tension and viscosity (e.g. silicone oil, 10 cSt), an increase in the drop velocity changes the splashing to spreading. We relate such behaviors to the thickness, shape, and the velocity of the drop's lamella. Finally, to predict the splashing, we developed an empirical correlation which covers all of the previous reported data, hence clarifying the ostensible existing contradictions.

  8. Sonic boom predictions using a modified Euler code

    Science.gov (United States)

    Siclari, Michael J.

    1992-04-01

    The environmental impact of a next generation fleet of high-speed civil transports (HSCT) is of great concern in the evaluation of the commercial development of such a transport. One of the potential environmental impacts of a high speed civilian transport is the sonic boom generated by the aircraft and its effects on the population, wildlife, and structures in the vicinity of its flight path. If an HSCT aircraft is restricted from flying overland routes due to excessive booms, the commercial feasibility of such a venture may be questionable. NASA has taken the lead in evaluating and resolving the issues surrounding the development of a high speed civilian transport through its High-Speed Research Program (HSRP). The present paper discusses the usage of a Computational Fluid Dynamics (CFD) nonlinear code in predicting the pressure signature and ultimately the sonic boom generated by a high speed civilian transport. NASA had designed, built, and wind tunnel tested two low boom configurations for flight at Mach 2 and Mach 3. Experimental data was taken at several distances from these models up to a body length from the axis of the aircraft. The near field experimental data serves as a test bed for computational fluid dynamic codes in evaluating their accuracy and reliability for predicting the behavior of future HSCT designs. Sonic boom prediction methodology exists which is based on modified linear theory. These methods can be used reliably if near field signatures are available at distances from the aircraft where nonlinear and three dimensional effects have diminished in importance. Up to the present time, the only reliable method to obtain this data was via the wind tunnel with costly model construction and testing. It is the intent of the present paper to apply a modified three dimensional Euler code to predict the near field signatures of the two low boom configurations recently tested by NASA.

  9. SPLASH-SXDF Multi-wavelength Photometric Catalog

    Science.gov (United States)

    Mehta, Vihang; Scarlata, Claudia; Capak, Peter; Davidzon, Iary; Faisst, Andreas; Hsieh, Bau Ching; Ilbert, Olivier; Jarvis, Matt; Laigle, Clotilde; Phillips, John; Silverman, John; Strauss, Michael A.; Tanaka, Masayuki; Bowler, Rebecca; Coupon, Jean; Foucaud, Sébastien; Hemmati, Shoubaneh; Masters, Daniel; McCracken, Henry Joy; Mobasher, Bahram; Ouchi, Masami; Shibuya, Takatoshi; Wang, Wei-Hao

    2018-04-01

    We present a multi-wavelength catalog in the Subaru/XMM-Newton Deep Field (SXDF) as part of the Spitzer Large Area Survey with Hyper-Suprime-Cam (SPLASH). We include the newly acquired optical data from the Hyper-Suprime-Cam Subaru Strategic Program, accompanied by IRAC coverage from the SPLASH survey. All available optical and near-infrared data is homogenized and resampled on a common astrometric reference frame. Source detection is done using a multi-wavelength detection image including the u-band to recover the bluest objects. We measure multi-wavelength photometry and compute photometric redshifts as well as physical properties for ∼1.17 million objects over ∼4.2 deg2, with ∼800,000 objects in the 2.4 deg2 HSC-Ultra-Deep coverage. Using the available spectroscopic redshifts from various surveys over the range of 0 fraction of 3.2%. The SPLASH-SXDF catalog is a valuable, publicly available resource, perfectly suited for studying galaxies in the early universe and tracing their evolution through cosmic time.

  10. X-Boom, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed X-Boom is an innovation on rollable boom design directly relevant to NASA SBIR topic H5.01, Deployable Structures. The X-boom is a rollable Carbon Fiber...

  11. Numerical analysis of splashing fluid using hybrid method of mesh-based and particle-based modelings

    International Nuclear Information System (INIS)

    Tanaka, Nobuatsu; Ogawara, Takuya; Kaneda, Takeshi; Maseguchi, Ryo

    2009-01-01

    In order to simulate splashing and scattering fluid behaviors, we developed a hybrid method of mesh-based model for large-scale continuum fluid and particle-based model for small-scale discrete fluid particles. As for the solver of the continuum fluid, we adopt the CIVA RefIned Multiphase SimulatiON (CRIMSON) code to evaluate two phase flow behaviors based on the recent computational fluid dynamics (CFD) techniques. The phase field model has been introduced to the CRIMSON in order to solve the problem of loosing phase interface sharpness in long-term calculation. As for the solver of the discrete fluid droplets, we applied the idea of Smoothed Particle Hydrodynamics (SPH) method. Both continuum fluid and discrete fluid interact each other through drag interaction force. We verified our method by applying it to a popular benchmark problem of collapse of water column problems, especially focusing on the splashing and scattering fluid behaviors after the column collided against the wall. We confirmed that the gross splashing and scattering behaviors were well reproduced by the introduction of particle model while the detailed behaviors of the particles were slightly different from the experimental results. (author)

  12. Realism Assessment of Sonic Boom Simulators

    Science.gov (United States)

    Sullivan, Brenda M.; Davies, Patrica; Hodgdon, Kthleen K.; Salamone, Joseph A., III; Pilon, Anthony

    2008-01-01

    Developments in small supersonic aircraft design are predicted to result in low-intensity sonic booms. Booms generated by current aircraft are similar to those that led to the ban on commercial supersonic fli ght over the US, so are unsuitable for parametric studies of psychoac oustic response to low-intensity booms. Therefore, simulators have be en used to study the impact of predicted low-intensity sonic booms. H owever, simulators have been criticized because, when simulating conv entional-level booms, the sounds were observed to be unrealistic by p eople experienced in listening to sonic booms. Thus, two studies were conducted to measure the perceived realism of three sonic boom simul ators. Experienced listeners rated the realism of conventional sonic boom signatures when played in these simulators. The effects on percei ved realism of factors such as duration of post-boom noise, exclusion of very low frequency components, inclusion of ground reflections, a nd type of simulator were examined. Duration of post-boom noise was f ound to have a strong effect on perceived realism, while type of simu lator had a weak effect. It was determined that post-boom noise had t o be at least 1.5 seconds long for the sound to be rated very realist ic. Loudness level did not affect realism for the range of sounds pla yed in the tests (80-93 dB ASEL).

  13. Water Quality Survey of Splash Pads After A Waterborne Salmonellosis Outbreak--Tennessee, 2014.

    Science.gov (United States)

    Clayton, Joshua L; Manners, Judy; Miller, Susan; Shepherd, Craig; Dunn, John R; Schaffner, William; Jones, Timothy F

    2017-06-01

    Waterborne outbreaks of salmonellosis are uncommon. The Tennessee Department of Health investigated a salmonellosis outbreak of 10 cases with the only common risk factor being exposure to a single splash pad. Risks included water splashed in the face at the splash pad and no free residual chlorine in the water system. We surveyed water quality and patron behaviors at splash pads statewide. Of the 29 splash pads participating in the water quality survey, 24 (83%) used a recirculating water system. Of the 24, 5 (21%) water samples were tested by polymerase chain reaction and found to be positive for E. coli, Giardia, norovirus, or Salmonella. Among 95 patrons observed, we identified common high-risk behaviors of sitting on the fountain or spray head and putting mouth to water. Water venue regulations and improved education of patrons are important to aid prevention efforts.

  14. Drop impact splashing and air entrapment

    KAUST Repository

    Thoraval, Marie-Jean

    2013-03-01

    Drop impact is a canonical problem in fluid mechanics, with numerous applications in industrial as well as natural phenomena. The extremely simple initial configuration of the experiment can produce a very large variety of fast and complex dynamics. Scientific progress was made in parallel with major improvements in imaging and computational technologies. Most recently, high-speed imaging video cameras have opened the exploration of new phenomena occurring at the micro-second scale, and parallel computing allowed realistic direct numerical simulations of drop impacts. We combine these tools to bring a new understanding of two fundamental aspects of drop impacts: splashing and air entrapment. The early dynamics of a drop impacting on a liquid pool at high velocity produces an ejecta sheet, emerging horizontally in the neck between the drop and the pool. We show how the interaction of this thin liquid sheet with the air, the drop or the pool, can produce micro-droplets and bubble rings. Then we detail how the breakup of the air film stretched between the drop and the pool for lower impact velocities can produce a myriad of micro-bubbles.

  15. Modeling and simulation of the agricultural sprayer boom leveling system

    KAUST Repository

    Sun, Jian

    2011-01-01

    According to the agricultural precision requirements, the distance from sprayer nozzles to the corps should be kept between 50 cm to 70 cm. The sprayer boom also needs to be kept parallel to the field during the application process. Thus we can guarantee the quality of the chemical droplets distribution on the crops. In this paper we design a sprayer boom leveling system for agricultural sprayer vehicles combined with a four-rod linkage self-leveling suspension and electro-hydraulic auto-leveling system. The dynamic analysis shows that the suspension can realize an excellent self-leveling in a comparative small inclination range. In addition we build compensation controller for the electro-hydraulic system based on the mathematical model. With simulations we can optimize the performance of this controller to make sure a fast leveling response to the inclined sprayer boom. © 2011 IEEE.

  16. Theory and experimental validation of SPLASH (Single Panel Lamp and Shroud Helper).

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, Marvin Elwood; Porter, Jason M.

    2005-06-01

    The radiant heat test facility develops test sets providing well-characterized thermal environments, often representing fires. Many of the components and procedures have become standardized to such an extent that the development of a specialized design tool was appropriate. SPLASH (Single Panel Lamp and Shroud Helper) is that tool. SPLASH is implemented as a user-friendly program that allows a designer to describe a test setup in terms of parameters such as lamp number, power, position, and separation distance. Thermal radiation is the dominant mechanism of heat transfer and the SPLASH model solves a radiation enclosure problem to estimate temperature distributions in a shroud providing the boundary condition of interest. Irradiance distribution on a specified viewing plane is also estimated. This document provides the theoretical development for the underlying model. A series of tests were conducted to characterize SPLASH's ability to analyze lamp and shroud systems. The comparison suggests that SPLASH succeeds as a design tool. Simplifications made to keep the model tractable are demonstrated to result in estimates that are only approximately as uncertain as many of the properties and characteristics of the operating environment.

  17. Structural analysis of oil containment booms

    International Nuclear Information System (INIS)

    Badesha, S.S.; Hunt, J.; Wenck, E.

    1993-01-01

    In recent years, major oil spills, such as the Exxon Valdez incident, and many smaller spills have given rise to a worldwide marine environmental concern. One of the most successful devices for containing and facilitating the recovery of spilled oil, and one which does not endanger or alter the environment in any way, is the oil containment boom. Described in this paper is a finite element (FE)-based method for structural analysis of oil booms. In general, a number of FE models for a typical oil boom section are set up using the COSMOS FEA code. These models differ from one another in oil boom geometry, deployment configurations, and oil boom components. The FEA (fimite element analysis) models are made from the plate elements (skirt and tube), truss elements (tension members and ballast chain), and beam elements (end connector). Loads due to tow/current velocity, wind velocity, wave action, and ballasting, as determined from aero/hydrodynamics analysis, are applied as distributed pressures on the plate and beam elements. This method will predict boom tensile load strength, detailed stress distribution, and distortion characteristics for a particular boom with specific deployment configuration and environmental condition. The derived information can be used to highlight critical design features, thereby optimizing the oil boom design. Alternatively, this information can be used for the selection of an oil boom suited for a particular application and, more importantly, can provide the user with a control evaluation tool to determine whether a given oil boom design can withstand the stresses of its intended application

  18. Roughness influence on human blood drop spreading and splashing

    Science.gov (United States)

    Smith, Fiona; Buntsma, Naomi; Brutin, David

    2017-11-01

    The impact behaviour of complex fluid droplets is a topic that has been extensively studied but with much debate. The Bloodstain Pattern Analysis (BPA) community is encountering this scientific problem with daily practical cases since they use bloodstains as evidence in crime scene reconstruction. We aim to provide fundamental explanations in the study of blood drip stains by investigating the influence of surface roughness and wettability on the splashing limit of droplets of blood, a non-Newtonian colloidal fluid. Droplets of blood impacting perpendicularly different surfaces at different velocities were recorded. The recordings were analysed as well as the surfaces characteristics in order to find an empirical solution since we found that roughness plays a major role in the threshold of the splashing/non-splashing behaviour of blood compared to the wettability. Moreover it appears that roughness alters the deformation of the drip stains. These observations are key in characterising features of drip stains with the impacting conditions, which would answer some forensic issues.

  19. Complexities of splashing

    International Nuclear Information System (INIS)

    Deegan, R D; Brunet, P; Eggers, J

    2008-01-01

    We study the impact of a drop of liquid onto a thin layer of the same liquid. We give an overview of the sequence of events that occur as the two most important dimensionless control parameters are varied. In particular, multiple cohorts of droplets can be ejected at different stages after impact due to different mechanisms. Edgerton's famous Milkdrop Coronet is only observed for a narrow range of parameters. Outside this range, the splash is either qualitatively different, or suffers from a much lower level of regularity. (cover illustration)

  20. Evaluation of Droplet Splashing Algorithm in LEWICE 3.0

    Science.gov (United States)

    Homenko, Hilary N.

    2004-01-01

    The Icing Branch at NASA Glenn Research has developed a computer program to simulate ice formation on the leading edge of an aircraft wing during flight through cold, moist air. As part of the branch's current research, members have developed software known as LEWICE. This program is capable of predicting the formation of ice under designated weather conditions. The success of LEWICE is an asset to airplane manufacturers, ice protection system manufacturers, and the airline industry. Simulations of ice formation conducted in the tunnel and in flight is costly and time consuming. However, the danger of in-flight icing continues to be a concern for both commercial and military pilots. The LEWICE software is a step towards inexpensive and time efficient prediction of ice collection. In the most recent version of the program, LEWICE contains an algorithm for droplet splashing. Droplet splashing is a natural occurrence that causes accumulation of ice on aircraft surfaces. At impingement water droplets lose a portion of their mass to splashing. With part of each droplet joining the airflow and failing to freeze, early versions of LEWICE without the splashing algorithm over-predicted the collection of ice on the leading edge. The objective of my project was to determine whether the revised version of LEWICE accurately reflected the ice collection data obtained from the Icing Research Tunnel (IRT). The experimental data from the IRT was collected by Mark Potapczuk in January, March and July of 2001 and April and December of 2002. Experimental data points were the result of ice tracings conducted shortly after testing in the tunnel. Run sheets, which included a record of velocity, temperature, liquid water content and droplet diameter, served as the input of the LEWICE computer program. Parameters identical to the tunnel conditions were used to run LEWICE 2.0 and LEWICE 3.0. The results from IRT and versions of LEWICE were compared graphically. After entering the raw

  1. High-Quality Seismic Observations of Sonic Booms

    Science.gov (United States)

    Wurman, Gilead; Haering, Edward A., Jr.; Price, Michael J.

    2011-01-01

    The SonicBREWS project (Sonic Boom Resistant Earthquake Warning Systems) is a collaborative effort between Seismic Warning Systems, Inc. and NASA Dryden Flight Research Center. This project aims to evaluate the effects of sonic booms on Earthquake Warning Systems in order to prevent such systems from experiencing false alarms due to sonic booms. The airspace above the Antelope Valley, California includes the High Altitude Supersonic Corridor and the Black Mountain Supersonic Corridor. These corridors are among the few places in the US where supersonic flight is permitted, and sonic booms are commonplace in the Antelope Valley. One result of this project is a rich dataset of high-quality accelerometer records of sonic booms which can shed light on the interaction between these atmospheric phenomena and the solid earth. Nearly 100 sonic booms were recorded with low-noise triaxial MEMS accelerometers recording 1000 samples per second. The sonic booms had peak overpressures ranging up to approximately 10 psf and were recorded in three flight series in 2010 and 2011. Each boom was recorded with up to four accelerometers in various array configurations up to 100 meter baseline lengths, both in the built environment and the free field. All sonic booms were also recorded by nearby microphones. We present the results of the project in terms of the potential for sonic-boom-induced false alarms in Earthquake Warning Systems, and highlight some of the interesting features of the dataset.

  2. Are splash plumes the origin of minor hotspots?

    Science.gov (United States)

    Davies, J. H.; Bunge, H.-P.

    2006-05-01

    It has been claimed that focused hot cylindrical upwelling plumes cause many of the surface volcanic hotspots on Earth. It has also been argued that they must originate from thermal boundary layers. In this paper, we present spherical simulations of mantle circulation at close to Earth-like vigor with significant internal heating. These show, in addition to thermal boundary layer plumes, a new class of plumes that are not rooted in thermal boundary layers. These plumes develop as instabilities from the edge of bowls of hot mantle, which are produced by cold downwelling material deforming hot sheets of mantle. The resulting bowl and plume structure can look a bit like the “splash” of a water droplet. These splash plumes might provide an explanation for some hotspots that are not underlain by thermal boundary layer sourced plumes and not initiated by large igneous provinces. We suggest that in Earth's mantle, lithospheric instabilities or small pieces of subducting slab could play the role of the model downwelling material in initiating splash plumes. Splash plumes would have implications for interpreting ocean-island basalt geochemistry, plume fixity, excess plume temperature, and estimating core heat flux. Improved seismic imaging will ultimately test this hypothesis.

  3. User manual for SPLASH (Single Panel Lamp and Shroud Helper).

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, Marvin Elwood

    2006-02-01

    The radiant heat test facility develops test sets providing well-characterized thermal environments, often representing fires. Many of the components and procedures have become standardized to such an extent that the development of a specialized design tool to determine optimal configurations for radiant heat experiments was appropriate. SPLASH (Single Panel Lamp and Shroud Helper) is that tool. SPLASH is implemented as a user-friendly, Windows-based program that allows a designer to describe a test setup in terms of parameters such as number of lamps, power, position, and separation distance. This document is a user manual for that software. Any incidental descriptions of theory are only for the purpose of defining the model inputs. The theory for the underlying model is described in SAND2005-2947 (Ref. [1]). SPLASH provides a graphical user interface to define lamp panel and shroud designs parametrically, solves the resulting radiation enclosure problem for up to 2500 surfaces, and provides post-processing to facilitate understanding and documentation of analyzed designs.

  4. Recent Progress on Sonic Boom Research at NASA

    Science.gov (United States)

    Loubeau, Alexandra

    2012-01-01

    Sonic boom research conducted at NASA through the Supersonics Project of the Fundamental Aeronautics Program is oriented toward understanding the potential impact of sonic boom noise on communities from new low-boom supersonic aircraft designs. Encompassing research in atmospheric propagation, structural response, and human response, NASA research contributes to knowledge in key areas needed to support development of a new noise-based standard for supersonic aircraft certification. Partnerships with several industry, government, and academic institutions have enabled the recent execution of several acoustic field studies on sonic booms. An overview of recent activities funded by NASA includes: focus boom model development and experimental validation, field experiments of structural transmission of sonic booms into large buildings, and low boom community response testing.

  5. Analysis of Nozzle Jet Plume Effects on Sonic Boom Signature

    Science.gov (United States)

    Bui, Trong

    2010-01-01

    An axisymmetric full Navier-Stokes computational fluid dynamics (CFD) study was conducted to examine nozzle exhaust jet plume effects on the sonic boom signature of a supersonic aircraft. A simplified axisymmetric nozzle geometry, representative of the nozzle on the NASA Dryden NF-15B Lift and Nozzle Change Effects on Tail Shock (LaNCETS) research airplane, was considered. The highly underexpanded nozzle flow is found to provide significantly more reduction in the tail shock strength in the sonic boom N-wave pressure signature than perfectly expanded and overexpanded nozzle flows. A tail shock train in the sonic boom signature, similar to what was observed in the LaNCETS flight data, is observed for the highly underexpanded nozzle flow. The CFD results provide a detailed description of the nozzle flow physics involved in the LaNCETS nozzle at different nozzle expansion conditions and help in interpreting LaNCETS flight data as well as in the eventual CFD analysis of a full LaNCETS aircraft. The current study also provided important information on proper modeling of the LaNCETS aircraft nozzle. The primary objective of the current CFD research effort was to support the LaNCETS flight research data analysis effort by studying the detailed nozzle exhaust jet plume s imperfect expansion effects on the sonic boom signature of a supersonic aircraft. Figure 1 illustrates the primary flow physics present in the interaction between the exhaust jet plume shock and the sonic boom coming off of an axisymmetric body in supersonic flight. The steeper tail shock from highly expanded jet plume reduces the dip of the sonic boom N-wave signature. A structured finite-volume compressible full Navier-Stokes CFD code was used in the current study. This approach is not limited by the simplifying assumptions inherent in previous sonic boom analysis efforts. Also, this study was the first known jet plume sonic boom CFD study in which the full viscous nozzle flow field was modeled, without

  6. Basin sidewall effects during comparable boom testing

    International Nuclear Information System (INIS)

    DeVitis, D.S.; Hannon, L.

    1995-01-01

    A quantitative investigation of the effects of boom sidewall clearance during first and gross oil loss speed tests was discussed. A second measure of sidewall was quantified in terms of flow characteristics at specific location in the boom apex. The test boom was rigged in 5 different configurations. First oil loss and gross oil loss tow speeds, and relative horizontal flow velocities within the boom apex were obtained for each configuration. Flow velocities of 0.5 to 1.5 knots in 0.25 knot increments were measured. Flow velocities illustrated similar flow characteristics within the apex regardless of side wall clearance. The results of the study illustrated that boom to basin sidewall clearance may be an independent test parameter without a significant bias. 5 tabs., 8 figs.,

  7. UNDESIRED SPLASH OVER ON EQUIPMENTS USING INDUCTIVE SENSORS FOR MONITORING AUTOMOTIVE VEHICLES' CONTROLLED SPEED

    Directory of Open Access Journals (Sweden)

    Silvio Monteiro

    Full Text Available This article aims to evaluate instruments that oversight traffic flow electronically, using inductive surface sensors, based on the change of local magnetic field. More specifically, we study the possibility of false speed detections, due to the manifestation of the phenomenon called splash over - which means a space splash of the magnetic field lines out of the measuring zone. We show, through the literature, and practical simulations, the damage that can be caused by splash on the correct speed measurement and identification of the car under suspicions. It is also presented solutions to inhibiting unwanted velocity measurements due to this effect.

  8. Swarm Deployable Boom Assembly (DBA) Development of a Deployable Magnetometer Boom for the Swarm Spacecraft

    Science.gov (United States)

    McMahon, Paul; Jung, Hans-Juergen; Edwards, Jeff

    2013-09-01

    The Swarm programme consists of 3 magnetically clean satellites flying in close formation designed to measure the Earth's magnetic field using 2 Magnetometers mounted on a 4.3m long deployable boom.Deployment is initiated by releasing 3 HDRMs, once released the boom oscillates back and forth on a pair of pivots, similar to a restaurant kitchen door hinge, for around 120 seconds before coming to rest on 3 kinematic mounts which are used to provide an accurate reference location in the deployed position. Motion of the boom is damped through a combination of friction, spring hysteresis and flexing of the 120+ cables crossing the hinge. Considerable development work and accurate numerical modelling of the hinge motion was required to predict performance across a wide temperature range and ensure that during the 1st overshoot the boom did not damage itself, the harness or the spacecraft.Due to the magnetic cleanliness requirements of the spacecraft no magnetic materials could be used in the design of the hardware.

  9. A natural ice boom

    Energy Technology Data Exchange (ETDEWEB)

    Hopper, H.R. [Manitoba Hydro, Winnipeg, MB (Canada)

    1998-10-01

    Planning for ice jams and ice movements are critical on the Nelson River in northern Manitoba in designing cofferdams. Experience on the St. Lawrence River demonstrated the possibility of exercising some control over ice action by judicious placement of log booms or ice control structures. The success of experiments with man-made controls led to field tests in which an ice sheet of sufficient magnitude and competence was introduced into the open water stream of the Nelson River. The ice sheet was subsequently jammed in a narrow channel, thereby creating a natural ice bridge or boom upstream of a proposed hydro development. Under favourable conditions, this boom would initiate the progression of the ice cover from its location upstream, cutting off the downstream reach from the ice producing potential of the upstream reach. Although ice would still be generated downstream, the length of the reach between the ice boom and the development site would be short enough that ice jamming at the development site would never occur. Although problems in blasting prevented the introduction of a competent ice sheet into the main stream of the river at the location chosen, sufficient confidence in the theory was gained to warrant further consideration. 4 refs., 1 tab., 10 figs.

  10. Domestic Crop Booms, Livelihood Pathways and Nested Transitions: Charting the Implications of Bangladesh’s Pangasius Boom

    NARCIS (Netherlands)

    Belton, B.; Asseldonk, van I.J.M.; Bush, S.R.

    2017-01-01

    Rapidly transforming Asian food systems are oriented largely towards domestic markets, yet literature on Asian crop booms deals almost exclusively with commodities produced for export. With reference to pangasius aquaculture in Bangladesh, we argue that ‘domestic crop booms’ - agricultural booms

  11. Distribution and function of splash, an achaete-scute homolog in the adult olfactory organ of the Caribbean spiny lobster Panulirus argus

    Science.gov (United States)

    Tadesse, Tizeta; Schmidt, Manfred; Walthall, William W.; Tai, Phang C.; Derby, Charles D.

    2011-01-01

    achaete-scute complex (ASC) genes, which encode basic helix-loop-helix transcription factors, regulate embryonic and adult neurogenesis in many animals. In adult arthropods, including crustaceans, ASC homologs have been identified but rarely functionally characterized. We took advantage of the recently identified crustacean homolog, splash (spiny lobster achaete scute homolog), in the olfactory organ of the Caribbean spiny lobster Panulirus argus to examine its role in adult neurogenesis. We tested the hypothesis that splash is associated with but not restricted to sensory neuron formation in the olfactory organ, the antennular lateral flagellum (LF), of adult spiny lobsters. We demonstrated splash labeling in epithelial cells across LF developmental zones (i.e., proliferation and mature zones), in auxiliary cells surrounding dendrites of olfactory receptor neurons (ORNs), and in immature and mature ORNs, but not in granulocytes or chromatophores. Since ORN proliferation varies with molt stage, we examined splash expression across molt stages and found that molt stage affected splash expression in the ORN mature zone but not in the proliferation zone. In vivo incorporation of bromodeoxyuridine (BrdU) showed no correlation in the cellular pattern of splash expression and BrdU labeling. The intensity of splash labeling was dramatically enhanced in the proliferation zones following LF damage, suggesting enhanced splash expression during repair and/or regeneration. We conclude that splash is not closely associated with the formation of sensory neurons under normal physiological conditions, and we propose that splash is involved in repair and regeneration. We also propose that splash has additional roles other than neurogenesis in adult crustaceans. PMID:21394934

  12. Testing fire resistant boom in waves and flames

    International Nuclear Information System (INIS)

    McCourt, J.; Buist, I.; Pratte, B.; Jamieson, W.; Mullin, J.

    1997-01-01

    A near full-scale screening test to evaluate the durability and ability of refractory-fabric fire resistant booms to contain oil during an in-situ burn without the environmental problems of burning crude oil or the cost of testing offshore, was developed. The boom was first flexed under tension for two hours, then deployed in a U-configuration in an outdoor wave tank. Propane gas was burned in the pocket of the boom to simulate the collection and burning phases of an in-situ burn. Finally, the boom was returned to the indoor wave flume for another two hours of wave action and then inspected for damage. Results indicated damage of the same type as suffered in previously conducted sea trials, although the extent of damage was less severe. These results led to recommendations for improvement of the test protocol which included: (1) increasing the heat flux to the boom, (2) improving the heat flux measurement, (3) increasing the tension in the fire boom during flame testing, and (4) improving the characterization of the waves near the fire boom. 16 refs., 6 figs

  13. Waveforms and Sonic Boom Perception and Response (WSPR): Low-Boom Community Response Program Pilot Test Design, Execution, and Analysis

    Science.gov (United States)

    Page, Juliet A.; Hodgdon, Kathleen K.; Krecker, Peg; Cowart, Robbie; Hobbs, Chris; Wilmer, Clif; Koening, Carrie; Holmes, Theresa; Gaugler, Trent; Shumway, Durland L.; hide

    2014-01-01

    The Waveforms and Sonic boom Perception and Response (WSPR) Program was designed to test and demonstrate the applicability and effectiveness of techniques to gather data relating human subjective response to multiple low-amplitude sonic booms. It was in essence a practice session for future wider scale testing on naive communities, using a purpose built low-boom demonstrator aircraft. The low-boom community response pilot experiment was conducted in California in November 2011. The WSPR team acquired sufficient data to assess and evaluate the effectiveness of the various physical and psychological data gathering techniques and analysis methods.

  14. Del Boom y otras onomatopeyas literarias

    Directory of Open Access Journals (Sweden)

    Jorge Iván Parra Londoño

    2016-03-01

    Full Text Available Este artículo trata de examinar los alcances literarios del llamado Boom latinoamericano, a medio siglo de su estallido, las cuatro obras más representativas y sus respectivos autores, además de proponer un quinto autor, según la invitación que hiciera en su momento el crítico Ángel Rama. Por otro lado, evalua la respuesta literaria por parte del Post Boom, analizando sus características y su vigencia y, de manera concomitante, los movimientos anejos o posteriores a dicho movimiento, como el Crack y la Generación Granta. A manera de propuesta, se pondrán a consideración treinta autores como integrantes del Post Boom y una novela de Carlos Fuentes como el “crash” del Boom. Por último, presenta un breve vistazo a la narrativa española paralela a los mencionados movimientos.

  15. COVER ILLUSTRATION: Complexities of splashing

    Science.gov (United States)

    Deegan, R. D.; Brunet, P.; Eggers, J.

    2008-01-01

    We study the impact of a drop of liquid onto a thin layer of the same liquid. We give an overview of the sequence of events that occur as the two most important dimensionless control parameters are varied. In particular, multiple cohorts of droplets can be ejected at different stages after impact due to different mechanisms. Edgerton's famous Milkdrop Coronet is only observed for a narrow range of parameters. Outside this range, the splash is either qualitatively different, or suffers from a much lower level of regularity.

  16. The Effect of Sonic Booms on Earthquake Warning Systems

    Science.gov (United States)

    Wurman, Gilead; Haering, Edward A, Jr.; Price, Michael J.

    2011-01-01

    Several aerospace companies are designing quiet supersonic business jets for service over the United States. These aircraft have the potential to increase the occurrence of mild sonic booms across the country. This leads to interest among earthquake warning (EQW) developers and the general seismological community in characterizing the effect of sonic booms on seismic sensors in the field, their potential impact on EQW systems, and means of discriminating their signatures from those of earthquakes. The SonicBREWS project (Sonic Boom Resistant Earthquake Warning Systems) is a collaborative effort between Seismic Warning Systems, Inc. (SWS) and NASA Dryden Flight Research Center. This project aims to evaluate the effects of sonic booms on EQW sensors. The study consists of exposing high-sample-rate (1000 sps) triaxial accelerometers to sonic booms with overpressures ranging from 10 to 600 Pa in the free field and the built environment. The accelerometers record the coupling of the sonic boom to the ground and surrounding structures, while microphones record the acoustic wave above ground near the sensor. Sonic booms are broadband signals with more high-frequency content than earthquakes. Even a 1000 sps accelerometer will produce a significantly aliased record. Thus the observed peak ground velocity is strongly dependent on the sampling rate, and increases as the sampling rate is reduced. At 1000 sps we observe ground velocities that exceed those of P-waves from ML 3 earthquakes at local distances, suggesting that sonic booms are not negligible for EQW applications. We present the results of several experiments conducted under SonicBREWS showing the effects of typical-case low amplitude sonic booms and worst-case high amplitude booms. We show the effects of various sensor placements and sensor array geometries. Finally, we suggest possible avenues for discriminating sonic booms from earthquakes for the purposes of EQW.

  17. Is splash erosion potential species specific? Measuring of splash erosion potential under forest in different succession stages along a biodiversity gradient in the humid subtropics

    Science.gov (United States)

    Geißler, C.; Kühn, P.; Scholten, T.

    2009-04-01

    It is widely accepted that (forest) vegetation is a key control for the type and intensity of soil erosion. The current paradigm is that natural or quasi-natural vegetation protects the soil from erosion and that agricultural vegetation or land use generally enhances erosion. The latter was in focus of most research during the last decades and less interest was paid on natural systems, which are more difficult to study. Nevertheless, afforestation is widely used as a measure of soil protection against soil erosion. Rainfall can be highly erosive particularly in the humid subtropics. Regarding climate change, also precipitation regime may change in direction to even more severe storms and higher rainfall intensities; it is a research field of growing importance. Key mechanisms of a vegetation cover in reducing or enhancing erosion are modifications of drop-size distribution, retention of raindrop impact on the soil and changes in amount and spatial distribution of rainfall at the ground surface. Controlling determinants are rainfall intensity, drop size distribution, drop fall velocity, height of the canopy as well as density of the canopy, crown and leaf traits, LAI and coverage by a litter layer. Large drops are supposed to be significant sources of splash detachment in forests (Brandt 1989; Vis 1986). However, the mechanisms of reducing (or enhancing?) splash detachment under forest in relation to species richness and species composition are not well understood. Some studies indicate that raindrop impact is species specific (Calder 2001; Nanko et al. 2006) and some neglect the effects of species specific impacts (Foot & Morgan 2005). Our research uses different methods of rainfall characterization (splash cups, tipping-bucket rain gauge, laser distrometer) to reveal the described mechanisms from the canopy through different vegetation layers to the ground. First results of splash cup measurements (revised after Ellison 1947) show that sand loss under vegetation

  18. Real estate boom and export performance bust in Croatia

    Directory of Open Access Journals (Sweden)

    Marina Tkalec

    2014-06-01

    Full Text Available The goal of this research is to estimate the effect of resource reallocation from the manufacturing to the real estate economic sector on exporting activity in Croatia, a small open post-transition country that experienced a real estate boom during the previous decade. This paper follows the work by Égert and Kierzenkowski (2014 as we test the hypothesis that the real estate boom had an adverse impact on country’s export performance. For that purpose we use quarterly data ranging from 1Q1998 to 3Q2013, and estimate export equations using maximum likelihood and dynamic ordinary least squares estimators of cointegration. Our results indicate that the distortion of relative prices in favor of non-tradable sectors (construction and real estate, which is a direct by-product of the real estate boom, has had stifling effects on export performance. Our results also suggest that ailing cost competitiveness and governments’ inability to implement policies promoting private sector economic development adversely influenced export performance during the period analyzed. The basic conclusion of our research is that the expansion of a non-tradable sector in a country with limited supply of production factors can have a detrimental effect on the ability of the tradable sector to increase its output and compete in international markets.

  19. Beam Splashes seen by the CMS detector #RestartLHC 2017 (end of April 2017)

    CERN Multimedia

    Mc Cauley, Thomas; Zevi Della Porta, Giovanni

    2017-01-01

    CMS event display from LHC beam splash on Saturday, 29th April 2017. This is the first time the full detector has seen particles produced since the beginning of the Extended Year-End Technical Stop (EYETS) 2017. In contrast to proton-proton collisions where the particles come from the center of the detector, in splash events, particles traverse the detector horizontally from one side to the other.

  20. 78 FR 28492 - Special Local Regulation; Low Country Splash, Wando River, Cooper River, and Charleston Harbor...

    Science.gov (United States)

    2013-05-15

    ...-AA08 Special Local Regulation; Low Country Splash, Wando River, Cooper River, and Charleston Harbor... establishing a special local regulation on the waters of the Wando River, Cooper River, and Charleston Harbor... rulemaking (NPRM) entitled, ``Special Local Regulation; Low Country Splash, Wando River, Cooper River, and...

  1. Corrosion Behavior of Low-C Medium-Mn Steel in Simulated Marine Immersion and Splash Zone Environment

    Science.gov (United States)

    Zhang, Dazheng; Gao, Xiuhua; Su, Guanqiao; Du, Linxiu; Liu, Zhenguang; Hu, Jun

    2017-05-01

    The corrosion behavior of low-C medium-Mn steel in simulated marine immersion and splash zone environment was studied by static immersion corrosion experiment and wet-dry cyclic corrosion experiment, respectively. Corrosion rate, corrosion products, surface morphology, cross-sectional morphology, elemental distribution, potentiodynamic polarization curves and electrochemical impedance spectra were used to elucidate the corrosion behavior of low-C medium-Mn steel. The results show that corrosion rate in immersion zone is much less than that in splash zone owing to its relatively mild environment. Manganese compounds are detected in the corrosion products and only appeared in splash zone environment, which can deteriorate the protective effect of rust layer. With the extension of exposure time, corrosion products are gradually transformed into dense and thick corrosion rust from the loose and porous one in these two environments. But in splash zone environment, alloying elements of Mn appear significant enrichment in the rust layer, which decrease the corrosion resistance of the steel.

  2. 78 FR 18277 - Special Local Regulation; Low Country Splash, Wando River, Cooper River, and Charleston Harbor...

    Science.gov (United States)

    2013-03-26

    ...-AA08 Special Local Regulation; Low Country Splash, Wando River, Cooper River, and Charleston Harbor... proposes to issue a special local regulation on the waters of the Wando River, Cooper River, and Charleston... Country Splash is scheduled to take place on the waters of the Wando River, Cooper River, and Charleston...

  3. Subjective Response to Simulated Sonic Booms in Homes

    Science.gov (United States)

    McCurdy, David A.; Brown, Sherilyn A.

    1996-01-01

    One of the environmental issues affecting the development of a second-generation supersonic commercial transport is the impact of sonic booms on people. Aircraft designers are attempting to design the transport to produce sonic boom signatures that will have minimum impact on the public. Current supersonic commercial aircraft produce an 'N-wave' sonic boom pressure signature that is considered unacceptable by the public. This has resulted in first-generation supersonic transports being banned from flying supersonic over land in the United States, a severe economic constraint. By tailoring aircraft volume and lift distributions, designers hope to produce sonic boom signatures having specific shapes other than 'N-wave' that may be more acceptable to the public. As part of the effort to develop a second-generation supersonic commercial transport, Langley Research Center is conducting research to study people's subjective response to sonic booms. As part of that research, a system was developed for performing studies of the subjective response of people to the occurrence of simulated sonic booms in their homes. The In-Home Noise Generation/Response System (IHONORS) provides a degree of situational realism not available in the laboratory and a degree of control over the noise exposure not found in community surveys. The computer-controlled audio system generates the simulated sonic booms, measures the noise levels, and records the subjects' ratings and can be placed and operated in individual homes for extended periods of time. The system was used to conduct an in-home study of subjective response to simulated sonic booms. The primary objective of the study was to determine the effect on annoyance of the number of sonic boom occurrences in a realistic environment. The effects on annoyance of several other parameters were also examined. Initially, data analyses were based on all the data collected. However, further analyser found that test subjects adapted to the sonic

  4. Low-Boom and Low-Drag Optimization of the Twin Engine Version of Silent Supersonic Business Jet

    Science.gov (United States)

    Sato, Koma; Kumano, Takayasu; Yonezawa, Masahito; Yamashita, Hiroshi; Jeong, Shinkyu; Obayashi, Shigeru

    Multi-Objective Optimization has been applied to a design problem of the twin engine concept for Silent Supersonic Business Jet (SSBJ). This problem aims to find main wing, body, tail wing and engine nacelle configurations, which can minimize both sonic boom and drag in a supersonic cruising flight. The multi-objective genetic algorithm (MOGA) coupled with the Kriging model has been used to globally and effectively search for optimal design candidates in the multi-objective problem. The drag and the sonic boom have been evaluated by the computational fluid dynamics (CFD) simulation and the waveform parameter method. As a result, the present optimization has successfully obtained low-boom and low-drag design candidates, which are better than the baseline design by more than 40% regarding each performance. Moreover, the structure of design space has been visualized by the self-organizing map (SOM).

  5. Beam Splashes seen by the CMS detector #RestartLHC 2018 (end of Mar 2018)

    CERN Multimedia

    Mc Cauley, Thomas; Olivito, Dominick

    2018-01-01

    CMS event displays from LHC beam splash on Friday, 30th March 2018. In contrast to proton-proton collisions where the particles come from the center of the detector, in splash events, particles traverse the detector horizontally from one side to the other. The time sampling for the picture, which is optimized for collisions at the center of the detector, amplifies the appearance of an asymmetric energy deposit in the end that the particles traverse last.

  6. Two mechanisms of droplet splashing on a solid substrate

    KAUST Repository

    Jian, Zhen; Josserand, Christophe; Popinet, Sté phane; Ray, Pascal; Zaleski, Sté phane

    2017-01-01

    related to the gas density. The two different splashing mechanisms initially suggested theoretically are observed numerically, depending on whether a jet is created before or after the impacting droplet wets the substrate. Finally, we provide a phase

  7. 77 FR 23120 - Special Local Regulations; Lowcountry Splash Open Water Swim, Wando River and Cooper River, Mount...

    Science.gov (United States)

    2012-04-18

    ...-AA08 Special Local Regulations; Lowcountry Splash Open Water Swim, Wando River and Cooper River, Mount... establishing special local regulations on the waters of the Wando River and Cooper River in Mount Pleasant... River and Cooper River along the shoreline of Mount Pleasant, South Carolina. The Lowcountry Splash...

  8. Mutations in MITF and PAX3 Cause “Splashed White” and Other White Spotting Phenotypes in Horses

    Science.gov (United States)

    Blatter, Marlis; Brooks, Samantha A.; Burger, Dominik; Drögemüller, Cord; Gerber, Vincent; Henke, Diana; Janda, Jozef; Jude, Rony; Magdesian, K. Gary; Matthews, Jacqueline M.; Poncet, Pierre-André; Svansson, Vilhjálmur; Tozaki, Teruaki; Wilkinson-White, Lorna; Penedo, M. Cecilia T.; Rieder, Stefan; Leeb, Tosso

    2012-01-01

    During fetal development neural-crest-derived melanoblasts migrate across the entire body surface and differentiate into melanocytes, the pigment-producing cells. Alterations in this precisely regulated process can lead to white spotting patterns. White spotting patterns in horses are a complex trait with a large phenotypic variance ranging from minimal white markings up to completely white horses. The “splashed white” pattern is primarily characterized by an extremely large blaze, often accompanied by extended white markings at the distal limbs and blue eyes. Some, but not all, splashed white horses are deaf. We analyzed a Quarter Horse family segregating for the splashed white coat color. Genome-wide linkage analysis in 31 horses gave a positive LOD score of 1.6 in a region on chromosome 6 containing the PAX3 gene. However, the linkage data were not in agreement with a monogenic inheritance of a single fully penetrant mutation. We sequenced the PAX3 gene and identified a missense mutation in some, but not all, splashed white Quarter Horses. Genome-wide association analysis indicated a potential second signal near MITF. We therefore sequenced the MITF gene and found a 10 bp insertion in the melanocyte-specific promoter. The MITF promoter variant was present in some splashed white Quarter Horses from the studied family, but also in splashed white horses from other horse breeds. Finally, we identified two additional non-synonymous mutations in the MITF gene in unrelated horses with white spotting phenotypes. Thus, several independent mutations in MITF and PAX3 together with known variants in the EDNRB and KIT genes explain a large proportion of horses with the more extreme white spotting phenotypes. PMID:22511888

  9. Splash albedo protons between 4 and 315 MeV at high and low geomagnetic latitudes

    International Nuclear Information System (INIS)

    Wenzel, K.; Stone, E.C.; Vogt, R.E.

    1975-01-01

    The differential energy spectrum of splash albedo protons has been measured at high geomagnetic latitude near Fort Churchill, Manitoba, at three periods of the solar cycle in 1966, and 1969 and at low latitude near Palestine, Texas, in 1967 by using a balloon-borne solid state detector telescope. We observed splash albedo proton fluxes between 4 and 315 MeV of 81plus-or-minus11, 70plus-or-minus11, and 48plus-or-minus8 protons/(m 2 s sr) at high latitude in 1966, 1967, and 1969 and of 37plus-or-minus9 protons/(m 2 s sr) at low latitude in 1967. The decreases from 1966 to 1969 are due to solar modulation of the cosmic ray parent nuclei. The albedo spectrum shows a similar shape for both latitudes. The difference in intensity can be explained by different local geomagnetic cutoffs; i.e., a significant contribution to the splash albedo flux arises from primary particles with rigidity below 4.5 GV. The splash albedo flux near Fort Churchill is consistent with corresponding fluxes previously reported near 53degree--55degreeN. The flux below 100 MeV near Palestine is significantly lower than that reported by Verma (1967)

  10. ATLAS Splash event - 6 April 2018

    CERN Multimedia

    ATLAS Collaboration

    2018-01-01

    The image shows a visualization of experimental data coming from the 'beam splash' tests run in April 2018 as part of the restart process of the LHC accelerator, after the winter break for maintenance. The image shows the hits of part of the tracking detector (in red, at the center), the energy deposits in the electromagnetic calorimeter (in green), and those in the hadronic calorimeter (in yellow). The semi-transparent azure volumes are part of the hadronic calorimeter, while the grey outer structure is part of the muon spectrometer.

  11. Full-Carpet Design of a Low-Boom Demonstrator Concept

    Science.gov (United States)

    Ordaz, Irian; Wintzer, Mathias; Rallabhandi, Sriram K.

    2015-01-01

    The Cart3D adjoint-based design framework is used to mitigate the undesirable o -track sonic boom properties of a demonstrator concept designed for low-boom directly under the flight path. First, the requirements of a Cart3D design mesh are determined using a high-fidelity mesh adapted to minimize the discretization error of the CFD analysis. Low-boom equivalent area targets are then generated at the under-track and one off-track azimuthal position for the baseline configuration. The under-track target is generated using a trim- feasible low-boom target generation process, ensuring that the final design is not only low-boom, but also trimmed at the specified flight condition. The o -track equivalent area target is generated by minimizing the A-weighted loudness using an efficient adjoint-based approach. The configuration outer mold line is then parameterized and optimized to match the off-body pressure distributions prescribed by the low-boom targets. The numerical optimizer uses design gradients which are calculated using the Cart3D adjoint- based design capability. Optimization constraints are placed on the geometry to satisfy structural feasibility. The low-boom properties of the final design are verified using the adaptive meshing approach. This analysis quantifies the error associated with the CFD mesh that is used for design. Finally, an alternate mesh construction and target positioning approach offering greater computational efficiency is demonstrated and verified.

  12. Effects of Fire on Soil Splash Erosion in Semi-steppe Rangelandof Karsanak Region,Chaharmahal and Bakhtiari

    Directory of Open Access Journals (Sweden)

    D. Baharlooi

    2016-02-01

    Full Text Available Introduction: The detachment process can be conceptually divided in two sub-processes included aggregate breakdown (Le Bissonnais, 1996 and movement initiation of breakdown products(Kinnell, 2005. soil detachment depends on raindrop size and mass(Elison, 1944; Bisal, 1960, drop velocity(Elison, 1944; Bisal, 1960, intensity rainfall (Ting et al, 2008, kinetic energy (Kinnell, 2003; Fernandez- Raga et al, 2010, runoff depth(Torri et al, 1987; Kinnell,1991 and 2005, crop covers(Bancy, 1994; Ghahremani et al, 2011, wind speed( Erpul et al, 2000 and experimental area (cup size (Leguedois et al, 2005; Luk, 1979; Torri and poesen, 1988. Many of studies have been conducted to evaluate the relationship between splash and slope (Bryan, 1979; Torri and Poesen, 1992; Wan et al, 1996.Torri and Poesen (1992 expressed that in steep slope the gravity force adds to the drop detaching force and decreases of soil resistance, consequently increases splash erosion rate with increasing slope. Soil splash erosion is also strongly influenced by soil properties including soil particles size distribution (Mazurak and Mosher, 1968; Legout et al, 2005; fan and li, 1993, soil shear strength(Cruse and Larson, 1977; Al-Durrah and Bradford,1981; Ekwue and ohi; 1990 , soil cohesion(Torri et al, 1987, soil organic matter content and aggregate size (Ekwue and Maiduguri, 1991; Qinjuan et al, 2008, soil aggregates stability(Qinjuan et al, 2008, surface crust (Qinjuan et al, 2008. Fire, play an important role in splash erosion. The absence of vegetation cover in disturbed lands accelerates splash erosion rates by as much as several folds compared to undisturbed sites (Lal, 2001; Thomaz and luiz, 2012.The detachment of soil particles by splash depends on several raindrop characteristics, including raindrop size and mass, drop velocity, kinetic energy, and water drop impact angle (Sharma et al., 1993; Singer and Le Bissonnais, 1998; Cruse et al., 2000, Bhattacharyya et al., 2010

  13. Spray boom for selectively spraying a herbicidal composition onto dicots

    DEFF Research Database (Denmark)

    2012-01-01

    There is provided a method and spray boom for discriminating cereal crop (monocot) and weeds (dicots). The spray boom includes means for digitally recording an image of a selected area to be treated by a nozzle on the spray boom, whereby a plant material is identified based on a segmentation proc...

  14. Development in helicopter tail boom strake applications in the US

    Science.gov (United States)

    Wilson, John C.; Kelley, Henry L.; Donahue, Cynthia C.; Yenni, Kenneth R.

    1988-01-01

    The use of a strake or spoiler on a helicopter tail boom to beneficially change helicopter tail boom air loads was suggested in the United States in 1975. The anticipated benefits were a change of tail boom loads to reduce required tail rotor thrust and power and improve directional control. High tail boom air loads experienced by the YAH-64 and described in 1978 led to a wind tunnel investigation of the usefullness of strakes in altering such loads on the AH-64, UH-60, and UH-1 helicopters. The wind tunnel tests of 2-D cross sections of the tail boom of each demonstrated that a strake or strakes would be effective. Several limited test programs with the U.S. Army's OH-58A, AH-64, and UH-60A were conducted which showed the effects of strakes were modest for those helicopters. The most recent flight test program, with a Bell 204B, disclosed that for the 204B the tail boom strake or strakes would provide more than a modest improvement in directional control and reduction in tail rotor power.

  15. NOFI oil Vee-Sweep and extension boom test at OHMSETT

    International Nuclear Information System (INIS)

    Bitting, K.R.; Vicedomine, J.

    1993-01-01

    The NOFI Vee-Sweep is an inflatable oil collection boom held in a V configuration by cross netting attached to the skirt of the boom. The NOFI 600S is an inflatable oil boom used to divert oil into the Vee-Sweep. The lower section of the 600S skirt consists of a feather net and a ballast chain. The booms are designed for open-ocean skimming where a skimmer is placed in the Vee-Sweep apex to remove the collected oil. During testing, the booms were preloaded with oil and towed in the OHMSETT tank at various speeds and wave conditions. Each boom was tested for its first and gross (continuous) oil loss speeds. The Vee-Sweep was also evaluated for wave performance, oil thickness vs tow speed, oil loss rate, and critical tow speed. Finally, a DESMI-250 oil skimmer was placed in the Vee-Sweep apex and oil loss tests were run while the skimmer was operating. During the critical tow speed testing, failures occurred due to apex submergence at ca 3.5 knots in calm water and short-crested waves, and 2.4 knots in harbor chop. The oil loss tests showed that the Vee-Sweep retains oil at speeds significantly higher than conventional booms. First oil loss speeds ranged from 1.3 knots in calm water to 1.0 knot in regular waves. The Vee-Sweep's high buoyancy/weight ratio gave it good wave performance in all conditions tested. The 600S oil loss speeds were higher than those of most conventional booms, and performance was better when the feather net was attached. 1 ref., 4 figs., 4 tabs

  16. Environmental Pollution: Noise Pollution - Sonic Boom

    Science.gov (United States)

    1977-06-01

    UNCLASSIFIED AD-A041 400 DDC/BIB-77/06 ENVIRONMENTAL POLLUTION NOISE POLLUTION SONIC BOOM A DDC BIBLIOGRAPHY DDC-TAS Cameron Station Alexandria, Va...rn7Sttio 658S-A041 400 4 TITLE xand r.VuhtlVlia) 2 TA i b- 1iblog ra ph y ENVIRONMENTAL POLLUTION : --. Apr-l IM59-Jul, 7NOISE POLLUTION -SONIC BOOM. 1,976...BIBLIOGRAPHY SEARCH CONTROL NO. /2OM09 AD- 769 970 20/1 1/3 DEFENSE UOCUMENTATION CENTER ALEXANDRIA VA ENVIRONMENTAL POLLUTION : NOISE POLLUTION

  17. Alternative Fuels Data Center: Hybrid and Electric Vehicles Boom Coast to

    Science.gov (United States)

    Coast Hybrid and Electric Vehicles Boom Coast to Coast to someone by E-mail Share Alternative Fuels Data Center: Hybrid and Electric Vehicles Boom Coast to Coast on Facebook Tweet about Alternative Fuels Data Center: Hybrid and Electric Vehicles Boom Coast to Coast on Twitter Bookmark Alternative

  18. Evaluating a protocol for testing fire-resistant oil-spill containment boom

    International Nuclear Information System (INIS)

    Walton, W.D.; Twilley, W.H.; Hiltabrand, R.R.; Mullin, J.V.

    1998-01-01

    A series of experiments were conducted to evaluate a protocol for testing the ability of fire-resistant booms to withstand both fire and waves. Most response plans for in situ burning of oil at sea require the use of a fire-resistant boom to contain the oil during a burn. For this study, a wave tank was designed and constructed to assess the capabilities of a 15 m section of a boom subjected to a 5 m diameter fire with 0.15 m high waves. Five typical fire-resistant oil-spill containment booms were tested. The purpose of the project was to evaluate the test procedure, therefore the overall performance of the boom was not evaluated on a pass-fail criterion. The two most important aspects of the test method were repeatability and reproducibility. Some of the parameters tested included the effect of wind, waves, fire size, and fire duration. Methods to constrain the booms were also tested. 7 refs., 6 tabs., 7 figs

  19. Methodology for the Regulation of Boom Sprayers Operating in Circular Trajectories

    Directory of Open Access Journals (Sweden)

    Alfredo Serreta

    2011-04-01

    Full Text Available A methodology for the regulation of boom sprayers working in circular trajectories has been developed. In this type of trajectory, the areas of the plots of land treated by the outer nozzles of the boom are treated at reduced rates, and those treated by the inner nozzles are treated in excess. The goal of this study was to establish the methodology to determine the flow of the individual nozzles on the boom to guarantee that the dose of the product applied per surface unit is similar across the plot. This flow is a function of the position of the equipment (circular trajectory radius and of the displacement velocity such that the treatment applied per surface unit is uniform. GPS technology was proposed as a basis to establish the position and displacement velocity of the tractor. The viability of this methodology was simulated considering two circular plots with radii of 160 m and 310 m, using three sets of equipment with boom widths of 14.5, 24.5 and 29.5 m. Data showed as increasing boom widths produce bigger errors in the surface dose applied (L/m2. Error also increases with decreasing plot surface. As an example, considering the three boom widths of 14.5, 24.5 and 29.5 m working on a circular plot with a radius of 160 m, the percentage of surface with errors in the applied surface dose greater than 5% was 30%, 58% and 65% respectively. Considering a circular plot with radius of 310 m the same errors were 8%, 22% and 31%. To obtain a uniform superficial dose two sprayer regulation alternatives have been simulated considering a 14.5 m boom: the regulation of the pressure of each nozzle and the regulation of the pressure of each boom section. The viability of implementing the proposed methodology on commercial boom sprayers using GPS antennas to establish the position and displacement velocity of the tractor was justified with a field trial in which a self-guiding commercial GPS system was used along with three precision GPS systems located in

  20. Stress Analysis of Boom of Special Mobile Crane for Plain Region in Transmission Line

    Science.gov (United States)

    Qin, Jian; Shao, Tao; Chen, Jun; Wan, Jiancheng; Li, Zhonghuan; Jiang, Ming

    2017-10-01

    Basis of the boom force analysis of special mobile crane for plain region in transmission line, the load type of boom design is confirmed. According to the different combinations of boom sections, the composite pattern of the different boom length is obtained to suit the actual conditions of boom overlapping. The large deformation model is employed with FEM to simulate the stress distribution of boom, and the calculation results are checked. The performance curves of rated load with different arm length and different working range are obtained, which ensures the lifting capacity of special mobile crane meeting the requirement of tower erection of transmission line. The proposed FEM of boom of mobile crane would provide certain guiding and reference to the boom design.

  1. Design of the De-Orbit Sail Boom Deployment Unit

    Science.gov (United States)

    Meyer, Sebastian; Hillebrandt, Martin; Straubel, Marco; Huhne, Christian

    2014-06-01

    The design of the De-Orbit Sail boom deployment unit is strongly driven by volume constraints, which are given by the cubesat container. Four CFRP (carbon fiber reinforced polymer) booms [4] with a cross-sectional shape of a double-omega and a length of 3.6 m are reeled on one spool in the center of the unit. The deployment of the four booms are controlled by an electric motor, which acts on the boom spool. Due to the volume limitation caused by the dimensions of the cubesat deployer the deployment unit has little room for the mechanisms components. With the aim to achieve a robust design, the deployment concept of the unit has greatly changed during the development process. The history of the design as well as the mechanisms are described. Additionally the results of the flight model testing are presented.

  2. Applications of flow visualization to the development of an innovative boom system

    International Nuclear Information System (INIS)

    Wong, K.F.V.; Wolek, A.

    1996-01-01

    A new oil retention boom system design was developed using a flow visualization technique. Hydrogen bubbles were generated on a fine wire cathode and placed in a stream of moving water with a strong light source to visualize the flow. Observations were made of the flow patterns around some basic shapes and booms modelled as cylinders with and without a skirt. The most effective system design had two booms with skirts in parallel with a submerged airfoil designed to cause the oil to separate and recirculate. Oil was allowed to flow above the airfoil into the recirculation region between the two floating booms. The new system is expected to outperform the conventional boom system only when flow velocity is high. Its most successful application would be in situations where flow is perpendicular to the length of the boom. 1 ref., 6 figs

  3. Shuttle sonic boom - Technology and predictions. [environmental impact

    Science.gov (United States)

    Holloway, P. F.; Wilhold, G. A.; Jones, J. H.; Garcia, F., Jr.; Hicks, R. M.

    1973-01-01

    Because the shuttle differs significantly in both geometric and operational characteristics from conventional supersonic aircraft, estimation of sonic boom characteristics required a new technology base. The prediction procedures thus developed are reviewed. Flight measurements obtained for both the ascent and entry phases of the Apollo 15 and 16 and for the ascent phase only of the Apollo 17 missions are presented which verify the techniques established for application to shuttle. Results of extensive analysis of the sonic boom overpressure characteristics completed to date are presented which indicate that this factor of the shuttle's environmental impact is predictable, localized, of short duration and acceptable. Efforts are continuing to define the shuttle sonic boom characteristics to a fine level of detail based on the final system design.

  4. The Effects of Mulch Cover on Splash Erosion in Makurdi Town ...

    African Journals Online (AJOL)

    Soil erosion has continued to be a serious environmental problem, particularly among the farming communities. In Benue State, the dominant economic activity is subsistence farming which is done under sub humid rainfall conditions. Splash erosion resulting from intense rainfall therefore poses severe problems that can be ...

  5. High-Speed Research: 1994 Sonic Boom Workshop. Configuration, Design, Analysis and Testing

    Science.gov (United States)

    McCurdy, David A. (Editor)

    1999-01-01

    The third High-Speed Research Sonic Boom Workshop was held at NASA Langley Research Center on June 1-3, 1994. The purpose of this workshop was to provide a forum for Government, industry, and university participants to present and discuss progress in their research. The workshop was organized into sessions dealing with atmospheric propagation; acceptability studies; and configuration design, and testing. Attendance at the workshop was by invitation only. The workshop proceedings include papers on design, analysis, and testing of low-boom high-speed civil transport configurations and experimental techniques for measuring sonic booms. Significant progress is noted in these areas in the time since the previous workshop a year earlier. The papers include preliminary results of sonic boom wind tunnel tests conducted during 1993 and 1994 on several low-boom designs. Results of a mission performance analysis of all low-boom designs are also included. Two experimental methods for measuring near-field signatures of airplanes in flight are reported.

  6. USAF Flight Test Investigation of Focused Sonic Booms: Project Have Bears

    Science.gov (United States)

    Downing, Micah; Zamot, Noel; Moss, Chris; Morin, Daniel; Wolski, Ed; Chung, Sukhwan; Plotkin, Kenneth; Maglieri, Domenic

    1996-01-01

    Supersonic operations from military aircraft generate sonic booms that can affect people, animals and structures. A substantial experimental data base exists on sonic booms for aircraft in steady flight and confidence in the predictive techniques has been established. All the focus sonic boom data that are in existence today were collected during the 60's and 70's as part of the information base to the US Supersonic Transport program and the French Jericho studies for the Concorde. These experiments formed the data base to develop sonic boom propagation and prediction theories for focusing. There is a renewed interest in high-speed transports for civilian application. Moreover, today's fighter aircraft have better performance capabilities, and supersonic flights ars more common during air combat maneuvers. Most of the existing data on focus booms are related to high-speed civil operations such as transitional linear accelerations and mild turns. However, military aircraft operating in training areas perform more drastic maneuvers such as dives and high-g turns. An update and confirmation of USAF prediction capabilities is required to demonstrate the ability to predict and control sonic boom impacts, especially those produced by air combat maneuvers.

  7. Laboratory hydro-mechanical characterisation of Boom Clay at Essen and Mol

    International Nuclear Information System (INIS)

    Deng, Y. F.; Tang, A. M.; Cui, Y. J.; Nguyen, X. P.; Li, X. L.; Wouters, L.

    2011-01-01

    Boom Clay has been selected as a potential host rock formation for the geological disposal of radioactive waste in Belgium. In the present work, the hydro-mechanical behaviour of Boom Clay samples from the borehole Essen-1 at a depth of 220-260 m and from HADES that is the underground rock laboratory at Mol in Belgium, at 223-m depth was investigated in the laboratory by performing low pressure odometer tests (vertical effective stress ranging from 0.05 to 3.2 MPa), high pressure odometer tests (vertical effective stress ranging from 0.125 to 32 MPa), isotropic consolidation tests (confining effective stress ranging from the in situ stress to 20 MPa) and triaxial shear tests. It has been observed that the mineralogy, geotechnical properties and hydro-mechanical behaviour of Boom Clay from Essen at 227-m, 240-m and 248-m depths are similar to that of Boom Clay from Mol. As in the case of Boom Clay at Mol, the failure envelope of Boom Clay at Essen in the p'- q plane is not linear. The slope of the portion beyond the pre-consolidation stress of Boom Clay from Essen is almost the same as that from Mol, suggesting a similar internal friction angle of about 13 deg. The compression curves (void index I v versus logarithm of vertical stress) beyond the pre-consolidation stress are the same for both samples from Mol and Essen, and situated between the intrinsic compression line (ICL) and the sedimentation compression line (SCL). The yield stress determined from odometer tests seems to be stress-path dependent and lower than the pre-consolidation stress. Thus determining the over-consolidation ratio (OCR) using the yield stress value would lead to an incorrect estimate. From a practical point view, the laboratory test results from Essen and their comparison with those from Mol provide important information regarding the transferability of knowledge on Boom Clay at different sites, taking into account the fact that most investigations have been carried out on Boom Clay at

  8. Facts and features of radionuclide migration in Boom Clay

    International Nuclear Information System (INIS)

    De Regge, P.; Henrion, P.; Monsecour, M.; Put, M.

    1988-01-01

    The evolution which took place during ten years of research on the behaviour of radionuclides in Boom Clay is described. Initially, the Boom Clay was regarded as a chemically inert exchanger and the radiochemical research aimed at determining the distribution of cations between the clay and some liquid phases. The observation that Boom Clay deteriorates in contact with air and loses important intrinsic properties formed a major breakthrough in the research and led to a careful examination of the real in-situ conditions. Efforts devoted to the understanding of the chemical factors pertaining to the pH, the redox potential, the extent of the buffering capacity of FeS 2 and CaCO 3 in equilibrium with the interstitial aqueous phase are reviewed. Also emerging from the overall picture was the role of the organic material present in the Boom Clay. In contrast to the water percolating fractured formations which may not be in equilibrium with the rock, the interstitial aqueous phase is completely in equilibrium with Boom Clay mainly because of its low permeability and the large excesses of buffering components. As the retention mechanisms are better understood, a more coherent picture is obtained from distribution and diffusion experiments and the effects of consolidation are being investigated in detail. 23 refs.; 4 figs.; 3 tabs

  9. Boom Booom Net Radio

    DEFF Research Database (Denmark)

    Grimshaw, Mark Nicholas; Yong, Louisa; Dobie, Ian

    1999-01-01

    of an existing Internet radio station; Boom Booom Net Radio. Whilst necessity dictates some use of technology-related terminology, wherever possible we have endeavoured to keep such jargon to a minimum and to either explain it in the text or to provide further explanation in the appended glossary....

  10. Effects of Rainfall Intensity and Slope Angle on Splash Erosion in ...

    African Journals Online (AJOL)

    Soil erosion is a critical global environmental problem, especially in the developing countries including Nigeria. In the humid and sub-humid tropics, splash erosion resulting from intense rainfall and slope degree pose severe land degradation problems. The objective of this study is to assess the effects of some rainfall ...

  11. Water-cooled, fire boom blanket, test and evaluation for system prototype development

    International Nuclear Information System (INIS)

    Stahovec, J. G.; Urban, R. W.

    1999-01-01

    Initial development of actively cooled fire booms indicated that water-cooled barriers could withstand direct oil fire for several hours with little damage if cooling water were continuously supplied. Despite these early promising developments, it was realized that to build reliable full-scale system for Navy host salvage booms would require several development tests and lengthy evaluations. In this experiment several types of water-cooled fire blankets were tested at the Oil and Hazardous Materials Simulated Test Tank (OHMSETT). After the burn test the blankets were inspected for damage and additional tests were conducted to determine handling characteristics for deployment, recovery, cleaning and maintenance. Test results showed that water-cooled fire boom blankets can be used on conventional offshore oil containment booms to extend their use for controlling large floating-oil marine fires. Results also demonstrated the importance of using thermoset rubber coated fabrics in the host boom to maintain sufficient reserve seam strength at elevated temperatures. The suitability of passively cooled covers should be investigated to protect equipment and boom from indirect fire exposure. 1 ref., 2 tabs., 8 figs

  12. Inlet Trade Study for a Low-Boom Aircraft Demonstrator

    Science.gov (United States)

    Heath, Christopher M.; Slater, John W.; Rallabhandi, Sriram K.

    2016-01-01

    Propulsion integration for low-boom supersonic aircraft requires careful inlet selection, placement, and tailoring to achieve acceptable propulsive and aerodynamic performance, without compromising vehicle sonic boom loudness levels. In this investigation, an inward-turning streamline-traced and axisymmetric spike inlet are designed and independently installed on a conceptual low-boom supersonic demonstrator aircraft. The airframe was pre-shaped to achieve a target ground under-track loudness of 76.4 PLdB at cruise using an adjoint-based design optimization process. Aircraft and inlet performance characteristics were obtained by solution of the steady-state Reynolds-averaged Navier-Stokes equations. Isolated cruise inlet performance including total pressure recovery and distortion were computed and compared against installed inlet performance metrics. Evaluation of vehicle near-field pressure signatures, along with under- and off-track propagated loudness levels is also reported. Results indicate the integrated axisymmetric spike design offers higher inlet pressure recovery, lower fan distortion, and reduced sonic boom. The vehicle with streamline-traced inlet exhibits lower external wave drag, which translates to a higher lift-to-drag ratio and increased range capability.

  13. Effectiveness of elastic damping in the pivot joints of cargo boom of crane-manipulating installations at large gaps

    Directory of Open Access Journals (Sweden)

    Lagerev I.A.

    2016-03-01

    Full Text Available The article was the analysis of dynamic processes in the cylindrical hinges with large gaps in the cargo boom crane-manipulating installations of mobile machines in operation. Consider the design of damping device for articulated joints, which creates a braking force of elastic resistance to the displacement of the hinge pin within the large gap. The mechanism of action of the damping devices was considered. Analysis of the effectiveness of damping device for re-ducing the dynamic stress state in the elements of cargo boom metal structures depending on the gap size and the stiff-ness of the damping device was performed. Damping device with an elastic shock absorbing elements substantially reduces the additional impact load at the time of selection of the gap in the joint, slow the growth of clearance in the pivot joint, limit the size of the gap specified value, which must not be exceeded during the entire service life of swivel independently from the intensity of his load.

  14. Droplet Splashing by a Slingshot Mechanism

    KAUST Repository

    Thoroddsen, Sigurdur T; Thoraval, M.-J.; Takehara, K.; Etoh, T. G.

    2011-01-01

    When a drop impacts onto a liquid pool, it ejects a thin horizontal sheet of liquid, which emerges from the neck region connecting the two liquid masses. The leading section of this ejecta bends down to meet the pool liquid. When the sheet touches the pool, at an “elbow,” it ruptures and sends off microdroplets by a slingshot mechanism, driven by surface tension. High-speed imaging of the splashing droplets suggests the liquid sheet is of submicron thickness, as thin as 300 nm. Experiments in partial vacuum show that air resistance plays the primary role in bending the sheet. We identify a parameter regime where this slingshot occurs and also present a simple model for the sheet evolution, capable of reproducing the overall shape.

  15. Droplet Splashing by a Slingshot Mechanism

    KAUST Repository

    Thoroddsen, Sigurdur T.

    2011-01-18

    When a drop impacts onto a liquid pool, it ejects a thin horizontal sheet of liquid, which emerges from the neck region connecting the two liquid masses. The leading section of this ejecta bends down to meet the pool liquid. When the sheet touches the pool, at an “elbow,” it ruptures and sends off microdroplets by a slingshot mechanism, driven by surface tension. High-speed imaging of the splashing droplets suggests the liquid sheet is of submicron thickness, as thin as 300 nm. Experiments in partial vacuum show that air resistance plays the primary role in bending the sheet. We identify a parameter regime where this slingshot occurs and also present a simple model for the sheet evolution, capable of reproducing the overall shape.

  16. Bust without boom.

    Science.gov (United States)

    Goldzieher, J W

    2000-01-01

    Just like injectables, oral contraceptives (OCs), including progestin-only ¿minipill¿ and ¿morning-after¿ pill regimens, have experienced a bust without a boom. Fear of political and religious backlash over emergency contraceptives containing estrogen and progestin prompted large companies not to market these regimens. Another major factor in the bust phase of OC use and acceptance has been a small coterie of English and American epidemiologists focused on the adverse effects of Ocs, including risks of thrombotic events, heart attacks, and strokes. The media played a crucial role in the bust phase of these OCs. In the UK, the alleged increase of cancer risk with pill use, which leaked before publication in London newspapers, resulted in 50,000 additional unintended pregnancies. Nevertheless, there is no doubt that boom-and-bust cycles will continue simply because many of the actors in this drama have too great a vested interest to desist. Groups involved in this field must recognize the hazards that come with the territory and be proactive, anticipatory, and well armed with facts--and get good with media access. Drug companies should think on a long-term basis the potential effects of leaving the field, as they have done, or shooting down competitive innovations.

  17. Gravity-gradient dynamics experiments performed in orbit utilizing the Radio Astronomy Explorer (RAE-1) spacecraft

    Science.gov (United States)

    Walden, H.

    1973-01-01

    Six dynamic experiments were performed in earth orbit utilizing the RAE spacecraft in order to test the accuracy of the mathematical model of RAE dynamics. The spacecraft consisted of four flexible antenna booms, mounted on a rigid cylindrical spacecraft hub at center, for measuring radio emissions from extraterrestrial sources. Attitude control of the gravity stabilized spacecraft was tested by using damper clamping, single lower leading boom operations, and double lower boom operations. Results and conclusions of the in-orbit dynamic experiments proved the accuracy of the analytic techniques used to model RAE dynamical behavior.

  18. Visualization and mechanisms of splashing erosion of electrodes in a DC air arc

    International Nuclear Information System (INIS)

    Wu, Yi; Cui, Yufei; Rong, Mingzhe; Yang, Fei; Sun, Hao; Niu, Chunping; Fan, Shaodi; Murphy, Anthony B

    2017-01-01

    The splashing erosion of electrodes in a DC atmospheric-pressure air arc has been investigated by visualization of the electrode surface and the sputtered droplets, and tracking of the droplet trajectories, using image processing techniques. A particle tracking velocimetry algorithm has been introduced to measure the sputtering velocity distribution. Erosion of both tungsten–copper and tungsten–ceria electrodes is studied; in both cases electrode erosion is found to be dominated by droplet splashing rather than metal evaporation. Erosion is directly influenced by both melting and the formation of plasma jets, and can be reduced by the tuning of the plasma jet and electrode material. The results provide an understanding of the mechanisms that lead to the long lifetime of tungsten–copper electrodes, and may provide a path for the design of the electrode system subjected to electric arc to minimize erosion. (letter)

  19. Visualization and mechanisms of splashing erosion of electrodes in a DC air arc

    Science.gov (United States)

    Wu, Yi; Cui, Yufei; Rong, Mingzhe; Murphy, Anthony B.; Yang, Fei; Sun, Hao; Niu, Chunping; Fan, Shaodi

    2017-11-01

    The splashing erosion of electrodes in a DC atmospheric-pressure air arc has been investigated by visualization of the electrode surface and the sputtered droplets, and tracking of the droplet trajectories, using image processing techniques. A particle tracking velocimetry algorithm has been introduced to measure the sputtering velocity distribution. Erosion of both tungsten-copper and tungsten-ceria electrodes is studied; in both cases electrode erosion is found to be dominated by droplet splashing rather than metal evaporation. Erosion is directly influenced by both melting and the formation of plasma jets, and can be reduced by the tuning of the plasma jet and electrode material. The results provide an understanding of the mechanisms that lead to the long lifetime of tungsten-copper electrodes, and may provide a path for the design of the electrode system subjected to electric arc to minimize erosion.

  20. Micro-splashing by drop impacts

    KAUST Repository

    Thoroddsen, Sigurdur T; Takehara, Kohsei; Etoh, Takeharugoji

    2012-01-01

    We use ultra-high-speed video imaging to observe directly the earliest onset of prompt splashing when a drop impacts onto a smooth solid surface. We capture the start of the ejecta sheet travelling along the solid substrate and show how it breaks up immediately upon emergence from the underneath the drop. The resulting micro-droplets are much smaller and faster than previously reported and may have gone unobserved owing to their very small size and rapid ejection velocities, which approach 100 m s-1, for typical impact conditions of large rain drops. We propose a phenomenological mechanism which predicts the velocity and size distribution of the resulting microdroplets. We also observe azimuthal undulations which may help promote the earliest breakup of the ejecta. This instability occurs in the cusp in the free surface where the drop surface meets the radially ejected liquid sheet. © 2012 Cambridge University Press.

  1. Micro-splashing by drop impacts

    KAUST Repository

    Thoroddsen, Sigurdur T.

    2012-07-18

    We use ultra-high-speed video imaging to observe directly the earliest onset of prompt splashing when a drop impacts onto a smooth solid surface. We capture the start of the ejecta sheet travelling along the solid substrate and show how it breaks up immediately upon emergence from the underneath the drop. The resulting micro-droplets are much smaller and faster than previously reported and may have gone unobserved owing to their very small size and rapid ejection velocities, which approach 100 m s-1, for typical impact conditions of large rain drops. We propose a phenomenological mechanism which predicts the velocity and size distribution of the resulting microdroplets. We also observe azimuthal undulations which may help promote the earliest breakup of the ejecta. This instability occurs in the cusp in the free surface where the drop surface meets the radially ejected liquid sheet. © 2012 Cambridge University Press.

  2. Raw material boom in an industrial country. Rohstoffboom in einem Industrieland

    Energy Technology Data Exchange (ETDEWEB)

    Enders, K S

    1984-01-01

    First of all, a theoretical investigation is carried out to discover under which conditions a raw material boom displaces traditional sectors of industry, and which groups win and lose in the process. Subsequently, the peculiarities of the adaption process induced by the boom are analysed. Particular attention is paid to the possibility of transition (short-term) unemployment (Dutch disease). In conclusion, Norway's experiences in the oil and gas boom in the North Sea ar described and then compared with theoretical statements.

  3. Sonic Boom Pressure Signature Uncertainty Calculation and Propagation to Ground Noise

    Science.gov (United States)

    West, Thomas K., IV; Bretl, Katherine N.; Walker, Eric L.; Pinier, Jeremy T.

    2015-01-01

    The objective of this study was to outline an approach for the quantification of uncertainty in sonic boom measurements and to investigate the effect of various near-field uncertainty representation approaches on ground noise predictions. These approaches included a symmetric versus asymmetric uncertainty band representation and a dispersion technique based on a partial sum Fourier series that allows for the inclusion of random error sources in the uncertainty. The near-field uncertainty was propagated to the ground level, along with additional uncertainty in the propagation modeling. Estimates of perceived loudness were obtained for the various types of uncertainty representation in the near-field. Analyses were performed on three configurations of interest to the sonic boom community: the SEEB-ALR, the 69o DeltaWing, and the LM 1021-01. Results showed that representation of the near-field uncertainty plays a key role in ground noise predictions. Using a Fourier series based dispersion approach can double the amount of uncertainty in the ground noise compared to a pure bias representation. Compared to previous computational fluid dynamics results, uncertainty in ground noise predictions were greater when considering the near-field experimental uncertainty.

  4. Packaging, deployment, and panel design concepts for a truss-stiffened 7-panel precision deployable reflector with feed boom

    Science.gov (United States)

    Heard, Walter L., Jr.; Collins, Timothy J.; Dyess, James W.; Kenner, Scott; Bush, Harold G.

    1993-01-01

    A concept is presented for achieving a remotely deployable truss-stiffened reflector consisting of seven integrated sandwich panels that form the reflective surface, and an integrated feed boom. The concept has potential for meeting aperture size and surface precision requirements for some high-frequency microwave remote sensing applications. The packaged reflector/feed boom configuration is a self-contained unit that can be conveniently attached to a spacecraft bus. The package has a cylindrical envelope compatible with typical launch vehicle shrouds. Dynamic behavior of a deployed configuration having a 216-inch focal length and consisting of 80-inch-diameter, two-inch-thick panels is examined through finite-element analysis. Results show that the feed boom and spacecraft bus can have a large impact on the fundamental frequency of the deployed configuration. Two candidate rib-stiffened sandwich panel configurations for this application are described, and analytical results for panel mass and stiffness are presented. Results show that the addition of only a few rib stiffeners, if sufficiently deep, can efficiently improve sandwich panel stiffness.

  5. Flow distortion on boom mounted cup anemometers

    DEFF Research Database (Denmark)

    Lindelöw, Per Jonas Petter; Friis Pedersen, Troels; Gottschall, Julia

    In this report we investigate on wind direction dependent errors in the measurement of the horizontal wind speed by boom mounted cup anemometers. The boom mounting on the studied lattice tower is performed according to IEC standard design rules, yet, larger deviations than predicted by flow models...... are observed. The errors on the measurements are likely caused by an underestimation of the flow distortions around the tower. In this paper an experimental method for deriving a correction formula and an in-field calibration is suggested. The method is based on measurements with two cup anemometers mounted...

  6. Booming markets for Moroccan argan oil appear to benefit some rural households while threatening the endemic argan forest.

    Science.gov (United States)

    Lybbert, Travis J; Aboudrare, Abdellah; Chaloud, Deborah; Magnan, Nicholas; Nash, Maliha

    2011-08-23

    Morocco's argan oil is now the most expensive edible oil in the world. High-value argan markets have sparked a bonanza of argan activity. Nongovernmental organizations, international and domestic development agencies, and argan oil cooperatives aggressively promote the win-win aim of simultaneously benefiting local people and the health of the argan forest. This paper tests some of these win-win claims. Analysis of a panel of detailed household data suggests that the boom has enabled some rural households to increase consumption, increase their goat herds (which bodes poorly for the argan forest), and send their girls to secondary school. The boom has predictably made households vigilant guardians of fruit on the tree, but it has not incited investments in longer term tree and forest health. We evaluate landscape-level impacts of these changes using commune-level data on educational enrollment and normalized difference vegetation index data over the period from 1981 to 2009. The results of the mesoanalysis of enrollment are consistent with the microanalysis: the argan boom seems to have improved educational outcomes, especially for girls. Our normalized difference vegetation index analysis, however, suggests that booming argan prices have not improved the forest and may have even induced degradation. We conclude by exploring the dynamic interactions between argan markets, local institutions, rural household welfare, and forest conservation and sustainability.

  7. Sheath-Based Rollable Lenticular-Shaped and Low-Stiction Composite Boom

    Science.gov (United States)

    Fernandez, Juan M. (Inventor)

    2018-01-01

    Various embodiments provide rollable and deployable composite booms that may be used in a wide range of applications both for space and terrestrial structural solutions. Various embodiment composite booms may be bistable, i.e. having a stable strain energy minimum in the coiled configuration as well as the in the deployed configuration. In various embodiments, a boom may be fabricated by aligning two independent tape-springs front-to-front encircled by a durable seamless polymer sleeve. The durable seamless polymer sleeve may allow the two tape-springs to slide past each other during the coiling/deployment process so as to reduce, e.g., minimize, shear and its derived problems.

  8. Effect of splash on the deposition and re-entrainment in annular mist flow

    International Nuclear Information System (INIS)

    Xie, Heng; Koshizuka, Seiichi; Oka, Yoshiaki

    2004-01-01

    The three-dimensional Moving Particle Semi-implicit (MPS) method is employed to simulate the deposition process of single droplet on the liquid film. The model accounts for the presence of inertial, gravitation, viscous and surface tension and is validated by comparison with experiment results. A one-dimensional mixture model is developed to calculate the necessary parameters for the simulation of deposition on the Boiling Water Reactor (BWR) condition. The correlations and methods on void fraction, entertainment fraction and droplet velocity and size distribution are employed to get the parameters of droplet and liquid film. The simulation results are analyzed to study the effect of splash on the deposition and re-entrainment process in annular-mist flow on the condition of BWR. It is found that the splash plays an important role in the deposition and re-entrainment process in high quality conditions of BWR. (author)

  9. Experimental investigations on the contribution of the splash-zones in counter-flow cooling towers for water cooling

    International Nuclear Information System (INIS)

    Vladea, I.; Barbu, V.

    1976-01-01

    The relatively high cost of cooling tower packs has led to investigate the contribution of the splash-zones in counter-flow cooling towers, and thereby to determine whether the pack could not be reduced so far, as to be - under certain circumstance - completely eliminated. In this case, one would come to a pure splash cooling tower which would contain inside the equipment required for drop formation only. This problem was investigated experimentally, and it was found that the pack of such a cooling tower could not be eliminated without a reduction in tower effectiveness. (orig.) [de

  10. The Effect of Salt Splash on Nylon 6,6

    OpenAIRE

    Steward, Scott D

    1999-01-01

    Abstract: One of the most common environmental exposures that nylon undergoes, when used for automotive applications, is that of salt splash, which commonly occurs during winter driving. This study looks at the effect of various salts (NaCl, KCl, CaCl2) on the thermal and mechanical properties of nylon when exposed to one and four molar aqueous salt solutions. It was found that the diffusion of salt solutions into nylon 6,6 occurred in a pseudo-Fickian manner. Also, it was found that the p...

  11. Impact induced splash and spill in a quasi-confided granular medium

    Science.gov (United States)

    Ogale, S. B.

    2005-03-01

    Dissipation of the energy of impact in a granular medium and its effects has been a subject of considerable scientific for quite some time. In this work we have explored and analyzed the splash and spill effects caused by the impact of a ball dropped from a height into a granular medium in a open container. Three different granular media, namely rice, mustard seeds, and cream of wheat were used. The amount of spilled-over granular matter was measured as a function of the ball-drop height. Digital pictures of the splash process were also recorded. The quantity of spilled granular matter varies linearly with the impact energy. However additional step like structures are also noted. Specifically, a distinct and large jump is seen in the spilled quantity at a specific impact energy in the case of mustard seeds, which also exhibit obvious charging effects and repulsion. Although the parameters such as mass per grain and packing density for the case of mustard seeds are intermediate between those for rice and cream of wheat, the spill quantity for comparable impact energy is considerably higher. These data will be presented and discussed.

  12. Model of liquid-metal splashing in the cathode spot of a vacuum arc discharge

    International Nuclear Information System (INIS)

    Gashkov, M. A.; Zubarev, N. M.; Zubareva, O. V.; Mesyats, G. A.; Uimanov, I. V.

    2016-01-01

    The formation of microjets is studied during the extrusion of a melted metal by the plasma pressure from craters formed on a cathode in a burning vacuum arc. An analytic model of liquid-metal splashing that includes two stages is proposed. At the first stage, the liquid motion has the axial symmetry and a liquid-metal wall surrounding the crater is formed. At the second stage, the axial symmetry is broken due to the development of the Plateau–Rayleigh instability in the upper part of the wall. The wall breakup process is shown to have a threshold. The minimal plasma pressure and the minimal electric current flowing through the crater required for obtaining the liquid-metal splashing regime are found. The basic spatial and temporal characteristics of the jet formation process are found using the analytic model.

  13. SWFSC/MMTD/AK: Structure of Populations, Level of Abundance, and Status of Humpbacks (SPLASH) 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project was part of a larger international project (SPLASH) designed to estimate the abundance and determine the population structure for humpback whales...

  14. The NET articulated boom: Preliminary investigations and justification for a full scale prototype

    International Nuclear Information System (INIS)

    Suppan, A.

    1990-12-01

    The articulated boom system is the favourite in-vessel handling system for NET which will be used to maintain or replace in-vessel components during short term interventions. The testbed EDITH is the prototype of this system and is the logical step between the proof of principle of the system, which is already performed by the JET articulated boom, and the operational equipment for NET. EDITH is required to demonstrate that maintenance of plasma facing components can be carried out with the anticipated reliability and time. To achieve this aim EDITH is based on the experience of the JET boom and will be constructed in full scale, supplemented by a full scale mock-up. A further goal of EDITH is to allow the testing of boom components and subassemblies. The results of preliminary investigations for the boom are summarized, the need of the testbed EDITH and a full scale mock-up is discussed and both EDITH and the mock-up are described. (orig.) [de

  15. Icelandic boom and bust - Immigration and the housing market

    OpenAIRE

    Lúðvík Elíasson

    2014-01-01

    Possible explanations for the rapid increase in house prices and housing investment in Iceland between 2004 and 2007 and the subsequent market crash are studied. The boom was driven in part by banking liberalisation, international financial conditions, and domestic policies. A simple demand and supply model, based on the study by Elíasson and Pétursson (2009), is fitted to data through the recent boom-bust period. The model is remarkably robust through the cycle despite its unprecedented ampl...

  16. Study of a 30-M Boom For Solar Sail-Craft: Model Extendibility and Control Strategy

    Science.gov (United States)

    Keel, Leehyun

    2005-01-01

    Space travel propelled by solar sails is motivated by the fact that the momentum exchange that occurs when photons are reflected and/or absorbed by a large solar sail generates a small but constant acceleration. This acceleration can induce a constant thrust in very large sails that is sufficient to maintain a polar observing satellite in a constant position relative to the Sun or Earth. For long distance propulsion, square sails (with side length greater than 150 meters) can reach Jupiter in two years and Pluto in less than ten years. Converting such design concepts to real-world systems will require accurate analytical models and model parameters. This requires extensive structural dynamics tests. However, the low mass and high flexibility of large and light weight structures such as solar sails makes them unsuitable for ground testing. As a result, validating analytical models is an extremely difficult problem. On the other hand, a fundamental question can be asked. That is whether an analytical model that represents a small-scale version of a solar-sail boom can be extended to much larger versions of the same boom. To answer this question, we considered a long deployable boom that will be used to support the solar sails of the sail-craft. The length of fully deployed booms of the actual solar sail-craft will exceed 100 meters. However, the test-bed we used in our study is a 30 meter retractable boom at MSFC. We first develop analytical models based on Lagrange s equations and the standard Euler-Bernoulli beam. Then the response of the models will be compared with test data of the 30 meter boom at various deployed lengths. For this stage of study, our analysis was limited to experimental data obtained at 12ft and 18ft deployment lengths. The comparison results are positive but speculative. To observe properly validate the analytic model, experiments at longer deployment lengths, up to the full 30 meter, have been requested. We expect the study to answer the

  17. Presence and evolution of natural organic matter in the boom clay

    International Nuclear Information System (INIS)

    Van Geet, M.; Deniau, I.; Largeau, C.; Bruggeman, C.; Maes, A.; Dierckx, A.

    2004-01-01

    Because of its very low hydraulic conductivity, reducing conditions, slightly alkaline pH, high specific surface, high cation exchange capacity and high plasticity, the Boom Clay is studied as a reference host formation for the deep disposal of high-level long-lived radioactive waste (NIRAS/ONDRAF, 1989). However, Boom Clay also contains up to 5% wt. of organic matter (OM). As radionuclides can form complexes with this organic matter, a detailed characterisation and knowledge of the evolution of the organic matter is necessary. An overview of the characteristics of the organic matter present in Boom Clay is given by Van Geet et al., (2003). The solid phase OM can be up to 5%. The dissolved OM fraction is around 200 mg C per liter of Boom Clay pore water. Both kinds of OM will be discussed. Concerning the solid phase OM the focus will be on the past evolution and its possible future evolution due to a thermal stress. For the dissolved OM, the focus will be on its origin. (author)

  18. Influence of Rust Permeability on Corrosion of E690 Steel in Industrial and Non-industrial Marine Splash Zones

    Science.gov (United States)

    Chen, Mindong; Pang, Kun; Liu, Zhiyong; Wu, Junsheng; Li, Xiaogang

    2018-05-01

    The corrosion behaviour of E690 steel in industrial and non-industrial marine splash environments was studied by environmental testing, morphology analysis, electrochemical measurements, and scanning Kelvin probe microscopy. Chloride and sulphide anions were found to diffuse across the rust layer following the evaporation of seawater splashed on the steel's surface. The cation-selective permeability of the rust layer resulted in an anion concentration gradient across the rust layer, which was more significant in the presence of sulphur dioxide. In addition, sulphur dioxide enhanced the formation of α-FeOOH, which led to the formation of distinct anode and cathode areas at the rust/steel interface.

  19. A summary of the lateral cutoff analysis and results from NASA's Farfield Investigation of No-boom Thresholds

    Science.gov (United States)

    Cliatt, Larry J.; Hill, Michael A.; Haering, Edward A.; Arnac, Sarah R.

    2015-10-01

    In support of the ongoing effort by the National Aeronautics and Space Administration (NASA) to bring supersonic commercial travel to the public, NASA, in partnership with other industry organizations, conducted a flight research experiment to analyze acoustic propagation at the lateral edge of the sonic boom carpet. The name of the effort was the Farfield Investigation of No-boom Thresholds (FaINT). The research from FaINT determined an appropriate metric for sonic boom waveforms in the transition and shadow zones called Perceived Sound Exposure Level, established a value of 65 dB as a limit for the acoustic lateral extent of a sonic boom's noise region, analyzed change in sonic boom levels near lateral cutoff, and compared between real sonic boom measurements and numerical predictions.

  20. Sobre o Boom e outras onomatopeias literárias

    OpenAIRE

    Londoño, Jorge Iván Parra

    2016-01-01

    Este artículo trata de examinar los alcances literarios del llamado Boom latinoamericano, a medio siglo de su estallido, las cuatro obras más representativas y sus respectivos autores, además de proponer un quinto autor, según la invitación que hiciera en su momento el crítico Ángel Rama. Por otro lado, evalua la respuesta literaria por parte del Post Boom, analizando sus características y su vigencia y, de manera concomitante, los movimientos anejos o posteriores a dicho movimiento, como el ...

  1. LHC Beam Splash seen by the ATLAS detector - 5 Apr 2015 - run 260272 - event 6539

    CERN Multimedia

    ATLAS Collaboration

    2015-01-01

    Event display of one of the collimator "splash" events seen by the ATLAS experiment in LHC Run-2, on Tuesday April the 5th : run 260272, event 6539 . The collimator position is 140m in front of the ATLAS interaction point.

  2. Measuring and explaining the baby boom in the developed world in the mid-twentieth century

    Directory of Open Access Journals (Sweden)

    Jesús J. Sánchez-Barricarte

    2018-03-01

    Full Text Available Background: The early research on the baby boom tried to account for it as a logical recovery following the end of the Second World War (WWII. But it cannot be understood merely as a post-war phenomenon because its origins go back to the 1930s and early 1940s. Objective: I shall describe the methodology used to measure the total and marital baby boom and provide a detailed description of it. I shall attempt to explain the possible reasons that led to the sharp increase in the marital fertility rates and its subsequent decline. Methods: I will use various fertility indices that track the historical development of fertility (total and marital; period and cohort. Results: I show that there are major differences in the measurement of the baby boom depending on the index used. I found that the baby boom is highly heterogeneous in the 25 countries that form part of my study. It represented the logical response that families made to one period of prolonged political, economic, and military crisis (the crash of 1929 and WWII. Conclusions: Researchers who use only the total fertility indices are really analysing only the nuptiality boom, which took place during those years, rather than changes in reproductive behaviour. Contribution: I measure total and marital baby boom for 25 developed countries and perform the calculations to measure the impact of marital fertility and nuptiality on the total baby boom (TBB. I present a new explanation of the origins of the baby boom.

  3. Design methodology for a community response questionnaire on sonic boom exposure

    Science.gov (United States)

    Farbry, John E., Jr.; Fields, James M.; Molino, John A.; Demiranda, Gwendolyn A.

    1991-01-01

    A preliminary draft questionnaire concerning community response to sonic booms was developed. Interviews were conducted in two communities that had experienced supersonic overflights of the SR-71 airplane for several years. Even though the overflights had ceased about 6 months prior to the interviews, people clearly remembered hearing sonic booms. A total of 22 people living in central Utah and 23 people living along Idaho/Washington state border took part in these interviews. The draft questionnaire was constantly modified during the study in order to evaluate different versions. Questions were developed which related to annoyance, startle, sleep disturbance, building vibration, and building damage. Based on the data collected, a proposed community response survey response instrument was developed for application in a full-scale sonic boom study.

  4. Numerical Predictions of Sonic Boom Signatures for a Straight Line Segmented Leading Edge Model

    Science.gov (United States)

    Elmiligui, Alaa A.; Wilcox, Floyd J.; Cliff, Susan; Thomas, Scott

    2012-01-01

    A sonic boom wind tunnel test was conducted on a straight-line segmented leading edge (SLSLE) model in the NASA Langley 4- by 4- Foot Unitary Plan Wind Tunnel (UPWT). The purpose of the test was to determine whether accurate sonic boom measurements could be obtained while continuously moving the SLSLE model past a conical pressure probe. Sonic boom signatures were also obtained using the conventional move-pause data acquisition method for comparison. The continuous data acquisition approach allows for accurate signatures approximately 15 times faster than a move-pause technique. These successful results provide an incentive for future testing with greatly increased efficiency using the continuous model translation technique with the single probe to measure sonic boom signatures. Two widely used NASA codes, USM3D (Navier-Stokes) and CART3D-AERO (Euler, adjoint-based adaptive mesh), were used to compute off-body sonic boom pressure signatures of the SLSLE model at several different altitudes below the model at Mach 2.0. The computed pressure signatures compared well with wind tunnel data. The effect of the different altitude for signature extraction was evaluated by extrapolating the near field signatures to the ground and comparing pressure signatures and sonic boom loudness levels.

  5. First beam splashes at the LHC

    CERN Multimedia

    CERN Bulletin

    2015-01-01

    After a two-year shutdown, the first beams of Run 2 circulated in the LHC last Sunday. On Tuesday, the LHC operators performed dedicated runs to allow some of the experiments to record their first signals coming from particles splashed out when the circulating beams hit the collimators. Powerful reconstruction software then transforms the electronic signals into colourful images.     “Splash” events are used by the experiments to test their numerous subdetectors and to synchronise them with the LHC clock. These events are recorded when the path of particles travelling in the LHC vacuum pipe is intentionally obstructed using collimators – one-metre-long graphite or tungsten jaws that are also used to catch particles that wander too far from the beam centre and to protect the accelerator against unavoidable regular and irregular beam losses. The particles sprayed out of the collision between the beam and the collimators are mostly muons. ATLAS and CMS&...

  6. A Flight Research Overview of WSPR, a Pilot Project for Sonic Boom Community Response

    Science.gov (United States)

    Cliatt, Larry James; Haering, Ed; Jones, Thomas P.; Waggoner, Erin R.; Flattery, Ashley K.; Wiley, Scott L.

    2014-01-01

    In support of NASAs ongoing effort to bring supersonic commercial travel to the public, NASA Dryden Flight Research Center and NASA Langley Research Center, in cooperation with other industry organizations, conducted a flight research experiment to identify the methods, tools, and best practices for a large-scale quiet (or low) sonic boom community human response test. The name of the effort was Waveforms and Sonic boom Perception and Response. Such tests will go towards building a dataset that governing agencies like the Federal Aviation Administration and International Civil Aviation Organization will use to establish regulations for acceptable sound levels of overland sonic booms. Until WSPR, there had never been an effort that studied the response of people in their own homes and performing daily activities to non-traditional, low sonic booms.WSPR was a NASA collaborative effort with several industry partners, in response to a NASA Aeronautics Research Mission Directorate Research Opportunities in Aeronautics. The primary contractor was Wyle. Other partners included Gulfstream Aerospace Corporation, Pennsylvania State University, Tetra Tech, and Fidell Associates, Inc.A major objective of the effort included exposing a community with the sonic boom magnitudes and occurrences expected in high-air traffic regions with a network of supersonic commercial aircraft in place. Low-level sonic booms designed to simulate those produced by the next generation of commercial supersonic aircraft were generated over a small residential community. The sonic boom footprint was recorded with an autonomous wireless microphone array that spanned the entire community. Human response data was collected using multiple survey methods. The research focused on essential elements of community response testing including subject recruitment, survey methods, instrumentation systems, flight planning and operations, and data analysis methods.This paper focuses on NASAs role in the efforts

  7. Migrant labor supply in a booming non-renewable resource economy: Cure and transmission mechanism for de-industrialization?

    Science.gov (United States)

    Nulle, Grant Mark

    This paper challenges the determinism that booming resource economies suffer from de-industrialization, the "Dutch Disease". For several decades, economists have attempted to explain how a sudden surge in mineral and energy extraction affects an economy's output and employment from an aggregate and sectoral perspective. Economic theory shows that a "boom" in mineral and energy production is welfare enhancing to the economy experiencing it. However, the phenomenon also induces inter-sectoral adjustments among non-renewable resource (NRR), traditional traded, and non-traded industries that tend to crowd out traditional export sectors such as agriculture and manufacturing. In turn, this paper asks two fundamental questions: 1) Can the inter-sectoral adjustments wrought by a boom in NRR production be mitigated in the resource-abundant economy experiencing it; 2) Can the inter-sectoral adjustments be exported to a neighboring non-resource economy by movements in migrant labor supply? The theoretical model and empirical estimation approach presented in this paper introduces an endogenous migrant labor supply response to booms in NRR output to test the extent traditional tradable sectors shrink in the NRR-abundant economy during the boom and if such effects are exported to a neighboring jurisdiction. Using data at the U.S. county level, the empirical results show that booming economies experience positive and statistically significant rates of real income and traded sector job growth during the boom, attributable to the influx of migrant labor. By contrast, little evidence is found that non-booming counties adjacent to the booming counties experience declines in income or job growth because of labor supply outflows. Instead, the results suggest the larger the number of potential "donor" counties that can supply labor to the booming economies, the more likely the transmission of booming economy effects, namely evidence of de-industrialization, is diffused across all of the

  8. Economic booms and risky sexual behavior: evidence from Zambian copper mining cities.

    Science.gov (United States)

    Wilson, Nicholas

    2012-12-01

    Existing studies suggest that individual and household level economic shocks affect the demand for and supply of risky sex. However, little evidence exists on the effects of an aggregate shock on equilibrium risky sexual behavior. This paper examines the effects of the early twenty-first century copper boom on risky sexual behavior in Zambian copper mining cities. The results suggest that the copper boom substantially reduced rates of transactional sex and multiple partnerships in copper mining cities. These effects were partly concentrated among young adults and copper boom induced in-migration to mining cities appears to have contributed to these reductions. Copyright © 2012. Published by Elsevier B.V.

  9. 1995 NASA High-Speed Research Program Sonic Boom Workshop. Volume 2; Configuration Design, Analysis, and Testing

    Science.gov (United States)

    Baize, Daniel G. (Editor)

    1999-01-01

    The High-Speed Research Program and NASA Langley Research Center sponsored the NASA High-Speed Research Program Sonic Boom Workshop on September 12-13, 1995. The workshop was designed to bring together NASAs scientists and engineers and their counterparts in industry, other Government agencies, and academia working together in the sonic boom element of NASAs High-Speed Research Program. Specific objectives of this workshop were to: (1) report the progress and status of research in sonic boom propagation, acceptability, and design; (2) promote and disseminate this technology within the appropriate technical communities; (3) help promote synergy among the scientists working in the Program; and (4) identify technology pacing, the development C, of viable reduced-boom High-Speed Civil Transport concepts. The Workshop was organized in four sessions: Sessions 1 Sonic Boom Propagation (Theoretical); Session 2 Sonic Boom Propagation (Experimental); Session 3 Acceptability Studies-Human and Animal; and Session 4 - Configuration Design, Analysis, and Testing.

  10. Influence of Chair Vibrations on Indoor Sonic Boom Annoyance

    Science.gov (United States)

    Rathsam, Jonathan; Klos, Jacob; Loubeau, Alexandra

    2015-01-01

    One goal of NASA’s Commercial Supersonic Technology Project is to identify candidate noise metrics suitable for regulating quiet sonic boom aircraft. A suitable metric must consider the short duration and pronounced low frequency content of sonic booms. For indoor listeners, rattle and creaking sounds and floor and chair vibrations may also be important. The current study examined the effect of such vibrations on the annoyance of test subjects seated indoors. The study involved two chairs exposed to nearly identical acoustic levels: one placed directly on the floor, and the other isolated from floor vibrations by pneumatic elastomeric mounts. All subjects experienced both chairs, sitting in one chair for the first half of the experiment and the other chair for the remaining half. Each half of the experiment consisted of 80 impulsive noises played at the exterior of the sonic boom simulator. When all annoyance ratings were analyzed together there appeared to be no difference in mean annoyance with isolation condition. When the apparent effect of transfer bias was removed, a subtle but measurable effect of vibration on annoyance was identified.

  11. Transients drive the demographic dynamics of plant populations in variable environments

    DEFF Research Database (Denmark)

    McDonald, Jenni L; Stott, Iain; Townley, Stuart

    2016-01-01

    clear patterns related to growth form. We find a surprising tendency for plant populations to boom rather than bust in response to temporal changes in vital rates and that stochastic growth rates increase with increasing tendency to boom. Synthesis. Transient dynamics contribute significantly...

  12. 76 FR 20532 - Safety Zone; Boom Days, Niagara River, Niagara Falls, NY

    Science.gov (United States)

    2011-04-13

    ...-AA00 Safety Zone; Boom Days, Niagara River, Niagara Falls, NY AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing a temporary safety zone on the Niagara River... Marina and a portion of the Niagara River, Niagara Falls, NY during the Boom Days Fireworks on April 16...

  13. Simulation and controller design for an agricultural sprayer boom leveling system

    KAUST Repository

    Sun, Jian

    2011-01-01

    According to the agricultural precision requirements, the distance from sprayer nozzles to the corps should be kept between 50 cm to 70 cm. The sprayer boom also needs to be kept parallel to the field during the operation process. Thus we can guarantee the quality of the chemical droplets distribution on the crops. In this paper we introduced a sprayer boom leveling system for agricultural sprayer vehicles with electro-hydraulic auto-leveling system. The suitable hydraulic actuating cylinder and valve were selected according to the specific systemic specifications. Furthermore, a compensation controller for the electro-hydraulic system was designed based on the mathematical model. With simulations we can optimize the performance of this controller to make sure a fast leveling response to the inclined sprayer boom. © 2011 IEEE.

  14. Babies Bottom Out--A 'Maybe Boom'

    Science.gov (United States)

    Science News, 1977

    1977-01-01

    Data for the period September 1976 through April 1977 indicate a rise in the United States birth rate; however, the rate is still below the replacement level. It is speculated that the increase is an "echo" effect to the post-World War II baby boom which peaked in 1957. (SL)

  15. 2D-SPLASH spectroscopy to determine the fat/water ratio in the muscle of the rotator cuff

    International Nuclear Information System (INIS)

    Koestler, H.; Kenn, W.; Huemmer, C.; Hahn, D.; Boehm, D.

    2002-01-01

    Aim: The degree of fatty infiltration of the rotator cuff is an important factor for the prognosis of an operative reconstruction after rotator cuff tear. The aim of this work was to develop a method using a clinical MR scanner that allows the quantification of the fat/water ratio with the necessary spatial resolution. Method: A SPLASH sequence consisting of 19 complex 2D-FLASH images was implemented on a clinical 1.5 T MR scanner. The echo time was gradually increased from 5.0 ms to 50.0 ms. A spatial in plane resolution of 1.17 mm, a spectral resolution of 0.33 ppm and a spectral width of 6.25 ppm were achieved in a total acquisition time of about 3 min. The quantitative evaluation of the spectra in arbitrarily shaped regions of interest (ROIs) was obtained using a home-built reconstruction program and the time domain fit program AMARES. Results: Phantom studies show a linear relation of the concentration determined by SPLASH spectroscopy (r=0.997). Because of the high spatial resolution and the possibility to evaluate arbitrarily shaped ROIs, the determination of the fat/water ratio in single muscles in the shoulder has been possible. Conclusions: By the use of the 2D-SPLASH sequence the degree of fatty infiltration in the rotator cuff can now be determined quantitatively for the first time. (orig.) [de

  16. A Flight Research Overview of WSPR, a Pilot Project for Sonic Boom Community Response

    Science.gov (United States)

    Cliatt, Larry J., II; Haering, Edward A., Jr.; Jones, Thomas P.; Waggoner, Erin R.; Flattery, Ashley K.; Wiley, Scott L.

    2014-01-01

    In support of the ongoing effort by the National Aeronautics and Space Administration (NASA) to bring supersonic commercial travel to the public, the NASA Armstrong Flight Research Center and the NASA Langley Research Center, in cooperation with other industry organizations, conducted a flight research experiment to identify the methods, tools, and best practices for a large-scale quiet (or low) sonic boom community human response test. The name of the effort was Waveforms and Sonic boom Perception and Response (WSPR). Such tests will be applied to building a dataset that governing agencies such as the Federal Aviation Administration and the International Civil Aviation Organization will use to establish regulations for acceptable sound levels of overland sonic booms. The WSPR test was the first such effort that studied responses to non-traditional low sonic booms while the subject persons were in their own homes and performing daily activities.The WSPR test was a NASA collaborative effort with several industry partners, in response to a NASA Aeronautics Research Mission Directorate Research Opportunities in Aeronautics. The primary contractor was Wyle (El Segundo, California). Other partners included Gulfstream Aerospace Corporation (Savannah, Georgia); Pennsylvania State University (University Park, Pennsylvania); Tetra Tech, Inc. (Pasadena, California); and Fidell Associates, Inc. (Woodland Hills, California).A major objective of the effort included exposing a community to the sonic boom magnitudes and occurrences that would be expected to occur in high-air traffic regions having a network of supersonic commercial aircraft in place. Low-level sonic booms designed to simulate those produced by the next generation of commercial supersonic aircraft were generated over a small residential community. The sonic boom footprint was recorded with an autonomous wireless microphone array that spanned the entire community. Human response data were collected using multiple

  17. A second hydrocarbon boom threatens the Peruvian Amazon: trends, projections, and policy implications

    Energy Technology Data Exchange (ETDEWEB)

    Finer, Matt [Save America' s Forests, 4 Library Court NW, Washington, DC 20003 (United States); Orta-Martinez, Marti, E-mail: matt@saveamericasforests.or, E-mail: martiorta@gmail.co [Institut de Ciencia i Tecnologia Ambiental, Universitat Autonoma de Barcelona, 08193 Bellaterra (Barcelona) (Spain)

    2010-01-15

    The Peruvian Amazon is home to extraordinary biological and cultural diversity, and vast swaths of this mega-diverse region remain largely intact. Recent analysis indicates, however, that the rapid proliferation of oil and gas exploration zones now threatens the region's biodiversity, indigenous peoples, and wilderness areas. To better elucidate this dynamic situation, we analyzed official Peruvian government hydrocarbon information and generated a quantitative analysis of the past, present, and future of oil and gas activities in the Peruvian Amazon. We document an extensive hydrocarbon history for the region-over 104 000 km of seismic lines and 679 exploratory and production wells-highlighted by a major exploration boom in the early 1970s. We show that an unprecedented 48.6% of the Peruvian Amazon has been recently covered by oil and gas concessions, up from just 7.1% in 2003. These oil and gas concessions overlap 17.1% of the Peruvian Amazon protected area system and over half of all titled indigenous lands. Moreover, we found that up to 72% of the Peruvian Amazon has been zoned for hydrocarbon activities (concessions plus technical evaluation agreements and proposed concessions) in the past two years, and over 84% at some point during the past 40 years. We project that the recent rapid proliferation of hydrocarbon zones will lead to a second exploration boom, characterized by over 20 000 km of new seismic testing and construction of over 180 new exploratory wells in remote, intact, and sensitive forest areas. As the Peruvian Amazon oil frontier rapidly expands, we conclude that a rigorous policy debate is urgently needed in order to avoid the major environmental impacts associated with the first exploration boom of the 1970s and to minimize the social conflict that recently led to deadly encounters between indigenous protesters and government forces.

  18. A second hydrocarbon boom threatens the Peruvian Amazon: trends, projections, and policy implications

    International Nuclear Information System (INIS)

    Finer, Matt; Orta-Martinez, Marti

    2010-01-01

    The Peruvian Amazon is home to extraordinary biological and cultural diversity, and vast swaths of this mega-diverse region remain largely intact. Recent analysis indicates, however, that the rapid proliferation of oil and gas exploration zones now threatens the region's biodiversity, indigenous peoples, and wilderness areas. To better elucidate this dynamic situation, we analyzed official Peruvian government hydrocarbon information and generated a quantitative analysis of the past, present, and future of oil and gas activities in the Peruvian Amazon. We document an extensive hydrocarbon history for the region-over 104 000 km of seismic lines and 679 exploratory and production wells-highlighted by a major exploration boom in the early 1970s. We show that an unprecedented 48.6% of the Peruvian Amazon has been recently covered by oil and gas concessions, up from just 7.1% in 2003. These oil and gas concessions overlap 17.1% of the Peruvian Amazon protected area system and over half of all titled indigenous lands. Moreover, we found that up to 72% of the Peruvian Amazon has been zoned for hydrocarbon activities (concessions plus technical evaluation agreements and proposed concessions) in the past two years, and over 84% at some point during the past 40 years. We project that the recent rapid proliferation of hydrocarbon zones will lead to a second exploration boom, characterized by over 20 000 km of new seismic testing and construction of over 180 new exploratory wells in remote, intact, and sensitive forest areas. As the Peruvian Amazon oil frontier rapidly expands, we conclude that a rigorous policy debate is urgently needed in order to avoid the major environmental impacts associated with the first exploration boom of the 1970s and to minimize the social conflict that recently led to deadly encounters between indigenous protesters and government forces.

  19. Investigation and prevention of droplet splashing during operation of a sodium free jet flow

    International Nuclear Information System (INIS)

    Stoppel, L.; Gordeev, S.; Wetzel, T.; Fellmoser, F.; Daubner, M.

    2010-01-01

    Many accelerator application concepts consider liquid metal as a windowless target, at which the particle beam does directly hit the liquid. One of such concepts is studied in the European project ''DIRAC-Secondary beams - Design Study''. This project is focused on the preliminary research work for construction of a new international particle accelerator - Facility for Antiproton and Ion Research (FAIR) in Darmstadt. The planned accelerator is aimed to work with high-energy heavy-ions, such as U 238 . One of the key elements of the FAIR facility is a liquid-metal-target, made in the form of a rectangular shaped Lithium jet aligned with the gravity vector. In the course of preliminary investigations the theoretical and practical conditions for a stable liquid-metal-jet conforming to the FAIR-requirements have been studied in the Karlsruhe Liquid Metal Laboratory (KALLA) sodium facility. The acquired scientific and technological results can be transferred to liquid-metal targets in nuclear applications, for example, the IFMIF-Target for the study of fusion reactor materials and the Myrrah/XT-ADS target. The main goals of the KALLA-part of the project were to design and build a facility for experimental research on hydrodynamic phenomena of the free surface liquid metal flow as well as to look at technological problems influencing the hydrodynamic stability of such flows. One of such problems emerged already during the startup of the facility: Splashing of liquid metal drops in the vacuum volume of the target box. As a result of such splashing process, liquid metal droplets are accumulated on various internal constructional elements of the target box, for example, on the inspection windows. This effect prohibits long term operation with the facility. The present paper describes the methods used to reduce the splashing to a minimum. (orig.)

  20. Spill-Overs of a Resource Boom: Evidence from Zambian Copper Mines

    OpenAIRE

    Alexander Lippert

    2014-01-01

    Do local populations benefit from resource booms? How strong are market linkages between the mining sector and the regional economy? This paper exploits exogenous variation in mine-level production volumes generated by the recent copper boom in Zambia to shed light on these questions. Using a novel dataset, I find robust evidence that an increase in local copper production improves living standards in the surroundings of the mines even for households not directy employed in the mining sector:...

  1. Impact-induced splash and spill in a quasi-confined granular medium

    Science.gov (United States)

    Ogale, S. B.; Shinde, S. R.; Karve, P. A.; Ogale, Abhijit S.; Kulkarni, A.; Athawale, A.; Phadke, A.; Thakurdas, R.

    2006-05-01

    The splash and spill effects caused by the impact of a ball dropped from a height into a granular medium held in a small open container are examined. Different granular media, namely rice, mustard seeds, cream of wheat and plastic beads are used. The quantity of spilled-over granular matter ( W, grams) is measured as a function of the ball-drop height and compared for different cases. Digital pictures of the splash process are also recorded. The quantity W is seen to vary approximately linearly with the energy of impact. Interestingly, a distinct upward jump is seen in the spilled quantity at specific impact energy in the case of mustard seeds, which have spherical shape and also exhibit some charging effects. Similar jump was also confirmed for the case of plastic beads with broadly similar properties. Although the parameters such as mass per grain and packing density for the case of mustard seeds are intermediate between those for rice and cream of wheat, the spill quantity for comparable impact energy is considerably higher in the former case. The possible reasons for this non-monotonicity of behavior are discussed in terms of the differences in grain shapes and properties. Experiments are also performed using plastic beads of the same type but with four different sizes to explore the dependence of spilled quantity on bead size. The container size dependence is also examined for various bead types. Interesting systematics are seen, which are discussed qualitatively.

  2. Vibration characteristics of a deployable controllable-geometry truss boom

    Science.gov (United States)

    Dorsey, J. T.

    1983-01-01

    An analytical study was made to evaluate changes in the fundamental frequency of a two dimensional cantilevered truss boom at various stages of deployment. The truss could be axially deployed or retracted and undergo a variety of controlled geometry changes by shortening or lengthening the telescoping diagonal members in each bay. Both untapered and tapered versions of the truss boom were modeled and analyzed by using the finite element method. Large reductions in fundamental frequency occurred for both the untapered and tapered trusses when they were uniformly retracted or maneuvered laterally from their fully deployed position. These frequency reductions can be minimized, however, if truss geometries are selected which maintain cantilever root stiffness during truss maneuvers.

  3. ATLAS IV in situ heating test in Boom Clay

    International Nuclear Information System (INIS)

    Chen, Guangjing; Li, Xiangling; Verstricht, Jan; Sillen, Xavier

    2012-01-01

    Document available in extended abstract form only. The small scale in-situ ATLAS (Admissible Thermal Loading for Argillaceous Storage) tests are performed to assess the hydro-mechanical effects of a thermal transient on the host Boom clay at the HADES underground research facility in Mol, Belgium. The initial test set-up, consisting of a heater borehole and two observation boreholes, was installed in 1991-1992. The first test (later named 'ATLAS I') was then performed from July 1993 to June 1996; during this time, the heater dissipated a constant power of 900 W. During the second phase ('ATLAS II'), the heating power was doubled (1800 W) and maintained constant from June 1996 to May 1997. This was followed by shutdown and natural cooling starting from June 1997 on. To broaden the THM characterization of the Boom clay at a larger scale and at different temperature levels, the test set-up was extended in 2006 by drilling two additional instrumented boreholes (AT97E and AT98E). The heater was switched on again from April 2007 to April 2008 with a stepwise power increase, followed by an instantaneous shutdown. This phase is called 'ATLAS III'. The above tests have provided a large set of good quality and well documented data on temperature, pore water pressure and total stress; these data allowed to make several interesting observations regarding the thermal anisotropy and THM coupling in the Boom clay. The straightforward geometry and well defined boundary conditions of the tests facilitate the comparison between measurement and numerical modeling studies. Based on the three dimensional coupled THM modeling of the ATLAS III test, the good agreement between measurement and numerical modeling of temperature and pore water pressure yields a set of THM parameters and confirms the thermo-mechanical anisotropy of the Boom clay. To get a better insight in the anisotropic THM behavior of the Boom clay, a new upward instrumented borehole was drilled above the ATLAS heater at

  4. Elastic Deployable Composite Tubular Roll-Out Boom, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Deployable Space Systems (DSS) has developed an affordable and ultra-lightweight elastically self-deployable Roll-Out Boom technology that provides affordability and...

  5. Untamed Jianghu or Emerging Profession: Diagnosing the Psycho-Boom amid China's Mental Health Legislation.

    Science.gov (United States)

    Huang, Hsuan-Ying

    2017-09-25

    This article focuses on the psychotherapy debate in China that was triggered by the country's mental health legislation. Seeing the release of the draft Mental Health Law in 2011 as a "diagnostic event" (Moore in Am Ethnol 14(4):727-736, 1987), I examine the debate in order to unravel the underlying logic and ongoing dynamics of the psycho-boom that has become a conspicuous trend in urban China since the early 2000s. Drawing on my fieldwork in Beijing and Shanghai, I use the two keywords of the debate-"jianghu" (literally "rivers and lakes"), an indigenous term that evokes an untamed realm, and "profession," a foreign concept whose translation requires re-translation-to organize my delineation of its contours. I describe how anticipation of state regulation prompted fears and discontents as well as critical reflections and actions that aimed to transform the field into a profession. The efforts to mark out a professional core against the backdrop of unruly jianghu further faced the challenge of an alternative vision that saw popularization as an equally noble cause. The Mental Health Law came into effect in 2013; ultimately, however, it did not introduce substantive regulation. Finally, I discuss the implications of this debate and the prospects of the psycho-boom.

  6. The marriage boom and marriage bust in the United States: An age-period-cohort analysis.

    Science.gov (United States)

    Schellekens, Jona

    2017-03-01

    In the 1950s and 1960s there was an unprecedented marriage boom in the United States. This was followed in the 1970s by a marriage bust. Some argue that both phenomena are cohort effects, while others argue that they are period effects. The study reported here tested the major period and cohort theories of the marriage boom and bust, by estimating an age-period-cohort model of first marriage for the years 1925-79 using census microdata. The results of the analysis indicate that the marriage boom was mostly a period effect, although there were also cohort influences. More specifically, the hypothesis that the marriage boom was mostly a response to rising wages is shown to be consistent with the data. However, much of the marriage bust can be accounted for by unidentified cohort influences, at least until 1980.

  7. 2D SPLASH: a new method to determine the fatty infiltration of the rotator cuff muscles

    International Nuclear Information System (INIS)

    Kenn, Werner; Huemmer, Christian; Koestler, Herbert; Hahn, Dietbert; Boehm, Dirk; Gohlke, Frank

    2004-01-01

    The objective of this paper is to quantify the fatty degeneration (infiltration) of rotator cuff muscles with a new spectroscopic FLASH (SPLASH) sequence. Before planned surgery (reconstruction or muscle transfer), 20 patients (13 men, 7 women; 35-75 years) with different stages of rotator cuff disease underwent an MR examination in a 1.5-T unit. The protocol consists of imaging sequences and a newly implemented SPLASH, which allows an exact quantification of the fat/water ratio with a high spatial resolution in an arbitrarily shaped region of interest (ROI). The percentages of fat in the rotator cuff muscles were determined. To determine statistically significant differences between the different stages of rotator cuff tear, a Kruskal-Wallis H test was used. Fatty infiltration of the supraspinatus muscle was correlated with cross-sectional area (CSA) measures (Bravais-Pearson). We found significant differences between different stages of rotator cuff disease, the fatty infiltration and the volume loss (determined by the occupation ratio) of the supraspinatus muscle. With the increasing extent of rotator cuff disease, fatty infiltration increases significantly, as does the volume loss of the supraspinatus muscle. Comparing fatty infiltration and the occupation ratio individually, there was only a moderate inverse correlation between fatty infiltration and the occupation ratio, with considerable variation of data. Fatty infiltration of the infraspinatus muscle occurred when the infraspinatus tendon was involved to a lesser extent. The SPLASH sequence allows exact quantification of fatty infiltration in an arbitrarily shaped ROI. The extent of atrophy and fatty infiltration correlates with the size of the tear. Atrophy and fatty infiltration correlate only moderately and should be evaluated separately. (orig.)

  8. 30 CFR 77.807-2 - Booms and masts; minimum distance from high-voltage lines.

    Science.gov (United States)

    2010-07-01

    ...-voltage lines. 77.807-2 Section 77.807-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... WORK AREAS OF UNDERGROUND COAL MINES Surface High-Voltage Distribution § 77.807-2 Booms and masts; minimum distance from high-voltage lines. The booms and masts of equipment operated on the surface of any...

  9. Characterization of groundwater flow in the environment of the Boom Clay (Campine, Belgium)

    International Nuclear Information System (INIS)

    Gedeon, M.; Labat, S.; Wemaere, I.; Wouters, L.

    2010-01-01

    Document available in extended abstract form only. In Belgium, the Boom Clay formation is considered as reference host rock for the geological disposal of radioactive waste. Aquifers surrounding the Boom Clay play a passive role in the context of the disposal safety whereby the radionuclides are diluted by groundwater flow. The groundwater flow in these aquifers has been studied since decades. This research involves observations of groundwater levels in the regional and local piezo-metric networks, several site investigations including geophysics and core-drilled boreholes and groundwater modelling. In this context, groundwater modelling represents the integration of the site characterization efforts and provides a comprehensive tool for constraining the models used in the safety assessment of the geological disposal. Since 1985, groundwater levels are observed monthly in the regional piezo-metric network. It consists of 142 filters monitoring the groundwater levels at 45 sites. Along with the observed groundwater levels from the local piezo-metric network (concentrated around the Mol-Dessel site for surface disposal), these data provide an excellent insight into the evolution of the groundwater levels. Moreover, they represent a calibration (validation) dataset for groundwater flow modelling. The groundwater system forming the environment of the Boom Clay host rock was characterized during several site investigation campaigns, within which seven core-drilled boreholes were realized, whereby hydraulic parameters and hydro-stratigraphy of the groundwater system could be collected. The dataset obtained from the above mentioned campaigns was complemented by archived data on hydraulic testing in the aquifers in order to build a comprehensive groundwater model integrating these data into a single numerical representation of the groundwater system. Three regional groundwater models have been developed integrating the site characterization data collected in the north

  10. An evaluation of propane as a fuel for testing fire-resistant oil spill containment booms

    International Nuclear Information System (INIS)

    Walton, W. D.; Twilley, W. H.

    1997-01-01

    A series of experiments have been conducted to measure and compare the thermal exposure to a fire-resistant boom from liquid hydrocarbon fuel and propane fires. The objective was to test the potential of propane fueled fires as a fire source for testing fire-resistant oil spill containment booms.Thermal exposure from propane fires have been measured with and without waves. Results indicated that although propane diffusion flames on water look like liquid hydrocarbon fuel flames and produce very little smoke, the heat flux at the boom location from propane fires is about 60 per cent of that from liquid hydrocarbon fuel fires. Despite the attractive features in terms of ease of application, control and smoke emissions, it was concluded that the low heat flux would preclude the application of propane as a fuel for evaluating fire resistant containment booms. 2 refs., 7 figs

  11. Economic Booms and Risky Sexual Behavior: Evidence from Zambian Copper Mining Cities

    OpenAIRE

    Nicholas Wilson

    2010-01-01

    Existing studies suggest that individual and household level economic shocks affect the demand for and supply of risky sex. However, little evidence exists on the effects of an aggregate shock on equilibrium risky sexual behavior. This paper examines the effects of the early twenty-first century copper boom on risky sexual behavior in Zambian copper mining cities. The results indicate that the copper boom substantially reduced rates of transactional sex and multiple partnerships in copper min...

  12. A study of the flexible body dynamics of the RAE-A satellite

    Science.gov (United States)

    1971-01-01

    Spacecraft flight data was compared with simulated data computed by the RAE and IMP dynamics simulator computer programs. There was not sufficient data available to provide definitive data on antenna boom position to the Radio Astronomy experimenter. There was, however, enough data to indicate the trend of antenna boom stiffness and temperature gradient. It was possible to obtain a good fit of simulated data to measured spacecraft attitude data when the antenna booms were extended to 450 feet. The value of the RAE-A antenna boom stiffness appears to be significantly less than the preflight ground measured value. It was confirmed that an improved simulation can be obtained by using values of the root angles of the antenna booms and by using an angle of the damper plane of motion, relative to the plane of the antennas, which differed from preflight ground measurements.

  13. Bearings for the biomass boom

    Energy Technology Data Exchange (ETDEWEB)

    MacQueen, Duncan

    2011-03-15

    Biomass energy is booming –– more than two billion people depend on biomass for their energy and the International Energy Agency predicts that biomass' share of the global energy supply will treble by 2050. But in many developing countries it is still regarded as a traditional and dirty solution that is often criminalised, unsustainable and poorly paid. A more sophisticated approach that legalises and secures sustainable production by and for local people could help improve energy security, cut carbon emissions, protect forests and reduce poverty.

  14. The research and application of electricity economic boom model under the constraint of energy conservation and emission reduction

    Science.gov (United States)

    Chen, Guangyan; Xia, Huaijian; Chen, Meiling; Wang, Dong; Jia, Sujin

    2017-10-01

    Energy saving and emission reduction policies affects the development of high power industry, thereby affecting electricity demand, so the study of the electricity industry boom helps to master the national economy. This paper analyses the influence of energy saving and emission reduction on power generation structure and pollutant emission in power industry. Through the construction of electricity market composite boom index to indicate electricity boom, using boom index to study volatility characteristics and trend of electricity market. Here we provide a method for the enterprise and the government, that it can infer the overall operation of the national economy situation from power data.

  15. Rural North Dakota's oil boom and its impact on social services.

    Science.gov (United States)

    Weber, Bret A; Geigle, Julia; Barkdull, Carenlee

    2014-01-01

    Over the last five years, North Dakota has experienced an oil boom based on high oil prices and hydraulic fracturing technologies. This has brought economic expansion and population growth to rural communities that had previously experienced decades of depopulation and economic struggle. Although the state has enjoyed many benefits--especially in juxtaposition to a sluggish national economy--the boom has also meant the arrival of economic refugees and dramatic impacts on largely rural social service systems. In the midst of a rapidly changing situation, available information tends to swing between euphoria over economic success and hysteria about rising crime and shifting cultures. In response, the authors used a primary focus group with county social service directors from across the state and a followup focus group with social workers operating on the edge of oil activity. Grounded in resilience theory, qualitative analysis of the primary focus group, and triangulation of data from other sources, this study provides a more objective report of the housing and social challenges, the benefits of the boom, and the challenges to solutions.

  16. Environmental Pollution: Noise Pollution - Sonic Boom. Volume I.

    Science.gov (United States)

    Defense Documentation Center, Alexandria, VA.

    The unclassified, annotated bibliography is Volume I of a two-volume set on Noise Pollution - Sonic Boom in a series of scheduled bibliographies on Environmental Pollution. Volume II is Confidential. Corporate author-monitoring agency, subject, title, contract, and report number indexes are included. (Author/JR)

  17. Effects of temperature and thermally-induced microstructure change on hydraulic conductivity of Boom Clay

    Directory of Open Access Journals (Sweden)

    W.Z. Chen

    2017-06-01

    Full Text Available Boom Clay is one of the potential host rocks for deep geological disposal of high-level radioactive nuclear waste in Belgium. In order to investigate the mechanism of hydraulic conductivity variation under complex thermo-mechanical coupling conditions and to better understand the thermo-hydro-mechanical (THM coupling behaviour of Boom Clay, a series of permeability tests using temperature-controlled triaxial cell has been carried out on the Boom Clay samples taken from Belgian underground research laboratory (URL HADES. Due to its sedimentary nature, Boom Clay presents across-anisotropy with respect to its sub-horizontal bedding plane. Direct measurements of the vertical (Kv and horizontal (Kh hydraulic conductivities show that the hydraulic conductivity at 80 °C is about 2.4 times larger than that at room temperature (23 °C, and the hydraulic conductivity variation with temperature is basically reversible during heating–cooling cycle. The anisotropic property of Boom Clay is studied by scanning electron microscope (SEM tests, which highlight the transversely isotropic characteristics of intact Boom Clay. It is shown that the sub-horizontal bedding feature accounts for the horizontal permeability higher than the vertical one. The measured increment in hydraulic conductivity with temperature is lower than the calculated one when merely considering the changes in water kinematic viscosity and density with temperature. The nuclear magnetic resonance (NMR tests have also been carried out to investigate the impact of microstructure variation on the THM properties of clay. The results show that heating under unconstrained boundary condition will produce larger size of pores and weaken the microstructure. The discrepancy between the hydraulic conductivity experimentally measured and predicted (considering water viscosity and density changes with temperature can be attributed to the microstructural weakening effect on the thermal volume change

  18. The geochemical behaviour of selenium in the Boom Clay system - a XANES and EXAFS study

    International Nuclear Information System (INIS)

    2S, KULeuven, B-3001Leuven (Belgium))" data-affiliation=" (Center for surface Chemistry and Catalysis - M2S, KULeuven, B-3001Leuven (Belgium))" >Breynaert, Eric; 2S, KULeuven, B-3001Leuven (Belgium))" data-affiliation=" (Center for surface Chemistry and Catalysis - M2S, KULeuven, B-3001Leuven (Belgium))" >Dom, Dirk; 2S, KULeuven, B-3001Leuven (Belgium))" data-affiliation=" (Center for surface Chemistry and Catalysis - M2S, KULeuven, B-3001Leuven (Belgium))" >Vancluysen, Jacqueline; 2S, KULeuven, B-3001Leuven (Belgium))" data-affiliation=" (Center for surface Chemistry and Catalysis - M2S, KULeuven, B-3001Leuven (Belgium))" >Kirschhock, Christine E.A.; 2S, KULeuven, B-3001Leuven (Belgium))" data-affiliation=" (Center for surface Chemistry and Catalysis - M2S, KULeuven, B-3001Leuven (Belgium))" >Maes, Andre; Scheinost, Andreas C.

    2010-01-01

    Document available in extended abstract form only. In Belgium, the Boom Clay formation is studied as a reference host formation for the geological disposal of high-level and long-lived radioactive waste for more than 30 years. This formation mainly consists of mixed clay minerals (illite, inter-stratified illite-smectite), pyrite and immobile and dissolved natural organic matter. Since it provides good sorption capacities, very low permeability, and chemically reducing conditions due to the presence of pyrite (FeS 2 ), the Boom clay formation itself is considered to be the main barrier preventing radionuclide migration from the geological repository. Within this concept for geological storage Se 79 has been identified as one of the critical elements contributing to the final dose to man. Although the sorption and migration behaviour of Se in the Boom Clay system has been thoroughly studied, the speciation of Se in the Boom Clay system has never been identified spectroscopically. In all previous studies, the interpretation of the behaviour of Se in Boom Clay conditions has always been based on circumstantial evidence such as solubility measurements or comparison with the spectroscopically identified speciation of Se in model systems. Based on the XANES analysis, selenite is transformed into Se 0 confirming the previously proposed reduction of selenite in the Boom Clay system. Combination of the mass-balance for Se with the results from linear combination analysis of the XANES spectra provided new evidence for the sorption-reduction mechanism proposed to explain the interaction between Se(IV) and the BC solid phase. In addition, evidence was found that that the fate of Se(IV) in the BC system is completely dominated by its interaction with pyrite present in the Boom Clay. The combined EXAFS analysis of Se in Se 0 reference phases (hexagonal, monoclinic, Se-loaded pyrite) allowed to elucidate further details on the short-range structure of the reaction products formed

  19. Boom in boarfish abundance: insight from otolith analysis

    DEFF Research Database (Denmark)

    Coad, Julie Olivia; Hüssy, Karin

    2012-01-01

    The boarfish Capros aper is a pelagic shoaling species widely distributed along the Northeast Atlantic continental shelf. In recent years, this species has experienced a dramatic boom in abundance in the Bay of Biscay and Celtic Sea. This study aims at resolving the mechanisms responsible for thi...

  20. Introduction of a theoretical splashing degree to assess the performance of low-viscosity oils in filling of capsules.

    Science.gov (United States)

    Niederquell, Andreas; Kuentz, Martin

    2011-03-01

    These days an alternative to soft capsules is liquid-filled hard capsules. Their filling technology was investigated earlier with highly viscous formulations, while hardly any academic research focused on low-viscosity systems. Accordingly, this work addressed the filling of such oils that are splashing during the dosing process. It was aimed to first study capsule filling, using middle-chain triglycerides as reference oil, in order to then evaluate the concept of a new theoretical splashing degree for different oils. A laboratory-scale filling machine was used that included capsule sealing. Thus, the liquid encapsulation by microspray technology was employed to seal the dosage form. As a result of the study with reference oil, the filling volume and the temperature were found to be significant for the rate of leaking capsules. The filling volume was also important for weight variability of the capsules. However, most critical for this variability was the diameter of the filling nozzle. We proposed a power law for the coefficient of weight variability as a function of the nozzle diameter and the obtained exponent agreed with the proposed theory. Subsequently, a comparison of different oils revealed that the relative splashing degree shared a correlation with the coefficient of the capsule weight variability (Pearson product moment correlation of r=0.990). The novel theoretical concept was therefore found to be predictive for weight variability of the filled capsules. Finally, guidance was provided for the process development of liquid-filled capsules using low-viscosity oils. © 2011 American Association of Pharmaceutical Scientists

  1. Modelling of natural organic matter-linked radionuclide transport in Boom clay

    International Nuclear Information System (INIS)

    Govaerts, J.; Maes, N.

    2012-01-01

    Document available in extended abstract form only. In the framework of the Belgian research program on long term management of high-level and/or long-lived radioactive wastes coordinated by ONDRAF/NIRAS, Boom Clay is investigated for its potential to host a deep geological disposal repository. In order to demonstrate the suitability of the Boom Clay as a host rock, the mobility of critical radionuclides in this clay layer has been the subject of research during many years. As actinides, lanthanides and transition metals are known to form strong complexes with organic substances, the influence of the Natural Organic Matter (NOM) present in Boom Clay on the mobility of these critical radionuclides is of crucial importance. Interaction of radionuclides with OM present in Boom Clay could on the one hand retard the migration due to complexation/colloid interaction with the immobile OM, and on the other hand the mobility and solubility of the radionuclide can be enhanced by the formation of complexes/colloids with the mobile OM. The conceptual understanding (and its numerical modelling) of the kinetic stability and transport of these complexes/colloids is therefore regarded as highly important for the the long-term safety assesment of the geological disposal. This can be broken down into two subproblems: 1. Describing the transport behaviour of mobile OM in Boom Clay; 2. Describing the interaction of RN with mobile OM and the transport behaviour of the resulting complexes in Boom Clay. The first part of this paper revolves around the first subproblem, where a robust model for the description of the migration behaviour of Natural Organic Matter (NOM) is derived based on data from column migration experiments using 14 C-labelled NOM Tracer solution, obtained in the framework of the EC TRANCOM-II project. Clay plugs of different lengths and different Darcy velocities were used. Inverse modelling with the MATLAB and COMSOL numerical code was done in order to identify the

  2. A Boom in Boomerangs

    Science.gov (United States)

    1992-01-01

    Ted Bailey, a highly-ranked international boomerang designer and thrower, used information from a variety of NASA technical reports on aerodynamics and low-speed airfoils to design more competitive boomerangs. Because the boomerang is essentially an airfoil like an airplane wing, the technology transferred effectively and even contributed to the 1981 American victory over Australian throwers. In 1985, using four NASA reports, Bailey designed a new MTA (maximum time aloft) boomerang that broke the one-minute barrier, enabled throwers to throw and catch in less than three minutes and allowed competitors to complete the difficult "Super Catch" - five throw/catch sequences after launching the original boom while it is still aloft. Bailey is now considering other boomerang applications.

  3. On the thermal behaviour of Boom clay

    International Nuclear Information System (INIS)

    Delage, P.; Cui Yu Jun; Sultan, N.

    2004-01-01

    When temperature is increased, the various phenomena that occur in a saturated natural potential host clay for nuclear waste disposal (Boom clay from SCK-CEN in Mol, Belgium) were experimentally investigated in a temperature controlled high stress triaxial cell. Firstly, the pore pressure build-up due to the difference in thermal dilation of both water and minerals was investigated through thermal consolidation tests. Interesting information was obtained about the dissipation of thermally induced pore pressure in Boom clay, based on the standard Terzaghi consolidation theory. Secondly, the volume change behaviour in drained conditions (i.e. under a very slow temperature increase) confirmed that the clay overconsolidation ratio (OCR) controlled the nature of the volume changes. Whereas overconsolidated soils use to dilate as any material when temperature is elevated, normally consolidated soils present a decrease in volume, which is less common. The principles of a coupled thermo-elasto-plastic model that was specifically developed to model this particular behaviour are finally presented. Obviously, it appears necessary to account in detail for these thermal phenomena in order to properly understand the response of the geological barrier in the near field once nuclear waste has been stored. (orig.)

  4. Analysis of Offshore Knuckle Boom Crane - Part Two: Motion Control

    Directory of Open Access Journals (Sweden)

    Morten K. Bak

    2013-10-01

    Full Text Available In this paper design of electro-hydraulic motion control systems for offshore knuckle boom cranes is discussed. The influence of the control valve bandwidth along with the ramp time for the control signal are investigated both analytically with simplified system models and numerically with an experimentally verified crane model. The results of both types of investigations are related to general design rules for selection of control valves and ramp times and the relevance of these design rules is discussed. Generally, they are useful but may be too conservative for offshore knuckle boom cranes. However, as demonstrated in the paper, the only proper way to determine this is to evaluate the motion control system design by means of simulation.

  5. Pilot Test of a Novel Method for Assessing Community Response to Low-Amplitude Sonic Booms

    Science.gov (United States)

    Fidell, Sanford; Horonjeff, Richard D.; Harris, Michael

    2012-01-01

    A pilot test of a novel method for assessing residents annoyance to sonic booms was performed. During a two-week period, residents of the base housing area at Edwards Air Force Base provided data on their reactions to sonic booms using Smartphone-based interviews. Noise measurements were conducted at the same time. The report presents information about data collection methods and about test participants reactions to low-amplitude sonic booms. The latter information should not be viewed as definitive for several reasons. It may not be reliably generalized to the wider U.S. residential population (because it was not derived from a representative random sample) and the sample itself was not large.

  6. Ash wettability conditions splash erosion in the postfire

    Science.gov (United States)

    Gordillo-Rivero, Ángel J.; de Celis, Reyes; García-Moreno, Jorge; Jiménez-Compán, Elizabeth; Alanís, Nancy; Cerdà, Artemi; Pereira, Paulo; Zavala, Lorena M.; Jordán, Antonio

    2015-04-01

    à and Doerr, 2008; Woods and Balfour, 2008; Zavala et al., 2009). The presence of an ash layer may be ephemeral, as it often is quickly removed or redistributed by water and wind erosion, animals or traffic (Zavala et al., 2009a). Many authors have observed that the capacity of ash to protect soil depends on properties as the topography, the meteorological conditions and the thickness of ash coverage (Cerdà and Doerr, 2008; Pereira et al., 2013; Woods and Balfour, 2010; Zavala et al., 2009). Taking this into account, in this study we hypothesized that the wettability / hydrophobicity of the ash layer may have a significant effect on the soil response to splash erosion. Therefore, the aim of this study is to evaluate the dispersion of sediments produced by the impact of raindrops in function of ash wettability after a prescribed fire at plot scale. 2. MATERIAL AND METHODS In 20 November 2012, a prescribed fire was carried out in an area located in the public mount "Las Navas", near Almaden de la Plata, Sevilla (approx. 37° 50' 44.44'' N / 6° 3' 7.44''W and 428 masl). Soils are acidic and shallow, developed from acidic metamorphic rocks (schists, slates and pyrophyllites). Vegetation is dominated by shrub legumes (Calicotome villosa and several species of Ulex and Genista). The experimental area was framed and plowed to eliminate the risk of fire spreading during the experiment. Previously to burn, level staffs were installed for determination of flame height. The temperature reached in the soil was monitored during the fire by a set of six thermocouples which were buried in soil (2 cm depth) and connected to a data-logger for monitoring the topsoil temperature every 60 s. The environmental conditions were also monitored during the experiment by a mobile weather station. At the moment of the ignition, the temperature was around 20 °C and the wind speed was near 0.0 m/s. After ignition, the experimental area was allowed to burn during 2.5 h. During burning, flames

  7. Simplified High-Performance Roll Out Composite Magnetometer Boom, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — In response to NASA's need for compact, low-cost deployable magnetometer booms for CubeSats, Roccor proposes to develop a Simple High-performance Roll-Out Composite...

  8. Partitioning washoff of manure-borne fecal indicators (Escherichia coli and stanols) into splash and hydraulic components: field rainfall simulations in a tropical agro-ecosystem.

    Science.gov (United States)

    Ribolzi, Olivier; Rochelle-Newall, Emma J.; Janeau, Jean-Louis; Viguier, Marion; Jardé, Emilie; Latsachack, Keooudone; Henri-Des-Tureaux, Thierry; Thammahacksac, Chanthamousone; Mugler, Claude; Valentin, Christian; Sengtaheuanghoung, Oloth

    2017-04-01

    Overland flow from manured fields and pastures is known to be an important mechanism by which organisms of faecal origin are transferred to streams in rural watersheds. In the tropical montane areas of South-East Asia, recent changes in land use have induced increased runoff, soil erosion, in-stream suspended sediment loads resulting in increased microbial pathogen dissemination and contamination of stream waters. The majority of enteric and environmental bacteria in aquatic systems are associated with particles such as sediments which can strongly influence their survival and transport characteristics. Escherichia coli (E. coli) has emerged as one of the most appropriate microbial indicators of faecal contamination of natural waters, with the presence of E. coli indicating that faecal contamination is present. In association with E. coli, faecal stanols can also be used as microbial source tracking tool for the identification of the origin of the faecal contamination (e.g. livestock, human, etc). Field rain simulations were used to examine how E.coli and stanols are exported from the surface of upland, agricultural soils during overland flow events. The objectives were to characterize the loss dynamics of these indicators from agricultural soils contaminated with livestock waste, and to partition total detachment into the splash and hydraulic components. Nine 1m2 microplots were divided in triplicated treatment groups: (a) controls with no amendments, (b) amended with pig manure or (c) poultry manure. Each plot was divided into two 0.5m2 rectangular subplots. For each simulation, one subplot was designated as a rain splash treatment; the other was covered with 2-mm grid size wire screen 10 cm above the soil surface to break the raindrops into fine droplets, thus drastically reducing their kinetic energy. E. coli concentrations in overland flow were estimated for both the attached and free living fractions and stanols were measured on the particulate matter washed

  9. Passenger Spaceplanes and Airplanes that Have Variable Configuration for Sonic Boom Reduction

    Directory of Open Access Journals (Sweden)

    Constantin SANDU

    2018-06-01

    Full Text Available In the last time, the interest for passenger space plane, supersonic passenger aircraft and supersonic business jets is increasing. For reducing sonic boom effects at ground level, some companies proposed airplanes having fuselage with small traversal section or having curved fuselage. This paper presents a new practical method for exciting vibrations in the leading edge of wing, tail and airplane's nose surfaces in order to scatter the shock wave and to reduce the sonic boom impact at ground level. The leading edges of wing, tail and airplane nose are covered with thin elastic fairings made of carbon fiber composite material which are separated through small gaps by the adjacent surfaces of wing, tail and nose. When the aircraft flies over populated areas, compressed air bleed from the engine compressors excites the vibration of carbon fiber fairings. The air is released through calibrated nozzles and directly impinges on the fairing surface generating their vibration. Thus, the shock waves are scattered and the impact of sonic boom on ground is much reduced.

  10. LHC Beam Splash seen by the ATLAS detector, 7 Apr 2015 - Run 260466 - event 22425

    CERN Multimedia

    Adam Bourdarios, Claire

    2015-01-01

    Event display of one of the collimator "splash" event seen by the ATLAS experiment in LHC Run-2 , on Tuesday April the 7th : event 22425, run 260466. The collimator position is 140m in front of the ATLAS interaction point. The spray of particles enters ATLAS from the left hand side of the picture. The length of the yellow bars indicates the energy deposited in the ATLAS calorimeter.

  11. A study of sonic boom overpressure trends with respect to weight, altitude, Mach number, and vehicle shaping

    Science.gov (United States)

    Needleman, Kathy E.; Mack, Robert J.

    1990-01-01

    This paper presents and discusses trends in nose shock overpressure generated by two conceptual Mach 2.0 configurations. One configuration was designed for high aerodynamic efficiency, while the other was designed to produce a low boom, shaped-overpressure signature. Aerodynamic lift, sonic boom minimization, and Mach-sliced/area-rule codes were used to analyze and compute the sonic boom characteristics of both configurations with respect to cruise Mach number, weight, and altitude. The influence of these parameters on the overpressure and the overpressure trends are discussed and conclusions are given.

  12. The Control of Welding Deformation of the Three-Section Arm of Placing Boom of HB48B Pump Truck

    Science.gov (United States)

    Wang, Zhi-ling

    2018-02-01

    The concrete pump truck is the construction equipment of conveying concrete with self contained base plate and distributing boom. It integrates the pump transport mechanism of the concrete pump, and the hydraulic roll-folding type distributing boom used to distribute materials, and the supporting mechanism into the automobile chassis, and it is the concrete conveying equipment with high efficient and the functions of driving, pumping, and distributing materials. The placing boom of the concrete pump truck is the main force member in the pump parts with bearing great pressure, and its stress condition is complex. Taking the HB48B placing boom as an example, this paper analyzes and studies the deformation produced by placing boom of pump truck, and then obtains some main factors affecting the welding deformation. Through the riveter “joint” size, we controlled the process parameters, post-welding processing, and other aspects. These measures had some practical significance to prevent, control, and reduce the deformation of welding.

  13. Radionuclide solubilities in boom clay. Final report, part 2 : a report produced for ONDRAF/NIRAS

    International Nuclear Information System (INIS)

    Baker, S.; Baston, G.M.N.; Boult, K.A.

    2000-01-01

    The release of radionuclides from a High Level Radioactive Waste repository situated in the Boom Clay at Mol would depend, in part, on their retardation within the Boom Clay. A number of parameters are required to assess such retardation; these include the solubilities of key radionuclides and their sorption behaviour. ONDRAF/NIRAS has identified neptunium, technetium, selenium, uranium and plutonium as elements for study. AEA Technology plc was requested to undertake a joint experimental and modelling study to determine the solubilities of these five elements under conditions representative of those in the Boom Clay (the in situ chemical conditions are pH∼8, Eh ∼ -230 mV). The work programme was carried out over three years, and for completeness this final report includes all the results

  14. Leading the next boom? competitive Eastern limb platinum supply

    CSIR Research Space (South Africa)

    McGill, JE

    2010-07-01

    Full Text Available in USD/troy oz (Data source: Johnson Matthey) Figure 4. Variation in nominal PGEs spot price from July 1992 till July 2010 in USD/troy oz (Data source: Johnson Matthey) PLATINUM IN TRANSITION ?BOOM OR BUST?4 each. In 1996 and 2003 merger attempts...

  15. Drilling Down: An Examination of the Boom-Crime Relationship in Resource Based Boom Counties

    Directory of Open Access Journals (Sweden)

    Rick Ruddell

    2017-03-01

    Full Text Available Objective to examine the boomcrime relationship in resourcebased boom counties and to propose socioeconomic and legal measures to reduce the boomtown effect. Methods dialectical approach to cognition of social phenomena allowing to analyze them in historical development and functioning in the context of the totality of objective and subjective factors that determined the choice of the following research methods formallogical comparativelegal survey interview focus groups generalized least squares method. Results The expansion in natural resource development in rural communities has led to a number of social problems in these places. The media community stakeholders as well as law enforcement and human service personnel have reported that the rapid growth in these communities leads to increased crime and other social ills. In order to better understand the boomcrime relationship index crimes in oil and natural gas producing counties in Montana and North Dakota were examined. Comparison of 2012 crime rates in a matched sample of counties revealed that crime rates were higher in oilimpacted counties. A prepost analysis found that violent crime in boom counties increased 18.5 between 2006 and 2012 while decreasing 25.6 in a matched sample of counties that had no oil or gas production. Inconsistent with the media portrayal of these communities as a new quotwild westquot we did not find a significant association between oil or natural gas production and property or violent crime in a series of OLS regression models. Scientific novelty for the first time the article uses index crimes in oil and natural gas producing counties in Montana and North Dakota to reveal the association between the rapid growth of towns and the crime rates. Practical significance the main provisions and conclusions of the article can be used in research and educational activity as well as for predicting the socialeconomic development of boomtowns.

  16. The Iron Law of Financial Markets: Self-fulfilling Prophecies and Speculative Booms and Busts

    Directory of Open Access Journals (Sweden)

    Ognjen Radonjić

    2016-02-01

    Full Text Available This paper discusses the factors which, in the absence of strong financial regulation, sustain the Iron Law of the Financial Markets asserting that speculative booms and busts occur more or less regularly from 17 century to the present. The first factor is that financial markets are self-fulfilling system. The second is that human nature does not change and is based on egoism, materialism, loss aversion, exaggerated hopes and fears, emulation, propensity to gamble, herd behavior and so on. Lastly, there is the extreme brevity of the financial memory. In order to enable economic authorities and/or individuals to detect timely that the unsustainable boom is under the way, we have identified the common features of historically recorded speculative episodes. Stages through which the system passes on its way from unsustainable rise to inevitable fall are: displacement, boom, overtrading, financial distress and discredit or revulsion.

  17. Radionuclide solubilities in boom clay. Final report, part 2 : a report produced for ONDRAF/NIRAS

    Energy Technology Data Exchange (ETDEWEB)

    Baker, S.; Baston, G.M.N.; Boult, K.A. [and others

    2000-07-01

    The release of radionuclides from a High Level Radioactive Waste repository situated in the Boom Clay at Mol would depend, in part, on their retardation within the Boom Clay. A number of parameters are required to assess such retardation; these include the solubilities of key radionuclides and their sorption behaviour. ONDRAF/NIRAS has identified neptunium, technetium, selenium, uranium and plutonium as elements for study. AEA Technology plc was requested to undertake a joint experimental and modelling study to determine the solubilities of these five elements under conditions representative of those in the Boom Clay (the in situ chemical conditions are pH{approx}8, Eh {approx} -230 mV). The work programme was carried out over three years, and for completeness this final report includes all the results.

  18. Physical model of a floating trash boom to control aquatic weeds at the TVA Widows Creek Fossil Plant

    International Nuclear Information System (INIS)

    Hopping, P.N.

    1991-01-01

    This paper reports that the Tennessee Valley Authority (TVA) Widows Creek Fossil plant seasonally encounters adverse accumulations of aquatic weeds at the intakes of the condenser cooling water pumps. To reduce the accumulations, a floating trash boom has been proposed for the intakes. To evaluate the hydraulic feasibility of a boom, a physical model of the intakes has been built at the TVA Engineering Laboratory. The model was used to determine the boom alignment and depth of skimming needed to successfully deflect weeds away from the intakes and provide self-cleaning

  19. Prisons as Panacea or Pariah? The Countervailing Consequences of the Prison Boom on the Political Economy of Rural Towns

    Directory of Open Access Journals (Sweden)

    John M. Eason

    2017-01-01

    Full Text Available The nascent literature on prison proliferation in the United States typically reveals negative impacts for communities of color. Given that Southern rural communities were the most likely to build during the prison boom (1970–2010, however, a more nuanced understanding of prison impact is warranted. Using a dataset matching and geocoding all 1663 U.S. prisons with their Census-appointed place, this study explores the countervailing consequences of the prison boom on rural towns across multiple periods. For example, locales that adopted prisons at earlier stages of the prison boom era received a short-term boom compared to those that did not, but these effects were not lasting. Furthermore, later in the boom, prison-building protected towns against additional economic decline. Thus, neither entirely pariah nor panacea, the prison functions as a state-sponsored public works program for disadvantaged rural communities but also supports perverse economic incentives for prison proliferation. Methodological, substantive, theoretical, and policy implications regarding the intersection of race and punishment are explored.

  20. Investigating the pore-water chemistry effects on the volume change behaviour of Boom clay

    Science.gov (United States)

    Deng, Y. F.; Cui, Y. J.; Tang, A. M.; Nguyen, X. P.; Li, X. L.; Van Geet, M.

    The Essen site has been chosen as an alternative site for nuclear waste disposal in Belgium. The soil formation involved at this site is the same as at Mol site: Boom clay. However, owing to its geographical situation closer to the sea, Boom clay at Essen presents a pore water salinity 4-5 times higher than Boom clay at Mol. This study aims at studying the effects of pore water salinity on the hydro-mechanical behaviour of Boom clay. Specific oedometer cells were used allowing “flushing” the pore water in soil specimen by synthetic pore water or distilled water. The synthetic pore water used was prepared with the chemistry as that for the site water: 5.037 g/L for core Ess83 and 5.578 g/L for core Ess96. Mechanical loading was then carried out on the soil specimen after flushing. The results show that water salinity effect on the liquid limit is negligible. The saturation or pore water replacement under the in situ effective stress of 2.4 MPa does not induce significant volume change. For Ess83, hydro-mechanical behaviour was found to be slightly influenced by the water salinity; on the contrary, no obvious effect was identified on the hydro-mechanical behaviour of Ess96. This can be attributed to the higher smectite content in Ess83 than in Ess96.

  1. Performance study of protective clothing against hot water splashes: from bench scale test to instrumented manikin test.

    Science.gov (United States)

    Lu, Yehu; Song, Guowen; Wang, Faming

    2015-03-01

    Hot liquid hazards existing in work environments are shown to be a considerable risk for industrial workers. In this study, the predicted protection from fabric was assessed by a modified hot liquid splash tester. In these tests, conditions with and without an air spacer were applied. The protective performance of a garment exposed to hot water spray was investigated by a spray manikin evaluation system. Three-dimensional body scanning technique was used to characterize the air gap size between the protective clothing and the manikin skin. The relationship between bench scale test and manikin test was discussed and the regression model was established to predict the overall percentage of skin burn while wearing protective clothing. The results demonstrated strong correlations between bench scale test and manikin test. Based on these studies, the overall performance of protective clothing against hot water spray can be estimated on the basis of the results of the bench scale hot water splashes test and the information of air gap size entrapped in clothing. The findings provide effective guides for the design and material selection while developing high performance protective clothing. Published by Oxford University Press on behalf of the British Occupational Hygiene Society 2014.

  2. Seagrass Control Project: Containment Boom Evaluation. A Method to Protect Seawater Intakes from Seagrass Accumulation.

    Science.gov (United States)

    1983-10-01

    containment booms at other mooring sites with significantly different physical and environ- mental conditions is recommended before full-scale application...deployment pattern for the different ship types. Modified procedures may also be needed to deploy the boom under a different set of physical and environmental... STPM Press Publ. New York, 353pp. 1980. Pulich, W., S. Barnes and P. Parker. Trace metal cycles in seagrass communities. pp 493-506 in M. Wiley, ed

  3. Modeling and simulation of the agricultural sprayer boom leveling system

    KAUST Repository

    Sun, Jian; Miao, Yubin

    2011-01-01

    According to the agricultural precision requirements, the distance from sprayer nozzles to the corps should be kept between 50 cm to 70 cm. The sprayer boom also needs to be kept parallel to the field during the application process. Thus we can

  4. Experimental Investigation of a Large-Scale Low-Boom Inlet Concept

    Science.gov (United States)

    Hirt, Stefanie M.; Chima, Rodrick V.; Vyas, Manan A.; Wayman, Thomas R.; Conners, Timothy R.; Reger, Robert W.

    2011-01-01

    A large-scale low-boom inlet concept was tested in the NASA Glenn Research Center 8- x 6- foot Supersonic Wind Tunnel. The purpose of this test was to assess inlet performance, stability and operability at various Mach numbers and angles of attack. During this effort, two models were tested: a dual stream inlet designed to mimic potential aircraft flight hardware integrating a high-flow bypass stream; and a single stream inlet designed to study a configuration with a zero-degree external cowl angle and to permit surface visualization of the vortex generator flow on the internal centerbody surface. During the course of the test, the low-boom inlet concept was demonstrated to have high recovery, excellent buzz margin, and high operability. This paper will provide an overview of the setup, show a brief comparison of the dual stream and single stream inlet results, and examine the dual stream inlet characteristics.

  5. Thermomechanical behaviour of boom clay

    International Nuclear Information System (INIS)

    Sultan, N.; Delage, P.; Cui, Y.J.

    2000-01-01

    Special attention has been recently paid on temperature effects on the behaviour of deep saturated clays, in relation with nuclear deep waste storage. However, few experimental data are presently available, and existing constitutive models need to be completed. This note is aimed at completing, both experimentally and theoretically, the understanding of the effects of the over-consolidation ration on the thermal volume changes of Boom clay (Belgium). The experimental data obtained here are in a good agreement with existing data. As a complement to existing data, they are used to develop a new elastoplastic model. The adoption of a second coupled plastic mechanism provides good simulations on a complex thermo-mechanical path. (authors)

  6. In situ chemical osmosis experiment in the Boom Clay at the Mol underground research laboratory

    Science.gov (United States)

    Garavito, A. M.; De Cannière, P.; Kooi, H.

    Studies on the compatibility of Boom Clay with large amounts of nitrate- bearing bituminized radioactive waste have recently raised a particular interest for osmosis-induced effects in this reference formation in Belgium. Indeed, water flow and solute transport may be associated with several types of driving forces, or gradients (chemical, electrical, thermal), in addition to the hydraulic forces, resulting in the so-called coupled flows. Fluid flow caused by driving forces different than hydraulic gradients is referred to as osmosis. Chemical osmosis, the water flow induced by a chemical gradient across a semi-permeable membrane, can generate pressure increase. The question thus arises if there is a risk to create high pore pressures that could damage the near-field of medium-level waste (MLW) galleries, if osmotically driven water flows towards the galleries are produced by the release of large amounts of NaNO 3 (750 t) in the formation. To what extent a low-permeability clay formation such as the Boom Clay acts as an osmotic membrane is thus a key issue to assess the relevance of osmosis phenomena for the disposal of medium-level waste. An in situ osmosis experiment has been conducted at the H ADES underground research laboratory to determine the osmotic efficiency of Boom Clay at the field scale. A recently developed chemical osmosis flow continuum model has been used to design the osmosis experiment, and to interpret the water pressure measurements. Experimental data could be reproduced quite accurately by the model, and the inferred parameter values are consistent with independent determinations for Boom Clay. A rapid water pressure increase (but limited to about a 2 m water column) was observed after 12 h in the filter containing the more saline water. Then, the osmotically induced water pressure slowly decays on several months. So, the experimental results obtained in situ confirm the occurrence of non-hydraulic flow phenomena (chemical osmosis) in a low

  7. Dinámicas espaciales generadas a partir de las agroexportaciones: el boom de los espárragos en Ica

    Directory of Open Access Journals (Sweden)

    Brenda Toledo Asenjo

    2011-12-01

    Full Text Available Spatial Dynamics Generated by Agroexports: The Asparragus Boom at IcaDifferent economic and subsistence activities respond to changes or dynamics that are formed in each context. At present, globalization appears as one of the main factors that influence on the economic activities. That is, it is undeniable that all economic activities transform their processes induced by that phenomenon as well as the distinct regions have required to get integrated to that process. In that sense, the states, procuring to get integrated to the global context have contributed to the configuration of the new commercial scenery. This implies that many societies with distinct living patterns have had to adequate to a new commercial dynamics, where exports are the principal connection to the global market. The main objective of this paper is to identify and analyze the spatial dynamics originated as result of agro exports such as the case of the asparagus’ «boom» at the Ica Valley. Moreover, there is a revision of some environmental dynamics or impacts that the process has given way in order to have a correct vision of the topic. To do this, there was a spatial review of the study area based on satellite images in identified dates, from which it was possible to see gross evidence of a spatial transformation and the appearance of new land use formsLas distintas actividades económicas y de subsistencia responden a los cambios o dinámicas que se forman en cada contexto. Actualmente, la globalización aparece como uno de los factores principales de influencia sobre las actividades económicas. Es decir, es innegable que todas las actividades económicas transforman sus procesos inducidas por ese fenómeno, en la medida que las distintas regiones han requerido integrarse al proceso. En ese sentido, los Estados, al procurar sumarse al contexto global han contribuido a la configuración del nuevo escenario comercial. Esto implica que muchas sociedades con costumbres

  8. Design of an Indoor Sonic Boom Simulator at NASA Langley Research Center

    Science.gov (United States)

    Klos, Jacob; Sullivan, Brenda M.; Shepherd, Kevin P.

    2008-01-01

    Construction of a simulator to recreate the soundscape inside residential buildings exposed to sonic booms is scheduled to start during the summer of 2008 at NASA Langley Research Center. The new facility should be complete by the end of the year. The design of the simulator allows independent control of several factors that create the indoor soundscape. Variables that will be isolated include such factors as boom duration, overpressure, rise time, spectral shape, level of rattle, level of squeak, source of rattle and squeak, level of vibration and source of vibration. Test subjects inside the simulator will be asked to judge the simulated soundscape, which will represent realistic indoor boom exposure. Ultimately, this simulator will be used to develop a functional relationship between human response and the sound characteristics creating the indoor soundscape. A conceptual design has been developed by NASA personnel, and is currently being vetted through small-scale risk reduction tests that are being performed in-house. The purpose of this document is to introduce the conceptual design, identify how the indoor response will be simulated, briefly outline some of the risk reduction tests that have been completed to vet the design, and discuss the impact of these tests on the simulator design.

  9. Internal Stellar Kinematics of M32 from the SPLASH Survey: Dark Halo Constraints

    Science.gov (United States)

    Howley, K. M.; Guhathakurta, P.; van der Marel, R.; Geha, M.; Kalirai, J.; Yniguez, B.; Kirby, E.; Cuillandre, J.-C.; Gilbert, K.

    2013-03-01

    As part of the SPLASH survey of the Andromeda (M31) system, we have obtained Keck/DEIMOS spectra of the compact elliptical (cE) satellite M32. This is the first resolved-star kinematical study of any cE galaxy. In contrast to most previous kinematical studies that extended out to r information to account statistically for M31 contamination. The rotation curve and velocity dispersion profile extend well beyond the radius (r ~ 150'') where the isophotes are distorted. Unlike NGC 205, another close dwarf companion of M31, M32's kinematics appear regular and symmetric and do not show obvious sharp gradients across the region of isophotal elongation and twists. We interpret M31's kinematics using three-integral axisymmetric dynamical equilibrium models constructed using Schwarzschild's orbit superposition technique. Models with a constant mass-to-light ratio can fit the data remarkably well. However, since such a model requires an increasing tangential anisotropy with radius, invoking the presence of an extended dark halo may be more plausible. Such an extended dark halo is definitely required to bind a half-dozen fast-moving stars observed at the largest radii, but these stars may not be an equilibrium component of M32. Data herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

  10. Optical MEMS: boom, bust and beyond

    Science.gov (United States)

    Ramani, Chandra Mouli

    2005-10-01

    Optical Telecommunications bandwidth, spurred by the growth of the internet, experienced unprecedented growth in the late 1990's. The creation of new enterprises was vast and the expansion of established component, system and services companies was also breathtaking. This period of speculative growth was followed in 2001-2004 by one of the most significant market crashes in history. While $20B of venture capital was invested in optical telecom in the last 10 years, the vast majority of that has been written off in the last four. Countless start-ups inaugurated with great fanfare at the end of the 20th century were unceremoniously shut down at the start of the 21st. (1) As in all speculative bubbles, innovative technologies were born and buried. Nonetheless, new capabilities emerge from the chaos and disruption; one such example is the advent of Optical MEMS (MOEMS). Its development was vigorously pursued in both academic and corporate laboratories during the boom and, in the author's view; MOEMS constitutes a powerful and versatile tool set that is an invaluable residual of the last few years. In Telecommunications, MOEMS has proven to be the technology of choice for many optical switching and wavelength management applications. (2) Variable Optical Attenuators (VOA), Wavelength Blockers (WB), Dynamic Gain Equalizers (DGE), and most recently Wavelength Selective Switches (WSS) are being used in the numerous recent network deployments. Moreover, agile networks of the future will have MOEMS at every node. This presentation will provide an overview of the history of MOEMS in Telecommunications, discuss its byproducts and project the future of the technology.

  11. Credit Booms and Busts in Emerging Markets: The Role of Bank Governance and Risk Management

    OpenAIRE

    Brown, Martin; Andries, Alin Marius

    2014-01-01

    This paper investigates to what extent risk management and corporate governance mitigate the involvement of banks in credit boom and bust cycles. Using a unique, hand-collected dataset on 156 banks from Central and Eastern Europe during 2005-2012, we assess whether banks with stronger risk management and corporate governance display more moderate credit growth in the pre-crisis credit boom as well as a smaller credit contraction and fewer credit losses in the crisis period. With respect to ba...

  12. A study on entrapment: splashing of liquid UO2 over small sodium volumes

    International Nuclear Information System (INIS)

    Schins, H.; Klein, K.; Jorzik, E.

    1978-01-01

    Three experiments were done in which each time more than 1 kg of liqid UO 2 was splashed over a plate in which different stainless steel cups full of sodium were contained. No whatsoever indication of entrapment of sodium could be found. The pressure tests indicate up to 1,8 atm and they relax in some second time. These pressure diagrams have been satisfactorily analysed as indicating a sodium vapor formation. In the third experiment e.g. the quenching of 800 g UO 2 in 720 g of sodium in a closed volume of argon of 225 l will provide the requested maximum pressure

  13. Pembuatan Alur Pelayaran dalam Rencana Pelabuhan Marina Pantai Boom, Banyuwangi

    Directory of Open Access Journals (Sweden)

    Muhammad Didi Darmawan

    2017-01-01

    Full Text Available Pantai Boom merupakan pantai yang ada di Kabupaten Banyuwangi. Pantai ini terletak di Kelurahan Kampung Mandar, Kecamatan Banyuwangi, Banyuwangi, Jawa Timur. Pantai tersebut rencananya akan dibangun pelabuhan marina. Pelabuhan harus dilengkapi dengan beberapa fasilitas untuk mendukung rencana tersebut seperti salah satunya adalah alur pelayaran. Untuk membuat alur pelayaran diperlukan penelitian mengenai pasang surut, topografi dasar laut, serta jenis kapal yang melintas untuk memastikan kapal yang berlayar aman dari kemungkinan kecelakaan. Penelitian ini menggunakan data hasil pemeruman, data pasang surut yang diperoleh dari pengamatan langsung, serta berbagai jenis kapal yacht. Hasil dari penelitian ini didapatkan bahwa rencana dermaga sebaiknya dibangun 60 meter menjorok ke arah laut dengan panjang dermaga 25 meter. Dalam keadaan air rendah terendah (LLWL, ketiga jenis kapal yang ditentukan dapat merapat ke rencana Dermaga Pelabuhan Marina Pantai Boom, Banyuwangi. Daerah yang tidak bisa dilewati pada saat LLWL, pada saat MSL daerah tersebut sudah dapat dilewati oleh ketiga jenis kapal tersebut. Pada keadaan muka air tinggi tertinggi (HHWL, Kapal Yacht Class 8 dan 6 dapat melewati sebagian perairan sungai Pantai Boom.         Waktu yang tidak tepat untuk melakukan pelayaran pada saat LLWL dari alur pelayaran yang telah dibuat yaitu antara pukul 04:00 – 06:00 WIB pada saat bulan November 2015-Februari 2016 dan pukul 16:00-18:00 pada saat bulan Juni-Agustus 2016. Sedangkan Waktu yang tepat untuk melakukan pelayaran pada saat HHWL yaitu antara pukul 20:00–23:00 WIB pada saat bulan Desember 2015- Maret 2016 dan pukul 8:00-11:00 pada saat bulan Juni-September 2016.

  14. Current-driven plasmonic boom instability in three-dimensional gated periodic ballistic nanostructures

    Science.gov (United States)

    Aizin, G. R.; Mikalopas, J.; Shur, M.

    2016-05-01

    An alternative approach of using a distributed transmission line analogy for solving transport equations for ballistic nanostructures is applied for solving the three-dimensional problem of electron transport in gated ballistic nanostructures with periodically changing width. The structures with varying width allow for modulation of the electron drift velocity while keeping the plasma velocity constant. We predict that in such structures biased by a constant current, a periodic modulation of the electron drift velocity due to the varying width results in the instability of the plasma waves if the electron drift velocity to plasma wave velocity ratio changes from below to above unity. The physics of such instability is similar to that of the sonic boom, but, in the periodically modulated structures, this analog of the sonic boom is repeated many times leading to a larger increment of the instability. The constant plasma velocity in the sections of different width leads to resonant excitation of the unstable plasma modes with varying bias current. This effect (that we refer to as the superplasmonic boom condition) results in a strong enhancement of the instability. The predicted instability involves the oscillating dipole charge carried by the plasma waves. The plasmons can be efficiently coupled to the terahertz electromagnetic radiation due to the periodic geometry of the gated structure. Our estimates show that the analyzed instability should enable powerful tunable terahertz electronic sources.

  15. Boom clay pore water, home of a diverse microbial community

    International Nuclear Information System (INIS)

    Wouters, Katinka; Moors, Hugo; Leys, Natalie

    2012-01-01

    Document available in extended abstract form only. Boom Clay pore water (BCPW) has been studied in the framework of geological disposal of nuclear waste for over two decades, thereby mainly addressing its geochemical properties. A reference composition for synthetic clay water has been derived earlier by modelling and spatial calibration efforts, mainly based on interstitial water sampled from different layers within the Boom clay. However, since microbial activity is found in a range of extreme circumstances, the possibility of microbes interacting with future radioactive waste in a host formation like Boom Clay, cannot be ignored. In this respect, BCPW was sampled from different Boom Clay layers using the Morpheus piezometer and subsequently analysed by a complementary set of microbiological and molecular techniques, in search for overall shared and abundant microorganisms. Similar to the previous characterization of the 'average' BCPW chemical composition, the primary aim of this microbiological study is to determine a representative BCPW microbial community which can be used in laboratory studies. Secondly, the in situ activity and the metabolic properties of members of this community were addressed, aiming to assess their survival and proliferation chances in repository conditions. In a first approach, total microbial DNA of the community was extracted from the BCPW samples. This molecular approach allows a broad insight in the total microbial ecology of the BCPW samples. By polymerase chain reaction (PCR) on the highly conserved 16S rRNA genes in this DNA pool and subsequent sequencing and bio-informatics analysis, operational taxonomic units (OTUs) could be assigned to the microbial community. The bacterial community was found to be quite diverse, with OTUs belonging to 8 different phyla (Proteobacteria, Actinobacteria, Firmicutes, Bacteroidetes, Chlorobi, Spirochetes, Chloroflexi and Deinococcus-Thermus). These results provide an overall view of the

  16. Boom clay pore water, home of a diverse microbial community

    Energy Technology Data Exchange (ETDEWEB)

    Wouters, Katinka; Moors, Hugo; Leys, Natalie [SCK.CEN, Environment, Health and Safety Institute, B-2400 Mol (Belgium)

    2012-10-15

    Document available in extended abstract form only. Boom Clay pore water (BCPW) has been studied in the framework of geological disposal of nuclear waste for over two decades, thereby mainly addressing its geochemical properties. A reference composition for synthetic clay water has been derived earlier by modelling and spatial calibration efforts, mainly based on interstitial water sampled from different layers within the Boom clay. However, since microbial activity is found in a range of extreme circumstances, the possibility of microbes interacting with future radioactive waste in a host formation like Boom Clay, cannot be ignored. In this respect, BCPW was sampled from different Boom Clay layers using the Morpheus piezometer and subsequently analysed by a complementary set of microbiological and molecular techniques, in search for overall shared and abundant microorganisms. Similar to the previous characterization of the 'average' BCPW chemical composition, the primary aim of this microbiological study is to determine a representative BCPW microbial community which can be used in laboratory studies. Secondly, the in situ activity and the metabolic properties of members of this community were addressed, aiming to assess their survival and proliferation chances in repository conditions. In a first approach, total microbial DNA of the community was extracted from the BCPW samples. This molecular approach allows a broad insight in the total microbial ecology of the BCPW samples. By polymerase chain reaction (PCR) on the highly conserved 16S rRNA genes in this DNA pool and subsequent sequencing and bio-informatics analysis, operational taxonomic units (OTUs) could be assigned to the microbial community. The bacterial community was found to be quite diverse, with OTUs belonging to 8 different phyla (Proteobacteria, Actinobacteria, Firmicutes, Bacteroidetes, Chlorobi, Spirochetes, Chloroflexi and Deinococcus-Thermus). These results provide an overall view of the

  17. LHC Beam Splash seen by the ATLAS detector - 7 Apr 2015 - Run 260466 - LB 731 - Event 16848

    CERN Multimedia

    ATLAS, EXPERIMENT

    2015-01-01

    Event display of a collimator "splash" event seen by the ATLAS experiment in LHC Run-2, on Tuesday April the 7th 2015: event 16848, run 260466. The collimator position is 140m in front of the ATLAS interaction point. The figure on the left shows an axial view of the various components of the ATLAS detector. The figure on the right shows the energy deposits in the cells of the ATLAS calorimeter.

  18. Simulation and controller design for an agricultural sprayer boom leveling system

    KAUST Repository

    Sun, Jian; Miao, Yubin

    2011-01-01

    According to the agricultural precision requirements, the distance from sprayer nozzles to the corps should be kept between 50 cm to 70 cm. The sprayer boom also needs to be kept parallel to the field during the operation process. Thus we can

  19. Mobility of the dissolved organic matter through intact boom clay cores

    International Nuclear Information System (INIS)

    Put, M.J.; Dierckx, A.; Aertsens, M.; Canniere, P. de

    1998-01-01

    Performance assessment studies are expected to predict the enhancement of the migration of trivalent lanthanides and actinides due to their complexation with organic matter, which play a role as a transport agent [1]. Therefore, the mobility of the dissolved organic matter in the interstitial boom clay water is studied. For the first time, the mobile fraction present in the clay water is concentrated and labelled with a radioisotope to study the mobility of the organic matter in clay and the interaction of the mobile with the non-mobile. The isotopes tested as label are 125 I and 14 C. The 125 I label proved to be unstable and hence discarded. The labelled organic matter is then diluted for migration experiments on boom clay cores under anaerobic conditions. The influence of the molecular size on its mobility is studied by the separation of the labelled organic matter in different size fractions. (orig.)

  20. Prime Borrowers and Financial Innovation in the Housing Boom and Bust

    DEFF Research Database (Denmark)

    Bäckman, Claes; Lutz, Chandler

    for better consumption smoothing, even absent any shift in credit supply. In support of the model, we find that the introduction of interest-only mortgages was followed by a large increase in the number of buyers, even as credit quality remained constant. On the aggregate level the results indicate...... that interest-only mortgages amplified the boom-bust pattern in housing: house prices increased an additional 35 percent during the boom due to IO loans, and subsequently reverse during the bust. These effects, which cannot be explained by changes in lending standards or shifts in credit supply, are magnified...... in local housing markets with higher ex-ante house price expectations. Together, the findings document the consequences of introducing IO loans on the micro- and macro level, and illustrates how new mortgage products can have large impacts even in the absence of a shift in credit supply...

  1. Changing Fortunes: How China’s Boom Caused the Financial Crisis

    NARCIS (Netherlands)

    H. Mees (Heleen)

    2012-01-01

    textabstractThis dissertation includes five academic papers that – one way or the other – all relate to China. The first paper delivers proof for the central thesis of this thesis, which is that China’s boom caused the 2008 financial crisis and ensuing recession. As much as I hoped from the outset

  2. Financial services in England in the late XVII century and first equity market boom (1691–1693

    Directory of Open Access Journals (Sweden)

    S.Z. Moshenskyi

    2016-09-01

    Full Text Available The article shows the formation of the British financial services industry in the 1690's and the reasons of the first joint-stock companies’ boom of 1691–1693's. The author describes the course of events of this boom, and data on the volume of transactions in shares. The reasons of the joint-stock boom end are associated with very low capitalization of most of the new companies. The consequence of rapid economic growth in England in the late XVII century was the appearance and rapid development of financial services. Financial intermediaries appeared first and their services, in particular the services of insurance companies, were in demand. The rapid increase in the number of insurance companies has become prerequisite for becoming financial capitalism that led to the emergence of other intermediaries which provided financial services. Among them there were the so-called "notaries" that offered a full range of services related to land transactions and "bankers, jewelers," that woke the first private bankers. Thus, in the early 1690's London had a favorable environment for the rapid growth of the financial market, which was the main precondition for expanding market shares and led to the joint-stock boom.

  3. Developments in modelling of thermohydro-geomechanical behaviour of Boom clay and clay-based buffer materials (volume 2)

    International Nuclear Information System (INIS)

    Baldi, G.; Hueckel, T.; Peano, A.; Pellegrini, R.

    1991-01-01

    This study is composed of two parts: The first part (Volume 1) lays the foundations of a comprehensive theoretical treatment of the interaction between water and soil skeleton during thermal dilatation. The second part (volume 2) is devoted to the development and the application of advance constitutive modelling of mechanical behaviour of clays taking into account the extensive tests of Boom clay reported in the first volume. The development concentrated on the improvement of prediction of the volumetric response of clay skeleton: (a) improving the dilatancy prediction at low to high overconsolidation ratios (Section 2). An elasto-plastic constitutive model has been developed to account for this effect (Section 3.2.); (b) modelling of swelling effects (Section 2.5). A preliminary interpretative model for swelling prediction has been developed (Section 2.5). The application part consisted in interpreting the experimental results obtained for Boom clay to calibrate a set of constants (Section 3) for performing numerical analyses (Section 4) for the thermomechanical model already calibrated for Boom clay (Appendix). Interpretation of the tests required an assessment of influence of the strong anisotropy effects revealed by Boom clay on the basis of an interpretative model characterized by a kinematic hardening plasticity and coupled elasticity (section 3)

  4. Being young in a boom town

    Energy Technology Data Exchange (ETDEWEB)

    O' Connor, Christopher

    2011-08-15

    Fort McMurray is a booming town, having grown from small town to big city in a short time. A study was conducted to determine how this change affected young people. Results show they felt the changing environment required them to adapt all the time, which was a challenge but also a source of opportunities. Fort McMurray, with a labour shortage, afforded young people a lot of well-paid, flexible part time jobs during high school. These jobs were important to fund their post-secondary education. Although most of the young people saw themselves living elsewhere in 10 years, they could possibly stay if local challenges in the city were addressed.

  5. Baby boom generation at the retirement onset

    Directory of Open Access Journals (Sweden)

    Stojilković Jelena

    2010-01-01

    Full Text Available Sudden increase in the number of live births after the Second World War due to an increase in fertility rates has led to the formation of cohorts with specific characteristics or baby boom generation. This generation is unique in the history of the demographic phenomenon that has affected and affects the functioning of many segments of society. The aim of this paper is to assess structure of baby boomers who are few years away from retirement, using demographic data. Impact of baby boomer age structure of current and future retirees is described with a graphical display of current and projected age pyramid of baby boomers. Demographic pattern that women live longer than men is evident in the projected pyramid. In addition, the number of baby boomers will lead to a "younger" old population. The imbalance in the number of men and women pensioners, as well as older cohorts of women and female baby boomers was analyzed. As a result, an increasing trend of women's age pensioners who are members of the baby boom generation was clearly observed, which is opposite to the older cohort of women who often were family pensioners. Different circumstances and conditions in which female boomers lived and worked will form a new "pension model" because they will gain their benefits as well as men, for the first time in significant number, unlike their mothers, which gained the right to retire after they become widows. Number of women age pensioners is getting greater comparing to men, as the result of changes in the economic activities of women in the last half of the 20th century. When baby boomers retire and exit the working population, this will create a vacuum, because the numerically smaller generations will enter working population, while the sudden and very shortly, the number of population older than 60 or 65 will increase, most of them will likely to acquire the right to a pension. It is undeniable that baby boomers had impact on demographic structure

  6. Proposed gravity-gradient dynamics experiments in lunar orbit using the RAE-B spacecraft

    Science.gov (United States)

    Blanchard, D. L.; Walden, H.

    1973-01-01

    A series of seven gravity-gradient dynamics experiments is proposed utilizing the Radio Astronomy Explorer (RAE-B) spacecraft in lunar orbit. It is believed that none of the experiments will impair the spacecraft structure or adversely affect the continuation of the scientific mission of the satellite. The first experiment is designed to investigate the spacecraft dynamical behavior in the absence of libration damper action and inertia. It requires stable gravity-gradient capture of the spacecraft in lunar orbit with small amplitude attitude librations as a prerequisite. Four subsequent experiments involve partial retraction, ultimately followed by full redeployment, of one or two of the 230-meter booms forming the lunar-directed Vee-antenna. These boom length change operations will induce moderate amplitude angular librations of the spacecraft.

  7. In situ and laboratory migration experiments through boom clay at Mol

    International Nuclear Information System (INIS)

    Preter, P. de; Put, M.; Canniere, P. de

    1993-01-01

    Physico-chemical characterization and migration studies in the Boom clay, envisaged as a potential host sediment for high level waste disposal in Belgium, were started some 15 years ago. A synthesis study of this experimental work has recently been conducted to compile all available data. From a comparison of the available migration data and the data requirements as derived from the performance assessment studies PAGIS (1988) and PACOMA (1991) the new migration programme (1991-1995) was defined. The critical radionuclides, both with relation to dose rates to man and to missing or unreliable migration data, turned out to be 14 C, 99 Tc. 135 Cs and 237 Np. A second group of radionuclides was found to be possibly critical: 79 Se, 93 Zr, 107 Pd, U - , Am - , Cm - , and Pu-isotopes. This report concentrates on the experimental results as obtained from the migration experiments started in the previous migration programme. Some of the reported radionuclides e.g. 90 Sr) have lost their critical character and will not be further studied within the new programme. New experimental data from laboratory tests have become available for Np, Cs, Sr and C (as HC0 3 - ) and the first results on the migration of organic molecules dissolved in the interstitial Boom clay water are reported. The hydraulic parameters (the hydraulic conductivity K and the storage coefficient S o ) were calculated from both laboratory percolation experiments and in situ piezometric measurements. Conclusions concerning Boom clay anisotropy are drawn. Finally, a short description of the ongoing in situ HTO injection experiment is given and the experimental data are analyzed and discussed. 10 refs., 4 figs., 1 tab

  8. Dynamic simulation of the NET In-Vessel Handling Unit

    International Nuclear Information System (INIS)

    Reim, J.

    1991-01-01

    During the conceptual design phase of the Next European Torus (NET) a large remote maintenance transporter system, the In-Vessel Handling Unit (IVHU), is being developed. It consists of an articulated boom with four rotational joints, which is mounted on a carrier outside the vessel. This boom will be able to carry master-slave manipulators or special work units. The engineering design is supported by dynamic computations. Main topics of the dynamic simulation are the evaluation of IVHU performance, selection and optimisation of the actuator design and of the control algorithms. This simulation task requires full three-dimensional modelling regarding structural elasticity and non-linear actuator dynamics. The Multibody dynamics of the transporter system are modelled with a commerical analysis package. Elastic links and a precise dynamic actuator model are introduced by applied forces, spring elements and differential equations. The actuator model comprises electric motors, gears and linear control algorithms. Non-linear effects which have an influence on control stability and accuracy are taken into account. Most important effects are backlash and static friction. The simulations concentrate on test and optimisation of the control layout and performance studies for critical remote handling tasks. Simulations for control layout and critical remote maintenance tasks correspond to the design objectives of the transporter system. (orig.)

  9. Did the Aid Boom Pacify Sub-Saharan Africa?

    OpenAIRE

    Azam, Jean-Paul; Thelen, Véronique

    2017-01-01

    The incidence of civil war in Sub-Saharan Africa since the turn of the century is less than half of what it was on average in the last quarter of the 20th century. This paper shows that the aid boom triggered by 9/11 played a key role in achieving purposefully this result using panel data for 46 African countries over four decades. It applies a nearidentification approach to test the aid-conflict tradeoff, taking due account of asymmetric information between the donors and the econometrician....

  10. NASA's Advanced Solar Sail Propulsion System for Low-Cost Deep Space Exploration and Science Missions that Use High Performance Rollable Composite Booms

    Science.gov (United States)

    Fernandez, Juan M.; Rose, Geoffrey K.; Younger, Casey J.; Dean, Gregory D.; Warren, Jerry E.; Stohlman, Olive R.; Wilkie, W. Keats

    2017-01-01

    Several low-cost solar sail technology demonstrator missions are under development in the United States. However, the mass saving derived benefits that composites can offer to such a mass critical spacecraft architecture have not been realized yet. This is due to the lack of suitable composite booms that can fit inside CubeSat platforms and ultimately be readily scalable to much larger sizes, where they can fully optimize their use. With this aim, a new effort focused at developing scalable rollable composite booms for solar sails and other deployable structures has begun. Seven meter booms used to deploy a 90 m2 class solar sail that can fit inside a 6U CubeSat have already been developed. The NASA road map to low-cost solar sail capability demonstration envisioned, consists of increasing the size of these composite booms to enable sailcrafts with a reflective area of up to 2000 m2 housed aboard small satellite platforms. This paper presents a solar sail system initially conceived to serve as a risk reduction alternative to Near Earth Asteroid (NEA) Scout's baseline design but that has recently been slightly redesigned and proposed for follow-on missions. The features of the booms and various deployment mechanisms for the booms and sail, as well as ground support equipment used during testing, are introduced. The results of structural analyses predict the performance of the system under microgravity conditions. Finally, the results of the functional and environmental testing campaign carried out are shown.

  11. Background Pressure Profiles for Sonic Boom Vehicle Testing in the NASA Glenn 8- by 6-Foot Supersonic Wind Tunnel

    Science.gov (United States)

    Castner, Raymond; Shaw, Stephen; Adamson, Eric; Simerly, Stephanie

    2013-01-01

    In an effort to identify test facilities that offer sonic boom measurement capabilities, an exploratory test program was initiated using wind tunnels at NASA research centers. The subject of this report is the sonic boom pressure rail data collected in the Glenn Research Center 8- by 6-Foot Supersonic Wind Tunnel. The purpose is to summarize the lessons learned based on the test activity, specifically relating to collecting sonic boom data which has a large amount of spatial pressure variation. The wind tunnel background pressure profiles are presented as well as data which demonstrated how both wind tunnel Mach number and model support-strut position affected the wind tunnel background pressure profile. Techniques were developed to mitigate these effects and are presented.

  12. Nondestructive Online Detection of Welding Defects in Track Crane Boom Using Acoustic Emission Technique

    Directory of Open Access Journals (Sweden)

    Yong Tao

    2014-04-01

    Full Text Available Nondestructive detection of structural component of track crane is a difficult and costly problem. In the present study, acoustic emission (AE was used to detect two kinds of typical welding defects, that is, welding porosity and incomplete penetration, in the truck crane boom. Firstly, a subsidiary test specimen with special preset welding defect was designed and added on the boom surface with the aid of steel plates to get the synchronous deformation of the main boom. Then, the AE feature information of the welding defect could be got without influencing normal operation of equipment. As a result, the rudimentary location analysis can be attained using the linear location method and the two kinds of welding defects can be distinguished clearly using AE characteristic parameters such as amplitude and centroid frequency. Also, through the comparison of two loading processes, we concluded that the signal produced during the first loading process was mainly caused by plastic deformation damage and during the second loading process the stress release and structure friction between sections in welding area are the main acoustic emission sources. Thus, the AE is an available tool for nondestructive online detection of latent welding defects of structural component of track crane.

  13. The Use of Structural-Acoustic Techniques to Assess Potential Structural Damage From Sonic Booms

    Science.gov (United States)

    Garrelick, Joel; Martini, Kyle

    1996-01-01

    The potential impact of supersonic operations includes structural damage from the sonic boom overpressure. This paper describes a study of how structural-acoustic modeling and testing techniques may be used to assess the potential for such damage in the absence of actual flyovers. Procedures are described whereby transfer functions relating structural response to sonic boom signature may be obtained with a stationary acoustic source and appropriate data processing. Further, by invoking structural-acoustic reciprocity, these transfer functions may also be acquired by measuring the radiated sound from the structure under a mechanical drive. The approach is based on the fundamental assumption of linearity, both with regard to the (acoustic) propagation of the boom in the vicinity of the structure and to the structure's response. Practical issues revolve around acoustic far field and source directivity requirements. The technique was implemented on a specially fabricated test structure at Edwards AFB, CA with the support of Wyle Laboratories, Inc. Blank shots from a cannon served as our acoustic source and taps from an instrumented hammer generated the mechanical drive. Simulated response functions were constructed. Results of comparisons with corresponding measurements recorded during dedicated supersonic flyovers with F-15 aircraft are presented for a number of sensor placements.

  14. Radionuclide transport in the Neogene aquifer system located in the environment of the Boom clay

    International Nuclear Information System (INIS)

    Gedeon, M.; Marivoet, J.; Vandersteen, K.

    2012-01-01

    Document available in extended abstract form only. In the framework the Belgian research program on the long term management of high-level and/or long-lived radioactive waste coordinated by ONDRAF/NIRAS, the Boom Clay is considered as a reference host rock for the geological disposal of high-level radioactive waste in NE-Belgium (Campine area). In the frame of the performance assessments of a disposal system located in the Boom Clay Formation, the transport of radionuclides diffusing through the clay barrier into the aquifers located above is modelled. The transport model for the Neogene aquifer is based on a series of groundwater flow models simulating the aquifer systems in the surroundings of the Boom Clay. This series of groundwater models include the regional north-eastern Belgium model simulating flow both above and below the Boom Clay, the recently updated deep-aquifer pumping model, simulating transient flow in the over-exploited aquifers below the Boom Clay and finally the catchment-scale Neogene aquifer model, simulating flow in the aquifer system above the Boom Clay. The Neogene aquifer system consists of two main aquifers. The Pliocene aquifer is located at the top, separated from the underlying Miocene aquifer by the Kasterlee Clay aquitard. The Miocene aquifer consists of three hydrostratigraphic units: the Diest, Berchem and Voort Formations; with the last two having a lower hydraulic conductivity than the Diest unit. The transport model for the Neogene aquifer represents a fraction of the catchment-scale Neogene aquifer model. It stretches from the local divide between the Grote and Kleine Nete Rivers up to the Kleine Nete River, representing the main model sink. The boundary conditions and the sources/sinks in the Pliocene aquifer are defined mostly by the surface water features, such as the rivers, brooks, lakes and canals. In the partially confined Miocene aquifer, the effect of the surface water features is dampened and the heads at the model

  15. Accelerator boom hones China's engineering expertise

    Science.gov (United States)

    Normile, Dennis

    2018-02-01

    In raising the curtain on the China Spallation Neutron Source, China has joined just four other nations in having mastered the technology of accelerating and controlling beams of protons. The $277 million facility, set to open to users this spring in Dongguan, is expected to yield big dividends in materials science, chemistry, and biology. More world class machines are on the way, as China this year starts construction on four other major accelerator facilities. The building boom is prompting a scramble to find enough engineers and technicians to finish the projects. But if they all come off as planned, the facilities would position China to tackle the next global megaproject: a giant accelerator that would pick up where Europe's Large Hadron Collider leaves off.

  16. Higher Education and the Minerals Boom: A View from the Regions

    Science.gov (United States)

    Bell, Philip

    2014-01-01

    This paper examines the impact of the minerals boom to date on the demand for higher education in Central Queensland, and the sustainability of higher education providers in high economic growth environments. Several datasets were used to examine changes in the demand for higher education among specific student groups within the region, the…

  17. The secret of neuroscience boom: Are there secret human experiments in Latin América?

    Directory of Open Access Journals (Sweden)

    David Salinas Flores

    2016-01-01

    Full Text Available About 6 years ago there sparked a phenomenon in science called the neuroscientific boom. Neurologists underpin this phenomenon to cost reduction techniques such as electroencephalograms and to improved noninvasive technology such as functional MRI. But the human brain, the most complex organ in the universe, has not yet been fully investigated with the existing noninvasive technologies. Thus, there is a suspicion that the real reason for this boom is a secret, forced, and illicit human experimentation in Latin America. Physicians should investigate, be alert, and report these potential unethical human experiments to prevent any further damage to the public health of the citizens of Latin societies.

  18. Thermo-hydro-mechanical behaviour of Boom clay; Comportement thermo-hydro-mecanique de l'argile de Boom

    Energy Technology Data Exchange (ETDEWEB)

    Le, T.T

    2008-01-15

    This thesis studied the thermo-hydro-mechanical properties of Boom clay, which was chosen to be the host material for the radioactive waste disposal in Mol, Belgium. Firstly, the research was concentrated on the soil water retention properties and the hydro-mechanical coupling by carrying out axial compression tests with suction monitoring. The results obtained permitted elaborating a rational experimental procedure for triaxial tests. Secondly, the systems for high pressure triaxial test at controlled temperature were developed to carry out compression, heating, and shearing tests at different temperatures. The obtained results showed clear visco-elasto-plastic behaviour of the soil. This behaviour was modelled by extending the thermo-elasto-plastic model of Cui et al. (2000) to creep effect. (author)

  19. Thermal shock and splash effects on burned gypseous soils from the Ebro Basin (NE Spain)

    Science.gov (United States)

    León, J.; Seeger, M.; Badía, D.; Peters, P.; Echeverría, M. T.

    2014-03-01

    Fire is a natural factor of landscape evolution in Mediterranean ecosystems. The middle Ebro Valley has extreme aridity, which results in a low plant cover and high soil erodibility, especially on gypseous substrates. The aim of this research is to analyze the effects of moderate heating on physical and chemical soil properties, mineralogical composition and susceptibility to splash erosion. Topsoil samples (15 cm depth) were taken in the Remolinos mountain slopes (Ebro Valley, NE Spain) from two soil types: Leptic Gypsisol (LP) in a convex slope and Haplic Gypsisol (GY) in a concave slope. To assess the heating effects on the mineralogy we burned the soils at 105 and 205 °C in an oven and to assess the splash effects we used a rainfall simulator under laboratory conditions using undisturbed topsoil subsamples (0-5 cm depth of Ah horizon). LP soil has lower soil organic matter (SOM) and soil aggregate stability (SAS) and higher gypsum content than GY soil. Gypsum and dolomite are the main minerals (>80%) in the LP soil, while gypsum, dolomite, calcite and quartz have similar proportions in GY soil. Clay minerals (kaolinite and illite) are scarce in both soils. Heating at 105 °C has no effect on soil mineralogy. However, heating to 205 °C transforms gypsum to bassanite, increases significantly the soil salinity (EC) in both soil units (LP and GY) and decreases pH only in GY soil. Despite differences in the content of organic matter and structural stability, both soils show no significant differences (P pores is reduced by heating, as derived from variations in soil water retention capacity.

  20. China’s Internet Finance Boom and Tyrannies of Inclusion

    OpenAIRE

    Loubere, Nicholas

    2018-01-01

    One of the main drivers of China’s e-commerce boom is the dramatic expansion of the country’s Internet finance industry, which has grown and diversified at a staggering rate over the past decade. The emergence of Chinese Internet finance has been discussed in largely positive terms as facilitating commercial activity. It has also been linked to the wider developmental goal of promoting financial inclusion through the provision of financial services to previously excluded populations. Emerging...

  1. The baby boom, the baby bust, and the housing market.

    Science.gov (United States)

    Mankiw, N G; Weil, D N

    1989-05-01

    This paper explores the impact of demographic changes on the housing market in the US, 1st by reviewing the facts about the Baby Boom, 2nd by linking age and housing demand using census data for 1970 and 1980, 3rd by computing the effect of demand on price of housing and on the quantity of residential capital, and last by constructing a theoretical model to plot the predictability of the jump in demand caused by the Baby Boom. The Baby Boom in the U.S. lasted from 1946-1964, with a peak in 1957 when 4.3 million babies were born. In 1980 19.7% of the population were aged 20-30, compared to 13.3% in 1960. Demand for housing was modeled for a given household from census data, resulting in the finding that demand rises sharply at age 20-30, then declines after age 40 by 1% per year. Thus between 1970 and 1980 the real value of housing for an adult at any given age jumped 50%, while the real disposable personal income per capita rose 22%. The structure of demand is such that the swelling in the rate of growth in housing demand peaked in 1980, with a rate of 1.66% per year. Housing demand and real price of housing were highly correlated and inelastic. If this relationship holds in the future, the real price of housing should fall about 3% per year, or 47% by 2007. The theoretical model, a variation of the Poterba model, ignoring inflation and taxation, suggests that fluctuations in prices caused by changes in demand are not foreseen by the market, even though they are predictable in principle 20 years in advance. As the effects of falling housing prices become apparent, there may be a potential for economic instability, but people may be induced to save more because their homes will no longer provide the funds for retirement.

  2. In situ burning via towed boom of oil spilled at sea

    International Nuclear Information System (INIS)

    Carrier, G.; Fendell, F.; Mitchell, J.

    1992-01-01

    In this paper, operational guidance for the efficient use of combustion in the cleanup of a surface oil film, formed as a result of a spill at sea, is sought by approximate analysis. In remediation by burning, the spilled oil itself provides the energy for its cleanup. Attention is focused on situations holding relatively far from the source of the spill and/or relatively long after the spill: the oil is taken to have so dispersed that the thickness of the film is on the order of a few millimeters. Under such conditions, the oil film is unlikely to burn without the use of multiple towed booms, each boom spreading its already-ignited, localized fire to continuously collected, previously unignited portions of the oil film. A simple, quasisteady, two-dimensional analysis suggests efficient values for the tow speed and the tow--line length as functions of such parameters as the oil density, oil-film thickness, oil burn/evaporation rate, etc. The analysis leads to specific suggestions for apparently unreported laboratory experiments that may be informative prior to at-sea operation

  3. Operational comparison of two types of tractor sprayers (microner and boom-type against wheat crop weeds

    Directory of Open Access Journals (Sweden)

    M Hamid

    2015-09-01

    Full Text Available Introduction: Nowadays, the tractor mounted boom sprayer is used in many agricultural fields. These sprayers have many advantages compared to other sprayers, but in Iran, their field efficiency is much lower than that of the developed countries, because the tank volume and consumption of pesticides per hectare is often so highthat spraying per hectare takesa long time for handling the solutions and transporting the sprayers. Also spray droplet size is ordinarily high and its distribution is unknot uniform. So, often spraying and dropping top parts of plants on the earth is inevitable. According to studies carried out in the country during the years 2005-2008 in the agricultural research centers in several provinces such as Khuzestan, four types of sprayers including tractor mounted sprayer, atomizer, microner, and electrostatic atomizer were studied and some of the results obtained include the following. From the point of view of percentage of crash crop, tractor mounted sprayer has the highest percentage, but microner sprayer had the lowest. From the point of view of the solution of consumption amount and spraying cost per hectare, the operation of the tractor mounted sprayer and electrostatic sprayer had the highest and the lowest ranks, respectively. Atomizer sprayer had the highest effect on the percentage amount of weed control, but it requires a high amount of water consumption, high drift and low operation (Safari and Lovaimi, 2010. Materials and Methods: The experiment was carried out during 2012-2013 in the field of agricultural research located in the Mollasani city located 20 km near Ahvaz. In this study, tractor mounted spinning disk sprayer (mounted microner sprayer was evaluated in comparison with conventional boom sprayer on weeds control. The treatments included medium (3500 rpm and low (2000 rpm speed rotation disk sprayer and two types of nozzle in conventional boom sprayer. One of them was an Italian tee jet nozzle and the

  4. Fracturing and Self-Healing in the Boom Clay: Evidences and Further Studies

    International Nuclear Information System (INIS)

    Bernier, Frederic

    2001-01-01

    The Boom Clay is considered as a potential host-rock for the disposal of Belgian radioactive waste. During the sinking of a new shaft to extend the underground facility HADES, an important fracturing has been evidenced around the excavation. Fracturing was already observed previously but to a lesser extent. The low support pressure imposed by the primary shaft lining, combined with the large time over which this support condition held, has favoured the decompression of the clay massif through delayed effects, and therefore the development of fracturing. In the frame of the overall performance of a radioactive waste repository, it is of prime importance to understand the fracturing process induced by excavation in Boom Clay, as well as the self-healing process. Some self-healing evidences have been observed around the HADES underground laboratory but need further investigation to be confirmed. This will be done in the SELFRAC EC project (Fractures and Self-healing within the Excavation Disturbed Zone in clays)

  5. 75 FR 49843 - Regulated Navigation Area; Boom Deployment Strategy Testing, Great Bay, NH

    Science.gov (United States)

    2010-08-16

    ... will be marked with 32-inch floating balls to make the ends of each boom segment more visible to... east, a line drawn between the easternmost end of the Scammel Bridge (Route 4) in position 43[deg]07'41...

  6. Regional modelling of the confined aquifers below the Boom clay in NE-Belgium

    International Nuclear Information System (INIS)

    Vandersteen, K.; Gedeon, M.; Marivoet, J.; Wouters, L.

    2012-01-01

    Document available in extended abstract form only. In the framework of the Belgian research program on the long term management of high-level and/or long-lived radioactive waste coordinated by ONDRAF/NIRAS, the Boom Clay is considered as a reference host rock for the geological disposal of high-level radioactive waste in NE-Belgium (Campine area). The hydrogeological program at SCK.CEN supports the long-term performance assessments of the geological disposal of radioactive waste by performing a phenomenological research of the aquifer systems surrounding the studied disposal system. One of the important components of this programme is the regional hydrogeological modelling. The regional hydrogeology is studied using two main models - the steady state Neogene aquifer model (NAM) and the transient deep aquifer pumping model (DAP), developed to characterize and quantify the regional groundwater flow in, respectively, the aquifers lying above the Boom Clay in the Nete catchment area (NAM), and the aquifers lying below the Boom Clay in the Campine area (DAP). This paper describes the most recent update of the DAP model. The DAP model represents the confined part of the groundwater system located stratigraphically below the Boom Clay. This includes the parts of the Oligocene aquifer, the Bartoon aquitard system and the Ledo-Paniselian-Brusselian aquifer buried under the Boom Clay. Due to the considerable pumping from these aquifers in combination with a limited recharge, a gradual decrease in groundwater levels has been observed in more than 30-year piezometric records. In the DAP model, the shallow aquifer system overlying the Boom Clay is replaced by fixed head boundaries: this aquifer system is dominated by close-to-surface hydrological processes and the heads fluctuate seasonally without any apparent long-term trend. In the horizontal direction, the model extends to the south as far as the outcrops of the major aquitards: the Maldegem Formation confining the Ledo

  7. Dynamics and Control of a Flexible Solar Sail

    OpenAIRE

    Jiafu Liu; Siyuan Rong; Fan Shen; Naigang Cui

    2014-01-01

    Solar sail can merely make use of solar radiation pressure (SRP) force as the thrust for space missions. The attitude dynamics is obtained for the highly flexible solar sail with control vanes, sliding masses, and a gimbaled control boom. The vibration equations are derived considering the geometric nonlinearity of the sail structure subjected to the forces generated by the control vanes, solar radiation pressure (SRP), and sliding masses. Then the dynamic models for attitude/vibration contr...

  8. Modelling of radionuclide migration and heat transport from an High-Level-Radioactive-Waste-repository (HLW) in Boom clay

    International Nuclear Information System (INIS)

    Put, M.; Henrion, P.

    1992-01-01

    For the modelling of the migration of radionuclides in the Boom clay formation, the analytical code MICOF has been updated with a 3-dimensional analytical solution for discrete sources. the MICOF program is used for the calculation of the release of α and β emitters from the HIGH LEVEL RADIOACTIVE WASTES (HLW). A coherent conceptual model is developed which describes all the major physico-chemical phenomena influencing the migration of radionuclides in the Boom clay. The concept of the diffusion accessible porosity is introduced and included in the MICOF code. Different types of migration experiments are described with their advantages and disadvantages. The thermal impact of the HLW disposal in the stratified Boom clay formation has been evaluated by a finite element simulation of the coupled heat and mass transport equation. The results of the simulations show that under certain conditions thermal convection cells may form, but the convective heat transfer in the clay formation is negligible. 6 refs., 19 figs., 2 tabs., 5 appendices

  9. Politics and Nigerian agriculture in the first decade of the "Oil boom ...

    African Journals Online (AJOL)

    Politics and Nigerian agriculture in the first decade of the "Oil boom", 1970-1980: a preliminary assessment. A Olorunfemi, OC Adesina. Abstract. No Abstract. The Nigerian Journal of Economic History VoL. 1, 1998: 57-69. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  10. Asia-Pacific focus of coming LNG trade boom

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This paper reports that the Asia-Pacific region remains the centerpiece of a booming world trade in liquefied natural gas. Biggest growth in LNG demand is expected from some of the region's strongest economies such as Japan, South Korea, and Taiwan, Key LNG exporters such as Brunei, Malaysia, and Indonesia are scrambling to implement projects to meet that expected demand growth. Uncertainties cloud the outlook for Far East LNG trade, Australia, for one, is more cautious in pressing expansion of its LNG export capacity as more competing LNG expansions spring up around the world, notably in the Middle East and Africa

  11. The effect of high pH alkaline solutions on the mineral stability of the Boom Clay - Batch experiments at 60 deg. C

    International Nuclear Information System (INIS)

    Honty, M.; De Craen, M.; Wang, L.; Madejova, J.; Czimerova, A.; Pentrak, M.; Stricek, I.; Van Geet, M.

    2010-01-01

    Boom Clay is currently viewed as a reference host formation for studies on deep geological disposal of radioactive waste in Belgium. The interactions between bulk rock Boom Clay and 0.1 M KOH, 0.1 M NaOH, 0.1 M Ca(OH) 2 , young cement water and evolved cement water solutions, ranging in pH from 12.5 to 13.2, were examined as static batch experiments at 60 deg. C to simulate alkaline plume perturbations, which are expected to occur in the repository due to the presence of concrete. Both liquids and solids were investigated at specific times between 90 and 510 days in order to control the elemental budget and to search for potential mineralogical alterations. Also, the clay fraction was separated from the whole-rock Boom Clay at the end of each run and characterized for its mineralogical composition. Thereby, the importance of the mineral matrix to buffer the alkaline attack and the role of organic matter to protect clay minerals were also addressed. The results indicate that the degree of geochemical perturbation in Boom Clay is dependent on the initial pH of the applied solution together with the nature of the major cation in the reactant fluids. The higher the initial pH of the media, the stronger its interaction with Boom Clay. No major non-clay mineralogical alteration of the Boom Clay was detected, but dissolution of kaolinite, smectite and illite occurred within the studied experimental conditions. The dissolution of clays is accompanied by the decrease in the layer charge, followed by a decrease in the cation-exchange capacity. The highest TOC values coincide with the highest total elemental concentrations in the leachates, and correspondingly, the highest dissolution degree. However, no quantitative link could be established between the degree of organic matter decomposition and clay dissolution.

  12. Results from the Splash Survey: Spectroscopic and Photometric Landscape of Andromeda's Stellar Halo

    Science.gov (United States)

    Guhathakurta, Puragra; SPLASH Collaboration

    2009-01-01

    Detailed studies of nearby galaxies provide vital clues about their formation and evolutionary history. This "fossil record" approach is complementary to direct look-back studies of distant galaxies. Our Galaxy and the Andromeda spiral galaxy (M31) have long been cornerstones in the former category. M31 provides an external perspective on a large galaxy similar to our own and yet is close enough to allow detailed studies of individual stars. In my talk, I will present results from the SPLASH collaboration: Spectroscopic and Photometric Landscape of Andromeda's Stellar Halo. The collective data set from this large international team includes thousands of Keck/DEIMOS spectra of individual red giant branch stars, ground-based deep wide-field imaging and photometry with KPNO/Mosaic, CFHT/MegaCam, and Subaru/Suprime-Cam, and ultra-deep pencil-beam probes with HST/ACS imaging reaching below the main-sequence turnoff. Our recent discovery of an extended stellar halo in M31 (R > 150 kpc) shows that most previous studies of its spheroid have been sampling its inner bulge-like spheroidal component, not its halo. In my talk I will touch upon several related topics related to the general theme of hierarchical galaxy formation including: M31's global structure and subcomponents (halo, bulge/central bar, and disk), stellar dynamics, statistical properties of substructure, detailed chemical abundance measurements, detailed forensic reconstruction of recent collision events, dwarf satellites as tracers and building blocks of larger galaxies, and empirical constraints on the tangential motion of the M31 system. I will also discuss recent results on the chemical abundance of the lowest luminosity Galactic satellites (recently discovered by SDSS) and implications for the formation of the Milky Way halo. This research was supported by funds from the National Science Foundation, NASA, and the Institute for Geophysics and Planetary Physics.

  13. Adaptive Aft Signature Shaping of a Low-Boom Supersonic Aircraft Using Off-Body Pressures

    Science.gov (United States)

    Ordaz, Irian; Li, Wu

    2012-01-01

    The design and optimization of a low-boom supersonic aircraft using the state-of-the- art o -body aerodynamics and sonic boom analysis has long been a challenging problem. The focus of this paper is to demonstrate an e ective geometry parameterization scheme and a numerical optimization approach for the aft shaping of a low-boom supersonic aircraft using o -body pressure calculations. A gradient-based numerical optimization algorithm that models the objective and constraints as response surface equations is used to drive the aft ground signature toward a ramp shape. The design objective is the minimization of the variation between the ground signature and the target signature subject to several geometric and signature constraints. The target signature is computed by using a least-squares regression of the aft portion of the ground signature. The parameterization and the deformation of the geometry is performed with a NASA in- house shaping tool. The optimization algorithm uses the shaping tool to drive the geometric deformation of a horizontal tail with a parameterization scheme that consists of seven camber design variables and an additional design variable that describes the spanwise location of the midspan section. The demonstration cases show that numerical optimization using the state-of-the-art o -body aerodynamic calculations is not only feasible and repeatable but also allows the exploration of complex design spaces for which a knowledge-based design method becomes less effective.

  14. Growth and instability of the liquid rim in the crown splash regime

    Science.gov (United States)

    Agbaglah, G.; Deegan, R. D.

    2014-08-01

    We study the formation, growth, and disintegration of jets following impact of a drop on a thin film of the same liquid for We < 1000 and Re < 2000 using a combination of numerical simulations and linear stability theory (Agbaglah et al. 2013). Our simulations faithfully capture this phenomena and are in good agreement with experimental profiles obtained from high-speed X-ray imaging.We obtain scaling relations from our simulations and use these as inputs to our stability analysis. The resulting prediction for the most unstable wavelength are in excellent agreement with experimental data. Our calculations show that the dominant destabilizing mechanism is a competition between capillarity and inertia but that deceleration of the rim provides an additional boost to growth. We also predict over the entire parameter range of our study the number and timescale for formation of secondary droplets formed during a splash, based on the assumption that the most unstable mode sets the droplet number.

  15. Literatura y arte latinoamericanos hoy: ¿Boom o Burbuja?

    OpenAIRE

    Sánchez, Yvette

    2016-01-01

    Resumen El presente artículo intenta caracterizar el reemplazamiento de las letras latinoamericanas por las artes visuales, en lo referido a su proyección internacional, en el último medio siglo. Mientras que el Boom latinoamericano de la literatura de los años 60 se extinguía paulatina y casi imperceptiblemente, hay críticos que afirman que la difusión, la demanda en el mercado y el explotado valor monetario de las artes visuales amenazan con desaparecer repentinamente. Este fenómeno suele e...

  16. Pendulation control system and method for rotary boom cranes

    Science.gov (United States)

    Robinett, III, Rush D.; Groom, Kenneth N.; Feddema, John T.; Parker, Gordon G.

    2002-01-01

    A command shaping control system and method for rotary boom cranes provides a way to reduce payload pendulation caused by real-time input signals, from either operator command or automated crane maneuvers. The method can take input commands and can apply a command shaping filter to reduce contributors to payload pendulation due to rotation, elevation, and hoisting movements in order to control crane response and reduce tangential and radial payload pendulation. A filter can be applied to a pendulation excitation frequency to reduce residual radial pendulation and tangential pendulation amplitudes.

  17. Dual-chamber inflatable oil boom

    International Nuclear Information System (INIS)

    Blair, R.M.; Tedeschi, E.T.

    1993-01-01

    An elongated floating material containment boom section is described having a normally vertical ballasted skirt depending from flotation means, and convertible from a flattened collapsed condition to a deployable condition wherein buoyancy chamber means extending along the upper edge of said skirt are inflated to expanded buoyant configuration, including: a gas-impervious sleeve extending along the upper edge of said normally vertical skirt forming a first outer collapsible and inflatable flotation chamber, a first inflation valve connecting the interior of said sleeve with the ambient atmosphere, through which gas under pressure may be introduced into said sleeve to inflate said first buoyant outer flotation chamber, elongated gas-impervious tube means positioned inside said outer flotation chamber and forming second collapsible and inflatable internal flotation bladder chamber means, second inflation valve means connecting the interior of said bladder means through said outer flotation chamber to the ambient atmosphere through which gas under pressure may be introduced into said bladder means to inflate it forming said second flotation chamber means inside said outer flotation chamber

  18. The Funding of the Irish Domestic Banking System During the Boom?

    OpenAIRE

    Lane, Philip R.

    2015-01-01

    (read before the Society, 15th January 2015) This paper analyses the funding of the Irish domestic banking system during the boom period. We highlight: the shifting roles of deposit and bond funding; the prominence of foreign banks as funding counterparties; the role of interoffice funding; and the scale of US dollar and Sterling funding. From August 2007, the deterioration in funding conditions is clearly evident across a range of indicators.

  19. Technetium migration in Boom Clay - Assessing the role of colloid-facilitated transport in a deep clay formation

    International Nuclear Information System (INIS)

    Bruggeman, C.; Martens, E.; Maes, N.; Jacops, E.; Van Gompel, M.; Van Ravestyn, L.

    2010-01-01

    Document available in extended abstract form only. The role of colloids - mainly dissolved natural organic matter (NOM, 50-150 mg/l) - in the transport of radionuclides in the Boom Clay formation (Mol, Belgium), has long since been a matter of (heavy) debate. For more than 20 years, batch experiments with Boom Clay suspensions showed a pronounced influence of the dissolved organic carbon concentration on the aqueous concentrations of different radionuclides like Tc, Np, Am and U. Moreover, small fractions of these radionuclides were also observed to elute almost un-retarded out of confined clay cores in percolation experiments. In the past years, a new conceptual model for the speciation of the long-lived fission product Technetium- 99 ( 99 Tc) under Boom Clay conditions has been drafted. In brief, the stable oxidation state of 99 Tc in these conditions is +IV, and, therefore, Tc solution concentrations are limited by the solubility of TcO 2 .nH 2 O(s). However, during reduction of TcVII (in the TcO 4 - form) to TcIV, precursor TcO 2 .nH 2 O colloids are formed, which are stabilised by the dissolved organic matter present in Boom Clay interstitial pore water, and in supernatants of Boom Clay batch suspensions. Moreover, this stabilisation process occurs in such a systematic way, that (conditional) interaction constants could be established, and the behaviour was described as a 'hydrophobic sorption', or, more accurately, a 'colloid-colloid' interaction. This conceptual model was implemented into PHREEQC geochemical and Hydrus transport code to come to a reactive transport model that was used to simulate both the outflow and the tracer profile in several long-term running percolation experiments (both in lab and under in situ conditions). To account for slow dissociation kinetics of Tc from the NOM colloid, a first-order kinetic rate equation was also added to the model. In order to describe the migration of colloidal particles (NOM), an

  20. ACCURATE OH MASER POSITIONS FROM THE SPLASH PILOT REGION

    Energy Technology Data Exchange (ETDEWEB)

    Qiao, Hai-Hua; Shen, Zhi-Qiang [Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai, 200030 (China); Walsh, Andrew J.; Jordan, Christopher H. [International Centre for Radio Astronomy Research, Curtin University, GPO Box U1987, Perth WA 6845 (Australia); Green, James A. [CSIRO Astronomy and Space Science, Australia Telescope National Facility, PO Box 76, Epping, NSW 2121 (Australia); Breen, Shari L. [Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, NSW 2006 (Australia); Dawson, J. R. [Department of Physics and Astronomy and MQ Research Centre in Astronomy, Astrophysics and Astrophotonics, Macquarie University, NSW 2109 (Australia); Ellingsen, Simon P. [School of Physical Sciences, Private Bag 37,University of Tasmania, Hobart 7001, TAS (Australia); Gómez, José F. [Instituto de Astrofísica de Andalucía, CSIC, Glorieta de la Astronomía s/n, E-18008, Granada (Spain); Lowe, Vicki; Jones, Paul A., E-mail: qiaohh@shao.ac.cn [Department of Astrophysics and Optic, School of Physics, University of New South Wales, Sydney, NSW 2052 (Australia)

    2016-12-01

    We report on high spatial resolution observations, using the Australia Telescope Compact Array (ATCA), of ground-state OH masers. These observations were carried out toward 196 pointing centers previously identified in the Southern Parkes Large-Area Survey in Hydroxyl (SPLASH) pilot region, between Galactic longitudes of 334° and 344° and Galactic latitudes of −2° and +2°. Supplementing our data with data from the MAGMO (Mapping the Galactic Magnetic field through OH masers) survey, we find maser emission toward 175 of the 196 target fields. We conclude that about half of the 21 nondetections were due to intrinsic variability. Due to the superior sensitivity of the followup ATCA observations, and the ability to resolve nearby sources into separate sites, we have identified 215 OH maser sites toward the 175 fields with detections. Among these 215 OH maser sites, 111 are new detections. After comparing the positions of these 215 maser sites to the literature, we identify 122 (57%) sites associated with evolved stars (one of which is a planetary nebula), 64 (30%) with star formation, two sites with supernova remnants, and 27 (13%) of unknown origin. The infrared colors of evolved star sites with symmetric maser profiles tend to be redder than those of evolved star sites with asymmetric maser profiles, which may indicate that symmetric sources are generally at an earlier evolutionary stage.

  1. Decline in the risk of hepatitis A virus infection in China, a country with booming economy and changing lifestyles.

    Science.gov (United States)

    Xu, Zhi-Yu; Wang, Xuan-Yi; Liu, Chang-Qing; Li, Yang-Ting; Zhuang, Fang-Chen

    2008-10-01

    The objective of the study was to identify the protective factors for the rapid decline in the risk of hepatitis A virus (HAV) infection in China between 1990 and 2006. Results of serological follow-up and data on annual hepatitis A incidence were analysed and correlated with economic growth and HAV vaccine output during the same period. In conclusion, both HAV vaccination and changing lifestyles associated with the booming economy contributed to the rapid risk decline. Changing lifestyles played a major role in the decline especially in the areas with booming economy.

  2. Studying the migration behaviour of radionuclides in boom clay by electromigration

    Energy Technology Data Exchange (ETDEWEB)

    Norbert Maes, H.; Moors, H.; Dierckx, A.; Aertsens, M.; Wang, L.; Canniere, P. de; Put, M. [SCK-CEN, Belgian Nuclear Research Centre, Waste and Disposal - R and D Geological Disposal Mol (Belgium)

    2001-07-01

    Migration studies are an important part in the assessment of the performance of the Boom Clay Formation as a candidate for geological disposal of High-Level radwaste in Belgium. However, classical diffusion experiments take a long time because of the excellent retention characteristics of the Boom Clay. Electrical fields can be used to move ionic species. Especially for low permeability soils/sediments (such as clays), this driving force is far more efficient than a hydraulic gradient. As a consequence, the experimental time can be reduced drastically. This paper gives an overview on the quantitative and qualitative use of electromigration as a powerful technique to study radionuclides migration in clays. The enormous time gain in the determination of migration parameters for strongly retarded radionuclides as {sup 137}Cs{sup +} and {sup 226}Ra{sup 2+} is first demonstrated. Secondly, we want to demonstrate that electromigration has some useful features to study the behaviour of radionuclides with a more complex chemistry like the redox sensitive element uranium and Am-Organic Matter (OM) complexes. In the case of uranium, electromigration provides information on the speciation of the migrating species while for the Am-organic Matter complexes the role of OM as a possible carrier of actinides is investigated. (orig.)

  3. Studying the migration behaviour of radionuclides in boom clay by electromigration

    International Nuclear Information System (INIS)

    Norbert Maes, H.; Moors, H.; Dierckx, A.; Aertsens, M.; Wang, L.; Canniere, P. de; Put, M.

    2001-01-01

    Migration studies are an important part in the assessment of the performance of the Boom Clay Formation as a candidate for geological disposal of High-Level radwaste in Belgium. However, classical diffusion experiments take a long time because of the excellent retention characteristics of the Boom Clay. Electrical fields can be used to move ionic species. Especially for low permeability soils/sediments (such as clays), this driving force is far more efficient than a hydraulic gradient. As a consequence, the experimental time can be reduced drastically. This paper gives an overview on the quantitative and qualitative use of electromigration as a powerful technique to study radionuclides migration in clays. The enormous time gain in the determination of migration parameters for strongly retarded radionuclides as 137 Cs + and 226 Ra 2+ is first demonstrated. Secondly, we want to demonstrate that electromigration has some useful features to study the behaviour of radionuclides with a more complex chemistry like the redox sensitive element uranium and Am-Organic Matter (OM) complexes. In the case of uranium, electromigration provides information on the speciation of the migrating species while for the Am-organic Matter complexes the role of OM as a possible carrier of actinides is investigated. (orig.)

  4. Homogeneity vs. Heterogeneity of Porosity in Boom Clay

    International Nuclear Information System (INIS)

    Hemes, Susanne; Desbois, Guillaume; Urai, Janos L.; De Craen, Mieke; Honty, Miroslav

    2013-01-01

    Microstructural investigations on Boom Clay at nano- to micrometer scale, using BIB-SEM methods, result in porosity characterization for different mineral phases from direct observations on high resolution SE2-images of representative elementary areas (REAs). High quality, polished surfaces of cross-sections of ∼ 1 mm 2 size were produced on three different samples from the Mol-Dessel research site (Belgium). More than 33,000 pores were detected, manually segmented and analyzed with regard to their size, shape and orientation. Two main pore classes were defined: Small pores (< 500 nm (ED)) within the clay matrices of samples and =big' pores (> 500 nm (ED)) at the interfaces between clay and non-clay mineral (NCM) grains. Samples investigated show similar porosities regarding the first pore-class, but differences occur at the interfaces between clay matrix and NCM grains. These differences were interpreted to be due to differences in quantitative mineralogy (amount of non-clay mineral grains) and grain-size distributions between samples investigated. Visible porosities were measured as 15 to 17 % for samples investigated. Pore-size distributions of pores in clay are similar for all samples, showing log-normal distributions with peaks around 60 nm (ED) and more than 95 % of the pores being smaller than 500 nm (ED). Fitting pore-size distributions using power-laws with exponents between 1.56 and 1.7, assuming self-similarity of the pore space, thus pores smaller than the pore detection resolution following the same power-laws and using these power-laws for extrapolation of pore-size distributions below the limit of pore detection resolution, results in total estimated porosities between 20 and 30 %. These results are in good agreement with data known from Mercury Porosimetry investigations (35-40 % porosity) and water content porosity measurements (∼ 36 %) performed on Boom Clay. (authors)

  5. Analysis of the Effects of Streamwise Lift Distribution on Sonic Boom Signature

    Science.gov (United States)

    Yoo, Paul

    2013-01-01

    Investigation of sonic boom has been one of the major areas of study in aeronautics due to the benefits a low-boom aircraft has in both civilian and military applications. This work conducts a numerical analysis of the effects of streamwise lift distribution on the shock coalescence characteristics. A simple wing-canard-stabilator body model is used in the numerical simulation. The streamwise lift distribution is varied by fixing the canard at a deflection angle while trimming the aircraft with the wing and the stabilator at the desired lift coefficient. The lift and the pitching moment coefficients are computed using the Missile DATCOM v. 707. The flow field around the wing-canard- stabilator body model is resolved using the OVERFLOW-2 flow solver. Overset/ chimera grid topology is used to simplify the grid generation of various configurations representing different streamwise lift distributions. The numerical simulations are performed without viscosity unless it is required for numerical stability. All configurations are simulated at Mach 1.4, angle-of-attack of 1.50, lift coefficient of 0.05, and pitching moment coefficient of approximately 0. Four streamwise lift distribution configurations were tested.

  6. Design study for a macropermeability test in an argillaceous formation (Boom clay)

    International Nuclear Information System (INIS)

    Bronders, J.

    1992-01-01

    In the present report a test design has been developed for determining the in-situ permeability of the Boom clay on a large scale at the Mol site (Belgium). Since in the Boom clay at the Mol site an Underground Repository Facility (URF) is operational the test has been designed to be run in or from this facility. The proposal is an in-situ macropermeability test with a set-up comprising a central borehole (metric scale in length) designed to allow various types of control of the water-level, surrounded by a lattice of piezometers installed in the clay mass for the monitoring of the interstitial water pressure changes in function of the various water-level controls. In one part the report describes the potential set-ups and a theoretical background as far as it can be done on the basis of existing literature and experiments. In a second part the method (technical and practical data of a test set-up) is described and documented. The method proposed is largely based on the several years of expertise gained within the field of in-situ migration and hydrogeologic investigations in the Hades-URF. 14 refs., 9 figs., 2 tabs

  7. NASA's Pursuit of Low-Noise Propulsion for Low-Boom Commercial Supersonic Vehicles

    Science.gov (United States)

    Bridges, James; Brown, Clifford A.; Seidel, Jonathan A.

    2018-01-01

    Since 2006, when the Fundamental Aeronautics Program was instituted within NASA's Aeronautics Mission Directorate, there has been a Project looking at the technical barriers to commercial supersonic flight. Among the barriers is the noise produced by aircraft during landing and takeoff. Over the years that followed, research was carried out at NASA aeronautics research centers, often in collaboration with academia and industry, addressing the problem. In 2013, a high-level milestone was established, described as a Technical Challenge, with the objective of demonstrating the feasibility of a low-boom supersonic airliner that could meet current airport noise regulations. The Technical Challenge was formally called "Low Noise Propulsion for Low Boom Aircraft", and was completed in late 2016. This paper reports the technical findings from this Technical Challenge, reaching back almost 10 years to review the technologies and tools that were developed along the way. It also discusses the final aircraft configuration and propulsion systems required for a supersonic civilian aircraft to meet noise regulations using the technologies available today. Finally, the paper documents the model-scale tests that validated the acoustic performance of the study aircraft.

  8. Big boom ahead for New Brunswick

    Energy Technology Data Exchange (ETDEWEB)

    Reid, Wes

    2011-10-15

    The technological advances in shale gas extraction make it now feasible to exploit this hydrocarbon resource. Shale gas activity has been booming recently in New Brunswick and the province possibly holds more than 80 trillion cubic feet of natural gas. A new pipeline system has already been put in place. New Brunswick is a socially, politically and economically stable region. In addition, the royalty system in New Brunswick is competitive. For example, right now Corridor Resources Inc. is working on three major projects and some existing production from the McCully field in New Brunswick. Corridor also has prospects at Anticosti Island, Prince Edward Island and Old Harry. Although the government can benefit from royalty revenues generated by the hydrocarbon industry, environmental issues are of concern to citizens' groups, environmentalists and political opposition parties. A moratorium has been called for to make sure the proper protections are in place and the industry is adequately monitored.

  9. Hypofolins A - L, ent-Labdane Diterpenoids from the Roots of Hypoestes phyllostachya 'Pink Splash'.

    Science.gov (United States)

    Cheng, Bin; Ding, Lin-Fen; Yan, Tong; Xie, Zhang-Qiao; Zhang, Zhi-Jun; Song, Liu-Dong; Wu, Xing-De; Zhao, Qin-Shi

    2018-06-01

    Twelve new ent-labdane diterpenoids, hypofolins A - F (1 - 6) and hypofolins G - L (7a/7b, 8a/8b, and 9a/9b), were isolated from the roots of Hypoestes phyllostachya 'Pink Splash'. Their structures were elucidated by extensive 1D- and 2D-NMR spectroscopic and HR-MS data. The absolute configurations of 1, 2, 5, and 7a/7b were determined by single crystal X-ray diffraction and ECD analysis, as well as chemical transformations. Compounds 7a/7b, 8a/8b, and 9a/9b were isolated as three pairs of interconverting mixture of two isomers between ketone and hemiketal types. Compound 1 showed weak cytotoxicity against SMMC-7721 cell line with IC 50 value of 31.40 μm. © 2018 Wiley-VHCA AG, Zurich, Switzerland.

  10. Hollow Cylinder Tests on Boom Clay: Modelling of Strain Localization in the Anisotropic Excavation Damaged Zone

    Science.gov (United States)

    François, Bertrand; Labiouse, Vincent; Dizier, Arnaud; Marinelli, Ferdinando; Charlier, Robert; Collin, Frédéric

    2014-01-01

    Boom Clay is extensively studied as a potential candidate to host underground nuclear waste disposal in Belgium. To guarantee the safety of such a disposal, the mechanical behaviour of the clay during gallery excavation must be properly predicted. In that purpose, a hollow cylinder experiment on Boom Clay has been designed to reproduce, in a small-scale test, the Excavation Damaged Zone (EDZ) as experienced during the excavation of a disposal gallery in the underground. In this article, the focus is made on the hydro-mechanical constitutive interpretation of the displacement (experimentally obtained by medium resolution X-ray tomography scanning). The coupled hydro-mechanical response of Boom Clay in this experiment is addressed through finite element computations with a constitutive model including strain hardening/softening, elastic and plastic cross-anisotropy and a regularization method for the modelling of strain localization processes. The obtained results evidence the directional dependency of the mechanical response of the clay. The softening behaviour induces transient strain localization processes, addressed through a hydro-mechanical second grade model. The shape of the obtained damaged zone is clearly affected by the anisotropy of the materials, evidencing an eye-shaped EDZ. The modelling results agree with experiments not only qualitatively (in terms of the shape of the induced damaged zone), but also quantitatively (for the obtained displacement in three particular radial directions).

  11. Natural Resources Management: The Effect of the Commodity Boom on Indonesia’s Industrial Development and Welfare

    Directory of Open Access Journals (Sweden)

    Maria Monica Wihardja

    2016-03-01

    Full Text Available The end of the commodity boom in 2012 once again exposed Indonesia to the vulnerability of the commodity price shocks. This article reviews how Indonesia managed its natural resources in 2001–12 and when the commodity boom ends. What are the lessons learned? Indonesia’s experience is similar to that of other countries rich in natural resources, including the crowding-out of non-commodity sectors, protectionist trade regimes, fiscal inefficiency, slow skill accumulation, rising inequality and environmental damages. In the aftermath of the global financial crisis of 2008–09, the early trade -policy response at the end of the commodity boom is inward-looking and protective of domestic markets and industries and aims to increase the added value of commodities by downstreaming. This trend is clearly reflected in the 2014 Trade Law, the 2014 Industry Law and the mineral export ban, which was introduced in 2009 through the 2009 Law on Mining of Coal and Minerals and took effect in 2014. Indonesia should learn from other countries in managing its resource revenues, such as through a commodity fund designed to fit its domestic specificity. Reindustrializing, increasing agricultural productivity beyond palm oil and tapping the country’s potential in the services sector including tourism and creative industries are also necessary to promote diversification in production and trade. Resource management policy should also include stronger environmental regulations.

  12. Macro policy responses to oil booms and busts in the United Arab Emirates

    International Nuclear Information System (INIS)

    Al-Mutawa, A.K.

    1991-01-01

    The effects of oil shocks and macro policy changes in the United Arab Emirates are analyzed. A theoretical model is developed within the framework of the Dutch Disease literature. It contains four unique features that are applicable to the United Arab Emirates' economy. There are: (1) the presence of a large foreign labor force; (2) OPEC's oil export quotas; (3) the division of oil profits; and (4) the important role of government expenditures. The model is then used to examine the welfare effects of the above-mentioned shocks. An econometric model is then specified that conforms to the analytical model. In the econometric model the method of 'principal components' is applied owing to the undersized sample data. The principal components methodology is used in both the identification testing and the estimation of the structural equations. The oil and macro policy shocks are then simulated. The simulation results show that an oil-quantity boom leads to a higher welfare gain than an oil-price boom. Under certain circumstances, this finding is also confirmed by the comparative statistics that follow from the analytical model

  13. Amsterdam Book Design: Irma Boom, Hansje van Halem, Lesley Moore = Amsterdamskij knižnyj dizajn

    NARCIS (Netherlands)

    Lommen, M.

    2012-01-01

    Published on the occasion of the exhibition 'Amsterdam Book Design : Irma Boom, Hansje van Halem, Lesley Moore', from May 26th until June 17th 2012 in the creative platform Taiga Space, Saint Petersburg. In cooperation with Netherlands Institute Saint-Petersburg.

  14. Boom or bust? A comparative analysis of transient population dynamics in plants

    DEFF Research Database (Denmark)

    Stott, Iain; Franco, Miguel; Carslake, David

    2010-01-01

    researchers as further possible effectors of complicated dynamics. Previously published methods of transient analysis have tended to require knowledge of initial population structure. However, this has been overcome by the recent development of the parametric Kreiss bound (which describes how large...... a population must become before reaching its maximum possible transient amplification following a disturbance) and the extension of this and other transient indices to simultaneously describe both amplified and attenuated transient dynamics. We apply the Kreiss bound and other transient indices to a data base...... worrying artefact of basic model parameterization. Synthesis. Transient indices describe how big or how small plant populations can get, en route to long-term stable rates of increase or decline. The patterns we found in the potential for transient dynamics, across many species of plants, suggest...

  15. A study on the secondary consolidation of Boom Clay at Essen site under loading and unloading compression

    International Nuclear Information System (INIS)

    Deng, Y.F.; Cui, Y.J.; Tang, A.M.; Li, X.L.; Sillen, X.

    2010-01-01

    Document available in extended abstract form only. Boom clay formation, a thick deposit of over-consolidated marine clay has been selected as a possible host material of nuclear waste disposal in Belgium. For this purpose, its deformation behaviour, especially its long-term deformation behaviour (secondary consolidation) is essential for the safety of the whole storage system and therefore needs to be investigated deeply. In the present work, odometer consolidation tests were performed on Boom clay taken from the Essen site. The loading and unloading were run in steps and the secondary consolidation coefficient C α (C α = de/dlogt) was determined for each step. This allows the secondary consolidation behaviour to be analysed. Four soil cores of Boom clay were taken from the site of Essen, Belgium, at the depths of 220-248 m. The geotechnical identification characteristics of these cores are similar: specific gravity, γ s = 2.64-2.68; liquid limit, w L = 68-78%; plastic limit, w P = 29-33%; and plastic index, I P 36-45. The soil water content (w) is between 26.5 and 29.7% and the void ratio (e) between 0.700 and 0.785. The blue methylene values (VBS) are equally similar, VBS = 6.20-6.67 (g/100 g). The clay fraction (< 2 μm) is relatively high (more than 50%). An example of the results obtained is presented (void ratio versus vertical stress and secondary consolidation coefficient versus vertical stress, determined in the e/log t plot) for the core taken at 227 m depth. After the installation of specimen in the odometer cell, an initial loading to the in-situ stress gave rise to a decrease of the void ratio from 0.730 to 0.651. The drainage system was then saturated for the subsequent loading/unloading paths in steps. The results show that the void ratio decreased to 0.270 when the vertical stress reached σ v = 32 MPa. A compression index Cc of about 0.31 can be estimated and the swelling index is estimated at 0.14. C α > 0 during loading and C α < 0 during

  16. The Canon is el Boom, et. al., or the Hispanic Difference

    OpenAIRE

    Bell-Villada, Gene H.

    2002-01-01

    In his article, Gene H. Bell-Villada's "The Canon is el Boom, et. al., or the Hispanic Difference," argues that the rich, globally acclaimed, foundational yet contestatory prose literature produced in Latin America allows teachers and scholars of Spanish to teach what is essentially the "canon" via work that is still fresh, yet historically provocative. Bell-Villada argues that in a time of reconsidering the importance of literature in literature programs, programs of Spanish language and cul...

  17. Baby Booming Inequality? Demographic Change and Inequality in Norway, 1967{2004.

    OpenAIRE

    Almås, Ingvild; Havnes, Tarjei; Mogstad, Magne

    2011-01-01

    We demonstrate how age-adjusted inequality measures can be used to evaluate whether changes in inequality over time are because of changes in the age structure. In particular, we explore the hypothesis that the substantial rise in earnings inequality since the early 1980s is driven by the large baby boom cohorts approaching the peak of the age-earnings profile. Using administrative data on earnings for every Norwegian male over the period 1967-2004, we find that the impact of age ...

  18. Geotechnical characterization of boom clay in relation to the disposal of radioactive waste

    International Nuclear Information System (INIS)

    Horseman, S.T.; Winter, M.G.; Enwistle, D.C.

    1987-01-01

    This report describes the results of a laboratory study on the geotechnical properties of the Tertiary Boom clay. Tests were performed on 'undisturbed' samples of clay taken from a location 247 m below surface at the SCK/CEN experimental site at Mol in Belgium. In geotechnical terms, the Boom clay (at depth) may be described as a hard, high-plasticity, overconsolidated clay. Test methods have included (a) the one-dimensional consolidation test with consolidation stresses up to 32 MPa, (b) the one dimensional swelling pressure test, (c) the isotropically-consolidated, undrained (CIU) triaxial test with pore pressure measurement, and (d) the unconsolidated undrained (UU) triaxial test. All triaxial tests were load-controlled. Limited test results are presented on pore pressure responses during heating under undrained conditions and on the effect of elevated temperature (80 O C) on deformability and strength. It is found that significantly large excess pore pressures (circa 1 MPa under in situ stress conditions) may be developed during heating from ambient laboratory temperature to 80 O C. The effect is due, at least in part, to the expansion of the pore fluid

  19. The design and testing of a memory metal actuated boom release mechanism

    Science.gov (United States)

    Powley, D. G.; Brook, G. B.

    1979-01-01

    A boom latch and release mechanism was designed, manufactured and tested, based on a specification for the ISEE-B satellite mechanism. From experimental results obtained, it is possible to calculate the energy available and the operating torques which can be achieved from a torsional shape memory element in terms of the reversible strain induced by prior working. Some guidelines to be followed when designing mechanisms actuated by shape memory elements are included.

  20. Energy Saving Potential in Knuckle Boom Cranes using a Novel Pump Controlled Cylinder Drive

    Directory of Open Access Journals (Sweden)

    Søren Ketelsen

    2018-04-01

    Full Text Available This paper is considering the application of a novel pump controlled cylinder drive, the so-called Speed-variable Switched Differential Pump (SvSDP, for knuckle boom crane actuation. Especially the control system for the SvSDP drive is considered, and aiming on improving energy efficiency a refinement of the existing control structure is proposed. An energy efficient sizing algorithm for the SvSDP drive is developed, and fundamental differences between the achievable operating range for the SvSDP drive compared to a conventional valve-cylinder drive are discussed. A case study is conducted with knuckle boom crane actuation, and compared to a conventional valve actuation. Simulation results show that the motion tracking performance is on a similar level compared to the valve actuation approach, while the energy consumption is drastically decreased. For the given test trajectory the valve actuation system consumes 0.79 kWh of electrical energy, while the SvSDP drive consume 0.06 kWh, if ideal energy recovery and storage is assumed.

  1. Reactive transport modelling of a heating and radiation experiment in the Boom clay (Belgium)

    International Nuclear Information System (INIS)

    Montenegro, L.; Samper, J.; Delgado, J.

    2003-01-01

    Most countries around the world consider Deep Geological Repositories (DGR) as the most safe option for the final disposal of high level radioactive waste (HLW). DGR is based on adopting a system of multiple barriers between the HLW and the biosphere. Underground laboratories provide information about the behaviour of these barriers at real conditions. Here we present a reactive transport model for the CERBERUS experiment performed at the HADES underground laboratory at Mol (Belgium) in order to characterize the thermal (T), hydrodynamic (H) and geochemical (G) behaviour of the Boon clay. This experiment is unique because it addresses the combined effect of heat and radiation produced by the storage of HLW in a DGR. Reactive transport models which are solved with CORE, are used to perform quantitative predictions of Boom clay thermo-hydro-geochemical (THG) behaviour. Numerical results indicate that heat and radiation cause a slight oxidation near of the radioactive source, pyrite dissolution, a pH decrease and slight changes in the pore water chemical composition of the Boom clay. (Author) 33 refs

  2. Prediction of sonic boom from experimental near-field overpressure data. Volume 2: Data base construction

    Science.gov (United States)

    Glatt, C. R.; Reiners, S. J.; Hague, D. S.

    1975-01-01

    A computerized method for storing, updating and augmenting experimentally determined overpressure signatures has been developed. A data base of pressure signatures for a shuttle type vehicle has been stored. The data base has been used for the prediction of sonic boom with the program described in Volume I.

  3. Sleipner mishap jolts booming Norway

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    This paper reports on Norway's buoyant offshore industry that was stunned when the concrete substructure for Sleipner natural gas field's main production platform sank in the Grandsfjord off Stavanger late last month. The accident, a blow to Norway's gas sales program in Europe, came with offshore activity in the Norwegian North Sea moving into a new boom period. Currently, 10 oil and gas fields are under development, and several projects are on the drawing board. Aker Oil and Gas, a leading offshore firm, says the country's construction industry will be working at capacity for the next 4 years. Norwegian oil production has been hovering just below 2 million b/d since the beginning of this year, making Norway the North Sea's largest producer, a position formerly held by the U.K. Gas production averages about 3 bcfd. With European gas demand sharply increasing, Norway is under pressure to increase output from new fields in the mid to late 1990s. The Sleipner setback forces state owned Den norske stats oljeselskap AS (Statoil) to cast around for supplies. Sleipner was to have begun deliveries to a consortium of continental gas companies in October 1993. Statoil believes it can fill the gap from existing fields in Norwegian waters

  4. The Canadian unemployment rate – with and without Alberta’s Boom

    Directory of Open Access Journals (Sweden)

    Ronald D. Kneebone

    2014-11-01

    Full Text Available Over the past two decades there has occurred a shift in economic power from central Canada to other parts of the country. Saskatchewan and Newfoundland and Labrador have both claimed a noticeably larger share of Canada’s GDP since 1995 but easily the largest shift of economic output has been to Alberta. This adjustment in the Canadian economy is most easily observed in the large migration between provinces of Canadians seeking employment. Data from Statistics Canada’s Labour Force Survey shows that over the period 1995-2014 Alberta has maintained an average annual rate of growth in employment of 2.50 per cent. This is well above the 1.44 percentage rate of employment growth in second-place Ontario and double the average rate of growth in neighbouring British Columbia. This begs the question: What would Canada’s unemployment rate be today if Alberta’s job creation boom hadn’t happened? Since the national jobless rate is a weighted average of the provincial figures, getting an answer is straightforward. Assume Alberta’s employment growth was no higher than Ontario’s over the same period and the impact on Canada’s unemployment rate is startling. By August 2014, Canada’s unemployment would have been 9.39 per cent — 2.23 percentage points higher than the real figure of 7.16 per cent — and the Alberta economy would have created 411,000 fewer jobs; jobs which typically pay $200 to $300 per week more than jobs in Ontario and Quebec. This gloomy scenario means that Canada’s present unemployment rate would be 2.5 percentage points higher than it was in mid-2000, and 411,000 Canadians, along with their dependents, would be clearly much worse off were it not for the boom in Alberta. Obviously this simple experiment can’t capture the situation’s full economic complexity. Would some of those jobs have cropped up in other provinces? Stubbornly lacklustre growth could very well have forced governments and the Bank of Canada to adopt

  5. On the role of anisotropy in the perturbation of Boom Clay by a deep disposal repository for high-level wastes

    International Nuclear Information System (INIS)

    Sillen, X.; Li, X.L.; Van Marcke, P.; Chen, G.; Bastiaens, W.

    2010-01-01

    Document available in extended abstract form only. All along the characterisation programme of the Boom Clay, a potential host rock for geological disposal of long-lived, heat-emitting radioactive waste, evidences of anisotropy of key thermo-hydro-mechanical (THM) properties have been collected through direct observations and laboratory measurements. In parallel, evidences of anisotropic THM behaviour of the clay massif were obtained during excavations and in-situ experiments in the underground research laboratory HADES at Mol. Careful analysis of the observations and simple modelling reveal the key role of the anisotropy of the material properties and, to a lesser extent, the in situ stresses in the development of a damaged zone around the galleries and the hydro-mechanical perturbation in the clay massif. As a consequence of the sedimentary deposition process, clay formations often exhibit visible bedding. This is the case for Boom Clay. Like other deep clays, Boom Clay also exhibits pronounced strain anisotropy under certain hydro-mechanical loading. Isotropic compression tests performed in the early nineties have shown that, for Boom Clay at a depth of about 225 m, the increments of deformation perpendicular to the bedding planes, i.e. vertical, are about two times larger than increments of deformation parallel to the bedding planes, i.e. horizontal. Moreover, it was observed that this mechanical anisotropy decreases progressively as the isotropic stress is increased. Drained heating tests under constant isotropic loading also evidenced anisotropic behaviour during thermo-consolidation. Like the mechanical properties, hydraulic and thermal properties of the Boom Clay also show anisotropy: lab and in situ measurements suggest that the horizontal hydraulic conductivity is about twice the vertical one while the ratio between horizontal and vertical thermal conductivities is about 1.4. The anisotropic THM behaviour of the Boom Clay was evidenced during excavations

  6. Impact of Air Oxidation on Dissolved Organic Matter from Boom Clay: Comparison Between Natural and Artificial Oxidation Series and In Situ Piezometers Water From Hades Galleries

    International Nuclear Information System (INIS)

    Blanchart, Pascale; Faure, Pierre; Michels, Raymond; Bruggeman, Christophe; De Craen, Mieke; Parant, Stephane

    2012-01-01

    Document available in extended abstract form only. The Boom Clay is considered by the Belgian radioactive waste management agency Ondraf/Niras as a possible host rock for the geological disposal of high-level and long-lived radioactive waste. The drilling of galleries and corings in the Boom Clay (Mol, Belgium) leads to perturbations of the initial physical and chemical conditions. In piezometers, the DOC may show considerable and irregular variations through time, with values ranging from 80 to 425 mg/L. The origin and bio-physico-chemical controls of such variations are yet unknown but oxidation and biodegradation were considered as most likely. Three categories of samples were collected with the aim of determining and quantifying different molecular markers representative for the oxidation process: - Fresh as well as air-oxidized Boom Clay samples were collected in the Underground Research Facility HADES of EURIDICE (Mol, Belgium): they represent a natural series of oxidation; - A fresh Boom Clay sample was submitted to laboratory air oxidation (artificial series). In these experiments, powdered clay was heated at 80 deg. C under air flow during 1, 3, 6, 9, 12, 18 months; - Four water samples were collected during January 2010 from different horizons in the Boom Clay by means of piezometers located in the Underground Research Facility. The DOM (dissolved organic matter) of Boom Clay samples (artificial and natural series) was isolated by Soxhlet using pure water as well as by leaching experiments. The quantitative analysis shows an increasing in DOC (Dissolved Organic Carbon) content with oxidation. Qualitative characterizations including spectroscopic (3D-fluorescence) as well as molecular analyses (flash pyrolysis - gas chromatography - mass spectrometry (PyGC-MS) and size exclusion chromatography (SEC-HPLC)) show an evolution of the DOM chemistry with oxidation: - An enrichment in oxygen bearing molecules (acidic poly functional groups); - A decrease in

  7. Low-Speed Control of Heavy-Load Transfer Robot with Long Telescopic Boom Based on Stribeck Friction Model

    Directory of Open Access Journals (Sweden)

    Bo You

    2012-01-01

    Full Text Available The severe low-speed creep phenomenon occurs in the telescopic boom system of a heavy-load transfer robot with a long telescopic boom as a result of nonlinear friction. In order to improve control precision and operation performance at low speeds, we built a three-loop control nonlinear model of an AC servo motor with Stribeck friction disturbance. Traditional proportional-integral-derivative controller (PID and fuzzy PID controls were, respectively, adopted in the position loop, and the control performance was simulated. The results showed that a system with fuzzy PID control eliminates “flat top” position tracking and “dead zone” speed tracking, which are generated by traditional PID, and thereby decreases the effect of friction on the performance of the servo system. This elimination also improved the tracking accuracy and robustness of the system.

  8. A new and improved methodology for qualitative and quantitative mineralogical analysis of Boom Clay

    International Nuclear Information System (INIS)

    Zeelmaekers, E.; Vandenberghe, N.; Honty, M.; De Craen, M.; Derkowski, A.; Van Geet, M.

    2010-01-01

    Document available in extended abstract form only. A good knowledge of the mineralogy of any host formation studied for geological disposal of high-level radioactive waste, is a prerequisite for understanding the geochemical environment which will determine the migration and retention behaviour of radionuclides. In this respect, the Boom Clay mineralogical composition has been extensively studied last decades as reference host formation (e.g. ARCHIMEDEARGILE project, OECD-NEA clay catalogue report) with the aim to provide reliable data for a safety assessment. However, a comparison of the available literature data clearly showed a serious discrepancy among studies, not only in the quantitative, but also in the qualitative mineralogical composition of the Boom Clay (SAFIR II). The reason for such a huge disagreement could be related, among others, to variable grain size distributions of the studied samples (sample heterogeneity) and differences in the methodological approaches. In particular, the unambiguous characterisation of clay minerals and the quantification of mixed-layer phases appeared as an everlasting problem. This study is aimed at achieving a consensus on the qualitative and quantitative mineralogical data of the Boom Clay using the most advanced techniques currently available in the clay science. A new sampling campaign was performed in such a way that samples are (20 in total) more or less regularly distributed over Boom Clay Formation, ensuring that variations in the grain size distributions due to silty clay-clayey silt layers alternations are accounted for. The novel concept based on an analysis at two levels was applied: (1) bulk rock and (2) clay fraction analysis. (1) A bulk rock analysis consists of conventional XRD analysis with the identification of the principal mineral phases. As a next step, the bulk rock was mixed with a ZnO internal standard and experimental diffraction patterns of randomly oriented powders were analyzed using &apos

  9. Popular Demobilization, Agribusiness Mobilization, and the Agrarian Boom in Post-Neoliberal Argentina

    Directory of Open Access Journals (Sweden)

    Pablo Lapegna

    2015-08-01

    Full Text Available Based on ethnographic research, archival data, and a catalog of protest events, this article analyzes the relationship between popular social movements, business mobilization, and institutional politics in Argentina during the post-neoliberal phase, which arguably began circa 2003. How did waves of popular mobilization in the 1990s shape business mobilization in the 2000s? How did contentious politics influence institutional politics in the post-neoliberal period? What are the changes and continuities of the agrarian boom that cut across the neoliberal and post-neoliberal periods? While I zoom in on Argentina, the article goes beyond this case by contributing to three discussions. First, rather than limiting the analysis to the customary focus on the mobilization of subordinated actors, it examines the demobilization of popular social movements, the mobilization of business sectors, and the connections between the two. Second, it shows the ways in which the state can simultaneously challenge neoliberal principles while also favoring the global corporations that dominate the contemporary neoliberal food regime. Finally, the case of Argentina sheds light on the political economy of the "Left turn" in Latin America, particularly the negative socio-environmental impacts of commodity booms. The article concludes that researchers need to pay closer attention to the connections between contentious and institutional politics, and to the protean possibilities of neoliberalism to inspire collective actions.

  10. Dynamics at Solid State Surfaces and Interfaces, Volume 1 Current Developments

    CERN Document Server

    Bovensiepen, Uwe; Wolf, Martin

    2010-01-01

    This two-volume work covers ultrafast structural and electronic dynamics of elementary processes at solid surfaces and interfaces, presenting the current status of photoinduced processes. Providing valuable introductory information for newcomers to this booming field of research, it investigates concepts and experiments, femtosecond and attosecond time-resolved methods, as well as frequency domain techniques. The whole is rounded off by a look at future developments.

  11. Mindfulness as a booming, diverse and (non) religious phenomenon

    DEFF Research Database (Denmark)

    Borup, Jørn

    2016-01-01

    Mindfulness has become a phenomenon with widespread appeal in many Western countries. Like yoga, it has an Eastern religious origin, but through a long history it has been transformed and adapted to new cultural and social contexts. While the majority of research on mindfulness has been conducted...... within the health sciences, the aim of this article is to investigate the distribution, meaning and function of this practice through quantitative mapping and qualitative interviews with 16 mindfulness providers in the city of Aarhus in Denmark. The analysis reveals not just a booming phenomenon......, but also a field characterized by diversity in terms of authority claims, motivations and uses. The discussion focuses on whether mindfulness can be seen as a religious practice or as a typical expression of an individualized and secularized technique....

  12. China expands refining sector to handle booming oil demand

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    China's refining sector is in the midst of a major expansion and reorganization in response to booming domestic demand for petroleum products. Plans call for hiking crude processing capacity to 3.9 million b/d in 1995 from the current 3.085 million b/d. Much of that 26% increase will come where the products demand growth is the strongest: China's coastal provinces, notably those in the southeast. Despite the demand surge, China's refineries operated at only 74% of capacity in 1991, and projections for 1992 weren't much better. Domestic crude supply is limited because of Beijing's insistence on maintaining crude export levels, a major source of hard currency foreign exchange. The paper discusses the superheated demand; exports and imports; the refining infrastructure; the Shenzhen refinery; Hong Kong demand; southeast coast demand; 1993 plans; and foreign investment

  13. Technetium behaviour in Boom Clay - a laboratory and field study

    International Nuclear Information System (INIS)

    Baston, G.M.N.; Ilett, D.J.; Cowper, M.M.; Pilkington, N.J.; Tweed, C.J.; Williams, S.J.; Canniere, P.R. de; Wang, L.

    2002-01-01

    This paper describes a study of technetium solubility and migration under chemical conditions representative of those prevailing in a Boom Clay environment. Laboratory and in situ measurements yielded similar aqueous concentrations of technetium, of about 1 x 10 -8 mol dm -3 , close to the concentrations measured for hydrated technetium(IV) oxide TcO 2 .1.6H 2 O in the solubility studies. From fitting the curves of the Tc concentrations as function of time, distribution coefficient (K d ) values were estimated to lie between 0.8 cm 3 g -1 and 1.8 cm 3 g -1 . Exposure of the system at 80 C and to γ-radiation dose rates of several hundred Gy h -1 resulted in only minor differences in behaviour. (orig.)

  14. F*** Yeah Fluid Dynamics: On science outreach and appealing to broad audiences

    Science.gov (United States)

    Sharp, Nicole

    2015-11-01

    Sharing scientific research with general audiences is important for scientists both in terms of educating the public and in pursuing funding opportunities. But it's not always apparent how to make a big splash. Over the past five years, fluid dynamics outreach blog FYFD has published more than 1300 articles and gained an audience of over 215,000 readers. The site appeals to a wide spectrum of readers in both age and field of study. This talk will utilize five years' worth of site content and reader feedback to examine what makes science appealing to general audiences and suggest methods researchers can use to shape their work's broader impact.

  15. Air oxidation and biodegradation of the organic matter from the Boom Claycomparison between artificial and natural altered series

    International Nuclear Information System (INIS)

    Blanchart, Pascale; Faure, Pierre; Michels, Raymond; Bruggeman, Christophe; De Craen, Mieke

    2010-01-01

    Document available in extended abstract form only. The Boom Clay formation (Belgium) is studied as the reference host rock for methodological studies on the geological disposal of high-level and long-lived radioactive waste. The drilling of galleries in the Boom Clay at Mol lead to the perturbation of the initial physical and chemical conditions. Since organic matter is present in this argillaceous formation, it is important to know its response to these new conditions. The Boom Clay is of Tertiary age (Rupelian) and has a TOC content up to 5%. Its pore water (20% in mass of rock) contains significant quantities of Dissolved Organic Carbon (DOC) with a mean concentration of 115+/-15 mg/L, determined on the basis of piezometer water as well as squeezing and leaching experiments. Yet, in piezometers, the DOC may show considerable and irregular variations through time, with values ranging between 80 and 425 mg/L. The origin and bio-physico-chemical controls of such variations are yet unknown. Perturbation of the in-situ conditions of the clay is a possible reason for such observation. More likely the introduction of air as well as micro-organisms may have an impact that needs to be estimated. Well-preserved, freshly-drilled Boom Clay samples, as well as samples of different degrees of alteration (air exposed clay from the older galleries) were collected with the aim of determining and quantifying different molecular markers representative for the alteration degree. Additionally, increasing artificial air oxidation experiments were carried out on fresh Praclay samples (sampled during the PRACLAY gallery excavation) in order to obtain an altered reference series. Moreover PRACLAY samples previously extracted with an organic solvent (dichloromethane) were also prepared in order to identify the influence of the kerogen during oxidation. In these experiments, powdered clay was heated at 80 deg. C under air flow during 1, 3, 6, 9, 12, 18 months. Organic matter composition

  16. Ultimate Cavity Dynamics of Hydrophobic Spheres Impacting on Free Water Surfaces

    KAUST Repository

    Mansoor, Mohammad M.

    2012-12-01

    Cavity formation resulting from the water-entry of solid objects has been the subject of extensive research owing to its practical relevance in naval, military, industrial, sports and biological applications. The cavity formed by an impacting hydrophobic sphere normally seals at two places, one below (deep seal) and the other above the water surface (surface seal). For Froude numbers , the air flow into the resulting cavity is strong enough to suck the splash crown above the surface and disrupt the cavity dynamics before it deep seals. In this research work we eliminate surface seals by means of a novel practice of using cone splash-guards and examine the undisturbed transient cavity dynamics by impact of hydrophobic spheres for Froude numbers ranging . This enabled the measurement of extremely accurate pinch-off heights, pinch-off times, radial cavity collapse rates, and jet speeds in an extended range of Froude numbers compared to the previous work of Duclaux et al. (2007). Results in the extended regime were in remarkable agreement with the theoretical prediction of scaled pinch-off depth, and experimentally derived pinch-off time for . Furthermore, we investigated the influence of confinement on cavity formation by varying the cross-sectional area of the tank of liquid. In conjunction with surface seal elimination we observed the formation of multiple pinch-off points where a maximum of four deep seals were obtained in a sequential order for the Froude number range investigated. The presence of an elongated cavity beneath the first pinch-off point 5 resulted in evident "kinks" primarily related to the greatly diminished air pressure at the necking region caused by supersonic air flows (Gekle et al. 2010). Such flows passing through second pinch-offs were also found to choke the cavities beneath the first pinch- off depths causing radial expansion and hence disappearance of downward jets.

  17. The role of natural organic matter in the migration behaviour of americium in the Boom clay - Part II: analysis of migration experiments

    International Nuclear Information System (INIS)

    Hicks, T.; Bennett, D.; Maes, N.; Wang, L.; Warwick, P.; Hall, T.; Walker, G.; Dierckx, A.

    2005-01-01

    Full text of publication follows: In demonstrating the suitability of Boom Clay as a potential site for the disposal of radioactive waste in Belgium, the role of the relatively high amount of Natural Organic Matter (NOM) present in the Boom Clay on the mobility of critical radionuclides needs investigation. Trivalent actinides and lanthanides form strong complexes with humic substances. Complexation of these trivalent radionuclides with NOM present in the Boom Clay may have opposing effects. If complexed by the aqueous phase (mobile) NOM, radionuclide transport will be governed by the mobility of these dissolved radionuclide-NOM species. If complexed by the solid phase (immobile) NOM, migration will be retarded. One of the aims of the EC projects TRANCOM-Clay and TRANCOM-II was to investigate the role of mobile NOM as radionuclide carrier with the objective of deriving conceptual models that can be implemented in repository performance assessment (PA) models. A separate paper describes the results of column migration experiments involving the transport of 241 Am- 14 C-NOM complexes through Boom Clay cores. This paper describes the transport model, POPCORN, that was developed to describe and evaluate the influence of NOM on radionuclide transport in clay, taking into account attachment/detachment rates of NOM to clay surfaces and the kinetics of RN complexation to, and destabilization from, NOM. The POPCORN model was used to evaluate diffusion experiments involving injection of 14 C-labelled NOM in Boom Clay cores. Model fits were obtained by varying the rates of filtration of NOM by attachment to the surface of the clay matrix. POPCORN was then used to analyse the 241 Am- 14 C-NOM migration experiments. The stability properties of the 241 Am-NOM were characterised by kinetic constants, and good matches to the migration data were achieved for the experiments. The findings suggest that a small sub-population of the original 241 Am-OM is the most stable, and that this

  18. Testing the Deployment Repeatability of a Precision Deployable Boom Prototype for the Proposed SWOT Karin Instrument

    Science.gov (United States)

    Agnes, Gregory S.; Waldman, Jeff; Hughes, Richard; Peterson, Lee D.

    2015-01-01

    NASA's proposed Surface Water Ocean Topography (SWOT) mission, scheduled to launch in 2020, would provide critical information about Earth's oceans, ocean circulation, fresh water storage, and river discharge. The mission concept calls for a dual-antenna Ka-band radar interferometer instrument, known as KaRIn, that would map the height of water globally along two 50 km wide swaths. The KaRIn antennas, which would be separated by 10 meters on either side of the spacecraft, would need to be precisely deployable in order to meet demanding pointing requirements. Consequently, an effort was undertaken to design build and prototype a precision deployable Mast for the KaRIn instrument. Each mast was 4.5-m long with a required dilitation stability of 2.5 microns over 3 minutes. It required a minimum first mode of 7 Hz. Deployment repeatability was less than +/- 7 arcsec in all three rotation directions. Overall mass could not exceed 41.5 Kg including any actuators and thermal blanketing. This set of requirements meant the boom had to be three times lighter and two orders of magnitude more precise than the existing state of the art for deployable booms.

  19. Layout of the manipulator-arm (boom) for the TFTR fusion reactor (Princeton, USA) under UHV-conditions

    International Nuclear Information System (INIS)

    Klaubert, J.

    1987-01-01

    This presentation shows the main criteria for the layout of the manipulator - arm and the antechamber - vessel of the TFTR - FUSION - REACTOR at Princeton University, PLASMA PHYSICS LABORATORY (USA). The main problem during layout of a manipulator system like the TFTR - Boom has been the limitation of the vertical deflections due to deadweight of the construction. The design problem is rather a deformation problem and a problem of stability than a stress problem. The way of optimizing the ratio between stiffness and deadweight is the most important part during the complete design - process. Additional earthquake requirements need further investigations for a satisfying layout (horizontal forces, weak-axis of moment of inertia). The details of the construction (welding, connections etc.) have to be designed in respect to UHV - requirements --> no holes and no fillet welds (outgasing - rate.) are allowed. All weldings have to be designed as bevel-welds. This manipulator system is designed for working in a plane system (two degrees of freedom). A manipulator system with the same operating capabilities in a three degree of freedom system needs larger cross sections for the different beam-elements than those of the discussed TFTR - BOOM

  20. The Perceived Work Ethic of K-12 Teachers by Generational Status: Generation X vs. Baby Boom Generation

    Science.gov (United States)

    Petty, Gregory C.

    2013-01-01

    This was an investigation of the work ethic of K-12 educators from Generation X and Baby Boomer generations. Teachers of the baby boom generation were born between 1946 and 1964, and many are beginning to retire. There is an impending teacher shortage due to the large numbers of this group retiring or leaving the profession. School administrators…

  1. Geo-scientific characterisation of the Boom Clay in the Netherlands in light of permanent confinement of radio-active waste

    NARCIS (Netherlands)

    Griffioen, J.J.; Simmelink, E.; Westerhoff, W.; Koenen, M.; Tambach, T.; Behrends, T.

    2012-01-01

    Recently, the OPERA research program has been initiated in the Netherlands. Its central objective is to develop initial, conditional safety cases for repositories in the Boom Clay and Zechstein rocksalt formations. TNO Geological Survey of the Netherlands has been granted two projects that deal with

  2. An alternative method for identifying booms and busts in the euro area housing market

    OpenAIRE

    Gerdesmeier, Dieter; Roffia, Barbara; Lenarcic, Andreja

    2012-01-01

    The main aim of this paper is to apply a method based on fundamentals ─ which has already been applied in the stock market analysis ─ to detect boom/bust in the housing market, with a focus on the euro area. In this context, an underlying model is developed and tested. It turns out that the user cost rate, a demographic variable, the unemployment rate, disposable income (or disposable income per capita), the debt-to-income ratio and, finally, the housing stock are fundamental variables which ...

  3. Technetium behaviour in Boom Clay - a laboratory and field study

    Energy Technology Data Exchange (ETDEWEB)

    Baston, G.M.N.; Ilett, D.J.; Cowper, M.M.; Pilkington, N.J.; Tweed, C.J.; Williams, S.J. [AEA Technology plc, Harwell, Didcot, Oxfordshire (United Kingdom); Canniere, P.R. de; Wang, L. [SCK.CEN, Waste and Disposal Project, Boeretang, Mol (Belgium)

    2002-07-01

    This paper describes a study of technetium solubility and migration under chemical conditions representative of those prevailing in a Boom Clay environment. Laboratory and in situ measurements yielded similar aqueous concentrations of technetium, of about 1 x 10{sup -8} mol dm{sup -3}, close to the concentrations measured for hydrated technetium(IV) oxide TcO{sub 2}.1.6H{sub 2}O in the solubility studies. From fitting the curves of the Tc concentrations as function of time, distribution coefficient (K{sub d}) values were estimated to lie between 0.8 cm{sup 3} g{sup -1} and 1.8 cm{sup 3} g{sup -1}. Exposure of the system at 80 C and to {gamma}-radiation dose rates of several hundred Gy h{sup -1} resulted in only minor differences in behaviour. (orig.)

  4. Use of bore logging for the determination of lithological characteristics of the Boom clay formation and interest for correlations in clay

    International Nuclear Information System (INIS)

    Neerdael, B.; Bonne, A.; Manfroy, P.; Vandenberghe, N.; Fierens, E.; Laga, P.

    1981-01-01

    It is first recalled that the purpose of the HADES project of the CEN/SCK at Mol (Belgium) is to study the possibility of geological disposal for radioactive wastes in the Boom clay formation at a depth between +-160 and 270 m. The different steps and aspects of the site investigation are exposed, and for each of them, the specific techniques used are reviewed. One of these steps is elaborated more in detail. It covers namely the lateral extrapolation of the lithological variations as established from a very detailed analysis of the initial cored boring. Among the usefull methods, the most practical and refined results were obtained from the resistivity logs in the reconnaissance holes. Finally, examples are shown of very detailed correlation on site scale, scale of the hydrogeological entity and regional scale (occurrence of Boom clay on the belgian territory)

  5. An Economic Rationale for the West African Scramble? The Commercial Transition and the Commodity Price Boom of 1835-1885

    NARCIS (Netherlands)

    Frankema, Ewout; Williamson, Jeffrey; Woltjer, Pieter

    2018-01-01

    We use a new trade dataset showing that nineteenth century Sub-Saharan Africa experienced a terms of trade boom comparable to other parts of the ‘global periphery’. A sharp rise in export prices in the five decades before the scramble (1835-1885) was followed by an equally impressive decline during

  6. The Speed of Light and the Hubble parameter: The Mass-Boom Effect

    International Nuclear Information System (INIS)

    Alfonso-Faus, Antonio

    2008-01-01

    We prove here that Newton's universal gravitation and momentum conservation laws together reproduce Weinberg's relation. It is shown that the Hubble parameter H must be built in this relation, or equivalently the age of the Universe t. Using a wave-to-particle interaction technique we then prove that the speed of light c decreases with cosmological time, and that c is proportional to the Hubble parameter H. We see the expansion of the Universe as a local effect due to the LAB value of the speed of light co taken as constant. We present a generalized red shift law and find a predicted acceleration for photons that agrees well with the result from Pioneer 10/11 anomalous acceleration. We finally present a cosmological model coherent with the above results that we call the Mass-Boom. It has a linear increase of mass m with time as a result of the speed of light c linear decrease with time, and the conservation of momentum mc. We obtain the baryonic mass parameter equal to the curvature parameter, Ω m Ω k , so that the model is of the type of the Einstein static, closed, finite, spherical, unlimited, with zero cosmological constant. This model is the cosmological view as seen by photons, neutrinos, tachyons etc. in contrast with the local view, the LAB reference. Neither dark matter nor dark energy is required by this model. With an initial constant speed of light during a short time we get inflation (an exponential expansion). This converts, during the inflation time, the Planck's fluctuation length of 10 -33 cm to the present size of the Universe (about 10 28 cm, constant from then on). Thereafter the Mass-Boom takes care to bring the initial values of the Universe (about 10 15 gr) to the value at the present time of about 10 55 gr

  7. Pore-water chemistry effects on the compressibility behaviour of Boom Clay

    International Nuclear Information System (INIS)

    Deng, Y.F.; Cui, Y.J.; Tang, A.M.; Nguyen, X.P.; Li, X.L.; Maarten, V.G.

    2010-01-01

    Document available in extended abstract form only. Boom clay is a thick deposit of over-consolidated marine clay, and belongs to the Oligocene series. Its hydraulic conductivity has been investigated since many years in Belgium within the site characterization program related to the performance assessment of potential geological disposal of high-level radioactive waste in this formation. Recently, the work of Wemaere et al. (2008) shows a significant variability of the hydraulic conductivity of the Boom clay. Indeed, they performed measurements on soil cores taken from four distant boreholes at various depths. The vertical hydraulic conductivity was found to vary from 3 x 10 -12 to 10 x 10 -12 m/s. It is suspected that this variability would be partly related to the water chemistry effects. Indeed, De Craen et al. (2006) shows that the pore-water chemical composition of soil cores taken from the Essen site is significantly different from that at the Mol site. If the pore water chemistry has strong effect on the hydraulic conductivity, its effect on the mechanical behaviour needs to be investigated too. The aim of this paper is to verify whether there are significant effects of pore-water chemistry on the soil compressibility. This study would be helpful to transpose the knowledge obtained from the Mol site to other sites of Boom clay formation where the geochemical components are different from the former site, as the hydro-mechanical characteristics of Boom clay at the Mol site has been widely investigated since the last decades. Two soil cores were taken from the Essen site at a depth of 227 m (Ess83) and 240 m (Ess96). Based on the geochemical analysis presented by De Craen et al. (2006), synthetic water having similar chemical composition of the in-situ pore-water was prepared. The identification geotechnical characteristics of these cores are shown in Table 2. It can be observed that the clay content (particle size < 2 μm) is relatively high (more than 50

  8. Parametric Study of the Effect of Membrane Tension on Sunshield Dynamics

    Science.gov (United States)

    Ross, Brian; Johnston, John D.; Smith, James

    2002-01-01

    The NGST sunshield is a lightweight, flexible structure consisting of pretensioned membranes supported by deployable booms. The structural dynamic behavior of the sunshield must be well understood in order to predict its influence on observatory performance. A 1/10th scale model of the sunshield has been developed for ground testing to provide data to validate modeling techniques for thin film membrane structures. The validated models can then be used to predict the behaviour of the full scale sunshield. This paper summarizes the most recent tests performed on the 1/10th scale sunshield to study the effect of membrane preload on sunshield dynamics. Topics to be covered include the test setup, procedures, and a summary of results.

  9. FORMING CHONDRULES IN IMPACT SPLASHES. II. VOLATILE RETENTION

    Energy Technology Data Exchange (ETDEWEB)

    Dullemond, Cornelis Petrus; Harsono, Daniel; Stammler, Sebastian Markus [Institute for Theoretical Astrophysics, Heidelberg University, Albert-Ueberle-Strasse 2, D-69120 Heidelberg (Germany); Johansen, Anders [Lund Observatory, Department of Astronomy and Theoretical Physics, Lund University, Box 43, SE-22100 Lund (Sweden)

    2016-11-20

    Solving the mystery of the origin of chondrules is one of the most elusive goals in the field of meteoritics. Recently, the idea of planet(esimal) collisions releasing splashes of lava droplets, long considered out of favor, has been reconsidered as a possible origin of chondrules by several papers. One of the main problems with this idea is the lack of quantitative and simple models that can be used to test this scenario by directly comparing to the many known observables of chondrules. In Paper I of this series, we presented a simple thermal evolution model of a spherically symmetric expanding cloud of molten lava droplets that is assumed to emerge from a collision between two planetesimals. The production of lava could be either because the two planetesimals were already in a largely molten (or almost molten) state due to heating by {sup 26}Al, or due to impact jetting at higher impact velocities. In the present paper, number II of this series, we use this model to calculate whether or not volatile elements such as Na and K will remain abundant in these droplets or whether they will get depleted due to evaporation. The high density of the droplet cloud (e.g., small distance between adjacent droplets) causes the vapor to quickly reach saturation pressure and thus shuts down further evaporation. We show to what extent, and under which conditions, this keeps the abundances of these elements high, as is seen in chondrules. We find that for most parameters of our model (cloud mass, expansion velocity, initial temperature) the volatile elements Mg, Si, and Fe remain entirely in the chondrules. The Na and K abundances inside the droplets will initially stay mostly at their initial values due to the saturation of the vapor pressure, but at some point start to drop due to the cloud expansion. However, as soon as the temperature starts to decrease, most or all of the vapor recondenses again. At the end, the Na and K elements retain most of their initial abundances, albeit

  10. El boom, Barral y Barcelona : gestación editorial de un movimiento transoceánico

    OpenAIRE

    Ruiz Ortega, José Luis

    2014-01-01

    En los años sesenta la pequeña editorial barcelonesa de Carlos Barral brindó al peruano Vargas Llosa la posibilidad de publicar su primera novela. Desde entonces, el editor Barral se convierte en el promotor principal del surgimiento y desarrollo del boom latinoamericano y, por consiguiente, en pieza clave para el fortalecimiento de las relaciones editoriales y literarias entre América Latina y España. In the 1960s Carlos Barral's small publishing house in Barcelona affords the Peruvian Va...

  11. Developments in modelling of thermohydro-geomechanical behaviour of Boom clay and clay-based buffer materials (Volume 1)

    International Nuclear Information System (INIS)

    Baldi, G.; Hueckel, T.; Peano, A.; Pellegrini, R.

    1991-01-01

    The results of two years of research on thermomechanics of clays performed within CEC contract Fl1W/0150 are described herein. Previous studies (research contracts with CEC/WAS/380.83.7 l) performed by ISMES have evidenced the need for an improved modelling of the volumetric response of natural clays. In a coupled approach, this leads to an improved prediction of pore-pressure development and dissipation. This is crucial for assessing conditions of a possible local thermal failure as verified in laboratory tests done at ISMES. The first part of the study lays the foundations of a comprehensive theoretical treatment of the interaction between water and soil skeleton. It consists in: (a) developing a framework for inclusion of water/soil particle thermally induced interaction into a thermodynamically consistent mixture theory approach (Section 2); (b) studying possible modelling approaches of considering the effective thermal expansion coefficient of pore water dependency on pore water status (Section 2); (c) testing artificial clays to assess pore water thermal expansion dependence on temperature in the presence of different amounts of active clay minerals and also Boom clay (Section 3); (d) performing a laboratory test campaign on Boom clay with special attention to the response in the overconsolidated domain (Section 4). 89 figs., 18 tabs., 102 refs

  12. Boom-bust dynamics in biological invasions: towards an improved application of the concept

    Czech Academy of Sciences Publication Activity Database

    Strayer, D.L.; D'Antonio, C. M.; Essl, F.; Fowler, M. S.; Geist, J.; Hilt, S.; Jaric, I.; Jöhnk, K.; Jones, C. G.; Lambin, X.; Latzka, A. W.; Pergl, Jan; Pyšek, Petr; Robertson, P.; von Schmalensee, M.; Stefansson, R. A.; Wright, J.; Jeschke, J.M.

    2017-01-01

    Roč. 20, č. 10 (2017), s. 1337-1350 ISSN 1461-023X R&D Projects: GA ČR GA17-19025S; GA ČR GB14-36079G Grant - others:AV ČR(CZ) AP1002 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:67985939 Keywords : invasions * population dynamics * alien species Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 9.449, year: 2016

  13. Solar dynamic power systems for space station

    Science.gov (United States)

    Irvine, Thomas B.; Nall, Marsha M.; Seidel, Robert C.

    1986-01-01

    The Parabolic Offset Linearly Actuated Reflector (POLAR) solar dynamic module was selected as the baseline design for a solar dynamic power system aboard the space station. The POLAR concept was chosen over other candidate designs after extensive trade studies. The primary advantages of the POLAR concept are the low mass moment of inertia of the module about the transverse boom and the compactness of the stowed module which enables packaging of two complete modules in the Shuttle orbiter payload bay. The fine pointing control system required for the solar dynamic module has been studied and initial results indicate that if disturbances from the station are allowed to back drive the rotary alpha joint, pointing errors caused by transient loads on the space station can be minimized. This would allow pointing controls to operate in bandwidths near system structural frequencies. The incorporation of the fine pointing control system into the solar dynamic module is fairly straightforward for the three strut concentrator support structure. However, results of structural analyses indicate that this three strut support is not optimum. Incorporation of a vernier pointing system into the proposed six strut support structure is being studied.

  14. An empirical model of the Baltic Sea reveals the importance of social dynamics for ecological regime shifts.

    Science.gov (United States)

    Lade, Steven J; Niiranen, Susa; Hentati-Sundberg, Jonas; Blenckner, Thorsten; Boonstra, Wiebren J; Orach, Kirill; Quaas, Martin F; Österblom, Henrik; Schlüter, Maja

    2015-09-01

    Regime shifts triggered by human activities and environmental changes have led to significant ecological and socioeconomic consequences in marine and terrestrial ecosystems worldwide. Ecological processes and feedbacks associated with regime shifts have received considerable attention, but human individual and collective behavior is rarely treated as an integrated component of such shifts. Here, we used generalized modeling to develop a coupled social-ecological model that integrated rich social and ecological data to investigate the role of social dynamics in the 1980s Baltic Sea cod boom and collapse. We showed that psychological, economic, and regulatory aspects of fisher decision making, in addition to ecological interactions, contributed both to the temporary persistence of the cod boom and to its subsequent collapse. These features of the social-ecological system also would have limited the effectiveness of stronger fishery regulations. Our results provide quantitative, empirical evidence that incorporating social dynamics into models of natural resources is critical for understanding how resources can be managed sustainably. We also show that generalized modeling, which is well-suited to collaborative model development and does not require detailed specification of causal relationships between system variables, can help tackle the complexities involved in creating and analyzing social-ecological models.

  15. chemo-Hydro-mechanical modelling of in-situ disposal of a bituminized radioactive waste in boom clay

    International Nuclear Information System (INIS)

    Mokni, N.; Olivella, S.; Valcke, E.; Marien, A.; Smets, S.; Li, X.; Sillen, X.

    2012-01-01

    Document available in extended abstract form only. The current reference solution of the Belgian Agency for the Management of Radioactive Waste and Fissile Materials (ONDRAF/NIRAS) envisages underground disposal of Eurobitum Bituminized radioactive Waste (BW) in a geologically stable clay formation. In Belgium, the Boom Clay, which is a 30 to 35 million years old and ∼100 m thick marine sediment is being studied as a potential host formation because of its favorable properties to limit and delay the migration of the leached radionuclides to the biosphere over extended periods of time. The current disposal concept foresees that several drums (220 litres) of Eurobitum would be grouped in thick-walled cement-based secondary containers, which in turn would be placed in concrete-lined disposal galleries that are excavated at mid-depth in the clay layer. Only 80-90 % of the total volume of the drum is filled with Eurobitum.The remaining voids between the containers would be backfilled with a cement-based material. The interaction between the BW and the host clay formation is a very complicated chemo-hydro-mechanical process and depends not only on the hydro-mechanical behaviour of the Boom Clay itself, but also on that of the BW. In fact, the osmosis-induced uptake of water by the dehydrated hygroscopic salts embedded in the waste induces a geo-mechanical perturbation of the host formation, caused by the swelling and the increase of the pressure in and around the waste. The objectives of the Chemo-Hydro-Chemical (CHM) analysis presented in this work are (i) to get insights on the kinetics of water uptake by BW, dissolution of the embedded NaNO 3 crystals, solute leaching, and maximum generated pressure under disposal conditions and (ii) to study the stress redistribution due to the recompression of the clay around a gallery caused by the swelling pressure of the bitumen and the admissible swelling pressure for Boom clay. Firstly, a CHM formulation of chemically and

  16. Analysis of Offshore Knuckle Boom Crane - Part One: Modeling and Parameter Identification

    Directory of Open Access Journals (Sweden)

    Morten K. Bak

    2013-10-01

    Full Text Available This paper presents an extensive model of a knuckle boom crane used for pipe handling on offshore drilling rigs. The mechanical system is modeled as a multi-body system and includes the structural flexibility and damping. The motion control system model includes the main components of the crane's electro-hydraulic actuation system. For this a novel black-box model for counterbalance valves is presented, which uses two different pressure ratios to compute the flow through the valve. Experimental data and parameter identification, based on both numerical optimization and manual tuning, are used to verify the crane model. The demonstrated modeling and parameter identification techniques target the system engineer and takes into account the limited access to component data normally encountered by engineers working with design of hydraulic systems.

  17. Study of the Boom clay layer as a geochemical barrier for long-lived radionuclides

    International Nuclear Information System (INIS)

    Baetsle, L.H.; Henrion, P.; Put, M.; Cremers, A.

    1985-01-01

    The Boom clay layer below the nuclear site of Mol, Belgium has been thoroughly investigated on its geohydrologic and physicochemical characteristics as well as by laboratory experiments and in situ tests in the underground laboratory. Hydraulic permeabilities have been measured in situ; the chemical composition of the interstitial clay water is related to the mineralogical composition. Radionuclide sorption data and sorption mechanisms are given for Cs, Sr, Eu, Tc, Am, Pu and Np; experimental diffusion coefficients were determined by clay plug migration tests in representative conditions. Results of model calculations for the migration of radionuclides in dense porous media are given for Cs, Sr, Pu and Np

  18. Organic matter linked radionuclide transport in Boom clay - Phenomenological understanding and abstraction to PA

    International Nuclear Information System (INIS)

    Maes, N.; Bruggeman, C.; Liu, D.J.; Salah, S.; Van Laer, L.; Wang, L.; Weetjens, E.; Govaerts, J.; Marivoet, J.; Brassinnes, S.

    2012-01-01

    Document available in extended abstract form only. In the frame of the Belgian research program on long term management of high-level and/or long-lived radioactive wastes coordinated by ONDRAF/NIRAS, plastic clays (i.e., Boom Clay and Ypresian clays) are investigated for their potential to host a deep geological disposal repository for radioactive waste because of, among others, their ability to significantly retard radionuclide releases to the biosphere. The Boom Clay is characterised by the presence of a relatively high amount of dissolved organic matter (DOM, humic substances) which show a strong interaction with a suite of radionuclides (RN) like lanthanides, actinides and transition metals. This interaction with DOM leads in general to an increased mobility of the radionuclide as the OM can act as a colloidal carrier for the radionuclide. Therefore, the quantification and the understanding of the underlying processes are needed for the demonstration of confidence in the host formation to act as a suitable barrier. However, this is not an easy task, given the multitude of processes involved: complexation/colloid formation, sorption, kinetics, filtration, -. In this presentation, we will provide an overview of the research work that leads to a straightforward reactive transport model capturing fairly well the experimental observations. The model can be considered as an intermediate model providing a good basis for further safety abstraction on the one hand and the way to a more detailed phenomenological understanding on the other hand. The research is focussed on the underlying processes that govern speciation, sorption and transport. These underlying processes are investigated in a bottom-up approach, from simple systems to more complex systems. Interpretation is done using thermodynamic based models. Whereas the contribution of Bruggeman et al. focusses mainly on (batch) sorption studies (of trivalent RN), this presentation will provide more details on the

  19. Dynamics and Control of a Flexible Solar Sail

    Directory of Open Access Journals (Sweden)

    Jiafu Liu

    2014-01-01

    Full Text Available Solar sail can merely make use of solar radiation pressure (SRP force as the thrust for space missions. The attitude dynamics is obtained for the highly flexible solar sail with control vanes, sliding masses, and a gimbaled control boom. The vibration equations are derived considering the geometric nonlinearity of the sail structure subjected to the forces generated by the control vanes, solar radiation pressure (SRP, and sliding masses. Then the dynamic models for attitude/vibration controller design and dynamic simulation are obtained, respectively. The linear quadratic regulator (LQR based and optimal proportional-integral (PI based controllers are designed for the coupled attitude/vibration models with constant disturbance torques caused by the center-of-mass (cm/center-of-pressure (cp offset, respectively. It can be concluded from the theoretical analysis and simulation results that the optimal PI based controller performs better than the LQR based controller from the view of eliminating the steady-state errors. The responses with and without the geometrical nonlinearity are performed, and the differences are observed and analyzed. And some suggestions are also presented.

  20. A Whitham-Theory Sonic-Boom Analysis of the TU-144 Aircraft at a Mach Number of 2.2

    Science.gov (United States)

    Mack, Robert J.

    1999-01-01

    Officially, the Tu-144 was the first supersonic-cruise, passenger-carrying aircraft to enter commercial service. Design, construction, and testing were carried out by the Soviet Union, flight certification was by the Soviet Union, and the only regular passenger flights were scheduled and flown across the territory of the Soviet Union. Although it was not introduced to international passenger service, there were many significant engineering accomplishments achieved in the design, production, and flight of this aircraft. Development of the aircraft began with a prototype stage. Systematic testing and redesign led to a production aircraft in discrete stages that measurably improved the performance of the aircraft from the starting concept to final aircraft certification. It flew in competition with the English-French Concorde for a short time, but was withdrawn from national commercial service due to a lack of interest by airlines outside the Soviet Union. NASA became interested in the Tu- 144 aircraft when it was offered for use as a flying "testbed" in the study of operating characteristics of a supersonic-cruise commercial airplane. Since it had been in supersonic-cruise service, the Tu- 144 had operational characteris'tics similar to those anticipated in the conceptual aircraft designs being studied by the United States aircraft companies. In addition to the other operational tests being conducted on the Tu-144 aircraft, it was proposed that two sets of sonic-boom pressure signature measurements be made. The first set would be made on the ground, using techniques and devices similar to those in reference I and many other subsequent studies. A second set would be made in the air with an instrumented aircraft flying close under the Tu-144 in supersonic flight. Such in-flight measurements would require pressure gages that were capable of accurately recording the flow-field overpressures generated by the Tu- 144 at relatively close distances under the vehicle

  1. Electron microprobe analysis (WDS EPMA) of Zhamanshin glass reveals the impactor and a common role of accretion in the origin of splash-form impact glass

    International Nuclear Information System (INIS)

    Vetvicka, I; Frank, J; Drtina, J

    2010-01-01

    Impact glass samples collected during expeditions to the Zhamashin and Lonar craters were subjected to a morphology survey and compared to Wabar, Henbury and Darwin impact glasses to reveal that the accretion of fibres and spherules is not exclusive for irghizites but occurs in other splash form glasses over the world. WDS EPMA and LA-ICP-MS assays of Zhamanshin and Lonar glasses enabled the definition of akmurynites as Zhamanshin glass of specific morphology, chemistry and absence of extraterrestrial contamination. However, extraterrestrial contamination in irghizites was verified and further WDS EPMA analyses led to the conclusion that the Zhamanshin crater had been formed by the impact of a primitive achondrite of Lodran chemistry.

  2. Boom and bust: ancient and recent diversification in bichirs (Polypteridae: Actinopterygii), a relictual lineage of ray-finned fishes.

    Science.gov (United States)

    Near, Thomas J; Dornburg, Alex; Tokita, Masayoshi; Suzuki, Dai; Brandley, Matthew C; Friedman, Matt

    2014-04-01

    Understanding the history that underlies patterns of species richness across the Tree of Life requires an investigation of the mechanisms that not only generate young species-rich clades, but also those that maintain species-poor lineages over long stretches of evolutionary time. However, diversification dynamics that underlie ancient species-poor lineages are often hidden due to a lack of fossil evidence. Using information from the fossil record and time calibrated molecular phylogenies, we investigate the history of lineage diversification in Polypteridae, which is the sister lineage of all other ray-finned fishes (Actinopterygii). Despite originating at least 390 million years (Myr) ago, molecular timetrees support a Neogene origin for the living polypterid species. Our analyses demonstrate polypterids are exceptionally species depauperate with a stem lineage duration that exceeds 380 million years (Ma) and is significantly longer than the stem lineage durations observed in other ray-finned fish lineages. Analyses of the fossil record show an early Late Cretaceous (100.5-83.6 Ma) peak in polypterid genus richness, followed by 60 Ma of low richness. The Neogene species radiation and evidence for high-diversity intervals in the geological past suggest a "boom and bust" pattern of diversification that contrasts with common perceptions of relative evolutionary stasis in so-called "living fossils." © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  3. Atributos mecânicos e erosão por salpicamento em amostras de latossolo vermelho-amarelo sob efeito de vinhaça Soil mechanical attributes and splash erosion on samples of red-yellow latosol influenced by sugarcane vinasse

    Directory of Open Access Journals (Sweden)

    Luiz Gustavo Fernandes Julião

    2011-02-01

    Full Text Available Objetivou-se, neste trabalho, quantificar o efeito da vinhaça no comportamento compressivo e nos atributos mecânicos, como consistência, umidade ótima de compactação e densidade máxima, de um Latossolo Vermelho-Amarelo (LVA; avaliar o efeito da vinhaça e do estado de compactação no salpicamento de partículas, da região de Lavras, MG. A vinhaça foi proveniente de um alambique de cachaça artesanal. Foram coletadas amostras deformadas e indeformadas nas profundidades de 0 a 3 cm e 60 a 63 cm. As amostras deformadas destinaram-se à caracterização do solo, determinação dos limites de consistência e realização do ensaio de Proctor Normal, após a incubação do material com vinhaça. As amostras indeformadas foram saturadas com vinhaça ou água destilada (controle, por 48 horas e destinaram-se aos ensaios de compressibilidade e resistência ao salpicamento, usando-se um minisimulador de chuvas. A vinhaça alterou os limites de consistência das camadas estudadas. Para a camada de 0-3 cm a vinhaça reduziu a faixa friável e para a camada 60-63 cm aumentou. Para ambas as camadas, a vinhaça aumentou a Dmáx e reduziu a Uótima. As camadas 0-3 cm e 60-63 cm, independentemente do tratamento com vinhaça, apresentaram a mesma capacidade suporte de carga. O estado de compactação das amostras influenciou a erosão por salpicamento. O aumento da pressão aplicada sobre as amostras resultou no aumento da quantidade de material salpicado. Na camada 60-63 cm, o tratamento com vinhaça reduziu a quantidade de material salpicado com o aumento da pressão aplicada, notadamente com as amostras na capacidade de campo.The objective of this study was to quantify the effect of plonk on compressive behavior and mechanical attributes such as consistency, optimum moisture for compaction and maximum density of a Red-Yellow Latosol (Oxisol to evaluate the effect of plonk and compaction state in splashed particles, from Lavras (MG region. The plonk

  4. Automatic path-planning for a multilink articulated boom within the torus of a fusion reactor

    International Nuclear Information System (INIS)

    Smidt, D.

    1986-08-01

    For in-torus maintenance of fusion machines a manipulator is conveyed to the working area by a multilink-transporter, also called 'articulated boom'. Systems of this type have in general four to five links and move in the midplane of the torus. They are kinematically redundant and have a very restricted working space. In this paper automatic methods for the collision free approach of any position of the final joint within the reach of the transporter are presented, including insertion and removal. By automatic teach-in with the CAD-simulation a table of safe configurations can be generated and supplemented by a fine-positioning algorithm. (orig.) [de

  5. Analysis of RAE-1 inversion

    Science.gov (United States)

    Hedland, D. A.; Degonia, P. K.

    1974-01-01

    The RAE-1 spacecraft inversion performed October 31, 1972 is described based upon the in-orbit dynamical data in conjunction with results obtained from previously developed computer simulation models. The computer simulations used are predictive of the satellite dynamics, including boom flexing, and are applicable during boom deployment and retraction, inter-phase coast periods, and post-deployment operations. Attitude data, as well as boom tip data, were analyzed in order to obtain a detailed description of the dynamical behavior of the spacecraft during and after the inversion. Runs were made using the computer model and the results were analyzed and compared with the real time data. Close agreement between the actual recorded spacecraft attitude and the computer simulation results was obtained.

  6. After Welfare Reform and an Economic Boom: Why Is Child Poverty Still So Much Higher in the U.S. Than in Europe?

    Science.gov (United States)

    Danziger, Sheldon

    This paper argues that the U.S.'s experience during the economic boom of the 1990s, together with its choices concerning social welfare policies, imply that child poverty in the United States will be much higher than that in most European countries. It hypothesizes that Americans reveal their preferences about the extent of poverty they are…

  7. Study of the 'Clay of Boom' with regard to the storage of nuclear waste. Appendices; Onderzoek Klei van Boom in verband met eventuele opslag kernafval. Bijlagen

    Energy Technology Data Exchange (ETDEWEB)

    Brugge, J.V.M.; Vrouwe, B.J. [T and A Survey, Amsterdam (Netherlands)

    2011-01-15

    The Dutch government aims to store nuclear waste in the Dutch soil. Geological research organization T and A Survey mapped the areas that match with the demands of the Dutch government regarding underground storage of nuclear waste. These are areas in which the Clay layer of Boom has a minimal thickness of 100 meters and the depth of the top of the clay formation is at least 500 meters. This report contains the appendices with (geological) maps and data. [Dutch] De Nederlandse overheid wil kernafval ondergronds opslaan in de Nederlandse bodem. Geologisch onderzoeksbureau T and A Survey brengt de gebieden in kaart, die voldoen aan de door de overheid gestelde eisen voor mogelijke ondergrondse opslag van kernafval. Het gaat om gebieden waar de Boomse kleilaag een minimale dikte van 100 meter heeft en de diepte van de top van de kleiformatie minimaal 500 meter bedraagt. Dit rapport bevat de bijlagen met (geologische) kaarten en gegevens.

  8. One last boom : Alberta's rapidly expanding oil mines may be the largest and messiest industrial projects in Canadian history

    International Nuclear Information System (INIS)

    Laird, G.

    2001-01-01

    The bitumen deposits of Alberta, 2.5 trillion barrels of oil, of which 300 billion are considered recoverable, represent the greatest single petroleum resources of the world, based on surface and subsurface calculations. Four deposits, covering an area the size of New Brunswick, are located in the area stretching from Cold Lake to Lloydminster (east of Edmonton), the upper reaches of the Athabasca River east to the Peace River. The largest by far is the Athabasca deposit in the vicinity of Fort McMurray, spread over 4.3 million hectares. The deposit is at the centre of the biggest industrial expansion witnessed by the province. Since 1996, 38 billion dollars worth of new projects have been announced. It is estimated that by 2025, the bulk of the national oil production will originate from open-pit mines and underground wells around Fort McMurray. This oil boom has economic benefits for the population, from welders to real estate agents to stakeholders. The environmental effects are not as beneficial. Huge strip mines are being carved next to the Athabasca River, with great amounts of greenhouse gases emissions. The Suncor and Syncrude oil-sands plants combined represent the fourth largest carbon dioxide emission source in Canada. The development of these projects dramatically affects global warming. The nitrogen and sulphur emissions could also acidify lakes and soil in the region. The Suncor mine resulted from the first boom to hit Fort McMurray in 1964. The Syncrude mine is the result of the second boom which took place in 1973. In 1996, Suncor installed a sulphur scrubber system that removes 95 per cent of sulphur dioxide from the electricity and steam-generation plant. Suncor also invested in various projects, such as wind-power, rainforest cultivation and biomass generation. The volume of pollution increases as the operations expand, even if operations are cleaner. If no new gains in pollution control are achieved, it is expected that by 2015, the total

  9. The Baby Boom As It Ages: How Has It Affected Patterns of Consumptions and Savings in the United States?

    OpenAIRE

    Diane Macunovich

    1999-01-01

    Using detailed estimates of personal consumption expenditures at the state level for 1900, 1929, 1970, and 1982 developed by Stanley Lebergott, this paper demonstrates that the passage of the Baby Boom from childhood through the teen years and into family formation would have caused market swings in patterns of aggregate consumption and savings in the United States during the past 50 years. The effect of age structure on personal consumption expenditures is estimated using population by singl...

  10. Real-time monitoring of viscosity changes triggered by chemical reactions using a high-speed imaging method

    Directory of Open Access Journals (Sweden)

    Wooseok Jung

    2015-09-01

    Full Text Available We present a method to monitor in real time peptide self-assembly or polymerization events. The temperature controlled modification of a previously reported splash test setup using high speed imaging enables to observe and measure rheological changes in liquid samples and can, in turn, monitor a peptide self-assembly or polymerization reaction accompanied with specific changes in solution viscosity. A series of 2 mm glass beads were dropped into an Fmoc-L3-OMe (methylated Fluorenylmethyloxycarbonyl-trileucine solution mixed with Alcalase 2.4 L (EC 3.4.21.62 or first dipped in Tetramethylethylenediamine (TEMED, a catalyst for acrylamide polymerization, then dropped into acrylamide. The resulting splashes were observed using a high speed camera. The results demonstrate that the viscosity changes of the peptide sample during the peptide self-assembly or acrylamide polymerization affect the specific shape and evolution of the splashing event. Typically, the increase in viscosity while the reaction occurs decreased the size of the splash and the amount of time for the splash to reach maximum extension from the moment for the beads to impact the sample. The ability to observe rheological changes of sample state presents the opportunity to monitor the real time dynamics of peptide self-assembly or cross-polymerization. Keywords: High-speed imaging, Self-assembly, Viscosity sensor

  11. Measured Sonic Boom Signatures Above and Below the XB-70 Airplane Flying at Mach 1.5 and 37,000 Feet

    Science.gov (United States)

    Maglieri, Domenic J.; Henderson, Herbert R.; Tinetti, Ana F.

    2011-01-01

    During the 1966-67 Edwards Air Force Base (EAFB) National Sonic Boom Evaluation Program, a series of in-flight flow-field measurements were made above and below the USAF XB-70 using an instrumented NASA F-104 aircraft with a specially designed nose probe. These were accomplished in the three XB-70 flights at about Mach 1.5 at about 37,000 ft. and gross weights of about 350,000 lbs. Six supersonic passes with the F-104 probe aircraft were made through the XB-70 shock flow-field; one above and five below the XB-70. Separation distances ranged from about 3000 ft. above and 7000 ft. to the side of the XB-70 and about 2000 ft. and 5000 ft. below the XB-70. Complex near-field "sawtooth-type" signatures were observed in all cases. At ground level, the XB-70 shock waves had not coalesced into the two-shock classical sonic boom N-wave signature, but contained three shocks. Included in this report is a description of the generating and probe airplanes, the in-flight and ground pressure measuring instrumentation, the flight test procedure and aircraft positioning, surface and upper air weather observations, and the six in-flight pressure signatures from the three flights.

  12. Effects of Sonic Booms on Marine Mammals: Problem Review and Recommended Research

    Science.gov (United States)

    Bowles, Ann E.

    1996-01-01

    By flying the High-Speed Civil Transport (HSCT) exclusively over uninhabited areas and mo over water, human annoyance will be reduced to acceptable levels. However, this strategy will for HSCT proponents to contend with the potential effects of sonic booms on animals, particularly ma mammals. What follows is a summary of the environmental regulations that must be addressed, the scientific community's concerns about the potential effects of the HSCT, and recommendations fox research to address the most important concerns. The recommendations included herein are based both on existing scientific evidence and regulatory needs. One cannot over-emphasize the importance of obtaining the appropriate information prior to substantial public exposure. Recent controversies over other human-made acoustic sources in the ocean suggest that the HSCT will receive intense scrutiny. It seems certain that an Environmental Impact Statement (EIS) and Incidental Harassment Authorization (IHA) under the Marine Mammal Protection Act (MMPA) or its equivalent will be necessary.

  13. The experimental testing of the long-term behaviour of cemented radioactive waste from nuclear research reactors in the geological disposal conditions of the boom clay

    International Nuclear Information System (INIS)

    Sneyers, A.; Marivoet, J.; Iseghem, P. van

    1998-01-01

    Liquid wastes, resulting from the reprocessing of spent nuclear fuel from the BR-2 Materials Testing Reactor, will be conditioned in a cement matrix at the dedicated cementation facility of UKAEA at Dounreay. In Belgium, the Boom clay formation is studied as a potential host rock for the final geological disposal of cemented research reactor waste. In view of evaluating the safety of disposal, laboratory leach experiments and in situ tests have been performed. Leach experiments in synthetic clay water indicate that the leach rates of calcium and silicium are relatively low compared to those of sodium and potassium. In situ experiments on inactive samples are performed in order to obtain information on the microchemical and mineralogical changes of the cemented waste in contact with the Boom clay. Finally, results from a preliminary performance assessment calculation suggest a non-negligible maximum dose rate of 5 10 -9 Sv/a for 129 I. (author)

  14. The experimental testing of the long-term behaviour of cemented radioactive waste from nuclear research reactors in the geological disposal conditions of the boom clay

    Energy Technology Data Exchange (ETDEWEB)

    Sneyers, A.; Marivoet, J.; Iseghem, P. van [SCK-CEN, B-2400 Mol (Belgium)

    1998-07-01

    Liquid wastes, resulting from the reprocessing of spent nuclear fuel from the BR-2 Materials Testing Reactor, will be conditioned in a cement matrix at the dedicated cementation facility of UKAEA at Dounreay. In Belgium, the Boom clay formation is studied as a potential host rock for the final geological disposal of cemented research reactor waste. In view of evaluating the safety of disposal, laboratory leach experiments and in situ tests have been performed. Leach experiments in synthetic clay water indicate that the leach rates of calcium and silicium are relatively low compared to those of sodium and potassium. In situ experiments on inactive samples are performed in order to obtain information on the microchemical and mineralogical changes of the cemented waste in contact with the Boom clay. Finally, results from a preliminary performance assessment calculation suggest a non-negligible maximum dose rate of 5 10{sup -9} Sv/a for {sup 129}I. (author)

  15. Non linear shock wave propagation in heterogeneous fluids: a numerical approach beyond the parabolic approximation with application to sonic boom.

    Science.gov (United States)

    Dagrau, Franck; Coulouvrat, François; Marchiano, Régis; Héron, Nicolas

    2008-06-01

    Dassault Aviation as a civil aircraft manufacturer is studying the feasibility of a supersonic business jet with the target of an "acceptable" sonic boom at the ground level, and in particular in case of focusing. A sonic boom computational process has been performed, that takes into account meteorological effects and aircraft manoeuvres. Turn manoeuvres and aircraft acceleration create zones of convergence of rays (caustics) which are the place of sound amplification. Therefore two elements have to be evaluated: firstly the geometrical position of the caustics, and secondly the noise level in the neighbourhood of the caustics. The modelling of the sonic boom propagation is based essentially on the assumptions of geometrical acoustics. Ray tracing is obtained according to Fermat's principle as paths that minimise the propagation time between the source (the aircraft) and the receiver. Wave amplitude and time waveform result from the solution of the inviscid Burgers' equation written along each individual ray. The "age variable" measuring the cumulative nonlinear effects is linked to the ray tube area. Caustics are located as the place where the ray tube area vanishes. Since geometrical acoustics does not take into account diffraction effects, it breaks down in the neighbourhood of caustics where it would predict unphysical infinite pressure amplitude. The aim of this study is to describe an original method for computing the focused noise level. The approach involves three main steps that can be summarised as follows. The propagation equation is solved by a forward marching procedure split into three successive steps: linear propagation in a homogeneous medium, linear perturbation due to the weak heterogeneity of the medium, and non-linear effects. The first step is solved using an "exact" angular spectrum algorithm. Parabolic approximation is applied only for the weak perturbation due to the heterogeneities. Finally, non linear effects are performed by solving the

  16. Uptake of phosphorus from surfactant solutions by wheat leaves: spreading kinetics, wetted area, and drying time.

    Science.gov (United States)

    Peirce, Courtney A E; Priest, Craig; McBeath, Therese M; McLaughlin, Mike J

    2016-01-07

    The delivery and uptake of nutrients at the surface of plant leaves is an important physicochemical phenomenon that depends on leaf surface morphology and chemistry, fertilizer formulation chemistry (including adjuvant and associated surfactants), wetting dynamics, and many other physical, chemical and biological factors. In this study, the role of spreading dynamics in determining uptake of the macronutrient phosphorus from phosphoric acid fertilizer solution in combination with three different adjuvants was measured in the absence of droplet run-off and splashing. When run-off and splashing losses were zero, spreading and drying rates had a small to negligible effect on the uptake efficiency. The results suggest that uptake may be much less sensitive to the specific choice of adjuvant and long time-scale spreading behaviour than one might intuitively expect.

  17. Propulsion System Dynamic Modeling for the NASA Supersonic Concept Vehicle: AeroPropulsoServoElasticity

    Science.gov (United States)

    Kopasakis, George; Connolly, Joseph; Seidel, Jonathan

    2014-01-01

    A summary of the propulsion system modeling under NASA's High Speed Project (HSP) AeroPropulsoServoElasticity (APSE) task is provided with a focus on the propulsion system for the low-boom supersonic configuration developed by Lockheed Martin and referred to as the N+2 configuration. This summary includes details on the effort to date to develop computational models for the various propulsion system components. The objective of this paper is to summarize the model development effort in this task, while providing more detail in the modeling areas that have not been previously published. The purpose of the propulsion system modeling and the overall APSE effort is to develop an integrated dynamic vehicle model to conduct appropriate unsteady analysis of supersonic vehicle performance. This integrated APSE system model concept includes the propulsion system model, and the vehicle structural-aerodynamics model. The development to date of such a preliminary integrated model will also be summarized in this report.propulsion system dynamics, the structural dynamics, and aerodynamics.

  18. An Economic Rationale for the West African Scramble? The Commercial Transition and the Commodity Price Boom of 1835-1885

    OpenAIRE

    Frankema, E.H.P.; Williamson, J.G.; Woltjer, P.J.

    2018-01-01

    We use a new trade dataset showing that nineteenth century Sub-Saharan Africa experienced a terms of trade boom comparable to other parts of the ‘global periphery’. A sharp rise in export prices in the five decades before the scramble (1835-1885) was followed by an equally impressive decline during the colonial era. This study revises the view that the scramble for West Africa occurred when its major export markets were in decline and argues that the larger weight of West Africa in French imp...

  19. Nutrition, fertility and steady-state population dynamics in a pre-industrial community in Penrith, northern England.

    Science.gov (United States)

    Scott, S; Duncan, C J

    1999-10-01

    The effect of nutrition on fertility and its contribution thereby to population dynamics are assessed in three social groups (elite, tradesmen and subsistence) in a marginal, pre-industrial population in northern England. This community was particularly susceptible to fluctuations in the price of grains, which formed their basic foodstuff. The subsistence class, who formed the largest part of the population, had low levels of fertility and small family sizes, but women from all social groups had a characteristic and marked subfecundity in the early part of their reproductive lives. The health and nutrition of the mother during pregnancy was the most important factor in determining fertility and neonatal mortality. Inadequate nutrition had many subtle effects on reproduction which interacted to produce a complex web of events. A population boom occurred during the second half of the 18th century; fertility did not change but there was a marked improvement in infant mortality and it is suggested that the steadily improving nutritional standards of the population, particularly during crucial periods in pregnancy (i.e. the last trimester), probably made the biggest contribution to the improvement in infant mortality and so was probably the major factor in triggering the boom.

  20. Technical feasibility of a concept radioactive waste disposal facility in Boom clay in the Netherlands

    International Nuclear Information System (INIS)

    Vardon, P.J.; Hicks, M.A.; Fokker, P.A.; Fokkens, J.H.

    2012-01-01

    Document available in extended abstract form only. The current management strategy in the Netherlands for radioactive waste is interim storage for approximately 100 years, followed by final deep geological disposal. At present, both Boom Clay and Salt formations are being considered and investigated via the OPERA (Onderzoeks Programma Eindberging Radioactief Afval) and CORA (Commissie Opberging Radioactief Afval) research programmes respectively, instigated by COVRA (Centrale Organisatie Voor Radioactief Afval). This paper outlines the on-going investigation into the initial technical feasibility of a high-level radioactive waste disposal facility, located within a stratum of Boom Clay, as part of the OPERA research programme. The feasibility study is based on the current Belgian Super-container concept, incorporating specific features relevant to the Netherlands, including the waste inventory and possible future glaciation. The repository is designed to be situated at approximately 500 m depth in a Boom Clay stratum of approximately 100 m thickness, and will co-host vitrified High Level Waste (HLW), spent fuel from research reactors, non-heat generating HLW, Low and Intermediate Level Waste (LILW) and depleted uranium. The total footprint is designed to be 3050 m by 1300 m, and will be segregated by waste type. The waste will be stored in drifts drilled perpendicular to the main galleries and will vary in length and diameter depending upon waste type. The repository life-cycle can be considered in three phases: (i) the pre-operation phase, including the conceptual development, site investigation and selection, design and construction; (ii) the operational phase, including waste emplacement and any period of time prior to closure; and (iii) the post-operational phase. The research on the technical feasibility of the repository will investigate whether the repository can be constructed and whether it is able to perform the appropriate safety functions and meet

  1. Prioritizing Wetlands for Waterbirds in a Boom and Bust System: Waterbird Refugia and Breeding in the Murray-Darling Basin.

    Science.gov (United States)

    Bino, Gilad; Kingsford, Richard T; Porter, John

    2015-01-01

    Dryland rivers have considerable flow variability, producing complex ecosystems, processes, and communities of organisms that vary over space and time. They are also among the more vulnerable of the world's ecosystems. A key strategy for conservation of dryland rivers is identifying and maintaining key sites for biodiversity conservation, particularly protecting the quantity and quality of flow and flooding regimes. Extreme variability considerably challenges freshwater conservation planning. We systematically prioritised wetlands for waterbirds (simultaneously for 52 species), across about 13.5% of the Murray-Darling Basin (1,061,469 km2), using a 30-year record of systematic aerial surveys of waterbird populations. Nine key wetlands in this area, primarily lakes, floodplains, and swamps, consistently contributed to a representation target (80%) of total abundances of all 52 waterbird species. The long temporal span of our data included dramatic availability (i.e., booms) and scarcity (i.e., busts) of water, providing a unique opportunity to test prioritisation at extremes of variation. These extremes represented periods when waterbirds were breeding or concentrating on refugia, varying wetland prioritisation. In dry years, important wetlands for waterbirds were riverine and lacustrine (12 wetlands) but this changed in wet years to lacustrine and palustrine (8 wetlands). Such variation in ecosystem condition substantially changes the relative importance of individual wetlands for waterbirds during boom and bust phases. Incorporating this variability is necessary for effective conservation of Murray-Darling Basin waterbirds, with considerable generality for other similarly variable systems around the world.

  2. Prioritizing Wetlands for Waterbirds in a Boom and Bust System: Waterbird Refugia and Breeding in the Murray-Darling Basin.

    Directory of Open Access Journals (Sweden)

    Gilad Bino

    Full Text Available Dryland rivers have considerable flow variability, producing complex ecosystems, processes, and communities of organisms that vary over space and time. They are also among the more vulnerable of the world's ecosystems. A key strategy for conservation of dryland rivers is identifying and maintaining key sites for biodiversity conservation, particularly protecting the quantity and quality of flow and flooding regimes. Extreme variability considerably challenges freshwater conservation planning. We systematically prioritised wetlands for waterbirds (simultaneously for 52 species, across about 13.5% of the Murray-Darling Basin (1,061,469 km2, using a 30-year record of systematic aerial surveys of waterbird populations. Nine key wetlands in this area, primarily lakes, floodplains, and swamps, consistently contributed to a representation target (80% of total abundances of all 52 waterbird species. The long temporal span of our data included dramatic availability (i.e., booms and scarcity (i.e., busts of water, providing a unique opportunity to test prioritisation at extremes of variation. These extremes represented periods when waterbirds were breeding or concentrating on refugia, varying wetland prioritisation. In dry years, important wetlands for waterbirds were riverine and lacustrine (12 wetlands but this changed in wet years to lacustrine and palustrine (8 wetlands. Such variation in ecosystem condition substantially changes the relative importance of individual wetlands for waterbirds during boom and bust phases. Incorporating this variability is necessary for effective conservation of Murray-Darling Basin waterbirds, with considerable generality for other similarly variable systems around the world.

  3. Do high levels of unemployment influence the health of those who are not unemployed? A gendered comparison of young men and women during boom and recession.

    Science.gov (United States)

    Novo, M; Hammarström, A; Janlert, U

    2001-08-01

    Research has shown that health among young people, particularly women, deteriorates during a recession compared to a boom. It seems that the trade cycle mainly affects the health of those who are not long-term unemployed. The aim of this study was to analyse the relation between the health of non-unemployed people and the levels of unemployment in society. Two groups of young people aged 21 were surveyed, one in 1986 (the boom group, n = 1083) and one in 1994 (the recession group, n = 898). The non-response rate was 2% in the first and 10% in the second group. Both groups were investigated with a self-administered questionnaire, which included questions about somatic and psychological health, as well as experiences of employment, unemployment, education and labour market programmes. Young men and women generally reported more somatic and psychological symptoms during recession than boom. The only exception was psychological symptoms among men, which was of the same magnitude during both periods. Poorer health during recession was found among women in work and in labour market programmes, as well as among both male and female students. Multiple regression analysis was performed in order to analyse if the occupational-related health effects of the trade cycle remained after controlling for possible moderating factors. The effects of unemployment in society on young people's health may be mediated through pessimism about the future, high demands and financial problems. Lack of control over the work situation may also be an important contributing factor to ill health among women during recession. The trade cycle was correlated with ill health among women only. Possible explanations for poorer health among women during a recession were discussed.

  4. Experimental evaluation of the hydraulic resistance of compacted bentonite/boom clay interface

    International Nuclear Information System (INIS)

    Tang, Anh-Minh; Cui, Yu-Jun; Delage, Pierre; Munoz, Juan Jorge; Li, Xiang-Ling

    2008-01-01

    In the framework of the in-situ PRACLAY Heater experiment to be performed in the HADES URF in Mol (Belgium), the feasibility of a hydraulic cut-off of the Excavation Damaged Zone (EDZ) and the Repository Components (RC) of the disposal galleries by using a horizontal seal will be examined. It has been planned to install an annular seal composed of compacted bentonite between the heated zone and the access gallery (PRACLAY seal test), so that to avoid any hydraulic shortcut towards the access gallery. According to numerical scoping calculations, heating until 80 deg C will induce a pore pressure of the order of 3.0 MPa. In order to verify the effects of this water pressure on the performance of the annular seal system and more specifically on the hydraulic resistance of the interface between the compacted bentonite and the host rock (Boom clay), laboratory percolation tests at 20 and 80 deg C were performed. The results confirm the performance of the compacted bentonite seal to avoid the hydraulic shortcut to the access gallery under the foreseen hydraulic and thermal conditions. (author)

  5. [Cigarette and advertising poster: history of a dangerous connection in the post-war economic boom].

    Science.gov (United States)

    Olivier, Jacques

    2013-11-27

    The advertising poster's main characteristic is the ability to convey a commercial message quickly and publicly thanks to its straightforward image and text. The young people, being the tobacco industry's principal target, are particularly exposed to these messages. This kind of advertisement becomes a mean of counterstroke as soon as the cigarette's harmfulness is acknowledged. Some of the cigarette industry's strategies can be revealed by the historical analysis of a 253 posters corpus selected among the main cigarette manufacturers in Switzerland at the time of the post-war economic boom. With the misuse of sport's theme, the overvaluation of the filter's efficiency, the use of a vocabulary that implies lightness and by erasing the image of smoke in its advertisement, the industry tries to reassure the smoker wrongly.

  6. A see-saw of pre-Columbian boom regions in southern Peru, determined by large-scale circulation changes

    Science.gov (United States)

    Mächtle, B.; Schittek, K.; Forbriger, M.; Schäbitz, F.; Eitel, B.

    2012-04-01

    Environmental changes and cultural transitions during several periods of Peruvian history show a strong coincidence between humid and dry climatic oscillations and the rise and decline of cultures. It is noteworthy, that alternating periods of geo-ecological fragility and stability occurred in time and space between the coastal Nasca region (14.5° S) and the high Andean northern Titicaca basin, just a few hundred kilometers to the east. Based on a multi-proxy palynological and sedimentological approach to reconstruct palaeoenvironmental changes, we found that the Nasca region received a maximum of precipitation during the archaeological boom times of the Early Horizon and the Early Intermediate Period (800 BC - 650 AD, Paracas and Nasca cultures) as well as during the late intermediate period (1150-1450 AD), whereas, in contrast, the Titicaca region further to the south-east experienced drought and cultural depression during that times. During the Middle Horizon (650 - 1150 AD), the Tiwanaku agronomy and culture boomed in the Titicaca region and expanded to the west, contemporaneous with a raised lake level and more humid conditions. In the Nasca region, runoff for irrigation purposes was reduced and less reliable due to drought. Considering a coincidence between environmental and cultural changes, we state that success and decline of civilizations were controlled by hydrological oscillations, triggering fertility as well as a critical loss of natural resources. In response to spatial changing resources, cultural foci were shifted. Therefore, the success of pre-Columbian civilizations was closely coupled to areas of geo-ecological favorability, which were directly controlled by distinct regional impacts of large-scale circulation mechanisms, including El Niño - Southern Oscillation (ENSO). Changes in the position of the intertropical convergence zone (ITCZ) and the Bolivian anticyclone determined meridional shifts in moisture transport across the Andes, which

  7. Energy revolution: Fracking. In booming speed back to petroleum and natural gas; Energierevolution: Fracking. Im Boomtempo zurueck zu Oel und Gas

    Energy Technology Data Exchange (ETDEWEB)

    Mardo, Dietrich

    2013-06-06

    Fracking is the extraction of petroleum and shale gas from deep layers of earth. This technology is not new, as it was already used in the year 1940 and is comparable to geothermal drilling. In the United State of America as well as in the People's Republic of China fracking experiences an economic boom. The deposits are large. However, fracking can be a deathblow for the German energy policy turnaround. In this regard, the contribution under consideration reports on the developments.

  8. Morphogenic Regulators Baby boom and Wuschel Improve Monocot Transformation[OPEN

    Science.gov (United States)

    Lowe, Keith; Wu, Emily; Cho, Myeong-Je; Lenderts, Brian; Chamberlin, Mark; Cushatt, Josh; Ryan, Larisa; Khan, Tanveer; Chow-Yiu, Julia; Hua, Wei; Banh, Jenny; Bao, Zhongmeng; Brink, Kent; Igo, Elizabeth; Rudrappa, Bhojaraja; Shamseer, PM; Shen, Bo; Zheng, Peizhong; Bidney, Dennis; Falco, Carl; Zhao, Zuo-Yu; Xu, Deping

    2016-01-01

    While transformation of the major monocot crops is currently possible, the process typically remains confined to one or two genotypes per species, often with poor agronomics, and efficiencies that place these methods beyond the reach of most academic laboratories. Here, we report a transformation approach involving overexpression of the maize (Zea mays) Baby boom (Bbm) and maize Wuschel2 (Wus2) genes, which produced high transformation frequencies in numerous previously nontransformable maize inbred lines. For example, the Pioneer inbred PHH5G is recalcitrant to biolistic and Agrobacterium tumefaciens transformation. However, when Bbm and Wus2 were expressed, transgenic calli were recovered from over 40% of the starting explants, with most producing healthy, fertile plants. Another limitation for many monocots is the intensive labor and greenhouse space required to supply immature embryos for transformation. This problem could be alleviated using alternative target tissues that could be supplied consistently with automated preparation. As a major step toward this objective, we transformed Bbm and Wus2 directly into either embryo slices from mature seed or leaf segments from seedlings in a variety of Pioneer inbred lines, routinely recovering healthy, fertile T0 plants. Finally, we demonstrated that the maize Bbm and Wus2 genes stimulate transformation in sorghum (Sorghum bicolor) immature embryos, sugarcane (Saccharum officinarum) callus, and indica rice (Oryza sativa ssp indica) callus. PMID:27600536

  9. Boom, Bust and Beyond: Arts and Sustainability in Calumet, Michigan

    Directory of Open Access Journals (Sweden)

    Richelle Winkler

    2016-03-01

    Full Text Available Cycles of boom and bust plague mining communities around the globe, and decades after the bust the skeletons of shrunken cities remain. This article evaluates strategies for how former mining communities cope and strive for sustainability in the decades well beyond the bust, using a case study of Calumet, Michigan. In 1910, Calumet was at the center of the mining industry in the Upper Peninsula of Michigan, but in the century since its peak, mining employment steadily declined until the last mine closed in 1968, and the population declined by over 80%. This paper explores challenges, opportunities, and progress toward sustainability associated with arts-related development in this context. Methods are mixed, including observation, interviews, document review, a survey, and secondary data analysis. We follow Flora and Flora’s Community Capitals Framework to analyze progress toward sustainability. Despite key challenges associated with the shrunken city context (degraded tax base, overbuilt and aging infrastructure, diminished human capital, and a rather limited set of volunteers and political actors, we find the shrunken city also offers advantages for arts development, including low rents, less risk of gentrification, access to space, and political incentive. In Calumet, we see evidence of a spiraling up pattern toward social sustainability resulting from arts development; however impacts on environmental and economic sustainability are limited.

  10. On the oxidation of the dissolved organic matter in Boom clay by NaNO3 and NaNO2 from disposed Eurobitum bituminized waste

    International Nuclear Information System (INIS)

    Vasile, M.; Bleyen, N.; Valcke, E.; Bruggeman, C.; Marien, A.

    2012-01-01

    Document available in extended abstract form only. In Belgium, Boom Clay is studied as a potential host clay formation for the final disposal of EUROBITUM bituminized waste, which consists of 60 wt% hard bitumen (Mexphalt R85/40) and 40 wt% waste. The main salts that are present in the bituminized waste are NaNO 3 , 20-30 wt%, and CaSO 4 , 4-6 wt%. After disposal of the waste in the clay, an uptake of pore water by the embedded, dehydrated and hygroscopic salts will lead to a swelling of the waste and to a release of the salts into the Boom Clay. A possible consequence of the salt release is the oxidation of the clay by nitrate and, possibly, nitrite, resulting in a lower reducing capacity of the clay towards redox sensitive radionuclides, which in turn could have an impact on the migration behaviour of these radionuclides. The extent of oxidation of authigenic Boom Clay redox sensitive components, like organic matter and pyrite is studied at the SCK.CEN. As a first step in the study of the influence of nitrate and nitrite on the redoxactive Boom Clay components, we performed batch tests with dissolved organic matter (DOM). DOM was exposed to different concentrations of nitrate and nitrite for more than one year in both biotic and abiotic conditions. This paper will discuss the results obtained by exposing DOM to nitrate and nitrite and comparing two methods for the determination of its redox capacity. NaNO 3 or NaNO 2 , previously stored under inert atmosphere to remove all oxygen gas, was added to Boom Clay water collected from a piezometer to obtain final salt concentrations of 0.1 and 0.005 M NaNO 3 , or 0.05 and 0.005 M NaNO 2 . Sodium azide, also stored under inert atmosphere, was added (0.2 wt. %) to inhibit the microbial activity in the tests, creating abiotic conditions. All solutions were prepared in an anaerobic glove box. The nitrate and nitrite reduction by DOM was followed by analysing the concentrations of nitrate, nitrite and ammonium in the

  11. Determination of gas diffusion coefficients in undisturbed Boom clay

    International Nuclear Information System (INIS)

    Jacops, E.; Volckaert, G.; Maes, N.; Govaerts, J.; Weetjens, E.

    2012-01-01

    Document available in extended abstract form only. The Belgian agency for radioactive waste and enriched fissile materials Ondraf/Niras presently considers Boom Clay as a potential host formation for the disposal of high-level and long-lived radioactive waste. The production of gas is unavoidable within a geological repository. Gas is produced by different mechanisms: anaerobic corrosion of metals in waste and packaging, radiolysis of water and organic materials in the waste and engineered barriers and microbial degradation of various organic wastes. Corrosion and radiolysis yield mainly hydrogen while microbial degradation leads to methane and carbon dioxide. The gas generated in the near field of a geological repository will dissolve in the pore water and is transported away from the repository by diffusion as dissolved species. If the gas generation rate is larger than the diffusive flux, the pore water will become over-saturated and a free gas phase will form. Initially, isolated gas bubbles will accumulate until a continuous gas phase is formed. As gas pressure continues to increase, discrete gas pathways may be formed by tensile fractures within the rock fabric. Consequently, this entire process may locally and at least temporarily alter the hydraulic and mechanical properties of the engineered barriers and the clay and, perhaps, their performance. Therefore it is important to assess whether or not gas production rates might exceed the diffusive gas flux. The currently available gas diffusion parameters (D eff : effective diffusion coefficient) for hydrogen in Boom Clay, obtained from the MEGAS project, and re-evaluated after lead to an estimated D eff between 1.9 10 -12 and 1.5 10 -10 m 2 /s. Sensitivity calculations showed that this uncertainty on the diffusion coefficient, combined with that on the gas source term, made it impossible to exclude the formation of a free gas phase. To reduce the uncertainty, an experimental method was developed to determine

  12. Synthesis of Fe–Ni bimetallic nanoparticles from pixel target ablation: plume dynamics and surface characterization

    International Nuclear Information System (INIS)

    Niu Xiaoxu; Murray, Paul T.; Sarangan, Andrew

    2012-01-01

    A novel Fe–Ni bimetallic nanoparticle synthesis technique, denoted pixel target ablation, is reported. The technique entails ablating a thin film target consisting of patterned Fe and Ni pixels with a selected ratio using a KrF excimer laser. The laser energy breaks a known amount of target materials into metal atoms, which then form nanoparticles by recombination in the gas phase. Due to the nature of thin-film ablation, splashing of large particles was eliminated with the added benefit of minimizing nanoparticle agglomeration. Plume dynamics and surface characterizations were carried out to exploit the formation of Fe–Ni nanoparticles more fully. The composition was readily controlled by varying the initial relative amount of Fe and Ni target pixels. Synthesis of multi-element nanoparticles by pixel target ablation should be possible with any element combination that can be prepared as a thin-film target.

  13. Socio-ecological dynamics of Caribbean coral reef ecosystems and conservation opinion propagation.

    Science.gov (United States)

    Thampi, Vivek A; Anand, Madhur; Bauch, Chris T

    2018-02-07

    The Caribbean coral reef ecosystem has experienced a long history of deterioration due to various stressors. For instance, over-fishing of parrotfish - an important grazer of macroalgae that can prevent destructive overgrowth of macroalgae - has threatened reef ecosystems in recent decades and stimulated conservation efforts such as the formation of marine protected areas. Here we develop a mathematical model of coupled socio-ecological interactions between reef dynamics and conservation opinion dynamics to better understand how natural and human factors interact individually and in combination to determine coral reef cover. We find that the coupling opinion and reef systems generates complex dynamics that are difficult to anticipate without use of a model. For instance, instead of converging to a stable state of constant coral cover and conservationist opinion, the system can oscillate between low and high live coral cover as human opinion oscillates in a boom-bust cycle between complacency and concern. Out of various possible parameter manipulations, we also find that raising awareness of coral reef endangerment best avoids counter-productive nonlinear feedbacks and always increases and stabilizes live coral reef cover. In conclusion, an improved understanding of coupled opinion-reef dynamics under anthrogenic stressors is possible using coupled socio-ecological models, and such models should be further researched.

  14. The Tangdan Copper Mines and the 1733 Earthquake: A Mining Community before the Boom in the Far Southwest of Qing China

    Directory of Open Access Journals (Sweden)

    Nanny Kim

    2014-12-01

    Full Text Available In the official records, copper mines in the southwest of the Qing empire seem to suddenly appear in the late 1730s. In part, this impression is an effect of government attention. Copper, which was the most important metal for casting cash coins, became a pressing concern when imports of Japanese copper dwindled. The government responded by developing domestic resources. Seemingly overnight, Yunnan mines reached impressive levels of productivity and replaced imports. For several decades, the Tangdan mines in northeastern Yunnan supplied most of the copper consumed by the centrally important metropolitan mints. The sudden boom is remarkable and not entirely plausible. This article reassesses the history of Qing-period mining by examining a particular case study. It explores an essay about the Dongchuan earthquake of 1733 that provides a glimpse at the empire’s leading copper mines on the eve of the recorded boom. A close analysis of figures, mining technology, and organizational structures reveals that the mines had been developed by mining entrepreneurs and migrant workers for a considerable period of time outside government attention, operating in a gray zone of unlicensed exploitation. The studied case permits a new assessment of the role of the state and of nonstate players in the industry. Moreover, it throws a new light on the image of Qing society and economy created by the official emphasis on agriculture and the actual role of the nonagrarian sector.

  15. Splash M-knife versus Flush Knife BT in the technical outcomes of endoscopic submucosal dissection for early gastric cancer: a propensity score matching analysis.

    Science.gov (United States)

    Esaki, Mitsuru; Suzuki, Sho; Hayashi, Yasuyo; Yokoyama, Azusa; Abe, Shuichi; Hosokawa, Taizo; Ogino, Haruei; Akiho, Hirotada; Ihara, Eikichi; Ogawa, Yoshihiro

    2018-02-27

    Endoscopic submucosal dissection (ESD) is a standard treatment for early gastric cancer. A new multi-functional ESD device was developed to achieve complete ESD with a single device. A metal plate attached to its distal sheath achieves better hemostasis during the procedure than the other needle-knife device, Flush Knife BT®, that has been conventionally used. The aim of this study was to compare the technical outcomes of ESD for early gastric cancer using the Splash M-Knife® with those using the Flush Knife BT. We conducted a retrospective review of the case records of 149 patients with early gastric cancer treated with ESD using the needle-type ESD knives between January 2012 and August 2016 at Kitakyushu Municipal Medical Center. Lesions treated with ESD using the Splash M-knife (ESD-M) and the Flush Knife BT (ESD-F) were compared. Multivariate analyses and propensity score matching were used to compensate for the differences in age, gender, underlying disease, antithrombotic drug use, lesion location, lesion position, macroscopic type, tumor size, presence of ulceration, operator level and types of electrosurgical unit used. The primary endpoint was the requirement to use hemostatic forceps in the two groups. The secondary endpoints of procedure time, en bloc and complete resection rates, and adverse events rates were evaluated for the two groups. There were 73 patients in the ESD-M group, and 76 patients in the ESD-F group. Propensity score matching analysis created 45 matched pairs. Adjusted comparisons between the two groups showed a significantly lower usage rate of hemostatic forceps in the ESD-M group than in the ESD-F group (6.7% vs 84.4%, p < 0.001). Treatment outcomes showed an en bloc resection rate of 100% in both groups; complete resection rate of 95.6% vs 100%, p = 0.49; median procedure time of 74.0 min vs 71.0 min, p = 0.90; post-procedure bleeding of 2.2% vs 2.2%, p = 1, in the ESD-M and ESD-F groups, respectively. There were

  16. Ordinary Chondrites Viewed as Reassembled 'Splash Ejecta'

    Science.gov (United States)

    Sanders, I. S.

    1995-09-01

    A case has already been made favouring chondrites as re-assembled "splash ejecta" following low velocity collisions between molten planetesimals[1]. Here I briefly review this hypothesis, then develop further arguments in its support. The scenario envisaged may be summarized as follows. Planetesimals grew to radii greater than 30 km in less than 1 Ma after the formation of CAIs, and they were heated rapidly by the decay of 26Al. By 2 Ma each planetesimal had a molten interior insulated by a cool, dusty carapace. Low velocity collisions at this stage released enormous, turbulent, expanding clouds of incandescent spray mixed with dust and solid grains from the carapace. The cloud constituted a rather special, transient nebular environment; as it cooled the melt droplets became chondrules. Much of the cloud's contents re-assembled under gravity onto the surface of the hot, residual planetesimal and the accumulated debris became re-heated and metamorphosed. Collisions recurred over the few million years that relative velocities remained low and planetesimals remained molten. Thus, the cumulative debris contained many recycled and broken chondrules. This scenario is apparently reconcilable with chondrule cooling rates, the preservation of clasts of "planetary" rock in chondrites, the retention of volatiles in chondrules, the preservation of solar chemistry and more than a dozen other features. Is it reasonable to claim that 30 km radius bodies existed by 1 Ma, and were substantially molten by 2 Ma? Cameron[2] argued that CAIs were saved from drifting into the sun by their incorporation, soon after formation, into planetesimals whose mass was sufficient to hold them in orbits, decoupled from the drag of nebular gas. Wetherill's models [3] show that many bodies >100 km radius may have formed on a timescale of 10^5 years. In these terms, the proposed 30 km by 1 Ma is quite conservative. Regarding 26Al heating, the remarkably constant initial ratio of 26Al/27Al (5 x 10

  17. Indoor spray measurement of spray drift potential using a spray drift test bench : effect of drift-reducing nozzle types, spray boom height, nozzle spacing and forward speed

    NARCIS (Netherlands)

    Moreno Ruiz, J.R.

    2014-01-01

    In a series of indoor experiments spray drift potential was assessed when spraying over a spray drift testbench with two different driving speeds, 2m/s and 4m/s, two different spray boom heights, 30 cm and 50 cm, and two different nozzle spacing, 25 cm and 50 cm, for six different nozzle types. The

  18. Calibration of mathematical models for simulation of thermal, seepage and mechanical behaviour of boom clay

    International Nuclear Information System (INIS)

    Baldi, G.; Borsetto, M.; Hueckel, T.

    1987-01-01

    This report presents results of research on the verification of the validity of a generalized thermo-elastoplastic-hydraulic mathematical model elaborated at Ismes for description of the behaviour of boom clay. The model is described in Section 2. Experimental results performed at Ismes for the identification of the material constants in athermal and thermal drained conditions are then presented. Procedures for the identification are described in Section 4. The undrained consolidated constant total stress heating test is then discussed. The undrained test shows the possibility of clay yielding due to effective pressure decrease during heating, caused by water pressure growth. The test has been simulated numerically, confirming the interpretation of the experiment. Further simulation of plane strain and plane stress central heating axisymmetric problem shows again a formation of a yielded clay zone around the heater. Interpretation of the results and recommendations for further research are given

  19. Biofuels policy and the US market for motor fuels: Empirical analysis of ethanol splashing

    Energy Technology Data Exchange (ETDEWEB)

    Walls, W.D., E-mail: wdwalls@ucalgary.ca [Department of Economics, University of Calgary, 2500 University Drive NW, Calgary, Alberta, T2N 1N4 (Canada); Rusco, Frank; Kendix, Michael [US GAO (United States)

    2011-07-15

    Low ethanol prices relative to the price of gasoline blendstock, and tax credits, have resulted in discretionary blending at wholesale terminals of ethanol into fuel supplies above required levels-a practice known as ethanol splashing in industry parlance. No one knows precisely where or in what volume ethanol is being blended with gasoline and this has important implications for motor fuels markets: Because refiners cannot perfectly predict where ethanol will be blended with finished gasoline by wholesalers, they cannot know when to produce and where to ship a blendstock that when mixed with ethanol at 10% would create the most economically efficient finished motor gasoline that meets engine standards and has comparable evaporative emissions as conventional gasoline without ethanol blending. In contrast to previous empirical analyses of biofuels that have relied on highly aggregated data, our analysis is disaggregated to the level of individual wholesale fuel terminals or racks (of which there are about 350 in the US). We incorporate the price of ethanol as well as the blendstock price to model the wholesaler's decision of whether or not to blend additional ethanol into gasoline at any particular wholesale city-terminal. The empirical analysis illustrates how ethanol and gasoline prices affect ethanol usage, controlling for fuel specifications, blend attributes, and city-terminal-specific effects that, among other things, control for differential costs of delivering ethanol from bio-refinery to wholesale rack. - Research Highlights: > Low ethanol prices and tax credits have resulted in discretionary blending of ethanol into fuel supplies above required levels. > This has important implications for motor fuels markets and vehicular emissions. > Our analysis incorporates the price of ethanol as well as the blendstock price to model the wholesaler's decision of whether or not to blend additional ethanol into gasoline at any particular wholesale city

  20. Biofuels policy and the US market for motor fuels: Empirical analysis of ethanol splashing

    International Nuclear Information System (INIS)

    Walls, W.D.; Rusco, Frank; Kendix, Michael

    2011-01-01

    Low ethanol prices relative to the price of gasoline blendstock, and tax credits, have resulted in discretionary blending at wholesale terminals of ethanol into fuel supplies above required levels-a practice known as ethanol splashing in industry parlance. No one knows precisely where or in what volume ethanol is being blended with gasoline and this has important implications for motor fuels markets: Because refiners cannot perfectly predict where ethanol will be blended with finished gasoline by wholesalers, they cannot know when to produce and where to ship a blendstock that when mixed with ethanol at 10% would create the most economically efficient finished motor gasoline that meets engine standards and has comparable evaporative emissions as conventional gasoline without ethanol blending. In contrast to previous empirical analyses of biofuels that have relied on highly aggregated data, our analysis is disaggregated to the level of individual wholesale fuel terminals or racks (of which there are about 350 in the US). We incorporate the price of ethanol as well as the blendstock price to model the wholesaler's decision of whether or not to blend additional ethanol into gasoline at any particular wholesale city-terminal. The empirical analysis illustrates how ethanol and gasoline prices affect ethanol usage, controlling for fuel specifications, blend attributes, and city-terminal-specific effects that, among other things, control for differential costs of delivering ethanol from bio-refinery to wholesale rack. - Research highlights: → Low ethanol prices and tax credits have resulted in discretionary blending of ethanol into fuel supplies above required levels. → This has important implications for motor fuels markets and vehicular emissions. → Our analysis incorporates the price of ethanol as well as the blendstock price to model the wholesaler's decision of whether or not to blend additional ethanol into gasoline at any particular wholesale city-terminal.

  1. Dynamic model reduction using data-driven Loewner-framework applied to thermally morphing structures

    Science.gov (United States)

    Phoenix, Austin A.; Tarazaga, Pablo A.

    2017-05-01

    The work herein proposes the use of the data-driven Loewner-framework for reduced order modeling as applied to dynamic Finite Element Models (FEM) of thermally morphing structures. The Loewner-based modeling approach is computationally efficient and accurately constructs reduced models using analytical output data from a FEM. This paper details the two-step process proposed in the Loewner approach. First, a random vibration FEM simulation is used as the input for the development of a Single Input Single Output (SISO) data-based dynamic Loewner state space model. Second, an SVD-based truncation is used on the Loewner state space model, such that the minimal, dynamically representative, state space model is achieved. For this second part, varying levels of reduction are generated and compared. The work herein can be extended to model generation using experimental measurements by replacing the FEM output data in the first step and following the same procedure. This method will be demonstrated on two thermally morphing structures, a rigidly fixed hexapod in multiple geometric configurations and a low mass anisotropic morphing boom. This paper is working to detail the method and identify the benefits of the reduced model methodology.

  2. A method for the determination of gas diffusion coefficients in undisturbed Boom Clay

    International Nuclear Information System (INIS)

    Jacops, E.; Volckaert, G.; Maes, N.; Weetjens, E.; Maes, T.; Vandervoort, F.

    2010-01-01

    Document available in extended abstract form only. The main mechanisms by which gas will be generated in deep geological repositories are: anaerobic corrosion of metals in wastes and packaging; radiolysis of water and organic materials in the packages, and microbial degradation of various organic wastes. Corrosion and radiolysis yield mainly hydrogen while microbial degradation leads to methane and carbon dioxide. The gas generated in the near field of a geological repository in clay will dissolve in the ground water and be transported away from the repository by diffusion as dissolved species. However if the gas generation rate is larger than the diffusive flux, the pore water will get over-saturated and a free gas phase will be formed. This will lead to a gas pressure build-up and finally to an advective gas flux. The latter might influence the performance of the repository. Therefore it is important to assess whether or not gas production rates can exceed the capacity of the near field to store and dissipate these gases by dissolution and diffusion only. The current available gas diffusion parameters for hydrogen in Boom Clay, obtained from the MEGAS project, suffer from an uncertainty of 1 to 2 orders of magnitude. Sensitivity calculations performed by Weetjens et al. (2006) for the disposal of vitrified high-level waste showed that with this uncertainty on the diffusion coefficient, the formation of a free gas phase cannot be excluded. Furthermore, recent re-evaluations of the MEGAS experiments by Krooss (2008) and Aertsens (2008) showed that the applied technique does not allow precise determination of the diffusion coefficient. Therefore a new method was developed to determine more precisely the gas diffusion coefficient for dissolved gases (especially dissolved hydrogen) in Boom Clay. This should allow for a more realistic assessment of the gas flux evolution of a repository as function of the estimated gas generation rates. The basic idea is to perform a

  3. Elevated nonlinearity as an indicator of shifts in the dynamics of populations under stress.

    Science.gov (United States)

    Dakos, Vasilis; Glaser, Sarah M; Hsieh, Chih-Hao; Sugihara, George

    2017-03-01

    Populations occasionally experience abrupt changes, such as local extinctions, strong declines in abundance or transitions from stable dynamics to strongly irregular fluctuations. Although most of these changes have important ecological and at times economic implications, they remain notoriously difficult to detect in advance. Here, we study changes in the stability of populations under stress across a variety of transitions. Using a Ricker-type model, we simulate shifts from stable point equilibrium dynamics to cyclic and irregular boom-bust oscillations as well as abrupt shifts between alternative attractors. Our aim is to infer the loss of population stability before such shifts based on changes in nonlinearity of population dynamics. We measure nonlinearity by comparing forecast performance between linear and nonlinear models fitted on reconstructed attractors directly from observed time series. We compare nonlinearity to other suggested leading indicators of instability (variance and autocorrelation). We find that nonlinearity and variance increase in a similar way prior to the shifts. By contrast, autocorrelation is strongly affected by oscillations. Finally, we test these theoretical patterns in datasets of fisheries populations. Our results suggest that elevated nonlinearity could be used as an additional indicator to infer changes in the dynamics of populations under stress. © 2017 The Author(s).

  4. Construction of an underground facility for ''in-situ'' experimentation in the boom clay

    International Nuclear Information System (INIS)

    Bonne, A.; Manfroy, P.; Van Haelewijn, R.; Heremans, R.

    1985-01-01

    The Belgian R and D Programme concerning the disposal of high-level and alpha-bearing radioactive waste in continental geological formations was launched by SCK/CEN, Mol in 1974. The programme is characterised by its site and formation specific approach, i.e. Mol and Boom clay. In the framework of site confirmation, an important issue is the ''in situ'' experimentation which should allow to determine with a higher degree of confidence the numerical value of the data needed for the evaluations, assessments and designs. The present report deals with the construction of an underground experimental facility, which was scheduled to be fully completed in mid 1984. Initially, the completion was scheduled for the end of 1983, but supplementary experiments related to geomechanics and mining capabilities and to be performed during the construction phase of the experimental facility delayed the completion of the underground facility. During the construction, a continuous observation was made of the behaviour of the clay mass and the structures. In this final contract-report, only the as-built structure, the time schedule and the ''in situ'' experiments launched or performed during the construction phase are dealt with

  5. Exploring droplet impact near a millimetre-sized hole: comparing a closed pit with an open-ended pore

    NARCIS (Netherlands)

    de Jong, Rianne; Enriquez Paz y Puente, O.R.; van der Meer, Roger M.

    2015-01-01

    We investigate drop impact dynamics near closed pits and open-ended pores experimentally. The resulting impact phenomena differ greatly in each case. For a pit, we observe three distinct phenomena, which we denote as a splash, a jet and an air bubble, whose appearance depends on the distance between

  6. ’n Murgtere saak: ’n Gendermatige lees van Boom van my lewe en Ad hominem

    Directory of Open Access Journals (Sweden)

    Louisemarié Combrink

    2012-11-01

    Full Text Available Hierdie artikel bied ontleed twee kunstenaarsboeke deur manlike kunstenaars wat aan die praktykgebaseerderde navorsingsprojek Oor die einders van die bladsy deelgeneem het. Die gekose kunstenaars spreek spesifiek die gedagte van manlike weerloosheid en verwonding aan en maak in die proses van ’n aantal sogenaamde manlike maar veral ook vroulike genderbetekenaars gebruik. Schutte se Boom van my lewe en Strydom en Burger se Ad hominem word ondersoek. Daar word aangevoer dat die gebruik van veral konvensioneel vroulike mediums tesame met temas wat sowel ’n manlike as vroulike karakter het, meewerk om die ervaring van manlike weerloosheid en verwonding op so ’n wyse te kommunikeer dat ’n ongewone manlike subjekposisie daargestel word. Hierdie subjekposisie bied ’n meer genuanseerde beskouing van manlikheid as wat konvensionele (heteronormatiewe en selfs ook sogenaamde ‘nuwe’ of alternatiewe manlike subjekposisies (soos transgender, homoseksueel en dies meer diskoerse bied.

  7. A High-Speed, Event-Driven, Active Pixel Sensor Readout for Photon-Counting Microchannel Plate Detectors

    Science.gov (United States)

    Kimble, Randy A.; Pain, Bedabrata; Norton, Timothy J.; Haas, J. Patrick; Oegerle, William R. (Technical Monitor)

    2002-01-01

    Silicon array readouts for microchannel plate intensifiers offer several attractive features. In this class of detector, the electron cloud output of the MCP intensifier is converted to visible light by a phosphor; that light is then fiber-optically coupled to the silicon array. In photon-counting mode, the resulting light splashes on the silicon array are recognized and centroided to fractional pixel accuracy by off-chip electronics. This process can result in very high (MCP-limited) spatial resolution while operating at a modest MCP gain (desirable for dynamic range and long term stability). The principal limitation of intensified CCD systems of this type is their severely limited local dynamic range, as accurate photon counting is achieved only if there are not overlapping event splashes within the frame time of the device. This problem can be ameliorated somewhat by processing events only in pre-selected windows of interest of by using an addressable charge injection device (CID) for the readout array. We are currently pursuing the development of an intriguing alternative readout concept based on using an event-driven CMOS Active Pixel Sensor. APS technology permits the incorporation of discriminator circuitry within each pixel. When coupled with suitable CMOS logic outside the array area, the discriminator circuitry can be used to trigger the readout of small sub-array windows only when and where an event splash has been detected, completely eliminating the local dynamic range problem, while achieving a high global count rate capability and maintaining high spatial resolution. We elaborate on this concept and present our progress toward implementing an event-driven APS readout.

  8. From Boom to Bust: The Effects of Economic Recession on Minority Groups' Experience in the Housing Market

    Directory of Open Access Journals (Sweden)

    From Boom to Bust: The Effects of Economic Recession on Minority Groups' Experience in the Housing Market

    2013-06-01

    Full Text Available The homeownership rate in the US reached an all-time high of 69.2 percent by 2006, attributed to factors like favorable mortgage lending practice, economic boom, and incentive policies. The recent subprime mortgage crisis and economic recession, however, widened the gap in homeownership between racial minorities and whites. A sharp drop in housing price also posed a threat to the amount of equity one could accumulate. In this paper, we examined how the changing economy and both structural and individual-level factors affected the racial disparities in homeownership and home equity, using the 2005 and 2009 American Housing Survey national data. The major finding was that the economic recession affected Blacks the most, followed by Hispanics. Asians, though showing a decline in their home equity, were able to maintain their advantages in the housing market.

  9. The CEC benchmark interclay on rheological models for clays results of pilot phase (January-June 1989) about the boom clay at Mol (B)

    International Nuclear Information System (INIS)

    Come, B.

    1990-01-01

    A pilot phase of a benchmark exercise for rheological models for boom clay, called interclay, was launched by the CEC in January 1989. The purpose of the benchmark is to compare predictions of calculations made about well-defined rock-mechanical problems, similar to real cases at the Mol facilities, using existing data from laboratory tests on samples. Basically, two approaches were to be compared: one considering clay as an elasto-visco-plastic medium (rock-mechanics approach), and one isolating the role of pore-pressure dissipation (soil-mechanics approach)

  10. Validation Results for LEWICE 3.0

    Science.gov (United States)

    Wright, William B.

    2005-01-01

    A research project is underway at NASA Glenn to produce computer software that can accurately predict ice growth under any meteorological conditions for any aircraft surface. This report will present results from version 3.0 of this software, which is called LEWICE. This version differs from previous releases in that it incorporates additional thermal analysis capabilities, a pneumatic boot model, interfaces to computational fluid dynamics (CFD) flow solvers and has an empirical model for the supercooled large droplet (SLD) regime. An extensive comparison of the results in a quantifiable manner against the database of ice shapes and collection efficiency that have been generated in the NASA Glenn Icing Research Tunnel (IRT) has also been performed. The complete set of data used for this comparison will eventually be available in a contractor report. This paper will show the differences in collection efficiency between LEWICE 3.0 and experimental data. Due to the large amount of validation data available, a separate report is planned for ice shape comparison. This report will first describe the LEWICE 3.0 model for water collection. A semi-empirical approach was used to incorporate first order physical effects of large droplet phenomena into icing software. Comparisons are then made to every single element two-dimensional case in the water collection database. Each condition was run using the following five assumptions: 1) potential flow, no splashing; 2) potential flow, no splashing with 21 bin drop size distributions and a lift correction (angle of attack adjustment); 3) potential flow, with splashing; 4) Navier-Stokes, no splashing; and 5) Navier-Stokes, with splashing. Quantitative comparisons are shown for impingement limit, maximum water catch, and total collection efficiency. The results show that the predicted results are within the accuracy limits of the experimental data for the majority of cases.

  11. Time extrapolation aspects in the performance assessment of high and medium level radioactive waste disposal in the Boom Clay at Mol (Belgium)

    International Nuclear Information System (INIS)

    Volckaert, G.

    2000-01-01

    SCK-CEN is studying the disposal of high and long-lived medium level waste in the Boom Clay at Mol, Belgium. In the performance assessment for such a repository time extrapolation is an inherent problem due to the extremely long half-life of some important radionuclides. To increase the confidence in these time extrapolations SCK-CEN applies a combination of different experimental and modelling approaches including laboratory and in situ experiments, natural analogue studies, deterministic (or mechanistic) models and stochastical models. An overview is given of these approaches and some examples of applications to the different repository system components are given. (author)

  12. Contingency plans and successful response strategies for oil spills into rivers

    Energy Technology Data Exchange (ETDEWEB)

    Owens, Edward H. [Polaris Applied Sciences Inc., Bainbridge Island, WA (United States)]. E-mail: ehowens@polarisappliedsciences.com

    2003-07-01

    Oil spilled into a river enters a dynamic environment. An effective response can only succeed if the dynamics of the river system are understood and if the strategies and tactics are designed to match these conditions. Oil is transported downstream at the speed of the current, therefore, an estimate of the rate of movement is essential to identify effective intercept locations. Boom performance is affected by local surface water velocities as entrainment of oil typically begins when velocities exceed 0.4 m/s. However, boom configurations can be effective in current velocities as great as 2.5 m/s. Response operations can be successful if staging or control locations have been identified as part of contingency planning and if booms are deployed to take into account local surface current characteristics. Tracking and control of submerged or sunken oil is difficult and may not be practical. Recovery operations for sunken oil depend on the channel depth, current velocities, and on the distribution and concentration of the oil. (author)

  13. Dynamic simulation of cable shovel specific energy in oil sands excavation

    Energy Technology Data Exchange (ETDEWEB)

    Awuah-Offei, K. [Missouri-Rolla Univ., Rolla, MO (United States). School of Materials, Energy and Earth Resources; Frimpong, S. [Missouri-Rolla Univ., Rolla, MO (United States). Dept. of Mining Engineering, Mining and Nuclear Engineering; Askari-Nasab, H. [Alberta Univ., Edmonton, AB (Canada). School of Mining and Petroleum Engineering

    2005-07-01

    Oil sand excavation requires the use cable shovels which constitute one of the major costs in surface mining operations. Random occurrences of shales and limestones within the Athabasca oil sands formation result in varying shovel diggability and stress loading of the boom-crowd-dipper-teeth assembly which reduces digging efficiency. This inefficient use of cable shovels negatively affects the return on capital investment in these otherwise effective machines. In the Athabasca oil sands, varying stress loading has the potential to increase shovel downtime and increase maintenance costs. This paper presented a newly developed cable shovel simulator that uses shovel kinematics and dynamics, dynamic cutting resistance and payload models. It can model the specific energy needed to overcome the resistance to machine motion and material digging. The comprehensive model considers both machine motion and machine-formation interaction forces. It also provides a comprehensive theoretical assessment of shovel performance. The model is useful to mining engineers when examining both the machine operating parameters and material parameters that influence shovel performance. The study showed that bulk density is the most important material property influencing diggability. Operator preferences also influence the specific energy of excavation. 12 refs., 2 tabs., 6 figs.

  14. Geochemical characterisation of kerogen from the Boom Clay Formation (Mol, Belgium) and evolution under different thermal stress

    International Nuclear Information System (INIS)

    Deniau, I.

    2002-12-01

    The Boom clay formation in Belgium has been chosen as test site for the disposal of high level radioactive wastes. The organic matter present in the clay (kerogen) is sensible to the thermal stress and can generate a huge number of gaseous and liquid compounds leading to local pH changes and to fracturing processes. In particular, some polar compounds can complex radionuclides. The samples analyzed in this work were taken in the underground laboratory of Mol at a 223 m depth. They have been analyzed in detail using geochemical methods (Rock-Eval pyrolysis, element analysis, transmission and scanning electron microscopy), spectroscopic methods (Fourier transformation infrared spectroscopy, solid state 13 C NMR, Raman) and pyrolytic methods (off-line, on-line and in sealed tubes combined with coupled CG/SM analyses). The study of a representative sample of this formation has permitted to characterize the organic matter at the molecular scale, to determine its fossilization mechanisms and the nature of the organic compounds trapped inside the kerogen. The organic matter of the Boom clays comes mainly from phyto-planktonic matter with an important contribution of terrestrial and bacterial matter. The degradation-recondensation played an important role in its preservation but the presence of numerous oxygenated molecules implies that oxidative incorporation also participated to this preservation. Finally, various products (hydrocarbons, oxygenated and nitrogenous polar compounds) trapped in significant amount inside the macro-molecular structure are released under a relatively weak thermal stress. Moreover several small polar organic molecules are released and can play a significant role in the retention or migration of radionuclides inside the geologic barrier. A sample submitted to a in-situ thermal stress of 80 deg. C during 5 years (Cerberus experiment) do not show any significant change in its kerogen structure with respect to the non-heated reference sample

  15. Fashion cycle dynamics in a model with endogenous discrete evolution of heterogeneous preferences

    Science.gov (United States)

    Naimzada, A. K.; Pireddu, M.

    2018-05-01

    We propose a discrete-time exchange economy evolutionary model, in which two groups of agents are characterized by different preference structures. The reproduction level of a group is related to its attractiveness degree, which depends on the social visibility level, determined by the consumption choices of the agents in that group. The attractiveness of a group is initially increasing with its visibility level, but it becomes decreasing when its visibility exceeds a given threshold value, due to a congestion effect. Thanks to the combined action of the price mechanism and of the share updating rule, the model is able to reproduce the recurrent dynamic behavior typical of the fashion cycle, presenting booms and busts both in the agents' consumption choices and in the population shares. More precisely, we investigate the existence of equilibria and their stability, and we perform a qualitative bifurcation analysis on varying the parameter describing the group's heterogeneity degree. From a global viewpoint, we detect, among others, multistability phenomena in which the group coexistence is dynamic, either regular or irregular, and the fashion cycle occurs. The existence of complex dynamics is proven via the method of the turbulent maps, working with homoclinic orbits. Finally, we provide a social and economic interpretation of the main scenarios.

  16. Boom-to-bust. The scallop (Argopecten purpuratus fishery in the Pisco-Paracas region, southern Peruvian coast Auge y crisis: la pesquería de la concha de abanico (Argopecten purpuratus en la región Pisco-Paracas, costa sur del Perú

    Directory of Open Access Journals (Sweden)

    Ricardo M. González Hunt

    2010-12-01

    Full Text Available This paper examines scallop (Argopecten purpuratus booms experienced in the Pisco-Paracas Region of southern Peru, triggered by the 1982-1983 and the 1997-1998 mega-El Niño Southern Oscillation (ENSO events.The quiet fishing ports have been transformed by these booms, which have attracted outside stakeholders transforming the local society. Government institutions in their role as resource managers and environmental stewards have attempted to control access to a region that until recently contained the only marine protected area of Peru.This situation has led to rapid growth in the scallop industry, the overexploitation and depletion of the shellfish, creating a sustainability crisis. Furthermore, this paper examines contradictions and relationships across local, regional, national, and international scales.Este trabajo examina los ciclos de expansión (boom de la explotación de la concha de abanico (Argopecten purpuratus observados en la región Pisco-Paracas del sur del Perú, resultantes de los fenómenos El Niño de 1982-1983 y 1997-1998.Los apacibles puertos de pesca han sido transformados por estos booms productivos que han atraído actores externos y han generado un impacto en la sociedad local. Las instituciones gubernamentales, en su papel de administradores de recursos y protectores del medio ambiente, han tratado de controlar el acceso a una región que hasta hace poco contenía la única área marina protegida del Perú.Esta situación ha producido un rápido crecimiento de la industria de la concha de abanico, su sobreexplotación y el agotamiento de dicho recurso, y ha producido una crisis de sostenibilidad. Asimismo, este trabajo examina las contradicciones y las relaciones entre las escalas local, regional, nacional e internacional.

  17. A consistent phenomenological model for natural organic matter linked migration of Cm(III), Pu(III/IV), Np(IV), Tc(IV) and Pa(V) in the Boom Clay

    International Nuclear Information System (INIS)

    Martens, E.; Maes, N.; Bruggeman, C.; Van Gompel, M.

    2010-01-01

    Document available in extended abstract form only. As Natural Organic Matter (NOM) may modify/enhance the mobility of radionuclides (RNs) through complexation or colloidal interactions, it is essential to evaluate the impact of these processes before performing safety assessments aiming at demonstrating the suitability of deep-seated clayey formations for geological disposal of radioactive waste. Column migration experiments with Cm, Pu, Np, Tc and Pa in Boom Clay, initiated about 10 years ago, showed strikingly similar features despite their different chemical speciation. On a relative short time, these RNs began percolating through the clay core until a constant concentration at the outlet side was reached. As most of the aqueous forms of these RNs are supposed to sorb strongly onto the Boom Clay solid phase, it was assumed that their relative fast transport was due to colloids (either intrinsic colloids or NOM-colloids). The constant concentration percolating from the core was thought to result from a solubility limiting phase precipitated at the source position. However, the concentrations in the percolate were systematically lower than the thermodynamic calculated solubilities, and all the more, complexation to NOM would likely result in an increased RN concentration. Although these curves could be modelled by a simple diffusion-advection relationship with linear sorption, they could not be backed up by a mechanistic understanding. As the concentration in the percolate remained constant for many years, the RN-species eluting from the core are assumed to be well in equilibrium with the Boom Clay geochemical conditions. Therefore, they were used as input source (constant concentration boundary condition) for a migration experiment through a fresh clay core (i.e. the outlet of a first cell was coupled to the inlet of a second cell). The measured concentrations at the outlet of the second clay core also reached a constant value, but this value is about one order

  18. Fluid Dynamic Mechanisms and Interactions within Separated Flows and Their Effects on Missile Aerodynamics

    Science.gov (United States)

    1983-05-01

    or blow-by, flow which, in turn, caused the pressure in the annular region (at PS4 and at pS5)41 to rise slightly then decrease. The slight pressure...pulse was much less than that measured during the Rip-Zap program. Thus, the splash- hack mass flow-rate apparently was relatively small for the Arrow

  19. Liquid Water may Stick on Hydrophobic Surfaces

    Indian Academy of Sciences (India)

    IAS Admin

    Common Perception. A surface can be classified as. > Wetting. > Non-wetting. Depending on the spreading characteristics of a droplet of water that splashes on the surface. The behavior of fluid on a solid surface under static and dynamic ..... color of the number density profile. Ions at the interface tend to form pinning zones ...

  20. A passively controlled appendage deployment system for the San Marco D/L spacecraft

    Science.gov (United States)

    Lang, W. E.; Frisch, H. P.; Schwartz, D. A.

    1984-01-01

    The analytical simulation of deployment dynamics of these two axis concepts as well as the evolution of practical designs for the add on deployable inertia boom units is described. With the boom free to swing back in response to Coriolis forces as well as outwards in response to centrifugal forces, the kinematics of motion are complex but admit the possibility of absorbing deployment energy in frictional or other damping devices about the radial axis, where large amplitude motions can occur and where the design envelope allows more available volume. An acceptable range is defined for frictional damping for any given spin rate. Inadequate damping allows boom motions which strike the spacecraft; excessive damping causes the boom to swing out and latch with damaging violence. The acceptable range is a design parameter and must accommodate spin rate tolerance and also the tolerance and repeatability of the damping mechanisms.

  1. The Dynamics of Share-Price Formation

    NARCIS (Netherlands)

    J. Tinbergen (Jan)

    1939-01-01

    textabstractIn a recent investigation which the author has made for the League of Nations Secretariat, it was found that share prices seem to have exerted a considerable influence on the course of the American cycle beginning in 1924 and having its boom year in 1929. The chief reason for this

  2. Fake news of baby booms 9months after major sporting events distorts the public's understanding of early human development science.

    Science.gov (United States)

    Grech, Victor; Masukume, Gwinyai

    2017-12-01

    In France on 27/6/16, Iceland's men's national football team won 2-1, knocking England out of the UEFA European Championship. Nine months after this momentous Icelandic victory, Ásgeir Pétur Þorvaldsson a medical doctor in Iceland, posted a tweet in jest suggesting that a baby boom had occurred as a result of increased celebratory coital activity following the win. The media covered this widely but statistical analysis shows otherwise and this was confirmed by the original tweet source. Given the increase in fake scientific news, it is especially important for scientists to correct misinformation lest the public loses trust in science or gains a distorted understanding of known facts. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. The costs of the diesel boom; Die Kosten des Dieselbooms. Eine Uebersicht

    Energy Technology Data Exchange (ETDEWEB)

    Helmers, E. [Fachhochschule Trier, Umweltcampus Birkenfeld (Germany)

    2006-02-15

    Background. In many European states the number of cars equipped with diesel engines has dramatically increased since around ten years. This situation is quantified for Germany. Driven by the political motivation to reduce CO{sub 2}-emissions, increase of diesel cars has been stimulated by governmental measures of European as well as state bodies in co-operation with the industry. Results. Reduction of CO{sub 2}-emissions with the help of diesel cars remained relatively small. On contrast, diesel cars are emitting much more of nitric oxides and fine particles compared with gasoline driven cars. Excess emissions by the 'diesel boom' are quantified. Health costs and impact on agricultural crops as well as on forestry are estimated with respect to the order of magnitude. Health costs caused by the inhalation of diesel combustion particles emitted by only the excess diesel cars in Germany are in the order of 200 Mio Euro per year. Knowledge gaps of the impact of ultra fine particles as well as of the action of particle traps are demonstrated. Conclusion and Recommendation. In the public, particle numbers need to be discussed instead of particle emission loads (g km{sup -1}) which have an insufficient correlation to health effects. Much more data are needed as to the toxicologically relevant particle size of <20 nm. Effectiveness and substainability of a CO{sub 2}-reduction strategy by diesel cars are generally questioned. (orig.)

  4. Two centuries of economic territorial dynamics: the case of France

    Directory of Open Access Journals (Sweden)

    Magali Talandier

    2016-01-01

    Full Text Available We propose an analysis of the socio-economic development processes at work in territories at the scale of French communes from 1806 to 2010. This is an extremely fine scale for such analysis, given that there are 36,000 communes in mainland France. The diachronic dimension, spanning two centuries, makes it possible to consider the temporal depth of territorial development. But the primary interest is not so much demographics as the socio-economic dimension of these variations over two centuries. We have analysed demographic changes as the expression of the socio-economic processes that shaped French territory over two centuries. Dynamic mapping of long-term population shifts reflects the industrial expansion of certain territories, decline due to the end of traditional farming practices, the shock produced by two world wars, the Fordist period and the post-war boom; the subsequent impact of an increasingly globalized, metropolitan economy then becomes apparent. We thus identify, map and analyse several historico-socio-economic phases.

  5. HADRON CALORIMETER (HCAL)

    CERN Multimedia

    J. Spalding and A. Skuja

    2010-01-01

    Splash and Collision Data HCAL recorded the beam-on-collimator (splash) and the first collision data in November and December 2009, and provided triggers to CMS with the forward calorimeter, HF. Splash events were used to improve the energy inter-calibration of the HB and HE channels, with the basic assumption that the energy deposited in the detector by the large flux of muons that passed through in splash events was a smooth function in eta and phi. The new HB and HE calibration coefficients were applied prior to the collision data taking. For HO, a similar analysis is being finalized. Splash events were also used to determine the relative timing between channels in HB and HE, and new delay settings were calculated based on splashes from one beam, applied and verified with the splash events from the other beam. During Fall 2009, the HF technical trigger was improved in order to be effectively used as one of the main CMS triggers during the collision data taking. Collisions were successfully recorded by all...

  6. Supply of the numerical simulation for the evaluation of the sonic boom of meteorites

    International Nuclear Information System (INIS)

    Henneton, Martin

    2013-01-01

    Within the framework of the Comprehensive Nuclear-Test-Ban Treaty, infra-sound is one survey technique monitoring nuclear explosions. These ones have to be distinguished from natural sources of infra-sound like atmospheric meteorite entries. With a view to investigate meteorites as an infra-sound source, finite volume simulations of the hypersonic flow are performed at sufficiently far distances to reach the acoustic regime. They are then matched to a nonlinear ray tracing method to propagate the signal within the atmosphere down to the ground. For perfect gases, this approach allows us to validate the theoretical model based on simplifying assumptions. More realistic simulations in real gases at thermochemical equilibrium, show a major modification of the pressure field in the near field but a moderate influence for infra-sound at the ground level. Numerical results are compared to infra-sound and seismic measurements in the case of the well-documented meteorite of Carancas (Peru, 2007). This confrontation highlights a good agreement for the spectrum of the waveform but a large overestimation of the overpressure at receptors located near the impact crater. This study also allowed us to propose a new entry trajectory for the meteorite, and to identify one of the recorded signals as a sonic boom. (author) [fr

  7. Insight conference reports : proceedings of the water and land use in Alberta forum : sustainable resource management in a boom economy

    International Nuclear Information System (INIS)

    2006-01-01

    Alberta's booming oil and gas industry has led to concerns over land and water use in the province. This forum provided a venue for the discussion of issues related to water and land use in Alberta. Various strategies for land use planning were evaluated. Regulatory frameworks for water and land pollution abatement were considered along with strategies for reducing the environmental impacts of oil and gas resource development in the province. The Wildlife, Habitat, and Species at Risk Act was discussed, as well as issues related to Canada's new endangered species laws. Issues concerning water scarcity and stakeholder relations were discussed. Various water management strategies were evaluated. One of the 14 presentations featured at this conference has been catalogued separately for inclusion in this database. refs., tabs., figs

  8. Boom or bust : developing countries' rough ride on the commodity price rollercoaster

    International Nuclear Information System (INIS)

    Brown, O.; Gibson, J.

    2006-10-01

    Current high commodity prices are driven by strong demand from the emerging economies of China and India in addition to high consumption in the United States. Many developing countries are experiencing massive windfall revenues from high commodity prices. However, commodity prices are highly volatile in the short term, and can vary as much as 50 per cent in a single year. While developed country producers are supported by subsidies and social safety nets, developing countries and smallholder producers feel the extent of commodity price volatility more directly. Many developing countries are becoming locked into the production and export of primary commodities whose volatile prices are declining over the long term, and over which they have very little control. Price volatility makes sound fiscal planning difficult for both countries and producers. Price booms and busts also drive social inequalities, livelihood inequalities, and corruption. Price swings can cause conflict over valuable land and resources, and does not create incentives for sound environmental stewardship. This paper described the impacts of commodity price volatility in developing countries with the aim of promoting discussion about what can be done to help stabilize revenues for countries as well as producers. Price trends and their importance were reviewed, and the theoretical benefits of liberalized commodity markets were examined. Previous attempts to stabilize commodity prices were reviewed. It was concluded that the best long-term solution to the commodity price problem is economic diversification. Recommendations for promoting economic diversification were provided. 43 refs., 1 tab., 2 figs

  9. Modeling and advanced sliding mode controls of crawler cranes considering wire rope elasticity and complicated operations

    Science.gov (United States)

    Tuan, Le Anh; Lee, Soon-Geul

    2018-03-01

    In this study, a new mathematical model of crawler cranes is developed for heavy working conditions, with payload-lifting and boom-hoisting motions simultaneously activated. The system model is built with full consideration of wind disturbances, geometrical nonlinearities, and cable elasticities of cargo lifting and boom luffing. On the basis of this dynamic model, three versions of sliding mode control are analyzed and designed to control five system outputs with only two inputs. When used in complicated operations, the effectiveness of the controllers is analyzed using analytical investigation and numerical simulation. Results indicate the effectiveness of the control algorithms and the proposed dynamic model. The control algorithms asymptotically stabilize the system with finite-time convergences, remaining robust amid disturbances and parametric uncertainties.

  10. Central and Eastern Europe After the Boom - Time for a Stragegy Change for Foreign Multinationals?

    Directory of Open Access Journals (Sweden)

    Arnold Schuh

    2013-06-01

    Full Text Available In 2008 the global financial and economic crisis ended a six-year-long boom period with an average growth rate well above 5% in Central and Eastern Europe (CEE. Although not the originators of the crisis some CEE countries such as the Baltic States and Ukraine were among the worst hit by this economic downturn. The crisis did not only shatter the financial markets, banks and the real economy but also the growth image of CEE. The huge market potential and expected higher growth rates resulting from the catching-up process to West European standards have been the main reason for the flood of foreign direct investments into the countries of the region in the two decades before. Suddenly, foreign direct investors were confronted with stalled and even collapsing market growth, shrinking disposable household income, business customers and partners on the verge of bankruptcy and no real sign of a quick recovery. While the situation improved a little in 2011, the economic outlook and the sentiment of foreign investors have remained gloomy, at least for parts of the region. It is obvious that when faced with such a huge economic downturn companies stop geographic expansion and put the brakes on investments.

  11. Newtonian liquid jet impaction on a high-speed moving surface

    International Nuclear Information System (INIS)

    Keshavarz, B.; Green, S.I.; Davy, M.H.; Eadie, D.T.

    2011-01-01

    Highlights: ► We studied experimentally the interaction of a liquid jet with a moving surface. ► Decreasing the Reynolds number reduced the incidence of splash. ► The Weber number had a much smaller impact on splash than the Reynolds number. ► The jet impingement angle had only a small effect on the splash. ► Increasing the surface roughness substantially decreased the splash threshold. - Abstract: In the railroad industry a friction modifying agent may be applied to the rail or wheel in the form of a liquid jet. In this mode of application the interaction between the high-speed liquid jet and a fast moving surface is important. Seven different Newtonian liquids with widely varying shear viscosities were tested to isolate the effect of viscosity from other fluid properties. Tests were also done on five surfaces of different roughness heights to investigate the effects of surface roughness. High-speed video imaging was employed to scrutinize the interaction between the impacting jet and the moving surface. For all surfaces, decreasing the Reynolds number reduced the incidence of splash and consequently enhanced the transfer efficiency. At the elevated Weber numbers of the testing, the Weber number had a much smaller impact on splash than the Reynolds number. The ratio of the surface velocity to the jet velocity has only a small effect on the splash, whereas increasing the roughness-height-to-jet-diameter ratio substantially decreased the splash threshold.

  12. Time-delay-induced dynamical behaviors for an ecological vegetation growth system driven by cross-correlated multiplicative and additive noises.

    Science.gov (United States)

    Wang, Kang-Kang; Ye, Hui; Wang, Ya-Jun; Li, Sheng-Hong

    2018-05-14

    In this paper, the modified potential function, the stationary probability distribution function (SPDF), the mean growth time and the mean degeneration time for a vegetation growth system with time delay are investigated, where the vegetation system is assumed to be disturbed by cross-correlated multiplicative and additive noises. The results reveal some fact that the multiplicative and additive noises can both reduce the stability and speed up the decline of the vegetation system, while the strength of the noise correlation and time delay can both enhance the stability of the vegetation and slow down the depression process of the ecological system. On the other hand, with regard to the impacts of noises and time delay on the mean development and degeneration processes of the ecological system, it is discovered that 1) in the development process of the vegetation population, the increase of the noise correlation strength and time delay will restrain the regime shift from the barren state to the boom one, while the increase of the additive noise can lead to the fast regime shift from the barren state to the boom one. 2) Conversely, in the depression process of the ecological system, the increase of the strength of the correlation noise and time delay will prevent the regime shift from the boom state to the barren one. Comparatively, the increase of the additive and multiplicative noises can accelerate the regime shift from the boom state to the barren state.

  13. A worker attaches covers for the nose pitot boom before removing the unpiloted X-40 from the runway

    Science.gov (United States)

    2001-01-01

    A worker attaches covers for the nose pitot boom before removing the unpiloted X-40 from the runway at Edwards Air Force Base, California, following its successful free-flight on March 14, 2001. The unpiloted X-40 is a risk-reduction vehicle for the X-37, which is intended to be a reusable space vehicle. NASA's Marshall Space Flight Center in Huntsville, Ala, manages the X-37 project. At Dryden, the X-40A underwent a series of ground and air tests to reduce possible risks to the larger X-37, including drop tests from a helicopter to check guidance and navigation systems planned for use in the X-37. The X-37 is designed to demonstrate technologies in the orbital and reentry environments for next-generation reusable launch vehicles that will increase both safety and reliability, while reducing launch costs from $10,000 per pound to $1,000 per pound. The X-37, carried into orbit by the Space Shuttle, is planned to fly two orbital missions to test reusable launch vehicle technologies.

  14. Uniformidade de deposição da calda de pulverização de herbicidas em barra lateral protegida com diferentes combinações de pontas de pulverização Herbicide spray deposition uniformity from a protected lateral spray boom with different spray tip combinations

    Directory of Open Access Journals (Sweden)

    A.C. Furlanetti

    2001-12-01

    h-1 e pressão de 414 kPa (60 lbf pol-2, com distância de caminhamento do tronco da árvore de 30 cm. A velocidade de deslocamento do pulverizador de 5 km h-1 proporcionou melhores condições para que os herbicidas estudados apresentassem melhor controle de plantas daninhas, quando comparada com a velocidade de deslocamento do pulverizador de 4 km h-1.This work aimed to study herbicide spray distribution uniformity of a shielded lateral boom, in the rows of perennial tree crops, using combinations of nozzle tips, operated at small distance from the target. A computer software program was developed to simulate the overlapping of the spray pattern from the nozzles positioned in the shielded boom portion and at the end of the boom. After computer selection of nozzle tip combinations (coefficients of variation lower than 10%, some combinations were studied under field conditions, using a systemic herbicide (glyphosate and a contact herbicide (paraquat application. The results indicated that the software could be a powerful tool in nozzle tip combination selection. The most efficient tip combinations for both herbicides studied (glyphosate and paraquat at reduced spray volume (100 L ha-1 were: a TT110015 nozzle tips spaced 52.5 cm, combined with the tip TK-0.5 at the boom extremity (50 cm from the last nozzle, ground speed of 5 km h-1, 15 psi (103 kPa working pressure, with the distance of the last boom nozzle of 20 cm from the tree trunk; b SMCE-2 nozzle tips spaced 15 cm combined with the tip TK-0.5 at the boom extremity (20 cm from the last nozzle, with ground speed of 4 km h-1, 60 psi (414 kPa working pressure, with the distance of the last boom nozzle of 30 cm from the tree trunk; and c TLX-2 nozzle tips spaced 15 cm combined with the tip TK-0.5 at the boom extremity (20 cm from the last nozzle, with ground speed of 5 km h-1, 60 psi (414 kPa working pressure, with the distance of the last boom nozzle of 30 cm from the tree trunk. The sprayer speed of 5 km h-1

  15. Pravilnõi gorod reshajet problemõ tsivilizatsii zhutkim obrazom

    Index Scriptorium Estoniae

    2005-01-01

    Hollandi arhitektide Neville Marsi ja Saskia Vendeli asutatud rahvusvaheline arhitektide grupp Dynamic City Foundation analüüsib ja loob pilti tulevikulinnast. Nende projektist "Beijing Boom Tower", mis modelleerib maketil fragmenti Pekingist 2020. aastal

  16. Lifecycle effects of a recession on health behaviors: Boom, bust, and recovery in Iceland.

    Science.gov (United States)

    Ásgeirsdóttir, Tinna Laufey; Corman, Hope; Noonan, Kelly; Reichman, Nancy E

    2016-03-01

    This study uses individual-level longitudinal data from Iceland, a country that experienced a severe economic crisis in 2008 and substantial recovery by 2012, to investigate the extent to which the effects of a recession on health behaviors are lingering or short-lived and to explore trajectories in health behaviors from pre-crisis boom, to crisis, to recovery. Health-compromising behaviors (smoking, heavy drinking, sugared soft drinks, sweets, fast food, and tanning) declined during the crisis, and all but sweets continued to decline during the recovery. Health-promoting behaviors (consumption of fruit, fish oil, and vitamins/minerals and getting recommended sleep) followed more idiosyncratic paths. Overall, most behaviors reverted back to their pre-crisis levels or trends during the recovery, and these short-term deviations in trajectories were probably too short-lived in this recession to have major impacts on health or mortality. A notable exception is for binge drinking, which declined by 10% during the 2 crisis years, continued to fall (at a slower rate of 8%) during the 3 recovery years, and did not revert back to the upward pre-crisis trend during our observation period. These lingering effects, which directionally run counter to the pre-crisis upward trend in consumption and do not reflect price increases during the recovery period, suggest that alcohol is a potential pathway by which recessions improve health and/or reduce mortality. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. The combined effect of wind and rain on interrill erosion processes

    International Nuclear Information System (INIS)

    Erpul, G.; Gabriels, D.; Norton, L.D.

    2004-01-01

    Wind-driven rain is described as raindrops falling through a wind field at an angle from vertical under the effects of both gravitational and drag forces. Wind-driven raindrops gain some degree of horizontal velocity and strike the soil surface with an angle deviated from vertical. Additionally, the distribution and intensity of rainfall on sloping surfaces differs depending on wind direction and velocity. The changes in raindrop trajectory and frequency with wind velocity and direction can have significant effects on rain splash detachment process. The resultant impact velocity, impact angle, and impact frequency of raindrops determine the magnitude of rain splash detachment by wind-driven rain. This differs from the detachment process by windless rain, in which a straight-line trajectory of raindrops and accordingly greatest rainfall intensity for a given rain are implicitly assumed. Wind, as well as slope and overland flow, is another possible factor capable of transporting detached particles by raindrop impact. Once soil particles are entrained in the splash droplets that have risen into the air by raindrop impact, wind velocity gradient will transport these particles. Obviously, in addition to its role in the rain splash detachment process, the wind accompanying rain is an important consideration in the rain splash transport process, which can cause a net transportation in wind direction. In wind-driven rains, wind velocity and direction is expected to affect not only rain splash detachment and transport processes but also shallow flow sediment transport induced by raindrop impacts with an angle on flow and the rain splash trajectories of soil particles within flow. Under wind-driven rain, the interrill transport process is a combined work of both rain splash sediment transport and raindrop-impacted shallow flow sediment transport. The rain splash process acts alone until runoff occurs, and net soil transport is caused by wind. As soon as runoff starts, the

  18. Global Properties of M31’s Stellar Halo from the SPLASH Survey. III. Measuring the Stellar Velocity Dispersion Profile

    Science.gov (United States)

    Gilbert, Karoline M.; Tollerud, Erik; Beaton, Rachael L.; Guhathakurta, Puragra; Bullock, James S.; Chiba, Masashi; Kalirai, Jason S.; Kirby, Evan N.; Majewski, Steven R.; Tanaka, Mikito

    2018-01-01

    We present the velocity dispersion of red giant branch stars in M31’s halo, derived by modeling the line-of-sight velocity distribution of over 5000 stars in 50 fields spread throughout M31’s stellar halo. The data set was obtained as part of the Spectroscopic and Photometric Landscape of Andromeda’s Stellar Halo (SPLASH) Survey, and covers projected radii of 9 to 175 kpc from M31’s center. All major structural components along the line of sight in both the Milky Way (MW) and M31 are incorporated in a Gaussian Mixture Model, including all previously identified M31 tidal debris features in the observed fields. The probability that an individual star is a constituent of M31 or the MW, based on a set of empirical photometric and spectroscopic diagnostics, is included as a prior probability in the mixture model. The velocity dispersion of stars in M31’s halo is found to decrease only mildly with projected radius, from 108 km s‑1 in the innermost radial bin (8.2 to 14.1 kpc) to ∼80 to 90 km s‑1 at projected radii of ∼40–130 kpc, and can be parameterized with a power law of slope ‑0.12 ± 0.05. The quoted uncertainty on the power-law slope reflects only the precision of the method, although other sources of uncertainty we consider contribute negligibly to the overall error budget. The data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation.

  19. Il boom dell’Italia in Giappone: riflessioni critiche su Occidentalismo e Italianismo

    Directory of Open Access Journals (Sweden)

    Toshio Miyake

    2011-05-01

    Full Text Available In the modern age, Occidentalism as a process of signifying practices based upon the notion of “the West” has played a hegemonic role in the configuration of collective identity and alterity. The imaginary geography of “the West” has been one of the most effective in inscribing the whole world and humanity along hierarchic and fluid lines of inclusion and exclusion, encompassing global relations of power in geopolitical contexts, as well as knowledge practices in geocultural spheres. In spite of post-colonial engagements aimed to de-naturalize the notions of “the West” and “the East”, little critical attentions has been paid so far to the inter-relational and complicit processes between Occidentalism, Orientalism and self-Orientalism.             This paper shall explore the historical genalogy of discourses on Italy (Italianism in modern Japan, which brought to the Italian boom in the 1990s, elevating at present Italy to the rank of the most-loved foreign country among Japanese women and youth. This study suggests that the prevailing image of Italy has been articulated and re-produced since modern age as an ambivalent icon: a superior-seeming and ‘archetypical West’ based on the insistence of its antique and classical features (Roman Empire, Humanism, Renaissance, and at the same time, an inferior-seeming and ‘backward West’ based on the insistence of its pre-moderns aspects (history, gastronomy, fashion, landscapes, cheerful people, etc.. The popularity of this configuration suggests the strategic relevance of the Italian looking glass self which enables to mediate deep rooted and contradictory pro-western and anti-western tensions in modern and contemporary Japan.

  20. Demography of the Early Neolithic Population in Central Balkans: Population Dynamics Reconstruction Using Summed Radiocarbon Probability Distributions.

    Directory of Open Access Journals (Sweden)

    Marko Porčić

    Full Text Available The Central Balkans region is of great importance for understanding the spread of the Neolithic in Europe but the Early Neolithic population dynamics of the region is unknown. In this study we apply the method of summed calibrated probability distributions to a set of published radiocarbon dates from the Republic of Serbia in order to reconstruct population dynamics in the Early Neolithic in this part of the Central Balkans. The results indicate that there was a significant population growth after ~6200 calBC, when the Neolithic was introduced into the region, followed by a bust at the end of the Early Neolithic phase (~5400 calBC. These results are broadly consistent with the predictions of the Neolithic Demographic Transition theory and the patterns of population booms and busts detected in other regions of Europe. These results suggest that the cultural process that underlies the patterns observed in Central and Western Europe was also in operation in the Central Balkan Neolithic and that the population increase component of this process can be considered as an important factor for the spread of the Neolithic as envisioned in the demic diffusion hypothesis.

  1. Boom komiksowy. Polski rynek historii obrazkowych w latach 2000-2003

    Directory of Open Access Journals (Sweden)

    Mateusz Zapała

    2011-05-01

    Full Text Available Lata 2000-2003, ze względu na wzmożoną aktywność wydawniczą na polu historii obrazkowych oraz szum medialny jej towarzyszący, bywają określane „boomem komiksowym”. Gwałtowny wzrost koniunktury na komiks w początkach XXI wieku rozpoczęły należące do Egmont Polska: magazyn „Świat Komiksu” oraz imprint Klub Świata Komiksu (publikujący m.in. niebywale popularną serię Thorgal. Wkrótce po komercyjnym sukcesie Egmontu na rynek opowieści obrazkowych wkroczyli inni wydawcy, których można podzielić na dwie grupy. Pierwszą stanowili edytorzy, którzy wcześniej publikowali jedynie książki, np. wydawnictwa Amber, Muza, Siedmioróg. Drugi zbiór tworzyły oficyny stricte komiksowe, m.in. Kultura Gniewu, Mandragora, Post. „Boom komiksowy” doprowadził także do znacznych zmian w strukturze rynku periodycznych historii obrazkowych – prawie wszystkich odbiorców utracił TM-Semic (lider rynku komiksowego w latach 90, wydawca czasopism z przygodami superbohaterów, np. „Batmana”,  nowych czytelników zyskały natomiast niskonakładowe magazyny, które publikowały głównie polski komiks autorski (m.in. „AQQ”, „Krakers”, „KKK”, „Produkt”. W latach 2000-2003 rozwinął się również polski rynek mang (komiksów japońskich, którego liderem w tym czasie było wydawnictwo Japonica Polonica Fantastica (63% udział w rynku. Podczas „boomu komiksowego” rynek  historii obrazkowych skierowanych do dzieci zdominowała oferta Egmontu (np. magazyny „Kaczor Donald” i „Czarodziejki: W.I.T.C.H.” oraz cykl Gigant Poleca. Łącznie w latach 2000-2003 we wszystkich segmentach polskiego rynku komiksowego ukazało się 1455 pozycji komiksowych, czyli prawie o jedną czwartą więcej niż w ciągu całych lat dziewięćdziesiątych.

  2. [Changes in tobacco consumption: boom of roll-your-own cigarettes and emergence of e-cigarettes].

    Science.gov (United States)

    Tarrazo, Marina; Pérez-Ríos, Mónica; Santiago-Pérez, María I; Malvar, Alberto; Suanzes, Jorge; Hervada, Xurxo

    To assess changes in smoking prevalence and study roll-your-own (RYO) tobacco and e-cigarette use in the Galician population between 2007 and 2015. Data were obtained from five independent, cross-sectional studies carried out in Galicia (Spain) between 2007-2015 in the population aged 16 and over (n=8,000/year). Prevalence of use was estimated, with 95% confidence intervals, overall, according to sex and by age group, area of residence and level of education. Smoking prevalence decreased from 25.4% in 2007 to 21.8% in 2015. In 2007, 1.8% of current smokers declared that they had smoked RYO tobacco, compared to 18.6% in 2015. Among smokers, RYO tobacco consumption increased across all demographic groups. In both 2014 and 2015, ever use of e-cigarettes was 0.7%. E-cigarette use was more frequent in urban settings. Smoking prevalence decreased in Galicia between 2007 and 2015, and there has been rapid growth in the prevalence of RYO tobacco use. Although smokers are more likely to use e-cigarettes, both former and never smokers declared their use. The boom of RYO cigarettes and the emergence of e-cigarettes highlight the importance of having continuous surveillance systems to identify smoking behavioural changes. Copyright © 2016 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

  3. Small Body GN and C Research Report: G-SAMPLE - An In-Flight Dynamical Method for Identifying Sample Mass [External Release Version

    Science.gov (United States)

    Carson, John M., III; Bayard, David S.

    2006-01-01

    G-SAMPLE is an in-flight dynamical method for use by sample collection missions to identify the presence and quantity of collected sample material. The G-SAMPLE method implements a maximum-likelihood estimator to identify the collected sample mass, based on onboard force sensor measurements, thruster firings, and a dynamics model of the spacecraft. With G-SAMPLE, sample mass identification becomes a computation rather than an extra hardware requirement; the added cost of cameras or other sensors for sample mass detection is avoided. Realistic simulation examples are provided for a spacecraft configuration with a sample collection device mounted on the end of an extended boom. In one representative example, a 1000 gram sample mass is estimated to within 110 grams (95% confidence) under realistic assumptions of thruster profile error, spacecraft parameter uncertainty, and sensor noise. For convenience to future mission design, an overall sample-mass estimation error budget is developed to approximate the effect of model uncertainty, sensor noise, data rate, and thrust profile error on the expected estimate of collected sample mass.

  4. Proposta metodológica para avaliação de controlador automático de seções e pulverização Proposed methodology for evaluation of automatic controller of boom sections and spray

    Directory of Open Access Journals (Sweden)

    Étore F Reynaldo

    2011-02-01

    Full Text Available Na aplicação de produtos fitossanitários, a utilização de equipamentos que controlam automaticamente as seções da barra e a pulverização já é realidade; entretanto, ainda não há resultados que demonstrem a sua eficácia. Por esse motivo, este trabalho teve por finalidade desenvolver uma metodologia para a avaliação de um equipamento que controla automaticamente as seções e a pulverização. Avaliou-se um controlador automático de seções e pulverização de mercado, e, para tanto, foram utilizados três níveis de acurácia do sinal de GPS (algoritmo interno, SBAS e RTK, três ângulos para a simulação de entrada e saída da barra de pulverização em relação à borda do talhão (0; 45 e 60º e três velocidades de trabalho (1,66; 5,00 e 8,33 m s-1. A metodologia proposta possibilitou a determinação dos tempos e distâncias de abertura e fechamento das seções. Os coeficientes de variação para os tempos e distâncias de abertura e fechamento das seções indicaram uma variação considerável. Houve interações significativas em função do tipo de sinal de GPS. A configuração recomendada pelo fabricante e adotada para a avaliação do controlador automático de seções e pulverização não atende a todas as situações simuladas.In the application of pesticides, the use of equipment that automatically controls the sections of the boom and the spray is already reality. However, there are no results to show its effectiveness. Therefore, this work was to develop a methodology for the evaluation of equipments which automatically controls the boom sections and the spraying pattern. A commercial automatic controller of boom spraying sections was evaluated using three levels of GPS accuracy (internal algorithm, SBAS and RTK, three angles for the simulation of entry and exit of the spray bar on field edges (0, 45 and 60 º and three forward speeds (1.66, 5.00 and 8.33 m s-1. The proposed methodology allowed the

  5. Poor compliance with standard precautions against infections during minor gynaecological procedures.

    Science.gov (United States)

    Maharaj, Dushyant; Lawton, Beverley; Garrett, Sue

    2012-06-01

    Splash injuries occurring during minor surgical procedures are associated with a significant infective risk to the operator. It is a common misconception that minor operations carry low risks. To determine the prevalence of the practice of Standard Precautions by medical staff in the obstetric and gynaecology (O & G) units of two hospitals in New Zealand, and to assess self-observed splash injury rates. A cross-sectional survey of all doctors working in the O & G units of two public hospitals servicing a population of 435 000. A self-administered questionnaire was provided to 43 doctors with questions related to the use of Standard Precautions, perceived likelihood of infection from a splash and splash injuries sustained during procedures. The response rate was 76.6% (n = 33/43). Of the respondents, only 30.3% (n = 10) used Standard Precautions during minor procedures. Sixty-four per cent (n = 21) routinely used goggles/visor for eye protection. Forty-five per cent (n = 15) thought they were likely to get an infection from a splash, and 55% (n = 18) of clinicians had experienced a splash injury. Of the minor procedures during which splash injuries had occurred, repair of episiotomy 45.8% (n = 11) was the commonest. This survey shows poor compliance with guidelines for Standard Precautions to protect from infection despite self-reported rates of splash injury being high at 55%. Effective interventions are needed to increase compliance and prevent infection. © 2012 The Authors ANZJOG © 2012 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.

  6. Children of boom and recession and the scars to the mental health--a comparative study on the long term effects of youth unemployment.

    Science.gov (United States)

    Virtanen, Pekka; Hammarström, Anne; Janlert, Urban

    2016-01-20

    Earlier research shows that there is an association between unemployment and poor mental health, and that recovery from the damages to mental health obtained during unemployment remains incomplete over a long period of time. The present study relates this 'mental health scarring' to the trade cycle, exploring if those exposed to youth unemployment during boom differ from those exposed during recession with respect to mental health in the middle age. The sample consists of two cohorts from the same industrial town in Northern Sweden: the cohort born in 1965 and the cohort born in 1973 included all pupils attending the last grade of compulsory school, respectively, in 1981 and in 1989. Their depressiveness and anxiousness were assessed by questionnaires at age 21 and again at age 43/39. Mental health at follow-up was related to exposure to unemployment during age years 21-25. Statistical significance of the cohort*exposure interactions from binary logistic regression analyses were used to assess the cohort differences in the mental health between Cohort65 and Cohort73, entering the labour market, respectively, during a boom and a recession. Compared to the unexposed, high exposure to unemployment at the age from 21 to 25 was associated to increased probability of poor mental health in the middle age in both in Cohort65 (odds ratio 2.19 [1.46-3.30] for anxiousness and 1.85 [1.25-2.74]for depressiveness) and in Cohort73 (odds ratio 2.13 [1.33-3.39] for anxiousness and 1.38 [0.89-2.14] for depressiveness). The differences between the cohorts also turned out as statistically non-significant. The scars of unemployment exposure onto future health seem to be rather insensitive to economic trades. Thus, at the population level this would mean that the long-term health costs that can be attributed to youth unemployment are more widespread in the generation that suffers of recession around the entry to the work life.

  7. Thermo-hydraulic behaviour of Boom Clay using a heating cell. experimental and numerical study

    International Nuclear Information System (INIS)

    Lima, A.; Romero, E.; Vaunat, J.; Gens, A.; Li, X.L.

    2010-01-01

    Document available in extended abstract form only. Boom clay is the subject of extensive research in Belgium dealing with all phenomena that may possibly affect the performance of this geological formation as potential radioactive waste repository. Specifically, thermal loads may play an important role on this low-permeability clay. There are a number of laboratory results concerning the saturated hydro-mechanical behaviour of Boom clay under different temperatures and recent studies on this area are described in Le (2008). Nevertheless, information on clay hydro-mechanical response on heating and cooling paths under small-scale laboratory conditions is less known. To this aim, non-isothermal tests on intact borehole samples were carried out using an axisymmetric heating cell described in Munoz et al. (2009). Heating and cooling paths under nearly constant volume and different target temperatures (maximum 85 deg. C) were performed under controlled hydraulic boundary conditions. The paper presents results of an exhaustive experimental programme performed on a fully-instrumented cell (sample 75 mm in diameter and 100 mm high) with a controlled-power heater installed along the axis of the sample. Different transducers were monitoring the sample response: two miniature pore water pressure transducers located at different heights of the lateral wall of the cell, three thermocouples (two at equivalent locations in relation to the pressure transducers and one near the heater), and top and lateral strain gauges attached to reduced thickness sections of the walls. The cell has top and bottom valves to apply the hydraulic conditions. The protocol of the tests presented three important phases: hydration, heating and cooling. Throughout the heating and cooling phases, the bottom drainage was maintained open at a constant water pressure of 1 MPa using an automatic pressure/volume controller, while the upper valve was kept closed. This back-pressure was important since it

  8. Propulsion System Dynamic Modeling of the NASA Supersonic Concept Vehicle for AeroPropulsoServoElasticity

    Science.gov (United States)

    Kopasakis, George; Connolly, Joseph W.; Seiel, Jonathan

    2016-01-01

    A summary of the propulsion system modeling under NASA's High Speed Project (HSP) AeroPropulsoServoElasticity (APSE) task is provided with a focus on the propulsion system for the low-boom supersonic configuration developed by Lockheed Martin and referred to as the N+2 configuration. This summary includes details on the effort to date to develop computational models for the various propulsion system components. The objective of this paper is to summarize the model development effort in this task, while providing more detail in the modeling areas that have not been previously published. The purpose of the propulsion system modeling and the overall APSE effort is to develop an integrated dynamic vehicle model to conduct appropriate unsteady analysis of supersonic vehicle performance. This integrated APSE system model concept includes the propulsion system model, and the vehicle structural aerodynamics model. The development to date of such a preliminary integrated model will also be summarized in this report

  9. Dynamic and Structural Performances of a New Sailcraft Concept for Interplanetary Missions

    Directory of Open Access Journals (Sweden)

    Alessandro Peloni

    2015-01-01

    Full Text Available Typical square solar-sail design is characterised by a central hub with four-quadrant sails, conferring to the spacecraft the classical X-configuration. One of the critical aspects related to this architecture is due to the large deformations of both membrane and booms, which leads to a reduction of the performance of the sailcraft in terms of thrust efficiency. As a consequence, stiffer sail architecture would be desirable, taking into account that the rigidity of the system strongly affects the orbital dynamics. In this paper, we propose a new solar-sail architecture, which is more rigid than the classical X-configuration. Among the main pros and cons that the proposed configuration presents, this paper aims to show the general concept, investigating the performances from the perspectives of both structural response and attitude control. Membrane deformations, structural offset, and sail vibration frequencies are determined through finite element method, adopting a variable pretensioning scheme. In order to evaluate the manoeuvring performances of this new solar-sail concept, a 35-degree manoeuvre is studied using a feedforward and feedback controller.

  10. Doom and boom on a resilient reef: climate change, algal overgrowth and coral recovery.

    Directory of Open Access Journals (Sweden)

    Guillermo Diaz-Pulido

    Full Text Available Coral reefs around the world are experiencing large-scale degradation, largely due to global climate change, overfishing, diseases and eutrophication. Climate change models suggest increasing frequency and severity of warming-induced coral bleaching events, with consequent increases in coral mortality and algal overgrowth. Critically, the recovery of damaged reefs will depend on the reversibility of seaweed blooms, generally considered to depend on grazing of the seaweed, and replenishment of corals by larvae that successfully recruit to damaged reefs. These processes usually take years to decades to bring a reef back to coral dominance.In 2006, mass bleaching of corals on inshore reefs of the Great Barrier Reef caused high coral mortality. Here we show that this coral mortality was followed by an unprecedented bloom of a single species of unpalatable seaweed (Lobophora variegata, colonizing dead coral skeletons, but that corals on these reefs recovered dramatically, in less than a year. Unexpectedly, this rapid reversal did not involve reestablishment of corals by recruitment of coral larvae, as often assumed, but depended on several ecological mechanisms previously underestimated.These mechanisms of ecological recovery included rapid regeneration rates of remnant coral tissue, very high competitive ability of the corals allowing them to out-compete the seaweed, a natural seasonal decline in the particular species of dominant seaweed, and an effective marine protected area system. Our study provides a key example of the doom and boom of a highly resilient reef, and new insights into the variability and mechanisms of reef resilience under rapid climate change.

  11. Report of a study on the characteristics of the 'Clay of Boom' that are relevant in considering this clay layer package for the storage of nuclear waste; Rapportage van onderzoek aan eigenschappen van de Klei van Boom die relevant zijn bij de beschouwing van dit laagpakket voor opslag van kernafval

    Energy Technology Data Exchange (ETDEWEB)

    Brugge, J.V.M.; Vrouwe, B.J. [T and A Survey, Amsterdam (Netherlands)

    2010-12-15

    The Dutch government aims to store nuclear waste in the Dutch soil. Geological research organization T and A Survey mapped the areas that match with the demands of the Dutch government regarding underground storage of nuclear waste. These are areas in which the Clay layer of Boom has a minimal thickness of 100 meters and the depth of the top of the clay formation is at least 500 meters. [Dutch] De Nederlandse overheid wil kernafval ondergronds opslaan in de Nederlandse bodem. Geologisch onderzoeksbureau T and A Survey brengt de gebieden in kaart, die voldoen aan de door de overheid gestelde eisen voor mogelijke ondergrondse opslag van kernafval. Het gaat om gebieden waar de Boomse kleilaag een minimale dikte van 100 meter heeft en de diepte van de top van de kleiformatie minimaal 500 meter bedraagt.

  12. Responses of Raptorial Birds to Low Level Military Jets and Sonic Booms: Results of the 1980-1981 Joint U.S. Air Force-U.S. Fish and Wildlife Service Study

    Science.gov (United States)

    Ellis, D.H.

    1981-01-01

    Summary: For this study, we gathered several kinds of data to determine the likely effects of low level jets and sonic booms on nesting Peregrine Falcons and other raptors. We directly observed responses to worst case stimulus loads: responses to extremely frequent and extremely nearby jet aircraft were often minimal, seldom significant and never associated with reproductive failure. Likewise, responses to real and simulated sonic booms were often minimal and never productivity limiting. In addition to directly observing behavioral responses, in 1981 we invited jet passes at four Prairie Falcon eyries during courtship and incubation when the adults were most likely to abandon, on an ad libitum basis. All four eyries fledged young. Nesting success and site reoccupancy rates were high for all eyries. In tests of two relatively naive captive Peregrine Falcons, we failed to detect significantly negative responses. Typically the birds either quickly resumed feeding or other activities within a few seconds following a pass or boom. The female falcon repeatedly made hunting forays as jets swept overhead. From heart rate (HR) data taken via a telemetering egg during incubation at a wild Prairie Falcon eyrie, we determined that stimulus induced HR alterations were comparable to rate changes of the birds settling to incubate following flight. No significant long term responses were identified. The falcons successfully fledged two young even with the more disruptive activities associated with entering the eyrie three times to position and recover the telemetering eggs. Significantly, birds ofprey of several genera commonly nest in the supersonic military operations areas in southern Arizona. In addition, raptor eyries are frequently found at locations where low level jet traffic naturally concentrates. For example, Prairie Falcon Site 11 is directly on the approach path to strafing and bombing targets. Prairie Falcon Site 1 is in a narrow canyon through which A-10 aircraft

  13. ATTITUDE DETERMINATION AND CONTROL SYSTEM OF KITSAT-1

    Directory of Open Access Journals (Sweden)

    Hyunwoo Lee

    1996-06-01

    Full Text Available The attitude dynamics of KITSAT-1 are modeled including the gravity gradient stabilization method. We define the operation scenario during the initial attitude stabilization period by means of a magnetorquering control algorithm. The required constraints for the gravity gradient boom deployment are also examined. Attitude dynamics model and control laws are verified by analyzing in-orbit attitude sensor telemetry data.

  14. A prospective study of blood splatter in ENT.

    Science.gov (United States)

    Lakhani, Raj; Loh, Yiwen; Zhang, Ting Ting; Kothari, Prasad

    2015-07-01

    Surgeons face an occupational risk of daily exposure to blood and body fluids. Potential sources of infection include sharps injuries and mucocutaneous contact. The transmission of blood-borne viruses, in particular human immunodeficiency virus (HIV), Hepatitis B and Hepatitis C from the patient to healthcare workers is well documented in the literature. We studied the incidence and degree of blood splash in all otolaryngology (ENT) procedures undertaken in a single unit over a 12 week period. In addition, we investigated which intraoperative factors might predict the degree of splash. We undertook a prospective, non-blinded study of 102 patients undergoing a range of 'routine' elective ENT within one department over 12 weeks. A surgical mask with visor attached was worn in all procedures. Following each procedure, all splatter masks were collected and examined macroscopically and microscopically for blood splash. In addition, the procedure performed, technique used, total blood loss, operating time and grade of surgeon was noted. 54% of procedures resulted in splash mask contamination. The median number of splash spots per mask was 4.7 (range 0-63). Tonsillectomy was the most commonly performed procedure, accounting for over one-third of total procedures investigated. Each mask had an average of 8.2 splash marks. Tonsillectomy had a splash rate of 76.9%. Although the risk of developing HIV is low the operating surgeon has a duty to take all precautions to protect themselves during a procedure and therefore a protective mask and visor or suitable goggles must be worn.

  15. Enhanced somatic embryogenesis in Theobroma cacao using the homologous BABY BOOM transcription factor.

    Science.gov (United States)

    Florez, Sergio L; Erwin, Rachel L; Maximova, Siela N; Guiltinan, Mark J; Curtis, Wayne R

    2015-05-16

    Theobroma cacao, the chocolate tree, is an important economic crop in East Africa, South East Asia, and South and Central America. Propagation of elite varieties has been achieved through somatic embryogenesis (SE) but low efficiencies and genotype dependence still presents a significant limitation for its propagation at commercial scales. Manipulation of transcription factors has been used to enhance the formation of SEs in several other plant species. This work describes the use of the transcription factor Baby Boom (BBM) to promote the transition of somatic cacao cells from the vegetative to embryonic state. An ortholog of the Arabidopsis thaliana BBM gene (AtBBM) was characterized in T. cacao (TcBBM). TcBBM expression was observed throughout embryo development and was expressed at higher levels during SE as compared to zygotic embryogenesis (ZE). TcBBM overexpression in A. thaliana and T. cacao led to phenotypes associated with SE that did not require exogenous hormones. While transient ectopic expression of TcBBM provided only moderate enhancements in embryogenic potential, constitutive overexpression dramatically increased SE proliferation but also appeared to inhibit subsequent development. Our work provides validation that TcBBM is an ortholog to AtBBM and has a specific role in both somatic and zygotic embryogenesis. Furthermore, our studies revealed that TcBBM transcript levels could serve as a biomarker for embryogenesis in cacao tissue. Results from transient expression of TcBBM provide confirmation that transcription factors can be used to enhance SE without compromising plant development and avoiding GMO plant production. This strategy could compliment a hormone-based method of reprogramming somatic cells and lead to more precise manipulation of SE at the regulatory level of transcription factors. The technology would benefit the propagation of elite varieties with low regeneration potential as well as the production of transgenic plants, which

  16. The development of ecological environment in China based on the system dynamics method from the society, economy and environment perspective.

    Science.gov (United States)

    Guang, Yang; Ge, Song; Han, Liu

    2016-01-01

    The harmonious development in society, economy and environment are crucial to regional sustained boom. However, the society, economy and environment are not respectively independent, but both mutually promotes one which, or restrict mutually complex to have the long-enduring overall process. The present study is an attempt to investigate the relationship and interaction of society, economy and environment in China based on the data from 2004 to 2013. The principal component analysis (PCA) model was employed to identify the main factors effecting the society, economy and environment subsystems, and SD (system dynamics) method used to carry out dynamic assessment for future state of sustainability from society, economy and environment perspective with future indicator values. Sustainable development in China was divided in the study into three phase from 2004 to 2013 based competitive values of these three subsystems. According to the results of PCA model, China is in third phase, and the economy growth is faster than the environment development, while the social development still maintained a steady and rapid growth, implying that the next step for sustainable development in China should focus on society development, especially the environment development.

  17. Gas fluxing of aluminum: a bubble probe for optimization of bubbles/bubble distribution and minimization of splashing/droplet formation

    International Nuclear Information System (INIS)

    James W. Evans; Auitumn Fjeld

    2006-01-01

    totaling 1.549 million lbs. for only thirteen of the twenty three primary smelters then in operation in the US. The research work described in the body of this report (the doctoral dissertation of Dr. Autumn M. Fjeld) had as its objective the improvement of gas fluxing technology to reduce emissions while still maintaining fluxing unit metal throughput. A second objective was a better understanding of the splashing and droplet emission that occurs during fluxing at high gas throughput rates. In the extreme such droplets can form undesired accretions on the walls and gas exit lines of the fluxing unit. Consequently, the productivity of a fluxing unit is sometimes limited by the need to avoid such spraying of droplets produced as gas bubbles break at the metal surface. The approach used was a combination of experimental work in laboratories at UC Berkeley and at the Alcoa Technical Center. The experimental work was mostly on a bubble probe that could be used to determine the extent of dispersion of gas bubbles in the fluxing unit (a parameter affecting the utilization of the injected chlorine). Additionally a high speed digital movie camera was used to study droplet formation due to gas bubbles bursting at the surface of a low melting point alloy. The experimental work was supported by mathematical modeling. In particular, two FLUENT? base mathematical models were developed to compute the metal flow and distribution of the gas within a fluxing unit. Results from these models were then used in a third model to compute emissions and the progress of impurity removal as a function of parameters such as rotor speed. The project was successful in demonstrating that the bubble probe could detect bubbles in a gas fluxing unit at the Alcoa technical Center outside Pittsburgh, PA. This unit is a commercial sized one and the probe, with its associated electronics, was subjected to the hostile molten aluminum, electrical noise etc. Despite this the probes were, on several occasions

  18. Erosion dynamics of tungsten fuzz during ELM-like heat loading

    Science.gov (United States)

    Sinclair, G.; Tripathi, J. K.; Hassanein, A.

    2018-04-01

    Transient heat loading and high-flux particle loading on plasma facing components in fusion reactors can lead to surface melting and possible erosion. Helium-induced fuzz formation is expected to exacerbate thermal excursions, due to a significant drop in thermal conductivity. The effect of heating in edge-localized modes (ELMs) on the degradation and erosion of a tungsten (W) fuzz surface was examined experimentally in the Ultra High Flux Irradiation-II facility at the Center for Materials Under Extreme Environment. W foils were first exposed to low-energy He+ ion irradiation at a fluence of 2.6 × 1024 ions m-2 and a steady-state temperature of 1223 K. Then, samples were exposed to 1000 pulses of ELM-like heat loading, at power densities between 0.38 and 1.51 GW m-2 and at a steady-state temperature of 1223 K. Comprehensive erosion analysis measured clear material loss of the fuzz nanostructure above 0.76 GW m-2 due to melting and splashing of the exposed surface. Imaging of the surface via scanning electron microscopy revealed that sufficient heating at 0.76 GW m-2 and above caused fibers to form tendrils to conglomerate and form droplets. Repetitive thermal loading on molten surfaces then led to eventual splashing. In situ erosion measurements taken using a witness plate and a quartz crystal microbalance showed an exponential increase in mass loss with energy density. Compositional analysis of the witness plates revealed an increase in the W 4f signal with increasing energy density above 0.76 GW m-2. The reduced thermal stability of the fuzz nanostructure puts current erosion predictions into question and strengthens the importance of mitigation techniques.

  19. The detection and prevention of unintentional consumption of DOx and 25x-NBOMe at Portugal's Boom Festival.

    Science.gov (United States)

    Martins, Daniel; Barratt, Monica J; Pires, Cristiana Vale; Carvalho, Helena; Vilamala, Mireia Ventura; Espinosa, Iván Fornís; Valente, Helena

    2017-05-01

    This paper describes the misrepresentation of LSD at Portugal's Boom Festival 2014 and the prevention of unintentional consumption of DOx and 25x-NBOMe among LSD consumers attending a drug-checking service. Two hundred forty-five drug samples expected to contain LSD were submitted to the drug-checking service for chemical analysis. One hundred ten post-test questionnaires were successfully matched with test results. About 67.3% of the alleged LSD samples tested contained only LSD; 0.8% contained LSD combined with adulterants; 24.1% did not contain LSD but did contain another psychoactive substance, including 11.4% that were 2,5-dimethoxyamphetamine derivatives and 9.8% that were N-benzyl-2,5-dimethoxyphenethylamine derivatives; and no psychoactive substance was detected in 7.8%. The majority of service users who received unexpected test results regarding their alleged LSD (74.2%) reported that they did not intend to consume the drug. Following dissemination of alerts on day 2, a larger than expected proportion of all tests conducted were for LSD, when comparing the 2014 festival to 2012, where no such alert was disseminated. Although these results support the provision of integrated drug-checking services in party settings, evidence of their utility and effectiveness would be improved through future research incorporating more robust measures of outcomes following provision of drug-checking results. Copyright © 2017 John Wiley & Sons, Ltd.

  20. Some aspects of floating ice related to sea surface operations in the Barents sea

    International Nuclear Information System (INIS)

    Loeset, S.

    1993-01-01

    The present work highlights some aspects of floating ice related to sea surface operations in the Barents sea. The thesis consists of eight papers which fall into two main categories; one part deals with numerical modeling of the temperature distribution and ablation of icebergs (three papers), and the other part studies the behavior of broken ice, focusing on both laboratory experiments and numerical modeling. The temperature distribution within an iceberg affects the mechanical strength of the ice and is therefore crucial in engineering applications when estimating loads from impinging icebergs on offshore structures. A numerical model which simulates the temperature distribution and ablation of icebergs has been developed. The model shows that the depth of the thermal disturbance and slope of the temperature gradient of an iceberg depend on the boundary conditions and the time at sea. By about 12 m into the ice, the temperature is virtually free of any thermal boundary influence. Oil spill response techniques are vulnerable to the presence of sea ice. Deflecting ice upstream of a spill site by means of a flexible boom will facilitate the application of conventional oil spill recovery systems such as oil skimmers and booms. Experiments with such an ice deflecting boom were conducted in an ice tank to determine the loads on the boom and to study the ice-free wake. The study indicated the technical feasibility of the ice boom concept as an operational tool for oil spill cleanups. A two-dimensional discrete element model has been developed. This model simulates the dynamics and interaction forces between distinct ice floes in a broken ice field. The numerical model was applied to estimate the loads on a boom used for ice management. 121 refs., 70 figs., 10 tabs

  1. Melt layer erosion of metallic armour targets during off-normal events in tokamaks

    International Nuclear Information System (INIS)

    Bazylev, B.; Wuerz, H.

    2002-01-01

    Melt layer erosion by melt motion is the dominating erosion mechanism for metallic armours under high heat loads. A 1-D fluid dynamics simulation model for calculation of melt motion was developed and validated against experimental results for tungsten from the e-beam facility JEBIS and beryllium from the e-beam facility JUDITH. The driving force in each case is the gradient of the surface tension. Due to the high velocity which develops in the Be melt considerable droplet splashing occurs

  2. Melt layer erosion of metallic armour targets during off-normal events in tokamaks

    Science.gov (United States)

    Bazylev, B.; Wuerz, H.

    2002-12-01

    Melt layer erosion by melt motion is the dominating erosion mechanism for metallic armours under high heat loads. A 1-D fluid dynamics simulation model for calculation of melt motion was developed and validated against experimental results for tungsten from the e-beam facility JEBIS and beryllium from the e-beam facility JUDITH. The driving force in each case is the gradient of the surface tension. Due to the high velocity which develops in the Be melt considerable droplet splashing occurs.

  3. Was Bernanke right? Targeting asset prices may not be a good idea after all

    NARCIS (Netherlands)

    Assenza, T.; Berardi, M.; Delli Gatti, D.

    2011-01-01

    Should the central bank prevent "excessive" asset price dynamics or should it wait until the boom spontaneously turns into a crash and intervene only afterwards? The debate over this issue goes back at least to the exchange between Bernanke-Gertler (BG) and Cecchetti but has not settled yet. In

  4. Advances in modeling soil erosion after disturbance on rangelands

    Science.gov (United States)

    Research has been undertaken to develop process based models that predict soil erosion rate after disturbance on rangelands. In these models soil detachment is predicted as a combination of multiple erosion processes, rain splash and thin sheet flow (splash and sheet) detachment and concentrated flo...

  5. BRAZILIAN ECONOMY’S BOOM

    Directory of Open Access Journals (Sweden)

    Gheorghe CARALICEA MĂRCULESCU

    2010-09-01

    Full Text Available Brazil owns an economy directed towards the free market and the export and nowadays it is on the 9th place in the world and on the 1sr place in frame of the countries in Latin America. Internal economy: The service sector has the biggest weight of 67.7% in PIB frame followed by the industrial one with a share of 25.8%. The agriculture represents only 6.5% of PIB. The manpower owned by Brazil is around 95 million (from a total population of about 195 million inhabitants shared as follows: 20% in agriculture, 14% in industry and 66% in service sector. Due to the scientific and technological development of Brazil, this country is very attractive for the foreign investors, the average being somewhere around 2- billion $ comparing to the average value of 2 billion $ according to the years 1990 – 2000. External economy: Lula administration used the solid increase of the global demand in the last years in order to decrease the external duty, to smooth the profile of the date of payment of the debt and to improve the interest dynamics and the currency. The massive capital influxes have led to the increase of the currency reserves at 245.8 billion $ (the equivalent of the importers’ value for more than a year. However, the current account deficit will reach about 3.5% of PIB, and even if the foreign direct investments could not cover this deficit, we do not see any problems at horizon in its financing. Fiscal sector: even if the government has managed to maintain most of the macro-economical indicators in positive values, the lack of certain tools of limiting the public expenditures was translated by a continuous increase and a damage of the report between the public debt and PIB across the last years. Actually, the gross public debt (63% of PIB in 2009 stays at a relatively big level comparing to other countries whose credit ranking is at least equal to BBB-. In addition, at a level of 10% of PIB, the financing needs of the budgetary sector

  6. Publications | Page 69 | IDRC - International Development Research ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Results 681 - 690 of 6341 ... To reduce undernutrition in India, significant reform in public policy ... Both gender and caste dynamics limit the impact of nutritional. ... Many forms of violence affect women and girls, such as physical and sexual abuse, ... Policy options deal with resources booms in Lao PDR (restricted access).

  7. The Poor Little Rich District: The Effects of Suburbanization on a Rural School and Community

    Science.gov (United States)

    Howley, Aimee; Carnes, Marilyn; Eldridge, Anita; Huber, Donna; Lado, Longun Moses; Kotler, Ruth; Turner, Maryalice

    2005-01-01

    Contextualized in relationship to other case studies about rural districts that have experienced population growth and decline as well as in relationship to the small sociological literature on "boom towns," this study considered the dynamics that seem to be interfering with one previously rural and now suburbanizing district's ability to address…

  8. Seasonal Dynamics of Haptophytes and dsDNA Algal Viruses Suggest Complex Virus-Host Relationship.

    Science.gov (United States)

    Johannessen, Torill Vik; Larsen, Aud; Bratbak, Gunnar; Pagarete, António; Edvardsen, Bente; Egge, Elianne D; Sandaa, Ruth-Anne

    2017-04-20

    Viruses influence the ecology and diversity of phytoplankton in the ocean. Most studies of phytoplankton host-virus interactions have focused on bloom-forming species like Emiliania huxleyi or Phaeocystis spp. The role of viruses infecting phytoplankton that do not form conspicuous blooms have received less attention. Here we explore the dynamics of phytoplankton and algal viruses over several sequential seasons, with a focus on the ubiquitous and diverse phytoplankton division Haptophyta, and their double-stranded DNA viruses, potentially with the capacity to infect the haptophytes. Viral and phytoplankton abundance and diversity showed recurrent seasonal changes, mainly explained by hydrographic conditions. By 454 tag-sequencing we revealed 93 unique haptophyte operational taxonomic units (OTUs), with seasonal changes in abundance. Sixty-one unique viral OTUs, representing Megaviridae and Phycodnaviridae , showed only distant relationship with currently isolated algal viruses. Haptophyte and virus community composition and diversity varied substantially throughout the year, but in an uncoordinated manner. A minority of the viral OTUs were highly abundant at specific time-points, indicating a boom-bust relationship with their host. Most of the viral OTUs were very persistent, which may represent viruses that coexist with their hosts, or able to exploit several host species.

  9. Bayesian estimation and entropy for economic dynamic stochastic models: An exploration of overconsumption

    International Nuclear Information System (INIS)

    Argentiero, Amedeo; Bovi, Maurizio; Cerqueti, Roy

    2016-01-01

    This paper examines psycho-induced overconsumption in a dynamic stochastic context. As emphasized by well-established psychological results, these psycho-distortions derive from a decision making based on simple rules-of-thumb, not on analytically sounded optimizations. To our end, we therefore compare two New Keynesian models. The first is populated by optimizing Muth-rational agents and acts as the normative benchmark. The other is a “psycho-perturbed” version of the benchmark that allows for the potential presence of overoptimism and, hence, of overconsumption. The parameters of these models are estimated through a Bayesian-type procedure, and performances are evaluated by employing an entropy measure. Such methodologies are particularly appropriate here since they take in full consideration the complexity generated by the randomness of the considered systems. In particular, they let to derive a not negligible information on the size and on the cyclical properties of the biases. In line with cognitive psychology suggestions our evidence shows that the overoptimism/overconsumption is: widespread—it is detected in nation-wide data; persistent—it emerges in full-sample estimations; it moves according to the expected cyclical behavior—larger in booms, and it disappears in crises. Moreover, by taking into account the effect of these psycho-biases, the model fits actual data better than the benchmark. All considered, then, enhancing the existing literature our findings: i) sustain the importance of inserting psychological distortions in macroeconomic models and ii) underline that system dynamics and psycho biases have statistically significant and economically important connections.

  10. Analysis of RAE-B attitude data

    Science.gov (United States)

    Hedland, D. A.; Degonia, P. K.

    1975-01-01

    Attempts made to obtain a description of the in-orbit dynamic behavior of the RAE-B spacecraft and account for the discrepancies between predicted and actual in-orbit performance are reported. In particular, attitude dynamics during the final despin operations in lunar orbit, throughout all deployment operations, and into the final steady state mission mode were investigated. Attempts made to match computer simulation results to the observed equilibrium data are discussed. Due to a damaged antenna boom and the unavailability of sufficient attitude and dynamics data, most of the objectives were not realized.

  11. The long-term behaviour of cemented research reactor waste under the geological disposal conditions of the Boom Clay Formation: results from leach experiments

    International Nuclear Information System (INIS)

    Sneyers, A.; Fays, J.; Iseghem, P. van

    2001-01-01

    The Belgian Nuclear Research Centre SCK-CEN has carried out a number of studies to evaluate the long-term behaviour of cemented research reactor waste under the geological disposal conditions of the Boom Clay Formation. Static leach experiments in synthetic clay water were performed on active samples of cemented research reactor waste. The leach experiments were carried out under anaerobic conditions at two testing temperatures (23 and 85 o C). Leach rates of seven radionuclides ( 60 Co, 90 Sr, 134 Cs, 137 Cs, 144 Ce, 154 Eu and 241 Am) were measured. Most investigated radionuclides are well retained within the cement matrix over a 280 days testing period. Results on the source term of radionuclides were complemented with data on the leaching behaviour of cement matrix constituents as Ca, Si, Al, Na, K, Mg and SO 4 as well as with data from performance assessment calculations and in situ tests. Despite limitations inherent to short-term experiments, combined results from these investigations indicate only limited interactions of disposed research reactor waste with the near field of a geological repository in clay. (author)

  12. Endogenous Price Bubbles in a Multi-Agent System of the Housing Market

    NARCIS (Netherlands)

    Kouwenberg, R.; Zwinkels, R.C.J.

    2015-01-01

    Economic history shows a large number of boom-bust cycles, with the U.S. real estate market as one of the latest examples. Classical economic models have not been able to provide a full explanation for this type of market dynamics. Therefore, we analyze home prices in the U.S. using an alternative

  13. Feasibility study of teleoperational maintenance using real-time simulator for experimental fusion reactor

    International Nuclear Information System (INIS)

    Hamada, Tomoyuki; Tanaka, Keiji; Oka, Kiyoshi; Shibanuma, Kiyoshi

    2004-01-01

    The maintenance manipulator for the experimental fusion reactor has long vertical and horizontal telescopic booms to access the neutral beam injector of the fusion reactor. Due to this boom structure, the vibration and deflection of the manipulator are the critical issues for the accurate operation. A real-time simulation system was constructed to evaluate the maneuverability of the manipulator under these vibration and deflection. In this simulation system, the dynamic behavior of the flexible manipulator is calculated synchronized with the real-time control input of the human operator. A vibration and position compensation method was adapted to improve the maneuverability. Through the evaluation using the real-time simulation system, it was verified that the manipulator is maneuverable by using vibration and position compensation. (author)

  14. Particle Trajectory and Icing Analysis of the E(sup 3) Turbofan Engine Using LEWICE3D Version 3

    Science.gov (United States)

    Bidwell, Colin S.

    2011-01-01

    Particle trajectory and ice shape calculations were made for the Energy Efficient Engine (E(sup 3)) using the LEWICE3D Version 3 software. The particle trajectory and icing computations were performed using the new "block-to-block" collection efficiency method which has been incorporated into the LEWICE3D Version 3 software. The E(sup 3) was developed by NASA and GE in the early 1980 s as a technology demonstrator and is representative of a modern high bypass turbofan engine. The E(sup 3) flow field was calculated using the NASA Glenn ADPAC turbomachinery flow solver. Computations were performed for the low pressure compressor of the E(sup 3) for a Mach 0.8 cruise condition at 11,887 m assuming a standard warm day for three drop sizes and two drop distributions typically used in aircraft design and certification. Particle trajectory computations were made for water drop sizes of 5, 20, and 100 microns. Particle trajectory and ice shape predictions were made for a 20 micron Langmuir-D distribution and for a 92 mm Super-cooled Large Droplet (SLD) distribution with and without splashing effects for a Liquid Water Content (LWC) of 0.3 g/cu m and an icing time of 30 min. The E3 fan and spinner combination proved to be an effective ice removal mechanism as they removed greater than 36 percent of the mass entering the inlet for the icing cases. The maximum free stream catch fraction for the fan and spinner combination was 0.60 while that on the elements downstream of the fan was 0.03. The non-splashing trajectory and collection efficiency results showed that as drop size increased impingement rates increased on the spinner and fan leaving less mass to impinge on downstream components. The SLD splashing case yielded more mass downstream of the fan than the SLD non-splashing case due to mass being splashed from the upstream inlet lip, spinner and fan components. The ice shapes generated downstream of the fan were either small or nonexistent due to the small available mass

  15. An experimental study of the dynamics of saltation within a three-dimensional framework

    Science.gov (United States)

    O'Brien, Patrick; McKenna Neuman, Cheryl

    2018-04-01

    Our understanding of aeolian sand transport via saltation lacks an experimental determination of the particle borne kinetic energy partitioned into 3 dimensions relative to the mean flow direction. This in turn creates a disconnect between global wind erosion estimates and particle scale processes. The present study seeks to address this deficiency through an extended analysis of data obtained from a series of particle tracking velocimetry experiments conducted in a boundary layer wind tunnel under transport limited conditions. Particle image diameter, as it appeared within each camera frame, was extensively calibrated against that obtained by sieving, and the ballistic trajectories detected were disassembled into discrete particle image pairs whose distribution and dynamics were then examined in vertical profile with sub-millimeter resolution. The vertical profile of the wind aligned particle transport rate was found to follow a power relation within 10 mm of the bed surface. The exponent of this power function changes with increasing spanwise angle (θ) to produce a family of curves representing particle diffusion in 3 dimensions. Particle mass was found to increase with θ, and the distribution of the total particle kinetic energy was found to be very similar to that for the particle concentration. The spanwise component of the kinetic energy of a saltating particle peaks at θ = 45°, with the stream-aligned component an order of magnitude higher in value. Low energy, splashed particles near the bed account for a majority of the kinetic energy distributed throughout the particle cloud, regardless of their orientation.

  16. Youth sexual behaviour in a boomtown: implications for the control of sexually transmitted infections.

    Science.gov (United States)

    Goldenberg, S; Shoveller, J; Ostry, A; Koehoorn, M

    2008-06-01

    Northeastern British Columbia, Canada, is undergoing rapid in-migration of young, primarily male, workers in response to the "boom" in the oil/gas industries. Chlamydia rates in the region exceed the provincial average by 32% (294.6 cases per 100 000 persons compared with 213.3). Evidence indicates that sociocultural and structural determinants of young people's sexual health are key to consider in the design of interventions. To investigate how sociocultural and structural features related to the oil/gas boom are perceived to affect the sexual behaviour of youth in a Northeastern "boomtown". The study included ethnographic fieldwork (8 weeks) and in-depth interviews with 25 youth (ages 15-25 years) and 14 health/social service providers. Participants identified four main ways in which the sociocultural and structural conditions created by the boom affect sexual behaviours, fuelling the spread of sexually transmitted infections (STIs): mobility of oil/gas workers; binge partying; high levels of disposable income and gendered power dynamics. The sociocultural and structural conditions that are fostered by a resource-extraction boom appear to exacerbate sexual health inequalities among youths who live and work in these rapidly urbanising, remote locales. To meet the needs of this population, we recommend STI prevention and testing service delivery models that incorporate STI testing outreach to oil/gas workers and condom distribution. Global, national and local STI control efforts should consider the realities and needs of similar subpopulations of young people.

  17. Particle transport patterns of short-distance soil erosion by wind-driven rain, rain and wind

    Science.gov (United States)

    Marzen, Miriam; Iserloh, Thomas; de Lima, João L. M. P.; Ries, Johannes B.

    2015-04-01

    Short distance erosion of soil surface material is one of the big question marks in soil erosion studies. The exact measurement of short-distance transported soil particles, prior to the occurrence of overland flow, is a challenge to soil erosion science due to the particular requirements of the experimental setup and test procedure. To approach a quantification of amount and distance of each type of transport, we applied an especially developed multiple-gutter system installed inside the Trier Portable Wind and Rainfall Simulator (PWRS). We measured the amount and travel distance of soil particles detached and transported by raindrops (splash), wind-driven rain (splash-saltation and splash-drift) and wind (saltation). The test setup included three different erosion agents (rain/ wind-driven rain/ wind), two substrates (sandy/ loamy), three surface structures (grain roughness/ rills lengthwise/ rills transversal) and three slope angles (0°/+7°/-7°). The results present detailed transport patterns of the three erosion agents under the varying soil and surface conditions up to a distance of 1.6 m. Under the applied rain intensity and wind velocity, wind-driven rain splash generates the highest erosion. The erodibility and travel distance of the two substrates depend on the erosion agent. The total erosion is slightly higher for the slope angle -7° (downslope), but for wind-driven rain splash, the inclination is not a relevant factor. The effect of surface structures (rills) changes with traveling distance. The wind driven rain splash generates a much higher amount of erosion and a further travel distance of the particles due to the combined action of wind and rain. The wind-driven rain factor appears to be much more significant than the other factors. The study highlights the effects of different erosion agents and surface parameters on short-distance particle transport and the powerful impact of wind-driven rain on soil erosion.

  18. Homelessness in Queensland mining communities: A down payment on Australia’s wealth or inevitable product of a neo-liberalist society’s response to the cyclical fortunes of mining

    Directory of Open Access Journals (Sweden)

    Shane Matthew Warren

    2015-09-01

    Full Text Available The mining boom in Australia of the first decade of the Twenty-First Century yielded prosperity for many Australians living in rural, regional and urban locations. This sense of prosperity was grounded in the widely reported experiences of people usually employed directly through the mining industry, or related industry, on high incomes, able to afford regular overseas holidays, ownership of multiple properties, material possessions and other hallmarks of an affluent lifestyle. However, less attention was given to vulnerable and homeless Australians in mining communities who did not benefit at all during the mining boom. In fact what evidence does exist indicates their disadvantage was further compounded through the high cost of housing. It is now widely accepted that the mining industry has been in a state of downturn over the last three years and this has served to highlight the social issues facing mining communities now and into the future. What is to be learnt from the decade long mining boom? Specifically this paper critiques the evidence, research literature and theories about urban-centric homelessness and assesses their relevance to homelessness in mining communities. This paper argues that the dynamics of homelessness in mining communities challenge existing homelessness theory and knowledge and argues that further evidence is needed to properly understand structural causes of homelessness in mining communities and to guide policy responses that may help prevent homelessness or otherwise assist homeless people access housing and support services. Identifying the mining boom and mining downturn cycle will be explored. Finally this paper outlines the case for further research to improve policy and planning responses to address homelessness in these communities taking into account planning requirements to address the mining boom and down turn cycle.

  19. Lifetime prediction of structures submitted to thermal fatigue loadings; Prediction de duree de vie de structures sous chargement de fatigue thermique

    Energy Technology Data Exchange (ETDEWEB)

    Amiable, S

    2006-01-15

    The aim of this work is to predict the lifetime of structures submitted to thermal fatigue loadings. This work lies within the studies undertaken by the CEA on the thermal fatigue problems from the french reactor of Civaux. In particular we study the SPLASH test: a specimen is heated continuously and cyclically cooled down by a water spray. This loading generates important temperature gradients in space and time and leads to the initiation and the propagation of a crack network. We propose a new thermo-mechanical model to simulate the SPLASH experiment and we propose a new fatigue criterion to predict the lifetime of the SPLASH specimen. We propose and compare several numerical models with various complexity to estimate the mechanical response of the SPLASH specimen. The practical implications of this work are the reevaluation of the hypothesis used in the French code RCC, which are used to simulate thermal shock and to interpret the results in terms of fatigue. This work leads to new perspectives on the mechanical interpretation of the fatigue criterion. (author)

  20. Lifetime prediction of structures submitted to thermal fatigue loadings

    International Nuclear Information System (INIS)

    Amiable, S.

    2006-01-01

    The aim of this work is to predict the lifetime of structures submitted to thermal fatigue loadings. This work lies within the studies undertaken by the CEA on the thermal fatigue problems from the french reactor of Civaux. In particular we study the SPLASH test: a specimen is heated continuously and cyclically cooled down by a water spray. This loading generates important temperature gradients in space and time and leads to the initiation and the propagation of a crack network. We propose a new thermo-mechanical model to simulate the SPLASH experiment and we propose a new fatigue criterion to predict the lifetime of the SPLASH specimen. We propose and compare several numerical models with various complexity to estimate the mechanical response of the SPLASH specimen. The practical implications of this work are the reevaluation of the hypothesis used in the French code RCC, which are used to simulate thermal shock and to interpret the results in terms of fatigue. This work leads to new perspectives on the mechanical interpretation of the fatigue criterion. (author)

  1. A shuttle and space station manipulator system for assembly, docking, maintenance, cargo handling and spacecraft retrieval (preliminary design). Volume 2: Concept development and selection

    Science.gov (United States)

    1972-01-01

    The overall program background, the various system concepts considered, and the rationale for the selected design are described. The concepts for each subsystem are also described and compared. Details are given for the requirements, boom configuration and dynamics, actuators, man/machine interface and control, visual system, control system, environmental control and life support, data processing, and materials.

  2. Magnetospheric Multiscale Mission Attitude Dynamics: Observations from Flight Data

    Science.gov (United States)

    Williams, Trevor; Shulman, Seth; Sedlak, Joseph; Ottenstein, Neil; Lounsbury, Brian

    2016-01-01

    Extensive flight data is being collected throughout the MMS mission that includes quantities that are of interest for attitude dynamics studies such as spin rate, spin axis orientation nutation rate, etc. One example of such data is the long-term evolution of the spin rates of the four spacecraft. Spikes in these rates are observed that are separated by the MMS orbital period (just under 24 hr) and occur around perigee due to gravity-gradient torque. Periodic discontinuities in spin rate are caused by the controller resetting the spin rate approximately to the nominal 3.1 RPM value at the time of each maneuver. In between, a slow decay in spin rate can be seen to occur. The paper will discuss various disturbance torque mechanisms that could potentially be responsible for this behavior: these include magnetic hysteresis, eddy currents, solar radiation pressure, and a possible interaction between gravity-gradient and wire boom flexibility effects. One additional disturbance mechanism is produced by the Active Spacecraft Potential Control (ASPOC) devices: these emit positive indium ions to keep the MMS spacecraft electrically neutral, so as not to corrupt the electric field observations that are made by some of the on-board instruments. The spin rate decays that could be produced by these various mechanisms will be quantified in the paper, and their signatures described. Comparing these with the observations from flight data then allow the most likely candidate to be determined.

  3. Opting Out and Leaning In: The Life Course Employment Profiles of Early Baby Boom Women in the United States.

    Science.gov (United States)

    García-Manglano, Javier

    2015-12-01

    Most literature on female employment focuses on the intersection between women's labor supply and family events such as marriage, divorce, or childbearing. Even when using longitudinal data and methods, most studies estimate average net effects over time and assume homogeneity among women. Less is known about diversity in women's cumulative work patterns over the long run. Using group-based trajectory analysis, I model the employment trajectories of early Baby Boom women in the United States from ages 20 to 54. I find that women in this cohort can be classified in four ideal-type groups: those who were consistently detached from the labor force (21 %), those who gradually increased their market attachment (27 %), those who worked intensely in young adulthood but dropped out of the workforce after midlife (13 %), and those who were steadily employed across midlife (40 %). I then explore a variety of traits associated with membership in each of these groups. I find that (1) the timing of family events (marriage, fertility) helps to distinguish between groups with weak or strong attachment to the labor force in early adulthood; (2) external constraints (workplace discrimination, husband's opposition to wife's work, ill health) explain membership in groups that experienced work trajectory reversals; and (3) individual preferences influence labor supply across women's life course. This analysis reveals a high degree of complexity in women's lifetime working patterns, highlighting the need to understand women's labor supply as a fluid process.

  4. DYNAMIC TRENDS OF FOREIGN DIRECT INVESTEMENTS AND MACROECONOMIC CHANGES IN CENTRAL AND EASTERN COUNTRIES DURING 2000-2010

    Directory of Open Access Journals (Sweden)

    DENISIA VINTILA

    2012-09-01

    Full Text Available For the transition economies, foreign direct investments (FDI were considered the engine of theireconomic transformation. The purpose of this article is to highlight the evolution of FDI during 2000-2010 for 7countries of Central and Eastern Europe, precisely: Poland, Hungary, Czech Republic, Slovakia, Slovenia,Romania and Bulgaria (CEE-7 and the changes in the patterns of the FDI received. There are large differencesamong these countries regarding the investments received and we tried to identity the determinants thatcontributed to this uneven distribution of FDI .We analyzed the boom of FDI registered by these countriesduring 2000-2008 and the structure and dynamics of FDI after the break out of the crisis in 2008. FDI inCentral and Eastern Europe experienced a collapse in 2009, after 8 year of impressive increase, which followeda strong economic growth. Poland was the most attractive country of the region, even during the financial crisis.Romania and Bulgaria, which experienced an impressive increase of FDI during 2004-2008, were severelyaffected by the crisis. The collapse of FDI, which coincides with the economic recession, brought also somechanges in the structure and form of the FDI received.

  5. The influence of the surrounding gas on drop impact onto a wet substrate

    Science.gov (United States)

    Deegan, Robert; Zhang, Li; Toole, Jameson

    2011-11-01

    The impact of a droplet with a wet or solid substrate creates a spray of secondary droplets. The effect of the surrounding gas on this process was widely neglected prior to the work of Xu, Zhang, & Nagel which showed that lowering the gas pressure suppresses splashing for impact with a dry solid substrate. Here we present the results of our experimental investigation of the effect of the surrounding gas on the evolution of splashes from a wet substrate. We varied the density and pressure of the surrounding gas. We find quantitative changes to the onset thresholds of splashing and on the size distribution of, but no qualitative changes. The effects are most pronounced on the evolution of the ejecta sheet.

  6. Engineering parameter determination from the radio astronomy explorer /RAE I/ satellite attitude data

    Science.gov (United States)

    Lawlor, E. A.; Davis, R. M.; Blanchard, D. L.

    1974-01-01

    An RAE-I satellite description is given, taking into account a dynamics experiment and the attitude sensing system. A computer program for analyzing flexible spacecraft attitude motions is considered, giving attention to the geometry of rod deformation. The characteristics of observed attitude data are discussed along with an analysis of the main boom root angle, the bending rigidity, and the damper plane angle.

  7. Dynamic Network Model for Smart City Data-Loss Resilience Case Study: City-to-City Network for Crime Analytics.

    Science.gov (United States)

    Kotevska, Olivera; Kusne, A Gilad; Samarov, Daniel V; Lbath, Ahmed; Battou, Abdella

    2017-01-01

    Today's cities generate tremendous amounts of data, thanks to a boom in affordable smart devices and sensors. The resulting big data creates opportunities to develop diverse sets of context-aware services and systems, ensuring smart city services are optimized to the dynamic city environment. Critical resources in these smart cities will be more rapidly deployed to regions in need, and those regions predicted to have an imminent or prospective need. For example, crime data analytics may be used to optimize the distribution of police, medical, and emergency services. However, as smart city services become dependent on data, they also become susceptible to disruptions in data streams, such as data loss due to signal quality reduction or due to power loss during data collection. This paper presents a dynamic network model for improving service resilience to data loss. The network model identifies statistically significant shared temporal trends across multivariate spatiotemporal data streams and utilizes these trends to improve data prediction performance in the case of data loss. Dynamics also allow the system to respond to changes in the data streams such as the loss or addition of new information flows. The network model is demonstrated by city-based crime rates reported in Montgomery County, MD, USA. A resilient network is developed utilizing shared temporal trends between cities to provide improved crime rate prediction and robustness to data loss, compared with the use of single city-based auto-regression. A maximum improvement in performance of 7.8% for Silver Spring is found and an average improvement of 5.6% among cities with high crime rates. The model also correctly identifies all the optimal network connections, according to prediction error minimization. City-to-city distance is designated as a predictor of shared temporal trends in crime and weather is shown to be a strong predictor of crime in Montgomery County.

  8. Dynamic Network Model for Smart City Data-Loss Resilience Case Study: City-to-City Network for Crime Analytics

    Science.gov (United States)

    Kotevska, Olivera; Kusne, A. Gilad; Samarov, Daniel V.; Lbath, Ahmed; Battou, Abdella

    2017-01-01

    Today’s cities generate tremendous amounts of data, thanks to a boom in affordable smart devices and sensors. The resulting big data creates opportunities to develop diverse sets of context-aware services and systems, ensuring smart city services are optimized to the dynamic city environment. Critical resources in these smart cities will be more rapidly deployed to regions in need, and those regions predicted to have an imminent or prospective need. For example, crime data analytics may be used to optimize the distribution of police, medical, and emergency services. However, as smart city services become dependent on data, they also become susceptible to disruptions in data streams, such as data loss due to signal quality reduction or due to power loss during data collection. This paper presents a dynamic network model for improving service resilience to data loss. The network model identifies statistically significant shared temporal trends across multivariate spatiotemporal data streams and utilizes these trends to improve data prediction performance in the case of data loss. Dynamics also allow the system to respond to changes in the data streams such as the loss or addition of new information flows. The network model is demonstrated by city-based crime rates reported in Montgomery County, MD, USA. A resilient network is developed utilizing shared temporal trends between cities to provide improved crime rate prediction and robustness to data loss, compared with the use of single city-based auto-regression. A maximum improvement in performance of 7.8% for Silver Spring is found and an average improvement of 5.6% among cities with high crime rates. The model also correctly identifies all the optimal network connections, according to prediction error minimization. City-to-city distance is designated as a predictor of shared temporal trends in crime and weather is shown to be a strong predictor of crime in Montgomery County. PMID:29250476

  9. Increased anthropogenic pressure on land resources has led to the ...

    African Journals Online (AJOL)

    Iorkua

    GLOBAL JOURNAL OF PURE AND APPLIED SCIENCES VOL. ... the splash yield shows that splash from bare surface is(46.48kg/m2/yr) more than that from the four mulch .... placed by the sides of the 5 soil trays using 1.27cm flat ... 2 laterals, 1 each of downslope and upslope) (See plate 1) ... A 4cm thick layer of coarse (8-.

  10. Crisis intervention related to the use of psychoactive substances in recreational settings--evaluating the Kosmicare Project at Boom Festival.

    Science.gov (United States)

    Carvalho, Maria Carmo; de Sousa, Mariana Pinto; Frango, Paula; Dias, Pedro; Carvalho, Joana; Rodrigues, Marta; Rodrigues, Tania

    2014-01-01

    Kosmicare project implements crisis intervention in situations related to the use of psychoactive substances at Boom Festival (Portugal). We present evaluation research that aims to contribute to the transformation of the project into an evidence-based intervention model. It relies on harm reduction and risk minimization principles, crisis intervention models, and Grof's psychedelic psychotherapy approach for crisis intervention in situations related to unsupervised use of psychedelics. Intervention was expected to produce knowledge about the relation between substance use and mental health impact in reducing potential risk related to the use of psychoactive substances and mental illness, as well as an impact upon target population's views of themselves, their relationship to substance use, and to life events in general. Research includes data on process and outcome indicators through a mixed methods approach, collected next to a sample of n=176 participants. Sample size varied considerably, however, among different research measures. 52% of Kosmicare visitors reported LSD use. Over 40% also presented multiple drug use. Pre-post mental state evaluation showed statistically significant difference (p<.05) confirming crisis resolution. Crisis episodes that presented no resolution were more often related with mental health outburst episodes, with psychoactive substance use or not. Visitors showed high satisfaction with intervention (n=58) and according to follow-up (n=18) this perception was stable over time. Crisis intervention was experienced as very significant. We discuss limitations and implications of evaluating natural setting based interventions, and the relation between psychoactive substance use and psychopathology. Other data on visitor's profile and vulnerability to crisis showed inconclusive.

  11. Endogenous Price Bubbles in a Multi-Agent System of the Housing Market.

    Science.gov (United States)

    Kouwenberg, Roy; Zwinkels, Remco C J

    2015-01-01

    Economic history shows a large number of boom-bust cycles, with the U.S. real estate market as one of the latest examples. Classical economic models have not been able to provide a full explanation for this type of market dynamics. Therefore, we analyze home prices in the U.S. using an alternative approach, a multi-agent complex system. Instead of the classical assumptions of agent rationality and market efficiency, agents in the model are heterogeneous, adaptive, and boundedly rational. We estimate the multi-agent system with historical house prices for the U.S. market. The model fits the data well and a deterministic version of the model can endogenously produce boom-and-bust cycles on the basis of the estimated coefficients. This implies that trading between agents themselves can create major price swings in absence of fundamental news.

  12. Endogenous Price Bubbles in a Multi-Agent System of the Housing Market.

    Directory of Open Access Journals (Sweden)

    Roy Kouwenberg

    Full Text Available Economic history shows a large number of boom-bust cycles, with the U.S. real estate market as one of the latest examples. Classical economic models have not been able to provide a full explanation for this type of market dynamics. Therefore, we analyze home prices in the U.S. using an alternative approach, a multi-agent complex system. Instead of the classical assumptions of agent rationality and market efficiency, agents in the model are heterogeneous, adaptive, and boundedly rational. We estimate the multi-agent system with historical house prices for the U.S. market. The model fits the data well and a deterministic version of the model can endogenously produce boom-and-bust cycles on the basis of the estimated coefficients. This implies that trading between agents themselves can create major price swings in absence of fundamental news.

  13. Endogenous Price Bubbles in a Multi-Agent System of the Housing Market

    Science.gov (United States)

    2015-01-01

    Economic history shows a large number of boom-bust cycles, with the U.S. real estate market as one of the latest examples. Classical economic models have not been able to provide a full explanation for this type of market dynamics. Therefore, we analyze home prices in the U.S. using an alternative approach, a multi-agent complex system. Instead of the classical assumptions of agent rationality and market efficiency, agents in the model are heterogeneous, adaptive, and boundedly rational. We estimate the multi-agent system with historical house prices for the U.S. market. The model fits the data well and a deterministic version of the model can endogenously produce boom-and-bust cycles on the basis of the estimated coefficients. This implies that trading between agents themselves can create major price swings in absence of fundamental news. PMID:26107740

  14. The asymmetric relationship between oil revenues and economic activities: The case of oil-exporting countries

    International Nuclear Information System (INIS)

    Mehrara, Mohsen

    2008-01-01

    This paper examines the nonlinear or asymmetric relationship between oil revenues and output growth in oil-exporting countries, applying a dynamic panel framework and two different measures of oil shocks. The main results in this paper confirm the stylized facts that in heavily oil-dependent countries lacking the institutional mechanisms de-linking fiscal expenditure from current revenue, oil revenue shocks tend to affect the output in asymmetric and nonlinear ways. The findings suggest that output growth is adversely affected by the negative oil shocks, while oil booms or the positive oil shocks play a limited role in stimulating economic growth. The findings have practical policy implications for decision makers in the area of macroeconomic planning. The use of stabilization and savings funds and diversification of the real sector seems crucial to minimize the harmful effects of oil booms and busts

  15. Curvature singularity and film-skating during drop impact

    Science.gov (United States)

    Duchemin, Laurent; Josserand, Christophe

    2011-09-01

    We study the influence of the surrounding gas in the dynamics of drop impact on a smooth surface. We use an axisymmetric model for which both the gas and the liquid are incompressible; lubrication regime applies for the gas film dynamics and the liquid viscosity is neglected. In the absence of surface tension a finite time singularity whose properties are analysed is formed and the liquid touches the solid on a circle. When surface tension is taken into account, a thin jet emerges from the zone of impact, skating above a thin gas layer. The thickness of the air film underneath this jet is always smaller than the mean free path in the gas suggesting that the liquid film eventually wets the surface. We finally suggest an aerodynamical instability mechanism for the splash.

  16. Does replacing coal with wood lower CO2 emissions? Dynamic lifecycle analysis of wood bioenergy

    Science.gov (United States)

    Sterman, John D.; Siegel, Lori; Rooney-Varga, Juliette N.

    2018-01-01

    Bioenergy is booming as nations seek to cut their greenhouse gas emissions. The European Union declared biofuels to be carbon-neutral, triggering a surge in wood use. But do biofuels actually reduce emissions? A molecule of CO2 emitted today has the same impact on radiative forcing whether it comes from coal or biomass. Biofuels can only reduce atmospheric CO2 over time through post-harvest increases in net primary production (NPP). The climate impact of biofuels therefore depends on CO2 emissions from combustion of biofuels versus fossil fuels, the fate of the harvested land and dynamics of NPP. Here we develop a model for dynamic bioenergy lifecycle analysis. The model tracks carbon stocks and fluxes among the atmosphere, biomass, and soils, is extensible to multiple land types and regions, and runs in ≈1s, enabling rapid, interactive policy design and sensitivity testing. We simulate substitution of wood for coal in power generation, estimating the parameters governing NPP and other fluxes using data for forests in the eastern US and using published estimates for supply chain emissions. Because combustion and processing efficiencies for wood are less than coal, the immediate impact of substituting wood for coal is an increase in atmospheric CO2 relative to coal. The payback time for this carbon debt ranges from 44-104 years after clearcut, depending on forest type—assuming the land remains forest. Surprisingly, replanting hardwood forests with fast-growing pine plantations raises the CO2 impact of wood because the equilibrium carbon density of plantations is lower than natural forests. Further, projected growth in wood harvest for bioenergy would increase atmospheric CO2 for at least a century because new carbon debt continuously exceeds NPP. Assuming biofuels are carbon neutral may worsen irreversible impacts of climate change before benefits accrue. Instead, explicit dynamic models should be used to assess the climate impacts of biofuels.

  17. Two-Dimensional Physical and CFD Modelling of Large Gas Bubble Behaviour in Bath Smelting Furnaces

    Directory of Open Access Journals (Sweden)

    Yuhua Pan

    2010-09-01

    Full Text Available The behaviour of large gas bubbles in a liquid bath and the mechanisms of splash generation due to gas bubble rupture in high-intensity bath smelting furnaces were investigated by means of physical and mathematical (CFD modelling techniques. In the physical modelling work, a two-dimensional Perspex model of the pilot plant furnace at CSIRO Process Science and Engineering was established in the laboratory. An aqueous glycerol solution was used to simulate liquid slag. Air was injected via a submerged lance into the liquid bath and the bubble behaviour and the resultant splashing phenomena were observed and recorded with a high-speed video camera. In the mathematical modelling work, a two-dimensional CFD model was developed to simulate the free surface flows due to motion and deformation of large gas bubbles in the liquid bath and rupture of the bubbles at the bath free surface. It was concluded from these modelling investigations that the splashes generated in high-intensity bath smelting furnaces are mainly caused by the rupture of fast rising large gas bubbles. The acceleration of the bubbles into the preceding bubbles and the rupture of the coalescent bubbles at the bath surface contribute significantly to splash generation.

  18. Drop Impact on a Solid Surface

    KAUST Repository

    Josserand, C.

    2015-09-22

    © Copyright 2016 by Annual Reviews. All rights reserved. A drop hitting a solid surface can deposit, bounce, or splash. Splashing arises from the breakup of a fine liquid sheet that is ejected radially along the substrate. Bouncing and deposition depend crucially on the wetting properties of the substrate. In this review, we focus on recent experimental and theoretical studies, which aim at unraveling the underlying physics, characterized by the delicate interplay of not only liquid inertia, viscosity, and surface tension, but also the surrounding gas. The gas cushions the initial contact; it is entrapped in a central microbubble on the substrate; and it promotes the so-called corona splash, by lifting the lamella away from the solid. Particular attention is paid to the influence of surface roughness, natural or engineered to enhance repellency, relevant in many applications.

  19. A dynamic simulation model for assessing the overall impact of incentive policies on power system reliability, costs and environment

    International Nuclear Information System (INIS)

    Ibanez-Lopez, A.S.; Martinez-Val, J.M.; Moratilla-Soria, B.Y.

    2017-01-01

    The liberalization of power markets has entailed dramatic changes in power system planning worldwide. The inception of new alternative technologies, smart grids and distributed generation and storage is expected to make system planning even more challenging. Government policies still play a major role in the evolution of a country's power generation mix, even in those countries with liberalized markets. This paper presents a System Dynamics model aimed at assessing the overall technical, economic and environmental impact of renewable energy incentives and capacity payment policies. The model has been used to simulate Spain's power industry in order to assess the impact of electric power policies with the goal of getting insights regarding how to achieve an optimum power generation mix. The main conclusions of the present paper are (i) the necessity of specific regulatory actions in Spain in order to keep adequate reliability levels, avoid price spikes and boom and bust investment cycles as well as to deploy specific technologies, (ii) the fact that capacity payments are a better instrument for keeping adequate reserve margins and avoiding power price spikes than renewable energy incentives and (iii) the evidence that both instruments entail additional system costs over the base case scenario. - Highlights: • A System Dynamics model of Spain's power generation mix is proposed. • The overall policy impact on system costs, environment and reliability is assessed. • Current policies are not enough to keep adequate reliability levels. • Capacity payments are an adequate instrument for guaranteeing system reliability. • RES incentives do not solve reliability issues and entail greater system costs.

  20. ARTICLES: Thermohydrodynamic models of the interaction of pulse-periodic radiation with matter

    Science.gov (United States)

    Arutyunyan, R. V.; Baranov, V. Yu; Bol'shov, Leonid A.; Malyuta, D. D.; Mezhevov, V. S.; Pis'mennyĭ, V. D.

    1987-02-01

    Experimental and theoretical investigations were made of the processes of drilling and deep melting of metals by pulsed and pulse-periodic laser radiation. Direct photography of the surface revealed molten metal splashing due to interaction with single CO2 laser pulses. A proposed thermohydrodynamic model was used to account for the experimental results and to calculate the optimal parameters of pulse-periodic radiation needed for deep melting. The melt splashing processes were simulated numerically.

  1. ROTARY SPRAY DUSTER

    Directory of Open Access Journals (Sweden)

    E. S. Nechaeva

    2013-01-01

    Full Text Available Results of researches of hydraulic resistance, ablation of splashes and efficiency of dedusting in the rotor spray dust collector are given. Influence of frequency of rotation of the spray, the specified speed of gas and diameter of spattering holes on hydraulic resistance, size ablation of splashes and efficiency of a dedusting the device by diameter 0,25 m is investigated. As model liquid water is used. Results of mathematical processing are presented.

  2. Coupling environmental, social and economic models to understand land-use change dynamics in the Mekong Delta

    Directory of Open Access Journals (Sweden)

    Alexis eDrogoul

    2016-03-01

    Full Text Available The Vietnamese Mekong Delta has undergone in recent years a considerable transformation in agricultural land-use, fueled by a boom of the exportation, an increase of population, a focus on intensive crops, but also environmental factors like sea level rise or the progression of soil salinity. These transformations have been, however, largely misestimated by the ten-year agricultural plans designed at the provincial levels, on the predictions of which, though, most of the large-scale investments (irrigation infrastructures, protection against flooding or salinity intrusion, and so on are normally planned. This situation raises the question of how to explain the divergence between the predictions used as a basis for these plans and the actual situation. Answering it could, as a matter of fact, offer some insights on the dynamics at play and hopefully allow designing them more accurately.The dynamics of land-use change at a scale of a region results from the interactions between heterogeneous actors and factors at different scales, among them institutional policies, individual farming choices, land-cover and environmental changes, economic conditions, social dynamics, just to name a few. Understanding its evolution, for example, in this case, to better support agricultural planning, therefore requires the use of models that can represent the individual contributions of each actor or factor, and of course their interactions.We address this question through the design of an integrated hybrid model of land-use change in a specific and carefully chosen case study, which relies on the central hypothesis that the main force driving land-use change is actually the individual choices made by farmers at their local level. Farmers are the actors who decide (or not to switch from one culture to another and the shifts observed at more global levels (village, district, province, region are considered, in this model, as a consequence of the aggregation of these

  3. Analysis of load monitoring system in hydraulic mobile cranes

    Science.gov (United States)

    Kalairassan, G.; Boopathi, M.; Mohan, Rijo Mathew

    2017-11-01

    Load moment limiters or safe load control systems or are very important in crane safety. The system detects the moment of lifting load and compares this actual moment with the rated moment. The system uses multiple sensors such as boom angle sensor, boom length sensor for telescopic booms, pressure transducers for measuring the load, anti-two block switch and roller switches. The system works both on rubber and on outriggers. The sensors measure the boom extension, boom angle and load to give as inputs to the central processing, which calculate the safe working load range for that particular configuration of the crane and compare it with the predetermined safe load. If the load exceeds the safe load, actions will be taken which will reduce the load moment, which is boom telescopic retraction and boom lifting. Anti-two block switch is used to prevent the two blocking condition. The system is calibrated and load tested for at most precision.

  4. Institutional dynamics and barriers in wind energy development. A case study of Tamil Nadu and Andhra Pradesh, India

    Energy Technology Data Exchange (ETDEWEB)

    Jagadeesh, Anumakonda

    1999-09-01

    In India, there was a boom in 1995-96 when 282 MW windfarms were set up in Tamil Nadu and the capacity in Andhra Pradesh increased by 39 MW. Then there was a steady decline in the windfarm development in both states. The case study described in this report attempts to trace the reasons for the boom and the factors that have contributed to the slump in windfarm development in these two states. The role of institutions in determining the effectiveness of national and regional public sector initiatives to promote and disseminate wind energy in the two states is discussed. The study also examines the financial, technical, transaction and institutional barriers, which inhibit the diffusion of wind energy in the states. It is suggested that important measures must be taken if wind energy is to develop rapidly in the two states. The result of the case study may be used to improve public policy intervention in disseminating wind energy in India. It may also be relevant to multilateral and bilateral aid agencies in their projects and/or programmes to promote cost-effective wind energy technology dissemination in developing countries. 25 refs., 6 tabs.

  5. Drop Impact on to Moving Liquid Pools

    Science.gov (United States)

    Muñoz-Sánchez, Beatriz Natividad; Castrejón-Pita, José Rafael; Castrejón-Pita, Alfonso Arturo; Hutchings, Ian M.

    2014-11-01

    The deposition of droplets on to moving liquid substrates is an omnipresent situation both in nature and industry. A diverse spectrum of phenomena emerges from this simple process. In this work we present a parametric experimental study that discerns the dynamics of the impact in terms of the physical properties of the fluid and the relative velocity between the impacting drop and the moving liquid pool. The behaviour ranges from smooth coalescence (characterized by little mixing) to violent splashing (generation of multiple satellite droplets and interfacial vorticity). In addition, transitional regimes such as bouncing and surfing are also found. We classify the system dynamics and show a parametric diagram for the conditions of each regime. This work was supported by the EPSRC (Grant EP/H018913/1), the Royal Society, Becas Santander Universidades and the International Relationships Office of the University of Extremadura.

  6. Ultra-wideband pose detection system for boom-type roadheader based on Caffery transform and Taylor series expansion

    Science.gov (United States)

    Fu, Shichen; Li, Yiming; Zhang, Minjun; Zong, Kai; Cheng, Long; Wu, Miao

    2018-01-01

    To realize unmanned pose detection of a coalmine boom-type roadheader, an ultra-wideband (UWB) pose detection system (UPDS) for a roadheader is designed, which consists of four UWB positioning base stations and three roadheader positioning nodes. The positioning base stations are used in turn to locate the positioning nodes of the roadheader fuselage. Using 12 sets of distance measurement information, a time-of-arrival (TOA) positioning model is established to calculate the 3D coordinates of three positioning nodes of the roadheader fuselage, and the three attitude angles (heading, pitch, and roll angles) of the roadheader fuselage are solved. A range accuracy experiment of a UWB P440 module was carried out in a narrow and closed tunnel, and the experiment data show that the mean error and standard deviation of the module can reach below 2 cm. Based on the TOA positioning model of the UPDS, we propose a fusion-positioning algorithm based on a Caffery transform and Taylor series expansion (CTFPA). We derived the complete calculation process, designed a flowchart, and carried out a simulation of CTFPA in MATLAB, comparing 1000 simulated positioning nodes of CTFPA and the Caffery positioning algorithm (CPA) for a 95 m long tunnel. The positioning error field of the tunnel was established, and the influence of the spatial variation on the positioning accuracy of CPA and CTFPA was analysed. The simulation results show that, compared with CPA, the positioning accuracy of CTFPA is clearly improved, and the accuracy of each axis can reach more than 5 mm. The accuracy of the X-axis is higher than that of the Y- and Z-axes. In section X-Y of the tunnel, the root mean square error (RMSE) contours of CTFPA are clear and orderly, and with an increase in the measuring distance, RMSE increases linearly. In section X-Z, the RMSE contours are concentric circles, and the variation ratio is nonlinear.

  7. Assessment of the Performance of Several Roadway Mixes under Rain, Snow, and Winter Maintenance Activities

    OpenAIRE

    Flintsch, Gerardo W.

    2004-01-01

    The purpose of this study was to assess the relative functional performance, including skid resistance and splash and spray, of five hot-mix-asphalt (HMA) surfaces and a tinned portland cement concrete highway surface during controlled wet and wintry weather events. The study compared the way that these surfaces respond to various deicing and anti-icing snow removal and ice control techniques under artificial wintry conditions. In addition, the splash and spray characteristics of the surfaces...

  8. Bonds Boom.

    Science.gov (United States)

    Reynolds, Cathryn

    1989-01-01

    The combined effect of the "Serrano" decision and Proposition 13 left California school districts with aging, overcrowded facilities. Chico schools won a $18.5 million general obligation bond election for facilities construction. With $11 billion needed for new school construction, California will need to tap local sources. A sidebar…

  9. A study of the influence of air-knife tilting on coating thickness in hot-dip galvanizing

    Science.gov (United States)

    Cho, Tae-Seok; Kwon, Young-Doo; Kwon, Soon-Bum

    2009-09-01

    Gas wiping is a decisive operation in hot-dip galvanizing process. In special, it has a crucial influence on the thickness and uniformity in coating film, but may be subsequently responsible for the problem of splashing. The progress of industry demands continuously the reduction of production costs which may relate directly with the increase of coating speed, and the speed up of coating results in the increase of stagnation pressure in gas wiping system in final. It is known that the increase of stagnation pressure may accompany a harmful problem of splashing in general. Together with these, also, from the view point of energy consumption, it is necessary to design a nozzle optimally. And there is known that the downward tilting of nozzle using in air knife system is effective to prevent in somewhat the harmful problem of splashing. In these connections, first, we design a nozzle with constant expansion rate. Next, for the case of actual coating conditions in field, the effects of tilting of the constant expansion rate nozzle are investigated by numerical analysis. Under the present numerical conditions, it was turned out that the nozzle of constant expansion rate of p = having a downward jet angle of 5° is the most effective to diminish the onset of splashing, while the influence of small tilting of the nozzle on impinging wall pressure itself is not so large.

  10. The effect of slope steepness and antecedent moisture content on interrill erosion, runoff and sediment size distribution in the highlands of Ethiopia

    Directory of Open Access Journals (Sweden)

    M. B. Defersha

    2011-07-01

    Full Text Available Soil erosion is a two-phase process consisting of the detachment of individual particles and their transport by the flowing water. This study discusses the results of laboratory experiments in which for three soils, the runoff depth, sediment yield, splash erosion and sediment size were measured. Rainfall intensity, slope and antecedent moisture contents were varied in the experiment. The soil types ranged from clay to sandy clay loam (Alemaya Black soil, Regosols and Cambisols. Rainfall was applied for six sequential 15-min periods with rainfall intensities varying between 55 and 120 mm h−1. The three slopes tested were 9, 25, and 45 %. Results show that as slope increased from 9 to 25 %, splash erosion and sediment yield increased. An increase in slope from 25 to 45 % generally decreases in splash erosion. Sediment yield for one soil increased and one soil decreased with slope and for the third soil the trend was different between the two initial moisture contents. Sediment yield was correlated (r = 0.66 with runoff amounts but not with splash erosion. Interrill erosion models that were based on the flowing water and rainfall intensity fitted the data better than when based on rainfall intensity solely. Models that assume a positive linear relationship between erosion and slope may overestimate sediment yield.

  11. Time trends of polybrominated diphenyl ethers in East China Seas: Response to the booming of PBDE pollution industry in China.

    Science.gov (United States)

    Li, Yuanyuan; Lin, Tian; Hu, Limin; Feng, Jialiang; Guo, Zhigang

    2016-01-01

    The East China Seas (ECSs) are the receptors of the land-based persistent organic pollutants (POPs), such as polybrominated diphenyl ethers (PBDEs) mainly from China through atmospheric deposition driven by the East Asian winter monsoon and fluvial discharge (e.g., Yangtze River and Yellow River), making the offshore sediments to be a good proxy to reconstruct history of those pollutants in China. In this work, four well-placed sediment cores were extracted from the mud areas in the ECSs, and the (210)Pb-dated cores were analyzed to yield historical concentration profiles of PBDEs in the area. The results showed that there was a persistent increase from 1970s and almost no clear sign in the decline of PBDEs until recently in China. More importantly, there was a faster increase of PBDEs from 1990s in China; while this period was just shown as gradually leveling off or even declining trends in developed countries. The persistently increasing trend of PBDEs in China since 1990s could be largely due to the booming of the manufacturing industry and unexpectedly transfer of PBDE pollution from developed countries to China. Besides, the relative high concentrations and fluxes of PBDEs in the core from coastal ECS located near a well-known electrical/electronic waste (e-waste) recycling area suggests an important contribution of PBDE emissions from recycling centers of e-waste in China. Although efforts in environmental monitoring of PBDE contamination have been substantially increased over the last decade, China is still lagging behind in terms of nationwide regulation of PBDE usage and treatment of disposal PBDE-containing products. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Entity-Based Landscape Modelling to Assess the Impacts of Different Incentives Mechanisms on Argan Forest Dynamics

    Directory of Open Access Journals (Sweden)

    Farid El Wahidi

    2015-11-01

    Full Text Available Illegal occupation of argan forest parcels by local households is a new phenomenon in South West Morocco. This is primarily due to the weakening of traditional common control systems and to the boom of the argan oil price. The scope of this work is to develop a decision support system based on dynamic spatial modelling, allowing to anticipate the land tenure dynamics and their impact on forest stand degradation under different policy scenarios. The model simulates the change of land possession by locals and the forest stand degradation levels. The methodological approach combines a Markov chain analysis (MCA with stakeholders’ preferences for land tenure. First, parcels’ transition probabilities are computed using the MCA. Second, the acquiring suitability map is derived from multi-criteria evaluation procedure (AHP using biophysical and socio-economic data. Finally, uncertainty is introduced in the simulation based on probabilistic analysis for supporting socio-economic diversity and non-mechanistic human behavior. The modelling approach was successfully used to compare three scenarios: business as usual (continuation of illegal acquiring, total disengagement of the population and private/public partnership with incentives for restoring argan parcel. The model yields geographic information about (i the magnitude of the on-going process; (ii the potential occurrence of land use conflicts induced by new policies; and (iii the location of land conservation or degradation hot-spots. The outcomes of the “business as usual” and of the “total disengagement” models were similar over a 30-year simulation period: in both cases, the proportion of “highly degraded” parcels was doubled and the number of “quite degraded” parcels was increased by 50%. On the other hand, should the private/public partnership effectively work, about 40% of the parcels could be restored to a sustainable level.

  13. Fluxgate Magnetometry on the Experimental Albertan Satellite #1 (Ex-Alta-1) CubeSat Mission: Steps Toward a Magnetospheric Constellation Mission

    Science.gov (United States)

    Mann, I. R.; Miles, D.; Nokes, C.; Cupido, C.; Elliott, D.; Ciurzynski, M.; Barona, D.; Narod, B. B.; Bennest, J.; Pakhotin, I.; Kale, A.; Bruner, B.; Haluza-DeLay, T.; Forsyth, C.; Rae, J.; Lange, C.; Sameoto, D.; Milling, D. K.

    2017-12-01

    Making low noise magnetic measurements is a significant challenge to the use of cube-satellite (CubeSat) platforms for scientific constellation class missions for studies of geospace. We describe the design, validation, and test, and initial on-orbit results from a miniature, low-mass, low-power, and low-magnetic noise boom-mounted fluxgate magnetometer flown on the University of Alberta Experimental Albertan Satellite #1 (Ex-Alta-1) Cube Satellite, launched in 2017 from the International Space Station as part of the QB50 constellation mission. The miniature instrument achieves a magnetic noise floor of 150-200 pT/√Hz at 1 Hz, consumes 400 mW of power, has a mass of 121 g (sensor and boom), stows on the hull, and deploys on a 60 cm boom from a three-unit CubeSat reducing the noise from the onboard reaction wheel to less than 1.5 nT at the sensor. The instrument's capabilities are being demonstrated and validated in space with flight on Ex-Alta-1. We present on-orbit data from the boom-deployment and initial operations of the fluxgate sensor and illustrate the potential scientific returns and utility of using CubeSats carrying such fluxgate magnetometers to constitute a magnetospheric constellation mission. We further illustrate the value of scientific constellations using example data from the low-Earth orbit European Space Agency Swarm mission. Swarm data reveal significant changes in the spatiotemporal characteristics of the magnetic fields in the coupled magnetosphere-ionosphere system, even when the spacecraft are separated by only approximately 10 s along track and approximately 1.4° in longitude. This indicates the likely energetic significance of Alfven wave dynamics, and we use Swarm measurements to illustrate the value of satellite constellations for diagnosing magnetosphere-ionosphere coupling even in low-Earth orbit.

  14. SHOCK AND VIBRATION COMPUTER PROGRAMS. REVIEWS AND SUMMARIES

    Science.gov (United States)

    1975-01-01

    earth at all times. It is also possible that the orientation of certain parts of the spacecraft (such as solar panels) must remain fixed in an inertial... solar pressure, temperature gradients, aero- dynamic drag, and magnetic torques. Internal forces due to dampers, thrusters, snd momentum wheels are...on the spin axis. 4. For gravity-gradient stsbllized spacscraft, a llbration diaper can be simulated constating of a long dampar boom that can rotate

  15. Reintroducción de algodón nativo (Gossypium Barbadense) en la costa norte del Perú: Análisis de factibilidad económica para pequeños productores

    OpenAIRE

    Pisani, Elena; Masiero, Mauro; Scrocco, Stefano

    2015-01-01

    In Peru the agro-export boom has determined a major shift of large farmers from traditional agro-industrial crops (coffee and cotton) to new agribusinesses (asparagus, oranges, avocados, apples). These dynamics have left room for the small farmers to enter the traditional agro-industrial sector, or into new niche markets as in the case of native cotton. On the North coast of Peru the cultivation of the native and naturally coloured cotton (Gos...

  16. Portable instrument for acquisition and processing data from radiometric experiments performed in the field industrial conditions

    International Nuclear Information System (INIS)

    Urbanski, P; Mirowicz, J.; Owczarczyk, A.; Pienkos, E.; Swistowski, E.; Machaj, B.

    2004-01-01

    To facilitate radiotracer investigations in field or industrial environment a battery operated FIR-1 Field Industrial Radiometer has been developed. The radiometer is equipped with 4 splash-proof NaI(Tl) operating in counting mode, 4 water-proof GM probes, 1 splash-proof spectrometric scintillation probe NaI(Tl) Φ50 x 50 mm equipped with 256 channel analyser. The detectors are connected to controller by means of 4 water-proof connecting cables 100 m long, or 4 splash-proof connecting cables 100 m long. Pulses originating from gamma radiation are periodically counted and stored in non-volatile memory. The measured count rate against time is displayed on graphic display. Radiation spectra measured with spectrometric probe are also stored in the memory and are displayed on graphic display. Total count number in selected range of energy of the spectrum can be computed. Stored in memory measuring data are transmitted to an external computer employing serial port RS232. (author)

  17. Pressão de aplicação com pulverizador de barra e eficiência de bioinseticidas fúngicos comerciais Application pressure in boom sprayer and efficiency of commercial fungal bioinsecticides

    Directory of Open Access Journals (Sweden)

    Cesar de Oliveira Guimarães

    2004-12-01

    Full Text Available Bioinseticidas fúngicos são aplicados com pulverizadores convencionais e algumas características destes equipamentos podem não ser adequadas e afetar a eficiência dos bioinseticidas. O objetivo deste trabalho foi verificar se pressões usuais, em aplicações com o pulverizador de barra, podem afetar a ação inseticida de conídios de Beauveria bassiana e Metarhizium anisopliae, componentes de produtos comerciais brasileiros. Para isso, suspensões aquosas de três bioinseticidas foram submetidas à passagem pelo equipamento em três pressões (20, 40 e 60 lbf pol-2 e avaliadas quanto ao rompimento, à viabilidade e à virulência dos conídios. Avaliou-se a viabilidade em lâminas de microscopia cobertas com meio de cultura, após incubação a 26±0,5ºC e fotoperíodo de 12 horas. A concentração foi determinada por meio de contagens em câmara de Neubauer e a virulência foi avaliada para lagartas de Diatraea saccharalis. Não foram encontradas, nos três produtos, influências significativas em nenhum dos parâmetros. Nas pressões avaliadas, a aplicação com o pulverizador de barra não reduz a viabilidade e nem a virulência dos conídios dos bioinseticidas testados, tampouco provoca destruição dos conídios.Fungal biopesticides are applied with conventional sprayers and this equipment may be inappropriate, and therefore affect field control efficacy of biopesticides. The objective of this research was to find out if the usual pressures used in the boom sprayers can affect the conidia pesticide activity of the Brazilian commercial entomopathogenic fungi Beauveria bassiana and Metarhizium anisopliae. Water fungi suspensions were passed through the equipment under three pressures (20, 40 and 60 psi and evaluated for viability, virulence and conidia disruption. The viability was evaluated in slides covered by culture media after incubation at 26±0.5ºC and 12 hours photophase. The concentration was determined through Neubauer

  18. Model Deformation Measurements of Sonic Boom Models in the NASA Ames 9- by 7-Ft Supersonic Wind Tunnel

    Science.gov (United States)

    Schairer, Edward T.; Kushner, Laura K.; Garbeff, Theodore J.; Heineck, James T.

    2015-01-01

    The deformations of two sonic-boom models were measured by stereo photogrammetry during tests in the 9- by 7-Ft Supersonic Wind Tunnel at NASA Ames Research Center. The models were geometrically similar but one was 2.75 times as large as the other. Deformation measurements were made by simultaneously imaging the upper surfaces of the models from two directions by calibrated cameras that were mounted behind windows of the test section. Bending and twist were measured at discrete points using conventional circular targets that had been marked along the leading and trailing edges of the wings and tails. In addition, continuous distributions of bending and twist were measured from ink speckles that had been applied to the upper surfaces of the model. Measurements were made at wind-on (M = 1.6) and wind-off conditions over a range of angles of attack between 2.5 deg. and 5.0 deg. At each condition, model deformation was determined by comparing the wind-off and wind-on coordinates of each measurement point after transforming the coordinates to reference coordinates tied to the model. The necessary transformations were determined by measuring the positions of a set of targets on the rigid center-body of the models whose model-axes coordinates were known. Smoothly varying bending and twist measurements were obtained at all conditions. Bending displacements increased in proportion to the square of the distance to the centerline. Maximum deflection of the wingtip of the larger model was about 5 mm (2% of the semispan) and that of the smaller model was 0.9 mm (1% of the semispan). The change in wing twist due to bending increased in direct proportion to distance from the centerline and reached a (absolute) maximum of about -1? at the highest angle of attack for both models. The measurements easily resolved bending displacements as small as 0.05 mm and bending-induced changes in twist as small as 0.05 deg.

  19. Investigation of the Flow in Pelton Turbines and the Influence of the Casing

    OpenAIRE

    Heinz-Bernd Matthias; Josef Prost; Christian Rossegger

    1997-01-01

    At the institute for waterpower and pumps at the University of Technology Vienna we do a lot of research work observing the flow in the casing and the buckets of Pelton turbines. One interest of our research is to find criteria to estimate the influence of the splash water distribution in the casing on the turbine efficiency. Knowing the splash water distribution it is further possible to develop methods to provide visual documentation of the flow in and around the buckets from the beginning ...

  20. Resource price turbulence and macroeconomic adjustment for a resource exporter. A conceptual framework for policy analysis

    International Nuclear Information System (INIS)

    Cox, Grant M.; Harvie, Charles

    2010-01-01

    Increased global demand for energy and other resources, particularly from the rapidly developing economies of China and India and the opening up of global resource markets to global investors and speculative activity, has resulted in considerable recent turbulence in resource prices. The recent magnitude of change in resource prices, both positive and negative, and their macroeconomic implications is of considerable contemporary importance to both resource importing and exporting economies. For a resource exporting economy, such as that of Australia, the recent resource price boom has resulted in: increased government taxation revenue, increased employment and wages in the resource and resource related sectors, increased spending in the domestic economy that contributed to buoyant economic growth, increased resource exports to the booming economies of China and India and contributed to a stronger domestic currency with beneficial effects upon inflation. On the other hand these developments have had adverse effects on the non-resource sector by: subjecting it to more intense competition for limited resources, contributing to a loss of international competitiveness and reduced exports arising from a stronger exchange rate, reducing employment in the relatively more labour intensive non-resource sector, and contributing to an eventual slow down in the overall economy. These positive and negative effects, and the overall impact of a resource price boom, require a fundamentally closer analysis of the structure of the economy under scrutiny. In this context the policy response by government is likely to be pivotal in determining the overall macroeconomic outcomes from a resource price boom. The aim of this paper is to develop a generic analytical framework to appraise economic outcomes in the wake of a resource price boom for a resource producing and exporting economy. To this end a dynamic long run macroeconomic model is developed, emphasising the important role and

  1. Temperature-Driven Shape Changes of the Near Earth Asteroid Scout Solar Sail

    Science.gov (United States)

    Stohlman, Olive R.; Loper, Erik R.; Lockett, Tiffany E.

    2017-01-01

    Near Earth Asteroid Scout (NEA Scout) is a NASA deep space Cubesat, scheduled to launch on the Exploration Mission 1 flight of the Space Launch System. NEA Scout will use a deployable solar sail as its primary propulsion system. The sail is a square membrane supported by rigid metallic tapespring booms, and analysis predicts that these booms will experience substantial thermal warping if they are exposed to direct sunlight in the space environment. NASA has conducted sunspot chamber experiments to confirm the thermal distortion of this class of booms, demonstrating tip displacement of between 20 and 50 centimeters in a 4-meter boom. The distortion behavior of the boom is complex and demonstrates an application for advanced thermal-structural analysis. The needs of the NEA Scout project were supported by changing the solar sail design to keep the booms shaded during use of the solar sail, and an additional experiment in the sunspot chamber is presented in support of this solution.

  2. HYLIFE-II reactor chamber mechanical design

    International Nuclear Information System (INIS)

    House, P.A.

    1992-01-01

    Mechanical design features of the reactor chamber for the HYLIFE-11 inertial confinement fusion power plant are presented. A combination of oscillating and steady, molten salt streams are used for shielding and blast protection. The system is designed for an 8 Hz repetition rate. Beam path clearing, between shots, is accomplished with the oscillating flow. The mechanism for generating the oscillating streams is described. A design configuration of the vessel wall allows adequate cooling and provides extra shielding to reduce thermal stresses to tolerable levels. The bottom portion of the reactor chamber is designed to minimize splash back of the high velocity (20 m/s) salt streams and also recover up to half of the dynamic head

  3. Interactions between the Real Economy and the Stock Market: A Simple Agent-Based Approach

    Directory of Open Access Journals (Sweden)

    Frank Westerhoff

    2012-01-01

    Full Text Available We develop a simple behavioral macromodel to study interactions between the real economy and the stock market. The real economy is represented by a Keynesian-type goods market approach while the setup for the stock market includes heterogeneous speculators. Using a mixture of analytical and numerical tools we find, for instance, that speculators may create endogenous boom-bust dynamics in the stock market which, by spilling over into the real economy, can cause lasting fluctuations in economic activity. However, fluctuations in economic activity may, by shaping the firms' fundamental values, also have an impact on the dynamics of the stock market.

  4. Automatic limit switch system for scintillation device and method of operation

    International Nuclear Information System (INIS)

    Brunnett, C.J.; Ioannou, B.N.

    1976-01-01

    A scintillation scanner is described having an automatic limit switch system for setting the limits of travel of the radiation detection device which is carried by a scanning boom. The automatic limit switch system incorporates position responsive circuitry for developing a signal representative of the position of the boom, reference signal circuitry for developing a signal representative of a selected limit of travel of the boom, and comparator circuitry for comparng these signals in order to control the operation of a boom drive and indexing mechanism. (author)

  5. A graphics based remote handling control system

    International Nuclear Information System (INIS)

    Leinemann, K.

    1984-08-01

    A control and simulation system with an interactive graphic man-machine interface is proposed for the articulated boom in JET. The system shall support 1. the study of boom movements in the planning phase, 2. the training of operators by appropriate simulations, 3. the programming of boom movements, and 4. the on-line control of the boom. A combination of computer graphic display and TV-images is proposed for providing optimum recognition of the actual situation and for echoing to the operator actions. (orig.) [de

  6. Needlestick and other potential blood and body fluid exposures among health care workers in British Columbia, Canada.

    Science.gov (United States)

    Alamgir, Hasanat; Cvitkovich, Yuri; Astrakianakis, George; Yu, Shicheng; Yassi, Annalee

    2008-02-01

    Health care workers have high risk of exposure to human blood and body fluids (BBF) from patients in acute care and residents in nursing homes or personal homes. This analysis examined the epidemiology for BBF exposure across health care settings (acute care, nursing homes, and community care). Detailed analysis of BBF exposure among the health care workforce in 3 British Columbian health regions was conducted by Poisson regression modeling, with generalized estimating equations to determine the relative risk associated with various occupations. Acute care had the majority of needlestick, sharps, and splash events with the BBF exposure rate in acute care 2 to 3 times higher compared with nursing home and community care settings. Registered nurses had the highest frequency of needlestick, sharps, and splash events. Laboratory assistants had the highest exposure rates from needlestick injuries and splashes, whereas licensed practical nurses had the highest exposure rate from sharps. Most needlestick injuries (51.3%) occurred at the patient's bedside. Sharps incidents occurred primarily in operating rooms (26.9%) and at the patient's bedside (20.9%). Splashes occurred most frequently at the patient's bedside (46.1%) and predominantly affected the eyes or face/mouth. The majority of needlestick/sharps injuries occurred during use for registered nurses, during disposal for licensed practical nurses, and after disposal for care aides. The high risk of BBF exposure for some occupations indicates there is room for improvement to reduce BBF exposure by targeting high-risk groups for prevention strategies.

  7. Financial Innovation, the Discovery of Risk, and the U.S. Credit Crisis

    OpenAIRE

    Enrique G. Mendoza; Emine Boz

    2010-01-01

    Financial innovation and overconfidence about asset values and the riskiness of new financial products were important factors behind the U.S. credit crisis. We show that a boom-bust cycle in debt, asset prices and consumption characterizes the equilibrium dynamics of a model with a collateral constraint in which agents learn \\by observation" the true riskiness of a new financial environment. Early realizations of states with high ability to leverage assets into debt turn agents overly optimis...

  8. Macroprudential policies in an agent-based artificial economy

    OpenAIRE

    Raberto, Marco; Teglio, Andrea; Cincotti, Silvano

    2012-01-01

    Basel III is a recently-agreed regulatory standard for bank capital adequacy with focus on the macroprudential dimension of banking regulation, i.e., the system- wide implications of banks’ lending and risk. An important Basel III provision is to reduce procyclicality of present banking regulation and promote countercyclical capital buffers for banks. The Eurace agent-based macroeconomic model and sim- ulator has been recently showed to be able to reproduce a credit-fueled boom-bust dynamics ...

  9. Possibilities for the development of rural tourism in the Republic of Macedonia

    OpenAIRE

    Koteski, Cane; Majhosev, Darko; Jakovlev, Zlatko

    2017-01-01

    Abstract: Rural tourism as part of the overall tourist offer in Macedonia is currently booming. Almost every tourist offer of all the travel agencies contains, among other things, visiting interesting rural tourist areas. This kind of tourism is an important alternative form of tourism that offers a higher level of meeting modern man’s needs that urban lifestyle is not able to satisfy. The dynamic and stressful life in urban areas contributes to people seeking peace...

  10. European Scientific Notes. Volume 34, Number 3,

    Science.gov (United States)

    1980-03-31

    34big established from the density gradient , boom" contest. While there is undoubtedly so mixing of air and methane begins on some value to these big...dynamic mechanical chopped-fiber materials which are find- properties of solids and much of his work ing applicattion in automobiles, housing, is on...medical re- a geologist from Australia, an instru- search but results from a social or ment maker from West Germany, a math - political bias prevalent at

  11. On the impact of a concave nosed axisymmetric body on a free surface

    OpenAIRE

    Mathai, Varghese; Govardhan, Raghuraman N.; Arakeri, Vijay H.

    2017-01-01

    We report on an experimental study of the vertical impact of a concave nosed axisymmetric body on a free surface. Previous studies have shown that bodies with a convex nose, like a sphere, produce a well defined splash with a relatively large cavity behind the model. In contrast, we find that with a concave nose, there is hardly a splash and the cavity extent is greatly reduced. This may be explained by the fact that in the concave nosed case, the initial impact is between a confined air pock...

  12. Complex Dynamics in Nonequilibrium Economics and Chemistry

    Science.gov (United States)

    Wen, Kehong

    Complex dynamics provides a new approach in dealing with economic complexity. We study interactively the empirical and theoretical aspects of business cycles. The way of exploring complexity is similar to that in the study of an oscillatory chemical system (BZ system)--a model for modeling complex behavior. We contribute in simulating qualitatively the complex periodic patterns observed from the controlled BZ experiments to narrow the gap between modeling and experiment. The gap between theory and reality is much wider in economics, which involves studies of human expectations and decisions, the essential difference from natural sciences. Our empirical and theoretical studies make substantial progress in closing this gap. With the help from the new development in nonequilibrium physics, i.e., the complex spectral theory, we advance our technique in detecting characteristic time scales from empirical economic data. We obtain correlation resonances, which give oscillating modes with decays for correlation decomposition, from different time series including S&P 500, M2, crude oil spot prices, and GNP. The time scales found are strikingly compatible with business experiences and other studies in business cycles. They reveal the non-Markovian nature of coherent markets. The resonances enhance the evidence of economic chaos obtained by using other tests. The evolving multi-humped distributions produced by the moving-time -window technique reveal the nonequilibrium nature of economic behavior. They reproduce the American economic history of booms and busts. The studies seem to provide a way out of the debate on chaos versus noise and unify the cyclical and stochastic approaches in explaining business fluctuations. Based on these findings and new expectation formulation, we construct a business cycle model which gives qualitatively compatible patterns to those found empirically. The soft-bouncing oscillator model provides a better alternative than the harmonic oscillator

  13. Crusader Automated Docking System: Technology support for the Crusader Resupply Team. Interim report, Ammunition Logistics Program

    Energy Technology Data Exchange (ETDEWEB)

    Kring, C.T.; Varma, V.K.; Jatko, W.B.

    1995-11-01

    The US Army and Team Crusader (United Defense, Lockheed Martin Armament Systems, etc.) are developing the next generation howitzer, the Crusader. The development program includes an advanced, self-propelled liquid propellant howitzer and a companion resupply vehicle. The resupply vehicle is intended to rendezvous with the howitzer near the battlefront and replenish ammunition, fuel, and other material. The Army has recommended that Crusader incorporate new and innovative technologies to improve performance and safety. One conceptual design proposes a robotic resupply boom on the resupply vehicle to upload supplies to the howitzer. The resupply boom would normally be retracted inside the resupply vehicle during transit. When the two vehicles are within range of the resupply boom, the boom would be extended to a receiving port on the howitzer. In order to reduce exposure to small arms fire or nuclear, biological, and chemical hazards, the crew would remain inside the resupply vehicle during the resupply operation. The process of extending the boom and linking with the receiving port is called docking. A boom operator would be designated to maneuver the boom into contact with the receiving port using a mechanical joystick. The docking operation depends greatly upon the skill of the boom operator to manipulate the boom into docking position. Computer simulations at the National Aeronautics and Space Administration have shown that computer-assisted or autonomous docking can improve the ability of the operator to dock safely and quickly. This document describes the present status of the Crusader Autonomous Docking System (CADS) implemented at Oak Ridge National laboratory (ORNL). The purpose of the CADS project is to determine the feasibility and performance limitations of vision systems to satisfy the autonomous docking requirements for Crusader and conduct a demonstration under controlled conditions.

  14. Field evaluation of a self-propelled sprayer and effects of the application rate on spray deposition and losses to the ground in greenhouse tomato crops.

    Science.gov (United States)

    Sánchez-Hermosilla, Julián; Rincón, Víctor J; Páez, Francisco; Agüera, Francisco; Carvajal, Fernando

    2011-08-01

    In the greenhouses of south-eastern Spain, plant protection products are applied using mainly sprayers at high pressures and high volumes. This results in major losses on the ground and less than uniform spray deposition on the canopy. Recently, self-propelled vehicles equipped with vertical spray booms have appeared on the market. In this study, deposition on the canopy and the losses to the ground at different spray volumes have been compared, using a self-propelled vehicle with vertical spray booms versus a gun sprayer. Three different spray volumes have been tested with a boom sprayer, and two with a spray gun. The vehicle with the vertical spray boom gave similar depositions to those made with the gun, but at lower application volumes. Also, the distribution of the vertical spray boom was more uniform, with lower losses to the ground. The vertical spray booms used in tomato crops improve the application of plant protection products with respect to the spray gun, reducing the application volumes and the environmental risks of soil pollution. Copyright © 2011 Society of Chemical Industry.

  15. Model of the saltation transport by Discrete Element Method coupled with wind interaction

    Directory of Open Access Journals (Sweden)

    Oger Luc

    2017-01-01

    Full Text Available We study the Aeolian saltation transport problem by analysing the collision of incident energetic beads with granular packing. We investigate the collision process for the case where the incident bead and those from the packing have identical mechanical properties. We analyse the features of the consecutive collision process. We used a molecular dynamics method known as DEM (soft Discrete Element Method with 20000 particles (2D. The grains were displayed randomly in a box (250X60. A few incident disks are launched with a constant velocity and angle with high random position to initiate the flow. A wind velocity profile is applied on the flowing zone of the saltation. The velocity profile is obtained by the calculi of the counter-flow due to the local packing fraction induced by the granular flow. We analyse the evolution of the upper surface of the disk packing. In the beginning, the saltation process can be seen as the classical “splash function” in which one bead hits a fully static dense packing. Then, the quasi-fluidized upper layer of the packing creates a completely different behaviour of the “animated splash function”. The dilation of the upper surface due to the previous collisions is responsible for a need of less input energy for launching new ejected disks. This phenomenon permits to maintain a constant granular flow with a “small” wind velocity on the surface of the disk bed.

  16. Evaluation of a depth proportional intake device for automatic pumping samplers

    Science.gov (United States)

    Rand E. Eads; Robert B. Thomas

    1983-01-01

    Abstract - A depth proportional intake boom for portable pumping samplers was used to collect suspended sediment samples in two coastal streams for three winters. The boom pivots on the stream bed while a float on the downstream end allows debris to depress the boom and pass without becoming trapped. This equipment modifies point sampling by maintaining the intake...

  17. Discrete dynamics versus analytic dynamics

    DEFF Research Database (Denmark)

    Toxværd, Søren

    2014-01-01

    For discrete classical Molecular dynamics obtained by the “Verlet” algorithm (VA) with the time increment h there exists a shadow Hamiltonian H˜ with energy E˜(h) , for which the discrete particle positions lie on the analytic trajectories for H˜ . Here, we proof that there, independent...... of such an analytic analogy, exists an exact hidden energy invariance E * for VA dynamics. The fact that the discrete VA dynamics has the same invariances as Newtonian dynamics raises the question, which of the formulations that are correct, or alternatively, the most appropriate formulation of classical dynamics....... In this context the relation between the discrete VA dynamics and the (general) discrete dynamics investigated by Lee [Phys. Lett. B122, 217 (1983)] is presented and discussed....

  18. Dynamics of investor spanning trees around dot-com bubble.

    Directory of Open Access Journals (Sweden)

    Sindhuja Ranganathan

    Full Text Available We identify temporal investor networks for Nokia stock by constructing networks from correlations between investor-specific net-volumes and analyze changes in the networks around dot-com bubble. The analysis is conducted separately for households, financial, and non-financial institutions. Our results indicate that spanning tree measures for households reflected the boom and crisis: the maximum spanning tree measures had a clear upward tendency in the bull markets when the bubble was building up, and, even more importantly, the minimum spanning tree measures pre-reacted the burst of the bubble. At the same time, we find less clear reactions in the minimal and maximal spanning trees of non-financial and financial institutions around the bubble, which suggests that household investors can have a greater herding tendency around bubbles.

  19. Dynamics of investor spanning trees around dot-com bubble.

    Science.gov (United States)

    Ranganathan, Sindhuja; Kivelä, Mikko; Kanniainen, Juho

    2018-01-01

    We identify temporal investor networks for Nokia stock by constructing networks from correlations between investor-specific net-volumes and analyze changes in the networks around dot-com bubble. The analysis is conducted separately for households, financial, and non-financial institutions. Our results indicate that spanning tree measures for households reflected the boom and crisis: the maximum spanning tree measures had a clear upward tendency in the bull markets when the bubble was building up, and, even more importantly, the minimum spanning tree measures pre-reacted the burst of the bubble. At the same time, we find less clear reactions in the minimal and maximal spanning trees of non-financial and financial institutions around the bubble, which suggests that household investors can have a greater herding tendency around bubbles.

  20. Influence mechanism of low-dose ionizing radiation on Escherichia coli DH5α population based on plasma theory and system dynamics simulation

    International Nuclear Information System (INIS)

    Sun, Yi; Hu, Dawei; Li, Liang; Jing, Zheng; Wei, Chuanfeng; Zhang, Lantao; Fu, Yuming

    2016-01-01

    It remains a mystery why the growth rate of bacteria is higher in low-dose ionizing radiation (LDIR) environment than that in normal environment. In this study, a hypothesis composed of environmental selection and competitive exclusion was firstly proposed from observed phenomena, experimental data and microbial ecology. Then a LDIR environment simulator (LDIRES) was built to cultivate a model organism of bacteria, Escherichia coli (E. coli) DH5α, the accurate response of bacterial population to ionizing radiation intensity variation was measured experimentally, and then the precise relative dosage of ionizing radiation E. coli DH5α population received was calculated by finite element analysis based on drift-diffusion equations of plasma. Finally, a highly valid mathematical model expressing the relationship between E. coli DH5α population and LDIR intensity was developed by system dynamics based on hypotheses, experimental data and microbial ecology. Both experiment and simulation results clearly showed that the E. coli DH5α individuals with greater specific growth rate and lower substrate consumption coefficient would adapt and survive in LDIR environment and those without such adaptability were finally eliminated under the combined effects of ionizing radiation selection and competitive exclusion. - Highlights: • Establishment of a low-dose ionizing radiation (LDIR) environment simulator. • Escherichiacoli DH5α was selected as a bacterial representative for investigation. • Precise LDIR intensity for E. coli DH5α was calculated by FEA and plasma theory. • Development of system dynamics model of LDIR influence on E. coli DH5α population. • Mechanism of bacterial boom in LDIR environment was elucidated by computer simulation.

  1. Oil spillage recovery by vacuum trawl

    International Nuclear Information System (INIS)

    Birkett, H.

    1992-01-01

    In this invention, floating oil is sucked from the surface of the sea under a skirt and into a tubular floating boom, along whose interior it is carried to water-oil separation means. The suction is produced by one or more ejectors which are supplied with sea water under pressure and may be located inside the boom, or immediately below it and connected into a separate pipe. The boom is used to enclose an oil slick and drawn tighter to increase the thickness of the oil layer. The oil enters the boom through holes in its upper half and then flows to the ejector(s) along separate internal tubes or between buoyancy balls. A fraction of the oil-water mixture withdrawn from the boom is pressurised and returned to ejector(s) and the rest is diverted to the separation means. (author)

  2. NET in-vessel vehicle system

    International Nuclear Information System (INIS)

    Jones, H.

    1991-02-01

    The CFFTP/Spar In-vessel Vehicle System concept for in-vessel remote maintenance of the NET/ITER machine is described. It comprises a curved deployable boom, a vehicle which can travel on the boom and an end effector or work unit mounted on the vehicle. The stowed boom, vehicle, and work unit are inserted via the equatorial access port of the torus. Following insertion the boom is deployed and locked in place. The vehicle may then travel along the boom to transport the work unit to any desired location. A novel feature of the concept is the deployable boom. When fully deployed, it closely resembles a conventional curved truss structure in configuration and characteristics. However, the joints of the truss structure are hinged so that it can fold into a compact package, of less than 20% of deployed volume for storage, transportation and insertion into the torus. A full-scale 2-metre long section of this boom was produced for demonstration purposes. As part of the concept definition the work unit for divertor handling was studied to demonstrate that large payloads could be manipulated within the confines of the torus using the in-vessel vehicle system. Principal advantages of the IVVS are its high load capacity and rigidity, low weight and stowed volume, simplicity of control and operation, and its relatively high speed of transportation

  3. Dynamic behavior of plasma-facing materials during plasma instabilities in tokamak reactors

    International Nuclear Information System (INIS)

    Hassanein, A.; Konkashbaev, I.

    1997-01-01

    Damage to plasma-facing and nearby components due to plasma instabilities remains a major obstacle to a successful tokamak concept. The high energy deposited on facing materials during plasma instabilities can cause severe erosion, plasma contamination, and structural failure of these components. Erosion damage can take various forms such as surface vaporization, spallation, and liquid ejection of metallic materials. Comprehensive thermodynamic and radiation hydrodynamic codes have been developed, integrated, and used to evaluate the extent of various damage to plasma-facing and nearby components. The eroded and splashed materials will be transported and then redeposited elsewhere on other plasma-facing components. Detailed physics of plasma/solid-liquid/vapor interaction in a strong magnetic field have been developed, optimized, and implemented in a self-consistent model. The plasma energy deposited in the evolving divertor debris is quickly and intensely reradiated, which may cause severe erosion and melting of other nearby components. Factors that influence and reduce vapor-shielding efficiency such as vapor diffusion and turbulence are also discussed and evaluated

  4. Advanced Concept Studies for Supersonic Commercial Transports Entering Service in the 2018-2020 Period Phase 2

    Science.gov (United States)

    Morgenstern, John; Buonanno, Michael; Yao, Jixian; Murugappan, Mugam; Paliath, Umesh; Cheung, Lawrence; Malcevic, Ivan; Ramakrishnan, Kishore; Pastouchenko, Nikolai; Wood, Trevor; hide

    2015-01-01

    significant fidelity to the design of the configuration in this phase by performing a low speed wind tunnel test at our LTWT facility in Palmdale, by more complete modelling of propulsion effects in our sonic boom analysis, and by refining our configuration packaging and performance assessments. Working with General Electric, LM performed an assessment of the impact of inlet and nozzle effects on the sonic boom signature of the LM N+2 configurations. Our results indicate that inlet/exhaust streamtube boundary conditions are adequate for conceptual design studies, but realistic propulsion modeling at similar stream-tube conditions does have a small but measurable impact on the sonic boom signature. Previous supersonic transport studies have identified aeroelastic effects as one of the major challenges associated with the long, slender vehicles particularly common with shaped boom aircraft (Ref. 3). Under the Phase 2 effort, we have developed a detailed structural analysis model to evaluate the impact of flexibility and structural considerations on the feasibility of future quiet supersonic transports. We looked in particular at dynamic structural modes and flutter as a failure that must be avoided. We found that for our N+2 design in particular, adequate flutter margin existed. Our flutter margin is large enough to cover uncertainties like large increases in engine weight and the margin is relatively easy to increase with additional stiffening mass. The lack of major aeroelastic problems probably derives somewhat from an early design bias. While shaped boom aircraft require long length, they are not required to be thin. We intentionally developed our structural depths to avoid major flexibility problems. So at the end of Phase 2, we have validated that aeroelastic problems are not necessarily endemic to shaped boom designs. Experimental validation of sonic boom design and analysis techniques was the primary objective of the N+2 Supersonic Validations contract; and in this

  5. Effect of spray application technique on spray deposition in greenhouse strawberries and tomatoes.

    Science.gov (United States)

    Braekman, Pascal; Foque, Dieter; Messens, Winy; Van Labeke, Marie-Christine; Pieters, Jan G; Nuyttens, David

    2010-02-01

    Increasingly, Flemish greenhouse growers are using spray booms instead of spray guns to apply plant protection products. Although the advantages of spray booms are well known, growers still have many questions concerning nozzle choice and settings. Spray deposition using a vertical spray boom in tomatoes and strawberries was compared with reference spray equipment. Five different settings of nozzle type, size and pressure were tested with the spray boom. In general, the standard vertical spray boom performed better than the reference spray equipment in strawberries (spray gun) and in tomatoes (air-assisted sprayer). Nozzle type and settings significantly affected spray deposition and crop penetration. Highest overall deposits in strawberries were achieved using air-inclusion or extended-range nozzles. In tomatoes, the extended-range nozzles and the twin air-inclusion nozzles performed best. Using smaller-size extended-range nozzles above the recommended pressure range resulted in lower deposits, especially inside the crop canopy. The use of a vertical spray boom is a promising technique for applying plant protection products in a safe and efficient way in tomatoes and strawberries, and nozzle choice and setting should be carefully considered.

  6. The quinoa boom of the southern Bolivian Altiplano - linking geomorphology, erosion and spatial production patterns

    Science.gov (United States)

    Sander, Lasse; Jacobsen, Sven-Erik

    2014-05-01

    . While agricultural exploitation prior to 2003 was mainly restricted to quaternary alluvial deposit, the post-2003 expansion entered the flat shoreface topography of late Pleistocene Lake Tauca (18-14 ka BP; Placzek et al 2006) and hence a domain of increased soil salinity. These recent developments pretty well illustrate southern Bolivia's "quinoa boom": an escalating, land-intensive production on marginal soils, characterized by high erosion rates and a dissipative resource use. Given the arid conditions and the resulting low resilience of the landscape, the current trends are likely to trigger widespread land degradation, jeopardizing future livelihood opportunities. References Placzek C, Quade J, Patchett, PJ 2006. Geochronology and stratigraphy of late Pleistocene lake cycles on the southern Bolivian Altiplano: Implications for causes of tropical climate change. GSA Bulletin 118, 515-532. Jacobsen, S-E 2011. The situation for quinoa and its production in Southern Bolivia: From economic success to environmental disaster. J. Agronomy & Crop Science 197, 390-399.

  7. KC-135 Cockpit Modernization Study. Phase 1 Equipment Evaluation

    Science.gov (United States)

    1994-07-01

    No comment Boom 6: No. No comment Piot 7: Y...s. Compared INS #1 & INS #2 then verified with a TACAN fix that #1 had drifted. Copilot 7: Yes. INS - Yes, RADAR - No. Boom 7: No. No comment . Pilot 8...No. No comment . Copilot 8: No. No comment . Boom 8: No. No comment . 3. The drifting of the INS system/radar fluctuations caused (a) increase

  8. The microprocessor boom

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    The applications of microprocessors in high energy physics experiments are discussed. Many benefits are predicted for data acquisition and handling systems and for control and monitoring functions. (W.D.L.).

  9. Boom. Bust. Build.

    Science.gov (United States)

    Kite, Vance; Park, Soonhye

    2018-01-01

    In 2006 Jeanette Wing, a professor of computer science at Carnegie Mellon University, proposed computational thinking (CT) as a literacy just as important as reading, writing, and mathematics. Wing defined CT as a set of skills and strategies computer scientists use to solve complex, computational problems (Wing 2006). The computer science and…

  10. Biking Is Booming

    Science.gov (United States)

    Truesdell, William H.; Wicks, Carol A.

    1978-01-01

    One hundred thousand bicycle-motor vehicle accidents will occur this year. Close to 1,100 of the mishaps will result in death. Education is the first, last and best hope for cyclists and motorists alike and one facet of bike safety programs is teaching students to understand a machine they may take for granted. Here are some ideas for starters.…

  11. A computational fluid dynamics modeling study of guide walls for downstream fish passage

    Science.gov (United States)

    Mulligan, Kevin; Towler, Brett; Haro, Alexander J.; Ahlfeld, David P.

    2017-01-01

    A partial-depth, impermeable guidance structure (or guide wall) for downstream fish passage is typically constructed as a series of panels attached to a floating boom and anchored across a water body (e.g. river channel, reservoir, or power canal). The downstream terminus of the wall is generally located nearby to a fish bypass structure. If guidance is successful, the fish will avoid entrainment in a dangerous intake structure (i.e. turbine intakes) while passing from the headpond to the tailwater of a hydroelectric facility through a safer passage route (i.e. the bypass). The goal of this study is to determine the combination of guide wall design parameters that will most likely increase the chance of surface-oriented fish being successfully guided to the bypass. To evaluate the flow field immediately upstream of a guide wall, a parameterized computational fluid dynamics model of an idealized power canal was constructed in © ANSYS Fluent v 14.5 (ANSYS Inc., 2012). The design parameters investigated were the angle and depth of the guide wall and the average approach velocity in the power canal. Results call attention to the importance of the downward to sweeping flow ratio and demonstrate how a change in guide wall depth and angle can affect this important hydraulic cue to out-migrating fish. The key findings indicate that a guide wall set at a small angle (15° is the minimum in this study) and deep enough such that sweeping flow dominant conditions prevail within the expected vertical distribution of fish approaching the structure will produce hydraulic conditions that are more likely to result in effective passage.

  12. A miniature, low-power scientific fluxgate magnetometer: A stepping-stone to cube-satellite constellation missions

    Science.gov (United States)

    Miles, D. M.; Mann, I. R.; Ciurzynski, M.; Barona, D.; Narod, B. B.; Bennest, J. R.; Pakhotin, I. P.; Kale, A.; Bruner, B.; Nokes, C. D. A.; Cupido, C.; Haluza-DeLay, T.; Elliott, D. G.; Milling, D. K.

    2016-12-01

    Difficulty in making low noise magnetic measurements is a significant challenge to the use of cube-satellite (CubeSat) platforms for scientific constellation class missions to study the magnetosphere. Sufficient resolution is required to resolve three-dimensional spatiotemporal structures of the magnetic field variations accompanying both waves and current systems of the nonuniform plasmas controlling dynamic magnetosphere-ionosphere coupling. This paper describes the design, validation, and test of a flight-ready, miniature, low-mass, low-power, and low-magnetic noise boom-mounted fluxgate magnetometer for CubeSat applications. The miniature instrument achieves a magnetic noise floor of 150-200 pT/√Hz at 1 Hz, consumes 400 mW of power, has a mass of 121 g (sensor and boom), stows on the hull, and deploys on a 60 cm boom from a three-unit CubeSat reducing the noise from the onboard reaction wheel to less than 1.5 nT at the sensor. The instrument's capabilities will be demonstrated and validated in space in late 2016 following the launch of the University of Alberta Ex-Alta 1 CubeSat, part of the QB50 constellation mission. We illustrate the potential scientific returns and utility of using a CubeSats carrying such fluxgate magnetometers to constitute a magnetospheric constellation using example data from the low-Earth orbit European Space Agency Swarm mission. Swarm data reveal significant changes in the spatiotemporal characteristics of the magnetic fields in the coupled magnetosphere-ionosphere system, even when the spacecraft are separated by only approximately 10 s along track and approximately 1.4° in longitude.

  13. BUDAYA DALAM LINTASAN SEJARAH: BOOMING NONTON BIOSKOP DI PADANG TEMPO DULU

    Directory of Open Access Journals (Sweden)

    Meri Erawati

    2015-07-01

    Full Text Available This article discusses the existence of cinema as entertainment for the people in Padang during the period 1970s to 2000s. Cinema is a mass entertainment and can be enjoyed by all the community at that time. Cinema became a phenomenal because the movies have become part of people's lifestyles. Cinema furor enlivened by promotions to attract people to come to the cinema through flyers, posters, banners and advertisements in the mass media. The development of technology led to the existence of cinema began to be replaced by the presence of new entertainment media such as television and media screenings of other films such as VCD players so that the film is no longer only be enjoyed in the cinema. Cinema audience popularity and dynamics as well as aspects related to cinema in 1970 this will be discussed within this article.

  14. Advanced Deployable Structural Systems for Small Satellites

    Science.gov (United States)

    Belvin, W. Keith; Straubel, Marco; Wilkie, W. Keats; Zander, Martin E.; Fernandez, Juan M.; Hillebrandt, Martin F.

    2016-01-01

    One of the key challenges for small satellites is packaging and reliable deployment of structural booms and arrays used for power, communication, and scientific instruments. The lack of reliable and efficient boom and membrane deployment concepts for small satellites is addressed in this work through a collaborative project between NASA and DLR. The paper provides a state of the art overview on existing spacecraft deployable appendages, the special requirements for small satellites, and initial concepts for deployable booms and arrays needed for various small satellite applications. The goal is to enhance deployable boom predictability and ground testability, develop designs that are tolerant of manufacturing imperfections, and incorporate simple and reliable deployment systems.

  15. von Kármán Vortex Street within an Impacting Drop

    KAUST Repository

    Thoraval, Marie-Jean

    2012-06-29

    The splashing of a drop impacting onto a liquid pool produces a range of different sized microdroplets. At high impact velocities, the most significant source of these droplets is a thin liquid jet emerging at the start of the impact from the neck that connects the drop to the pool. We use ultrahigh-speed video imaging in combination with high-resolution numerical simulations to show how this ejecta gives way to irregular splashing. At higher Reynolds numbers, its base becomes unstable, shedding vortex rings into the liquid from the free surface in an axisymmetric von Kármán vortex street, thus breaking the ejecta sheet as it forms.

  16. von Kármán Vortex Street within an Impacting Drop

    KAUST Repository

    Thoraval, Marie-Jean; Takehara, Kohsei; Etoh, Takeharu Goji; Popinet, Sté phane; Ray, Pascal; Josserand, Christophe; Zaleski, Sté phane; Thoroddsen, Sigurdur T

    2012-01-01

    The splashing of a drop impacting onto a liquid pool produces a range of different sized microdroplets. At high impact velocities, the most significant source of these droplets is a thin liquid jet emerging at the start of the impact from the neck that connects the drop to the pool. We use ultrahigh-speed video imaging in combination with high-resolution numerical simulations to show how this ejecta gives way to irregular splashing. At higher Reynolds numbers, its base becomes unstable, shedding vortex rings into the liquid from the free surface in an axisymmetric von Kármán vortex street, thus breaking the ejecta sheet as it forms.

  17. Air-assisted boom sprayer and spray deposition on bean plants Assistência de ar em barra de pulverização e a deposição da calda em feijoeiro

    Directory of Open Access Journals (Sweden)

    Fernando Cesar Bauer

    2003-01-01

    Full Text Available The development of safe pesticide application techniques with low volume rates, frequency and spray drift, along with the need to obtain better control level of crop pest control levels, justify the air-assistance in boom sprayers. The aim of this research was to evaluate the spray deposition on bean plants with different nozzles and volume rates by air-assisted and non-assisted sprayers. A completely randomized experiment was carried out using copper oxide as a tracer (50% metalic copper for deposit evaluation. The artificial targets were fixed on the upper and under-side of the leaflets, at the top and lower third of the same plants under the spray boom. After application, targets were washed individually with an extracting solution of nitric acid (1.0 mol L-1. The tracer deposition on the artificial targets was quantified by atomic absorption spectrofotometry. The effects of air-assisted spray were not significant in relation to spray deposition 48 days after emergence of the bean plants.A possibilidade do desenvolvimento de técnicas de aplicação de produtos fitossanitários mais seguras, com menores volumes de calda, número de aplicações e deriva, aliados à necessidade de se obter melhores níveis de controle dos agentes nocivos às plantas cultivadas, justificam o uso da assistência de ar junto à barra de pulverização. Com o objetivo de avaliar a deposição da pulverização na cultura do feijoeiro (Phaseolus vulgaris, em presença e ausência da assistência de ar junto à barra de pulverização, com diferentes pontas de pulverização e volumes de calda, foi conduzido um experimento em delineamento inteiramente casualizado, utilizando-se como traçador o óxido cuproso. Alvos artificiais (papel filtro com 3 x 3 cm foram afixados nas superfícies adaxial e abaxial de folíolos posicionados nos terços superior e inferior de plantas, selecionadas ao acaso, distribuídas perpendicularmente ao deslocamento do pulverizador. Ap

  18. Design and simulation of the rotating test rig in the INDUFLAP project

    DEFF Research Database (Denmark)

    Barlas, Thanasis K.; Aagaard Madsen, Helge; Løgstrup Andersen, Tom

    The general description and objectives of the rotating test rig at the Risø campus of DTU are presented, as used for the aeroelastic testing of a controllable rubber trailing edge flap (CRTEF) system in the INDUFLAP project. The design of all new components is presented, including the electrical...... drive, the pitch system, the boom, and the wing/flap section. The overall instrumentation of the components used for the aeroelastic testing is described. Moreover, the aeroelastic model simulating the setup is described, and predictions of steady and dynamic loading along with the aeroelastic analysis...

  19. On a new concept of community: social networks, personal communities and collective intelligence

    Directory of Open Access Journals (Sweden)

    Rogério da Costa

    2006-01-01

    Full Text Available This text essentially deals with the transmutation of the concept of "community" into "social networks". This change is due largely to the boom of virtual communities in cyberspace, a fact that has generated a number of studies not only on this new way of weaving a society, but also on the dynamic structure of communication networks. At the core of this transformation, concepts such as social capital, trust and partial sympathy are called upon, to enable us to think about the new forms of association that regulate human activity in our time.

  20. Étude des interactions mécaniques et physico-chimiques entre les argiles et les fluides de forage. Application à l'argile de Boom (Belgique A Study O the Mechanical and Physicochemical Interactions Between the Clay Materials and the Drilling Fluids. Application to the Boom Clay (Belgium

    Directory of Open Access Journals (Sweden)

    Tshibangu J. P.

    2006-11-01

    Full Text Available Ce travail est motivé par les problèmes posés par la stabilité des puits forés dans des formations argileuses avec des boues de forage à base d'eau. En effet, les roches argileuses ou argilites (shales en anglais ont la propriété d'absorber de l'eau, entraînant ainsi la déstabilisation des puits, soit par gonflement de certaines espèces minérales, soit par annulation de la pression de soutènement de la paroi par suite de la modification de la pression de pore. La déstabilisation peut être purement mécanique avec une plastification entraînant un cavage du trou, ou dépendre essentiellement des interactions physicochimiques entre le fluide de forage et l'argile. Le but de ce travail est donc de mettre expérimentalement en évidence les mécanismes susceptibles de jouer un rôle dans les phénomènes évoqués, et de tenter de quantifier l'importance de ces mécanismes pour en tenir compte dans les modèles de calcul. Le système expérimental que nous utilisons est basé sur une cellule triaxiale perméable aux rayons X, et donc destinée à un fonctionnement sous scanner (tomographie. Ce système, conçu et construit à l'Institut Français du Pétrole (IFP, est nouveau et nous avons contribué dans le cadre de ce travail à sa mise au point. La démarche consiste à mettre un échantillon d'argile sous confinement au contact avec un fluide de composition déterminée et à voir si les composants de ce fluide migrent dans l'argile ou non. Bien entendu, la tomographie ne permet que d'avoir des densités globales avec des résolutions de loin supérieures à la dimension du pore d'un matériau argileux sous confinement. Il est donc évident que les indications fournies par cette méthode doivent être complétées avec d'autres types de méthodes pour arriver à une étude sélective de la migration des éléments en solution. Pour ce qui concerne le matériau, notre choix s'est porté sur l'argile de Boom en Belgique, d'une part