WorldWideScience

Sample records for catapults

  1. Bow and catapult internal dynamics

    CERN Document Server

    Denny, M

    2003-01-01

    A simple model of bow and arrow dynamics is presented, which makes clear the physical principles, and reproduces the features obtained via more detailed, but less accessible calculations. We apply this instructive model to determine the efficiency of bows and of torsion-spring catapults.

  2. Bow and catapult internal dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Denny, Mark [4665 Amblewood Drive, Victoria, BC V8Y 1C1 (Canada)

    2003-07-01

    A simple model of bow and arrow dynamics is presented, which makes clear the physical principles, and reproduces the features obtained via more detailed, but less accessible calculations. We apply this instructive model to determine the efficiency of bows and of torsion-spring catapults.

  3. Perspectives on Greek and Roman catapults

    Directory of Open Access Journals (Sweden)

    Mark Hassall

    1998-11-01

    Full Text Available Both the Greeks and the Romans showed great ingenuity in developing catapults as artillery weapons. Evidence of how these complicated machines worked comes from surviving descriptions, experimental reconstructions and archaeological remains. Ancient technical drawings are a valuable but relatively neglected source of information about catapult design, and one that poses challenging problems of interpretation.

  4. Vortices catapult droplets in atomization

    Science.gov (United States)

    Jerome, J. John Soundar; Marty, Sylvain; Matas, Jean-Philippe; Zaleski, Stéphane; Hoepffner, Jérôme

    2013-11-01

    A droplet ejection mechanism in planar two-phase mixing layers is examined. Any disturbance on the gas-liquid interface grows into a Kelvin-Helmholtz wave, and the wave crest forms a thin liquid film that flaps as the wave grows downstream. Increasing the gas speed, it is observed that the film breaks up into droplets which are eventually thrown into the gas stream at large angles. In a flow where most of the momentum is in the horizontal direction, it is surprising to observe these large ejection angles. Our experiments and simulations show that a recirculation region grows downstream of the wave and leads to vortex shedding similar to the wake of a backward-facing step. The ejection mechanism results from the interaction between the liquid film and the vortex shedding sequence: a recirculation zone appears in the wake of the wave and a liquid film emerges from the wave crest; the recirculation region detaches into a vortex and the gas flow over the wave momentarily reattaches due to the departure of the vortex; this reattached flow pushes the liquid film down; by now, a new recirculation vortex is being created in the wake of the wave—just where the liquid film is now located; the liquid film is blown up from below by the newly formed recirculation vortex in a manner similar to a bag-breakup event; the resulting droplets are catapulted by the recirculation vortex.

  5. Vortices catapult droplets in atomization

    Energy Technology Data Exchange (ETDEWEB)

    Jerome, J. John Soundar, E-mail: soundar@dalembert.upmc.fr; Zaleski, Stéphane; Hoepffner, Jérôme [Institut Jean Le Rond d' Alembert, UPMC Univ. Paris 06 and CNRS-UMR 7190, F-75005 Paris (France); Marty, Sylvain; Matas, Jean-Philippe [Laboratoire des Écoulements Géophysiques et Industriels (LEGI), Univ. Grenoble Alpes and CNRS - UMR 5519, F-38000 Grenoble (France)

    2013-11-15

    A droplet ejection mechanism in planar two-phase mixing layers is examined. Any disturbance on the gas-liquid interface grows into a Kelvin-Helmholtz wave, and the wave crest forms a thin liquid film that flaps as the wave grows downstream. Increasing the gas speed, it is observed that the film breaks up into droplets which are eventually thrown into the gas stream at large angles. In a flow where most of the momentum is in the horizontal direction, it is surprising to observe these large ejection angles. Our experiments and simulations show that a recirculation region grows downstream of the wave and leads to vortex shedding similar to the wake of a backward-facing step. The ejection mechanism results from the interaction between the liquid film and the vortex shedding sequence: a recirculation zone appears in the wake of the wave and a liquid film emerges from the wave crest; the recirculation region detaches into a vortex and the gas flow over the wave momentarily reattaches due to the departure of the vortex; this reattached flow pushes the liquid film down; by now, a new recirculation vortex is being created in the wake of the wave—just where the liquid film is now located; the liquid film is blown up from below by the newly formed recirculation vortex in a manner similar to a bag-breakup event; the resulting droplets are catapulted by the recirculation vortex.

  6. The fern sporangium: a unique catapult.

    Science.gov (United States)

    Noblin, X; Rojas, N O; Westbrook, J; Llorens, C; Argentina, M; Dumais, J

    2012-03-16

    Various plants and fungi have evolved ingenious devices to disperse their spores. One such mechanism is the cavitation-triggered catapult of fern sporangia. The spherical sporangia enclosing the spores are equipped with a row of 12 to 13 specialized cells, the annulus. When dehydrating, these cells induce a dramatic change of curvature in the sporangium, which is released abruptly after the cavitation of the annulus cells. The entire ejection process is reminiscent of human-made catapults with one notable exception: The sporangia lack the crossbar that arrests the catapult arm in its returning motion. We show that much of the sophistication and efficiency of the ejection mechanism lies in the two very different time scales associated with the annulus closure.

  7. Catapulting tentacles in a sticky carnivorous plant.

    Directory of Open Access Journals (Sweden)

    Simon Poppinga

    Full Text Available Among trapping mechanisms in carnivorous plants, those termed 'active' have especially fascinated scientists since Charles Darwin's early works because trap movements are involved. Fast snap-trapping and suction of prey are two of the most spectacular examples for how these plants actively catch animals, mainly arthropods, for a substantial nutrient supply. We show that Drosera glanduligera, a sundew from southern Australia, features a sophisticated catapult mechanism: Prey animals walking near the edge of the sundew trigger a touch-sensitive snap-tentacle, which swiftly catapults them onto adjacent sticky glue-tentacles; the insects are then slowly drawn within the concave trap leaf by sticky tentacles. This is the first detailed documentation and analysis of such catapult-flypaper traps in action and highlights a unique and surprisingly complex mechanical adaptation to carnivory.

  8. Catapulting tentacles in a sticky carnivorous plant.

    Science.gov (United States)

    Poppinga, Simon; Hartmeyer, Siegfried Richard Heinrich; Seidel, Robin; Masselter, Tom; Hartmeyer, Irmgard; Speck, Thomas

    2012-01-01

    Among trapping mechanisms in carnivorous plants, those termed 'active' have especially fascinated scientists since Charles Darwin's early works because trap movements are involved. Fast snap-trapping and suction of prey are two of the most spectacular examples for how these plants actively catch animals, mainly arthropods, for a substantial nutrient supply. We show that Drosera glanduligera, a sundew from southern Australia, features a sophisticated catapult mechanism: Prey animals walking near the edge of the sundew trigger a touch-sensitive snap-tentacle, which swiftly catapults them onto adjacent sticky glue-tentacles; the insects are then slowly drawn within the concave trap leaf by sticky tentacles. This is the first detailed documentation and analysis of such catapult-flypaper traps in action and highlights a unique and surprisingly complex mechanical adaptation to carnivory.

  9. The fern sporangium: an ultrafast natural catapult

    Science.gov (United States)

    Noblin, Xavier; Argentina, Mederic; Westbrook, Jared; Llorens, Coraline; Rojas, Nicolas; Dumais, Jacques

    2012-02-01

    Plants have developed fascinating mechanisms to create ultra fast movements that often reach the upper limit allowed by physical laws. Inspiration for new technologies is one of the reasons for the strong interest for these mechanisms, along with the deep interest of understanding complex, natural systems. The fern sporangium is a capsule that contains the spores, it is surrounded by a row of cells called the annulus which acts as a beam. Due to the water evaporation from its cells, the annulus bends strongly and induces elastic energy storage during an opening phase. The tension in the cells breaks when cavitation bubbles appear in the cells, leading to a fast release of the elastic energy. The fern sporangium then acts as a catapult which ejects rapidly its spores by closing back to the initial closed shape. We have analyzed the slow opening motion and the fast catapulting mechanism. We found that the catapult motion involves two time scales, showing a very original behavior. In man-made catapults, the recoil motion needs to be arrested by a cross bar so that the projectile is released from the arm. We show here that the fern sporangium replaces the essential cross bar by an elegant poroelastic damping, leading to a completely autonomous, efficient device.

  10. The fern sporangium: a unique catapult.

    OpenAIRE

    Noblin, X.; Rojas, N. O.; Westbrook, J; Llorens, C.; Argentina, M.; Dumais, J.

    2012-01-01

    International audience; Various plants and fungi have evolved ingenious devices to disperse their spores. One such mechanism is the cavitation-triggered catapult of fern sporangia. The spherical sporangia enclosing the spores are equipped with a row of 12 to 13 specialized cells, the annulus. When dehydrating, these cells induce a dramatic change of curvature in the sporangium, which is released abruptly after the cavitation of the annulus cells. The entire ejection process is reminiscent of ...

  11. Botany: a record-breaking pollen catapult.

    Science.gov (United States)

    Edwards, Joan; Whitaker, Dwight; Klionsky, Sarah; Laskowski, Marta J

    2005-05-12

    The release of stored elastic energy often drives rapid movements in animal systems, and plant components employing this mechanism should be able to move with similar speed. Here we describe how the flower stamens of the bunchberry dogwood (Cornus canadensis) rely on this principle to catapult pollen into the air as the flower opens explosively. Our high-speed video observations show that the flower opens in less than 0.5 ms--to our knowledge, the fastest movement so far recorded in a plant.

  12. The cable catapult - Putting it there and keeping it there

    Science.gov (United States)

    Forward, Robert L.; Conley, Buford R.; Stanek, Clay; Ramsey, William

    1992-01-01

    The cable catapult is the previously proposed method of using long space tethers for high speed interplanetary transport. A long conductive multistrand cable would be connected to a power supply and pointed in the desired direction. A linear motor would pull itself along the powered cable strands and launch a payload capsule toward a distant planet, where it would be caught and decelerated by another cable catapult positioned there. In this paper it is shown how cable catapults can be used to transport themselves to a distant planet and keep themselves in position near the planet despite the tendency of the payload capsule momentum transfer to push them apart.

  13. Design of Dsppool Based on Catapult C%基于Catapult C的Dsppool设计

    Institute of Scientific and Technical Information of China (English)

    罗锋; 刘新宁

    2009-01-01

    在此使用高级语言进行运算加速模块Dsppool描述,再使用Mentor公司的Catapult C工具完成RTL设计,并为Dsppool模块进行满足APB接口的封装,使之能够作为一个AMBA总线上的Slave模块.实验结果显示,使用硬件描述语言手动设计的Dsppool模块与CatapultC设计的RTL代码功能完全一致,并且综合后性能相当,因为高级语言忽略了硬件设计中的细节,设计速度比直接使用硬件描述语言快几倍到几十倍.

  14. The new Drop Tower catapult system

    Science.gov (United States)

    von Kampen, Peter; Kaczmarczik, Ulrich; Rath, Hans J.

    2006-07-01

    The Center of Applied Space Technology and Microgravity (ZARM) was founded in 1985 as an institute of the University Bremen, which focuses on research on gravitational and space-related phenomena. In 1988, the construction of the "Drop Tower" began. Since then, the eye-catching tower with a height of 146 m and its characteristic glass roof has become the emblem of the technology centre in Bremen. The Drop Tower Bremen provides a facility for experiments under conditions of weightlessness. Items are considered weightless, when they are in "free fall", i.e. moving without propulsion within the gravity field of the earth. The height of the tower limits the simple "free fall" experiment period to max. 4.74 s. With the inauguration of the catapult system in December 2004, the ZARM is entering a new dimension. This world novelty will meet scientists' demands of extending the experiment period up to 9.5 s. Since turning the first sod on May 3rd, 1988, the later installation of the catapult system has been taken into account by building the necessary chamber under the tower. The catapult system is located in a chamber 10 m below the base of the tower. This chamber is almost completely occupied by 12 huge pressure tanks. These tanks are placed around the elongation of the vacuum chamber of the drop tube. In its centre there is the pneumatic piston that accelerates the drop capsule by the pressure difference between the vacuum inside the drop tube and the pressure inside the tanks. The acceleration level is adjusted by means of a servo hydraulic breaking system controlling the piston velocity. After only a quarter of a second the drop capsule achieves its lift-off speed of 175 km/h. With this exact speed, the capsule will rise up to the top of the tower and afterwards fall down again into the deceleration unit which has been moved under the drop tube in the meantime. The scientific advantages of the doubled experiment time are obvious: during almost 10 s of high

  15. 'Catapult' offshore renewables into commercial use

    Energy Technology Data Exchange (ETDEWEB)

    Block, Elizabeth

    2012-07-01

    In February, the Technology Strategy Board, the UK's government innovation agency, appointed a consortium to set up the Offshore Renewable Energy Catapult centre, with Sterling Pounds 50 million to be spent over five years. (orig.)

  16. TC-13 Mod 0 and Mod 2 Steam Catapult Test Site

    Data.gov (United States)

    Federal Laboratory Consortium — Located on 11,000 feet of test runway, the TC-13 Mod 0 and Mod 2 Steam Catapult Test Site has in-ground catapults identical to those aboard carriers. This test site...

  17. Construct-a-Catapult. Science by Design Series.

    Science.gov (United States)

    Pulis, Lee

    This book is one of four books in the Science-by-Design Series crated by TERC and funded by the National Science Foundation (NSF). It integrates history, physics, mathematics, and technology in its challenge to high school students to design and build a working catapult system. Students investigate elasticity, projectile launching, and learn about…

  18. Concept of an induction-dynamic catapult for a ballistic laser gravimeter

    OpenAIRE

    Bolyukh, V.F.; Vinnichenko, A. I.

    2014-01-01

    A design is proposed for an inductive-dynamic catapult in a ballistic laser gravimeter with a fixed inductor and an electrically conducting armature that moves together with the test object along a vertical axis. The catapult ensures improved accuracy of the gravimeter through direct conversion of electrical into kinetic energy. The electrical circuit of the catapult provides two successive current pulses to the inductor for launching and braking of the armature during the operating cycle.

  19. Catapult launch-associated cardioversion of atrial fibrillation.

    Science.gov (United States)

    Bohnker, B K; Feeks, E F; McEwen, G

    1993-10-01

    A patient is presented with new-onset atrial fibrillation. While being air-evacuated, he cardioverted during the acceleration associated with aircraft carrier catapult launch. This case suggests a possible myocardial response to the kinetic energy produced by the acceleration force, similar to the electrical energy commonly used for cardioversion. Cardioversion using acceleration forces is probably not a clinically useful modality; however, this case demonstrates the importance of acceleration forces on patients during medical evacuation from aircraft carriers.

  20. 基于Catapult C的DCT算法设计

    Institute of Scientific and Technical Information of China (English)

    谢正; 张开锋

    2011-01-01

    以DCT(Discrete Cosine Transform)的实现为例,利用Catapult C探索不同的设计架构,快速设计出性能、面积和功耗之间折衷的最佳实现方案,并与传统的手工编写VHDL代码实现方式进行比较。

  1. 基于Catapult C的DCT算法设计%Design of DCT Algorithm Based on Catapult C

    Institute of Scientific and Technical Information of China (English)

    谢正; 张开锋

    2011-01-01

    以DCT( Discrete Cosine Transform)的实现为例,利用CatapultC探索不同的设计架构,快速设计出性能、面积和功耗之间折衷的最佳实现方案,并与传统的手工编写VHDL代码实现方式进行比较.

  2. Universities, Catapult Centres and the 2014 Hauser Review. Innovation and Growth Factsheet Series. No. 2

    Science.gov (United States)

    Universities UK, 2014

    2014-01-01

    This factsheet, the second in a series on innovation and growth, provides an overview of Catapult centres and how universities engage with them, with reference to the recommendations of the second Hauser review into the future of the Catapult network. The factsheet draws on a review of existing literature as well as the perspectives of businesses,…

  3. Analysis of the Design Criteria for Ancient Greek and Roman Catapults

    DEFF Research Database (Denmark)

    Paasch, Kasper

    2011-01-01

    for powerful torsion catapults emerged around 270 BC, based on one basic factor, the diameter of the torsion springs. This value is then scaled to give all vital structural dimensions of the catapult. How optimal this design is has until now not been fully understood and earlier work has been dominated......This paper will give a short overview of use of COMSOL Multiphysics for analyzing ancient Greek and Roman catapults with the main focus on the energy storing torsion springs. Catapults have been known and used in the Greek and Roman world from around 399 BC and a fully standardized design...... by trial-and-error methods. The use of COMSOL Multiphysics enables the construction of virtual catapults parts, non-linear analysis of structural parts where no analytical solution is known as well the analysis of the surviving designs, with respect to optimal performance. The result from COMSOL...

  4. A Catapult (Slingshot) Current Sheet Relaxation Model for Substorm Triggering

    Science.gov (United States)

    Machida, S.; Miyashita, Y.; Ieda, A.

    2010-12-01

    Based on the results of our superposed epoch analysis of Geotail data, we have proposed a catapult (slingshot) current sheet relaxation model in which earthward flows are produced in the central plasma sheet (CPS) due to the catapult (slingshot) current sheet relaxation, together with the rapid enhancement of Poynting flux toward the CPS in the lobe around X ~ -15 Re about 4 min before the substrom onset. These earthward flows are characterized by plasma pressure decrease and large amplitude magnetic field fluctuations. When these flows reach X ~ 12Re in the magnetotail, they give significant disturbances to the inner magnetosphere to initiate some instability such as a ballooning instability or other instabilities, and the substorm starts in the inner magnetosphere. The occurrence of the magnetic reconnection is a natural consequence of the initial convective earthward flows, because the relaxation of a highly stretched catapult current sheet produces a very thin current at its tailward edge being surrounded by intense magnetic fields which were formerly the off-equatorial lobe magnetic fields. Recently, Nishimura et al. [2010] reported that the substorm onset begins when faint poleward discrete arcs collide with equatorward quiet arcs. The region of earthward convective flows correlatively moves earthward prior to the onset. Thus, this region of the earthward convective flows seems to correspond to the faint poleward discrete arcs. Interestingly, our statistical analysis shows that the earthward convective flows are not produced by the magnetic reconnection, but they are attributed to the dominance of the earthward JxB force over the tailward pressure associated with the progress of the plasma sheet thinning.

  5. The fern cavitation catapult: mechanism and design principles.

    Science.gov (United States)

    Llorens, C; Argentina, M; Rojas, N; Westbrook, J; Dumais, J; Noblin, X

    2016-01-01

    Leptosporangiate ferns have evolved an ingenious cavitation catapult to disperse their spores. The mechanism relies almost entirely on the annulus, a row of 12-25 cells, which successively: (i) stores energy by evaporation of the cells' content, (ii) triggers the catapult by internal cavitation, and (iii) controls the time scales of energy release to ensure efficient spore ejection. The confluence of these three biomechanical functions within the confines of a single structure suggests a level of sophistication that goes beyond most man-made devices where specific structures or parts rarely serve more than one function. Here, we study in detail the three phases of spore ejection in the sporangia of the fern Polypodium aureum. For each of these phases, we have written the governing equations and measured the key parameters. For the opening of the sporangium, we show that the structural design of the annulus is particularly well suited to inducing bending deformations in response to osmotic volume changes. Moreover, the measured parameters for the osmoelastic design lead to a near-optimal speed of spore ejection (approx. 10 m s(-1)). Our analysis of the trigger mechanism by cavitation points to a critical cavitation pressure of approximately -100 ± 14 bar, a value that matches the most negative pressures recorded in the xylem of plants. Finally, using high-speed imaging, we elucidated the physics leading to the sharp separation of time scales (30 versus 5000 µs) in the closing dynamics. Our results highlight the importance of the precise tuning of the parameters without which the function of the leptosporangium as a catapult would be severely compromised.

  6. Capillary-Inertial Colloidal Catapult upon Drop Coalescence

    Science.gov (United States)

    Chavez, Roger; Liu, Fangjie; Feng, James; Chen, Chuan-Hua

    2014-11-01

    To discharge micron-sized particles such as colloidal contaminants and biological spores, an enormous power density is needed to compete against the strong adhesive forces between the small particles and the supporting surface as well as the significant air friction exerted on the particles. Here, we demonstrate a colloidal catapult that achieves such a high power density by extracting surface energy released upon drop coalescence within an extremely short time period, which is governed by the capillary-inertial process converting the released surface energy into the bulk inertia of the merged drop. When two drops coalesce on top of a spherical particle, the resulting capillary-inertial oscillation is perturbed by the solid particle, giving rise to a net momentum eventually propelling the particle to launch from the supporting surface. The measured launching velocity follows a scaling law that accounts for the redistribution of the momentum of the merged drop onto the particle-drop complex, and is therefore proportional to the capillary-inertial velocity characterizing the coalescing drops. The interfacial flow process associated with the colloidal catapult is elucidated with both high-speed imaging and phase-field simulations.

  7. 舰载机不同弹射系统的弹射过程%Catapult Process of Different Catapult Systems for Carrier-Based Aircraft

    Institute of Scientific and Technical Information of China (English)

    甄子洋; 江驹; 王新华; 朱熠

    2012-01-01

    针对目前世界上最典型的两种舰载机弹射系统:蒸汽弹射系统和电磁弹射系统,对比研究了不同弹射系统的结构原理、数学模型、弹射性能等问题.分析了常用的蒸汽弹射装置和电磁装置的组成部件及其功用,给出对比分析结果;根据蒸汽弹射装置和电磁弹射装置的运动学特性,获得两种弹射装置的数学模型,推导出它们的非线性运动学方程,并给出对比分析结果;针对两种不同的弹射系统,构建了舰载机在舰面加速段的弹射过程的Matlab数值仿真模型,通过仿真研究,分析了不同弹射系统中对弹射性能起主要影响作用的关键因素,并根据仿真结果进行了对比分析.%The structure, principle, mathematical models and performance were studied for the two typical methods, steam catapult and Electromagnetic Aircraft Launch System ( EMALS) , for catapult launch of carrier-based aircraft. The compositions of steam catapult and EMALS were analyzed. The functions of the different parts of the catapult systems were also discussed. According to the kinematical characteristics of steam catapult and EMALS, the mathematical models were established, their nonlinear kinematical equations were deduced and the comparative analysis reslult was given. Simulations were made for the two catapult methods on the speeding stage of the aircraft. The main factors that have effect on catapult launch performance were analysed for different catapult methods by using the simulation result. Comparison of the two catapult launch systems was also made.

  8. Capillary-inertial colloidal catapults upon drop coalescence

    Science.gov (United States)

    Chavez, Roger L.; Liu, Fangjie; Feng, James J.; Chen, Chuan-Hua

    2016-07-01

    Surface energy released upon drop coalescence is known to power the self-propelled jumping of liquid droplets on superhydrophobic solid surfaces, and the jumping droplets can additionally carry colloidal payloads toward self-cleaning. Here, we show that drop coalescence on a spherical particle leads to self-propelled launching of the particle from virtually any solid surface. The main prerequisite is an intermediate wettability of the particle, such that the momentum from the capillary-inertial drop coalescence process can be transferred to the particle. By momentum conservation, the launching velocity of the particle-drop complex is proportional to the capillary-inertial velocity based on the drop radius and to the fraction of the liquid mass in the total mass. The capillary-inertial catapult is not only an alternative mechanism for removing colloidal contaminants, but also a useful model system for studying ballistospore launching.

  9. Evidence for a vertebrate catapult: elastic energy storage in the plantaris tendon during frog jumping

    OpenAIRE

    Astley, Henry C.; Roberts, Thomas J.

    2011-01-01

    Anuran jumping is one of the most powerful accelerations in vertebrate locomotion. Several species are hypothesized to use a catapult-like mechanism to store and rapidly release elastic energy, producing power outputs far beyond the capability of muscle. Most evidence for this mechanism comes from measurements of whole-body power output; the decoupling of joint motion and muscle shortening expected in a catapult-like mechanism has not been demonstrated. We used high-speed marker-based biplana...

  10. Principles of laser microdissection and catapulting of histologic specimens and live cells.

    Science.gov (United States)

    Vogel, Alfred; Horneffer, Verena; Lorenz, Kathrin; Linz, Norbert; Hüttmann, Gereon; Gebert, Andreas

    2007-01-01

    Rapid contact- and contamination-free procurement of specific samples of histologic material for proteomic and genomic analysis as well as separation and transport of living cells can be achieved by laser microdissection (LMD) of the sample of interest followed by a laser-induced forward transport process [laser pressure "catapulting," (LPC)] of the dissected material. We investigated the dynamics of LMD and LPC with focused and defocused laser pulses by means of time-resolved photography. The working mechanism of microdissection was found to be plasma-mediated ablation. Catapulting is driven by plasma formation, when tightly focused pulses are used, and by ablation at the bottom of the sample for moderate and strong defocusing. Driving pressures of several hundred megapascals accelerate the specimen to initial velocities of 100-300 m/s before it is rapidly slowed down by air friction. With strong defocusing, driving pressure and initial flight velocity decrease considerably. On the basis of a characterization of the thermal and optical properties of the histologic specimens and supporting materials used, we calculated the temporal evolution of the heat distribution in the sample. After laser microdissection and laser pressure catapulting (LMPC), the samples were inspected by scanning electron microscopy. Catapulting with tightly focused or strongly defocused pulses results in very little collateral damage, while slight defocusing involves significant heat and UV exposure of up to about 10% of the specimen volume, especially if samples are catapulted directly from a glass slide. Time-resolved photography of live-cell catapulting revealed that in defocused catapulting strong shear forces originate from the flow of the thin layer of culture medium covering the cells. By contrast, pulses focused at the periphery of the specimen cause a fast rotational movement that makes the specimen wind its way out of the culture medium, thereby undergoing much less shear stresses

  11. Development of a New Specification for Aircraft Catapult Lubricant, LA7, NSN 9150-01-430-2884

    Science.gov (United States)

    2013-09-30

    DEVELOPMENT OF A NEW SPECIFICATION FOR AIRCRAFT CATAPULT LUBRICANT, LA7, NSN 9150-01-430-2884 NF&LCFT REPORT 441/13-009 30 September 2013...Page Table 1. Proposed Requirements For A Dedicated Mineral Oil Based Catapult Lubricant. ............. 21 LIST OF FIGURES Figure...September 2013 Page v EXECUTIVE SUMMARY The steam driven shipboard aircraft catapult systems have traditionally used qualified aviation

  12. Catapult effect in pole vaulting: is muscle coordination determinant?

    Science.gov (United States)

    Frère, Julien; Göpfert, Beat; Hug, François; Slawinski, Jean; Tourny-Chollet, Claire

    2012-02-01

    This study focused on the phase between the time of straightened pole and the maximum height (HP) of vaulter and aimed at determining the catapult effect in pole vaulting on HP. Seven experienced vaulters performed 5-10 vaults recorded by two video cameras, while the surface electromyography (sEMG) activity of 10 upper limbs muscles was recorded. HP was compared with an estimated maximum height (HP(est)) allowing the computation of a push-off index. Muscle synergies were extracted from the sEMG activity profiles using a non-negative matrix factorization algorithm. No significant difference (p>0.47) was found between HP(est) (4.64±0.21m) and HP (4.69±0.23m). Despite a high inter-individual variability in sEMG profiles, two muscle synergies were extracted for all the subjects which accounted for 96.1±2.9% of the total variance. While, the synergy activation coefficients were very similar across subjects, a higher variability was found in the muscle synergy vectors. Consequently, whatever the push-off index among the pole vaulters, the athletes used different muscle groupings (i.e., muscle synergy vectors) which were activated in a similar fashion (i.e., synergy activation coefficients). Overall, these results suggested that muscle coordination adopted between the time of straightened pole and the maximum height does not have a major influence on HP.

  13. Catapult current sheet relaxation model confirmed by THEMIS observations

    Science.gov (United States)

    Machida, S.; Miyashita, Y.; Ieda, A.; Nose, M.; Angelopoulos, V.; McFadden, J. P.

    2014-12-01

    In this study, we show the result of superposed epoch analysis on the THEMIS probe data during the period from November, 2007 to April, 2009 by setting the origin of time axis to the substorm onset determined by Nishimura with THEMIS all sky imager (THEMS/ASI) data (http://www.atmos.ucla.edu/~toshi/files/paper/Toshi_THEMIS_GBO_list_distribution.xls). We confirmed the presence of earthward flows which can be associated with north-south auroral streamers during the substorm growth phase. At around X = -12 Earth radii (Re), the northward magnetic field and its elevation angle decreased markedly approximately 4 min before substorm onset. A northward magnetic-field increase associated with pre-onset earthward flows was found at around X = -17Re. This variation indicates the occurrence of the local depolarization. Interestingly, in the region earthwards of X = -18Re, earthward flows in the central plasma sheet (CPS) reduced significantly about 3min before substorm onset. However, the earthward flows enhanced again at t = -60 sec in the region around X = -14 Re, and they moved toward the Earth. At t = 0, the dipolarization of the magnetic field started at X ~ -10 Re, and simultaneously the magnetic reconnection started at X ~ -20 Re. Synthesizing these results, we can confirm the validity of our catapult current sheet relaxation model.

  14. Disorienting effects of aircraft catapult launchings. II. Visual and postural contributions.

    Science.gov (United States)

    Cohen, M M

    1976-01-01

    Gx accelerations approximating those encountered in aircraft catapult launchings were generated on the human centrifuge Dynamic Flight Simulator at the Naval Air Development Center. Each of four catapult-experienced Naval aviators continuously oriented himself to the gravitational vertical both before and after exposure to the accelerations under two conditions: a) while he sat in total darkness, and b) while he viewed a small target projected at eye level in his mid-sagittal plane. The accelerations produce changes of pitch orientation that were affected by the presence or absence of the target, and the changes of orientation persisted well after the accelerations were terminated. Visual and postural illusions and their contributions to the disorientation are discussed, and the disorientation is related to certain water-collision accidents that have been reported to occur following aircraft catapult launchings at night.

  15. Design of image correction algorithm based on Catapult C Synthesis%基于 Catapult C Synthesis 的图像校正算法设计

    Institute of Scientific and Technical Information of China (English)

    李杨

    2016-01-01

    The jitter of remote sensor during exercise will cause the image position shift .To settle this problem ,a real‐time image correction algorithm is proposed .However ,the design of algorithm by using HDL has great difficulty and it leads to long development cycle .Therefore ,the design of algorithm is achieved by adopting C language .Then the abstract C algorithm is translated to RLT code by means of Calypto’s Catapult C Synthesis tools .Furthermore ,a co‐simulation test of C/C+ + and RLT is carried out in Catapult C Synthesis tools .It’s also verified in the platform of XC5VLX110T .The results of Simulation test and hardware verification show that the algorithm designed by applying Catapult C Synthesis tools can meet the design requirements both in timing and performance .And it can correct the shifted image in real‐time .%为解决遥感相机在运动过程中的抖动造成的图像位置偏移问题,提出了一种实时图像校正算法。由于在FPGA中采用HDL进行算法设计难度大、开发周期长,故设计中采用了C语言进行算法设计,然后借助Calypto公司的Catapult C Synthesis工具将抽象的C设计转换成硬件RTL代码。在Catapult C Synthesis中对设计的算法进行了C/C++、RLT协同仿真测试,并在Xilinx XC5VLX110T型FPGA上进行了验证。仿真测试及硬件验证结果表明,采用Catapult C Synthesis设计的算法在时序、性能方面均满足设计要求,能够对偏移的图像进行实时校正。

  16. Catapult mechanism renders the chaperone action of Hsp70 unidirectional.

    Science.gov (United States)

    Gisler, S M; Pierpaoli, E V; Christen, P

    1998-06-19

    Molecular chaperones of the Hsp70 type promote the folding and membrane translocation of proteins. The interaction of Hsp70s with polypeptides is linked to ATP binding and hydrolysis. We formed complexes of seven different fluorescence-labeled peptides with DnaK, the Hsp70 homolog of Escherichia coli, and determined the rate of peptide release under two different sets of conditions. (1) Upon addition of ATP to nucleotide-free peptide.DnaK complexes, all tested peptides were released with similar rate constants (2.2 s-1 to 6.7 s-1). (2) In the binding equilibrium of peptide and ATP-liganded DnaK, the dissociation followed one or two-step reactions, depending on the amino acid sequence of the peptide. For the monophasic reactions, the dissociation rate constants diverged by four orders of magnitude from 0.0004 s-1 to 5.7 s-1; for the biphasic reactions, the rate constants of the second, slower isomerization step were in the range from 0.3 s-1 to 0.0005 s-1. The release of the different peptides in case (1) is 1.4 to 14,000 times faster than in case (2). Apparently, binding of ATP induces a transient state of the chaperone which ejects target peptides before the final state of ATP-liganded DnaK is reached. This "catapult" mechanism provides the chaperone cycle with a mode of peptide release that does not correspond with the reverse of peptide binding. By allowing the conformation of the outgoing polypeptide to differ from that of the incoming polypeptide, a futile cycle with respect to conformational work exerted on the target protein is obviated.

  17. Low Acceleration Overload Catapult Technique for Throwing the Small Scout Robot

    Directory of Open Access Journals (Sweden)

    Jianzhong Wang

    2016-09-01

    Full Text Available The small scout robot is generally thrown into the war zone by soldier. The short thrown distance and the danger of soldier exposed to the enemy limit the application of the small scout robot. So this paper presents a type of low acceleration overload catapult device of no flash, no smoke and no sound. It can throw the small scout robot covertly to long distances with low acceleration overload, and avoid the danger that soldier be exposed to the enemy when artificial throwing. The high and low pressure chambers of the catapult device achieve the low acceleration overload launching, and eliminate the risk of robot damaged by huge acceleration overload. The covert launching of no flash, no smoke and no sound is achieved by the piston to seal the gun propellant gas in barrel. Based on the interior ballistic model, the interior ballistic performance is calculated. The experiment for measuring the acceleration overload of the projectile is achieved by using the catapult device prototype and the measurement system developed by authors. The simulation and test results show that this catapult device can meet the requirement to throw the small scout robot into the war zone.

  18. Evidence for a vertebrate catapult: elastic energy storage in the plantaris tendon during frog jumping.

    Science.gov (United States)

    Astley, Henry C; Roberts, Thomas J

    2012-06-23

    Anuran jumping is one of the most powerful accelerations in vertebrate locomotion. Several species are hypothesized to use a catapult-like mechanism to store and rapidly release elastic energy, producing power outputs far beyond the capability of muscle. Most evidence for this mechanism comes from measurements of whole-body power output; the decoupling of joint motion and muscle shortening expected in a catapult-like mechanism has not been demonstrated. We used high-speed marker-based biplanar X-ray cinefluoroscopy to quantify plantaris muscle fascicle strain and ankle joint motion in frogs in order to test for two hallmarks of a catapult mechanism: (i) shortening of fascicles prior to joint movement (during tendon stretch), and (ii) rapid joint movement during the jump without rapid muscle-shortening (during tendon recoil). During all jumps, muscle fascicles shortened by an average of 7.8 per cent (54% of total strain) prior to joint movement, stretching the tendon. The subsequent period of initial joint movement and high joint angular acceleration occurred with minimal muscle fascicle length change, consistent with the recoil of the elastic tendon. These data support the plantaris longus tendon as a site of elastic energy storage during frog jumping, and demonstrate that catapult mechanisms may be employed even in sub-maximal jumps.

  19. INSEAN REPORT DESCRIBING THE DESIGN OF THE CRANE AND THE CATAPULT SYSTEM FOR GUIDED DITCHING TESTS

    OpenAIRE

    Iafrati, Alessandro

    2012-01-01

    The present report describes the key points of the design of the facility to be used for the guided ditching test in T4.1. The system is made by three main components: guide, trolley, acceleration and release system (catapult). Each component is illustrated separately in the following.

  20. Open Innovation, Triple Helix and Regional Innovation Systems: Exploring CATAPULT Centres in the UK

    Science.gov (United States)

    Kerry, Christopher; Danson, Michael

    2016-01-01

    Through the lens of UK CATAPULT Centres this conceptual paper presents an examination of the links between open innovation, the Triple Helix model and regional innovation systems. Highlighting the importance of boundary-spanning intermediaries, the combined role of these concepts is explored in detail. A conceptual model is then proposed which…

  1. The Cell Therapy Catapult: growing a U.K. cell therapy industry generating health and wealth.

    Science.gov (United States)

    Thompson, Keith; Foster, Emma Palmer

    2013-12-01

    In a recent report on the regenerative medicine sector, the U.K. House of Lords made several recommendations to enable the United Kingdom to become a global leader in this important industry. Its recommendations in this regard were many and various, covering the regulatory system, clinical trials, manufacturing, funding, approval, and reimbursement. In its mission to tackle what it sees as three main types of barriers to the development of the cell therapy industry in the United Kingdom, the Cell Therapy Catapult is tackling many of these issues. Established as a center of excellence in the United Kingdom in 2012, the Cell Therapy Catapult is a research organization expected to grow to a team of around 100 experts. Its core financing of £ 70 million over the next 5 years is provided by the Technology Strategy Board, the United Kingdom's innovation agency, and with additional contract research income and access to collaborative funds, the Catapult expects to build up to annual revenues of around £ 30 million. Along with its sister Catapult programs in other areas of the economy, the Cell Therapy Catapult was established after identification of the massive early-stage expertise the country has, as well as an acute market failure-the lack of expertise to translate early-stage cell therapy research into commercial success. In this article, in addition to showing our progress so far, we will discuss the hurdles the industry faces-grouped into business, manufacturing/supply chain issues, and clinical/regulatory issues-and what we are doing to help the United Kingdom leap over them.

  2. The game of catapult to understand the design of experiments: one proposal of playful approach for teaching

    Directory of Open Access Journals (Sweden)

    Noel Torres Júnior

    2014-08-01

    Full Text Available This paper proposes the use of the Catapult game for teaching design of experiments. This game consists of a small catapult capable of launching small objects. This can have different settings, so up to five control variables can be changed. The possibility of introducing different adjustments to the catapult allows driving of several types of treatments and the use of various DOE techniques. In this direction, one 2k factorial experiment was performed and is presented. Moreover, the text addresses the DOE through the Multiple Linear Regression using the regression coefficient R2 as a measure for assessing the significance of the factors and the interaction between them. Despite the simplicity of the catapult device, several existing activities in conducting industrial experiments are present in this game. This work provides several important concepts of this technique through play.

  3. Characteristics of solid aerosols produced by optical catapulting studied by laser-induced breakdown spectroscopy

    Science.gov (United States)

    Fortes, F. J.; Laserna, J. J.

    2010-08-01

    Optical catapulting (OC) constitutes an effective method to transport small amounts of different materials in the form of a solid aerosol. In this report, laser-induced breakdown spectroscopy (LIBS) is used for the analysis of those aerosols produced by OC. For this purpose, materials were catapulted using a Q-switch Nd:YAG laser. A second Q-switch Nd:YAG laser was used for LIBS analysis of the ejected particles. Data processing of aerosols was conducted using conditional data analysis. Also, the standard deviation method was used for the qualitative identification of the ejected particles. Two modes of interaction in OC (OC with focused or defocused pulses) have been evaluated and discussed. LIBS demonstrates that the distribution (spreading) of the ejected particles along the propagation axis increased as a function of the interpulse delay time. The mass density and the thickness of the target also play an important role in OC-LIBS.

  4. The Technical Analysis of Unmanned Aircraft Catapult Launch%无人机弹射起飞技术分析

    Institute of Scientific and Technical Information of China (English)

    孙志宏

    2014-01-01

    针对无人机起飞安全问题,介绍了利用弹射架弹射起飞方式来提高无人机起飞安全系数,并详细阐述了弹射架种类及工作原理。%Aiming at the Security issues of Unmanned aircraft take off , the paper introduces that improving the safety factor of Un-manned Aircraft take off by using the technology of Catapult Launch , also introduces the Catapult Launch's species and principle .

  5. Pilot disorientation during aircraft catapult launchings at night - Historical and experimental perspectives

    Science.gov (United States)

    Cohen, Malcolm M.

    1992-01-01

    A review is presented of the investigations conducted into, and the recommendations made to avoid fatal A-7 Corsair II aircraft accidents during night carrier launchings in which the aircraft was apparently flown into the water. The investigating boards conjectured that the pilots were distracted from their normal cockpit procedures and that the distraction was of an insidious nature not previously experienced or expected in the night catapult/departure environment. A conference to discuss these accidents focused on aerodynamic and human factors analyses of the problem, with the goal of producing several recommendations for its resolution.

  6. Low Acceleration Overload Catapult Technique for Throwing the Small Scout Robot

    OpenAIRE

    Jianzhong Wang; Jiadong Shi; Tao Jiang

    2016-01-01

    The small scout robot is generally thrown into the war zone by soldier. The short thrown distance and the danger of soldier exposed to the enemy limit the application of the small scout robot. So this paper presents a type of low acceleration overload catapult device of no flash, no smoke and no sound. It can throw the small scout robot covertly to long distances with low acceleration overload, and avoid the danger that soldier be exposed to the enemy when artificial throwing. The high and lo...

  7. Targeting pancreatic islets with phage display assisted by laser pressure catapult microdissection.

    Science.gov (United States)

    Yao, Virginia J; Ozawa, Michael G; Trepel, Martin; Arap, Wadih; McDonald, Donald M; Pasqualini, Renata

    2005-02-01

    Heterogeneity of the microvasculature in different organs has been well documented by multiple methods including in vivo phage display. However, less is known about the diversity of blood vessels within functionally distinct regions of organs. Here, we combined in vivo phage display with laser pressure catapult microdissection to identify peptide ligands for vascular receptors in the islets of Langerhans in the murine pancreas. Protein database analyses of the peptides, CVSNPRWKC and CHVLWSTRC, showed sequence identity to two ephrin A-type ligand homologues, A2 and A4. Confocal microscopy confirmed that most immunoreactivity of CVSNPRWKC and CHVLWSTRC phage was associated with blood vessels in pancreatic islets. Antibodies recognizing EphA4, a receptor for ephrin-A ligands, were similarly associated with islet blood vessels. Importantly, binding of both islet-homing phage and anti-EphA4 antibody was strikingly increased in blood vessels of pancreatic islet tumors in RIP-Tag2 transgenic mice. These results indicate that endothelial cells of blood vessels in pancreatic islets preferentially express EphA4 receptors, and this expression is increased in tumors. Our findings show in vivo phage display and laser pressure catapult microdissection can be combined to reveal endothelial cell specialization within focal regions of the microvasculature.

  8. Production of aerosols by optical catapulting: Imaging, performance parameters and laser-induced plasma sampling rate

    Science.gov (United States)

    Abdelhamid, M.; Fortes, F. J.; Fernández-Bravo, A.; Harith, M. A.; Laserna, J. J.

    2013-11-01

    Optical catapulting (OC) is a sampling and manipulation method that has been extensively studied in applications ranging from single cells in heterogeneous tissue samples to analysis of explosive residues in human fingerprints. Specifically, analysis of the catapulted material by means of laser-induced breakdown spectroscopy (LIBS) offers a promising approach for the inspection of solid particulate matter. In this work, we focus our attention in the experimental parameters to be optimized for a proper aerosol generation while increasing the particle density in the focal region sampled by LIBS. For this purpose we use shadowgraphy visualization as a diagnostic tool. Shadowgraphic images were acquired for studying the evolution and dynamics of solid aerosols produced by OC. Aluminum silicate particles (0.2-8 μm) were ejected from the substrate using a Q-switched Nd:YAG laser at 1064 nm, while time-resolved images recorded the propagation of the generated aerosol. For LIBS analysis and shadowgraphy visualization, a Q-switched Nd:YAG laser at 1064 nm and 532 nm was employed, respectively. Several parameters such as the time delay between pulses and the effect of laser fluence on the aerosol production have been also investigated. After optimization, the particle density in the sampling focal volume increases while improving the aerosol sampling rate till ca. 90%.

  9. Bias determination for space accelerometers using the ZARM Catapult system - experimental setup and data analysis

    Science.gov (United States)

    Selig, Hanns; Santos Rodrigues, Manuel; Touboul, Pierre; Liorzou, Françoise

    2012-07-01

    Accelerometers for space applications - like the electrostatic differential accelrometer for the MICROSCOPE mission for testing the equivalence principle in space - have to be tested and qualified in μg-conditions in order to demonstrate the system operation and to determine the characteristic sensor parameters. One important characteristic property is the sensor bias. In principle one can determine the sensor bias directly by using the ZARM catapult system as test platform. Even in the evacuated drop tube the residual air pressure results in an air friction that depends on the capsule velocity. At the apex (highest point of the capsule trajectory) the acceleration (relative to the gravitational acceleration g) becomes zero due to the zero velocity at the apex. The direct measurement of the vertical linear acceleration sensor bias is affected by some additional effects that have to be understood in order to be able to determine the sensor bias. Two catapult campaigns have been carried out to demonstrate the principles of the bias determination using a SuperStar accelerometer (Onera). The presentation gives an overview on the experimental setup and on the corresponding data analysis.

  10. Multi-agent Based Hierarchy Simulation Models of Carrier-based Aircraft Catapult Launch

    Institute of Scientific and Technical Information of China (English)

    Wang Weijun; Qu Xiangju; Guo Linliang

    2008-01-01

    With the aid of multi-agent based modeling approach to complex systems,the hierarchy simulation models of carrier-based aircraft catapult launch are developed.Ocean,carrier,aircraft,and atmosphere are treated as aggregation agents,the detailed components like catapult,landing gears,and disturbances are considered as meta-agents,which belong to their aggregation agent.Thus,the model with two layers is formed i.e.the aggregation agent layer and the meta-agent layer.The information communication among all agents is described.The meta-agents within one aggregation agent communicate with each other directly by information sharing,but the meta-agents,which belong to different aggregation agents exchange their information through the aggregation layer fast,and then perceive it from the sharing environment,that is the aggregation agent.Thus,not only the hierarchy model is built,but also the environment perceived by each agent is specified.Meanwhile,the problem of balancing the independency of agent and the resource consumption brought by real-time communication within multi-agent system (MAS) is resolved.Each agent involved in carrier-based aircraft catapult launch is depicted,with considering the interaction within disturbed atmospheric environment and multiple motion bodies including carrier,aircraft,and landing gears.The models of reactive agents among them are derived based on tensors,and the perceived messages and inner frameworks of each agent are characterized.Finally,some results of a simulation instance are given.The simulation and modeling of dynamic system based on multi-agent system is of benefit to express physical concepts and logical hierarchy clearly and precisely.The system model can easily draw in kinds of other agents to achieve a precise simulation of more complex system.This modeling technique makes the complex integral dynamic equations of multibodies decompose into parallel operations of single agent,and it is convenient to expand,maintain,and reuse

  11. Assessment and regression analysis on instant catapult steam explosion pretreatment of corn stover.

    Science.gov (United States)

    Liu, Chen-Guang; Liu, Li-Yang; Zi, Li-Han; Zhao, Xin-Qing; Xu, You-Hai; Bai, Feng-Wu

    2014-08-01

    Instant catapult steam explosion (ICSE) offers enormous physical force on lignocellulosic biomass due to its extremely short depressure duration. In this article, the response surface methodology was applied to optimize the effect of working parameters including pressure, maintaining time and mass loading on the crystallinity index and glucose yield of the pretreated corn stover. It was found that the pressure was of essential importance, which determined the physical force that led to the morphological changes without significant chemical reactions, and on the other hand the maintaining time mainly contributed to the thermo-chemical reactions. Furthermore, the pretreated biomass was assessed by scanning electron microscope, X-ray diffraction and Fourier transform infrared spectra to understand mechanisms underlying the ICSE pretreatment.

  12. Pollen Dispersal by Catapult: Experiments of Lyman J. Briggs on the Flower of Mountain Laurel

    Science.gov (United States)

    Nimmo, John R.; Hermann, Paula M.; Kirkham, M. B.; Landa, Edward R.

    2014-09-01

    The flower of Kalmia latifolia L. employs a catapult mechanism that flings its pollen to considerable distances. Physicist Lyman J. Briggs investigated this phenomenon in the 1950s after retiring as longtime director of the National Bureau of Standards, attempting to explain how hydromechanical effects inside the flower's stamen could make it possible. Briggs's unfinished manuscript implies that liquid under negative pressure generates stress, which, superimposed on the stress generated from the flower's growth habit, results in force adequate to propel the pollen as observed. With new data and biophysical understanding to supplement Briggs's experimental results and research notes, we show that his postulated negative-pressure mechanism did not play the exclusive and crucial role that he credited to it, though his revisited investigation sheds light on various related processes. Important issues concerning the development and reproductive function of Kalmia flowers remain unresolved, highlighting the need for further biophysical advances.

  13. Heterosis, the catapult effect and establishment success of a colonizing bird.

    Science.gov (United States)

    Drake, John M

    2006-06-22

    The genetic basis of population colonization is poorly understood, particularly in animals. Here, I introduce the idea of a 'catapult effect' to explain how the effects of transient increases in fitness can be retained in population demography diminishing the chance of extinction. I tested this idea using information on historical introductions of hybrid and non-hybrid pheasants in the United States. I found that hybrid pheasants were 2.2 times more likely to establish than non-hybrid strains. Analysis of fitness components failed to support the alternative that the increased odds of establishment resulted from increased genetic variation conferring permanent fitness benefits through directional selection or by purging deleterious alleles. These results show that even ephemeral increases in fitness can affect the persistence of small populations.

  14. Physicochemical characterization of wet microalgal cells disrupted with instant catapult steam explosion for lipid extraction.

    Science.gov (United States)

    Cheng, Jun; Huang, Rui; Li, Tao; Zhou, Junhu; Cen, Kefa

    2015-09-01

    Instant catapult steam explosion (ICSE) was employed to disrupt wet microalgal cells for efficient lipid extraction. Physicochemical properties of exploded cells were investigated through SEM, TEM, FTIR, and TGA. The exploded cells increased in fractal dimension (1.53-1.65) when preheat time was prolonged from 0 min to 5 min and in surface pore area when steam pressure was increased. Meanwhile, the exploded cells decreased in mean size (1.69-1.44 μm) when the filling ratio of wet microalgal biomass in the preheat chamber decreased (75-12.5%). Flash evaporation and volume expansion exploded the cell walls and released the cytoplasm of the microalgal cells. These phenomena decreased the carbohydrate content and increased the lipid content in the exploded biomass. However, ICSE treatment did not change the lipid compositions in the microalgal cells. Using isopropanol as a cosolvent significantly increased the yield of lipids extracted with hexane from the exploded wet microalgal biomass.

  15. Disorienting effects of aircraft catapult launchings: III. Cockpit displays and piloting performance.

    Science.gov (United States)

    Cohen, M M

    1977-09-01

    Accelerations closely approximating those encountered in catapult launchings of carrier-based aircraft were generated on the Naval Air Development Center's human centrifuge Dynamic Flight Simulator. Flight instruments, controls, and flight dynamics of an A-7 aircraft were provided to four experienced Naval Aviators, who exercised closed-loop control of a simulated climbout immediately after they were exposed to the accelerations. Four experimental conditions were employed for each aviator: 1) no operational flight instruments, 2) conventional flight instruments, 3) a single carrier takeoff director display operating concurrently. Measures of flight parameters, including indicated airspeed, angle of attack, rate of climb, altitude, pitch attitude, and pitch trim adjustment were monitored throughout the simulation. Subjective reactions and piloting performance were examined under each of the four conditions. Results indicate that the carrier takeoff director display significantly reduced pilot workload and enhanced performance during the climbout.

  16. Chemical characterization of single micro- and nano-particles by optical catapulting-optical trapping-laser-induced breakdown spectroscopy

    Science.gov (United States)

    Fortes, Francisco J.; Fernández-Bravo, Angel; Javier Laserna, J.

    2014-10-01

    Spectral identification of individual micro- and nano-sized particles by the sequential intervention of optical catapulting, optical trapping and laser-induced breakdown spectroscopy is presented. The three techniques are used for different purposes. Optical catapulting (OC) serves to put the particulate material under inspection in aerosol form. Optical trapping (OT) permits the isolation and manipulation of individual particles from the aerosol, which are subsequently analyzed by laser-induced breakdown spectroscopy (LIBS). Once catapulted, the dynamics of particle trapping depends both on the laser beam characteristics (power and intensity gradient) and on the particle properties (size, mass and shape). Particles are stably trapped in air at atmospheric pressure and can be conveniently manipulated for a precise positioning for LIBS analysis. The spectra acquired from the individually trapped particles permit a straightforward identification of the material inspected. Variability of LIBS signal for the inspection of Ni microspheres was 30% relative standard deviation. OC-OT-LIBS permits the separation of particles in a heterogeneous mixture and the subsequent analysis of the isolated particle of interest. In order to evaluate the sensitivity of the approach, the number of absolute photons emitted by a single trapped particle was calculated. The limit of detection (LOD) for Al2O3 particles was calculated to be 200 attograms aluminium.

  17. 弹射药筒局部热处理%Local Thermal Treatment on Catapult Cartridge

    Institute of Scientific and Technical Information of China (English)

    闻国民; 杨国义; 牛俊杰; 魏军伟; 陈全明

    2014-01-01

    针对弹射药筒局部热处理的质量性能要求,对感应加热技术进行研究。基于加热时间、温度和升温速度对筒壁的影响,从频率选择、感应器和工装设计3个方面进行分析,得到频率、功率和时间参数。分析结果表明:该方法使工件的抗拉强度、延伸率达到了要求,产品性能稳定,并能有效控制药筒口部的物理性能。%The technology of induction heating fusing had been researched in allusion to the demand of quality and property of the local thermal treatment on catapult cartridge. In view of the effect on cylinder wall about heating time, temperature and the rate of warming, parameter of frequency, temperature and time had been found according to the analysis in these three points including frequency selection, sensors and equipment design. Interrelated analyses concluded that these measures ensured the tensile strength and elongation, and made the performance stable. Also, physical properties of cartridge mouth had been controlled effectively.

  18. Catapult-like release of mitochondrial DNA by eosinophils contributes to antibacterial defense.

    Science.gov (United States)

    Yousefi, Shida; Gold, Jeffrey A; Andina, Nicola; Lee, James J; Kelly, Ann M; Kozlowski, Evelyne; Schmid, Inès; Straumann, Alex; Reichenbach, Janine; Gleich, Gerald J; Simon, Hans-Uwe

    2008-09-01

    Although eosinophils are considered useful in defense mechanisms against parasites, their exact function in innate immunity remains unclear. The aim of this study is to better understand the role of eosinophils within the gastrointestinal immune system. We show here that lipopolysaccharide from Gram-negative bacteria activates interleukin-5 (IL-5)- or interferon-gamma-primed eosinophils to release mitochondrial DNA in a reactive oxygen species-dependent manner, but independent of eosinophil death. Notably, the process of DNA release occurs rapidly in a catapult-like manner--in less than one second. In the extracellular space, the mitochondrial DNA and the granule proteins form extracellular structures able to bind and kill bacteria both in vitro and under inflammatory conditions in vivo. Moreover, after cecal ligation and puncture, Il5-transgenic but not wild-type mice show intestinal eosinophil infiltration and extracellular DNA deposition in association with protection against microbial sepsis. These data suggest a previously undescribed mechanism of eosinophil-mediated innate immune responses that might be crucial for maintaining the intestinal barrier function after inflammation-associated epithelial cell damage, preventing the host from uncontrolled invasion of bacteria.

  19. Pollen dispersal by catapult: Experiments of Lyman J. Briggs on the flower of mountain laurel

    Science.gov (United States)

    Nimmo, John R.; Hermann, Paula M.; Kirkham, M.B.; Landa, Edward R.

    2014-01-01

    The flower of Kalmia latifolia L. employs a catapult mechanism that flings its pollen to considerable distances. Physicist Lyman J. Briggs investigated this phenomenon in the 1950s after retiring as longtime director of the National Bureau of Standards, attempting to explain how hydromechanical effects inside the flower’s stamen could make it possible. Briggs’s unfinished manuscript implies that liquid under negative pressure generates stress, which, superimposed on the stress generated from the flower’s growth habit, results in force adequate to propel the pollen as observed. With new data and biophysical understanding to supplement Briggs’s experimental results and research notes, we show that his postulated negative-pressure mechanism did not play the exclusive and crucial role that he credited to it, though his revisited investigation sheds light on various related processes. Important issues concerning the development and reproductive function of Kalmia flowers remain unresolved, highlighting the need for further biophysical advances.

  20. Implement complex DSP Algorithm rapidly by Mentor High level Synthesis tool (Catapult Synthesis)%利用Mentor高层次综合技术(Catapult Synthesis)快速实现复杂DSP算法

    Institute of Scientific and Technical Information of China (English)

    游余新

    2007-01-01

    为了满足产品上市时间和功能丰富性的要求,越来越多的先进设计公司开始提高设计的抽象层次进行复杂的DSP硬件设计,从RTL级提高到C/C++,以保持产品的持续领先地位.Mentor Graphics的高层次综合工具(Catapult Synthesis)是第一个综合标准的ANSI C++的产品,它可无误地生成针对ASIC/FPGA的高质量RTL代码,且速度比手工编码的快10-20倍.本文以FIR的实现为例,利用Catapult Synthesi s快速探索不同的设计架构,快速地找到性能、面积和功耗之间折衷的最佳实现方案,使得真正的IP复用成为可能,并以图表方式给出不同约束下的面积、延迟和吞吐率(36、3、1时钟周期)的性能,同时提供了集成的验证和综合流程,极大地提高了设计效率.

  1. Outline of a Twenty-Five Year Plan for Development and Deployment of A Catapult for A Third Generation Space Shuttle

    Science.gov (United States)

    Russell, John M.

    2002-01-01

    This report reviews the rationale for catapult assist in the launching a third generation space shuttle. It then furnishes lists of early design decisions, questions whose answers are prerequisite to later design decisions, preliminary inventories of carriage levitation and carriage propulsion concepts, phases of the project and major milestones, and some sources of expertise to support the project.

  2. 舰载机蒸汽弹射动力学仿真分析%Dynamics Simulation of Carrier-based Aircraft Steam Catapult

    Institute of Scientific and Technical Information of China (English)

    张雷; 冯蕴雯; 薛小锋; 冯元生

    2012-01-01

    This article illustrates the need for a steam catapult device applications. Proposed the dynamics simulation model of carrier- based aircraft steam catapult on the basis of comprehensive consideration of the thermodynamic model, the traction release device mathematical model , aircraft kinetics model and landing gear jump and other factors. Based on C - 13 catapult and a certain type of aircraft,a simulation analysis is presented. The results,which are compared with test data,provide a useful reference for the design of carrier- based aircraft steam catapult system and experimental verification.%阐明了蒸汽弹射装置应用的必要性.在综合考虑热力学模型、牵引释放装置数学模型、舰载机动力学模型以及起落架突伸等因素的基础上,提出了舰载机蒸汽弹射动力学仿真分析模型.以C-13型弹射器和某型飞机为例进行了仿真分析,并与相关实验数据进行对比分析,其分析结果可为舰栽机蒸汽弹射系统设计以及试验验证提供有益参考.

  3. Direct polymerase chain reaction amplification of formalin-fixed, paraffin-wax-embedded tissue after automated sequential laser microdissection and pressure catapulting.

    Science.gov (United States)

    O'Kane, S L; Garimella, V; Sivarajasingham, N; Drew, P J; Cawkwell, L

    2007-02-01

    A robust method to facilitate rapid laser microdissection and pressure catapulting (LMPC) coupled with direct polymerase chain reaction (dPCR) to eliminate the need for extraction of DNA before a PCR-based assay is described. This sequential LMPC-dPCR method is rapid and decreases the number of processing steps, reducing the chance of tissue loss and contamination.

  4. Ditching Tests with a 1/12-Scale Model of the Army A-26 Airplane in Langley Tank No. 2 and on an Outdoor Catapult

    Science.gov (United States)

    Jarvis, George A.; Hoffman, Edward L.

    1947-01-01

    Tests were conducted in calm water in Langley tank no. 2 and in calm and rough water at an outdoor catapult in order to determine the best way to make a forced landing of an Army A-26 airplane and to determine its probable ditching behavior. These tests were requested by the Air Materiel Command, Army Air Forces, in their letter of March 26, 1943, WEL:AW:50.

  5. Analysis of dynamic characteristics of catapult launch for a carrier-based aircraft with sudden load discharge%考虑载荷突卸的舰载机弹射起飞动力学分析

    Institute of Scientific and Technical Information of China (English)

    朱齐丹; 李新飞; 喻勇涛

    2012-01-01

    In order to study dynamic characteristics of catapult launch for a carrier-based aircraft, a simplified dynamic model of catapult launch with sudden load discharge of nose gear was constructed. Fast vibration in the vertical direction of nose gear caused by the sudden discharge of the holdback load in the beginning of catapult launch was studied, and the dynamic reason of this phenomenon was analyzed. The rules of fast extension of nose landing gear caused by the sudden discharge of the catapult bridle load at the end of catapult launch was researched, and the influence of all parameters on the extension of nose landing gear was analyzed. Two important conclusions were obtained: in order to reduce the vibration peak value of the strain of nose landing gear during catapult launch, the holdback and catapult bridle lengths should be increased appropriately, and the maximum holdback breaking load is suggested to increase properly. Secondly, in order to decrease the difficulties of catapult launch, the catapult bridle length is recommended to decrease moderately.%为了分析舰载机弹射起飞过程中的动力学特点,建立了一种考虑前起落架载荷突卸的弹射起飞动力学模型.研究了在弹射开始时由于牵制载荷突卸而引起的前起落架沿着垂直方向的快速振动现象,并分析了该现象的动力学成因;研究了在弹射末端由于弹射杆载荷突卸而引起的前起落架的快速突伸规律,分析了各种参数对前起落架突伸的影响.结果分析表明:为了减小前起落架支柱受力的波动峰值,应适当增加弹射杆长度和牵制杆长度,及牵制杆最大破坏力值;但为了降低弹射起飞难度,应适当减小弹射杆长度.

  6. 技术与创新中心在解决创新的"死亡之谷"问题中的作用——基于对英国Catapults项目实施效果的实证分析%Technology Innovation Centre and Its Role in Addressing the Valley of Death—— Analysis of the Effects of Catapults Program in UK

    Institute of Scientific and Technical Information of China (English)

    李振兴

    2015-01-01

    Catapults program is started and funded by UK government to address the "Valley of Death" of innovation. To date, seven Catapults such as High Value Manufacture Catapult were set up and open to public, another two Catapults named Energy System and Precise Medicine Catapult are under the way to open. The reason of Valley of Death and the unique role of Catapults playing in addressing the Valley of Death were introduced; the economics background of Catapults program and necessity of implementing Catapults program as a public policy tool were analyzed. Cases were given to illustrate how Catapults may help the business development, especially the commercialization of research and development driven by innovation.%为解决创新的"死亡之谷"难题,英国近年投入巨资建设新的技术与创新中心(Catapults).本文从"死亡之谷"的形成原因出发,介绍了技术与创新中心在破解"死亡之谷"难题中发挥的独特作用,并基于已经建成的七个Catapults 的实证,分析了Catapults 项目实施的经济学背景以及作为公共创新政策工具的必要性,通过案例分析介绍了Catapults 在实际运行中如何促进产业发展特别是促进研究商业化和创新发展,供决策参考.

  7. Ditching Tests of a 1/9-Size Model of the Army P-38 Airplane in Langley Tank No. 2 and at the Outdoor Catapult

    Science.gov (United States)

    Jarvis, George A.; Cederborg, Gibson A.

    1946-01-01

    A dynamically similar model of the Army P-38 airplane was tested to determine the best way to land this airplane on the water and to determine its probable ditching performance. The tests consisted of ditching the model at various landing attitudes, flap settings, speeds, weights, and conditions of simulated damage. The model was ditched in calm water from the tank towing carriage and a few ditching were made in both calm and rough water at the outdoor catapult. The performance of the model was determined by making visual observations, by recording lengths of run and time histories of decelerations, and by taking motion pictures of the ditchings.

  8. Modeling of Carrier-based Aircraft's Catapult Launch under Surf%有浪条件下舰载机弹射起飞建模研究

    Institute of Scientific and Technical Information of China (English)

    张磊; 王海峰; 宋笔锋

    2012-01-01

    有浪条件下,航空母舰的摇摆会影响舰载机的安全起飞.对有浪条件下舰载机弹射起飞过程受力、运动情况进行了分析.采用柔性起落架来实现航空母舰与舰载机之间的干涉,建立了模块化的仿真系统并研究了中等海况下航空母舰的摇摆对舰载机弹射起飞的影响.仿真结果表明,中等海况下纵摇是导致下沉的主要因素,最大下沉量可达15 m;横摇导致最大下沉约0.2m;垂荡导致最大下沉约1m;横摇会导致明显的横侧向运动;纵摇、横摇、垂荡均会导致起落架最大载荷显著增大.%The carrier' s swing can endanger the safety of carrier-based aircraft launching. The forces and motions during the carrier-based aircraft catapult launch under surf, adopted flexible gear model to achieve interaction between the carrier-based aircraft and the carrier are theoretically analyzed, founded a modularized simulation system and researched on the influence of carrier' s rocking on aircraft' s catapult launch. Simulation results show that under moderate sea conditions, the pitch is the main factor leading to the subsidence which can up to 15 meters while roll resulting about 0.2 m and heave resulting about 1 m in the maximum subsidence. Roll also leads to significant lateral movement. Pitch, roll and heave result are significantly increased in load of gear.

  9. 舰载机蒸汽弹射热力学仿真分析%The thermodynamic simulation and analysis of the aircraft steam catapults

    Institute of Scientific and Technical Information of China (English)

    梁傲; 陈辉; 张国磊; 郭家敏; 周科; 杨诚

    2016-01-01

    通过对蒸汽弹射器基本工作原理的了解,运用动力学与热力学知识对其进行分析,考虑风速和开槽汽缸导热及漏气对弹射的影响,在合理的假设前提下利用Matlab/Simulink仿真软件建立出了蒸汽弹射热力学动态仿真模型,并以美国C-13型蒸汽弹射器为对象进行仿真分析,得出弹射过程中舰载机的加速度、速度、位移和储汽筒和汽缸内压力、温度以及漏汽量及耗汽量等参数的变化规律,对进一步了解蒸汽弹射具有一定意义。%The paper using the knowledge of dynamics and thermodynamics and the understanding of the basic prin-ciple of steam catapult, developing an analysis on the steam ejection of carrier-based aircraft, which is considering the thermal conductivity, the wind speed and the cylinder leakage effects on ejection;furthermore, a thermodynamic steam cata-pult out of a dynamic simulation model is established under the reasonable assumptions of the use of Matlab/Simulink simu-lation software. Meanwhile, a simulation analysis on C-13 type steam ejection of America shows that the acceleration, the velocity, the displacement, the steam reservoir, the inner pressure of the cylinder, the temperature, the quantity of the steam leakage and the steam consumption etc. and such kind changing rule of parameters, which are of great significance to have a further understanding of the steam ejection.

  10. 舰载机弹射起飞动力学虚拟试验研究%Research on Dynamics during Catapult Takeoff of Carrier-based Aircraft

    Institute of Scientific and Technical Information of China (English)

    隋成国; 许锋; 聂宏

    2013-01-01

    基于多体动力软件LMS Virtual.lab建立了某型飞机弹射起飞的刚柔耦合虚拟样机模型,使用一对点和柔性曲线约束副来模拟活塞杆和外筒的运动,分析了目标飞机的弹射起飞安全性及弹射过程中飞机的动力学响应.仿真表明:目标飞机的舰首下沉量能够满求,可以安全起飞.纵摇和垂荡的耦合会使飞机舰首下沉量增大;分离时的动态响应情况与分离载荷的大小和衰减速度有关.%A flex-rigid virtual prototype model was built in LMS Virtual, lab to simulate the catapult launch process of carrier-based aircraft. A pair of flex point curve joints were used to simulate the movements of the piston rod and the outer tube. The catapult security and dynamics response of the target aircraft were analyzed. Simulation results show that: the target aircraft meets the criteria requirements,and can take off safelysthe coupling of pitch and heave will increase subsidence;the dynamic response caused by separation is related to the size and decay rate of separate load.

  11. 运输类飞机弹射起飞动力学特性分析%Analysis of dynamical characteristics for transport catapult-assisted take-off

    Institute of Scientific and Technical Information of China (English)

    杨生民; 刘超; 刘智汉

    2011-01-01

    根据运输类飞机弹射起飞特点,建立了运输类飞机、舰船和风场等数学模型,着重介绍了能够反映飞机和舰船间多体动力学关系的起落架模型、弹射器和舰船运动模型的建模方法;开展了运输类飞机弹射起飞动力学特性研究,重点分析了起飞重量、升降舵预置偏度、甲板运动、前起落架突伸等因素对弹射起飞的影响,以期为运输类舰载机的设计和飞行试验提供技术支持.%Based on dynamical characteristics of transport catapult-assisted take-off, several models of carrier-type transports, and their near zones between a carrier and wind fields are designed in this paper. It mainly introduces the modeling method of different models for landing gears, a catapult and carrier motions to be able to represent the multi-body dynamical relevance between aircraft and carrier, and discusses dynamical characteristics for the transport catapult-assisted take-off. It is focus on analyzing the effects of various factors, including the transport ' s take-off weight, elevator predefined deflections, deck motions and nose gear sudden extension on the catapult-assisted take-off. The simulation results will give a reference to design and flight test for carrier-type transports.

  12. 偏中心定位对弹射过程中飞机姿态的影响%Effects of off-center location on aircraft attitude during catapult launch

    Institute of Scientific and Technical Information of China (English)

    于浩; 聂宏

    2011-01-01

    Owing to the deck motion and some other factors, the aircraft often has off-center distance with the catapult orbit. To study with this phenomenon, considering the deck motion, landing gear cushion and flexible tires, a six-degree-of-freedom mathematic model of carrier-based aircraft off-center catapult launch was established. The aircraft attitude during catapult taxing affected by the off-center distance with typical deck motion was studied. From the off-center catapult launch calculation, three important conclusions were obtained. The yaw movement are affected clearly by the initial off-center distance and its amplitude increases with the increase of the initial off-center distance. The attenuation of the yaw movement is clearly during catapult taxing and the launch bar side bending moment increases with the increase of the initial off-center distance. The results provide theoretical foundation for carrier-based aircraft design.%舰载飞机弹射起飞时,由于航母运动等因素的影响,飞机往往无法与弹射轨道对中.针对这种情况,在考虑航母运动以及起落架缓冲和轮胎弹性的基础上,建立六自由度偏中心定位弹射起飞数学模型,研究了在航母典型运动状态下不同初始偏心距离对弹射起飞过程中飞机姿态的影响,结果表明:初始偏心距离对飞机的偏航运动影响最大,偏航运动的幅度随初始偏心距离的增大而增大;在弹射滑跑过程中,飞机的偏航运动有明显的衰减趋势;弹射杆所承受的侧向弯矩随初始偏心距离的增大而增大.研究结果为舰载飞机的设计提供了一定的理论参考.

  13. Static Balance Analysis of Carrier-Based Aircraft Catapult Launch with Six Degrees of Freedom%舰载机弹射起飞六自由度静平衡分析

    Institute of Scientific and Technical Information of China (English)

    白双刚; 胡孟权; 段进坦

    2012-01-01

    静平衡状态是弹射起飞动力学分析的初始条件,也是进行弹射起飞动力学建模的基础.将舰船、飞机、起落架等视作具有独立质量的多运动实体,并分析描述它们之间的运动耦合关系,建立了舰载机静平衡状态下的六自由度数学模型,考虑了航母运动和甲板风以及海面气流扰动对飞机的影响.利用这一模型仿真计算了在不同情况下舰载机的静平衡状态,并分析了不同情况下舰载机的运动规律.计算结果与实际情况吻合,为舰载机弹射起飞六自由度动力学分析奠定了基础.%Static balance is the initial condition of catapult launch dynamic analysis, and the foundation of establishing the catapult launch model. Carrier, aircraft and landing gears, etc. are considered as multi -motion bodies that have their own masses, and the coupling relationships within these multi - motion bodies are also analyzed. The six degrees of freedom model of carrier - based aircraft is established in the condition of static balance, with the influences of carrier movement, deck wind and the airflow interference on aircraft considered. This model is applied to calculate and simulate the static balance of aircraft in different situations. The simulation and calculation results are consistent with the actual situation, which lays a foundation of dynamics analysis on carrier - based aircraft catapult launch with the six degrees of freedom model.

  14. Modeling and analyze of the environmental factors of carrier-based aircraft catapult launch in complex environment%复杂环境下舰载机弹射起飞环境因素建模分析

    Institute of Scientific and Technical Information of China (English)

    郭元江; 李会杰; 申功璋; 杨汀

    2011-01-01

    舰载机弹射起飞过程复杂,受到甲板运动、舰首气流、地面效应等复杂环境因素的影响.通过构建甲板运动模型、甲板风模型和地面效应模型,描述了弹射起飞过程中复杂的外部环境,并视为附加项加入到常规飞机方程中,建立了舰载机弹射起飞模型.研究表明:地面效应不利于舰载机弹射起飞;甲板风与舰首气流可抑制航迹下沉;舰面运动对舰载机离舰后下沉量影响很大.%The process of carrier-based aircraft catapult launch was complex,disturbed by the motion of aircraft carrier,deck wind,disturbance ahead of the bow and ground effect.The condition of carrier-based aircraft catapult launch was described by the simulation model of motion of aircraft carrier,deck wind,disturbance ahead of the bow and ground effect.The simulation model considering the condition of circumstance was composed of the model of plane and the model of circumstance condition,as the added factor.The results indicate that ground effect increases the flight path sinking,and the deck wind can help to decrease the flight path sinking during the catapult takeoff process.In addition,the motion of aircraft carrier has some important effects on maximum sinking and angle of attack.

  15. Analysis of deck edge distance taking into account the catapult launch%考虑弹射起飞的航母剩余甲板长度研究

    Institute of Scientific and Technical Information of China (English)

    李新飞; 王立辉; 朱齐丹; 张智

    2015-01-01

    In order to study the range of deck edge distance after the catapult launch, the dynamics model of catapult launch is constructed considering the fast⁃extension of the nose gear. The dynamic process of the catapult launching on the deck is simulated and the most effective deck edge distance is designed considering the role of fast⁃extension of the nose gear. The take⁃off from the aircraft carrier is also analyzed and the minimum deck edge distance is chosen with respect to sink over the bow. The method of designing deck edge distance is proposed taking into account both the fast⁃extension of the nose gear and sink over the bow and it is validated in the catapult launch simulation. The re⁃search has practical significance and engineering value.%为了分析弹射行程结束之后剩余甲板长度的范围问题,建立了一种考虑舰载机前起落架突伸作用的弹射起飞动力学模型。对甲板弹射起飞阶段的动力学过程进行了仿真分析,从前起落架突伸作用的角度设计了最有效剩余甲板长度;对离舰起飞阶段进行了仿真分析,从舰载机下沉量的角度设计了最小剩余甲板长度。最后综合考虑前起落架突伸作用和下沉量,提出了一种剩余甲板长度设计方法,并得到了仿真结果的验证,具有重要的现实意义和工程价值。

  16. 舰载机弹射起飞上升段控制律研究%Control Law for Climbing Stage of Carrier-Based Aircraft in Catapult-Assisted Take-Off

    Institute of Scientific and Technical Information of China (English)

    朱熠; 江驹; 甄子洋; 王新华; 焦鑫

    2012-01-01

    针对舰载机的安全弹射起飞要求,研究了弹射起飞上升段控制律设计问题.分析了常用弹射装置原理以及弹射起飞的工作流程.构建了弹射起飞过程中的上升段相关数学模型,包括某型舰载机的纵向模型、前起落架突伸结构和阵风模型.设计了舰载机起飞离舰后上升段的飞行姿态控制律,在仿真中将加速滑跑阶段的各种因素转化成初始条件,同时分析了阵风干扰对上升段飞机飞行特性的影响.仿真结果表明:设计的姿态控制律可以改善舰载机在离舰上升段的姿态,抵抗气流干扰等因素的影响,提高弹射起飞的安全性.%According to the safety requirements of catapult-assisted take-off,the control law design for the aircraft in the climbing stage was studied. The principle of a common catapult device was studied and the process of catapult-assisted take-off was introduced. The mathematic models in the climbing stage were established, including the model of longitudinal small perturbation equations of the aircraft, the sudden stretch structure of the nose gear and the gust disturbance. The attitude control law of the climbing stage was designed. In simulation, the initial value was based on the influence of different factors in speeding stage. The influence of the gust disturbance on flight performance of the aircraft in its climbing stage was also analyzed. The results of simulation showed that the designed control law can improve the aircraft attitude in the climbing stage, decrease the adverse effect of gust disturbance, and thus can enhance the security of the catapult-assisted take-off.

  17. 应用电磁弹射器的舰载机起飞性能分析%Performance Analysis of Catapult Take-Off Process of Carrier-Based Aircraft Using Electromagnetic Aircraft Launch System

    Institute of Scientific and Technical Information of China (English)

    李静; 左斌; 路翠华

    2012-01-01

    针对应用电磁弹射器的舰载机弹射起飞过程,综合考虑了电磁弹射器的推力、舰载机前起落架突伸力和载舰的运动,建立了舰载机弹射起飞的数学模型,并据此,分析了上述各种因素对舰载机弹射起飞安全性的影响,计算得到在满足舰载机弹射起飞安全准则的条件下,各种起飞因素应该满足的适应范围。研究分析表明:在风浪较大的恶劣天气条件下,通过适当地增加电磁弹射器的电磁推力和前起落架的突伸力,可以有效抑制舰载机的航迹下沉现象,确保舰载机的安全起飞过程。%Taking into consideration the thrust force of electromagnetic launch system,the nose gear fast-extension force and the ship motion process,a mathematical model of a carrier-based aircraft using electromagnetic launch system during the catapult takeoff process was built.Based on the proposed model,the influence of the above factors on catapult take-off safety was analyzed.Moreover,the scales of several take-off factors which accord with the catapult take-off safety were computed.The results indicated that properly increasing the thrust force of electromagnetic launch system and enhancing the nose gear fast-extension force could help to decrease the flight path sinkage and guarantee the catapult take-off safety of the carrier-based aircraft under the condition of atrocious weather.

  18. 基于闭排队网络的弹射器数量配置方法%Method of the catapult quantity deployed by using closed queuing network

    Institute of Scientific and Technical Information of China (English)

    陈红召; 杨大鹏

    2016-01-01

    The catapult's quantity deployed is a major influencing factor on carrier aircrafts' sortie genera⁃tion rate. In the incipient designing period, the catapult quantity is also one of the important factors. Consid⁃ering the queuing characteristic of the launch process as well as the closed characteristic of the launch and recovery process, this paper proposes a closed queuing network based model for evaluating the influence of the catapult's quantity on sortie generation rate, which can be applied to the design of catapult's quantity. For validation, an example is designed based on the F/A-18's sortie and the recovery process in the Surge operation, whose calculating results agree well with the Surge operation.%弹射器配置数量对舰载机出动回收能力有很大影响,因此,在航母设计初期多方案论证阶段,弹射器的数量配置是必须考虑的关键问题之一。针对舰载机起飞过程的排队特点以及整个出动回收过程的闭环特点,基于排队理论建立舰载机出动回收过程的闭排队网络模型,分析弹射器数量对出动回收能力的影响,分析结果可用于支撑弹射器的数量配置设计方案。为验证模型的有效性,采用“高强度”演习中F/A-18舰载机的数据作为参数输入,结果显示模型计算分析结果与“高强度”演习结果一致。

  19. Study on Effect of Damping Hole in Pneumatic Catapult on Performance of System%气动弹射器阻尼孔对系统性能影响的研究

    Institute of Scientific and Technical Information of China (English)

    刘救世; 马胜钢; 董攀辉; 窦小鹏; 裴东杰

    2014-01-01

    以新型贮气瓶供气气动弹射器为研究对象,建立了系统的数学模型,借助MATLAB仿真软件编制了系统的仿真模型,通过仿真研究获得了该弹射器阻尼孔对弹射过程中关键工作参数及系统性能的影响的规律,为详细设计该系统提供了依据。%By taking a new type of pneumatic catapult powered by gas tanks as the research object,the mathematical model of the system was established,and the simulation model of ejection system was programmed using MATLAB simulation software.The rules of influences on main working parameters and performance of system by the damping hole of the catapult have been obtained in the ejec-tion process through the simulation research.Thus it lays a theoretical foundation for the detailed design of the system.

  20. Carrier-based aircraft steam catapult system with feedback linearization control%舰载机蒸汽弹射反馈线性控制系统研究

    Institute of Scientific and Technical Information of China (English)

    刘恒; 朱齐丹; 李晓琳; 董然

    2016-01-01

    To study the states'change of accumulator and cylinder in steam catapult aircraft launch, aiming at the nonlinear coupling characteristics of the cylinder system, considering the flashing phenomenon in the steam accu⁃mulator, the pressure change of chamber with rod and without rod in the steam cylinder, and the relationship be⁃tween launching valve's core displacement and flow area, the steam accumulator and launching valve mathematical model, cylinder thermodynamic model and the aircraft six degrees of freedom dynamics model were established, and the launching valve controller of steam catapult system was accomplished. The simulation finds that the pres⁃sure⁃drop steam catapult system was extremely small, almost negligible in the catapult period; moreover, because of the nonlinear and coupling characteristics of the cylinder system, the traditional control method cannot accom⁃plish a stable launching valve, whose opening degree experiences strong mutations when opened and closed. Based on the feedback linearization theory, the steam cylinder model can be completely linearized and can decouple cylin⁃der state variables, contributing to the design of the launching valve controller. The simulation shows that using the feedback linearization method, the launching valve regulator can perform in a stable manner, achieving acceptable acceleration tracking effect during the catapult process.%为了研究舰载机蒸汽弹射过程中储汽筒与汽缸中各状态的变化,针对汽缸系统的非线性强耦合特点,考虑储汽筒内闪蒸现象、汽缸有杆腔与无杆腔压力变化以及发射阀芯位移与流通面积之间的关系,建立储汽筒、发射阀的数学模型,汽缸的热力学模型以及舰载机的六自由度运动模型,完成蒸汽弹射系统发射阀控制器设计。通过仿真研究发现,蒸汽弹射系统的储汽筒在弹射阶段压降很小,其影响可以忽略;并且,由于汽缸系统的各状态

  1. 基于排队论的大型舰船甲板弹射器数量研究%Investigation into Deck Catapults Quantity of Large Ship by Using Queuing Theory

    Institute of Scientific and Technical Information of China (English)

    周鑫磊; 孟祥印; 解学参; 胡玉龙; 侯远杭

    2011-01-01

    The objective of this article is to establish a theoretical basis for determining the quantity of catapult on the flight deck of large ship. As for investigation, the approach of "dummy queue (virtual queue)" was presented from the view of aircraft handling officer, and the task flow model was set up and analysis was carried out by using the queuing theory. The realistic model of task flow of carrier-based aircraft in standby position for launch was also constructed. A multiple calculations were conducted for the key targets, ignoring all the other factors, with regard to the influence of different quantities of catapults on the virtual length of aircraft's waiting queue and time of the system standby based on the assumption of the queuing theory. The results enable to have a quantifying comparison of sortie generation capacities of carried-based aircraft on the flight deck. The calculations also showed that under a given set of conditions, increasing the quantity of the catapult can obviously minimize the queuing length of the birds waiting in a queue for launch on the flight deck, but, if the number of catapult was greater than four, this would be less effective. Through the calculating results, application of the queuing theory to the demonstration as well as quantity design of catapult on large ship is proved to be practicable.%为明确大型舰船飞行甲板弹射器数量设计的理论依据,从调运指挥官的角度提出了"虚拟队列"概念,分析了其工作特点,对其工作模式进行了排队论建模.同时分析、建立了舰载机在弹射等待过程中的真实排队模型.忽略其它甲板因素的影响,基于排队论假设代入数值计算了不同弹射器数量对虚拟队列中舰载机的等待队长、系统等待耗时等关键指标的影响,使弹射器数量影响下的大型舰船舰载机出动能力得到了量化比较.计算结果表明,在给定条件下,甲板弹射器数量的增加能有效减少大型舰船舰

  2. The UAV Airfoil Aerodynamic Interference of Missile Launched from Rail-catapult Integrated Launcher%无人机导弹滑弹一体式发射对机翼的气动干扰

    Institute of Scientific and Technical Information of China (English)

    王博; 马贵春; 陈阳; 董浩

    2016-01-01

    无人机机载导弹发射产生的尾喷流对机翼的气动干扰影响载机飞行安全。本研究以Fluent软件为基础,采用二维非结构动网格技术并选择标准k-ω二方程湍流模型,对导弹沿导轨弹射滑行后点火和直接点火的发射过程分别进行数值模拟,并对两组结果进行对比。结果表明:滑弹一体式发射装置在一定程度上降低导弹尾喷流对机翼的气动影响。该研究为无人机导弹滑弹一体式发射装置的研究提供一定参考。%When airborne missile launched from UAV , its exhaust jet has an impact on UAV airfoil and safety .This study is based on two-dimensional unstructured dynamic grids and standard k-omega tow-equation turbulence model of the software Fluent .In this research differ-ence between missile ignition firing and ignition firing after ejection was analyzed , and these two results were compared .The results show that the rail-catapult integrated launcher can reduce aerodynamic influence on airfoil caused by missile exhaust jet stream .The results will provide certain reference for research of rail-catapult integrated missile launcher of UAV .

  3. 舰载无人机与弹射装置适配性问题研究%Study on Adaptability of Carrier-based Unmanned Aircraft with Aircraft Catapult Device

    Institute of Scientific and Technical Information of China (English)

    许云飞; 陈良

    2016-01-01

    The adaptability of carrier-based aircraft with aircraft catapult device is composed of machinery interface adaptability, operation process adaptability, take-off capability adaptability and environment condition adaptability in terms of engineering. Carrier-based unmanned aircraft has some unique features compared with common carrier-based aircraft in which be told issues, because it has been constricted by some factors such as requirements, technology level and cost. Chinese industry is a junior in application and design for carrier-based aircraft. This paper discussed features of adaptability of carrier-based aircraft with aircraft catapult device. As well as it believes that discussion could promote the technology readiness level up.%从工程角度,舰载机与弹射装置的适配性由机械接口适配性、操作流程适配性、起飞(含性能)适配性和环境适应性等4个方面构成。舰载无人机作为舰载机的一个分支,受到需求、技术成熟度与成本等多因素影响或制约,在上述4个方面与有人驾驶的舰载机相比,具有其特殊性。我国在舰载机特别是可被弹射起飞的舰载机设计领域仍处于初级阶段,本文针对舰载无人机与弹射装置的适配性进行讨论,以提高未来舰载无人机研制中相关技术的成熟度,加快型号研制进展。

  4. Vortices catapult droplets in atomization

    CERN Document Server

    Jerome, J John Soundar; Matas, Jean-Philippe; Zaleski, Stéphane; Hoepffner, Jérôme

    2016-01-01

    A droplet ejection mechanism in planar two-phase mixing layers is examined. Any disturbance on the gas-liquid interface grows into a Kelvin-Helmholtz wave, and the wave crest forms a thin liquid film that flaps as the wave grows downstream. Increasing the gas speed, it is observed that the film breaks up into droplets which are eventually thrown into the gas stream at large angles. In a flow where most of the momentum is in the horizontal direction, it is surprising to observe these large ejection angles. Our experiments and simulations show that a recirculation region grows downstream of the wave and leads to vortex shedding similar to the wake of a backward-facing step. The ejection mechanism results from the interaction between the liquid film and the vortex shedding sequence: a recirculation zone appears in the wake of the wave and a liquid film emerges from the wave crest; the recirculation region detaches into a vortex and the gas flow over the wave momentarily reattaches due to the departure of the vor...

  5. 瞬间弹射蒸汽爆破增强离子液体对水稻秸秆的预处理效果%Enhanced effects of ionic liquid pretreatment on rice straw by instant catapult steam explosion

    Institute of Scientific and Technical Information of China (English)

    覃锦程; 郝学密; 刘黎阳; 刘晨光; 白凤武

    2015-01-01

    选取具有不同组分分离效果的离子液体 1-乙基-3-甲基咪唑醋酸盐([Emim]Ac)和 1-乙基-3-甲基咪唑氯盐([Emim]Cl),并联用瞬间弹射蒸汽爆破(instant catapult steam explosion, ICSE)对水稻秸秆进行预处理.离子液体导致了组分的重排,使纤维素更多地暴露于物料表面,同时减弱了木质素对纤维素紧密交联的程度.ICSE的使用提升了离子液体的预处理效果,酶解糖收率比单纯使用离子液体升高了14.83%([Emim]Ac)和13.14%([Emim]Cl),其中ICSE联用[Emim]Ac的糖收率最高达97.00%.采用扫描电镜(SEM)和热重分析仪(TGA)进行物料结构分析,证实了ICSE联用离子液体有助于破坏物料的致密结构,增加无定形区,从而提高酶解糖收率.%In this study, two kinds of ionic liquid, including 1-ethyl-3-methylimidazolium acetate and 1-ethyl-3-methylimidazolium chloride were used to pretreat rice straw with instant catapult steam explosion (ICSE). The rearrangement of components were caused by ionic liquid pretreatment, which made more cellulose exposed at the surface of rice straw and weakened the cross-link between lignin and cellulose. Through enzymatic hydrolysis analysis, ICSE enhanced the effects of ionic liquid pretreatment by improving the sugar yield. Compared with the sugar yield as using ionic liquid alone, the sugar yield as combination of ICSE and ionic liquid increased by 14.83% ([Emim]Ac) and 13.14% ([Emim]Cl). The highest value reached 97.00% under the pretreatment by ICSE combine with [Emim]Ac. The structural changes were also analyzed by scanning electron microscope (SEM) and thermo gravimetric analysis (TGA). The pretreated materials became more porous with larger amorphous region, and consequently the sugar yield raised.

  6. Portable catapult launcher for small aircraft

    Science.gov (United States)

    Rosenbaum, Bernard J. (Inventor); Petter, George E. (Inventor); Gessler, Joseph A. (Inventor); Hughes, Michael G. (Inventor)

    2005-01-01

    An apparatus for launching an aircraft having a multiplicity of interconnected elongated tracks of rigid material forming a track system and wherein each elongated track has a predetermined elongated track cross-sectional design, a winch system connected to the track system wherein the winch system has a variable mechanical advantage, one or more elongated elastic members wherein one end of each of the one or more elongated elastic members is adjustably connected to the track system, and a carrier slidably mounted to the track system wherein the carrier is connected to the winch system and to the other end of each of the one or more elongated elastic members.

  7. Evaluation of instant catapult steam explosion combined with chemical pretreatments on corn stalk by components and enzymatic hydrolysis analysis%瞬间弹射蒸汽爆破联用化学法预处理玉米秸秆的组分和酶解分析

    Institute of Scientific and Technical Information of China (English)

    刘黎阳; 郝学密; 刘晨光; 白凤武

    2014-01-01

    以瞬间弹射蒸汽爆破(instant catapult steam explosion, ICSE)为基础,联用稀酸法、碱法、氨水法、有机溶剂法以及离子液体法进行预处理,对不同方法采用组分和酶解分析,以探索出一种绿色和高效的预处理方法。ICSE处理后的物料能够显著促进传统的化学预处理过程,其中ICSE与碱法联用预处理的糖收率最高,达到了77.54%,而ICSE与离子液体联用预处理后糖收率比单纯使用离子液体提高了7.78倍,达到了60.04%。选取ICSE与离子液体联用预处理过程作为最优预处理方法,并对其采用傅里叶-红外光谱、X射线晶体衍射和扫描电镜进行表征,经 ICSE 处理后玉米秸秆变得蓬松且不完整,半纤维素组分减少,促进离子液体对于纤维素的溶解;而与离子液体联用预处理后,物料纤维素和木质素相应官能团吸收峰增强,纤维素结晶构型由纤维素-Ⅰ型转变为纤维素-Ⅱ型,结晶指数降低。%Combining with instant catapult steam explosion (ICSE), corn stalk was pretreated by different chemical methods, including dilute acid, sodium hydroxide, aqueous ammonia, organic solvent, and ionic liquid. In order to obtain a green and highly efficient process, materials were analyzed by components and enzymatic hydrolysis analysis. ICSE could significantly prompt the effects of chemical methods on lignocellulose pretreatment. Among these approaches, ICSE combined with sodium hydroxide had the highest glucose yield 77.54%. Meanwhile, compared with the solo ionic liquid pretreated method, ICSE combined with ionic liquid pretreatment increased glucose yield by 7.78 folds, reaching 60.04%. Considering the requirements of efficiency, green process and low energy cost on pretreatment, the method of ICSE plus ionic liquid was selected as the optimal method and materials then were analyzed with Fourier transformed infrared (FT-IR), X-ray diffraction (XRD) and scanning

  8. Development of a Virtual Environment for Catapult Launch Officers

    Science.gov (United States)

    2015-03-01

    environment. The hardware, which generates the environment will also impact the virtual environment based on the methods of its presen - tation. When determining...launch scan are measured by the pro- gram recording the amount of time the objects that need to be evaluated in Section 5.1 are observed by the user...testing may identify the need to re-size the collision boxes or the sphere radius to improve accuracy. The starting and ending values of both the

  9. Catapulting Shifts in Images, Understandings, and Actions for Family Members through Research-Based Drama

    Science.gov (United States)

    Dupuis, Sherry L.; Gillies, Jennifer; Mitchell, Gail J.; Jonas-Simpson, Christine; Whyte, Colleen; Carson, Jennifer

    2011-01-01

    This article examined how images, understandings, and actions change for family members of persons with dementia after the introduction of a research-based drama called I'm Still Here. Guided by interpretivist phenomenology, a set of seven pre- and post-performance focus groups were conducted with family members (n = 48) in four cities. Findings…

  10. Textual Research on Catapult Martial Skills%弹射武技考述

    Institute of Scientific and Technical Information of China (English)

    王开文

    2002-01-01

    征引大量历史资料,从弹射溯源、弹弓的形制、弹弓的弹丸、弹弓的技法及弹弓的功用等几个方面对弹射武技予以考证论述,力图对弹射武技有一个较为全面的认识.

  11. Revealling Secrets of the Catapult%弹射器的[秘密

    Institute of Scientific and Technical Information of China (English)

    远峰

    2005-01-01

    @@ 弹射器的制造难点在那里? 许多文章关于弹射器制造难点的说法不尽相同,有的说开口汽缸密封是关键,有的说是开口汽缸制造难度很大,还有的说是弹射器的加工精度很高,也有的认为必须要有第一流的焊接技术.实际上,弹射器的真正难点在储汽罐的制造上.以上说法只有焊接技术才算是说到了点子上.

  12. 蒸汽弹射器揭秘%Towards Steam Catapult of Aircraft Carrier

    Institute of Scientific and Technical Information of China (English)

    舰群

    2008-01-01

    弹射器是航空母舰的关键装备,能够帮助各种舰载飞机快速起飞,提高航母的快速反应能力,扩大作战与预警范围,对航母战斗力起到“倍增器”的作用。本文简要介绍蒸汽弹射器的工作原理,披露弹射器关键部件的结构,包括汽缸、汽缸盖、活塞以及水刹等。

  13. A Textual Research on the Catapult Sport%弹弓运动考

    Institute of Scientific and Technical Information of China (English)

    王国凡

    2006-01-01

    运用文献资料法考证了弹弓运动在我国历史上的产生和发展的历程,并就弹弓运动在历史上的作用作了概述;对弹弓的制作与练习方法作了简要的介绍对弹弓运动的开展进行了展望.

  14. Gold nanorod in reverse micelles: a fitting fusion to catapult lipase activity.

    Science.gov (United States)

    Maiti, Subhabrata; Ghosh, Moumita; Das, Prasanta Kumar

    2011-09-21

    Lipase solubilized within gold nanorod doped CTAB reverse micelles exhibited remarkable improvement in its activity mainly due to the enhanced interfacial domain of newly developed self-assembled nanocomposites.

  15. The Corrosion Control of Fastening Systems for Aircraft Carrier Steam Catapults

    Science.gov (United States)

    1976-03-31

    as in the screening test, along with HY80 steel for the bottom plate as shown in Figure 18. Because of the three different tcp plate material and the...many months of laboratory tests. J B. CONCLUSIONS. 1. The normally supplied cadmium thickness on alloy steel fasteners for bridle arrester track use is...I I i I 1.1 [ L 4 A’ 2 NAEC-ENG 7868 PAGE viii 9 :1. ’.iS7 OF PhOTOGRAPHS - 1 Page Steel cloc, - Coatings 1 and 2 after 9 months at Ocean Cit

  16. Dancing through the School Day: How Dance Catapults Learning in Elementary Education

    Science.gov (United States)

    Becker, Kelly Mancini

    2013-01-01

    The necessity for engaging the body in learning, the need for students to move throughout the school day, and the positive effects that dance has on students' development are all good reasons for dance to be included in the elementary curriculum. There are many ways for teachers to integrate movement into the school day, using math, science,…

  17. Dynamics analysis of the spatial catapult separation problem%空间弹射分离动力学分析

    Institute of Scientific and Technical Information of China (English)

    王志刚; 杨雅楠; 邓逸凡

    2014-01-01

    对装有分离滑轨的空间弹射分离进行动力学分析,为分离系统设计和地面试验提供理论支持.针对任意布置弹簧和滑轨位置方向的分离情况进行各分离阶段的受力分析.根据牛顿运动定理、刚体动量定理及动量矩定理,在平动惯性参考系中建立分离过程的12自由度全状态动力学模型.给出不同初始条件下的模型求解算例,通过数值仿真对比验证了模型的准确性和有效性.

  18. From the elastica compass to the elastica catapult: an essay on the mechanics of soft robot arm

    Science.gov (United States)

    Armanini, C.; Dal Corso, F.; Misseroni, D.

    2017-01-01

    An elastic rod is clamped at one end and has a dead load attached to the other (free) end. The rod is then slowly rotated using the clamp. When the load is smaller than the buckling value, the rod describes a continuous set of quasi-static forms and its end traces a (smooth, convex and simple) closed curve, which would be a circle if the rod were rigid. The closed curve is analytically determined through the integration of the Euler’s elastica, so that for sufficiently small loads the mechanical system behaves as an ‘elastica compass’. For loads higher than that of buckling, the elastica reaches a configuration from which a snap-back instability occurs, realizing a sort of ‘elastica catapult’. The whole quasi-static evolution leading to the critical configuration for snapping is calculated through the elastica and the subsequent dynamic motion simulated using two numerical procedures, one ad hoc developed and another based on a finite-element scheme. The theoretical results are then validated on a specially designed and built apparatus. An obvious application of the present model would be in the development of soft robotic limbs, but the results are also of interest for the optimization analysis in pole vaulting. PMID:28293144

  19. Simulation on dynamics of the steam-powered catapult%蒸汽弹射器的动力学仿真研究

    Institute of Scientific and Technical Information of China (English)

    余晓军; 高翔; 钟民军

    2005-01-01

    针对航母蒸汽弹射器,在对其受力及热力学分析的基础上,建立其动力学模型,利用MATLAB软件建立了仿真系统进行数值计算,得到舰载机运动加速度、速度的大小及其与位移的关系,其计算方法是可行的;对多种弹射工况进行了仿真分析,获得不同工况下舰载机的弹射起飞运动特性,为弹射器的设计提供了可选方法及参数.

  20. Simulation and Analysis of Thermodynamics for Carrier-based Aircraft Steam Catapult%舰载机蒸汽弹射器热力学仿真分析

    Institute of Scientific and Technical Information of China (English)

    高俊东; 崔帅; 冯蕴雯; 薛小峰

    2013-01-01

    舰载机依靠蒸汽弹射器输出的弹射力推动其达到起飞速度,因此控制弹射力的输出尤为重要,为了分析研究蒸汽弹射器对弹射力输出的控制,本文阐明了蒸汽弹射器中控制蒸汽流量的发射阀结构和基本工作原理,提出发射阀中测量杆的位移与流通面积的计算方法,从而求解蒸汽流量,并结合蒸汽弹射器的热力学变化过程进行数学建模.以C13型弹射器为例进行仿真,通过实验数据的对比分析,说明了本文所建模型的可行性和正确性,其仿真结果可为蒸汽弹射器的设计与试验提供有益参考.

  1. 无刷电磁弹射器中电磁力的仿真计算%The Simulation Calculation of Electromagnetic Force for Brushless Electromagnetic Catapult

    Institute of Scientific and Technical Information of China (English)

    李勇; 董化新; 程树康; 王莹

    2002-01-01

    设计了一个基于无刷直流直线电机的电磁弹射器模型,采用二维场仿真方法计算了模型的电磁力静态特性曲线,分析了结构参数如气隙长度,磁钢厚度,铁磁材料特性等对电磁力特性的影响.该分析对模型的设计具有重要的指导意义.

  2. 无人机弹射器缓冲系统性能的研究与分析%Analysis on Buffer System of UAV Catapult

    Institute of Scientific and Technical Information of China (English)

    刘晓瑞; 马胜钢; 何宗海; 尹威华

    2014-01-01

    以无人机弹射器新型缓冲系统为研究对象,利用功率键合图法和MATLAB软件分别建立了系统的数学模型和仿真模型,结合缓冲系统的应用约束条件,通过仿真得到了无人机弹射器缓冲过程中一系列重要性能的特性曲线,为确定缓冲系统的工作参数,改善系统的性能奠定了理论基础.

  3. 舰载机悬浮式电磁弹射器的系统研究%MAGLEV ELECTORMAGNETIC CATAPULT SYSTEM FOR SHIPBOARD AIRCRAFTS

    Institute of Scientific and Technical Information of China (English)

    王媛; 张伟

    2013-01-01

    电磁弹射技术一直是世界发达国家竞相发展的高新技术,电磁弹射器将代替目前航母上使用的蒸汽弹射器.本文从舰载飞机起飞运动分析入手,以磁悬浮导轨技术和永磁无刷直线电机技术运用到磁悬浮电磁弹射设计中,简述了该项技术的基本原理、组成及其特点,并对悬浮电磁弹射系统进行分析.

  4. Modeling and Control of Carrier-based Airplane During Catapult Launch%舰载机弹射起飞建模与控制

    Institute of Scientific and Technical Information of China (English)

    王俊彦; 吴文海; 高丽; 张晓杰

    2010-01-01

    舰载机弹射起飞过程由舰面滑跑和离舰上升两个阶段组成,各阶段舰载机的受力与约束不同.根据两阶段舰载机的气动特性和运动特性,建立了一种通用的舰载机纵向动力学模型确定其离舰速度、离舰迎角和预置舵偏角,从而选择合适的控制策略完成弹射起飞上升阶段的自动控制飞行.以某型机为例,建立了全量非线性模型,并在此基础上设计了离舰上升阶段的控制方案.仿真结果表明,该模型与控制方案具有较好的控制效果.

  5. Design of parameter measurement system of UAV catapult%无人机弹射器参数测量系统设计

    Institute of Scientific and Technical Information of China (English)

    张建强; 刘波峰

    2013-01-01

    基于MEMS加速度计,研究和设计了一种无人机弹射器参数测量系统.通过对传感器标定,校准了其零偏、灵敏度等参数,实际使用时对误差进行补偿,提高了测量精度.根据实际加速度信号特点,选择合适的带宽和采样频率,并设计了数字滤波器,在保证响应频率的同时,有效降低了噪声.实验证明:本系统不仅达到了技术要求,而且与其他测量方式相比,有效地降低了成本.

  6. Carrier-borne Aircraft Electromagnetic Catapult to Come out%即将登场的航母电磁弹射器

    Institute of Scientific and Technical Information of China (English)

    雪巴

    2007-01-01

    美国海军航母目前使用的飞机蒸汽弹射器不仅体积笨重、噪音大,而且能量效率低下,因此美国海军曾多次研究新原理的弹射器去取代它,但均由于某些技术原因而陆续放弃。20世纪90年代,美国海军开始设计下一代航母(先是CVN-21,后来定为CVN-78)时提出了一个非常先进的概念——全电军舰。它要求航母的动力传输都将以电力为基础,而不再采用蒸汽、液压等传统的机械手段,其中最重要的技术飞跃之一就是蒸汽弹射器将被电磁弹射器所取代。

  7. ELECTROMAGNETIC CATAPULT'S SIMULATION WITH THE FINITE ELEMENT METHOD BASED ON ANSOFT%基于Ansoft的电磁弹射器的有限元仿真

    Institute of Scientific and Technical Information of China (English)

    赵科义; 李治源; 杨秋学; 吕庆敖; 刘斌

    2006-01-01

    基于电磁场仿真软件Ansoft建立了一种电磁弹射器的几何模型,结合几何模型建立了仿真的数学模型,并利用该软件对模型进行了有限元分析与仿真,仿真结果验证了模型的可行性.

  8. 某型导弹弹射发动机装药的安全贮存寿命预估%Safe Storage Life Estimation of a Certain Catapult Missile Motor Charge

    Institute of Scientific and Technical Information of China (English)

    卢明章; 左英英; 刘所恩

    2008-01-01

    为了准确预估某型导弹弹射发动机装药的安全贮存寿命,对自然贮存10年后的发动机装药进行了X射线检测、燃烧性能、物理化学性能、化学安定性能、力学性能、内弹道性能等测试.结果表明,该导弹弹射发动机装药的安全贮存寿命至少为10年.

  9. 基于MC S51单片机的多频点无线寻呼发射机设计%Design of Multi-Frequency Radio Beeper Catapult Based on MCS51 Sing le-chip Computer

    Institute of Scientific and Technical Information of China (English)

    张航; 罗大庸

    2001-01-01

    提出了一种将单片机技术和集成锁相环技术相结合的设计多频点无线寻呼发射机的新方法.该方法具有16个频点的接口能力,还具有频点显示、监控和远程控制等多种操作方式,能真正做到无人值守,并给出了系统的软硬件设计以及干扰问题的多种防止措施.

  10. 舰载机偏中心定位弹射起飞弹射杆载荷分析%Launch Bar Load Analysis of Carrier-based Aircraft During Off-center Catapult Launch

    Institute of Scientific and Technical Information of China (English)

    于浩; 聂宏

    2010-01-01

    考虑舰载机偏中心定位,建立了六自由度弹射起飞动力学模型,对偏中心弹射过程中弹射杆受载情况进行了分析计算,讨论了初始偏心距离和起飞重量对弹射杆载荷的影响,并详细论述了其动力学成因.研究结果表明:飞机的滚转运动是导致弹射杆承受较大弯矩和扭矩的主要原因;弹射杆弯矩和扭矩随初始偏心距离的增大而迅速增大,但其轴向拉力受初始偏心距离影响较小;在弹射滑跑初始阶段,弹射杆的轴向拉力、弯矩以及扭矩随起飞重量的减小而增大,而在弹射滑跑后期,弹射杆所受载荷则随起飞重量的减小而减小.

  11. 高速液压弹射实验装置中高速液压缸的设计%Design of a high speed hydraulic cylinder in a hydraulic catapult system

    Institute of Scientific and Technical Information of China (English)

    陶小军; 李晓明; 朱祖超

    2006-01-01

    本文根据液压缸压杆稳定性计算理论及同步性,确定了高速液压缸的主要尺寸,并对同步性进行了验算;根据高速运动的特点,设计了一种高速密封结构,最后对设计结构进行仿真.校核和仿真结果表明,这种同步液压缸设计是合理可行的.

  12. 齿轮增速式液压弹射器弹射过程的仿真分析%Simulation Analysis on Hydraulic Catapult Ejection Process of Gear Increaser

    Institute of Scientific and Technical Information of China (English)

    刘兰荣; 马笑尘

    2016-01-01

    以齿轮增速式液压弹射器的弹射过程为研究对象,运用功率键合图法建立了弹射过程的数学模型,利用MATLAB软件建立仿真模型并进行了详细的仿真分析,得到了弹射过程中关键参数对弹射性能的影响,为中重型无人机弹射起飞的研究提供了理论依据.

  13. Two-dimensional Interior-ballistic Model and Numerical Research on Low-pressure Chamber of Catapult%弹射器低压室二维内弹道模型及数值研究

    Institute of Scientific and Technical Information of China (English)

    谭大成; 苗佩云

    2006-01-01

    文中以自弹式弹射器为例,建立了低压室二维内弹道模型,并进行了内弹道性能计算.计算表明,基于二维模型的数值模拟,可以给出低压室内气体流动的细节,能够更准确地描述低压室内弹道特性;从导弹离筒速度和筒内行程等总体指标看,零维模型和二维模型的计算结果相差不大;二维模型的计算工作量大、耗时长,而零维模型的计算工作量相对较小、计算速度快,二者各有优势,目前不能也没有必要以二维模型完全替代零维模型.

  14. 航母舰载机:弹射起飞还是滑橇起飞?%Catapult and Ski-Jump,Two Ways of Takeoff for Ship-Borne Aircrafts

    Institute of Scientific and Technical Information of China (English)

    李杰

    2006-01-01

    当今.世界各国海军航空母舰舰载机的起飞方式主要有弹射起飞、滑橇起飞和垂直,短距滑跑起飞等。弹射起飞是利用飞行甲板上布置的弹射装置.在一定行程内对舰载机施加推力.使其达到离舰起飞速度。滑橇起飞是利用航母艏部的上翘甲板。在机载发动机的大推力下实现起飞。垂直,短距滑跑起飞则是利用机载发动机的推力矢量控制来实现起飞.鉴于前苏联“雅克-38”垂直,短距起降攻击机已随着“基辅”级航母一起退役.以及英国垂直,短距起降式“海鹞”战斗机的携载量和航程难以满足需要。因此这种起飞方式目前用得较少。

  15. 气垫导轨实验中滑块的等速和定速发射%Glider catapult at identical or definite velocity in air track experiment

    Institute of Scientific and Technical Information of China (English)

    李维钧; 赵四建

    2006-01-01

    设计了由改进的弹射架和定位释放器组成的等速发射装置,实现了气垫导轨实验中滑块的等速发射,并可通过控制滑块初始位置使滑块获得预期发射速度.分析表明滑块发射所获得的速度和初始位置间的关系为近似的线性关系,这一结论和实验结果完全符合.

  16. Multibody Simulation Models in Tensor Form for Carrier-based Aircraft Catapult Launch%舰载弹射起飞多体动力学仿真张量模型

    Institute of Scientific and Technical Information of China (English)

    王维军; 屈香菊; 郭林亮

    2009-01-01

    舰载机弹射起飞过程复杂,目前完整考虑舰船、舰载飞机和大气运动及其相互作用的仿真模型尚未见到.将舰船、飞机、起落架等视作具有独立质量的多运动实体,基于张量理论建立了弹射起飞过程的全量多体动力学仿真模型.通过张量模型在不同坐标系的投影方程,分析、描述了多运动体之间的耦联关系.并考虑舰船运动、诱导风场等对舰载机的作用,通过某舰载机弹射起飞的仿真结果曲线,描述了舰载飞机弹射起飞过程的特殊动力学行为.

  17. Catapult Take-off Characteristics of a Carrier-based Airplane Influenced by Ship Motion%航母运动对舰载飞机弹射起飞特性影响研究

    Institute of Scientific and Technical Information of China (English)

    姚海林; 赵一飞; 张宏

    2015-01-01

    舰载飞机的弹射起飞安全受运动影响显著,本文针对舰载飞机的弹射起飞过程,进行了六自由度的仿真建模,通过弹射起飞仿真计算,分析了航母纵摇、垂荡运动对其弹射起飞特性的影响.结果表明由于舰首距离航母纵摇中心距离较大,航母纵摇运动相位变化对舰载飞机的弹射起飞影响较大,而选择在舰首抬升阶段离舰,有利于起飞安全.

  18. 飞机弹射起飞起落架动力学仿真分析%The Dynamic Simulation on Landing Gear of Catapult Take-Off for Carrier-Based Aircraft

    Institute of Scientific and Technical Information of China (English)

    乔鸽; 虞伟建

    2014-01-01

    基于多体系统动力学的方法理论,应用ADAMS软件建立前起落架和主起落架的动力学仿真模型,并且以此为基础建立全机的动力学虚拟样机模型,对飞机弹射起飞过程进行仿真分析,并针对不同飞机起飞质量和弹射力,对比分析了其对起落架动力学响应及全机起飞性能的影响,结果表明:应用ADAMS对飞机起落架结构进行动力学仿真分析对起落架设计能提供必要的依据,减小飞机起飞质量以及增大弹射力,能够有效提高飞机弹射起飞性能.

  19. Numerical Simulation of Missiles Launched by Rail-catapult Integrated Launcher with Different Firing Time%不同点火时间导弹滑弹一体式发射数值模拟

    Institute of Scientific and Technical Information of China (English)

    王博; 马贵春; 陈阳

    2016-01-01

    使用计算流体力学软件Fluent对导弹滑弹一体式发射的过程进行模拟研究.通过对比导弹弹射后不同点火时间对机翼的气动干扰情况,找出使用滑弹一体式发射装置时合适的导弹发动机点火时间.

  20. 无人机液压弹射器弹射过程的仿真分析与试验研究%Simulation Analysis and Experimental Research of UAV Hydraulic Catapult Ejection Process

    Institute of Scientific and Technical Information of China (English)

    刘兰荣; 马笑尘

    2016-01-01

    以液压蓄能器为动力源、液压马达为执行元件的无人机液压弹射器的弹射过程为研究对象,运用功率键合图法建立了弹射过程的数学模型,利用仿真分析结合实验对该过程进行了详细的研究,得到了弹射过程中关键工作参数对弹射性能的影响,为弹射系统的研发与改进提供了重要依据.

  1. 铁板小车弹射液压系统的设计与分析%Design and Analysis of Hydraulic System for Iron Plate Vehicle Catapult Hydraulic System

    Institute of Scientific and Technical Information of China (English)

    王文云

    2016-01-01

    在某型水中兵器电磁引信陆上试验中,针对短距离将大质量铁板加速至高速的需求,提出铁板小车液压弹射的方法,详细阐述了铁板小车弹射液压系统的设计思路、液压系统工作原理.此研究成果已应用于实际,效果很好,同时也为其他的高速弹射系统提供了良好的设计思路.

  2. Performance Increase and Key Problems of the Carrier-based Aircraft Ramp/Catapult Synthesized Take-off%舰载机斜板/弹射综合起飞的性能收益与关键问题

    Institute of Scientific and Technical Information of China (English)

    孙友师; 屈香菊

    2008-01-01

    弹射起飞技术难度大、能量消耗大,弹射系统质量体积大,而滑跃起飞又无法使推重比小的舰载机起飞,难以形成强大战斗力,针对这一问题,提出将弹射起飞和滑跃甲板结合起来的斜板/弹射综合起飞方式.针对这种起飞方式的特点进行了分析,并通过数值仿真,说明了这种起飞方式预期的性能收益以及存在的关键问题.

  3. Research on dynamic modeling and correlative problems of catapult launch for carrier-based airplane%舰载机弹射起飞的动力学建模与相关问题研究

    Institute of Scientific and Technical Information of China (English)

    车竞; 和争春

    2014-01-01

    为了对舰载机弹射起飞的动力学过程进行仿真,开展了舰载机弹射起飞的动力学建模与相关问题研究.对舰载机本体、起落架、弹射器、航母运动进行了建模,对起飞姿态预置、离舰导引律、安全起飞边界进行了初步探讨.其结果将为建立全面细致的舰载机起飞动力学模型、进行全因素的动力学仿真与安全边界评估奠定基础.

  4. Gradual Progress of Carrier-based Aircraft Catapult in U.S.Navy%五花八门的弹射器——美国海军航母弹射飞行发展史

    Institute of Scientific and Technical Information of China (English)

    雪巴

    2007-01-01

    随着中国综合国力的提高,国民的海洋意识有了很大改变,在民间对航母的热衷日渐高升,甚至人代会都有人考虑提出航母问题议案,民间也有为造航母发起捐款的。有人认为弹射器是中国建造航母的瓶颈,一时间国内媒体和专利局充斥着大量关于弹射器的发明创造。实际上,弹射器的知识目前还不够普及,本文将给关心航母的朋友一个清晰的认识和对弹射器的正确理解。

  5. Ditching Tests of a 1/18-Scale Model of the Navy XP4M-1 Airplane in Langley Tank No. 2 and on an Outdoor Catapult, TED No. NACA 2362

    Science.gov (United States)

    Fisher, Lloyd J.; Hoffman, Edward L.

    1947-01-01

    Tests with a dynamically similar model of the Navy XP4M-1 airplane were made to determine the best way to land the airplane in calm and rough water, to determine its probable ditching performance, and to determine practicable modifications which could be incorporated in the design of the airplane that would improve its ditching characteristics. The results were obtained by making visual observations, by recording longitudinal decelerations,a nd by taking motion pictures of the landings. A list of conclusions from the test results is included.

  6. 高剛性受動関節を有する閉ループ柔軟カタパルトと遊泳ロボットへの応用

    OpenAIRE

    山田, 篤史; 渡, 正充; 望山, 洋; 藤本, 英雄; ヤマダ, アツシ; フジモト, ヒデオ; Yamada, Atsushi; Fujimoto, Hideo

    2009-01-01

    In this paper, we propose a new robotic catapult with a high stiffness endpoint. The conventional robotic catapults based on the closed elastica are the robotic elements for generating impulsive motions by utilizing the snap-through buckling. In a typical closed elastic catapult, the two ends of an elastic strip are fixed to a free joint and an active joint, respectively. Here we found that by adding only the high stiffness at the free joint, compared to the conventional type, more elastic en...

  7. Holy graal of physics

    CERN Document Server

    Bührke, Thomas

    2006-01-01

    With the biggest "catapult" for elementar particles, the physicists want to explain why there is actually matter. Like in the USA some years ago, big accelerator started to find that black light would perhaps exist. (1 page)

  8. Brazil World Cup Challenges

    Directory of Open Access Journals (Sweden)

    MANSUR, R.

    2012-12-01

    Full Text Available Overcoming the productivity challenge is the main benefit of the 2014 World Cup for Brazilian people. The sustainable development of our cultural tourism industry will catapult the new middle class growing up rate.

  9. Development of a compact Bio-Optofluidic Cell Sorter

    DEFF Research Database (Denmark)

    Bañas, Andrew Rafael; Palima, Darwin; Pedersen, Finn;

    2012-01-01

    the extended axial manipulation range provided by the low numerical aperture geometry. Detected particles are catapulted axially by several hundred microns, allowing them to be moved from one laminar flow region to another. As the sorting motion is transverse to the viewing plane, multiple particles can...... be catapulted at the same time, therefore enabling parallel sorting. The sorter is developed with a minimal footprint such that it can operate as a table top device, an advantage over flow cytometry or FACS systems....

  10. Ad-Hoc Sensor Networks for Maritime Interdiction Operations and Regional Security

    Science.gov (United States)

    2012-09-01

    it to be carried and stored by a ship, but the launch and recovery system is a pneumatic catapult and Skyhook wingtip capture system respectively...picture of Integrator with its launch catapult is depicted in Figure 22. 51 Figure 22. UAV Integrator (From [48]) Another example of a...Networks,” in Proc of the 7th Annual International Conference on Mobile Computing and Networking, pp. 139-150, Rome , Italy, July 16–21, 2001 107

  11. Developing and Application of Dynamic Pressure Anchor Support Drift to Control Tearing Rockbolt Catapult Protection Device%动压锚网支护巷道控制断裂锚杆弹射防护装置的研究与应用

    Institute of Scientific and Technical Information of China (English)

    魏振红

    2008-01-01

    针对动压锚网支护巷道锚杆断裂后,断裂锚杆尾"弹射"的安全隐患,进行了技术分析并研制了弹性防护装置,保证了巷道安全的施工环境,消除了施工人员的恐惧心理,为锚网支护巷道施工的安全管理提供了新的防护模式.

  12. "弩炮计划"的缘起--1940年法国单独停战与英国的对策研究%The Origins of Operation Catapult: the French Armistice with Germany in 1940 and the British Reaction

    Institute of Scientific and Technical Information of China (English)

    梁占军

    2005-01-01

    "弩炮计划"是英国战时内阁在法国败降后做出的一项重要决策,旨在消除法国舰队的潜在威胁.作为对法国单独停战的回应,该计划不仅是一个预防性的军事行动计划,同时也是英国政府在国家存亡的危机关头决意单独对德作战的外交活动中的重要一环.其决策过程实际上是英国在战与和的战略问题上进行抉择的一个缩影.

  13. Principles of laser-induced separation and transport of living cells.

    Science.gov (United States)

    Horneffer, Verena; Linz, Norbert; Vogel, Alfred

    2007-01-01

    Separation and transport of defined populations of living cells grown on a thin membrane can be achieved by laser microdissection (LMD) of the sample of interest, followed by a laser-induced forward transport process [laser pressure "catapulting" (LPC)] of the dissected cell cluster. We investigate the dynamics of LMD and LPC with focused and defocused UV-A laser pulses by means of time-resolved photography. Catapulting is driven by plasma formation when tightly focused pulses are used, and by confined thermal ablation at the bottom of the sample for defocused catapulting. With both modalities, the initial specimen velocity amounts to about 50 to 60 ms. Time-resolved photography of live cell catapulting reveals that in defocused catapulting, strong shear forces arise when the sample is accelerated out of the culture medium covering the cells. By contrast, pulses focused at the periphery of the specimen cause a fast rotational movement that minimizes the flow of culture medium parallel to the sample surface, and thus the resulting shear stresses. Therefore, the recultivation rate of catapulted cells is much higher when focused pulses are used. Compared to collateral damage by mechanical forces, side effects by heat and UV exposure of the cells play only a minor role.

  14. 40 CFR 1700.4 - Discharges requiring control.

    Science.gov (United States)

    2010-07-01

    ... systems. (l) Gas Turbine Water Wash: the water released from washing gas turbine components. (m) Graywater... training, testing, or maintenance operations. (b) Catapult Water Brake Tank & Post-Launch Retraction Exhaust: the oily water skimmed from the water tank used to stop the forward motion of an aircraft...

  15. China’s Aircraft Carrier Ambitions: An Update

    Science.gov (United States)

    2010-01-01

    weapons acquisition budget during that time. The annual cost for regular training , maintenance, repairs, and fuel for two carrier battle groups can be...Technology], no. 2 (2008); and Ding Guoliang, Hu Yefa, and Liu Xiaojing, “ Maglev Electromagnetic Catapult System Structure Design and Magnetic Field

  16. Launch Options for the Future

    Science.gov (United States)

    1988-01-01

    B. Callaham Stephen W. Korthals-Altes Gordon Law Ray A- Williamson Administrative Staff Jannie Home Cecile Parker Jackie Robinson...more than half of current U.S. payload mass to low earth orbit. Coilgun for Cargo - Electric catapults and guns have been studied since the 1930s, but

  17. Using pico-LCoS SLMs for high speed cell sorting

    DEFF Research Database (Denmark)

    Bañas, Andrew Rafael; Aabo, Thomas; Palima, Darwin

    2012-01-01

    We propose the use of consumer pico projectors as cost effective spatial light modulators in cell sorting applications. The matched filtering Generalized Phase Contrast (mGPC) beam shaping method is used to produce high intensity optical spots for trapping and catapulting cells. A pico projector...

  18. A Tale of Two Kirzners

    DEFF Research Database (Denmark)

    Korsgaard, Steffen; Berglund, Henrik; Thrane, Claus;

    2016-01-01

    has exerted a strong influence on entrepreneurship research in the last decade, and helped catapult the field forward. We propose that Mark II, with its emphasis on time, uncertainty and creative action in pursuit of imagined opportunities, complements the discovery view and can provide an alternative...

  19. Radiocarbon dating of the bronze age bone pins from Eurasian steppe

    NARCIS (Netherlands)

    Shishlina, Natalia I.; Van der Plicht, Johan; Zazovskaya, Elya P.

    2011-01-01

    Bone catapult and hammer-headed pins played one of very specific roles in funerary offerings in the Bronze Age graves uncovered in the Eurasian Steppes and the North Caucasus. Scholars used different types of pins as key grave offerings for numerous chronological models. For the first time eight pin

  20. F-35 Joint Strike Fighter (JSF) Program: Background and Issues for Congress

    Science.gov (United States)

    2011-04-26

    suitability include, among other things, strengthened landing gear, a strengthened airframe, and an arresting hook so as to permit catapult launches and...Jane’s Defence Weekly, November 10, 2004. 79 Barbara Opall- Rome and David Pugliese, “Israeli Clarification Calms Canada’s Ire on Offsets,” Defense News

  1. USAFRICOM: The Militarization of U.S. Foreign Policy?

    Science.gov (United States)

    2008-01-01

    do” attitude, coupled with its large resource pool, has catapulted it to the front of Govern- ment agencies in its ability to implement and support...like the other combatant commands—is another prime example of American proconsuls plying foreign policy.28 In ancient Rome , proconsuls were

  2. Russian Political, Economic, and Security Issues and U.S. Interests

    Science.gov (United States)

    2008-10-06

    enlargement in Central and Eastern Europe, but reconciled itself to that. NATO and Russian leaders meeting in Rome signed the “NATO at 20” agreement...into Georgia. Tension between Moscow and Tbilisi sharpened further after Georgia’s “Rose Revolution” catapulted U.S.-educated Mikhiel Saakashvili into

  3. Strategic Importance of Saudi Arabia - Neither A Friend Nor Foe

    Science.gov (United States)

    2007-11-02

    civilizations to include Egypt, Greece, Mesopotamia, Rome , Byzantium, India, China, and Persia to mention just a few.2 The Koran, or book of faith for... catapulted the United States’ relationship with Saudi Arabia into the limelight. Many Americans around the country, to include influential members

  4. Preparing for the Chemical, Biological, Radiological and Nuclear (CBRN) Threat Within the Contemporary Operating Environment (COE)

    Science.gov (United States)

    2007-11-02

    Feodossia, Ukraine) in 1346. Rats and their fleas carried the plague to besieging Tatar soldiers. Seeking revenge, the Tatars catapulted the bodies...the days of Rome and Carthage had such a polarization of power existed. The stunned legislators agreed to endorse the program on the condition that

  5. CTC Sentinel. Volume 2, Issue 10

    Science.gov (United States)

    2009-10-01

    February 19, 2002, four Moroccan citizens were arrested in Rome after police found them in possession of a cyanide compound, allegedly destined to be...regional affiliates could ultimately carry out successful attacks on Israeli targets. Local Salafi-jihadi groups in the Gaza Strip could catapult

  6. F-35 Joint Strike Fighter (JSF) Program

    Science.gov (United States)

    2012-02-16

    strengthened airframe, and an arresting hook so as to permit catapult launches and arrested landings, as well as folding wing tips for more compact storage...80 Barbara Opall- Rome and David Pugliese, “Israeli Clarification Calms Canada’s Ire on Offsets

  7. Spatiotemporal cattle data - a plea for protocol standardization

    Science.gov (United States)

    It was not until the end of the 1990’s that animal born satellite receiver’s catapulted range cattle ecology into the 21st century world of microchip technology with all of its opportunities and challenges. With the global navigation satellite system (GNSS) insight into how cattle use a landscape i...

  8. The Latest Twist on Spreading Innovation: One School at a Time

    Science.gov (United States)

    Moreno, Carlos; Luria, Dana; Mojkowski, Charles

    2013-01-01

    Responding to the need for game-changing innovation that will catapult student achievement, some school districts seek assistance from school development organizations that specialize in helping schools. But such work presents problems when schools try to adopt and adapt innovation and outside partners face challenges in encouraging schools to…

  9. Bestrijding van aviaire influenza onder pluimvee: vaccinatie als aanvullende mogelijkheid

    NARCIS (Netherlands)

    Aarle, P van; Breytenbach, J; Schueller, S

    2006-01-01

    Since mid-December 2003, highly pathogenic avian influenza (HPAI) has caused an epidemic in the Asian poultry sector and avian influenza cases have been reported in Europe, the Middle East and Africa. Human fatalities catapulted avian influenza into the public arena with fears of a possible global i

  10. "Not Too Late to Take the Sanitation Test": Notes of a Non-Gifted Academic from the Working Class

    Science.gov (United States)

    Borkowski, David

    2004-01-01

    Working-class academic narratives reveal a number of common themes, like dual estrangement and internalized class conflict. A less popularized motif is the bookish child who is catapulted out of her working-class origins. But some working-class academics, like myself, were not academically ambitious as children. I am a nontraditional working-class…

  11. The OECD as Pivot of the Emerging Global Educational Accountability Regime: How Accountable Are the Accountants?

    Science.gov (United States)

    Meyer, Heinz-Dieter

    2014-01-01

    Background/Context: PISA has catapulted the OECD- an organization whose mission is the global growth of market economies-to a central role in international education policy making, rivaling and sometimes outdoing the various national governments in influence. While claiming scientific evidence as the basis for the accountability regime it…

  12. Hypermediated Art Criticism

    Science.gov (United States)

    Taylor, Pamela G.; Carpenter, B. Stephen, II

    2007-01-01

    Technological media catapults our perception into what Marshall McLuhan called "new transforming vision and awareness." As our lives become more and more immersed in such technologies as television, film, and interactive computers, we find ourselves inundated with a heightened sense of mindfulness--an aesthetic experience made possible through…

  13. Safety First: Houston, We Have Liftoff!

    Science.gov (United States)

    Roy, Ken

    2014-01-01

    A thrown basketball, a kicked football, an elastically launched catapult payload, and a free-falling solid fuel or pressurized gas-propelled rocket all have one thing in common. They are all projectiles familiar to elementary students. A projectile is an object thrown with an initial velocity and then allowed to move without thrust along its…

  14. Physics Notes.

    Science.gov (United States)

    School Science Review, 1979

    1979-01-01

    Included is information regarding: fabrication of light emitting diodes, their operation as semiconductors, and an experiment demonstrating electroluminescence; experimenting with Random Access Memory (RAM) circuits; demonstrating Coriolis effect; measuring the diameter of an electron beam, E.H.T. meters; launching a trolley by catapult; a "random…

  15. 舰载机前轮滑跃起飞技术%Carriered-Aircraft Taking-off with Nose Landing Gear on Ski-jump Ramp Profile

    Institute of Scientific and Technical Information of China (English)

    房兴波; 聂宏; 于浩

    2011-01-01

    The ramp profile is introduced to the aircraft carrier to make it sure that the nose landing gear goes to the ramp profile after the catapult process, so that the nose of the aircraft rise. The simplified model of the whole carriered-aircraft during the process of catapult take off is built. Dynamic equations about catapult run phase are presented. The dynamic response of the carriered-aircraft during the process of catapult take off is calculated via Runge-Kutta procedure. The results indicate that the introduction of ramp profile can decrease the flight path sinkage during the catapult take off, the off-carrier velocity of the aircraft, and increase the take off masses and the load of the nose landing-gear.%在航母甲板上引入斜坡跑道,使舰载机弹射冲程结束后,前轮单独进入斜坡跑道,从而使飞机抬头.建立了舰载机起飞时的简化分析模型,给出了基于该分析模型的运动微分方程及相关参数的表达式,并采用龙格库塔算法对舰载执在斜坡跑道上滑跑起飞速一过程的动态响应进行了数值仿真.仿真结果表明,斜坡跑道的引入可以明显降低舰载机离舰后航迹的下沉量,降低舰载机的离舰速度,增加起飞质量,增大前起落架载荷.

  16. Superconductivity

    Science.gov (United States)

    1989-07-01

    SUPERCONDUCTIVITY HIGH-POWER APPLICATIONS Electric power generation/transmission Energy storage Acoustic projectors Weapon launchers Catapult Ship propulsion • • • Stabilized...temperature superconductive shields could be substantially enhanced by use of high-Tc materials. 27 28 NRAC SUPERCONDUCTIVITY SHIP PROPULSION APPLICATIONS...motor shown in the photograph. As a next step in the evolution of electric-drive ship propulsion technology, DTRC has proposed to scale up the design

  17. 中软国际推出全新业务流程自动化解决方案Launch

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    日前.中软国际旗下企业Catapult Systems,领先的IT咨询及微软解决方案提供商.宣布推出全新的业务流程自动化懈决方案Launch。作为解决方案即服务套件的一部分.Launch用以满足每个企业的关键需求。

  18. Quantum leaps of black holes: Magnifying glasses of quantum gravity

    CERN Document Server

    Chakraborty, Sumanta

    2016-01-01

    We show using simple arguments, that the conceptual triad of a {\\it classical} black hole, semi-classical Hawking emission and geometry quantization is inherently, mutually incompatible. Presence of any two explicitly violates the third. We argue that geometry quantization, if realized in nature, magnifies the quantum gravity features hugely to catapult them into the realm of observational possibilities. We also explore a quantum route towards extremality of the black holes.

  19. 一种DES算法的FPGA快速实现方法%A High-speed FPGA Implementation of DES Algorithm

    Institute of Scientific and Technical Information of China (English)

    鄢斌

    2011-01-01

    该文阐述了密码算法FPGA快速实现的一种方法,利用Mentor Graphics的Catapult C综合工具,完成了DES算法从计算机仿真到硬件实现的全过程,代替了传统FPGA实现处理过程,可大大缩短项日的开发周期和降低作难度.

  20. Africa Command and the Militarization of U.S. Foreign Policy

    Science.gov (United States)

    2008-03-10

    its large resource pool has literally catapulted the military out in front of other government agencies in its ability to implement and support...that USAFRICOM--like the other GCCs--is another prime example of American Proconsuls plying foreign policy.83 In ancient Rome , proconsuls were...Keeping Peace With America’s Military, 70. 84 The Columbia Encyclopedia, “proconsul, in ancient Rome ,” The Columbia Encyclopedia, 6th ed., (New York

  1. Efficient lossy compression implementations of hyperspectral images: tools, hardware platforms, and comparisons

    Science.gov (United States)

    García, Aday; Santos, Lucana; López, Sebastián.; Callicó, Gustavo M.; Lopez, Jose F.; Sarmiento, Roberto

    2014-05-01

    Efficient onboard satellite hyperspectral image compression represents a necessity and a challenge for current and future space missions. Therefore, it is mandatory to provide hardware implementations for this type of algorithms in order to achieve the constraints required for onboard compression. In this work, we implement the Lossy Compression for Exomars (LCE) algorithm on an FPGA by means of high-level synthesis (HSL) in order to shorten the design cycle. Specifically, we use CatapultC HLS tool to obtain a VHDL description of the LCE algorithm from C-language specifications. Two different approaches are followed for HLS: on one hand, introducing the whole C-language description in CatapultC and on the other hand, splitting the C-language description in functional modules to be implemented independently with CatapultC, connecting and controlling them by an RTL description code without HLS. In both cases the goal is to obtain an FPGA implementation. We explain the several changes applied to the original Clanguage source code in order to optimize the results obtained by CatapultC for both approaches. Experimental results show low area occupancy of less than 15% for a SRAM-based Virtex-5 FPGA and a maximum frequency above 80 MHz. Additionally, the LCE compressor was implemented into an RTAX2000S antifuse-based FPGA, showing an area occupancy of 75% and a frequency around 53 MHz. All these serve to demonstrate that the LCE algorithm can be efficiently executed on an FPGA onboard a satellite. A comparison between both implementation approaches is also provided. The performance of the algorithm is finally compared with implementations on other technologies, specifically a graphics processing unit (GPU) and a single-threaded CPU.

  2. Director, Operational Test and Evaluation

    Science.gov (United States)

    2007-12-01

    rack . The improved configuration will enhance the flight medic’s ability to care for patients during transport for all 81...wall mounted MEDEVAC equipment rack , the Army plans to assess the flight medic’s ability to care for patients during transport. • The LUH meets...incorporate electromagnetic catapults (instead of steam powered) and have a smaller island with a Dual Band Phased Array Radar. • Weapons stowage

  3. Quantum leaps of black holes: Magnifying glasses of quantum gravity

    Science.gov (United States)

    Chakraborty, Sumanta; Lochan, Kinjalk

    2016-10-01

    We show using simple arguments, that the conceptual triad of a classical black hole, semi-classical Hawking emission and geometry quantization is inherently, mutually incompatible. Presence of any two explicitly violates the third. We argue that geometry quantization, if realized in nature, magnifies the quantum gravity features hugely to catapult them into the realm of observational possibilities. We also explore a quantum route towards extremality of the black holes.

  4. Book review: JFK in the senate: pathway to the presidency

    OpenAIRE

    Polo Alonso, Ana

    2013-01-01

    Before John F. Kennedy became a legendary young President, he was the junior Senator from Massachusetts. The Senate was where JFK’s presidential ambitions were born and first realized. In this forthcoming book, John T. Shaw looks at how the young Senator was able to catapult himself on the national stage. JFK in the Senate aims to provide an accessible introduction to Kennedy’s personality and his efforts to transform himself into a viable presidential candidate, and it will certainly appeal ...

  5. Neck Muscle Fatigue Resulting from Prolonged Wear of Weighted Helmets

    Science.gov (United States)

    2008-06-01

    documented neck injury rates of 50% or higher ranging from minor neck strain to cervical vertebral fracture3,11-14,17. Lighter helmets were developed...greater neck fatigue and susceptibility to neck injury. There may be an increase in cervical loads during aircraft ejections (catapult, windblast...and compromised effectiveness for long missions. The neck load limits ( flexion , extension, and rotation) under operational conditions are

  6. Traian Vuia – the Romanian inventor who first flew a powered airplane in 1906

    Directory of Open Access Journals (Sweden)

    Liviu FILIMON

    2011-09-01

    Full Text Available As observed the beginning of heavier than air devices started with Wright Brothers who flew in 1903 the first catapulted airplane equipped with an engine, similar to present motor gliders. In March 1906 took place the first flight of Vuia’s monoplane using on board installations. Since then a real competition between manufacturers has started to improve their airplanes as they become more efficient. Traian Vuia’s first flights and his beginnings are explained below.

  7. The Drop Tower Bremen -An Overview

    Science.gov (United States)

    von Kampen, Peter; Könemann, Thorben; Rath, Hans J.

    The Center of Applied Space Technology and Microgravity (ZARM) was founded in 1985 as an institute of the University of Bremen, which focuses on research on gravitational and space-related phenomena. In 1988, the construction of ZARM`s drop tower began. Since its inau-guration in September 1990, the eye-catching Drop Tower Bremen with a height of 146m and its characteristic glass roof has become twice a landmark on the campus of the University of Bremen and the emblem of the technology park Bremen. As such an outstanding symbol of space science in Bremen the drop tower provides an european unique facility for experiments under conditions of high-quality weightlessness with residual gravitational accelerations in the microgravity regime. The period of maximum 4.74s of each freely falling experiment at the Drop Tower Bremen is only limited by the height of the drop tower vacuum tube, which was fully manufactured of steal and enclosed by an outer concrete shell. Thus, the pure free fall height of each microgravity drop experiment is approximately 110m. By using the later in-stalled catapult system established in 2004 ZARM`s short-term microgravity laboratory is able to nearly double the time of free fall. This world-wide inimitable capsule catapult system meets scientists` demand of extending the period of weightlessness. During the catapult operation the experiment capsule performs a vertical parabolic flight within the drop tower vacuum tube. In this way the time of microgravity can be extended to slightly over 9s. Either in the drop or in the catapult operation routine the repetition rates of microgravity experiments at ZARM`s drop tower facility are the same, generally up to 3 times per day. In comparison to orbital platforms the ground-based laboratory Drop Tower Bremen represents an economic alternative with a permanent access to weightlessness on earth. Moreover, the exceptional high quality of weightlessness in order of 1e-6 g (in the frequency range below 100

  8. Take-off speed in jumping mantises depends on body size and a power-limited mechanism.

    Science.gov (United States)

    Sutton, G P; Doroshenko, M; Cullen, D A; Burrows, M

    2016-07-15

    Many insects such as fleas, froghoppers and grasshoppers use a catapult mechanism to jump, and a direct consequence of this is that their take-off velocities are independent of their mass. In contrast, insects such as mantises, caddis flies and bush crickets propel their jumps by direct muscle contractions. What constrains the jumping performance of insects that use this second mechanism? To answer this question, the jumping performance of the mantis Stagmomantis theophila was measured through all its developmental stages, from 5 mg first instar nymphs to 1200 mg adults. Older and heavier mantises have longer hind and middle legs and higher take-off velocities than younger and lighter mantises. The length of the propulsive hind and middle legs scaled approximately isometrically with body mass (exponent=0.29 and 0.32, respectively). The front legs, which do not contribute to propulsion, scaled with an exponent of 0.37. Take-off velocity increased with increasing body mass (exponent=0.12). Time to accelerate increased and maximum acceleration decreased, but the measured power that a given mass of jumping muscle produced remained constant throughout all stages. Mathematical models were used to distinguish between three possible limitations to the scaling relationships: first, an energy-limited model (which explains catapult jumpers); second, a power-limited model; and third, an acceleration -: limited model. Only the model limited by muscle power explained the experimental data. Therefore, the two biomechanical mechanisms impose different limitations on jumping: those involving direct muscle contractions (mantises) are constrained by muscle power, whereas those involving catapult mechanisms are constrained by muscle energy.

  9. Jumping performance of flea hoppers and other mirid bugs (Hemiptera, Miridae).

    Science.gov (United States)

    Burrows, M; Dorosenko, M

    2017-02-13

    The order Hemiptera includes jumping insects with the fastest take-off velocities, all generated by catapult mechanisms. It also contains the large family Miridae or plant bugs. Here we analysed the jumping strategies and mechanisms of six mirid species from high speed videos and from the anatomy of their propulsive legs and conclude that they use a different mechanism in which jumps are powered by the direct contractions of muscles. Three strategies were identified. First, jumping was propelled only by movements of the middle and hind legs which were respectively 140% and 190% longer than the front legs. In three species with masses ranging from 3.4 to 12.2 mg, depression of the coxo-trochanteral and extension of femoro-tibial joints accelerated the body in 8-17 ms to take-off velocities of 0.5 to 0.8 m s(- 1) The middle legs lost ground contact 5-6 ms before take-off so that the hind legs generated the final propulsion. The power requirements could be met by the direct muscle contractions so that catapult mechanisms are not implicated. Second, other species combined the same leg movements with wing beating to generate take-off during a wing downstroke. In the third strategy, up to four wing beat cycles preceded take-off and were not assisted by leg movements. Take-off velocities were reduced and acceleration times lengthened. Other species from the same habitat did not jump. The lower take-off velocities achieved by powering jumping by direct muscle contractions may be offset by eliminating the time taken to load catapult mechanisms.

  10. Take-off speed in jumping mantises depends on body size and a power-limited mechanism

    Science.gov (United States)

    Doroshenko, M.; Cullen, D. A.; Burrows, M.

    2016-01-01

    ABSTRACT Many insects such as fleas, froghoppers and grasshoppers use a catapult mechanism to jump, and a direct consequence of this is that their take-off velocities are independent of their mass. In contrast, insects such as mantises, caddis flies and bush crickets propel their jumps by direct muscle contractions. What constrains the jumping performance of insects that use this second mechanism? To answer this question, the jumping performance of the mantis Stagmomantis theophila was measured through all its developmental stages, from 5 mg first instar nymphs to 1200 mg adults. Older and heavier mantises have longer hind and middle legs and higher take-off velocities than younger and lighter mantises. The length of the propulsive hind and middle legs scaled approximately isometrically with body mass (exponent=0.29 and 0.32, respectively). The front legs, which do not contribute to propulsion, scaled with an exponent of 0.37. Take-off velocity increased with increasing body mass (exponent=0.12). Time to accelerate increased and maximum acceleration decreased, but the measured power that a given mass of jumping muscle produced remained constant throughout all stages. Mathematical models were used to distinguish between three possible limitations to the scaling relationships: first, an energy-limited model (which explains catapult jumpers); second, a power-limited model; and third, an acceleration-limited model. Only the model limited by muscle power explained the experimental data. Therefore, the two biomechanical mechanisms impose different limitations on jumping: those involving direct muscle contractions (mantises) are constrained by muscle power, whereas those involving catapult mechanisms are constrained by muscle energy. PMID:27284067

  11. cell-BOCS: Bio-Optofluidics Cell Sorter

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Palima, Darwin; Bañas, Andrew Rafael

    Within the framework of the recent DTU spin-out activity OptoRobotix we are developing an active cell sorter [1] that utilizes parallel microscopic machine vision for cell identification. Particles are identified based on visual features such as shape, size and color using image processing...... a large field of view, allowing them to be displaed from one laminar flow region to another. As the sorting motion is transverse to the viewing plane, multiple particles can be catapulted at the same time, therefore enabling a fully parallel sorting process [4, 5]. The cell-BOCS is developed with small...

  12. ACES II Seat Roller Study: Findings of Detrimental Friction under High Windblast or Adverse Flight Conditions

    Science.gov (United States)

    2015-08-12

    primarily the “Air Force seat”, since 1970’s) ADAMS = Automatic Dynamic Analysis of Mechanical Systems (6-DOF software , MSC Corporation) AEPS...friction, catapult thrust, net acceleration, etc.). The ADAMS Ejection Trajectory Model, built in www.ADAMS.com software … 45th Space Wing, Safety...test (110E-A1-Aft; 95th percentile pilot with a man-seat mass of ~390lbm, ejection from an F-16 mockup at 600KEAS, straight-and-level). In this test

  13. A NASA study of the impact of technology on future carrier based tactical aircraft - Overview

    Science.gov (United States)

    Wilson, S. B., III

    1992-01-01

    This paper examines the impact of technology on future carrier based tactical aircraft. The results were used in the Center for Naval Analysis Future Carrier Study. The NASA Team designed three classes of aircraft ('Fighter', 'Attack', and 'Multimission') with two different technology levels. The Multimission aircraft were further analyzed by examining the penalty on the aircraft for both catapult launch/arrested landing recovery (Cat/trap) and short take-off/vertical landing (STOVL). The study showed the so-called STOVL penalty was reduced by engine technology and the next generation Strike Fighter will pay more penalty for Cat/trap than for STOVL capability.

  14. Emerging Literature on Cognitive Intervention Techniques for Early Stage Dementia

    Directory of Open Access Journals (Sweden)

    John W Den Boer

    2016-10-01

    Full Text Available Dementia is a growing world-wide phenomenon, impacting more than six million people in the United States. Despite its high projected prevalence, it is a significantly under-represented phenomena, with (underestimate ranging from 15-25% of the general population. The effect of the aging of the population and significant increase in life expectancy has combined to catapult dementia into the range of one of most alarming healthcare problems. Diverse and emerging literature in the area of cognitive prevention/intervention for mild cognitive impairment (MCI/early stage dementia will be reviewed. Additionally, future research and clinical directions will be explored.

  15. Computer Forensics JumpStart

    CERN Document Server

    Solomon, Michael G; Tittel, Ed; Broom, Neil; Barrett, Diane

    2011-01-01

    Essential reading for launching a career in computer forensicsInternet crime is on the rise, catapulting the need for computer forensics specialists. This new edition presents you with a completely updated overview of the basic skills that are required as a computer forensics professional. The author team of technology security veterans introduces the latest software and tools that exist and they review the available certifications in this growing segment of IT that can help take your career to a new level. A variety of real-world practices take you behind the scenes to look at the root causes

  16. 汽车结构

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Development of a vehicle structure with enhanced pedestrian safety;Door slam Cycle Tests of an automobile structure;Dynamic interaction of vehicles moving on uniform bridge;Dynamical actions on highway bridge decks due to an irregular pavement surface;Electric Drive System for Electric and Hybrid Vehicles;Energy absorption and performance of a vehicle impact protection system;Fatigue strength evaluation on resistance spot welds of the vbehicle body;HyperG - a new hydro-pneumatic, catapult-type sled;Integration of a terrain-adaptive traction control system in the hierarchy of locomotion control system;……

  17. 世界轻武器史上的101个重要事件(100)

    Institute of Scientific and Technical Information of China (English)

    刘学昌

    1998-01-01

    @@ 100 弩在军事上的应用 弩(crossbow)是用机械力射箭的弓.一些武器史专家认为弩是诺曼底人发明的;另一些人说弩是希腊南部克里特岛上的居民发明的,第一次十字军东侵(11世纪末)后传入欧洲大陆.它很可能是由围城和守城用的笨重的弩炮(ballista或catapult)改进而成的.

  18. 从欧洲杯看可穿戴设备风生水起

    Institute of Scientific and Technical Information of China (English)

    梁春丽

    2016-01-01

    正火热的欧洲杯现场可以说是可穿戴装备的盛宴。以使用STAT Sporcs设备为代表的欧洲球员在训练时和比赛中穿着的球衣普遍内置了具有追踪系统的传感器;Catapult Sports和GPS Sports为全球范围的许多球队提供了球员状态监测,帮助球员在赛场上呈现最好的竞技状态。

  19. Primary level management of eye injuries

    Directory of Open Access Journals (Sweden)

    Bakary Ceesay

    2005-10-01

    Full Text Available Eye injuries are common and a leading cause of preventable unilateral blindness worldwide. The causes vary, but drawing upon experience from The Gambia and Senegal, trauma is more common during the farming season and among small-scale metal workers working without eye protection. Stick injury is common in children and farmers, sometimes causing a penetrating injury that can result in the affected eye quickly becoming infected. Blunt trauma is common among children, who can be injured with a catapult or stone. The dusty environment is a common cause of corneal, conjunctival and sub-tarsal foreign bodies injuries.

  20. PVT roadmap. A European guide for the development and market introduction of PVT technology

    Energy Technology Data Exchange (ETDEWEB)

    Zondag, H.A.; Van Helden, W.G.J.; Bakker, M. [ECN Renewable Energy in the Built Environment DEGO, Petten (Netherlands); Affolter, P. [Solstis, Lausanne (Switzerland); Eisenmann, W. [Institut fuer Solarenergieforschung ISFH, Emmerthal (Germany); Fechner, H. [Arsenal Research, Vienna (Austria); Rommel, M. [Fraunhofer ISE, Freiburg (Germany); Schaap, A. [Ecofys, Utrecht (Netherlands); Soerensen, H. [Esbensen, Copenhagen (Denmark); Tripanagnostopoulos, Y. [University of Patras, Patras (Greece)

    2005-11-15

    In PVT technology, heat is extracted from PV cells. In this way, a device is made that produces both electricity and heat. In the EU-funded co-ordination action PV-Catapult, workshops on PVT were organised at the PVSEC 2004 Conference in Paris and the Eurosun 2004 conference in Freiburg, to obtain active participation of the PV and solar thermal communities. Currently, the results of the workshops are used in the drafting of a roadmap for the large-scale introduction of PVT technology on the market. First results will be presented here.

  1. A novel method of strain - bending moment calibration for blade testing

    Science.gov (United States)

    Greaves, P.; Prieto, R.; Gaffing, J.; van Beveren, C.; Dominy, R.; Ingram, G.

    2016-09-01

    A new method of interpreting strain data in full scale static and fatigue tests has been implemented as part of the Offshore Renewable Energy Catapult's ongoing development of biaxial fatigue testing of wind turbine blades. During bi-axial fatigue tests, it is necessary to be able to distinguish strains arising from the flapwise motion of the blade from strains arising from the edgewise motion. The method exploits the beam-like structure of blades and is derived using the equations of beam theory. It offers several advantages over the current state of the art method of calibrating strain gauges.

  2. Penrose At Work

    CERN Document Server

    Cen, Renyue

    2011-01-01

    If a supermassive black hole has some material orbiting around it at close to its innermost stable circular orbit (ISCO), then, when it plunges into a second supermassive black hole, the orbiting material has a velocity dispersion of order of speed of light about the orbital velocity of its host black hole. It becomes plausible that some of the orbiting material will be "catapulted" to the negative-energy ergosphere orbits of the second black hole at the plunge. This may provide an astrophysically plausible way to extract energy from the black hole, originally suggested by Penrose.

  3. A roadmap for the development and market introduction of PVT technology

    Energy Technology Data Exchange (ETDEWEB)

    Zondag, H.A.; Van Helden, W.G.J.; Bakker, M.; Elswijk, M.J. [ECN Renewable Energy in the Built Environment DEGO, Petten (Netherlands)

    2005-11-15

    In PVT technology, heat is extracted from PV cells. In this way, a device is made that produces both electricity and heat. In the EU funded coordination action PV-Catapult, workshops on PVT were organised at the PVSEC 2004 Conference in Paris and the Eurosun 2004 conference in Freiburg, to obtain active participation of the PV and solar thermal communities. Currently, the results of the workshops are used in the drafting of a roadmap for the large scale introduction of PVT technology on the market. First results will be presented here.

  4. 我所知道的——关于踩槌的一切(四)

    Institute of Scientific and Technical Information of China (English)

    李果

    2008-01-01

    而台湾的GIBRALTAR新研发的GCLMSP Catapult Linear Motion Bass Drum Pedal[图044]也因为其古怪的制动方式被我归入此类,这样说起来,SONOR的Gtep 3 Giant Step Twin Effect Pedal[图045]、Gtep 3 Giant Step Triple Pedal [图046]、GMP 4 Giant Step Middle Pedal[图047]也绝对属于此例。

  5. Effects of Foreign Perceptions of U.S. Casualty Aversion on U.S. International Relations

    Science.gov (United States)

    2007-11-02

    career catapulted forward when he told the angry Serbs that “no one should dare to beat you!”3 With the crowd chanting “Slobo, Slobo!” he began...Athens I Kathimerini (in Greek) 25 March 2000, 10, FBIS Document ID: GMP20000326000175. 30Adriano Sofri, “When US Soldiers Die,” Rome La Repubblica...FTS19991016000039. 7See Adriano Sofri, “When US Soldiers Die,” Rome La Repubblica (in Italian) 11 January 2002, 1, 17, FBIS Document ID

  6. Don Winslow, autor de un clásico y otras obras dentro de la narconarrativa mexicano-estadounidense (una guía para forasteros)

    OpenAIRE

    Arturo E. García Niño

    2015-01-01

    Anclado en lo que se ha dado en llamar la narconarrativa, una expresión literaria binacional fronteriza compartida por México y Estados Unidos, se encuentra Don Winslow, quien con su novela El poder del perro catapultó y cimentó el enunciado subgénero literario para, de ahí, generar otras novelas que tienen al crimen organizado, y sus relaciones con el mundo empresarial y político, como protagonista y tópico, así como a la frontera como espacio donde se desarrollan los hechos narrados. Y sob...

  7. The National Shipbuilding Research Program. Thermal Spray Manual

    Science.gov (United States)

    1996-04-01

    CATAPULT STEAM PACKING CuNi STEAM BOND PP EUTECTIC 21021 FINAL PP METCO 130 BABBITT BEARING TURBINE GENERATOR INSIDE DIAMETER BABBITT OIL FINAL AW...COATING SYSTEM PP-25 444 445 21021 21031 PP-25/130 444/130 445/130 47/130 21021 /130 21031/130 PP-25/143 444/143 445/143 447/143 21021 /143 21031/143 1-8...Machinery Applications” Encl: (1) Puget Sound Naval Shipyard Thermal Spray Procedure Specification No. 4329 Eutectic 21021 /Metco 143 on 410 Stainless

  8. Un depósito de proyectiles de catapulta hallado en Calahorra (La Rioja

    Directory of Open Access Journals (Sweden)

    Cinca, José Luis

    2003-12-01

    Full Text Available [es] El propósito de este trabajo es presentar el depósito de proyectiles de catapulta hallado en Calahorra (La Rioja, y analizar las hipótesis más verosímiles sobre el contexto histórico de estos documentos. [fr] L'objectif de ce travail est présenter le dépôt de projectiles de catapulte trouvé à Calahorra (La Rioja et d'analyser les hypothèses les plus vraisemblables autour du contexte historique de ces documents.

  9. Extending the Endurance, Missions and Capabilities of Most UAVs Using Advanced Flexible/Ridged Solar Cells and New High Power Density Batteries Technology

    Science.gov (United States)

    2011-03-01

    weight, it must be launched from a pneumatic catapult and can be recovered automatically by a "SkyHook" system, where a rope hanging from a 15 m pole ...is a rechargeable galvanic cell with a very high energy density and Li-S cells may succeed lithium-ion cells because of their higher energy...that are applied to low-cost backing materials, such as glass, stainless steel sheet, polyimide or metal foils. CIGS cells can also be prepared on

  10. Western armament and tactics in the writings of Anna Komnene

    Directory of Open Access Journals (Sweden)

    Drašković Marko

    2006-01-01

    Full Text Available In this work, first we reconstructed and commented the western horseman's armament witch Anna Komnene had known (long spear, cross-bow, chain mail "Norman" shield, solarets. Afterwards, we established that Anne knew four types of western horseman's attack (attack in full gallop, attack from back slow march, attack from flank and three types of their battle formation (strewn formation, congested formation, formation of two columns. Also, we commented Anna's knowledge of western siege engines (battering-ram, tortoise catapult, siege tower; we established that Anne knew five types of western siege tower. In the end, we commented several fragments witch show Anna Komnene's knowledge of the western siege tactics.

  11. Vietnam 2035

    OpenAIRE

    World Bank; Ministry of Planning and Investment of Vietnam

    2016-01-01

    OVERVIEW. FULL BOOK EXPECTED LATER IN 2016. The year 2015 marks 70 years since Vietnam’s Declaration of Independence, 40 years since reunification, and just short of 30 years from the launch of Doi Moi reforms, which catapulted the nation from the ranks of the world’s poorest to one of the great development success stories. Critical ingredients of success have been visionary leaders, a sense of shared societal purpose, and a focus on the future. Starting in the late 1980s, these elemen...

  12. Adrenal lesions encountered in current medical practice − a review of their radiological imaging

    Directory of Open Access Journals (Sweden)

    Vanesha Naidu

    2013-11-01

    Full Text Available Modern radiological technology has transformed the way that adrenal lesions are currently investigated. The contemporary radiologist has been catapulted to the forefront in the management of adrenal disease. With the increasing use of cross-sectional imaging, adrenal lesions are being serendipitously discovered in radiological studies undertaken for non-adrenal-related conditions – the so-called adrenal ‘incidentaloma’. This review discusses the imaging modalities available for characterising these lesions, highlighting current concepts and controversies in differentiating benign from malignant pathology. The article also provides a brief overview of the spectrum of adrenal pathology commonly encountered in the adult population.

  13. Prediction and validation of gene-disease associations using methods inspired by social network analyses.

    Directory of Open Access Journals (Sweden)

    U Martin Singh-Blom

    Full Text Available Correctly identifying associations of genes with diseases has long been a goal in biology. With the emergence of large-scale gene-phenotype association datasets in biology, we can leverage statistical and machine learning methods to help us achieve this goal. In this paper, we present two methods for predicting gene-disease associations based on functional gene associations and gene-phenotype associations in model organisms. The first method, the Katz measure, is motivated from its success in social network link prediction, and is very closely related to some of the recent methods proposed for gene-disease association inference. The second method, called Catapult (Combining dATa Across species using Positive-Unlabeled Learning Techniques, is a supervised machine learning method that uses a biased support vector machine where the features are derived from walks in a heterogeneous gene-trait network. We study the performance of the proposed methods and related state-of-the-art methods using two different evaluation strategies, on two distinct data sets, namely OMIM phenotypes and drug-target interactions. Finally, by measuring the performance of the methods using two different evaluation strategies, we show that even though both methods perform very well, the Katz measure is better at identifying associations between traits and poorly studied genes, whereas Catapult is better suited to correctly identifying gene-trait associations overall [corrected].

  14. C综合工具拥有较大的容量

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Mentor Graphics公司推出了基于其Catapult CANSI-C++的综合工具的一款高容量版本,现在,设计师们可以采用它来完成一个基于DSP的完整子系统的原型设计。Mentor公司于2004年推出了其第一版Cata.pultC工具,旨在帮助IC设计师在算法级上进行以DSP为中心的SoC(系统级芯片)设计。与其它依靠特殊语言来运行的ESL(电子系统级)设计工具不同,CatapultC工具把ANSI.C++用作一个输入,并生成了用于硬件设计的RTL(寄存器转换层)基础方案以及一个用于仿真的System C事务层模型。

  15. Atomization efficiency and photon yield in laser-induced breakdown spectroscopy analysis of single nanoparticles in an optical trap

    Science.gov (United States)

    Purohit, Pablo; Fortes, Francisco J.; Laserna, J. Javier

    2017-04-01

    Laser-induced breakdown spectroscopy (LIBS) was employed for investigating the influence of particle size on the dissociation efficiency and the absolute production of photons per mass unit of airborne solid graphite spheres under single-particle regime. Particles of average diameter of 400 nm were probed and compared with 2 μm particles. Samples were first catapulted into aerosol form and then secluded in an optical trap set by a 532 nm laser. Trap stability was quantified before subjecting particles to LIBS analysis. Fine alignment of the different lines comprising the optical catapulting-optical trapping-laser-induced breakdown spectroscopy instrument and tuning of excitation parameters conditioning the LIBS signal such as fluence and acquisition delay are described in detail with the ultimate goal of acquiring clear spectroscopic data on masses as low as 75 fg. The atomization efficiency and the photon yield increase as the particle size becomes smaller. Time-resolved plasma imaging studies were conducted to elucidate the mechanisms leading to particle disintegration and excitation.

  16. 基于前起落架突伸技术的新型缓冲器仿真设计分析%Simulation and Analysis of a New Type Buffer's Design Based on Nose Landing Gear Extension Technology

    Institute of Scientific and Technical Information of China (English)

    王彤; 许锋; 聂宏

    2012-01-01

    Most carrier-based airplanes were catapult launched from carrier decks,and nose landing gear extended at the moment of separating.In this situation,the problem of an oleo-pneumatic buffer was studied to suit for catapult launch.Some different extension modes of buffer were discussed,and a new oleo-pneumatic buffer with two-stage chambers was studied for better take-off performance.The co-simulation models of nose landing gear were well established,subsequently,the catapult launch-extension simulation was carried out.The simulation results indicate that the combination of injecting high pressure gas and releasing potential energy is more effective;in addition,the improved buffer can actually extent more quickly.%针对舰载机的前轮拖曳弹射起飞方式,结合前起落架突伸技术对缓冲器构型进行了研究,确定了缓冲器的组合突伸模式。基于常规型双腔油气式缓冲器提出了改进的缓冲器构型,并通过适当减小缓冲器的反弹阻尼来缩短突伸时间。应用动力学仿真软件LMS Virtual.Lab与机械/液压仿真软件AMESim实现了舰载机前起落架弹射-突伸动力学联合仿真。仿真结果表明:缓冲器各关键参数的变化与理论计算结果一致;增加高压充气的突伸模式比单纯释放储存势能的突伸模式能够获得更好的突伸效果,改进设计型缓冲器可有效缩短突伸时间。

  17. Dynamics and Test Method of Carrier-based Aircraft Nose Landing Gear Sudden Extension%舰载机前起落架突伸动力学分析及试验方法

    Institute of Scientific and Technical Information of China (English)

    魏小辉; 刘成龙; 聂宏; 张明; 尹乔之

    2013-01-01

    为了了解舰载机前起落架突伸试验与实际突伸过程的当量关系,本文以某舰载机为研究对象,建立了全机弹射起飞动力学模型,进行了全机弹射起飞动力学分析,得到了前起落架突伸过程中的动态响应.提出了基于当量质量的前起落架突伸动力学试验方法,设计了试验方案,建立了前起落架突伸动力学试验分析模型,进行了突伸动力学分析.进而依据全机突伸动力学分析结果,对基于当量质量的前起落架突伸动力学试验中相关参数的选取进行了探讨研究,结果表明:当突伸当量质量系数取0.8时,突伸动力学响应特性与全机弹射起飞突伸过程的动态响应结果比较吻合.%In order to understand the equivalent relationship of a landing gear's sudden-extension test and the real suddenextension process of a carrier-based aircraft,a dynamics model of a certain carrier-based aircraft catapult-assisted takeoff process is established.The catapult-assisted takeoff dynamics is simulated and the nose landing gears dynamic response to the sudden-extension process is obtained.A test method is introduced to study the nose landing gear 's sudden extension based on equivalent mass.Accordingly,a test program is presented for independent nose landing gear sudden-extension analysis.With simulated results of the models introduced above,the value range of relevant test parameters is studied.It is shown that the independent nose landing gear sudden-extension dynamic response is relatively consistent with the full-aircraft catapult-assisted takeoff dynamics when the equivalent mass coefficient is equal to 0.8.

  18. Machine-vision based optofluidic cell sorting

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Bañas, Andrew

    In contemporary life science there is an increasing emphasis on sorting rare disease-indicating cells within small dilute quantities such as in the confines of optofluidic lab-on-chip devices. Our approach to this is based on the use of optical forces to isolate red blood cells detected by advanced...... machine vision1. This approach is gentler, less invasive and more economical compared to conventional FACS-systems. As cells are less responsive to plastic or glass objects commonly used in the optical manipulation literature2, and since laser safety would be an issue in clinical use, we develop efficient...... the available light and creating 2D or 3D beam distributions aimed at the positions of the detected cells. Furthermore, the beam shaping freedom provided by GPC can allow optimizations in the beam’s propagation and its interaction with the laser catapulted and sorted cells....

  19. A real explosion: the requirement of steam explosion pretreatment.

    Science.gov (United States)

    Yu, Zhengdao; Zhang, Bailiang; Yu, Fuqiang; Xu, Guizhuan; Song, Andong

    2012-10-01

    The severity factor is a common term used in steam explosion (SE) pretreatment that describes the combined effects of the temperature and duration of the pretreatment. However, it ignores the duration of the explosion process. This paper describes a new parameter, the explosion power density (EPD), which is independent of the severity factor. Furthermore, we present the adoption of a 5m(3) SE model for a catapult explosion mode, which completes the explosion within 0.0875 s. The explosion duration ratio of this model to a conventional model of the same volume is 1:123. The comparison between the two modes revealed a qualitative change by explosion speed, demonstrating that this real explosion satisfied the two requirements of consistency, and suggested a guiding mechanism for the design of SE devices.

  20. Famous people and genetic disorders: from monarchs to geniuses--a portrait of their genetic illnesses.

    Science.gov (United States)

    Ho, Nicola C; Park, Susan S; Maragh, Kevin D; Gutter, Emily M

    2003-04-15

    Famous people with genetic disorders have always been a subject of interest because such news feeds the curiosity the public has for celebrities. It gives further insight into their lives and provides a medical basis for any unexplained or idiosyncratic feature or behavior they exhibit. It draws admiration from society of those who excel in their specialized fields despite the impositions of their genetic illnesses and also elicits sympathy even in the most casual observer. Such news certainly catapults a rare genetic disorder into the realm of public awareness. We hereby present six famous figures: King George III, Toulouse-Lautrec, Queen Victoria, Nicolo Paganini, Abraham Lincoln, and Vincent van Gogh, all of whom made a huge indelible mark in either the history of politics or that of the arts.

  1. Webometrics for an Open Access Start-Up Journal (Editorial

    Directory of Open Access Journals (Sweden)

    Ulf-Dietrich Reips

    2009-01-01

    Full Text Available Before you stands the fourth issue of the International Journal of Internet Science. It will be the last one that is the only issue in its volume, because an increasing rate of manuscript submissions of high quality to this start-up journal forces us to jump to two issues next year. From citation analysis to webometrics Our citation analysis in the previous issue (Reips & Matzat, 2008 revealed a surprisingly high journal impact for the International Journal of Internet Science. To publish very few high quality articles has already catapulted this start-up journal beyond many of the long-standing journals in the field. Looking up "International Journal of Internet Science" in Google Scholar now returns 90 instead of 50 references (December 15, 2009, compared to the same day in 2008. Among them are many new citations relevant to the journal's impact factor.

  2. A bright point source of ultrashort hard x-rays from laser bioplasmas

    CERN Document Server

    Krishnamurthy, M; Lad, Amit D; Ahmad, Saima; Narayanan, V; Rajeev, R; Kundu, M; Kumar, G Ravindra; Ray, Krishanu

    2010-01-01

    Micro and nano structures scatter light and amplify local electric fields very effectively. Energy incident as intense ultrashort laser pulses can be converted to x-rays and hot electrons more efficiently with a substrate that suitably modifies the local fields. Here we demonstrate that coating a plain glass surface with a few micron thick layer of an ubiquitous microbe, {\\it Escherichia coli}, catapults the brightness of hard x-ray bremsstrahlung emission (up to 300 keV) by more than two orders of magnitude at an incident laser intensity of 10$^{16}$ W cm$^{-2}$. This increased yield is attributed to the local enhancement of electric fields around individual {\\it E. coli} cells and is reproduced by detailed particle-in-cell (PIC) simulations. This combination of laser plasmas and biological targets can lead to turnkey, multi-kilohertz and environmentally safe sources of hard x-rays.

  3. Ocean sciences after September 11

    Science.gov (United States)

    McPhaden, Michael J.

    The terrorist attacks in New York City and Washington D.C. on September 11, 2001 shocked the world with their audacity and destruction. Shortly thereafter, bioterrorists struck through the U.S. postal system. Virtually overnight, major policy shifts took place in the United States that catapulted national security and homeland defense to the top of the political agenda. The consequences were unimaginable just a few months before: an international coalition at war against the Taliban in Afghanistan, major increases in U.S. defense spending, tightened security measures at airports, government facilities, and research laboratories, and a new sense of vulnerability in the post-cold war era. AGU itself was directly affected: three of its members perished in the hijacked planes, or on the ground in New York City.

  4. Muscle-tendon interaction and elastic energy usage in human walking

    DEFF Research Database (Denmark)

    Ishikawa, Masaki; Komi, Paavo V.; Grey, Michael James;

    2005-01-01

    The present study was designed to explore how the interaction between the fascicles and tendinous tissues is involved in storage and utilization of elastic energy during human walking. Eight male subjects walked with a natural cadence (1.4 +/- 0.1 m/s) on a 10-m-long force plate system. In vivo...... techniques were employed to record the Achilles tendon force and to scan real-time fascicle lengths for two muscles (medial gastrocnemius and soleus). The results showed that tendinous tissues of both medial gastrocnemius and soleus muscles lengthened slowly throughout the single-stance phase......-stance phase. In contrast, the soleus fascicles were lengthened until the end of the single-stance phase. These findings suggest that the elastic recoil takes place not as a spring-like bouncing but as a catapult action in natural human walking. The interaction between the muscle fascicles and tendinous...

  5. Thermal Management of Battery Systems in Electric Vehicle and Smart Grid Application

    DEFF Research Database (Denmark)

    Khan, Mohammad Rezwan

    on the power-system domain. The dumb grids are turning into a smart grid that contains computer intelligence and networking abilities to accommodate dispersed renewable generations (e.g. solar, wind power, geothermal, wave energy and so forth). The battery takes a primary role both as stationary......Last few years’ governments are tightening the carbon emission regulations. Moreover, the availability of different financial assistances is available to cut the market share of the fossil fuel vehicles. Conversely, to fill up the gap of the required demand, higher penetration of electrical...... vehicles is foreseen. The future battery manufacturers strive to meet the ever growing requirement of consumer’s demand using the battery as a primary power source of these cars. So naturally, the growing popularity of battery electric and hybrid vehicles have catapulted the car industry in the recent...

  6. Nanotechnology in dentistry: reduction to practice.

    Science.gov (United States)

    Ure, David; Harris, Jonathan

    2003-01-01

    The speed at which advances are being made in science has catapulted nanotechnology from its theoretical foundations straight into the real world. There are now many examples of commercially available products demonstrating that, in given situations, the technology really does work and that its scope for further application is wide. Healthcare, along with society as a whole, is facing a major revolution in the wake of ongoing technological developments in the field of nanotechnology. Dentistry as an individual healthcare discipline is not exempt, having already been targeted directly with novel 'nano-materials' at the same time as indirectly enjoying the benefits of nano-related advances in the electronics industry through the ongoing computerization of the modern practice. This article examines current practical applications of nanotechnology alongside proposed applications in the future and aims to demonstrate that, as well as a good deal of science fiction, there is some tangible science fact emerging from this novel multi-disciplinary science.

  7. The Making of the Indian National Innovation Systems: Lessons on the specific characteristics of the domestic and the external co-evolutions of technologies, institutions and incentives

    DEFF Research Database (Denmark)

    Muchie, Mammo; Baskaran, Angathevar

    for its low quality manufactured good, and inability to eradicate poverty. Key issues taken up for this paper are: § What is the effort of India to create an efficient national system of innovation? § Can India's system of innovation catapult it to a developed nation status in the next fifteen to twenty...... is growing at a nearly 8 % of GDP and is seen as an emerging economy on a par with China. The policy makers in India have asked: can India become a developed country by 2020? (see Kalam, 1998).  India has tried to apply science and technology to industrialise agriculture and build a modern economy......, diffusion and incentives. Despite its significant achievements in areas such as building strong industrial and R & D base, establishing a large number of science and technology institutions, and creating large pool of scientists and engineers, the Indian national innovation system has been criticised...

  8. Genome-Wide Identification of Epigenetic Hotspots Potentially Related to Cardiovascular Risk in Adult Women after a Complicated Pregnancy.

    Directory of Open Access Journals (Sweden)

    Cees Oudejans

    Full Text Available The physiological demands of pregnancy on the maternal cardiovascular system can catapult women into a metabolic syndrome that predisposes to atherosclerosis in later life. We sought to identify the nature of the epigenomic changes associated with the increased cardiovascular disease (CVD risk in adult women following pre-eclampsia.We assessed the genome wide epigenetic profile by methyl-C sequencing of monozygotic parous twin sister pairs discordant for a severe variant of pre-eclampsia. In the adult twin sisters at risk for CVD as a consequence of a complicated pregnancy, a set of 12 differentially methylated regions with at least 50% difference in methylation percentage and the same directional change was found to be shared between the affected twin sisters and significantly different compared to their unaffected monozygous sisters.The current epigenetic marker set will permit targeted analysis of differentially methylated regions potentially related to CVD risk in large cohorts of adult women following complicated pregnancies.

  9. A global strategy for the European PV industry

    Energy Technology Data Exchange (ETDEWEB)

    Viaud, M.; Despotou, E.; Latour, M. [European Photovoltaic Industry Association (EPIA) secretariat, Brussels (Belgium); Hoffmann, W.; Macias, E.; Cameron, M.; Laborde, E. [European Photovoltaic Industry Association (EPIA), Brussels (Belgium)

    2004-07-01

    The objective was to develop a comprehensive strategy that answers to the need of today European PV industry. Namely: - Develop PV markets in Europe - Develop export markets. - Position the European PV industry within the European political environment and support the effort of national actors in their local objectives. This method lends itself to brainstorming to create actions and synergies, on order to achieve strategy objectives. The whole work is based on working groups clearly defined on the purpose, where all EPIA members are invited to participate. The overall first results are presented during the 19. EU PV Conference in Paris and EPIA will do recommendations on actions to be undertaken in the future. This strategy is co-financed by EPIA members and the 6. Framework Programme for research of the European Commission through the PV Catapult project. (authors)

  10. An Efficient Circulant MIMO Equalizer for CDMA Downlink: Algorithm and VLSI Architecture

    Directory of Open Access Journals (Sweden)

    Cavallaro Joseph R

    2006-01-01

    Full Text Available We present an efficient circulant approximation-based MIMO equalizer architecture for the CDMA downlink. This reduces the direct matrix inverse (DMI of size with complexity to some FFT operations with complexity and the inverse of some submatrices. We then propose parallel and pipelined VLSI architectures with Hermitian optimization and reduced-state FFT for further complexity optimization. Generic VLSI architectures are derived for the high-order receiver from partitioned submatrices. This leads to more parallel VLSI design with further complexity reduction. Comparative study with both the conjugate-gradient and DMI algorithms shows very promising performance/complexity tradeoff. VLSI design space in terms of area/time efficiency is explored extensively for layered parallelism and pipelining with a Catapult C high-level-synthesis methodology.

  11. 国际要闻

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    芯原完成第三轮融资购买LSI Logic的ZSP部门;Mentor Graphics公司Catapult C综合器的组件库通过意法半导体认证;Broadcom推出首款全集成48端口快速以太网交换芯片;科利登的Sapphire S测试系统被Sun公司采用;IR助力洗衣机节能70%;TI赢得国际工程协会InfoVision大奖;Silicon Labs推出业界最高集成度的以太网络供电控制器.

  12. A roadmap for photovoltaic-thermal panels. Combination of techniques offers many advantages; Een roadmap voor pv-thermische panelen. Combinatie van technieken biedt vele voordelen

    Energy Technology Data Exchange (ETDEWEB)

    Zondag, H.A.; Van Helden, W.G.J.; Bakker, M. [ECN Energie Gebouwde Omgeving en Netten, Petten (Netherlands)

    2006-10-15

    In PVT technology, heat is extracted from PV cells. In this way, a device is made that produces both electricity and heat. In the EU funded coordination action PV-Catapult, workshops on PVT were organised at the PVSEC 2004 Conference in Paris and the Eurosun 2004 conference in Freiburg, to obtain active participation of the PV and solar thermal communities. Currently, the results of the workshops are used in the drafting of a roadmap for the large scale introduction of PVT technology on the market. First results will be presented here. [Dutch] Zonnepanelen (oftewel pv-panelen) produceren elektriciteit uit zonlicht. In de volle zon kan de temperatuur van zonnepanelen flink oplopen. Gewone zonnepanelen maken van deze warmte geen gebruik, maar in PVT-modules (pv-thermische modules) wordt deze warmte benut voor de productie van warm water of warme lucht. Het resultaat is een apparaat dat zowel warmte als stroom produceert uit zonlicht.

  13. Inter-linkages: the Kyoto Protocol and the international trade and investment regimes

    Energy Technology Data Exchange (ETDEWEB)

    Chambers, W.B. [Institute of Advanced Studies, United Nations University, Tokyo (Japan)

    2001-07-01

    In 1997, delegates to the third session of the Conference of the Parties to the UN Framework Convention on Climate Change (UNFCCC) agreed by consensus to adopt the Kyoto Protocol under which industrialised countries would reduce their combined greenhouse gas emissions by an average 5.2% from their 1992 levels. This will require a fundamental shift in the way in which energy is produced and the way it is used. This factor, in itself, is enough to catapult the Protocol out of the purely environmental realm and into the domain of global economics. The publication examines the Climate Change Convention in the context of potential synergies and conflicts that could arise between it and the World Trade Organization, international investment agreements, and private and contractual trade law. This practical study demonstrates how synergism and coordination could be accomplished in practical terms.

  14. FPGA高级语言设计开发环境构建%The Construction of FPGA High-Level Language Design Environment

    Institute of Scientific and Technical Information of China (English)

    谷会涛; 鄢斌; 周跃; 田楠

    2013-01-01

    针对传统FPGA芯片开发流程对开发人员要求高,开发难度大、周期长的难题,基于FPGA芯片高级综合工具Catapult C Synthesis以及配套的设计验证工具,构建了新的FPGA高级语言设计开发环境,支持将C语言算法快速高效地实现到FPGA芯片上.实验表明,该开发环境能有效降低设计人员的开发难度,缩短工程研发周期.

  15. 舰载机机舰适配性体系研究%Study on Adaptation System of Carrier-based Aircraft

    Institute of Scientific and Technical Information of China (English)

    郭润兆; 段卓毅; 李小卫

    2014-01-01

    针对固定翼舰载机和采用弹射装置的大型航母,分析了舰载机与航母之间的约束接口关系,提出了较为完整的舰载机机舰适配性研究框架。该体系框架涵盖了量化的机舰适配性设计要素,为舰载机的全程研制提供了指导和依据。%In Based on the ifxed wing carrier-based aircraft and large carrier with catapult, the constraint interface between aircrafts and carrier is analyzed and a carrier-based aircraft adaptation system architecture is proposed. This system architecture, which involves quantized adaptation design factors, provides guidance and basis for the carrier-based aircraft design.

  16. Statistical visualization of the Earth's magnetotail based on Geotail data and the implied substorm model

    Directory of Open Access Journals (Sweden)

    S. Machida

    2009-03-01

    Full Text Available We investigated the temporal and spatial development of the near-Earth magnetotail during substorms based on multi-dimensional superposed-epoch analysis of Geotail data. The start time of the auroral break-up (t=0 of each substorm was determined from auroral data obtained by the Polar and IMAGE spacecraft. The key parameters derived from the plasma, magnetic-field, and electric-field data from Geotail were sorted by their meridional X(GSM–Z(proxy coordinates.

    The results show that the Poynting flux toward the plasma-sheet center starts at least 10 min before the substorm onset, and is further enhanced at X~−12 RE (Earth radii around 4 min before the onset. Simultaneously, large-amplitude fluctuations occurred, and earthward flows in the central plasma sheet between X~−11 RE and X~−19 RE and a duskward flow around X=−10 RE were enhanced. The total pressure starts to decrease around X=−16 RE about 4 min before the onset of the substorm. After the substorm onset, a notable dipolarization is observed and tailward flows commence, characterised by southward magnetic fields in the form of a plasmoid.

    We confirm various observable-parameter variations based on or predicted by the relevant substorm models; however, none of these can explain our results perfectly. Therefore, we propose a catapult (slingshot current-sheet relaxation model, in which an earthward convective flow produced by catapult current-sheet relaxation and a converted duskward flow near the Earth are enhanced through flow braking around 4 min before the substorm onset. These flows induce a ballooning instability or other instabilities, causing the observed current disruption. The formation of the magnetic neutral line is a natural consequence of the present model, because the relaxation of a highly stretched

  17. What makes a champion! over fifty extraordinary individuals share their insights

    CERN Document Server

    2014-01-01

    What drives great and successful individuals — be they athletes, artists, or scientists — or businesses, to achieve the extraordinary? Over fifty champions from all walks of life, brought together by Allan Snyder, draw on their experiences to explore the secrets of success in this inspiring, revealing and thought-provoking book. Hear from the authors what made a McDonalds' branch become the most successful in the world; how a cottage business is catapulted into a world brand; how a visual artist's works crosses almost every medium imaginable; how an Ernst and Young setup becomes a top-notch employer; or why many geniuses or brilliant individuals never become champions, while many 'ordinary' individuals do; why many people don't know about their talent; what constitutes a champion outcome; and the neurological explanation for championship. Straddling academia and practitioners in all fields — government, entertainment, sports, business, arts, education, medicine, media — the authors include business...

  18. Cell sorting using efficient light shaping approaches

    DEFF Research Database (Denmark)

    Banas, Andrew; Palima, Darwin; Villangca, Mark Jayson;

    2016-01-01

    distributions aimed at the positions of the detected cells. Furthermore, the beam shaping freedom provided by GPC can allow optimizations in the beam’s propagation and its interaction with the catapulted cells. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading...... is gentler, less invasive and more economical compared to conventional FACS systems. As cells are less responsive to plastic or glass beads commonly used in the optical manipulation literature, and since laser safety would be an issue in clinical use, we develop efficient approaches in utilizing lasers...... and light modulation devices. The Generalized Phase Contrast (GPC) method that can be used for efficiently illuminating spatial light modulators or creating well-defined contiguous optical traps is supplemented by diffractive techniques capable of integrating the available light and creating 2D or 3D beam...

  19. Proportionality, just war theory and weapons innovation.

    Science.gov (United States)

    Forge, John

    2009-03-01

    Just wars are supposed to be proportional responses to aggression: the costs of war must not greatly exceed the benefits. This proportionality principle raises a corresponding 'interpretation problem': what are the costs and benefits of war, how are they to be determined, and a 'measurement problem': how are costs and benefits to be balanced? And it raises a problem about scope: how far into the future do the states of affairs to be measured stretch? It is argued here that weapons innovation always introduces costs, and that these costs cannot be determined in advance of going to war. Three examples, the atomic bomb, the AK-47 and the ancient Greek catapult, are given as examples. It is therefore argued that the proportionality principle is inapplicable prospectively. Some replies to the argument are discussed and rejected. Some more general defences of the proportionality principle are considered and also rejected. Finally, the significance of the argument for Just War Theory as a whole is discussed.

  20. Ditching Tests of Two Models of the Army B-36 Airplane

    Science.gov (United States)

    Fisher, Lloyd J.; Cederborg, Gibson, A.

    1948-01-01

    The ditching characteristics of the Army B-36 airplane were determined by testing 1/20- and 1/30-scale dynamic models in calm water in Langley tank no. 2 and at the outdoor catapult. The scope of the tests consisted of ditching the models at various conditions of simulated damage, landing attitudes, and speeds, with various flap settings using several degrees of restraint of the flap hinges. The ditching behavior was evaluated from recordings of deceleration, length of run, and motions of the models. The results showed that the airplane should be ditched at an attitude of about 9 deg with flaps full down. The probable ditching behavior will be a smooth run with a maximum longitudinal deceleration of 3g to 4g and a landing run of 4 to 5 fuselage lengths. Structural failure of the underside of the fuselage will not seriously affect the behavior of the airplane.

  1. Development of space manufacturing systems concepts utilizing lunar resources

    Science.gov (United States)

    Bock, E. H.

    1979-01-01

    Results of a NASA sponsored study to evaluate the merits of constructing solar power satellites using lunar and terrestrial resources are reviewed. Three representative lunar resources utilization (LRU) concepts were developed and compared with a previously designed earth baseline concept, and major system hardware elements as well as personnel requirements were defined. LRU for space construction was shown to be competitive with earth baseline approach for a program requiring 10 to the 5th metric tons per year of completed satellites. Results also indicated that LRU can reduce earth launched cargo requirements to less than 10% of that needed to build satellites exclusively from earth materials, with a significant percentage of the reduction due to the use of liquid oxygen derived from lunar soil. A concept using the mass driver to catapult lunar material into space was found to be superior to the other LRU logistics techniques investigated.

  2. Mechanical Enterogenesis - A Review

    Directory of Open Access Journals (Sweden)

    Rebecca Stark

    2012-01-01

    Full Text Available Mechanical enterogenesis is a novel method of lengthening pre-existing intestine with distractive force. The application of mechanical force on small intestine aims to induce cellular proliferation and ultimately increase bowel length. This has been investigated primarily for the treatment of short bowel syndrome (SBS. Research has been ongoing for well over a decade in this arena and a multitude of advances have been made, both in the understanding of the biology behind force induced cellular proliferation and in the basic mechanics of force delivery systems. Important experimental models have been developed for studying this phenomenon and the collaboration of engineers and medical researchers has lead to the design of several devices that successfully lengthen small intestine. This has catapulted the field forward and there may soon be a device suitable for medical use in humans. This review analyses the past, present and future of mechanical enterogenesis.

  3. Aircraft Carriers

    DEFF Research Database (Denmark)

    Nødskov, Kim; Kværnø, Ole

    in Asia and will balance the carrier acquisitions of the United States, the United Kingdom, Russia and India. China’s current military strategy is predominantly defensive, its offensive elements being mainly focused on Taiwan. If China decides to acquire a large carrier with offensive capabilities......, then the country will also acquire the capability to project military power into the region beyond Taiwan, which it does not possess today. In this way, China will have the military capability to permit a change of strategy from the mainly defensive, mainland, Taiwan-based strategy to a more assertive strategy...... catapult with which to launch the fi ghter aircraft, not to mention the possible development of a nuclear power plant for the ship. The Russian press has indicated that China is negotiating to buy SU-33 fi ghters, which Russia uses on the Kuznetsov carrier. The SU-33 is, in its modernized version...

  4. Balancing Energy, Food, Natural Resources and Environment in Nepal

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Dilli Bahadur

    2010-09-15

    Nepal could harness less than 1% of its 83000 MW hydropower potential. Pancheshwar Multipurpose Project (6720 MW) is a bi-national project on Mahakali River bordering between Nepal and India. The earnings from: electricity (NRs. 34.55 billion/year); irrigation (NRs. 5.55 billion/year), fish farming (NRs. 8.65 billion/year), carbon trading (NRs. 4.42 billion/year) and many billions from other sources e.g. eco-tourism, industry, horticulture, herbiculture, floriculture, sericulture, rafting and water sports, educational and vocational training and other industrial/commercial activities can catapult the socioeconomic horizon of Nepal. Hence, PMP should be jointly developed in the earliest and build confidence for the further hydropower development.

  5. Interaction of two differently sized oscillating bubbles in a free field.

    Science.gov (United States)

    Chew, Lup Wai; Klaseboer, Evert; Ohl, Siew-Wan; Khoo, Boo Cheong

    2011-12-01

    Most real life bubble dynamics applications involve multiple bubbles, for example, in cavitation erosion prevention, ultrasonic baths, underwater warfare, and medical applications involving microbubble contrast agents. Most scientific dealings with bubble-bubble interaction focus on two similarly sized bubbles. In this study, the interaction between two oscillating differently sized bubbles (generated in tap water) is studied using high speed photography. Four types of bubble behavior were observed, namely, jetting toward each other, jetting away from each other, bubble coalescence, and a behavior termed the "catapult" effect. In-phase bubbles jet toward each other, while out-of-phase bubbles jet away from each other. There exists a critical phase difference that separates the two regimes. The behavior of the bubbles is fully characterized by their dimensionless separation distance, their phase difference, and their size ratio. It is also found that for bubbles with large size difference, the smaller bubble behaves similarly to a single bubble oscillating near a free surface.

  6. Don Winslow, autor de un clásico y otras obras dentro de la narconarrativa mexicano-estadounidense (una guía para forasteros

    Directory of Open Access Journals (Sweden)

    Arturo E. García Niño

    2015-12-01

    Full Text Available Anclado en lo que se ha dado en llamar la narconarrativa, una expresión literaria binacional fronteriza compartida por México y Estados Unidos, se encuentra Don Winslow, quien con su novela El poder del perro catapultó y cimentó el enunciado subgénero literario para, de ahí, generar otras novelas que tienen al crimen organizado, y sus relaciones con el mundo empresarial y político, como protagonista y tópico, así como a la frontera como espacio donde se desarrollan los hechos narrados. Y sobre la narconarrativa, sobre el autor enunciado, su obra y el contexto binacional versa el análisis aquí incluido

  7. IMPROVEMENT SIMULATION AGAIN OF SUB -AGENCIES OF THE FIXED FORAGE BALERS%压捆机杠杆组分捆机构的改进仿真

    Institute of Scientific and Technical Information of China (English)

    赵洪刚; 杨竹君; 李红星

    2011-01-01

    In the trial process, having mainly based on self - developed fixed forage balers,further improved the trigger catapult style Leveraged sub - agencies and their relevant agencies, movements relevance of compression agencies and sub - agencies is simulated with SimMechanics. Sub - agencies was moved away from point 260 mm at compression, the time that allowed off the board increased to 0.795 s, while free - fall time of the divider was 0.271 s, so removed catapult to simplify the structure. Because forage of different types and different moisture have higher difference the amount of forage compression rebound, changed the crank length to 480 mm, extended the compression stroke to forage rebound off the boards to avoid clogging drop -plate - mouth.%根据自行研制的固定式饲草压捆机,针对触发弹射式杠杆组分捆机构进行改进研制和仿真.采用SimMe.chanics对压缩机构和分捆机构运动关联进行仿真,将分捆机构移至距离压缩止点260mm处,使允许落板时间增至0.795 s,而分隔板自由下落时间为0.271 s,因此撤去弹射器,简化了结构.由于不同种类、不同含水率的饲草压缩反弹量区别较大,将曲柄长度改为480 mm,延长了压缩行程,避免饲草反弹堵塞落板口.

  8. Reduced prosthetic stiffness lowers the metabolic cost of running for athletes with bilateral transtibial amputations.

    Science.gov (United States)

    Beck, Owen N; Taboga, Paolo; Grabowski, Alena Marie

    2017-01-19

    Inspired by the spring-like action of biological legs, running-specific prostheses are designed to enable athletes with lower-limb amputations to run. Yet, manufacturer recommendations for prosthetic stiffness and height may not optimize running performance. Therefore, we investigated the effects of using different prosthetic configurations on the metabolic cost and biomechanics of running. Five athletes with bilateral transtibial amputations each performed fifteen trials on a force-measuring treadmill at 2.5 or 3.0 m/s. Athletes ran using each of three different prosthetic models (Freedom Catapult FX6, Össur Flex-Run, and Ottobock 1E90 Sprinter) with five combinations of stiffness categories (manufacturer recommended and ± 1) and heights (International Paralympic Committee's maximum competition height and ± 2 cm) while we measured metabolic rates and ground reaction forces. Overall, prosthetic stiffness (fixed effect (β)=0.036; p=0.008) but not height (p≥0.089) affected the net metabolic cost of transport; less stiff prostheses reduced metabolic cost. While controlling for prosthetic stiffness (kN/m), using the Flex-Run (β=-0.139; p=0.044) and 1E90 Sprinter prostheses (β=-0.176; p=0.009) reduced net metabolic costs by 4.3% to 4.9% compared to using the Catapult prostheses, respectively. The metabolic cost of running improved when athletes used prosthetic configurations that decreased peak horizontal braking ground reaction forces (β=2.786; p=0.001), stride frequencies (β=0.911; p<0.001), and leg stiffness values (β=0.053; p=0.009). Remarkably, athletes did not maintain overall leg stiffness across prosthetic stiffness conditions. Rather, the in-series prosthetic stiffness governed overall leg stiffness. The metabolic cost of running in athletes with bilateral transtibial amputations is influenced by prosthetic model and stiffness, but not height.

  9. Progress on Concepts for Next-Generation Drop Tower Systems

    Science.gov (United States)

    Könemann, Thorben; Eigenbrod, Christian; Von Kampen, Peter; Laemmerzahl, Claus; Kaczmarczik, Ulrich

    2016-07-01

    The Center of Applied Space Technology and Microgravity (ZARM) founded by Prof. Dr.-Ing. Hans J. Rath in 1985 is part of the Department of Production Engineering at the University of Bremen, Germany. ZARM is mainly concentrated on fundamental investigations of gravitational and space-related phenomenas under conditions of weightlessness as well as questions and developments related to technologies for space. At ZARM about 100 scientists, engineers, and administrative staff as well as many students from different departments are employed. Today, ZARM is still one of the largest and most important research center for space sciences and technologies in Europe. With a height of 146 m the Bremen Drop Tower is the predominant facility of ZARM and also the only drop tower of its class in Europe. ZARM's ground-based laboratory offers the opportunity for daily short-term experiments under conditions of high-quality weightlessness at a level of 10-6 g (microgravity), which is one of the best achievable for ground-based flight opportunities. Scientists may choose up to three times a day between a single drop experiment with 4.74 s in simple free fall and an experiment in ZARM's worldwide unique catapult system with 9.3 s in weightlessness. Since the start of operation of the facility in 1990, over 7500 drops or catapult launches of more than 160 different experiment types from various scientific fields like fundamental physics, combustion, fluid dynamics, planetary formation / astrophysics, biology and materials sciences have been accomplished so far. In addition, more and more technology tests have been conducted under microgravity conditions at the Bremen Drop Tower in order to effectively prepare appropriate space missions in advance. In this paper we report on the progress on concepts for next-generation drop tower systems based on the GraviTower idea utilizing a guided electro-magnetic linear drive. Alternative concepts motivated by the scientific demand for higher

  10. Analysis on the Dynamic Characteristics of Carrier-based Aircraft Nose Landing Gear with Sudden Holdback Load Discharge%舰载机弹射起飞前起落架牵制载荷突卸动力学分析

    Institute of Scientific and Technical Information of China (English)

    于浩; 聂宏; 魏小辉

    2011-01-01

    舰载机弹射起飞过程中,由于牵制载荷突卸而产生的前起落架沿航向的快速振动会给机体结构和设备都带来严重的疲劳问题,为研究该振动现象并提出解决方案,建立了舰载机弹射起飞动力学模型,分析计算了前起落架的受载情况,并详细论述其动力学成因,推导了消除前起落架振动现象的充分必要条件.研究结果表明:牵制载荷沿下扭力臂轴向的载荷分量所造成的缓冲器活塞杆的向后弯曲是导致牵制载荷突卸后前起落架振动的主要原因;牵制载荷突卸后,起落架的前后振动导致起落架与机身铰接处的载荷快速、大幅的振荡,对机体结构以及机载设备的寿命和使用安全都会产生不利影响;牵制杆的长度直接影响牵制载荷沿下扭力臂轴向的载荷分量,降低该载荷分量可以有效地解决前起落架由于牵制载荷突卸所带来的振动问题.%The vibration of a nose landing gear caused by the sudden discharge of holdback load during the catapult launch of a carrier-based aircraft could bring serious fatigue both to the structure of the launch and the airborne equipment. To investigate the vibration and seek a solution, a dynamic model of the catapult launch is established. The load of the nose landing gear is calculated, while the kinetics and the way to deal with the phenomenon is also discussed in detail. From the catapult launch calculation, three important conclusions are obtained: during the tension stage, there is a long stroke and aft bending of the nose landing gear; once the holdback load suddenly discharges, the landing gear strut extends and springs forward rapidly; the fore-aft vibration of the nose landing gear produces a rapid and drastic load change at the joint of the gear and the fuselage. This vibration load has an adverse effect on the life and safety of the structure and the equipment of the aircraft. The length of the holdback bar influences the load

  11. Аппаратная реализация вычислительных алгоритмов с помощью инструментов алгоритмического синтеза

    OpenAIRE

    Монахов, Вадим; Керницкий, Игорь

    2010-01-01

    Описан процесс алгоритмического синтеза с помощью ПО Mentor Graphics Catapult C. Впервые реализована масштабируемая реализация алгоритма БПФ с параметризацией при помощи рекурсивных шаблонов, обеспечивающая возможность последующего синтеза в Mentor Graphics Catapult C. Показано, что производительность созданной с помощью инструментов алгоритмического синтеза аппаратной реализации алгоритмов на основе ПЛИС сопоставима с производительностью процессоров персональных компьютеров. Описаны недостат...

  12. 舰载机变长度减振牵制装置动力学分析%Analysis on Anti-Vibration Holdback Device of Carrier-Based Aircraft

    Institute of Scientific and Technical Information of China (English)

    魏小辉; 贲亮亮; 聂宏; 张明

    2013-01-01

    舰载机弹射起飞过程中,由于牵制载荷突卸而产生的前起落架沿航向的快速振动对机体结构和设备都会带来严重的疲劳问题.本文建立了舰载机弹射起飞动力学模型,设计了具有减振功能的舰载机弹射起飞变长度牵制装置,分析了该装置的动力学特性,并对该装置的减振效果进行了参数分析.研究结果表明:牵制载荷沿下扭力臂轴向的载荷分量所造成的缓冲器活塞杆的向后弯曲是导致牵制载荷突卸后前起落架振动的主要原因;变长度减振牵制装置通过实时改变牵制杆长度和牵制角,可大幅降低牵制载荷突卸后前起落架振动以及各铰接点振荡载荷,该装置在解决牵制载荷突卸振动问题中效果明显.%The vibration of the nose landing gear caused by the sudden discharge of holdback load during catapult launch of a carrier-based aircraft could bring serious fatigue problem to the structure and airborne equipment. With the purpose to solve the vibration problem, a dynamics model of catapult launch is established. An anti-vibration holdback device is designed while the dynamic characteristic and the effect of the device are discussed. From the research, the conclusions show that; the aft bending of the strut is the primarily reason of the fore-aft vibration of nose landing gear; the anti-vibration device would reduce the vibration load at the joint of gear and fuselage sharply with changing the length of the holdbar and the hold angle. The anti-vibration hold back device is effective in solving the vibration phenomenon.

  13. Hardware Design and Implementation of Electronic Throttle Controller Based on FPGA%基于FPGA的电子节气门控制器硬件设计与实现

    Institute of Scientific and Technical Information of China (English)

    许月亭; 季冬冬; 许芳; 陈虹

    2014-01-01

    In order to meet the control performance requirements of ETCS( Electronic Throttle Control System) , such as fast computational performance, low-cost, miniaturization, FPGA( Field Programmable Gate Array) is adopted as the hardware implementation of controller and integral separation is added to mature PID ( Proportional, Integral, Differential) control algorithm. And the integral separation PID controller with Catapult C high-level synthesis tools is implemented based on FPGA full hardware solution. An integral separation PID controller on a FPGA chip is designed for ETCS. In addition, AD/DA acquisition board is designed to implement the data transmission between integral separation PID controller based on FPGA and electronic throttle. Finally, tracking experiments of electronic throttle are performed and the results demonstrate the effectiveness of the designed integral separation PID controller based on FPGA.%针对电子节气门控制系统对控制器的快速性、低成本、微型化等控制性能的要求,通过现场可编程门阵列( FPGA:Field Programmable Gate Array)实现控制器的硬件设计,在发展较为成熟的增量式PID( Proportional, Integral, Differential)算法基础上加入积分分离环节,利用高级综合工具Catapult C实现了基于FPGA全硬件方案的积分分离PID控制器。设计制作了AD/DA采集板,实现了基于FPGA的积分分离PID控制器与电子节气门之间的数据通信,并进行了电子节气门的实物跟踪控制实验。实验结果表明,基于FPGA的全硬件积分分离PID控制器实现了电子节气门跟踪控制,提高了控制器的运算精度。

  14. The Problem with Hitler. The Man Nobody Knows

    Directory of Open Access Journals (Sweden)

    Ben Novak

    2009-12-01

    Full Text Available Conocemos mucho sobre Adolf Hitler. Probablemente tenemos más información –hechos, detalles y horarios- sobre la vida de este hombre que la de cualquier otra figura significativa de la contemporaneidad. Sin embargo, todavía sentimos que desconocemos a este hombre. Su vida es uno de los mayores misterios en la historia de la Humanidad. ¿Por qué Hitler, sobre el que conocemos mayores hechos y detalles que ninguna otra figura en la historia contemporánea (quizás en la historia, permanece siendo un misterio? Hitler frustró a sus oponentes, sorprendió a observadores neutrales, y deleitó a sus seguidores consiguiendo lo “imposible”. Él jamás habría accedido al poder sin haber conseguido estos cinco “improbabilidades” que describiremos a continuación, y lo que es más, consiguiendo el apoyo incondicional de sus seguidores, le dio un aura de excepcionalidad y catapultó a este pequeño y feo hombre al poder. Este artículo tratará sobre esas cinco “improbabilidades” y su influencia en la personalidad de Hitler: sus primeros años (1919-1923; el juicio por el Putsch; la refundación del partido; el terremoto político de 1930 y su ascenso al poder._____________________ABSTRACT:We know so much about Adolf Hitler. We probably have more information—facts, details, and minutiae—about this man’s life than any other major figure of modern times. Nonetheless, we still feel that we do not know the man. His life is one of the greatest mysteries in human history. Why is it that Hitler, about whom more facts and details are known than perhaps any other figure in modern history (perhaps in all history, remains such a mystery?  Hitler frustrated his opponents, amazed neutral observers, and delighted his supporters by pulling off the seemingly “impossible”. He never would have made it into power except by accomplishing these five “impossibilities”; and it was this, more than anything else, that bound his supporters to him

  15. Microgravity Experiment Programs for Students at the Bremen Drop Tower

    Science.gov (United States)

    Könemann, Thorben; Eigenbrod, Christian; Von Kampen, Peter; Laemmerzahl, Claus

    The Center of Applied Space Technology and Microgravity (ZARM) founded by Prof. Dr.-Ing. Hans J. Rath in 1985 is part of the Department of Production Engineering at the University of Bremen, Germany. ZARM established as a research center and currently headed by Prof. Dr. Claus Lämmerzahl is mainly concentrated on fundamental investigations of gravitational and space-related phenomenas under conditions of weightlessness as well as questions and developments related to technologies for space. At ZARM more than 70 scientists, engineers and administrative staff as well as many students from different departments are employed. Today, ZARM is still one of the largest and most important university institutes for space sciences and technologies in Europe as well as worldwide well known in the space community. With a height of 146 m the Bremen Drop Tower is the predominant facility of ZARM and also the only drop tower of its class in Europe. ZARM’s ground-based laboratory offers the opportunity for daily short-term experiments under conditions of high-quality weightlessness at a level of 10 (-6) g (microgravity). The provided quality is one of the purest for experiments under weightlessness worldwide achieved. The scientists may choose between a single drop experiment with 4.74 s in simple free fall and a catapult experiment with 9.3 s of weightlessness. Either in the drop or in the worldwide unique catapult operation routine the repetition rates of microgravity experiments at ZARM are always the same, generally up to 3 times per day. Since the start of operation of the facility in 1990, over 6750 launches of more than 160 different experiment types from various scientific fields like Fundamental Physics, Combustion, Fluid Dynamics, Planetary Formation / Astrophysics, Biology and Materials Sciences have been successfully accomplished so far. In our paper we will report and inform about microgravity experiment programs for students like „Drop Your Thesis!“ by ESA and

  16. 航母关键系统对架次率的影响研究%The influence of critical systems on the sortie generation rate of aircraft carriers

    Institute of Scientific and Technical Information of China (English)

    赵远征

    2016-01-01

    The sortie generation rate is a basic criterion to judge the combat capability of an aircraft carrier and its em-barked air wing, and it is also an important technical index of an aircraft carrier. In this paper, the influence of several critic-al systems on the sortie generation rate of aircraft carriers is discussed. The direct impact of the catapults, the approaching and landing system, the aircraft elevators, and the aviation weapon handling system are analyzed. The different impacts of the accelerating capability between nuclear aircraft carriers and conventional aircraft carriers are also analyzed.%航母舰载机的出动架次率是衡量航母及其航空联队作战能力的基本标准,是航母重要的战技指标。本文着重探讨了航母关键系统对架次率的影响,分析了弹射装置、着舰引导系统、飞机升降机、航空弹药贮运系统的能力对舰载机出动架次率的直接影响,对比了常规动力航母和核动力航母的加速性能对架次率的间接作用。

  17. Pneumatic Performance Study of a High Pressure Ejection Device Based on Real Specific Energy and Specific Enthalpy

    Directory of Open Access Journals (Sweden)

    Jie Ren

    2014-09-01

    Full Text Available In high-pressure dynamic thermodynamic processes, the pressure is much higher than the air critical pressure, and the temperature can deviate significantly from the Boyle temperature. In such situations, the thermo-physical properties and pneumatic performance can’t be described accurately by the ideal gas law. This paper proposes an approach to evaluate the pneumatic performance of a high-pressure air catapult launch system, in which esidual functions are used to compensate the thermal physical property uncertainties of caused by real gas effects. Compared with the Nelson-Obert generalized compressibility charts, the precision of the improved virial equation of state is better than Soave-Redlich-Kwong (S-R-K and Peng-Robinson (P-R equations for high pressure air. In this paper, the improved virial equation of state is further used to establish a compressibility factor database which is applied to evaluate real gas effects. The specific residual thermodynamic energy and specific residual enthalpy of the high-pressure air are also derived using the modified corresponding state equation and improved virial equation of state which are truncated to the third virial coefficient. The pneumatic equations are established on the basis of the derived residual functions. The comparison of the numerical results shows that the real gas effects are strong, and the pneumatic performance analysis indicates that the real dynamic thermodynamic process is obviously different from the ideal one.

  18. The buzz on buzz.

    Science.gov (United States)

    Dye, R

    2000-01-01

    Word-of-mouth promotion has become an increasingly potent force, capable of catapulting products from obscurity into runaway commercial successes. Harry Potter, collapsible scooters, the Chrysler PT Cruiser, and The Blair Witch Project are all recent examples of the considerable power of buzz. Yet many top executives and marketing managers are misinformed about the phenomenon and remain enslaved to some common myths. In her article, author Renée Dye explores the truth behind these myths. Myth 1: Only outrageous or edgy products are buzz-worthy. That's simply not true. The most unlikely products, like prescription drugs, can generate tremendous buzz. Myth 2: Buzz just happens. Not so, says Dye. Buzz is increasingly the result of shrewd marketing tactics in which companies seed a vanguard group, ration supplies, use celebrity endorsements, leverage the power of lists, and initiate grassroots marketing. Myth 3: The best buzz-starters are your best customers. Often, a counterculture has a greater ability to start buzz. Myth 4: To profit from buzz, you must act first and fast. In fact, copycat companies can reap substantial profits if they know when and when not to jump in. Myth 5: The media and advertising are needed to create buzz. When used either too early or too much, the media and advertising can squelch buzz before it ignites. As globalization and brand proliferation continue, writes Dye, buzz may come to dominate the shaping of markets. Indeed, companies that are unable to control buzz may soon find the phenomenon controlling them.

  19. 联合应用实时量RT-PCR和激光显微切割检测单个肝细胞RNA的表达%Quantitative analysis of RNA levels from single hepatocytes in vivo: combined use of real- time RT- PCR and laser microdissection

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    AIM: The manner in which a cell responds to and influences its environment is ultimately determined by the genes that are expressed. To better understand cellular functions, the isolation of single cells and subsequent quantification of the expressed genes is essential. METHODS: Normal liver tissue was obtained from operation, snapfrozen in liquid nitrogen and sectioned in crystat. Individual hepatocytes were microdissected. RNA was extracted, then reverse transcribed and amplified using real- time quantitative polymerase chain reaction (PCR). RESULTS: Single hepatocytes were dissected by laser beam and catapulted to the microcentrifuge cap which was put above the slide. In this way,cells were collected, RNA was extracted, reverse transcribed to cDNA and used for analysis of RNA expression by realtime quantitative PCR. The amplification results showed that quantitation of the RNA inside the cell was compatible with the number of cells. CONCLUSION: The expression of RNA in single cells can be quantitated successfully by using laser microdissection and real -time PCR. These techniques provide an opportunity to monitor in vivo gene expression levels in single hepatocytes.

  20. Optimization design of satellite separation systems based on Multi-Island Genetic Algorithm

    Science.gov (United States)

    Hu, Xingzhi; Chen, Xiaoqian; Zhao, Yong; Yao, Wen

    2014-03-01

    The separation systems are crucial for the launch of satellites. With respect to the existing design issues of satellite separation systems, an optimization design approach based on Multi-Island Genetic Algorithm is proposed, and a hierarchical optimization of system mass and separation angular velocity is designed. Multi-Island Genetic Algorithm is studied for the problem and the optimization parameters are discussed. Dynamic analysis of ADAMS used to validate the designs is integrated with iSIGHT. Then the optimization method is employed for a typical problem using the helical compression spring mechanism, and the corresponding objective functions are derived. It turns out that the mass of compression spring catapult is decreased by 30.7% after optimization and the angular velocity can be minimized considering spring stiffness errors. Moreover, ground tests and on-orbit flight indicate that the error of separation speed is controlled within 1% and the angular velocity is reduced by nearly 90%, which proves the design result and the optimization approach.

  1. The " Daphnia" Lynx Mark I Suborbital Flight Experiment: Hardware Qualification at the Drop Tower Bremen

    Science.gov (United States)

    Knie, Miriam; Schoppmann, Kathrin; Eck, Hendrik; Ribeiro, Bernard Wolfschoon; Laforsch, Christian

    2016-06-01

    The Drop Tower Bremen, a ground-based facility enabling research under real microgravity conditions, is an excellent platform for testing new types of experimental hardware to ensure full performance when deployed in costly and rare flight opportunities such as suborbital flights. Here we describe the " Daphnia" experiment which will fly on XCOR Aerospace Lynx Mark I and our experience from the hardware tests with the catapult system at the drop tower. The aim of the " Daphnia" experiment is to obtain data on the biological performance of daphnids and predator-prey interactions in microgravity, which are important for the development of aquatic bioregenerative life support systems (BLSS). The experiment consists of two subunits: The first unit is dedicated to predator-prey interactions, where behavioural analysis should reveal if microgravity interfere with prey ( Daphnia) detection or feeding and therefore may interrupt the trophic cascade. The functioning of such an artificial food web is indispensable for a long-lasting BLSS suitable for long-duration manned space missions or Earth-based explorations to extreme habitats. The second unit is designed to investigate the impact of microgravity on gene expression and the cytoskeleton in Daphnia. Next to data collection, the real microgravity conditions at the drop tower have helped to identify the weak points of the " Daphnia" experimental hardware and lead to further improvement. Hence, the drop tower is ideal for testing new experimental hardware which is indispensable before the implementation in suborbital flights.

  2. Insights into the microstructures of hygroscopic movement in plant seed dispersal.

    Science.gov (United States)

    Elbaum, Rivka; Abraham, Yael

    2014-06-01

    As non-motile organisms, plants develop means to spread their progenies. Hygroscopic movement is a very common mechanism employed in seed dispersal. This type of movement is created when the tissue desiccates and the cell walls dry and shrink. A contraction force develops, the direction and strength of which depends on the architecture of the tissue. This force may be utilized for a simple release of seeds, their catapultion, and for pushing seeds along the soil to a germination locus. We review the formation of a bend, a twist and a coil within various dispersal apparatuses as a reaction to the dehydration of the tissue. We compare the microscopic structures of hygroscopic devices supporting slow or fast movement, adaptations to dry or wet climates, and single use versus repeated movement. We discuss the development of the disconnecting tissues in relation to the development of a hygroscopic mechanism. As plant cultivation is dependent on seed dispersal control, we demonstrate that during the domestication of sesame and wheat, seed dispersal is avoided not due to a defective hygroscopic tissue, but rather a missing dehiscence tissue. Seed dispersal is a crucial stage in the life cycle of plants. Thus, hygroscopic movement plays a central part in plant ecology and agriculture.

  3. Electricity 2001: The new electricity industry -- challenges and opportunities

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-01-01

    This annual industry review provides an overview of the current state of the electric power industry in Canada, the challenges and accomplishments of CEA members, a picture from coast to coast of the state of electricity, and how the industry is repositioning itself to seize new opportunities and take charge of transforming the current business environment to shape the future of the industry. Two major developments of recent years continue to engage the attention of industry leaders: (1) electricity restructuring and deregulation which have catapulted issues of public attitudes and customer satisfaction into the foreground, and (2) climate change and air quality issues which continue to require the best efforts of governments and industry to ensure a sustainable electricity future. In addition to industry-wide concerns and actions, the review contains an account of how each of the CEA member utilities view the challenges, the results of their achievements to date and plans for the immediate future. Over and above these, there are more detailed considerations of continental issues, the key role of taxation in Canada's changing electricity industry, investing in alternative energy, the environmental challenge and registry program and changes in CEA's Benchmarking Business Entity (BBE) program to address the changing needs of members as they deal with a multitude of new problems ranging from regulatory requirements to detailed benchmarking initiatives.

  4. Yachting club

    CERN Multimedia

    Yachting club

    2011-01-01

    WARNING: your C key is about to expire... Good, we hoped that would draw your attention! A gentle reminder that, following the purchase of our fast, sophisticated racing catamaran Hobie Tiger Meerkat last season, your Committee decided to create a new key to reflect this, the EC (Experienced Catamaran). Those taking a C course will be assessed during a test as to whether they will gain the C key or the C plus EC key, so need only practise hard. Those - and we are many - who possess the C key from past years need to refresh our knowledge and prove our competence to sail Meerkat effectively with the EC key. This requires a few attested outings under good wind conditions, use of the gennaker, general control. And if it’s any consolation, we (remembering the Darts and then the Mysteres, and now both SL16 and Tiger) can confirm that she is really a pussycat, and really very willing to tack if you treat her right... Plan on trying for her or indeed Catapult on Thursdays, then talk to your Committee (f.i...

  5. Dynamic tensile failure mechanics of the musculoskeletal neck using a cadaver model.

    Science.gov (United States)

    Yliniemi, Eno M; Pellettiere, Joseph A; Doczy, Erica J; Nuckley, David J; Perry, Chris E; Ching, Randal P

    2009-05-01

    Although the catapult phase of pilot ejections has been well characterized in terms of human response to compressive forces, the effect of the forces on the human body during the ensuing ejection phases (including windblast and parachute opening shock) has not been thoroughly investigated. Both windblast and parachute opening shock have been shown to induce dynamic tensile forces in the human cervical spine. However, the human tolerance to such loading is not well known. Therefore, the main objective of this research project was to measure human tensile neck failure mechanics to provide data for computational modeling, anthropometric test device development, and improved tensile injury criteria. Twelve human cadaver specimens, including four females and eight males with a mean age of 50.1+/-9 years, were subjected to dynamic tensile loading through the musculoskeletal neck until failure occurred. Failure load, failure strain, and tensile stiffness were measured and correlated with injury type and location. The mean failure load for the 12 specimens was 3100+/-645 N, mean failure strain was 16.7+/-5.4%, and mean tensile stiffness was 172+/-54.5 N/mm. The majority of injuries (8) occurred in the upper cervical spine (Oc-C3), and none took place in the midcervical region (C3-C5). The results of this study assist in filling the existing void in dynamic tensile injury data and will aid in developing improved neck injury prevention strategies.

  6. Caviar and Friendship: Sensational Trials and the Reinvention of Public Space

    Directory of Open Access Journals (Sweden)

    Nicola Evans

    2013-08-01

    Full Text Available Sensational trials are a venue for the performance of social knowledge—the kind of knowledge that does not regularly make an appearance on the front pages of national newspapers. if sensational trials routinely catapult private matters into the public sphere, it is less such exciting revelations that concern me here, than the dross kicked up in their wake. Sensational trials, I contend, are a point of entry into everyday life, that far more elusive zone of ordinary beliefs and practices situated between the institution and the bedroom, in the interstices of the scripted and chronicled domains of private and public life. To address the everyday is to confront those undocumented procedures and forms of knowledge that exist beyond the realm of official discourse, practices that cultural theorists are increasingly eager to explore and increasingly sceptical of finding. As Barry Sandywell recently observed, ‘Like the omnipollent term “community”, “everyday life” is in continuous use within lay and theoretical discourse and yet continuously evades definition. Perhaps ... we should ask “where is everyday life”?’ This paper argues that one answer to this question lies in the study of sensational trials.

  7. Antibody labelling of resilin in energy stores for jumping in plant sucking insects.

    Directory of Open Access Journals (Sweden)

    Malcolm Burrows

    Full Text Available The rubbery protein resilin appears to form an integral part of the energy storage structures that enable many insects to jump by using a catapult mechanism. In plant sucking bugs that jump (Hemiptera, Auchenorrhyncha, the energy generated by the slow contractions of huge thoracic jumping muscles is stored by bending composite bow-shaped parts of the internal thoracic skeleton. Sudden recoil of these bows powers the rapid and simultaneous movements of both hind legs that in turn propel a jump. Until now, identification of resilin at these storage sites has depended exclusively upon characteristics that may not be specific: its fluorescence when illuminated with specific wavelengths of ultraviolet (UV light and extinction of that fluorescence at low pH. To consolidate identification we have labelled the cuticular structures involved with an antibody raised against a product of the Drosophila CG15920 gene. This encodes pro-resilin, the first exon of which was expressed in E. coli and used to raise the antibody. We show that in frozen sections from two species, the antibody labels precisely those parts of the metathoracic energy stores that fluoresce under UV illumination. The presence of resilin in these insects is thus now further supported by a molecular criterion that is immunohistochemically specific.

  8. PVT roadmap. A European guide for the development and market introduction of PVT technology

    Energy Technology Data Exchange (ETDEWEB)

    Zondag, H.A.; Van Helden, W.G.J.; Bakker, M. [ECN Renewable Energy in the Built Environment DEGO, Petten (Netherlands); Affolter, P. [Solstis, Lausanne (Switzerland); Eisenmann, W. [Institut fuer Solarenergieforschung ISFH, Emmerthal (Germany); Fechner, H. [Arsenal Research, Vienna (Austria); Rommel, M. [Fraunhofer ISE, Freiburg (Germany); Schaap, A. [Ecofys, Utrecht (Netherlands); Soerensen, H. [Esbensen, Copenhagen (Denmark); Tripanagnostopoulos, Y. [University of Patras, Patras (Greece)

    2006-06-15

    The aim of the roadmap is to identify promising markets for PVT (PhotoVoltaic Thermal) technology , and to identify the economical, policy, legislative and technical bottlenecks. In addition, the roadmap wants to inform the parties in the market on PVT. It thereby targets a broad range of professionals, including policy makers, solar manufacturers, installers and researchers. This work has been carried out within the PVT forum project, which is part of the EU-supported project PV-Catapult. The aim of PVT Forum is to lay the foundations for a large-scale introduction of PVT technology in Europe by means of this roadmap. In order to construct the roadmap, a two-step approach was taken. As a first step, PVT experts, PV and solar thermal industries and other stakeholders were brought together in two workshops, connected to the PVSEC 2004 in Paris and the Eurosun conference 2004 in Freiburg, to identify drivers and barriers for PVT. The results of these two workshops, that were presented in two workshop reports, were used as input for the roadmap presented here. As a second step, the PVT roadmap was written, formulating the necessary actions that should be taken on short, medium and long term in order to enlarge the market for PVT products. The chapters of the roadmap are written and reviewed by the various participants in PVT Forum. These participants have been selected for this project on the basis of their contribution to PVT development over the last years.

  9. Maintenance - practically changing perception via technology - the 'PLAN' view

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, I.D. [Monition Ltd, Nottinghamshire (United Kingdom)

    2001-07-01

    The author and presenter of this paper intends to show how the PLAN project is helping to focus engineering professionals minds on 'helping themselves' when it comes to Maintenance matters. As co- ordinator of the Maintenance Cluster of the PLAN project, the presenter will describe how the work of three Cluster Tasks, has already convinced many scientific and engineering biased professionals that adopting certain key philosophies can assist the Maintenance function to achieve performance standards previously thought unattainable. The paper will show how the use of the very latest technological developments, particularly in the Condition Monitoring field, together with 'Accountancy Justification' can bring about 'Purse String Loosening Effects'. The presentation will go on to show how the 'Purse String Loosening Effects' become self perpetuating and can catapult the Maintenance function to the forefront of a business. In conclusion the author will show how the PLAN project work, within the Maintenance Cluster, has assessed the State of the Art in many areas of Maintenance Engineering and will go on to describe some of the contents of an 'Easy to Understand', practical guide to really, achieving business results through Focused Maintenance, which is to be produced. (orig.)

  10. FY05 LDRD Final ReportTime-Resolved Dynamic Studies using Short Pulse X-Ray Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, A; Dunn, J; van Buuren, T; Budil, K; Sadigh, B; Gilmer, G; Falcone, R; Lee, R; Ng, A

    2006-02-10

    Established techniques must be extended down to the ps and sub-ps time domain to directly probe product states of materials under extreme conditions. We used short pulse ({le} 1 ps) x-ray radiation to track changes in the physical properties in tandem with measurements of the atomic and electronic structure of materials undergoing fast laser excitation and shock-related phenomena. The sources included those already available at LLNL, including the picosecond X-ray laser as well as the ALS Femtosecond Phenomena beamline and the SSRL based sub-picosecond photon source (SPPS). These allow the temporal resolution to be improved by 2 orders of magnitude over the current state-of-the-art, which is {approx} 100 ps. Thus, we observed the manifestations of dynamical processes with unprecedented time resolution. Time-resolved x-ray photoemission spectroscopy and x-ray scattering were used to study phase changes in materials with sub-picosecond time resolution. These experiments coupled to multiscale modeling allow us to explore the physics of materials in high laser fields and extreme non-equilibrium states of matter. The ability to characterize the physical and electronic structure of materials under extreme conditions together with state-of-the-art models and computational facilities will catapult LLNL's core competencies into the scientific world arena as well as support its missions of national security and stockpile stewardship.

  11. Zeroing in on a new goal

    Energy Technology Data Exchange (ETDEWEB)

    O`Connell, K.A.

    1997-05-01

    A recent survey by Resource Services (Atlanta) showed that Georgia had a 32.6% recycling rate, which would catapult the state into the top 10 states in terms of recycling rates. Although these claims have since been disputed by certain environmental and recycling advocacy groups, arguably the state has taken important steps to increase its recycling levels. While recycling has become a growing presence in the home, at the curb, and in the office, another place where recycling has been thrust into the forefront is the Georgia state house in Atlanta. One state legislator in particular, Sen. Donzella James (D), has introduced a spate of recycling-related legislation that could change the face of solid waste management in Georgia. James introduced far-reaching legislation that would establish an ambitious goal of zero waste by the year 2020. The bill is in part a response to the state`s failure to meet a 25% waste diversion goal set in 1992. The bill mandates a graduated reduction in municipal solid waste, with a 25% diversion by 2002 and a 50% diversion by 2007, with total diversion by 2020.

  12. Direct Lorentz force compensation flowmeter for electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Vasilyan, S., E-mail: suren.vasilyan@tu-ilmenau.de; Froehlich, Th. [Institute of Process Measurement and Sensor Technology, Ilmenau University of Technology, 98684 Ilmenau (Germany)

    2014-12-01

    A simplified method of contactless Lorentz force (LF) measurements for flow meters on electrolytes is described and realized. Modification and comparative representation are discussed against recently well-developed methods. Based on the catapult effect, that current carrying conductor experiences a repulsive force in a magnetic field, we demonstrate force measurement method of LF velocimetry applications by commonly known “electromagnetic force” compensation principle. Measurement approach through zero point stability is considered to minimize mechanical influences and avoid gravimetric uncertainties. Here, the current carrying wires are static fixed in the vicinity of magnet system at zero point stable position, while occurring deflection of magnets by electrolyte flow is compensated by external applied current within wires. Measurements performed by developed servo-system which drives control loop by means of optical position sensor for simplified (i) single wire and (ii) coil-like extended compensation schemes. Guided by experiments on electrolyte flow, we demonstrate the applicability of adopted principle for conductivities ranging from 2 to 20 S/m. Further improvements are discussed in agreement with the parameters of demonstration setup, straightforward theory, and experimental results. We argue that this method is potentially suitable for: (a) applications with higher conductivity like molten metal (order of 10{sup 6 }S/m) assuming spatial configuration of setup and (b) for lower range of conductivity (below 1 S/m) while this is strongly subject to stiffness of system and noise mainly mechanical and thermal radiations.

  13. Behaviour of a birch plywood under various experimental conditions

    Directory of Open Access Journals (Sweden)

    Caetano Lydie

    2015-01-01

    Full Text Available Liquid Natural Gaz -LNG- carriers must provide cryogenic reliability and safety for at least 40 years. Most of the insulation systems belong to the so-called membrane type, in which the “insulation complex” is composed of a metal membrane as a barrier, a plywood panel, insulation foam and a plywood panel glued to the inner hull. During construction and exploitation at cryogenic temperature, an impact of the membrane may occur and could lead to a LNG leakage. In order to evaluate this risk, and the role of the plywood in the perforation process of the membrane, a series of original impact tests are carried out at room and cryogenic temperatures on metal-plywood samples thanks to a specially designed catapult. In order to obtain a reliable numerical simulation of the impact, a series of impact and out of plane compression tests at room and cryogenic temperatures are carried out. Thanks to a design experiment, we identified the influence of the moisture content, from 2% up to 30%, and of the temperature, from − 173 ∘C up to +20 ∘C, on the strain rate sensitivity of the plywood.

  14. Ultra High Energy Electrons Powered by Pulsar Rotation

    CERN Document Server

    Mahajan, Swadesh; Osmanov, Zaza; Chkheidze, Nino

    2013-01-01

    A new mechanism of particle acceleration to ultra high energies, driven by the rotational slow down of a pulsar (Crab pulsar, for example), is explored. The rotation, through the time dependent centrifugal force, can very efficiently excite unstable Langmuir waves in the e-p plasma of the star magnetosphere via a parametric process. These waves, then, Landau damp on electrons accelerating them in the process. The net transfer of energy is optimal when the wave growth and the Landau damping times are comparable and are both very short compared to the star rotation time. We show, by detailed calculations, that these are precisely the conditions for the parameters of the Crab pulsar. This highly efficient route for energy transfer allows the electrons in the primary beam to be catapulted to multiple TeV ($\\sim 100$ TeV) and even PeV energy domain. It is expected that the proposed mechanism may, partially, unravel the puzzle of the origin of ultra high energy cosmic ray electrons.

  15. Obstacle avoidance and path planning for carrier aircraft launching

    Directory of Open Access Journals (Sweden)

    Wu Yu

    2015-06-01

    Full Text Available Launching safety and efficiency are important indexes to measure the fighting capacity of carrier. The study on path planning for taxi of carrier aircraft launching under actual deck environment is of great significance. In actual deck scheduling, manual command is applied to taxi of carrier aircraft, which has negative effects on the safety of staff and carrier aircraft launching. In consideration of both the safety and efficiency of carrier aircraft launching, the key elements of the problem are abstracted based on the analysis of deck environment, carrier aircraft maneuver performance and task requirements. According to the problem description, the mathematical model is established including various constraints. The carrier aircraft and the obstacles are reasonably simplified as circle and polygons respectively. What’s more, the proposed collision detection model reduces the calculations. Aimed at the features of model, the theory of model predictive control (MPC is applied to the path search. Then a dynamic weight heuristic function is designed and a dynamic multistep optimization algorithm is proposed. Taking the Nimitz-class aircraft carrier as an example, the paths from parking place to catapult are planned, which indicate the rationality of the model and the effectiveness of the algorithm by comparing the planning results under different simulation environments. The main contribution of research is the establishment of obstacle avoidance and path planning model. In addition, it provides the solution of model and technological foundations for comprehensive command and real-time decision-making of the carrier aircraft.

  16. Pharmacodynamics and Systems Pharmacology Approaches to Repurposing Drugs in the Wake of Global Health Burden.

    Science.gov (United States)

    Bai, Jane P F

    2016-10-01

    There are emergent needs for cost-effective treatment worldwide, for which repurposing to develop a drug with existing marketing approval of disease(s) for new disease(s) is a valid option. Although strategic mining of electronic health records has produced real-world evidences to inform drug repurposing, using omics data (drug and disease), knowledge base of protein interactions, and database of transcription factors have been explored. Structured integration of all the existing data under the framework of drug repurposing will facilitate decision making. The ability to foresee the need to integrate new data types produced by emergent technologies and to enable data connectivity in the context of human biology and targeted diseases, as well as to use the existing crucial quality data of all approved drugs will catapult the number of drugs being successfully repurposed. However, translational pharmacodynamics databases for modeling information across human biology in the context of host factors are lacking and are critically needed for drug repurposing to improve global public health, especially for the efforts to combat neglected tropic diseases as well as emergent infectious diseases such as Zika or Ebola virus.

  17. Prediction of MicroRNA-Disease Associations Based on Social Network Analysis Methods

    Directory of Open Access Journals (Sweden)

    Quan Zou

    2015-01-01

    Full Text Available MicroRNAs constitute an important class of noncoding, single-stranded, ~22 nucleotide long RNA molecules encoded by endogenous genes. They play an important role in regulating gene transcription and the regulation of normal development. MicroRNAs can be associated with disease; however, only a few microRNA-disease associations have been confirmed by traditional experimental approaches. We introduce two methods to predict microRNA-disease association. The first method, KATZ, focuses on integrating the social network analysis method with machine learning and is based on networks derived from known microRNA-disease associations, disease-disease associations, and microRNA-microRNA associations. The other method, CATAPULT, is a supervised machine learning method. We applied the two methods to 242 known microRNA-disease associations and evaluated their performance using leave-one-out cross-validation and 3-fold cross-validation. Experiments proved that our methods outperformed the state-of-the-art methods.

  18. 小型气象无人机作业与起降方式试验研究%Tests of Takeoff and Landing Approach Of Small Meteorological UAV

    Institute of Scientific and Technical Information of China (English)

    吴朝晖; 刘志平; 马瑞升; 孙涵; 林宗桂

    2011-01-01

    通过对比分析2003年以来6种气象无人机起飞和5种降落方式的飞行测试,得出30Kg以下无人机的起飞和降落方式对场地的要求,以及优点和不足;试验证明,弹射起飞和伞降与滑降相结合的回收方式在民用领域中适应性最好,可广泛用于我国的山地、丘陵和平原地形环境,是经济性、安全性俱佳的小型无人机起降方式。%Basing the MUAV (Meteorological Unmanned Aerial Vehicle) flight tests of six kinds of takeoff and 5 kinds of landing approach, the space requirements for MUAV takeoff and landing were discussed, as well as the strengths and weaknesses. It shows that catapult takeoff and the recovery way of parachute combined with downhill race made a best adaptation to the civil field, which can be widely used in China's mountains, hills and plains terrain environment.

  19. 英国成立卫星应用技术与创新中心

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    据新华网2012年1月29日报道,英国技术战略委员会(TSB)1月4日宣布成立卫星应用技术与创新中心(Catapult Centre),它将成为英国卫星的通信、广播、定位及观测产品和服务商业化开发的重要支撑。卫星服务产业被认为是英国未来十年经济发展的重要领域,该领域的全球产业规模到2030年可达4000亿英镑。该中心将依照英国《空间创新战略》和《增长战略》,计划到2030年创造10万个就业岗位,达到占世界的市场份额从目前的6%提高到10%的目标。

  20. Cell sorting using efficient light shaping approaches

    Science.gov (United States)

    Bañas, Andrew; Palima, Darwin; Villangca, Mark; Glückstad, Jesper

    2016-03-01

    Early detection of diseases can save lives. Hence, there is emphasis in sorting rare disease-indicating cells within small dilute quantities such as in the confines of lab-on-a-chip devices. In our work, we use optical forces to isolate red blood cells detected by machine vision. This approach is gentler, less invasive and more economical compared to conventional FACS systems. As cells are less responsive to plastic or glass beads commonly used in the optical manipulation literature, and since laser safety would be an issue in clinical use, we develop efficient approaches in utilizing lasers and light modulation devices. The Generalized Phase Contrast (GPC) method that can be used for efficiently illuminating spatial light modulators or creating well-defined contiguous optical traps is supplemented by diffractive techniques capable of integrating the available light and creating 2D or 3D beam distributions aimed at the positions of the detected cells. Furthermore, the beam shaping freedom provided by GPC can allow optimizations in the beam's propagation and its interaction with the catapulted cells.

  1. Dal protettore al controllore. Uno sguardo sociologico sulla letteratura disegnata a tema supereroistico

    Directory of Open Access Journals (Sweden)

    Pier Paolo Zampieri

    2015-12-01

    Full Text Available 1938: a flying man with an S on his breast appears in the sky of an American metropolis, catapulting cartoon mass entertainment into a new dimension. 1986: a spot of blood on a Smiley icon (Moore, 1986 puts an end to the innocence of an entire narrative genre. The two logos, which share a great retroactive symbolic impact, are presented as the two great epistemic divides (Foucault, 1966 of the superheroic cartoon literature. This paper is aimed at offering a sociological view on a whole genre, made up of pure visual grammar and accounted as being particularly suitable for the representation of the implicit tensions of contemporary societies (Di Nocera, 2000. The paper offers genealogic systematizing and discussion of the implications inherent to Watchmen’s, mature and conscious production. Starting from the title, Watchmen (Moore, 1986 stands as a deliberate investigation of the archetype on which the whole genre rests. In the end, in more and more complex systems and societies, “who controls the controllers?”

  2. Development of corrosion risk map for Peninsular Malaysia using climatic and air pollution data

    Science.gov (United States)

    U, Fathoni; M, Zakaria C.; O, Rohayu C.

    2013-06-01

    Malaysia has catapulted to an era of major transition. This rapid transition has also cause impact to the environment. The human activities contribute to pollutions. Buildings and it component's performances are affected directly or indirectly by air pollutions and climate factors. It has triggering and accelerating degradation processes. When deterioration start, service life of the buildings and its components will decrease. This paper presents initial development of corrosion risk map for Peninsular Malaysia using Geographical Information System (GIS). The air pollution and climate data obtained from Malaysia Meteorology Department (MMD). The air pollution data was the salt ion deposition of nitrate, chloride and sulphate in a form of wet fall out (WFO). The corrosion risk map generated using geographical information system (GIS) using inverse distance weighing (IDW) and weighted overlay method. It found that the corrosion risk map can be generated with further site verification and it can be used by engineers for further prediction of service life of building components in achieving sustainable construction design.

  3. 1999 Gordon Research Conference on Mammalian DNA Repair. Final Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-02-12

    This Conference will examine DNA repair as the key component in genomic surveillance that is so crucial to the overall integrity and function of mammalian cells. Recent discoveries have catapulted the field of DNA repair into a pivotal position for fundamental investigations into oncology, aging, environmental health, and developmental biology. We hope to highlight the most promising and exciting avenues of research in robust discussions at this conference. This Mammalian DNA Repair Gordon Conference differs from the past conferences in this series, in which the programs were broader in scope, with respect to topics and biological systems covered. A conference sponsored by the Genetics Society in April 1998 emphasized recombinational mechanisms for double-strand break repair and the role of mismatch repair deficiency in colorectal cancer. These topics will therefore receive somewhat less emphasis in the upcoming Conference. In view of the recent mechanistic advances in mammalian DNA repair, an upcoming comprehensive DNA repair meeting next autumn at Hilton Head; and the limited enrollment for Gordon Conferences we have decided to focus session-by-session on particular areas of controversy and/or new developments specifically in mammalian systems. Thus, the principal presentations will draw upon results from other cellular systems only to the extent that they impact our understanding of mammalian DNA repair.

  4. Gaucher disease: Progress and ongoing challenges.

    Science.gov (United States)

    Mistry, Pramod K; Lopez, Grisel; Schiffmann, Raphael; Barton, Norman W; Weinreb, Neal J; Sidransky, Ellen

    Over the past decades, tremendous progress has been made in the field of Gaucher disease, the inherited deficiency of the lysosomal enzyme glucocerebrosidase. Many of the colossal achievements took place during the course of the sixty-year tenure of Dr. Roscoe Brady at the National Institutes of Health. These include the recognition of the enzymatic defect involved, the isolation and characterization of the protein, the localization and characterization of the gene and its nearby pseudogene, as well as the identification of the first mutant alleles in patients. The first treatment for Gaucher disease, enzyme replacement therapy, was conceived of, developed and tested at the Clinical Center of the National Institutes of Health. Advances including recombinant production of the enzyme, the development of mouse models, pioneering gene therapy experiments, high throughput screens of small molecules and the generation of induced pluripotent stem cell models have all helped to catapult research in Gaucher disease into the twenty-first century. The appreciation that mutations in the glucocerebrosidase gene are an important risk factor for parkinsonism further expands the impact of this work. However, major challenges still remain, some of which are described here, that will provide opportunities, excitement and discovery for the next generations of Gaucher investigators.

  5. Tackle and impact detection in elite Australian football using wearable microsensor technology.

    Science.gov (United States)

    Gastin, Paul B; McLean, Owen C; Breed, Ray V P; Spittle, Michael

    2014-01-01

    The effectiveness of a wearable microsensor device (MinimaxX(TM) S4, Catapult Innovations, Melbourne, VIC, Australia) to automatically detect tackles and impact events in elite Australian football (AF) was assessed during four matches. Video observation was used as the criterion measure. A total of 352 tackles were observed, with 78% correctly detected as tackles by the manufacturer's software. Tackles against (i.e. tackled by an opponent) were more accurately detected than tackles made (90% v 66%). Of the 77 tackles that were not detected at all, the majority (74%) were categorised as low-intensity. In contrast, a total of 1510 "tackle" events were detected, with only 18% of these verified as tackles. A further 57% were from contested ball situations involving player contact. The remaining 25% were in general play where no contact was evident; these were significantly lower in peak Player Load™ than those involving player contact (P < 0.01). The tackle detection algorithm, developed primarily for rugby, was not suitable for tackle detection in AF. The underlying sensor data may have the potential to detect a range of events within contact sports such as AF, yet to do so is a complex task and requires sophisticated sport and event-specific algorithms.

  6. The history of the oldest self-sustaining laboratory animal: 150 years of axolotl research.

    Science.gov (United States)

    Reiß, Christian; Olsson, Lennart; Hoßfeld, Uwe

    2015-07-01

    Today the Mexican axolotl is critically endangered in its natural habitat in lakes around Mexico City, but thrives in research laboratories around the world, where it is used for research on development, regeneration, and evolution. Here, we concentrate on the early history of the axolotl as a laboratory animal to celebrate that the first living axolotls arrived in Paris in 1864, 150 years ago. Maybe surprisingly, at first the axolotl was distributed across Europe without being tied to specific research questions, and amateurs engaged in acclimatization and aquarium movements played an important role for the rapid proliferation of the axolotl across the continent. But the aquarium also became an important part of the newly established laboratory, where more and more biological and medical research now took place. Early scientific interest focused on the anatomical peculiarities of the axolotl, its rare metamorphosis, and whether it was a larva or an adult. Later, axolotl data was used to argue both for (by August Weismann and others) and against (by e.g., Albert von Kölliker) Darwinism, and the axolotl even had a brief history as a laboratory animal used in a failed attempt to prove Lysenkoism in Jena, Germany. Nowadays, technical developments such as transgenic lines, and the very strong interest in stem cell and regeneration research has again catapulted the axolotl into becoming an important laboratory animal.

  7. Sporangium Exposure and Spore Release in the Peruvian Maidenhair Fern (Adiantum peruvianum, Pteridaceae.

    Directory of Open Access Journals (Sweden)

    Simon Poppinga

    Full Text Available We investigated the different processes involved in spore liberation in the polypod fern Adiantum peruvianum (Pteridaceae. Sporangia are being produced on the undersides of so-called false indusia, which are situated at the abaxial surface of the pinnule margins, and become exposed by a desiccation-induced movement of these pinnule flaps. The complex folding kinematics and functional morphology of false indusia are being described, and we discuss scenarios of movement initiation and passive hydraulic actuation of these structures. High-speed cinematography allowed for analyses of fast sporangium motion and for tracking ejected spores. Separation and liberation of spores from the sporangia are induced by relaxation of the annulus (the 'throwing arm' of the sporangium catapult and conservation of momentum generated during this process, which leads to sporangium bouncing. The ultra-lightweight spores travel through air with a maximum velocity of ~5 m s(-1, and a launch acceleration of ~6300 g is measured. In some cases, the whole sporangium, or parts of it, together with contained spores break away from the false indusium and are shed as a whole. Also, spores can stick together and form spore clumps. Both findings are discussed in the context of wind dispersal.

  8. An On-Line Algorithm for Measuring the Translational and Rotational Velocities of a Table Tennis Ball

    Science.gov (United States)

    Liu, Chunfang; Hayakawa, Yoshikazu; Nakashima, Akira

    This paper proposes an on-line method for estimating both translational and rotational velocities of a table tennis ball by using only a few consecutive frames of image data which are sensed by two high speed cameras. In order to estimate the translational velocity, three-dimensional (3D) position of the ball's center at each instant of camera frame is obtained, where the on-line method of reconstructing the 3D position from the two-dimensional (2D) image data of two cameras is proposed without the pattern matching process. The proposed method of estimating the rotational velocity belongs to the image registration methods, where in order to avoid the pattern matching process too, a rotation model of the ball is used to make an estimated image data from an image data sensed at the previous instant of camera frame and then the estimated image data are compared with the image data sensed at the next instant of camera frame to obtain the most plausible rotational velocity by using the least square and the conjugate gradient method. The effectiveness of the proposed method is shown by some experimental results in the case of a ball rotated by a rotation machine as well as in the case of a flying ball shot from a catapult machine.

  9. Functional diversity of resilin in Arthropoda

    Directory of Open Access Journals (Sweden)

    Jan Michels

    2016-09-01

    Full Text Available Resilin is an elastomeric protein typically occurring in exoskeletons of arthropods. It is composed of randomly orientated coiled polypeptide chains that are covalently cross-linked together at regular intervals by the two unusual amino acids dityrosine and trityrosine forming a stable network with a high degree of flexibility and mobility. As a result of its molecular prerequisites, resilin features exceptional rubber-like properties including a relatively low stiffness, a rather pronounced long-range deformability and a nearly perfect elastic recovery. Within the exoskeleton structures, resilin commonly forms composites together with other proteins and/or chitin fibres. In the last decades, numerous exoskeleton structures with large proportions of resilin and various resilin functions have been described. Today, resilin is known to be responsible for the generation of deformability and flexibility in membrane and joint systems, the storage of elastic energy in jumping and catapulting systems, the enhancement of adaptability to uneven surfaces in attachment and prey catching systems, the reduction of fatigue and damage in reproductive, folding and feeding systems and the sealing of wounds in a traumatic reproductive system. In addition, resilin is present in many compound eye lenses and is suggested to be a very suitable material for optical elements because of its transparency and amorphousness. The evolution of this remarkable functional diversity can be assumed to have only been possible because resilin exhibits a unique combination of different outstanding properties.

  10. Dinamika Elit Lokal Madura

    Directory of Open Access Journals (Sweden)

    Imam Zamroni

    2012-01-01

    Full Text Available The priyayi played a vital role in leading the Indonesian community during the colonial era. The same applies to Madura society. During the colonial era, power wielded by the priyayi was constricted on the basis of Madura culture and was strengthened by the bureaucratic power structure at both the village and district/ city level. This was manifested in such ways as serving as a klébun or bupati. However, the pattern of priyayi power, which was underpinned by feudalism waned, being replaced by Islamic religious leaders known as kiai. During the New Order regime, kiai in Madura played a very dominant role which was not only limited to the realm of religion, but also all aspects of life ranging from social, politics, economic, to culture. Nevertheless, with the dawn of the reformation era, economic elites have catapulted themselves to prominence, and there are growing signs that they are replacing the role which religious leaders used to play in Madura society in general and in the political domain in particular through forming shadow state as a tool used to exert control over Madura Political dynamics. This concise paper presents as discussion of ‘political fights’ among cultural, religious, bureaucratic, and economic elites in Madura.

  11. An examination of amphibian sensitivity to environmental contaminants: are amphibians poor canaries?

    Science.gov (United States)

    Kerby, Jacob L; Richards-Hrdlicka, Kathryn L; Storfer, Andrew; Skelly, David K

    2010-01-01

    Nearly two decades ago, the global biodiversity crisis was catapulted to the front pages of newspapers with the recognition of worldwide amphibian declines. Amphibians earned their appellation, 'canaries in a coal mine', because of apparent high sensitivity to human-mediated environmental change. The most frequently cited causes for high susceptibility include permeable skin, a dual aquatic-terrestrial life cycle and a relatively rudimentary immune system. While some researchers have questioned the basis for the canary assertion, there has been no systematic evaluation of amphibian sensitivity to environmental challenges relative to other taxa. Here, we apply a database representing thousands of toxicity tests to compare the responses of amphibians relative to that of other taxonomic groups. The use of standardized methods combined with large numbers of identical challenges enables a particularly powerful test of relative effect size. Overall, we found that amphibians only exhibit moderate relative responses to water-borne toxins. Our findings imply that, as far as chemical contaminants are concerned, amphibians are not particularly sensitive and might more aptly be described as 'miners in a coal mine'. To the extent that amphibian declines have been mediated by chemical contaminants, our findings suggest that population losses and extinctions may have already occurred in a variety of taxa much more sensitive than amphibians.

  12. Evolution of Scholarly Publishing and Library Services in Astronomy Its Impact, Challenges, and Opportunities

    Science.gov (United States)

    Wesley, Hema; Sheshadri, Geetha

    2016-10-01

    Scholarly publishing and its procedures have evolved rapidly, forcefully, and incredibly. Technical advances in the production and promotion of science content have dramatically augmented the visibility and reach, deepened the impact and intensified the thrust of science journal content. These changes range from checking text on perforated tapes to pit stop; from hot metal types to CTP; and from Gutenberg to colour digital printers. Intrinsic and inextricable to this revolutionary aspect of evolution in scholarly publishing is the evolution of library services in astronomy which catapulted library resources from preprints on shelves to customised digital repositories and from communicating observational data through postal telegrams to Tablets. What impact does this unique blend of revolutionary advances have on science and society, what are the consequent challenges, and what are the opportunities that can metamorphose from challenges inherent in the power and potential of the `published word'? The perspectives expressed in this paper stem from learning experiences of the authors at the Indian Academy of Sciences, publishers of ten science journals including the Journal of Astrophysics and Astronomy, and at the Raman Research Institute Library (in which Astronomy is one of the core subjects for research)

  13. Quantifying the physical demands of collision sports: does microsensor technology measure what it claims to measure?

    Science.gov (United States)

    Gabbett, Tim J

    2013-08-01

    The physical demands of rugby league, rugby union, and American football are significantly increased through the large number of collisions players are required to perform during match play. Because of the labor-intensive nature of coding collisions from video recordings, manufacturers of wearable microsensor (e.g., global positioning system [GPS]) units have refined the technology to automatically detect collisions, with several sport scientists attempting to use these microsensors to quantify the physical demands of collision sports. However, a question remains over the validity of these microtechnology units to quantify the contact demands of collision sports. Indeed, recent evidence has shown significant differences in the number of "impacts" recorded by microtechnology units (GPSports) and the actual number of collisions coded from video. However, a separate study investigated the validity of a different microtechnology unit (minimaxX; Catapult Sports) that included GPS and triaxial accelerometers, and also a gyroscope and magnetometer, to quantify collisions. Collisions detected by the minimaxX unit were compared with video-based coding of the actual events. No significant differences were detected in the number of mild, moderate, and heavy collisions detected via the minimaxX units and those coded from video recordings of the actual event. Furthermore, a strong correlation (r = 0.96, p sports. Until such validation research is completed, sport scientists should be circumspect of the ability of other units to perform similar functions.

  14. Electric field responsive origami structures using electrostriction-based active materials

    Science.gov (United States)

    Ahmed, Saad; Arrojado, Erika; Sigamani, Nirmal; Ounaies, Zoubeida

    2015-04-01

    The objective of origami engineering is to combine origami principles with advanced materials to yield active origami shapes, which fold and unfold in response to external stimuli. We are investigating the use of P(VDF-TrFE-CTFE), a relaxor ferroelectric terpolymer, to realize origami-inspired folding and unfolding of structures and to actuate so-called action origami structures. To accomplish these two objectives, we have explored different approaches to the P(VDF-TrFECTFE) polymer actuator construction, ranging from unimorph to multilayered stacks. Electromechanical characterization of the terpolymer-based actuators is conducted with a focus on free strain, force-displacement and blocked force. Moreover dynamic thickness strains of P(VDF-TrFE-CTFE) terpolymer at different frequencies ranging from 0.1Hz to 10Hz is also measured. Quantifying the performance of terpolymer-based actuators is important to the design of action origami structures. Following these studies, action origami prototypes based on catapult, flapping butterfly wings and barking fox are actuated and characterization of these prototypes are conducted by studying impact of various parameters such as electric field magnitude and frequency, number of active layers, and actuator dimensions.

  15. Direct Lorentz force compensation flowmeter for electrolytes

    Science.gov (United States)

    Vasilyan, S.; Froehlich, Th.

    2014-12-01

    A simplified method of contactless Lorentz force (LF) measurements for flow meters on electrolytes is described and realized. Modification and comparative representation are discussed against recently well-developed methods. Based on the catapult effect, that current carrying conductor experiences a repulsive force in a magnetic field, we demonstrate force measurement method of LF velocimetry applications by commonly known "electromagnetic force" compensation principle. Measurement approach through zero point stability is considered to minimize mechanical influences and avoid gravimetric uncertainties. Here, the current carrying wires are static fixed in the vicinity of magnet system at zero point stable position, while occurring deflection of magnets by electrolyte flow is compensated by external applied current within wires. Measurements performed by developed servo-system which drives control loop by means of optical position sensor for simplified (i) single wire and (ii) coil-like extended compensation schemes. Guided by experiments on electrolyte flow, we demonstrate the applicability of adopted principle for conductivities ranging from 2 to 20 S/m. Further improvements are discussed in agreement with the parameters of demonstration setup, straightforward theory, and experimental results. We argue that this method is potentially suitable for: (a) applications with higher conductivity like molten metal (order of 106 S/m) assuming spatial configuration of setup and (b) for lower range of conductivity (below 1 S/m) while this is strongly subject to stiffness of system and noise mainly mechanical and thermal radiations.

  16. Oppenheimer the tragic intellect

    CERN Document Server

    Thorpe, Charles

    2008-01-01

    At a time when the Manhattan Project was synonymous with large-scale science, physicist J. Robert Oppenheimer (1904-67) represented the new sociocultural power of the American intellectual. Catapulted to fame as director of the Los Alamos atomic weapons laboratory, Oppenheimer occupied a key position in the compact between science and the state that developed out of World War II. By tracing the making-and unmaking-of Oppenheimer's wartime and postwar scientific identity, Charles Thorpe illustrates the struggles over the role of the scientist in relation to nuclear weapons, the state, and culture.  A stylish intellectual biography, Oppenheimer maps out changes in the roles of scientists and intellectuals in twentieth-century America, ultimately revealing transformations in Oppenheimer's persona that coincided with changing attitudes toward science in society.  "This is an outstandingly well-researched book, a pleasure to read and distinguished by the high quality of its observations and judgments. It will b...

  17. Genetic analysis of the early natural history of epithelial ovarian carcinoma.

    Directory of Open Access Journals (Sweden)

    Bhavana Pothuri

    Full Text Available BACKGROUND: The high mortality rate associated with epithelial ovarian carcinoma (EOC reflects diagnosis commonly at an advanced stage, but improved early detection is hindered by uncertainty as to the histologic origin and early natural history of this malignancy. METHODOLOGY/PRINCIPAL FINDINGS: Here we report combined molecular genetic and morphologic analyses of normal human ovarian tissues and early stage cancers, from both BRCA mutation carriers and the general population, indicating that EOCs frequently arise from dysplastic precursor lesions within epithelial inclusion cysts. In pathologically normal ovaries, molecular evidence of oncogenic stress was observed specifically within epithelial inclusion cysts. To further explore potential very early events in ovarian tumorigenesis, ovarian tissues from women not known to be at high risk for ovarian cancer were subjected to laser catapult microdissection and gene expression profiling. These studies revealed a quasi-neoplastic expression signature in benign ovarian cystic inclusion epithelium compared to surface epithelium, specifically with respect to genes affecting signal transduction, cell cycle control, and mitotic spindle formation. Consistent with this gene expression profile, a significantly higher cell proliferation index (increased cell proliferation and decreased apoptosis was observed in histopathologically normal ovarian cystic compared to surface epithelium. Furthermore, aneuploidy was frequently identified in normal ovarian cystic epithelium but not in surface epithelium. CONCLUSIONS/SIGNIFICANCE: Together, these data indicate that EOC frequently arises in ovarian cystic inclusions, is preceded by an identifiable dysplastic precursor lesion, and that increased cell proliferation, decreased apoptosis, and aneuploidy are likely to represent very early aberrations in ovarian tumorigenesis.

  18. ESA Parabolic Flight, Drop Tower and Centrifuge Opportunities for University Students

    Science.gov (United States)

    Callens, Natacha; Ventura-Traveset, Javier; Zornoza Garcia-Andrade, Eduardo; Gomez-Calero, Carlos; van Loon, Jack J. W. A.; Pletser, Vladimir; Kufner, Ewald; Krause, Jutta; Lindner, Robert; Gai, Frederic; Eigenbrod, Christian

    The European Space Agency (ESA) Education Office was established in 1998 with the purpose of motivating young people to study science, engineering and technology subjects and to ensure a qualified workforce for ESA and the European space sector in the future. To this end the ESA Education Office is supporting several hands-on activities including small student satellites and student experiments on sounding rockets, high altitude balloons as well as microgravity and hypergravity platforms. This paper is intended to introduce three new ESA Education Office hands-on activities called "Fly Your Thesis!", "Drop Your Thesis!" and "Spin Your Thesis!". These activities give re-spectively access to aircraft parabolic flight, drop tower and centrifuge campaigns to European students. These educational programmes offer university students the unique opportunity to design, build, and eventually perform, in microgravity or hypergravity, a scientific or techno-logical experiment which is linked to their syllabus. During the "Fly Your Thesis!" campaigns, the students accompany their experiments onboard the A300 Zero-G aircraft, operated by the company Novespace, based in Bordeaux, France, for a series of three flights of 30 parabolas each, with each parabola providing about 20s of microgravity [1]. "Drop Your Thesis!" campaigns are held in the ZARM Drop Tower, in Bremen, Germany. The installation delivers 4.74s of microgravity in dropping mode and 9.3s in the catapulting mode [2]. Research topics such as fluid physics, fundamental physics, combustion, biology, material sciences, heat transfer, astrophysics, chemistry or biochemistry can greatly benefit from using microgravity platforms. "Spin Your Thesis!" campaigns take place in the Large Diameter Centrifuge (LDC) facility, at ESTEC, Noordwijk, in the Netherlands. This facility offers an acceleration from 1 to 20 times Earth's gravity [3]. The use of hypergravity allows completing the scientific picture of how gravity has an

  19. Shooting Mechanisms in Nature: A Systematic Review.

    Directory of Open Access Journals (Sweden)

    Aimée Sakes

    Full Text Available In nature, shooting mechanisms are used for a variety of purposes, including prey capture, defense, and reproduction. This review offers insight into the working principles of shooting mechanisms in fungi, plants, and animals in the light of the specific functional demands that these mechanisms fulfill.We systematically searched the literature using Scopus and Web of Knowledge to retrieve articles about solid projectiles that either are produced in the body of the organism or belong to the body and undergo a ballistic phase. The shooting mechanisms were categorized based on the energy management prior to and during shooting.Shooting mechanisms were identified with projectile masses ranging from 1·10-9 mg in spores of the fungal phyla Ascomycota and Zygomycota to approximately 10,300 mg for the ballistic tongue of the toad Bufo alvarius. The energy for shooting is generated through osmosis in fungi, plants, and animals or muscle contraction in animals. Osmosis can be induced by water condensation on the system (in fungi, or water absorption in the system (reaching critical pressures up to 15.4 atmospheres; observed in fungi, plants, and animals, or water evaporation from the system (reaching up to -197 atmospheres; observed in plants and fungi. The generated energy is stored as elastic (potential energy in cell walls in fungi and plants and in elastic structures in animals, with two exceptions: (1 in the momentum catapult of Basidiomycota the energy is stored in a stalk (hilum by compression of the spore and droplets and (2 in Sphagnum energy is mainly stored in compressed air. Finally, the stored energy is transformed into kinetic energy of the projectile using a catapult mechanism delivering up to 4,137 J/kg in the osmotic shooting mechanism in cnidarians and 1,269 J/kg in the muscle-powered appendage strike of the mantis shrimp Odontodactylus scyllarus. The launch accelerations range from 6.6g in the frog Rana pipiens to 5,413,000g in

  20. MicroRNA Profiling of Laser-Microdissected Hepatocellular Carcinoma Reveals an Oncogenic Phenotype of the Tumor Capsule

    Directory of Open Access Journals (Sweden)

    Jan Peveling-Oberhag

    2014-12-01

    Full Text Available Several microRNAs (miRNAs are associated with the molecular pathogenesis of hepatocellular carcinoma (HCC. However, previous studies analyzing the dysregulation of miRNAs in HCC show heterogeneous results. We hypothesized that part of this heterogeneity might be attributable to variations of miRNA expression deriving from the HCC capsule or the fibrotic septa within the peritumoral tissue used as controls. Tissue from surgically resected hepatitis C–associated HCC from six well-matched patients was microdissected using laser microdissection and pressure catapulting technique. Four distinct histologic compartments were isolated: tumor parenchyma (TP, fibrous capsule of the tumor (TC, tumor-adjacent liver parenchyma (LP, and cirrhotic septa of the tumor-adjacent liver (LC. MiRNA expression profiling analysis of 1105 mature miRNAs and precursors was performed using miRNA microarray. Principal component analysis and consecutive pairwise supervised comparisons demonstrated distinct patterns of expressed miRNAs not only for TP versus LP (e.g., intratumoral down-regulation of miR-214, miR-199a, miR-146a, and miR-125a; P< .05 but also for TC versus LC (including down-regulation within TC of miR-126, miR-99a/100, miR-26a, and miR-125b; P< .05. The tumor capsule therefore demonstrates a tumor-like phenotype with down-regulation of well-known tumor-suppressive miRNAs. Variations of co-analyzed fibrotic tissue within the tumor or in controls may have profound influence on miRNA expression analyses in HCC. Several miRNAs, which are proposed to be HCC specific, may indeed be rather associated to the tumor capsule. As miRNAs evolve to be important biomarkers in liver tumors, the presented data have important translational implications on diagnostics and treatment in patients with HCC.

  1. MicroRNA Profiling of Laser-Microdissected Hepatocellular Carcinoma Reveals an Oncogenic Phenotype of the Tumor Capsule123

    Science.gov (United States)

    Peveling-Oberhag, Jan; Seiz, Anna; Döring, Claudia; Hartmann, Sylvia; Köberle, Verena; Liese, Juliane; Zeuzem, Stefan; Hansmann, Martin-Leo; Piiper, Albrecht

    2014-01-01

    Several microRNAs (miRNAs) are associated with the molecular pathogenesis of hepatocellular carcinoma (HCC). However, previous studies analyzing the dysregulation of miRNAs in HCC show heterogeneous results. We hypothesized that part of this heterogeneity might be attributable to variations of miRNA expression deriving from the HCC capsule or the fibrotic septa within the peritumoral tissue used as controls. Tissue from surgically resected hepatitis C–associated HCC from six well-matched patients was microdissected using laser microdissection and pressure catapulting technique. Four distinct histologic compartments were isolated: tumor parenchyma (TP), fibrous capsule of the tumor (TC), tumor-adjacent liver parenchyma (LP), and cirrhotic septa of the tumor-adjacent liver (LC). MiRNA expression profiling analysis of 1105 mature miRNAs and precursors was performed using miRNA microarray. Principal component analysis and consecutive pairwise supervised comparisons demonstrated distinct patterns of expressed miRNAs not only for TP versus LP (e.g., intratumoral down-regulation of miR-214, miR-199a, miR-146a, and miR-125a; P< .05) but also for TC versus LC (including down-regulation within TC of miR-126, miR-99a/100, miR-26a, and miR-125b; P< .05). The tumor capsule therefore demonstrates a tumor-like phenotype with down-regulation of well-known tumor-suppressive miRNAs. Variations of co-analyzed fibrotic tissue within the tumor or in controls may have profound influence on miRNA expression analyses in HCC. Several miRNAs, which are proposed to be HCC specific, may indeed be rather associated to the tumor capsule. As miRNAs evolve to be important biomarkers in liver tumors, the presented data have important translational implications on diagnostics and treatment in patients with HCC. PMID:25500075

  2. Interest of the MICROSTAR Accelerometer to improve the GRASP Mission.

    Science.gov (United States)

    Perrot, E.; Lebat, V.; Foulon, B.; Christophe, B.; Liorzou, F.; Huynh, P. A.

    2015-12-01

    The Geodetic Reference Antenna in Space (GRASP) is a micro satellite mission concept proposed by JPL to improve the definition of the Terrestrial Reference Frame (TRF). GRASP collocates GPS, SLR, VLBI, and DORIS sensors on a dedicated spacecraft in order to establish precise and stable ties between the key geodetic techniques used to define and disseminate the TRF. GRASP also offers a space-based reference antenna for the present and future Global Navigation Satellite Systems (GNSS). By taking advantage of the new testing possibilities offer by the catapult facility at the ZARM drop tower, the ONERA's space accelerometer team proposes an up-dated version, called MICROSTAR, of its ultra sensitive electrostatic accelerometers which have contributed to the success of the last Earth's gravity missions GRACE and GOCE. Built around a cubic proof-mass, it provides the 3 linear accelerations with a resolution better than 10-11 ms-2/Hz1/2 into a measurement bandwidth between 10-3 Hz and 0.1 Hz and the 3 angular accelerations about its 3 orthogonal axes with 5´10-10 rad.s-2/Hz1/2 resolution. Integrated at the centre of mass of the satellite, MICROSTAR improves the Precise Orbit Determination (POD) by accurate measurement of the non-gravitational force acting on the satellite. It offers also the possibility to calibrate the change in the position of the satellite center of mass with an accuracy better than 100 μm as demonstrated in the GRACE mission. Assuming a sufficiently rigid structure between the antennas and the accelerometer, its data can participate to reach the mission objective of 1 mm precision for the TRF position.

  3. Use of integrated technology in team sports: a review of opportunities, challenges, and future directions for athletes.

    Science.gov (United States)

    Dellaserra, Carla L; Gao, Yong; Ransdell, Lynda

    2014-02-01

    Integrated technology (IT), which includes accelerometers, global positioning systems (GPSs), and heart rate monitors, has been used frequently in public health. More recently, IT data have been used in sports settings to assess training and performance demands. However, the impact of IT in sports settings is yet to be evaluated, particularly in field-based team sports. This narrative-qualitative review provides an overview of the emerging impact of IT in sports settings. Twenty electronic databases (e.g., Medline, SPORTdiscus, and ScienceDirect), print publications (e.g., Signal Processing Magazine and Catapult Innovations news releases), and internet resources were searched using different combinations of keywords as follows: accelerometers, heart rate monitors, GPS, sport training, and field-based sports for relevant articles published from 1990 to the present. A total of 114 publications were identified, and 39 that examined a field-based team sport using a form of IT were analyzed. The articles chosen for analysis examined a field-based team sport using a form of IT. The uses of IT can be divided into 4 categories: (a) quantifying movement patterns (n = 22), (b) assessing the differences between demands of training and competition (n = 12), (c) measuring physiological and metabolic responses (n = 16), and (d) determining a valid definition for velocity and a sprint effort (n = 8). Most studies used elite adult male athletes as participants and analyzed the sports of Australian Rules football, field hockey, cricket, and soccer, with sample sizes between 5 and 20 participants. The limitations of IT in a sports setting include scalability issues, cost, and the inability to receive signals within indoor environments. Integrated technology can contribute to significant improvements in the preparation, training, and recovery aspects of field-based team sports. Future research should focus on using IT with female athlete populations and developing resources to use IT

  4. Creativity in action: elegantly simple idea puts firm on international pipeline map

    Energy Technology Data Exchange (ETDEWEB)

    Podlubny, J.

    2002-05-06

    A saddle bag-like device, a relatively simple invention to carry weights to hold pipelines stable in wet environments, has catapulted a small Athabasca, Alberta, company to international prominence. The saddle bag is made of 100 per cent non-biodegradable material called geotextile, commonly referred to as road matting. The bags have a life expectancy of 100 years or more, easily outlasting the pipe they protect from shifting. Weighting systems are used on pipelines to achieve the negative buoyancy required to prevent them from floating out of wet ground. They are essential in wide swats of the northern areas where the oil and gas industry operates. The saddle bags replace the traditional concrete weights which have been either bolted down or set on top of the pipe. They were bulky and hard to transport, as well as difficult to place on the pipe. In contrast, the saddle bags are easy to transport and easy to install. Indeed, the production process is portable, so that the weighted saddle bags can be made at the site of the pipeline construction job involved. This makes it easier to do pipeline weighting jobs in cold weather, at remote locations or in spots where considerable travel time is involved in completing projects. Saddle Tech has recently joined forces with the giant in the weighting system world from the United States, CRC-Evans. The U.S. firm is marketing the bags under a trademarked name 'the saddle bag'. The product being used on projects in California, as well as on almost 90 per cent of wetlands pipeline work in Alberta and British Columbia. Production was 17,000 bags in the first year of operation. So far this season, more than 40,000 bags have been made and distributed throughout North America. Plans are afoot to expand and convert the production facility to an automated operation, running 24 hours a day.

  5. Designing Electrostatic Accelerometers for Next Gravity Missions

    Science.gov (United States)

    Huynh, Phuong-Anh; Foulon, Bernard; Christophe, Bruno; Liorzou, Françoise; Boulanger, Damien; Lebat, Vincent

    2016-04-01

    Square cuboid electrostatic accelerometers sensor core have been used in various combinations in recent and still flying missions (CHAMP, GRACE, GOCE). ONERA is now in the process of delivering such accelerometers for the GRACE Follow-On mission. The goal is to demonstrate the performance benefits of an interferometry laser ranging method for future low-low satellite to satellite missions. The electrostatic accelerometer becoming thus the system main performance limiter, we propose for future missions a new symmetry which will allow for three ultrasensitive axes instead of two. This implies no performance ground testing, as the now cubic proof-mass will be too heavy, but only free fall tests in catapult mode, taking advantage of the additional microgravity testing time offered by the updated ZARM tower. The updated mission will be in better adequacy with the requirements of a next generation of smaller and drag compensated micro-satellites. In addition to the measurement of the surface forces exerted on the spacecraft by the atmospheric drag and by radiation pressures, the accelerometer will become a major part of the attitude and orbit control system by acting as drag free sensor and by accurately measuring the angular accelerations. ONERA also works on a hybridization of the electrostatic accelerometer with an atomic interferometer to take advantage of the absolute nature of the atomic interferometer acceleration measurement and its great accuracy in the [5-100] mHz bandwidth. After a description of the improvement of the GRACE-FO accelerometer with respect to the still in-orbit previous models and a status of its development, the presentation will describe the new cubic configuration and how its operations and performances can be verified in the Bremen drop tower.

  6. A Timely Shift from Shotgun to Targeted Proteomics and How It Can Be Groundbreaking for Cancer Research.

    Science.gov (United States)

    Faria, Sara S; Morris, Carlos F M; Silva, Adriano R; Fonseca, Micaella P; Forget, Patrice; Castro, Mariana S; Fontes, Wagner

    2017-01-01

    The fact that cancer is a leading cause of death all around the world has naturally sparked major efforts in the pursuit of novel and more efficient biomarkers that could better serve as diagnostic tools, prognostic predictors, or therapeutical targets in the battle against this type of disease. Mass spectrometry-based proteomics has proven itself as a robust and logical alternative to the immuno-based methods that once dominated the field. Nevertheless, intrinsic limitations of classic proteomic approaches such as the natural gap between shotgun discovery-based methods and clinically applicable results have called for the implementation of more direct, hypothesis-based studies such as those made available through targeted approaches, that might be able to streamline biomarker discovery and validation as a means to increase survivability of affected patients. In fact, the paradigm shifting potential of modern targeted proteomics applied to cancer research can be demonstrated by the large number of advancements and increasing examples of new and more useful biomarkers found during the course of this review in different aspects of cancer research. Out of the many studies dedicated to cancer biomarker discovery, we were able to devise some clear trends, such as the fact that breast cancer is the most common type of tumor studied and that most of the research for any given type of cancer is focused on the discovery diagnostic biomarkers, with the exception of those that rely on samples other than plasma and serum, which are generally aimed toward prognostic markers. Interestingly, the most common type of targeted approach is based on stable isotope dilution-selected reaction monitoring protocols for quantification of the target molecules. Overall, this reinforces that notion that targeted proteomics has already started to fulfill its role as a groundbreaking strategy that may enable researchers to catapult the number of viable, effective, and validated biomarkers in

  7. Broomstick injuries to the eye; An emerging cause of blindness among children in Nigeria

    Directory of Open Access Journals (Sweden)

    Catherine U Ukponmwan

    2015-01-01

    Full Text Available Background: Ocular trauma among children is responsible for a high incidence of uni-ocular blindness. Objective: To evaluate the pattern of presentation and complications from broomstick eye injury at University of Benin Teaching Hospital (UBTH, Benin City with a view to proffering solutions on ways to reduce this trend. Materials and Methods: The hospital records of all consecutive patients who suffered ocular trauma from broomstick injury and presented at the eye clinic of the UBTH between 2003 and 2014 were evaluated. Information retrieved from the case records included social demographic characteristics, interval between the occurrence of injury and presentation, mechanism of injury, activity at time of injury, examination findings, treatments and complications. Data were analyzed using SPSS, IBM, Chicago, USA. Results: A total of 20 eyes in 20 patients were seen. They were all children <14 years old. The mean age was 7.10 ± 4.03 (standard deviation years. The male: female ratio was 3:1. Twelve children (60% sustained trauma from broomstick shot as a missile with a rubber band and/or catapult sling by other children and siblings while at play. Ten children (50% presented within 24 h of occurrence of the injury. Nineteen (95%, n = 19 of the children were blind at presentation in the affected eye with visual acuity ranging from count finger to no light perception. Ninety percent (90% of the cases were open globe injuries. Only 10% (n = 2 were closed (lamellar injuries. Most of the patients had multiple complications such as corneal laceration (80%, traumatic cataract (40%, endophthalmitis/panophthalmitis (55% and orbital cellulitis (15%. Conclusion: Ocular trauma from broomstick results in devastating, penetrating eye injury with loss of vision. Young male children are vulnerable as targets of dangerous game-play. Primary prevention is important by sensitization of caregivers and children of the risks. There is a need for effective

  8. ArcticDEM; A Publically Available, High Resolution Elevation Model of the Arctic

    Science.gov (United States)

    Morin, Paul; Porter, Claire; Cloutier, Michael; Howat, Ian; Noh, Myoung-Jong; Willis, Michael; Bates, Brian; Willamson, Cathleen; Peterman, Kennith

    2016-04-01

    A Digital Elevation Model (DEM) of the Arctic is needed for a large number of reasons, including: measuring and understanding rapid, ongoing changes to the Arctic landscape resulting from climate change and human use and mitigation and adaptation planning for Arctic communities. The topography of the Arctic is more poorly mapped than most other regions of Earth due to logistical costs and the limits of satellite missions with low-latitude inclinations. A convergence of civilian, high-quality sub-meter stereo imagery; petascale computing and open source photogrammetry software has made it possible to produce a complete, very high resolution (2 to 8-meter posting), elevation model of the Arctic. A partnership between the US National Geospatial-intelligence Agency and a team led by the US National Science Foundation funded Polar Geospatial Center is using stereo imagery from DigitalGlobe's Worldview-1, 2 and 3 satellites and the Ohio State University's Surface Extraction with TIN-based Search-space Minimization (SETSM) software running on the University of Illinois's Blue Water supercomputer to address this challenge. The final product will be a seemless, 2-m posting digital surface model mosaic of the entire Arctic above 60 North including all of Alaska, Greenland and Kamchatka. We will also make available the more than 300,000 individual time-stamped DSM strip pairs that were used to assemble the mosaic. The Arctic DEM will have a vertical precision of better than 0.5m and can be used to examine changes in land surfaces such as those caused by permafrost degradation or the evolution of arctic rivers and floodplains. The data set can also be used to highlight changing geomorphology due to Earth surface mass transport processes occurring in active volcanic and glacial environments. When complete the ArcticDEM will catapult the Arctic from the worst to among the best mapped regions on Earth.

  9. Development and deposition of resilin in energy stores for locust jumping.

    Science.gov (United States)

    Burrows, Malcolm

    2016-08-15

    Locusts jump by using a catapult mechanism in which energy produced by slow contractions of the extensor tibiae muscles of the hind legs is stored in distortions of the exoskeleton, most notably (1) the two semi-lunar processes at each knee joint and (2) the tendons of the extensor muscles themselves. The energy is then suddenly released from these stores to power the rapid, propulsive movements of the hind legs. The reliance on the mechanical storage of energy is likely to impact on jumping because growth occurs by a series of five moults, at each of which the exoskeleton is replaced by a new one. All developmental stages (instars) nevertheless jump as a means of forward locomotion, or as an escape movement. Here, I show that in each instar, resilin is added to the semi-lunar processes and to the core of the extensor tendons so that their thickness increases. As the next moult approaches, a new exoskeleton forms within the old one, with resilin already present in the new semi-lunar processes. The old exoskeleton, the tendons and their resilin are discarded at moulting. The resilin of the semi-lunar processes and tendons of the new instar is initially thin, but a similar pattern of deposition results in an increase of their thickness. In adults, resilin continues to be deposited so that at 4 weeks old the thickness in the semi-lunar processes has increased fourfold. These changes in the energy stores accompany changes in jumping ability and performance during each moulting cycle.

  10. Metal cask RT-5000 for the dry storage and transportation of spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Vorobyov, A.I.; Kazeev, V.G.; Krayev, V.S.; Shcherbina, A.N.; Churikov, Y.I. [All-Russian Research Inst. of Technical Physics, Snezhinsk (Russian Federation)

    2003-05-01

    Presentation of new-type cask, developed at RFNC-VNIITF, is in the article. The prototype model of the shipping cask was subjected to tests imitating normal shipment conditions (free fall, pressing, and impact) and to tests imitating emergency situation during shipment (a drop from the 9-m height onto a pin is replaced by acceleration of the shipping cask at a guide rail of the rocket-catapult installation (RCI), a 1-m drop onto a pin, heat tests a 30-minutes fire at the temperature of for 8500 C, submergence to the depth of 15 and 200 meters). After each test the hermeticity preservation is examined. Parallel with the real testing, a mathematical simulation of physical processes induced by the corresponding tests was conducted at the RFNC-VNIITF. The required parameters obtained from the tests are used to calibrate the calculation methods. As a result it has been possible to obtain a good agreement between the results of calculations and experiments; this will allow the mathematic simulation to be used wider. The advantage of the RT-5000 metal cask in comparison with metal-concrete analogs are as follows: SFA are placed into the RT-5000 entirely without cutting into two bunches of fuel elements; the expensive hot doom is not required for automatic cutting the SFA and for loading the bunches of fuel elements into intermediate cases; the possibility remains to transport the RT-5000 without reloading SFA after 50-year storage, although this is a problem for the metal-concrete casks.

  11. Accelerated deflation promotes homogeneous airspace liquid distribution in the edematous lung.

    Science.gov (United States)

    Wu, You; Nguyen, Tam L; Perlman, Carrie E

    2016-12-15

    Edematous lungs contain regions with heterogeneous alveolar flooding. Liquid is trapped in flooded alveoli by a pressure barrier--higher liquid pressure at the border than in the center of flooded alveoli--that is proportional to surface tension, T Stress is concentrated between aerated and flooded alveoli, to a degree proportional to T Mechanical ventilation, by cyclically increasing T, injuriously exacerbates stress concentrations. Overcoming the pressure barrier to redistribute liquid more homogeneously between alveoli should reduce stress concentration prevalence and ventilation injury. In isolated rat lungs, we test whether accelerated deflation can overcome the pressure barrier and catapult liquid out of flooded alveoli. We generate a local edema model with normal T by microinfusing liquid into surface alveoli. We generate a global edema model with high T by establishing hydrostatic edema, which does not alter T, and then gently ventilating the edematous lungs, which increases T at 15 cmH2O transpulmonary pressure by 52%. Thus ventilation of globally edematous lungs increases T, which should increase stress concentrations and, with positive feedback, cause escalating ventilation injury. In the local model, when the pressure barrier is moderate, accelerated deflation causes liquid to escape from flooded alveoli and redistribute more equitably. Flooding heterogeneity tends to decrease. In the global model, accelerated deflation causes liquid escape, but--due to elevated T--the liquid jumps to nearby, aerated alveoli. Flooding heterogeneity is unaltered. In pulmonary edema with normal T, early ventilation with accelerated deflation might reduce the positive feedback mechanism through which ventilation injury increases over time.

  12. Jumping mechanisms and performance in beetles. I. Flea beetles (Coleoptera: Chrysomelidae: Alticini).

    Science.gov (United States)

    Nadein, Konstantin; Betz, Oliver

    2016-07-01

    The present study analyses the anatomy, mechanics and functional morphology of the jumping apparatus, the performance and the kinematics of the natural jump of flea beetles (Coleoptera: Chrysomelidae: Galerucinae: Alticini). The kinematic parameters of the initial phase of the jump were calculated for five species from five genera (average values from minimum to maximum): acceleration 0.91-2.25 (×10(3)) m s(-2), velocity 1.48-2.80 m s(-1), time to take-off 1.35-2.25 ms, kinetic energy 2.43-16.5 µJ, G: -force 93-230. The jumping apparatus is localized in the hind legs and formed by the femur, tibia, femoro-tibial joint, modified metafemoral extensor tendon, extensor ligament, tibial flexor sclerite, and extensor and flexor muscles. The primary role of the metafemoral extensor tendon is seen in the formation of an increased attachment site for the extensor muscles. The rubber-like protein resilin was detected in the extensor ligament, i.e. a short, elastic element connecting the extensor tendon with the tibial base. The calculated specific joint power (max. 0.714 W g(-1)) of the femoro-tibial joint during the jumping movement and the fast full extension of the hind tibia (1-3 ms) suggest that jumping is performed via a catapult mechanism releasing energy that has beforehand been stored in the extensor ligament during its stretching by the extensor muscles. In addition, the morphology of the femoro-tibial joint suggests that the co-contraction of the flexor and the extensor muscles in the femur of the jumping leg is involved in this process.

  13. Inductive matrix completion for predicting gene–disease associations

    Science.gov (United States)

    Natarajan, Nagarajan; Dhillon, Inderjit S.

    2014-01-01

    Motivation: Most existing methods for predicting causal disease genes rely on specific type of evidence, and are therefore limited in terms of applicability. More often than not, the type of evidence available for diseases varies—for example, we may know linked genes, keywords associated with the disease obtained by mining text, or co-occurrence of disease symptoms in patients. Similarly, the type of evidence available for genes varies—for example, specific microarray probes convey information only for certain sets of genes. In this article, we apply a novel matrix-completion method called Inductive Matrix Completion to the problem of predicting gene-disease associations; it combines multiple types of evidence (features) for diseases and genes to learn latent factors that explain the observed gene–disease associations. We construct features from different biological sources such as microarray expression data and disease-related textual data. A crucial advantage of the method is that it is inductive; it can be applied to diseases not seen at training time, unlike traditional matrix-completion approaches and network-based inference methods that are transductive. Results: Comparison with state-of-the-art methods on diseases from the Online Mendelian Inheritance in Man (OMIM) database shows that the proposed approach is substantially better—it has close to one-in-four chance of recovering a true association in the top 100 predictions, compared to the recently proposed Catapult method (second best) that has bigdata.ices.utexas.edu/project/gene-disease. Contact: naga86@cs.utexas.edu PMID:24932006

  14. The perils of the imitation age.

    Science.gov (United States)

    Bonabeau, Eric

    2004-06-01

    Imitation exerts enormous influence over society, and business and finance in particular. And its influence has grown as the avenues by which people imitate--and are imitated--have multiplied and the process has gotten faster. Thousands of communications channels make it possible for virtually anyone in the developed world to know, almost instantaneously, what others do, think, believe, claim, or predict. More significantly, we can and do act upon such knowledge. The resulting fads and fashions, bubbles and crashes are ever more frequent, severe, and complex. The information age has cast up more than its share of paradoxes, including this one: When information is plentiful, we often use it not to make better decisions but to imitate others--and their mistakes. In consumer purchases, financial markets, and corporate strategy, what others do matters more to us than the facts. When there's too much information, imitation becomes a convenient heuristic. This is the basis for a self-referential society. Imitation has its virtues, but it also promotes instability and unpredictability. That's because, by definition a multiplier, it can swell a single opinion into a mass movement or catapult the smallest player to the forefront of a market. Mastering the dynamics of self-reference won't ensure mastery of its consequences. But businesses that understand how imitation works can at least attempt to gird themselves against its worst effects--by accounting for it in their forecasts and risk-management plans, by becoming more sensitive to unexpectedly changing circumstances, and by avoiding mindless imitation of other companies' moves. In some instances, they may even be able to build strategies around self-reference and use the tools of imitation to capture new business. That won't make the world any less confusing. But it may make it more profitable.

  15. Electrostatic Positioning System for a free fall test at drop tower Bremen and an overview of tests for the Weak Equivalence Principle in past, present and future

    Science.gov (United States)

    Sondag, Andrea; Dittus, Hansjörg

    2016-08-01

    The Weak Equivalence Principle (WEP) is at the basis of General Relativity - the best theory for gravitation today. It has been and still is tested with different methods and accuracies. In this paper an overview of tests of the Weak Equivalence Principle done in the past, developed in the present and planned for the future is given. The best result up to now is derived from the data of torsion balance experiments by Schlamminger et al. (2008). An intuitive test of the WEP consists of the comparison of the accelerations of two free falling test masses of different composition. This has been carried through by Kuroda & Mio (1989, 1990) with the up to date most precise result for this setup. There is still more potential in this method, especially with a longer free fall time and sensors with a higher resolution. Providing a free fall time of 4.74 s (9.3 s using the catapult) the drop tower of the Center of Applied Space Technology and Microgravity (ZARM) at the University of Bremen is a perfect facility for further improvements. In 2001 a free fall experiment with high sensitive SQUID (Superconductive QUantum Interference Device) sensors tested the WEP with an accuracy of 10-7 (Nietzsche, 2001). For optimal conditions one could reach an accuracy of 10-13 with this setup (Vodel et al., 2001). A description of this experiment and its results is given in the next part of this paper. For the free fall of macroscopic test masses it is important to start with precisely defined starting conditions concerning the positions and velocities of the test masses. An Electrostatic Positioning System (EPS) has been developed to this purpose. It is described in the last part of this paper.

  16. The C1q family of proteins: insights into the emerging non-traditional functions

    Directory of Open Access Journals (Sweden)

    Berhane eGhebrehiwet

    2012-04-01

    Full Text Available Research conducted over the past 20 years have helped us unravel not only the hidden structural and functional subtleties of human C1q, but also has catapulted the molecule from a mere recognition unit of the classical pathway to a well-recognized molecular sensor of damage modified self or non-self antigens. Thus, C1q is involved in a rapidly expanding list of pathological disorders—including autoimmunity, trophoblast migration, preeclampsia and cancer. The results of two recent reports are provided to underscore the critical role C1q plays in health and disease. First is the observation by Singh and colleagues showing that pregnant C1q-/- mice recapitulate the key features of human preeclampsia that correlate with increased fetal death. Treatment of the C1q-/- mice with pravastatin restored trophoblast invasiveness, placental blood flow, and angiogenic balance and, thus, prevented the onset of preeclampsia. Second is the report by Hong et al., which showed that C1q can induce apoptosis of prostate cancer cells by activating the tumor suppressor molecule WW-domain containing oxydoreductase (WWOX or WOX1 and destabilizing cell adhesion. Downregulation of C1q on the other hand enhanced prostate hyperplasia and cancer formation due to failure of WOX1 activation. Recent evidence also shows that C1q belongs to a family of structurally and functionally related TNFα-like family of proteins that may have arisen from a common ancestral gene. Therefore C1q not only shares the diverse functions with the TNF family of proteins, but also explains why C1q has retained some of its ancestral cytokine-like activities. This review is intended to highlight some of the structural and functional aspects of C1q by underscoring the growing list of its non-traditional functions.

  17. Break free from the product life cycle.

    Science.gov (United States)

    Moon, Youngme

    2005-05-01

    Most firms build their marketing strategies around the concept of the product life cycle--the idea that after introduction, products inevitably follow a course of growth, maturity, and decline. It doesn't have to be that way, says HBS marketing professor Youngme Moon. By positioning their products in unexpected ways, companies can change how customers mentally categorize them. In doing so, they can shift products lodged in the maturity phase back--and catapult new products forward--into the growth phase. The author describes three positioning strategies that marketers use to shift consumers' thinking. Reverse positioning strips away"sacred" product attributes while adding new ones (JetBlue, for example, withheld the expected first-class seating and in-flight meals on its planes while offering surprising perks like leather seats and extra legroom). Breakaway positioning associates the product with a radically different category (Swatch chose not to associate itself with fine jewelry and instead entered the fashion accessory category). And stealth positioning acclimates leery consumers to a new offering by cloaking the product's true nature (Sony positioned its less-than-perfect household robot as a quirky pet). Clayton Christensen described how new, simple technologies can upend a market. In an analogous way, these positioning strategies can exploit the vulnerability of established categories to new positioning. A company can use these techniques to go on the offensive and transform a category by demolishing its traditional boundaries. Companies that disrupt a category through positioning create a lucrative place to ply their wares--and can leave category incumbents scrambling.

  18. Validity and interunit reliability of 10 Hz and 15 Hz GPS units for assessing athlete movement demands.

    Science.gov (United States)

    Johnston, Richard J; Watsford, Mark L; Kelly, Stephen J; Pine, Matthew J; Spurrs, Robert W

    2014-06-01

    The purpose of this study was to assess the validity and interunit reliability of 10 Hz (Catapult) and 15 Hz (GPSports) Global Positioning System (GPS) units and investigate the differences between these units as measures of team sport athlete movement demands. A team sport simulation circuit was completed by 8 trained male participants. The movement demands examined included: total distance covered (TD), average peak speed, and the distance covered, time spent, and the number of efforts performed low-speed running (0.00-13.99 km · h(-1)), high-speed running (14.00-19.99 km · h(-1)), and very high-speed running (>20.00 km · h(-1)). The degree of difference between the 10 Hz and the 15 Hz GPS units and validity was assessed using a paired samples t-test. Pearson's correlations were also used for validity assessment. Interunit reliability was established using percentage typical error of measurement (%TEM) and intraclass correlations. The findings revealed that 10 Hz GPS units were a valid (p > 0.05) and reliable (%TEM = 1.3%) measure of TD. In contrast, the 15 Hz GPS units exhibited lower validity for TD and average peak speed. Further, as the speed of movement increased the level of error for the 10 Hz and 15 Hz GPS units increased (%TEM = 0.8-19.9). The findings from this study suggest that comparisons should not be undertaken between 10 Hz and 15 Hz GPS units. In general, the 10 Hz GPS units measured movement demands with greater validity and interunit reliability than the 15 Hz units, however, both 10 Hz and 15 Hz units provided the improved measures of movement demands in comparison to 1 Hz and 5 Hz GPS units.

  19. Resilin and chitinous cuticle form a composite structure for energy storage in jumping by froghopper insects

    Directory of Open Access Journals (Sweden)

    Shaw Stephen R

    2008-09-01

    Full Text Available Abstract Background Many insects jump by storing and releasing energy in elastic structures within their bodies. This allows them to release large amounts of energy in a very short time to jump at very high speeds. The fastest of the insect jumpers, the froghopper, uses a catapult-like elastic mechanism to achieve their jumping prowess in which energy, generated by the slow contraction of muscles, is released suddenly to power rapid and synchronous movements of the hind legs. How is this energy stored? Results The hind coxae of the froghopper are linked to the hinges of the ipsilateral hind wings by pleural arches, complex bow-shaped internal skeletal structures. They are built of chitinous cuticle and the rubber-like protein, resilin, which fluoresces bright blue when illuminated with ultra-violet light. The ventral and posterior end of this fluorescent region forms the thoracic part of the pivot with a hind coxa. No other structures in the thorax or hind legs show this blue fluorescence and it is not found in larvae which do not jump. Stimulating one trochanteral depressor muscle in a pattern that simulates its normal action, results in a distortion and forward movement of the posterior part of a pleural arch by 40 μm, but in natural jumping, the movement is at least 100 μm. Conclusion Calculations showed that the resilin itself could only store 1% to 2% of the energy required for jumping. The stiffer cuticular parts of the pleural arches could, however, easily meet all the energy storage needs. The composite structure therefore, combines the stiffness of the chitinous cuticle with the elasticity of resilin. Muscle contractions bend the chitinous cuticle with little deformation and therefore, store the energy needed for jumping, while the resilin rapidly returns its stored energy and thus restores the body to its original shape after a jump and allows repeated jumping.

  20. Functional food red yeast rice (RYR) for metabolic syndrome amelioration: a review on pros and cons.

    Science.gov (United States)

    Patel, Seema

    2016-05-01

    Red yeast rice (RYR), the fermentation product of mold Monascus purpureus has been an integral part of Oriental food and traditional Chinese medicine, long before the discovery of their medicinal roles. With the identification of bioactive components as polyketide pigments (statins), and unsaturated fatty acids, RYR has gained a nutraceutical status. Hypercholesterolemic effect of this fermented compound has been validated and monacolin K has been recognized as the pivotal component in cholesterol alleviation. Functional similarity with commercial drug lovastatin sans the side effects has catapulted its popularity in other parts of the world as well. Apart from the hypotensive role, ameliorative benefits of RYR as anti-inflammatory, antidiabetic, anticancer and osteogenic agent have emerged, fueling intense research on it. Mechanistic studies have revealed their interaction with functional agents like coenzyme Q10, astaxanthin, vitamin D, folic acid, policosanol, and berberine. On the other hand, concurrence of mycotoxin citrinin and variable content of statin has marred its integration in mainstream medication. In this disputable scenario, evaluation of the scopes and lacunae to overcome seems to contribute to an eminent area of healthcare. Red yeast rice (RYR), the rice-based fermentation product of mold Monascus purpureus is a functional food. Its bioactive component monacolin K acts like synthetic drug lovastatin, without the severe side effects of the latter. RYR has been validated to lower cholesterol, control high blood pressure; confer anti-flammation, hypoglycaemic, anticancer and osteogenic properties. However, dose inconsistency and co-occurrence of toxin citrinin hampers its dietary supplementation prospect. Further research might facilitate development of RYR as a nutraceutical.

  1. Investigation of a robust tendon-sheath mechanism for flexible membrane wing application in mini-UAV

    Science.gov (United States)

    Lee, Shian; Tjahjowidodo, Tegoeh; Lee, Hsuchew; Lai, Benedict

    2017-02-01

    Two inherent issues manifest themselves in flying mini-unmanned aerial vehicles (mini-UAV) in the dense area at tropical climate regions, namely disturbances from gusty winds and limited space for deployment tasks. Flexible membrane wing (FMW) UAVs are seen to be potentials to mitigate these problems. FMWs are adaptable to gusty airflow as the wings are able to flex according to the gust load to reduce the effective angle-of-attack, thus, reducing the aerodynamic loads on the wing. On the other hand, the flexible structure is allowing the UAV to fold in a compact package, and later on, the mini-UAV can be deployed instantly from the storage tube, e.g. through a catapult mechanism. This paper discusses the development of an FMW UAV actuated by a tendon-sheath mechanism (TSM). This approach allows the wing to morph to generate a rolling moment, while still allowing the wing to fold. Dynamic characteristics of the mechanism that exhibits the strong nonlinear phenomenon of friction on TSM are modeled and compensated for. A feed-forward controller was implemented based on the identified nonlinear behavior to control the warping position of the wing. The proposed strategy is validated experimentally in a wind tunnel facility by creating a gusty environment that is imitating a realistic gusty condition based upon the results of computational fluid dynamics (CFD) simulation. The results demonstrate a stable and robust wing-warping actuation, even in gusty conditions. Accurate wing-warping can be achieved via the TSM, while also allowing the wings to fold.

  2. Capture of Asteroids and Transport of Asteroid Materials to Earth

    Science.gov (United States)

    Chiu, Hong-Yee; no Team

    2014-01-01

    Recently there has been much discussion on the capture of asteroids or mining the asteroids. While the technology might be years away, in this paper we will discuss an energy efficient method to transport either a small asteroid or materials gathered from asteroids to the Earth. In particular, I will concentrate on a large and nearby asteroid, 8 Flora in the Flora Family. Generally, asteroids are located between 2 to 3 AU (astronomical unit) from the Earth, and in transporting materials from asteroids to the Earth, an energy equivalent of the gravitational potential energy difference between the Earth and the asteroids to the Sun. This amount of potential energy is a sizable fraction of the orbital kinetic energy of the Earth around the Sun. This amount of energy is considerable. In this paper I propose to use the planet Mars as a medium to remove much of the gravitational energy difference. In the case of the asteroid 8 Flora, it is only necessary to decelerate the asteroid mate- rials by a small decrement, of the order of 3 km/sec. This decrement could even be achieved (pending on the availability of technology) by mechanical devices such as catapults on 8 Flora. It is also proposed to separate a pair of contact asteroid binaries by using impulse propulsion, and to propel one component of the separated asteroids to pass by Mars to be decelerated to reach the Earth orbit and captured by the Earth or the Moon. The plausibility of this ambitious project will be discussed. The author is NASA-GSFC Astrophysicist, Retired.

  3. Bio-electrosprays: from bio-analytics to a generic tool for the health sciences.

    Science.gov (United States)

    Jayasinghe, Suwan N

    2011-03-07

    Electrosprays or electrospraying is a process by which an aerosol is generated between two charged electrodes. This aerosol generation methodology has been known for well over a century, and has undergone exploration in aerosol and materials sciences, to many other areas of research and development. In one such exploration, electrosprays were partnered with mass spectrometry for the accurate characterisation of molecules. This technology now widely referred to as electrospray ionisation mass spectrometry (ESI MS) significantly contributes to molecular analysis and cancer biology to name a few. In fact these findings were recognised by the Chemistry Nobel Committee in 2002, and have catapulted electrosprays to many areas of research and development. In this review, the author wishes to introduce and discuss another such recent discovery, where electrosprays have been investigated for directly handling living cells and whole organisms. Over the past few years these electrosprays now referred to as "bio-electrosprays" have undergone rigorous developmental studies both in terms of understanding all the associate physical, chemical and biological sciences for completely assessing their effects, if any on the direct handling of living biological materials. Therefore, the review will bring together all the work that has contributed to fully understanding that bio-electrosprays are an inert technology for directly handling living biological materials, while elucidating some unique features they possess over competing technologies. Hence, demonstrating this approach as a flexible methodology for a wide range of applications spanning bio-analytics, diagnostics to the possible creation of synthetic tissues, for repairing and replacing damaged/ageing tissues, to the targeted and controlled delivery of personalised medicine through experimental and/or medical cells and/or genes. Therefore, elucidating the far reaching ramifications bio-electrosprays have to our health sciences

  4. FPGA implementation of the hyperspectral Lossy Compression for Exomars (LCE) algorithm

    Science.gov (United States)

    García, Aday; Santos, L.; López, S.; Callicó, G. M.; López, J. F.; Sarmiento, R.

    2014-10-01

    The increase of data rates and data volumes in present remote sensing payload instruments, together with the restrictions imposed in the downlink connection requirements, represent at the same time a challenge and a must in the field of data and image compression. This is especially true for the case of hyperspectral images, in which both, reduction of spatial and spectral redundancy is mandatory. Recently the Consultative Committee for Space Data Systems (CCSDS) published the Lossless Multispectral and Hyperespectral Image Compression recommendation (CCSDS 123), a prediction-based technique resulted from the consensus of its members. Although this standard offers a good trade-off between coding performance and computational complexity, the appearance of future hyperspectral and ultraspectral sensors with vast amount of data imposes further efforts from the scientific community to ensure optimal transmission to ground stations based on greater compression rates. Furthermore, hardware implementations with specific features to deal with solar radiation problems play an important role in order to achieve real time applications. In this scenario, the Lossy Compression for Exomars (LCE) algorithm emerges as a good candidate to achieve these characteristics. Its good quality/compression ratio together with its low complexity facilitates the implementation in hardware platforms such as FPGAs or ASICs. In this work the authors present the implementation of the LCE algorithm into an antifuse-based FPGA and the optimizations carried out to obtain the RTL description code using CatapultC, a High Level Synthesis (HLS) Tool. Experimental results show an area occupancy of 75% in an RTAX2000 FPGA from Microsemi, with an operating frequency of 18 MHz. Additionally, the power budget obtained is presented giving an idea of the suitability of the proposed algorithm implementation for onboard compression applications.

  5. Tests Results of the Electrostatic Accelerometer Flight Models for Gravity Recovery and Climate Experiment Follow-On Mission (GRACE FO)

    Science.gov (United States)

    Perrot, E.; Boulanger, D.; Christophe, B.; Foulon, B.; Lebat, V.; Huynh, P. A.; Liorzou, F.

    2015-12-01

    The GRACE FO mission, led by the JPL (Jet Propulsion Laboratory), is an Earth-orbiting gravity mission, continuation of the GRACE mission, which will produce an accurate model of the Earth's gravity field variation providing global climatic data during five years at least. The mission involves two satellites in a loosely controlled tandem formation, with a micro-wave link measuring the inter-satellites distance variation. Earth's mass distribution non-uniformities cause variations of the inter-satellite distance. This variation is measured to recover gravity, after subtracting the non-gravitational contributors, as the residual drag. ONERA (the French Aerospace Lab) is developing, manufacturing and testing electrostatic accelerometers measuring this residual drag applied on the satellites. The accelerometer is composed of two main parts: the Sensor Unit (including the Sensor Unit Mechanics - SUM - and the Front-End Electronic Unit - FEEU) and the Interface Control Unit - ICU. In the Accelerometer Core, located in the Sensor Unit Mechanics, the proof mass is levitated and maintained at the center of an electrode cage by electrostatic forces. Thus, any drag acceleration applied on the satellite involves a variation on the servo-controlled electrostatic suspension of the mass. The voltage on the electrodes providing this electrostatic force is the output measurement of the accelerometer. The impact of the accelerometer defaults (geometry, electronic and parasitic forces) leads to bias, misalignment and scale factor error, non-linearity and noise. Some of these accelerometer defaults are characterized by tests with micro-gravity pendulum bench on ground and with drops in ZARM catapult. The Critical Design Review was achieved successfully on September 2014. The Engineering Model (EM) was integrated and tested successfully, with ground levitation, drops, Electromagnetic Compatibility and thermal vacuum. The integration of the two Flight Models was done on July 2015. The

  6. Status of Electrostatic Accelerometer Development for Gravity Recovery and Climate Experiment Follow-On Mission (GRACE FO)

    Science.gov (United States)

    Perrot, Eddy; Boulanger, Damien; Christophe, Bruno; Foulon, Bernard; Liorzou, Françoise; Lebat, Vincent; Huynh, Phuong-Anh

    2015-04-01

    The GRACE FO mission, led by the JPL (Jet Propulsion Laboratory), is an Earth-orbiting gravity mission, continuation of the GRACE mission, which will produce an accurate model of the Earth's gravity field variation providing global climatic data during five years at least. The mission involves two satellites in a loosely controlled tandem formation, with a micro-wave link measuring the inter-satellites distance variation. Earth's mass distribution non-uniformities cause variations of the inter-satellite distance. This variation is measured to recover gravity, after subtracting the non-gravitational contributors, as the residual drag. ONERA (the French Aerospace Lab) is developing, manufacturing and testing electrostatic accelerometers measuring this residual drag applied on the satellites. The accelerometer is composed of two main parts: the Sensor Unit (including the Sensor Unit Mechanics - SUM - and the Front-End Electronic Unit - FEEU) and the Interface Control Unit - ICU. In the Accelerometer Core, located in the Sensor Unit Mechanics, the proof mass is levitated and maintained at the center of an electrode cage by electrostatic forces. Thus, any drag acceleration applied on the satellite involves a variation on the servo-controlled electrostatic suspension of the mass. The voltage on the electrodes providing this electrostatic force is the measurement output of the accelerometer. The impact of the accelerometer defaults (geometry, electronic and parasitic forces) leads to bias, misalignment and scale factor error, non-linearity and noise. Some of these accelerometer defaults are characterized by tests with micro-gravity pendulum bench on ground and with drops in ZARM catapult. The Critical Design Review was achieved successfully on September 2014. The Engineering Model (EM) was integrated and tested successfully, with ground levitation, drops, Electromagnetic Compatibility and thermal vacuum. The integration of the first Flight Model has begun on December 2014

  7. Revictimización un fenómeno invisibilizado en las instituciones Revictimization an invisiblelized phenomena in institutions

    Directory of Open Access Journals (Sweden)

    Berenice Smith Bonilla

    2007-03-01

    Full Text Available El presente trabajo de investigación sobre la revictimiación institucional pone de manifiesto la existencia de dicho fenómeno dentro del sistema judicial. Se analizan las causas de esta situación la cual aparenta no tener la debida cobertura del sistema ni la de los propios funcionarios que laboran en tal situación. Se hace una exposición de motivos que explica el fenómeno que incluye las políticas existentes, las estrategias de capacitación, difusión y consistencia. Además se estudia la existencia de la Oficina de Atención a la Víctima del Delito desde su iniciativa, la cual catapulta la figura de la víctima a un lugar hasta entonces negado, sin que su actuar trascienda al ámbito requerido por razones que se analizan. En las conclusiones se brindan recomendaciones pertinentes para quienes están sufriendo como victimas por su labor.This investigation about institutional revictimization demonstrates the existence of this phenomenon within the judicial system. The causes of this situation are analyzed, that seems not to have the appropriate coverage from the system nor from the employees of the institutions. An exposition of the different motives is done to explain the phenomenon that includes current policies, capacitating strategies, diffusion and consistency. Also the existence of the Attention to Victim of Crime Office is studied from its initiative, which catapults the victim figure to a previously denied place. As conclusions, some recommendations are brought for those who are suffering as victims.

  8. Aerospace Workforce Development: The Nebraska Proposal; and Native View Connections: A Multi-Consortium Workforce Development Proposal. UNO Aviation Monograph Series

    Science.gov (United States)

    Bowen, Brent D.; Russell, Valerie; Vlasek, Karisa; Avery, Shelly; Calamaio, Larry; Carstenson, Larry; Farritor, Shane; deSilva, Shan; Dugan, James; Farr, Lynne

    2003-01-01

    The NASA Nebraska Space Grant Consortium (NSGC) continues to recognize the necessity of increasing the quantity and quality of highly skilled graduates and faculty involved with NASA. Through NASA Workforce Development funds awarded in 2002, NSGC spearheaded customer- focused workforce training and higher education, industry and community partnerships that are significantly impacting the state s workforce in the science, technology, engineering, and mathematics (STEM) competencies. NSGC proposes to build upon these accomplishments to meet the steadily increasing demand for STEM skills and to safeguard minority representation in these disciplines. A wide range of workforce development activities target NASA s need to establish stronger connections among higher education, industry, and community organizations. Participation in the National Student Satellite Program (NSSP), Community Internship Program, and Nebraska Science and Technology Recruitment Fair will extend the pipeline of employees benefiting NASA as well as Nebraska. The diversity component of this proposal catapults from the exceptional reputation NSGC has built by delivering geospatial science experiences to Nebraska s Native Americans. For 6 years, NSGC has fostered and sustained partnerships with the 2 tribal colleges and 4 reservation school districts in Nebraska to foster aeronautics education and outreach. This program, the Nebraska Native American Outreach Program (NNAOP), has grown to incorporate more than educational institutions and is now a partnership among tribal community leaders, academia, tribal schools, and industry. The content focus has broadened from aeronautics in the school systems to aerospace technology and earth science applications in tribal community decision-making and workforce training on the reservations. To date, participants include faculty and staff at 4 Nebraska tribal schools, 2 tribal colleges, approximately 1,000 Native American youth, and over 1,200 community members

  9. Pattern of paediatric corneal laceration injuries in the University of port Harcourt teaching hospital, Rivers state, Nigeria

    Directory of Open Access Journals (Sweden)

    Omobolanle Adio

    2012-12-01

    Full Text Available Abstract Background Corneal lacerations mostly affect younger children, commonly males, who will constitute the majority of the workforce. Clinical outcomes are reviewed and compared so that measures to reduce their occurrence and improve outcome can be proffered. Methods Records of all children between the ages of 1-18 yrs, who presented with penetrating eye injuries at the eye clinic of the University of Port Harcourt teaching Hospital, Rivers state, Nigeria between January 2002 and December 2009 were included. Information retrieved -patient’s Bio data, presenting symptoms, presenting visual acuity (VA, source of injury, surgical intervention and outcome using VA. All data analysed with EPI Info version 6 with the aid of a statistician. Results Folders of thirty-six children (36 eyes between the ages of 0–18 years diagnosed with corneal laceration over a period of 8 years out of 65 cases managed within that period available. Other folders reported as missing. Male female ratio 3:1, the mean age is 8.7 years (SD ± 3.67. Only one presented within 24 hours. Objects causing injury mainly missiles with stones/catapult injuries (n = 8, 22.2%. Presenting VAs in those that could be measured, ranged from 6/24 to 6/60 (n = 4, 11% to no light perception (NLP (n = 5, 13.9%. Associated injuries include lid laceration, cataract, vitreous haemorrhage and retinal detachment. Twenty one patients had primary corneal repair (58.3% carried out within 7 days of presentation. Four had endophthalmitis. After 3 months follow up, VA of 6/60 and better was achieved in 11 of 18 eyes left in follow up (6/60-6/24 in 8 eyes (22.2%, 6/18 and better in 3 eyes (8.3%. Conclusion Most eye injuries in children are preventable. In this study, the prognosis was better in those whose injuries were confined to a peripheral part of the cornea, with no other associated injury, who presented within 5 days and who did not have any intraocular

  10. Genetic mixture of multiple source populations accelerates invasive range expansion.

    Science.gov (United States)

    Wagner, Natalie K; Ochocki, Brad M; Crawford, Kerri M; Compagnoni, Aldo; Miller, Tom E X

    2017-01-01

    A wealth of population genetic studies have documented that many successful biological invasions stem from multiple introductions from genetically distinct source populations. Yet, mechanistic understanding of whether and how genetic mixture promotes invasiveness has lagged behind documentation that such mixture commonly occurs. We conducted a laboratory experiment to test the influence of genetic mixture on the velocity of invasive range expansion. The mechanistic basis for effects of genetic mixture could include evolutionary responses (mixed invasions may harbour greater genetic diversity and thus elevated evolutionary potential) and/or fitness advantages of between-population mating (heterosis). If driven by evolution, positive effects of source population mixture should increase through time, as selection sculpts genetic variation. If driven by heterosis, effects of mixture should peak following first reproductive contact and then dissipate. Using a laboratory model system (beetles spreading through artificial landscapes), we quantified the velocity of range expansion for invasions initiated with one, two, four or six genetic sources over six generations. Our experiment was designed to test predictions corresponding to the evolutionary and heterosis mechanisms, asking whether any effects of genetic mixture occurred in early or later generations of range expansion. We also quantified demography and dispersal for each experimental treatment, since any effects of mixture should be manifest in one or both of these traits. Over six generations, invasions with any amount of genetic mixture (two, four and six sources) spread farther than single-source invasions. Our data suggest that heterosis provided a 'catapult effect', leaving a lasting signature on range expansion even though the benefits of outcrossing were transient. Individual-level trait data indicated that genetic mixture had positive effects on local demography (reduced extinction risk and enhanced

  11. 木石复合兵器——投石索、投石器、投石机

    Institute of Scientific and Technical Information of China (English)

    陈明远; 金岷彬

    2014-01-01

    在跨越百万年、几乎遍及世界的木—石器时代遗址中,都发现有大小不一的石球.本-石器时代中期,狩猎技术出现飞跃,主要表现在远距离投射的弓矢、标枪等发明.弓矢遗物大量出土,已得到历史学界的共识.但是对于“石球”的使用形态和结构功能,迄今尚留下许多疑团.由于投掷石球的木质器械(绳索、木架等)易腐朽,目前难以见到史前的实物;但从人类学、民族学的调查资料可以给我们启示,至今一些原始部落还在使用投掷石球的木石复合工具——投石索(Bolas)、投石器(Sling)等.投石索在木质绳索两端拴上石球,有单球、双球及多球投石索之分;这些是直接利用人的体力动能抛掷石头的器械类型;后来发展出了依靠重力势能或者弹性材料的弹性势能,来抛掷石头的大型木石复合武器——投石机(Catapult),这是远古遍及华夏及西亚、古波斯、古希腊罗马的一种攻城武器,中文又称为“石砲”((瑕)),可同时投掷单枚或多枚破坏性重物,如巨石等.投石机在世界兵器发展史上占据重要地位,直接促成了后世热兵器——火炮的产生.而最初火炮使用的铁制弹丸,仍然是球形,这与原始人的石球,力学性质一样.投石索、投石器、投石机等最早的使用年代,尚待进一步考证确定.

  12. Fiabilidad intra-participante de diferentes modelos de dispositivos GPS implementados en un partido de Fútbol 7

    Directory of Open Access Journals (Sweden)

    Julen Castellano

    2010-01-01

    Full Text Available El objetivo de este estudio fue estimar la fiabilidad intra-participante de tres modelos de GPS (Global Positioning System MinimaxX (Catapult Innovations, Australia, SPI10 y WiSpi (GPSports, Australia que operan a una frecuencia de 5,1 y 1 Hz, respectivamente. Se midieron distancias recorridas a distintas intensidades a 5 jugadores de fútbol (edad, 20,1 ± 1,2 años; altura, 176,3 ± 9,9 cm; peso, 63,5 ± 8,4 kg en un partido de entrenamiento de 33 min, en un campo de fútbol-7 (6 jugadores de campo y 1 portero. La distancia total recorrida (DT media fue de 3.288,8 m para los modelos MinimaxX, 3.050,3 m para el WiSPI y de 3.247,5 m para el SPI10. La velocidad máxima obtenida por cada modelo fue de 30.3 km·h-1 en los dispositivos MinimaxX, y de 25,1 y de 25.2 km·h-1 en los dispositivos WiSPI y SPI10, respectivamente. Se estimó el coeficiente de variación (CV entre los 3 modelos estudiados para la distancia recorrida en cada uno de los 4 niveles de velocidad, así como para la distancia total recorrida, y la velocidad media y máxima, siendo el tamaño de la muestra la principal limitación. En base a los resultados podemos concluir que los diferentes dispositivos presentan una alta fiabilidad para medir la distancia total recorrida y las recorridas en categorías de baja velocidad. Sin embargo la velocidad de los desplazamientos realizados durante el partido condiciona la fiabilidad de los diferentes dispositivos, aumentando la dispersión de las medidas obtenidas (CV a medida que se incrementa la velocidad de carrera; especialmente cuando se supera la velocidad de 13 km·h-1.

  13. SOME REASONS OF DISPLACES OF THE NOMADIC TRIBES IN EURASIA AND EXAMPLE OF THE BLACK DEATH IN CAFFA, 1346

    Directory of Open Access Journals (Sweden)

    Assoc. Prof. Dr. Mehmet TEZCAN

    2008-09-01

    Full Text Available The nomadic tribes in Eurasian steppes, adopted a manner oflife in nomadism, were scarcely abandoning their own residences, towhich caused some factors like generally epidemics, famines, locustattacks, or dangerous foreign threats just as oppressions by theXiongnu (to the Yuezhi or the Chinese (to the Xiongnu etc. Beingone of the reasons which led the nomadic tribes as far as to theWestern Asia and the Middle Europe, the epidemics appeared also inEurasia from the very beginnings of the history and during the MiddleAges, and spread out in the Central Asia that was on the greatcommercial routes, through the great Silk Roads in general.The epidemic named as “Black Death” appeared north of theBlack Sea in Caffa in 1346 and very influenced Medieval Europenegatively, which, there existed the period of the “Hundred Years’War”. However, there is not any exact information about its origin.According to the available information and the report by Gabriele de’Mussi, it occurred first in China in 1320s, and expanded into the NearEast rapidly through the invasion routes of the Mongol armies andcommercial ones. When Janibek Khan, the khan of the Golden Hordebegan again to besiege Caffa in 1345, the Black Death occurredamong the Mongol army. And the two Genoese ships, departed fromCaffa and came in the Mediterranean Sea in 1347, caused itsexpansion to the whole European countries, except for only Polandand Czechoslovakia, in 1348-49, and then, to Russia in 1351-53.Consequently, thirty per cent of the European population perished.As to how the epidemic influenced the nomadic world inEurasia, there is not enough information about it. However, thanks toit, we can reach to some interesting valuable data about Mongolstrategies of warfare: upon that many Mongolian soldiers of theMongolian army died due to this epidemic, the Mongol khan heldresponsible the Genoese in Caffa for the death. He made their corpses thrown into the citadel by catapults, and then

  14. Two Islands, One Commodity: Cuba, Java, and the Global Sugar Trade (1790-1930

    Directory of Open Access Journals (Sweden)

    Jonathan Curry-Machado

    2012-12-01

    Full Text Available Sugar had become, by the eighteenth century, a global commodity. Originating in East Asia, plantations in the Americas fed the growing taste for its use in Europe, with its consumption increasingly popularised. The 1791 Revolution in Saint Domingue (Haiti and the 1807 British abolition of the slave trade prompted shifts in the epicentres of sugar, the most important of these being arguably to Cuba and Java. These two fertile islands saw the burgeoning development of sugar-plantation systems with major inputs of foreign capital and forced labour. In the process the two islands each, respectively, became central to the very much truncated Spanish and Dutch colonial empires left after the Napoleonic wars and the Latin American wars of liberation; and by the mid-nineteenth century in the case of Cuba, and by the late nineteenth century in the case of Java, they had been catapulted to global sugar pre-eminence. There has been an abundance of study on the two islands each in their own right, but none systematically examines their parallel trajectories. Yet the question arises as to how sugar came to dominate the agriculture, industry and trade of these two islands; and how these two islands in particular, in two different colonial systems and parts of the world, should rise to sugar pre-eminence in the way they did and when they did. Are there connections and similarities between the two that help explain this phenomenon? This article analyses the conditions that led Java and Cuba to become the prime cane-sugar exporters of the nineteenth and early twentieth centuries. Initiative for this came from the linkages between their dominant elites and the transnational, transimperial networks of trade and capital. This furthered the stimulation of technological and scientific innovation in both, enabled not only through the introduction of the latest advances in machinery and method, but also the immigration of technical skilled workers from Europe and North

  15. The effect of physical contact on changes in fatigue markers following rugby union field-based training.

    Science.gov (United States)

    Roe, Gregory; Darrall-Jones, Joshua; Till, Kevin; Phibbs, Padraic; Read, Dale; Weakley, Jonathon; Rock, Andrew; Jones, Ben

    2017-02-26

    Repeated physical contact in rugby union is thought to contribute to post-match fatigue; however, no evidence exists on the effect of contact activity during field-based training on fatigue responses. Therefore, the purpose of this study was to examine the effect of contact during training on fatigue markers in rugby union players. Twenty academy rugby union players participated in the cross-over study. The magnitude of change in upper- and lower-body neuromuscular function (NMF), whole blood creatine kinase concentration [CK] and perception of well-being was assessed pre-training (baseline), immediately and 24 h post-training following contact and non-contact, field-based training. Training load was measured using mean heart rate, session rating of perceived exertion (sRPE) and microtechnology (Catapult Optimeye S5). The inclusion of contact during field-based training almost certainly increased mean heart rate (9.7; ±3.9%) and sRPE (42; ±29.2%) and resulted in likely and very likely greater decreases in upper-body NMF (-7.3; ±4.7% versus 2.7; ±5.9%) and perception of well-being (-8.0; ±4.8% versus  -3.4; ±2.2%) 24 h post-training, respectively, and almost certainly greater elevations in [CK] (88.2; ±40.7% versus 3.7; ±8%). The exclusion of contact from field-based training almost certainly increased running intensity (19.8; ±5%) and distance (27.5; ±5.3%), resulting in possibly greater decreases in lower-body NMF (-5.6; ±5.2% versus 2.3; ±2.4%). Practitioners should be aware of the different demands and fatigue responses of contact and non-contact, field-based training and can use this information to appropriately schedule such training in the weekly microcycle.

  16. Polymerase chain reaction: basic protocol plus troubleshooting and optimization strategies.

    Science.gov (United States)

    Lorenz, Todd C

    2012-05-22

    In the biological sciences there have been technological advances that catapult the discipline into golden ages of discovery. For example, the field of microbiology was transformed with the advent of Anton van Leeuwenhoek's microscope, which allowed scientists to visualize prokaryotes for the first time. The development of the polymerase chain reaction (PCR) is one of those innovations that changed the course of molecular science with its impact spanning countless subdisciplines in biology. The theoretical process was outlined by Keppe and coworkers in 1971; however, it was another 14 years until the complete PCR procedure was described and experimentally applied by Kary Mullis while at Cetus Corporation in 1985. Automation and refinement of this technique progressed with the introduction of a thermal stable DNA polymerase from the bacterium Thermus aquaticus, consequently the name Taq DNA polymerase. PCR is a powerful amplification technique that can generate an ample supply of a specific segment of DNA (i.e., an amplicon) from only a small amount of starting material (i.e., DNA template or target sequence). While straightforward and generally trouble-free, there are pitfalls that complicate the reaction producing spurious results. When PCR fails it can lead to many non-specific DNA products of varying sizes that appear as a ladder or smear of bands on agarose gels. Sometimes no products form at all. Another potential problem occurs when mutations are unintentionally introduced in the amplicons, resulting in a heterogeneous population of PCR products. PCR failures can become frustrating unless patience and careful troubleshooting are employed to sort out and solve the problem(s). This protocol outlines the basic principles of PCR, provides a methodology that will result in amplification of most target sequences, and presents strategies for optimizing a reaction. By following this PCR guide, students should be able to: • Set up reactions and thermal cycling

  17. Estado social de derecho o estado de opinión: dilema sin resolver en América Latina

    Directory of Open Access Journals (Sweden)

    Orlando José Cadrazco Salcedo

    2010-01-01

    catapult or a ruleror government at a particular status.Key Words:Social State of Law, State of Opinion, Government, Democracy, Constitution, Population, Surveys, Media,Social Rights.

  18. Electrostatic Accelerometer for the Gravity Recovery and Climate Experiment Follow-On Mission (GRACE FO)

    Science.gov (United States)

    Perrot, Eddy; Boulanger, Damien; Christophe, Bruno; Foulon, Bernard; Liorzou, Françoise; Lebat, Vincent

    2014-05-01

    micro-gravity pendulum bench and with drops in ZARM catapult. The post-processing needed to achieve the performance, in particular with regards to the temperature stability, will be explained.

  19. El espejismo nacional-socialista. La relación entre dos catedráticos de Prehistoria, Oswald Menghin y Julio Martínez Santa-Olalla (1935-1952

    Directory of Open Access Journals (Sweden)

    Mederos Martín, Alfredo

    2014-12-01

    Full Text Available Oswald Menghin, Professor of Prehistoric Man at the University of Vienna from 1922-45, supported the unity of Austria with Germany, and a sympathizer about the NSDAP ideas on the need to avoid racial mixing between Aryans and Jews. During his time as Professor at the University of Fouad in Cairo from 1930-33 he came into contact with Hermann Junker. This radicalized Menghin’s views and, as a result, he wrote his book, Spirit and Blood. The Basic Principles of Race, Language, Culture and Nation. His time as Rector of the University of Viena from 1936 to 1937 catapulted him into politics: he was a board member of the Austrian fascist party, Vaterländische Front from 1936 to 1937 and was appointed Minister of Education between March and May 1938, just after Hitler’s invasion of Austria. As Minister, he applied for membership in the NSDAP, but because his prior membership in secret Catholic organizations, it was not accepted until June 1940. Menghin was in contact with Martinez Santa-Olalla, after the celebration of the Jubilee of the Institute for Cultural Morphology at Frankfurt in June and July 1938. After Almagro Basch’s research period in Germany and Austria in January and February 1942 and his own visit to Barcelona in June 1942, however, Menghin chose to distance from Martinez Santa-Olalla, not visiting Madrid, cutting the epistolary relationship and reporting negatively about him to the SS-Ahnenerbe. After being imprisoned in two American concentration camps between May 1945 and February 1947, Menghin fled to Argentina in 1948, followed shortly afterwards by his wife and daughter. In Argentina Menghin was supported by Jose Imbelloni, director of the Ethnographic Museum at the University of Buenos Aires since 1947, who hired him as a researcher without teaching. He also received support from Martinez Santa-Olalla through the Spanish Ambassador, Jose Maria de Areilza, and from the Professor of History at the University of Buenos Aires

  20. Solar-powered Gossamer Penguin in flight

    Science.gov (United States)

    1979-01-01

    Gossamer Penguin in flight above Rogers Dry Lakebed at Edwards, California, showing the solar panel perpendicular to the wing and facing the sun. Background The first flight of a solar-powered aircraft took place on November 4, 1974, when the remotely controlled Sunrise II, designed by Robert J. Boucher of AstroFlight, Inc., flew following a launch from a catapult. Following this event, AeroVironment, Inc. (founded in 1971 by the ultra-light airplane innovator--Dr. Paul MacCready) took on a more ambitious project to design a human-piloted, solar-powered aircraft. The firm initially took the human-powered Gossamer Albatross II and scaled it down to three-quarters of its previous size for solar-powered flight with a human pilot controlling it. This was more easily done because in early 1980 the Gossamer Albatross had participated in a flight research program at NASA Dryden in a program conducted jointly by the Langley and Dryden research centers. Some of the flights were conducted using a small electric motor for power. Gossamer Penguin The scaled-down aircraft was designated the Gossamer Penguin. It had a 71-foot wingspan compared with the 96-foot span of the Gossamer Albatross. Weighing only 68 pounds without a pilot, it had a low power requirement and thus was an excellent test bed for solar power. AstroFlight, Inc., of Venice, Calif., provided the power plant for the Gossamer Penguin, an Astro-40 electric motor. Robert Boucher, designer of the Sunrise II, served as a key consultant for both this aircraft and the Solar Challenger. The power source for the initial flights of the Gossamer Penguin consisted of 28 nickel-cadmium batteries, replaced for the solar-powered flights by a panel of 3,920 solar cells capable of producing 541 Watts of power. The battery-powered flights took place at Shafter Airport near Bakersfield, Calif. Dr. Paul MacCready's son Marshall, who was 13 years old and weighed roughly 80 pounds, served as the initial pilot for these flights to

  1. PV solar electricity: status and future

    Science.gov (United States)

    Hoffmann, Winfried

    2006-04-01

    Within the four main market segments of PV solar electricity there are already three areas competitive today. These are off-grid industrial and rural as well as consumer applications. The overall growth within the past 8 years was almost 40 % p.a. with a "normal" growth of about 18 % p.a. for the first three market segments whereas the grid connected market increased with an astonishing 63 % p.a. The different growth rates catapulted the contribution of grid connected systems in relation to the total market from about one quarter 6 years ago towards more than three quarters today. The reason for this development is basically due to industry-politically induced market support programs in the aforementioned countries. It is quite important to outline under which boundary conditions grid connected systems will be competitive without support programs like the feed in tariff system in Germany, Spain and some more to come in Europe as well as investment subsidies in Japan, US and some other countries. It will be shown that in a more and more liberalized utility market worldwide electricity produced by PV solar electricity systems will be able to compete with their generating cost against peak power prices from utilities. The point of time for this competitiveness is mainly determined by the following facts: 1. Price decrease for PV solar electricity systems leading to an equivalent decrease in the generated cost for PV produced kWh. 2. Development of a truly liberalized electricity market. 3. Degree of irradiation between times of peak power demand and delivery of PV electricity. The first topic is discussed using price experience curves. Some explanations will be given to correlate the qualitative number of 20 % price decrease for doubling cumulative worldwide sales derived from the historic price experience curve with a more quantitative analysis based on our EPIA-Roadmap (productivity increase and ongoing improvements for existing technologies as well as development

  2. Moon (Form-Origin)

    Science.gov (United States)

    Tsiapas, Elias

    2016-04-01

    above mentioned process, the thick clouds surrounding Earth-Moon were causing heavy storms and on the outer surface of the rolling Moon, wherever small cavities - or pockets - existed, these would fill up with water. Then, due to the Moon's changing tilt, these pockets were sealed by sediments and as a result, small water tanks are scattered on the successive layers of the Moon, from its centre to its surface. . As this sphere (the Moon) continued to grow, the Earth-Moon system was displaying a double-planet image. The Moon's reverse rolling velocity increased according to the increase of its mass and volume. As the temperature on the surface of the Earth continued to fall, a larger number of bigger sized solid masses were descending from the poles towards the equator, and the Moon could no longer aggregate them. The gathering and interference of solid rocks of great mass acted as the catapult on which the Moon bounced off the Earth and was put into orbit around it.

  3. Reliability of Triaxial Accelerometry for Measuring Load in Men's Collegiate Ice-Hockey.

    Science.gov (United States)

    Van Iterson, Erik H; Fitzgerald, John S; Dietz, Calvin C; Snyder, Eric M; Peterson, Ben J

    2016-08-18

    Wearable microsensor technology incorporating triaxial accelerometry is used to quantify an index of mechanical stress associated with sport-specific movements termed PlayerLoad™. The test-retest reliability of PlayerLoad™ in the environmental-setting of ice-hockey is unknown. The primary aim of this study was to quantify the test-retest reliability of PlayerLoad™ in ice-hockey players during performance of tasks simulating game-conditions. Division I collegiate male ice-hockey players (N=8) wore Catapult Optimeye S5 monitors during repeat performance of 9 ice-hockey tasks simulating game-conditions. Ordered ice-hockey tasks during repeated bouts included: acceleration (forward/backward), 60% top-speed, top-speed (forward/backward), repeated shift circuit, ice-coasting, slap-shot, and bench-sitting. Coefficient of variation (CV), intraclass correlation coefficient (ICC), and minimum differences (MD) were used to assess PlayerLoad™ reliability. Test-retest CVs and ICCs of PlayerLoad™ were: Forward (8.6, 0.54) or backward (13.8, 0.78) acceleration, 60% top-speed (2.2, 0.96), forward (7.5, 0.79) or backwards (2.8, 0.96) top-speed, repeated-shift test (26.6, 0.95), slap-shot (3.9, 0.68), coasting (3.7, 0.98), and bench-sitting (4.1, 0.98), respectively. Raw differences between bouts were not significant for ice-hockey tasks (P>0.05). For each task, between bout raw differences were lower versus MD: Forward (0.06 vs. 0.35) or backward (0.07 vs. 0.36) acceleration, 60% top-speed (0.00 vs. 0.06), forward (0.03 vs. 0.20) or backwards (0.02 vs. 0.09) top-speed, repeated-shift test (0.18 vs. 0.64), slap-shot (0.02 vs. 0.10), coasting (0.00 vs. 0.10), and bench-sitting (0.01 vs. 0.11), respectively. These data suggest PlayerLoad™ demonstrates moderate-to-large test-retest reliability in the environmental-setting of male Division I collegiate ice-hockey. Without previously testing reliability, these data are important as PlayerLoad™ is routinely quantified in

  4. Electrostatic Accelerometer for the Gravity Recovery and Climate Experiment Follow-On Mission (GRACE FO)

    Science.gov (United States)

    Lebat, V.; Foulon, B.; Christophe, B.

    2013-12-01

    The GRACE FO mission, led by the JPL (Jet Propulsion Laboratory), is an Earth-orbiting gravity mission, continuation of the GRACE mission, that will produce an accurate model of the Earth's gravity field variation providing global climatic data during five year at least. The mission involves two satellites in a loosely controlled tandem formation, with a micro-wave link measuring the inter-satellites distance variation. Non-uniformities in the distribution of the Earth's mass cause the distance between the two satellites to vary. This variation is measured to recover gravity, after subtracting the non-gravitational contributors, as the residual drag. ONERA (the French Aerospace Lab) is developing, manufacturing and testing electrostatic accelerometers measuring this residual drag applied on the satellites. The accelerometer is composed of two main parts: the Sensor Unit (including the Sensor Unit Mechanics and the Front-End Electronic Unit) and the Interface Control Unit. In the Accelerometer Core, located in the Sensor Unit Mechanics, the proof mass is levitated and maintained in a center of an electrode cage by electrostatic forces. Thus, any drag acceleration applied on the satellite involves a variation on the servo-controlled electrostatic suspension of the mass. The voltage on the electrodes providing this electrostatic force is the measurement output of the accelerometer. The impact of the accelerometer defaults (geometry, electronic and parasitic forces) leads to bias, misalignment and scale factor error, non-linearity and noise. Some of these accelerometer defaults are characterized by tests with micro-gravity pendulum bench and with drops in ZARM catapult. Besides, a thermal stability is needed for the accelerometer core and front-end electronics to avoid bias and scale factor variation, and reached by a thermal box designed by Astrium, spacecraft manufacturer. The accelerometers are designed to endure the launch vibrations and the thermal environment at

  5. Astronomers Trace Microquasar's Path Back in Time

    Science.gov (United States)

    2003-01-01

    Astronomers have traced the orbit through our Milky Way Galaxy of a voracious neutron star and a companion star it is cannibalizing, and conclude that the pair joined more than 30 million years ago and probably were catapulted out of a cluster of stars far from the Galaxy's center. Path of Microquasar and Sun Path of Microquasar (red) and Sun (yellow) through the Milky Way Galaxy for the past 230 million years. Animations: GIF Version MPEG Version CREDIT: Mirabel & Rodrigues, NRAO/AUI/NSF The pair of stars, called Scorpius X-1, form a "microquasar," in which material sucked from the "normal" star forms a rapidly-rotating disk around the superdense neutron star. The disk becomes so hot it emits X-rays, and also spits out "jets" of subatomic particles at nearly the speed of light. Using precise positional data from the National Science Foundation's Very Long Baseline Array (VLBA) and from optical telescopes, Felix Mirabel, an astrophysicist at the Institute for Astronomy and Space Physics of Argentina and French Atomic Energy Commission, and Irapuan Rodrigues, also of the French Atomic Energy Commission, calculated that Scorpius X-1 is not orbiting the Milky Way's center in step with most other stars, but instead follows an eccentric path far above and below the Galaxy's plane. Scorpius X-1, discovered with a rocket-borne X-ray telescope in 1962, is about 9,000 light-years from Earth. It is the brightest continuous source of X-rays beyond the Solar System. The 1962 discovery and associated work earned a share of the 2002 Nobel Prize in physics for Riccardo Giacconi. Mirabel and Rodrigues used a number of published observations to calculate the path of Scorpius X-1 over the past few million years. "This is the most accurate determination we have made of the path of an X-ray binary," said Mirabel. By tracing the object's path backward in time, the scientists were able to conclude that the neutron star and its companion have been traveling together for more than 30

  6. The science of the lunar poles

    Science.gov (United States)

    Lucey, P. G.

    2011-12-01

    imaging of interiors of polar shadowed craters has been accomplished by many instruments from the ultraviolet to the radar. Imaging radars on Chandrayaan-1 and LRO have identified anomalous craters that may contain rich water ice deposits. Neutron spectrometers on Lunar Prospector and LRO directly detected hydrogen enhancements at both poles. Spectacularly, the LCROSS impact experiment detected a wide range of volatile elements and species at Cabeus crater in the lunar south polar region. While these measurements have catapulted polar science forward, much remains to be understood about the polar system, both from analysis of the current data, and new missions planned and in development. The general state of the lunar atmosphere is planned to be addressed by the UV and neutral mass spectrometers carried by the planned NASA LADEE (Lunar Atmosphere And Dust Environment Explorer) spacecraft creating an important baseline. But more data is necessary, from an in situ direct assay of polar volatiles to measurements of species and fluxes into and out of the cold traps over lengthy timescales.

  7. Fundamentals of Physics, Part 2 (Chapters 12-20)

    Science.gov (United States)

    Halliday, David; Resnick, Robert; Walker, Jearl

    2003-12-01

    Chapter 12 Equilibrium and Elasticity. What injury can occur to a rock climber hanging by a crimp hold? 12-1 What Is Physics? 12-2 Equilibrium. 12-3 The Requirements of Equilibrium. 12-4 The Center of Gravity. 12-5 Some Examples of Static Equilibrium. 12-6 Indeterminate Structures. 12-7 Elasticity. Review & Summary Questions Problems. Chapter 13 Gravitation. What lies at the center of our Milky Way galaxy? 13-1 What Is Physics? 13-2 Newton's Law of Gravitation. 13-3 Gravitation and the Principle of Superposition. 13-4 Gravitation Near Earth's Surface. 13-5 Gravitation Inside Earth. 13-6 Gravitational Potential Energy. 13-7 Planets and Satellites: Kepler's Laws. 13-8 Satellites: Orbits and Energy. 13-9 Einstein and Gravitation. Review & Summary Questions Problems. Chapter 14 Fluids. What causes ground effect in race car driving? 14-1 What Is Physics? 14-2 What Is a Fluid? 14-3 Density and Pressure. 14-4 Fluids at Rest. 14-5 Measuring Pressure. 14-6 Pascal's Principle. 14-7 Archimedes' Principle. 14-8 Ideal Fluids in Motion. 14-9 The Equation of Continuity. 14-10 Bernoulli's Equation. Review & SummaryQuestionsProblems. Chapter 15 Oscillations. What is the "secret" of a skilled diver's high catapult in springboard diving? 15-1 What Is Physics? 15-2 Simple Harmonic Motion. 15-3 The Force Law for Simple Harmonic Motion. 15-4 Energy in Simple Harmonic Motion. 15-5 An Angular Simple Harmonic Oscillator. 15-6 Pendulums. 15-7 Simple Harmonic Motion and Uniform Circular Motion. 15-8 Damped Simple Harmonic Motion. 15-9 Forced Oscillations and Resonance. Review & Summary Questions Problems. Chapter 16 Waves--I. How can a submarine wreck be located by distant seismic stations? 16-1 What Is Physics? 16-2 Types of Waves. 16-3 Transverse and Longitudinal Waves. 16-4 Wavelength and Frequency. 16-5 The Speed of a Traveling Wave. 16-6 Wave Speed on a Stretched String. 16-7 Energy and Power of a Wave Traveling Along a String. 16-8 The Wave Equation. 16-9 The Principle of Superposition

  8. RELIABILITY AND ACCURACY OF 10 HZ GPS DEVICES FOR SHORT-DISTANCE EXERCISE

    Directory of Open Access Journals (Sweden)

    Julen Castellano

    2011-03-01

    Full Text Available The use of GPS technology for training and research purposes requires a study of the reliability, validity and accuracy of the data generated (Petersen et al., 2009. To date, studies have focused on devices with a logging rate of 1 Hz and 5 Hz (Coutts and Duffield, 2010; Duffield et al., 2010; Jennings et al., 2010; MacLeod et al., 2009; Petersen et al., 2009; Portas et al., 2010, although it seems that more frequent sampling can increase the accuracy of the information provided by these devices (Jennings et al., 2010; MacLeod et al., 2009, Portas et al., 2010. However, we are unaware of any study of the reliability and accuracy of GPS devices using a sampling frequency of 10 Hz. Thus, the aim of the present research was to determine the reliability and accuracy of GPS devices operating at a sampling frequency of 10 Hz, in relation here to sprints of 15 m and 30 m and using both video and photoelectric cells.Nine trained male athletes participated in the study. Each participant completed 7 and 6 linear runs of 15 m and 30 m, respectively (n = 117, with only one GPS device being used per participant. Each repetition required them to complete the route as quickly as possible, with 1 min recovery between sets. Distance was monitored through the use of GPS devices (MinimaxX v4.0, Catapult Innovations, Melbourne, Australia operating at the above mentioned sampling frequency of 10 Hz. In addition, all tests were filmed with a video camera operating at a sampling frequency of 25 frames. Data were collected during what were considered to be good GPS conditions in terms of the weather and satellite conditions (number of satellites = 10.0 ± 0.2 and 10.3 ± 0.4 for sprints of 15 m and 30 m, respectively.Distance was measured using a tape measure. Electronic timing gates (TAG- Heuer, CP 520 Training model, Switzerland were used to obtain a criterion sprint time accurate to 0.01 s, with gates being placed at the beginning and end of the route (Petersen et

  9. Methods of Mathematical and Computational Physics for Industry, Science, and Technology

    Science.gov (United States)

    Melnik, Roderick V. N.; Voss, Frands

    2006-11-01

    Many industrial problems provide scientists with important and challenging problems that need to be solved today rather than tomorrow. The key role of mathematical physics, modelling, and computational methodologies in addressing such problems continues to increase. Science has never been exogenous to applied research. Gigantic ships and steam engines, repeating catapult of Dionysius and the Antikythera `computer' invented around 80BC are just a few examples demonstrating a profound link between theoretical and applied science in the ancient world. Nowadays, many industrial problems are typically approached by groups of researchers who are working as a team bringing their expertise to the success of the entire enterprise. Since the late 1960s several groups of European mathematicians and scientists have started organizing regular meetings, seeking new challenges from industry and contributing to the solution of important industrial problems. In particular, this often took the format of week-long workshops originally initiated by the Oxford Study Groups with Industry in 1968. Such workshops are now held in many European countries (typically under the auspices of the European Study Groups with Industry - ESGI), as well as in Australia, Canada, the United States, and other countries around the world. Problems given by industrial partners are sometimes very difficult to complete within a week. However, during a week of brainstorming activities these problems inevitably stimulate developing fruitful new ideas, new approaches, and new collaborations. At the same time, there are cases where as soon as the problem is formulated mathematically, it is relatively easy to solve. Hence, putting the industrial problem into a mathematical framework, based on physical laws, often provides a key element to the success. In addition to this important first step, the value in such cases is the real, practical applicability of the results obtained for an industrial partner who presents

  10. Book Review:

    Science.gov (United States)

    Webb, Steve

    2008-11-01

    The Polish physicist Józio (Joseph, Josh, Jo) Rotblat was catapulted into the public eye when he (and the 'Pugwash Conferences' organization) received the 1995 Nobel Peace Prize. His life prior to that had been most distinguished but conducted well out of the public eye. Born and raised as a Jewish physicist in pre-World War II Poland, and thus potentially educationally disadvantaged, he battled away for education and scientific achievement. He came to Liverpool University just before the outbreak of World War II, worked in James Chadwick's laboratory on the early beginnings of neutron fission physics, moved to Los Alamos to take part in the US-UK collaborative Manhattan Project to build a nuclear bomb and was motivated by a desire to rid Poland of Nazi 'racial cleansing'. On realizing the US-UK goal was somewhat wider, he resigned this work and dedicated his life to the peaceful uses of radiation and the campaigns to rid the world of the potential world-eliminating possibility of nuclear war. For this purpose he interacted with Albert Einstein and Bertrand Russell, and in July 1957 founded the 'Pugwash Conferences', named for a small fishing village in Nova Scotia, Canada where the first was held. Along the way his personal life was no less dramatic. Cruel events conspired, and his wife Tola remained in Poland and was killed in the Nazi extermination camp at Majdanek. He grieved for his beloved Poland and those left behind or unaccounted for. He was suspected by some Americans of being a spy and had his personal papers and family artefacts impounded. After the war he was Professor of Medical Physics at St Bartholomew's Hospital, London for 30 years up to retirement. After John Roberts, he was the second editor of this journal Physics in Medicine and Biology from 1961-72 (see e.g. Bob Burns' paper in our 50th birthday issue, 2006. Kit Hill's little book which chronicles the life and times of Rotblat weaves together the key events in his personal and professional

  11. People

    Science.gov (United States)

    2001-01-01

    underneath me; I really wanted to be catapulted into a different culture. Going to teach in Zimbabwe just meant fulfilling an awful lot of things in one go really - teaching science as well as going to live in a completely different place and being the only white person for 60 miles. But I didn't want to teach in a school forever. With something like science communication, and the joy of working on this exhibition at @Bristol for example, I've been able to try to appeal to all ages and kinds of people. And I've also been able to use different media, such as hands-on exhibits or computers, give talks or run events. What do you think the role of the exhibition is? We're much more interested in getting people excited, motivated and inspired by science and natural history rather than just trying to get across facts. We also think it's important to enable people to feel more confident about their own science and feel they can have a view about science issues. Do you have a wide range of visitors from primary school children to adults? Absolutely. I think a lot of people see hands-on science centres as being places for kids and we really wanted to make sure that teenagers, adults and senior citizens would see it as a place that was appropriate for them. So we actually split the exhibition up into four different areas in order to appeal to different age groups in different ways. For instance our area on the brain and body is more appropriate for teenagers, adults and senior citizens; small children will still find fun things to do, but there are other areas that are much more engaging for them. Whereas for adults finding out about themselves, finding out what they react to emotionally, finding out more about sex and reproduction, is something that they have responded to really well. And the great thing has been seeing teenagers coming in, choosing to come to a science centre on a Saturday afternoon. Quite a few teenagers have said that they came here with their families and now

  12. Fundamentals of Physics, Volume 1, (Chapters 1 - 21)

    Science.gov (United States)

    Walker, Jearl

    2004-01-01

    skilled diver's high catapult in springboard diving? 15-1 What Is Physics? 15-2 Simple Harmonic Motion. 15-3 The Force Law for Simple Harmonic Motion. 15-4 Energy in Simple Harmonic Motion. 15-5 An Angular Simple Harmonic Oscillator. 15-6 Pendulums. 15-7 Simple Harmonic Motion and Uniform Circular Motion. 15-8 Damped Simple Harmonic Motion. 15-9 Forced Oscillations and Resonance. Review & Summary. Questions. Problems. Chapter 16. Waves--I. How can a submarine wreck be located by distant seismic stations? 16-1 What Is Physics? 16-2 Types of Waves. 16-3 Transverse and Longitudinal Waves. 16-4 Wavelength and Frequency. 16-5 The Speed of a Traveling Wave. 16-6 Wave Speed on a Stretched String. 16-7 Energy and Power of a Wave Traveling Along a String. 16-8 The Wave Equation. 16-9 The Principle of Superposition for Waves. 16-10 Interference of Waves. 16-11 Phasors. 16-12 Standing Waves. 16-13 Standing Waves and Resonance. Review & Summary. Questions. Problems. Chapter 17. Waves--II. How can an emperor penguin .nd its mate among thousands of huddled penguins? 17-1 What Is Physics? 17-2 Sound Waves. 17-3 The Speed of Sound. 17-4 Traveling Sound Waves. 17-5 Interference. 17-6 Intensity and Sound Level. 17-7 Sources of Musical Sound. 17-8 Beats. 17-9 The Doppler Effect. 17-10 Supersonic Speeds, Shock Waves. Review & Summary. Questions. Problems. Chapter 18. Temperature, Heat, and the First Law of Thermodynamics. How can a dead rattlesnake detect and strike a reaching hand? 18-1 What Is Physics? 18-2 Temperature. 18-3 The Zeroth Law of Thermodynamics. 18-4 Measuring Temperature. 18-5 The Celsius and Fahrenheit Scales. 18-6 Thermal Expansion. 18-7 Temperature and Heat. 18-8 The Absorption of Heat by Solids and Liquids. 18-9 A Closer Look at Heat and Work. 18-10 The First Law of Thermodynamics. 18-11 Some Special Cases of the First Law of Thermodynamics. 18-12 Heat Transfer Mechanisms. Review & Summary. Questions. Problems. Chapter 19. The Kinetic Theory of Gases. How can cooling

  13. An Interview with David Dabydeen on Literature and Politics

    Directory of Open Access Journals (Sweden)

    Ruzbeh Babaee

    2016-07-01

    suffering, and the sheer injustices of colonial rule. Yet, we became acquainted with Samuel Johnson’s DICTIONARY and the magical properties of the English language; with the lyricism and storytelling of the Bible, of Shakespeare, of Victorian poetry. These new texts supplemented the ones we brought from Africa and India ( the KORAN, the RAMAYANA . Ancient and living Carib, Arawak and other Amerindian stories fertilised the situation.  We rewrote and reimagined our inheritance, hence Walcott, Naipaul, Jean Rhys, Pauline Melville, Grace Nichols, John Agard, and a host of others. I write about the injustice (historical, but also self-inflicted in our postcolonial condition but more about the urge to creativity and expression that emerged from being on the margins; the fierce resolve to become educated, literate, creative, venturing beyond boundaries. Our postcolonial politicians may have failed us repeatedly, but I am forever astonished at how resilient Guyanese are.  When I visit parts of India,  parts of China,  the nature of poverty there is brutal and overwhelming. We don’t have that level of deprivation, because we have created the means of survival and the prospect of abundance, whether on the plate or on the page.   RB: Do you believe that there is any nation on earth that enjoys true freedom and independence? DD: I don’t know what true freedom or independence mean, we are all constrained and liberated and catapulted into creativity by being with each other. However, I recall what Walcott said about slavery: that the enslaved African being herded to the cane fields would have seen something sensationally beautiful along the way, given how lush Caribbean landscapes are. A hummingbird or kiskadee or blue-saki or brightly coloured viper…Walcott said that such encounters with beauty were moments of freedom which could only be partially understood, partially described, because they also contained the seeds of tragedy and terror. If you venture into Guyana