WorldWideScience

Sample records for hypervelocity impact penetration

  1. Hypervelocity impact cratering calculations

    Science.gov (United States)

    Maxwell, D. E.; Moises, H.

    1971-01-01

    A summary is presented of prediction calculations on the mechanisms involved in hypervelocity impact cratering and response of earth media. Considered are: (1) a one-gram lithium-magnesium alloys impacting basalt normally at 6.4 km/sec, and (2) a large terrestrial impact corresponding to that of Sierra Madera.

  2. Effect of compressibility on the hypervelocity penetration

    Science.gov (United States)

    Song, W. J.; Chen, X. W.; Chen, P.

    2018-02-01

    We further consider the effect of rod strength by employing the compressible penetration model to study the effect of compressibility on hypervelocity penetration. Meanwhile, we define different instances of penetration efficiency in various modified models and compare these penetration efficiencies to identify the effects of different factors in the compressible model. To systematically discuss the effect of compressibility in different metallic rod-target combinations, we construct three cases, i.e., the penetrations by the more compressible rod into the less compressible target, rod into the analogously compressible target, and the less compressible rod into the more compressible target. The effects of volumetric strain, internal energy, and strength on the penetration efficiency are analyzed simultaneously. It indicates that the compressibility of the rod and target increases the pressure at the rod/target interface. The more compressible rod/target has larger volumetric strain and higher internal energy. Both the larger volumetric strain and higher strength enhance the penetration or anti-penetration ability. On the other hand, the higher internal energy weakens the penetration or anti-penetration ability. The two trends conflict, but the volumetric strain dominates in the variation of the penetration efficiency, which would not approach the hydrodynamic limit if the rod and target are not analogously compressible. However, if the compressibility of the rod and target is analogous, it has little effect on the penetration efficiency.

  3. Hypervelocity impact technology and applications: 2007.

    Energy Technology Data Exchange (ETDEWEB)

    Reinhart, William Dodd; Chhabildas, Lalit C. (Air Force Research Laboratory, AFRL/RWMW, Eglin AFB, FL)

    2008-07-01

    The Hypervelocity Impact Society is devoted to the advancement of the science and technology of hypervelocity impact and related technical areas required to facilitate and understand hypervelocity impact phenomena. Topics of interest include experimental methods, theoretical techniques, analytical studies, phenomenological studies, dynamic material response as related to material properties (e.g., equation of state), penetration mechanics, and dynamic failure of materials, planetary physics and other related phenomena. The objectives of the Society are to foster the development and exchange of technical information in the discipline of hypervelocity impact phenomena, promote technical excellence, encourage peer review publications, and hold technical symposia on a regular basis. It was sometime in 1985, partly in response to the Strategic Defense Initiative (SDI), that a small group of visionaries decided that a conference or symposium on hypervelocity science would be useful and began the necessary planning. A major objective of the first Symposium was to bring the scientists and researchers up to date by reviewing the essential developments of hypervelocity science and technology between 1955 and 1985. This Symposia--HVIS 2007 is the tenth Symposium since that beginning. The papers presented at all the HVIS are peer reviewed and published as a special volume of the archival journal International Journal of Impact Engineering. HVIS 2007 followed the same high standards and its proceedings will add to this body of work.

  4. Hypervelocity impacts into graphite

    Science.gov (United States)

    Latunde-Dada, S.; Cheesman, C.; Day, D.; Harrison, W.; Price, S.

    2011-03-01

    Studies have been conducted into the characterisation of the behaviour of commercial graphite (brittle) when subjected to hypervelocity impacts by a range of projectiles. The experiments were conducted with a two-stage gas gun capable of launching projectiles of differing density and strength to speeds of about 6kms-1 at right angles into target plates. The damage caused is quantified by measurements of the crater depth and diameters. From the experimental data collected, scaling laws were derived which correlate the crater dimensions to the velocity and the density of the projectile. It was found that for moderate projectile densities the crater dimensions obey the '2/3 power law' which applies to ductile materials.

  5. Hypervelocity impacts into graphite

    International Nuclear Information System (INIS)

    Latunde-Dada, S; Cheesman, C; Day, D; Harrison, W; Price, S

    2011-01-01

    Studies have been conducted into the characterisation of the behaviour of commercial graphite (brittle) when subjected to hypervelocity impacts by a range of projectiles. The experiments were conducted with a two-stage gas gun capable of launching projectiles of differing density and strength to speeds of about 6kms -1 at right angles into target plates. The damage caused is quantified by measurements of the crater depth and diameters. From the experimental data collected, scaling laws were derived which correlate the crater dimensions to the velocity and the density of the projectile. It was found that for moderate projectile densities the crater dimensions obey the '2/3 power law' which applies to ductile materials.

  6. Hypervelocity impact of concrete

    International Nuclear Information System (INIS)

    Watson, A.J.; Anderson, W.F.; Archer, B.

    1982-01-01

    Blocks of concrete and various other materials were impacted by high speed copper jets at the centre of one face, the resulting transient phenomena were measured using ultra high speed photography and various electrical signal transducers. Measurements were made of the jet velocity, penetration rate, crack velocity and initiation time, and strain pulse propagation. Post test measurements were made using electron microscopy, ultra sonics and stereoscopic photography. (orig.) [de

  7. Recent Representative IAT Studies in Hypervelocity Penetration Mechanics With Bibliographies

    National Research Council Canada - National Science Library

    Reinecke, W

    2002-01-01

    .... The IAT's investigations are experimental, analytical, and numerical and are concerned primarily with slender rods impacting armor steel and ceramic targets at hypervelocity that is, above about two km...

  8. Development of Techniques for Investigating Energy Contributions to Target Deformation and Penetration During Reactive Projectile Hypervelocity Impact

    Science.gov (United States)

    2011-07-01

    inertial system, one can use the Bernoulli equation to describe the process [Wil03]. Estimating an stationary adiabatic process with an incompressible...cally the model is based on the conservation of momentum and energy, supplemented by a correctional term. 9It can be seen, that a smaller liner...system vjet minus the penetration velocity22: vjet,theoretical = vjet − u (9) The whole process can now be described by a simplified Bernoulli formula

  9. Theoretical Research Progress in High-Velocity/Hypervelocity Impact on Semi-Infinite Targets

    Directory of Open Access Journals (Sweden)

    Yunhou Sun

    2015-01-01

    Full Text Available With the hypervelocity kinetic weapon and hypersonic cruise missiles research projects being carried out, the damage mechanism for high-velocity/hypervelocity projectile impact on semi-infinite targets has become the research keystone in impact dynamics. Theoretical research progress in high-velocity/hypervelocity impact on semi-infinite targets was reviewed in this paper. The evaluation methods for critical velocity of high-velocity and hypervelocity impact were summarized. The crater shape, crater scaling laws and empirical formulae, and simplified analysis models of crater parameters for spherical projectiles impact on semi-infinite targets were reviewed, so were the long rod penetration state differentiation, penetration depth calculation models for the semifluid, and deformed long rod projectiles. Finally, some research proposals were given for further study.

  10. Inertial fusion with hypervelocity impact

    International Nuclear Information System (INIS)

    Olariu, S.

    1998-01-01

    The physics of the compression and ignition processes in inertial fusion is to a certain extent independent of the nature of the incident energy pulse. The present strategy in the field of inertial fusion is to study several alternatives of deposition of the incident energy, and, at the same time, of conducting studies with the aid of available incident laser pulses. In a future reactor based on inertial fusion, the laser beams may be replaced by ion beams, which have a better energy efficiency. The main projects in the field of inertial fusion are the National Ignition Facility (NIF) in USA, Laser Megajoule (LMJ) in France, Gekko XII in Japan and Iskra V in Russia. NIF will be constructed at Lawrence Livermore National Laboratory, in California. LMJ will be constructed near Bordeaux. In the conventional approach to inertial confinement fusion, both the high-density fuel mass and the hot central spot are supposed to be produced by the deposition of the driver energy in the outer layers of the fuel capsule. Alternatively, the driver energy could be used only to produce the radial compression of the fuel capsule to high densities but relatively low temperatures, while the ignition of fusion reactions in the compressed capsule should be effected by a synchronized hypervelocity impact. Using this arrangement, it was supposed that a 54 μm projectile is incident with a velocity of 3 x 10 6 m s -1 upon a large-yield deuterium-tritium target at rest. The collision of the incident projectile and of the large-yield target takes place inside a high-Z cavity. A laser or heavy-ion pulse is converted at the walls of the cavity into X-rays, which compresses the incident projectile and the large-yield target in high-density states. The laser pulse and the movement of the incident projectile are synchronized such that the collision should take place when the densities are the largest. The collision converts the kinetic energy of the incident projectile into thermal energy, the

  11. Simulating plasma production from hypervelocity impacts

    Energy Technology Data Exchange (ETDEWEB)

    Fletcher, Alex, E-mail: alexcf@stanford.edu; Close, Sigrid [Stanford University, Aeronautics and Astronautics, 496 Lomita Mall, Stanford, California 94305 (United States); Mathias, Donovan [NASA Ames Research Center, Bldg. 258, Moffett Field, California 94035 (United States)

    2015-09-15

    Hypervelocity particles, such as meteoroids and space debris, routinely impact spacecraft and are energetic enough to vaporize and ionize themselves and as well as a portion of the target material. The resulting plasma rapidly expands into the surrounding vacuum. While plasma measurements from hypervelocity impacts have been made using ground-based technologies such as light gas guns and Van de Graaff dust accelerators, some of the basic plasma properties vary significantly between experiments. There have been both ground-based and in-situ measurements of radio frequency (RF) emission from hypervelocity impacts, but the physical mechanism responsible and the possible connection to the impact-produced plasma are not well understood. Under certain conditions, the impact-produced plasma can have deleterious effects on spacecraft electronics by providing a new current path, triggering an electrostatic discharge, causing electromagnetic interference, or generating an electromagnetic pulse. Multi-physics simulations of plasma production from hypervelocity impacts are presented. These simulations incorporate elasticity and plasticity of the solid target, phase change and plasma formation, and non-ideal plasma physics due to the high density and low temperature of the plasma. A smoothed particle hydrodynamics method is used to perform a continuum dynamics simulation with these additional physics. By examining a series of hypervelocity impacts, basic properties of the impact produced plasma plume (density, temperature, expansion speed, charge state) are determined for impactor speeds between 10 and 72 km/s. For a large range of higher impact speeds (30–72 km/s), we find the temperature is unvarying at 2.5 eV. We also find that the plasma plume is weakly ionized for impact speeds less than 14 km/s and fully ionized for impact speeds greater than 20 km/s, independent of impactor mass. This is the same velocity threshold for the detection of RF emission in recent

  12. Igneous rocks formed by hypervelocity impact

    Science.gov (United States)

    Osinski, Gordon R.; Grieve, Richard A. F.; Bleacher, Jacob E.; Neish, Catherine D.; Pilles, Eric A.; Tornabene, Livio L.

    2018-03-01

    Igneous rocks are the primary building blocks of planetary crusts. Most igneous rocks originate via decompression melting and/or wet melting of protolith lithologies within planetary interiors and their classification and compositional, petrographic, and textural characteristics, are well-studied. As our exploration of the Solar System continues, so too does the inventory of intrusive and extrusive igneous rocks, settings, and processes. The results of planetary exploration have also clearly demonstrated that impact cratering is a ubiquitous geological process that has affected, and will continue to affect, all planetary objects with a solid surface, whether that be rock or ice. It is now recognized that the production of igneous rocks is a fundamental outcome of hypervelocity impact. The goal of this review is to provide an up-to-date synthesis of our knowledge and understanding of igneous rocks formed by hypervelocity impact. Following a brief overview of the basics of the impact process, we describe how and why melts are generated during impact events and how impact melting differs from endogenic igneous processes. While the process may differ, we show that the products of hypervelocity impact can share close similarities with volcanic and shallow intrusive igneous rocks of endogenic origin. Such impact melt rocks, as they are termed, can display lobate margins and cooling cracks, columnar joints and at the hand specimen and microscopic scale, such rocks can display mineral textures that are typical of volcanic rocks, such as quench crystallites, ophitic, porphyritic, as well as features such as vesicles, flow textures, and so on. Historically, these similarities led to the misidentification of some igneous rocks now known to be impact melt rocks as being of endogenic origin. This raises the question as to how to distinguish between an impact versus an endogenic origin for igneous-like rocks on other planetary bodies where fieldwork and sample analysis may not

  13. Characterizing Hypervelocity Impact Plasma Through Experiments and Simulations

    Science.gov (United States)

    Close, Sigrid; Lee, Nicolas; Fletcher, Alex; Nuttall, Andrew; Hew, Monica; Tarantino, Paul

    2017-10-01

    Hypervelocity micro particles, including meteoroids and space debris with masses produce a strong electromagnetic pulse (EMP) with a broad frequency spectrum. Subsequent plasma oscillations resulting from instabilities can also emit significant power and may be responsible for many reported satellite anomalies. We present theory and recent results from ground-based impact tests aimed at characterizing hypervelocity impact plasma. We also show results from particle-in-cell (PIC) and computational fluid dynamics (CFD) simulations that allow us to extend to regimes not currently possible with ground-based technology. We show that significant impact-produced radio frequency (RF) emissions occurred in frequencies ranging from VHF through L-band and that these emissions were highly correlated with fast (>20 km/s) impacts that produced a fully ionized plasma.

  14. Survey of the hypervelocity impact technology and applications.

    Energy Technology Data Exchange (ETDEWEB)

    Chhabildas, Lalit Chandra; Orphal, Dennis L.

    2006-05-01

    HVIS 2005 was a clear success. The Symposium brought together nearly two hundred active researchers and students from thirteen countries around the world. The 84 papers presented at HVIS 2005 constitute an ''update'' on current research and the state-of-the-art of hypervelocity science. Combined with the over 7000 pages of technical papers from the eight previous Symposia, beginning in 1986, all published in the International Journal of Impact Engineering, the papers from HVIS 2005 add to the growing body of knowledge and the progressing state-of-the-art of hypervelocity science. It is encouraging to report that even with the limited funding resources compared to two decades ago, creativity and ingenuity in hypervelocity science are alive and well. There is considerable overlap in different disciplines that allows researchers to leverage. Experimentally, higher velocities are now available in the laboratory and are ideally suited for space applications that can be tied to both civilian (NASA) and DoD military applications. Computationally, there is considerable advancement both in computer and modeling technologies. Higher computing speeds and techniques such as parallel processing allow system level type applications to be addressed directly today, much in contrast to the situation only a few years ago. Needless to say, both experimentally and computationally, the ultimate utility will depend on the curiosity and the probing questions that will be incumbent upon the individual researcher. It is quite satisfying that over two dozen students attended the symposium. Hopefully this is indicative of a good pool of future researchers that will be needed both in the government and civilian industries. It is also gratifying to note that novel thrust areas exploring different and new material phenomenology relevant to hypervelocity impact, but a number of other applications as well, are being pursued. In conclusion, considerable progress is still being

  15. Burst Pressure Failure of Titanium Tanks Damaged by Secondary Plumes from Hypervelocity Impacts on Aluminum Shields

    Science.gov (United States)

    Nahra, Henry; Ghosn, Louis; Christiansen, Eric; Davis, B. Alan; Keddy, Chris; Rodriquez, Karen; Miller, Joshua; Bohl, William

    2011-01-01

    Metallic pressure tanks used in space missions are inherently vulnerable to hypervelocity impacts from micrometeoroids and orbital debris; thereby knowledge of impact damage and its effect on the tank integrity is crucial to a spacecraft risk assessment. This paper describes tests that have been performed to assess the effects of hypervelocity impact (HVI) damage on Titanium alloy (Ti-6Al-4V) pressure vessels burst pressure and characteristics. The tests consisted of a pair of HVI impact tests on water-filled Ti-6Al-4V tanks (water being used as a surrogate to the actual propellant) and subsequent burst tests as well as a burst test on an undamaged control tank. The tanks were placed behind Aluminum (Al) shields and then each was impacted with a 7 km/s projectile. The resulting impact debris plumes partially penetrated the Ti-6Al-4V tank surfaces resulting in a distribution of craters. During the burst tests, the tank that failed at a lower burst pressure did appear to have the failure initiating at a crater site with observed spall cracks. A fracture mechanics analysis showed that the tanks failure at the impact location may have been due to a spall crack that formed upon impact of a fragmentation on the Titanium surface. This result was corroborated with a finite element analysis from calculated Von-Mises and hoop stresses.

  16. Axial focusing of energy from a hypervelocity impact on earth

    International Nuclear Information System (INIS)

    Boslough, M.B.; Chael, E.P.; Trucano, T.G.; Crawford, D.A.

    1994-01-01

    We have performed computational simulations to determine how energy from a large hypervelocity impact on the Earth's surface would couple to its interior. Because of the first-order axial symmetry of both the impact energy source and the stress-wave velocity structure of the Earth, a disproportionate amount of energy is dissipated along the axis defined by the impact point and its antipode (point opposite the impact). For a symmetric and homogeneous Earth model, all the impact energy that is radiated as seismic waves into the Earth at a given takeoff angle (ray parameter), independent of azimuthal direction, is refocused (minus attenuation) on the axis of symmetry, regardless of the number of reflections and refractions it has experienced. Material on or near the axis of symmetry experiences more strain cycles with much greater amplitude than elsewhere, and therefore experiences more irreversible heating. The focusing is most intense in the upper mantle, within the asthenosphere, where seismic energy is most effectively converted to heat. For a sufficiently energetic impact, this mechanism might generate enough local heating to create an isostatic instability leading to uplift, possibly resulting in rifting, volcanism, or other rearrangement of the interior dynamics of the planet. These simulations demonstrate how hypervelocity impact energy can be transported to the Earth's interior, supporting the possibility of a causal link between large impacts on Earth and major internally-driven geophysical processes

  17. Axial focusing of energy from a hypervelocity impact on earth

    Energy Technology Data Exchange (ETDEWEB)

    Boslough, M.B.; Chael, E.P.; Trucano, T.G.; Crawford, D.A.

    1994-12-01

    We have performed computational simulations to determine how energy from a large hypervelocity impact on the Earth`s surface would couple to its interior. Because of the first-order axial symmetry of both the impact energy source and the stress-wave velocity structure of the Earth, a disproportionate amount of energy is dissipated along the axis defined by the impact point and its antipode (point opposite the impact). For a symmetric and homogeneous Earth model, all the impact energy that is radiated as seismic waves into the Earth at a given takeoff angle (ray parameter), independent of azimuthal direction, is refocused (minus attenuation) on the axis of symmetry, regardless of the number of reflections and refractions it has experienced. Material on or near the axis of symmetry experiences more strain cycles with much greater amplitude than elsewhere, and therefore experiences more irreversible heating. The focusing is most intense in the upper mantle, within the asthenosphere, where seismic energy is most effectively converted to heat. For a sufficiently energetic impact, this mechanism might generate enough local heating to create an isostatic instability leading to uplift, possibly resulting in rifting, volcanism, or other rearrangement of the interior dynamics of the planet. These simulations demonstrate how hypervelocity impact energy can be transported to the Earth`s interior, supporting the possibility of a causal link between large impacts on Earth and major internally-driven geophysical processes.

  18. Discrete Particle Method for Simulating Hypervelocity Impact Phenomena

    Directory of Open Access Journals (Sweden)

    Erkai Watson

    2017-04-01

    Full Text Available In this paper, we introduce a computational model for the simulation of hypervelocity impact (HVI phenomena which is based on the Discrete Element Method (DEM. Our paper constitutes the first application of DEM to the modeling and simulating of impact events for velocities beyond 5 kms-1. We present here the results of a systematic numerical study on HVI of solids. For modeling the solids, we use discrete spherical particles that interact with each other via potentials. In our numerical investigations we are particularly interested in the dynamics of material fragmentation upon impact. We model a typical HVI experiment configuration where a sphere strikes a thin plate and investigate the properties of the resulting debris cloud. We provide a quantitative computational analysis of the resulting debris cloud caused by impact and a comprehensive parameter study by varying key parameters of our model. We compare our findings from the simulations with recent HVI experiments performed at our institute. Our findings are that the DEM method leads to very stable, energy–conserving simulations of HVI scenarios that map the experimental setup where a sphere strikes a thin plate at hypervelocity speed. Our chosen interaction model works particularly well in the velocity range where the local stresses caused by impact shock waves markedly exceed the ultimate material strength.

  19. Determine ISS Soyuz Orbital Module Ballistic Limits for Steel Projectiles Hypervelocity Impact Testing

    Science.gov (United States)

    Lyons, Frankel

    2013-01-01

    A new orbital debris environment model (ORDEM 3.0) defines the density distribution of the debris environment in terms of the fraction of debris that are low-density (plastic), medium-density (aluminum) or high-density (steel) particles. This hypervelocity impact (HVI) program focused on assessing ballistic limits (BLs) for steel projectiles impacting the enhanced Soyuz Orbital Module (OM) micrometeoroid and orbital debris (MMOD) shield configuration. The ballistic limit was defined as the projectile size on the threshold of failure of the OM pressure shell as a function of impact speeds and angle. The enhanced OM shield configuration was first introduced with Soyuz 30S (launched in May 2012) to improve the MMOD protection of Soyuz vehicles docked to the International Space Station (ISS). This test program provides HVI data on U.S. materials similar in composition and density to the Russian materials for the enhanced Soyuz OM shield configuration of the vehicle. Data from this test program was used to update ballistic limit equations used in Soyuz OM penetration risk assessments. The objective of this hypervelocity impact test program was to determine the ballistic limit particle size for 440C stainless steel spherical projectiles on the Soyuz OM shielding at several impact conditions (velocity and angle combinations). This test report was prepared by NASA-JSC/ HVIT, upon completion of tests.

  20. Optimum structure of Whipple shield against hypervelocity impact

    International Nuclear Information System (INIS)

    Lee, M

    2014-01-01

    Hypervelocity impact of a spherical aluminum projectile onto two spaced aluminum plates (Whipple shield) was simulated to estimate an optimum structure. The Smooth Particle Hydrodynamics (SPH) code which has a unique migration scheme from a rectangular coordinate to an axisymmetic coordinate was used. The ratio of the front plate thickness to sphere diameter varied from 0.06 to 0.48. The impact velocities considered here were 6.7 km/s. This is the procedure we explored. To guarantee the early stage simulation, the shapes of debris clouds were first compared with the previous experimental pictures, indicating a good agreement. Next, the debris cloud expansion angle was predicted and it shows a maximum value of 23 degree for thickness ratio of front bumper to sphere diameter of 0.23. A critical sphere diameter causing failure of rear wall was also examined while keeping the total thickness of two plates constant. There exists an optimum thickness ratio of front bumper to rear wall, which is identified as a function of the size combination of the impacting body, front and rear plates. The debris cloud expansion-correlated-optimum thickness ratio study provides a good insight on the hypervelocity impact onto spaced target system.

  1. Optimum structure of Whipple shield against hypervelocity impact

    Science.gov (United States)

    Lee, M.

    2014-05-01

    Hypervelocity impact of a spherical aluminum projectile onto two spaced aluminum plates (Whipple shield) was simulated to estimate an optimum structure. The Smooth Particle Hydrodynamics (SPH) code which has a unique migration scheme from a rectangular coordinate to an axisymmetic coordinate was used. The ratio of the front plate thickness to sphere diameter varied from 0.06 to 0.48. The impact velocities considered here were 6.7 km/s. This is the procedure we explored. To guarantee the early stage simulation, the shapes of debris clouds were first compared with the previous experimental pictures, indicating a good agreement. Next, the debris cloud expansion angle was predicted and it shows a maximum value of 23 degree for thickness ratio of front bumper to sphere diameter of 0.23. A critical sphere diameter causing failure of rear wall was also examined while keeping the total thickness of two plates constant. There exists an optimum thickness ratio of front bumper to rear wall, which is identified as a function of the size combination of the impacting body, front and rear plates. The debris cloud expansion-correlated-optimum thickness ratio study provides a good insight on the hypervelocity impact onto spaced target system.

  2. Flash characteristics of plasma induced by hypervelocity impact

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Kai [State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China); Beijing Automotive Technology Center, Beijing 100021 (China); Long, Renrong, E-mail: longrenrong@bit.edu.cn, E-mail: qmzhang@bit.edu.cn; Zhang, Qingming, E-mail: longrenrong@bit.edu.cn, E-mail: qmzhang@bit.edu.cn; Xue, Yijiang; Ju, Yuanyuan [State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China)

    2016-08-15

    Using a two-stage light gas gun, a series of hypervelocity impact experiments was conducted in which 6.4-mm-diameter spherical 2024-aluminum projectiles impact 23-mm-thick targets made of the same material at velocities of 5.0, 5.6, and 6.3 km/s. Both an optical pyrometer composed of six photomultiplier tubes and a spectrograph were used to measure the flash of the plasma during hypervelocity impact. Experimental results show that, at a projectile velocity of 6.3 km/s, the strong flash lasted about 10 μs and reached a temperature of 4300 K. Based on the known emission lines of AL I, spectral methods can provide the plasma electron temperature. An electron-temperature comparison between experiment and theoretical calculation indicates that single ionization and secondary ionization are the two main ionizing modes at velocities 5.0–6.3 km/s.

  3. Hypervelocity Impact Testing of Nickel Hydrogen Battery Cells

    Science.gov (United States)

    Frate, David T.; Nahra, Henry K.

    1996-01-01

    Nickel-Hydrogen (Ni/H2) battery cells have been used on several satellites and are planned for use on the International Space Station. In January 1992, the NASA Lewis Research Center (LeRC) conducted hypervelocity impact testing on Ni/H2 cells to characterize their failure modes. The cell's outer construction was a 24 mil-thick Inconel 718 pressure vessel. A sheet of 1.27 cm thick honeycomb was placed in front of the battery cells during testing to simulate the on-orbit box enclosure. Testing was conducted at the NASA White Sands Test Facility (WSTF). The hypervelocity gun used was a 7.6 mm (0.30 caliber) two-stage light gas gun. Test were performed at speeds of 3, 6, and 7 km/sec using aluminum 2017 spherical particles of either 4.8 or 6.4 mm diameter as the projectile. The battery cells were electrically charged to about 75 percent of capacity, then back-filled with hydrogen gas to 900 psi simulating the full charge condition. High speed film at 10,000 frames/sec was taken of the impacts. Impacts in the dome area (top) and the electrode area (middle) of the battery cells were investigated. Five tests on battery cells were performed. The results revealed that in all of the test conditions investigated, the battery cells simply vented their hydrogen gas and some electrolyte, but did not burst or generate any large debris fragments.

  4. Theoretical model for plasma expansion generated by hypervelocity impact

    International Nuclear Information System (INIS)

    Ju, Yuanyuan; Zhang, Qingming; Zhang, Dongjiang; Long, Renrong; Chen, Li; Huang, Fenglei; Gong, Zizheng

    2014-01-01

    The hypervelocity impact experiments of spherical LY12 aluminum projectile diameter of 6.4 mm on LY12 aluminum target thickness of 23 mm have been conducted using a two-stage light gas gun. The impact velocity of the projectile is 5.2, 5.7, and 6.3 km/s, respectively. The experimental results show that the plasma phase transition appears under the current experiment conditions, and the plasma expansion consists of accumulation, equilibrium, and attenuation. The plasma characteristic parameters decrease as the plasma expands outward and are proportional with the third power of the impact velocity, i.e., (T e , n e ) ∝ v p 3 . Based on the experimental results, a theoretical model on the plasma expansion is developed and the theoretical results are consistent with the experimental data

  5. Theoretical model for plasma expansion generated by hypervelocity impact

    Energy Technology Data Exchange (ETDEWEB)

    Ju, Yuanyuan; Zhang, Qingming, E-mail: qmzhang@bit.edu.cn; Zhang, Dongjiang; Long, Renrong; Chen, Li; Huang, Fenglei [State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China); Gong, Zizheng [National Key Laboratory of Science and Technology on Reliability and Environment Engineering, Beijing Institute of Spacecraft Environment Engineering, Beijing 100094 (China)

    2014-09-15

    The hypervelocity impact experiments of spherical LY12 aluminum projectile diameter of 6.4 mm on LY12 aluminum target thickness of 23 mm have been conducted using a two-stage light gas gun. The impact velocity of the projectile is 5.2, 5.7, and 6.3 km/s, respectively. The experimental results show that the plasma phase transition appears under the current experiment conditions, and the plasma expansion consists of accumulation, equilibrium, and attenuation. The plasma characteristic parameters decrease as the plasma expands outward and are proportional with the third power of the impact velocity, i.e., (T{sub e}, n{sub e}) ∝ v{sub p}{sup 3}. Based on the experimental results, a theoretical model on the plasma expansion is developed and the theoretical results are consistent with the experimental data.

  6. Mass spectrometry of hyper-velocity impacts of organic micrograins.

    Science.gov (United States)

    Srama, Ralf; Woiwode, Wolfgang; Postberg, Frank; Armes, Steven P; Fujii, Syuji; Dupin, Damien; Ormond-Prout, Jonathan; Sternovsky, Zoltan; Kempf, Sascha; Moragas-Klostermeyer, Georg; Mocker, Anna; Grün, Eberhard

    2009-12-01

    The study of hyper-velocity impacts of micrometeoroids is important for the calibration of dust sensors in space applications. For this purpose, submicron-sized synthetic dust grains comprising either polystyrene or poly[bis(4-vinylthiophenyl)sulfide] were coated with an ultrathin overlayer of an electrically conductive organic polymer (either polypyrrole or polyaniline) and were accelerated to speeds between 3 and 35 km s(-1) using the Heidelberg Dust Accelerator facility. Time-of-flight mass spectrometry was applied to analyse the resulting ionic impact plasma using a newly developed Large Area Mass Analyser (LAMA). Depending on the projectile type and the impact speed, both aliphatic and aromatic molecular ions and cluster species were identified in the mass spectra with masses up to 400 u. Clusters resulting from the target material (silver) and mixed clusters of target and projectile species were also observed. Impact velocities of between 10 and 35 km s(-1) are suitable for a principal identification of organic materials in micrometeoroids, whereas impact speeds below approximately 10 km s(-1) allow for an even more detailed analysis. Molecular ions and fragments reflect components of the parent molecule, providing determination of even complex organic molecules embedded in a dust grain. In contrast to previous measurements with the Cosmic Dust Analyser instrument, the employed LAMA instrument has a seven times higher mass resolution--approximately 200--which allowed for a detailed analysis of the complex mass spectra. These fundamental studies are expected to enhance our understanding of cometary, interplanetary and interstellar dust grains, which travel at similar hyper-velocities and are known to contain both aliphatic and aromatic organic compounds. Copyright 2009 John Wiley & Sons, Ltd.

  7. The electromagnetic properties of plasma produced by hypervelocity impact

    Science.gov (United States)

    Zhang, Qingming; Gong, Liangfei; Ma, Yuefen; Long, Renrong; Gong, Zizheng

    2018-02-01

    The change of electron density in moving plasma in this paper is empirically determined according to multiple ground-based experimental results and the assumption of the Maxwell distribution. Moreover, the equation of the magnetic field intensity, dominated by the current due to the collective electron movement during the expansion, is presented on the basis of the Biot-Savart law, and its relationship with time and space is subsequently depicted. In addition, hypervelocity impact experiments on a 2AL12 target have been carried out using a two-stage light gas gun to accelerate a 2AL12 projectile of 6.4 mm to 6.2 km/s. Spiral coils are designed to measure the intensity of the electromagnetic field induced by this impact. The experimental results show that the magnetic field strength is an alternate pulse maintaining nearly 1 ms and its maximum is close to 15 μT, which is strong enough to interfere with the communication circuit and chip in spacecrafts. Lastly, numerical simulation of the magnetic field intensity using this experimental parameter reveals that the intensity in our estimation from our theory tends to be well consistent with the experimental data in the first peak of the pulse signal.

  8. Failure mechanism of monolayer graphene under hypervelocity impact of spherical projectile

    Science.gov (United States)

    Xia, Kang; Zhan, Haifei; Hu, De'An; Gu, Yuantong

    2016-09-01

    The excellent mechanical properties of graphene have enabled it as appealing candidate in the field of impact protection or protective shield. By considering a monolayer graphene membrane, in this work, we assessed its deformation mechanisms under hypervelocity impact (from 2 to 6 km/s), based on a serial of in silico studies. It is found that the cracks are formed preferentially in the zigzag directions which are consistent with that observed from tensile deformation. Specifically, the boundary condition is found to exert an obvious influence on the stress distribution and transmission during the impact process, which eventually influences the penetration energy and crack growth. For similar sample size, the circular shape graphene possesses the best impact resistance, followed by hexagonal graphene membrane. Moreover, it is found the failure shape of graphene membrane has a strong relationship with the initial kinetic energy of the projectile. The higher kinetic energy, the more number the cracks. This study provides a fundamental understanding of the deformation mechanisms of monolayer graphene under impact, which is crucial in order to facilitate their emerging future applications for impact protection, such as protective shield from orbital debris for spacecraft.

  9. Emission spectroscopy of hypervelocity impacts on aluminum, organic and high-explosive targets

    NARCIS (Netherlands)

    Verreault, J.; Day, J.P.R.; Halswijk, W.H.C.; Loiseau, J.; Huneault, J.; Higgins, A.J.; Devir, A.D.

    2015-01-01

    Laboratory experiments of hypervelocity impacts on aluminum, nylon and high-explosive targets are presented. Spectral measurements of the impact flash are recorded, together with radiometric measurements to derive the temperature of the flash. Such experiments aim at demonstrating that the impact

  10. Hypervelocity Impact Performance of Open Cell Foam Core Sandwich Panel Structures

    Science.gov (United States)

    Ryan, S.; Ordonez, E.; Christiansen, E. L.; Lear, D. M.

    2010-01-01

    Open cell metallic foam core sandwich panel structures are of interest for application in spacecraft micrometeoroid and orbital debris shields due to their novel form and advantageous structural and thermal performance. Repeated shocking as a result of secondary impacts upon individual foam ligaments during the penetration process acts to raise the thermal state of impacting projectiles ; resulting in fragmentation, melting, and vaporization at lower velocities than with traditional shielding configurations (e.g. Whipple shield). In order to characterize the protective capability of these structures, an extensive experimental campaign was performed by the Johnson Space Center Hypervelocity Impact Technology Facility, the results of which are reported in this paper. Although not capable of competing against the protection levels achievable with leading heavy shields in use on modern high-risk vehicles (i.e. International Space Station modules), metallic foam core sandwich panels are shown to provide a substantial improvement over comparable structural panels and traditional low weight shielding alternatives such as honeycomb sandwich panels and metallic Whipple shields. A ballistic limit equation, generalized in terms of panel geometry, is derived and presented in a form suitable for application in risk assessment codes.

  11. Hypervelocity impact on Zr51Ti5Ni10Cu25Al9 bulk metallic glass

    International Nuclear Information System (INIS)

    Zheng, W.; Huang, Y.J.; Pang, B.J.; Shen, J.

    2011-01-01

    Highlights: → Hypervelocity impact experiments were performed on a bulk metallic glass. → Morphology of the bullet hole presents three different regions. → The post-impact samples keep glassy structure. → Mechanical properties of the post-impact samples were studied by nanoindentation. → Mechanical properties of the post-impact samples were discussed by free-volume model. - Abstract: In this study, the hypervelocity impact experiments were performed on Zr 51 Ti 5 Ni 10 Cu 25 Al 9 bulk metallic glass using a two-stage light gas gun. The morphologies of the bullet holes exhibit three different regions: melting area, vein-pattern area, and radiating core feature area, suggesting that various regions experience different stress states during the hypervelocity impact. For the post-impact samples, the nano-hardness increases and plastic deformability decreases both with the increase in the distance from the bullet hole and with the decrease in the impact velocity, which is discussed by means of spherical stress wave theory and free-volume model.

  12. Hypervelocity Dust Impacts in Space and the Laboratory

    Science.gov (United States)

    Horanyi, Mihaly; Colorado CenterLunar Dust; Atmospheric Studies (CCLDAS) Team

    2013-10-01

    Interplanetary dust particles continually bombard all objects in the solar system, leading to the excavation of material from the target surfaces, the production of secondary ejecta particles, plasma, neutral gas, and electromagnetic radiation. These processes are of interest to basic plasma science, planetary and space physics, and engineering to protect humans and instruments against impact damages. The Colorado Center for Lunar Dust and Atmospheric Studies (CCLDAS) has recently completed a 3 MV dust accelerator, and this talk will summarize our initial science results. The 3 MV Pelletron contains a dust source, feeding positively charged micron and sub-micron sized particles into the accelerator. We will present the technical details of the facility and its capabilities, as well as the results of our initial experiments for damage assessment of optical devices, and penetration studies of thin films. We will also report on the completion of our dust impact detector, the Lunar Dust Experiment (LDEX), is expected to be flying onboard the Lunar Atmosphere and Dust Environment Explorer (LADEE) mission by the time of this presentation. LDEX was tested, and calibrated at our dust accelerator. We will close by offering the opportunity to use this facility by the planetary, space and plasma physics communities.

  13. Hyper-velocity impacts on the molten silica of the LMJ facility: experimental results and related simulations

    International Nuclear Information System (INIS)

    Bertron, I.; Chevalier, J.M.; Malaise, F.; Barrio, A.; Courchinoux, R.

    2003-01-01

    This work presents a damaging study of the molten silica splinter-guards of the experiment chamber of the Megajoule laser facility. Damaging is due to the impact of hyper-velocity particulates coming from the interaction between X-rays and the diagnostic supports. Experiments have been carried out with the light-gas dual-stage launcher MICA in parallel with numerical simulations using a silica fragmentation and fissuring model embedded in the HESIONE code. First tests concern hyper-velocity impacts of steel balls of 550 μm diameter on silica samples. Samples are expertized to measure the craters and damaging characteristics generated by the impact. Experimental results are compared to numerical simulations in order to check the capability of the model to reproduce the effect of hyper-velocity impacts on molten silica. The final goal is to evaluate the lifetime of splinter-guards. (J.S.)

  14. Hypervelocity dust impact craters on photovoltaic devices imaged by ion beam induced charge

    International Nuclear Information System (INIS)

    Yang, Changyi; Wu, Yiyong; Lv, Gang; Rubanov, Sergey; Jamieson, David N.

    2015-01-01

    Hypervelocity dust has a speed of greater than 5 km/s and is a significant problem for equipment deployed in space such as satellites because of impacts that damage vulnerable components. Photovoltaic (PV) arrays are especially vulnerable because of their large surface area and the performance can be degraded owing to the disruption of the structure of the junction in the cells making up the array. Satellite PV arrays returned to Earth after service in orbit reveal a large number of craters larger than 5 μm in diameter arising from hypervelocity dust impacts. Extensive prior work has been done on the analysis of the morphology of craters in PV cells to understand the origin of the micrometeoroid that caused the crater and to study the corresponding mechanical damage to the structure of the cell. Generally, about half the craters arise from natural micrometeoroids, about one third from artificial Al-rich debris, probably from solid rocket exhausts, and the remainder from miscellaneous sources both known and unknown. However to date there has not been a microscopic study of the degradation of the electrical characteristics of PV cells exposed to hypervelocity dust impacts. Here we present an ion beam induced charge (IBIC) pilot study by a 2 MeV He microbeam of craters induced on a Hamamatsu PIN diode exposed to artificial hypervelocity Al dust from a dust accelerator. Numerous 5–30 μm diameter craters were identified and the charge collection efficiency of the crater and surrounds mapped with IBIC with bias voltages between 0 and 20 V. At highest bias, it was found the efficiency of the crater had been degraded by about 20% compared to the surrounding material. The speed distribution achieved in the Al dust accelerator was peaked at about 4 km/s compared to 11–68 km/s for dust encountered in low Earth orbit. We are able to extrapolate the charge collection efficiency degradation rate of unbiased cells in space based on our current measurements and the

  15. Hypervelocity dust impact craters on photovoltaic devices imaged by ion beam induced charge

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Changyi [School of Physics, University of Melbourne, Parkville, VIC 3010 (Australia); Wu, Yiyong; Lv, Gang [National Key Laboratory of Materials Behavior and Evaluation Technology in Space Environments, Harbin Institute of Technology, Harbin (China); Rubanov, Sergey [Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC 3010 (Australia); Jamieson, David N., E-mail: d.jamieson@unimelb.edu.au [School of Physics, University of Melbourne, Parkville, VIC 3010 (Australia)

    2015-04-01

    Hypervelocity dust has a speed of greater than 5 km/s and is a significant problem for equipment deployed in space such as satellites because of impacts that damage vulnerable components. Photovoltaic (PV) arrays are especially vulnerable because of their large surface area and the performance can be degraded owing to the disruption of the structure of the junction in the cells making up the array. Satellite PV arrays returned to Earth after service in orbit reveal a large number of craters larger than 5 μm in diameter arising from hypervelocity dust impacts. Extensive prior work has been done on the analysis of the morphology of craters in PV cells to understand the origin of the micrometeoroid that caused the crater and to study the corresponding mechanical damage to the structure of the cell. Generally, about half the craters arise from natural micrometeoroids, about one third from artificial Al-rich debris, probably from solid rocket exhausts, and the remainder from miscellaneous sources both known and unknown. However to date there has not been a microscopic study of the degradation of the electrical characteristics of PV cells exposed to hypervelocity dust impacts. Here we present an ion beam induced charge (IBIC) pilot study by a 2 MeV He microbeam of craters induced on a Hamamatsu PIN diode exposed to artificial hypervelocity Al dust from a dust accelerator. Numerous 5–30 μm diameter craters were identified and the charge collection efficiency of the crater and surrounds mapped with IBIC with bias voltages between 0 and 20 V. At highest bias, it was found the efficiency of the crater had been degraded by about 20% compared to the surrounding material. The speed distribution achieved in the Al dust accelerator was peaked at about 4 km/s compared to 11–68 km/s for dust encountered in low Earth orbit. We are able to extrapolate the charge collection efficiency degradation rate of unbiased cells in space based on our current measurements and the

  16. Effect of impact angles on ejecta and crater shape of aluminum alloy 6061-T6 targets in hypervelocity impacts

    Directory of Open Access Journals (Sweden)

    Hayashi K.

    2012-08-01

    Full Text Available The effect of the impact angle of projectiles on the crater shape and ejecta in thick aluminum alloy targets was investigated in hypervelocity impacts. When polycarbonate projectiles and aluminum alloy 6061-T6 target were used, the impact angle of the projectiles clearly affected the crater shape, as expected. The impact angle also affected the ejecta mass, ejecta size and scatter angle. However, the effect at 15∘ and 22.5∘ was not great. When the impact angles were 30∘ and 45∘, the effect was clearly confirmed. The impact angle clearly affected the axial ratio of ejecta fragments, c/a.

  17. Design and testing of miniaturized plasma sensor for measuring hypervelocity impact plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Goel, A., E-mail: ashish09@stanford.edu; Tarantino, P. M.; Lauben, D. S.; Close, S. [Department of Aeronautics and Astronautics, Stanford University, Stanford, California 94305 (United States)

    2015-04-15

    An increasingly notable component of the space environment pertains to the impact of meteoroids and orbital debris on spacecraft and the resulting mechanical and electrical damages. Traveling at speeds of tens of km/s, when these particles, collectively referred to as hypervelocity particles, impact a satellite, they vaporize, ionize, and produce a radially expanding plasma that can generate electrically harmful radio frequency emission or serve as a trigger for electrostatic discharge. In order to measure the flux, composition, energy distribution, and temperature of ions and electrons in this plasma, a miniaturized plasma sensor has been developed for carrying out in-situ measurements in space. The sensor comprises an array of electrostatic analyzer wells split into 16 different channels, catering to different species and energy ranges in the plasma. We present results from numerical simulation based optimization of sensor geometry. A novel approach of fabricating the sensor using printed circuit boards is implemented. We also describe the test setup used for calibrating the sensor and show results demonstrating the energy band pass characteristics of the sensor. In addition to the hypervelocity impact plasmas, the plasma sensor developed can also be used to carry out measurements of ionospheric plasma, diagnostics of plasma propulsion systems, and in other space physics experiments.

  18. Analysis of simulated hypervelocity impacts on a titanium fuel tank from the Salyut 7 space station

    Science.gov (United States)

    Jantou, V.; McPhail, D. S.; Chater, R. J.; Kearsley, A.

    2006-07-01

    The aim of this project was to gain a better understanding of the microstructural effects of hypervelocity impacts (HVI) in titanium alloys. We investigated a titanium fuel tank recovered from the Russian Salyut 7 space station, which was launched on April 19, 1982 before being destroyed during an un-controlled re-entry in 1991, reportedly scattering debris over parts of South America. Several sections were cut out from the tank in order to undergo HVI simulations using a two-stage light gas gun. In addition, a Ti-6Al-4V alloy was studied for further comparison. The crater morphologies produced were successfully characterised using microscope-based white light interferometry (Zygo ® Corp, USA), while projectile remnants were identified via secondary ion mass spectrometry (SIMS). Microstructural alterations were investigated using focused ion beam (FIB) milling and depth profiling, as well as transmission electron microscopy (TEM). There was evidence of a very high density of dislocations in the vicinity of the crater. The extent of the deformation was localised in a region of about one to two radii of the impact craters. No notable differences were observed between the titanium alloys used during the hypervelocity impact tests.

  19. Asteroid deflection using a kinetic impactor: Insights from hypervelocity impact experiments

    Science.gov (United States)

    Hoerth, Tobias; Schäfer, Frank

    2016-04-01

    Within the framework of the planned AIDA mission [1], an impactor spacecraft (DART) hits the second component of the asteroid Didymos at hypervelocity. The impact crater will be observed from the AIM spacecraft and an observation of the ejecta plume is possible [1]. This allows conclusions to be drawn about the physical properties of the target material, and the momentum transfer will be studied [1]. In preparation for this mission, hypervelocity impact experiments can provide valuable information about the outcome of an impact event as a function of impactor and target material properties and, thus, support the interpretation of the data from the DART impact. In addition, these impact experiments provide an important means to validate numerical impact simulations required to simulate large-scale impacts that cannot be studied in laboratory experiments. Impact experiments have shown that crater morphology and size, crater growth and ejecta dynamics strongly depend on the physical properties of the target material [2]. For example, porous materials like sandstone lead to a shallower and slower ejection than low-porous materials like quartzite, and the cratering efficiency is reduced in porous targets leading to a smaller amount of ejected mass [3]. These phenomena result in a reduced momentum multiplication factor (often called "beta-value"), i.e. the ratio of the change in target momentum after the impact and the momentum of the projectile is smaller for porous materials. Hypervelocity impact experiments into target materials with different porosities and densities such as quartzite (2.9 %, 2.6 g/cm3), sandstone (25.3 %, 2 g/cm3), limestone (31 %, 1.8 g/cm3), and highly porous aerated concrete (87.5 %, 0.4 g/cm3) were conducted. Projectile velocities were varied between about 3 km/s and almost 7 km/s. A ballistic pendulum was used to measure the momentum transfer. The material strength required for scaling laws was determined for all target materials. The highest

  20. Multichannel fiber laser Doppler vibrometer studies of low momentum and hypervelocity impacts

    Science.gov (United States)

    Posada-Roman, Julio E.; Jackson, David A.; Cole, Mike J.; Garcia-Souto, Jose A.

    2017-12-01

    A multichannel optical fiber laser Doppler vibrometer was demonstrated with the capability of making simultaneous non-contact measurements of impacts at 3 different locations. Two sets of measurements were performed, firstly using small ball bearings (1 mm-5.5 mm) falling under gravity and secondly using small projectiles (1 mm) fired from an extremely high velocity light gas gun (LGG) with speeds in the range 1 km/s-8 km/s. Determination of impact damage is important for industries such as aerospace, military and rail, where the effect of an impact on the structure can result in a major structural damage. To our knowledge the research reported here demonstrates the first trials of a multichannel fiber laser Doppler vibrometer being used to detect hypervelocity impacts.

  1. Hypervelocity impact of tungsten cubes on spaced armour

    International Nuclear Information System (INIS)

    Chandel, Pradeep S; Sood, Dharmanshu; Kumar, Rajeev; Sharma, Prince; Sewak, Bhupinder; Bhardwaj, Vikas; Athwal, Manoj; Mangla, Vikas; Biswas, Ipsita; Singh, Manjit

    2012-01-01

    The paper summarizes the experimental observations and simulation studies of damage potential of tungsten alloy cubes on relatively thin mild steel spaced armour target plates in the velocity regime 1300 – 4000 ms −1 using Two Stage Light Gas Gun technique. The cubes of size 9.5 mm and 12 mm having mass 15 g and 30 g respectively were made to impact normally on three target plates of size 300 mm × 300 mm of thickness 4, 4 and 10 mm at 100 mm distance apart. Flash radiography has been used to image the projectile-target interaction in the nitrogen environment at 300 mbar vacuum at room temperature. The results reveal clear perforation by 9.5 mm cube in all the three target plates up to impact velocity of about 2000 m/s. While 12 mm cube can perforate the spaced armour upto impact velocity of 4000 m/s. This shows that 9.5mm tungsten alloy cube is not effective beyond 2000 m/s while 12 mm tungsten alloy cube can defeat the spaced armour upto 4000 m/s. The simulation studies have been carried out using Autodyn 3D nonlinear code using Lagrange solver at velocities 1200 – 4000 m/s. The simulation results are in good agreement with the experimental findings.

  2. Vulnerability analysis of a pressurized aluminum composite vessel against hypervelocity impacts

    Directory of Open Access Journals (Sweden)

    Hereil Pierre-Louis

    2015-01-01

    Full Text Available Vulnerability of high pressure vessels subjected to high velocity impact of space debris is analyzed with the response of pressurized vessels to hypervelocity impact of aluminum sphere. Investigated tanks are CFRP (carbon fiber reinforced plastics overwrapped Al vessels. Explored internal pressure of nitrogen ranges from 1 bar to 300 bar and impact velocity are around 4400 m/s. Data obtained from Xrays radiographies and particle velocity measurements show the evolution of debris cloud and shock wave propagation in pressurized nitrogen. Observation of recovered vessels leads to the damage pattern and to its evolution as a function of the internal pressure. It is shown that the rupture mode is not a bursting mode but rather a catastrophic damage of the external carbon composite part of the vessel.

  3. Ejection and Lofting of Dust from Hypervelocity Impacts on the Moon

    Science.gov (United States)

    Hermalyn, B.; Schultz, P. H.

    2011-12-01

    Hypervelocity impact events mobilize and redistribute fine-grained regolith dust across the surfaces of planetary bodies. The ejecta mass-velocity distribution controls the location and emplacement of these materials. The current flux of material falling on the moon is dominated by small bolides and should cause frequent impacts that eject dust at high speeds. For example, approximately 25 LCROSS-sized (~20-30m diameter) craters are statistically expected to be formed naturally on the moon during any given earth year. When scaled to lunar conditions, the high-speed component of ejecta from hypervelocity impacts can be lofted for significant periods of time (as evidenced by the LCROSS mission results, c.f., Schultz, et al., 2010, Colaprete, et al., 2010). Even at laboratory scales, ejecta can approach orbital velocities; the higher impact speeds and larger projectiles bombarding the lunar surface may permit a significant portion of material to be launched closer to escape velocity. When these ejecta return to the surface (or encounter local topography), they impact at hundreds of meters per second or faster, thereby "scouring" the surface with low mass oblique impacts. While these high-speed ejecta represent only a small fraction of the total ejected mass, the lofting and subsequent ballistic return of this dust has the highest mobilization potential and will be directly applicable to the upcoming LADEE mission. A suite of hypervelocity impact experiments into granular materials was performed at the NASA Ames Vertical Gun Range (AVGR). This study incorporates both canonical sand targets and air-fall pumice dust to simulate the mechanical properties of lunar regolith. The implementation of a Particle Tracking Velocimetry (PTV) technique permits non-intrusive measurement of the ejecta velocity distribution within the ejecta curtain by following the path of individual ejecta particles. The PTV system developed at the AVGR uses a series of high-speed cameras (ranging

  4. Plasma and collision processes of hypervelocity meteorite impact in the prehistory of life

    Science.gov (United States)

    Managadze, G.

    2010-07-01

    A new concept is proposed, according to which the plasma and collision processes accompanying hypervelocity impacts of meteorites can contribute to the arising of the conditions on early Earth, which are necessary for the appearance of primary forms of living matter. It was shown that the processes necessary for the emergence of living matter could have started in a plasma torch of meteorite impact and have continued in an impact crater in the case of the arising of the simplest life form. It is generally accepted that planets are the optimal place for the origin and evolution of life. In the process of forming the planetary systems the meteorites, space bodies feeding planet growth, appear around stars. In the process of Earth's formation, meteorite sizes ranged from hundreds and thousands of kilometres. These space bodies consisted mostly of the planetesimals and comet nucleus. During acceleration in Earth's gravitational field they reached hypervelocity and, hitting the surface of planet, generated powerful blowouts of hot plasma in the form of a torch. They also created giant-size craters and dense dust clouds. These bodies were composed of all elements needed for the synthesis of organic compounds, with the content of carbon being up to 5%-15%. A new idea of possible synthesis of the complex organic compounds in the hypervelocity impact-generated plasma torch was proposed and experimentally confirmed. A previously unknown and experimentally corroborated feature of the impact-generated plasma torch allowed a new concept of the prehistory of life to be developed. According to this concept the intensive synthesis of complex organic compounds arose during meteoritic bombardment in the first 0.5 billion years at the stage of the planet's formation. This most powerful and destructive action in Earth's history could have played a key role and prepared conditions for the origin of life. In the interstellar gas-dust clouds, the synthesis of simple organic matter could

  5. Integrity assessment of the spacecraft subjected to the hypervelocity impact by ceramic and metal projectiles simulating space debris and micrometeoroids

    International Nuclear Information System (INIS)

    Katayama, Masahide; Takeba, Atsushi; Nitta, Kumi; Kawakita, Shirou; Matsumoto, Haruhisa; Kitazawa, Yukihito

    2010-01-01

    In order to establish the guidelines for the protection of unmanned spacecrafts from the space debris and micrometeoroid impacts, the experimental and numerical investigations have been conducted at Japan Aerospace Exploration Agency. This paper presents mainly its numerical methodology, especially from the viewpoint of highly non-linear and dynamic material model: i.e. the equation of state, constitutive model and fracture or failure model, including a brittle material model for ceramics and an equation of state for the shock-induced vaporization accompanied by hypervelocity impact. The experimental results of hypervelocity impact by two-stage light-gas gun and plasma drag gun are compared with corresponding numerical simulation results by using a hydrocode, and both results are demonstrated to be overall in good agreement with each other.

  6. Integrity assessment of the spacecraft subjected to the hypervelocity impact by ceramic and metal projectiles simulating space debris and micrometeoroids

    Energy Technology Data Exchange (ETDEWEB)

    Katayama, Masahide, E-mail: masahide.katayama@ctc-g.co.jp [Science and Engineering Systems Division, ITOCHU Techno-Solutions, 3-2-5, Kasumigaseki, Chiyoda-ku, Tokyo 100-6080 (Japan); Materials and Structures Laboratory, Tokyo Institute of Technology, 4259, Nagatsuta, Midori-ku, Yokohama-shi, Kanagawa 226-8503 (Japan); Takeba, Atsushi [Science and Engineering Systems Division, ITOCHU Techno-Solutions, 3-2-5, Kasumigaseki, Chiyoda-ku, Tokyo 100-6080 (Japan); Nitta, Kumi; Kawakita, Shirou; Matsumoto, Haruhisa [Aerospace Research and Development Directorate, Japan Aerospace Exploration Agency, 2-1-1, Sengen, Tsukuba-city, Ibaraki 305-8505 (Japan); Kitazawa, Yukihito [Aerospace Research and Development Directorate, Japan Aerospace Exploration Agency, 2-1-1, Sengen, Tsukuba-city, Ibaraki 305-8505 (Japan); Aero-Engine and Space Operations, IHI Corporation, 3-1-1, Toyosu, Koto-ku, Tokyo 135-8710 (Japan)

    2010-10-15

    In order to establish the guidelines for the protection of unmanned spacecrafts from the space debris and micrometeoroid impacts, the experimental and numerical investigations have been conducted at Japan Aerospace Exploration Agency. This paper presents mainly its numerical methodology, especially from the viewpoint of highly non-linear and dynamic material model: i.e. the equation of state, constitutive model and fracture or failure model, including a brittle material model for ceramics and an equation of state for the shock-induced vaporization accompanied by hypervelocity impact. The experimental results of hypervelocity impact by two-stage light-gas gun and plasma drag gun are compared with corresponding numerical simulation results by using a hydrocode, and both results are demonstrated to be overall in good agreement with each other.

  7. Characterizing Hypervelocity Impact (HVI-Induced Pitting Damage Using Active Guided Ultrasonic Waves: From Linear to Nonlinear

    Directory of Open Access Journals (Sweden)

    Menglong Liu

    2017-05-01

    Full Text Available Hypervelocity impact (HVI, ubiquitous in low Earth orbit with an impacting velocity in excess of 1 km/s, poses an immense threat to the safety of orbiting spacecraft. Upon penetration of the outer shielding layer of a typical two-layer shielding system, the shattered projectile, together with the jetted materials of the outer shielding material, subsequently impinge the inner shielding layer, to which pitting damage is introduced. The pitting damage includes numerous craters and cracks disorderedly scattered over a wide region. Targeting the quantitative evaluation of this sort of damage (multitudinous damage within a singular inspection region, a characterization strategy, associating linear with nonlinear features of guided ultrasonic waves, is developed. Linear-wise, changes in the signal features in the time domain (e.g., time-of-flight and energy dissipation are extracted, for detecting gross damage whose characteristic dimensions are comparable to the wavelength of the probing wave; nonlinear-wise, changes in the signal features in the frequency domain (e.g., second harmonic generation, which are proven to be more sensitive than their linear counterparts to small-scale damage, are explored to characterize HVI-induced pitting damage scattered in the inner layer. A numerical simulation, supplemented with experimental validation, quantitatively reveals the accumulation of nonlinearity of the guided waves when the waves traverse the pitting damage, based on which linear and nonlinear damage indices are proposed. A path-based rapid imaging algorithm, in conjunction with the use of the developed linear and nonlinear indices, is developed, whereby the HVI-induced pitting damage is characterized in images in terms of the probability of occurrence.

  8. Elemental analyses of hypervelocity microparticle impact sites on Interplanetary Dust Experiment sensor surfaces

    Science.gov (United States)

    Simon, Charles G.; Hunter, J. L.; Griffis, D. P.; Misra, V.; Ricks, D. A.; Wortman, Jim J.; Brownlee, D. E.

    1993-01-01

    The Interplanetary Dust Experiment (IDE) had over 450 electrically active ultra-high purity metal-oxide-silicon impact detectors located on the six primary sides of the Long Duration Exposure Facility (LDEF). Hypervelocity microparticles (approximately 0.2 to approximately 100 micron diameter) that struck the active sensors with enough energy to break down the 0.4 or 1.0 micron thick SIO2 insulator layer separating the silicon base (the negative electrode), and the 1000 A thick surface layer of aluminum (the positive electrode) caused electrical discharges that were recorded for the first year of orbit. The high purity Al-SiO2-Si substrates allowed detection of trace (ppm) amounts of hypervelocity impactor residues. After sputtering through a layer of surface contamination, secondary ion mass spectrometry (SIMS) was used to create two-dimensional elemental ion intensity maps of microparticle impact sites on the IDE sensors. The element intensities in the central craters of the impacts were corrected for relative ion yields and instrumental conditions and then normalized to silicon. The results were used to classify the particles' origins as 'manmade,' 'natural,' or 'indeterminate.' The last classification resulted from the presence of too little impactor residue, analytical interference from high background contamination, the lack of information on silicon and aluminum residues, or a combination of these circumstances. Several analytical 'blank' discharges were induced on flight sensors by pressing down on the sensor surface with a pure silicon shard. Analyses of these blank discharges showed that the discharge energy blasts away the layer of surface contamination. Only Si and Al were detected inside the discharge zones, including the central craters of these features. Thus far a total of 79 randomly selected microparticle impact sites from the six primary sides of the LDEF have been analyzed: 36 from tray C-9 (Leading (ram), or East, side), 18 from tray C-3

  9. Development of a Numerical Model of Hypervelocity Impact into a Pressurized Composite Overwrapped Pressure Vessel

    Science.gov (United States)

    Garcia, M. A.; Davis, B. A.; Miller, J. E.

    2017-01-01

    considered a catastrophic failure. This assumption is conservative and made due to lack of knowledge on the level of allow-able damage to the composite overwrap that can be sustained and still allow successful completion of the mission. To quantify the allowable damage level to the composite overwrap involves assessing stress redistribution following damage as well as evaluating possible time-dependent mechanisms involved in the COPV response to an impact event. Limited published work in this subject has shown that COPV can withstand at least some level of damage due to high energy impacts. These observations have been confirmed and expanded upon in recent experimental research performed by NASA. This research has demonstrated that there is not only robustness in a COPV to compensate for CFRP damage, but has also identified two significant failure modes for pressurized COPV. The lowest threshold failure mode involves the perforation of the vessel, and the highest threshold failure mode is the catastrophic rupture. While both of these failure modes mean a loss of the COPV, system robustness affords some tolerance to the venting as opposed to the more catastrophic rupture. As a consequence, it is necessary to understand the conditions that result in the transition between these failure modes. The aforementioned experimental research has been performed in both the unpressurized and pressurized condition to identify the damage level that triggered the failure thresh-old. This COPV test program was sponsored by the NASA Engineering and Safety Center (NESC), and tests were performed at NASA White Sands Test Facility (WSTF). Planning and coordination were provided by NASA JSC Hypervelocity Impact Technology (HVIT) group, and the COPVs were provided by the ISS Program. Unpressurized testing has been conducted at the pressure of the vacuum test chamber, while, the pressurized testing has been conducted at 290 +/- 10 bar (4,200 ? 100 psi) using nitrogen as the pressurizing gas, which

  10. A meteorite crater on Earth formed on September 15, 2007: The Carancas hypervelocity impact

    Science.gov (United States)

    Tancredi, G.; Ishitsuka, J.; Schultz, P. H.; Harris, R. S.; Brown, P.; Revelle, D. O.; Antier, K.; Le Pichon, A.; Rosales, D.; Vidal, E.; Varela, M. E.; Sánchez, L.; Benavente, S.; Bojorquez, J.; Cabezas, D.; Dalmau, A.

    2009-01-01

    On September 15, 2007, a bright fireball was observed and a big explosion was heard by many inhabitants near the southern shore of Lake Titicaca. In the community of Carancas (Peru), a 13.5 m crater and several fragments of a stony meteorite were found close to the site of the impact. The Carancas event is the first impact crater whose formation was directly observed by several witnesses as well as the first unambiguous seismic recording of a crater-forming meteorite impact on Earth. We present several lines of evidence that suggest that the Carancas crater was a hypervelocity impact. An event like this should have not occurred according to the accepted picture of stony meteoroids ablating in the Earth’s atmosphere, therefore it challenges our present models of entry dynamics. We discuss alternatives to explain this particular event. This emphasizes the weakness in the pervasive use of “average” parameters (such as tensile strength, fragmentation behavior and ablation behavior) in current modeling efforts. This underscores the need to examine a full range of possible values for these parameters when drawing general conclusions from models about impact processes.

  11. Two-dimensional computer simulation of hypervelocity impact cratering: some preliminary results for Meteor Crater, Arizona

    International Nuclear Information System (INIS)

    Bryan, J.B.; Burton, D.E.; Cunningham, M.E.; Lettis, L.A. Jr.

    1978-04-01

    A computational approach used for subsurface explosion cratering has been extended to hypervelocity impact cratering. Meteor (Barringer) Crater, Arizona, was selected for our first computer simulation because it was the most thoroughly studied. It is also an excellent example of a simple, bowl-shaped crater and is one of the youngest terrestrial impact craters. Shoemaker estimates that the impact occurred about 20,000 to 30,000 years ago [Roddy (1977)]. Initial conditions for this calculation included a meteorite impact velocity of 15 km/s. meteorite mass of 1.57E + 08 kg, with a corresponding kinetic energy of 1.88E + 16 J (4.5 megatons). A two-dimensional Eulerian finite difference code called SOIL was used for this simulation of a cylindrical iron projectile impacting at normal incidence into a limestone target. For this initial calculation a Tillotson equation-of-state description for iron and limestone was used with no shear strength. A color movie based on this calculation was produced using computer-generated graphics. Results obtained for this preliminary calculation of the formation of Meteor Crater, Arizona, are in good agreement with Meteor Crater Measurements

  12. Two-dimensional computer simulation of hypervelocity impact cratering: some preliminary results for Meteor Crater, Arizona

    International Nuclear Information System (INIS)

    Bryan, J.B.; Burton, D.E.; Cunningham, M.E.; Lettis, L.A. Jr.

    1978-06-01

    A computational approach used for subsurface explosion cratering was extended to hypervelocity impact cratering. Meteor (Barringer) Crater, Arizona, was selected for the first computer simulation because it is one of the most thoroughly studied craters. It is also an excellent example of a simple, bowl-shaped crater and is one of the youngest terrestrial impact craters. Initial conditions for this calculation included a meteorite impact velocity of 15 km/s, meteorite mass of 1.67 x 10 8 kg, with a corresponding kinetic energy of 1.88 x 10 16 J (4.5 megatons). A two-dimensional Eulerian finite difference code called SOIL was used for this simulation of a cylindrical iron projectile impacting at normal incidence into a limestone target. For this initial calculation, a Tillotson equation-of-state description for iron and limestone was used with no shear strength. Results obtained for this preliminary calculation of the formation of Meteor Crater are in good agreement with field measurements. A color movie based on this calculation was produced using computer-generated graphics. 19 figures, 5 tables, 63 references

  13. Two-dimensional computer simulation of hypervelocity impact cratering: some preliminary results for Meteor Crater, Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, J.B.; Burton, D.E.; Cunningham, M.E.; Lettis, L.A. Jr.

    1978-06-01

    A computational approach used for subsurface explosion cratering was extended to hypervelocity impact cratering. Meteor (Barringer) Crater, Arizona, was selected for the first computer simulation because it is one of the most thoroughly studied craters. It is also an excellent example of a simple, bowl-shaped crater and is one of the youngest terrestrial impact craters. Initial conditions for this calculation included a meteorite impact velocity of 15 km/s, meteorite mass of 1.67 x 10/sup 8/ kg, with a corresponding kinetic energy of 1.88 x 10/sup 16/ J (4.5 megatons). A two-dimensional Eulerian finite difference code called SOIL was used for this simulation of a cylindrical iron projectile impacting at normal incidence into a limestone target. For this initial calculation, a Tillotson equation-of-state description for iron and limestone was used with no shear strength. Results obtained for this preliminary calculation of the formation of Meteor Crater are in good agreement with field measurements. A color movie based on this calculation was produced using computer-generated graphics. 19 figures, 5 tables, 63 references.

  14. Secondary ion mass spectrometry (SIMS) analysis of hypervelocity microparticle impact sites on LDEF surfaces

    Science.gov (United States)

    Simon, C. G.; Buonaquisti, A. J.; Batchelor, D. A.; Hunter, J. L.; Griffis, D. P.; Misra, V.; Ricks, D. R.; Wortman, J. J.; Brownlee, D. E.; Best, S. R.

    1995-01-01

    Two dimensional elemental ion maps have been recorded for hundreds of microparticle impact sites and contamination features on LDEF surfaces. Since the majority of the analyzed surfaces were metal-oxide-silicon (MOS) impact detectors from the Interplanetary Dust Experiment, a series of 'standard' and 'blank' analyses of these surfaces are included. Hypervelocity impacts of forsterite olivine microparticles on activated flight sensors served as standards while stylus and pulsed laser simulated 'impacts' served as analytical blanks. Results showed that despite serious contamination issues, impactor residues can be identified in greater than 1/3 of the impact sites. While aluminum oxide particles could not be detected on aluminum surfaces, they were detected on germanium surfaces from row 12. Remnants of manmade debris impactors consisting of paint chips and bits of metal were identified on surfaces from LDEF Rows 3 (west or trailing side), 6 (south), 9 (ram or leading side), 12 (north) and the space end. Higher than expected ratios of manmade microparticle impacts to total microparticle impacts were found on the space end and the trailing side. These results were consistent with time-tagged and time-segregated microparticle impact data from the IDE and other LDEF experiments. A myriad of contamination interferences were identified and their effects on impactor debris identification mitigated during the course of this study. These interferences include pre-, post and inflight deposited surface contaminants as well as indigenous heterogeneous material contaminants. Non-flight contaminations traced to human origins, including spittle and skin oils, contributed significant levels of alkali-rich carbonaceous interferences. A ubiquitous layer of in-flight deposited silicaceous contamination varied in thickness with location on LDEF, even on a micro scale. In-flight deposited (low velocity) contaminants include urine droplets and bits of metal film from eroded thermal

  15. Hydrocode modeling of the spallation process during hypervelocity impacts: Implications for the ejection of Martian meteorites

    Science.gov (United States)

    Kurosawa, Kosuke; Okamoto, Takaya; Genda, Hidenori

    2018-02-01

    Hypervelocity ejection of material by impact spallation is considered a plausible mechanism for material exchange between two planetary bodies. We have modeled the spallation process during vertical impacts over a range of impact velocities from 6 to 21 km/s using both grid- and particle-based hydrocode models. The Tillotson equations of state, which are able to treat the nonlinear dependence of density on pressure and thermal pressure in strongly shocked matter, were used to study the hydrodynamic-thermodynamic response after impacts. The effects of material strength and gravitational acceleration were not considered. A two-dimensional time-dependent pressure field within a 1.5-fold projectile radius from the impact point was investigated in cylindrical coordinates to address the generation of spalled material. A resolution test was also performed to reject ejected materials with peak pressures that were too low due to artificial viscosity. The relationship between ejection velocity veject and peak pressure Ppeak was also derived. Our approach shows that "late-stage acceleration" in an ejecta curtain occurs due to the compressible nature of the ejecta, resulting in an ejection velocity that can be higher than the ideal maximum of the resultant particle velocity after passage of a shock wave. We also calculate the ejecta mass that can escape from a planet like Mars (i.e., veject > 5 km/s) that matches the petrographic constraints from Martian meteorites, and which occurs when Ppeak = 30-50 GPa. Although the mass of such ejecta is limited to 0.1-1 wt% of the projectile mass in vertical impacts, this is sufficient for spallation to have been a plausible mechanism for the ejection of Martian meteorites. Finally, we propose that impact spallation is a plausible mechanism for the generation of tektites.

  16. Sphere impact and penetration into wet sand

    KAUST Repository

    Marston, J. O.

    2012-08-07

    We present experimental results for the penetration of a solid sphere when released onto wet sand. We show, by measuring the final penetration depth, that the cohesion induced by the water can result in either a deeper or shallower penetration for a given release height compared to dry granular material. Thus the presence of water can either lubricate or stiffen the granular material. By assuming the shear rate is proportional to the impact velocity and using the depth-averaged stopping force in calculating the shear stress, we derive effective viscosities for the wet granular materials.

  17. Sphere impact and penetration into wet sand

    KAUST Repository

    Marston, J. O.; Vakarelski, Ivan Uriev; Thoroddsen, Sigurdur T

    2012-01-01

    We present experimental results for the penetration of a solid sphere when released onto wet sand. We show, by measuring the final penetration depth, that the cohesion induced by the water can result in either a deeper or shallower penetration for a given release height compared to dry granular material. Thus the presence of water can either lubricate or stiffen the granular material. By assuming the shear rate is proportional to the impact velocity and using the depth-averaged stopping force in calculating the shear stress, we derive effective viscosities for the wet granular materials.

  18. DebriSat: The New Hypervelocity Impact Test for Satellite Breakup Fragment Characterization

    Science.gov (United States)

    Cowardin, Heather

    2015-01-01

    To replicate a hyper-velocity fragmentation event using modern-day spacecraft materials and construction techniques to better improve the existing DoD and NASA breakup models: DebriSat is intended to be representative of modern LEO satellites. Major design decisions were reviewed and approved by Aerospace subject matter experts from different disciplines. DebriSat includes 7 major subsystems. Attitude determination and control system (ADCS), command and data handling (C&DH), electrical power system (EPS), payload, propulsion, telemetry tracking and command (TT&C), and thermal management. To reduce cost, most components are emulated based on existing design of flight hardware and fabricated with the same materials. center dotA key laboratory-based test, Satellite Orbital debris Characterization Impact Test (SOCIT), supporting the development of the DoD and NASA satellite breakup models was conducted at AEDC in 1992. Breakup models based on SOCIT have supported many applications and matched on-orbit events reasonably well over the years.

  19. Hypervelocity Impact Test Fragment Modeling: Modifications to the Fragment Rotation Analysis and Lightcurve Code

    Science.gov (United States)

    Gouge, Michael F.

    2011-01-01

    Hypervelocity impact tests on test satellites are performed by members of the orbital debris scientific community in order to understand and typify the on-orbit collision breakup process. By analysis of these test satellite fragments, the fragment size and mass distributions are derived and incorporated into various orbital debris models. These same fragments are currently being put to new use using emerging technologies. Digital models of these fragments are created using a laser scanner. A group of computer programs referred to as the Fragment Rotation Analysis and Lightcurve code uses these digital representations in a multitude of ways that describe, measure, and model on-orbit fragments and fragment behavior. The Dynamic Rotation subroutine generates all of the possible reflected intensities from a scanned fragment as if it were observed to rotate dynamically while in orbit about the Earth. This calls an additional subroutine that graphically displays the intensities and the resulting frequency of those intensities as a range of solar phase angles in a Probability Density Function plot. This document reports the additions and modifications to the subset of the Fragment Rotation Analysis and Lightcurve concerned with the Dynamic Rotation and Probability Density Function plotting subroutines.

  20. Study on Penetration Characteristics of Tungsten Cylindrical Penetrator

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Jong Hyun; Lee, Young Shin; Kim, Jae Hoon [Chungnam Nat' l Univ., Daejeon (Korea, Republic of); Bae, Yong Woon [Agency for Defense Development, Daejeon (Korea, Republic of)

    2013-09-15

    The design of missile require extremely small warheads that must be highly efficient and lethal. The penetration characteristics of each penetrator and the total number of penetrators on the warhead are obvious key factors that influence warhead lethality. The design of the penetrator shape and size are directly related to the space and weight of the warhead. The design of the penetrator L/D was directly related to the space and weight of the warhead. L and D are the length and the diameter of the projectile, respectively. The AUTODYN-3a code was used to study the effect of penetrator penetration. The objective of numerical analysis was to determine the penetration characteristics of penetrator produced by hypervelocity impacts under different initial conditions such as initial velocity, obliquity angle and L/D of penetrator. The residual velocity and residual mass were decreased with increasing initial impact velocity under L/D{<=}4.

  1. Production of Prebiotic Molecule Precursors from Hypervelocity Impact Simulation Experiments on Carbonate Sediments

    Science.gov (United States)

    Farcy, B. J.; Grubisic, A.; Li, X.; Pinnick, V. T.; Sutton, M.; Pavlov, A.; Brinckerhoff, W. B.

    2017-12-01

    Organic molecules, including amino acids and other biotic precursors, have been shown to form in the cooling and expanding plasma plume generated from hypervelocity impacts through the processes of atomization, ionization, and molecular recombination of impactor and impact surface. Various sources of carbon, such as atmospheric methane and carbonaceous material from meteorites, are known to yield cyano-bearing molecules and simple amino acids from impact plasmas. However, the role of mineralogical carbon has not yet been investigated in this process. We have performed experiments using laser ablation mass spectrometry (LA-MS) to study the negative ion yield of plasma-produced prebiotic molecules. A mixture of 10% NH4Cl and 90% CaCO3 was pressed into a pellet and ablated with a 1064 nm Nd:YAG laser, and the resultant negative ions were measured by a plasma analyzer quadrupole MS. Mass spectra show characteristic peaks at m/z = 26 and m/z = 42, indicating the presence of CN- and CNO- ions. When isotopically labeled 15NH4Cl and Ca13CO3 were used in the sample ablation pellet, the purported CN- and CNO- peaks shifted according to their added isotopic mass. Indeed, comparison of resulting ion formation from momentum-based techniques, such as massive cluster secondary ion mass spectrometry, show comparable fragmentation and recombination of CN- and CNO- ions. These findings show that CN- ions, as well as CN radicals and thus HCN, can be formed during meteoritic bombardment of carbonate minerals. During the late heavy bombardment of the earth from 4.1-3.8 Ga, impact-driven chemistry could have played a dominant role in shaping the earth's early prebiotic inventory and sources of chemical energy. As carbonate sediments are common in the Archean, carbonate deposits are most likely an important contributor of carbon for this process, along with atmospheric and meteoritic carbon sources.

  2. Effects of Hypervelocity Impacts on Silicone Elastomer Seals and Mating Aluminum Surfaces

    Science.gov (United States)

    deGroh, Henry C., III; Steinetz, Bruce M.

    2009-01-01

    While in space silicone based elastomer seals planned for use on NASA's Crew Exploration Vehicle (CEV) are exposed to threats from micrometeoroids and orbital debris (MMOD). An understanding of these threats is required to assess risks to the crew, the CEV orbiter, and missions. An Earth based campaign of hypervelocity impacts on small scale seal rings has been done to help estimate MMOD threats to the primary docking seal being developed for the Low Impact Docking System (LIDS). LIDS is being developed to enable the CEV to dock to the ISS (International Space Station) or to Altair (NASA's next lunar lander). The silicone seal on LIDS seals against aluminum alloy flanges on ISS or Altair. Since the integrity of a seal depends on both sealing surfaces, aluminum targets were also impacted. The variables considered in this study included projectile mass, density, speed, incidence angle, seal materials, and target surface treatments and coatings. Most of the impacts used a velocity near 8 km/s and spherical aluminum projectiles (density = 2.7 g/cubic cm), however, a few tests were done near 5.6 km/s. Tests were also performed using projectile densities of 7.7, 2.79, 2.5 or 1.14 g/cubic cm. Projectile incidence angles examined included 0 deg, 45 deg, and 60 deg from normal to the plane of the target. Elastomer compounds impacted include Parker's S0383-70 and Esterline's ELA-SA-401 in the as received condition, or after an atomic oxygen treatment. Bare, anodized and nickel coated aluminum targets were tested simulating the candidate mating seal surface materials. After impact, seals and aluminum plates were leak tested: damaged seals were tested against an undamaged aluminum plate; and undamaged seals were placed at various locations over craters in aluminum plates. It has been shown that silicone elastomer seals can withstand an impressive level of damage before leaking beyond allowable limits. In general on the tests performed to date, the diameter of the crater in

  3. Risk Assessment of Cassini Sun Sensor Integrity Due to Hypervelocity Impact of Saturn Dust Particles

    Science.gov (United States)

    Lee, Allan Y.

    2016-01-01

    A sophisticated interplanetary spacecraft, Cassini is one of the heaviest and most sophisticated interplanetary spacecraft humans have ever built and launched. Since achieving orbit at Saturn in 2004, Cassini has collected science data throughout its four-year prime mission (2004-08), and has since been approved for first and second extended missions through September 2017. In late 2016, the Cassini spacecraft will begin a daring set of ballistic orbits that will hop the rings and dive between the upper atmosphere of Saturn and its innermost D-ring twenty-two times. The "dusty" environment of the inner D-ring region the spacecraft must fly through is hazardous because of the possible damage that dust particles, travelling at speeds as high as 31.4 km/s, can do to spacecraft hardware. During hazardous proximal ring-plane crossings, the Cassini mission operation team plans to point the high-gain antenna to the RAM vector in order to protect most of spacecraft instruments from the incoming energetic ring dust particles. However, this particular spacecraft attitude will expose two Sun sensors (that are mounted on the antenna dish) to the incoming dust particles. High-velocity impacts on the Sun sensor cover glass might penetrate the 2.54-mm glass cover of the Sun sensor. Even without penetration damage, craters created by these impacts on the surface of the cover glass will degrade the transmissibility of light through it. Apart from being directly impacted by the dust particles, the Sun sensors are also threatened by some fraction of ricochet ejecta that are produced by dust particle impacts on the large antenna dish (made of graphite fiber epoxy composite material). Finally, the spacecraft attitude control system must cope with disturbances due to both the translational and angular impulses imparted on the large antenna dish and the long magnetometer boom by the incoming high-velocity projectiles. Analyses performed to quantify the risks the Sun sensors must contend

  4. Numerical investigations on pressurized AL-composite vessel response to hypervelocity impacts: Comparison between experimental works and a numerical code

    Directory of Open Access Journals (Sweden)

    Mespoulet Jérôme

    2015-01-01

    Full Text Available Response of pressurized composite-Al vessels to hypervelocity impact of aluminum spheres have been numerically investigated to evaluate the influence of initial pressure on the vulnerability of these vessels. Investigated tanks are carbon-fiber overwrapped prestressed Al vessels. Explored internal air pressure ranges from 1 bar to 300 bar and impact velocity are around 4400 m/s. Data obtained from experiments (Xray radiographies, particle velocity measurement and post-mortem vessels have been compared to numerical results given from LS-DYNA ALE-Lagrange-SPH full coupling models. Simulations exhibit an under estimation in term of debris cloud evolution and shock wave propagation in pressurized air but main modes of damage/rupture on the vessels given by simulations are coherent with post-mortem recovered vessels from experiments. First results of this numerical work are promising and further simulation investigations with additional experimental data will be done to increase the reliability of the simulation model. The final aim of this crossed work is to numerically explore a wide range of impact conditions (impact angle, projectile weight, impact velocity, initial pressure that cannot be explore experimentally. Those whole results will define a rule of thumbs for the definition of a vulnerability analytical model for a given pressurized vessel.

  5. Influence of different gaps among the split targets with gradient potential to the discharge effects generated by hypervelocity impact

    Science.gov (United States)

    Tang, Enling; Zhao, Liangliang; Han, Yafei; Zhang, Qingming; Wang, Ruizhi; He, Liping; Liu, Shuhua

    2018-04-01

    Due to the actual situation of spacecraft surface' charging, such as convex corners, weld line, whalebone and a multiple-interfaces with different materials, all these are main factors leading to uneven charging of spacecraft surface, even creating gradient potential. If the charging spacecraft surface is impacted by debris or micrometeor, discharge effect induced by impacting will pose a serious threat to spacecraft in orbit. So realizing spacecraft charging surface with different potential differences and grasping discharge characteristics are a decisive importance at the different experimental conditions in laboratory. To simulate the spacecraft surface with a gradient potential in laboratory, spacecraft surface is split into different parts, which different gaps reserved in 2 adjacent surface is added resistance to create different potential surfaces, and the high potential surface as a impact target in the split targets. Charging circuit system realizing different gradient potential and discharge test system are built by ourselves, combining with two-stage light gas gun loading system, six sets of experiments have been performed about hypervelocity impact on 2A12 aluminum split targets with gradient potentials. In the experiments, gaps of 2A12 aluminum target are the same among different parts in every experiments, the gaps of the split targets are 2mm, 3mm, 5mm, 7mm and 10mm in the experiments, respectively. And the applied voltage is 300V in all the experiments and high-potential 2A12 aluminum plate as the impact target. The experiments have been performed at the impact velocity of about 3km/s and the incidence angles of 60o and 90o (between projectile flying trajectory and target plane), respectively. Voltage probe and current probes are used for acquiring discharge voltages and currents during the process of the impact. The experimental results showed that the discharge induced by impact plasma were generated among high and low-potential target by forming

  6. Influence of different gaps among the split targets with gradient potential to the discharge effects generated by hypervelocity impact

    Directory of Open Access Journals (Sweden)

    Enling Tang

    2018-04-01

    Full Text Available Due to the actual situation of spacecraft surface’ charging, such as convex corners, weld line, whalebone and a multiple-interfaces with different materials, all these are main factors leading to uneven charging of spacecraft surface, even creating gradient potential. If the charging spacecraft surface is impacted by debris or micrometeor, discharge effect induced by impacting will pose a serious threat to spacecraft in orbit. So realizing spacecraft charging surface with different potential differences and grasping discharge characteristics are a decisive importance at the different experimental conditions in laboratory. To simulate the spacecraft surface with a gradient potential in laboratory, spacecraft surface is split into different parts, which different gaps reserved in 2 adjacent surface is added resistance to create different potential surfaces, and the high potential surface as a impact target in the split targets. Charging circuit system realizing different gradient potential and discharge test system are built by ourselves, combining with two-stage light gas gun loading system, six sets of experiments have been performed about hypervelocity impact on 2A12 aluminum split targets with gradient potentials. In the experiments, gaps of 2A12 aluminum target are the same among different parts in every experiments, the gaps of the split targets are 2mm, 3mm, 5mm, 7mm and 10mm in the experiments, respectively. And the applied voltage is 300V in all the experiments and high-potential 2A12 aluminum plate as the impact target. The experiments have been performed at the impact velocity of about 3km/s and the incidence angles of 60o and 90o (between projectile flying trajectory and target plane, respectively. Voltage probe and current probes are used for acquiring discharge voltages and currents during the process of the impact. The experimental results showed that the discharge induced by impact plasma were generated among high and low

  7. First Principles Based Reactive Atomistic Simulations to Understand the Effects of Molecular Hypervelocity Impact on Cassini's Ion and Neutral Mass Spectrometer

    Science.gov (United States)

    Jaramillo-Botero, A.; Cheng, M-J; Cvicek, V.; Beegle, Luther W.; Hodyss, R.; Goddard, W. A., III

    2011-01-01

    We report here on the predicted impact of species such as ice-water, CO2, CH4, and NH3, on oxidized titanium, as well as HC species on diamond surfaces. These simulations provide the dynamics of product distributions during and after a hypervelocity impact event, ionization fractions, and dissociation probabilities for the various species of interest as a function of impact velocity (energy). We are using these results to determine the relevance of the fragmentation process to Cassini INMS results, and to quantify its effects on the observed spectra.

  8. Water Penetration through a Superhydrophobic Mesh During a Drop Impact

    Science.gov (United States)

    Ryu, Seunggeol; Sen, Prosenjit; Nam, Youngsuk; Lee, Choongyeop

    2017-01-01

    When a water drop impacts a mesh having submillimeter pores, a part of the drop penetrates through the mesh if the impact velocity is sufficiently large. Here we show that different surface wettability, i.e., hydrophobicity and superhydrophobicity, leads to different water penetration dynamics on a mesh during drop impact. We show, despite the water repellence of a superhydrophobic surface, that water can penetrate a superhydrophobic mesh more easily (i.e., at a lower impact velocity) over a hydrophobic mesh via a penetration mechanism unique to a superhydrophobic mesh. On a superhydrophobic mesh, the water penetration can occur during the drop recoil stage, which appears at a lower impact velocity than the critical impact velocity for water penetration right upon impact. We propose that this unique water penetration on a superhydrophobic mesh can be attributed to the combination of the hydrodynamic focusing and the momentum transfer from the water drop when it is about to bounce off the surface, at which point the water drop retrieves most of its kinetic energy due to the negligible friction on superhydrophobic surfaces.

  9. The Impact of IPv6 on Penetration Testing

    NARCIS (Netherlands)

    Ottow, Christiaan; van Vliet, Frank; de Boer, Pieter-Tjerk; Pras, Aiko

    In this paper we discuss the impact the use of IPv6 has on remote penetration testing of servers and web applications. Several modifications to the penetration testing process are proposed to accommodate IPv6. Among these modifications are ways of performing fragmentation attacks, host discovery and

  10. A SELF-CONSISTENT MODEL OF THE CIRCUMSTELLAR DEBRIS CREATED BY A GIANT HYPERVELOCITY IMPACT IN THE HD 172555 SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, B. C.; Melosh, H. J. [Department of Physics, Purdue University, 525 Northwestern Avenue, West Lafayette, IN 47907 (United States); Lisse, C. M. [JHU-APL, 11100 Johns Hopkins Road, Laurel, MD 20723 (United States); Chen, C. H. [STScI, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Wyatt, M. C. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Thebault, P. [LESIA, Observatoire de Paris, F-92195 Meudon Principal Cedex (France); Henning, W. G. [NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States); Gaidos, E. [Department of Geology and Geophysics, University of Hawaii at Manoa, Honolulu, HI 96822 (United States); Elkins-Tanton, L. T. [Department of Terrestrial Magnetism, Carnegie Institution for Science, Washington, DC 20015 (United States); Bridges, J. C. [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom); Morlok, A., E-mail: johns477@purdue.edu [Department of Physical Sciences, Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom)

    2012-12-10

    Spectral modeling of the large infrared excess in the Spitzer IRS spectra of HD 172555 suggests that there is more than 10{sup 19} kg of submicron dust in the system. Using physical arguments and constraints from observations, we rule out the possibility of the infrared excess being created by a magma ocean planet or a circumplanetary disk or torus. We show that the infrared excess is consistent with a circumstellar debris disk or torus, located at {approx}6 AU, that was created by a planetary scale hypervelocity impact. We find that radiation pressure should remove submicron dust from the debris disk in less than one year. However, the system's mid-infrared photometric flux, dominated by submicron grains, has been stable within 4% over the last 27 years, from the Infrared Astronomical Satellite (1983) to WISE (2010). Our new spectral modeling work and calculations of the radiation pressure on fine dust in HD 172555 provide a self-consistent explanation for this apparent contradiction. We also explore the unconfirmed claim that {approx}10{sup 47} molecules of SiO vapor are needed to explain an emission feature at {approx}8 {mu}m in the Spitzer IRS spectrum of HD 172555. We find that unless there are {approx}10{sup 48} atoms or 0.05 M{sub Circled-Plus} of atomic Si and O vapor in the system, SiO vapor should be destroyed by photo-dissociation in less than 0.2 years. We argue that a second plausible explanation for the {approx}8 {mu}m feature can be emission from solid SiO, which naturally occurs in submicron silicate ''smokes'' created by quickly condensing vaporized silicate.

  11. A SELF-CONSISTENT MODEL OF THE CIRCUMSTELLAR DEBRIS CREATED BY A GIANT HYPERVELOCITY IMPACT IN THE HD 172555 SYSTEM

    International Nuclear Information System (INIS)

    Johnson, B. C.; Melosh, H. J.; Lisse, C. M.; Chen, C. H.; Wyatt, M. C.; Thebault, P.; Henning, W. G.; Gaidos, E.; Elkins-Tanton, L. T.; Bridges, J. C.; Morlok, A.

    2012-01-01

    Spectral modeling of the large infrared excess in the Spitzer IRS spectra of HD 172555 suggests that there is more than 10 19 kg of submicron dust in the system. Using physical arguments and constraints from observations, we rule out the possibility of the infrared excess being created by a magma ocean planet or a circumplanetary disk or torus. We show that the infrared excess is consistent with a circumstellar debris disk or torus, located at ∼6 AU, that was created by a planetary scale hypervelocity impact. We find that radiation pressure should remove submicron dust from the debris disk in less than one year. However, the system's mid-infrared photometric flux, dominated by submicron grains, has been stable within 4% over the last 27 years, from the Infrared Astronomical Satellite (1983) to WISE (2010). Our new spectral modeling work and calculations of the radiation pressure on fine dust in HD 172555 provide a self-consistent explanation for this apparent contradiction. We also explore the unconfirmed claim that ∼10 47 molecules of SiO vapor are needed to explain an emission feature at ∼8 μm in the Spitzer IRS spectrum of HD 172555. We find that unless there are ∼10 48 atoms or 0.05 M ⊕ of atomic Si and O vapor in the system, SiO vapor should be destroyed by photo-dissociation in less than 0.2 years. We argue that a second plausible explanation for the ∼8 μm feature can be emission from solid SiO, which naturally occurs in submicron silicate ''smokes'' created by quickly condensing vaporized silicate.

  12. Excess of L-Alanine in Amino Acids Synthesized in a Plasma Torch Generated by a Hypervelocity Meteorite Impact Reproduced in the Laboratory

    Science.gov (United States)

    Managadze, George G.; Engle, Michael H.; Getty, Stephanie A.; Wurz, Peter; Brinckerhoff, William B.; Shokolov, Anatoly; Sholin, Gennady; Terent'ev, Sergey A.; Chumikov, Alexander E.; Skalkin, Alexander S

    2016-01-01

    We present a laboratory reproduction of hypervelocity impacts of a carbon containing meteorite on a mineral substance representative of planetary surfaces. The physical conditions of the resulting impact plasma torch provide favorable conditions for abiogenic synthesis of protein amino acids: We identified glycine and alanine, and in smaller quantities serine, in the produced material. Moreover, we observe breaking of alanine mirror symmetry with L excess, which coincides with the bioorganic world. Therefore the selection of L-amino acids for the formation of proteins for living matter could have been the result from plasma processes occurring during the impact meteorites on the surface. This indicates that the plasma torch from meteorite impacts could play an important role in the formation of biomolecular homochirality. Thus, meteorite impacts possibly were the initial stage of this process and promoted conditions for the emergence of a living matter.

  13. Hypervelocity dust particle impacts observed by the Giotto Magnetometer and Plasma Experiments

    OpenAIRE

    Neubauer, F. M.; Glassmeier, K. H.; Coates, A. J.; Goldstein, R.; Acuña, M. H.; Musmann, G.

    1990-01-01

    We report thirteen very short events in the magnetic field of the inner magnetic pile‐up region of comet Halley observed by the Giotto magnetometer experiment together with simultaneous plasma data obtained by the Johnstone plasma analyzer and the ion mass spectrometer experiments. The events are due to dust impacts in the milligram range on the spacecraft at the relative velocity between the cemetery dust and the spacecraft of 68 km/sec. They are generally consistent with dust impact events ...

  14. Impact of Flight Enthalpy, Fuel Simulant, and Chemical Reactions on the Mixing Characteristics of Several Injectors at Hypervelocity Flow Conditions

    Science.gov (United States)

    Drozda, Tomasz G.; Baurle, Robert A.; Drummond, J. Philip

    2016-01-01

    conditions. The mixing parameters of interest, such as mixing efficiency and total pressure recovery, are then computed and compared to the values obtained from RAS under the true enthalpy conditions and using helium and hydrogen. Finally, the impact of combustion on mixing, often deemed small enough to neglect at hypervelocity conditions, is assessed by comparing the results obtained from the hydrogen-fueled reacting and non-reacting RAS. For reacting flows, in addition to mixing efficiency and total pressure recovery, the combustion efficiency and thrust potential are also considered. In all of the simulations, the incoming air Mach number and the fuel-to-air ratio are the same, while the total pressure, total enthalpy, and the fuel simulant vary depending on the case considered. It is found that under some conditions the "cold" flow experiments are a good approximation of the flight.

  15. Hypervelocity dust particle impacts observed by the Giotto magnetometer and plasma experiments

    International Nuclear Information System (INIS)

    Neubauer, F.M.; Glassmeier, K.H.; Goldstein, R.; Acuna, M.H.; Musmann, G.; Coates, A.J.

    1990-01-01

    The authors report thirteen very short events in the magnetic field of the inner magnetic pile-up region of comet Halley observed by the Giotto magnetometer experiment together with simultaneous plasma data obtained by the Johnstone plasma analyzer and the ion mass spectrometer experiments. The events are due to dust impacts in the milligram range on the spacecraft at the relative velocity between the cometary dust and the spacecraft of 68 km/sec. They are generally consistent with dust impact events derived from spacecraft attitude perturbations by the Giotto camera [Curdt and Keller, private communication]. Their characteristic shape generally involves a sudden decrease in magnetic field magnitude, a subsequent overshoot beyond initial field values and an asymptotic approach to the initial field somewhat reminiscent of the magnetic field signature after the AMPTE releases in the solar wind. These observations give a new way of analyzing ultra-fast dust particles incident on a spacecraft

  16. Hypervelocity dust particle impacts observed by the Giotto magnetometer and plasma experiments

    Science.gov (United States)

    Neubauer, F. M.; Glassmeier, K.-H.; Coates, A. J.; Goldstein, R.; Acuna, M. H.

    1990-01-01

    This paper describes 13 very short events in the magnetic field of the inner magnetic pile-up region of Comet Halley observed by the Giotto magnetometer experiment together with simultaneous plasma data obtained by the Johnstone plasma analyzer and the ion mass spectrometer experiments. The events are due to dust impacts in the milligram range on the spacecraft at the relative velocity between the cometary dust and the spacecraft of 68 km/sec. They are generally consistent with dust impact events derived from spacecraft attitude perturbations by the Giotto camera. Their characteristic shape generally involves a sudden decrease in magnetic-field magnitude, a subsequent overshoot beyond initial field values, and an asymptotic approach to the initial field (somewhat reminiscent of the magnetic-field signature after the AMPTE releases in the solar wind). These observations give a new way of analyzing ultra-fast dust particles incident on a spacecraft.

  17. Magnetic linear accelerator (MAGLAC) for hypervelocity acceleration in impact fusion (IF)

    International Nuclear Information System (INIS)

    Chen, K.W.

    1980-01-01

    This paper presents considerations on the design of a magnetic linear accelerator suitable as driver for impact fusion. We argue that the proposed approach offers an attractive option to accelerate macroscopic matter to centiluminal velocity suitable for fusion applications. The design goal is to attain a velocity approaching 200 km/sec. Recent results in suitable target design suggest that a velocity in the range of 40-100 km/sec might be sufficient to include fusion. An accelerator in this velocity range can be constructed with current-day technology. We present both design and practical engineering considerations. Future work are outlined and recommended. (orig.)

  18. Impacts of Large Scale Wind Penetration on Energy Supply Industry

    Directory of Open Access Journals (Sweden)

    John Kabouris

    2009-11-01

    Full Text Available Large penetration of Renewable Energy Sources (RES impacts Energy Supply Industry (ESI in many aspects leading to a fundamental change in electric power systems. It raises a number of technical challenges to the Transmission System Operators (TSOs, Distribution System Operators (DSOs and Wind Turbine Generators (WTG constructors. This paper aims to present in a thorough and coherent way the redrawn picture for Energy Systems under these conditions. Topics related to emergent technical challenges, technical solutions required and finally the impact on ESI due to large wind power penetration, are analyzed. Finally, general conclusions are extracted about the ESI current and future state and general directions are recommended.

  19. Two-stage light-gas magnetoplasma accelerator for hypervelocity impact simulation

    International Nuclear Information System (INIS)

    Khramtsov, P P; Vasetskij, V A; Makhnach, A I; Grishenko, V M; Chernik, M Yu; Shikh, I A; Doroshko, M V

    2016-01-01

    The development of macroparticles acceleration methods for high-speed impact simulation in a laboratory is an actual problem due to increasing of space flights duration and necessity of providing adequate spacecraft protection against micrometeoroid and space debris impacts. This paper presents results of experimental study of a two-stage light- gas magnetoplasma launcher for acceleration of a macroparticle, in which a coaxial plasma accelerator creates a shock wave in a high-pressure channel filled with light gas. Graphite and steel spheres with diameter of 2.5-4 mm were used as a projectile and were accelerated to the speed of 0.8-4.8 km/s. A launching of particle occurred in vacuum. For projectile velocity control the speed measuring method was developed. The error of this metod does not exceed 5%. The process of projectile flight from the barrel and the process of a particle collision with a target were registered by use of high-speed camera. The results of projectile collision with elements of meteoroid shielding are presented. In order to increase the projectile velocity, the high-pressure channel should be filled with hydrogen. However, we used helium in our experiments for safety reasons. Therefore, we can expect that the range of mass and velocity of the accelerated particles can be extended by use of hydrogen as an accelerating gas. (paper)

  20. Two-stage light-gas magnetoplasma accelerator for hypervelocity impact simulation

    Science.gov (United States)

    Khramtsov, P. P.; Vasetskij, V. A.; Makhnach, A. I.; Grishenko, V. M.; Chernik, M. Yu; Shikh, I. A.; Doroshko, M. V.

    2016-11-01

    The development of macroparticles acceleration methods for high-speed impact simulation in a laboratory is an actual problem due to increasing of space flights duration and necessity of providing adequate spacecraft protection against micrometeoroid and space debris impacts. This paper presents results of experimental study of a two-stage light- gas magnetoplasma launcher for acceleration of a macroparticle, in which a coaxial plasma accelerator creates a shock wave in a high-pressure channel filled with light gas. Graphite and steel spheres with diameter of 2.5-4 mm were used as a projectile and were accelerated to the speed of 0.8-4.8 km/s. A launching of particle occurred in vacuum. For projectile velocity control the speed measuring method was developed. The error of this metod does not exceed 5%. The process of projectile flight from the barrel and the process of a particle collision with a target were registered by use of high-speed camera. The results of projectile collision with elements of meteoroid shielding are presented. In order to increase the projectile velocity, the high-pressure channel should be filled with hydrogen. However, we used helium in our experiments for safety reasons. Therefore, we can expect that the range of mass and velocity of the accelerated particles can be extended by use of hydrogen as an accelerating gas.

  1. Hypervelocity Impact Testing of Materials for Additive Construction: Applications on Earth, the Moon, and Mars

    Science.gov (United States)

    Ordonez, Erick; Edmunson, Jennifer; Fiske, Michael; Christiansen, Eric; Miller, Josh; Davis, Bruce Alan; Read, Jon; Johnston, Mallory; Fikes, John

    2017-01-01

    Additive Construction is the process of building infrastructure such as habitats, garages, roads, berms, etcetera layer by layer (3D printing). The National Aeronautics and Space Administration (NASA) and the United States Army Corps of Engineers (USACE) are pursuing additive construction to build structures using resources available in-situ. Using materials available in-situ reduces the cost of planetary missions and operations in theater. The NASA team is investigating multiple binders that can be produced on planetary surfaces, including the magnesium oxide-based Sorel cement; the components required to make Ordinary Portland Cement (OPC), the common cement used on Earth, have been found on Mars. The availability of OPC-based concrete on Earth drove the USACE to pursue additive construction for base housing and barriers for military operations. Planetary and military base structures must be capable of resisting micrometeoroid impacts with velocities ranging from 11 to 72km/s for particle sizes 200 micrometers or more (depending on protection requirements) as well as bullets and shrapnel with a velocity of 1.036km/s with projectiles 5.66mm diameter and 57.40mm in length, respectively.

  2. Europa Kinetic Ice Penetrator (EKIP)

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of the proposed work is to validate an initial design for a Europa penetrator that can withstand the high g load associated with the expected hypervelocity...

  3. Microgrid optimal scheduling considering impact of high penetration wind generation

    Science.gov (United States)

    Alanazi, Abdulaziz

    The objective of this thesis is to study the impact of high penetration wind energy in economic and reliable operation of microgrids. Wind power is variable, i.e., constantly changing, and nondispatchable, i.e., cannot be controlled by the microgrid controller. Thus an accurate forecasting of wind power is an essential task in order to study its impacts in microgrid operation. Two commonly used forecasting methods including Autoregressive Integrated Moving Average (ARIMA) and Artificial Neural Network (ANN) have been used in this thesis to improve the wind power forecasting. The forecasting error is calculated using a Mean Absolute Percentage Error (MAPE) and is improved using the ANN. The wind forecast is further used in the microgrid optimal scheduling problem. The microgrid optimal scheduling is performed by developing a viable model for security-constrained unit commitment (SCUC) based on mixed-integer linear programing (MILP) method. The proposed SCUC is solved for various wind penetration levels and the relationship between the total cost and the wind power penetration is found. In order to reduce microgrid power transfer fluctuations, an additional constraint is proposed and added to the SCUC formulation. The new constraint would control the time-based fluctuations. The impact of the constraint on microgrid SCUC results is tested and validated with numerical analysis. Finally, the applicability of proposed models is demonstrated through numerical simulations.

  4. Determination of parameters for hypervelocity dust grains encountered in near-Earth space

    Science.gov (United States)

    Tanner, William G.; Maag, Carl R.; Alexander, W. Merle; Sappenfield, Patricia

    1993-01-01

    Primarily interest was in the determination of the population of micrometeoroids and space debris and interpretation of the hole size in a thin film or in a micropore foam returned from space with theoretical calculations describing the event. In order to augment the significance of the theoretical calculations of the impact event, an experiment designed to analyze the charge production due to hypervelocity impacts on thin films also produced data which described the penetration properties of micron and sub-micron sized projectiles. The thin film penetration sites in the 500 A and 1000 A aluminum films were counted and a size distribution function was derived. In the case of the very smallest dust grains, there were no independent measurements of velocities like that which existed for the larger dust grains (d(sub p) is less than or equal to 1 micron). The primary task then became to assess the relationship between the penetration hole and the particle diameter of the projectile which made the hole. The most promising means to assess the measure of the diameters of impacting grains came in the form of comparing cratering mechanics to penetration mechanics. Future experimentation will produce measurements of the cratering as opposed to the penetrating event. Particles encountered by surfaces while being flown in space will degrade that surface in a systematic manner even when the impact is with small hypervelocity particles, d(sub p) is less than or equal to 10 microns. Though not to a degree which would precipitate a catastrophic failure of a system, the degradation of the materials comprising the interconnected system will occur. It is the degradation of the optical system and the subsequent embrittlement of other materials that can lead to degradation if not to failure. It is to this end that research was conducted to compare the primary consequences for experiments which will be flown to those which have been returned.

  5. Dimensional analysis and extended hydrodynamic theory applied to long-rod penetration of ceramics

    Directory of Open Access Journals (Sweden)

    J.D. Clayton

    2016-08-01

    Full Text Available Principles of dimensional analysis are applied in a new interpretation of penetration of ceramic targets subjected to hypervelocity impact. The analysis results in a power series representation – in terms of inverse velocity – of normalized depth of penetration that reduces to the hydrodynamic solution at high impact velocities. Specifically considered are test data from four literature sources involving penetration of confined thick ceramic targets by tungsten long rod projectiles. The ceramics are AD-995 alumina, aluminum nitride, silicon carbide, and boron carbide. Test data can be accurately represented by the linear form of the power series, whereby the same value of a single fitting parameter applies remarkably well for all four ceramics. Comparison of the present model with others in the literature (e.g., Tate's theory demonstrates a target resistance stress that depends on impact velocity, linearly in the limiting case. Comparison of the present analysis with recent research involving penetration of thin ceramic tiles at lower typical impact velocities confirms the importance of target properties related to fracture and shear strength at the Hugoniot Elastic Limit (HEL only in the latter. In contrast, in the former (i.e., hypervelocity and thick target experiments, the current analysis demonstrates dominant dependence of penetration depth only by target mass density. Such comparisons suggest transitions from microstructure-controlled to density-controlled penetration resistance with increasing impact velocity and ceramic target thickness.

  6. Impact of adult atopic dermatitis on topical drug penetration

    DEFF Research Database (Denmark)

    Garcia Ortiz, Patricia; Hansen, Steen H; Shah, Vinod P

    2009-01-01

    Appropriate methodologies for the determination of drug penetration in diseased skin have not yet been established. The aim of this study was to determine the cutaneous penetration of a metronidazole cream formulation in atopic dermatitis, employing dermal microdialysis and tape strip sampling...

  7. Impacted thoracic foreign bodies after penetrating chest trauma.

    Science.gov (United States)

    Sersar, Sameh I; Albohiri, Khalid A; Abdelmohty, Hysam

    2016-10-01

    Retained foreign bodies in the chest may include shell fragments, bullets, shrapnel, pieces of clothing, bones, and rib fragments. The risks of removal of foreign bodies must be weighed against the complications of leaving them inside the chest. We treated 90 cases of retained intrathoracic foreign bodies in patients admitted to 3 tertiary centers in Saudi Arabia between March 2015 and March 2016. Sixty patients were injured by shrapnel, 26 had one or more bullets, 3 had broken rib fragments, and one had a metal screw. The chest wall was site of impaction in 48 cases, the lungs in 24, pleura in 14, and mediastinum in 4. Removal of the retained foreign body was carried out in 12 patients only: bullets in 9 cases, bone fragments in 2, and a metal screw in one. The predictors for removal were bullets, female sex, and mediastinal position with bilateral chest injury, especially with fracture ribs. Retained intrathoracic foreign bodies due to penetrating chest trauma are treated mainly conservatively unless there is another indication for chest exploration. © The Author(s) 2016.

  8. Hypervelocity Impact: Proceedings of the 1992 Symposium Held in Austin, Texas on 17-19 November 1992

    Science.gov (United States)

    1993-10-01

    hardening of the impact surface. The metals, copper and aluminum, are both represented in a wealth of impact data obtained in macroscopic impacts at...both theoretical and computational modeling of deformation physics. We have obtained a wealth of impact data in the form of cratered targets, many still...Lawrence Livermore National Laboratory Nellis, William J. Lawrence Livermore Naitonal Laboratory Normandia, Dr. Michael J. Kaman Sciences Corporation

  9. The intact capture of hypervelocity dust particles using underdense foams

    Science.gov (United States)

    Maag, Carl R.; Borg, J.; Tanner, William G.; Stevenson, T. J.; Bibring, J.-P.

    1994-01-01

    probability of survival for the impacting particle. The primary objectives of the experiment are to (1) Examine the morphology of primary and secondary hypervelocity impact craters. Primary attention will be paid to craters caused by ejecta during hypervelocity impacts of different substrates. (2) Determine the size distribution of ejecta by means of witness plates and collect fragments of ejecta from craters by means of momentum-sensitive mcropore foam. (3) Assess the directionality of the flux by means of penetration-hole alignment of thin films placed above the cells. (4) Capture intact the particles that perforated the thin film and entered the cell. Capture media consisted of both previously flight-tested micropore foams and aerogel. The foams had different latent heats of fusion and, accordingly, will capture particles over a range of momenta. Aerogel was incorporated into the cells to determine the minimum diameter than can be captured intact.

  10. Survival of organic materials in hypervelocity impacts of ice on sand, ice, and water in the laboratory.

    Science.gov (United States)

    Burchell, Mark J; Bowden, Stephen A; Cole, Michael; Price, Mark C; Parnell, John

    2014-06-01

    The survival of organic molecules in shock impact events has been investigated in the laboratory. A frozen mixture of anthracene and stearic acid, solvated in dimethylsulfoxide (DMSO), was fired in a two-stage light gas gun at speeds of ~2 and ~4 km s(-1) at targets that included water ice, water, and sand. This involved shock pressures in the range of 2-12 GPa. It was found that the projectile materials were present in elevated quantities in the targets after impact and in some cases in the crater ejecta as well. For DMSO impacting water at 1.9 km s(-1) and 45° incidence, we quantify the surviving fraction after impact as 0.44±0.05. This demonstrates successful transfer of organic compounds from projectile to target in high-speed impacts. The range of impact speeds used covers that involved in impacts of terrestrial meteorites on the Moon, as well as impacts in the outer Solar System on icy bodies such as Pluto. The results provide laboratory evidence that suggests that exogenous delivery of complex organic molecules from icy impactors is a viable source of such material on target bodies.

  11. The impact of mobile phone penetration on African inequality

    OpenAIRE

    Asongu Simplice

    2013-01-01

    Purpose – The aim of this paper is to complement theoretical and qualitative literature with empirical evidence on the income-redistributive effect of mobile phone penetration in 52 African countries. Design/methodology/approach – Robust Ordinary Least Squares and Two Stage Least Squares empirical strategies are employed. Findings – The findings suggest that mobile penetration is pro-poor, as it has a positive income equality effect. Social implications – 'Mobile phone'-oriented poverty reduc...

  12. Does Medicaid managed care market penetration impact provider participation, costs, utilization, and access?

    Science.gov (United States)

    Minott, Jenny

    2010-09-01

    Key findings. (1) An increase in commercial plan penetration increased the liklihood [sic] that a physician would accept new Medicaid patients, but this did not significantly impact enrollee costs. (2) An increase in Medicaid-dominant HMO market penetration increased the probability that individuals reported using the ED as their primary source of care.

  13. Ink Penetration of Uncoated Inkjet Paper and Impact on Printing Quality

    Directory of Open Access Journals (Sweden)

    Ren'ai Li

    2015-10-01

    Full Text Available This study investigated ink penetration through imaging technology, first by gray and contour mapping and then calculating the ink penetration depth by programing. Next, a series of further analyses were carried out, including average ink permeability, ink distributions, and printability of different uncoated inkjet paper with different parameters. The impact on ink penetration of the microstructure and hydrophilicity of the uncoated paper was also studied. The experimental results indicated that paper specimens with sizing agent were resistant to the ink, resulting in a slow and shallow ink penetration. Paper containing filler had a more hydrophilic surface and porous structure, leading to a faster and deeper ink penetration. However, the calendering operation could make the paper structure more compact and reduce the porosity and penetration depth. When an appropriate combination of sizing agent, filler content, and the calendering process was utilized, a more stable hue could be produced with improvements in optical density, saturation, and color.

  14. High Penetrated Wind Farm Impacts on the Electricity Price

    DEFF Research Database (Denmark)

    Haji Bashi, Mazaher; Yousefi, G. R.; Bak, Claus Leth

    2016-01-01

    of the high penetrated wind farm integration into electricity markets. Then, stochastic programming approach is employed to compare the volume of trades for a typical wind farm in a high and low wind penetrated market. Although increasing price spikes and volatility was reported in the literature......Energy trading policies, intermittency of wind farm output power, low marginal cost of the production, are the key factors that cause the wind farms to be effective on the electricity price. In this paper, the Danish electricity market is studied as a part of Nord Pool. Considering the completely...... fossil fuel free overview in Danish energy policies, and the currently great share of wind power (more than 100% for some hours) in supplying the load, it is an interesting benchmark for the future electricity markets. Negative prices, price spikes, and price volatility are considered as the main effects...

  15. Impact of location on outcome after penetrating colon injuries.

    Science.gov (United States)

    Sharpe, John P; Magnotti, Louis J; Weinberg, Jordan A; Zarzaur, Ben L; Shahan, Charles P; Parks, Nancy A; Fabian, Timothy C; Croce, Martin A

    2012-12-01

    Most studies examining suture line failure after penetrating colon injuries have focused on right- versus left-sided injuries. In our institution, operative decisions (resection plus anastomosis vs. diversion) are based on a defined management algorithm regardless of injury location. The purpose of this study was to evaluate the effect of injury location on outcomes after penetrating colon injuries. Consecutive patients with full thickness penetrating colon injuries for 13 years were stratified by age, injury location and mechanism, and severity of shock. According to the algorithm, patients with nondestructive injuries underwent primary repair. Destructive wounds underwent resection plus anastomosis in the absence of comorbidities or large preoperative or intraoperative transfusion requirements (>6 U of packed red blood cells); otherwise, they were diverted. Injury location was defined as ascending, transverse, descending (including splenic flexure), and sigmoid. Multivariable logistic regression was performed to determine whether injury location was an independent predictor of either morbidity or mortality. Four hundred sixty-nine patients were identified: 314 (67%) underwent primary repair and 155 (33%) underwent resection. Most injuries involved the transverse colon (39%), followed by the ascending colon (26%), the descending colon (21%), and the sigmoid colon (14%). Overall, there were 13 suture line failures (3%) and 72 abscesses (15%). Most suture line failures involved injuries to the descending colon (p = 0.06), whereas most abscesses followed injuries to the ascending colon (p = 0.37). Multivariable logistic regression failed to identify injury location as an independent predictor of either morbidity or mortality after adjusting for 24-hour transfusions, base excess, shock index, injury mechanism, and operative management. Injury location did not affect morbidity or mortality after penetrating colon injuries. Nondestructive injuries should be primarily

  16. Numerical analysis of impact-penetration problems for nuclear reactor safety

    International Nuclear Information System (INIS)

    Dubois, J.J.; Chedmail, J.F.; Bianchini, J.C.

    1977-01-01

    This paper discusses the finite element and finite difference analysis of two impact penetration problems, namely a fuel cask drop on a foundation slab and a missile penetration into a reinforced concrete structure. For a realistic detailed analysis, advanced techniques were required in the following areas: reinforced concrete simulation; remeshing algorithms for penetration induced distortions; boundary condition. The fuel cask drop on a concrete slab generates complex elasto plastic waves which propagate towards the pool where tensile cracks might appear. The problem is analysed in two steps: calculation of the energy absorbed locally around the impacted area; calculation of the three dimensional wave propagation towards the pool. For the analysis of missile penetration problems, two examples are shown: a 3000 kg missile with a velocity of 132 m/s penetrates a 1.2 m thick concrete wall (PAM-GDYNS) and a 3600 kg missile with a velocity of 90 m/s (F.D. Program HEMP-ESI) penetrates a wall at a floor level. For the second case, the computed impact-penetration mechanism is

  17. Simulation of depth of penetration during ballistic impact on thick ...

    Indian Academy of Sciences (India)

    One-dimensional discrete element model for the ballistic impact is used ... Simulation of ballistic impact process has been done using several ..... MATLAB 7.0 platform is used to simulate impact process using 1-D DEM and to perform the.

  18. Environmental impacts of high penetration renewable energy scenarios for Europe

    Science.gov (United States)

    Berrill, Peter; Arvesen, Anders; Scholz, Yvonne; Gils, Hans Christian; Hertwich, Edgar G.

    2016-01-01

    The prospect of irreversible environmental alterations and an increasingly volatile climate pressurises societies to reduce greenhouse gas emissions, thereby mitigating climate change impacts. As global electricity demand continues to grow, particularly if considering a future with increased electrification of heat and transport sectors, the imperative to decarbonise our electricity supply becomes more urgent. This letter implements outputs of a detailed power system optimisation model into a prospective life cycle analysis framework in order to present a life cycle analysis of 44 electricity scenarios for Europe in 2050, including analyses of systems based largely on low-carbon fossil energy options (natural gas, and coal with carbon capture and storage (CCS)) as well as systems with high shares of variable renewable energy (VRE) (wind and solar). VRE curtailments and impacts caused by extra energy storage and transmission capabilities necessary in systems based on VRE are taken into account. The results show that systems based largely on VRE perform much better regarding climate change and other impact categories than the investigated systems based on fossil fuels. The climate change impacts from Europe for the year 2050 in a scenario using primarily natural gas are 1400 Tg CO2-eq while in a scenario using mostly coal with CCS the impacts are 480 Tg CO2-eq. Systems based on renewables with an even mix of wind and solar capacity generate impacts of 120-140 Tg CO2-eq. Impacts arising as a result of wind and solar variability do not significantly compromise the climate benefits of utilising these energy resources. VRE systems require more infrastructure leading to much larger mineral resource depletion impacts than fossil fuel systems, and greater land occupation impacts than systems based on natural gas. Emissions and resource requirements from wind power are smaller than from solar power.

  19. Environmental impacts of high penetration renewable energy scenarios for Europe

    International Nuclear Information System (INIS)

    Berrill, Peter; Arvesen, Anders; Hertwich, Edgar G; Scholz, Yvonne; Gils, Hans Christian

    2016-01-01

    The prospect of irreversible environmental alterations and an increasingly volatile climate pressurises societies to reduce greenhouse gas emissions, thereby mitigating climate change impacts. As global electricity demand continues to grow, particularly if considering a future with increased electrification of heat and transport sectors, the imperative to decarbonise our electricity supply becomes more urgent. This letter implements outputs of a detailed power system optimisation model into a prospective life cycle analysis framework in order to present a life cycle analysis of 44 electricity scenarios for Europe in 2050, including analyses of systems based largely on low-carbon fossil energy options (natural gas, and coal with carbon capture and storage (CCS)) as well as systems with high shares of variable renewable energy (VRE) (wind and solar). VRE curtailments and impacts caused by extra energy storage and transmission capabilities necessary in systems based on VRE are taken into account. The results show that systems based largely on VRE perform much better regarding climate change and other impact categories than the investigated systems based on fossil fuels. The climate change impacts from Europe for the year 2050 in a scenario using primarily natural gas are 1400 Tg CO 2 -eq while in a scenario using mostly coal with CCS the impacts are 480 Tg CO 2 -eq. Systems based on renewables with an even mix of wind and solar capacity generate impacts of 120–140 Tg CO 2 -eq. Impacts arising as a result of wind and solar variability do not significantly compromise the climate benefits of utilising these energy resources. VRE systems require more infrastructure leading to much larger mineral resource depletion impacts than fossil fuel systems, and greater land occupation impacts than systems based on natural gas. Emissions and resource requirements from wind power are smaller than from solar power. (letter)

  20. Impact of reconfiguration period and photovoltaic penetration on distribution grid reconfiguration

    DEFF Research Database (Denmark)

    Chittur Ramaswamy, Parvathy; Deconinck, Geert; Pillai, Jayakrishnan Radhakrishna

    2014-01-01

    of reconfiguration and its impact on network losses in the context of time-varying load. Though reconfiguring a network reduces the losses, this paper calls for a comparison of number of switching vs. the loss reduction in order to decide the period of reconfiguration. This paper considers also the impact of varying...... photovoltaic (PV) penetration on the resulting optimal configuration. It validates the method of using a parameter namely minimum loss reduction parameter to avoid tedious computational efforts in finding the optimal configuration when an infinitesimal change in PV penetration occurs....

  1. Concentrated solar power plants impact on PV penetration level and grid flexibility under Egyptian climate

    Science.gov (United States)

    Moukhtar, Ibrahim; Elbaset, Adel A.; El Dein, Adel Z.; Qudaih, Yaser; Mitani, Yasunori

    2018-05-01

    Photovoltaic (PV) system integration in the electric grid has been increasing over the past decades. However, the impact of PV penetration on the electric grid, especially during the periods of higher and lower generation for the solar system at the middle of the day and during cloudy weather or at night respectively, limit the high penetration of solar PV system. In this research, a Concentrated Solar Power (CSP) with Thermal Energy Storage (TES) has been aggregated with PV system in order to accommodate the required electrical power during the higher and lower solar energy at all timescales. This paper analyzes the impacts of CSP on the grid-connected PV considering high penetration of PV system, particularly when no energy storages in the form of batteries are used. Two cases have been studied, the first when only PV system is integrated into the electric grid and the second when two types of solar energy (PV and CSP) are integrated. The System Advisor Model (SAM) software is used to simulate the output power of renewable energy. Simulation results show that the performance of CSP has a great impact on the penetration level of PV system and on the flexibility of the electric grid. The overall grid flexibility increases due to the ability of CSP to store and dispatch the generated power. In addition, CSP/TES itself has inherent flexibility. Therefore, CSP reduces the minimum generation constraint of the conventional generators that allows more penetration of the PV system.

  2. Do HMO penetration and hospital competition impact quality of hospital care?

    Science.gov (United States)

    Rivers, P A; Fottler, M D

    2004-11-01

    This study examines the impact of HMO penetration and competition on hospital markets. A modified structure-conduct-performance paradigm was applied to the health care industry in order to investigate the impact of HMO penetration and competition on risk-adjusted hospital mortality rates (i.e. quality of hospital care). Secondary data for 1957 acute care hospitals in the USA from the 1991 American Hospital Association's Annual Survey of Hospitals were used. The outcome variables were risk-adjusted mortality rates in 1991. Predictor variables were market characteristics (i.e. managed care penetration and hospital competition). Control variables were environmental, patient, and institutional characteristics. Associations between predictor and outcome variables were investigated using statistical regression techniques. Hospital competition had a negative relationship with risk-adjusted mortality rates (a negative indicator of quality of care). HMO penetration, hospital competition, and an interaction effect of HMO penetration and competition were not found to have significant effects on risk-adjusted mortality rates. These findings suggest that when faced with intense competition, hospitals may respond in ways associated with reducing their mortality rates.

  3. Sub-hourly impacts of high solar penetrations in the Western United States

    Energy Technology Data Exchange (ETDEWEB)

    Lew, Debra; Brinkman, Greg; Florita, Anthony; Heaney, Michael; Hodge, Bri-Mathias; Hummon, Marissa; Ibanez, Eduardo [National Renewable Energy Lab. (NREL), Golden, CO (United States); King, Jack [RePPAE, Wexford, PA (United States)

    2012-07-01

    Until recently, it has been difficult to study the impacts of significant penetrations of hypothetical, utility-scale solar photovoltaic (PV) plants over large geographic regions. This was because of the lack of credible data to simulate the output of these plants with appropriate spatial and temporal correlation, especially on a sub-hourly basis. In the Western Wind and Solar Integration Study Phase 2 (WWSIS2), we used new technigues to synthesize sub-hourly high-resolution solar output for PV rooftops, utility-scale PV, and concentrating solar power (CSP). This allowed us to examine implications of 25 % solar (60/40 split of PV and CSP) and 8 % wind. In this paper, we present results of analysis on the sub-hourly impacts of high solar penetrations. Extreme event analysis showed that most of the large ramps were because of sunrise and sunset events, which have a significant predictability component. Variability in general was much higher with high penetrations of solar than with high penetrations of wind. Reserve methodologies that had already been developed for wind were therefore modified to take into account the predictability component of solar variability. Significantly less transmission was required for high solar penetrations than wind and significantly less curtailment occurred in the high solar cases. (orig.)

  4. PENETRATION OF CONICAL INDENTER INTO FOUNDATION MATERIAL AT COMBINED PERCUSSION AND SUBSEQUENT ULTRASONIC IMPACTS

    Directory of Open Access Journals (Sweden)

    M. G. Kiselev

    2012-01-01

    Full Text Available The aim of this paper is theoretical and experimental studys of a percussion and subsequent ultrasonic impacts on the indenter depth penetration into material of rigid-plastic foundation.The obtained results allow us to estimate an influence of percussion (low-frequency and ultrasound (high-frequency component parameters on a charging process.

  5. Exploratory investigations of hypervelocity intact capture spectroscopy

    Science.gov (United States)

    Tsou, P.; Griffiths, D. J.

    1993-01-01

    The ability to capture hypervelocity projectiles intact opens a new technique available for hypervelocity research. A determination of the reactions taking place between the projectile and the capture medium during the process of intact capture is extremely important to an understanding of the intact capture phenomenon, to improving the capture technique, and to developing a theory describing the phenomenon. The intact capture of hypervelocity projectiles by underdense media generates spectra, characteristic of the material species of projectile and capture medium involved. Initial exploratory results into real-time characterization of hypervelocity intact capture techniques by spectroscopy include ultra-violet and visible spectra obtained by use of reflecting gratings, transmitting gratings, and prisms, and recorded by photographic and electronic means. Spectrometry proved to be a valuable real-time diagnostic tool for hypervelocity intact capture events, offering understanding of the interactions of the projectile and the capture medium during the initial period and providing information not obtainable by other characterizations. Preliminary results and analyses of spectra produced by the intact capture of hypervelocity aluminum spheres in polyethylene (PE), polystyrene (PS), and polyurethane (PU) foams are presented. Included are tentative emission species identifications, as well as gray body temperatures produced in the intact capture process.

  6. Hybrid Guidance Control for a Hypervelocity Small Size Asteroid Interceptor Vehicle

    Science.gov (United States)

    Zebenay, Melak M.; Lyzhoft, Joshua R.; Barbee, Brent W.

    2017-01-01

    Near-Earth Objects (NEOs) are comets and/or asteroids that have orbits in proximity with Earth's own orbit. NEOs have collided with the Earth in the past, which can be seen at such places as Chicxulub crater, Barringer crater, and Manson crater, and will continue in the future with potentially significant and devastating results. Fortunately such NEO collisions with Earth are infrequent, but can happen at any time. Therefore it is necessary to develop and validate techniques as well as technologies necessary to prevent them. One approach to mitigate future NEO impacts is the concept of high-speed interceptor. This concept is to alter the NEO's trajectory via momentum exchange by using kinetic impactors as well as nuclear penetration devices. The interceptor has to hit a target NEO at relative velocity which imparts a sufficient change in NEO velocity. NASA's Deep Impact mission has demonstrated this scenario by intercepting Comet Temple 1, 5 km in diameter, with an impact relative speed of approximately 10 km/s. This paper focuses on the development of hybrid guidance navigation and control (GNC) algorithms for precision hypervelocity intercept of small sized NEOs. The spacecraft's hypervelocity and the NEO's small size are critical challenges for a successful mission as the NEO will not fill the field of view until a few seconds before intercept. The investigation needs to consider the error sources modeled in the navigation simulation such as spacecraft initial state uncertainties in position and velocity. Furthermore, the paper presents three selected spacecraft guidance algorithms for asteroid intercept and rendezvous missions. The selected algorithms are classical Proportional Navigation (PN) based guidance that use a first order difference to compute the derivatives, Three Plane Proportional Navigation (TPPN), and the Kinematic Impulse (KI). A manipulated Bennu orbit that has been changed to impact Earth will be used as a demonstrative example to compare the

  7. Simple light gas guns for hypervelocity studies

    International Nuclear Information System (INIS)

    Combs, S.K.; Haselton, H.H.; Milora, S.L.

    1990-01-01

    Two-stage light guns are used extensively in hypervelocity research. The applications of this technology include impact studies and special materials development. Oak Ridge National Laboratory (ORNL) has developed two-stage guns that accelerate small projectiles (4-mm nominal diameter) to velocities of up to ∼5 km/s. These guns are relatively small and simple (thus, easy to operate), allowing a significant number of test shots to be carried out and data accumulated in a short time. Materials that have been used for projectiles include plastics, frozen isotopes of hydrogen, and lithium hydride. One gun has been used to demonstrate repetitive operation at a rate of 0.7 Hz; and, with a few design improvements, it appears capable of performing at firing frequencies of 1--2 Hz. A schematic of ORNL two-stage device is shown below. Unlike most such devices, no rupture disks are used. Instead, a fast valve (high-flow type) initiates the acceleration process in the first stage. Projectiles can be loaded into the gun breech via the slide mechanism; this action has been automated which allows repetitive firing. Alternatively, the device is equipped with ''pipe gun'' apparatus in which gas can be frozen in situ in the gun barrel to form the projectile. This equipment operates with high reliability and is well suited for small-scale testing at high velocity. 17 refs., 6 figs., 2 tabs

  8. Impact of HMO penetration and other environmental factors on hospital X-inefficiency.

    Science.gov (United States)

    Rosko, M D

    2001-12-01

    This study examined the impact of health maintenance organization (HMO) market penetration and other internal and external environmental factors on hospital X-inefficiency in a national sample (N = 1,966) of urban U.S. hospitals in 1997. Stochastic frontier analysis, a frontier regression technique, was used to measure X-inefficiency and estimate parameters of the correlates of X-inefficiency. Log-likelihood restriction tests were used to test a variety of assumptions about the empirical model that guided its selection. Average estimated X-inefficiency in study hospitals was 12.96 percent. Increases in managed care penetration, dependence on Medicare and Medicaid, membership in a multihospital system, and location in areas where competitive pressures and the pool of uncompensated care are greater were associated with less X-inefficiency. Not-for-profit ownership was associated with increased X-inefficiency.

  9. Methods for Analysis and Simulation of Ballistic Impact

    Science.gov (United States)

    2017-04-01

    carbide. All experiments were conducted in reverse mode [7], with long- rod hypervelocity impact and penetration into confined cylindrical ceramic...comprehensive treatment that encompasses curvilinear coordinates, see [17], with general kinematics addressed in more detail in [49]. Governing equations of...deformation and mechanically reversible changes in damage (e.g., elastic crack closure on load release), J accounts for plastic slip from dislocations

  10. Consideration of some fundamental erosion processes encountered in hypervelocity electromagnetic propulsion

    International Nuclear Information System (INIS)

    Buckingham, A.C.; Hawke, R.S.

    1982-01-01

    Experimental and theoretical research has been conducted jointly at the Livermore and Los Alamos National laboratories on dc electromagnetic railgun Lorentz accelerators. Pellets weighing a few grams to tens of grams have been launched at velocities up to better than 11 km/s. The research is addressed to attaining repeated launches of samples at hypervelocity in target impact experiments. In these experiments, shock-induced pressures in the tens of megabars range are obtained for high pressure equation-of-state research. Primary energy sources of the order of several hundred kJ to a MJ and induction currents of the order of 1 or more MA are necessary for these launches. Erosion and deformation of the conductor rails and the accelerated sample material are continuing problems. The heating, stress, and erosion resulting from simultaneous imposition of rail induction current, dense plasma (armature) interaction, current distribution, magnetic field stresses and projectile/rail contact friction are examined. It is found that while frictional heating and consequent sliding contact erosion are minor contributors to the overall erosion process, the same cannot be said for plasma impingement, penetration, and almost simultaneous induction current (Joule) heating

  11. Management and outcome of low velocity penetrating head injury caused by impacted foreign bodies.

    Science.gov (United States)

    Moussa, Wael Mohamed Mohamed; Abbas, Mohamed

    2016-05-01

    Penetrating head injuries with impacted foreign bodies are rare, associated with a high incidence of morbidity and potentially life-threatening. In this study, we aimed at investigating the outcome of these cases as well as analyzing the factors affecting the prognosis. A retrospective study in which the records of 16 patients who had penetrating head injuries caused by low-velocity impacted foreign bodies were revised. All patients were males with a mean age of 28.9 years (range, 18 to 50 years). The follow-up period ranged from 4 to 13 months with a mean of 8.1 months. Causes of injury were construction accidents in 6 (37.5 %) patients, assault in 6 (37.5 %) and road traffic accidents in 4 (25 %). The impacted objects included a bar of iron, a piece of wood, a nail, a sickle and a piece of glass. Diagnostic computerized tomography (CT) of the brain was carried out on admission in all patients. Thirteen (81.3 %) patients were submitted to surgery, and all had the appropriate management in the form of antibiotics and dehydrating measures as required. The primary outcome measure was the Glasgow Outcome Scale (GOS) at the end of follow-up. At the end of follow-up, ten (62.5 %) patients had a GOS score of 5, two (12.5 %) patients had a score of 4, and four (25 %) patients had a score of 1. Low-velocity penetrating head injuries are most common in young adult males. With the appropriate management, a majority of even the most severe cases can have a favorable outcome.

  12. The impact of high penetration of wind energy on the vulnerability of power systems

    Energy Technology Data Exchange (ETDEWEB)

    EL-Arroudi, K.; Joos, G.; McGillis, D. [McGill Univ., Montreal, PQ (Canada). Dept. of Electrical and Computer Engineering

    2006-07-01

    This paper examined the impact of higher penetrations of wind energy installations on the vulnerability of power systems. Vulnerability was defined in terms of migration of system states based on the contingencies that might occur. It was noted that both the penetration levels and physical locations of wind energy installations in power systems have a strong influence on system vulnerability. A methodology was proposed to analyze the impacts of wind energy on power system vulnerability through the construction of a decision-tree classification model at the point of common coupling (PCC) bus. The aim of the model was to determine planning criteria for wind power interconnection and to ensure that design concepts are adequate and secure. The model was built by simulating a pre-specified range of system contingencies to generate patterns at the PCC bus. Actual measurements were then compared against known patterns, from which the stress levels of disturbances were estimated. Stress levels were defined in terms of the performance level measures delineated by National Electricity Reliability Council (NERC) planning standards. The methodology is a non-parametric learning technique able to produce classifiers about given problems in order to deduce information from new, unobserved cases. A case study consisting of a 4-machine system with a total generation of 2295 MW was presented where wind-based generation accounted for 450 MW. The decision-tree classifier was constructed by simulating 120 events generated by combinations of contingencies; seasonal wind patterns and different wind production levels per season. Results showed that with a knowledge of the total penetration level and location of wind power installations, it is possible to estimate the effect of wind energy on the vulnerability of a power system. 12 refs., 6 figs.

  13. Hyvax: A hypervelocity railgun experiment

    International Nuclear Information System (INIS)

    Parker, J.V.; Cummings, C.E.; Parsons, W.M.; Peterson, D.R.

    1983-01-01

    The experiment is designed to utilize an existing 1.89 MJ, 20 kV capacitor bark which is configured as 7 independent modules which each store 270 kJ. Projectile size is a compromise between low mass and the desire to maintain a bore diameter which is characteristic of future hypervelocity railguns. The predicted performance for this design, assuming a net driving force of 80 percent theoretical, is 23.9 km/sec with an overall efficiency of 18.4 percent. The average driving current is about 480 kA; rising from 380 kA in the first stage to 560 kA in the last stage. The projectile will be injected at 0.5 km/sec using a helium driven injector. The planned diagnostics for the railgun include voltage and current at each stage, muzzle voltage, and magnetic loop position probes at 20 locations along the barrel. Altogether 38 channels of data will be recorded on a CAMAC-based transient digitizer system. Data will be read out by a dedicated microprocessor and processed to obtain position velocity, acceleration and driving force as a function of time. In addition, a number of diagnostics will be mounted on the experimental chamber including; an x-ray shadowgraph system to look for projectile damage and to determine if the projectile is tumbling, foil switches for an independent velocity measurement, and a plasma density probe to evaluate the efficacy of various muzzle flash suppression schemes. At the present time the railgun barrel is being assembled and installed in the capacitor bank facility. We anticipate testing the first two stages in June and the full railgun in July. An experimental program of 30 shots is planned for the period July-September

  14. Ultrahigh-speed X-ray imaging of hypervelocity projectiles

    Science.gov (United States)

    Miller, Stuart; Singh, Bipin; Cool, Steven; Entine, Gerald; Campbell, Larry; Bishel, Ron; Rushing, Rick; Nagarkar, Vivek V.

    2011-08-01

    High-speed X-ray imaging is an extremely important modality for healthcare, industrial, military and research applications such as medical computed tomography, non-destructive testing, imaging in-flight projectiles, characterizing exploding ordnance, and analyzing ballistic impacts. We report on the development of a modular, ultrahigh-speed, high-resolution digital X-ray imaging system with large active imaging area and microsecond time resolution, capable of acquiring at a rate of up to 150,000 frames per second. The system is based on a high-resolution, high-efficiency, and fast-decay scintillator screen optically coupled to an ultra-fast image-intensified CCD camera designed for ballistic impact studies and hypervelocity projectile imaging. A specially designed multi-anode, high-fluence X-ray source with 50 ns pulse duration provides a sequence of blur-free images of hypervelocity projectiles traveling at speeds exceeding 8 km/s (18,000 miles/h). This paper will discuss the design, performance, and high frame rate imaging capability of the system.

  15. The impact of a large penetration of intermittent sources on the power system operation and planning

    Science.gov (United States)

    Ausin, Juan Carlos

    This research investigated the impact on the power system of a large penetration of intermittent renewable sources, mainly wind and photovoltaic generation. Currently, electrical utilities deal with wind and PV plants as if they were sources of negative demand, that is to say, they have no control over the power output produced. In this way, the grid absorbs all the power fluctuation as if it were coming from a common load. With the level of wind penetration growing so quickly, there is growing concern amongst the utilities and the grid operators, as they will have to deal with a much higher level of fluctuation. In the same way, the potential cost reduction of PV technologies suggests that a similar development may be expected for solar production in the mid term. The first part of the research was focused on the issues that affect utility planning and reinforcement decision making. Although DG is located mainly on the distribution network, a large penetration may alter the flows, not only on the distribution lines, but also on the transmission system and through the transmission - distribution interfaces. The optimal capacity and production costs for the UK transmission network have been calculated for several combinations of load profiles and typical wind/PV output scenarios. A full economic analysis is developed, showing the benefits and disadvantages that a large penetration of these distributed generators may have on transmission system operator reinforcement strategies. Closely related to planning factors are institutional, revelatory, and economic considerations, such as transmission pricing, which may hamper the integration of renewable energy technologies into the electric utility industry. The second part of the research related to the impact of intermittent renewable energy technologies on the second by second, minute by minute, and half-hour by half-hour operations of power systems. If a large integration of these new generators partially replaces the

  16. On the failure behaviour to striking bow penetration of impacted marine-steel structures

    Science.gov (United States)

    Prabowo, Aditya Rio; Muttaqie, Teguh; Sohn, Jung Min; Bae, Dong Myung; Setiyawan, Agus

    2018-04-01

    Demands for water transportation modes are continuously increasing as rapid economic and industrial growths in the recent decade. Ship as representative of the water transportation is generally needed to carry various products from one location to another. Besides as product carrier, ship also acts as public facility to transport human across islands for number of reasons, such as tourism and vehicle. Considering its importance, structural damage due to accidental loads or so-called impact can cause unacceptable casualties which threat ship passenger, shipping industry and maritime environment in same time. The most frequent impact phenomena occur in forms of collision and grounding, which are targeting side structure and double bottom consecutively. However, since responses of the impacts on structure are highly nonlinear and vary due to development of ship structures, sustainable analysis as an update of pioneer calculation can be beneficial as rational reference for improving safety and navigational instruments. This work aims to assess failures of the side structures subjected to penetration of striking bow in ship-ship collision scenario. Locations of impact are idealized to happen on after-end, midsection and fore-end to provide complete assessment. Striking bow is to be deployed by varying input velocity to observe significance of the fractures on the side structure. This configuration is implemented on the designed collision scenario, and later calculated using nonlinear finite element method (NLFEM). Summary of the solution indicated that the midsection produced the highest resistance against side collision. Breaching of the inner shell was successfully avoided on the fore-end, but the critical damage to the cargo was observed during bow penetration to the after-end region. This location was recommended to be added by longitudinal framing to increase its resistance against ship collision.

  17. On the failure behaviour to striking bow penetration of impacted marine-steel structures

    Directory of Open Access Journals (Sweden)

    Prabowo Aditya Rio

    2018-04-01

    Full Text Available Demands for water transportation modes are continuously increasing as rapid economic and industrial growths in the recent decade. Ship as representative of the water transportation is generally needed to carry various products from one location to another. Besides as product carrier, ship also acts as public facility to transport human across islands for number of reasons, such as tourism and vehicle. Considering its importance, structural damage due to accidental loads or so-called impact can cause unacceptable casualties which threat ship passenger, shipping industry and maritime environment in same time. The most frequent impact phenomena occur in forms of collision and grounding, which are targeting side structure and double bottom consecutively. However, since responses of the impacts on structure are highly nonlinear and vary due to development of ship structures, sustainable analysis as an update of pioneer calculation can be beneficial as rational reference for improving safety and navigational instruments. This work aims to assess failures of the side structures subjected to penetration of striking bow in ship-ship collision scenario. Locations of impact are idealized to happen on after-end, midsection and fore-end to provide complete assessment. Striking bow is to be deployed by varying input velocity to observe significance of the fractures on the side structure. This configuration is implemented on the designed collision scenario, and later calculated using nonlinear finite element method (NLFEM. Summary of the solution indicated that the midsection produced the highest resistance against side collision. Breaching of the inner shell was successfully avoided on the fore-end, but the critical damage to the cargo was observed during bow penetration to the after-end region. This location was recommended to be added by longitudinal framing to increase its resistance against ship collision.

  18. Effect of internal short fibers, steel reinforcement, and surface layer on impact and penetration resistance of concrete

    Directory of Open Access Journals (Sweden)

    Ali Abd_Elhakam Aliabdo

    2013-09-01

    Full Text Available This paper presents an experimental program to investigate the impact and penetration resistance of concrete. The research work is divided into two approaches. These approaches are effect of concrete constituents and effect of surface layer. Effect of concrete aggregate type, w/c ratio, fiber type, fiber shape, fiber volume fraction, and steel reinforcement is considered in the first approach. The second approach includes using fiber reinforced concrete and glass fiber reinforced polymer as surface layers. The evaluating tests include standard impact test according to ASTM D 1557 and suggested simulated penetration test to measure the impact and penetration resistance of concrete. The test results of plain and fibrous concrete from ASTM D 1557 method indicated that steel fiber with different configurations and using basalt have a great positive effect on impact resistance of concrete. Moreover, the simulated penetration test indicates that steel fibers are more effective than propylene fibers, type of coarse aggregate has negligible effect, and steel fiber volume fraction has a more significant influence than fiber shape for reinforced concrete test panels. Finally, as expectable, surface properties of tested concrete panels have a significant effect on impact and penetration resistance.

  19. Penetration level and impact of ITS applications: economic analysis of ITS deployment plans and the role of governments

    NARCIS (Netherlands)

    Bie, Jing; Vreeswijk, Jacob Dirk; van Berkum, Eric C.

    2012-01-01

    The impact of Intelligent Transportation System (ITS) applications, especially cooperative driver assistance systems, depends greatly on the percentage of users equipped (i.e. the penetration rate). The application may have little impact if only a few drivers are using the application. A higher

  20. Generation of sub-gigabar-pressure shocks by a hyper-velocity impact in the collider driven by laser-induced cavity pressure

    Science.gov (United States)

    Badziak, J.; Kucharik, M.; Liska, R.

    2018-02-01

    The generation of high-pressure shocks in the newly proposed collider in which the projectile impacting a solid target is driven by the laser-induced cavity pressure acceleration (LICPA) mechanism is investigated using two-dimensional hydrodynamic simulations. The dependence of parameters of the shock generated in the target by the impact of a gold projectile on the impacted target material and the laser driver energy is examined. It is found that both in case of low-density (CH, Al) and high-density (Au, Cu) solid targets the shock pressures in the sub-Gbar range can be produced in the LICPA-driven collider with the laser energy of only a few hundreds of joules, and the laser-to-shock energy conversion efficiency can reach values of 10 - 20 %, by an order of magnitude higher than the conversion efficiencies achieved with other laser-based methods used so far.

  1. The collision of a hypervelocity massive projectile with free-standing graphene: Investigation of secondary ion emission and projectile fragmentation

    Science.gov (United States)

    Geng, Sheng; Verkhoturov, Stanislav V.; Eller, Michael J.; Della-Negra, Serge; Schweikert, Emile A.

    2017-02-01

    We present here the study of the individual hypervelocity massive projectiles (440-540 keV, 33-36 km/s Au4004+ cluster) impact on 1-layer free-standing graphene. The secondary ions were detected and recorded separately from each individual impact in the transmission direction using a time-of-flight mass spectrometer. We observed C1-10± ions emitted from graphene, the projectiles which penetrated the graphene, and the Au1-3± fragment ions in mass spectra. During the projectile-graphene interaction, the projectile loses ˜15% of its initial kinetic energy (˜0.18 keV/atom, 72 keV/projectile). The Au projectiles are neutralized when approaching the graphene and then partially ionized again via electron tunneling from the hot rims of the holes on graphene, obtaining positive and negative charges. The projectile reaches an internal energy of ˜450-500 eV (˜4400-4900 K) after the impact and then undergoes a ˜90-100 step fragmentation with the ejection of Au1 atoms in the experimental time range of ˜0.1 μs.

  2. A Progressive Damage Model for unidirectional Fibre Reinforced Composites with Application to Impact and Penetration Simulation

    Science.gov (United States)

    Kerschbaum, M.; Hopmann, C.

    2016-06-01

    The computationally efficient simulation of the progressive damage behaviour of continuous fibre reinforced plastics is still a challenging task with currently available computer aided engineering methods. This paper presents an original approach for an energy based continuum damage model which accounts for stress-/strain nonlinearities, transverse and shear stress interaction phenomena, quasi-plastic shear strain components, strain rate effects, regularised damage evolution and consideration of load reversal effects. The physically based modelling approach enables experimental determination of all parameters on ply level to avoid expensive inverse analysis procedures. The modelling strategy, implementation and verification of this model using commercially available explicit finite element software are detailed. The model is then applied to simulate the impact and penetration of carbon fibre reinforced cross-ply specimens with variation of the impact speed. The simulation results show that the presented approach enables a good representation of the force-/displacement curves and especially well agreement with the experimentally observed fracture patterns. In addition, the mesh dependency of the results were assessed for one impact case showing only very little change of the simulation results which emphasises the general applicability of the presented method.

  3. Analysis of the market penetration of clean coal technologies and its impacts in China's electricity sector

    International Nuclear Information System (INIS)

    Wang, Hao; Nakata, Toshihiko

    2009-01-01

    This paper discusses policy instruments for promoting the market penetration of clean coal technologies (CCTs) into China's electricity sector and the evaluation of corresponding effects. Based on the reality that coal will remain the predominant fuel to generate electricity and conventional pulverized coal boiler power plants have serious impacts on environment degradation, development of clean coal technologies could be one alternative to meet China's fast growing demand of electricity as well as protect the already fragile environment. A multi-period market equilibrium model is applied and an electricity model of China is established to forecast changes in the electricity system up to 2030s. Three policy instruments: SO 2 emission charge, CO 2 emission charge and implementing subsidies are considered in this research. The results show that all instruments cause a significant shift in China's electricity structure, promote CCTs' competitiveness and lead China to gain great benefit in both resource saving and environment improvement. Since resource security and environment degradation are becoming primary concerns in China, policies that could help to gain generations' market share of advanced coal-based technologies such as CCTs' is suitable for the current situation of China's electricity sector. (author)

  4. DebriSat Hypervelocity Impact Test

    Science.gov (United States)

    2015-08-01

    public release; distribution unlimited.  Targets: Scaled Multishock Shield, DebrisLV, and DebriSat  500-600 g hollow aluminum and nylon projectile... insulation . DebriSat’s internal components were structurally similar to real flight hardware but were nonfunctional. AEDC-TR-15-S-2 6...structures with an AL 5052 honeycomb core and M55J carbon fiber face sheets. The basic system characteristics of the DebriSat are given in Table 1

  5. A Quantitative Analysis of the Impact of Wind Energy Penetration on Electricity Prices in Ireland

    OpenAIRE

    O'Flaherty, Micheál; Riordan, Niall; O'Neill, Noel; Ahern, Ciara

    2014-01-01

    The maturity of wind technology combined with availability of suitable sites means Ireland is on course to generate 40% of its electricity from the wind by 2020.This work sets out to quantify, to what degree, if any, increased wind penetration translates into reduced wholesale and retail prices for electricity. The consensus from the literature is that increasing wind penetration reduces wholesale electricity prices, but views vary as to what degree this translates into reduced retail prices ...

  6. Technical impacts of high penetration levels of wind power on power system stability

    OpenAIRE

    Flynn, Damian; Rather, Z.; Ardal, Atle; Darco, Salvatore; Hansen, Anca Daniela; Cutululis, Nicolaos Antonio; Sørensen, Poul Ejnar; Estanqueiro, Ana; Gomez, Emilio; Menemenlis, Nickie; Smith, Charlie; Wang, Ye

    2017-01-01

    With increasing penetrations of wind generation, based on power-electronic converters, power systems are transitioning away from well-understood synchronous generator-based systems, with growing implications for their stability. Issues of concern will vary with system size, wind penetration level, geographical distribution and turbine type, network topology, electricity market structure, unit commitment procedures, and other factors. However, variable-speed wind turbines, both onshore and con...

  7. Numerical investigation on anti-penetration behavior of ceramic/metal target under ballistic impact

    International Nuclear Information System (INIS)

    Mei, H; Wang, Y C; Liu, X; Cao, D F; Liu, L S

    2013-01-01

    In the paper, we used the LS-DYNA FE code to simulate the bullet penetration against the target plate with different ceramic-steel ratio of thickness. The main stages of the bullet penetration and damage contours of the target were studied by analyzing the residual velocity-time curves. We also studied energy absorption of the ceramic/metal target. Considering curves of residual velocity-time, we reckon the process of penetration contains four stages. Ceramic performed good resistance before the formation of damage cone of ceramic. But after the damage cone formed, the anti-penetration behavior kept declining. When the bullet started to penetrate the layer of metal, the anti-penetration behavior of target rose slightly. Compared with thickness ratio of 0.4 and 0.6, ceramic with 0.2 absorbed more energy and works longer. Of several different thicknesses, layers of ceramic and steel were studied. Steel per cm absorbed more energy than ceramic per cm.

  8. Wound Ballistics Modeling for Blast Loading Blunt Force Impact and Projectile Penetration.

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Paul A. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-11-01

    Light body armor development for the warfighter is based on trial-and-error testing of prototype designs against ballistic projectiles. Torso armor testing against blast is nonexistent but necessary to protect the heart and lungs. In tests against ballistic projectiles, protective apparel is placed over ballistic clay and the projectiles are fired into the armor/clay target. The clay represents the human torso and its behind-armor, permanent deflection is the principal metric used to assess armor protection. Although this approach provides relative merit assessment of protection, it does not examine the behind-armor blunt trauma to crucial torso organs. We propose a modeling and simulation (M&S) capability for wound injury scenarios to the head, neck, and torso of the warfighter. We will use this toolset to investigate the consequences of, and mitigation against, blast exposure, blunt force impact, and ballistic projectile penetration leading to damage of critical organs comprising the central nervous, cardiovascular, and respiratory systems. We will leverage Sandia codes and our M&S expertise on traumatic brain injury to develop virtual anatomical models of the head, neck, and torso and the simulation methodology to capture the physics of wound mechanics. Specifically, we will investigate virtual wound injuries to the head, neck, and torso without and with protective armor to demonstrate the advantages of performing injury simulations for the development of body armor. The proposed toolset constitutes a significant advance over current methods by providing a virtual simulation capability to investigate wound injury and optimize armor design without the need for extensive field testing.

  9. Opportunities for the Reduction of Substances and Equipment Impact on Personnel in Penetrant and Magnetic Particles Testing

    OpenAIRE

    Yaremenko, Yuriy

    2015-01-01

    Penetrant testing (PT) and magnetic particles inspection (MPI) are widespread methods of non-destructive testing which are not required a lot of investments for manual application and are simple in terms of discontinuous interpretation. On the other hand, work with chemicals requires special precautions, safety instructions and disposal limitations. Growing demand among customers to decrease impact of consumables and equipment on personnel and environment, shift producers’ priorities to devel...

  10. Impact of small-scale storage systems on the photovoltaic penetration potential at the municipal scale

    Science.gov (United States)

    Ramirez Camargo, Luis; Dorner, Wolfgang

    2016-04-01

    The yearly cumulated technical energy generation potential of grid-connected roof-top photovoltaic power plants is significantly larger than the demand of domestic buildings in sparsely populated municipalities in central Europe. However, an energy balance with cumulated annual values does not deliver the right picture about the actual potential for photovoltaics since these run on a highly variable energy source as solar radiation. The mismatch between the periods of generation and demand creates hard limitations for the deployment of the theoretical energy generation potential of roof-top photovoltaics. The actual penetration of roof-top photovoltaic is restricted by the energy quality requirements of the grid and/or the available storage capacity for the electricity production beyond the coverage of own demands. In this study we evaluate in how far small-scale storage systems can contribute to increment the grid-connected roof-top photovoltaic penetration in domestic buildings at a municipal scale. To accomplish this, we calculate, in a first step, the total technical roof-top photovoltaic energy generation potential of a municipality in a high spatiotemporal resolution using a procedure that relies on geographic information systems. Posteriorly, we constrain the set of potential photovoltaic plants to the ones that would be necessary to cover the total yearly demand of the municipality. We assume that photovoltaic plants with the highest yearly yield are the ones that should be installed. For this sub-set of photovoltaic plants we consider five scenarios: 1) no storage 2) one 7 kWh battery is installed in every building with a roof-top photovoltaic plant 3) one 10 kWh battery is installed in every building with a roof-top photovoltaic plant 4) one 7 kWh battery is installed in every domestic building in the municipality 5) one 10 kWh battery is installed in every domestic building in the municipality. Afterwards we evaluate the energy balance of the

  11. Hypervelocity Dust Injection for Plasma Diagnostic Applications

    Science.gov (United States)

    Ticos, Catalin

    2005-10-01

    Hypervelocity micron-size dust grain injection was proposed for high-temperature magnetized plasma diagnosis. Multiple dust grains are launched simultaneously into high temperature plasmas at several km/s or more. The hypervelocity dust grains are ablated by the electron and ion fluxes. Fast imaging of the resulting luminous plumes attached to each grain is expected to yield local magnetic field vectors. Combination of multiple local magnetic field vectors reproduces 2D or even 3D maps of the internal magnetic field topology. Key features of HDI are: (1) a high spatial resolution, due to a relatively small transverse size of the elongated tail, and (2) a small perturbation level, as the dust grains introduce negligible number of particles compared to the plasma particle inventory. The latter advantage, however, could be seriously compromised if the gas load from the accelerator has an unobstructed access to the diagnosed plasma. Construction of a HDI diagnostic for National Spherical Torus Experiment (NSTX), which includes a coaxial plasma gun for dust grain acceleration, is underway. Hydrogen and deuterium gas discharges inside accelerator are created by a ˜ 1 mF capacitor bank pre-charged up to 10 kV. The diagnostic apparatus also comprises a dust dispenser for pre-loading the accelerator with dust grains, and an imaging system that has a high spatial and temporal resolution.

  12. The impact of HMO penetration on the rate of hospital cost inflation, 1985-1993.

    Science.gov (United States)

    Gaskin, D J; Hadley, J

    1997-01-01

    This paper provides evidence that growth in health maintenance organization (HMO) enrollment slows hospital cost inflation. During the period 1985-1993, hospitals in areas with high rates of HMO penetration and growth had a slower rate of growth in expenses (8.3%) than hospitals in low penetration areas (11.2%). From 1992-1993, HMO growth lowered the rate of hospital cost inflation by .34 to 3.40 percentage points, depending on the base-year level and the annual change in HMO penetration. Declines in Medicare Prospective Payment System (PPS) margins also lowered hospital cost inflation; over the time period, annual hospital cost inflation was reduced by .38 percentage points. The estimates imply that the cumulative effect of HMO growth on hospital costs has been a $56.2 billion reduction (in 1993 dollars).

  13. The impact of HMO penetration on the relationship between nurse staffing and quality.

    Science.gov (United States)

    Mark, Barbara A; Harless, David W; McCue, Michael

    2005-07-01

    While there are a number of studies examining the relationship between nurse staffing and quality, none has examined structural differences in the relationship between nurse staffing and quality contingent upon the level of managed care penetration. We used administrative data, and a dynamic panel data model to examine this relationship in a panel of 422 acute care hospitals from 1990 to 1995. We found that there were significant differences in the relationship between nurse staffing and both mortality and length of stay depending upon the level of HMO penetration in the hospital's market.

  14. The environment and its impact on gas penetration in the energy market east

    International Nuclear Information System (INIS)

    Mabro, R.E.; Stoppard, M.

    1995-01-01

    The thesis of this paper is that gas, although free from pollution problems is nevertheless more benign generally appreciated. The obstacles to gas penetration are flawed environmental legislation, political factors and,in some areas, a cost disadvantage relative to other fuels which turn out to be higher than the environmental premium which society is prepared to pay. (Author)

  15. Impact of carpet construction on fluid penetration: The case of blood.

    Science.gov (United States)

    Feng, Chengcheng; Michielsen, Stephen; Attinger, Daniel

    2018-03-01

    Bloodstains and bloodstain patterns are often observed at crime scenes and their analysis through bloodstain pattern analysis (BPA) can assist in reconstructing crime scenes. However, most published work related to BPA only deals with hard, non-porous surfaces and none of the studies have carefully characterized carpets. Soft and porous carpets are often encountered at crime scenes since they are common in American homes accounting for 51% of total U.S. flooring market; this has motivated the research described herein. To assess fluid penetration into tufted carpers, a new method for determining porosity and pore size distribution in tufted carpets has been developed for bloodstains on carpet. In this study, three kinds of nylon carpet were used: a low, a medium and a high face-weight carpet. Each carpet had an antistain treatment, which was removed from half of each carpet by steam-cleaning with a pH 12 NaOH solution. This resulted in six carpet samples. Yarn twist, carpet weight, pile height, water contact angles on carpets, water contact angles on individual fibers, and fiber cross-sectional shapes were characterized. Porosity and pore size distribution were analyzed using confocal laser scanning microscopy (CLSM). Porcine blood was used as a human blood substitute at three liquid volumes (30μL, 10μL, and 2μL). Analysis showed that porous carpet construction and antistain finishing both affected penetration. The depth of blood penetration decreased with the increase of carpet face-weight but increased with increased drop height. The removal of antistain treatment increased blood penetration into the carpets and changed the pore size distribution. Effects of antistain treatment, porosity and pore size distribution of tufted carpet, and blood wicking behaviors on carpets were found to strongly affect blood penetration into the carpets. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. Hypervelocity Expansion Facility for Fundamental High-Enthalpy Research

    Science.gov (United States)

    2017-02-27

    ii Final Technical Report of Contract ONR N00014-15-1-2260 Entitled: HYPERVELOCITY EXPANSION FACILITY FOR FUNDAMENTAL HIGH-ENTHALPY...previous DoD investments in high-energy pulsed laser diagnostics for instantaneous planar velocimetry and thermometry to perform scientific studies of...capability for fundamental and applied studies of hypervelocity high enthalpy flows. In this document, we report on the progress over the 18-month

  17. Technical impacts of high penetration levels of wind power on power system stability

    DEFF Research Database (Denmark)

    Flynn, Damian; Rather, Z.; Ardal, Atle

    2017-01-01

    With increasing penetrations of wind generation, based on power-electronic converters, power systems are transitioning away from well-understood synchronous generator-based systems, with growing implications for their stability. Issues of concern will vary with system size, wind penetration level......, geographical distribution and turbine type, network topology, electricity market structure, unit commitment procedures, and other factors. However, variable-speed wind turbines, both onshore and connected offshore through DC grids, offer many control opportunities to either replace or enhance existing...... capabilities. Achieving a complete understanding of future stability issues, and ensuring the effectiveness of new measures and policies, is an iterative procedure involving portfolio development and flexibility assessment, generation cost simulations, load flow, and security analysis, in addition...

  18. The impact of mechanism on the management and outcome of penetrating colonic trauma.

    Science.gov (United States)

    Oosthuizen, G V; Kong, V Y; Estherhuizen, T; Bruce, J L; Laing, G L; Odendaal, J J; Clarke, D L

    2018-02-01

    Introduction In light of continuing controversy surrounding the management of penetrating colonic injuries, we set out to compare the outcome of penetrating colonic trauma according to whether the mechanism of injury was a stab wound or a gunshot wound. Methods Our trauma registry was interrogated for the 5-year period from January 2012 to December 2016. All patients over the age of 18 years with penetrating trauma (stab or gunshot) and with intraoperatively proven colonic injury were reviewed. Details of the colonic and concurrent abdominal injuries were recorded, together with the operative management strategy. In-hospital morbidities were divided into colon-related and non-colon related morbidities. The length of hospital stay and mortality were recorded. Direct comparison was made between patients with stab wounds and gunshot wounds to the colon. Results During the 5-year study period, 257 patients sustained a colonic injury secondary to penetrating trauma; 95% (244/257) were male and the mean age was 30 years. A total of 113 (44%) sustained a gunshot wound and the remaining 56% (144/257) sustained a stab wound. Some 88% (226/257) of all patients sustained a single colonic injury, while 12% (31/257) sustained more than one colonic injury. A total of 294 colonic injuries were found at laparotomy. Multiple colonic injuries were less commonly encountered in stab wounds (6%, 9/144 vs. 19%, 22/113, P colonic stab wounds and colonic gunshot wounds are different in terms of severity of the injury and in terms of outcome. While primary repair is almost always applicable to the management of colonic stab wounds, the same cannot be said for colonic gunshot wounds. The management of colonic gunshot wounds should be examined separately from that of stab wounds.

  19. Impact of PHEVs Penetration on Ontario’s Electricity Grid and Environmental Considerations

    Directory of Open Access Journals (Sweden)

    Lena Ahmadi

    2012-11-01

    Full Text Available Plug-in hybrid electric vehicles (PHEVs have a large potential to reduce greenhouse gases emissions and increase fuel economy and fuel flexibility. PHEVs are propelled by the energy from both gasoline and electric power sources. Penetration of PHEVs into the automobile market affects the electrical grid through an increase in electricity demand. This paper studies effects of the wide spread adoption of PHEVs on peak and base load demands in Ontario, Canada. Long-term forecasting models of peak and base load demands and the number of light-duty vehicles sold were developed. To create proper forecasting models, both linear regression (LR and non-linear regression (NLR techniques were employed, considering different ranges in the demographic, climate and economic variables. The results from the LR and NLR models were compared and the most accurate one was selected. Furthermore, forecasting the effects of PHEVs penetration is done through consideration of various scenarios of penetration levels, such as mild, normal and aggressive ones. Finally, the additional electricity demand on the Ontario electricity grid from charging PHEVs is incorporated for electricity production planning purposes.

  20. High penetration wind generation impacts on spot prices in the Australian national electricity market

    International Nuclear Information System (INIS)

    Cutler, Nicholas J.; Boerema, Nicholas D.; MacGill, Iain F.; Outhred, Hugh R.

    2011-01-01

    This paper explores wind power integration issues for the South Australian (SA) region of the Australian National Electricity Market (NEM) by assessing the interaction of regional wind generation, electricity demand and spot prices over 2 recent years of market operation. SA's wind energy penetration has recently surpassed 20% and it has only a limited interconnection with other regions of the NEM. As such, it represents an interesting example of high wind penetration in a gross wholesale pool market electricity industry. Our findings suggest that while electricity demand continues to have the greatest influence on spot prices in SA, wind generation levels have become a significant secondary influence, and there is an inverse relationship between wind generation and price. No clear relationship between wind generation and demand has been identified although some periods of extremely high demand may coincide with lower wind generation. Periods of high wind output are associated with generally lower market prices, and also appear to contribute to extreme negative price events. The results highlight the importance of electricity market and renewable policy design in facilitating economically efficient high wind penetrations. - Highlights: → In South Australia (SA) wind generation is having an influence on market prices. → Little or no correlation is found between wind generation and demand. → Wind farms in SA are receiving a lower average price than in other States. → The results highlight the importance of appropriate electricity market design.

  1. Age-associated impact on presentation and outcome for penetrating thoracic trauma in the adult and pediatric patient populations.

    Science.gov (United States)

    Mollberg, Nathan M; Tabachnick, Deborah; Lin, Fang-Ju; Merlotti, Gary J; Varghese, Thomas K; Arensman, Robert M; Massad, Malek G

    2014-02-01

    Studies reporting on penetrating thoracic trauma in the pediatric population have been limited by small numbers and implied differences with the adult population. Our objectives were to report on a large cohort of pediatric patients presenting with penetrating thoracic trauma and to determine age-related impacts on management and outcome through comparison with an adult cohort. A Level I trauma center registry was queried between 2006 and 2012. All patients presenting with penetrating thoracic trauma were identified. Patient demographics, injury mechanism, injury severity, admission physiology, and outcome were recorded. Patients were compared, and outcomes were analyzed based on age at presentation, with patients 17 years or younger defining our pediatric cohort. A total of 1,423 patients with penetrating thoracic trauma were admitted during the study period. Two hundred twenty patients (15.5%) were pediatric, with 205 being adolescents (13-17 years) and 15 being children (≤ 12 years). In terms of management for the pediatric population, tube thoracostomy alone was needed in 32.7% (72 of 220), whereas operative thoracic exploration was performed in 20.0% (44 of 220). Overall mortality was 13.6% (30 of 220). There was no significant difference between the pediatric and adult population with regard to injury mechanism or severity, need for therapeutic intervention, operative approach, use of emergency department thoracotomy, or outcome. Stepwise logistic regression failed to identify age as a predictor for the need for either therapeutic intervention or mortality between the two age groups as a whole. However, subgroup analysis revealed that being 12 years or younger (odds ratio, 3.84; 95% confidence interval, 1.29-11.4) was an independent predictor of mortality. Management of traumatic penetrating thoracic injuries in terms of the need for therapeutic intervention and operative approach was similar between the adult and pediatric populations. Mortality from

  2. The Impact of Microwave Penetration Depth on the Process of Heating the Moulding Sand with Sodium Silicate

    Directory of Open Access Journals (Sweden)

    Nowak D.

    2017-12-01

    Full Text Available This paper presents the impact of microwave penetration depth on the process of heating the moulding sand with sodium silicate. For each material it is affected by: the wavelength in vacuum and the real and imaginary components of the relative complex electrical permittivity εr for a selected measurement frequency. Since the components are not constant values and they change depending on the electrical parameters of materials and the frequency of the electromagnetic wave, it is indispensable to carry out laboratory measurements to determine them. Moreover, the electrical parameters of materials are also affected by: temperature, packing degree, humidity and conductivity. The measurements of the dielectric properties of moulding sand with sodium silicate was carried out using the perturbation method on a stand of waveguide resonance cavity. The real and imaginary components of the relative complex electrical permittivity was determined for moulding sand at various contents of sodium silicate and at various packing degrees of the samples. On the basis of the results the microwave penetration depth of moulding sand with sodium silicate was established. Relative literature contains no such data that would be essential to predicting an effective process of microwave heating of moulding sand with sodium silicate. Both the packing degree and the amount of sodium silicate in moulding sand turned out to affect the penetration depth, which directly translates into microwave power density distribution in the process of microwave heating of moulding sand with sodium silicate.

  3. Assessing the impact of egg sweating on Salmonella Enteritidis penetration into shell eggs.

    Science.gov (United States)

    Gradl, Janet A; Curtis, Patricia A; Jones, Deana R; Anderson, Kenneth E

    2017-07-01

    Salmonella Enteritidis (SE) prevalence in eggs is a major concern to the egg industry. Some research has shown that egg sweating can increase Salmonella penetration into egg contents when refrigerated eggs are moved to a warmer temperature. This occurs when eggs are tempered before wash, to minimize thermal cracks. The effect of egg sweating on SE penetration into shell eggs over a 6 week storage period at 4°C was assessed. A 2 × 2 factorial of SE inoculation and egg sweating was utilized. Treatments included (SES) nalidixic acid (NA)-resistant SE inoculated and sweated, (SENS) NA-resistant SE inoculated and not sweated, (NSES) buffered peptone water (BPW) inoculated and sweated, and (NSENS) BPW inoculated and not sweated. Eggs were inoculated with 108 SE. Eggs formed condensation for approximately 17 min in a 32°C incubator. Shell rinse, shell emulsion, and egg contents were sampled then enumerated and assessed for prevalence of SE over a 6 wk storage period at 4°C. After wk 1, the SENS shell rinse had higher SE counts (0.32 log10 CFU/mL) than the other 3 treatments, where no SE was enumerated. A significant week by treatment interaction was found for the shell rinse SE detection (P egg shell rinse, shell emulsion, or egg contents. The SENS shell rinses had significantly higher SE prevalence than the SES rinses in weeks 1 (100% vs. 34.3%), 2 (57.6% vs. 22.2%), and 3 (38.2% vs. 11.1%) (P Egg sweating did not increase SE penetration into the shell emulsion across treatment or week (P egg sweating occurring under common US egg handling practices is not harmful to egg safety. © 2017 Poultry Science Association Inc.

  4. The impact of managed care penetration and hospital quality on efficiency in hospital staffing.

    Science.gov (United States)

    Mobley, Lee R; Magnussen, Jon

    2002-01-01

    The state of California has recently mandated minimum nurse-staffing ratios, raising concerns about possible affects on hospital efficiency. In this study, we examine how market factors and quality were related to staffing levels in California hospitals in 1995 (prior to implementation of the new law). We are particularly interested in the affect of managed care penetration on this aspect of hospital efficiency because the call to legislative action was predicated on fears that hospitals were reducing staffing below optimal levels in response to managed care pressures. We derive a unique measure of excess staffing in hospitals based on a data envelopment analysis (DEA) production function model, which explicitly includes ancillary care among the inputs and outputs. This careful specification of production is important because ancillary care use has risen relative to daily hospital services, with the spread of managed care and advances in medical technology. We find that market share (adjusted for size) and market concentration are the major determinants of excess staffing while managed care penetration is insignificant. We also find that poor quality (outcomes worse than expected) is associated with less efficient staffing. These findings suggest that the larger, more efficient urban hospitals will be penalized more heavily under binding staffing ratios than smaller, less-urban hospitals.

  5. Impacts of reserve methodology on production cost in high-penetration renewable scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Brinkman, G.; Lew, D.; Hummon, M.; Ibanez, E.; Ela, E.; Hodge, B.M. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2012-07-01

    Prior to wind and solar penetration, electric power systems were designed to handle variability in system load, uncertainty in load forecasts, and contingency events. Frequency regulations reserve typically handles high frequency (less than 5-minute time scale) variability. Contingency reserves supply energy in the case of the loss of a generator or transmission line. Wind and solar photovoltaic generation and variability to electric power system generation that must be balanced by the system operator. New ancillary service products may be necessary to minimize the cost of integrating these variable renewable generators. For example, California ISO is studying incorporating a flexible ramping product to ensure sufficient ramping capability. A flexibility reserve product could help ensure that sufficient capacity is online to handle unexpected variability in wind and solar generation. (orig.)

  6. Testing of a Plasmadynamic Hypervelocity Dust Accelerator

    Science.gov (United States)

    Ticos, Catalin M.; Wang, Zhehui; Dorf, Leonid A.; Wurden, G. A.

    2006-10-01

    A plasmadynamic accelerator for microparticles (or dust grains) has been designed, built and tested at Los Alamos National laboratory. The dust grains are expected to be accelerated to hypervelocities on the order of 1-30 km/s, depending on their size. The key components of the plasmadynamic accelerator are a coaxial plasma gun operated at 10 kV, a dust dispenser activated by a piezoelectric transducer, and power and remote-control systems. The coaxial plasma gun produces a high density (10^18 cm-3) and low temperature (˜ 1 eV) plasma in deuterium ejected by J x B forces, which provides drag on the dust particles in its path. Carbon dust particles will be used, with diameters from 1 to 50 μm. The plasma parameters produced in the coaxial gun are presented and their implication to dust acceleration is discussed. High speed dust will be injected in the National Spherical Torus Experiment to measure the pitch angle of magnetic field lines.

  7. A methodology for understanding the impacts of large-scale penetration of micro-combined heat and power

    International Nuclear Information System (INIS)

    Tapia-Ahumada, K.; Pérez-Arriaga, I.J.; Moniz, E.J.

    2013-01-01

    Co-generation at small kW-e scale has been stimulated in recent years by governments and energy regulators as one way to increasing energy efficiency and reducing CO 2 emissions. If a widespread adoption should be realized, their effects from a system's point of view are crucial to understand the contributions of this technology. Based on a methodology that uses long-term capacity planning expansion, this paper explores some of the implications for an electric power system of having a large number of micro-CHPs. Results show that fuel cells-based micro-CHPs have the best and most consistent performance for different residential demands from the customer and system's perspectives. As the penetration increases at important levels, gas-based technologies—particularly combined cycle units—are displaced in capacity and production, which impacts the operation of the electric system during summer peak hours. Other results suggest that the tariff design impacts the economic efficiency of the system and the operation of micro-CHPs under a price-based strategy. Finally, policies aimed at micro-CHPs should consider the suitability of the technology (in size and heat-to-power ratio) to meet individual demands, the operational complexities of a large penetration, and the adequacy of the economic signals to incentivize an efficient and sustainable operation. - Highlights: • Capacity displacements and daily operation of an electric power system are explored. • Benefits depend on energy mix, prices, and micro-CHP technology and control scheme. • Benefits are observed mostly in winter when micro-CHP heat and power are fully used. • Micro-CHPs mostly displace installed capacity from natural gas combined cycle units. • Tariff design impacts economic efficiency of the system and operation of micro-CHPs

  8. Impact Study of PMSG-Based Wind Power Penetration on Power System Transient Stability Using EEAC Theory

    Directory of Open Access Journals (Sweden)

    Zhongyi Liu

    2015-11-01

    Full Text Available Wind turbines with direct-driven permanent magnet synchronous generators (PMSGs are widely used in wind power generation. According to the dynamic characteristics of PMSGs, an impact analysis of PMSG-based wind power penetration on the transient stability of multi-machine power systems is carried out in this paper based on the theory of extended equal area criterion (EEAC. Considering the most severe PMSG integration situation, the changes in the system’s equivalent power-angle relationships after integrating PMSGs are studied in detail. The system’s equivalent mechanical input power and the fault period electrical output power curves are found to be mainly affected. The analysis demonstrates that the integration of PMSGs can cause either detrimental or beneficial effects on the system transient stability. It is determined by several factors, including the selection of the synchronous generators used to balance wind power, the reactive power control mode of PMSGs and the wind power penetration level. Two different simulation systems are also adopted to verify the analysis results.

  9. Impact of Wind Shear and Tower Shadow Effects on Power System with Large Scale Wind Power Penetration

    DEFF Research Database (Denmark)

    Hu, Weihao; Su, Chi; Chen, Zhe

    2011-01-01

    presents a simulation model of a variable speed wind farm with permanent magnet synchronous generators (PMSGs) and fullscale back-to-back converters in the simulation tool of DIgSILENT/PowerFactory. In this paper, the impacts of wind shear and tower shadow effects on the small signal stability of power......Grid connected wind turbines are fluctuating power sources due to wind speed variations, the wind shear and the tower shadow effects. The fluctuating power may be able to excite the power system oscillation at a frequency close to the natural oscillation frequency of a power system. This paper...... systems with large scale wind power penetrations are investigated during continuous operation based on the wind turbine model and the power system model....

  10. Impact of synthetic canine cerumen on in vitro penetration of auricular skin of dogs by florfenicol, terbinafine, and betamethasone acetate.

    Science.gov (United States)

    Ehling, Sarah; Baynes, Ronald E; Bäumer, Wolfgang

    2018-03-01

    OBJECTIVE To determine the pharmacokinetics of florfenicol, terbinafine, and betamethasone acetate after topical application to canine auricular skin and the influence of synthetic canine cerumen on pharmacokinetics. SAMPLE Auricular skin from 6 euthanized shelter dogs (3 females and 3 neutered males with no visible signs of otitis externa). PROCEDURES Skin adjacent to the external opening of the ear canal was collected and prepared for use in a 2-compartment flow-through diffusion cell system to evaluate penetration of an otic gel containing florfenicol, terbinafine, and betamethasone acetate over a 24-hour period. Radiolabeled 14 C-terbinafine hydrochloride and 3 H-betamethasone acetate were added to the gel to determine dermal penetration and distribution. Florfenicol absorption was determined by use of high-performance liquid chromatography-UV detection. Additionally, the effect of synthetic canine cerumen on the pharmacokinetics of all compounds was evaluated. RESULTS During the 24-hour experiment, mean ± SD percentage absorption without the presence of synthetic canine cerumen was 0.28 ± 0.09% for 3H-betamethasone acetate, 0.06 ± 0.06% for florfenicol, and 0.06 ± 0.02% for 14C-terbinafine hydrochloride. Absorption profiles revealed no impact of synthetic canine cerumen on skin absorption for all 3 active compounds in the gel or on skin distribution of 3 H-betamethasone acetate and 14 C-terbinafine hydrochloride. CONCLUSIONS AND CLINICAL RELEVANCE 3 H-betamethasone acetate, 14 C-terbinafine hydrochloride, and florfenicol were all absorbed in vitro through healthy auricular skin specimens within the first 24 hours after topical application. Synthetic canine cerumen had no impact on dermal absorption in vitro, but it may serve as a temporary reservoir that prolongs the release of topical drugs.

  11. Impact and Penetration of Thin Aluminum 2024 Flat Panels at Oblique Angles of Incidence

    Science.gov (United States)

    Ruggeri, Charles R.; Revilock, Duane M.; Pereira, J. Michael; Emmerling, William; Queitzsch, Gilbert K., Jr.

    2015-01-01

    The U.S. Federal Aviation Administration (FAA) and the National Aeronautics and Space Administration (NASA) are actively involved in improving the predictive capabilities of transient finite element computational methods for application to safety issues involving unintended impacts on aircraft and aircraft engine structures. One aspect of this work involves the development of an improved deformation and failure model for metallic materials, known as the Tabulated Johnson-Cook model, or MAT224, which has been implemented in the LS-DYNA commercial transient finite element analysis code (LSTC Corp., Livermore, CA) (Ref. 1). In this model the yield stress is a function of strain, strain rate and temperature and the plastic failure strain is a function of the state of stress, temperature and strain rate. The failure criterion is based on the accumulation of plastic strain in an element. The model also incorporates a regularization scheme to account for the dependency of plastic failure strain on mesh size. For a given material the model requires a significant amount of testing to determine the yield stress and failure strain as a function of the three-dimensional state of stress, strain rate and temperature. In addition, experiments are required to validate the model. Currently the model has been developed for Aluminum 2024 and validated against a series of ballistic impact tests on flat plates of various thicknesses (Refs. 1 to 3). Full development of the model for Titanium 6Al-4V is being completed, and mechanical testing for Inconel 718 has begun. The validation testing for the models involves ballistic impact tests using cylindrical projectiles impacting flat plates at a normal incidence (Ref. 2). By varying the thickness of the plates, different stress states and resulting failure modes are induced, providing a range of conditions over which the model can be validated. The objective of the study reported here was to provide experimental data to evaluate the model

  12. Stochastic Optimization Model to STudy the Operational Impacts of High Wind Penetrations in Ireland

    DEFF Research Database (Denmark)

    Meibom, Peter; Barth, R.; Hasche, B.

    2011-01-01

    A stochastic mixed integer linear optimization scheduling model minimizing system operation costs and treating load and wind power production as stochastic inputs is presented. The schedules are updated in a rolling manner as more up-to-date information becomes available. This is a fundamental...... change relative to day-ahead unit commitment approaches. The need for reserves dependent on forecast horizon and share of wind power has been estimated with a statistical model combining load and wind power forecast errors with scenarios of forced outages. The model is used to study operational impacts...

  13. A new method for the treatment of impact and penetration problems

    International Nuclear Information System (INIS)

    Bung, H.; Galon, P.; Lepareux, M.; Combescure, A.

    1993-01-01

    While analyzing the safety of nuclear plants, special attention should be paid to the problem of projectile impacts on certain structures. In some cases, the strains undergone by these structures can be important enough to perforate them. The Finite Element Method is a well suited tool to take into account the complexity of the geometries, the non linear behaviour laws, the contact modelling in the study of such problems. The Lagrangian algorithm is in its essence relatively simple and well suited for impact problems between solids. But it has drawbacks when the mesh is subject to large deformations and distorsions. One or various remeshing are thus required during the computation. The Eulerian or Euler-Lagrange formulation helps avoid these large distorsions but is more difficult to set up and present difficulties when the boundary conditions are of Lagrangian kind (for example a free surface). To solve these problems frequently encountered during collision between two structures, a new algorithm was developed in the PLEXUS code of Castem system: this algorithm enables to treat solid/solid or solid/fluid contacts, using for one body an updated lagrangian formulation, the other one being represented by a 'marble cluster' the cohesion of which is ensured by an interaction law acting on the cluster particles. The motion of the different particles is no longer hindered by the mesh distorsion: the marble connectivity is calculated throughout the computation according to the local state of the structure

  14. The impact of high PV penetration levels on electrical distribution networks

    Energy Technology Data Exchange (ETDEWEB)

    Collinson, A; Beddoes, A; Thornycroft, J [Halcrow (United Kingdom); Strbac, G; Jenkins, N [UMIST, Manchester (United Kingdom); Verhoeven, B [KEMA (Netherlands)

    2002-07-01

    This report describes the results of a collaborative study by EA Technology, UMIST and Halcrow into the effects of large-scale connection of dispersed photovoltaic (PV) power systems on the national electricity supply network. The report is intended to help manufacturers and installers of PV systems and electricity companies to understand the issues associated with grid connection of PV power systems. The increased use of PV systems is expected to have a significant impact on the design, operation and management of electricity supply networks. The study examined three main areas: probability and risk analysis of islanding; PV and network voltage control (including analysis of voltage control in a commercial, domestic retrofit and domestic new build scenarios); and future low voltage network design and operational policies.

  15. HYPERFUSE: a hypervelocity inertial confinement system for fusion energy production and fission waste transmutation

    International Nuclear Information System (INIS)

    Makowitz, H.; Powell, J.R.; Wiswall, R.

    1980-01-01

    Parametric system studies of an inertial confinement fusion (ICF) reactor system to transmute fission products from an LWR economy have been carried out. The ICF reactors would produce net power in addition to transmuting fission products. The particular ICF concept examined is an impact fusion approach termed HYPERFUSE, in which hypervelocity pellets, traveling on the order of 100 to 300 km/sec, collide with each other or a target block in a reactor chamber and initiate a thermonuclear reaction. The DT fusion fuel is contained in a shell of the material to be transmuted, e.g., 137 Cs, 90 Sr, 129 I, 99 Tc, etc. The 14-MeV fusion neutrons released during the pellet burn cause transmutation reactions (e.g., (n,2n), (n,α), (n,γ), etc.) that convert the long-lived fission products (FP's) either to stable products or to species that decay with a short half-life to a stable product. The transmutation parametric studies conclude that the design of the hypervelocity projectiles should emphasize the achievement of high densities in the transmutation regions (greater than the DT fusion fuel density), as well as the DT ignition and burn criterion (rho R=1.0 to 3.0) requirements

  16. HYPERFUSE: a hypervelocity inertial confinement system for fusion energy production and fission waste transmutation

    International Nuclear Information System (INIS)

    Makowitz, H.; Powell, J.R.; Wiswall, R.

    1980-01-01

    Parametric system studies of an inertial confinement fusion (ICF) reactor system to transmute fission products from a LWR economy have been carried out. The ICF reactors would produce net power in addition to transmuting fission products. The particular ICF concept examined is an impact fusion approach termed HYPERFUSE, in which hypervelocity pellets, traveling on the order of 100 to 300 km/sec, collide with each other or a target block in a reactor chamber and initiate a thermonuclear reaction. The DT fusion fuel is contained in a shell of the material to be transmuted, e.g., 137 Cs, 90 Sr, 129 I, 99 Tc, etc. The 14-MeV fusion neutrons released during the pellet burn cause transmutation reactions (e.g., (n,2n), (n,α), (n,γ), etc.) that convert the long-lived fission products (FP's) either to stable products or to species that decay with a short half-life to a stable product. The transmutation parametric studies conclude that the design of the hypervelocity projectiles should emphasize the achievement of high densities in the transmutation regions (greater than the DT fusion fuel density), as well as the DT ignition and burn criterion (rho R = 1.0 to 3.0) requirements. These studies also indicate that masses on the order of 1.0 g at densities of rho greater than or equal to 500.0 g/cm 3 are required for a practical fusion-based fission product transmutation system

  17. Wound Ballistics Modeling for Blast Loading Blunt Force Impact and Projectile Penetration

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Paul A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Cooper, Candice Frances [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Burnett, Damon J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    Light body armor development for the warfighter is based on trial-and-error testing of prototype designs against ballistic projectiles. Torso armor testing against blast is virtually nonexistent but necessary to ensure adequate protection against injury to the heart and lungs. In this report, we discuss the development of a high-fidelity human torso model, it's merging with the existing Sandia Human Head-Neck Model, and development of the modeling & simulation (M&S) capabilities necessary to simulate wound injury scenarios. Using the new Sandia Human Torso Model, we demonstrate the advantage of virtual simulation in the investigation of wound injury as it relates to the warfighter experience. We present the results of virtual simulations of blast loading and ballistic projectile impact to the tors o with and without notional protective armor. In this manner, we demonstrate the ad vantages of applying a modeling and simulation approach to the investigation of wound injury and relative merit assessments of protective body armor without the need for trial-and-error testing.

  18. The impact of demand side management strategies in the penetration of renewable electricity

    International Nuclear Information System (INIS)

    Pina, André; Silva, Carlos; Ferrão, Paulo

    2012-01-01

    High fuel costs, increasing energy security and concerns with reducing emissions have pushed governments to invest in the use of renewable energies for electricity generation. However, the intermittence of most renewable resources when renewable energy provides a significant share of the energy mix can create problems to electricity grids, which can be minimized by energy storage systems that are usually not available or expensive. An alternative solution consists on the use of demand side management strategies, which can have the double effect of reducing electricity consumption and allowing greater efficiency and flexibility in the grid management, namely by enabling a better match between supply and demand. This work analyzes the impact of demand side management strategies in the evolution of the electricity mix of Flores Island in the Azores archipelago which is characterized by high shares of renewable energy and therefore the introduction of more renewable energy sources makes it an interesting case study for testing innovative solutions. The electricity generation system is modeled in TIMES, a software which optimizes the investment and operation of wind and hydro plants until 2020 based on scenarios for demand growth, deployment of demand response technologies in the domestic sector and promotion of behavioral changes to eliminate standby power. The results show that demand side management strategies can lead to a significant delay in the investment on new generation capacity from renewable resources and improve the operation of the existing installed capacity. -- Highlights: ► Energy efficiency can help reduce the need for investment in more renewable energy. ► Dynamic demand helps increase the use of renewable energy in low demand periods. ► Around 40% of total consumption by domestic appliances is used as dynamic demand. ► The load of domestic appliances is mainly shifted to the 5:00 to 9:00 period.

  19. Electric Vehicle Market Penetration and Impacts on Energy Consumption and CO2 Emission in the Future: Beijing Case

    Directory of Open Access Journals (Sweden)

    Qian Zhang

    2017-02-01

    Full Text Available This study focuses on the development of electric vehicles (EV in the private passenger vehicle fleet in Beijing (China, analyzes how EVs will penetrate in the market, and estimates the resulting impacts on energy consumption and CO2 emissions up to 2030. A discrete choice model is adopted with consideration of variables including vehicle technical characteristics, fuel prices, charging conditions and support policies. Results show that by 2030, without technological breakthrough and support policies, the market share of EV will be less than 7%, with gasoline dominating the energy structure. With fast technological progress, charging facility establishment, subsidies and tax breaks, EVs will account for 70% of annual new vehicle sales and nearly half of the vehicle stock by 2030, resulting in the substitution of nearly 1 million tons of gasoline with 3.2 billion kWh electricity in 2030 and the reduction of 0.6 million tons of CO2 emission in 2030. Technological progress, charging conditions and fuel prices are the top three drivers. Subsidies play an important role in the early stage, while tax and supply-side policies can be good options as long-term incentives.

  20. Impact of soda-lime borosilicate glass composition on water penetration and water structure at the first time of alteration

    International Nuclear Information System (INIS)

    Rebiscoul, D.; Bruguier, F.; Gin, S.; Magnin, V.

    2012-01-01

    In this study, the impact of soda-lime borosilicate glass composition and particularly the effect of charge compensators such Ca and Na and, of network formers such Si and Zr, on water penetration and water structure at the first time of alteration were investigated. Two non-destructive techniques were combined: the Fourier transform infrared spectroscopy in attenuated total reflection geometry to precise the predominant alteration mechanisms and assess the water structure in altered zone and the grazing incidence X-ray reflectometry to determine the thickness of the altered glass zone allowing to calculate the water diffusion coefficients through the glasses. The results of glass alteration at pH = 3 and 30 degrees C have shown that hydrolysis was the predominant mechanism after few seconds for glass having a high amount of non-binding oxygen. For the other glasses, which for the diffusion was the limiting reaction, the calculated water diffusion coefficients were comprised between 10 -21 and 10 -19 m 2 .s -1 and vary as a function of glass composition. An activation energy of 76.9 kJ.mol -1 was calculated and appears to be higher than inert gas diffusion through the glass highlighting that water molecules strongly interact with the glass matrix. (authors)

  1. Development and application of streakline visualization in hypervelocity flows

    Energy Technology Data Exchange (ETDEWEB)

    Lemieux, P.; Hornung, H.G. [Graduate Aeronautical Laboratories, California Institute of Technology, Pasadena, CA 91125 (United States)

    2002-07-01

    A method for visualizing streaklines in hypervelocity flows has been developed. The method uses the high temperatures produced in hypervelocity flows to ablate small amounts of sodium deposited onto a wire stretched across the flow and to broaden the lines in the sodium spectrum. By using a dye laser, tuned to a wavelength close to one of the sodium D-lines, as the light source in shadowgraph or Schlieren visualization, streaklines seeded with sodium become visible through absorption and/or enhanced refractivity. The technique has been used to investigate the stability of the shear layer produced by the curved bow shock on a cylindrically blunted wedge. The results suggest that the shear layer is unstable, exhibiting structures with a wavelength that is comparable to half the nose radius of the body. (orig.)

  2. Hypervelocity launch capabilities to over 10 km/s

    International Nuclear Information System (INIS)

    Chhabildas, L.C.

    1991-01-01

    Very high pressure and acceleration is necessary to launch flier plates to hypervelocities. In addition, the high pressure loading must be uniform, structured, and shockless, i.e., time-dependent to prevent the flier plate from either fracturing or melting. In this paper, a novel technique is described which allows the use of megabar level loading pressures, and 10 9 g acceleration to launch intact flier plates to velocities of 12.2 km/s. 32 refs., 2 figs

  3. Distributed energy store powered railguns for hypervelocity launch

    Science.gov (United States)

    Maas, Brian L.; Bauer, David P.; Marshall, Richard A.

    1993-01-01

    Highly distributed power supplies are proposed as a basis for current difficulties with hypervelocity railgun power-supply compactness. This distributed power supply configuration reduces rail-to-rail voltage behind the main armature, thereby reducing the tendency for secondary armature current formation; secondary current elimination is essential for achieving the efficiencies associated with muzzle velocity above 6 km/sec. Attention is given to analytical and experimental results for two distributed energy storage schemes.

  4. Regional PV power estimation and forecast to mitigate the impact of high photovoltaic penetration on electric grid.

    Science.gov (United States)

    Pierro, Marco; De Felice, Matteo; Maggioni, Enrico; Moser, David; Perotto, Alessandro; Spada, Francesco; Cornaro, Cristina

    2017-04-01

    The growing photovoltaic generation results in a stochastic variability of the electric demand that could compromise the stability of the grid and increase the amount of energy reserve and the energy imbalance cost. On regional scale, solar power estimation and forecast is becoming essential for Distribution System Operators, Transmission System Operator, energy traders, and aggregators of generation. Indeed the estimation of regional PV power can be used for PV power supervision and real time control of residual load. Mid-term PV power forecast can be employed for transmission scheduling to reduce energy imbalance and related cost of penalties, residual load tracking, trading optimization, secondary energy reserve assessment. In this context, a new upscaling method was developed and used for estimation and mid-term forecast of the photovoltaic distributed generation in a small area in the north of Italy under the control of a local DSO. The method was based on spatial clustering of the PV fleet and neural networks models that input satellite or numerical weather prediction data (centered on cluster centroids) to estimate or predict the regional solar generation. It requires a low computational effort and very few input information should be provided by users. The power estimation model achieved a RMSE of 3% of installed capacity. Intra-day forecast (from 1 to 4 hours) obtained a RMSE of 5% - 7% while the one and two days forecast achieve to a RMSE of 7% and 7.5%. A model to estimate the forecast error and the prediction intervals was also developed. The photovoltaic production in the considered region provided the 6.9% of the electric consumption in 2015. Since the PV penetration is very similar to the one observed at national level (7.9%), this is a good case study to analyse the impact of PV generation on the electric grid and the effects of PV power forecast on transmission scheduling and on secondary reserve estimation. It appears that, already with 7% of PV

  5. Characterisation and dissolution of depleted uranium aerosols produced during impacts of kinetic energy penetrators against a tank

    Energy Technology Data Exchange (ETDEWEB)

    Chazel, V.; Gerasimo, P.; Debouis, V.; Laroche, P.; Paquet, F

    2003-07-01

    Aerosols produced during impacts of depleted uranium (DU) penetrators against the glacis (sloping armour) and the turret of a tank were sampled. The concentration and size distribution were determined. Activity median aerodynamic diameters were 1 {mu}m (geometric standard deviation, s{sub g} = 3.7) and 2 {mu}m (s{sub g} = 2.5), respectively, for glacis and turret. The mean air concentration was 120 Bq m{sup -3}, i.e. 8.5 mg m{sup -3} of DU. Filters analysed by scanning electron microscopy (SEM) and X ray diffraction showed two types of particles (fine particles and large molten particles) composed mainly of a mixture of uranium and aluminium. The uranium oxides were mostly U{sub 3}O{sub 8}, UO{sub 2.25} and probably UO{sub 3.01} and a mixed compound of U and Al. The kinetics of dissolution in three media (HCO{sub 3}{sup -}, HCl and Gamble's solution) were determined using in-vitro tests. The slow dissolution rates were respectively slow, and intermediate between slow and moderate, and the rapid dissolution fractions were mostly intermediate between moderate and fast. According to the in-vitro results for Gamble's solution, and based on a hypothetical single acute inhalation of 90 Bq, effective doses integrated up to 1 y after incorporation were 0.54 and 0.56 mSv respectively, for aerosols from glacis and turret. In comparison, the ICRP limits are 20 mSv y{sup -1} for workers and 1 mSv y{sup -1} for members of public. A kidney concentration of approximately 0.1 {mu}g U g{sup -1} was predicted and should not, in this case, lead to kidney damage. (author)

  6. Characterisation and dissolution of depleted uranium aerosols produced during impacts of kinetic energy penetrators against a tank

    International Nuclear Information System (INIS)

    Chazel, V.; Gerasimo, P.; Debouis, V.; Laroche, P.; Paquet, F.

    2003-01-01

    Aerosols produced during impacts of depleted uranium (DU) penetrators against the glacis (sloping armour) and the turret of a tank were sampled. The concentration and size distribution were determined. Activity median aerodynamic diameters were 1 μm (geometric standard deviation, s g = 3.7) and 2 μm (s g = 2.5), respectively, for glacis and turret. The mean air concentration was 120 Bq m -3 , i.e. 8.5 mg m -3 of DU. Filters analysed by scanning electron microscopy (SEM) and X ray diffraction showed two types of particles (fine particles and large molten particles) composed mainly of a mixture of uranium and aluminium. The uranium oxides were mostly U 3 O 8 , UO 2.25 and probably UO 3.01 and a mixed compound of U and Al. The kinetics of dissolution in three media (HCO 3 - , HCl and Gamble's solution) were determined using in-vitro tests. The slow dissolution rates were respectively slow, and intermediate between slow and moderate, and the rapid dissolution fractions were mostly intermediate between moderate and fast. According to the in-vitro results for Gamble's solution, and based on a hypothetical single acute inhalation of 90 Bq, effective doses integrated up to 1 y after incorporation were 0.54 and 0.56 mSv respectively, for aerosols from glacis and turret. In comparison, the ICRP limits are 20 mSv y -1 for workers and 1 mSv y -1 for members of public. A kidney concentration of approximately 0.1 μg U g -1 was predicted and should not, in this case, lead to kidney damage. (author)

  7. Characterisation and dissolution of depleted uranium aerosols produced during impacts of kinetic energy penetrators against a tank.

    Science.gov (United States)

    Chazel, V; Gerasimo, P; Dabouis, V; Laroche, P; Paquet, F

    2003-01-01

    Aerosols produced during impacts of depleted uranium (DU) penetrators against the glacis (sloping armour) and the turret of a tank were sampled. The concentration and size distribution were determined. Activity median aerodynamic diameters were 1 microm (geometric standard deviation, sigma(g) = 3.7) and 2 microm (sigma(g) = 2.5), respectively, for glacis and turret. The mean air concentration was 120 Bq m(-3), i.e. 8.5 mg m(-3) of DU. Filters analysed by scanning electron microscopy (SEM) and X ray diffraction showed two types of particles (fine particles and large molten particles) composed mainly of a mixture of uranium and aluminium. The uranium oxides were mostly U3O8, UO2.25 and probably UO3.01 and a mixed compound of U and Al. The kinetics of dissolution in three media (HCO3-, HCl and Gamble's solution) were determined using in-vitro tests. The slow dissolution rates were respectively slow, and intermediate between slow and moderate, and the rapid dissolution fractions were mostly intermediate between moderate and fast. According to the in-vitro results for Gamble's solution, and based on a hypothetical single acute inhalation of 90 Bq, effective doses integrated up to 1 y after incorporation were 0.54 and 0.56 mSv, respectively, for aerosols from glacis and turret. In comparison, the ICRP limits are 20 mSv y(-1) for workers and 1 mSv y(-1) for members of the public. A kidney concentration of approximately 0.1 microg U g(-1) was predicted and should not, in this case, lead to kidney damage.

  8. Finite element modeling of penetration of rigid cylindrical bar impacting on a clamped circular plate, employing a strain rate dependent flow rate and a Gruneisen equation of state

    International Nuclear Information System (INIS)

    Tariq, M.; Khan, I.A.

    2003-01-01

    A time dependent Finite Element simulation of penetration of a rigid cylindrical bar impacting on a copper plate is conducted, to demonstrate how material behavior appears to change when Johnson-Cook plasticity rule is employed along with a Gruneisen, equation of state with cubic shock velocity-particle relationship, and defining pressure both for compressed and expanded materials, as compared to the behavior when only isotropic strain-hardening model is employed. The bar impacts the plate with a velocity of 1000 m/s, and penetrates the plate, a portion of it coming out of the other side. Results are obtained and compared taking both an isotropic strain-hardening model, and a model incorporating Johnson-Cook flow rule along with Gruneisen equation of state. (author)

  9. Impact analysis on ESF design for Calico Hills penetration and exploratory drift and tuff main extension to limits of the repository block

    International Nuclear Information System (INIS)

    Grenia, J.; Weyand, L.

    1988-01-01

    The study covers the impacts on project costs, schedule, human resources and engineering designs caused by increases in site characterization activity consisting of penetration of the Calico Hills formation by ES-1 shaft with exploratory drifting to the Ghost Dance fault and/or drifting 10,000 feet southward from the MTL ESF test complex area to the end of the future repository block

  10. Reactive transport impacts on recovered freshwater quality during multiple partially penetrating wells (MPPW-)ASR in a brackish heterogeneous aquifer

    NARCIS (Netherlands)

    Zuurbier, Koen G.; Hartog, Niels; Stuyfzand, Pieter J.

    The use of multiple partially penetrating wells (MPPW) during aquifer storage and recovery (ASR) in brackish aquifers can significantly improve the recovery efficiency (RE) of unmixed injected water. The water quality changes by reactive transport processes in a field MPPW-ASR system and their

  11. Non-Covalent Interactions and Impact of Charge Penetration Effects in Linear Oligoacene Dimers and Single Crystals

    KAUST Repository

    Ryno, Sean; Risko, Chad; Bredas, Jean-Luc

    2016-01-01

    of charge penetration, which is shown to account for up to 50% of the total interaction energy in dimers extracted from the experimental single crystals; in the case of the most stable co-facial model dimers, this contribution is even larger than the total

  12. Regolith thickness at the Chang'E-3 landing site from the Lunar Penetrating Radar and impact craters

    Science.gov (United States)

    Fa, W.; Zhu, M.-H.; Liu, T.

    2015-10-01

    The Chang'E-3 lunar penetrating radar (LPR) observations reveal a newly formed regolith layer (<1 m), an ejecta layer (~2-6 m), and a palaeoregolith layer (~4-9 m) from the surface to a depth of ~ 20 m. The thicknesses of the newly formed regolith layer and the palaeoregolith layer are consistent with the estimations based on the excavation depth and morphology of small fresh craters.

  13. Plasma jet acceleration of dust particles to hypervelocities

    International Nuclear Information System (INIS)

    Ticos, C. M.; Wang, Zhehui; Wurden, G. A.; Kline, J. L.; Montgomery, D. S.

    2008-01-01

    A convenient method to accelerate simultaneously hundreds of micron-size dust particles to a few km/s over a distance of about 1 m is based on plasma drag. Plasma jets which can deliver sufficient momentum to the dust particles need to have speeds of at least several tens of km/s, densities of the order of 10 22 m -3 or higher, and low temperature ∼1 eV, in order to prevent dust destruction. An experimental demonstration of dust particles acceleration to hypervelocities by plasma produced in a coaxial gun is presented here. The plasma flow speed is deduced from photodiode signals while the plasma density is measured by streaked spectroscopy. As a result of the interaction with the plasma jet, the dust grains are also heated to high temperatures and emit visible light. A hypervelocity dust shower is imaged in situ with a high speed video camera at some distance from the coaxial gun, where light emission from the plasma flow is less intense. The bright traces of the flying microparticles are used to infer their speed and acceleration by employing the time-of-flight technique. A simple model for plasma drag which accounts for ion collection on the grain surface gives predictions for dust accelerations which are in good agreement with the experimental observations.

  14. Stopping of hypervelocity clusters in solids

    International Nuclear Information System (INIS)

    Anders, Christian; Ziegenhain, Gerolf; Urbassek, Herbert M; Bringa, Eduardo M

    2011-01-01

    Using molecular-dynamics simulations, we study the processes underlying the stopping of energetic clusters upon impact in matter. We investigate self-bombardment of both a metallic (Cu) and a van-der-Waals bonded (frozen Ar) target. Clusters with sizes up to N = 10 4 atoms and with energies per atom of E/N = 0.1-1600 eV atom -1 were studied. We find that the stopping force exerted on a cluster follows an N 2/3 -dependence with cluster size N; thus large clusters experience less stopping than equi-velocity atoms. In the course of being stopped, the cluster is strongly deformed and attains a roughly pancake shape. Due to the cluster inertia, maximum deformation occurs later than the maximum stopping force. The time scale of projectile stopping is set by t 0 , the time the cluster needs to cover its own diameter before impacting the target; it thus depends on both cluster size and velocity. The time when the cluster experiences its maximum stopping force is around (0.7-0.8)t 0 . We find that the cluster is deformed with huge strain rates of around 1/2t 0 ; this amounts to 10 11 -10 13 s -1 for the cases studied here. (paper)

  15. Non-Covalent Interactions and Impact of Charge Penetration Effects in Linear Oligoacene Dimers and Single Crystals

    KAUST Repository

    Ryno, Sean

    2016-05-18

    Non-covalent interactions determine in large part the thermodynamic aspects of molecular packing in organic crystals. Using a combination of symmetry-adapted perturbation theory (SAPT) and classical multipole electrostatics, we describe the interaction potential energy surfaces for dimers of the oligoacene family, from benzene to hexacene. An analysis of these surfaces and a thorough assessment of dimers extracted from the reported crystal structures underline that high-order interactions (i.e., three-body non-additive interactions) must be considered in order to rationalize the details of the crystal structures. A comparison of the SAPT electrostatic energy with the multipole interaction energy demonstrates the importance of the contribution of charge penetration, which is shown to account for up to 50% of the total interaction energy in dimers extracted from the experimental single crystals; in the case of the most stable co-facial model dimers, this contribution is even larger than the total interaction energy. Our results highlight the importance of taking account of charge penetration in studies of the larger oligoacenes.

  16. Impacts of fleet types and charging modes for electric vehicles on emissions under different penetrations of wind power

    Science.gov (United States)

    Chen, Xinyu; Zhang, Hongcai; Xu, Zhiwei; Nielsen, Chris P.; McElroy, Michael B.; Lv, Jiajun

    2018-05-01

    Current Chinese policy promotes the development of both electricity-propelled vehicles and carbon-free sources of power. Concern has been expressed that electric vehicles on average may emit more CO2 and conventional pollutants in China. Here, we explore the environmental implications of investments in different types of electric vehicle (public buses, taxis and private light-duty vehicles) and different modes (fast or slow) for charging under a range of different wind penetration levels. To do this, we take Beijing in 2020 as a case study and employ hourly simulation of vehicle charging behaviour and power system operation. Assuming the slow-charging option, we find that investments in electric private light-duty vehicles can result in an effective reduction in the emission of CO2 at several levels of wind penetration. The fast-charging option, however, is counter-productive. Electrifying buses and taxis offers the most effective option to reduce emissions of NOx, a major precursor for air pollution.

  17. Projectile penetration into ballistic gelatin.

    Science.gov (United States)

    Swain, M V; Kieser, D C; Shah, S; Kieser, J A

    2014-01-01

    Ballistic gelatin is frequently used as a model for soft biological tissues that experience projectile impact. In this paper we investigate the response of a number of gelatin materials to the penetration of spherical steel projectiles (7 to 11mm diameter) with a range of lower impacting velocities (projectile velocity are found to be linear for all systems above a certain threshold velocity required for initiating penetration. The data for a specific material impacted with different diameter spheres were able to be condensed to a single curve when the penetration depth was normalised by the projectile diameter. When the results are compared with a number of predictive relationships available in the literature, it is found that over the range of projectiles and compositions used, the results fit a simple relationship that takes into account the projectile diameter, the threshold velocity for penetration into the gelatin and a value of the shear modulus of the gelatin estimated from the threshold velocity for penetration. The normalised depth is found to fit the elastic Froude number when this is modified to allow for a threshold impact velocity. The normalised penetration data are found to best fit this modified elastic Froude number with a slope of 1/2 instead of 1/3 as suggested by Akers and Belmonte (2006). Possible explanations for this difference are discussed. © 2013 Published by Elsevier Ltd.

  18. FTIR Analyses of Hypervelocity Impact Deposits: DebriSat Tests

    Science.gov (United States)

    2015-03-27

    DEPT SPACE MATERIALS LABORATORY ENGINEERING & TECHNOLOGY GROUP Shant Kenderian, DIRECTOR DEPT MATERIALS PROCESSING DEPT SPACE MATERIALS LABORATORY...ENGINEERING & TECHNOLOGY GROUP © The Aerospace Corporation, 2015. All trademarks, service marks, and trade names are the property of their respective owners...mitchell.nolan.ctr@us.af.mil SECURITY CLASSIFICATION UNCLASSIFIED Brian Roebuck AEDC brian.roebuck@us.af.mil Norman Fitz-Coy University of Florida nfc

  19. Deep ocean model penetrator experiments

    International Nuclear Information System (INIS)

    Freeman, T.J.; Burdett, J.R.F.

    1986-01-01

    Preliminary trials of experimental model penetrators in the deep ocean have been conducted as an international collaborative exercise by participating members (national bodies and the CEC) of the Engineering Studies Task Group of the Nuclear Energy Agency's Seabed Working Group. This report describes and gives the results of these experiments, which were conducted at two deep ocean study areas in the Atlantic: Great Meteor East and the Nares Abyssal Plain. Velocity profiles of penetrators of differing dimensions and weights have been determined as they free-fell through the water column and impacted the sediment. These velocity profiles are used to determine the final embedment depth of the penetrators and the resistance to penetration offered by the sediment. The results are compared with predictions of embedment depth derived from elementary models of a penetrator impacting with a sediment. It is tentatively concluded that once the resistance to penetration offered by a sediment at a particular site has been determined, this quantity can be used to sucessfully predict the embedment that penetrators of differing sizes and weights would achieve at the same site

  20. Characterization of Orbital Debris via Hyper-Velocity Ground-Based Tests

    Science.gov (United States)

    Cowardin, Heather

    2016-01-01

    The purpose of the DebriSat project is to replicate a hyper-velocity fragmentation event using modern-day spacecraft materials and construction techniques to better improve the existing DoDand NASA breakup models.

  1. In-Flight Imaging Systems for Hypervelocity and Re-Entry Vehicles, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — It is proposed to create a rugged, reliable, compact, standardized imaging system for hypervelocity and re-entry vehicles using sapphire windows, small imagers, and...

  2. Development of an Extraterrestrial Organic Analyzer (EOA) for Highly Sensitive Organic Detection on an Ice Shell Impact Penetrator (IceShIP)

    Science.gov (United States)

    Stockton, A. M.; Duca, Z. A.; Cato, M.; Cantrell, T.; Kim, J.; Putman, P.; Schmidt, B. E.

    2016-12-01

    Kinetic penetrators have the potential to enable low cost in situ measurements of the ice of worlds including Europa and Enceladus [1]. Their small size and mass, critical to limiting their kinetic energy, makes them ideal small landers riding on primarily orbiter missions, while enabling sampling at several m depth due to burial and excavation. In situ microfluidic-based organic analysis systems are a powerful, miniaturized approach for detecting markers of habitability and recent biological activity. Development of microfluidic technology, like that of the Mars Organic Analyzer (MOA) [2,3] and Enceladus Organic Analyzer (EOA), has led to an instrument capable of in situ organic chemical analysis compatible with a kinetic penetrator platform. This technology uses an integrated microfluidic processor to prepare samples for analysis via fluorescent derivatization prior to highly sensitive laser-induced fluorescence (LIF) detection. Selective derivatization in the presence of a chiral selector enables distinction between amino acid enantiomers. Finite element analysis of the core microfluidic processing and analytical device indicated that the device itself is more than capable of surviving the stresses associated with an impact acceleration of >50,000g. However, a number of developments were still required to enable a flight-ready system. Preliminary experiments indicated that moving from a pneumatically-actuated to a hydraulically-actuated microvalve system may provide better impact resistance. A hydraulically-actuated microvalve system was developed and tested. A modification of an established microfabricated LIF detection system would use indium bump bonding to permanently weld optical components using standard microfabrication techniques with perfect alignment. Recent work has also focused on developing and characterizing impact-resistant electronics. This work shows the low-TRL development of EOA's LIF and microfluidic subsystems for future planetary impact

  3. Hypervelocity stars from young stellar clusters in the Galactic Centre

    Science.gov (United States)

    Fragione, G.; Capuzzo-Dolcetta, R.; Kroupa, P.

    2017-05-01

    The enormous velocities of the so-called hypervelocity stars (HVSs) derive, likely, from close interactions with massive black holes, binary stars encounters or supernova explosions. In this paper, we investigate the origin of HVSs as consequence of the close interaction between the Milky Way central massive black hole and a passing-by young stellar cluster. We found that both single and binary HVSs may be generated in a burst-like event, as the cluster passes near the orbital pericentre. High-velocity stars will move close to the initial cluster orbital plane and in the direction of the cluster orbital motion at the pericentre. The binary fraction of these HVS jets depends on the primordial binary fraction in the young cluster. The level of initial mass segregation determines the value of the average mass of the ejected stars. Some binary stars will merge, continuing their travel across and out of the Galaxy as blue stragglers.

  4. Market penetration of ethanol

    International Nuclear Information System (INIS)

    Szulczyk, Kenneth R.; McCarl, Bruce A.; Cornforth, Gerald

    2010-01-01

    This research examines in detail the technology and economics of substituting ethanol for gasoline. This endeavor examines three issues. First, the benefits of ethanol/gasoline blends are examined, and then the technical problems of large-scale implementation of ethanol. Second, ethanol production possibilities are examined in detail from a variety of feedstocks and technologies. The feedstocks are the starch/sugar crops and crop residues, while the technologies are corn wet mill, dry grind, and lignocellulosic fermentation. Examining in detail the production possibilities allows the researchers to identity the extent of technological change, production costs, byproducts, and GHG emissions. Finally, a U.S. agricultural model, FASOMGHG, is updated which predicts the market penetration of ethanol given technological progress, variety of technologies and feedstocks, market interactions, energy prices, and GHG prices. FASOMGHG has several interesting results. First, gasoline prices have a small expansionary impact on the U.S. ethanol industry. Both agricultural producers' income and cost both increase with higher energy prices. If wholesale gasoline is $4 per gallon, the predicted ethanol market penetration attains 53% of U.S. gasoline consumption in 2030. Second, the corn wet mill remains an important industry for ethanol production, because this industry also produces corn oil, which could be converted to biodiesel. Third, GHG prices expand the ethanol industry. However, the GHG price expands the corn wet mill, but has an ambiguous impact on lignocellulosic ethanol. Feedstocks for lignocellulosic fermentation can also be burned with coal to generate electricity. Both industries are quite GHG efficient. Finally, U.S. government subsidies on biofuels have an expansionary impact on ethanol production, but may only increase market penetration by an additional 1% in 2030, which is approximately 6 billion gallons. (author)

  5. Impact of Medicare Advantage penetration and hospital competition on technical efficiency of nursing care in US intensive care units.

    Science.gov (United States)

    Min, Ari; Scott, Linda D; Park, Chang; Vincent, Catherine; Ryan, Catherine J; Lee, Taewha

    2018-04-10

    This study aimed to evaluate technical efficiency of US intensive care units and determine the effects of environmental factors on technical efficiency in providing quality of nursing care. Data were obtained from the 2014 National Database of Nursing Quality Indicators and the Centers for Medicare and Medicaid Services. Data envelopment analysis was used to estimate technical efficiency for each intensive care unit. Multilevel modeling was used to determine the effects of environmental factors on technical efficiency. Overall, Medicare Advantage penetration and hospital competition in a market did not create pressure for intensive care units to become more efficient by reducing their inputs. However, these 2 environmental factors showed positive influences on technical efficiency in intensive care units with certain levels of technical efficiency. The implications of the study results for management strategies and health policy may vary according to the levels of technical efficiency in intensive care units. Further studies are needed to examine why and how intensive care units with particular levels of technical efficiency are differently affected by certain environmental factors. Copyright © 2018 John Wiley & Sons, Ltd.

  6. Determination of penetration depth at high velocity impact using finite element method and artificial neural network tools

    Directory of Open Access Journals (Sweden)

    Namık KılıÇ

    2015-06-01

    Full Text Available Determination of ballistic performance of an armor solution is a complicated task and evolved significantly with the application of finite element methods (FEM in this research field. The traditional armor design studies performed with FEM requires sophisticated procedures and intensive computational effort, therefore simpler and accurate numerical approaches are always worthwhile to decrease armor development time. This study aims to apply a hybrid method using FEM simulation and artificial neural network (ANN analysis to approximate ballistic limit thickness for armor steels. To achieve this objective, a predictive model based on the artificial neural networks is developed to determine ballistic resistance of high hardness armor steels against 7.62 mm armor piercing ammunition. In this methodology, the FEM simulations are used to create training cases for Multilayer Perceptron (MLP three layer networks. In order to validate FE simulation methodology, ballistic shot tests on 20 mm thickness target were performed according to standard Stanag 4569. Afterwards, the successfully trained ANN(s is used to predict the ballistic limit thickness of 500 HB high hardness steel armor. Results show that even with limited number of data, FEM-ANN approach can be used to predict ballistic penetration depth with adequate accuracy.

  7. Customer-economics of residential photovoltaic systems (Part 1): The impact of high renewable energy penetrations on electricity bill savings with net metering

    International Nuclear Information System (INIS)

    Darghouth, Naïm R.; Barbose, Galen; Wiser, Ryan H.

    2014-01-01

    Residential photovoltaic (PV) systems in the US are often compensated at the customer's underlying retail electricity rate through net metering. Given the uncertainty in future retail rates and the inherent links between rates and the customer–economics of behind-the-meter PV, there is growing interest in understanding how potential changes in rates may impact the value of bill savings from PV. In this article, we first use a production cost and capacity expansion model to project California hourly wholesale electricity market prices under two potential electricity market scenarios, including a reference and a 33% renewables scenario. Second, based on the wholesale electricity market prices generated by the model, we develop retail rates (i.e., flat, time-of-use, and real-time pricing) for each future scenario based on standard retail rate design principles. Finally, based on these retail rates, the bill savings from PV is estimated for 226 California residential customers under two types of net metering, for each scenario. We find that high renewable penetrations can drive substantial changes in residential retail rates and that these changes, together with variations in retail rate structures and PV compensation mechanisms, interact to place substantial uncertainty on the future value of bill savings from residential PV. - Highlights: • We investigate the impact of high renewables on customer economics of solar. • We model three types of residential retail electricity rates. • Based on the rates, we calculate the bill savings from photovoltaic (PV) generation. • High renewables penetration can lead to lower bill savings with time-varying rates. • There is substantial uncertainty in the future bill savings from residential PV

  8. MO-FG-CAMPUS-IeP2-05: Feasibility Demonstration of High-Voltage Clinical CT and Impact On X-Ray Penetration Through Metal Objects

    International Nuclear Information System (INIS)

    Jin, Y; De Man, B; Robinson, V; Gjesteby, L; Wang, G; Verburg, J; Giantsoudi, D; Paganetti, H

    2016-01-01

    Purpose: To demonstrate the possibility and quantify the impact of operating a clinical CT scanner at exceptionally high x-ray tube voltage for better penetration through metal objects and facilitating metal artifact reduction. Methods: We categorize metal objects according to the data corruption severeness (level of distortion and complete photon starvation fraction). To demonstrate feasibility and investigate the impact of high voltage scanning we modified a commercial GE LightSpeed VCT scanner (generator and software) to enable CT scans with x-ray tube voltages as high as 175 kVp. A 20 cm diameter water phantom with two metal rods (10 mm stainless and 25 mm titanium) and a water phantom with realistic metal object (spine cage) were used to evaluate the data corruption and image artifacts in the absence of any algorithm correction. We also performed simulations to confirm our understanding of the transmitted photon levels through metal objects with different size and composition. Results: The reconstructed images at 175 kVp still have significant dark shading artifacts, as expected since no special scatter correction or beam hardening was performed but show substantially lower noise and photon starvation than at lower kVp due to better beam penetration. Analysis of the raw data shows that the photon starved data is reduced from over 4% at 140 kVp to below 0.2% at 175 kVp. The simulations indicate that for clinically relevant titanium and stainless objects a 175 kVp tube voltage effectively avoids photon starvation. Conclusion: The use of exceptionally high tube voltage on a clinical CT system is a practical and effective solution to avoid photon starvation caused by certain metal implants. Sparse and hybrid high-voltage protocols are being considered to maintain low patient dose. This opens the door to algorithmic physics-based corrections rather than treating the data as missing and relying on missing data algorithms. Some of the authors are employees of General

  9. MO-FG-CAMPUS-IeP2-05: Feasibility Demonstration of High-Voltage Clinical CT and Impact On X-Ray Penetration Through Metal Objects

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Y; De Man, B [GE Global Research, Niskayuna, NY (United States); Robinson, V [GE, Global Research, Niskayuna, NY (United States); Gjesteby, L [Rensselaer Polytechnic Institute, Troy, NY (United States); Wang, G [Rensselaer Polytechnic Institute Troy, NY (United States); Verburg, J [Massachusetts, General Hospital, Boston, MA (United States); Giantsoudi, D; Paganetti, H [Massachusetts General Hospital, Boston, MA (United States)

    2016-06-15

    Purpose: To demonstrate the possibility and quantify the impact of operating a clinical CT scanner at exceptionally high x-ray tube voltage for better penetration through metal objects and facilitating metal artifact reduction. Methods: We categorize metal objects according to the data corruption severeness (level of distortion and complete photon starvation fraction). To demonstrate feasibility and investigate the impact of high voltage scanning we modified a commercial GE LightSpeed VCT scanner (generator and software) to enable CT scans with x-ray tube voltages as high as 175 kVp. A 20 cm diameter water phantom with two metal rods (10 mm stainless and 25 mm titanium) and a water phantom with realistic metal object (spine cage) were used to evaluate the data corruption and image artifacts in the absence of any algorithm correction. We also performed simulations to confirm our understanding of the transmitted photon levels through metal objects with different size and composition. Results: The reconstructed images at 175 kVp still have significant dark shading artifacts, as expected since no special scatter correction or beam hardening was performed but show substantially lower noise and photon starvation than at lower kVp due to better beam penetration. Analysis of the raw data shows that the photon starved data is reduced from over 4% at 140 kVp to below 0.2% at 175 kVp. The simulations indicate that for clinically relevant titanium and stainless objects a 175 kVp tube voltage effectively avoids photon starvation. Conclusion: The use of exceptionally high tube voltage on a clinical CT system is a practical and effective solution to avoid photon starvation caused by certain metal implants. Sparse and hybrid high-voltage protocols are being considered to maintain low patient dose. This opens the door to algorithmic physics-based corrections rather than treating the data as missing and relying on missing data algorithms. Some of the authors are employees of General

  10. Impacts on the Hubble Space Telescope Wide Field and Planetary Camera 2: Microanalysis and Recognition of Micrometeoroid Compositions

    Science.gov (United States)

    Kearsley, A. T.; Ross, D. K.; Anz-Meador, P.; Liou, J. C.; Opiela, J.; Grime, G. W.; Webb, R. P.; Jeynes, C.; Palitsin, V. V.; Colaux, J. L.; hide

    2014-01-01

    Postflight surveys of the Wide Field and Planetary Camera 2 (WFPC2) on the Hubble Space Telescope have located hundreds of features on the 2.2 by 0.8 m curved plate, evidence of hypervelocity impact by small particles during 16 years of exposure to space in low Earth orbit (LEO). The radiator has a 100 - 200 micron surface layer of white paint, overlying 4 mm thick Al alloy, which was not fully penetrated by any impact. Over 460 WFPC2 samples were extracted by coring at JSC. About half were sent to NHM in a collaborative program with NASA, ESA and IBC. The structural and compositional heterogeneity at micrometer scale required microanalysis by electron and ion beam microscopes to determine the nature of the impactors (artificial orbital debris, or natural micrometeoroids, MM). Examples of MM impacts are described elsewhere. Here we describe the development of novel electron beam analysis protocols, required to recognize the subtle traces of MM residues.

  11. Fragmentation of Millimeter-Size Hypervelocity Projectiles on Combined Mesh-Plate Bumpers

    Directory of Open Access Journals (Sweden)

    Aleksandr Cherniaev

    2017-01-01

    Full Text Available This numerical study evaluates the concept of a combined mesh-plate bumper as a shielding system protecting unmanned spacecraft from small (1 mm orbital debris impacts. Two-component bumpers consisting of an external layer of woven mesh (aluminum or steel directly applied to a surface of the aluminum plate are considered. Results of numerical modeling with a projectile velocity of 7 km/s indicate that, in comparison to the steel mesh-combined bumper, the combination of aluminum mesh and aluminum plate provides better fragmentation of small hypervelocity projectiles. At the same time, none of the combined mesh/plate bumpers provide a significant increase of ballistic properties as compared to an aluminum plate bumper. This indicates that the positive results reported in the literature for bumpers with metallic meshes and large projectiles are not scalable down to millimeter-sized particles. Based on this investigation’s results, a possible modification of the combined mesh/plate bumper is proposed for the future study.

  12. HYPERFUSE: a novel inertial confinement system utilizing hypervelocity projectiles for fusion energy production and fission waste transmutation

    International Nuclear Information System (INIS)

    Makowitz, H.; Powell, J.R.; Wiswall, R.

    1980-01-01

    Parametric system studies of an inertial confinement fusion (ICF) reactor system to transmute fission products from an LWR economy have been carried out. The ICF reactors would produce net power in addition to transmuting fission products. The particular ICF concept examined is an impact fusion approach termed HYPERFUSE, in which hypervelocity pellets, traveling on the order of 100 to 300 km/sec, collide with each other or a target block in a reactor chamber and initiate a thermonuclear reaction. The DT fusion fuel is contained in a shell of the material to be transmuted, e.g., 137 Cs or 90 Sr. The 14-MeV fusion neutrons released during the pellet burn cause transmutation reactions (e.g., (n, 2n), (n, α), etc.) that convert the long lived fission products (FP's) either to stable products or to species that decay with a short half-life to a stable product

  13. Hyper fuse: a novel inertial confinement system utilizing hypervelocity projectiles for fusion energy production and fission waste transmutation

    International Nuclear Information System (INIS)

    Makowitz, H.; Powell, J.R.; Wiswall, R.

    1979-01-01

    Parametric system studies of an inertial confinement fusion (ICF) reactor system to transmute fission products from an LWR economy have been carried out. The ICF reactors would produce net power in addition to transmuting fission products. The particular ICF concept examined is an impact fusion approach termed HYPERFUSE, in which hypervelocity pellets, traveling on the order of 100 to 300 km/sec, collide with a target in a reactor chamber and initiate a thermonuclear reaction. The DT fusion fuel is contained in a shell of the material to be transmuted, e.g., 137 Cs or 90 Sr. The 14 MeV fusion neutrons released during the pellet burn cause transmutation reactions [e.g., (n, 2n), (n, α), etc.] that convert the long lived fission products (FP's) either to stable products or to species that decay with a short half-life to a stable product

  14. Hypervelocity Launching and Frozen Fuels as a Major Contribution to Spaceflight

    Science.gov (United States)

    Cocks, F. H.; Harman, C. M.; Klenk, P. A.; Simmons, W. N.

    Acting as a virtual first stage, a hypervelocity launch together with the use of frozen hydrogen/frozen oxygen propellant, offers a Single-Stage-To-Orbit (SSTO) system that promises an enormous increase in SSTO mass-ratio. Ram acceleration provides hypervelocity (2 km/sec) to the orbital vehicle with a gas gun supplying the initial velocity required for ram operation. The vehicle itself acts as the center body of a ramjet inside a launch tube, filled with gaseous fuel and oxidizer, acting as an engine cowling. The high acceleration needed to achieve hypervelocity precludes a crew, and it would require greatly increased liquid fuel tank structural mass if a liquid propellant is used for post-launch vehicle propulsion. Solid propellants do not require as much fuel- chamber strengthening to withstand a hypervelocity launch as do liquid propellants, but traditional solid fuels have lower exhaust velocities than liquid hydrogen/liquid oxygen. The shock-stability of frozen hydrogen/frozen oxygen propellant has been experimentally demonstrated. A hypervelocity launch system using frozen hydrogen/frozen oxygen propellant would be a revolutionary new development in spaceflight.

  15. Initial response of a rock penetrator

    International Nuclear Information System (INIS)

    Longcope, D.B.; Grady, D.E.

    1977-12-01

    An analysis based on elastic rod theory is given for the early-time axisymmetric response of pointed penetrators. Results of measurements by laser interferometry of the back surface particle velocity of laboratory scale penetrators impacted by sandstone targets are presented. Values of the initial pressure on the penetrator tip are determined which give good agreement between the analytical and experimental results. These initial tip pressures are found to be approximated by the stress-particle velocity Hugoniot for the target material

  16. Penetrating ureteral trauma

    Directory of Open Access Journals (Sweden)

    Gustavo P. Fraga

    2007-04-01

    Full Text Available OBJECTIVE: The purpose of this series is to report our experience in managing ureteral trauma, focusing on the importance of early diagnosis, correct treatment, and the impact of associated injuries on the management and morbid-mortality. MATERIALS AND METHODS: From January 1994 to December 2002, 1487 laparotomies for abdominal trauma were performed and 20 patients with ureteral lesions were identified, all of them secondary to penetrating injury. Medical charts were analyzed as well as information about trauma mechanisms, diagnostic routine, treatment and outcome. RESULTS: All patients were men. Mean age was 27 years. The mechanisms of injury were gunshot wounds in 18 cases (90% and stab wounds in two (10%. All penetrating abdominal injuries had primary indication of laparotomy, and neither excretory urography nor computed tomography were used in any case before surgery. The diagnosis of ureteric injury was made intra-operatively in 17 cases (85%. Two ureteral injuries (10% were initially missed. All patients had associated injuries. The treatment was dictated by the location, extension and time necessary to identify the injury. The overall incidence of complications was 55%. The presence of shock on admission, delayed diagnosis, Abdominal Trauma Index > 25, Injury Severity Score > 25 and colon injuries were associated to a high complication rate, however, there was no statistically significant difference. There were no mortalities in this group. CONCLUSIONS: A high index of suspicion is required for diagnosis of ureteral injuries. A thorough exploration of all retroperitoneal hematoma after penetrating trauma should be an accurate method of diagnosis; even though it failed in 10% of our cases.

  17. Mitigation of the Impact of High Plug-in Electric Vehicle Penetration on Residential Distribution Grid Using Smart Charging Strategies

    Directory of Open Access Journals (Sweden)

    Chong Cao

    2016-12-01

    Full Text Available Vehicle electrification presents a great opportunity to reduce transportation greenhouse gas emissions. The greater use of plug-in electric vehicles (PEVs, however, puts stress on local distribution networks. This paper presents an optimal PEV charging control method integrated with utility demand response (DR signals to mitigate the impact of PEV charging to several aspects of a grid, including load surge, distribution accumulative voltage deviation, and transformer aging. To build a realistic PEV charging load model, the results of National Household Travel Survey (NHTS have been analyzed and a stochastic PEV charging model has been defined based on survey results. The residential distribution grid contains 120 houses and is modeled in GridLAB-D. Co-simulation is performed using Matlab and GridLAB-D to enable the optimal control algorithm in Matlab to control PEV charging loads in the residential grid modeled in GridLAB-D. Simulation results demonstrate the effectiveness of the proposed optimal charging control method in mitigating the negative impacts of PEV charging on the residential grid.

  18. Intracranial Pressure Response to Non-Penetrating Ballistic Impact: An Experimental Study Using a Pig Physical Head Model and Live Pigs

    Science.gov (United States)

    Liu, Hai; Kang, Jianyi; Chen, Jing; Li, Guanhua; Li, Xiaoxia; Wang, Jianmin

    2012-01-01

    This study was conducted to characterize the intracranial pressure response to non-penetrating ballistic impact using a "scalp-skull-brain" pig physical head model and live pigs. Forty-eight ballistic tests targeting the physical head model and anesthetized pigs protected by aramid plates were conducted with standard 9 mm bullets at low (279-297 m/s), moderate (350-372 m/s), and high (409-436 m/s) velocities. Intracranial pressure responses were recorded with pressure sensors embedded in similar brain locations in the physical head model and the anesthetized pigs. Three parameters of intracranial pressure were determined from the measured data: intracranial maximum pressure (Pmax), intracranial maximum pressure impulse (PImax), and the duration of the first positive phase (PPD). The intracranial pressure waves exhibited blast-like characteristics for both the physical model and l live pigs. Of all three parameters, Pmax is most sensitive to impact velocity, with means of 126 kPa (219 kPa), 178 kPa (474 kPa), and 241 kPa (751 kPa) for the physical model (live pigs) for low, moderate, and high impact velocities, respectively. The mean PPD becomes increasingly short as the impact velocity increases, whereas PImax shows the opposite trend. Although the pressure parameters of the physical model were much lower than those of the live pigs, good correlations between the physical model and the live pigs for the three pressure parameters, especially Pmax, were found using linear regression. This investigation suggests that Pmax is a preferred parameter for predicting the severity of the brain injury resulting from behind armor blunt trauma (BABT). PMID:23055817

  19. THE GALACTIC POTENTIAL AND THE ASYMMETRIC DISTRIBUTION OF HYPERVELOCITY STARS

    International Nuclear Information System (INIS)

    Perets, Hagai B.; Alexander, Tal; Wu Xufen; Zhao Hongsheng; Famaey, Benoit; Gentile, Gianfranco

    2009-01-01

    In recent years several hypervelocity stars (HVSs) have been observed in the halo of our Galaxy. Such HVSs have possibly been ejected from the Galactic center and then propagated in the Galactic potential up to their current position. The recent survey for candidate HVSs show an asymmetry in the kinematics of candidate HVSs (position and velocity vectors), where more outgoing stars than ingoing stars (i.e., positive Galactocentric velocities versus negative ones) are observed. We show that such kinematic asymmetry, which is likely due to the finite lifetime of the stars and Galactic potential structure, could be used in a novel method to probe and constrain the Galactic potential, identify the stellar type of the stars in the survey and estimate the number of HVSs. Kinematics-independent identification of the stellar types of the stars in such surveys (e.g., spectroscopic identification) could further improve these results. We find that the observed asymmetry between ingoing and outgoing stars favors specific Galactic potential models. It also implies a lower limit of ∼54 ± 8 main-sequence HVSs in the survey sample (∼>648 ± 96 in the Galaxy), assuming that all of the MS stars in the survey originate from the GC. The other stars in the survey are likely to be hot blue horizontal branch stars born in the halo rather than stars ejected from the GC.

  20. Hypervelocity star candidates in Gaia DR1/TGAS

    Science.gov (United States)

    Marchetti, T.; Rossi, E. M.; Kordopatis, G.; Brown, A. G. A.; Rimoldi, A.; Starkenburg, E.; Youakim, K.; Ashley, R.

    2018-04-01

    Hypervelocity stars (HVSs) are characterized by a total velocity in excess of the Galactic escape speed, and with trajectories consistent with coming from the Galactic Centre. We apply a novel data mining routine, an artificial neural network, to discover HVSs in the TGAS subset of the first data release of the Gaia satellite, using only the astrometry of the stars. We find 80 stars with a predicted probability >90% of being HVSs, and we retrieved radial velocities for 47 of those. We discover 14 objects with a total velocity in the Galactic rest frame >400 km s-1, and 5 of these have a probability >50% of being unbound from the Milky Way. Tracing back orbits in different Galactic potentials, we discover 1 HVS candidate, 5 bound HVS candidates, and 5 runaway star candidates with remarkably high velocities, between 400 and 780 km s-1. We wait for future Gaia releases to confirm the goodness of our sample and to increase the number of HVS candidates.

  1. Wake of a blunt planetary probe model under hypervelocity conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kastell, D.; Hannemann, D.; Eitelberg, G. [DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Goettingen (Germany). Inst. fuer Stroemungsmechanik

    1998-12-31

    The flow in the wake of a planetary probe under hypervelocity re-entry conditions has two idiosyncrasies not present in the conventional (cold) hypersonic flows: the strong dissociation reaction occurring behind the bow shock wave, and the freezing of the chemical reactions of the flow by the rapid expansion at the shoulder of the probe. The aim of the present study was to both understand the relative importance of the two phenomena upon the total heat and pressure loads on a planetary probe and its possible payload as well as to provide experimental validation data for those developing numerical codes for planetary probe design and analysis. For the experimental study an instrumented blunted 140 cone was tested in the High Enthalpy Shock Tunnel in Goettingen (HEG). The numerical calculations were performed with a Thin-Layer Navier-Stokes code which is capable of simulating chemical and thermal nonequilibrium flows. For the forebody loads the prediction methods were very reliable and capable of accounting for the kinetic effects caused by the high specific enthalpy of the flow. On the other side considerable discrepancies between experimental and numerical results for the wake of the model have been observed. (orig.)

  2. Wake of a blunt planetary probe model under hypervelocity conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kastell, D.; Hannemann, D.; Eitelberg, G. (DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Goettingen (Germany). Inst. fuer Stroemungsmechanik)

    1998-01-01

    The flow in the wake of a planetary probe under hypervelocity re-entry conditions has two idiosyncrasies not present in the conventional (cold) hypersonic flows: the strong dissociation reaction occurring behind the bow shock wave, and the freezing of the chemical reactions of the flow by the rapid expansion at the shoulder of the probe. The aim of the present study was to both understand the relative importance of the two phenomena upon the total heat and pressure loads on a planetary probe and its possible payload as well as to provide experimental validation data for those developing numerical codes for planetary probe design and analysis. For the experimental study an instrumented blunted 140 cone was tested in the High Enthalpy Shock Tunnel in Goettingen (HEG). The numerical calculations were performed with a Thin-Layer Navier-Stokes code which is capable of simulating chemical and thermal nonequilibrium flows. For the forebody loads the prediction methods were very reliable and capable of accounting for the kinetic effects caused by the high specific enthalpy of the flow. On the other side considerable discrepancies between experimental and numerical results for the wake of the model have been observed. (orig.)

  3. Formation and spatial distribution of hypervelocity stars in AGN outflows

    Science.gov (United States)

    Wang, Xiawei; Loeb, Abraham

    2018-05-01

    We study star formation within outflows driven by active galactic nuclei (AGN) as a new source of hypervelocity stars (HVSs). Recent observations revealed active star formation inside a galactic outflow at a rate of ∼ 15M⊙yr-1 . We verify that the shells swept up by an AGN outflow are capable of cooling and fragmentation into cold clumps embedded in a hot tenuous gas via thermal instabilities. We show that cold clumps of ∼ 103 M⊙ are formed within ∼ 105 yrs. As a result, stars are produced along outflow's path, endowed with the outflow speed at their formation site. These HVSs travel through the galactic halo and eventually escape into the intergalactic medium. The expected instantaneous rate of star formation inside the outflow is ∼ 4 - 5 orders of magnitude greater than the average rate associated with previously proposed mechanisms for producing HVSs, such as the Hills mechanism and three-body interaction between a star and a black hole binary. We predict the spatial distribution of HVSs formed in AGN outflows for future observational probe.

  4. MMT HYPERVELOCITY STAR SURVEY. II. FIVE NEW UNBOUND STARS

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Warren R.; Geller, Margaret J.; Kenyon, Scott J., E-mail: wbrown@cfa.harvard.edu, E-mail: mgeller@cfa.harvard.edu, E-mail: skenyon@cfa.harvard.edu [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States)

    2012-05-20

    We present the discovery of five new unbound hypervelocity stars (HVSs) in the outer Milky Way halo. Using a conservative estimate of Galactic escape velocity, our targeted spectroscopic survey has now identified 16 unbound HVSs as well as a comparable number of HVSs ejected on bound trajectories. A Galactic center origin for the HVSs is supported by their unbound velocities, the observed number of unbound stars, their stellar nature, their ejection time distribution, and their Galactic latitude and longitude distribution. Other proposed origins for the unbound HVSs, such as runaway ejections from the disk or dwarf galaxy tidal debris, cannot be reconciled with the observations. An intriguing result is the spatial anisotropy of HVSs on the sky, which possibly reflects an anisotropic potential in the central 10-100 pc region of the Galaxy. Further progress requires measurement of the spatial distribution of HVSs over the southern sky. Our survey also identifies seven B supergiants associated with known star-forming galaxies; the absence of B supergiants elsewhere in the survey implies there are no new star-forming galaxies in our survey footprint to a depth of 1-2 Mpc.

  5. MMT hypervelocity star survey. III. The complete survey

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Warren R.; Geller, Margaret J.; Kenyon, Scott J., E-mail: wbrown@cfa.harvard.edu, E-mail: mgeller@cfa.harvard.edu, E-mail: skenyon@cfa.harvard.edu [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States)

    2014-05-20

    We describe our completed spectroscopic survey for unbound hypervelocity stars (HVSs) ejected from the Milky Way. Three new discoveries bring the total number of unbound late B-type stars to 21. We place new constraints on the nature of the stars and on their distances using moderate resolution MMT spectroscopy. Half of the stars are fast rotators; they are certain 2.5-4 M {sub ☉} main sequence stars at 50-120 kpc distances. Correcting for stellar lifetime, our survey implies that unbound 2.5-4 M {sub ☉} stars are ejected from the Milky Way at a rate of 1.5 × 10{sup –6} yr{sup –1}. These unbound HVSs are likely ejected continuously over the past 200 Myr and do not share a common flight time. The anisotropic spatial distribution of HVSs on the sky remains puzzling. Southern hemisphere surveys like SkyMapper will soon allow us to map the all-sky distribution of HVSs. Future proper motion measurements with Hubble Space Telescope and Gaia will provide strong constraints on origin. Existing observations are all consistent with HVS ejections from encounters with the massive black hole in the Galactic center.

  6. MMT hypervelocity star survey. III. The complete survey

    International Nuclear Information System (INIS)

    Brown, Warren R.; Geller, Margaret J.; Kenyon, Scott J.

    2014-01-01

    We describe our completed spectroscopic survey for unbound hypervelocity stars (HVSs) ejected from the Milky Way. Three new discoveries bring the total number of unbound late B-type stars to 21. We place new constraints on the nature of the stars and on their distances using moderate resolution MMT spectroscopy. Half of the stars are fast rotators; they are certain 2.5-4 M ☉ main sequence stars at 50-120 kpc distances. Correcting for stellar lifetime, our survey implies that unbound 2.5-4 M ☉ stars are ejected from the Milky Way at a rate of 1.5 × 10 –6 yr –1 . These unbound HVSs are likely ejected continuously over the past 200 Myr and do not share a common flight time. The anisotropic spatial distribution of HVSs on the sky remains puzzling. Southern hemisphere surveys like SkyMapper will soon allow us to map the all-sky distribution of HVSs. Future proper motion measurements with Hubble Space Telescope and Gaia will provide strong constraints on origin. Existing observations are all consistent with HVS ejections from encounters with the massive black hole in the Galactic center.

  7. Characterization of Oribtal Debris via Hyper-Velocity Ground-Based Tests

    Science.gov (United States)

    Cowardin, H.

    2015-01-01

    Existing DoD and NASA satellite breakup models are based on a key laboratory-based test, Satellite Orbital debris Characterization Impact Test (SOCIT), which has supported many applications and matched on-orbit events involving older satellite designs reasonably well over the years. In order to update and improve the break-up models and the NASA Size Estimation Model (SEM) for events involving more modern satellite designs, the NASA Orbital Debris Program Office has worked in collaboration with the University of Florida to replicate a hypervelocity impact using a satellite built with modern-day spacecraft materials and construction techniques. The spacecraft, called DebriSat, was intended to be a representative of modern LEO satellites and all major designs decisions were reviewed and approved by subject matter experts at Aerospace Corporation. DebriSat is composed of 7 major subsystems including attitude determination and control system (ADCS), command and data handling (C&DH), electrical power system (EPS), payload, propulsion, telemetry tracking and command (TT&C), and thermal management. To reduce cost, most components are emulated based on existing design of flight hardware and fabricated with the same materials. All fragments down to 2 mm is size will be characterized via material, size, shape, bulk density, and the associated data will be stored in a database for multiple users to access. Laboratory radar and optical measurements will be performed on a subset of fragments to provide a better understanding of the data products from orbital debris acquired from ground-based radars and telescopes. The resulting data analysis from DebriSat will be used to update break-up models and develop the first optical SEM in conjunction with updates into the current NASA SEM. The characterization of the fragmentation will be discussed in the subsequent presentation.

  8. 3 MV hypervelocity dust accelerator at the Colorado Center for Lunar Dust and Atmospheric Studies.

    Science.gov (United States)

    Shu, Anthony; Collette, Andrew; Drake, Keith; Grün, Eberhard; Horányi, Mihály; Kempf, Sascha; Mocker, Anna; Munsat, Tobin; Northway, Paige; Srama, Ralf; Sternovsky, Zoltán; Thomas, Evan

    2012-07-01

    A hypervelocity dust accelerator for studying micrometeorite impacts has been constructed at the Colorado Center for Lunar Dust and Atmospheric Studies (CCLDAS) at the University of Colorado. Based on the Max-Planck-Institüt für Kernphysik (MPI-K) accelerator, this accelerator is capable of emitting single particles of a specific mass and velocity selected by the user. The accelerator consists of a 3 MV Pelletron generator with a dust source, four image charge pickup detectors, and two interchangeable target chambers: a large high-vacuum test bed and an ultra-high vacuum impact study chamber. The large test bed is a 1.2 m diameter, 1.5 m long cylindrical vacuum chamber capable of pressures as low as 10(-7) torr while the ultra-high vacuum chamber is a 0.75 m diameter, 1.1 m long chamber capable of pressures as low as 10(-10) torr. Using iron dust of up to 2 microns in diameter, final velocities have been measured up to 52 km/s. The spread of the dust particles and the effect of electrostatic focusing have been measured using a long exposure CCD and a quartz target. Furthermore, a new technique of particle selection is being developed using real time digital filtering techniques. Signals are digitized and then cross-correlated with a shaped filter, resulting in a suppressed noise floor. Improvements over the MPI-K design, which include a higher operating voltage and digital filtering for detection, increase the available parameter space of dust emitted by the accelerator. The CCLDAS dust facility is a user facility open to the scientific community to assist with instrument calibrations and experiments.

  9. 3 MV hypervelocity dust accelerator at the Colorado Center for Lunar Dust and Atmospheric Studies

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Anthony; Horanyi, Mihaly; Kempf, Sascha; Thomas, Evan [Colorado Center for Lunar Dust and Atmospheric Studies, Boulder, Colorado 80303 (United States); Department of Physics, University of Colorado, Boulder, Colorado 80309 (United States); Laboratory for Atmospheric and Space Physics, 1234 Innovation Drive, Boulder, Colorado 80303 (United States); Collette, Andrew; Drake, Keith; Northway, Paige [Colorado Center for Lunar Dust and Atmospheric Studies, Boulder, Colorado 80303 (United States); Laboratory for Atmospheric and Space Physics, 1234 Innovation Drive, Boulder, Colorado 80303 (United States); Gruen, Eberhard [Colorado Center for Lunar Dust and Atmospheric Studies, Boulder, Colorado 80303 (United States); MPI fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Mocker, Anna [Colorado Center for Lunar Dust and Atmospheric Studies, Boulder, Colorado 80303 (United States); MPI fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); IRS, Universitaet Stuttgart, Pfaffenwaldring 31, D-70569 Stuttgart (Germany); Munsat, Tobin [Colorado Center for Lunar Dust and Atmospheric Studies, Boulder, Colorado 80303 (United States); Department of Physics, University of Colorado, Boulder, Colorado 80309 (United States); Srama, Ralf [MPI fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); IRS, Universitaet Stuttgart, Pfaffenwaldring 31, D-70569 Stuttgart (Germany); and others

    2012-07-15

    A hypervelocity dust accelerator for studying micrometeorite impacts has been constructed at the Colorado Center for Lunar Dust and Atmospheric Studies (CCLDAS) at the University of Colorado. Based on the Max-Planck-Instituet fuer Kernphysik (MPI-K) accelerator, this accelerator is capable of emitting single particles of a specific mass and velocity selected by the user. The accelerator consists of a 3 MV Pelletron generator with a dust source, four image charge pickup detectors, and two interchangeable target chambers: a large high-vacuum test bed and an ultra-high vacuum impact study chamber. The large test bed is a 1.2 m diameter, 1.5 m long cylindrical vacuum chamber capable of pressures as low as 10{sup -7} torr while the ultra-high vacuum chamber is a 0.75 m diameter, 1.1 m long chamber capable of pressures as low as 10{sup -10} torr. Using iron dust of up to 2 microns in diameter, final velocities have been measured up to 52 km/s. The spread of the dust particles and the effect of electrostatic focusing have been measured using a long exposure CCD and a quartz target. Furthermore, a new technique of particle selection is being developed using real time digital filtering techniques. Signals are digitized and then cross-correlated with a shaped filter, resulting in a suppressed noise floor. Improvements over the MPI-K design, which include a higher operating voltage and digital filtering for detection, increase the available parameter space of dust emitted by the accelerator. The CCLDAS dust facility is a user facility open to the scientific community to assist with instrument calibrations and experiments.

  10. The impact of increased interconnection on electricity systems with large penetrations of wind generation. A case study of Ireland and Great Britain

    International Nuclear Information System (INIS)

    Denny, E.; Tuohy, A.; Keane, A.; Flynn, D.; O'Malley, M.; Meibom, P.; Mullane, A.

    2010-01-01

    Increased interconnection has been highlighted as potentially facilitating the integration of wind generation in power systems by increasing the flexibility to balance the variable wind output. This paper utilizes a stochastic unit commitment model to simulate the impacts of increased interconnection for the island of Ireland with large penetrations of wind generation. The results suggest that increased interconnection should reduce average prices in Ireland, and the variability of those prices. The simulations also suggest that while increased interconnection may reduce carbon dioxide emissions in Ireland, Great Britain would experience an increase in emissions, resulting in total emissions remaining almost unchanged. The studies suggest that increased interconnection would not reduce excess wind generation. This is because under unit commitment techniques which incorporate wind power forecasts in the scheduling decisions, wind curtailment is minimal even with low levels of interconnection. As would be expected an increase in interconnection should improve system adequacy considerably with a significant reduction in the number of hours when the load and reserve constraints are not met. (author)

  11. Market penetration rates of new energy technologies

    International Nuclear Information System (INIS)

    Lund, Peter

    2006-01-01

    The market penetration rates of 11 different new energy technologies were studied covering energy production and end-use technologies. The penetration rates were determined by fitting observed market data to an epidemical diffusion model. The analyses show that the exponential penetration rates of new energy technologies may vary from 4 up to over 40%/yr. The corresponding take-over times from a 1% to 50% share of the estimated market potential may vary from less than 10 to 70 years. The lower rate is often associated with larger energy impacts. Short take-over times less than 25 years seem to be mainly associated with end-use technologies. Public policies and subsides have an important effect on the penetration. Some technologies penetrate fast without major support explained by technology maturity and competitive prices, e.g. compact fluorescent lamps show a 24.2%/yr growth rate globally. The penetration rates determined exhibit some uncertainty as penetration has not always proceeded close to saturation. The study indicates a decreasing penetration rate with increasing time or market share. If the market history is short, a temporally decreasing functional form for the penetration rate coefficient could be used to anticipate the probable behavior

  12. Electromagnetic Effices from Impacts on Spacecraft

    Science.gov (United States)

    Close, Sigrid

    2018-04-01

    Hypervelocity micro particles, including meteoroids and space debris with masses electromagnetic pulse (EMP) with a broad frequency spectrum. Subsequent plasma oscillations resulting from instabilities can also emit significant power and may be responsible for many reported satellite anomalies. We present theory and recent results from ground-based impact tests aimed at characterizing hypervelocity impact plasma and show that impact-produced radio frequency (RF) emissions occurred in frequencies ranging from VHF through L-band and that these emissions were highly correlated with fast (> 20 km/s) impacts that produced a fully ionized plasma.

  13. Engineering Polymer Blends for Impact Damage Mitigation

    Science.gov (United States)

    Gordon, Keith L.; Smith, Russell W.; Working, Dennis C.; Siochi, Emilie J.

    2016-01-01

    Structures containing polymers such as DuPont's Surlyn® 8940, demonstrate puncture healing when impacted by a 9 millimeter projectile traveling from speeds near 300 meters per second (1,100 feet per second) to hypervelocity impacts in the micrometeoroid velocity range of 5 kilometers per second (16,000 feet per second). Surlyn® 8940 puncture heals over a temperature range of minus 30 degrees Centigrade to plus 70 degrees Centigrade and shows potential for use in pressurized vessels subject to impact damage. However, such polymers are difficult to process and limited in applicability due to their low thermal stability, poor chemical resistance and overall poor mechanical properties. In this work, several puncture healing engineered melt formulations were developed. Moldings of melt blend formulations were impacted with a 5.56 millimeter projectile with a nominal velocity of 945 meters per second (3,100 feet per second) at about 25 degrees Centigrade, 50 degrees Centigrade and 100 degrees Centigrade, depending upon the specific blend being investigated. Self-healing tendencies were determined using surface vacuum pressure tests and tensile tests after penetration using tensile dog-bone specimens (ASTM D 638-10). For the characterization of tensile properties both pristine and impacted specimens were tested to obtain tensile modulus, yield stress and tensile strength, where possible. Experimental results demonstrate a range of new puncture healing blends which mitigate damage in the ballistic velocity regime.

  14. Akon - A Penetrator for Europa

    Science.gov (United States)

    Jones, Geraint

    2016-04-01

    Jupiter's moon Europa is one of the most intriguing objects in our Solar System. This 2000km-wide body has a geologically young solid water ice crust that is believed to cover a global ocean of liquid water. The presence of this ocean, together with a source of heating through tidal forces, make Europa a conceivable location for extraterrestrial life. The science case for exploring all aspects of this icy world is compelling. NASA has selected the Europa Mission (formerly Europa Clipper) to study Europa in detail in the 2020s through multiple flybys, and ESA's JUICE mission will perform two flybys of the body in the 2030s. The US agency has extended to the European Space Agency an invitation to provide a contribution to their mission. European scientists interested in Europa science and exploration are currently organizing themselves, in the framework of a coordinated Europa M5 Inititative to study concurrently the main options for this ESA contribution, from a simple addition of individual instruments to the NASA spacecraft, to a lander to investigate Europa's surface in situ. A high speed lander - a penetrator - is by far the most promising technology to achieve this latter option within the anticipated mass constraints, and studies of such a hard lander, many funded by ESA, are now at an advanced level. An international team to formally propose an Europa penetrator to ESA in response to the anticipated ESA M5 call is growing. The working title of this proposal is Akon (Άκων), named after the highly accurate javelin gifted to Europa by Zeus in ancient Greek mythology. We present plans for the Akon penetrator, which would impact Europa's surface at several hundred metres per second, and travel up to several metres into the moon's subsurface. To achieve this, the penetrator would be delivered to the surface by a dedicated descent module, to be destroyed on impact following release of the penetrator above the surface. It is planned that the instruments to be

  15. The impact of increased interconnection on electricity systems with large penetrations of wind generation: A case study of Ireland and Great Britain

    DEFF Research Database (Denmark)

    Denny, E.; Tuohy, A.; Meibom, Peter

    2010-01-01

    interconnection for the island of Ireland with large penetrations of wind generation. The results suggest that increased interconnection should reduce average prices in Ireland, and the variability of those prices. The simulations also suggest that while increased interconnection may reduce carbon dioxide...

  16. Metasploit penetration testing cookbook

    CERN Document Server

    Agarwal, Monika

    2013-01-01

    This book follows a Cookbook style with recipes explaining the steps for penetration testing with WLAN, VOIP, and even cloud computing. There is plenty of code and commands used to make your learning curve easy and quick.This book targets both professional penetration testers as well as new users of Metasploit, who wish to gain expertise over the framework and learn an additional skill of penetration testing, not limited to a particular OS. The book requires basic knowledge of scanning, exploitation, and the Ruby language.

  17. Development of a Thermo-chemical Non-equilibrium Solver for Hypervelocity Flows

    Science.gov (United States)

    Balasubramanian, R.; Anandhanarayanan, K.

    2015-04-01

    In the present study, a three dimensional flowsolver is indigenously developed to numerically simulate hypervelocity thermal and chemical non equilibrium reactive air flow past flight vehicles. The two-temperature, five species, seventeen reactions, thermo-chemical non equilibrium, non-ionizing, air-chemistry model of Park is implemented in a compressible viscous code CERANS and solved in the finite volume framework. The energy relaxation is addressed by a conservation equation for the vibrational energy of the gas mixture resulting in the evaluation of its vibrational temperature. The AUSM-PW+ numerical flux function has been used for modeling the convective fluxes and a central differencing approximation is used for modeling the diffusive fluxes. The flowsolver had been validated for specifically chosen test cases with inherent flow complexities of non-ionizing hypervelocity thermochemical nonequilibrium flows and results obtained are in good agreement with results available in open literature.

  18. Penetration testing with Perl

    CERN Document Server

    Berdeaux, Douglas

    2014-01-01

    If you are an expert Perl programmer interested in penetration testing or information security, this guide is designed for you. However, it will also be helpful for you even if you have little or no Linux shell experience.

  19. penetrating abdominal trauma

    African Journals Online (AJOL)

    gender, mechanism of injury, injury severity scores (ISS), penetrating ... ileus, reduced pulmonary function and loss of muscle mass and function, all of .... pathophysiology and rehabilitation. ... quality of life after surgery for colorectal cancer.

  20. Experimental demonstration of plasma-drag acceleration of a dust cloud to hypervelocities.

    Science.gov (United States)

    Ticoş, C M; Wang, Zhehui; Wurden, G A; Kline, J L; Montgomery, D S; Dorf, L A; Shukla, P K

    2008-04-18

    Simultaneous acceleration of hundreds of dust particles to hypervelocities by collimated plasma flows ejected from a coaxial gun is demonstrated. Graphite and diamond grains with radii between 5 and 30 microm, and flying at speeds up to 3.7 km/s, have been recorded with a high-speed camera. The observations agree well with a model for plasma-drag acceleration of microparticles much larger than the plasma screening length.

  1. Barrier penetration database

    International Nuclear Information System (INIS)

    Fainberg, A.; Bieber, A.M. Jr.

    1978-11-01

    This document is intended to supply the NRC and nuclear power plant licensees with basic data on the times required to penetrate forcibly the types of barriers commonly found in nuclear plants. These times are necessary for design and evaluation of the physical protection system required under 10CFR73.55. Each barrier listed is described in detail. Minor variations in basic barrier construction that result in the same penetration time, are also described

  2. Nonlinear CARS measurement of nitrogen vibrational and rotational temperatures behind hypervelocity strong shock wave

    Science.gov (United States)

    Osada, Takashi; Endo, Youichi; Kanazawa, Chikara; Ota, Masanori; Maeno, Kazuo

    2009-02-01

    The hypervelocity strong shock waves are generated, when the space vehicles reenter the atmosphere from space. Behind the shock wave radiative and non-equilibrium flow is generated in front of the surface of the space vehicle. Many studies have been reported to investigate the phenomena for the aerospace exploit and reentry. The research information and data on the high temperature flows have been available to the rational heatproof design of the space vehicles. Recent development of measurement techniques with laser systems and photo-electronics now enables us to investigate the hypervelocity phenomena with greatly advanced accuracy. In this research strong shock waves are generated in low-density gas to simulate the reentry range gas flow with a free-piston double-diaphragm shock tube, and CARS (Coherent Anti-stokes Raman Spectroscopy) measurement method is applied to the hypervelocity flows behind the shock waves, where spectral signals of high space/time resolution are acquired. The CARS system consists of YAG and dye lasers, a spectroscope, and a CCD camera system. We obtain the CARS signal spectrum data by this special time-resolving experiment, and the vibrational and rotational temperatures of N2 are determined by fitting between the experimental spectroscopic profile data and theoretically estimated spectroscopic data.

  3. Nonlinear CARS measurement of nitrogen vibrational and rotational temperatures behind hypervelocity strong shock wave

    Energy Technology Data Exchange (ETDEWEB)

    Osada, Takashi; Endo, Youichi [Graduate Student, Chiba University 1-33 Yayoi, Inage, Chiba, 263-8522 (Japan); Kanazawa, Chikara [Undergraduate, Chiba University 1-33 Yayoi, Inage, Chiba, 63-8522 (Japan); Ota, Masanori; Maeno, Kazuo, E-mail: maeno@faculty.chiba-u.j [Graduate School of Engineering, Chiba University 1-33 Yayoi, Inage, Chiba, 263-8522 (Japan)

    2009-02-01

    The hypervelocity strong shock waves are generated, when the space vehicles reenter the atmosphere from space. Behind the shock wave radiative and non-equilibrium flow is generated in front of the surface of the space vehicle. Many studies have been reported to investigate the phenomena for the aerospace exploit and reentry. The research information and data on the high temperature flows have been available to the rational heatproof design of the space vehicles. Recent development of measurement techniques with laser systems and photo-electronics now enables us to investigate the hypervelocity phenomena with greatly advanced accuracy. In this research strong shock waves are generated in low-density gas to simulate the reentry range gas flow with a free-piston double-diaphragm shock tube, and CARS (Coherent Anti-stokes Raman Spectroscopy) measurement method is applied to the hypervelocity flows behind the shock waves, where spectral signals of high space/time resolution are acquired. The CARS system consists of YAG and dye lasers, a spectroscope, and a CCD camera system. We obtain the CARS signal spectrum data by this special time-resolving experiment, and the vibrational and rotational temperatures of N{sub 2} are determined by fitting between the experimental spectroscopic profile data and theoretically estimated spectroscopic data.

  4. Nonlinear CARS measurement of nitrogen vibrational and rotational temperatures behind hypervelocity strong shock wave

    International Nuclear Information System (INIS)

    Osada, Takashi; Endo, Youichi; Kanazawa, Chikara; Ota, Masanori; Maeno, Kazuo

    2009-01-01

    The hypervelocity strong shock waves are generated, when the space vehicles reenter the atmosphere from space. Behind the shock wave radiative and non-equilibrium flow is generated in front of the surface of the space vehicle. Many studies have been reported to investigate the phenomena for the aerospace exploit and reentry. The research information and data on the high temperature flows have been available to the rational heatproof design of the space vehicles. Recent development of measurement techniques with laser systems and photo-electronics now enables us to investigate the hypervelocity phenomena with greatly advanced accuracy. In this research strong shock waves are generated in low-density gas to simulate the reentry range gas flow with a free-piston double-diaphragm shock tube, and CARS (Coherent Anti-stokes Raman Spectroscopy) measurement method is applied to the hypervelocity flows behind the shock waves, where spectral signals of high space/time resolution are acquired. The CARS system consists of YAG and dye lasers, a spectroscope, and a CCD camera system. We obtain the CARS signal spectrum data by this special time-resolving experiment, and the vibrational and rotational temperatures of N 2 are determined by fitting between the experimental spectroscopic profile data and theoretically estimated spectroscopic data.

  5. Microstructural observations on the terminal penetration of long rod projectile

    OpenAIRE

    Krushna Kumbhar; P. Ponguru Senthil; A.K. Gogia

    2017-01-01

    Present study focuses on the terminal penetration of tungsten heavy alloy (WHA) long rod penetrator impacted against armour steel at an impact velocity of 1600 m/s. The residual penetrator and armour steel target recovered after the ballistic test have been characterized using optical microscope, scanning electron microscope (SEM) and electron probe micro analyzer (EPMA). Metallurgical changes in target steel and WHA remnant have been analysed. Large shear stresses and shear localization have...

  6. Meteorite impact in the ocean

    Science.gov (United States)

    Strelitz, R.

    1979-01-01

    In the present study, the dynamic of hypervelocity impacts and crater formation in water are examined with allowance for the unique properties of water. More precisely, the transient crater calculated is permitted to relax and act as a source of oceanic surface waves.

  7. HMO penetration and physicians' earnings.

    Science.gov (United States)

    Hadley, J; Mitchell, J M

    1999-11-01

    The goal of this study is to estimate whether cross-sectional variations in enrollment in health maintenance organizations (HMOs) affected physicians' earnings and hourly income in 1990. Using data from a nationally representative sample of 4,577 younger physicians (penetration is endogenous and used the instrumental variables approach to obtain unbiased estimates. HMO penetration had a negative and statistically significant impact on physicians earnings in 1990. A doubling of the average level of HMO penetration in the market is estimated to reduce annual earnings by 7% to 10.7%, and hourly earnings by approximately 6% to 9%. It appears that HMOs were successful in reducing physicians' annual and per hour earnings in 1990, presumably through a combination of fewer visits and lower payment rates for people covered by HMOs. Although these results cannot be generalized to all physicians, the experience of a younger cohort of physicians may still be a good indicator of the future effects of HMOs because younger physicians may be more susceptible to market forces than older and more established physicians. Moreover, these results may be somewhat conservative because they reflect market behavior in 1990, several years before the rapid growth and more aggressive market behavior of HMOs in recent years.

  8. Laboratory Impact Experiments

    Science.gov (United States)

    Horanyi, M.; Munsat, T.

    2017-12-01

    The experimental and theoretical programs at the SSERVI Institute for Modeling Plasmas, Atmospheres, and Cosmic Dust (IMPACT) address the effects of hypervelocity dust impacts and the nature of the space environment of granular surfaces interacting with solar wind plasma and ultraviolet radiation. These are recognized as fundamental planetary processes due their role in shaping the surfaces of airless planetary objects, their plasma environments, maintaining dust haloes, and sustaining surface bound exospheres. Dust impacts are critically important for all airless bodies considered for possible human missions in the next decade: the Moon, Near Earth Asteroids (NEAs), Phobos, and Deimos, with direct relevance to crew and mission safety and our ability to explore these objects. This talk will describe our newly developed laboratory capabilities to assess the effects of hypervelocity dust impacts on: 1) the gardening and redistribution of dust particles; and 2) the generation of ionized and neutral gasses on the surfaces of airless planetary bodies.

  9. Penetration portion shielding structure

    International Nuclear Information System (INIS)

    Hayashi, Katsumi; Narita, Hitoshi; Handa, Hiroyuki; Takeuchi, Jun; Tozuka, Fumio.

    1994-01-01

    Openings of a plurality of shieldings for penetration members are aligned to each other, and penetration members are inserted from the openings. Then, the openings of the plurality of shielding members are slightly displaced with each other to make the penetration portions into a helical configuration, so that leakage of radiation is reduced. Upon removal of the members, reverse operation is conducted. When a flowable shielding material is used, the penetration portions are constituted with two plates having previously formed openings and pipes for connecting the openings with each other and a vessel covering the entire of them. After passing the penetration members such as a cable, the relative position of the two plates is changed by twisting, to form a helical configuration which reduces radiation leakage. Since they are bent into the helical configuration, shielding performance is extremely improved compared with a case that radiation leakage is caused from an opening of a straight pipe. In addition, since they can be returned to straight pipes, attachment, detachment and maintenance can be conducted easily. (N.H.)

  10. Impact effects in thin-walled structures

    International Nuclear Information System (INIS)

    Zukas, J.A.; Gaskill, B.

    1996-01-01

    A key parameter in the design of protective structures is the critical impact velocity, also known as the ballistic limit. This is the velocity below which a striker will fail to penetrate a barrier or some protective device. For strikers with regular shapes, such as cylinders (long and short), spheres and cones, analytical and empirical formulations for the determination of a ballistic limit exist at impact velocities ranging from 250 m/s to 6 km/s or higher. For non-standard shapes, two- and three-dimensional wave propagation codes (hydrocodes) can be valuable adjuncts to experiments in ballistic limit determinations. This is illustrated with the help of the ZeuS code in determining the ballistic limit of a short, tubular projectile striking a thin aluminum barrier and contrasting it to the value of the ballistic limit of a spherical projectile of equal mass against the same target. Several interesting features of the debris cloud generated by a tubular projectile striking a Whipple shield at hypervelocity are also pointed out. The paper concludes with a consideration of hydrodynamic ram effects in fluid-filled thin-walled structures. Where possible, comparisons are made of computed results with experimental data

  11. Ground penetrating radar

    CERN Document Server

    Daniels, David J

    2004-01-01

    Ground-penetrating radar has come to public attention in recent criminal investigations, but has actually been a developing and maturing remote sensing field for some time. In the light of recent expansion of the technique to a wide range of applications, the need for an up-to-date reference has become pressing. This fully revised and expanded edition of the best-selling Surface-Penetrating Radar (IEE, 1996) presents, for the non-specialist user or engineer, all the key elements of this technique, which span several disciplines including electromagnetics, geophysics and signal processing. The

  12. Skull penetrating wound

    International Nuclear Information System (INIS)

    Gonzalez Orlandi, Yvei; Junco Martin, Reinel; Rojas Manresa, Jorge; Duboy Limonta, Victor; Matos Herrera, Omar; Saez Corvo, Yunet

    2011-01-01

    The cranioencephalic trauma is common in the emergence centers to care for patients with multiple traumata and it becames in a health problem in many countries. Skull penetrating trauma is located in a special place due to its low frequency. In present paper a case of male patient aged 52 severely skull-injured with penetrating wound caused by a cold steel that remained introduced into the left frontotemporal region. After an imaging study the emergence surgical treatment was applied and patient evolves adequately after 25 days of hospitalization. Nowadays, she is under rehabilitation treatment due to a residual right hemiparesis.(author)

  13. Quasi-static time-series simulation using OpenDSS in IEEE distribution feeder model with high PV penetration and its impact on solar forecasting

    Science.gov (United States)

    Mohammed, Touseef Ahmed Faisal

    Since 2000, renewable electricity installations in the United States (excluding hydropower) have more than tripled. Renewable electricity has grown at a compounded annual average of nearly 14% per year from 2000-2010. Wind, Concentrated Solar Power (CSP) and solar Photo Voltaic (PV) are the fastest growing renewable energy sectors. In 2010 in the U.S., solar PV grew over 71% and CSP grew by 18% from the previous year. Globally renewable electricity installations have more than quadrupled from 2000-2010. Solar PV generation grew by a factor of more than 28 between 2000 and 2010. The amount of CSP and solar PV installations are increasing on the distribution grid. These PV installations transmit electrical current from the load centers to the generating stations. But the transmission and distribution grid have been designed for uni-directional flow of electrical energy from generating stations to load centers. This causes imbalances in voltage and switchgear of the electrical circuitry. With the continuous rise in PV installations, analysis of voltage profile and penetration levels remain an active area of research. Standard distributed photovoltaic (PV) generators represented in simulation studies do not reflect the exact location and variability properties such as distance between interconnection points to substations, voltage regulators, solar irradiance and other environmental factors. Quasi-Static simulations assist in peak load planning hour and day ahead as it gives a time sequence analysis to help in generation allocation. Simulation models can be daily, hourly or yearly depending on duty cycle and dynamics of the system. High penetration of PV into the power grid changes the voltage profile and power flow dynamically in the distribution circuits due to the inherent variability of PV. There are a number of modeling and simulations tools available for the study of such high penetration PV scenarios. This thesis will specifically utilize OpenDSS, a open source

  14. Europa Kinetic Ice Penetrator System for Hyper Velocity Instrument Deposition

    Science.gov (United States)

    Robinson, Tessa

    Landing of a payload on any celestial body has only used a soft landing system. These systems use retro rockets and atmospheric components to match velocity and then overcome local gravity in order to land on the surface. This is a proposed system for depositing instrumentation on an icy surface at hypervelocity using the properties of different projectiles and ejecta properties that would negate the need for a soft landing system. This system uses two projectiles, a cylinder with inner aerodynamic surfaces and a payload section with a conical nose and aerodynamic surfaces. The cylinder lands first, creates a region of fractured ice, and directs that fractured material into a collimated ejecta stream. The payload travels through the ejecta and lands in the fractured region. The combination of the ejecta stream and the softened target material reduces the impact acceleration to within survivable levels.

  15. Tumor penetrating peptides

    Directory of Open Access Journals (Sweden)

    Tambet eTeesalu

    2013-08-01

    Full Text Available Tumor-homing peptides can be used to deliver drugs into tumors. Phage library screening in live mice has recently identified homing peptides that specifically recognize the endothelium of tumor vessels, extravasate, and penetrate deep into the extravascular tumor tissue. The prototypic peptide of this class, iRGD (CRGDKGPDC, contains the integrin-binding RGD motif. RGD mediates tumor homing through binding to αv integrins, which are selectively expressed on various cells in tumors, including tumor endothelial cells. The tumor-penetrating properties of iRGD are mediated by a second sequence motif, R/KXXR/K. This C-end Rule (or CendR motif is active only when the second basic residue is exposed at the C-terminus of the peptide. Proteolytic processing of iRGD in tumors activates the cryptic CendR motif, which then binds to neuropilin-1 activating an endocytic bulk transport pathway through tumor tissue. Phage screening has also yielded tumor-penetrating peptides that function like iRGD in activating the CendR pathway, but bind to a different primary receptor. Moreover, novel tumor-homing peptides can be constructed from tumor-homing motifs, CendR elements and protease cleavage sites. Pathologies other than tumors can be targeted with tissue-penetrating peptides, and the primary receptor can also be a vascular zip code of a normal tissue. The CendR technology provides a solution to a major problem in tumor therapy, poor penetration of drugs into tumors. The tumor-penetrating peptides are capable of taking a payload deep into tumor tissue in mice, and they also penetrate into human tumors ex vivo. Targeting with these peptides specifically increases the accumulation in tumors of a variety of drugs and contrast agents, such as doxorubicin, antibodies and nanoparticle-based compounds. Remarkably the drug to be targeted does not have to be coupled to the peptide; the bulk transport system activated by the peptide sweeps along any compound that is

  16. Hypervelocity Microparticle Impact Studies: Simulating Cosmic Dust Impacts on the Dustbuster

    Science.gov (United States)

    Austin, D. E.; Manning, H. L. K.; Bailey, C. L.; Farnsworth, J. T.; Ahrens, T. J.; Beauchamp, J. L.

    2002-01-01

    Iron and copper microparticles accelerated to 2-20 km/s in a 2 MV Van de Graaff accelerator were used to test a recently-developed cosmic dust mass spectrometer, known as the Dustbuster. Additional information is contained in the original extended abstract.

  17. Thermal protection for hypervelocity flight in earth's atmosphere by use of radiation backscattering ablating materials

    Science.gov (United States)

    Howe, John T.; Yang, Lily

    1991-01-01

    A heat-shield-material response code predicting the transient performance of a material subject to the combined convective and radiative heating associated with the hypervelocity flight is developed. The code is dynamically interactive to the heating from a transient flow field, including the effects of material ablation on flow field behavior. It accomodates finite time variable material thickness, internal material phase change, wavelength-dependent radiative properties, and temperature-dependent thermal, physical, and radiative properties. The equations of radiative transfer are solved with the material and are coupled to the transfer energy equation containing the radiative flux divergence in addition to the usual energy terms.

  18. Antibody tumor penetration

    Science.gov (United States)

    Thurber, Greg M.; Schmidt, Michael M.; Wittrup, K. Dane

    2009-01-01

    Antibodies have proven to be effective agents in cancer imaging and therapy. One of the major challenges still facing the field is the heterogeneous distribution of these agents in tumors when administered systemically. Large regions of untargeted cells can therefore escape therapy and potentially select for more resistant cells. We present here a summary of theoretical and experimental approaches to analyze and improve antibody penetration in tumor tissue. PMID:18541331

  19. Python penetration testing essentials

    CERN Document Server

    Mohit

    2015-01-01

    If you are a Python programmer or a security researcher who has basic knowledge of Python programming and want to learn about penetration testing with the help of Python, this book is ideal for you. Even if you are new to the field of ethical hacking, this book can help you find the vulnerabilities in your system so that you are ready to tackle any kind of attack or intrusion.

  20. Impact of whole brain radiation therapy on CSF penetration ability of Icotinib in EGFR-mutated non-small cell lung cancer patients with brain metastases: Results of phase I dose-escalation study.

    Science.gov (United States)

    Zhou, Lin; He, Jiazhuo; Xiong, Weijie; Liu, Yongmei; Xiang, Jing; Yu, Qin; Liang, Maozhi; Zhou, Xiaojuan; Ding, Zhenyu; Huang, Meijuan; Ren, Li; Zhu, Jiang; Li, Lu; Hou, Mei; Ding, Lieming; Tan, Fenlai; Lu, You

    2016-06-01

    Whole-brain radiation therapy (WBRT) and epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are both treatment options for EGFR-mutated non-small cell lung cancer (NSCLC) patients with brain metastases. However, the dose-escalation toxicity and efficacy of combination therapy, and the effect of WBRT on cerebrospinal fluid (CSF) penetration of EGFR-TKIs are still unclear. EGFR-mutated NSCLC patients with brain metastases were enrolled in this study, and the cohorts were constructed with a 3+3 design. The patients received icotinib with escalating doses (125-625mg, tid), and the concurrent WBRT (37.5Gy/15f/3weeks) started a week later. The CSF penetration rates of icotinib were tested before, immediately after, and 4 weeks after WBRT, respectively. Potential toxicities and benefits from dose-escalation treatment were analyzed. Fifteen patients were included in this study, 3 at each dose level from 125mg-375mg and 6 at 500mg with 3 occurred dose-limiting toxicities. The maximal tolerated dose of icotinib was 375mg tid in this combination therapy. There was a significant correlation between icotinib concentration in the CSF and plasma (R(2)=0.599, Picotinib, from 1.2% to 9.7%, reached a maximum at 375mg (median, 6.1%). There was no significant difference for CSF penetration rates among the three test points (median, 4.1% vs. 2.8% vs. 2.8%, P=0.16). The intracranial objective response rate and median intracranial progression free survival are 80% and 18.9 months. WBRT plus concurrent icotinib is well tolerated in EGFR-mutated NSCLC patients with brain metastases, up to an icotinib dose of 375mg tid. The icotinib CSF concentration seemed to have a potential ceiling effect with the dose escalation, and WBRT seemed to have no significant impact on CSF penetration of icotinib till 4 weeks after the treatment. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  1. Bodily action penetrates affective perception

    Science.gov (United States)

    Rigutti, Sara; Gerbino, Walter

    2016-01-01

    Fantoni & Gerbino (2014) showed that subtle postural shifts associated with reaching can have a strong hedonic impact and affect how actors experience facial expressions of emotion. Using a novel Motor Action Mood Induction Procedure (MAMIP), they found consistent congruency effects in participants who performed a facial emotion identification task after a sequence of visually-guided reaches: a face perceived as neutral in a baseline condition appeared slightly happy after comfortable actions and slightly angry after uncomfortable actions. However, skeptics about the penetrability of perception (Zeimbekis & Raftopoulos, 2015) would consider such evidence insufficient to demonstrate that observer’s internal states induced by action comfort/discomfort affect perception in a top-down fashion. The action-modulated mood might have produced a back-end memory effect capable of affecting post-perceptual and decision processing, but not front-end perception. Here, we present evidence that performing a facial emotion detection (not identification) task after MAMIP exhibits systematic mood-congruent sensitivity changes, rather than response bias changes attributable to cognitive set shifts; i.e., we show that observer’s internal states induced by bodily action can modulate affective perception. The detection threshold for happiness was lower after fifty comfortable than uncomfortable reaches; while the detection threshold for anger was lower after fifty uncomfortable than comfortable reaches. Action valence induced an overall sensitivity improvement in detecting subtle variations of congruent facial expressions (happiness after positive comfortable actions, anger after negative uncomfortable actions), in the absence of significant response bias shifts. Notably, both comfortable and uncomfortable reaches impact sensitivity in an approximately symmetric way relative to a baseline inaction condition. All of these constitute compelling evidence of a genuine top-down effect on

  2. Bodily action penetrates affective perception

    Directory of Open Access Journals (Sweden)

    Carlo Fantoni

    2016-02-01

    Full Text Available Fantoni & Gerbino (2014 showed that subtle postural shifts associated with reaching can have a strong hedonic impact and affect how actors experience facial expressions of emotion. Using a novel Motor Action Mood Induction Procedure (MAMIP, they found consistent congruency effects in participants who performed a facial emotion identification task after a sequence of visually-guided reaches: a face perceived as neutral in a baseline condition appeared slightly happy after comfortable actions and slightly angry after uncomfortable actions. However, skeptics about the penetrability of perception (Zeimbekis & Raftopoulos, 2015 would consider such evidence insufficient to demonstrate that observer’s internal states induced by action comfort/discomfort affect perception in a top-down fashion. The action-modulated mood might have produced a back-end memory effect capable of affecting post-perceptual and decision processing, but not front-end perception. Here, we present evidence that performing a facial emotion detection (not identification task after MAMIP exhibits systematic mood-congruent sensitivity changes, rather than response bias changes attributable to cognitive set shifts; i.e., we show that observer’s internal states induced by bodily action can modulate affective perception. The detection threshold for happiness was lower after fifty comfortable than uncomfortable reaches; while the detection threshold for anger was lower after fifty uncomfortable than comfortable reaches. Action valence induced an overall sensitivity improvement in detecting subtle variations of congruent facial expressions (happiness after positive comfortable actions, anger after negative uncomfortable actions, in the absence of significant response bias shifts. Notably, both comfortable and uncomfortable reaches impact sensitivity in an approximately symmetric way relative to a baseline inaction condition. All of these constitute compelling evidence of a genuine top

  3. Rainfall simulation experiments and Water Drop Penetration Time measurements shed light on the impact of water repellency on soils under organic farming management in Eastern Spain

    Science.gov (United States)

    Cerdà, Artemi; González, Óscar; León, Javier; Jordán, Antonio

    2015-04-01

    Water repellency is a well-know soil property since the research of professor Stefan Helmut Doerr recovered and powered the research developed by professor DeBano (Atanassova and Doerr, 2011; ; Jordán et al., 2011; Bodí et al., 2012; González Peñaloza et al., 2012 Bodí et al., 2013; García Moreno et al., 2013; Jordán et al., 2013; Badía-Villas et al., 2014; Jordán et al., 2013; Jiménez Morillo et al., 2015). However, little is known about the impact of water repellency in surface runoff generation, although usually is accepted that when more soil water repellent is a soil, higher will be the surface runoff discharge (Stoff et al., 2011; Madsen et al., 2011; León et al., 2013; Lozano et al., 2013; Mataix-Solera et al., 2013; Santos et al., 2015). And the impact of the water repellency and then the higher surface wash discharge can trigger high erosion rates (Kröpfl et al., 2013; Mandal and Sharda 2013; Zhao et al., 2013). However these relationships were not demonstrated as the most water repellent soils are the one with high organic contents, and those soils do not have soil losses, probably due to the high infiltration rates due to the macropore flow. Rainfall simulation experiments can shed light in the runoff generation mechanism as they can control the rainfall intensity (Bodí et al., 2012; Iserloh et al., 2012; Iserloh et al., 2013), and inform about the main mechanism of the soil erosion process Cerdà and Jurgensen, 2011; Daugherty et al., 2011; Podwojewski et al., 2011; Dunkerley, 2012; Garel et al., 2012; Jouquet et al., 2012; Kibet et al., 2013; Butzen et al., 2014; Ma et al., 2014; Martínez Murillo et al., 2013). To determine the relationship between surface runoff generated under simulated rainfall (Cerdà, 1988a; 1988b; Cerdà et al., 1998; Ziadat and Taimeh, 2013) with a small rainfall simulator (0.25 m2) and water repellency measurements with the Water Drop Penetration time methods were done (Bodí et al., 2012). The results show that

  4. Study of Penetration Technology

    Science.gov (United States)

    1976-11-01

    srecimens fabricated at the AFATL, AISI-01 oil quenched bar stock was used. Three of the projectiles used in the Eglin penetration experiments are shown...in the Mathema- tical Laboratory at Eglin AFB, is essencially a fourth order Runge-Kutta numerical method for solving simultaneous differential...C9G. VEL. X-COMPo (M4/5): d!10. I oil 140. 107. 82. RmCC~kr’ED TIME OF MAXIftjM/MINIM94U COIL VOLTAGE tSI MAX 0040 A 55 *.03J04A 0 0 05ji6 .000634 MIN

  5. Deep penetration calculations

    International Nuclear Information System (INIS)

    Thompson, W.L.; Deutsch, O.L.; Booth, T.E.

    1980-04-01

    Several Monte Carlo techniques are compared in the transport of neutrons of different source energies through two different deep-penetration problems each with two parts. The first problem involves transmission through a 200-cm concrete slab. The second problem is a 90 0 bent pipe jacketed by concrete. In one case the pipe is void, and in the other it is filled with liquid sodium. Calculations are made with two different Los Alamos Monte Carlo codes: the continuous-energy code MCNP and the multigroup code MCMG

  6. Modeling of Oblique Penetration into Geologic Targets Using Cavity Expansion Penetrator Loading with Target free-Surface Effects

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Joe; Longcope, Donald B.; Tabbara, Mazen R.

    1999-05-03

    A procedure has been developed to represent the loading on a penetrator and its motion during oblique penetration into geologic media. The penetrator is modeled with the explicit dynamics, finite element computer program PRONTO 3D and the coupled pressure on the penetrator is given in a new loading option based on a separate cavity expansion (CE) solution that accounts for the pressure-reduction from a nearby target free surface. The free-surface influ- ence distance is selected in a predictive manner by considering the pressure to expand a spherical cavity in a finite radius sphere of the target material. The CE/PRONTO 3D procedure allows a detailed description of the penetrator for predicting shock environments or structural failure dur- ing the entire penetration event and is sufficiently rapid to be used in design optimization. It has been evaluated by comparing its results with data from two field tests of a full-scale penetrator into frozen soil at an impact angles of 49.6 and 52.5 degrees from the horizontal. The measured penetrator rotations were 24 and 22 degrees, respectively. In the simulation, the rotation was21 degrees and predominately resulted from the pressure reduction of the free surface. Good agree- ment was also found for the penetration depth and axial and lateral acceleration at two locations in the penetrator.

  7. HMO penetration and the geographic mobility of practicing physicians.

    Science.gov (United States)

    Polsky, D; Kletke, P R; Wozniak, G D; Escarce, J J

    2000-09-01

    In this study, we assessed the influence of changes in health maintenance organization (HMO) penetration on the probability that established patient care physicians relocated their practices or left patient care altogether. For physicians who relocated their practices, we also assessed the impact of HMO penetration on their destination choices. We found that larger increases in HMO penetration decreased the probability that medical/surgical specialists in early career stayed in patient care in the same market, but had no impact on generalists, hospital-based specialists, or mid career medical/surgical specialists. We also found that physicians who relocated their practices were much more likely to choose destination markets with the same level of HMO penetration or lower HMO penetration compared with their origin markets than they were to choose destination markets with higher HMO penetration. The largely negligible impact of changes in HMO penetration on established physicians' decisions to relocate their practices or leave patient care is consistent with high relocation and switching costs. Relocating physicians' attraction to destination markets with the same level of HMO penetration as their origin markets suggests that, while physicians' styles of medical practice may adapt to changes in market conditions, learning new practice styles is costly.

  8. Competition and mobile penetration in sub-Saharan Africa | Belayeh ...

    African Journals Online (AJOL)

    Saharan African (SSA) countries between 2000 and 2006. We examine both the impact of introducing competition and the role of intensity of competition on mobile penetration in these countries. Different specifications with different measures of ...

  9. Penetrating abdominal trauma.

    Science.gov (United States)

    Henneman, P L

    1989-08-01

    The management of patients with penetrating abdominal trauma is outlined in Figure 1. Patients with hemodynamic instability, evisceration, significant gastrointestinal bleeding, peritoneal signs, gunshot wounds with peritoneal violation, and type 2 and 3 shotgun wounds should undergo emergency laparotomy. The initial ED management of these patients includes airway management, monitoring of cardiac rhythm and vital signs, history, physical examination, and placement of intravenous lines. Blood should be obtained for initial hematocrit, type and cross-matching, electrolytes, and an alcohol level or drug screen as needed. Initial resuscitation should utilize crystalloid fluid replacement. If more than 2 liters of crystalloid are needed to stabilize an adult (less in a child), blood should be given. Group O Rh-negative packed red blood cells should be immediately available for a patient in impending arrest or massive hemorrhage. Type-specific blood should be available within 15 minutes. A patient with penetrating thoracic and high abdominal trauma should receive a portable chest x-ray, and a hemo- or pneumothorax should be treated with tube thoracostomy. An unstable patient with clinical signs consistent with a pneumothorax, however, should receive a tube thoracostomy prior to obtaining roentgenographic confirmation. If time permits, a nasogastric tube and Foley catheter should be placed, and the urine evaluated for blood (these procedures can be performed in the operating room). If kidney involvement is suspected because of hematuria or penetrating trauma in the area of a kidney or ureter in a patient requiring surgery, a single-shot IVP should be performed either in the ED or the operating room. An ECG is important in patients with possible cardiac involvement and in patients over the age of 40 going to the operating room. Tetanus status should be updated, and appropriate antibiotics covering bowel flora should be given. Operative management should rarely be delayed

  10. Penetrating cardiothoracic war wounds.

    Science.gov (United States)

    Biocina, B; Sutlić, Z; Husedzinović, I; Rudez, I; Ugljen, R; Letica, D; Slobodnjak, Z; Karadza, J; Brida, V; Vladović-Relja, T; Jelić, I

    1997-03-01

    Penetrating cardiothoracic war wounds are very common among war casualties. Those injuries require prompt and specific treatment in an aim to decrease mortality and late morbidity. There are a few controversies about the best modality of treatment for such injuries, and there are not many large series of such patients in recent literature. We analysed a group of 259 patients with penetrating cardiothoracic war wounds admitted to our institutions between May 1991 and October 1992. There were 235 (90.7%) patients with thoracic wounds, 14 (5.4%) patients with cardiac, wounds and in 10 (3.7%) patients both heart and lungs were injured. The cause of injury was shrapnel in 174 patients (67%), bullets in 25 patients (9.7%), cluster bomb particles in 45 patients (17.3%) and other (blast etc.) in 15 patients (6%). Patients, 69, had concomitant injuries of various organs. The initial treatment in 164 operated patients was chest drainage in 76 (46.3%) patients, thoracotomy and suture of the lung in 71 (43.2%) patients, lobectomy in 12 (7.3%) patients and pneumonectomy in 5 (3%) patients. Complications include pleural empyema and/or lung abscess in 20 patients (8.4%), incomplete reexpansion of the lung in 10 patients (4.2%), osteomyelitis of the rib in 5 patients (2.1%) and bronchopleural fistula in 1 patient (0.4%). Secondary procedures were decortication in 12 patients, rib resection in 5 patients, lobectomy in 2 patients, pneumonectomy in 4 patients, reconstruction of the chest wall in 2 patients and closure of the bronchopleural fistula in 1 patient. The cardiac chamber involved was right ventricle in 12 patients, left ventricular in 6 patients, right atrium in 7 patients, left atrium in 3 patients, ascending aorta in 2 patients and 1 patient which involved descending aorta, right ventricle and coronary artery (left anterior descending) and inferior vena cava, respectively. The primary procedure was suture in 17 patients (in 10 patients with the additional suture of the

  11. Penetration Tester's Open Source Toolkit

    CERN Document Server

    Faircloth, Jeremy

    2011-01-01

    Great commercial penetration testing tools can be very expensive and sometimes hard to use or of questionable accuracy. This book helps solve both of these problems. The open source, no-cost penetration testing tools presented do a great job and can be modified by the user for each situation. Many tools, even ones that cost thousands of dollars, do not come with any type of instruction on how and in which situations the penetration tester can best use them. Penetration Tester's Open Source Toolkit, Third Edition, expands upon existing instructions so that a professional can get the most accura

  12. Discovery of Two New Hypervelocity Stars from the LAMOST Spectroscopic Surveys

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Y.; Liu, X.-W.; Chen, B.-Q. [South-Western Institute for Astronomy Research, Yunnan University, Kunming 650500 (China); Zhang, H.-W.; Wang, C.; Tian, Z.-J. [Department of Astronomy, Peking University, Beijing 100871 (China); Xiang, M.-S.; Li, Y.-B. [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Yuan, H.-B. [Department of Astronomy, Beijing Normal University, Beijing 100875 (China); Wang, B., E-mail: yanghuang@pku.edu.cn, E-mail: x.liu@pku.edu.cn, E-mail: zhanghw@pku.edu.cn [Key Laboratory for the Structure and Evolution of Celestial Objects, Yunnan Observatories, CAS, Kunming 650216 (China)

    2017-09-20

    We report the discovery of two new unbound hypervelocity stars (HVSs) from the LAMOST spectroscopic surveys. They are, respectively, a B2V-type star of ∼7 M {sub ⊙} with a Galactic rest-frame radial velocity of 502 km s{sup −1} at a Galactocentric radius of ∼21 kpc and a B7V-type star of ∼4 M {sub ⊙} with a Galactic rest-frame radial velocity of 408 km s{sup −1} at a Galactocentric radius of ∼30 kpc. The origins of the two HVSs are not clear given their currently poorly measured proper motions. However, the future data releases of Gaia should provide proper motion measurements accurate enough to solve this problem. The ongoing LAMOST spectroscopic surveys are expected to yield more HVSs to form a statistical sample, providing vital constraints on understanding the nature of HVSs and their ejection mechanisms.

  13. Mitigation of Autoignition Due to Premixing in a Hypervelocity Flow Using Active Wall Cooling

    Science.gov (United States)

    Axdahl, Erik; Kumar, Ajay; Wilhite, Alan

    2013-01-01

    Preinjection of fuel on the forebody of an airbreathing vehicle is a proposed method to gain access to hypervelocity flight Mach numbers. However, this creates the possibility of autoignition either near the wall or in the core of the flow, thereby consuming fuel prematurely as well as increasing the amount of pressure drag on the vehicle. The computational fluid dynamics code VULCAN was used to conduct three dimensional simulations of the reacting flow in the vicinity of hydrogen injectors on a flat plate at conditions relevant to a Mach 12 notional flight vehicle forebody to determine the location where autoignition occurs. Active wall cooling strategies were formulated and simulated in response to regions of autoignition. It was found that tangential film cooling using hydrogen or helium were both able to nearly or completely eliminate wall autoignition in the flow domain of interest.

  14. BINARY DISRUPTION BY MASSIVE BLACK HOLES: HYPERVELOCITY STARS, S STARS, AND TIDAL DISRUPTION EVENTS

    Energy Technology Data Exchange (ETDEWEB)

    Bromley, Benjamin C. [Department of Physics and Astronomy, University of Utah, 115 S 1400 E, Rm 201, Salt Lake City, UT 84112 (United States); Kenyon, Scott J.; Geller, Margaret J.; Brown, Warren R., E-mail: bromley@physics.utah.edu, E-mail: skenyon@cfa.harvard.edu, E-mail: mgeller@cfa.harvard.edu, E-mail: wbrown@cfa.harvard.edu [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States)

    2012-04-20

    We examine whether disrupted binary stars can fuel black hole growth. In this mechanism, tidal disruption produces a single hypervelocity star (HVS) ejected at high velocity and a former companion star bound to the black hole. After a cluster of bound stars forms, orbital diffusion allows the black hole to accrete stars by tidal disruption at a rate comparable to the capture rate. In the Milky Way, HVSs and the S star cluster imply similar rates of 10{sup -5} to 10{sup -3} yr{sup -1} for binary disruption. These rates are consistent with estimates for the tidal disruption rate in nearby galaxies and imply significant black hole growth from disrupted binaries on 10 Gyr timescales.

  15. The importance of high injection velocity to reduce plasma armature growth and drag in hypervelocity railguns

    International Nuclear Information System (INIS)

    Hawke, R.S.; Dixon, W.R.; Kang, S.W.; McCallen, R.C.; Susoeff, A.R.; Asay, J.R.; Shaninpoor, M.

    1987-01-01

    Plasmas are required to serve as armature in hypervelocity railguns. Typically, the plasmas are at temperatures of about 20-30,000 K and result in a high heat flux on the barrel wall. Slow moving plasmas radiate heat and melt the launcher wall causing it to ablate and resulting in a growth of the armature mass and length. As the velocity increases, the more massive and longer armature will result in greater viscous drag and ultimately limit the maximum achievable velocity. Several possible means of reducing the armature growth are possible. This paper discusses two of them, use of heat resistant barrel materials, and reduction of wall heating by reduction of exposure time through use of a high initial velocity. A summary of experimentally based, material ablation resistance calculations is presented. Second, the benefit of high injection velocity is evaluated. Finally, a joint SNLA and LLNL railgun research project based on the above considerations are described

  16. Modeling of Oblique Penetration into Geologic Targets Using Cavity Expansion Penetrator Loading with Target free-Surface Effects

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Joe; Longcope, Donald B.; Tabbara, Mazen R.

    1999-06-01

    A procedure has been developed to represent the loading on a penetrator and its motion during oblique penetration into geologic media. The penetrator is modeled with the explicit dynamics, finite element computer program PRONTO 3D and the coupled pressure on the penetrator is given in a new loading option based on a separate cavity expansion (CE) solution that accounts for the pressure reduction from a nearby target free surface. The free-surface influence distance is selected in a predictive manner by considering the pressure to expand a spherical cavity in a finite radius sphere of the target material. The CE/PRONTO 3D procedure allows a detailed description of the penetrator for predicting shock environments or structural failure during the entire penetra- tion event and is sufficiently rapid to be used in design optimization. It has been evaluated by comparing its results with data from two field tests of a full-scale penetrator into frozen soil at an impact angles of 49.6 and 52.5 degrees from the horizontal. The measured penetrator rotations were 24 and 22 degrees, respectively. In the simulation, the rotation was 21 degrees and predom- inately resulted from the pressure reduction of the free surface. Good agreement was also found for the penetration depth and axial and lateral acceleration at two locations in the penetrator.

  17. Shock Tunnel Studies of the Hypersonic Flowfield around the Hypervelocity Ballistic Models with Aerospikes

    Science.gov (United States)

    Balakalyani, G.; Saravanan, S.; Jagadeesh, G.

    Reduced drag and aerodynamic heating are the two basic design requirements for any hypersonic vehicle [1]. The flowfield around an axisymmetric blunt body is characterized by a bow shockwave standing ahead of its nose. The pressure and temperature behind this shock wave are very high. This increased pressure and temperature are responsible for the high levels of drag and aerodynamic heating over the body. In the past, there have been many investigations on the use of aerospikes as a drag reduction tool. These studies on spiked bodies aim at reducing both the drag and aerodynamic heating by modifying the hypersonic flowfield ahead of the nose of the body [2]. However, most of them used very simple configurations to experimentally study the drag reduction using spikes at hypersonic speeds [3] and therefore very little experimental data is available for a realistic geometric configuration. In the present study, the standard AGARD Hypervelocity Ballistic model 1 is used as the test model. The addition of the spike to the blunt body significantly alters the flowfield ahead of the nose, leading to the formation of a low pressure conical recirculation region, thus causing a reduction in drag and wall heat flux [4]. In the present investigation, aerodynamic drag force is measured over the Hypervelocity Ballistic model-1, with and without spike, at a flow enthalpy of 1.7 MJ/kg. The experiments are carried out at a Mach number of 8 and at zero angle of attack. An internally mountable accelerometer based 3-component force balance system is used to measure the aerodynamic forces on the model. Also computational studies are carried out to complement the experiments.

  18. Physical Penetration Testing: A Whole New Story in Penetration Testing

    NARCIS (Netherlands)

    Dimkov, T.; Pieters, Wolter

    2011-01-01

    Physical penetration testing plays an important role in assuring a company that the security policies are properly enforced and that the security awareness of the employees is on the appropriate level. In physical penetration tests the tester physically enters restricted locations and directly

  19. Impact of copper oxide nanomaterials on differentiated and undifferentiated Caco-2 intestinal epithelial cells; assessment of cytotoxicity, barrier integrity, cytokine production and nanomaterial penetration.

    Science.gov (United States)

    Ude, Victor C; Brown, David M; Viale, Luca; Kanase, Nilesh; Stone, Vicki; Johnston, Helinor J

    2017-08-23

    Copper oxide nanomaterials (CuO NMs) are exploited in a diverse array of products including antimicrobials, inks, cosmetics, textiles and food contact materials. There is therefore a need to assess the toxicity of CuO NMs to the gastrointestinal (GI) tract since exposure could occur via direct oral ingestion, mucocillary clearance (following inhalation) or hand to mouth contact. Undifferentiated Caco-2 intestinal cells were exposed to CuO NMs (10 nm) at concentrations ranging from 0.37 to 78.13 μg/cm 2 Cu (equivalent to 1.95 to 250 μg/ml) and cell viability assessed 24 h post exposure using the alamar blue assay. The benchmark dose (BMD 20), determined using PROAST software, was identified as 4.44 μg/cm 2 for CuO NMs, and 4.25 μg/cm 2 for copper sulphate (CuSO 4 ), which informed the selection of concentrations for further studies. The differentiation status of cells and the impact of CuO NMs and CuSO 4 on the integrity of the differentiated Caco-2 cell monolayer were assessed by measurement of trans-epithelial electrical resistance (TEER), staining for Zonula occludens-1 (ZO-1) and imaging of cell morphology using scanning electron microscopy (SEM). The impact of CuO NMs and CuSO 4 on the viability of differentiated cells was performed via assessment of cell number (DAPI staining), and visualisation of cell morphology (light microscopy). Interleukin-8 (IL-8) production by undifferentiated and differentiated Caco-2 cells following exposure to CuO NMs and CuSO 4 was determined using an ELISA. The copper concentration in the cell lysate, apical and basolateral compartments were measured with Inductive Coupled Plasma Optical Emission Spectrometry (ICP-OES) and used to calculate the apparent permeability coefficient (P app ); a measure of barrier permeability to CuO NMs. For all experiments, CuSO 4 was used as an ionic control. CuO NMs and CuSO 4 caused a concentration dependent decrease in cell viability in undifferentiated cells. CuO NMs and CuSO 4

  20. Hypervelocity launchers

    CERN Document Server

    Igra, Ozer

    2016-01-01

    In the present volume numerous descriptions of Ram accelerators are presented. These descriptions provide good overview on the progress made and the present state of the Ram accelerator technology worldwide.  In addition, articles describing light gas gun, ballistic range including a chapter dealing with shock waves in solids are given. Along with the technical description of considered facilities, samples of obtained results are also included. Each chapter is written by an expert in the described topic providing a comprehensive description of the discussed phenomena.  .

  1. Penetration resistance and ballistic-impact behavior of Ti/TiAl3 metal/intermetallic laminated composites (MILCs: A computational investigation

    Directory of Open Access Journals (Sweden)

    Jennifer S. Snipes

    2016-06-01

    Full Text Available A comprehensive computational engineering analysis is carried out in order to assess suitability of the Ti/TiAl3 metal/intermetallic laminated composites (MILCs for use in both structural and add-on armor applications. This class of composite materials consists of alternating sub-millimeter thick layers of Ti (the ductile and tough constituent and TiAl3 (the stiff and hard constituent. In recent years, this class of materials has been investigated for potential use in light-armor applications as a replacement for the traditional metallic or polymer-matrix composite materials. Within the computational analysis, an account is given to differing functional requirements for candidate materials when used in structural and add-on ballistic armor. The analysis employed is of a transient, nonlinear-dynamics, finite-element character, and the problem investigated involves normal impact (i.e. under zero obliquity angle of a Ti/TiAl3 MILC target plate, over a range of incident velocities, by a fragment simulating projectile (FSP. This type of analysis can provide more direct information regarding the ballistic limit of the subject armor material, as well as help with the identification of the nature and the efficacy of various FSP material-deformation/erosion and kinetic-energy absorption/dissipation phenomena and processes. The results obtained clearly revealed that Ti/TiAl3 MILCs are more suitable for use in add-on ballistic, than in structural armor applications.

  2. Penetration of Photovoltaics in Greece

    Directory of Open Access Journals (Sweden)

    Eugenia Giannini

    2015-06-01

    Full Text Available Recently, an interesting experiment was completed in Greece concerning photovoltaic penetration into the electricity production sector. Based on the relevant laws and in accordance to the related European directives, an explosive penetration process was completed in less than three years, resulting in a 7% share of photovoltaics in electricity production instead of the previous negligible share. The legislation was based on licensing simplification and generous feed-in-tariffs. This approach transformed photovoltaic technology from a prohibitively expensive to a competitive one. This work aims to summarize the relevant legislation and illustrate its effect on the resulting penetration. A sigmoid-shape penetration was observed which was explained by a pulse-type driving force. The return on investment indicator was proposed as an appropriate driving force, which incorporates feed-in-tariffs and turnkey-cost. Furthermore, the resulting surcharge on the electricity price due to photovoltaic penetration was also analyzed.

  3. Theoretical Model of Penetrator with Enhanced Lateral Effect Impacting Thin Metal Target%横向效应增强型侵彻体撞击金属薄板理论模型

    Institute of Scientific and Technical Information of China (English)

    杜忠华; 宋丽丽

    2011-01-01

    To analyze the factors influencing the lateral velocity of penetrator with enhanced lateral effect(PELE)shell,a theoretical analysis model for its lateral velocity is established. According to the requirement of thin metal target sensitivity, the model based on the kinetic energy theorem and momentum theorem is combined with the principle and features of the PELE penetrating thin metal targets. The acoustic impedances of fillers and target materials, the density and Poisson's ratio of shells, the density and thickness of targets, the target impact velocities, the ratios of the inner-outer diameters and the length-diameter ratios are considered comprehensively in this model. Combining with the structure of PELE, the condition of the target and the speed range in the practical application of combat,a three-dimension numerical simulation is proposed by using the software of LS-DYNA. The result shows the lateral velocity of the PELE shell increases with the increase of the acoustic impedance of the filler and the target impact velocity under the interaction of the shell and the filler. The calculating result of the theoretical model agrees with that of the numerical simulation.%为了分析影响横向效应增强型侵彻体( PELE)弹壳体横向速度的因素,该文建立了其横向速度的理论分析模型.该模型基于动能定理和动量定理,考虑了PELE弹对金属薄板灵敏度的要求,结合了PELE弹作用原理及其对金属薄板的作用特点.综合考虑了装填材料及靶板材料的声阻抗、弹体的密度和泊松比、靶板密度及厚度、着靶速度、弹丸壳体的内外径比和长径比因素.结合实战用PELE弹的结构、靶板条件和速度范围,利用LS-DYNA软件进行了三维数值仿真.研究结果发现:PELE弹在壳体自身和装填材料的共同作用下,壳体的横向速度随着弹丸着靶速度和装填材料声阻抗的增大而增大,其理论分析模型计算结果与仿真结果一致性较好.

  4. Penetration in bimodal, polydisperse granular material

    KAUST Repository

    Kouraytem, Nadia; Thoroddsen, Sigurdur T; Marston, J. O.

    2016-01-01

    We investigate the impact penetration of spheres into granular media which are compositions of two discrete size ranges, thus creating a polydisperse bimodal material. We examine the penetration depth as a function of the composition (volume fractions of the respective sizes) and impact speed. Penetration depths were found to vary between delta = 0.5D(0) and delta = 7D(0), which, for mono-modal media only, could be correlated in terms of the total drop height, H = h + delta, as in previous studies, by incorporating correction factors for the packing fraction. Bimodal data can only be collapsed by deriving a critical packing fraction for each mass fraction. The data for the mixed grains exhibit a surprising lubricating effect, which was most significant when the finest grains [d(s) similar to O(30) mu m] were added to the larger particles [d(l) similar to O(200 - 500) mu m], with a size ratio, epsilon = d(l)/d(s), larger than 3 and mass fractions over 25%, despite the increased packing fraction. We postulate that the small grains get between the large grains and reduce their intergrain friction, only when their mass fraction is sufficiently large to prevent them from simply rattling in the voids between the large particles. This is supported by our experimental observations of the largest lubrication effect produced by adding small glass beads to a bed of large sand particles with rough surfaces.

  5. Penetration in bimodal, polydisperse granular material

    KAUST Repository

    Kouraytem, N.

    2016-11-07

    We investigate the impact penetration of spheres into granular media which are compositions of two discrete size ranges, thus creating a polydisperse bimodal material. We examine the penetration depth as a function of the composition (volume fractions of the respective sizes) and impact speed. Penetration depths were found to vary between delta = 0.5D(0) and delta = 7D(0), which, for mono-modal media only, could be correlated in terms of the total drop height, H = h + delta, as in previous studies, by incorporating correction factors for the packing fraction. Bimodal data can only be collapsed by deriving a critical packing fraction for each mass fraction. The data for the mixed grains exhibit a surprising lubricating effect, which was most significant when the finest grains [d(s) similar to O(30) mu m] were added to the larger particles [d(l) similar to O(200 - 500) mu m], with a size ratio, epsilon = d(l)/d(s), larger than 3 and mass fractions over 25%, despite the increased packing fraction. We postulate that the small grains get between the large grains and reduce their intergrain friction, only when their mass fraction is sufficiently large to prevent them from simply rattling in the voids between the large particles. This is supported by our experimental observations of the largest lubrication effect produced by adding small glass beads to a bed of large sand particles with rough surfaces.

  6. Microstructural observations on the terminal penetration of long rod projectile

    Directory of Open Access Journals (Sweden)

    Krushna Kumbhar

    2017-12-01

    Full Text Available Present study focuses on the terminal penetration of tungsten heavy alloy (WHA long rod penetrator impacted against armour steel at an impact velocity of 1600 m/s. The residual penetrator and armour steel target recovered after the ballistic test have been characterized using optical microscope, scanning electron microscope (SEM and electron probe micro analyzer (EPMA. Metallurgical changes in target steel and WHA remnant have been analysed. Large shear stresses and shear localization have resulted in local failure and formation of erosion products. Severe plastic deformation acts as precursor for formation of adiabatic shear band (ASB induced cracks in target steel. Recovered WHA penetrator remnant also exhibits severe plastic deformation forming localized shear bands, ASB induced cracks and shock induced cracks.

  7. Age-related percutaneous penetration part 1: skin factors.

    Science.gov (United States)

    Konda, S; Meier-Davis, S R; Cayme, B; Shudo, J; Maibach, H I

    2012-05-01

    Changes in the skin that occur in the elderly may put them at increased risk for altered percutaneous penetration from pharmacotherapy along with potential adverse effects. Skin factors that may have a role in age-related percutaneous penetration include blood flow, pH, skin thickness, hair and pore density, and the content and structure of proteins, glycosaminoglycans (GAGs), water, and lipids. Each factor is examined as a function of increasing age along with its potential impact on percutaneous penetration. Additionally, topical drugs that successfully overcome the barrier function of the skin can still fall victim to cutaneous metabolism, thereby producing metabolites that may have increased or decreased activity. This overview discusses the current data and highlights the importance of further studies to evaluate the impact of skin factors in age-related percutaneous penetration.

  8. Long-rod penetration: the transition zone between rigid and hydrodynamic penetration modes

    Directory of Open Access Journals (Sweden)

    Jian-feng Lou

    2014-06-01

    Full Text Available Long-rod penetration in a wide range of velocity means that the initial impact velocity varies in a range from tens of meters per second to several kilometers per second. The long rods maintain rigid state when the impact velocity is low, the nose of rod deforms and even is blunted when the velocity gets higher, and the nose erodes and fails to lead to the consumption of long projectile when the velocity is very high due to instantaneous high pressure. That is, from low velocity to high velocity, the projectile undergoes rigid rods, deforming non-erosive rods, and erosive rods. Because of the complicated changes of the projectile, no well-established theoretical model and numerical simulation have been used to study the transition zone. Based on the analysis of penetration behavior in the transition zone, a phenomenological model to describe target resistance and a formula to calculate penetration depth in transition zone are proposed, and a method to obtain the boundary velocity of transition zone is determined. A combined theoretical analysis model for three response regions is built by analyzing the characteristics in these regions. The penetration depth predicted by this combined model is in good agreement with experimental result.

  9. Life insurance density and penetration: panel data analysis across countries

    OpenAIRE

    Urbanavičiūtė, Greta

    2016-01-01

    Life Insurance Density and Penetration: Panel Data Analysis Across Countries This bachelor thesis examines two key indicators in the life insurance market: density and penetration. The main purpose is to analyse which factors have the biggest impact on these two indicators in 39 countries around the world. Panel data models, which represent the collected data best, were created. This paper examines the latest public data available in 39 countries, including the Baltic States, and new signific...

  10. Chronic Disease Prevalence and Medicare Advantage Market Penetration

    OpenAIRE

    Steven W. Howard; Stephanie Lazarus Bernell; Faizan M. Casim; Jennifer Wilmott; Lindsey Pearson; Caitlin M. Byler; Zidong Zhang

    2015-01-01

    By March 2015, 30% of all Medicare beneficiaries were enrolled in Medicare Advantage (MA) plans. Research to date has not explored the impacts of MA market penetration on individual or population health outcomes. The primary objective of this study is to examine the relationships between MA market penetration and the beneficiary?s portfolio of cardiometabolic diagnoses. This study uses 2004 to 2008 Medical Expenditure Panel Survey (MEPS) Household Component data to construct an aggregate inde...

  11. Ga penetration into polymers

    Czech Academy of Sciences Publication Activity Database

    Hnatowicz, Vladimír; Švorčík, V.; Efimenko, K.; Rybka, V.

    1999-01-01

    Roč. 68, - (1999), s. 357-358 ISSN 0947-8396 R&D Projects: GA ČR GA202/96/0077; GA AV ČR KSK1048601 Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.753, year: 1999

  12. DebrisLV Hypervelocity Impact Post-Shot Physical Results Summary

    Science.gov (United States)

    2015-02-27

    simulaFng  a  solar-­‐panel   •  15  MJoules  energy   •  6061-T6 Frame •  Nylon Body •  Hollow Center for Electronics BODY...model  results  to  predict   plasm  jet  formaOon  in  relaOvely  simple  structures.    More  modeling  needs  to...Post-­‐Shot  Materials  Physics  Results,”   TOR-­‐2014-­‐03192   Approved Electronically by: Technical Peer Review Performed by

  13. Development of a capacitor powered rail gun for hypervelocity impact studies

    International Nuclear Information System (INIS)

    Shrader, J.E.

    1983-01-01

    Boeing has built and tested several rail gun designs using two different capacitor banks as power sources. For each design, the muzzle velocity predicted with the Boeing Electromagnetic Gun code (BEMG) matched the measured muzzle velocity within 5%, providing gas sealing between the rails and the dielectric of the barrel was maintained. This did not validate the model, but gave reasonable confidence in it. Using the BEMG model, a parametric study was conducted to determine the sensitivity of muzzle velocities between 2 and 5 km/s to the input variables. A practical point design was assumed, and then each parameter individually varied while the others were held constant. The point design assumed an initial velocity of 0.5 km/s and an inductance per unit length (L') of 0.8 x 10 -6 H/m. Other parameters were similar to the earlier designs. The earlier designs tested had no initial velocity, and an L' of 0.3 x 10 6 H/m. A gas gun was assumed to produce the initial velocity, and resulted in only modest increases in muzzle velocity. However, it eliminated a separate make switch, since a foil across the back of the projectile becomes a make switch, and it is expected to substantially reduce rail erosion near the breech of the gun. Rail erosion was a significant problem for repeated firings in earlier designs. The parametric study showed that for the velocities of interest, increasing L' was the single best way to improve gun performance. In a practical gun, this will be achieved by making a two turn barrel, rather than a single turn barrel. The results of this study will be used to design, build and test a small gun (about 9 mm bore) using a 150 kJ capacitor bank as a power source. Using the experience gained with this gun, a large gun (about 20 mm bore) will be designed, built and tested using a 1.3 MJ capacitor bank

  14. Experimentation and Modeling of Hypervelocity Impacts of Spacecraft MMOD Shielding with Incorporated Shear Thickening Fluid

    Data.gov (United States)

    National Aeronautics and Space Administration — The student is beginning a doctoral program at Mississippi State University (MSU) with an expected graduation date of December 2015. The proposed research will...

  15. Penetration of Photovoltaics in Greece

    OpenAIRE

    Eugenia Giannini; Antonia Moropoulou; Zacharias Maroulis; Glykeria Siouti

    2015-01-01

    Recently, an interesting experiment was completed in Greece concerning photovoltaic penetration into the electricity production sector. Based on the relevant laws and in accordance to the related European directives, an explosive penetration process was completed in less than three years, resulting in a 7% share of photovoltaics in electricity production instead of the previous negligible share. The legislation was based on licensing simplification and generous feed-in-tariffs. This approach ...

  16. Calculations of Earth Penetrators Impacting Soils

    Science.gov (United States)

    1975-09-30

    time. In addition, the use of automatic rezoning permitted the problems to be run to completion without manually rezoning the computing grid. 2. THE...Department of t~w Army ATTN: 1. W. Apgar ATTN: DAMA-CSM-N, L.TC G. Ogden ATTN: Techical ILibrary Commander & Director ATTN: DAMA(CS) , MAJ A. (-leim I’S Army

  17. Lost Impacts (Invited)

    Science.gov (United States)

    Schultz, P. H.; Stickle, A. M.

    2009-12-01

    The absence of a clearly identified crater (or craters) for the proposed YDB impact has raised questions concerning the reality of such an event. Geologic studies have identified impact deposits well before recognizing a causative crater (e.g., Chicxulub and Chesapeake Bay); some have yet to be discovered (e.g., Australasian tektite strewnfields). The absence of a crater, therefore, cannot be used as an argument against the reality of the YDB impact (and its possible consequences). The study here addresses how a large on-land impact during the late Pleistocene or early Holocene could avoid easy detection today. It does not argue the case for a YDB impact, since such evidence must come from the rock record. During the late Pleistocene, the receding Laurentide ice sheet still covered a significant portion of Canada. While a large (1km) body impacting vertically (90°) would penetrate such a low-impedance ice layer and excavate the substrate, an oblique impact couples more of its energy into the surface layer, thereby partially shielding the substrate. Three approaches address the effectiveness of this flak-jacket effect. First, hypervelocity impact experiments at the NASA Ames Vertical Gun Range investigated the effectiveness of low-impedance layers of different thicknesses for mitigating substrate damage. Second, selected experiments were compared with hydrocode models (see Stickle and Schultz, this volume) and extended to large scales. Third, comparisons were made with relict craters found in eroding sediment and ice covers on Mars. Oblique impacts (30 degrees) into soft particulates (no. 24 sand) covering a solid substrate (aluminum) have no effect on the final crater diameter for layer thicknesses exceeding a projectile diameter and result in only plastic deformation in the substrate. In contrast, a vertical impact requires a surface layer at least 3 times the projectile diameter to achieve the same diameter (with significant substrate damage). Oblique impacts

  18. Can the biogenicity of Europa's surfical sulfur be tested simultaneously with penetrators and ion traps?

    Science.gov (United States)

    Chela-Flores, J.; Bhattacherjee, A. B.; Dudeja, S.; Kumar, N.; Seckbach, J.

    2009-04-01

    with microbial mats—well understood in the context of the Antarctic dry valley lakes for the expulsion of a large quantity of sulfur—are used in tests on the icy surface of Europa, it is pertinent to evaluate the stopping-depth for the harsh radiation on the Europan surface. Recently, we have estimated the stopping-depth that should be probed by penetrators in proposed missions, such as LAPLACE, or in future projects. We find, in agreement with others (Greenberg, 2005), that beyond a few millimeters a penetrator would be testing biogeochemistry without any interference from radiation effects (Dudeja et al., 2009). Simultaneously with the penetrators there is an alternative suitable technology available. The isotopic S fractionation on the cloud surrounding Europa should reflect to a large extent the same biogenically-driven S fractionation that is taking place on the surface. We should recall that the origin of the cloud is due to particles that have been expelled by hypervelocity impacts of micrometeoroids on the surface. The instrumentation of ion-trap mass spectrometry has already been successfully completed for tests on a comet nucleus (the Ptolemy instrument and the Rosetta space mission). Ion traps have once again been in the planning stages for their eventual application in LAPLACE, or elsewhere (Todd et al., 2006; Taylor et al., 2007). Since the cloud around Europa is constantly being replenished by the above-mentioned micrometeorites, it would be reasonable to expect the cloud to mirror the large S-isotope deviations that may be caused locally by the assumed sulfate-reducing microorganisms. Consequently, dust detectors in orbit around this satellite should record similar large fluctuations of the Luria-Delbrück type that we have conjectured to take place on Europa's icy surface. This possibility has been explained in detail recently (Chela-Flores and Kumar, 2008). Consequently, we argue in favor that the instrumentation to be selected should include

  19. Cutaneous mucormycosis secondary to penetrative trauma.

    Science.gov (United States)

    Zahoor, Bilal; Kent, Stephen; Wall, Daryl

    2016-07-01

    Mucormycosis is a rare but serious sequelae of penetrating trauma [1-5]. In spite of aggressive management, mortality remains high due to dissemination of infection. We completed a review of literature to determine the most optimal treatment of cutaneous mucormycosis which occurs secondary to penetrating trauma. We completed a review regarding the management of mucormycosis in trauma patients. We selected a total of 36 reports, of which 18 were case-based, for review. Surgical debridement is a primary predictor of improved outcomes in the treatment of mucormycosis [3,6,7]. Anti-fungal therapy, especially lipid soluble formulation of Amphotericin B, is helpful as an adjunct or when surgical debridement has been maximally achieved. Further research is needed to fully evaluate the impact of topical dressings; negative pressure wound therapy is helpful. An aggressive and early surgical approach, even at the expense of disfigurement, is necessary to reduce mortality in the setting of cutaneous mucormycosis that results from penetrating trauma [4,8,9]. Anti-fungal therapy and negative pressure wound therapy are formidable adjuncts. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Scaling of heat transfer augmentation due to mechanical distortions in hypervelocity boundary layers

    Science.gov (United States)

    Flaherty, W.; Austin, J. M.

    2013-10-01

    We examine the response of hypervelocity boundary layers to global mechanical distortions due to concave surface curvature. Surface heat transfer and visual boundary layer thickness data are obtained for a suite of models with different concave surface geometries. Results are compared to predictions using existing approximate methods. Near the leading edge, good agreement is observed, but at larger pressure gradients, predictions diverge significantly from the experimental data. Up to a factor of five underprediction is reported in regions with greatest distortion. Curve fits to the experimental data are compared with surface equations. We demonstrate that reasonable estimates of the laminar heat flux augmentation may be obtained as a function of the local turning angle for all model geometries, even at the conditions of greatest distortion. This scaling may be explained by the application of Lees similarity. As a means of introducing additional local distortions, vortex generators are used to impose streamwise structures into the boundary layer. The response of the large scale vortices to an adverse pressure gradient is investigated. Surface streak evolution is visualized over the different surface geometries using fast response pressure sensitive paint. For a flat plate baseline case, heat transfer augmentation at similar levels to turbulent flow is measured. For the concave geometries, increases in heat transfer by factors up to 2.6 are measured over the laminar values. The scaling of heat transfer with turning angle that is identified for the laminar boundary layer response is found to be robust even in the presence of the imposed vortex structures.

  1. THE NATURE OF HYPERVELOCITY STARS AND THE TIME BETWEEN THEIR FORMATION AND EJECTION

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Warren R.; Geller, Margaret J.; Kenyon, Scott J. [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Cohen, Judith G., E-mail: wbrown@cfa.harvard.edu, E-mail: mgeller@cfa.harvard.edu, E-mail: skenyon@cfa.harvard.edu, E-mail: jlc@astro.caltech.edu [Palomar Observatory, Mail Stop 249-17, California Institute of Technology, Pasadena, CA 91125 (United States)

    2012-07-20

    We obtain Keck HIRES spectroscopy of HVS5, one of the fastest unbound stars in the Milky Way halo. We show that HVS5 is a 3.62 {+-} 0.11 M{sub Sun} main-sequence B star at a distance of 50 {+-} 5 kpc. The difference between its age and its flight time from the Galactic center is 105 {+-} 18 (stat) {+-}30 (sys) Myr; flight times from locations elsewhere in the Galactic disk are similar. This 10{sup 8} yr 'arrival time' between formation and ejection is difficult to reconcile with any ejection scenario involving massive stars that live for only 10{sup 7} yr. For comparison, we derive arrival times of 10{sup 7} yr for two unbound runaway B stars, consistent with their disk origin where ejection results from a supernova in a binary system or dynamical interactions between massive stars in a dense star cluster. For HVS5, ejection during the first 10{sup 7} yr of its lifetime is ruled out at the 3{sigma} level. Together with the 10{sup 8} yr arrival times inferred for three other well-studied hypervelocity stars (HVSs), these results are consistent with a Galactic center origin for the HVSs. If the HVSs were indeed ejected by the central black hole, then the Galactic center was forming stars {approx_equal}200 Myr ago, and the progenitors of the HVSs took {approx_equal}100 Myr to enter the black hole's loss cone.

  2. THE NATURE OF HYPERVELOCITY STARS AND THE TIME BETWEEN THEIR FORMATION AND EJECTION

    International Nuclear Information System (INIS)

    Brown, Warren R.; Geller, Margaret J.; Kenyon, Scott J.; Cohen, Judith G.

    2012-01-01

    We obtain Keck HIRES spectroscopy of HVS5, one of the fastest unbound stars in the Milky Way halo. We show that HVS5 is a 3.62 ± 0.11 M ☉ main-sequence B star at a distance of 50 ± 5 kpc. The difference between its age and its flight time from the Galactic center is 105 ± 18 (stat) ±30 (sys) Myr; flight times from locations elsewhere in the Galactic disk are similar. This 10 8 yr 'arrival time' between formation and ejection is difficult to reconcile with any ejection scenario involving massive stars that live for only 10 7 yr. For comparison, we derive arrival times of 10 7 yr for two unbound runaway B stars, consistent with their disk origin where ejection results from a supernova in a binary system or dynamical interactions between massive stars in a dense star cluster. For HVS5, ejection during the first 10 7 yr of its lifetime is ruled out at the 3σ level. Together with the 10 8 yr arrival times inferred for three other well-studied hypervelocity stars (HVSs), these results are consistent with a Galactic center origin for the HVSs. If the HVSs were indeed ejected by the central black hole, then the Galactic center was forming stars ≅200 Myr ago, and the progenitors of the HVSs took ≅100 Myr to enter the black hole's loss cone.

  3. Penetrator strength effect in long-rod critical ricochet angle

    International Nuclear Information System (INIS)

    Daneshjou, K.; Shahravi, M.

    2008-01-01

    3D numerical simulations were performed in order to further investigate the role of penetrator strength in the interaction of long-rods and oblique targets. Three distinctive regimes resulting from oblique impact depending on the obliquity, namely simple ricochet, critical ricochet and target perforation, were investigated in detail. Critical ricochet angles were calculated with a full 3D explicit finite element method for various impact velocities and strength of target plates and projectiles. Numerical predictions were compared with existing two-dimensional analytical models and test results. It was predicted that critical ricochet angle increases with decreasing impact velocity and that higher ricochet angles were expected if higher strength target materials are employed. But there are differences between analytical models and 3D numerical simulation results or test results. The causes for these discrepancies are established by numerical simulations which explore the validity of the penetrator strength parameter in the analytical model as a physical entity. As a matter of fact, in this paper we first investigate the role of penetrator dynamic strength using two-dimensional simulation which resulted in different penetrator strengths out of different impact velocities. Next, by applying these amounts for penetrator strength in Rosenberg analytical model the critical ricochet angle is calculated. Finally, a comparison between the present analytical method with the 3D simulation and test results shows that the new analytical approach leads to modified results with respect to Rosenberg ones

  4. High-Penetration Photovoltaic Planning Methodologies

    Energy Technology Data Exchange (ETDEWEB)

    Gao, David Wenzhong [Alternative Power Innovations, LLC, Broomfield, CO (United States); Muljadi, Eduard [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tian, Tian [National Renewable Energy Lab. (NREL), Golden, CO (United States); Miller, Mackay [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-02-24

    The main objective of this report is to provide an overview of select U.S. utility methodologies for performing high-penetration photovoltaic (HPPV) system planning and impact studies. This report covers the Federal Energy Regulatory Commission's orders related to photovoltaic (PV) power system interconnection, particularly the interconnection processes for the Large Generation Interconnection Procedures and Small Generation Interconnection Procedures. In addition, it includes U.S. state interconnection standards and procedures. The procedures used by these regulatory bodies consider the impacts of HPPV power plants on the networks. Technical interconnection requirements for HPPV voltage regulation include aspects of power monitoring, grounding, synchronization, connection to the overall distribution system, back-feeds, disconnecting means, abnormal operating conditions, and power quality. This report provides a summary of mitigation strategies to minimize the impact of HPPV. Recommendations and revisions to the standards may take place as the penetration level of renewables on the grid increases and new technologies develop in future years.

  5. Review of Power System Stability with High Wind Power Penetration

    DEFF Research Database (Denmark)

    Hu, Rui; Hu, Weihao; Chen, Zhe

    2015-01-01

    analyzing methods and stability improvement approaches. With increasing wind power penetration, system balancing and the reduced inertia may cause a big threaten for stable operation of power systems. To mitigate or eliminate the wind impacts for high wind penetration systems, although the practical......This paper presents an overview of researches on power system stability with high wind power penetration including analyzing methods and improvement approaches. Power system stability issues can be classified diversely according to different considerations. Each classified issue has special...... and reliable choices currently are the strong outside connections or sufficient reserve capacity constructions, many novel theories and approaches are invented to investigate the stability issues, looking forward to an extra-high penetration or totally renewable resource based power systems. These analyzing...

  6. Plutonium in depleted uranium penetrators

    International Nuclear Information System (INIS)

    McLaughlin, J.P.; Leon-Vintro, L.; Smith, K.; Mitchell, P.I.; Zunic, Z.S.

    2002-01-01

    Depleted Uranium (DU) penetrators used in the recent Balkan conflicts have been found to be contaminated with trace amounts of transuranic materials such as plutonium. This contamination is usually a consequence of DU fabrication being carried out in facilities also using uranium recycled from spent military and civilian nuclear reactor fuel. Specific activities of 239+240 Plutonium generally in the range 1 to 12 Bq/kg have been found to be present in DU penetrators recovered from the attack sites of the 1999 NATO bombardment of Kosovo. A DU penetrator recovered from a May 1999 attack site at Bratoselce in southern Serbia and analysed by University College Dublin was found to contain 43.7 +/- 1.9 Bq/kg of 239+240 Plutonium. This analysis is described. An account is also given of the general population radiation dose implications arising from both the DU itself and from the presence of plutonium in the penetrators. According to current dosimetric models, in all scenarios considered likely ,the dose from the plutonium is estimated to be much smaller than that due to the uranium isotopes present in the penetrators. (author)

  7. Penetration shielding applications of CYLSEC

    International Nuclear Information System (INIS)

    Dexheimer, D.T.; Hathaway, J.M.

    1985-01-01

    Evaluation of penetration and discontinuity shielding is necessary to meet 10CFR20 regulations for ensuring personnel exposures are as low as reasonably achievable (ALARA). Historically, those shielding evaluations have been done to some degree on all projects. However, many early plants used conservative methods due to lack of an economical computer code, resulting in costly penetration shielding programs. With the increased industry interest in cost effectively reducing personnel exposures to meet ALARA regulations and with the development of the CYLSEC gamma transport computer code at Bechtel, a comprehensive effort was initiated to reduce penetration and discontinuity shielding but still provide a prudent degree of protection for plant personnel from radiation streaming. This effort was more comprehensive than previous programs due to advances in shielding analysis technology and increased interest in controlling project costs while maintaining personnel exposures ALARA. Methodology and resulting cost savings are discussed

  8. High speed photography of the plasma flow and the projectiles in the T.U.M. hypervelocity accelerator

    International Nuclear Information System (INIS)

    Igenbergs, E.; Kuczera, H.; Schroeder, B.

    1979-01-01

    The hypervelocity accelerator at the Technische Universitaet Muenchen, FRG, accelerates small projectiles (0.1 to 1.0 mm diameter) to velocities around 20 km/s. The photographic equipment consists of two Cordin single-frame image converter cameras and one TRW image converter camera with streak units and multiple-frame units. They are used for plasma flow diagnostics and the measurement of the position and the velocity of the projectiles. The single-frame cameras are triggered with a Laser light bar and the photographic measurement of the projectile velocity will be compared with Doppler-Radar. (author)

  9. An artificial neural network to discover hypervelocity stars: candidates in Gaia DR1/TGAS

    Science.gov (United States)

    Marchetti, T.; Rossi, E. M.; Kordopatis, G.; Brown, A. G. A.; Rimoldi, A.; Starkenburg, E.; Youakim, K.; Ashley, R.

    2017-09-01

    The paucity of hypervelocity stars (HVSs) known to date has severely hampered their potential to investigate the stellar population of the Galactic Centre and the Galactic potential. The first Gaia data release (DR1, 2016 September 14) gives an opportunity to increase the current sample. The challenge is the disparity between the expected number of HVSs and that of bound background stars. We have applied a novel data mining algorithm based on machine learning techniques, an artificial neural network, to the Tycho-Gaia astrometric solution catalogue. With no pre-selection of data, we could exclude immediately ˜99 per cent of the stars in the catalogue and find 80 candidates with more than 90 per cent predicted probability to be HVSs, based only on their position, proper motions and parallax. We have cross-checked our findings with other spectroscopic surveys, determining radial velocities for 30 and spectroscopic distances for five candidates. In addition, follow-up observations have been carried out at the Isaac Newton Telescope for 22 stars, for which we obtained radial velocities and distance estimates. We discover 14 stars with a total velocity in the Galactic rest frame >400 km s-1, and five of these have a probability of >50 per cent of being unbound from the Milky Way. Tracing back their orbits in different Galactic potential models, we find one possible unbound HVS with v ˜ 520 km s-1, five bound HVSs and, notably, five runaway stars with median velocity between 400 and 780 km s-1. At the moment, uncertainties in the distance estimates and ages are too large to confirm the nature of our candidates by narrowing down their ejection location, and we wait for future Gaia releases to validate the quality of our sample. This test successfully demonstrates the feasibility of our new data-mining routine.

  10. Prediction of electric vehicle penetration.

    Science.gov (United States)

    2017-05-01

    The object of this report is to present the current market status of plug-in-electric : vehicles (PEVs) and to predict their future penetration within the world and U.S. : markets. The sales values for 2016 show a strong year of PEV sales both in the...

  11. FAA Fluorescent Penetrant Laboratory Inspections

    Energy Technology Data Exchange (ETDEWEB)

    WINDES,CONNOR L.; MOORE,DAVID G.

    2000-08-02

    The Federal Aviation Administration Airworthiness Assurance NDI Validation Center currently assesses the capability of various non-destructive inspection (NDI) methods used for analyzing aircraft components. The focus of one such exercise is to evaluate the sensitivity of fluorescent liquid penetrant inspection. A baseline procedure using the water-washable fluorescent penetrant method defines a foundation for comparing the brightness of low cycle fatigue cracks in titanium test panels. The analysis of deviations in the baseline procedure will determine an acceptable range of operation for the steps in the inspection process. The data also gives insight into the depth of each crack and which step(s) of the inspection process most affect penetrant sensitivities. A set of six low cycle fatigue cracks produced in 6.35-mm thick Ti-6Al-4V specimens was used to conduct the experiments to produce sensitivity data. The results will document the consistency of the crack readings and compare previous experiments to find the best parameters for water-washable penetrant.

  12. Industrial Penetration and Internet Intensity

    NARCIS (Netherlands)

    C-L. Chang (Chia-Lin); M.J. McAleer (Michael); Y-C. Wu (Yu-Chieh)

    2016-01-01

    textabstractThis paper investigates the effect of industrial penetration and internet intensity for Taiwan manufacturing firms, and analyses whether the relationships are substitutes or complements. The sample observations are based on 153,081 manufacturing plants, and covers 26 two-digit industry

  13. Import market penetration in services

    OpenAIRE

    Langhammer, Rolf J.

    1991-01-01

    The EC-1992 programme foresees the complete liberalization of trade in services among member countries. To what extent has import market penetration in the Community already begun in selected service industries? Which EC member countries have been the forerunners to date? The following paper uses a new data base released recently by EUROSTAT in an attempt to answer these and other related questions.

  14. Chronic Disease Prevalence and Medicare Advantage Market Penetration

    Science.gov (United States)

    Bernell, Stephanie Lazarus; Casim, Faizan M.; Wilmott, Jennifer; Pearson, Lindsey; Byler, Caitlin M.; Zhang, Zidong

    2015-01-01

    By March 2015, 30% of all Medicare beneficiaries were enrolled in Medicare Advantage (MA) plans. Research to date has not explored the impacts of MA market penetration on individual or population health outcomes. The primary objective of this study is to examine the relationships between MA market penetration and the beneficiary’s portfolio of cardiometabolic diagnoses. This study uses 2004 to 2008 Medical Expenditure Panel Survey (MEPS) Household Component data to construct an aggregate index that captures multiple diagnoses in one outcome measure (Chronic Disease Severity Index [CDSI]). The MEPS data for 8089 Medicare beneficiaries are merged with MA market penetration data from Centers for Medicare and Medicaid Services (CMS). Ordinary least squares regressions are run with SAS 9.3 to model the effects of MA market penetration on CDSI. The results suggest that each percentage increase in MA market penetration is associated with a greater than 2-point decline in CDSI (lower burden of cardiometabolic chronic disease). Spill-over effects may be driving improvements in the cardiometabolic health of beneficiary populations in counties with elevated levels of MA market penetration. PMID:28462266

  15. Chronic Disease Prevalence and Medicare Advantage Market Penetration

    Directory of Open Access Journals (Sweden)

    Steven W. Howard

    2015-10-01

    Full Text Available By March 2015, 30% of all Medicare beneficiaries were enrolled in Medicare Advantage (MA plans. Research to date has not explored the impacts of MA market penetration on individual or population health outcomes. The primary objective of this study is to examine the relationships between MA market penetration and the beneficiary’s portfolio of cardiometabolic diagnoses. This study uses 2004 to 2008 Medical Expenditure Panel Survey (MEPS Household Component data to construct an aggregate index that captures multiple diagnoses in one outcome measure (Chronic Disease Severity Index [CDSI]. The MEPS data for 8089 Medicare beneficiaries are merged with MA market penetration data from Centers for Medicare and Medicaid Services (CMS. Ordinary least squares regressions are run with SAS 9.3 to model the effects of MA market penetration on CDSI. The results suggest that each percentage increase in MA market penetration is associated with a greater than 2-point decline in CDSI (lower burden of cardiometabolic chronic disease. Spill-over effects may be driving improvements in the cardiometabolic health of beneficiary populations in counties with elevated levels of MA market penetration.

  16. Southern California Edison High Penetration Photovoltaic Project - Year 1

    Energy Technology Data Exchange (ETDEWEB)

    Mather, B.; Kroposki, B.; Neal, R.; Katiraei, F.; Yazdani, A.; Aguero, J. R.; Hoff, T. E.; Norris, B. L.; Parkins, A.; Seguin, R.; Schauder, C.

    2011-06-01

    This report discusses research efforts from the first year of a project analyzing the impacts of high penetration levels of photovoltaic (PV) resources interconnected onto Southern California Edison's (SCE's) distribution system. SCE will be interconnecting a total of 500 MW of commercial scale PV within their service territory by 2015. This Year 1 report describes the need for investigating high-penetration PV scenarios on the SCE distribution system; discusses the necessary PV system modeling and distribution system simulation advances; describes the available distribution circuit data for the two distribution circuits identified in the study; and discusses the additional inverter functionality that could be implemented in order to specifically mitigate some of the undesirable distribution system impacts caused by high-penetration PV installations.

  17. [Professor WU Zhongchao's experience of penetration needling].

    Science.gov (United States)

    Zhang, Ning; Wang, Bing; Zhou, Yu

    2016-08-12

    Professor WU Zhongchao has unique application of penetration needling in clinical treatment. Professor WU applies penetration needling along meridians, and the methods of penetration needling include self-meridian penetration, exterior-interior meridian penetration, identical-name meridian penetration, different meridian penetration. The meridian differentiation is performed according to different TCM syndromes, locations and natures of diseases and acupoint nature, so as to make a comprehensive assessment. The qi movement during acupuncture is focused. In addition, attention is paid on anatomy and long-needle penetration; the sequence and direction of acupuncture is essential, and the reinforcing and reducing methods have great originality, presented with holding, waiting, pressing and vibrating. Based on classical acupoint, the acupoint of penetration needling is flexible, forming unique combination of acupoints.

  18. Cryo-braking using penetrators for enhanced capabilities for the potential landing of payloads on icy solar system objects

    Science.gov (United States)

    Winglee, R. M.; Robinson, T.; Danner, M.; Koch, J.

    2018-03-01

    The icy moons of Jupiter and Saturn are important astrobiology targets. Access to the surface of these worlds is made difficult by the high ΔV requirements which is typically in the hypervelocity range. Passive braking systems cannot be used due to the lack of an atmosphere, and active braking by rockets significantly adds to the missions costs. This paper demonstrates that a two-stage landing system can overcome these problems and provide significant improvements in the payload fraction that can be landed The first stage involves a hypervelocity impactor which is designed to penetrate to a depth of a few tens of meters. This interaction is the cryo-breaking component and is examined through laboratory experiments, empirical relations and modeling. The resultant ice-particle cloud creates a transient artificial atmosphere that can be used to enable passive braking of the second stage payload dd, with a substantially higher mass payload fraction than possible with a rocket landing system. It is shown that a hollow cylinder design for the impactor can more efficiently eject the material upwards in a solid cone of ice particles relative to solid impactors such as spheres or spikes. The ejected mass is shown to be of the order of 103 to 104 times the mass of the impactor. The modeling indicates that a 10 kg payload with a braking system of 3 m2 (i.e. an areal density of 0.3 kg/m2) is sufficient to allow the landing of the payload with the deceleration limited to less than 2000 g's. Modern electronics can withstand this deceleration and as such the system provides an important alternative to landing payloads on icy solar system objects.

  19. Control of penetration zone GMAW

    Directory of Open Access Journals (Sweden)

    Віталій Петрович Iванов

    2016-11-01

    Full Text Available Thermal properties of the base metal, shielding medium and the nature of the electrode metal transfer to a great extent determine the penetration area formation in gas-arc welding. It is not always possible to take into account the influence of these factors on penetration front forming within the existing models. The aim of the work was to research the penetration area forming in gas-arc welding. The research of the penetration area forming in gas-arc welding of CrNi austenitic steels was made. The parameters of the regime as well as the kind of the gaseous medium influence on the formation of the penetration zone were studied. The article shows a linear proportional relationship between the electrode feed rate and the size of the base metal plate. The penetration area formation mode for welding in argon and carbon dioxide have been worked out. Diameter, feed rate and the speed of the electrode movement have been chosen as the main input parameters. Multiple regression analysis method was used to make up the modes. The relations of the third order that make it possible to take into account the electrode metal transfer and thermal properties change of the materials to be welded were used. These relationships show quite good agreement with the experimental measurements in the calculation of the fusion zone shape with consumable electrode in argon and carbon dioxide. It was determined that the shape of the melting front curve can be shown as a generalized function in which the front motion parameters depend on feed rate and the diameter of the electrode. Penetration zone growth time is determined by the welding speed and is calculated as a discrete function of the distance from the electrode with the spacing along the movement coordinate. The influence of the mode parameters on the formation of the fusion zone has been investigated and the ways to manage and stabilize the weld pool formation have been identified. The modes can be used to develop

  20. Bioportide: an emergent concept of bioactive cell-penetrating peptides

    Czech Academy of Sciences Publication Activity Database

    Howl, J.; Matou-Nasri, S.; West, D. C.; Farquhar, M.; Slaninová, Jiřina; Ostenson, C. G.; Zorko, M.; Ostlund, P.; Kumar, S.; Langel, U.; McKeating, J.; Jones, S.

    2012-01-01

    Roč. 69, č. 17 (2012), s. 2951-2966 ISSN 1420-682X Institutional research plan: CEZ:AV0Z40550506 Keywords : angiogenesis * bioportide * cell-penetrating peptide * second messenger * insulin secretion Subject RIV: CE - Biochemistry Impact factor: 5.615, year: 2012

  1. Assessing high wind energy penetration

    DEFF Research Database (Denmark)

    Tande, J.O.

    1995-01-01

    In order to convincingly promote installing wind power capacity as a substantial part of the energy supply system, a set of careful analyses must be undertaken. This paper applies a case study concentrated on assessing the cost/benefit of high wind energy penetration. The case study considers...... expanding the grid connected wind power capacity in Praia, the capital of Cape Verde. The currently installed 1 MW of wind power is estimated to supply close to 10% of the electric energy consumption in 1996. Increasing the wind energy penetration to a higher level is considered viable as the project...... with the existing wind power, supply over 30% of the electric consumption in 1996. Applying the recommended practices for estimating the cost of wind energy, the life-cycle cost of this 2.4 MW investment is estimated at a 7% discount rate and a 20 year lifetime to 0.26 DKK/kW h....

  2. Mobile Termination and Mobile Penetration

    OpenAIRE

    Hurkens, Sjaak; Jeon, Doh-Shin

    2009-01-01

    In this paper, we study how access pricing affects network competition when subscription demand is elastic and each network uses non-linear prices and can apply termination-based price discrimination. In the case of a fixed per minute termination charge, we find that a reduction of the termination charge below cost has two oppos- ing effects: it softens competition but helps to internalize network externalities. The former reduces mobile penetration while the latter boosts it. We find that fi...

  3. Mobile termination and mobile penetration

    OpenAIRE

    Hurkens, Sjaak

    2009-01-01

    In this paper, we study how access pricing affects network competition when subscription demand is elastic and each network uses non-linear prices and can apply termination-based price discrimination. In the case of a fixed per minute termination charge, we find that a reduction of the termination charge below cost has two opposing effects: it softens competition but helps to internalize network externalities. The former reduces mobile penetration while the latter boosts it. We find that firm...

  4. Fluorescent penetration crack testing method

    International Nuclear Information System (INIS)

    Roth, A.

    1979-01-01

    The same cleaning, penetration, washing, development and evaluation agents are used in this method as for known methods. In order to accelerate or shorten the testing, the drying process is performed only to optical dryness of the material surface by blowing on it with pressurized air, the development by simple pressing into or dusting of the material with the developer and the temperature of the washing water is selected within room temperature range. (RW) [de

  5. Penetrating eye injury in war.

    Science.gov (United States)

    Biehl, J W; Valdez, J; Hemady, R K; Steidl, S M; Bourke, D L

    1999-11-01

    The percentage of penetrating eye injuries in war has increased significantly in this century compared with the total number of combat injuries. With the increasing use of fragmentation weapons and possibly laser weapons on the battle-field in the future, the rate of eye injuries may exceed the 13% of the total military injuries found in Operations Desert Storm/Shield. During the Iran-Iraq War (1980-1988), eye injuries revealed that retained foreign bodies and posterior segment injuries have an improved prognosis in future military ophthalmic surgery as a result of modern diagnostic and treatment modalities. Compared with the increasing penetrating eye injuries on the battlefield, advances in ophthalmic surgery are insignificant. Eye armor, such as visors that flip up and down and protect the eyes from laser injury, needs to be developed. Similar eye protection is being developed in civilian sportswear. Penetrating eye injury in the civilian sector is becoming much closer to the military model and is now comparable for several reasons.

  6. Real-Time Penetrating Particle Analyzer (PAN)

    Science.gov (United States)

    Wu, X.; Ambrosi, G.; Bertucci, B.

    2018-02-01

    The PAN can measure penetrating particles with great precision to study energetic particles, solar activities, and the origin and propagation of cosmic rays. The real-time monitoring of penetrating particles is crucial for deep space human travel.

  7. Fault Analysis and Detection in Microgrids with High PV Penetration

    Energy Technology Data Exchange (ETDEWEB)

    El Khatib, Mohamed [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hernandez Alvidrez, Javier [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ellis, Abraham [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-05-01

    In this report we focus on analyzing current-controlled PV inverters behaviour under faults in order to develop fault detection schemes for microgrids with high PV penetration. Inverter model suitable for steady state fault studies is presented and the impact of PV inverters on two protection elements is analyzed. The studied protection elements are superimposed quantities based directional element and negative sequence directional element. Additionally, several non-overcurrent fault detection schemes are discussed in this report for microgrids with high PV penetration. A detailed time-domain simulation study is presented to assess the performance of the presented fault detection schemes under different microgrid modes of operation.

  8. Network Penetration Testing and Research

    Science.gov (United States)

    Murphy, Brandon F.

    2013-01-01

    This paper will focus the on research and testing done on penetrating a network for security purposes. This research will provide the IT security office new methods of attacks across and against a company's network as well as introduce them to new platforms and software that can be used to better assist with protecting against such attacks. Throughout this paper testing and research has been done on two different Linux based operating systems, for attacking and compromising a Windows based host computer. Backtrack 5 and BlackBuntu (Linux based penetration testing operating systems) are two different "attacker'' computers that will attempt to plant viruses and or NASA USRP - Internship Final Report exploits on a host Windows 7 operating system, as well as try to retrieve information from the host. On each Linux OS (Backtrack 5 and BlackBuntu) there is penetration testing software which provides the necessary tools to create exploits that can compromise a windows system as well as other operating systems. This paper will focus on two main methods of deploying exploits 1 onto a host computer in order to retrieve information from a compromised system. One method of deployment for an exploit that was tested is known as a "social engineering" exploit. This type of method requires interaction from unsuspecting user. With this user interaction, a deployed exploit may allow a malicious user to gain access to the unsuspecting user's computer as well as the network that such computer is connected to. Due to more advance security setting and antivirus protection and detection, this method is easily identified and defended against. The second method of exploit deployment is the method mainly focused upon within this paper. This method required extensive research on the best way to compromise a security enabled protected network. Once a network has been compromised, then any and all devices connected to such network has the potential to be compromised as well. With a compromised

  9. Ethical Dilemmas and Dimensions in Penetration Testing

    OpenAIRE

    Faily, Shamal; McAlaney, John; Iacob, C.

    2015-01-01

    Penetration testers are required to attack systems to evaluate their security, but without engaging in unethical behaviour while doing so. Despite work on hacker values and studies into security practice, there is little literature devoted to the ethical pressures associated with penetration testing. This paper presents several ethical dilemmas and dimensions associated with penetration testing;\\ud these shed light on the ethical positions taken by Penetration testers, and help identify poten...

  10. Import Penetration, Export Orientation and Plant Size in Indonesian Manufacturing

    OpenAIRE

    Sadayuki TAKII

    2014-01-01

    This paper empirically examines differential impacts of globalisation on plant size among plants with different characteristics, including initial plant size, import and export status, and ownership. After accounting for other characteristics, results of this analysis suggest that both import penetration and export orientation do not have differential impacts on the size of larger and smaller plants. This is contrary to fears that only relatively large plants can benefit from globalisation wh...

  11. Kali Linux wireless penetration testing essentials

    CERN Document Server

    Alamanni, Marco

    2015-01-01

    This book is targeted at information security professionals, penetration testers and network/system administrators who want to get started with wireless penetration testing. No prior experience with Kali Linux and wireless penetration testing is required, but familiarity with Linux and basic networking concepts is recommended.

  12. Development of penetrant materials from used oil

    International Nuclear Information System (INIS)

    Mohamad Pauzi Ismail; Azhar Azmi

    2014-01-01

    This paper described the results of experiment to produce penetrant for nondestructive testing using used engine oil. The used engine oil was obtained from motor vehicle. It was mixed with kerosene at several mix proportion. The penetrability of these mixing were measured and compared with the penetrant available on the market. The results of measurement were explained and discussed. (author)

  13. Developing an Efficient and Cost Effective Ground-Penetrating Radar Field Methodology for Subsurface Exploration and Mapping of Cultural Resources on Public Lands

    National Research Council Canada - National Science Library

    Conyers, Lawrence B

    2006-01-01

    .... A new, emerging technology is the use of ground penetrating radar (GPR). However, in using this device due to the number of variables that can impact energy penetration and resolution, researchers are often not guaranteed a successful survey...

  14. Study on penetration-induced initiation of energetic fragment

    Science.gov (United States)

    Qiao, Xiangxin; Xu, Heyang

    2017-09-01

    In order to investigate penetration-induced initiation of energetic fragment penetrating target, PTFE/Al (mass ratio 73.5/26.5) pressed and sintered into a Ф8mm × 8mm cylinder. To form energetic fragment, the cylinder was put into a closed container made by 35CrMnSiA. The container is 12mm long, 2mm thick. Energetic fragments were launched by a 14.5mm ballistic gun with a series of velocities and the penetrate process was simulated by AUTODYN-3D. The results show that the stress peak of energetic material exceed the initiation threshold, and energetic material will deflagrate, when energetic fragments impact velocity more than 800 m/s. The research results can provide reference for designs of energetic warhead.

  15. FAA Fluorescent Penetrant Activities - An Update

    Energy Technology Data Exchange (ETDEWEB)

    Moore, D.G.

    1998-10-20

    The Federal Aviation Administration's Airworthiness Assurance NDI Validation Center (AANC) is currently characterizing low cycle fatigue specimens that will support the needs of penetrant manufacturers, commercial airline industry and the Federal Aviation Administration. The main focus of this characterization is to maintain and enhance the evaluation of penetrant inspection materials and apply resources to support the aircraft community needs. This paper discusses efforts to-date to document the Wright Laboratory penetrant evaluation process and characterize penetrant brightness readings in the initial set of sample calibration panels using Type 1 penetrant.

  16. Web penetration testing with Kali Linux

    CERN Document Server

    Muniz, Joseph

    2013-01-01

    Web Penetration Testing with Kali Linux contains various penetration testing methods using BackTrack that will be used by the reader. It contains clear step-by-step instructions with lot of screenshots. It is written in an easy to understand language which will further simplify the understanding for the user.""Web Penetration Testing with Kali Linux"" is ideal for anyone who is interested in learning how to become a penetration tester. It will also help the users who are new to Kali Linux and want to learn the features and differences in Kali versus Backtrack, and seasoned penetration testers

  17. Penetration through the Skin Barrier

    DEFF Research Database (Denmark)

    Nielsen, Jesper Bo; Benfeldt, Eva; Holmgaard, Rikke

    2016-01-01

    The skin is a strong and flexible organ with barrier properties essential for maintaining homeostasis and thereby human life. Characterizing this barrier is the ability to prevent some chemicals from crossing the barrier while allowing others, including medicinal products, to pass at varying rates......-through diffusion cells) as well as in vivo methods (microdialysis and microperfusion). Then follows a discussion with examples of how different characteristics of the skin (age, site and integrity) and of the penetrants (size, solubility, ionization, logPow and vehicles) affect the kinetics of percutaneous...

  18. Penetrating abdominal injuries: management controversies

    Science.gov (United States)

    Butt, Muhammad U; Zacharias, Nikolaos; Velmahos, George C

    2009-01-01

    Penetrating abdominal injuries have been traditionally managed by routine laparotomy. New understanding of trajectories, potential for organ injury, and correlation with advanced radiographic imaging has allowed a shift towards non-operative management of appropriate cases. Although a selective approach has been established for stab wounds, the management of abdominal gunshot wounds remains a matter of controversy. In this chapter we describe the rationale and methodology of selecting patients for non-operative management. We also discuss additional controversial issues, as related to antibiotic prophylaxis, management of asymptomatic thoracoabdominal injuries, and the use of colostomy vs. primary repair for colon injuries. PMID:19374761

  19. Penetrating abdominal injuries: management controversies

    Directory of Open Access Journals (Sweden)

    Velmahos George C

    2009-04-01

    Full Text Available Abstract Penetrating abdominal injuries have been traditionally managed by routine laparotomy. New understanding of trajectories, potential for organ injury, and correlation with advanced radiographic imaging has allowed a shift towards non-operative management of appropriate cases. Although a selective approach has been established for stab wounds, the management of abdominal gunshot wounds remains a matter of controversy. In this chapter we describe the rationale and methodology of selecting patients for non-operative management. We also discuss additional controversial issues, as related to antibiotic prophylaxis, management of asymptomatic thoracoabdominal injuries, and the use of colostomy vs. primary repair for colon injuries.

  20. Penetration testing with Raspberry Pi

    CERN Document Server

    Muniz, Joseph

    2015-01-01

    If you are looking for a low budget, small form-factor remotely accessible hacking tool, then the concepts in this book are ideal for you. If you are a penetration tester who wants to save on travel costs by placing a low-cost node on a target network, you will save thousands by using the methods covered in this book. You do not have to be a skilled hacker or programmer to use this book. It will be beneficial to have some networking experience; however, it is not required to follow the concepts covered in this book.

  1. Correlation Between Cone Penetration Rate And Measured Cone Penetration Parameters In Silty Soils

    DEFF Research Database (Denmark)

    Poulsen, Rikke; Nielsen, Benjaminn Nordahl; Ibsen, Lars Bo

    2013-01-01

    This paper shows, how a change in cone penetration rate affects the cone penetration measurements, hence the cone resistance, pore pressure, and sleeve friction in silty soil. The standard rate of penetration is 20 mm/s, and it is generally accepted that undrained penetration occurs in clay while...... drained penetration occurs in sand. When lowering the penetration rate, the soil pore water starts to dissipate and a change in the drainage condition is seen. In intermediate soils such as silty soils, the standard cone penetration rate may result in a drainage condition that could be undrained......, partially or fully drained. However, lowering the penetration rate in silty soils has a great significance because of the soil permeability, and only a small change in penetration rate will result in changed cone penetration measurements. In this paper, analyses will be done on data from 15 field cone...

  2. Penetrating performance and “self-sharpening” behavior of fine-grained tungsten heavy alloy rod penetrators

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Rongmei, E-mail: luorm_1999@126.com [School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu (China); College of Equipment Engineering, Shenyang Ligong University, Shenyang 110159, Liaoning (China); Huang, Dewu; Yang, Mingchuan; Tang, Enling; Wang, Meng; He, Liping [College of Equipment Engineering, Shenyang Ligong University, Shenyang 110159, Liaoning (China)

    2016-10-15

    Rod penetrators with 95W–3.75Ni–1.25Fe fine-grained tungsten heavy alloy (fine-grained 95W) and conventional tungsten heavy alloy rod penetrators with the same chemical composition (conventional 95W) were subjected to ballistic impact to compare their penetration performance. “Self-sharpening” behavior and an average 10.5% increase in penetration depth compared to conventional 95W penetrators. An acute head remained on the fine-grained 95W rod with SEM results revealing many micro-cracks and small debris on surface layer of the rod head. The stress-strain curves collected in the Split Hopkinson Pressure Bar (SHPB) experiment showed that critical failure strain values of the fine-grained 95W were 0.12 and 0.39 at strain rate of 2×10{sup 3} s{sup −1} and 3.9×10{sup 3} s{sup −1}, respectively, approximately 40% and 10% lower than those of the conventional 95W. The dynamic strength values of fine-grained 95W were 2100 MPa and 2520 MPa, respectively, which were 500 MPa and 520 MPa higher than those of the conventional 95W. The relationship among microstructure, mechanical property and “self-sharpening” behavior of fine-grained 95W is discussed in this work.

  3. A Comparative Analysis of Kalman Filters Using a Hypervelocity Missile Simulation.

    Science.gov (United States)

    1981-12-01

    quality to any comparable systemi deployed by NATTO (Ref. 4). The buildup in Soviet Forces has :gIenorated a ignificant numerical advantage In tanks...penetrate the comparntively thin upper surfaces of a tank. The other is to use the U.S. advantage in micro-electronics to develop precision-guided munitions...per target killed. These advantages have prompted the Air Force to proceed with feasibility studies and tests to demonstrate the capabilities of the

  4. Predicted space motions for hypervelocity and runaway stars: proper motions and radial velocities for the Gaia Era

    Energy Technology Data Exchange (ETDEWEB)

    Kenyon, Scott J.; Brown, Warren R.; Geller, Margaret J. [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Bromley, Benjamin C., E-mail: skenyon@cfa.harvard.edu, E-mail: wbrown@cfa.harvard.edu, E-mail: mgeller@cfa.harvard.edu, E-mail: bromley@physics.utah.edu [Department of Physics, University of Utah, 115 S 1400 E, Rm 201, Salt Lake City, UT 84112 (United States)

    2014-10-01

    We predict the distinctive three-dimensional space motions of hypervelocity stars (HVSs) and runaway stars moving in a realistic Galactic potential. For nearby stars with distances less than 10 kpc, unbound stars are rare; proper motions alone rarely isolate bound HVSs and runaways from indigenous halo stars. At large distances of 20-100 kpc, unbound HVSs are much more common than runaways; radial velocities easily distinguish both from indigenous halo stars. Comparisons of the predictions with existing observations are encouraging. Although the models fail to match observations of solar-type HVS candidates from SEGUE, they agree well with data for B-type HVS and runaways from other surveys. Complete samples of g ≲ 20 stars with Gaia should provide clear tests of formation models for HVSs and runaways and will enable accurate probes of the shape of the Galactic potential.

  5. Short-duration Lensing Events: Wide-orbit Planets? Free-floating Dwarfs? Or Hypervelocity Stellar Remnants?

    Science.gov (United States)

    Di Stefano, Rosanne; Patel, B.; Kallivayalil, N.; Primini, F. A.

    2009-01-01

    Ongoing microlensing observations by OGLE and MOA regularly detect and conduct high-cadence sampling of lensing events with Einstein diameter crossing times shorter than a few days. We show that many short-duration events are likely to have been caused by planet-mass or brown-dwarf lenses. Many of these low-mass lenses are located within a kpc. Information about some individual systems can be derived through a combination of lensing, radial velocity, and transit studies. The present discovery rate is high enough that the study of short-duration events could soon become the primary channel for planet detection via microlensing. We develop a protocol for observing and modeling these events, and apply it to archived data. A small number of short events may be caused by hypervelocity (v 10^3 km/s) masses located within a kpc.

  6. Heat-transfer distributions on biconics at incidence in hypersonic-hypervelocity He, N2, air, and CO2 flows

    Science.gov (United States)

    Miller, C. G.; Micol, J. R.; Gnoffo, P. A.; Wilder, S.E.

    1983-01-01

    Laminar heat-transfer rates were measured on spherically blunted, 13 degrees/F degrees on-axis and bent biconics (fore cone bent 7 degrees upward relative to aft cone) at hypersonic-hypervelocity flow conditions in the Langley Expansion Tube. Freestream velocities from 4.5 to 6.9 km/sec and Mach numbers from 6 to 9 were generated using helium, nitrogen, air, and carbon dioxide test gases, resulting in normal shock density ratios from 4 to 19. Angle of attack, referenced to the axis of the aft cone, was varied from zero to 20 degrees in 4 degree increments. The effect of nose bend, angle of attack, and real-gas phenomena on heating distributions are presented along with comparisons of measurement to prediction from a code which solves the three-dimensional 'parabolized Navier-Stokes' equations.

  7. Enabling kinetic micro-penetrator technology for Solar System research

    Science.gov (United States)

    Gowen, R. A.

    2008-09-01

    Whilst the concept of high speed impacting penetrator probes is not new, recent highly successful ground test results have considerably improved the perception that these can be a viable and useful addition to the current toolbox of planetary probes. Previous developments only led to a single deployment (Deep Space-2 to Mars on the ill fated NASA Mars Polar Lander mission in 1999) where neither the soft lander nor penetrator was ever heard from, which is not a logical basis for dismissing penetrator technology. Other space penetrator programmes have included the Russian Mars'96 ~80m/s penetrators for which the whole mission was lost before the spacecraft left Earth orbit, and the Japanese Lunar-A program which was cancelled after a lengthy development program which however saw multiple successful ground trials. The Japanese penetrators were designed for ~300m/s impact. The current UK penetrator developments are actively working towards full space qualification for a Lunar penetrators (MoonLITE mission), which would also provide a significant technical demonstration towards the development of smaller, shorter lived penetrators for exploring other solar system objects. We are advocating delivered micro-penetrators in the mass range ~4-10Kg, (preceded by ~13Kg Lunar penetrator MoonLITE development program), impacting at around 100-500m/s and carrying a scientific payload of around 2Kg. Additional mass is required to deliver the probes from `orbit' to surface which is dependent upon the particular planetary body in question. The mass per descent module therefore involves and additional element which, for a descent through an atmosphere could be quite modest, while for a flyby deployment, can be substantial. For Europa we estimate a descent module mass of ~13 Kg, while for Enceladus the value is ~40Kg for Enceladus since a deceleration of ~3.8 kms-1 is needed from a Titan orbit. The delivery system could consist of a rocket deceleration motor and attitude control system

  8. Linguistic Intuitions and Cognitive Penetrability

    Directory of Open Access Journals (Sweden)

    Michael Devitt

    2014-12-01

    Full Text Available Metalinguistic intuitions play a very large evidential role in both linguistics and philosophy. Linguists think that these intuitions are products of underlying linguistic competence. I call this view “the voice of competence” (“VoC”. Although many philosophers seem to think that metalinguistic intuitions are a priori many may implicitly hold the more scientifically respectable VoC. According to VoC, I argue, these intuitions can be cognitively penetrated by the central processor. But, I have argued elsewhere, VoC is false. Instead, we should hold “the modest explanation” (“ME” according to which these intuitions are fairly unreflective empirical theory-laden central-processor responses to phenomena. On ME, no question of cognitive penetration arises. ME has great methodological significance for the study of language. Insofar as we rely on intuitions as evidence we should prefer those of linguists and philosophers because they are more expert. But, more importantly, we should be seeking other evidence in linguistic usage.

  9. Analytical review of 664 cases of penetrating buttock trauma

    Science.gov (United States)

    2011-01-01

    A comprehensive review of data has not yet been provided as penetrating injury to the buttock is not a common condition accounting for 2-3% of all penetrating injuries. The aim of the study is to provide the as yet lacking analytical review of the literature on penetrating trauma to the buttock, with appraisal of characteristics, features, outcomes, and patterns of major injuries. Based on these results we will provide an algorithm. Using a set of terms we searched the databases Pub Med, EMBASE, Cochran, and CINAHL for articles published in English between 1970 and 2010. We analysed cumulative data from prospective and retrospective studies, and case reports. The literature search revealed 36 relevant articles containing data on 664 patients. There was no grade A evidence found. The injury population mostly consists of young males (95.4%) with a high proportion missile injury (75.9%). Bleeding was found to be the key problem which mostly occurs from internal injury and results in shock in 10%. Overall mortality is 2.9% with significant adverse impact of visceral or vascular injury and shock (P colon, or rectum injuries leading in shot wounds, whilst vascular injury leads in stab wounds (P trauma. In conclusion, penetrating buttock trauma should be regarded as a life-threatening injury with impact beyond the pelvis until proven otherwise. PMID:21995834

  10. Market penetration of biodiesel and ethanol

    Science.gov (United States)

    Szulczyk, Kenneth Ray

    This dissertation examines the influence that economic and technological factors have on the penetration of biodiesel and ethanol into the transportation fuels market. This dissertation focuses on four aspects. The first involves the influence of fossil fuel prices, because biofuels are substitutes and have to compete in price. The second involves biofuel manufacturing technology, principally the feedstock-to-biofuel conversion rates, and the biofuel manufacturing costs. The third involves prices for greenhouse gas offsets. The fourth involves the agricultural commodity markets for feedstocks, and biofuel byproducts. This dissertation uses the Forest and Agricultural Sector Optimization Model-Greenhouse Gas (FASOM-GHG) to quantitatively examine these issues and calculates equilibrium prices and quantities, given market interactions, fossil fuel prices, carbon dioxide equivalent prices, government biofuel subsidies, technological improvement, and crop yield gains. The results indicate that for the ranges studied, gasoline prices have a major impact on aggregate ethanol production but only at low prices. At higher prices, one runs into a capacity constraint that limits expansion on the capacity of ethanol production. Aggregate biodiesel production is highly responsive to gasoline prices and increases over time. (Diesel fuel price is proportional to the gasoline price). Carbon dioxide equivalent prices expand the biodiesel industry, but have no impact on ethanol aggregate production when gasoline prices are high again because of refinery capacity expansion. Improvement of crop yields shows a similar pattern, expanding ethanol production when the gasoline price is low and expanding biodiesel. Technological improvement, where biorefinery production costs decrease over time, had minimal impact on aggregate ethanol and biodiesel production. Finally, U.S. government subsidies have a large expansionary impact on aggregate biodiesel production. Finally, U.S. government

  11. Improving Outcomes Following Penetrating Colon Wounds

    Science.gov (United States)

    Miller, Preston R.; Fabian, Timothy C.; Croce, Martin A.; Magnotti, Louis J.; Elizabeth Pritchard, F.; Minard, Gayle; Stewart, Ronald M.

    2002-01-01

    Introduction During World War II, failure to treat penetrating colon injuries with diversion could result in court martial. Based on this wartime experience, colostomy for civilian colon wounds became the standard of care for the next 4 decades. Previous work from our institution demonstrated that primary repair was the optimal management for nondestructive colon wounds. Optimal management of destructive wounds requiring resection remains controversial. To address this issue, we performed a study that demonstrated risk factors (pre or intraoperative transfusion requirement of more than 6 units of packed red blood cells, significant comorbid diseases) that were associated with a suture line failure rate of 14%, and of whom 33% died. Based on these outcomes, a clinical pathway for management of destructive colon wounds was developed. The results of the implementation of this pathway are the focus of this report. Methods Patients with penetrating colon injury were identified from the registry of a level I trauma center over a 5-year period. Records were reviewed for demographics, injury characteristics, and outcome. Patients with nondestructive injuries underwent primary repair. Patients with destructive wounds but no comorbidities or large transfusion requirement underwent resection and anastomosis, while patients with destructive wounds and significant medical illness or transfusion requirements of more than 6 units/blood received end colostomy. The current patients (CP) were compared to the previous study (PS) to determine the impact of the clinical pathway. Outcomes examined included colon related mortality and morbidity (suture line leak and abscess). Results Over a 5.5-year period, 231 patients had penetrating colon wounds. 209 survived more 24 hours and comprise the study population. Primary repair was performed on 153 (73%) patients, and 56 patients had destructive injuries (27%). Of these, 40 (71%) had resection and anastomosis and 16 (29%) had diversion

  12. Cable Braid Electromagnetic Penetration Model.

    Energy Technology Data Exchange (ETDEWEB)

    Warne, Larry K. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Langston, William L. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Basilio, Lorena I. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Johnson, W. A. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-06-01

    The model for penetration of a wire braid is rigorously formulated. Integral formulas are developed from energy principles and reciprocity for both self and transfer immittances in terms of potentials for the fields. The detailed boundary value problem for the wire braid is also setup in a very efficient manner; the braid wires act as sources for the potentials in the form of a sequence of line multipoles with unknown coefficients that are determined by means of conditions arising from the wire surface boundary conditions. Approximations are introduced to relate the local properties of the braid wires to a simplified infinite periodic planar geometry. This is used in a simplified application of reciprocity to be able to treat nonuniform coaxial geometries including eccentric interior coaxial arrangements and an exterior ground plane.

  13. Assessing high wind energy penetration

    International Nuclear Information System (INIS)

    Tande, J.O.

    1995-01-01

    In order to convincingly promote installing wind power capacity as a substantial part of the energy supply system, a set of careful analyses must be undertaken. This paper applies a case study concentrated on assessing the cost/benefit of high wind energy penetration. The case study considers expanding the grid connected wind power capacity in Praia, the capital of Cape Verde. The currently installed 1 MW of wind power is estimated to supply close to 10% of the electric energy consumption in 1996. Increasing the wind energy penetration to a higher level is considered viable as the project settings are close to ideal, including a very capable national utility company, Electra, a conventional power supply system based on imported heavy fuel and gas oil, and favourable wind conditions with an estimated annual average of 9.3 m/s at the hub height of the wind turbines. With the applied case study assumptions, simulations with WINSYS over the lifetime of the assessed wind power investment show that investments up to 4.2 MW are economically viable. The economic optimum is found at 2.4 MW reaching an internal rate of return of almost 8% p.a. This 2.4 MW of wind power would, together with the existing wind power, supply over 30% of the electric consumption in 1996. Applying the recommended practices for estimating the cost of wind energy, the life-cycle cost of this 2.4 MW investment is estimated at a 7% discount rate and a 20 year lifetime to 0.26 DKK/kW h. (Author)

  14. Varieties of cognitive penetration in visual perception.

    Science.gov (United States)

    Vetter, Petra; Newen, Albert

    2014-07-01

    Is our perceptual experience a veridical representation of the world or is it a product of our beliefs and past experiences? Cognitive penetration describes the influence of higher level cognitive factors on perceptual experience and has been a debated topic in philosophy of mind and cognitive science. Here, we focus on visual perception, particularly early vision, and how it is affected by contextual expectations and memorized cognitive contents. We argue for cognitive penetration based on recent empirical evidence demonstrating contextual and top-down influences on early visual processes. On the basis of a perceptual model, we propose different types of cognitive penetration depending on the processing level on which the penetration happens and depending on where the penetrating influence comes from. Our proposal has two consequences: (1) the traditional controversy on whether cognitive penetration occurs or not is ill posed, and (2) a clear-cut perception-cognition boundary cannot be maintained. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Percutaneous penetration studies for risk assessment

    DEFF Research Database (Denmark)

    Sartorelli, Vittorio; Andersen, Helle Raun; Angerer, Jürgen

    2000-01-01

    . In order to predict the systemic risk of dermally absorbed chemicals and to enable agencies to set safety standards, data is needed on the rates of percutaneous penetration of important chemicals. Standardization of in vitro tests and comparison of their results with the in vivo data could produce...... internationally accepted penetration rates and/or absorption percentages very useful for regulatory toxicology. The work of the Percutaneous Penetration Subgroup of EC Dermal Exposure Network has been focussed on the standardization and validation of in vitro experiments, necessary to obtain internationally...... accepted penetration rates for regulatory purposes. The members of the Subgroup analyzed the guidelines on percutaneous penetration in vitro studies presented by various organizations and suggested a standardization of in vitro models for percutaneous penetration taking into account their individual...

  16. Ethical hacking and penetration testing guide

    CERN Document Server

    Baloch, Rafay

    2014-01-01

    Requiring no prior hacking experience, Ethical Hacking and Penetration Testing Guide supplies a complete introduction to the steps required to complete a penetration test, or ethical hack, from beginning to end. You will learn how to properly utilize and interpret the results of modern-day hacking tools, which are required to complete a penetration test. The book covers a wide range of tools, including Backtrack Linux, Google reconnaissance, MetaGooFil, dig, Nmap, Nessus, Metasploit, Fast Track Autopwn, Netcat, and Hacker Defender rootkit. Supplying a simple and clean explanation of how to effectively utilize these tools, it details a four-step methodology for conducting an effective penetration test or hack.Providing an accessible introduction to penetration testing and hacking, the book supplies you with a fundamental understanding of offensive security. After completing the book you will be prepared to take on in-depth and advanced topics in hacking and penetration testing. The book walks you through each ...

  17. In-place HEPA filter penetration test

    International Nuclear Information System (INIS)

    Bergman, W.; Wilson, K.; Elliott, J.; Bettencourt, B.; Slawski, J.W.

    1997-01-01

    We have demonstrated the feasibility of conducting penetration tests on high efficiency particulate air (HEPA) filters as installed in nuclear ventilation systems. The in-place penetration test, which is designed to yield equivalent penetration measurements as the standard DOP efficiency test, is based on measuring the aerosol penetration of the filter installation as a function of particle size using a portable laser particle counter. This in-place penetration test is compared to the current in-place leak test using light scattering photometers for single HEPA filter installations and for HEPA filter plenums using the shroud method. Test results show the in-place penetration test is more sensitive than the in-place leak test, has a similar operating procedure, but takes longer to conduct. Additional tests are required to confirm that the in-place penetration test yields identical results as the standard dioctyl phthalate (DOP) penetration test for HEPA filters with controlled leaks in the filter and gasket and duct by-pass leaks. Further development of the procedure is also required to reduce the test time before the in- place penetration test is practical

  18. In-place HEPA filter penetration test

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, W.; Wilson, K.; Elliott, J. [Lawrence Livermore National Lab., CA (United States)] [and others

    1997-08-01

    We have demonstrated the feasibility of conducting penetration tests on high efficiency particulate air (HEPA) filters as installed in nuclear ventilation systems. The in-place penetration test, which is designed to yield equivalent penetration measurements as the standard DOP efficiency test, is based on measuring the aerosol penetration of the filter installation as a function of particle size using a portable laser particle counter. This in-place penetration test is compared to the current in-place leak test using light scattering photometers for single HEPA filter installations and for HEPA filter plenums using the shroud method. Test results show the in-place penetration test is more sensitive than the in-place leak test, has a similar operating procedure, but takes longer to conduct. Additional tests are required to confirm that the in-place penetration test yields identical results as the standard dioctyl phthalate (DOP) penetration test for HEPA filters with controlled leaks in the filter and gasket and duct by-pass leaks. Further development of the procedure is also required to reduce the test time before the in-place penetration test is practical. 14 refs., 14 figs., 3 tabs.

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

    Directory of Open Access Journals (Sweden)

    N. A. Fedorova

    2014-01-01

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

  20. Value of flexibility in systems with large wind penetration

    OpenAIRE

    Silva , Vera

    2010-01-01

    The focus of this thesis is the quantification of the value of operation flexibility in systems with large penetration of wind generation. This begins with the quantification of the impact of wind generation (WG) uncertainty on the system's needs for frequency regulation and reserve. This is done by combing the stochastic behaviour of wind generation, demand uncertainty and generation outages. Two different approaches are compared to access the implications of using normal distribution approx...

  1. A study of the penetration of projectiles into marine sediments

    International Nuclear Information System (INIS)

    Boisson, J.Y.

    1985-01-01

    The work described in this document consists of three main parts: - Application, after having reviewed calculation methods and known codes, of a dynamic plasticity model based on the upper bound-method (with dissipated energy calculations by plastic deformations). The soil model used for this calculation is the Cambridge Clay Model. - Carrying out a programme of tests with instrumented small scale penetrators in centrifuge on a consolidated clay-target. The trials are done under 50 g, with projectiles, fired with an airgun at high impact velocity (50 m/s). The penetrators' instrumentation consists of either measuring acceleration, or tip force with strain gauges. - The mounting of a small instrumented penetrator for shallow water depth experimentations, with an accelerometer, and a local cell for tip resistance. A rapid electronic data acquisition system has been developed for these experimentations. The preliminary tests are done in a large tank filled with clay. The geotechnical characteristics of the clay are perfectly controlled. The tests performed under these conditions have shown the following observations: the rapid electronic data acquisition system works perfectly and could be used as a basic component for a deep water instrumentated penetrator; the results, obtained in these particular test conditions, are in a perfect agreement with the predictions of the model developed in the frame of this contract

  2. Assessment of high penetration of solar photovoltaics in Wisconsin

    International Nuclear Information System (INIS)

    Myers, Kevin S.; Klein, Sanford A.; Reindl, Douglas T.

    2010-01-01

    This paper provides an assessment of the large-scale implementation of distributed solar photovoltaics in Wisconsin with regard to its interaction with the utility grid, economics of varying levels of high penetration, and displaced emissions. These assessment factors are quantified using simulations with measured hourly solar radiation and weather data from the National Solar Radiation Database as primary inputs. Hourly utility load data for each electric utility in Wisconsin for a complete year were used in combination with the simulated PV output to quantify the impacts of high penetration of distributed PV on the aggregate Wisconsin electric utility load. As the penetration rate of distributed PV systems increases, both economic and environmental benefits experience diminishing returns. At penetration rates exceeding 15-20% of the aggregate utility load peak, less of the PV-energy is utilized and the contribution of the aggregate electricity generated from PV approaches a practical limit. The limit is not affected by costs, but rather by the time-distribution of available solar radiation and mismatch with the coincidence of aggregate utility electrical loads. The unsubsidized levelized cost of electricity from PV is more than four times greater than the current market price for electricity, based on time-of-use rates, in Wisconsin. At the present time, the investment in solar PV as a cost-effective means to reduce emissions from traditional electricity generation sources is not justified. (author)

  3. Consistent constitutive modeling of metallic target penetration using empirical, analytical, and numerical penetration models

    Directory of Open Access Journals (Sweden)

    John (Jack P. Riegel III

    2016-04-01

    Full Text Available Historically, there has been little correlation between the material properties used in (1 empirical formulae, (2 analytical formulations, and (3 numerical models. The various regressions and models may each provide excellent agreement for the depth of penetration into semi-infinite targets. But the input parameters for the empirically based procedures may have little in common with either the analytical model or the numerical model. This paper builds on previous work by Riegel and Anderson (2014 to show how the Effective Flow Stress (EFS strength model, based on empirical data, can be used as the average flow stress in the analytical Walker–Anderson Penetration model (WAPEN (Anderson and Walker, 1991 and how the same value may be utilized as an effective von Mises yield strength in numerical hydrocode simulations to predict the depth of penetration for eroding projectiles at impact velocities in the mechanical response regime of the materials. The method has the benefit of allowing the three techniques (empirical, analytical, and numerical to work in tandem. The empirical method can be used for many shot line calculations, but more advanced analytical or numerical models can be employed when necessary to address specific geometries such as edge effects or layering that are not treated by the simpler methods. Developing complete constitutive relationships for a material can be costly. If the only concern is depth of penetration, such a level of detail may not be required. The effective flow stress can be determined from a small set of depth of penetration experiments in many cases, especially for long penetrators such as the L/D = 10 ones considered here, making it a very practical approach. In the process of performing this effort, the authors considered numerical simulations by other researchers based on the same set of experimental data that the authors used for their empirical and analytical assessment. The goals were to establish a

  4. A review of penetration mechanisms and dynamic properties of tungsten and depleted uranium penetrators

    International Nuclear Information System (INIS)

    Andrew, S.P.; Caligiuri, R.D.; Eiselstein, L.E.

    1991-01-01

    Kinetic energy penetrators must posses the best possible combination of hardness, stiffness, strength, and fracture toughness characteristics to be effective against modern armor systems. Over the last decade, depleted uranium (DU) and tungsten alloys have been the materials of choice for kinetic energy penetrators. Du and tungsten perform abut the same against semi-infinite targets, and DU outperforms tungsten penetrators in oblique, spaced array targets, but because of environmental and subsequent cost concerns, effort has focused on improving the performance of tungsten penetrators over the last few years. However, despite recent improvements in material properties, the penetration performance of tungsten still lags behind that of DU. One possible reason is the difference in deformation mechanisms at the leading edge of the penetrator during the penetration process-DU alloys tend to shear band and sharpen as they penetrate the target material, whereas tungsten penetrators tend to mushroom and blunt. As a first step to determine whether shear banding is truly the reason for superior DU performance, a review of the fabrication, high strain-rate properties, and penetration phenomena of penetrators manufactured from both tungsten and DU alloys. Specifically, the effects of composition, processing, and heat treatment on material properties and penetration mechanisms of these alloys are discussed

  5. Quantitative penetration testing with item response theory

    NARCIS (Netherlands)

    Pieters, W.; Arnold, F.; Stoelinga, M.I.A.

    2013-01-01

    Existing penetration testing approaches assess the vulnerability of a system by determining whether certain attack paths are possible in practice. Therefore, penetration testing has thus far been used as a qualitative research method. To enable quantitative approaches to security risk management,

  6. Generic penetration in the retail antidepressant market.

    Science.gov (United States)

    Ventimiglia, Jeffrey; Kalali, Amir H

    2010-06-01

    In this article, we explore the accelerated penetration of generic antidepressants in the United States market following the availability of generic citalopram and sertraline. Analysis suggests that overall, generic penetration into the antidepressant market has grown from approximately 41 percent in January 2004 to over 73 percent in January 2010. Similar trends are uncovered when branded and generic prescriptions are analyzed by specialty.

  7. Quantitative Penetration Testing with Item Response Theory

    NARCIS (Netherlands)

    Arnold, Florian; Pieters, Wolter; Stoelinga, Mariëlle Ida Antoinette

    2014-01-01

    Existing penetration testing approaches assess the vulnerability of a system by determining whether certain attack paths are possible in practice. Thus, penetration testing has so far been used as a qualitative research method. To enable quantitative approaches to security risk management, including

  8. Quantitative penetration testing with item response theory

    NARCIS (Netherlands)

    Arnold, Florian; Pieters, Wolter; Stoelinga, Mariëlle

    2013-01-01

    Existing penetration testing approaches assess the vulnerability of a system by determining whether certain attack paths are possible in practice. Thus, penetration testing has so far been used as a qualitative research method. To enable quantitative approaches to security risk management, including

  9. Chemical Penetration Enhancers for Transdermal Drug Delivery ...

    African Journals Online (AJOL)

    for transdermal administration. The permeation of drug through skin can be enhanced by both chemical penetration enhancement and physical methods. In this review, we have discussed the chemical penetration enhancement technology for transdermal drug delivery as well as the probable mechanisms of action.

  10. MDCT diagnosis of penetrating diaphragm injury

    Energy Technology Data Exchange (ETDEWEB)

    Bodanapally, Uttam K.; Shanmuganathan, Kathirkamanathan; Mirvis, Stuart E.; Sliker, Clint W.; Fleiter, Thorsten R.; Sarada, Kamal; Miller, Lisa A. [University of Maryland School of Medicine, Department of Diagnostic Radiology, Baltimore, MD (United States); Stein, Deborah M. [University of Maryland, Department of Surgery, Shock Trauma Center, Baltimore, MD (United States); Alexander, Melvin [National Study Center for Trauma and Emergency Medical Systems, Baltimore, MD (United States)

    2009-08-15

    The purpose of the study was to determine the diagnostic sensitivity and specificity of multidetector CT (MDCT) in detection of diaphragmatic injury following penetrating trauma. Chest and abdominal CT examinations performed preoperatively in 136 patients after penetrating trauma to the torso with injury trajectory in close proximity to the diaphragm were reviewed by radiologists unaware of surgical findings. Signs associated with diaphragmatic injuries in penetrating trauma were noted. These signs were correlated with surgical diagnoses, and their sensitivity and specificity in assisting the diagnosis were calculated. CT confirmed diaphragmatic injury in 41 of 47 injuries (sensitivity, 87.2%), and an intact diaphragm in 71 of 98 patients (specificity, 72.4%). The overall accuracy of MDCT was 77%. The most accurate sign helping the diagnosis was contiguous injury on either side of the diaphragm in single-entry penetrating trauma (sensitivity, 88%; specificity, 82%). Thus MDCT has high sensitivity and good specificity in detecting penetrating diaphragmatic injuries. (orig.)

  11. MDCT diagnosis of penetrating diaphragm injury

    International Nuclear Information System (INIS)

    Bodanapally, Uttam K.; Shanmuganathan, Kathirkamanathan; Mirvis, Stuart E.; Sliker, Clint W.; Fleiter, Thorsten R.; Sarada, Kamal; Miller, Lisa A.; Stein, Deborah M.; Alexander, Melvin

    2009-01-01

    The purpose of the study was to determine the diagnostic sensitivity and specificity of multidetector CT (MDCT) in detection of diaphragmatic injury following penetrating trauma. Chest and abdominal CT examinations performed preoperatively in 136 patients after penetrating trauma to the torso with injury trajectory in close proximity to the diaphragm were reviewed by radiologists unaware of surgical findings. Signs associated with diaphragmatic injuries in penetrating trauma were noted. These signs were correlated with surgical diagnoses, and their sensitivity and specificity in assisting the diagnosis were calculated. CT confirmed diaphragmatic injury in 41 of 47 injuries (sensitivity, 87.2%), and an intact diaphragm in 71 of 98 patients (specificity, 72.4%). The overall accuracy of MDCT was 77%. The most accurate sign helping the diagnosis was contiguous injury on either side of the diaphragm in single-entry penetrating trauma (sensitivity, 88%; specificity, 82%). Thus MDCT has high sensitivity and good specificity in detecting penetrating diaphragmatic injuries. (orig.)

  12. An Innovative Solution to NASA's NEO Impact Threat Mitigation Grand Challenge and Flight Validation Mission Architecture Development

    Data.gov (United States)

    National Aeronautics and Space Administration — A Hypervelocity Asteroid Intercept Vehicle (HAIV) mission architecture, which blends a hypervelocity kinetic impactor with a subsurface nuclear explosion for optimal...

  13. Transconjunctival penetration of mitomycin C

    Directory of Open Access Journals (Sweden)

    Velpandian T

    2008-01-01

    Full Text Available Aims: The study was performed to estimate transconjunctival penetration of mitomycin C (MMC to Tenon′s tissue following application over the intact conjunctiva before routine trabeculectomy. Settings and Design: Institution-based case series. Materials and Methods: In 41 eyes of 41 patients, MMC (0.4 mg/ml for 3 min was applied over the intact conjunctiva before beginning trabeculectomy. Tenon′s capsule directly beneath the site of application was excised during trabeculectomy and was homogenized, centrifuged and MMC concentrations were analyzed using high-performance liquid chromatography (HPLC. Statistical Analysis Used: Statistical analysis was performed using stata0 8.0 version software (STATA Corporation, Houston, TX, USA. In this study, P -values less than 0.05 were considered as statistically significant. Results: The average weight of the sample of Tenon′s tissue excised was 5.51 ± 4.42 mg (range: 0.9-17.1 and the average estimated MMC concentration found to be present in Tenon′s tissue using HPLC was 18.67 ± 32.36 x 10−6 moles/kg of the tissue (range: 0.38-197.05 x 10−6 . In 36 of the 41 patients (87.80%, the MMC concentration reached above 2 x 10−6 moles/kg of the tissue concentration required to inhibit human conjunctival fibroblasts. Conclusions: Mitomycin C does permeate into the subconjunctival tissue after supraconjunctival application for 3 min. Application of MMC over the conjunctiva may be a useful alternative to subconjunctival or subscleral application during routine trabeculectomy and as an adjunct for failing blebs.

  14. HMO market penetration and hospital cost inflation in California.

    Science.gov (United States)

    Robinson, J C

    1991-11-20

    OBJECTIVE--Health maintenance organizations (HMOs) have stimulated price competition in California hospital markets since 1983, when the state legislature eliminated barriers to selective contracting by conventional health insurance plans. This study measures the impact of HMO-induced price competition on the rate of inflation in average cost per admission for 298 private, non-HMO hospitals between 1982 and 1988. DATA--HMO market penetration was calculated using discharge abstract data on insurance coverage, ZIP code of residence, and hospital of choice for 3.35 million patients in 1983 and 3.41 million patients in 1988. Data on hospital characteristics were obtained from the American Hospital Association and other sources. -HMO coverage grew from an average of 8.3% of all admissions in local hospital markets in 1983 to 17.0% of all admissions in 1988. The average rate of growth in costs per admission between 1982 and 1988 was 9.4% lower in markets with relatively high HMO penetration compared with markets with relatively low HMO penetration (95% confidence interval, 5.2 to 13.8). Cost savings for these 298 hospitals are estimated at $1.04 billion for 1988. CONCLUSION--Price competition between HMOs and conventional health insurers can significantly reduce hospital cost inflation if legislative barriers to selective contracting are removed. The impact of competition in California was modest, however, when evaluated in terms of the 74.5% average rate of California hospital cost inflation during these years.

  15. A numerical study on the disturbance of explosive reactive armors to jet penetration

    Directory of Open Access Journals (Sweden)

    Xiang-dong Li

    2014-03-01

    Full Text Available The disturbance of flat and V-shaped sandwich reactive armor configurations to shaped-charge jet is studied by a numerical approach. The disturbing and cutting effects of the two reactive armor configurations to the jet are successfully captured. The predicted disturbance characteristics and patterns are in fairly good agreement with the X-ray photographic observations. The residual depth of penetration into a semi-infinitive homogeneous steel target behind the reactive armor is computed for a series of jet/armor parameters. For the flat configuration, it is demonstrated that the residual penetration depth is not significantly reduced for a normal impact while it is reduced up to 75% for an oblique impact. In comparison, the V-shaped configuration reduces the penetration depth of the jet to 90%, and it is observed that the penetration depth is not sensitive to the V-shaped angle.

  16. The Current Status of the Japanese Penetrator Mission: LUNAR-A

    Science.gov (United States)

    Tanaka, S.; Shiraishi, H.; Fujimura, A.; Hayakawa, H.

    The scientific objective of the LUNAR-A, Japanese Penetrator Mission, is to explore the lunar interior by seismic and heat-flow experiments. Two penetrators containing two seismometers (horizontal and vertical components) and heat-flow probes will be deployed from a spacecraft onto the lunar surface, one on the nearside and the other on the farside of the moon. The final impact velocity of the penetrator will be about 300m/sec; it will encounter a shock of about 8000 G at impact on the lunar surface. According to numerous experimental impact tests using model penetrators and a lunar regolith analog target, each penetrator is predicted to penetrate to a depth of 1 to 3 m. The data obtained by the penetrators will be transmitted to the earth station via the LUNAR-A mother spacecraft orbiting at an altitude of about 200 km. The penetrator is a missile-shaped instrument carrier, which is about 14cm in diameter, 75cm in length, and about 14kg in weight without attitude control system. It contains a two-component seismometer and heat flow probes together with other supporting instruments such as a tilt meter and an accelerometer. The seismic observations are expected to provide key data on the size of the lunar core, as well as data on deep lunar mantle structure. The heat flow measurements at two penetrator deployment sites will also provide important data on the thermal structure and bulk concentrations of heat-generating elements in the Moon. These data will provide much stronger geophysical constraints on the origin and evolution of the Moon than has been obtained so far. The LUNAR-A spacecraft was supposed to be launched in the summer of 2004, but it was postponed due to the necessity of a replacement of the valves used in the RCS propulsion system of the spacecraft, following a recall issued by the manufacturer who found a malfunction of similar valves. Then, the technological review boards by ISAS and JAXA recommended that both the more robustness of the

  17. Miniature Ground Penetrating Radar, CRUX GPR

    Science.gov (United States)

    Kim, Soon Sam; Carnes, Steven R.; Haldemann, Albert F.; Ulmer, Christopher T.; Ng, Eddie; Arcone, Steven A.

    2006-01-01

    Under NASA instrument development programs (PIDDP 2000-2002, MIPD 2003-2005, ESR and T, 2005) we have been developing miniature ground penetrating radars (GPR) for use in mapping subsurface stratigraphy from planetary rovers for Mars and lunar applications. The Mars GPR is for deeper penetration (up to 50 m depth) into the Martian subsurface at moderate resolution (0.5 m) for a geological characterization. As a part of the CRUX (Construction and Resource Utilization Explorer) instrument suite, the CRUX GPR is optimized for a lunar prospecting application. It will have shallower penetration (5 m depth) with higher resolution (10 cm) for construction operations including ISRU (in-situ resource utilization).

  18. Development of coring, consolidating, subterrene penetrators

    International Nuclear Information System (INIS)

    Murphy, H.D.; Neudecker, J.W.; Cort, G.E.; Turner, W.C.; McFarland, R.D.; Griggs, J.E.

    1976-02-01

    Coring penetrators offer two advantages over full face-melting penetrators, i.e., formation of larger boreholes with no increase in power and the production of glass-lined, structurally undisturbed cores which can be recovered with conventional core-retrieval systems. These cores are of significant value in geological exploratory drilling programs. The initial design details and fabrication features of a 114-mm-diam coring penetrator are discussed; significant factors for design optimization are also presented. Results of laboratory testing are reported and compared with performance predictions, and an initial field trial is described

  19. Final Results of Shuttle MMOD Impact Database

    Science.gov (United States)

    Hyde, J. L.; Christiansen, E. L.; Lear, D. M.

    2015-01-01

    The Shuttle Hypervelocity Impact Database documents damage features on each Orbiter thought to be from micrometeoroids (MM) or orbital debris (OD). Data is divided into tables for crew module windows, payload bay door radiators and thermal protection systems along with other miscellaneous regions. The combined number of records in the database is nearly 3000. Each database record provides impact feature dimensions, location on the vehicle and relevant mission information. Additional detail on the type and size of particle that produced the damage site is provided when sampling data and definitive spectroscopic analysis results are available. Guidelines are described which were used in determining whether impact damage is from micrometeoroid or orbital debris impact based on the findings from scanning electron microscopy chemical analysis. Relationships assumed when converting from observed feature sizes in different shuttle materials to particle sizes will be presented. A small number of significant impacts on the windows, radiators and wing leading edge will be highlighted and discussed in detail, including the hypervelocity impact testing performed to estimate particle sizes that produced the damage.

  20. A Mass Loss Penetration Model to Investigate the Dynamic Response of a Projectile Penetrating Concrete considering Mass Abrasion

    Directory of Open Access Journals (Sweden)

    NianSong Zhang

    2015-01-01

    Full Text Available A study on the dynamic response of a projectile penetrating concrete is conducted. The evolutional process of projectile mass loss and the effect of mass loss on penetration resistance are investigated using theoretical methods. A projectile penetration model considering projectile mass loss is established in three stages, namely, cratering phase, mass loss penetration phase, and remainder rigid projectile penetration phase.

  1. The penetration of aerosols through fine orifices

    International Nuclear Information System (INIS)

    Marshall, I.A.; Latham, L.J.; Ball, M.H.E.; Mitchell, J.P.

    1991-07-01

    A novel experimental technique has been extended to study the migration of gas-borne glass microspheres in the size range from about 1 to 15 μm volume equivalent diameter through orifices with bores and thicknesses in the range from 2 to 100 μm and 12.7 to 509 μm respectively. The penetration of these particles was significant with all orifices greater than 10 μm bore at a constant driving pressure of 100 kPa. However, few particles penetrated the 5 μm bore orifice, while virtually no particles penetrated the 2 μm bore orifice. Particle size distributions determined after penetration through the orifices were very similar to that of the upstream aerosol except when significant attenuation occurred. (author)

  2. Temporary fire sealing of penetrations on TFTR

    International Nuclear Information System (INIS)

    Hondorp, H.L.

    1981-02-01

    The radiation shielding provided for TFTR for D-D and D-T operation will be penetrated by numerous electrical and mechanical services. Eventually, these penetrations will have to be sealed to provide the required fire resistance, tritium sealability, pressure integrity and radiation attenuation. For the initial hydrogen operation, however, fire sealing of the penetrations in the walls and floor is the primary concern. This report provides a discussion of the required and desirable properties of a temporary seal which can be used to seal these penetrations for the hydrogen operation and then subsequently be removed and replaced as required for the D-D and D-T operations. Several candidate designs are discussed and evaluated and recommendations are made for specific applications

  3. Identifying structural damage with ground penetrating radar

    CSIR Research Space (South Africa)

    Van Schoor, Abraham M

    2008-07-01

    Full Text Available Ground penetrating radar (GPR) and electrical resistance tomography (ERT) surveys were conducted in an urban environment in an attempt to identify the cause of severe structural damage to a historically significant residential property...

  4. Thyroid Emphysema Following Penetrating Neck Trauma

    Directory of Open Access Journals (Sweden)

    Demet Karadağ

    2011-03-01

    Full Text Available Although traumatic thyroid gland rupture or hemorrhage is usually seen in goitrous glands, injuries of the normal thyroid gland after neck trauma have rarely been described in the literature. We describe a 44-year-old man who presented with thyroid emphysema and subcutaneous emphysema (SCE that occurred after penetrating neck trauma. CT images showed complete resolution of thyroid emphysema and subcutaneous emphysema at follow-up examination. Neck injuries can be life threatening. After penetrating neck traumas, physicians should consider subtle esophageal or tracheal laceration. Thyroid emphysema can occur as the result of penetrating neck trauma. The mechanism of emphysema of the thyroid parenchyma can be explained by the thyroid gland’s presence in a single visceral compartment that encompasses the larynx, trachea and thyroid gland. We describe an unusual case of thyroid emphysema of a normal thyroid gland following a penetrating neck injury.

  5. Kali Linux wireless penetration testing beginner's guide

    CERN Document Server

    Ramachandran, Vivek

    2015-01-01

    If you are a security professional, pentester, or anyone interested in getting to grips with wireless penetration testing, this is the book for you. Some familiarity with Kali Linux and wireless concepts is beneficial.

  6. Penetration testing protecting networks and systems

    CERN Document Server

    Henry, Kevin M

    2012-01-01

    This book is a preparation guide for the CPTE examination, yet is also a general reference for experienced penetration testers, ethical hackers, auditors, security personnel and anyone else involved in the security of an organization's computer systems.

  7. The penetration of aerosols through fine capillaries

    International Nuclear Information System (INIS)

    Mitchell, J.P.; Edwards, R.T.; Ball, M.H.E.

    1989-10-01

    A novel experimental technique has been developed to study the penetration of aerosol particles ranging from about 1 to 15 μm aerodynamic diameter through capillaries varying from 20 to 80 μm bore and from 10 to 50 mm in length. When the driving pressure was 100 kPa, the penetration of the airborne particles was considerably smaller than expected from a simple comparison of particle diameter with the bore of the capillary. Particle size distributions determined after penetration through the capillaries were in almost all cases similar to the particle size distribution of the aerosol at the capillary entrance. This lack of size-selectivity can be explained in terms of the capillary behaving as a conventional suction-based sampler from a near still (calm) air environment. The resulting particle penetration data are important in assessing the potential for the leakage of aerosols through seals in containers used to transport radioactive materials. (author)

  8. Low Force Penetration of Icy Regolith

    Science.gov (United States)

    Mantovani, J. G.; Galloway, G. M.; Zacny, K.

    2016-01-01

    A percussive cone penetrometer measures the strength of granular material by using percussion to deliver mechanical energy into the material. A percussive cone penetrometer was used in this study to penetrate a regolith ice mixture by breaking up ice and decompacting the regolith. As compared to a static cone penetrometer, percussion allows low reaction forces to push a penetrometer probe tip more easily into dry regolith in a low gravity environment from a planetary surface rover or a landed spacecraft. A percussive cone penetrates icy regolith at ice concentrations that a static cone cannot penetrate. In this study, the percussive penetrator was able to penetrate material under 65 N of down-force which could not be penetrated using a static cone under full body weight. This paper discusses using a percussive cone penetrometer to discern changes in the concentration of water-ice in a mixture of lunar regolith simulant and ice to a depth of one meter. The rate of penetration was found to be a function of the ice content and was not significantly affected by the down-force. The test results demonstrate that this method may be ideal for a small platform in a reduced gravity environment. However, there are some cases where the system may not be able to penetrate the icy regolith, and there is some risk of the probe tip becoming stuck so that it cannot be retracted. It is also shown that a percussive cone penetrometer could be used to prospect for water ice in regolith at concentrations as high as 8 by weight.

  9. Defining the coupled effects of cryogenic, space-radiation, and hypervelocity impact damamge on COPV's, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The intent of the proposed effort is to investigate the detailed composite overwrapped pressure vessel (COPV) performance characteristics after being subject to...

  10. In vitro penetration of bleaching agents into the pulp chamber

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Valera, M C; Mancini, M N G

    2004-01-01

    To investigate pulp chamber penetration of bleaching agents in teeth following restorative procedures.......To investigate pulp chamber penetration of bleaching agents in teeth following restorative procedures....

  11. DebriSat - A Planned Laboratory-Based Satellite Impact Experiment for Breakup Fragment Characterization

    Science.gov (United States)

    Liou, J.-C.; Fitz-Coy, N.; Werremeyer, M.; Huynh, T.; Voelker, M.; Opiela, J.

    2012-01-01

    DebriSat is a planned laboratory ]based satellite hypervelocity impact experiment. The goal of the project is to characterize the orbital debris that would be generated by a hypervelocity collision involving a modern satellite in low Earth orbit (LEO). The DebriSat project will update and expand upon the information obtained in the 1992 Satellite Orbital Debris Characterization Impact Test (SOCIT), which characterized the breakup of a 1960 's US Navy Transit satellite. There are three phases to this project: the design and fabrication of an engineering model representing a modern, 50-cm/50-kg class LEO satellite known as DebriSat; conduction of a laboratory-based hypervelocity impact to catastrophically break up the satellite; and characterization of the properties of breakup fragments down to 2 mm in size. The data obtained, including fragment size, area ]to ]mass ratio, density, shape, material composition, optical properties, and radar cross ]section distributions, will be used to supplement the DoD fs and NASA fs satellite breakup models to better describe the breakup outcome of a modern satellite. Updated breakup models will improve mission planning, environmental models, and event response. The DebriSat project is sponsored by the Air Force fs Space and Missile Systems Center and the NASA Orbital Debris Program Office. The design and fabrication of DebriSat is led by University of Florida with subject matter experts f support from The Aerospace Corporation. The major milestones of the project include the complete fabrication of DebriSat by September 2013, the hypervelocity impact of DebriSat at the Air Force fs Arnold Engineering Development Complex in early 2014, and fragment characterization and data analyses in late 2014.

  12. Cell penetration to nanofibrous scaffolds

    Czech Academy of Sciences Publication Activity Database

    Rampichová, Michala; Buzgo, Matej; Chvojka, J.; Prosecká, Eva; Kofroňová, Olga; Amler, Evžen

    2014-01-01

    Roč. 8, č. 1 (2014), s. 36-41 ISSN 1933-6918 Grant - others:GA UK(CZ) 384311; GA UK(CZ) 626012; GA UK(CZ) 270513; GA UK(CZ) 330611; GA UK(CZ) 648112; GA MZd(CZ) NT12156; GA MŠk(CZ) project IPv6 Institutional support: RVO:68378041 ; RVO:61388971 Keywords : fibrous scaffold * mesenchymal stem cells * Forcespinning (R) Subject RIV: FP - Other Medical Disciplines Impact factor: 4.505, year: 2014

  13. A review of penetration mechanisms and dynamic properties of tungsten and depleted uranium penetrators

    International Nuclear Information System (INIS)

    Andrew, S.P.; Caligiuri, R.D.; Eiselstein, L.E.

    1991-01-01

    Over the last decade, depleted uranium (DU) and tungsten alloys have been the materials of choice for kinetic energy penetrators. However, despite improvements in mechanical properties in recent years, the penetration performance of tungsten still lags behind that of DU. One possible reason is the difference in deformation mechanisms- DU alloys tend to shear band as they penetrate the target material, whereas tungsten penetrators tend to mushroom. As a first step to determining whether shear banding is truly the reason for superior DU performance, a review and summary of the available information was performed. This paper presents a state-of-the-art review of the formulation, high strain- rate properties, and penetration phenomena of penetrators manufactured from both tungsten and DU alloys. Specifically, the effects of composition, processing, and heat treatment on mechanical properties and penetration mechanisms of these alloys are discussed. Penetration data and models for penetration mechanisms (in particular shear banding) are also presented, as well as the applicability of these models and their salient features

  14. Rapid penetration into granular media visualizing the fundamental physics of rapid earth penetration

    CERN Document Server

    Iskander, Magued

    2015-01-01

    Rapid Penetration into Granular Media: Visualizing the Fundamental Physics of Rapid Earth Penetration introduces readers to the variety of methods and techniques used to visualize, observe, and model the rapid penetration of natural and man-made projectiles into earth materials. It provides seasoned practitioners with a standard reference that showcases the topic's most recent developments in research and application. The text compiles the findings of new research developments on the subject, outlines the fundamental physics of rapid penetration into granular media, and assembles a com

  15. On the Inertia Term of Projectile's Penetration Resistance

    Directory of Open Access Journals (Sweden)

    Yu Shan

    2013-01-01

    Full Text Available The effect of the target inertia term of rigid kinetic energy projectiles (KEP’s penetration resistance is investigated using nonlinear dynamic code LS-DYNA and four constitutive models. It is found that the damage number of target can be used to measure the influence of the inertia term. The smaller the damage number is, the less influence the inertia term has. The less dependent the resistance has on projectile velocity, the more accurate it is to treat the resistance as a constant. For the ogive-nose projectile with CRH of 3, when the target is aluminum, steel, or other metals, the threshold velocity for the constant resistance is at least 1258 m/s; when the target is concrete, rock, or other brittle materials, if the velocity of the projectile is greater than 400 m/s or so, the damage number would be very large, and the penetration resistance would clearly depend on the projectile’s velocity. The higher the elastic wave velocity is, the more penetration process is affected by the impact face.

  16. Analytical review of 664 cases of penetrating buttock trauma

    Directory of Open Access Journals (Sweden)

    Schulte Klaus-Martin

    2011-10-01

    Full Text Available Abstract A comprehensive review of data has not yet been provided as penetrating injury to the buttock is not a common condition accounting for 2-3% of all penetrating injuries. The aim of the study is to provide the as yet lacking analytical review of the literature on penetrating trauma to the buttock, with appraisal of characteristics, features, outcomes, and patterns of major injuries. Based on these results we will provide an algorithm. Using a set of terms we searched the databases Pub Med, EMBASE, Cochran, and CINAHL for articles published in English between 1970 and 2010. We analysed cumulative data from prospective and retrospective studies, and case reports. The literature search revealed 36 relevant articles containing data on 664 patients. There was no grade A evidence found. The injury population mostly consists of young males (95.4% with a high proportion missile injury (75.9%. Bleeding was found to be the key problem which mostly occurs from internal injury and results in shock in 10%. Overall mortality is 2.9% with significant adverse impact of visceral or vascular injury and shock (P P

  17. Accelerator experiments with soft protons and hyper-velocity dust particles: application to ongoing projects of future X-ray missions

    DEFF Research Database (Denmark)

    Perinati, E.; Diebold, S.; Kendziorra, E.

    2012-01-01

    and hyper-velocity dust particles off X-ray mirror shells. These activities have been identified as a goal in the context of a number of ongoing space projects in order to assess the risk posed by environmental radiation and dust and qualify the adopted instrumentation with respect to possible damage...... or performance degradation. In this paper we focus on tests for the Silicon Drift Detectors (SDDs) used aboard the LOFT space mission. We use the Van de Graaff accelerators at the University of T\\"ubingen and at the Max Planck Institute for Nuclear Physics (MPIK) in Heidelberg, for soft proton and hyper...

  18. An energy approach study of the penetration of concrete by rigid missiles

    International Nuclear Information System (INIS)

    Guirgis, Sameh; Guirguis, Ehab

    2009-01-01

    This paper presents an energy approach for investigating the penetration of concrete by rigid missiles and the associated phenomena. However, the principal assumptions made here must be validated experimentally before giving the proposed subject further considerations. In the following, a new measure for concrete resistance to penetration by hard missiles is presented. The suggested term for this measure is 'the Volumetric Crushing Energy Density' of concrete which can be described as the energy required for converting a unit volume of concrete to separate particles under compressive loading so that the particles of the crushed volume meet certain gradation criteria. Using this quantity, an explanation of the scale effect is postulated. Moreover, a dimensionless semi-analytical formula for the penetration depth of a rigid missile in a concrete target is proposed which includes a large number of the variables of the problem. The formula assumes that the penetration incident may include several successive phases where the set of variables that governs the impact is different during each phase, and the variables that characterize the impact during each phase correlate in a different manner as well. Furthermore, many of the penetration depth formulae available in the literature are rewritten according to the formula proposed here where the concrete penetration resistance of any incident is estimated by modifying the resistance of 'reference impact incidents.' The rewritten formulae show the wide variation of the values of concrete resistance which are implicitly included in the original formulae. Finally, the proposed formula is applied using data of penetration experiments presented by Forrestal et al. [Forrestal, M.J., Altman, B.S., Cargile, J.D., Hanchak, S.J., 1994. An empirical equation for penetration depth of ogive-nose projectiles into concrete targets. Int. J. Impact Eng. 15(4), 395-405; Forrestal, M.J., Frew, D.J., Hickerson, J.P., Rohwer, T.A., 2003

  19. Predicting the Consequences of MMOD Penetrations on the International Space Station

    Science.gov (United States)

    Hyde, James; Christiansen, E.; Lear, D.; Evans

    2018-01-01

    The threat from micrometeoroid and orbital debris (MMOD) impacts on space vehicles is often quantified in terms of the probability of no penetration (PNP). However, for large spacecraft, especially those with multiple compartments, a penetration may have a number of possible outcomes. The extent of the damage (diameter of hole, crack length or penetration depth), the location of the damage relative to critical equipment or crew, crew response, and even the time of day of the penetration are among the many factors that can affect the outcome. For the International Space Station (ISS), a Monte-Carlo style software code called Manned Spacecraft Crew Survivability (MSCSurv) is used to predict the probability of several outcomes of an MMOD penetration-broadly classified as loss of crew (LOC), crew evacuation (Evac), loss of escape vehicle (LEV), and nominal end of mission (NEOM). By generating large numbers of MMOD impacts (typically in the billions) and tracking the consequences, MSCSurv allows for the inclusion of a large number of parameters and models as well as enabling the consideration of uncertainties in the models and parameters. MSCSurv builds upon the results from NASA's Bumper software (which provides the probability of penetration and critical input data to MSCSurv) to allow analysts to estimate the probability of LOC, Evac, LEV, and NEOM. This paper briefly describes the overall methodology used by NASA to quantify LOC, Evac, LEV, and NEOM with particular emphasis on describing in broad terms how MSCSurv works and its capabilities and most significant models.

  20. Relaxation near Supermassive Black Holes Driven by Nuclear Spiral Arms: Anisotropic Hypervelocity Stars, S-stars, and Tidal Disruption Events

    Energy Technology Data Exchange (ETDEWEB)

    Hamers, Adrian S. [Institute for Advanced Study, School of Natural Sciences, Einstein Drive, Princeton, NJ 08540 (United States); Perets, Hagai B., E-mail: hamers@ias.edu [Technion—Israel Institute of Technology, Haifa 32000 (Israel)

    2017-09-10

    Nuclear spiral arms are small-scale transient spiral structures found in the centers of galaxies. Similarly to their galactic-scale counterparts, nuclear spiral arms can perturb the orbits of stars. In the case of the Galactic center (GC), these perturbations can affect the orbits of stars and binaries in a region extending to several hundred parsecs around the supermassive black hole (SMBH), causing diffusion in orbital energy and angular momentum. This diffusion process can drive stars and binaries to close approaches with the SMBH, disrupting single stars in tidal disruption events (TDEs), or disrupting binaries, leaving a star tightly bound to the SMBH and an unbound star escaping the galaxy, i.e., a hypervelocity star (HVS). Here, we consider diffusion by nuclear spiral arms in galactic nuclei, specifically the Milky Way GC. We determine nuclear-spiral-arm-driven diffusion rates using test-particle integrations and compute disruption rates. Our TDE rates are up to 20% higher compared to relaxation by single stars. For binaries, the enhancement is up to a factor of ∼100, and our rates are comparable to the observed numbers of HVSs and S-stars. Our scenario is complementary to relaxation driven by massive perturbers. In addition, our rates depend on the inclination of the binary with respect to the Galactic plane. Therefore, our scenario provides a novel potential source for the observed anisotropic distribution of HVSs. Nuclear spiral arms may also be important for accelerating the coalescence of binary SMBHs and for supplying nuclear star clusters with stars and gas.

  1. Factors Controlling the Pharmacokinetics, Biodistribution and Intratumoral Penetration of Nanoparticles

    Science.gov (United States)

    Ernsting, Mark J.; Murakami, Mami; Roy, Aniruddha; Li, Shyh-Dar

    2014-01-01

    Nanoparticle drug delivery to the tumor is impacted by multiple factors: nanoparticles must evade clearance by renal filtration and the reticuloendothelial system, extravasate through the enlarged endothelial gaps in tumors, penetrate through dense stroma in the tumor microenvironment to reach the tumor cells, remain in the tumor tissue for a prolonged period of time, and finally release the active agent to induce pharmacological effect. The physicochemical properties of nanoparticles such as size, shape, surface charge, surface chemistry (PEGylation, ligand conjugation) and composition affect the pharmacokinetics, biodistribution, intratumoral penetration and tumor bioavailability. On the other hand, tumor biology (blood flow, perfusion, permeability, interstitial fluid pressure and stroma content) and patient characteristics (age, gender, tumor type, tumor location, body composition and prior treatments) also have impact on drug delivery by nanoparticles. It is now believed that both nanoparticles and the tumor microenvironment have to be optimized or adjusted for optimal delivery. This review provides a comprehensive summary of how these nanoparticle and biological factors impact nanoparticle delivery to tumors, with discussion on how the tumor microenvironment can be adjusted and how patients can be stratified by imaging methods to receive the maximal benefit of nanomedicine. Perspectives and future directions are also provided. PMID:24075927

  2. Drop spreading and penetration into pre-wetted powders

    KAUST Repository

    Marston, Jeremy

    2013-05-01

    We present results from an experimental study of the impact of liquid drops onto powder beds which are pre-wetted with the impacting liquid. Using high-speed video imaging, we study both the dynamics of the initial spreading regime and drainage times once the drop has reached its maximum spread on the surface. During the initial spreading stage, we compare our experimental data to a previously developed model which incorporates imbibition into the spreading dynamics and observe reasonable agreement. We find that the maximum spread is a strong function of the moisture content in the powder bed and that the total time from impact to complete drainage is always shorter than that for dry powder. Our results indicate that there is an optimum moisture content (or saturation) which leads to the fastest penetration. We use simple scaling arguments which also identify an optimum moisture content for fastest penetration, which agrees very well with the experimental result. © 2013 Elsevier B.V.

  3. Deformation analysis of shallow penetration in clay

    Science.gov (United States)

    Sagaseta, C.; Whittle, A. J.; Santagata, M.

    1997-10-01

    A new method of analysis is described for estimating the deformations and strains caused by shallow undrained penetration of piles and caissons in clay. The formulation combines previous analyses for steady, deep penetration, with methods used to compute soil deformations due to near-surface ground loss, and is referred to as the Shallow Strain Path Method (SSPM). Complete analytical solutions for the velocity and strain rates are given for a planar wall, an axisymmetric, closed-ended pile and unplugged, open-ended pile geometries. In these examples, the analyses consider a single source penetrating through the soil at a constant rate, generating a family of penetrometers with rounded tips, referred to as simple wall, pile and tube geometries. Soil deformations and strains are obtained by integrating the velocity and strain rates along the particle paths.The transition from shallow to deep penetration is analysed in detail. Shallow penetration causes heave at the ground surface, while settlements occur only in a thin veneer of material adjacent to the shaft and in a bulb-shaped region around the tip. The size of this region increases with the embedment depth. Deformations inside an open-ended pile/caisson are affected significantly by details of the simple tube wall geometry.

  4. Meteorite Impact "Earthquake" Features (Rock Liquefaction, Surface Wave Deformations, Seismites) from Ground Penetrating Radar (GPR) and Geoelectric Complex Resistivity/Induced Polarization (IP) Measurements, Chiemgau (Alpine Foreland, Southeast Germany)

    Science.gov (United States)

    Ernstson, K.; Poßekel, J.

    2017-12-01

    Densely spaced GPR and complex resistivity measurements on a 30,000 square meters site in a region of enigmatic sinkhole occurrences in unconsolidated Quaternary sediments have featured unexpected and highlighting results from both a meteorite impact research and an engineering geology point of view. The GPR measurements and a complex resistivity/IP electrical imaging revealed extended subrosion depressions related with a uniformly but in various degrees of intensity deformed loamy and gravelly ground down to at least 10 m depth. Two principle observations could be made from both the GPR high-resolution measurements and the more integrating resistivity and IP soundings with both petrophysical evidences in good complement. Subrosion can be shown to be the result of prominent sandy-gravelly intrusions and extrusions typical of rock liquefaction processes well known to occur during strong earthquakes. Funnel-shaped structures with diameters up to 25 m near the surface and reaching down to the floating ground water level at 10 m depth were measured. GPR radargrams could trace prominent gravelly-material transport bottom-up within the funnels. Seen in both GPR tomography and resistivity/IP sections more or less the whole investigated area is overprinted by wavy deformations of the unconsolidated sediments with wavelengths of the order of 5 - 10 m and amplitudes up to half a meter, likewise down to 10 m depth. Substantial earthquakes are not known in this region. Hence, the observed heavy underground disorder is considered the result of the prominent earthquake shattering that must have occurred during the Holocene (Bronze Age/Celtic era) Chiemgau meteorite impact event that produced a 60 km x 30 km sized crater strewn field directly hosting the investigated site. Depending on depth and size of floating aquifers local concentrations of rock liquefaction and seismic surface waves (probably LOVE waves) to produce the wavy deformations could develop, when the big

  5. Two methodologies for physical penetration testing using social engineering

    NARCIS (Netherlands)

    Dimkov, T.; van Cleeff, A.; Pieters, Wolter; Hartel, Pieter H.

    2010-01-01

    Penetration tests on IT systems are sometimes coupled with physical penetration tests and social engineering. In physical penetration tests where social engineering is allowed, the penetration tester directly interacts with the employees. These interactions are usually based on deception and if not

  6. Opportunities for high wind energy penetration

    DEFF Research Database (Denmark)

    Tande, J.O.; Hansen, J.C.

    1997-01-01

    Wind power is today a mature technology, which at windy locations, is economically competitive to conventional power generation technologies. This and growing global environmental concerns have led governments to encourage and plan for wind energy development, a typical aim being 10% of electricity...... consumption. The successful operation of the three major power systems of Cape Verde, with a total wind energy penetration of about 15% since December 1994, demonstrates that power systems can be operated with high penetration of wind energy by adding simple control and monitoring systems only. Thorough...... analyses conclude that expanding to even above 15% wind energy penetration in the Cape Verde power systems is economical. Worldwide, numerous locations with favorable wind conditions and power systems similar to the Capeverdean provide good opportunities for installing wind farms and achieving high wind...

  7. WAPTT - Web Application Penetration Testing Tool

    Directory of Open Access Journals (Sweden)

    DURIC, Z.

    2014-02-01

    Full Text Available Web applications vulnerabilities allow attackers to perform malicious actions that range from gaining unauthorized account access to obtaining sensitive data. The number of reported web application vulnerabilities in last decade is increasing dramatically. The most of vulnerabilities result from improper input validation and sanitization. The most important of these vulnerabilities based on improper input validation and sanitization are: SQL injection (SQLI, Cross-Site Scripting (XSS and Buffer Overflow (BOF. In order to address these vulnerabilities we designed and developed the WAPTT (Web Application Penetration Testing Tool tool - web application penetration testing tool. Unlike other web application penetration testing tools, this tool is modular, and can be easily extended by end-user. In order to improve efficiency of SQLI vulnerability detection, WAPTT uses an efficient algorithm for page similarity detection. The proposed tool showed promising results as compared to six well-known web application scanners in detecting various web application vulnerabilities.

  8. Penetrating power of resonant electromagnetic induction imaging

    Directory of Open Access Journals (Sweden)

    Roberta Guilizzoni

    2016-09-01

    Full Text Available The possibility of revealing the presence and identifying the nature of conductive targets is of central interest in many fields, including security, medicine, industry, archaeology and geophysics. In many applications, these targets are shielded by external materials and thus cannot be directly accessed. Hence, interrogation techniques are required that allow penetration through the shielding materials, in order for the target to be identified. Electromagnetic interrogation techniques represent a powerful solution to this challenge, as they enable penetration through conductive shields. In this work, we demonstrate the power of resonant electromagnetic induction imaging to penetrate through metallic shields (1.5-mm-thick and image targets (having conductivities σ ranging from 0.54 to 59.77 MSm−1 concealed behind them.

  9. Wireless Network Penetration Testing and Security Auditing

    Directory of Open Access Journals (Sweden)

    Wang Shao-Long

    2016-01-01

    Full Text Available IEEE802.11 wireless wireless networks have security issues that are vulnerable to a variety of attacks. Due to using radio to transport data, attackers can bypass firewalls, sniff sensitive information, intercept packets and send malicious packets. Security auditing and penetration testing is expected to ensure wireless networks security. The contributions of this work are analyzed the vulnerability and types of attacks pertaining to IEEE 802.11 WLAN, performed well known attacks in a laboratory environment to conduct penetration tests to confirm whether our wireless network is hackable or not. WAIDPS is configured as auditing tool to view wireless attacks, such as WEP/WPA/WPA2 cracking, rouge access points, denial of service attack. WAIDPS is designed to detect wireless intrusion with additional features. Penetration testing and auditing will mitigate the risk and threatening to protect WALN.

  10. Penetrating chest injury: A miraculous life salvage

    Directory of Open Access Journals (Sweden)

    Santosh B Dalavi

    2013-01-01

    Full Text Available An unusual penetrating chest injury was caused by high velocity road traffic accident. An 18-year-old had a four wheeler accident and was brought in emergency department with a ′bamboo′ stick on the left side chest exiting through back. After the stabilization of vital parameters, an inter-costal tube drainage was done on the left side. Except the minor brochopleural fistula which healed by 10 th day, his recovery was uneventful. The outcome was consistent with current aggressive management of penetrating chest injuries. Management of penetrating chest injury involving pulmonary trauma is based on three principles. One is stabilization of hemodynamics of patient with proper clinical evaluation. Second, a mere intercostal tube drainage sufficient for majority of the cases. Third, post-operative active as well as passive physiotherapy is necessary for speedy recovery.

  11. The Microstructure of Lunar Micrometeorite Impact Craters

    Science.gov (United States)

    Noble, S. K.; Keller, L. P.; Christoffersen, R.; Rahman, Z.

    2016-01-01

    The peak of the mass flux of impactors striking the lunar surface is made up of objects approximately 200 micrometers in diameter that erode rocks, comminute regolith grains, and produce agglutinates. The effects of these micro-scale impacts are still not fully understood. Much effort has focused on evaluating the physical and optical effects of micrometeorite impacts on lunar and meteoritic material using pulsed lasers to simulate the energy deposited into a substrate in a typical hypervelocity impact. Here we characterize the physical and chemical changes that accompany natural micrometeorite impacts into lunar rocks with long surface exposure to the space environment (12075 and 76015). Transmission electron microscope (TEM) observations were obtained from cross-sections of approximately 10-20 micrometers diameter craters that revealed important micro-structural details of micrometeorite impact processes, including the creation of npFe (sup 0) in the melt, and extensive deformation around the impact site.

  12. Development Of The Nuclear Optical Penetration

    Science.gov (United States)

    Inoue, K.; Koike, K.; Imada, Y.

    1984-10-01

    We have developed the nuclear optical penetration to be incorporated in the wall penetration of the shell to introduce a data transmission system using optical fibers into a nuclear power plant with a pressurized water reactor. Radiation-induced coloration in optical glass seriously affects transmission characteristics of optical fibers, whereas it has been revealed that the pure-silica core optical fiber without any dopant in the core has wide applicability in radiation fields thanks to its very low radiation-induced attenuation. The wall penetration of the shell should have airtightness and resistivity to heat, vibration, and pressure, let alone radiation, excellent enough to be invariable in data transmission efficiency even when subjected to severe environmental tests. The sealing modules of this newly developed nuclear optical penetration are hermetically sealed. The gap between the optical fiber rod (100 pm in core diameter and 5 mm in rod diameter) and stainless steel tube is sealed with lamingted glass layer. As the result of He gas leakage test, high airtightness of less than 10 cc/sec was achieved. No thermal deformation of the core was caused by sealing with laminated glass layer, nor was observed transmission loss. Then the sealiing modules were subjected to the irradiation test using 60 Co gamma ray exposure of 2 x 10 rads. Though silica glass layer supporting the fiber rod and sealing glass portion turned blackish purple, transparency of the fiber was not affected. Only less than 0.5 dB of connecting loss was observed at the connecting point with the optical fiber cable. The sealing modules were also found to have resistivity to vibration and pressure as excellent as that of existing nuclear electric penetrations. We expect the nuclear optical fiber penetration will be much effective in improving reliability of data transmission systems using optical fibers in radiation fields.

  13. HMO penetration: has it hurt public hospitals?

    Science.gov (United States)

    Clement, J P; Grazier, K L

    2001-01-01

    The purpose of this study is to determine the extent to which health maintenance organization (HMO) penetration within the public hospitals' market area affects the financial performance and viability of these institutions, relative to private hospitals. Hospital- and market-specific measures are examined in a fully interacted model of over 2,300 hospitals in 321 metropolitan statistical areas (MSAs) in 1995. Although hospitals located in markets with higher HMO penetration have lower financial performance as reflected in revenues, expenses and operating margin, public hospitals are not more disadvantaged than other hospitals by managed care.

  14. Operational experience of extreme wind penetrations

    Energy Technology Data Exchange (ETDEWEB)

    Estanqueiro, Ana [INETI/LNEG - National Laboratory for Energy and Geology, Lisbon (Portugal); Mateus, Carlos B. [Instituto de Meteorologia, Lisboa (Portugal); Pestana, Rui [Redes Energeticas Nacionais (REN), Lisboa (Portugal)

    2010-07-01

    This paper reports the operational experience from the Portuguese Power System during the 2009/2010 winter months when record wind penerations were observed: the instantaneous wind power penetration peaked at 70% of consumption during no-load periods and the wind energy accounted for more than 50% of the energy consumed for a large period. The regulation measures taken by the TSO are presented in the paper, together with the additional reserves operated for added system security. Information on the overall power system behavior under such extreme long-term wind power penetrations will also be addressed. (org.)

  15. Hybrid treatment of penetrating aortic ulcer

    International Nuclear Information System (INIS)

    Lara, Juan Antonio Herrero; Martins-Romeo, Daniela de Araujo; Escudero, Carlos Caparros; Falcon, Maria del Carmen Prieto; Batista, Vinicius Bianchi; Vazquez, Rosa Maria Lepe

    2015-01-01

    Penetrating atherosclerotic aortic ulcer is a rare entity with poor prognosis in the setting of acute aortic syndrome. In the literature, cases like the present one, located in the aortic arch, starting with chest pain and evolving with dysphonia, are even rarer. The present report emphasizes the role played by computed tomography in the diagnosis of penetrating atherosclerotic ulcer as well as in the differentiation of this condition from other acute aortic syndromes. Additionally, the authors describe a new therapeutic approach represented by a hybrid endovascular surgical procedure for treatment of the disease. (author)

  16. Hybrid treatment of penetrating aortic ulcer

    Energy Technology Data Exchange (ETDEWEB)

    Lara, Juan Antonio Herrero; Martins-Romeo, Daniela de Araujo; Escudero, Carlos Caparros; Falcon, Maria del Carmen Prieto; Batista, Vinicius Bianchi, E-mail: jaherrero5@hotmail.com [Unidade de Gestao Clinica (UGC) de Diagnostico por Imagem - Hosppital Universitario Virgen Macarena, Sevilha (Spain); Vazquez, Rosa Maria Lepe [Unit of Radiodiagnosis - Hospital Nuestra Senora de la Merced, Osuna, Sevilha (Spain)

    2015-05-15

    Penetrating atherosclerotic aortic ulcer is a rare entity with poor prognosis in the setting of acute aortic syndrome. In the literature, cases like the present one, located in the aortic arch, starting with chest pain and evolving with dysphonia, are even rarer. The present report emphasizes the role played by computed tomography in the diagnosis of penetrating atherosclerotic ulcer as well as in the differentiation of this condition from other acute aortic syndromes. Additionally, the authors describe a new therapeutic approach represented by a hybrid endovascular surgical procedure for treatment of the disease. (author)

  17. Roentgenologic image of penetrating duodenal bulb ulcer

    International Nuclear Information System (INIS)

    Strunin, A.E.

    1986-01-01

    When studying a series of aimed roentgenograms in patients with peptic ulcer a gas bubble of irregular spherical configuration or two-layer niche were determined near the bulb medial contour. Gas bubble was from 0.5-0.7 to 3.5 cm in diameter. In such cases penetrating ulcers were determined in operations. Along with other signs gas bubble symptom, sometimes two-layer signs may be used for timely and exact roentgenological diagnosis of penetrating duodenal bulb ulcer in peptic ulcer disease

  18. Fractal measures in a deep penetration problem

    International Nuclear Information System (INIS)

    Murthy, K.P.N.; Indira, R.; John, T.M.

    1993-01-01

    In the Monte Carlo simulation of a deep penetration problem the parameter, say b in the importance function must be assigned a value b' such that variance is minimum. If b b' the sample mean is still not reliable; but the sample fluctuations would be small and misleading, though the actual fluctuations are quite large. This is because the distribution of transmission has a tail which becomes prominent when b > b'. Considering a model deep penetration problem, and employing exact enumeration techniques, it is shown that in the limit of large biasing the long tailed distribution to the transmission is multifractal. (author). 5 refs., 3 figs

  19. Generic Penetration of the SSRI Market.

    Science.gov (United States)

    Cascade, Elisa F; Kalali, Amir H

    2008-04-01

    In this article, we investigate the penetration of generic selective serotonin reuptake inhibitors (SSRIs) in the US market and the implications for patient out-of-pocket expense. The data suggest that generic penetration into the SSRI market has grown from approximately nine percent in 2000, the year that the patent for Prozac((R)) expired, to 72 percent in 2007. For December, 2007, the difference in patient out-of-pocket expense for branded vs. generic agents was, on average, $55.42 for patients paying by cash (i.e., they had no prescription drug insurance) and $22.39 for patients with insurance coverage.

  20. Penetrating ocular trauma from trampoline spring.

    Science.gov (United States)

    Spokes, David; Siddiqui, Salina; Vize, Colin

    2010-02-01

    The case is presented of a 12-year old boy who sustained severe penetrating ocular trauma while playing on a domestic trampoline. A main spring broke under tension and the hook had struck the eye at high velocity and penetrated the sclera. Primary repair was undertaken but on review it became apparent the eye could not be salvaged. Evisceration was carried out and an orbital implant was placed. Post-operative cosmesis is acceptable. This type of injury has not been reported before. Adult supervision of children on trampolines is recommended to minimise the chance of serious injury.

  1. Modeling and Simulation of Ballistic Penetration of Ceramic-Polymer-Metal Layered Systems

    Science.gov (United States)

    2016-01-01

    experimental study of penetration resistance of ceramic armour subjected to projectile impact,” International Journal of Impact Engineering, vol. 32...composite armour defeat,” International Journal of Impact Engineering, vol. 9, no. 4, pp. 455–474, 1990. [7] I. S. Chocron Benloulo and V. Sánchez-Gálvez...composite armour ,” International Journal of Machine Tools and Manufacture, vol. 44, no. 2-3, pp. 307–316, 2004. [9] M. L. Wilkins, “Mechanics of

  2. Tree root mapping with ground penetrating radar

    CSIR Research Space (South Africa)

    Van Schoor, Abraham M

    2009-09-01

    Full Text Available In this paper, the application of ground penetrating radar (GPR) for the mapping of near surface tree roots is demonstrated. GPR enables tree roots to be mapped in a non-destructive and cost-effective manner and is therefore a useful prospecting...

  3. Penetration and haptenation of p-phenylenediamine

    NARCIS (Netherlands)

    Pot, Laura M.; Scheitza, Simone M.; Coenraads, Pieter-Jan; Bloemeke, Brunhilde; Blomeke, B.

    Although p-phenylenediamine (PPD) has been recognized as an extreme sensitizer for many years, the exact mechanism of sensitization has not been elucidated yet. Penetration and the ability to bind to proteins are the first two hurdles that an allergen has to overcome to be able to sensitize. This

  4. Mechanical behaviour of pressure vessel head penetrations

    International Nuclear Information System (INIS)

    Faidy, C.; Ternon, F.; Vagner, J.; Vaindirlis, M.

    1994-01-01

    After leaks on Bugey 3 penetrations EdF and Framatome have started a study on the stress corrosion phenomenon of Inconel 600. In this paper, limited to the mechanical aspect, we present an estimation of in service stresses, the experimental program on mockup for visualize the surface stress and the noxiousness of potential cracks. 5 figs., 6 tabs., 5 refs

  5. Standard Penetration Test and Relative Density

    Science.gov (United States)

    1971-02-01

    Se OPSeS Debido a que el agua subterranea granclemente influve la resistencia a suelo, se establecio una relacion empirica entre el nurmero de golpes...de laboratorio ejecutados con un penetr6metro est’tico pequeno. INTRODUCTION One of the main problems encountered in subsoil e’xploration is in situ

  6. Penetration of electronic beams in ionizing media

    International Nuclear Information System (INIS)

    Martiarena, M.L.; Zanete, D.H.; Garibotti, C.R.

    1988-01-01

    It is studied the penetration of an electron beam in an ionizable medium by means of a generalized kinetic equation. This equation is related to elastic collisions, processes of creation and destruction of particles. By integrating numerically the transport equation, it can be evaluated the relative effects of all the processes involved in the evolution of the system. (A.C.A.S.) [pt

  7. Penetration of amalgam constituents into dentine

    NARCIS (Netherlands)

    Scholtanus, Johannes D.; Ozcan, Mutlu; Huysmans, Marie-Charlotte D. N. J. M.

    Objectives: Amalgam restorations are replaced by adhesively placed composite resin restorations at an increasing rate. After the removal of amalgam dentine often shows marked dark discoloration that is attributed to the penetration of corrosion products from overlying amalgams. it is questioned

  8. Penetration of amalgam constituents into dentine.

    NARCIS (Netherlands)

    Scholtanus, J.D.; Ozcan, M.; Huysmans, M.C.D.N.J.M.

    2009-01-01

    OBJECTIVES: Amalgam restorations are replaced by adhesively placed composite resin restorations at an increasing rate. After the removal of amalgam dentine often shows marked dark discoloration that is attributed to the penetration of corrosion products from overlying amalgams. It is questioned

  9. Computed tomographic findings in penetrating peptic ulcer

    International Nuclear Information System (INIS)

    Madrazo, B.L.; Halpert, R.D.; Sandler, M.A.; Pearlberg, J.L.

    1984-01-01

    Four cases of peptic ulcer penetrating the head of the pancreas were diagnosed by computed tomography (CT). Findings common to 3 cases included (a) an ulcer crater, (b) a sinus tract, and (c) enlargement of the head of the pancreas. Unlike other modalities, the inherent spatial resolution of CT allows a convenient diagnosis of this important complication of peptic ulcer disease

  10. Reduced penetrance in human inherited disease

    African Journals Online (AJOL)

    Rabah M. Shawky

    2014-01-31

    Jan 31, 2014 ... tant role in cellular senescence, tumorigenesis and in several diseases including type ... between epigenetic DNA modifications and human life span has also been shown .... penetrance mutation that is age dependent especially when compared with the ..... on healthy aging and longevity. Immunity Aging ...

  11. An Experimental Model for Market Penetration.

    Science.gov (United States)

    Caren, William L.

    1987-01-01

    A plan for college market penetration that has been successful in increasing the applicant pool for one institution is outlined and discussed. It includes development of performance objectives, a schedule, a promotional plan, market survey, and promotional activities including alumni, media, and other community resources. (MSE)

  12. STYLET PENETRATION BEHAVIOURS OF FOUR Cicadulina ...

    African Journals Online (AJOL)

    ACSS

    Feeding from phloem cells, overall probing and probe mean (the average time per probe) were higher ... Key Words: Cicadulina spp., electrical penetration graph, MSV, Zea mays .... wire and alligator clip clamped to the stem of the .... á All measures are in minutes except for frequency of probing; - Main effect not significant.

  13. Percutaneous penetration studies for risk assessment

    DEFF Research Database (Denmark)

    Sartorelli, Vittorio; Andersen, Helle Raun; Angerer, Jürgen

    2000-01-01

    experiences, literature data and guidelines already in existence. During the meetings of Percutaneous Penetration Subgroup they presented a number of short papers of up to date information on the key issues. The objective was to focus the existing knowledge and the gaps in the knowledge in the field...

  14. Penetration of albendazole sulphoxide into hydatid cysts.

    OpenAIRE

    Morris, D L; Chinnery, J B; Georgiou, G; Stamatakis, G; Golematis, B

    1987-01-01

    The penetration of albendazole sulphoxide, the principal metabolite of albendazole into hydatid cysts (E granulosus) was measured by means of in vitro animal and clinical studies. The drug freely diffuses across the parasitic membranes. Cyst/serum concentrations of 22% were achieved in patients, longer pre-operative therapy produced higher concentrations.

  15. Modeling of light dynamic cone penetration test - Panda 3 ® in granular material by using 3D Discrete element method

    Science.gov (United States)

    Tran, Quoc Anh; Chevalier, Bastien; Benz, Miguel; Breul, Pierre; Gourvès, Roland

    2017-06-01

    The recent technological developments made on the light dynamic penetration test Panda 3 ® provide a dynamic load-penetration curve σp - sp for each impact. This curve is influenced by the mechanical and physical properties of the investigated granular media. In order to analyze and exploit the load-penetration curve, a numerical model of penetration test using 3D Discrete Element Method is proposed for reproducing tests in dynamic conditions in granular media. All parameters of impact used in this model have at first been calibrated by respecting mechanical and geometrical properties of the hammer and the rod. There is a good agreement between experimental results and the ones obtained from simulations in 2D or 3D. After creating a sample, we will simulate the Panda 3 ®. It is possible to measure directly the dynamic load-penetration curve occurring at the tip for each impact. Using the force and acceleration measured in the top part of the rod, it is possible to separate the incident and reflected waves and then calculate the tip's load-penetration curve. The load-penetration curve obtained is qualitatively similar with that obtained by experimental tests. In addition, the frequency analysis of the measured signals present also a good compliance with that measured in reality when the tip resistance is qualitatively similar.

  16. Terminal ballistics of a reduced-mass penetrator. Final report, January 1990--December 1995

    Energy Technology Data Exchange (ETDEWEB)

    Silsby, G.F.

    1996-07-01

    This report presents the results of an experimental program to examine the performance of a reduced-mass concept penetrator impacting semi-infinite rolled homogeneous armor (RHA) at normal incidence. The reduced-mass penetrator used in this program is a solid tungsten alloy rod with eight holes drilled parallel to its axis, equally spaced on a circle, with axes parallel to the rod axis. Its performance was contrasted with baseline data for length-to- diameter ratios (L/D) 4 and 5 solid tungsten alloy penetrators. Striking velocity was nominally 1.6 km/s. A determined effort to reduce the scatter in the data by analysis of collateral data from the US Army Research Laboratory (ARL) and literature sources suggested only a rather weak influence of L/D on penetration even at L/Ds approaching 1 and provided a tentative relationship to remove the influence of target lateral edge effects. It tightened up the holed-out rod data enough to be able to conclude with a moderate degree of certainty that there was no improvement in penetration as suggested by a simplistic density law model. A companion work by Kimsey of ARL examines the performance of this novel penetrator concept computationally, using the Eulerian code CTH. His work explains the possible causes of reduced performance suggested by analysis by Zook and Frank of ARL, though with some relative improvement in performance at higher velocities.

  17. Chronic Disease Prevalence and Medicare Advantage Market Penetration: Findings From the Medical Expenditure Panel Survey.

    Science.gov (United States)

    Howard, Steven W; Bernell, Stephanie Lazarus; Casim, Faizan M; Wilmott, Jennifer; Pearson, Lindsey; Byler, Caitlin M; Zhang, Zidong

    2015-01-01

    By March 2015, 30% of all Medicare beneficiaries were enrolled in Medicare Advantage (MA) plans. Research to date has not explored the impacts of MA market penetration on individual or population health outcomes. The primary objective of this study is to examine the relationships between MA market penetration and the beneficiary's portfolio of cardiometabolic diagnoses. This study uses 2004 to 2008 Medical Expenditure Panel Survey (MEPS) Household Component data to construct an aggregate index that captures multiple diagnoses in one outcome measure (Chronic Disease Severity Index [CDSI]). The MEPS data for 8089 Medicare beneficiaries are merged with MA market penetration data from Centers for Medicare and Medicaid Services (CMS). Ordinary least squares regressions are run with SAS 9.3 to model the effects of MA market penetration on CDSI. The results suggest that each percentage increase in MA market penetration is associated with a greater than 2-point decline in CDSI (lower burden of cardiometabolic chronic disease). Spill-over effects may be driving improvements in the cardiometabolic health of beneficiary populations in counties with elevated levels of MA market penetration.

  18. A study on the particle penetration in RMS Right Single Quotation Marks particle transport system

    International Nuclear Information System (INIS)

    Son, S. M.; Oh, S. H.; Choi, C. R.

    2014-01-01

    In nuclear facilities, a radiation monitoring system (RMS) monitors the exhaust gas containing the radioactive material. Samples of exhaust gas are collected in the downstream region of air cleaning units (ACUs) in order to examine radioactive materials. It is possible to predict an amount of radioactive material by analyzing the corrected samples. Representation of the collected samples should be assured in order to accurately sense and measure of radioactive materials. The radius of curvature is mainly 5 times of tube diameter. Sometimes, a booster fan is additionally added to enhance particle penetration rate... In this study, particle penetrations are calculated to evaluate particle penetration rate with various design parameters (tube lengths, tube declined angles, radius of curvatures, etc). The particle penetration rates have been calculated for several elements in the particle transport system. In general, the horizontal length of tube and the number of bending tube have a big impact on the penetration rate in the particle transport system. If the sampling location is far from the radiation monitoring system, additional installation of booster fans could be considered in case of large diameter tubes, but is not recommended in case of small diameter tube. In order to enhance particle penetration rate, the following works are recommended by priority. 1) to reduce the interval between sampling location and radiation monitoring system 2) to reduce the number of the bending tube

  19. The Basics of Hacking and Penetration Testing Ethical Hacking and Penetration Testing Made Easy

    CERN Document Server

    Engebretson, Patrick

    2011-01-01

    The Basics of Hacking and Penetration Testing serves as an introduction to the steps required to complete a penetration test or perform an ethical hack. You learn how to properly utilize and interpret the results of modern day hacking tools; which are required to complete a penetration test. Tool coverage will include, Backtrack Linux, Google, Whois, Nmap, Nessus, Metasploit, Netcat, Netbus, and more. A simple and clean explanation of how to utilize these tools will allow you  to gain a solid understanding of each of the four phases and prepare them to take on more in-depth texts and topi

  20. Storability evaluation of Golab apple with acoustic and penetration methods

    Directory of Open Access Journals (Sweden)

    M. R Bayati

    2016-04-01

    mechanical and acoustic response of the flesh tissue to compression, using a texture analyzer coupled with an acoustic device. The methodology was applied to a 86 different apple cultivars, measured after two months postharvest cold storage and characterised by 16 acoustic and mechanical parameters. The results demonstrate the good performance of our combined acoustic-mechanical strategy in measuring apple crispness as it is perceived by human senses (costa et al, 2011. Hence, present study was about postharvest durability evaluation of this apple in cold storage and effect of methylcellulose coating on durability of this sensitive apple for both intact and damaged ones. Materials and Methods: After obtaining Golab apples, from one of the gardens of Karaj (Alborz province, Iran, 240 of them were selected. Our aim in this study was to evaluate the firmness of apples with two methods: penetration (destructive and acoustic (non destructive. The tests were performed in Agricultural Engineering Research Institute in Karaj. Firmness is one of the fruit characteristics that changes during storage. In present study, this characteristic of the apple fruit was assessed by two mentioned methods. Half of the apples were damaged with identified and controlled impact. In the next stage, another half of apples in both groups (the intact apples and the bruised apples were coated with methylcellulose. Effect storage on apple in four groups, including: Intact and uncoated apples, intact and coated (with methylcellulose apples, bruised and uncoated apples and bruised and coated apples during about ten weeks of cold storage at 2˚C and 85% RH was studied by the acoustic and the penetration tests. Acoustic parameters including: natural frequency, firmness index, elasticity coefficient were measured by recording audio signals resulting from non destructive impacts of a pendulum using a sound analyzer microphone and then the conversion of those parameters were performed from the time domain to the

  1. Radon penetration of concrete slab cracks, joints, pipe penetrations, and sealants

    NARCIS (Netherlands)

    Nielson, KK; Rogers, VC; Holt, RB; Pugh, TD; Grondzik, WA; deMeijer, RJ

    1997-01-01

    Radon movement through 12 test slabs with different cracks, pipe penetrations, cold joints, masonry blocks, sealants, and tensile stresses characterized the importance of these anomalous structural domains, Diffusive and advective radon transport were measured with steady-state air pressure

  2. Microstructured barbs on the North American porcupine quill enable easy tissue penetration and difficult removal.

    Science.gov (United States)

    Cho, Woo Kyung; Ankrum, James A; Guo, Dagang; Chester, Shawn A; Yang, Seung Yun; Kashyap, Anurag; Campbell, Georgina A; Wood, Robert J; Rijal, Ram K; Karnik, Rohit; Langer, Robert; Karp, Jeffrey M

    2012-12-26

    North American porcupines are well known for their specialized hairs, or quills that feature microscopic backward-facing deployable barbs that are used in self-defense. Herein we show that the natural quill's geometry enables easy penetration and high tissue adhesion where the barbs specifically contribute to adhesion and unexpectedly, dramatically reduce the force required to penetrate tissue. Reduced penetration force is achieved by topography that appears to create stress concentrations along regions of the quill where the cross sectional diameter grows rapidly, facilitating cutting of the tissue. Barbs located near the first geometrical transition zone exhibit the most substantial impact on minimizing the force required for penetration. Barbs at the tip of the quill independently exhibit the greatest impact on tissue adhesion force and the cooperation between barbs in the 0-2 mm and 2-4 mm regions appears critical to enhance tissue adhesion force. The dual functions of barbs were reproduced with replica molded synthetic polyurethane quills. These findings should serve as the basis for the development of bio-inspired devices such as tissue adhesives or needles, trocars, and vascular tunnelers where minimizing the penetration force is important to prevent collateral damage.

  3. The penetrating depth analysis of Lunar Penetrating Radar onboard Chang’e-3 rover

    Science.gov (United States)

    Xing, Shu-Guo; Su, Yan; Feng, Jian-Qing; Dai, Shun; Xiao, Yuan; Ding, Chun-Yu; Li, Chun-Lai

    2017-04-01

    Lunar Penetrating Radar (LPR) has successfully been used to acquire a large amount of scientific data during its in-situ detection. The analysis of penetrating depth can help to determine whether the target is within the effective detection range and contribute to distinguishing useful echoes from noise. First, this study introduces two traditional methods, both based on a radar transmission equation, to calculate the penetrating depth. The only difference between the two methods is that the first method adopts system calibration parameters given in the calibration report and the second one uses high-voltage-off radar data. However, some prior knowledge and assumptions are needed in the radar equation and the accuracy of assumptions will directly influence the final results. Therefore, a new method termed the Correlation Coefficient Method (CCM) is provided in this study, which is only based on radar data without any a priori assumptions. The CCM can obtain the penetrating depth according to the different correlation between reflected echoes and noise. To be exact, there is a strong correlation in the useful reflected echoes and a random correlation in the noise between adjacent data traces. In addition, this method can acquire a variable penetrating depth along the profile of the rover, but only one single depth value can be obtained from traditional methods. Through a simulation, the CCM has been verified as an effective method to obtain penetration depth. The comparisons and analysis of the calculation results of these three methods are also implemented in this study. Finally, results show that the ultimate penetrating depth of Channel 1 and the estimated penetrating depth of Channel 2 range from 136.9 m to 165.5 m ({\\varepsilon }r=6.6) and from 13.0 m to 17.5 m ({\\varepsilon }r=2.3), respectively.

  4. Pumped storage in systems with very high wind penetration

    International Nuclear Information System (INIS)

    Tuohy, A.; O'Malley, M.

    2011-01-01

    This paper examines the operation of the Irish power system with very high levels of wind energy, with and without pumped storage. A unit commitment model which accounts for the uncertainty in wind power is used. It is shown that as wind penetration increases, the optimal operation of storage depends on wind output as well as load. The main benefit from storage is shown to be a decrease in wind curtailment. The economics of the system are examined to find the level at which storage justifies its capital costs and inefficiencies. It is shown that the uncertainty of wind makes the option of storage more attractive. The size of the energy store has an impact on results. At lower levels of installed wind (up to approximately 50% of energy from wind in Ireland), the reduction in curtailment is insufficient to justify building storage. At greater levels of wind, storage reduces curtailment sufficiently to justify the additional capital costs. It can be seen that if storage replaces OCGTs in the plant mix instead of CCGTs, then the level at which it justifies itself is lower. Storage increases the level of carbon emissions at wind penetration below 60%. - Research highlights: → Examines operation of pumped storage unit in a system with levels of wind from 34%-68% of energy. → High capital cost of storage is not justified until system has high (approx. 45%) wind penetration. → Results are driven by the amount of wind curtailment avoided and plant mix of system. → Other flexible options (e.g. interconnection) offer many of the same benefits as storage.

  5. Civilian Penetrating Gunshot Injury to the Neurocranium in Enugu.

    Science.gov (United States)

    Onyia, Ephraim Eziechina; Chikani, Mark C; Mezue, Wilfred C; Uche, Enoch O; Iloabachie, Izuchukwu; Mesi, Matthew; Ejembi, Sunday; Agunwa, Chuka

    2017-01-01

    Civilian penetrating gunshot injuries to the neurocranium are no longer uncommon in Nigeria. Such injuries are however poorly reported. They are associated with poor outcome and, at close range, are frequently fatal, especially when inflicted by high-velocity weapons. Prompt transfer to neurosurgical service and urgent intervention may improve outcome in those that are not mortally wounded. Fifty-two patients with civilian penetrating gunshot wounds seen over a 10-year period (2004-2014) at the University of Nigeria Teaching Hospital and Memfys Hospital for Neurosurgery Enugu were reviewed retrospectively, and their data were analyzed to evaluate factors that impacted on outcome. Only patients with clinical and imaging evidence of cranial gunshot injuries who reached hospital alive were included in the study. The overall mortality and Glasgow outcome score were analyzed. Fifty-two patients with isolated civilian penetrating gunshot wounds were identified (M:F = 7.7:1); mean (standard deviation) age was 32.8 (11.9) years. There was a high correlation (0.983) between the sex of the patients and the outcome. The overall mortality was 30.8%, whereas the mortality for patients with postresuscitation Glasgow coma scale (GCS) score ≤8 was 57%, as against 12.9% in those in whom postresuscitation GCS was >8; meaning that 87.1% of patients in whom postresuscitation GCS was >8 survived. Thirty-one patients (59.6%) had papillary abnormalities. Majority of patients with monohemispheric lesions survived while all those with diencephalic, transventricular, and posterior fossa involvement had 100% mortality. Admitting GCS and bullet trajectory were predictive of outcome.

  6. Civilian penetrating gunshot injury to the neurocranium in Enugu

    Directory of Open Access Journals (Sweden)

    Ephraim Eziechina Onyia

    2017-01-01

    Full Text Available Introduction: Civilian penetrating gunshot injuries to the neurocranium are no longer uncommon in Nigeria. Such injuries are however poorly reported. They are associated with poor outcome and, at close range, are frequently fatal, especially when inflicted by high-velocity weapons. Prompt transfer to neurosurgical service and urgent intervention may improve outcome in those that are not mortally wounded. Materials and Methods: Fifty-two patients with civilian penetrating gunshot wounds seen over a 10-year period (2004–2014 at the University of Nigeria Teaching Hospital and Memfys Hospital for Neurosurgery Enugu were reviewed retrospectively, and their data were analyzed to evaluate factors that impacted on outcome. Only patients with clinical and imaging evidence of cranial gunshot injuries who reached hospital alive were included in the study. The overall mortality and Glasgow outcome score were analyzed. Results: Fifty-two patients with isolated civilian penetrating gunshot wounds were identified (M:F = 7.7:1; mean (standard deviation age was 32.8 (11.9 years. There was a high correlation (0.983 between the sex of the patients and the outcome. The overall mortality was 30.8%, whereas the mortality for patients with postresuscitation Glasgow coma scale (GCS score ≤8 was 57%, as against 12.9% in those in whom postresuscitation GCS was> 8; meaning that 87.1% of patients in whom postresuscitation GCS was> 8 survived. Thirty-one patients (59.6% had papillary abnormalities. Majority of patients with monohemispheric lesions survived while all those with diencephalic, transventricular, and posterior fossa involvement had 100% mortality. Conclusions: Admitting GCS and bullet trajectory were predictive of outcome.

  7. Prophylactic antibiotics for penetrating abdominal trauma.

    Science.gov (United States)

    Brand, Martin; Grieve, Andrew

    2013-11-18

    Penetrating abdominal trauma occurs when the peritoneal cavity is breached. Routine laparotomy for penetrating abdominal injuries began in the 1800s, with antibiotics first being used in World War II to combat septic complications associated with these injuries. This practice was marked with a reduction in sepsis-related mortality and morbidity. Whether prophylactic antibiotics are required in the prevention of infective complications following penetrating abdominal trauma is controversial, however, as no randomised placebo controlled trials have been published to date. There has also been debate about the timing of antibiotic prophylaxis. In 1972 Fullen noted a 7% to 11% post-surgical infection rate with pre-operative antibiotics, a 33% to 57% infection rate with intra-operative antibiotic administration and 30% to 70% infection rate with only post-operative antibiotic administration. Current guidelines state there is sufficient class I evidence to support the use of a single pre-operative broad spectrum antibiotic dose, with aerobic and anaerobic cover, and continuation (up to 24 hours) only in the event of a hollow viscus perforation found at exploratory laparotomy. To assess the benefits and harms of prophylactic antibiotics administered for penetrating abdominal injuries for the reduction of the incidence of septic complications, such as septicaemia, intra-abdominal abscesses and wound infections. Searches were not restricted by date, language or publication status. We searched the following electronic databases: the Cochrane Injuries Group Specialised Register, CENTRAL (The Cochrane Library 2013, issue 12 of 12), MEDLINE (OvidSP), Embase (OvidSP), ISI Web of Science: Science Citation Index Expanded (SCI-EXPANDED), ISI Web of Science: Conference Proceedings Citation Index- Science (CPCI-S) and PubMed. Searches were last conducted in January 2013. All randomised controlled trials of antibiotic prophylaxis in patients with penetrating abdominal trauma versus no

  8. The contemporary management of penetrating splenic injury.

    Science.gov (United States)

    Berg, Regan J; Inaba, Kenji; Okoye, Obi; Pasley, Jason; Teixeira, Pedro G; Esparza, Michael; Demetriades, Demetrios

    2014-09-01

    Selective non-operative management (NOM) is standard of care for clinically stable patients with blunt splenic trauma and expectant management approaches are increasingly utilised in penetrating abdominal trauma, including in the setting of solid organ injury. Despite this evolution of clinical practice, little is known about the safety and efficacy of NOM in penetrating splenic injury. Trauma registry and medical record review identified all consecutive patients presenting to LAC+USC Medical Center with penetrating splenic injury between January 2001 and December 2011. Associated injuries, incidence and nature of operative intervention, local and systemic complications and mortality were determined. During the study period, 225 patients experienced penetrating splenic trauma. The majority (187/225, 83%) underwent emergent laparotomy. Thirty-eight clinically stable patients underwent a deliberate trial of NOM and 24/38 (63%) were ultimately managed without laparotomy. Amongst patients failing NOM, 3/14 (21%) underwent splenectomy while an additional 6/14 (42%) had splenorrhaphy. Hollow viscus injury (HVI) occurred in 21% of all patients failing NOM. Forty percent of all NOM patients had diaphragmatic injury (DI). All patients undergoing delayed laparotomy for HVI or a splenic procedure presented symptomatically within 24h of the initial injury. No deaths occurred in patients undergoing NOM. Although the vast majority of penetrating splenic trauma requires urgent operative management, a group of patients does present without haemodynamic instability, peritonitis or radiologic evidence of hollow viscus injury. Management of these patients is complicated as over half may remain clinically stable and can avoid laparotomy, making them potential candidates for a trial of NOM. HVI is responsible for NOM failure in up to a fifth of these cases and typically presents within 24h of injury. Delayed laparotomy, within this limited time period, did not appear to increase

  9. Microparticle impacts at ultrahigh velocities and their relation to macroparticle impacts

    International Nuclear Information System (INIS)

    Walsh, J.M.; Stradling, G.L.; Idzorek, G.C.; Shafer, B.P.; Curling, H.L. Jr.

    1992-01-01

    The Hypervelocity Microparticle Impact project at Los Alamos has utilized electrostatically accelerated iron spheres of microscopic dimensions to generate ultra-high velocity impact experiments to about 100 km/S, an order of magnitude beyond data range for precisely controlled impact tests with ordinary macroscopic projectiles. Extreme smallness of the micro impact events brings into question whether usual shock-hydrodynamic size scaling can be assumed. Validity of size scaling (and its refinement) is questioned in the present study. Impact experiments are compared in which two impact events at a given velocity, a microscopic impact and a macroscopic impact, are essentially identical except that the projectile masses and crater volumes differ by nearly 12 orders of magnitude -- linear dimensions and times differing by 4 orders of magnitude. Strain rates at corresponding points in a deforming crater increase 4 orders of magnitude with the size reduction. Departures from exact scaling, by a factor of 3.7 in crater volume, are observed for copper targets -- with micro craters being smaller than scaling would predict. Measurement of impact craters for very small impact events leads to determination of metal yield stresses at strain rates more than two orders of magnitude greater than have been obtained by other methods. Determination of material strengths at these exceedingly high strain rates is important. Results are compared to recent theoretical models by Follansbee, Kochs and Rollett. The problem is addressed of predicting crater sizes in a target material with strain rate effects. Basic results are recalled on the late stage equivalence of hypervelocity impacts. For the strain rate dependent material to show that the curve of dimensionless crater volume versus impact velocity is replaced by a family of curves, each member of which is for one final crater size. The spacing of the curves is determined by the stress versus strain properties of the material

  10. Self-association of a highly charged arginine-rich cell-penetrating peptide

    Czech Academy of Sciences Publication Activity Database

    Tesei, G.; Vazdar, M.; Jensen, M. R.; Cragnell, C.; Mason, Philip E.; Heyda, J.; Skepö, M.; Jungwirth, Pavel; Lund, M.

    2017-01-01

    Roč. 114, č. 43 (2017), s. 11428-11433 ISSN 0027-8424 R&D Projects: GA ČR(CZ) GA16-01074S Institutional support: RVO:61388963 Keywords : cell-penetrating peptide * self-association * MD simulations * SAXS * NMR Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 9.661, year: 2016

  11. Size-Resolved Penetration of Filtering Materials from CE-Marked Filtering Facepiece Respirators.

    Czech Academy of Sciences Publication Activity Database

    Serfozo, N.; Ondráček, Jakub; Zíková, Naděžda; Lazaridis, M.; Ždímal, Vladimír

    2017-01-01

    Roč. 17, č. 5 (2017), s. 1305-1315 ISSN 1680-8584 EU Projects: European Commission(XE) 315760 - HEXACOMM Institutional support: RVO:67985858 Keywords : size-resolved penetration * CE-marked respirator * monodisperse ammonium sulfate Subject RIV: DI - Air Pollution ; Quality OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 2.606, year: 2016

  12. Manikin-Based Size-Resolved Penetrations of CE-marked Filtering Facepiece Respirators.

    Czech Academy of Sciences Publication Activity Database

    Serfozo, N.; Ondráček, Jakub; Otáhal, P.; Lazaridis, M.; Ždímal, Vladimír

    2017-01-01

    Roč. 14, č. 12 (2017), s. 965-974 ISSN 1545-9624 EU Projects: European Commission(XE) 315760 - HEXACOMM Institutional support: RVO:67985858 Keywords : size-resolved penetration * manikin-based study * CE-marked respirator Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 1.200, year: 2016

  13. Size-Resolved Penetration Through High-Efficiency Filter Media Typically Used for Aerosol Sampling

    Czech Academy of Sciences Publication Activity Database

    Zíková, Naděžda; Ondráček, Jakub; Ždímal, Vladimír

    2015-01-01

    Roč. 49, č. 4 (2015), s. 239-249 ISSN 0278-6826 R&D Projects: GA ČR(CZ) GBP503/12/G147 Institutional support: RVO:67985858 Keywords : filters * size-resolved penetration * atmospheric aerosol sampling Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.953, year: 2015

  14. Transdermal Delivery and Cutaneous Targeting of Antivirals using a Penetration Enhancer and Lysolipid Prodrugs

    Czech Academy of Sciences Publication Activity Database

    Diblíková, D.; Kopečná, M.; Školová, B.; Krečmerová, Marcela; Roh, J.; Hrabálek, A.; Vávrová, K.

    2014-01-01

    Roč. 31, č. 4 (2014), s. 1071-1081 ISSN 0724-8741 Grant - others:GA ČR(CZ) GAP207/11/0365 Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonate antivirals * lysolipid prodrug * penetration enhancer * skin absorption * transdermal drug delivery Subject RIV: FR - Pharmacology ; Medidal Chemistry Impact factor: 3.420, year: 2014

  15. The impact imperative: Laser ablation for deflecting asteroids, meteoroids, and comets from impacting the earth

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Jonathan W [Advanced Projects/FD02, National Space Science and Technology Center, NASA/MSFC, Huntsville, Alabama, 35812 (United States); Phipps, Claude [Photonics Associates 200A Ojo de la Vaca Road Santa Fe, NM 87505 (United States); Smalley, Larry [Department of Physics, University of Alabama, Huntsville (United States); Reilly, James [Northeast Science and Technology, East Sandwich, MA (United States); Boccio, Dona [Queensborough Community College of the City, University of New York, New York (United States)

    2003-05-14

    Impacting at hypervelocity, an asteroid struck the Earth approximately 65 million years ago in the Yucatan Peninsula area. This triggered the extinction of almost 70% of the species of life on Earth including the dinosaurs. Other impacts prior to this one have caused even greater extinctions. Preventing collisions with the Earth by hypervelocity asteroids, meteoroids, and comets is the most important immediate space challenge facing human civilization. This is the Impact Imperative. We now believe that while there are about 2000 earth orbit crossing rocks greater than 1 kilometer in diameter, there may be as many as 200,000 or more objects in the 100 m size range. Can anything be done about this fundamental existence question facing our civilization? The answer is a resounding yes{exclamation_point} By using an intelligent combination of Earth and space based sensors coupled with an infra-structure of high-energy laser stations and other secondary mitigation options, we can deflect inbound asteroids, meteoroids, and comets and prevent them from striking the Earth. This can be accomplished by irradiating the surface of an inbound rock with sufficiently intense pulses so that ablation occurs. This ablation acts as a small rocket incrementally changing the shape of the rock's orbit around the Sun. One-kilometer size rocks can be moved sufficiently in about a month while smaller rocks may be moved in a shorter time span.

  16. The impact imperative: Laser ablation for deflecting asteroids, meteoroids, and comets from impacting the earth

    International Nuclear Information System (INIS)

    Campbell, Jonathan W.; Phipps, Claude; Smalley, Larry; Reilly, James; Boccio, Dona

    2003-01-01

    Impacting at hypervelocity, an asteroid struck the Earth approximately 65 million years ago in the Yucatan Peninsula area. This triggered the extinction of almost 70% of the species of life on Earth including the dinosaurs. Other impacts prior to this one have caused even greater extinctions. Preventing collisions with the Earth by hypervelocity asteroids, meteoroids, and comets is the most important immediate space challenge facing human civilization. This is the Impact Imperative. We now believe that while there are about 2000 earth orbit crossing rocks greater than 1 kilometer in diameter, there may be as many as 200,000 or more objects in the 100 m size range. Can anything be done about this fundamental existence question facing our civilization? The answer is a resounding yes! By using an intelligent combination of Earth and space based sensors coupled with an infra-structure of high-energy laser stations and other secondary mitigation options, we can deflect inbound asteroids, meteoroids, and comets and prevent them from striking the Earth. This can be accomplished by irradiating the surface of an inbound rock with sufficiently intense pulses so that ablation occurs. This ablation acts as a small rocket incrementally changing the shape of the rock's orbit around the Sun. One-kilometer size rocks can be moved sufficiently in about a month while smaller rocks may be moved in a shorter time span

  17. Containment penetration design criteria and implementation

    International Nuclear Information System (INIS)

    Perry, R.F.; Rigamonti, G.; Dainora, J.

    1975-01-01

    A rational design criteria is presented which serves as a basis for the design and analysis of containment piping penetrations. The criteria includes the effect of temperature as well as mechanical loads for the full range of plant conditions. With this criteria various penetration flued head designs have been compared and optimization achieved. Sleeve wall dimensions and containment loads have been determined without reference to piping configuration. An interaction theory which allows the implementation of the criteria for the determination of design loads and minimum sleeve wall thickness. The interaction theory developed applies to elastic-perfectly plastic cylinders (pipes and sleeves) and accounts for the simultaneous load resultants of transverse shear force, bending moment, torsional moment, and axial force in addition to internal pipe pressure. Application of the theory developed to the determination of sleeve thickness and containment design loads is presented in detail. (Auth.)

  18. Ureteric transection secondary to penetrating handlebar injury

    Directory of Open Access Journals (Sweden)

    K.P. Debbink

    2017-08-01

    Full Text Available Ureteric trauma is rare, occurring in <1% of all traumas. We present a unique case of a 13 year old female who sustained a penetrating abdominal injury from a bicycle handlebar. Upon initial examination there was herniation of bowel through the abdominal wound, so exploratory laparotomy was performed. A serosal injury of the colon and bleeding mesenteric veins were encountered; the retroperitoneum was not explored at that time. Postoperative course was remarkable for a doubling of the serum creatinine, increasing abdominal distention and pain. Computed tomography on postoperative day five demonstrated a large amount of intra-abdominal fluid. The patient was taken for re-exploration. The left ureter was found to be completely transected. It was repaired over a double-J stent. This case demonstrates the need for a high index of suspicion in the diagnosis of ureteric injury. Keywords: Ureter, Bicycle, Handlebar, Penetrating

  19. Corrosion and protection of uranium alloy penetrators

    International Nuclear Information System (INIS)

    Weirick, L.J.; Johnson, H.R.; Dini, J.W.

    1975-06-01

    Penetrators made from either a U--3/4 percent Ti alloy or a U--3/4 percent Mo--3/4 percent Zr--3/4 percent Nb--1/2 percent Ti alloy (''Quad'') corrode mildly in moist air, significantly in moist nitrogen, and severely in salt fog. Adequate protection was provided in moist air and nitrogen by coating with electroplated nickel, electroplated nickel and zinc with a chromate finish, and galvanized zinc with a chromate finish. In salt fog, electroplated nickel offered only temporary protection whereas galvanized zinc and electroplated nickel-zinc provided long-lasting protection. The resistance of uncoated penetrators was affected variously by dissimilar metal couplings. Aluminum protected the Quad alloy and adversely affected the U--3/4 percent Ti alloy, whereas steel enhanced localized corrosion in both. (U.S.)

  20. Eddy current testing with high penetration

    International Nuclear Information System (INIS)

    Becker, R.; Kroening, M.

    1999-01-01

    The low-frequency eddy current testing method is used when penetration into very deep layers is required. The achievable penetration depth is determined among other parameters by the lowest testing frequency that can be realised together with the eddy current sensor. When using inductive sensors, the measuring effect declines proportional to the lowering frequency (induction effect). Further reduction of testing frequency requires other types of sensors, as e.g. the GMR (Giant Magnetic Resistance), which achieves a constant measuring sensitivity down to the steady field. The multi-frequency eddy current testing method MFEC 3 of IZFP described here can be operated using three different scanning frequencies at a time. Two variants of eddy current probes are used in this case. Both have an inductive winding at their emitters, of the type of a measuring probe. The receiver end is either also an inductive winding, or a magnetic field-responsive resistance (GMR). (orig./CB) [de

  1. Large scale wind power penetration in Denmark

    DEFF Research Database (Denmark)

    Karnøe, Peter

    2013-01-01

    he Danish electricity generating system prepared to adopt nuclear power in the 1970s, yet has become the world's front runner in wind power with a national plan for 50% wind power penetration by 2020. This paper deploys a sociotechnical perspective to explain the historical transformation...... of "networks of power" via the interactions of politics, the techno-physics of electrons, and the market setting. The Danish case is about how an assemblage of new agencies has reorganized and reshaped society by building a new sociotechnical network. This has rendered developments highly unpredictable...... and highly experimental. The transformation process can be followed through the way successive technical engineering reports have represented the challenges associated with the penetration of wind power. The iteration shows how novel technical phenomena emerge and are assimilated, and how new engineering...

  2. Suicide bomb attack causing penetrating craniocerebral injury

    Directory of Open Access Journals (Sweden)

    Hussain Manzar

    2013-02-01

    Full Text Available 【Abstract】Penetrating cerebral injuries caused by foreign bodies are rare in civilian neurosurgical trauma, al-though there are various reports of blast or gunshot inju-ries in warfare due to multiple foreign bodies like pellets and nails. In our case, a 30-year-old man presented to neurosur-gery clinic with signs and symptoms of right-sided weak-ness after suicide bomb attack. The skull X-ray showed a single intracranial nail. Small craniotomy was done and the nail was removed with caution to avoid injury to surround-ing normal brain tissue. At 6 months’ follow-up his right-sided power improved to against gravity. Key words: Head injury, penetrating; Bombs; Nails

  3. Standardization of penetrating radiation testing system

    International Nuclear Information System (INIS)

    Wiley, P.A.; Aronson, H.L.

    1979-01-01

    Standardization is provided to control system gain of a penetrating radiation testing system by periodically inspecting a reference object in the same manner as the product samples so as to generate a stabilization signal which is compared to a reference signal. The difference, if any, between the stabilization signal and the reference signal is integrated and the integrated signal is used to correct the gain of the system

  4. Market penetration of new energy technologies

    Energy Technology Data Exchange (ETDEWEB)

    Packey, D.J.

    1993-02-01

    This report examines the characteristics, advantages, disadvantages, and, for some, the mathematical formulas of forecasting methods that can be used to forecast the market penetration of renewable energy technologies. Among the methods studied are subjective estimation, market surveys, historical analogy models, cost models, diffusion models, time-series models, and econometric models. Some of these forecasting methods are more effective than others at different developmental stages of new technologies.

  5. Intrauterine Devices Penetrated and Migrated: CT Findings

    International Nuclear Information System (INIS)

    Mejia Restrepo, Jorge; Lopez, Juan Esteban; Aldana Sepulveda, Natalia; Ruiz Zabaleta, Tania; Mazzaro Mauricio

    2011-01-01

    Intrauterine devices have been used for over 40 years, and they constitute the most widely accepted method of contraception among women because of the low rates of complications and low cost. Although uncommon, with the growing use of multidetector CT penetrated and migrated intrauterine devices have become a more common incidental finding. In some cases, intrauterine devices migrate to adjacent viscera, in particular the bladder and bowel and may give rise to symptoms. Consequently tomographic localization and characterization are essential for treatment planning.

  6. Models of fast-electron penetration

    International Nuclear Information System (INIS)

    Perry, D.J.; Raisis, S.K.

    1994-01-01

    We introduce multiple scattering models of charged-particle penetration which are based on the previous analyses of Yang and Perry. Our development removes the main limitations of the Fermi-Eyges approach while retaining its considerable potential as a theory which is useful for applied work. We illustrate key predictions with sample calculations that are of particular interest in therapeutic applications, 5-20 MeV electrons incident on water. 8 refs., 5 figs

  7. Thyroid Emphysema Following Penetrating Neck Trauma

    OpenAIRE

    Karadağ, Demet; Doner, Egemen; Adapınar, Baki

    2014-01-01

    Although traumatic thyroid gland rupture or hemorrhage is usually seen in goitrous glands, injuries of the normal thyroid gland after neck trauma have rarely been described in the literature. We describe a 44-year-old man who presented with thyroid emphysema and subcutaneous emphysema (SCE) that occurred after penetrating neck trauma. CT images showed complete resolution of thyroid emphysema and subcutaneous emphysema at follow-up examination. Neck injuries can be life threatening. After pene...

  8. Penetrating spinal injuries and their management

    Directory of Open Access Journals (Sweden)

    A Kumar

    2011-01-01

    Full Text Available Penetrating spinal trauma due to missile/gunshot injuries has been well reported in the literature and has remained the domain of military warfare more often. Civic society′s recent upsurge in gunshot injuries has created a dilemma for the treating neurosurgeon in many ways as their management has always involved certain debatable and controversial issues. Both conservative and surgical management of penetrating spinal injuries (PSI have been practiced widely. The chief neurosurgical concern in these types of firearm injuries is the degree of damage sustained during the bullet traversing through the neural tissue and the after-effects of the same in long term. We had an interesting case of a penetrating bullet injury to cervical spine at C2 vertebral level. He was operated and the bullets were removed from posterior midline approach. Usually, the management of such cases differs from region to region depending on the preference of the surgeon but still certain common principles are followed world over. Thus, we realized the need to review the literature regarding spinal injuries with special emphasis on PSI and to study the recent guidelines for their treatment in light of our case.

  9. Spanish RPV head penetrations. Regulatory status

    International Nuclear Information System (INIS)

    Figueras, J.M.; Colino, J.R.

    1995-01-01

    The paper presents the actual status of inspection results on the Spanish PWR RPV CRD head penetrations (CRDH's), after two years of a whole program of inspections in all affected plants. Actual situation of penetrations pertaining to ALMARAZ 1 and 2, ASCO 1 and 2 and VANDELLOS 2 NPP's show any damage in those CRDH's inspected in 1993 and 1994 (roughly 20 out of 65 CRDH's at each unit). The paper presents a summary of CRDH characteristics, inspection methods and results obtained in each plant. TRILLO NPP has a different CRDH design (KWU-SIEMENS type) and for that reason is not considered an affected plant nor has conducted any inspection up to now. JOSE CABRERA (ZORITA) NPP has shown extensive damage, both in the lower side (weldment to the vessel) and in the upper free span area, near bimetallic weldment to SS 304, in active and nonactive penetrations and also in the vent nozzle. The paper comments extensively on the CRDH materials general data, root-cause analysis and structural analysis of degraded zones, inspection results, repair actions and other additional actions applied up to now. Finally, the paper deals with the regulatory actions taken by CSN on this topic, both for those NPP's actually non affected by the IGSCC phenomenon in the RPV CRDH's and for the specific safety case of ZORITA NPP. (author)

  10. Deep penetration of light into biotissue

    Science.gov (United States)

    Bearden, Edward D.; Wilson, James D.; Zharov, Vladimir P.; Lowery, Curtis L.

    2001-07-01

    The results of a study of deep (several centimeters) light penetration into biological tissue are presented in order to estimate its significance to potentially photosensitive structures and processes including the fetal eyes. In order to accomplish this goal, samples of various tissues (fat, muscle, and uterus) from surgical patients and autopsies were examined with a double integrating sphere arrangement to determine their optical properties. The results were implemented in a Monte Carlo modeling program. Next, optical fiber probes were inserted into the uterus and abdominal wall of patients undergoing laparoscopic procedures. The fibers were couples to a photomultiplier tube with intervening filters allowing measurements of light penetration at various wavelengths. To determine the feasibility of stimulation in utero, a xenon lamp and waveguide were used to transilluminate the abdomen of several labor patients. Light in the range of 630 to 670 nm where the eye sensitivity and penetration depth are well matched, will likely provide the best chance of visual stimulation. Fetal heart rate, fetal movement, and fetal magnetoencephalography (SQUID) and electroencephalography (EEG) were observed in different studies to determine if stimulation has occurred. Since internal organs and the fetus are completely dark adapted, the amount of light required to simulate in our opinion could be on the order of 10(superscript -8 Watts.

  11. Penetrating chest wound of the foetus

    Directory of Open Access Journals (Sweden)

    Albert Wandaogo

    2016-01-01

    Full Text Available Traumas of the foetus caused by stabbings are rare but actually life-threatening for both the foetus and the mother. We report a case of penetrating chest wound on a baby taken from the obstetrics unit to the paediatric surgical department. His mother was assaulted by his father, a mentally sick person with no appropriate follow-up. The foetus did not show any sign of vital distress. Surgical exploration of the wound has revealed a section of the 10 th rib, a laceration of the pleura and a tearing of the diaphragm. A phrenorraphy and a pleural drainage were performed. The new-born and its mother were released from hospital after 5 days and the clinical control and X-ray checks 6 months later showed nothing abnormal. We insisted a medical, psychiatric follow-up be initiated for the father. As regards pregnant women with penetrating wounds, the mortality rate of the foetus is 80%. The odds are good for our newborn due to the mild injuries and good professional collaboration of the medical staff. Penetrating transuterine wounds of the foetus can be very serious. The health care needed should include many fields due to the mother and the foetus′ lesions extreme polymorphism. In our case, it could have prevented by a good psychiatric followed up of the offender.

  12. Impact of different solar penetration depths on climate simulations

    Directory of Open Access Journals (Sweden)

    Xiaobing Zhou

    2015-01-01

    Full Text Available Three different estimates of shortwave attenuation depth (SWAD of photosynthetically active radiation (PAR derived from remotely sensed ocean colour data have been tested in an ocean general circulation model (OGCM forced with interannual atmospheric forcings. Two estimates (referred to as [Kd(PAR]1-1 and [Kd(PAR]2-1 are calculated from different algorithms based on the diffusive attenuation coefficient at 490 nm and the third one ([Kd(AVE]1-1 is just an average of [Kd(PAR]1-1 and [Kd(PAR]2-1. [Kd(PAR]2-1 is larger than [Kd(PAR]1-1 almost everywhere in the tropical oceans. Our results show that the OGCM with [Kd(PAR]2-1 produces warmer sea surface temperature (SST in the eastern equatorial Pacific and Atlantic and leads to reduce a cold bias in the equatorial cold tongue regions. It has warmer subsurface temperatures in the low latitude, a slower meridional velocity and Pacific equatorial undercurrent (EUC than the model with [Kd(PAR]1-1. These results are similar to previous studies, although we use a different model and different methods. This study has further analysis and firstly reveals that slower EUC and meridional velocity in the model with [Kd(PAR]2-1 are mainly related to the changes of the acceleration due to zonal density gradient. This acceleration driving the EUC eastward in the subsurface becomes smaller in the subsurface along the equatorial Pacific. However, near the sea surface, the zonally averaged accelerations over the different ocean basins are larger in the model with [Kd(PAR]2-1 than that with [Kd(PAR]1-1, which pushes back the poleward meridional transport. The interannual variability in the model with [Kd(PAR]2-1 is generally weaker than that in the experiment with [Kd(PAR]1-1 due to a deeper mixed layer depth. The vertical temperature errors averaged horizontally within the domain of 30°S to 30°N in the experiment with [Kd(AVE]1-1 are almost in the middle of errors of the other two experiments. This indicates that the effect of the SWAD on the simulation of the vertical temperature profile is largely linear.

  13. CNS penetration of ART in HIV-infected children

    NARCIS (Netherlands)

    van den Hof, Malon; Blokhuis, Charlotte; Cohen, Sophie; Scherpbier, Henriette J.; Wit, Ferdinand W. N. M.; Pistorius, M. C. M.; Kootstra, Neeltje A.; Teunissen, Charlotte E.; Mathot, Ron A. A.; Pajkrt, Dasja

    2018-01-01

    Background: Paediatric data on CNS penetration of antiretroviral drugs are scarce. Objectives: To evaluate CNS penetration of antiretroviral drugs in HIV-infected children and explore associations with neurocognitive function. Patients and methods: Antiretroviral drug levels were measured in paired

  14. Further Insight on the Hypervelocity White Dwarf, LP 40–365 (GD 492): A Nearby Emissary from a Single-degenerate Type Ia Supernova

    Science.gov (United States)

    Raddi, R.; Hollands, M. A.; Koester, D.; Gänsicke, B. T.; Gentile Fusillo, N. P.; Hermes, J. J.; Townsley, D. M.

    2018-05-01

    The recently discovered hypervelocity white dwarf LP 40‑365 (aka GD 492) has been suggested as the outcome of the failed disruption of a white dwarf in a subluminous Type Ia supernova (SN Ia). We present new observations confirming GD 492 as a single star with unique spectral features. Our spectroscopic analysis suggests that a helium-dominated atmosphere, with ≃33% neon and 2% oxygen by mass, can reproduce most of the observed properties of this highly unusual star. Although our atmospheric model contrasts with the previous analysis in terms of dominant atmospheric species, we confirm that the atmosphere of GD 492 is strongly hydrogen deficient, {log}({{H}}/{He})Ia event over alternative scenarios.

  15. Market penetration of intersection AEB: Characterizing avoided and residual straight crossing path accidents.

    Science.gov (United States)

    Sander, Ulrich; Lubbe, Nils

    2018-06-01

    Car occupants account for one third of all junction fatalities in the European Union. Driver warning can reduce intersection accidents by up to 50 percent; adding Autonomous Emergency Braking (AEB) delivers a reduction of up to 70 percent. However, these findings are based on an assumed 100 percent equipment rate, which may take decades to achieve. Our study investigates the relationship between intersection AEB market penetration rates and avoidance of accidents and injuries in order to guide implementation strategies. Additionally, residual accident characteristics (impact configurations and severity) are analyzed to provide a basis for future in-crash protection requirements. We determined which accidents would have been avoided through the use of an Intersection AEB system with different sensor field-of-views (180° and 120°) by means of re-simulating the pre-crash phase of 792 straight crossing path (SCP) car-to-car accidents recorded in the German In-Depth Accident Study (GIDAS) and the associated Pre-Crash Matrix (PCM). Intersection AEB was activated when neither of the conflict opponents could avoid the crash through reasonable braking or steering reactions. For not-avoided accidents, we used the Kudlich-Slibar rigid body impulse model to calculate the change of velocity during the impact as a measure of impact severity and the principal direction of force. Accident avoidance over market penetration is not linear but exponential, with higher gains at low penetration rates and lower gains at higher rates. A wide field-of-view sensor (180°) substantially increased accident avoidance and injury mitigation rates compared to a 120° field-of-view sensor. For a 180° field-of-view sensor at 100 percent market penetration, about 80 percent of the accidents and 90 percent of the MAIS2 + F injuries could be avoided. For the remaining accidents, AEB intervention rarely affected side of impact. The median change of velocity (delta-V) of the remaining crashes

  16. Increasing penetration of renewable and distributed electricity generation and the need for different network regulation

    International Nuclear Information System (INIS)

    Joode, J. de; Jansen, J.C.; Welle, A.J. van der; Scheepers, M.J.J.

    2009-01-01

    The amount of decentralised electricity generation (DG) connected to distribution networks increases across EU member states. This increasing penetration of DG units poses potential costs and benefits for distribution system operators (DSOs). These DSOs are regulated since the business of electricity distribution is considered to be a natural monopoly. This paper identifies the impact of increasing DG penetration on the DSO business under varying parameters (network characteristics, DG technologies, network management type) and argues that current distribution network regulation needs to be improved in order for DSOs to continue to facilitate the integration of DG in the network. Several possible adaptations are analysed.

  17. Electricity demand profile with high penetration of heat pumps in Nordic area

    DEFF Research Database (Denmark)

    Liu, Zhaoxi; Wu, Qiuwei; Nielsen, Arne Hejde

    2013-01-01

    This paper presents the heat pump (HP) demand profile with high HP penetration in the Nordic area in order to achieve the carbon neutrality power system. The calculation method in the European Standard EN14825 was used to estimate the HP electricity demand profile. The study results show...... there will be high power demand from HPs and the selection of supplemental heating for heat pumps has a big impact on the peak electrical power load of heating. The study in this paper gives an estimate of the scale of the electricity demand with high penetration of heat pumps in the Nordic area....

  18. Analysis on the resistive force in penetration of a rigid projectile

    Directory of Open Access Journals (Sweden)

    Xiao-wei Chen

    2014-09-01

    Full Text Available According to the dimensionless formulae of DOP (depth of penetration of a rigid projectile into different targets, the resistive force which a target exerts on the projectile during the penetration of rigid projectile is theoretically analyzed. In particular, the threshold Vc of impact velocity applicable for the assumption of constant resistive force is formulated through impulse analysis. The various values of Vc corresponding to different pairs of projectile-target are calculated, and the consistency of the relative test data and numerical results is observed.

  19. Penetration Testing Curriculum Development in Practice

    Directory of Open Access Journals (Sweden)

    Chengcheng Li

    2015-04-01

    Full Text Available As both the frequency and the severity of network breaches have increased in recent years, it is essential that cybersecurity is incorporated into the core of business operations. Evidence from the U.S. Bureau of Labor Statistics (Bureau of Labor Statistics, 2012 indicates that there is, and will continue to be, a severe shortage of cybersecurity professionals nationwide throughout the next decade. To fill this job shortage we need a workforce with strong hands-on experience in the latest technologies and software tools to catch up with the rapid evolution of network technologies. It is vital that the IT professionals possess up-to-date technical skills and think and act one step ahead of the cyber criminals who are constantly probing and exploring system vulnerabilities. There is no perfect security mechanism that can defeat all the cyber-attacks; the traditional defensive security mechanism will eventually fail to the pervasive zero-day attacks. However, there are steps to follow to reduce an organization’s vulnerability to cyber-attacks and to mitigate damages. Active security tests of the network from a cyber-criminal’s perspective can identify system vulnerabilities that may lead to future breaches. “If you know yourself but not the enemy, for every victory gained you will also suffer a defeat. But if you know the enemy and know yourself, you need not fear the result of hundred battles” (Sun, 2013. Penetration testing is a discipline within cybersecurity that focuses on identifying and exploiting the vulnerabilities of a network, eventually obtaining access to the critical business information. The pentesters, the security professionals who perform penetration testing, or ethical hackers, break the triad of information security - Confidentiality, Integrity, and Accountability (CIA - as if they were a cyber-criminal. The purpose of ethical hacking or penetration testing is to know what the “enemy” can do and then generate a

  20. 40 CFR 1065.365 - Nonmethane cutter penetration fractions.

    Science.gov (United States)

    2010-07-01

    ... fractions. 1065.365 Section 1065.365 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Measurements § 1065.365 Nonmethane cutter penetration fractions. (a) Scope and frequency. If you use a FID... penetration fractions of methane, PFCH4, and ethane, PF C2H6. As detailed in this section, these penetration...

  1. Diffusion of radioactively tagged penetrants through rubbery polymers. II. Dependence on molecular length of penetrant

    International Nuclear Information System (INIS)

    Rhee, C.K.; Ferry, J.D.; Fetters, L.J.

    1977-01-01

    The diffusion of radioactively tagged n-hexadecane, n-dotriacontane, and a polybutadiene oligomer with molecular weight 1600 has been studied in 12 rubbery polymers. Diffusion coefficients were obtained from the theory for the thin smear method: for n-hexadecane and for n-dotriacontane (with one exception), in the form appropriate for a completely miscible polymer-penetrant pair, and for the oligomer in the form appropriate for slow entry of the pentrant across the penetrant-polymer interface. For the four flexible linear penetrants, n-dodecane, n-hexadecane, n-dotriacontane, and oligomer, the ratios of diffusion coefficients (or translational friction coefficients) are nearly the same in every polymer. It is concluded that these penetrants travel with similar segmentwise motions, although that is not the case with bulkier, more rigid penetrants. For the three normal paraffins, the friction coefficient is approximately proportional to molecular weight, but that for the oligomer is smaller than would be predicted on this basis

  2. Integration of electric drive vehicles in the Danish electricity network with high wind power penetration

    DEFF Research Database (Denmark)

    Chandrashekhara, Divya K; Østergaard, Jacob; Larsen, Esben

    2010-01-01

    /conventional) which are likely to fuel these cars. The study was carried out considering the Danish electricity network state around 2025, when the EDV penetration levels would be significant enough to have an impact on the power system. Some of the interesting findings of this study are - EDV have the potential......This paper presents the results of a study carried out to examine the feasibility of integrating electric drive vehicles (EDV) in the Danish electricity network which is characterised by high wind power penetration. One of the main aims of this study was to examine the effect of electric drive...... vehicles on the Danish electricity network, wind power penetration and electricity market. In particular the study examined the effect of electric drive vehicles on the generation capacity constraints, load curve, cross border transmission capacity and the type of generating sources (renewable...

  3. Penetration strategies of Turkish corporations in Kosovo’s market

    Directory of Open Access Journals (Sweden)

    Luan VARDARI

    2018-04-01

    Full Text Available Rapid developments and increasing competition in recent years have prevented companies from producing and selling only in domestic markets, but also causing their foreign resources and investments to be directed to foreign markets. In this case, once businesses decide to join a particular market, they have to decide which is the best way to penetrate there. Turkish multinational corporations, which have been spreading all over the world with their investments, have conquered world markets with their exports, initiatives and acquisitions, they have entered in foreign markets in various forms and have a significant share in world trade volume with their successful investments. From this point of view, this study examines the strategies by which Turkish multinationals enter foreign markets especially in Kosovo and the impact that those companies have had in the development of the Kosovo economy and the strategies by which Turkish multinationals enter foreign markets.

  4. Retaining the Value of PV at High Penetration Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, Sarah; Bolen, Michael

    2017-01-19

    PV prices have dropped and are now attractive without incentives for peaking applications in some locations. Modeling suggests and, empirically, some regions demonstrate that as PV penetration increases its value decreases, predominantly due to a decrease in energy and capacity value. It is not apparent what technologies and price may be needed for PV to supply tens of percent of electricity in the most economically efficient manner. A 1-day workshop was co-sponsored by EPRI and NREL with support from ASU. A dozen presentations and discussions introduced how the interplay of various technologies impact the value of PV, identified technical challenges and gaps impeding implementation, and discussed future R&D needs and opportunities.

  5. High-Penetration PV Integration Handbook for Distribution Engineers

    Energy Technology Data Exchange (ETDEWEB)

    Seguin, Rich [Electrical Distribution Design, Blacksburg, VA (United States); Woyak, Jeremy [Electrical Distribution Design, Blacksburg, VA (United States); Costyk, David [Electrical Distribution Design, Blacksburg, VA (United States); Hambrick, Josh [Electrical Distribution Design, Blacksburg, VA (United States); Mather, Barry [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-01-01

    This handbook has been developed as part of a five-year research project which began in 2010. The National Renewable Energy Laboratory (NREL), Southern California Edison (SCE), Quanta Technology, Satcon Technology Corporation, Electrical Distribution Design (EDD), and Clean Power Research (CPR) teamed together to analyze the impacts of high-penetration levels of photovoltaic (PV) systems interconnected onto the SCE distribution system. This project was designed specifically to leverage the experience that SCE and the project team would gain during the significant installation of 500 MW of commercial scale PV systems (1-5 MW typically) starting in 2010 and completing in 2015 within SCE’s service territory through a program approved by the California Public Utility Commission (CPUC).

  6. Penetration Testing Professional Ethics: a conceptual model and taxonomy

    Directory of Open Access Journals (Sweden)

    Justin Pierce

    2006-05-01

    Full Text Available In an environment where commercial software is continually patched to correct security flaws, penetration testing can provide organisations with a realistic assessment of their security posture. Penetration testing uses the same principles as criminal hackers to penetrate corporate networks and thereby verify the presence of software vulnerabilities. Network administrators can use the results of a penetration test to correct flaws and improve overall security. The use of hacking techniques, however, raises several ethical questions that centre on the integrity of the tester to maintain professional distance and uphold the profession. This paper discusses the ethics of penetration testing and presents our conceptual model and revised taxonomy.

  7. Assessing the credibility of diverting through containment penetrations

    International Nuclear Information System (INIS)

    Cooley, J.N.; Swindle, D.W. Jr.

    1980-01-01

    A viable approach has been developed for identifying those containment penetrations in a nuclear fuel reprocessing plant which are credible diversion routes. The approach is based upon systematic engineering and design analyses and is applied to each type of penetration to determine which penetrations could be utilized to divert nuclear material from a reprocessing facility. The approach is described and the results of an application are discussed. In addition, the concept of credibility is developed and discussed. For a typical reprocessing plant design, the number of penetrations determined to be credible without process or piping modifications was approx. 16% of the penetrations originally identified

  8. Market penetration scenarios for fuel cell vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, C.E.; James, B.D.; Lomax, F.D. Jr. [Directed Technologies, Inc., Arlington, VA (United States)

    1997-12-31

    Fuel cell vehicles may create the first mass market for hydrogen as an energy carrier. Directed Technologies, Inc., working with the US Department of Energy hydrogen systems analysis team, has developed a time-dependent computer market penetration model. This model estimates the number of fuel cell vehicles that would be purchased over time as a function of their cost and the cost of hydrogen relative to the costs of competing vehicles and fuels. The model then calculates the return on investment for fuel cell vehicle manufacturers and hydrogen fuel suppliers. The model also projects the benefit/cost ratio for government--the ratio of societal benefits such as reduced oil consumption, reduced urban air pollution and reduced greenhouse gas emissions to the government cost for assisting the development of hydrogen energy and fuel cell vehicle technologies. The purpose of this model is to assist industry and government in choosing the best investment strategies to achieve significant return on investment and to maximize benefit/cost ratios. The model can illustrate trends and highlight the sensitivity of market penetration to various parameters such as fuel cell efficiency, cost, weight, and hydrogen cost. It can also illustrate the potential benefits of successful R and D and early demonstration projects. Results will be shown comparing the market penetration and return on investment estimates for direct hydrogen fuel cell vehicles compared to fuel cell vehicles with onboard fuel processors including methanol steam reformers and gasoline partial oxidation systems. Other alternative fueled vehicles including natural gas hybrids, direct injection diesels and hydrogen-powered internal combustion hybrid vehicles will also be analyzed.

  9. Simulating barrier penetration during combat. Technical report

    International Nuclear Information System (INIS)

    De Laquil, P. III.

    1980-04-01

    A computer program, BARS, simulates combat between an adversary group attempting to hijack special nuclear material and escort personnel attempting to protect it. BARS is designed to investigate how various combat strategies and levels of performance affect the time required to penetrate barriers (armor, deterrent systems, etc.) against forcible entry. A Monte Carlo code, BARS uses a game theoretic approach to allocate the attacking and defending forces. Combat suppression is simulated using a stochastic state-transition model for the behavior of individuals under combat stress. The BARS program was developed as part of the overall combat modelling effort of the transportation safeguards program

  10. A medium energy neutron deep penetration experiment

    International Nuclear Information System (INIS)

    Amian, W.; Cloth, P.; Druecke, V.; Filges, D.; Paul, N.; Schaal, H.

    1986-11-01

    A deep penetration experiment conducted at the Los Alamos WNR facility's Spallation Neutron Target is compared with calculations using intra-nuclear-cascade and S N -transport codes installed at KFA-IRE. In the experiment medium energy reactions induced by neutrons between 15 MeV and about 150 MeV inside a quasi infinite slab of iron have been measured using copper foil monitors. Details of the experimental procedure and the theoretical methods are described. A comparison of absolute reaction rates for both experimentally and theoretically derived reactions is given. The present knowledge of the corresponding monitor reaction cross sections is discussed. (orig.)

  11. Income Inequality and Transnational Corporate Penetration

    Directory of Open Access Journals (Sweden)

    Linda Beer

    2015-08-01

    Full Text Available This study examines whether the positive association between national income inequality and transnational corporate penetration found previously by Bornschier and Chase-Dunn (1985 and others circa the late 1960s still holds for the mid-l980s. Both methodological and theoretical problems of earlier studies are discussed and solutions are offered. Economic development, political-institutional and regional variables are also included inthe analyses. While further research is warranted, the results provide support for a World-System/Dependency perspective in understanding income inequality cross-nationally.

  12. Premium Efficiency Motors And Market Penetration Policy

    Energy Technology Data Exchange (ETDEWEB)

    Benhaddadi, Mohamed; Olivier, Guy

    2010-09-15

    This paper illustrates the induced enormous energy saving potential, permitted by using high-efficiency motors. Furthermore, the most important barriers to larger high-efficiency motors utilization are identified, and some incentives recommendations are given to overcome identified impediments. The authors consider that there is a strong case to enhance incentives policies for larger market penetration. The US Energy Policy Act and the Canadian Energy Efficient Act have lead to North American leadership on motor efficiency implementation. North America is not on the leading edge for energy saving and conservation. Motor efficiency is an exception that should be at least maintained.

  13. Hacking with Kali practical penetration testing techniques

    CERN Document Server

    Broad, James

    2013-01-01

    Hacking with Kali introduces you the most current distribution of the de facto standard tool for Linux pen testing. Starting with use of the Kali live CD and progressing through installation on hard drives, thumb drives and SD cards, author James Broad walks you through creating a custom version of the Kali live distribution. You'll learn how to configure networking components, storage devices and system services such as DHCP and web services. Once you're familiar with the basic components of the software, you'll learn how to use Kali through the phases of the penetration testing lifecycle

  14. Penetration of relativistic heavy ions through matter

    International Nuclear Information System (INIS)

    Scheidenberger, C.; Geissel, H.

    1997-07-01

    New heavy-ion accelerators covering the relativistic and ultra-relativistic energy regime allow to study atomic collisions with bare and few-electron projectiles. High-resolution magnetic spectrometers are used for precise stopping-power and energy-loss straggling measurements. Refined theories beyond the Born approximation have been developed and are confirmed by experiments. This paper summarizes the large progress in the understanding of relativistic heavy-ion penetration through matter, which has been achieved in the last few years. (orig.)

  15. Penetrating the markets: biomass and commercial distribution

    International Nuclear Information System (INIS)

    Schmidl, J.

    1999-01-01

    Although biomass accounts for a significant proportion of renewable energy in Europe, its market penetration could be increased if certain barriers can be surmounted. Some of those barriers are identified and suggestions made as to how they may be overcome through improved 'distribution' in various sectors. To integrate biomass into the electricity distribution system, the commercial distribution of liquid biofuels, and in the commercial distribution of biomass in the heat sector, certain rewards and penalties could be introduced and these are discussed. The low temperature heat market is seen as very important for the further development of bioenergy in Europe. (UK)

  16. Neutron streaming studies along JET shielding penetrations

    Science.gov (United States)

    Stamatelatos, Ion E.; Vasilopoulou, Theodora; Batistoni, Paola; Obryk, Barbara; Popovichev, Sergey; Naish, Jonathan

    2017-09-01

    Neutronic benchmark experiments are carried out at JET aiming to assess the neutronic codes and data used in ITER analysis. Among other activities, experiments are performed in order to validate neutron streaming simulations along long penetrations in the JET shielding configuration. In this work, neutron streaming calculations along the JET personnel entrance maze are presented. Simulations were performed using the MCNP code for Deuterium-Deuterium and Deuterium- Tritium plasma sources. The results of the simulations were compared against experimental data obtained using thermoluminescence detectors and activation foils.

  17. Mastering Kali Linux for advanced penetration testing

    CERN Document Server

    Beggs, Robert W

    2014-01-01

    This book provides an overview of the kill chain approach to penetration testing, and then focuses on using Kali Linux to provide examples of how this methodology is applied in the real world. After describing the underlying concepts, step-by-step examples are provided that use selected tools to demonstrate the techniques. If you are an IT professional or a security consultant who wants to maximize the success of your network testing using some of the advanced features of Kali Linux, then this book is for you. This book will teach you how to become an expert in the pre-engagement, management,

  18. Market penetration of natural gas in Europe

    International Nuclear Information System (INIS)

    Haas, R.; Wirl, F.

    1992-01-01

    The strategy of restricting natural gas to noble uses (directive of EEC and endorsed by the IEA) impeded gas expansion despite substantial upward revisions in the assessment of available resources. However, increasing environmental concern slowly but gradually undermines this strategy because natural gas serves as a substitute for costly abatement. This article discusses the prospect of future natural gas consumption considering economic and ecological facts as well as strategic and political considerations. In fact, we argue that inconsistent political interventions first seriously lowered gas penetration but now favor its use

  19. Kali Linux assuring security by penetration testing

    CERN Document Server

    Ali, Shakeel; Allen, Lee

    2014-01-01

    Written as an interactive tutorial, this book covers the core of Kali Linux with real-world examples and step-by-step instructions to provide professional guidelines and recommendations for you. The book is designed in a simple and intuitive manner that allows you to explore the whole Kali Linux testing process or study parts of it individually.If you are an IT security professional who has a basic knowledge of Unix/Linux operating systems, including an awareness of information security factors, and want to use Kali Linux for penetration testing, then this book is for you.

  20. Ultraviolet and visible light penetration of epidermis

    International Nuclear Information System (INIS)

    Eggset, G.; Kavli, G.; Volden, G.; Krokan, H.

    1984-01-01

    Light penetration in untanned skin and skin tanned with UVB (middlewave ultraviolet light) or PUVA (Psoralen photochemotherapy) was compared. Transmission at different wavelengths was measured through sheets of intact epidermis isolated by a suction blister technique. Thick epidermis was collected from a newly formed palmar friction bulla. For these studies a monochromator was used and the range of wavelengths examined was 280-700 nm. The transmission was considerably lower in tanned skin and the difference was most pronounced in the UV range. In the UVB range (290-320 nm), transmission was 13-43% for untanned epidermis, 8-12% for UVB tanned and slightly lower for PUVA tanned epidermis. At wavelengths below 325 nm only a few per cent of light penetrate through thick palmar epidermis. Both UVB and PUVA induce increased melanin content and thickening of the epidermis. Our results indicate that melanin is the most efficient protection against UVA while thickening of epidermis may be as important as the increased melanin content for the protection of living basal cells against the harmful UVB rays. (Auth)

  1. Penetrating eye injuries from writing instruments

    Directory of Open Access Journals (Sweden)

    Kelly SP

    2011-12-01

    Full Text Available Simon P Kelly, Graham MB ReevesThe Royal Bolton Hospital, Bolton, UKPurpose: To consider the potential for ocular injury from writing implements by presenting four such cases, and to consider the incidence of such eye injuries from analysis of a national trauma database.Methods: The Home and Leisure Accident Surveillance System was searched for records of eye injuries from writing instruments to provide UK estimates of such injuries. Four patients with ocular penetrating injury from pens or pencils (especially when caused by children, and examined by the authors, are described which illustrate mechanisms of injury.Results: It is estimated that around 748 ocular pen injuries and 892 ocular pencil injuries of undetermined severity occurred annually in the UK during the database surveillance period 2000–2002. No eye injuries from swords, including toy swords and fencing foils, were reported.Conclusion: Ocular perforation sometimes occur from writing instruments that are thrown in the community, especially by children. Implications for policy and prevention are discussed. Non-specialists should have a low threshold for referring patients with eye injuries if suspicious of ocular penetration, even where caused by everyday objects, such as writing instruments.Keywords: eye injury, eye, children, mechanism, writing instruments, prevention

  2. Coulomb explosion of large penetrating molecular clusters

    International Nuclear Information System (INIS)

    Wegner, H.E.; Thieberger, P.

    1981-01-01

    The main purpose of these Coulomb explosion measurements is to determine what kind of structure these and other complex molecules may have and also to determine what other special phenomena may come into play as these complex molecules pass through matter. Although the first preliminary measurements involving the Coulomb explosion of these molecules was reported at this workshop last year, the results are briefly summarized before going on to the more recent measurements obtained with a completely new kind of detector system. This new image intensifier detector system, coupled with a microcomputer, has proven to be a valuable tool in the study of the Coulomb explosion of complex molecules that penetrate matter. In the future, with some additional improvements in the system, and much better statistics for most of the molecules studied to date, it is expected that much new information will be gained about the structure of many kinds of complex molecular ions including the special effects that may be encountered when these fast molecular ions penetrate matter

  3. Penetration of magnetic fields into plasmas

    International Nuclear Information System (INIS)

    Bengtson, R.D.

    1976-01-01

    A pulsed plasma experiment was constructed to study the penetration of a fast-rising magnetic pulse into an initially unmagnetized, weakly ionized plasma of density 10 11 to 10 13 cm -3 . Magnetic probe data was analyzed using a magnetohydrodynamic approach to obtain detailed information about the dynamics of the penetration mechanism. In particular it is possible to obtain the local resistivity and thus the collision frequency from this data. These collision frequencies compare favorably with theoretical estimates of turbulent collision frequencies. The data indicates that sufficient energy is absorbed to heat the bulk of the plasma to temeratures in excess of 1 keV. A differential rotation of a collisionless theta-pinch column during implosion has been observed and explained by a model in which the driving mechanism is the off-diagonal element p/sub r theta/ of the pressure tensor. Rotational motion was detected by directional probes and spectroscopic techniques. Experimental data were modeled by a one-dimensional hybrid code which included ionization and charge exchange of protons with neutral H atoms

  4. Mass transfer from penetrations in waste containers

    International Nuclear Information System (INIS)

    Pescatore, C.; Sastre, C.

    1987-01-01

    Recent studies have indicated that localized corrosion of a relatively small area of a waste container may impair the containment function to such an extent that larger releases may be possible than from the bare waste form. This would take place when a large number of holes coexist on the container while their concentration fields do not interact significantly with each other. After performing a steady state analysis of the release from a hole, it is shown that much fewer independent holes can coexist on a container surface than previously estimated. The calculated radionuclide release from multiple independent holes must be changed accordingly. Previous analyses did not proceed to a correct application of the linear superposition principle. This resulted in unacceptable physical conclusions and undue strain on the performance assessment necessary for a container licensing procedure. The paper also analyzes the steady state release from penetrations of finite length and whose concentration fields interact with one another. The predicted release from these penetrations is lower than the previously calculated release from holes of zero thickness. It is concluded here that the steady-state release from multiple holes on a waste container can not exceed the release from the bare waste form and that multiple perforations need not be a serious liability to container performance. 8 refs., 3 figs., 1 tab

  5. Preparation and characterization of enamel coating on pure titanium as a hydrogen penetration barrier

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Jie, E-mail: taojie@nuaa.edu.cn [College of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu 210016 (China); Guo, Xunzhong [College of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu 210016 (China); Huang, Zhendong [Graduate School of Human and Environmental Studies, Kyoto University, oshida-Nihonmatsu-Cho, Sakyo-Ku, Kyoto shi 606-8501 (Japan); Liu, Hongbing [Shanghai Aircraft Manufacturing Co,. Ltd, Shanghai 200436 (China); Wang, Tao [College of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu 210016 (China)

    2013-06-15

    Highlights: ► The enamel coating was prepared by spin-coating and enameling method. ► The dense enamel coatings were chemically bonded with TA1 substrate. ► The coatings possessed better thermal shock resistance property. ► The coatings had excellent ball-dropping impact properties. ► The enamel coating exhibited a good barrier effect to hydrogen isotope penetration. -- Abstract: The enamel coating with a thickness of 90–110 × 10{sup −6} m was prepared on TA1 substrate by spin-coating and enameling to solve the problems of hydrogen isotope penetration for commercial pure titanium TA1. The microstructure and the interfacial morphology of the samples were characterized respectively by X-ray diffraction, optical and scanning electron microscopy. The profiles of main elements at the interface were analyzed by EDS line-scanning. The experimental results indicated that the dense enamel coatings were chemically bonded with TA1 substrate, and possessed better thermal shock resistance and ball-dropping impact properties. It was concluded from the results of hydrogen charging test with Vickers microhardness measurement and deuterium penetration experiments that the as-prepared dense enamel coating exhibited a good barrier effect to hydrogen isotope penetration.

  6. Stylet penetration of Cacopsylla pyri; an electrical penetration graph (EPG) study

    NARCIS (Netherlands)

    Civolani, S.; Leis, M.; Grandi, G.; Garzo, E.; Pasqualini, E.; Musacchi, S.; Chicca, M.; Castaldelli, G.; Rossie, M.; Tjallingii, W.F.

    2011-01-01

    Detailed information on plant penetration activities by pear psylla Cacopsylla pyri L. (Hemiptera Psyllidae) is essential to study phytoplasma transmission of “Candidatus Phytoplasma pyri” responsible of pear decline disease (PD) and to trace and evaluate resistant traits in new pear tree selections

  7. Micrometeoroid impact simulations using a railgun electromagnetic accelerator

    International Nuclear Information System (INIS)

    Upshaw, J.L.; Kajs, J.P.

    1991-01-01

    The Center for Electromechanics at The University of Texas at Austin (CEM-UT), using a railgun electromagnetic (EM) accelerator, has done a series of hypervelocity micrometeoroid impact simulations. Simulations done to date (78 tests) were carried out under contracts with Lockheed Palo Alto Research Laboratory and Martin Marietta Corporation. The tests were designed to demonstrate that railguns can provide a repeatable means of accelerating particles between 10 -4 and 10 -7 g to hypervelocities within a high-vacuum flight chamber. Sodalime glass beads were accelerated up to 11 km/s impacting into silicon, aluminum, quartz and various proprietary targets. At the muzzle of the gun was a 5.8-m-long, high-vacuum flight chamber. Targets were placed in this chamber at various distances from the gun. Impact craters on all the targets were examined using a light-source microscope and several targets were further examined using a scanning electron microscope. Gun and flight range diagnostics, along with experimental setups and results for several of the experiments, are presented in this paper

  8. Medicaid HMO penetration and its mix: did increased penetration affect physician participation in urban markets?

    Science.gov (United States)

    Adams, E Kathleen; Herring, Bradley

    2008-02-01

    To use changes in Medicaid health maintenance organization (HMO) penetration across markets over time to test for effects on the extent of Medicaid participation among physicians and to test for differences in the effects of increased use of commercial versus Medicaid-dominant plans within the market. The nationally representative Community Tracking Study's Physician Survey for three periods (1996-1997, 1998-1999, and 2000-2001) on 29,866 physicians combined with Centers for Medicare and Medicaid Services (CMS) and InterStudy data. Market-level estimates of Medicaid HMO penetration are used to test for (1) any participation in Medicaid and (2) the degree to which physicians have an "open" (i.e., nonlimited) practice accepting new Medicaid patients. Models account for physician, firm, and local characteristics, Medicaid relative payment levels adjusted for geographic variation in practice costs, and market-level fixed effects. There is a positive effect of increases in commercial Medicaid HMO penetration on the odds of accepting new Medicaid patients among all physicians, and in particular, among office-based physicians. In contrast, there is no effect, positive or negative, from expanding the penetration of Medicaid-dominant HMO plans within the market. Increases in cost-adjusted Medicaid fees, relative to Medicare levels, were associated with increases in the odds of participation and of physicians having an "open" Medicaid practice. Provider characteristics that consistently lower participation among all physicians include being older, board certified, a U.S. graduate and a solo practitioner. The effects of Medicaid HMO penetration on physician participation vary by the type of plan. If states are able to attract and retain commercial plans, participation by office-based physicians is likely to increase in a way that opens existing practices to more new Medicaid patients. Other policy variables that affect participation include the presence of a federally

  9. Final Technical Report: Distributed Controls for High Penetrations of Renewables

    Energy Technology Data Exchange (ETDEWEB)

    Byrne, Raymond H. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Neely, Jason C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rashkin, Lee J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Trudnowski, Daniel J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wilson, David G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-12-01

    The goal of this effort was to apply four potential control analysis/design approaches to the design of distributed grid control systems to address the impact of latency and communications uncertainty with high penetrations of photovoltaic (PV) generation. The four techniques considered were: optimal fixed structure control; Nyquist stability criterion; vector Lyapunov analysis; and Hamiltonian design methods. A reduced order model of the Western Electricity Coordinating Council (WECC) developed for the Matlab Power Systems Toolbox (PST) was employed for the study, as well as representative smaller systems (e.g., a two-area, three-area, and four-area power system). Excellent results were obtained with the optimal fixed structure approach, and the methodology we developed was published in a journal article. This approach is promising because it offers a method for designing optimal control systems with the feedback signals available from Phasor Measurement Unit (PMU) data as opposed to full state feedback or the design of an observer. The Nyquist approach inherently handles time delay and incorporates performance guarantees (e.g., gain and phase margin). We developed a technique that works for moderate sized systems, but the approach does not scale well to extremely large system because of computational complexity. The vector Lyapunov approach was applied to a two area model to demonstrate the utility for modeling communications uncertainty. Application to large power systems requires a method to automatically expand/contract the state space and partition the system so that communications uncertainty can be considered. The Hamiltonian Surface Shaping and Power Flow Control (HSSPFC) design methodology was selected to investigate grid systems for energy storage requirements to support high penetration of variable or stochastic generation (such as wind and PV) and loads. This method was applied to several small system models.

  10. Projectile Nose Mass Abrasion of High-Speed Penetration into Concrete

    Directory of Open Access Journals (Sweden)

    Haijun Wu

    2012-01-01

    Full Text Available Based on the dynamic spherical cavity expansion theory of concrete and the analysis of experimental data, a mass abrasion model of projectile considering the hardness of aggregates, the relative strength of target and projectile, and the initial impact velocity is constructed in this paper. Furthermore, the effect of mass abrasion on the penetration depth of projectile and the influence of hardness of aggregates and strength of projectile on penetration depth and mass loss are also analyzed. The results show that, for the ogive-nose projectile with the CRH of 3 and aspect ratio of 7 penetrating the concrete of 35 MPa, the “rigid-body penetration” model is available when the initial impact velocity is lower than 800 m/s. However, when the initial impact velocity is higher than 800 m/s, the “deforming/eroding body penetration” model should be adopted. Through theoretical analysis and numerical calculation, the results indicate that the initial impact velocity is the most important factor of mass abrasion. The hardness of aggregates and the strength of projectile are also significant factors. But relatively speaking, the sensitivity of strength of projectile to mass abrasion is higher, which indicates that the effect of projectile material on mass abrasion is more dramatic than the hardness of aggregates.

  11. Carbonaceous Survivability on Impact

    Science.gov (United States)

    Bunch, T. E.; Becker, Luann; Morrison, David (Technical Monitor)

    1994-01-01

    In order to gain knowledge about the potential contributions of comets and cosmic dust to the origin of life on Earth, we need to explore the survivability of their potential organic compounds on impact and the formation of secondary products that may have arisen from the chaotic events sustained by the carriers as they fell to Earth. We have performed a series of hypervelocity impact experiments using carbon-bearing impactors (diamond, graphite, kerogens, PAH crystals, and Murchison and Nogoya meteorites) into Al plate targets at velocities - 6 km/s. Estimated peak shock pressures probably did not exceed 120 GPa and peak shock temperatures were probably less than 4000 K for times of nano- to microsecs. Nominal crater dia. are less than one mm. The most significant results of these experiments are the preservation of the higher mass PAHs (e. g., pyrene relative to napthalene) and the formation of additional alkylated PAHs. We have also examined the residues of polystyrene projectiles impacted by a microparticle accelerator into targets at velocities up to 15 km/s. This talk will discuss the results of these experiments and their implications with respect to the survival of carbonaceous deliverables to early Earth. The prospects of survivability of organic molecules on "intact" capture of cosmic dust in space via soft: and hard cosmic dust collectors will also be discussed.

  12. Racemization of Valine by Impact-Induced Heating

    Science.gov (United States)

    Furukawa, Yoshihiro; Takase, Atsushi; Sekine, Toshimori; Kakegawa, Takeshi; Kobayashi, Takamichi

    2018-03-01

    Homochirality plays an important role in all living organisms but its origin remains unclear. It also remains unclear whether such chiral molecules survived terrestrial heavy impact events. Impacts of extraterrestrial objects on early oceans were frequent and could have affected the chirality of oceanic amino acids when such amino acids accumulated during impacts. This study investigated the effects of shock-induced heating on enantiomeric change of valine with minerals such as olivine ([Mg0.9, Fe0.1]2SiO4), hematite (Fe2O3), and calcite (CaCO3). With a shock wave generated by an impact at 0.8 km/s, both d- and l-enriched valine were significantly decomposed and partially racemized under all experimental conditions. Different minerals had different shock impedances; therefore, they provided different P-T conditions for identical impacts. Furthermore, the high pH of calcite promoted the racemization of valine. The results indicate that in natural hypervelocity impacts, amino acids in shocked oceanic water would have decomposed completely, since impact velocity and the duration of shock compression and heating are typically greater in hypervelocity impact events than those in experiments. Even with the shock wave by the impact of small and decelerated projectiles in which amino acids survive, the shock heating may generate sufficient heat for significant racemization in shocked oceanic water. However, the duration of shock induced heating by small projectiles is limited and the population of such decelerated projectiles would be limited. Therefore, even though impacts of asteroids and meteorites were frequent on the prebiotic Earth, impact events would not have significantly changed the ee of proteinogenic amino acids accumulated in the entire ocean.

  13. Civil engineering applications of ground penetrating radar

    CERN Document Server

    Pajewski, Lara

    2015-01-01

    This book, based on Transport and Urban Development COST Action TU1208, presents the most advanced applications of ground penetrating radar (GPR) in a civil engineering context, with documentation of instrumentation, methods, and results. It explains clearly how GPR can be employed for the surveying of critical transport infrastructure, such as roads, pavements, bridges, and tunnels, and for the sensing and mapping of underground utilities and voids. Detailed attention is also devoted to use of GPR in the inspection of geological structures and of construction materials and structures, including reinforced concrete, steel reinforcing bars, and pre/post-tensioned stressing ducts. Advanced methods for solution of electromagnetic scattering problems and new data processing techniques are also presented. Readers will come to appreciate that GPR is a safe, advanced, nondestructive, and noninvasive imaging technique that can be effectively used for the inspection of composite structures and the performance of diagn...

  14. Cephalic Tetanus from Penetrating Orbital Wound

    Directory of Open Access Journals (Sweden)

    Eloïse Guyennet

    2009-01-01

    Full Text Available Tetanus is a neurologic disorder caused by tetanospasmin, a protein toxin elaborated by Clostridium tetani. Cephalic tetanus is a localized form of the disease causing trismus and dysfunction of cranial nerves. We report the case of a man who presented with facial trauma, complete ophthalmoplegia, exophthalmos, areactive mydriasis, and periorbital hematoma. An orbital CT revealed air bubbles in the right orbital apex. The patient was given a tetanus toxoid booster and antibiotherapy. After extraction of a wooden foreign body, the patient developed right facial nerve palsy, disorders of swallowing, contralateral III cranial nerve palsy, and trismus. Only one case of cephalic tetanus from penetrating orbital wound has been reported in literature 20 years ago. When a patient presents with an orbital wound with ophthalmoplegia and signs of anaerobic infection, cephalic tetanus should be ruled out.

  15. Penetration enhancer: monoethylether of diethylene glycol

    International Nuclear Information System (INIS)

    Koprda, V.; Kassai, Z.; Bohacik, L.; Bezek, S.; Hadcrafft, J.; Falson-Rieg, F.

    1999-01-01

    The monoethylether of diethylene glycol (Transcutol), an excellent solubilising agent, has been suggested as a penetration enhancer compatible with trans-dermal drug delivery systems. Using the abdominal skin of 5 day old rats and Franz-type diffusion cells the following topics were studied in this contribution: (1) Flux of Transcutol, labelled with [Ethyl- 14 C]-ether, across an intact skin model, (2) Changes in properties of the skin barrier after stripping with adhesive tape, and (3) Changes in flux of Transcutol when mixed with different co-solvents. The flux from pure solvent in donor compartment reached around 50 μg cm -2 hr -1 across the intact skin horny layer, whilst after 12 strips the flux increased about 200 times. In the presence of propylene glycol dipelargonate, the flux over 2 mg cm -2 hr -1 across non stripped skin was achieved. (authors)

  16. Penetrating Stab Wound of the Right Ventricle

    Directory of Open Access Journals (Sweden)

    Onursal Buğra

    2010-04-01

    Full Text Available 18 years old male patient was admitted to our emergency unit with a penetrating stab wound to the right ventricle. A stab wound to the right ventricle was found to be 3 cm in diameter. The bleeding was controlled by insertion of a Foley catheter and inflation of the balloon. The stab wound had transected distal acute marginal side ofthe right coronary artery. A successful repair was performed with the use of a foley catheter and application of the Medtronic Octopus Tissue Stabilization System. The wound was closed with pledgeted mattress sutures. The distal acute marginal side of the right coronary artery was ligated. In this presentation, the surgical intervention method was reported and followed by a discussion of emergency surgical procedures of the heart.

  17. Automatic control of oscillatory penetration apparatus

    Science.gov (United States)

    Lucon, Peter A

    2015-01-06

    A system and method for controlling an oscillatory penetration apparatus. An embodiment is a system and method for controlling a sonic drill having a displacement and an operating range and operating at a phase difference, said sonic drill comprising a push-pull piston and eccentrics, said method comprising: operating the push-pull piston at an initial push-pull force while the eccentrics are operated at a plurality of different operating frequencies within the operating range of the sonic drill and measuring the displacement at each operating frequency; determining an efficient operating frequency for the material being drilled and operating the eccentrics at said efficient operating frequency; determining the phase difference at which the sonic drill is operating; and if the phase difference is not substantially equal to minus ninety degrees, operating the push-pull piston at another push-pull force.

  18. Fluorescent Penetrant INSPECTION—CLEANING Study Update

    Science.gov (United States)

    Eisenmann, D.; Brasche, L.

    2009-03-01

    Fluorescent penetrant inspection (FPI) is widely used in the aviation industry and other industries for surface-breaking crack detection. As with all inspection methods, adherence to the process parameters is critical to the successful detection of defects. There is variety of lubricants and surface coatings used in the aviation industry which must be removed prior to FPI. Before the FPI process begins, components are cleaned using a variety of cleaning methods which are selected based on the alloy and the soil types which must be removed. It is also important that the cleaning process not adversely affect the FPI process. From the first three phases of this project it has been found that a hot water rinse can aid in the detection process when using this nondestructive method.

  19. Market penetration of energy supply technologies

    Science.gov (United States)

    Condap, R. J.

    1980-03-01

    Techniques to incorporate the concepts of profit-induced growth and risk aversion into policy-oriented optimization models of the domestic energy sector are examined. After reviewing the pertinent market penetration literature, simple mathematical programs in which the introduction of new energy technologies is constrained primarily by the reinvestment of profits are formulated. The main results involve the convergence behavior of technology production levels under various assumptions about the form of the energy demand function. Next, profitability growth constraints are embedded in a full-scale model of U.S. energy-economy interactions. A rapidly convergent algorithm is developed to utilize optimal shadow prices in the computation of profitability for individual technologies. Allowance is made for additional policy variables such as government funding and taxation. The result is an optimal deployment schedule for current and future energy technologies which is consistent with the sector's ability to finance capacity expansion.

  20. Convective penetration in a young sun

    Science.gov (United States)

    Pratt, Jane; Baraffe, Isabelle; Goffrey, Tom; MUSIC developers group

    2018-01-01

    To interpret the high-quality data produced from recent space-missions it is necessary to study convection under realistic stellar conditions. We describe the multi-dimensional, time implicit, fully compressible, hydrodynamic, implicit large eddy simulation code MUSIC. We use MUSIC to study convection during an early stage in the evolution of our sun where the convection zone covers approximately half of the solar radius. This model of the young sun possesses a realistic stratification in density, temperature, and luminosity. We approach convection in a stellar context using extreme value theory and derive a new model for convective penetration, targeted for one-dimensional stellar evolution calculations. This model provides a scenario that can explain the observed lithium abundance in the sun and in solar-like stars at a range of ages.