Stable Bound States of Asymmetric Dark Matter
Wise, Mark B.; Zhang, Yue
2014-01-01
The simplest renormalizable effective field theories with asymmetric dark matter bound states contain two additional gauge singlet fields one being the dark matter and the other a mediator particle that the dark matter annihilates into. We examine the physics of one such model with a Dirac fermion as the dark matter and a real scalar mediator. For a range of parameters the Yukawa coupling of the dark matter to the mediator gives rise to stable asymmetric dark matter bound states. We derive pr...
Energy Technology Data Exchange (ETDEWEB)
Gomez-Camacho, A; Aguilera, E F; Martinez-Quiroz, E [Departamento de Aceleradores, Instituto Nacional de Investigaciones Nucleares, Apartado Postal 18-1027, C.P. 11801, Mexico, D.F. (Mexico); Gomes, P R S; Lubian, J [Instituto de Fisica, Universidade Federal Fluminenese, Avenida Litoranea s/n, Gragoata, Niteroi, RJ, cep 24210-340 (Brazil); Canto, L F, E-mail: arturo.gomez@inin.gob.m [Instituto de Fisica, Universidade Federal do Rio de Janeiro, C.P. 68528, Rio de Janeiro, R.J., cep 21941-972 (Brazil)
2010-07-01
A thorough study of the energy dependence of the nuclear optical potential in reactions involving the weakly bound projectiles {sup 8}B, {sup 7}Be and {sup 6}Li on the target {sup 58}Ni and {sup 9}Be on {sup 27}Al is carried out by performing a {chi}{sup 2}-analysis of recent measurements of elastic scattering cross sections for energies around and above the Coulomb barrier. For this purpose two different potential types are used: the double folding Sao Paulo potential and the Woods-Saxon potential. The calculations performed for the energy dependence of the real and imaginary parts of the polarization potentials show that these potentials besides satisfying the dispersion relation, for some nuclear systems the uncertainties on the energy dependence of the polarization potentials allow to conclude that these systems present a behavior consistent with the Breakup Theshold Anomaly. In other cases, due to the large uncertainties, it is not possible to make a definitive conclusion about the anomalies.
Recurrent neural networks training with stable bounding ellipsoid algorithm.
Yu, Wen; de Jesús Rubio, José
2009-06-01
Bounding ellipsoid (BE) algorithms offer an attractive alternative to traditional training algorithms for neural networks, for example, backpropagation and least squares methods. The benefits include high computational efficiency and fast convergence speed. In this paper, we propose an ellipsoid propagation algorithm to train the weights of recurrent neural networks for nonlinear systems identification. Both hidden layers and output layers can be updated. The stability of the BE algorithm is proven.
Hydrodynamic Drag on Streamlined Projectiles and Cavities
Jetly, Aditya
2016-04-19
The air cavity formation resulting from the water-entry of solid objects has been the subject of extensive research due to its application in various fields such as biology, marine vehicles, sports and oil and gas industries. Recently we demonstrated that at certain conditions following the closing of the air cavity formed by the initial impact of a superhydrophobic sphere on a free water surface a stable streamlined shape air cavity can remain attached to the sphere. The formation of superhydrophobic sphere and attached air cavity reaches a steady state during the free fall. In this thesis we further explore this novel phenomenon to quantify the drag on streamlined shape cavities. The drag on the sphere-cavity formation is then compared with the drag on solid projectile which were designed to have self-similar shape to that of the cavity. The solid projectiles of adjustable weight were produced using 3D printing technique. In a set of experiments on the free fall of projectile we determined the variation of projectiles drag coefficient as a function of the projectiles length to diameter ratio and the projectiles specific weight, covering a range of intermediate Reynolds number, Re ~ 104 – 105 which are characteristic for our streamlined cavity experiments. Parallel free fall experiment with sphere attached streamlined air cavity and projectile of the same shape and effective weight clearly demonstrated the drag reduction effect due to the stress-free boundary condition at cavity liquid interface. The streamlined cavity experiments can be used as the upper bound estimate of the drag reduction by air layers naturally sustained on superhydrophobic surfaces in contact with water. In the final part of the thesis we design an experiment to test the drag reduction capacity of robust superhydrophobic coatings deposited on the surface of various model vessels.
Influence of projectile breakup on complete fusion
Indian Academy of Sciences (India)
illustrates the typical reaction mechanisms following the breakup of weakly bound projectiles. When whole of the projectile fuses with whole of the target, the process is known as direct complete fusion (DCF). If prior to fusion, the projectile breaks up and subsequently all the fragments fuse with the target to form a compound.
Systematics of the breakup probability function for {sup 6}Li and {sup 7}Li projectiles
Energy Technology Data Exchange (ETDEWEB)
Capurro, O.A., E-mail: capurro@tandar.cnea.gov.ar [Laboratorio TANDAR, Comisión Nacional de Energía Atómica, Av. General Paz 1499, B1650KNA San Martín, Buenos Aires (Argentina); Pacheco, A.J.; Arazi, A. [Laboratorio TANDAR, Comisión Nacional de Energía Atómica, Av. General Paz 1499, B1650KNA San Martín, Buenos Aires (Argentina); CONICET, Av. Rivadavia 1917, C1033AAJ Buenos Aires (Argentina); Carnelli, P.F.F. [CONICET, Av. Rivadavia 1917, C1033AAJ Buenos Aires (Argentina); Instituto de Investigación e Ingeniería Ambiental, Universidad Nacional de San Martín, 25 de Mayo y Francia, B1650BWA San Martín, Buenos Aires (Argentina); Fernández Niello, J.O. [Laboratorio TANDAR, Comisión Nacional de Energía Atómica, Av. General Paz 1499, B1650KNA San Martín, Buenos Aires (Argentina); CONICET, Av. Rivadavia 1917, C1033AAJ Buenos Aires (Argentina); Instituto de Investigación e Ingeniería Ambiental, Universidad Nacional de San Martín, 25 de Mayo y Francia, B1650BWA San Martín, Buenos Aires (Argentina); and others
2016-01-15
Experimental non-capture breakup cross sections can be used to determine the probability of projectile and ejectile fragmentation in nuclear reactions involving weakly bound nuclei. Recently, the probability of both type of dissociations has been analyzed in nuclear reactions involving {sup 9}Be projectiles onto various heavy targets at sub-barrier energies. In the present work we extend this kind of systematic analysis to the case of {sup 6}Li and {sup 7}Li projectiles with the purpose of investigating general features of projectile-like breakup probabilities for reactions induced by stable weakly bound nuclei. For that purpose we have obtained the probabilities of projectile and ejectile breakup for a large number of systems, starting from a compilation of the corresponding reported non-capture breakup cross sections. We parametrize the results in accordance with the previous studies for the case of beryllium projectiles, and we discuss their systematic behavior as a function of the projectile, the target mass and the reaction Q-value.
Jiskra, Martin; Wiederhold, Jan G; Skyllberg, Ulf; Kronberg, Rose-Marie; Kretzschmar, Ruben
2017-10-18
Terrestrial runoff represents a major source of mercury (Hg) to aquatic ecosystems. In boreal forest catchments, such as the one in northern Sweden studied here, mercury bound to natural organic matter (NOM) represents a large fraction of mercury in the runoff. We present a method to measure Hg stable isotope signatures of colloidal Hg, mainly complexed by high molecular weight or colloidal natural organic matter (NOM) in natural waters based on pre-enrichment by ultrafiltration, followed by freeze-drying and combustion. We report that Hg associated with high molecular weight NOM in the boreal forest runoff has very similar Hg isotope signatures as compared to the organic soil horizons of the catchment area. The mass-independent fractionation (MIF) signatures (Δ 199 Hg and Δ 200 Hg) measured in soils and runoff were in agreement with typical values reported for atmospheric gaseous elemental mercury (Hg 0 ) and distinctly different from reported Hg isotope signatures in precipitation. We therefore suggest that most Hg in the boreal terrestrial ecosystem originated from the deposition of Hg 0 through foliar uptake rather than precipitation. Using a mixing model we calculated the contribution of soil horizons to the Hg in the runoff. At moderate to high flow runoff conditions, that prevailed during sampling, the uppermost part of the organic horizon (Oe/He) contributed 50-70% of the Hg in the runoff, while the underlying more humified organic Oa/Ha and the mineral soil horizons displayed a lower mobility of Hg. The good agreement of the Hg isotope results with other source tracing approaches using radiocarbon signatures and Hg : C ratios provides additional support for the strong coupling between Hg and NOM. The exploratory results from this study illustrate the potential of Hg stable isotopes to trace the source of Hg from atmospheric deposition through the terrestrial ecosystem to soil runoff, and provide a basis for more in-depth studies investigating the
High-resolution nitrogen stable isotope sclerochronology of bivalve shell carbonate-bound organics
Gillikin, David P.; Lorrain, Anne; Jolivet, Aurélie; Kelemen, Zita; Chauvaud, Laurent; Bouillon, Steven
2017-03-01
Nitrogen stable isotope ratios (δ15N) of organic material have successfully been used to track food-web dynamics, nitrogen baselines, pollution, and nitrogen cycling. Extending the δ15N record back in time has not been straightforward due to a lack of suitable substrates in which δ15N records are faithfully preserved, thus sparking interest in utilizing skeletal carbonate-bound organic matter (CBOM) in mollusks, corals, and foraminifera. Here we test if calcite Pecten maximus shells from the Bay of Brest and the French continental shelf can be used as an archive of δ15N values over a large environmental gradient and at a high temporal resolution (approximately weekly). Bulk CBOM δ15N values from the growing tip of shells collected over a large nitrogen isotope gradient were strongly correlated with adductor muscle tissue δ15N values (R2 = 0.99, n = 6, p fossil shells. In conclusion, bivalve shell CBOM δ15N values can be used in a similar manner to soft-tissue δ15N values, and can track various biogeochemical events at a very high-resolution.
VANDERSTEEGE, G; NIEBOER, M; SWAVING, J; TEMPELAAR, MJ
1992-01-01
Chimaeric genes of promoter sequences from the potato gene encoding granule-bound starch synthase (GBSS) and the beta-glucuronidase (GUS) reporter gene were used to study GBSS expression and regulation. Analysis of stable transformants revealed that a GBSS promoter sequence of 0.4 kb was sufficient
Schnick, Jeffrey W.
1994-01-01
Presents an exercise that attempts to correct for the common discrepancies between theoretical and experimental predictions concerning projectile motion using a spring-loaded projectile ball launcher. Includes common correction factors for student use. (MVL)
Very stable silica-gel-bound laccase biocatalysts for the selective oxidation in continuous systems.
Rekuć, Adriana; Bryjak, Jolanta; Szymańska, Katarzyna; Jarzebski, Andrzej B
2010-04-01
Cerrena unicolor laccase was immobilized by adsorption and covalent bonds formation on silica-gel carriers, functionalized with different organosilanes and surface densities. The effects of protein concentration, pH value of the coupling mixture and the enzyme purity on immobilization efficiency of the best carrier, moderately modified (0.75 mmol/g carrier) with 3-aminopropyltriethoxysilane were investigated. Activity of the best biocatalysts, expressed in ABTS oxidation, was 4028 U/mL of the carrier or 3530 U/mg of bound protein. Properties of immobilized laccase were determined to find excellent thermal stability improvement; t(1/2) for freely suspended enzyme was 2-3 min at 80 degrees C, whereas after immobilization over 100 min. Kinetic experiments in both batch and packed-bed reactors gave only four times lower k(cat)/K(m) value than for the native enzyme. A packed-bed reactor with silica-gel-bound laccase beads appeared to be very efficient in ABTS oxidation and its exceptional potentials were shown in the continuous decolorization of indigo carmine for 18 days without loss in activity. This system offers perfect ability to degrade recalcitrant dyes, but we can also envisage its use, with ABTS acting as a mediator, in regeneration of nicotinamide cofactors. Copyright 2009 Elsevier Ltd. All rights reserved.
Vargas, A. I.; Schaffer, B.; Yuhong, L.; Sternberg, L. O.
2016-12-01
Stable oxygen (δ18O) and hydrogen (δ2H) isotope composition of precipitation, soil and plants have been studied over the years to understand the mechanism of soil water movement and the depth of plant water uptake in the soil water profile. Recent studies have suggested that in soil during the wet season, tightly bound water does not mix with mobile water but is retained in the soil until the dry season when it is taken up by plants via the force of transpiration. To test this, we sampled δ18O and δ2H in plant stems as a proxy for wet season mobile water and dry season bound water in two types of soils to determine if mixing occurs between mobile and tightly bound soil water. Plastic pots were filled with clay or very gravelly loam soil and a Persea americana tree was planted in each pot. Soil in each pot was first saturated with tap water to fully label the bound water with the isotopic identity of tap water and then fully saturated with either tap water (T) or isotopically-enriched pool water (P) and covered with white polyethylene to prevent evaporation. After saturating the soil, δ18O and δ2H of water draining from each pot were similar to those of water added to each pot for both the T and P treatments. For each treatment, δ18O and δ2H in plant stems were sampled 2-3 days after soil was initially saturated (simulated wet season; soil tension 80.0 kPa). During the "dry season", there was a significant difference between T and P treatments for δ18O and δ2H in plant stems, indicating that bound water accessed by plants in the P treatment did not retain the tap water label and mixing occurred between mobile and bound water in the soil. Comparing P-T in the wet season with P-T in the dry season indicated that as much as 95% of water freely exchanged between the mobile and bound components of the soil. This is contrary to recent studies suggesting that no mixing occurs.
Summers, M. K.
1977-01-01
Described is a novel approach to the teaching of projectile motion of sixth form level. Students are asked to use an analogue circuit to observe projectile motion and to graph the experimental results. Using knowledge of basic dynamics, students are asked to explain the shape of the curves theoretically. (Author/MA)
Lucie, Pierre
1979-01-01
Analyzes projectile motion using symmetry and simple geometry. Deduces the direction of velocity at any point, range, time of flight, maximum height, safety parabola, and maximum range for a projectile launched upon a plane inclined at any angle with respect to the horizontal. (Author/GA)
Inclusive breakup of three-fragment weakly bound nuclei
Energy Technology Data Exchange (ETDEWEB)
Carlson, B.V.; Frederico, T. [Instituto Tecnológico de Aeronáutica, DCTA, 12.228-900 São José dos Campos, SP (Brazil); Hussein, M.S., E-mail: hussein@if.usp.br [Instituto Tecnológico de Aeronáutica, DCTA, 12.228-900 São José dos Campos, SP (Brazil); Instituto de Estudos Avançados, Universidade de São Paulo, C.P. 72012, 05508-970 São Paulo, SP (Brazil); Instituto de Física, Universidade de São Paulo, C.P. 66318, 05314-970 São Paulo, SP (Brazil)
2017-04-10
The inclusive breakup of three-fragment projectiles is discussed within a four-body spectator model. Both the elastic breakup and the non-elastic breakup are obtained in a unified framework. Originally developed in the 80's for two-fragment projectiles such as the deuteron, in this paper the theory is successfully generalized to three-fragment projectiles. The expression obtained for the inclusive cross section allows the extraction of the incomplete fusion cross section, and accordingly generalizes the surrogate method to cases such as (t, p) and (t, n) reactions. It is found that two-fragment correlations inside the projectile affect in a conspicuous way the elastic breakup cross section. The inclusive non-elastic breakup cross section is calculated and is found to contain the contribution of a three-body absorption term that is also strongly influenced by the two-fragment correlations. This latter cross section contains the so-called incomplete fusion where more than one compound nuclei are formed. Our theory describes both stable weakly bound three-fragment projectiles and unstable ones such as the Borromean nuclei.
Warner, D.; Dijkstra, J.; Hendriks, W.H.; Pellikaan, W.F.
2013-01-01
Fractional passage rates are required to predict nutrient absorption in ruminants but data on nutrient-specific passage kinetics are largely lacking. With the use of the stable isotope ratio (d) as an internal marker, we assessed passage kinetics of fiber and fiber-bound nitrogen (N) of
Dynamic analysis of a guided projectile during engraving process
Directory of Open Access Journals (Sweden)
Tao Xue
2014-06-01
Full Text Available The reliability of the electronic components inside a guided projectile is highly affected by the launch dynamics of guided projectile. The engraving process plays a crucial role on determining the ballistic performance and projectile stability. This paper analyzes the dynamic response of a guided projectile during the engraving process. By considering the projectile center of gravity moving during the engraving process, a dynamics model is established with the coupling of interior ballistic equations. The results detail the stress situation of a guided projectile band during its engraving process. Meanwhile, the axial dynamic response of projectile in the several milliseconds following the engraving process is also researched. To further explore how the different performance of the engraving band can affect the dynamics of guided projectile, this paper focuses on these two aspects: (a the effects caused by the different band geometry; and (b the effects caused by different band materials. The time domain and frequency domain responses show that the dynamics of the projectile are quite sensitive to the engraving band width. A material with a small modulus of elasticity is more stable than one with a high modulus of elasticity.
Projectile Motion with Mathematica.
de Alwis, Tilak
2000-01-01
Describes how to use the computer algebra system (CAS) Mathematica to analyze projectile motion with and without air resistance. These experiments result in several conjectures leading to theorems. (Contains 17 references.) (Author/ASK)
Lamb, William G.
1985-01-01
Explains a projectile motion experiment involving a bow and arrow. Procedures to measure "muzzle" velocity, bow elastic potential energy, range, flight time, wind resistance, and masses are considered. (DH)
Projectile Demilitarization Facilities
Federal Laboratory Consortium — The Projectile Wash Out Facility is US Army Ammunition Peculiar Equipment (APE 1300). It is a pilot scale wash out facility that uses high pressure water and steam...
Small caliber guided projectile
Jones, James F [Albuquerque, NM; Kast, Brian A [Albuquerque, NM; Kniskern, Marc W [Albuquerque, NM; Rose, Scott E [Albuquerque, NM; Rohrer, Brandon R [Albuquerque, NM; Woods, James W [Albuquerque, NM; Greene, Ronald W [Albuquerque, NM
2010-08-24
A non-spinning projectile that is self-guided to a laser designated target and is configured to be fired from a small caliber smooth bore gun barrel has an optical sensor mounted in the nose of the projectile, a counterbalancing mass portion near the fore end of the projectile and a hollow tapered body mounted aft of the counterbalancing mass. Stabilizing strakes are mounted to and extend outward from the tapered body with control fins located at the aft end of the strakes. Guidance and control electronics and electromagnetic actuators for operating the control fins are located within the tapered body section. Output from the optical sensor is processed by the guidance and control electronics to produce command signals for the electromagnetic actuators. A guidance control algorithm incorporating non-proportional, "bang-bang" control is used to steer the projectile to the target.
Concrete structures under projectile impact
Fang, Qin
2017-01-01
In this book, the authors present their theoretical, experimental and numerical investigations into concrete structures subjected to projectile and aircraft impacts in recent years. Innovative approaches to analyze the rigid, mass abrasive and eroding projectile penetration and perforation are proposed. Damage and failure analyses of nuclear power plant containments impacted by large commercial aircrafts are numerically and experimentally analyzed. Ultra-high performance concrete materials and structures against the projectile impact are developed and their capacities of resisting projectile impact are evaluated. This book is written for the researchers, engineers and graduate students in the fields of protective structures and terminal ballistics.
Boman, Jan
2016-12-01
In applications of computerized tomography (CT) it is often of interest to reconstruct a function in a proper subset, the region of interest (ROI), of its support from a proper subset of a full CT-scan. In several recent works it has been shown that stable ROI reconstruction is possible in certain limited data situations. In this paper we investigate the limits of what is possible in that direction by proving that reconstruction in an interior ROI is severely unstable for a certain set of data that contains integrals over all lines that intersect the ROI and is large enough for the unknown function to be uniquely determined.
Directory of Open Access Journals (Sweden)
Sijie Li
2017-12-01
Full Text Available Through high-resolution electron microscopy, stacking faults (SFs due to Frank partial dislocations were found in an aluminum alloy following deformation with low strain and strain rate, while also remaining stable during artificial aging. Extrinsic stacking faults were found surrounded by dislocation areas and precipitates. An intrinsic stacking fault was found between two Guinier-Preston II (GP II zones when the distance of the two GP II zones was 2 nm. Defects (precipitates and dislocations are considered to have an influence on the formation of the SFs, as their appearance may cause local strain and promote the gathering of vacancies to lower the energy.
Patriotis, C; Djondjurov, L
1989-09-01
This study describes tightly bound DNA-protein complexes in DNA of matrices isolated from Friend erythroleukemia cells. When after radio-iodination of the associated proteins, such DNA is electrophoresed on agarose and the gel is subsequently subjected to autoradiography, the protein components of three or four complexes are visualized. Their two-dimensional electrophoretic analysis revealed that each possesses a simple but specific polypeptide composition, including a set of five non-histone proteins, characteristic for the matrix, and the core histones H3 and H4. Since the polypeptides dissociate from DNA by treatment with SDS, it is suggested that the linkage is not covalent. Reassociation and hybridization analysis of the DNA of the complexes indicated that it is enriched in highly repetitive, satellite sequences. The latter were found to be, to a great extent, similar to sequences localized at the base of large, dehistonized DNA loops obtained by high-salt extraction of isolated nuclei. Further experiments emphasized the complete conservation of this type of attachment throughout erythroid differentiation of Friend cells. It is proposed that the complexes represent attachment sites of basic, 30-100-kbp loop units of DNA.
Microspoiler Actuation for Guided Projectiles
2016-01-06
Fabrication at Georgia Tech Machine Shop (right). G. Special Comments None. Projectile Aft Body and Fin Set Cam Mechanism Spacer and Guide...between the Georgia Institute of Technology (Georgia Tech ) and the Army Research Laboratory (ARL) for DARPA. Objective 1: Perform Trade Studies to...authority trade studies will examine scalability of microspoiler performance to various calibers of fin -stabilized projectiles, including small, medium
Directory of Open Access Journals (Sweden)
Toshiyuki Mizui
Full Text Available The neuronal actin-binding protein drebrin A forms a stable structure with F-actin in dendritic spines. NMDA receptor activation causes an exodus of F-actin bound by drebrin A (DA-actin from dendritic spines, suggesting a pivotal role for DA-actin exodus in synaptic plasticity. We quantitatively assessed the extent of DA-actin localization to spines using the spine-dendrite ratio of drebrin A in cultured hippocampal neurons, and found that (1 chemical long-term potentiation (LTP stimulation induces rapid DA-actin exodus and subsequent DA-actin re-entry in dendritic spines, (2 Ca(2+ influx through NMDA receptors regulates the exodus and the basal accumulation of DA-actin, and (3 the DA-actin exodus is blocked by myosin II ATPase inhibitor, but is not blocked by myosin light chain kinase (MLCK or Rho-associated kinase (ROCK inhibitors. These results indicate that myosin II mediates the interaction between NMDA receptor activation and DA-actin exodus in LTP induction. Furthermore, myosin II seems to be activated by a rapid actin-linked mechanism rather than slow MLC phosphorylation. Thus the myosin-II mediated DA-actin exodus might be an initial event in LTP induction, triggering actin polymerization and spine enlargement.
Mercury as the Unaccreted Projectile: Thermal Consequences
Asphaug, Erik; Gabriel, Travis; Jackson, Alan; Perera, Viranga
2017-10-01
Mercury retained substantial volatiles during its formation, in far greater proportion than the Moon, despite losing ~2/3 of its rocky mantle. Its volatile-rich geochemistry would contraindicate a giant impact because it would drive away the volatiles, as in the hypothesis for the Moon. However, the thermal consequences of Mercury formation vary considerably between the two giant impact scenarios, ‘direct hit’ (DH; Benz et al. 1989) and ‘hit and run’ (HR; Asphaug and Reufer 2014). Each begins with a differentiated chondritic proto-Mercury (PM) a bit larger than Mars. In DH, PM gets eroded by a very energetic impactor half its mass, at ~6-7 times the escape velocity. To remove half of PM’s mantle, the post-impact target gets completely shock-vaporized and is sheared apart into space. The bound remnant in DH would experience a comparable deposition of shock enthalpy, as in Moon formation, and would expand into a much larger volume of heliocentric space, leading to a dry planet. The bound remnant will go on to re-accrete much of the silicate mantle that it just lost, another challenge for DH. In HR, PM is the projectile that slams into a terrestrial planet twice its size (proto-Venus or proto-Earth). For typical impact angle and speed, a typical outcome is to ‘bounce”. But for HR to explain Mercury, PM must avoid accretion every time it encounters the target, until it is scattered or migrates away (or is accreted, in which case there is no Mercury), leading to multi-HR scenarios. Tides are intense in HR because the projectile grazes the target core; gravity does most of the work of mantle stripping. Shocks play a secondary role. Whereas in DH the impactor blasts the target inside-out, in HR the runner emerges relatively unshocked, and undispersed except for losing the gravitationally-unbound material. HR is a mechanism for collecting low-shocked remnants, because the intensely shocked material ends up bound to the target or escaping to heliocentric space
An Experiment on Projectile Motion
Indian Academy of Sciences (India)
IAS Admin
reading is taken, the reset switch is pressed for taking the next reading. The photogates (attached to launcher and the contact sensor pad) are connected to the microcontroller through USB ports. The timer can also be used in simple pendulum and free fall experiments. In this article, only the projectile motion experiment.
Projectile Motion Gets the Hose
Goff, John Eric; Liyanage, Chinthaka
2011-01-01
Students take a weekly quiz in our introductory physics course. During the week in which material focused on projectile motion, we not-so-subtly suggested what problem the students would see on the quiz. The quiz problem was an almost exact replica of a homework problem we worked through in the class preceding the quiz. The goal of the problem is…
Novice Rules for Projectile Motion.
Maloney, David P.
1988-01-01
Investigates several aspects of undergraduate students' rules for projectile motion including general patterns; rules for questions about time, distance, solids and liquids; and changes in rules when asked to ignore air resistance. Reports approach differences by sex and high school physics experience, and that novice rules are situation…
On projectiles, missiles and history
Strnad, J.
2002-05-01
The trajectories of projectiles are easily calculated and the way to the trajectories of intercontinental ballistic missiles is only a little more demanding. The first can be considered as limiting cases of the second. However, at the beginning of physics the two cases were taken as completely unrelated.
Wind-influenced projectile motion
Bernardo, Reginald Christian; Perico Esguerra, Jose; Day Vallejos, Jazmine; Jerard Canda, Jeff
2015-03-01
We solved the wind-influenced projectile motion problem with the same initial and final heights and obtained exact analytical expressions for the shape of the trajectory, range, maximum height, time of flight, time of ascent, and time of descent with the help of the Lambert W function. It turns out that the range and maximum horizontal displacement are not always equal. When launched at a critical angle, the projectile will return to its starting position. It turns out that a launch angle of 90° maximizes the time of flight, time of ascent, time of descent, and maximum height and that the launch angle corresponding to maximum range can be obtained by solving a transcendental equation. Finally, we expressed in a parametric equation the locus of points corresponding to maximum heights for projectiles launched from the ground with the same initial speed in all directions. We used the results to estimate how much a moderate wind can modify a golf ball’s range and suggested other possible applications.
Sequential injection gas guns for accelerating projectiles
Lacy, Jeffrey M [Idaho Falls, ID; Chu, Henry S [Idaho Falls, ID; Novascone, Stephen R [Idaho Falls, ID
2011-11-15
Gas guns and methods for accelerating projectiles through such gas guns are described. More particularly, gas guns having a first injection port located proximate a breech end of a barrel and a second injection port located longitudinally between the first injection port and a muzzle end of the barrel are described. Additionally, modular gas guns that include a plurality of modules are described, wherein each module may include a barrel segment having one or more longitudinally spaced injection ports. Also, methods of accelerating a projectile through a gas gun, such as injecting a first pressurized gas into a barrel through a first injection port to accelerate the projectile and propel the projectile down the barrel past a second injection port and injecting a second pressurized gas into the barrel through the second injection port after passage of the projectile and to further accelerate the projectile are described.
Projectile Balloting Attributable to Gun Tube Curvature
Directory of Open Access Journals (Sweden)
Michael M. Chen
2010-01-01
Full Text Available Transverse motion of a projectile during launch is detrimental to firing accuracy, structural integrity, and/or on-board electronics performance of the projectile. One manifest contributing factor to the undesired motion is imperfect bore centerline straightness. This paper starts with the presentation of a deterministic barrel model that possesses both vertical and lateral deviations from centerline in accordance with measurement data, followed by a novel approach to simulating comprehensive barrel centerline variations for the investigation of projectile balloting^1 motions. A modern projectile was adopted for this study. In-bore projectile responses at various locations of the projectile while traveling through the simulated gun tubes were obtained. The balloting was evaluated in both time and frequency domains. Some statistical quantities and the significance were outlined.
Embolism of high energy firearm projectile
Directory of Open Access Journals (Sweden)
Jaime Álvarez Soler
2016-12-01
Full Text Available The embolism of a projectile is very rare and out of the normal context, so the cor-oner in front of a wound projectile firearm must make a very judicious and careful analysis to recover the projectile and/or its fragments. This case presents evidence how modern military high-velocity weapons have a high kinetic energy which is transferred to body tissues, so including their fragments and parts of the projectile can cause serious injury and embolism, requiring a great effort scientific and in-terdisciplinary to give technical support to justice.
Graphical Method for Determining Projectile Trajectory
Moore, J. C.; Baker, J. C.; Franzel, L.; McMahon, D.; Songer, D.
2010-01-01
We present a nontrigonometric graphical method for predicting the trajectory of a projectile when the angle and initial velocity are known. Students enrolled in a general education conceptual physics course typically have weak backgrounds in trigonometry, making inaccessible the standard analytical calculation of projectile range. Furthermore,…
El khissiin, A; Leclercq, G
1998-11-01
Estrogens and antiestrogens promote specific conformations of the estrogen receptor (ER). To analyze the influence of such configurations on the stability of the ligand-ER complexes, MCF-7 breast cancer cells were exposed for 1 h to either [3H]E2 or an unlabeled estrogen or antiestrogen (E2, DES, E1, BP; OH-Tam, RU 39,411, ICI 164,384, RU 58,668); mutual exchange rates of bound compounds (i.e., [3H]E2-->ligand; ligand-->[3H]E2) were then analyzed in cell extracts by measuring [3H]E2. Addition of cycloheximide (CHX) to the incubation medium eliminated the potential interference of E2-induced ER loss. Extracts from control untreated cells were labeled with [3H]E2 or one of these various ligands and similarly submitted to exchange. Displacement of bound compounds occurred at moderate temperature (18 degrees C) but not at 4 degrees C. Remarkably, exchange proceeded at a lower rate in extracts from cells preincubated with [3H]E2 or a ligand. Antiestrogens RU 39,411 and RU 58,668 appeared especially refractory to displacement. Such low exchange rates were also recorded in experiments conducted on whole cells although to a higher extent than in extracts from preincubated cells. Enzyme immunoassays demonstrated that absence of major exchange could not be attributed to ER loss. Moreover, displacement of bound ligands appeared independent of their binding affinity for the receptor. These data suggest that estrogen and antiestrogen binding is stabilized by at least one factor (coactivators or corepressors) thus fixing the receptor molecules in a configuration that is relatively resistant to subsequent exchange. FPLC and PgR induction revealed that a significant proportion of ER maintained in a sufficiently flexible status was still able to exchange and transduce the transcriptional message of the displacer ligand.
Isospin-dependent multifragmentation of relativistic projectiles
Ogul, R.; Botvina, A. S.; Atav, U.; Buyukcizmeci, N.; Mishustin, I. N.; Adrich, P.; Aumann, T.; Bacri, C. O.; Barczyk, T.; Bassini, R.; Bianchin, S.; Boiano, C.; Boudard, A.; Brzychczyk, J.; Chbihi, A.; Cibor, J.; Czech, B.; de Napoli, M.; Ducret, J.-É.; Emling, H.; Frankland, J. D.; Hellström, M.; Henzlova, D.; Immè, G.; Iori, I.; Johansson, H.; Kezzar, K.; Lafriakh, A.; Le Fèvre, A.; Le Gentil, E.; Leifels, Y.; Lühning, J.; Łukasik, J.; Lynch, W. G.; Lynen, U.; Majka, Z.; Mocko, M.; Müller, W. F. J.; Mykulyak, A.; Orth, H.; Otte, A. N.; Palit, R.; Pawłowski, P.; Pullia, A.; Raciti, G.; Rapisarda, E.; Sann, H.; Schwarz, C.; Sfienti, C.; Simon, H.; Sümmerer, K.; Trautmann, W.; Tsang, M. B.; Verde, G.; Volant, C.; Wallace, M.; Weick, H.; Wiechula, J.; Wieloch, A.; Zwiegliński, B.
2011-02-01
The N/Z dependence of projectile fragmentation at relativistic energies has been studied with the ALADIN forward spectrometer at the GSI Schwerionen Synchrotron (SIS). Stable and radioactive Sn and La beams with an incident energy of 600 MeV per nucleon have been used in order to explore a wide range of isotopic compositions. For the interpretation of the data, calculations with the statistical multifragmentation model for a properly chosen ensemble of excited sources were performed. The parameters of the ensemble, representing the variety of excited spectator nuclei expected in a participant-spectator scenario, are determined empirically by searching for an optimum reproduction of the measured fragment-charge distributions and correlations. An overall very good agreement is obtained. The possible modification of the liquid-drop parameters of the fragment description in the hot freeze-out environment is studied, and a significant reduction of the symmetry-term coefficient is found necessary to reproduce the mean neutron-to-proton ratios /Z and the isoscaling parameters of Z⩽10 fragments. The calculations are, furthermore, used to address open questions regarding the modification of the surface-term coefficient at freeze-out, the N/Z dependence of the nuclear caloric curve, and the isotopic evolution of the spectator system between its formation during the initial cascade stage of the reaction and its subsequent breakup.
Projectile orientation measurement during flight and just before impact
Carton, E.P.; Diederen, A.M.
2016-01-01
The angle between the line-of-fire and the rotation axis of a projectile is called the yaw angle. For fin and spin stabilized projectiles the yaw angle changes continuously during flight. Normally the yaw of a projectile is measured by orthogonal flash imaging of the projectile. However, this method
Penetration of fast projectiles into resistant media: From macroscopic to subatomic projectiles
Gaite, José
2017-09-01
The penetration of a fast projectile into a resistant medium is a complex process that is suitable for simple modeling, in which basic physical principles can be profitably employed. This study connects two different domains: the fast motion of macroscopic bodies in resistant media and the interaction of charged subatomic particles with matter at high energies, which furnish the two limit cases of the problem of penetrating projectiles of different sizes. These limit cases actually have overlapping applications; for example, in space physics and technology. The intermediate or mesoscopic domain finds application in atom cluster implantation technology. Here it is shown that the penetration of fast nano-projectiles is ruled by a slightly modified Newton's inertial quadratic force, namely, F ∼v 2 - β, where β vanishes as the inverse of projectile diameter. Factors essential to penetration depth are ratio of projectile to medium density and projectile shape.
National Research Council Canada - National Science Library
Ballester Pla, Coralio; Hernández, Penélope
2012-01-01
The observation of the actual behavior by economic decision makers in the lab and in the field justifies that bounded rationality has been a generally accepted assumption in many socio-economic models...
Gutiérrez-Rodríguez, A
2003-01-01
A bound on the nu /sup tau / magnetic moment is calculated through the reaction e/sup +/e/sup -/ to nu nu gamma at the Z/sub 1/-pole, and in the framework of a left-right symmetric model at LEP energies. We find that the bound is almost independent of the mixing angle phi of the model in the allowed experimental range for this parameter. (31 refs).
The representational dynamics of remembered projectile locations.
De Sá Teixeira, Nuno Alexandre; Hecht, Heiko; Oliveira, Armando Mónica
2013-12-01
When people are instructed to locate the vanishing location of a moving target, systematic errors forward in the direction of motion (M-displacement) and downward in the direction of gravity (O-displacement) are found. These phenomena came to be linked with the notion that physical invariants are embedded in the dynamic representations generated by the perceptual system. We explore the nature of these invariants that determine the representational mechanics of projectiles. By manipulating the retention intervals between the target's disappearance and the participant's responses, while measuring both M- and O-displacements, we were able to uncover a representational analogue of the trajectory of a projectile. The outcomes of three experiments revealed that the shape of this trajectory is discontinuous. Although the horizontal component of such trajectory can be accounted for by perceptual and oculomotor factors, its vertical component cannot. Taken together, the outcomes support an internalization of gravity in the visual representation of projectiles.
Additional Crime Scenes for Projectile Motion Unit
Fullerton, Dan; Bonner, David
2011-12-01
Building students' ability to transfer physics fundamentals to real-world applications establishes a deeper understanding of underlying concepts while enhancing student interest. Forensic science offers a great opportunity for students to apply physics to highly engaging, real-world contexts. Integrating these opportunities into inquiry-based problem solving in a team environment provides a terrific backdrop for fostering communication, analysis, and critical thinking skills. One such activity, inspired jointly by the museum exhibit "CSI: The Experience"2 and David Bonner's TPT article "Increasing Student Engagement and Enthusiasm: A Projectile Motion Crime Scene,"3 provides students with three different crime scenes, each requiring an analysis of projectile motion. In this lesson students socially engage in higher-order analysis of two-dimensional projectile motion problems by collecting information from 3-D scale models and collaborating with one another on its interpretation, in addition to diagramming and mathematical analysis typical to problem solving in physics.
Grenade launched imaging projectile system (GLIMPS)
Nunan, Scott C.; Coakley, Peter G.; Niederhaus, Gregory A.; Mallon, Charles E.; Vasel, Edward; Denson, Raymond; Lutjens, Steve; Wild, Norbert C.; Wondra, John
1999-07-01
A system has been developed for delivering and attaching a sensor payload to a target using a standard 40-mm grenade launcher. The projectile flight characteristics are similar to existing 40-mm rounds, with a useful range of up to 300 m. The projectile incorporates an attachment mechanism, a shock mitigation system, a power source, and a transmitter that allows sensor data to be transmitted to a receiver at up to 1/4 mile range. Impact g-loads have been limited to less than 10,000 g's, enabling sensor payloads to be assembled using Commercial Off-The-Shelf components. The GLIMPS projectile is intended to be a general purpose delivery system for a variety of sensor payloads under the Unattended Ground Sensors program, with Phase I proof-of- concept being demonstrated using a low-power CMOS camera.
Grenade-launched imaging projectile system (GLIMPS)
Nunan, Scott C.; Coakley, Peter G.; Niederhaus, Gregory A.; Lum, Chris
2001-09-01
A system has been developed for delivering and attaching a sensor payload to a target using a standard 40-mm grenade launcher. The projectile incorporates an attachment mechanism, a shock mitigation system, a power source, and a video-bandwidth transmitter. Impact and launch g-loads have been limited to less than 10,000 g's, enabling sensor payloads to be assembled using Commercial Off-The-Shelf components. The GLIMPS projectile is intended to be a general-purpose delivery system for a variety of sensor payloads under the Unattended Ground Sensors program. Test results and development issues are presented.
Energy Technology Data Exchange (ETDEWEB)
Rabern, D.A.
1991-12-31
Three-dimensional numerical simulations were performed to determine the effect of an asymmetric base pressure on kinetic energy projectiles during launch. A matrix of simulations was performed in two separate launch environments. One launch environment represented a severe lateral load environment, while the other represented a nonsevere lateral load environment based on the gun tube straightness. The orientation of the asymmetric pressure field, its duration, the projectile`s initial position, and the tube straightness were altered to determine the effects of each parameter. The pressure asymmetry translates down the launch tube to exit parameters and is washed out by tube profile. Results from the matrix of simulations are presented.
High School Students' Understanding of Projectile Motion Concepts
Dilber, Refik; Karaman, Ibrahim; Duzgun, Bahattin
2009-01-01
The aim of this study was to investigate the effectiveness of conceptual change-based instruction and traditionally designed physics instruction on students' understanding of projectile motion concepts. Misconceptions related to projectile motion concepts were determined by related literature on this subject. Accordingly, the Projectile Motion…
A note on stability of motion of a projectile
Indian Academy of Sciences (India)
A projectile is stabilised using either gyroscopic or aerodynamic stability. But subcalibre projectiles with sabot have both spin and ﬁns. Separate stability criteria are researched generally for each type of projectile. In this paper a stability criterion which can be used for all such bodies has been developed through the ...
Ballistics projectile image analysis for firearm identification.
Li, Dongguang
2006-10-01
This paper is based upon the observation that, when a bullet is fired, it creates characteristic markings on the cartridge case and projectile. From these markings, over 30 different features can be distinguished, which, in combination, produce a "fingerprint" for a firearm. By analyzing features within such a set of firearm fingerprints, it will be possible to identify not only the type and model of a firearm, but also each and every individual weapon just as effectively as human fingerprint identification. A new analytic system based on the fast Fourier transform for identifying projectile specimens by the line-scan imaging technique is proposed in this paper. This paper develops optical, photonic, and mechanical techniques to map the topography of the surfaces of forensic projectiles for the purpose of identification. Experiments discussed in this paper are performed on images acquired from 16 various weapons. Experimental results show that the proposed system can be used for firearm identification efficiently and precisely through digitizing and analyzing the fired projectiles specimens.
Comment on "The envelope of projectile trajectories"
Butikov, E I
2003-01-01
Several simple alternative methods to obtain the equation of the envelope of the family of projectile trajectories corresponding to the same initial speed are suggested, including methods in which the boundary of the region occupied by the parabolic trajectories is found as an envelope of a set of circles. Two possible generalizations of the discussed problem are also suggested. (letters and comments)
Bulldozing Your Way Through Projectile Motion.
Lamb, William G.
1983-01-01
Presents two models and two demonstrations targeted at student understanding of projectile motion as the sum of two independent, perpendicular vectors. Describes materials required, construction, and procedures used. Includes a discussion of teaching points appropriate to each demonstration or model. (JM)
Cambodian students’ prior knowledge of projectile motion
Piten, S.; Rakkapao, S.; Prasitpong, S.
2017-09-01
Students always bring intuitive ideas about physics into classes, which can impact what they learn and how successful they are. To examine what Cambodian students think about projectile motion, we have developed seven open-ended questions and applied into grade 11 students before (N=124) and after (N=131) conventional classes. Results revealed several consistent misconceptions, for instance, many students believed that the direction of a velocity vector of a projectile follows the curved path at every position. They also thought the direction of an acceleration (or a force) follows the direction of motion. Observed by a pilot sitting on the plane, the falling object, dropped from a plane moving at a constant initial horizontal speed, would travel backward and land after the point of its release. The greater angle of the launched projectile creates the greater horizontal range. The hand force imparted with the ball leads the ball goes straight to hit the target. The acceleration direction points from the higher position to lower position. The misconceptions will be used as primary resources to develop instructional instruments to promote Cambodian students’ understanding of projectile motion in the following work.
Teaching Projectile Motion to Eliminate Misconceptions
Prescott, Anne; Mitchelmore, Michael
2005-01-01
Student misconceptions of projectile motion are well documented, but their effect on the teaching and learning of the mathematics of motion under gravity has not been investigated. An experimental unit was designed that was intended to confront and eliminate misconceptions in senior secondary school students. The approach was found to be…
An Inexpensive Mechanical Model for Projectile Motion
Kagan, David
2011-01-01
As experienced physicists, we see the beauty and simplicity of projectile motion. It is merely the superposition of uniform linear motion along the direction of the initial velocity vector and the downward motion due to the constant acceleration of gravity. We see the kinematic equations as just the mathematical machinery to perform the…
Speed, Acceleration, Chameleons and Cherry Pit Projectiles
Planinsic, Gorazd; Likar, Andrej
2012-01-01
The paper describes the mechanics of cherry pit projectiles and ends with showing the similarity between cherry pit launching and chameleon tongue projecting mechanisms. The whole story is written as an investigation, following steps that resemble those typically taken by scientists and can therefore serve as an illustration of scientific…
Fatal lawn mower related projectile injury
DEFF Research Database (Denmark)
Colville-Ebeling, Bonnie; Lynnerup, Niels; Banner, Jytte
2014-01-01
the operator or a bystander is impacted by an object mobilized from the grass by the rotating mower blades. This type of injury often leaves only modest external trauma, which increases the risk of overlooking an entry wound. In this paper we present a case of a fatal lawn mower related projectile injury which...
In-flight dynamics of volcanic ballistic projectiles
Taddeucci, J.; Alatorre-Ibargüengoitia, M. A.; Cruz-Vázquez, O.; Del Bello, E.; Scarlato, P.; Ricci, T.
2017-09-01
Centimeter to meter-sized volcanic ballistic projectiles from explosive eruptions jeopardize people and properties kilometers from the volcano, but they also provide information about the past eruptions. Traditionally, projectile trajectory is modeled using simplified ballistic theory, accounting for gravity and drag forces only and assuming simply shaped projectiles free moving through air. Recently, collisions between projectiles and interactions with plumes are starting to be considered. Besides theory, experimental studies and field mapping have so far dominated volcanic projectile research, with only limited observations. High-speed, high-definition imaging now offers a new spatial and temporal scale of observation that we use to illuminate projectile dynamics. In-flight collisions commonly affect the size, shape, trajectory, and rotation of projectiles according to both projectile nature (ductile bomb versus brittle block) and the location and timing of collisions. These, in turn, are controlled by ejection pulses occurring at the vent. In-flight tearing and fragmentation characterize large bombs, which often break on landing, both factors concurring to decrease the average grain size of the resulting deposits. Complex rotation and spinning are ubiquitous features of projectiles, and the related Magnus effect may deviate projectile trajectory by tens of degrees. A new relationship is derived, linking projectile velocity and size with the size of the resulting impact crater. Finally, apparent drag coefficient values, obtained for selected projectiles, mostly range from 1 to 7, higher than expected, reflecting complex projectile dynamics. These new perspectives will impact projectile hazard mitigation and the interpretation of projectile deposits from past eruptions, both on Earth and on other planets.
Initiation of Gaseous Detonation by Conical Projectiles
Verreault, Jimmy
Initiation and stabilization of detonation by hypersonic conical projectiles launched into combustible gas mixtures is investigated. This phenomenon must be understood for the design and optimization of specific hypersonic propulsion devices, such as the oblique detonation wave engine and the ram accelerator. The criteria for detonation initiation by a projectile is also related to fundamental aspects of detonation research, such as the requirement for direct initiation of a detonation by a blast wave. Experimental results of this problem also offer useful references for validation of numerical and theoretical modeling. Projectiles with cone half angles varying from 15° to 60° were launched into stoichiometric mixtures of hydrogen/oxygen with 70% argon dilution at initial pressures between 10 and 200 kPa. The projectiles were launched from a combustion-driven gas gun at velocities up to 2.2 km/s (corresponding to 133% of the Chapman Jouguet velocity). Pictures of the flowfields generated by the projectiles were taken via Schlieren photography. Five combustion regimes were observed about the projectile ranging from prompt and delayed oblique detonation wave formation, combustion instabilities, a wave splitting, and an inert shock wave. Two types of transition from the prompt oblique detonation wave regime to the inert shock regime were observed. The first (the delayed oblique detonation wave regime) showed an inert shock attached to the tip of the projectile followed by a sharp kink at the onset of an oblique detonation wave; this regime occurred by decreasing the cone angle at high mixture pressures. The second (the combustion instabilities regime) exhibited large density gradients due to combustion ignition and quenching phenomena; this regime occurred by decreasing the mixture pressure at large cone angles. A number of theoretical models were considered to predict critical conditions for the initiation of oblique detonations. The Lee-Vasiljev model agreed
Electrical parameters of projectile stun guns.
McDaniel, Wayne C; Benwell, Andrew; Kovaleski, Scott
2009-01-01
Projectile stun guns have been developed as less-lethal devices that law enforcement officers can use to control potentially violent subjects, as an alternative to using firearms. These devices apply high voltage, low amperage, pulsatile electric shocks to the subject, which causes involuntary skeletal muscle contraction and renders the subject unable to further resist. In field use of these devices, the electric shock is often applied to the thorax, which raises the issue of cardiac safety of these devices. An important determinant of the cardiac safety of these devices is their electrical output. Here the outputs of three commercially available projectile stun guns were evaluated with a resistive load and in a human-sized animal model (a 72 kg pig).
Predicting the Accuracy of Unguided Artillery Projectiles
2016-09-01
would be the exact opposite if the projectile is fired into the southern hemisphere . This effect is depicted in Figure 15. Although it affects the...firing ranges. The model is able to take into account wind effects and varying levels of meteorological data staleness. The developed program is...firing table’s ballistic partials for typical firing ranges. The model is able to take into account wind effects and varying levels of meteorological data
Batch Computed Tomography Analysis of Projectiles
2016-05-01
for public release; distribution is unlimited. 1 1. Introduction The Russian 14.5-mm heavy machine gun is a threat encountered globally. The 14.5...replaced with an inert SiO2 powder filler. As part of an armor ceramic qualification testing campaign, Chesapeake Testing imaged (210) projectiles...indicated by high-value striping, or lines spanning the entire plot, meaning there is high-dissimilarity intersection with all tiles (e.g
Migration spontanee de projectile intracranien: presentation clinique ...
African Journals Online (AJOL)
Les traumatismes crâniens par arme à feu sont graves. Les manifestations cliniques sont variables et peuvent présenter quelques particularités. Les auteurs rapportent un cas de migration spontané de projectile intracérébral survenue après un traumatisme crânien par arme à feu au cours d'une partie de chasse. Elle a été ...
Intuitive Mechanics: Inferences of Vertical Projectile Motion
Directory of Open Access Journals (Sweden)
Milana Damjenić
2016-07-01
Full Text Available Our intuitive knowledge of physics mechanics, i.e. knowledge defined through personal experience about velocity, acceleration, motion causes, etc., is often wrong. This research examined whether similar misconceptions occur systematically in the case of vertical projectiles launched upwards. The first experiment examined inferences of velocity and acceleration of the ball moving vertically upwards, while the second experiment examined whether the mass of the thrown ball and force of the throw have an impact on the inference. The results showed that more than three quarters of the participants wrongly assumed that maximum velocity and peak acceleration did not occur at the initial launch of the projectile. There was no effect of object mass or effect of the force of the throw on the inference relating to the velocity and acceleration of the ball. The results exceed the explanatory reach of the impetus theory, most commonly used to explain the naive understanding of the mechanics of object motion. This research supports that the actions on objects approach and the property transmission heuristics may more aptly explain the dissidence between perceived and actual implications in projectile motion.
Energy Technology Data Exchange (ETDEWEB)
Rabern, D.A.
1991-01-01
Three-dimensional numerical simulations were performed to determine the effect of an asymmetric base pressure on kinetic energy projectiles during launch. A matrix of simulations was performed in two separate launch environments. One launch environment represented a severe lateral load environment, while the other represented a nonsevere lateral load environment based on the gun tube straightness. The orientation of the asymmetric pressure field, its duration, the projectile's initial position, and the tube straightness were altered to determine the effects of each parameter. The pressure asymmetry translates down the launch tube to exit parameters and is washed out by tube profile. Results from the matrix of simulations are presented.
Optimal design for projectile and blast protection during pressure testing
Storhaug, Eirik
2016-01-01
The thesis identifies the main hazards in hydrostatic pressure testing as pressure wave, water jet, burst of water hose, fragment and projectile discharge as well as ejection of plug or end section. A test, where a pressurized vessel ejected a projectile, was conducted as part of the thesis. The aim of this test was to find the relationship between potential energy inside pressure vessel and kinetic energy in a discharged projectile. The results showed that the Baker formula together with...
Visualization of Projectile Flying at High Speed in Dusty Atmosphere
Masaki, Chihiro; Watanabe, Yasumasa; Suzuki, Kojiro
2017-10-01
Considering a spacecraft that encounters particle-laden environment, such as dust particles flying up over the regolith by the jet of the landing thruster, high-speed flight of a projectile in such environment was experimentally simulated by using the ballistic range. At high-speed collision of particles on the projectile surface, they may be reflected with cracking into smaller pieces. On the other hand, the projectile surface will be damaged by the collision. To obtain the fundamental characteristics of such complicated phenomena, a projectile was launched at the velocity up to 400 m/s and the collective behaviour of particles around projectile was observed by the high-speed camera. To eliminate the effect of the gas-particle interaction and to focus on only the effect of the interaction between the particles and the projectile's surface, the test chamber pressure was evacuated down to 30 Pa. The particles about 400μm diameter were scattered and formed a sheet of particles in the test chamber by using two-dimensional funnel with a narrow slit. The projectile was launched into the particle sheet in the tangential direction, and the high-speed camera captured both projectile and particle motions. From the movie, the interaction between the projectile and particle sheet was clarified.
Directory of Open Access Journals (Sweden)
Ballester Pla, Coralio
2012-03-01
Full Text Available The observation of the actual behavior by economic decision makers in the lab and in the field justifies that bounded rationality has been a generally accepted assumption in many socio-economic models. The goal of this paper is to illustrate the difficulties involved in providing a correct definition of what a rational (or irrational agent is. In this paper we describe two frameworks that employ different approaches for analyzing bounded rationality. The first is a spatial segregation set-up that encompasses two optimization methodologies: backward induction and forward induction. The main result is that, even under the same state of knowledge, rational and non-rational agents may match their actions. The second framework elaborates on the relationship between irrationality and informational restrictions. We use the beauty contest (Nagel, 1995 as a device to explain this relationship.
La observación del comportamiento de los agentes económicos tanto en el laboratorio como en la vida real justifica que la racionalidad acotada sea un supuesto aceptado en numerosos modelos socio-económicos. El objetivo de este artículo es ilustrar las dificultades que conlleva una correcta definición de qué es un agente racional (irracional. En este artículo se describen dos marcos que emplean diferentes metodologías para analizar la racionalidad acotada. El primero es un modelo de segregación espacial donde se contrastan dos metodologías de optimización: inducción hacia atrás y hacia adelante. El resultado principal es que, incluso con el mismo nivel de conocimiento, tanto agentes racionales como irracionales podrían coincidir en sus acciones. El segundo marco trabaja sobre la relación entre irracionalidad y restricción de información. Se utiliza el juego llamado “beauty contest” (Nagel 1995 como mecanismo para explicar dicha relación.
Projectile fragmentation wall for CHICSi detector
Budzanowski, A; Siwek, A; Skwirczynska, I; Staszel, P
2002-01-01
The Forward Wall Detector (FWD) is designed to identify projectile-like fragments from heavy-ion reactions at the CELSIUS storage ring in Uppsala, Sweden. FWD covers the polar angle from 3.9 deg. to 11.7 deg. with geometrical efficiency of 81%. The single-detection module can be either of phoswich type (10 mm fast plastic+80 mm CsI(Tl)) or DELTA E-E telescope (750 mu m Si + 80 mm CsI(Tl)). It is expected to have charge identification up to Z=18 and mass resolution for H and He isotopes.
Corrected Launch Speed for a Projectile Motion Laboratory
Sanders, Justin M.; Boleman, Michael W.
2013-01-01
At our university, students in introductory physics classes perform a laboratory exercise to measure the range of a projectile fired at an assigned angle. A set of photogates is used to determine the initial velocity of the projectile (the launch velocity). We noticed a systematic deviation between the experimentally measured range and the range…
Commissioning the A1900 projectile fragment separator
Morrissey, D J; Steiner, M; Stolz, A; Wiedenhöver, I
2003-01-01
An important part of the recent upgrade of the NSCL facility is the replacement of the A1200 fragment separator with a new high acceptance device called the A1900. The design of the A1900 device represents a third generation projectile fragment separator (relative to the early work at LBL) as it is situated immediately after the primary accelerator, has a very large acceptance, a bending power significantly larger than that of the cyclotron and is constructed from large superconducting magnets (quadrupoles with 20 and 40 cm diameter warm bores). The A1900 can accept over 90% of a large range of projectile fragmentation products produced at the NSCL, leading to large gains in the intensity of the secondary beams. The results of initial tests of the system with a restricted momentum acceptance (+-0.5%) indicate that the A1900 is performing up to specifications. Further large gains in the intensities of primary beams, typically two or three orders of magnitude, will be possible as the many facets of high current...
Directory of Open Access Journals (Sweden)
Jan Kucera
1990-01-01
Full Text Available It is proved in [1] & [2] that a set bounded in an inductive limit E=indlim En of Fréchet spaces is also bounded in some En iff E is fast complete. In the case of arbitrary locally convex spaces En every bounded set in a fast complete indlim En is quasi-bounded in some En, though it may not be bounded or even contained in any En. Every bounded set is quasi-bounded. In a Fréchet space every quasi-bounded set is also bounded.
Trajectory Control of Small Rotating Projectiles by Laser Sparks
Starikovskiy, Andrey; Limbach, Christopher; Miles, Richard
2015-09-01
The possibility of controlling the trajectory of the supersonic motion of a rotating axisymmetric projectile using a remotely generated laser spark was investigated. The dynamic images of the interaction of thermal inhomogeneity created by the laser spark with the bow shock in front of the projectile were obtained. The criterion for a strong shock wave interaction with the thermal inhomogeneity at different angles of a shock wave was derived. Significant changes in the configuration of the bow shock wave and changes in the pressure distribution over the surface of the rotating projectile can appear for laser spark temperature of T' = 2500-3000 K. The experiment showed that strong interaction takes place for both plane and oblique shock waves. The measurement of the velocity of the precession of the rotating projectile axis from the initial position in time showed that the angle of attack of the projectile deviates with a typical time of perturbation propagation along the projectile's surface. Thus the laser spark can change the trajectory of the rotating projectile, moving at supersonic speed, through the creation of thermal heterogeneity in front of it.
Veterinary Forensics: Firearms and Investigation of Projectile Injury.
Bradley-Siemens, N; Brower, A I
2016-09-01
Projectile injury represents an estimated 14% of reported animal cruelty cases in the United States. Cases involving projectiles are complicated by gross similarities to other common types of injury, including bite wounds and motor vehicle injuries, by weapons and ammunition not commonly recognized or understood by veterinary medical professionals, and by required expertise beyond that employed in routine postmortem examination. This review describes the common types of projectile injuries encountered within the United States, as well as firearms and ammunition associated with this form of injury. The 3 stages of ballistics-internal, external, and terminal-and wounding capacity are discussed. A general understanding of firearms, ammunition, and ballistics is necessary before pursuing forensic projectile cases. The forensic necropsy is described, including gunshot wound examination, projectile trajectories, different imaging procedures, collection and storage of projectile evidence, and potential advanced techniques for gunpowder analysis. This review presents aspects of projectile injury investigation that must be considered in tandem with standard postmortem practices and procedures to ensure reliable conclusions are reached for medicolegal as well as diagnostic purposes. © The Author(s) 2016.
Stable rotating dipole solitons in nonlocal media
DEFF Research Database (Denmark)
Lopez-Aguayo, Servando; Skupin, Stefan; Desyatnikov, Anton S.
2006-01-01
We present the first example of stable rotating two-soliton bound states in nonlinear optical media with nonlocal response. We show that, in contrast to media with local response, nonlocality opens possibilities to generate stable azimuthons.......We present the first example of stable rotating two-soliton bound states in nonlinear optical media with nonlocal response. We show that, in contrast to media with local response, nonlocality opens possibilities to generate stable azimuthons....
Dynamic impact analysis of the M1 105mm projectile
Energy Technology Data Exchange (ETDEWEB)
Walls, J.C.; Webb, D.S.
1993-06-01
Evaluation of the effects of {open_quotes}rough-handling{close_quotes}-induced stresses in the nose region of a 105mm artillery projectile was performed to determine if these stresses could have contributed to the premature explosion of a projectile during a Desert Shield training mission of the 101st Army Airborne in Saudi Arabia. The rough-handling evaluations were simulated by dynamic impact analysis. It was concluded that the combined residual stress and dynamic impact-induced stress would not be of sufficient magnitude to cause cracking of the projectile in the nose region.
Dynamic impact analysis of the M1 105mm projectile
Energy Technology Data Exchange (ETDEWEB)
Walls, J.C.; Webb, D.S.
1993-06-01
Evaluation of the effects of [open quotes]rough-handling[close quotes]-induced stresses in the nose region of a 105mm artillery projectile was performed to determine if these stresses could have contributed to the premature explosion of a projectile during a Desert Shield training mission of the 101st Army Airborne in Saudi Arabia. The rough-handling evaluations were simulated by dynamic impact analysis. It was concluded that the combined residual stress and dynamic impact-induced stress would not be of sufficient magnitude to cause cracking of the projectile in the nose region.
Energy Technology Data Exchange (ETDEWEB)
Caliebe, D.; Arp, O.; Piel, A. [Institut fuer Experimentelle und Angewandte Physik, Christian-Albrechts-Universitaet, Kiel (Germany)
2011-07-15
The penetration of a dusty plasma by fast charged projectiles is studied under microgravity conditions. The mass and charge of the projectiles are larger than those of the target particles. A projectile generates a dust-free cavity in its wake, whose shape strongly depends on the projectile velocity. The faster the projectile the more elongated becomes the cavity while its cross-section decreases. The opening time of the cavity is found independent of the projectile velocity. For supersonic projectiles, the dynamics of the cavity can be decomposed into an initial impulse and a subsequent elastic response that can be modeled by a damped harmonic oscillator.
Penetration analysis of projectile with inclined concrete target
Directory of Open Access Journals (Sweden)
Kim S.B.
2015-01-01
Full Text Available This paper presents numerical analysis result of projectile penetration with concrete target. We applied dynamic material properties of 4340 steels, aluminium and explosive for projectile body. Dynamic material properties were measured with static tensile testing machine and Hopkinson pressure bar tests. Moreover, we used three concrete damage models included in LS-DYNA 3D, such as SOIL_CONCRETE, CSCM (cap model with smooth interaction and CONCRETE_DAMAGE (K&C concrete models. Strain rate effect for concrete material is important to predict the fracture deformation and shape of concrete, and penetration depth for projectiles. CONCRETE_DAMAGE model with strain rate effect also applied to penetration analysis. Analysis result with CSCM model shows good agreement with penetration experimental data. The projectile trace and fracture shapes of concrete target were compared with experimental data.
Guiding supersonic projectiles using optically generated air density channels
Johnson, Luke A.; Sprangle, Phillip
2015-09-01
We investigate the feasibility of using optically generated channels of reduced air density to provide trajectory correction (guiding) for a supersonic projectile. It is shown that the projectile experiences a force perpendicular to its direction of motion as one side of the projectile passes through a channel of reduced air density. A single channel of reduced air density can be generated by the energy deposited from filamentation of an intense laser pulse. We propose changing the laser pulse energy from shot-to-shot to build longer effective channels. Current femtosecond laser systems with multi-millijoule pulses could provide trajectory correction of several meters on 5 km trajectories for sub-kilogram projectiles traveling at Mach 3.
Projectile Motion with Quadratic Damping in a Constant ...
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 5. Projectile Motion with Quadratic Damping in a Constant Gravitational Field. Chandra Das Dhiranjan Roy. General Article Volume 19 Issue 5 May 2014 pp 446-465 ...
Determination of extra trajectory parameters of projectile layout motion
Ishchenko, A.; Burkin, V.; Faraponov, V.; Korolkov, L.; Maslov, E.; Diachkovskiy, A.; Chupashev, A.; Zykova, A.
2017-11-01
The paper presents a brief description of the experimental track developed and implemented on the base of the RIAMM TSU for external trajectory investigations on determining the main aeroballistic parameters of various shapes projectiles, in the wide velocity range. There is comparison between the experimentally obtained dependence of the fin-stabilized projectile mock-up aerodynamic drag coefficient on the Mach number with the 1958 aerodynamic drag law and aerodynamic tests of the same mock-up
Numerical Prediction of Pitch Damping Stability Derivatives for Finned Projectiles
2013-11-01
Air Force modified finner. ..............38 vii Acknowledgments The authors would like to thank Dr. James DeSpirito and Dr. Paul Weinacht of...section 4.3.2. For a symmetric finned projectile without fin cants or bevels , when , and only a single coning computation at some nonzero...within the linear range is required to compute . For a finned projectile with fin cants or bevels , since , then simulations at two
Active IR System for Projectile Detection and Tracking
Directory of Open Access Journals (Sweden)
STANCIC, I.
2017-11-01
Full Text Available Reliable detection and tracking of high-speed projectiles is crucial in providing modern battlefield protection or to be used as a forensic tool. Subsonic projectiles fired from silenced weapons are difficult to detect, whereas reliable tracking of the projectile trajectory is hard to accomplish. Contemporary radar based counter-battery systems showed to be valuable in detection of incoming artillery fire, but are unable to provide detection at close ranges. In this paper, an active IR system is proposed that aims to detect and track incoming projectiles at close ranges. Proposed system is able to reconstruct projectile’s trajectory in space, predict impact location and estimate direction of projectile origin. Active detector system is based on a pair of high-speed cameras in stereo-configuration synced with computer and IR illuminator that emits coded IR light bursts. Innovative IR light coding enables automated detection and tracking of a nearby projectile and elimination of false positive alarms caused by distant objects.
[Eye injury from a paintball projectile].
Karel, I; Pitrová, S; Lest'ák, J; Záhlava, J
2002-05-01
A fourteen-year-old adolescent suffered after a direct hit with a plastic projective (paintball) a severe injury of the anterior and posterior segment of the eye manifested by intraocular haemorrhage, cyclodialysis, detachment of the retina with two giant tears and oedema and haemorrhages of the retina. After cerclage, pars plana vitrectomy and transient four-month tamponade with silicone oil the retina reattached. Late complications, cataract, broad anterior adherence with scars of the chamber angle and ciliary body, a lamellar defect of the macula and partial atrophy of the optic disc determined the subsequent development and were an indication for cataract surgery, implantation of an artificial lens into the lenticular capsule and reconstruction of the pupil. The final result was from the cosmetic and functional aspect (visual acuity 0.3) very satisfactory. Plastic projectiles (paintballs) are a new cause of severe eye injuries. At risk are in particular participants of games who do not protect their eyes with spectacles or masks. To save the function of the eye in unnecessary injuries frequently several operations are needed and close collaboration of surgeons for the anterior and posterior segment.
N/z Dependence of Projectile Fragmentation
Trautmann, W.; Adrich, P.; Aumann, T.; Bacri, C. O.; Barczyk, T.; Bassini, R.; Bianchin, S.; Boiano, C.; Botvina, A. S.; Boudard, A.; Brzychczyk, J.; Chbihi, A.; Cibor, J.; Czech, B.; de Napoli, M.; Ducret, J.-É.; Emling, H.; Frankland, J. D.; Hellström, M.; Henzlova, D.; Immè, G.; Iori, I.; Johansson, H.; Kezzar, K.; Lafriakh, A.; Le Fèvre, A.; Le Gentil, E.; Leifels, Y.; Lühning, J.; Łukasik, J.; Lynch, W. G.; Lynen, U.; Majka, Z.; Mocko, M.; Müller, W. F. J.; Mykulyak, A.; Orth, H.; Otte, A. N.; Palit, R.; Pawłowski, P.; Pullia, A.; Raciti, G.; Rapisarda, E.; Sann, H.; Schwarz, C.; Sfienti, C.; Simon, H.; Sümmerer, K.; Tsang, M. B.; Verde, G.; Volant, C.; Wallace, M.; Weick, H.; Wiechula, J.; Wieloch, A.; Zwiegliński, B.
The N/Z dependence of projectile fragmentation at relativistic energies has been studied in a recent experiment at the GSI laboratory with the ALADiN forward spectrometer coupled to the LAND neutron detector. Besides a primary beam of 124Sn, also secondary beams of 124La and 107Sn delivered by the FRS fragment separator have been used in order to extend the range of isotopic compositions of the produced spectator sources. With the achieved mass resolution of ΔA/A ≈ 1.5%, lighter isotopes with atomic numbers Z ≤ 10 are individually resolved. The presently ongoing analyses of the measured isotope yields focus on isoscaling and its relation to the properties of hot fragments at freeze-out and on the derivation of chemical freeze-out temperatures which are found to be independent of the isotopic composition of the studied systems. The latter result is at variance with the predictions for limiting temperatures as obtained with finite-temperature Hartree-Fock calculations.
Impact Behaviour of Soft Body Projectiles
Kalam, Sayyad Abdul; Rayavarapu, Vijaya Kumar; Ginka, Ranga Janardhana
2018-02-01
Bird strike analysis is a common type of analysis done during the design and analysis of primary structures such as engine cowlings or fuselage panels. These simulations are done in order to predict whether various designs will pass the necessary certification tests. Composite materials are increasingly being used in aerospace industry and bird strike is a major threat which may lead to serious structural damage of those materials. Such phenomenon may arise from numerous impact scenarios. The focus of current study is on the finite element modeling for composite structures and simulation of high velocity impact loads from soft body projectiles with an explicit dynamics code AUTODYN. This paper investigates the methodology which can be utilized to certify an aircraft for bird strike resistance using computational technique by first demonstrating the accuracy of the method for bird impact on rigid target modeling and then applies the developed model to a more complex problem. The model developed for bird strike threat assessment incorporates parameters of bird number (bird density), bird body mass, equation of state (EOS) and bird path during impact.
Severe retinal injuries from paintball projectiles.
Baath, J; Ells, A L; Kherani, A; Williams, R G
2007-08-01
To determine the outcomes and circumstances of retinal injuries caused by blunt trauma from paintball pellet projectiles. Retrospective case series of all patients who presented with retinal injuries due to paintball-related trauma to 2 retina specialists in a clinical setting from 2004 to 2005. Patients were followed for a mean of 7.3 months, and retinal trauma was documented with retinal photographs and ocular coherence tomography as needed. Best corrected visual acuity (BCVA) was the main outcome measure. Three eyes of 3 patients suffered severe retinal injuries after blunt trauma from a paintball pellet. Together, the 3 eyes demonstrated extensive retinal findings, including commotio retinae, choroidal rupture, and macular hole. BCVA at last follow-up ranged from 20/80 to hand motions. Our small case series indicates that retinal trauma from paintball injuries is not uncommon and results in severe long-term visual morbidity. The sale of paintball guns and pellets should be strictly prohibited for minors, and adults should be educated about the need for appropriate ocular protection and the potentially serious consequences of the use of these guns outside of commercial settings.
Impact Behaviour of Soft Body Projectiles
Kalam, Sayyad Abdul; Rayavarapu, Vijaya Kumar; Ginka, Ranga Janardhana
2017-04-01
Bird strike analysis is a common type of analysis done during the design and analysis of primary structures such as engine cowlings or fuselage panels. These simulations are done in order to predict whether various designs will pass the necessary certification tests. Composite materials are increasingly being used in aerospace industry and bird strike is a major threat which may lead to serious structural damage of those materials. Such phenomenon may arise from numerous impact scenarios. The focus of current study is on the finite element modeling for composite structures and simulation of high velocity impact loads from soft body projectiles with an explicit dynamics code AUTODYN. This paper investigates the methodology which can be utilized to certify an aircraft for bird strike resistance using computational technique by first demonstrating the accuracy of the method for bird impact on rigid target modeling and then applies the developed model to a more complex problem. The model developed for bird strike threat assessment incorporates parameters of bird number (bird density), bird body mass, equation of state (EOS) and bird path during impact.
Systematic investigation of projectile fragmentation using beams of unstable B and C isotopes
Thies, R.; Heinz, A.; Adachi, T.; Aksyutina, Y.; Alcantara-Núñes, J.; Altstadt, S.; Alvarez-Pol, H.; Ashwood, N.; Aumann, T.; Avdeichikov, V.; Barr, M.; Beceiro-Novo, S.; Bemmerer, D.; Benlliure, J.; Bertulani, C. A.; Boretzky, K.; Borge, M. J. G.; Burgunder, G.; Camaño, M.; Caesar, C.; Casarejos, E.; Catford, W.; Cederkäll, J.; Chakraborty, S.; Chartier, M.; Chulkov, L. V.; Cortina-Gil, D.; Crespo, R.; Datta, U.; Díaz Fernández, P.; Dillmann, I.; Elekes, Z.; Enders, J.; Ershova, O.; Estradé, A.; Farinon, F.; Fraile, L. M.; Freer, M.; Freudenberger, M.; Fynbo, H. O. U.; Galaviz, D.; Geissel, H.; Gernhäuser, R.; Göbel, K.; Golubev, P.; Gonzalez Diaz, D.; Hagdahl, J.; Heftrich, T.; Heil, M.; Heine, M.; Henriques, A.; Holl, M.; Ickert, G.; Ignatov, A.; Jakobsson, B.; Johansson, H. T.; Jonson, B.; Kalantar-Nayestanaki, N.; Kanungo, R.; Knöbel, R.; Kröll, T.; Krücken, R.; Kurcewicz, J.; Kurz, N.; Labiche, M.; Langer, C.; Le Bleis, T.; Lemmon, R.; Lepyoshkina, O.; Lindberg, S.; Machado, J.; Marganiec, J.; Maroussov, V.; Mostazo, M.; Movsesyan, A.; Najafi, A.; Nilsson, T.; Nociforo, C.; Panin, V.; Paschalis, S.; Perea, A.; Petri, M.; Pietri, S.; Plag, R.; Prochazka, A.; Rahaman, A.; Rastrepina, G.; Reifarth, R.; Ribeiro, G.; Ricciardi, M. V.; Rigollet, C.; Riisager, K.; Röder, M.; Rossi, D.; Sanchez del Rio, J.; Savran, D.; Scheit, H.; Simon, H.; Sorlin, O.; Stoica, V.; Streicher, B.; Taylor, J. T.; Tengblad, O.; Terashima, S.; Togano, Y.; Uberseder, E.; Van de Walle, J.; Velho, P.; Volkov, V.; Wagner, A.; Wamers, F.; Weick, H.; Weigand, M.; Wheldon, C.; Wilson, G.; Wimmer, C.; Winfield, J. S.; Woods, P.; Yakorev, D.; Zhukov, M. V.; Zilges, A.; Zuber, K.; R3B Collaboration
2016-05-01
Background: Models describing nuclear fragmentation and fragmentation fission deliver important input for planning nuclear physics experiments and future radioactive ion beam facilities. These models are usually benchmarked against data from stable beam experiments. In the future, two-step fragmentation reactions with exotic nuclei as stepping stones are a promising tool for reaching the most neutron-rich nuclei, creating a need for models to describe also these reactions. Purpose: We want to extend the presently available data on fragmentation reactions towards the light exotic region on the nuclear chart. Furthermore, we want to improve the understanding of projectile fragmentation especially for unstable isotopes. Method: We have measured projectile fragments from 10,12 -18C and B-1510 isotopes colliding with a carbon target. These measurements were all performed within one experiment, which gives rise to a very consistent data set. We compare our data to model calculations. Results: One-proton removal cross sections with different final neutron numbers (1 p x n ) for relativistic 10,12 -18C and B-1510 isotopes impinging on a carbon target. Comparing model calculations to the data, we find that the epax code is not able to describe the data satisfactorily. Using abrabla07 on the other hand, we find that the average excitation energy per abraded nucleon needs to be decreased from 27 MeV to 8.1 MeV. With that decrease abrabla07 describes the data surprisingly well. Conclusions: Extending the available data towards light unstable nuclei with a consistent set of new data has allowed a systematic investigation of the role of the excitation energy induced in projectile fragmentation. Most striking is the apparent mass dependence of the average excitation energy per abraded nucleon. Nevertheless, this parameter, which has been related to final-state interactions, requires further study.
Injury risk assessment of non-lethal projectile head impacts.
Oukara, Amar; Nsiampa, Nestor; Robbe, Cyril; Papy, Alexandre
2014-01-01
Kinetic energy non-lethal projectiles are used to impart sufficient effect onto a person in order to deter uncivil or hazardous behavior with a low probability of permanent injury. Since their first use, real cases indicate that the injuries inflicted by such projectiles may be irreversible and sometimes lead to death, especially for the head impacts. Given the high velocities and the low masses involved in such impacts, the assessment approaches proposed in automotive crash tests and sports may not be appropriate. Therefore, there is a need of a specific approach to assess the lethality of these projectiles. In this framework, some recent research data referred in this article as "force wall approach" suggest the use of three lesional thresholds (unconsciousness, meningeal damages and bone damages) that depend on the intracranial pressure. Three corresponding critical impact forces are determined for a reference projectile. Based on the principle that equal rigid wall maximal impact forces will produce equal damage on the head, these limits can be determined for any other projectile. In order to validate the consistence of this innovative method, it is necessary to compare the results with other existing assessment methods. This paper proposes a comparison between the "force wall approach" and two different head models. The first one is a numerical model (Strasbourg University Finite Element Head Model-SUFEHM) from Strasbourg University; the second one is a mechanical surrogate (Ballistics Load Sensing Headform-BLSH) from Biokinetics.
Bound states and the Bekenstein bound
Energy Technology Data Exchange (ETDEWEB)
Bousso, Raphael
2003-10-16
We explore the validity of the generalized Bekenstein bound, S<= pi M a. We define the entropy S as the logarithm of the number of states which have energy eigenvalue below M and are localized to a flat space region of width alpha. If boundary conditions that localize field modes are imposed by fiat, then the bound encounters well-known difficulties with negative Casimir energy and large species number, as well as novel problems arising only in the generalized form. In realistic systems, however, finite-size effects contribute additional energy. We study two different models for estimating such contributions. Our analysis suggests that the bound is both valid and nontrivial if interactions are properly included, so that the entropy S counts the bound states of interacting fields.
Positivity bounds on double parton distributions
Energy Technology Data Exchange (ETDEWEB)
Diehl, Markus; Kasemets, Tomas
2013-03-15
Double hard scattering in proton-proton collisions is described in terms of double parton distributions. We derive bounds on these distributions that follow from their interpretation as probability densities, taking into account all possible spin correlations between two partons in an unpolarized proton. These bounds constrain the size of the polarized distributions and can for instance be used to set upper limits on the effects of spin correlations in double hard scattering. We show that the bounds are stable under leading-order DGLAP evolution to higher scales.
Fragmentation of Pb-Projectiles at SPS Energies
2002-01-01
% EMU17 \\\\ \\\\ We have exposed stacks consisting of solid state nuclear track detectors (CR-39 plastic and BP-1 glass) and different target materials at the SPS to beams of Pb projectiles. Our detectors record tracks of relativistic nuclei with charge numbers of Z~$\\geq$~6 for CR-39 and Z~$\\geq$75 for BP-1. After development of the tracks by etching they are detected and measured using completely automated microscope systems. Thus experiments with high statistics are possible. \\\\ \\\\BP-1 detectors were exposed to measure total charge changing cross sections and elemental production cross sections for heavy projectile fragments. These experiments were performed for different targets CH$ _{2} $, C, Al, Cu, Ag and Pb. Comparison of the results for different targets allows to investigate contributions to charge changing reactions by electromagnetic dissociation. Multifragmentation events in which several intermediate mass fragments are emitted from the heavy Pb projectile are studied using stacks containing CR-39 d...
Rapid Assessment of Small Changes to Major Gun and Projectile Dynamic Parameters
National Research Council Canada - National Science Library
Erline, Thomas
1997-01-01
.... The "Little RASCAL" program was used to estimate the tipoff angles and angular rates for the Mk 64 5-in projectile, and the "PC-PRODAS" computer program was used to estimate the projectile yaw...
Saturation Effect of Projectile Excitation in Ion-Atom Collisions
Mukoyama, Takeshi; Lin, Chii-Dong
Calculations of projectile K-shell electron excitation cross sections for He-like ions during ion-atom collisions have been performed in the distortion approximation by the use of Herman-Skillman wave functions. The calculated results are compared with the experimental data for several targets. The excitation cross sections deviate from the first-Born approximation and show the saturation effect as a function of target atomic number. This effect can be explained as the distortion of the projectile electronic states by the target nucleus.
Optimization of Construction of the rocket-assisted projectile
Directory of Open Access Journals (Sweden)
Arkhipov Vladimir
2017-01-01
Full Text Available New scheme of the rocket motor of rocket-assisted projectile providing the increase in distance of flight due to controlled and optimal delay time of ignition of the solid-propellant charge of the SRM and increase in reliability of initiation of the SRM by means of the autonomous system of ignition excluding the influence of high pressure gases of the propellant charge in the gun barrel has been considered. Results of the analysis of effectiveness of using of the ignition delay device on motion characteristics of the rocket-assisted projectile has been presented.
Locus of the apices of projectile trajectories under constant drag
Hernández-Saldaña, H.
2017-11-01
Using the hodograph method, we present an analytical solution for projectile coplanar motion under constant drag, parametrised by the velocity angle. We find the locus formed by the apices of the projectile trajectories, and discuss its implementation for the motion of a particle on an inclined plane in presence of Coulomb friction. The range and time of flight are obtained numerically, and we find that the optimal launching angle is smaller than in the drag-free case. This is a good example of a problem with constant dissipation of energy that includes curvature; it is appropriate for intermediate courses of mechanics.
Dispersion Analysis of the XM881APFSDS Projectile
Directory of Open Access Journals (Sweden)
Thomas F. Erline
2001-01-01
Full Text Available This study compares the results of a dispersion test with mathematical modeling. A 10-round group of modified 25-mm XM881 Armor Piercing Fin Stabilized Discarding Sabot projectiles was fired from the M242 chain gun into a designated target. The mathematical modeling results come from BALANS, a product of Arrow Tech Associates. BALANS is a finite-element lumped parameter code that has the capability to model a flexible projectile being fired from a flexible gun. It also has the unique feature of an automated statistical evaluation of dispersion. This study represents an effort to evaluate a simulation approach with experiment.
Livingstone, I.H.G.; Verolme, K.; Hayhurst, C.J.
2001-01-01
For cubes and spheres under high velocity impact there exists for each system of projectile and target, a threshold velocity that is just sufficient to shatter the projectile. This velocity, usually above 2km/s for metallic projectiles, is known as the fragmentation onset velocity. To determine the
Physical Uncertainty Bounds (PUB)
Energy Technology Data Exchange (ETDEWEB)
Vaughan, Diane Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Preston, Dean L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2015-03-19
This paper introduces and motivates the need for a new methodology for determining upper bounds on the uncertainties in simulations of engineered systems due to limited fidelity in the composite continuum-level physics models needed to simulate the systems. We show that traditional uncertainty quantification methods provide, at best, a lower bound on this uncertainty. We propose to obtain bounds on the simulation uncertainties by first determining bounds on the physical quantities or processes relevant to system performance. By bounding these physics processes, as opposed to carrying out statistical analyses of the parameter sets of specific physics models or simply switching out the available physics models, one can obtain upper bounds on the uncertainties in simulated quantities of interest.
DEFF Research Database (Denmark)
Emiris, Ioannis Z.; Mourrain, Bernard; Tsigaridas, Elias
2010-01-01
In this paper we derive aggregate separation bounds, named after Davenport-Mahler-Mignotte (DMM), on the isolated roots of polynomial systems, specifically on the minimum distance between any two such roots. The bounds exploit the structure of the system and the height of the sparse (or toric) re...... bound on the number of steps that subdivision-based algorithms perform in order to isolate all real roots of a polynomial system. This leads to the first complexity bound of Milne's algorithm [22] in 2D....
A note on stability of motion of a projectile
Indian Academy of Sciences (India)
Springer Verlag Heidelberg #4 2048 1996 Dec 15 10:16:45
Nielsen. & Synge1946). The motion of a nonlinear Lock–Fowler missile under the same conditon using the Routh–Hurwitz criterion has been discussed by Rath & Namboodiri (1980). The dynamical motion of an axi-symmetric projectile in the ...
Projectile Motion in the "Language" of Orbital Motion
Zurcher, Ulrich
2011-01-01
We consider the orbit of projectiles launched with arbitrary speeds from the Earth's surface. This is a generalization of Newton's discussion about the transition from parabolic to circular orbits, when the launch speed approaches the value [image omitted]. We find the range for arbitrary launch speeds and angles, and calculate the eccentricity of…
Apparatus for Teaching Physics: A Versatile Projectile Motion Board.
Prigo, Robert B.; Korda, Anthony
1984-01-01
Describes the design and use of a projectile motion apparatus to illustrate a variety of projective motion results typically discussed in an introductory course. They include independence of horizontal (constant speed) and vertical (constant acceleration) motions, parabolic path shape, and other types of motion. (JN)
The Long Decay Model of One-Dimensional Projectile Motion
Lattery, Mark Joseph
2008-01-01
This article introduces a research study on student model formation and development in introductory mechanics. As a point of entry, I present a detailed analysis of the Long Decay Model of one-dimensional projectile motion. This model has been articulated by Galileo ("in De Motu") and by contemporary students. Implications for instruction are…
Projectile General Motion in a Vacuum and a Spreadsheet Simulation
Benacka, Jan
2015-01-01
This paper gives the solution and analysis of projectile motion in a vacuum if the launch and impact heights are not equal. Formulas for the maximum horizontal range and the corresponding angle are derived. An Excel application that simulates the motion is also presented, and the result of an experiment in which 38 secondary school students…
Using Statcast to lift the discussion of projectile motion
Siegel, P. B.
2017-04-01
Home run data from Major League Baseball's Statcast can be described by adding a lift force to the equations of projectile motion commonly used in undergraduate computational physics courses. We discuss how the Statcast data can be implemented in the classroom.
Using Tracker as a Pedagogical Tool for Understanding Projectile Motion
Wee, Loo Kang; Chew, Charles; Goh, Giam Hwee; Tan, Samuel; Lee, Tat Leong
2012-01-01
This article reports on the use of Tracker as a pedagogical tool in the effective learning and teaching of projectile motion in physics. When a computer model building learning process is supported and driven by video analysis data, this free Open Source Physics tool can provide opportunities for students to engage in active enquiry-based…
Horizontal and vertical projectile motion in a resistant medium under ...
African Journals Online (AJOL)
Horizontal and vertical projectile motion in a resistant medium under the influence of magnetic field is carried out. Solutions to the governing equations is developed using integrating factor method. The results are in reasonable agreement with the findings of [2] and [3] JONAMP Vol. 11 2007: pp. 83-86 ...
Horizontal and vertical projectile motion in a resistant medium ...
African Journals Online (AJOL)
A study of projectile motion in a resistant medium subject to varying path angles and speed was carried out. Solutions to the governing equations of motion is developed employing double integration. Analysis of the results shows that the path of the particle in a resistant medium is affected by both increase in path angle and ...
On the Trajectories of Projectiles Depicted in Early Ballistic Woodcuts
Stewart, Sean M.
2012-01-01
Motivated by quaint woodcut depictions often found in many late 16th and 17th century ballistic manuals of cannonballs fired in air, a comparison of their shapes with those calculated for the classic case of a projectile moving in a linear resisting medium is made. In considering the asymmetrical nature of such trajectories, the initial launch…
Evaluation of different projectiles in matched experimental eye impact simulations.
Weaver, Ashley A; Kennedy, Eric A; Duma, Stefan M; Stitzel, Joel D
2011-03-01
Eye trauma results in 30,000 cases of blindness each year in the United States and is the second leading cause of monocular visual impairment. Eye injury is caused by a wide variety of projectile impacts and loading scenarios with common sources of trauma being motor vehicle crashes, military operations, and sporting impacts. For the current study, 79 experimental eye impact tests in literature were computationally modeled to analyze global and localized responses of the eye to a variety of blunt projectile impacts. Simulations were run with eight different projectiles (airsoft pellets, baseball, air gun pellets commonly known as BBs, blunt impactor, paintball, aluminum, foam, and plastic rods) to characterize effects of the projectile size, mass, geometry, material properties, and velocity on eye response. This study presents a matched comparison of experimental test results and computational model outputs including stress, energy, and pressure used to evaluate risk of eye injury. In general, the computational results agreed with the experimental results. A receiver operating characteristic curve analysis was used to establish the stress and pressure thresholds that best discriminated for globe rupture in the matched experimental tests. Globe rupture is predicted by the computational simulations when the corneoscleral stress exceeds 17.21 MPa or the vitreous pressure exceeds 1.01 MPa. Peak stresses were located at the apex of the cornea, the limbus, or the equator depending on the type of projectile impacting the eye. A multivariate correlation analysis revealed that area-normalized kinetic energy was the best single predictor of peak stress and pressure. Additional incorporation of a relative size parameter that relates the projectile area to the area of the eye reduced stress response variability and may be of importance in eye injury prediction. The modeling efforts shed light on the injury response of the eye when subjected to a variety of blunt projectile
Directory of Open Access Journals (Sweden)
Michaël Cadilhac
2011-08-01
Full Text Available The Parikh finite word automaton model (PA was introduced and studied by Klaedtke and Ruess in 2003. Here, by means of related models, it is shown that the bounded languages recognized by PA are the same as those recognized by deterministic PA. Moreover, this class of languages is the class of bounded languages whose set of iterations is semilinear.
Bounded Gaussian process regression
DEFF Research Database (Denmark)
Jensen, Bjørn Sand; Nielsen, Jens Brehm; Larsen, Jan
2013-01-01
We extend the Gaussian process (GP) framework for bounded regression by introducing two bounded likelihood functions that model the noise on the dependent variable explicitly. This is fundamentally different from the implicit noise assumption in the previously suggested warped GP framework. We...
Bounding Species Distribution Models
Stohlgren, Thomas J.; Jarnevich, Cahterine S.; Morisette, Jeffrey T.; Esaias, Wayne E.
2011-01-01
Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern. Many investigators now recognize that extrapolations of these models with geographic information systems (GIS) might be sensitive to the environmental bounds of the data used in their development, yet there is no recommended best practice for "clamping" model extrapolations. We relied on two commonly used modeling approaches: classification and regression tree (CART) and maximum entropy (Maxent) models, and we tested a simple alteration of the model extrapolations, bounding extrapolations to the maximum and minimum values of primary environmental predictors, to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States. Findings suggest that multiple models of bounding, and the most conservative bounding of species distribution models, like those presented here, should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 (5): 642-647, 2011].
Regularity of Tor for weakly stable ideals
Directory of Open Access Journals (Sweden)
Katie Ansaldi
2015-05-01
Full Text Available It is proved that if I and J are weakly stable ideals in a polynomial ring R = k[x_1, . . ., x_n], with k a field, then the regularity of Tor^R_i (R/I, R/J has the expected upper bound. We also give a bound for the regularity of Ext^i_R (R/I, R for I a weakly stable ideal.
Zhang, G. L.; Zhang, G. X.; Hu, S. P.; Zhang, H. Q.; Gomes, P. R. S.; Lubian, J.; Guo, C. L.; Wu, X. G.; Yang, J. C.; Zheng, Y.; Li, C. B.; He, C. Y.; Zhong, J.; Li, G. S.; Yao, Y. J.; Guo, M. F.; Sun, H. B.; Valiente-Dobòn, J. J.; Goasduff, A.; Siciliano, M.; Galtarosa, F.; Francesco, R.; Testov, D.; Mengoni, D.; Bazzacco, D.; John, P. R.; Qu, W. W.; Wang, F.; Zheng, L.; Yu, L.; Chen, Q. M.; Luo, P. W.; Li, H. W.; Wu, Y. H.; Zhou, W. K.; Zhu, B. J.; Li, E. T.; Hao, X.
2017-11-01
Investigation of the breakup and transfer effect of weakly bound nuclei on the fusion process has been an interesting research topic in the past several years. However, owing to the low intensities of the presently available radioactive ion beam (RIB), it is difficult to clearly explore the reaction mechanisms of nuclear systems with unstable nuclei. In comparison with RIB, the beam intensities of stable weakly bound nuclei such as 6,7Li and 9Be, which have significant breakup probability, are orders of magnitude higher. Precise fusion measurements have already been performed with those stable weakly bound nuclei, and the effect of breakup of those nuclei on the fusion process has been extensively studied. Those nuclei indicated large production cross sections for particles other than the α + x breakup. The particles are originated from non-capture breakup (NCBU), incomplete fusion (ICF) and transfer processes. However, the conclusion of reaction dynamics was not clear and has the contradiction. In our previous experiments we have performed 6Li+96Zr and 154Sm at HI-13 Tandem accelerator of China Institute of Atomic Energy (CIAE) by using HPGe array. It is shown that there is a small complete fusion (CF) suppression on medium-mass target nucleus 96Zr different from about 35% suppression on heavier target nucleus 154Sm at near-barrier energies. It seems that the CF suppression factor depends on the charge of target nuclei. We also observed one neutron transfer process. However, the experimental data are scarce for medium-mass target nuclei. In order to have a proper understanding of the influence of breakup and transfer of weakly bound projectiles on the fusion process, we performed the 6Li+89Y experiment with incident energies of 22 MeV and 34 MeV on Galileo array in cooperation with Si-ball EUCLIDES at Legnaro National Laboratory (LNL) in Italy. Using particle-particle and particle-γ coincidences, the different reaction mechanisms can be clearly explored.
Wound ballistics of injuries caused by handguns with different types of projectiles.
von See, Constantin; Stuehmer, Alexander; Gellrich, Nils-Claudius; Blum, Katrin S; Bormann, Kai-Hendrik; Rücker, Martin
2009-07-01
There are considerable differences in the shape and composition of military and civilian projectiles. Five different projectiles with the same kinetic energy were fired into the heads of freshly sacrificed pigs (n=30) through the submental region in the occipital direction. Computed tomography (CT) and 3D face scans of the animal skulls were obtained before and after firing. The image data sets were fused and provided the basis for a quantitative analysis of destruction patterns. As a result of the destruction of the parietal bone at the potential exit site, there were significant volume difference between the Action 4 (6.45 +/- 3.42 ml) and the Hydra-Shok projectile (12.71 +/- 2.86 ml). The partial metal-jacketed projectile showed a minor increase in volume (4.89 +/- 1.47 ml) and a partial loss of soft projectile components. Radiology showed differences between the various projectiles in fragmentation and bone and soft-tissue destruction. Although the projectiles had the same kinetic energy, there were considerable differences in injury patterns between full metal-jacketed projectiles, which are the only projectiles permitted for military use under the Geneva Conventions, and the other investigated projectiles. These injuries present a major medical challenge to both first responders and surgeons.
Study on miss distance based on projectile shock wave sensor
Gu, Guohua; Cheng, Gang; Zhang, Chenjun; Zhou, Lei
2017-05-01
The paper establishes miss distance models based on physical characteristic of shock-wave. The aerodynamic theory shows that the shock-wave of flying super-sonic projectile is generated for the projectile compressing and expending its ambient atmosphere. It advances getting miss distance according to interval of the first sensors, which first catches shock-wave, to solve the problem such as noise filtering on severe background, and signals of amplifier vibration dynamic disposal and electromagnetism compatibility, in order to improves the precision and reliability of gathering wave N signals. For the first time, it can identify the kinds of pills and firing units automatically, measure miss distance and azimuth when pills are firing. Application shows that the tactics and technique index is advanced all of the world.
Developmental changes in children's understanding of horizontal projectile motion.
Mou, Yi; Zhu, Liqi; Chen, Zhe
2015-08-01
This study investigated 5- to 13-year-old children's performance in solving horizontal projectile motion problems, in which they predicted the trajectory of a carried object released from a carrier in three different contexts. The results revealed that 5- and 8-year-olds' trajectory predictions were easily distracted by salient contextual features (e.g. the relative spatial locations between objects), whereas a proportion of 11- and 13-year-olds' performance suggested the engagement of the impetus concept in trajectory prediction. The impetus concept is a typical misconception of inertial motion that assumes that motion is caused by force. Children's performance across ages suggested that their naïve knowledge of projectile motion was neither well-developed and coherent nor completely fragmented. Instead, this study presented the dynamic process in which children with age gradually overcame the influences of contextual features and consistently used the impetus concept across motion problems. © 2014 International Union of Psychological Science.
Two dimensional fractional projectile motion in a resisting medium
Rosales, Juan; Guía, Manuel; Gómez, Francisco; Aguilar, Flor; Martínez, Juan
2014-07-01
In this paper we propose a fractional differential equation describing the behavior of a two dimensional projectile in a resisting medium. In order to maintain the dimensionality of the physical quantities in the system, an auxiliary parameter k was introduced in the derivative operator. This parameter has a dimension of inverse of seconds (sec)-1 and characterizes the existence of fractional time components in the given system. It will be shown that the trajectories of the projectile at different values of γ and different fixed values of velocity v 0 and angle θ, in the fractional approach, are always less than the classical one, unlike the results obtained in other studies. All the results obtained in the ordinary case may be obtained from the fractional case when γ = 1.
Developmental changes of misconception and misperception of projectiles.
Kim, In-Kyeong
2012-12-01
This study investigated the developmental changes of perceptual and cognitive commonsense physical knowledge. Children 4 to 9 years old (N = 156; 79 boys, 77 girls) participated. Each child was asked to predict the landing positions of balls that rolled down and fell off a virtual ramp and to choose the most natural-looking motion from different projectile motions depicted. The landing position of the most natural-looking projectile was compared with the predicted landing position and also compared with the actual landing position. The results showed children predicted the ball's landing position closer to the ramp than the actual position. Children also chose the depiction in which the ball fell closer to the ramp than the accurate position, although the error in the prediction task was larger than in the perception task and decreased with age. The results indicated the developmental convergence of explicit reasoning and implicit perception, which suggest a single knowledge system with representational re-description.
Perforation of aluminum plates by fragment simulating projectiles (FSP
Directory of Open Access Journals (Sweden)
T Fras
2016-10-01
Full Text Available The paper describes the ballistic impact test, in which fragment simulating projectiles (FSPs of a 20-mm-diameter have been used against 40-mmthick plates made of an aluminum alloy AA7020-T651. To perforate plates, the projectiles must have reached a velocity higher than 890 m/s. Based on the performed ballistic test, the plugging failure mode is numerically modeled using the LS-DYNA software package. Results obtained due to the calculations in the Finite Element Method (FEM are compared with the results from the Smoothed Particle Hydrodynamics (SPH. A condition of geometrical similarity between the target deformed experimentally and its numerical representation is introduced to evaluate the performed simulations.
Measuring the Effects of Lift and Drag on Projectile Motion
Cross, Rod
2012-01-01
The trajectory of a projectile through the air is affected both by gravity and by aerodynamic forces. The latter forces can conveniently be ignored in many situations, even when they are comparatively large. For example, if a 145-g, 74-mm diameter baseball is pitched at 40 ms[superscript -1] (89.5 mph), it experiences a drag force of about 1.5 N.…
Projectile - Mass asymmetry systematics for low energy incomplete fusion
Directory of Open Access Journals (Sweden)
Singh Pushpendra P.
2015-01-01
Full Text Available In the present work, low energy incomplete fusion (ICF in which only a part of projectile fuses with target nucleus has been investigated in terms of various entrance channel parameters. The ICF strength function has been extracted from the analysis of experimental excitation functions (EFs measured for different projectile-target combinations from near- to well above- barrier energies in 12C,16O(from 1.02Vb to 1.64Vb+169Tm systems. Experimental EFs have been analysed in the framework statistical model code PACE4 based on the idea of equilibrated compound nucleus decay. It has been found that the value of ICF fraction (FICF increases with incident projectile energy. A substantial fraction of ICF (FICF ≈ 7 % has been accounted even at energy as low as ≈ 7.5% above the barrier (at relative velocity νrel ≈0.027 in 12C+169Tm system, and FICF ≈ 10 % at νrel ≈0.014 in 16O+169Tm system. The probability of ICF is discussed in light of the Morgenstern’s mass-asymmetry systematics. The value of FICF for 16O+169Tm systems is found to be 18.3 % higher than that observed for 12C+169Tm systems. Present results together with the re-analysis of existing data for nearby systems conclusively demonstrate strong competition of ICF with CF even at slightly above barrier energies, and strong projectile dependence that seems to supplement the Morgenstern’s systematics.
Learning Projectile Motion with the Computer Game ``Scorched 3D``
Jurcevic, John S.
2008-01-01
For most of our students, video games are a normal part of their lives. We should take advantage of this medium to teach physics in a manner that is engrossing for our students. In particular, modern video games incorporate accurate physics in their game engines, and they allow us to visualize the physics through flashy and captivating graphics. I recently used the game "Scorched 3D" to help my students understand projectile motion.
Tate, Stephen James
2013-10-01
In the 1960s, the technique of using cluster expansion bounds in order to achieve bounds on the virial expansion was developed by Lebowitz and Penrose (J. Math. Phys. 5:841, 1964) and Ruelle (Statistical Mechanics: Rigorous Results. Benjamin, Elmsford, 1969). This technique is generalised to more recent cluster expansion bounds by Poghosyan and Ueltschi (J. Math. Phys. 50:053509, 2009), which are related to the work of Procacci (J. Stat. Phys. 129:171, 2007) and the tree-graph identity, detailed by Brydges (Phénomènes Critiques, Systèmes Aléatoires, Théories de Jauge. Les Houches 1984, pp. 129-183, 1986). The bounds achieved by Lebowitz and Penrose can also be sharpened by doing the actual optimisation and achieving expressions in terms of the Lambert W-function. The different bound from the cluster expansion shows some improvements for bounds on the convergence of the virial expansion in the case of positive potentials, which are allowed to have a hard core.
Ultrahigh-speed X-ray imaging of hypervelocity projectiles
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.
DEFF Research Database (Denmark)
Failla, Virgilio; Melillo, Francesca; Reichstein, Toke
2014-01-01
Is entrepreneurship a more stable career choice for high employment turnover individuals? We find that a transition to entrepreneurship induces a shift towards stayer behavior and identify job matching, job satisfaction and lock-in effects as main drivers. These findings have major implications...
African Journals Online (AJOL)
Results of the study suggest that there are two main carbon pathways for plankton and nekton in the Kariega estuary, carbon derived from the eelgrass and its associated epiphytes and carbon which has its origins in the salt marsh riparian vegetation and zooplankton. Keywords: stable isotope analysis; temperate estuary; ...
Satellite Splat: An Inelastic Collision with a Surface-launched Projectile
2015-04-23
conservation of mechanical energy and angular momentum for orbital motion . Consider the following problem: a projectile of mass m is launched...Satellite splat: an inelastic collision with a surface-launched projectile Philip R Blanco1 and Carl E Mungan2 1Department of Physics and Astronomy...revised 13 March 2015 Accepted for publication 1 April 2015 Published 23 April 2015 Abstract A projectile is launched vertically from the surface of an
Directory of Open Access Journals (Sweden)
Evgeny A. Khmelnikov
2015-03-01
Full Text Available The experimental results and numerical modeling of penetration process of fluoropolymer projectiles in aluminum-based targets are presented. Analysis of mathematical models for interaction of elastoplastic projectile and target without taking additional energy released during interaction of fluoropolymer and aluminum into consideration is carried out. Energy fraction which is spent effectively on the increase in cavity volume is determined. The experimental and calculated results of penetration by combined and inert projectiles are compared.
Multipole-bound molecular negative ions
Abdul-Karim, H; Desfrançois, C
2002-01-01
Within the framework of a simple electrostatic model, as compared to recent experimental results, we here discuss the stability of very weakly bound molecular negative ions. In contrast with the case of conventional valence anions, the excess electron is then located in a very diffuse orbital and is mainly bound by electrostatic dipolar, quadrupolar, and polarization forces, at large distances from the neutral molecular core. By fitting a single repulsion parameter of the model to the available experimental data, it is possible to make quantitative predictions of the excess-electron binding energies in these species. Critical values of the dipole moment, quadrupole moment or polarizability required for the observation of stable multipole-bound negative ions are predicted and compared to available experimental data and ab initio calculations. Refs. 26 (author)
Energy Technology Data Exchange (ETDEWEB)
Warne, L.K.; Merewether, K.O.; Chen, K.C.; Jorgenson, R.E.; Morris, M.E.; Solberg, J.E.; Lewis, J.G. [Sandia National Labs., Albuquerque, NM (United States); Derr, W. [Derr Enterprises, Albuquerque, NM (United States)
1996-07-01
Test data on canonical weapon-like fixtures are used to validate previously developed analytical bounding results. The test fixtures were constructed to simulate (but be slightly worse than) weapon ports of entry but have known geometries (and electrical points of contact). The exterior of the test fixtures exhibited exterior resonant enhancement of the incident fields at the ports of entry with magnitudes equal to those of weapon geometries. The interior consisted of loaded transmission lines adjusted to maximize received energy or voltage but incorporating practical weapon geometrical constraints. New analytical results are also presented for bounding the energies associated with multiple bolt joints and for bounding the exterior resonant enhancement of the exciting fields.
Hidrodinamički model podvodnog projektila / Hidrodinamical model of an underwater projectile
Directory of Open Access Journals (Sweden)
Miroslav Radosavljević
2008-07-01
Full Text Available Radi dobijanja kvalitetnog matematičkog modela podvodnog projektila u radu su definisane ulazne i izlazne veličine, brzine i ubrzanje projektila. Uz zadate uslove mogućeg kretanja projektila definisan je model podvodnog projektila sa šest jednačina. / The paper analyzes an underwater projectile. The input and output values, the projectile speed and acceleration are defined for a quality definition of the projectile mathematical model. With the conditions of the projectile potential movement previously set out, the torpedo model is defined by six equations.
National Research Council Canada - National Science Library
Weinacht, Paul
2003-01-01
... that are derived solely from computational fluid dynamics (CFD). As a demonstration of the capability, this report presents results for a family of axisymmetric projectiles in supersonic flight...
DEFF Research Database (Denmark)
Damgård, Ivan Bjerre; Faust, Sebastian; Mukherjee, Pratyay
2013-01-01
a bounded tamper and leakage resilient CCA secure public key cryptosystem based on the DDH assumption. We first define a weaker CPA-like security notion that we can instantiate based on DDH, and then we give a general compiler that yields CCA-security with tamper and leakage resilience. This requires...... a public tamper-proof common reference string. Finally, we explain how to boost bounded tampering and leakage resilience (as in 1. and 2. above) to continuous tampering and leakage resilience, in the so-called floppy model where each user has a personal hardware token (containing leak- and tamper...
Appell, Jürgen; Merentes Díaz, Nelson José
2013-01-01
This monographis a self-contained exposition of the definition and properties of functionsof bounded variation and their various generalizations; the analytical properties of nonlinear composition operators in spaces of such functions; applications to Fourier analysis, nonlinear integral equations, and boundary value problems. The book is written for non-specialists. Every chapter closes with a list of exercises and open problems.
Hoyer, Paul
2017-05-01
Bound state poles in the S-matrix of perturbative QED are generated by the divergence of the expansion in α . The perturbative corrections are necessarily singular when expanding around free, {O}( α ^0 ) in and out states that have no overlap with finite-sized atomic wave functions. Nevertheless, measurables such as binding energies do have well-behaved expansions in powers of α (and log α ). It is desirable to formulate the concept of "lowest order" for gauge theory bound states such that higher order corrections vanish in the α → 0 limit. This may allow to determine a lowest order term for QCD hadrons which incorporates essential features such as confinement and chiral symmetry breaking, and thus can serve as the starting point of a useful perturbative expansion. I discuss a "Born" (no loop, lowest order in \\hbar ) approximation. Born level states are bound by gauge fields which satisfy the classical field equations. Gauss' law determines a distinct field A^0({\\varvec{x}}) for each instantaneous position of the charges. A Poincaré covariant boundary condition for the gluon field leads to a confining potential for q\\bar{q} and qqq states. In frames where the bound state is in motion the classical gauge field is obtained by a Lorentz boost of the rest frame field.
2015-01-01
Stable beams: two simple words that carry so much meaning at CERN. When LHC page one switched from "squeeze" to "stable beams" at 10.40 a.m. on Wednesday, 3 June, it triggered scenes of jubilation in control rooms around the CERN sites, as the LHC experiments started to record physics data for the first time in 27 months. This is what CERN is here for, and it’s great to be back in business after such a long period of preparation for the next stage in the LHC adventure. I’ve said it before, but I’ll say it again. This was a great achievement, and testimony to the hard and dedicated work of so many people in the global CERN community. I could start to list the teams that have contributed, but that would be a mistake. Instead, I’d simply like to say that an achievement as impressive as running the LHC – a machine of superlatives in every respect – takes the combined effort and enthusiasm of everyone ...
Comment on ‘Wind-influenced projectile motion’
Winther Andersen, Poul
2015-11-01
We comment on the article ‘Wind-influenced projectile motion’ by Bernardo et al (2015 Eur. J. Phys. 36 025016) where they examine the trajectory of a particle that is subjected to gravity and a linear air resistance plus the influence from the wind. They find by using the Lambert W function that the particle's trajectory for a special angle, the critical angle {θ }{{C}}, between the initial velocity and the horizontal is part of a straight line. In this comment we will show that this result can be proved without using the Lambert W function which is not that well known to beginning students of physics.
Stagnation pressure activated fuel release mechanism for hypersonic projectiles
Cartland, Harry E.; Hunter, John W.
2003-01-01
A propulsion-assisted projectile has a body, a cowl forming a combustion section and a nozzle section. The body has a fuel reservoir within a central portion of the body, and a fuel activation system located along the central axis of the body and having a portion of the fuel activation system within the fuel reservoir. The fuel activation system has a fuel release piston with a forward sealing member where the fuel release piston is adapted to be moved when the forward sealing member is impacted with an air flow, and an air-flow channel adapted to conduct ambient air during flight to the fuel release piston.
An Investigation of Oblique Perforation of Metallic Plates by Projectiles
1975-03-01
34LISTICS, TERMINAL DYNAMIC PLASTICITY PERFORATION PENETRATION IMPACT (OBLIQUE) N OR *0. AOSTRACT (47"fifte an orev ie It moina.. y and Idon#ItV by’ bloc...follow that to good approximation (be/h’) - (b/h) and the second stage would comence when x - (h-b)/cosa. For the second stage of the perforation proceso ...rather than along the projectile path and has a rotational velocity, but this can be shown to have a small influence on the terminal velocity of the
Destructive behavior of iron oxide in projectile impact
Shang, Wang; Xiaochen, Wang; Quan, Yang; Zhongde, Shan
2017-12-01
The damage strain values of Q235-A surface oxide scale were obtained by scanning electron microscopy (SEM/EDS) and universal tensile testing machine. The finite element simulation was carried out to study the destruction effects of oxidation at different impact rates. The results show that the damage value of the oxide strain is 0.08%. With the increase of the projectile velocity, the damage area of the oxide scale is increased, and the damage area is composed of the direct destruction area and the indirect failure area. The indirect damage area is caused by the stress/strain to the surrounding expansion after the impact of the steel body.
Lu, Dong-dong; Gu, Jin-liang; Luo, Hong-e.; Xia, Yan
2017-10-01
According to specific requirements of the X-ray machine system for measuring velocity of outfield projectile, a DC high voltage power supply system is designed for the high voltage or the smaller current. The system comprises: a series resonant circuit is selected as a full-bridge inverter circuit; a high-frequency zero-current soft switching of a high-voltage power supply is realized by PWM output by STM32; a nanocrystalline alloy transformer is chosen as a high-frequency booster transformer; and the related parameters of an LCC series-parallel resonant are determined according to the preset parameters of the transformer. The concrete method includes: a LCC series parallel resonant circuit and a voltage doubling circuit are stimulated by using MULTISM and MATLAB; selecting an optimal solution and an optimal parameter of all parts after stimulation analysis; and finally verifying the correctness of the parameter by stimulation of the whole system. Through stimulation analysis, the output voltage of the series-parallel resonant circuit gets to 10KV in 28s: then passing through the voltage doubling circuit, the output voltage gets to 120KV in one hour. According to the system, the wave range of the output voltage is so small as to provide the stable X-ray supply for the X-ray machine for measuring velocity of outfield projectile. It is fast in charging and high in efficiency.
Anthropological analysis of projectile trauma to the bony regions of the trunk
Directory of Open Access Journals (Sweden)
Humphrey Caitlin
2017-06-01
Full Text Available Ballistics literature often focuses on soft tissue injures and projectile trauma to the cranium. Minimal details on the bony characteristics of projectile trauma to the thorax/abdomen regions have been published. This study aims to analyse projectile trauma to the bony trunk region including the ribs, vertebrae, scapula, sternum and the hip bone to form a better understanding of the characteristics and biomechanics of skeletal trauma caused by a projectile and contribute to the existing database on skeletal trauma caused by projectiles. Fourteen cases of documented projectile trauma to the bony regions of the trunk from the Hamman-Todd Human Osteological Collection at the Cleveland Natural History Museum, Ohio were analysed. Of the 14 individuals with gunshot wounds examined, 40 wounds occurred to the bones. Twenty- four injuries to the ribs, 1 ilium, 11 vertebrae, 3 scapulae, and 1 sternum. Fracture patterns, heaving and bevelling can be used to determine the direction of travel of the projectile which can be evident on the ribs, sternum, scapula and ilium. It is critical to understand the wounding patterns associated with projectile trauma to the torso region as this is often targeted, due to being the centre of mass.
Treatment of Ion-Atom Collisions Using a Partial-Wave Expansion of the Projectile Wavefunction
Wong, T. G.; Foster, M.; Colgan, J.; Madison, D. H.
2009-01-01
We present calculations of ion-atom collisions using a partial-wave expansion of the projectile wavefunction. Most calculations of ion-atom collisions have typically used classical or plane-wave approximations for the projectile wavefunction, since partial-wave expansions are expected to require prohibitively large numbers of terms to converge…
An Analytic Approach to Projectile Motion in a Linear Resisting Medium
Stewart, Sean M.
2006-01-01
The time of flight, range and the angle which maximizes the range of a projectile in a linear resisting medium are expressed in analytic form in terms of the recently defined Lambert W function. From the closed-form solutions a number of results characteristic to the motion of the projectile in a linear resisting medium are analytically confirmed,…
Projectile Motion on an Inclined Misty Surface: I. Capturing and Analysing the Trajectory
Ho, S. Y.; Foong, S. K.; Lim, C. H.; Lim, C. C.; Lin, K.; Kuppan, L.
2009-01-01
Projectile motion is usually the first non-uniform two-dimensional motion that students will encounter in a pre-university physics course. In this article, we introduce a novel technique for capturing the trajectory of projectile motion on an inclined Perspex plane. This is achieved by coating the Perspex with a thin layer of fine water droplets…
Solution to Projectile Motion with Quadratic Drag and Graphing the Trajectory in Spreadsheets
Benacka, Jan
2010-01-01
This note gives the analytical solution to projectile motion with quadratic drag by decomposing the velocity vector to "x," "y" coordinate directions. The solution is given by definite integrals. First, the impact angle is estimated from above, then the projectile coordinates are computed, and the trajectory is graphed at various launch angles and…
Benacka, Jan
2015-01-01
This paper provides the formula for the elevation angle at which a projectile has to be fired in a vacuum from a general position to hit a target at a given distance. A spreadsheet application that models the trajectory is presented, and the problem of finding the points of shot and impact of a projectile moving in a vacuum if three points of the…
Real-time estimation of projectile roll angle using magnetometers: in-lab experimental validation
Changey, S.; Pecheur, E.; Wey, P.; Sommer, E.
2013-12-01
The knowledge of the roll angle of a projectile is decisive to apply guidance and control law. For example, the goal of ISL's project GSP (Guided Supersonic Projectile) is to change the flight path of an airdefence projectile in order to correct the aim error due to the target manoeuvres. The originality of the concept is based on pyrotechnical actuators and onboard sensors which control the angular motion of the projectile. First of all, the control of the actuators requires the precise control of the roll angle of the projectile. To estimate the roll angle of the projectile, two magnetometers are embedded in the projectile to measure the projection of the Earth magnetic field along radial axes of the projectiles. Then, an extended Kalman filter (EKF) is used to compute the roll angle estimation. As the rolling frequency of the GSP is about 22 Hz, it was easy to test the navigation algorithm in laboratory. In a previous paper [1], the In-Lab demonstration of this concept showed that the roll angle estimation was possible with an accuracy of about 1◦ . In this paper, the demonstration is extended to high-speed roll rate, up to 1000 Hz. Thus, two magnetometers, a DSP (Digital Signal Processor) and a LED (Light Eminent Diode), are rotated using a pneumatic motor; the DSP runs an EKF and a guidance algorithm to compute the trigger times of the LED. By using a high-speed camera, the accuracy of the method can be observed and improved.
Energy Technology Data Exchange (ETDEWEB)
Della-Negra, S.; Gardes, D.; Le Beyec, Y.; Waast, B.
1991-12-31
Metal clusters and molecules are the one mean to realize simultaneous impacts of several atoms on a reduced surface({approx}100A). The interaction characteristics is the non-linearity of energy deposition; the perturbation that the cluster produces, is above than the sum of the perturbation induced by its components, taken separately. The purpose of ORION project is to accelerate these new projectiles at ORSAY Tandem. The considered mass range is from 100 Daltons to 100 000 Daltons and energy range from MeV to GeV.
Meyer, B. K.
In the preceding chapter, we concentrated on the properties of free excitons. These free excitons may move through the sample and hit a trap, a nonradiative or a radiative recombination center. At low temperatures, the latter case gives rise to either deep center luminescence, mentioned in Sect. 7.1 and discussed in detail in Chap. 9, or to the luminescence of bound exciton complexes (BE or BEC). The chapter continues with the most prominent of these BECs, namely A-excitons bound to neutral donors. The next aspects are the more weakly BEs at ionized donors. The Sect. 7.4 treats the binding or localization energies of BEC from a theoretical point of view, while Sect. 7.5 is dedicated to excited states of BECs, which contain either holes from deeper valence bands or an envelope function with higher quantum numbers. The last section is devoted to donor-acceptor pair transitions. There is no section devoted specifically to excitons bound to neutral acceptors, because this topic is still partly controversially discussed. Instead, information on these A0X complexes is scattered over the whole chapter, however, with some special emphasis seen in Sects. 7.1, 7.4, and 7.5.
Projectile charge state dependent sputtering of solid surfaces
Hayderer, G
2000-01-01
dependence on the ion kinetic energy. This new type of potential sputtering not only requires electronic excitation of the target material, but also the formation of a collision cascade within the target in order to initiate the sputtering process and has therefore been termed kinetically assisted potential sputtering. In order to study defects induced by potential sputtering on the atomic scale we performed measurements of multiply charged Ar ion irradiated HOPG (highly oriented pyrolitic graphite) samples with scanning tunneling microscopy (STM). The only surface defects found in the STM images are protrusions. The mean diameter of the defects increases with projectile charge state while the height of the protrusions stays roughly the same indicating a possible pre-equilibrium effect of the stopping of slow multiply charged projectiles in HOPG. Total sputter yields for impact of slow singly and multiply charged ions on metal- (Au), oxide- (Al2O3, MgO) and alkali-halide surfaces (LiF) have been measured as a...
Target and Projectile: Material Effects on Crater Excavation and Growth
Anderson, J. L. B.; Burleson, T.; Cintala, Mark J.
2010-01-01
Scaling relationships allow the initial conditions of an impact to be related to the excavation flow and final crater size and have proven useful in understanding the various processes that lead to the formation of a planetary-scale crater. In addition, they can be examined and tested through laboratory experiments in which the initial conditions of the impact are known and ejecta kinematics and final crater morphometry are measured directly. Current scaling relationships are based on a point-source assumption and treat the target material as a continuous medium; however, in planetary-scale impacts, this may not always be the case. Fragments buried in a megaregolith, for instance, could easily approach or exceed the dimensions of the impactor; rubble-pile asteroids could present similar, if not greater, structural complexity. Experiments allow exploration into the effects of target material properties and projectile deformation style on crater excavation and dimensions. This contribution examines two of these properties: (1) the deformation style of the projectile, ductile (aluminum) or brittle (soda-lime glass) and (2) the grain size of the target material, 0.5-1 mm vs. 1-3 mm sand.
Identifying flight modes of Aerial Planting Projectile using Hilbert-Huang transformation
Goodarzi, H.; Sabzehparvar, M.
2017-11-01
A novel method based on Hilbert Huang Transform (HHT) for analyzing the non-linear and non-stationary of Aerial Planting Projectile (APP) flight data signal is presented. Also an image processing method is used for acquire attitude signals of projectile. Experimental test setup includes an electrical fan, high speed digital camera and projectile that the images of projectile falling down against of fan flow is captured. The frequency components of the projectile attitude signal along separation phase and free falling are complicated. Empirical Mode Decomposition (EMD) can decompose the signal into Intrinsic Mode Functions (IMFs). After a Hilbert transform, the instantaneous frequency and damping ratio of each IMF is obtained to get the physical meaning of each IMF. Analysis results indicate that the flight modes of APP are identified with high accuracy.
On the Resistance of the Air at High Speeds and on the Automatic Rotation of Projectiles
Riabouchinski, D
1921-01-01
Here, the laws governing the flow of a compressible fluid through an opening in a thin wall are applied to the resistance of the air at high speeds, especially as applied to the automatic rotation of projectiles. The instability which we observe in projectiles shot into the air without being given a moment of rotation about their axis of symmetry, or without stabilizing planes, is a phenomenon of automatic rotation. It is noted that we can prevent this phenomenon of automatic rotation by bringing the center of gravity sufficiently near one end, or by fitting the projectile with stabilizing planes or a tail. The automatic rotation of projectiles is due to the suction produced by the systematic formation of vortices behind the extremity of the projectile moving with the wind.
Morales, Roberto; Casas, David
2016-01-01
The instantaneous charge state of uranium ions traveling through a fully ionized hydrogen plasma has been theoretically studied and compared with one of the first energy loss experiments in plasmas, carried out at GSI-Darmstadt by Hoffmann \\textit{et al.} in the 90's. For this purpose, two different methods to estimate the instantaneous charge state of the projectile have been employed: (1) rate equations using ionization and recombination cross sections, and (2) equilibrium charge state formulas for plasmas. Also, the equilibrium charge state has been obtained using these ionization and recombination cross sections, and compared with the former equilibrium formulas. The equilibrium charge state of projectiles in plasmas is not always reached, it depends mainly on the projectile velocity and the plasma density. Therefore, a non-equilibrium or an instantaneous description of the projectile charge is necessary. The charge state of projectile ions cannot be measured, except after exiting the target, and experime...
Molecular depth profiling in ice matrices using C{sub 60} projectiles
Energy Technology Data Exchange (ETDEWEB)
Wucher, A.; Sun, S.; Szakal, C.; Winograd, N
2004-06-15
The prospects of molecular sputter depth profiling using C{sub 60}{sup +} projectiles were investigated on thick ice layers prepared by freezing aqueous solutions of histamine onto a metal substrate. The samples were analyzed in a ToF-SIMS spectrometer equipped with a liquid metal Ga{sup +} ion source and a newly developed fullerene ion source. The C{sub 60}{sup +} beam was used to erode the surface, while static ToF-SIMS spectra were taken with both ion beams alternatively between sputtering cycles. We find that the signals both related to the ice matrix and to the histamine are about two orders of magnitude higher under 20-keV C{sub 60} than under 15-keV Ga bombardment. Histamine related molecular signals are found to increase drastically if the freshly introduced surface is pre-sputtered with C{sub 60} ions, until at a total ion fluence of about 10{sup 13} cm{sup -2} the spectra are completely dominated by the molecular ion and characteristic fragments of histamine. At larger fluence, the signal is found to decrease with a disappearance cross section of approximately 10{sup -14} cm{sup 2}, until at total fluences of about 10{sup 14} cm{sup -2} a steady state with stable molecular signals is reached. In contrast, no appreciable molecular signal could be observed if Ga{sup +} ions were used to erode the surface.
Energy Technology Data Exchange (ETDEWEB)
Maccari, Attilio
2003-03-01
The asymptotic perturbation (AP) method is applied to the study of the nonlinear Klein-Gordon equation in 3+1 dimensions with harmonic potential and external periodic excitation supposed to be in primary resonance with the frequency of a generic mode. The AP method uses two different procedures for the solutions: introducing an asymptotic temporal rescaling and balancing of the harmonic terms with a simple iteration. Standard quantum mechanics can be used to derive the lowest order approximate solution and amplitude and phase modulation equations are obtained. External force-response and frequency-response curves are found and the existence of dromions trapped in bound states is demonstrated.
Analysis of Price Stackelberg Duopoly Game with Bounded Rationality
Directory of Open Access Journals (Sweden)
Lian Shi
2014-01-01
Full Text Available The classical Stackelberg game is extended to boundedly rational price Stackelberg game, and the dynamic duopoly game model is described in detail. By using the theory of bifurcation of dynamical systems, the existence and stability of the equilibrium points of this model are studied. And some comparisons with Bertrand game with bounded rationality are also performed. Stable region, bifurcation diagram, The Largest Lyapunov exponent, strange attractor, and sensitive dependence on initial conditions are used to show complex dynamic behavior. The results of theoretical and numerical analysis show that the stability of the price Stackelberg duopoly game with boundedly rational players is only relevant to the speed of price adjustment of the leader and not relevant to the follower’s. This is different from the classical Cournot and Bertrand duopoly game with bounded rationality. And the speed of price adjustment of the boundedly rational leader has a destabilizing effect on this model.
Cheng, Bin; Yu, Yang; Baoyin, Hexi
2017-08-30
In-situ exploration and remote thermal infrared observation revealed that a large fraction of Solar System small bodies should be covered with granular regolith. The complex and varied geology of the regolith layer may preserve the historical records of the surface modification and topographic evolution experienced by asteroids, especially cratering processes, in which the projectile shape plays a crucial role. Regarding the impact sampling scheme, the projectile-shape dependence of both the cavity morphology and the collected mass remains to be explored. This paper studies the process of the low-speed impact sampling on granular regolith using projectiles of different shapes. The results demonstrate that the projectile shape significantly influences the excavation stage, forming cavities with different morphologies, i.e., cone-shaped, bowl-shaped and U-shaped. We further indicate that the different velocity distributions of the ejecta curtains due to the various projectile shapes result in various amounts of collected mass in sampler canister, regarding which the 60° conical projectile exhibits preferable performance for impact sampling scheme. The results presented in this article are expected to reveal the dependence of the excavation process on projectile shape under micro gravity and provide further information on the optimal designs of impact sampling devices for future sample-return space missions.
Fairly direct hit! Advances in imaging of shotgun projectiles in MRI.
Eggert, Sebastian; Kubik-Huch, Rahel A; Klarhöfer, Markus; Peters, Alexander; Bolliger, Stephan A; Thali, Michael J; Anderson, Suzanne; Froehlich, Johannes M
2015-09-01
To investigate the magnetic properties of different types of projectiles and qualify the metal artefact reduction technique for diagnostic and/or forensic MRI. Ten different projectiles embedded in ordnance gelatine blocks underwent an in vitro 1.5-T MR study with seven sequences including a recently developed metal artefact reduction sequence (Advanced WARP) combining VAT (view-angle-tilting) and SEMAC (slice-encoding metal-artefact-correction). Resulting image quality (five-point scale: 1=best; 5=worst) was scored. Quantifiable magnetic characteristics were correlated with qualitative rating of the MR sequences and torque dislodgment. Metal artefact reduction sequence (median: 2.5) significantly (p magnetic attracted ones (median: 5). Correlation (0.623) between deflection angle measurement (ferromagnetic mean 84.2°; paramagnetic 62°; diamagnetic mean 0°) and median qualitative image quality was highly significant (p = 0.027). Torque dislodgement was distinct for elongated magnetic attracted projectiles. Significant improvement of MR imaging of projectiles using metal artefact reduction techniques has important implications for diagnostic/forensic work-up. The correlations between magnetic attraction force, deflection-angle results and image properties demonstrate that the MR safety of projectiles can be estimated with one of these methods. • Metal artefact reduction sequence improves overall image quality of bullets (p Classification of projectiles' magnetic properties based on artefacts' characteristics is possible. • Classifying of bullets has important implications in diagnostic and forensic imaging. • Identification of projectiles' magnetic attributes improves estimation of patients' injury risk.
3D finite element simulations of high velocity projectile impact
Directory of Open Access Journals (Sweden)
Ožbolt Joško
2015-01-01
Full Text Available An explicit three-dimensional (3D finite element (FE code is developed for the simulation of high velocity impact and fragmentation events. The rate sensitive microplane material model, which accounts for large deformations and rate effects, is used as a constitutive law. In the code large deformation frictional contact is treated by forward incremental Lagrange multiplier method. To handle highly distorted and damaged elements the approach based on the element deletion is employed. The code is then used in 3D FE simulations of high velocity projectile impact. The results of the numerical simulations are evaluated and compared with experimental results. It is shown that it realistically predicts failure mode and exit velocities for different geometries of plain concrete slab. Moreover, the importance of some relevant parameters, such as contact friction, rate sensitivity, bulk viscosity and deletion criteria are addressed.
Selected Screen for Engaging Students in Projectile Motion
Dramae, A.; Toedtanya, K.; Wuttiprom, S.
2017-09-01
Connecting physics concepts to activities that are interesting to students or what they encounter in everyday life will help students build a strong foundation. When there is an interesting activity for the student, it will result in the student responding, engaging, and enthusiasm in learning. Learning activities that are based on what students are interested in and regularly experience will enable students to understand the long and memorable experience. Both of these will enhance the student’s learning experience. One of the activities that can be described in this research used the learning activity through movies, which is the application of the basic motion projectile for students to understand the characteristics of such movement. It also aims to further develop critical thinking skills of learners.
Aerodynamic Jump: A Short Range View for Long Rod Projectiles
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Mark Bundy
2001-01-01
Full Text Available It is shown that aerodynamic jump for a nonspinning kinetic energy penetrator is not – as conventional definitions may infer – a discontinuous change in the direction of motion at the origin of free flight, nor is it the converse, a cumulative redirection over a domain of infinite extent. Rather, with the aid of an alternative kinematical definition, it is shown that aerodynamic jump for such a projectile is a localized redirection of the center-of-gravity motion, caused by the force of lift due to yaw over the relatively short region from entry into free flight until the yaw reaches its first maximum. A rigorous proof of this statement is provided, but the primary objective of this paper is to provide answers to the questions: what is aerodynamic jump, what does it mean, and what aspects of the flight trajectory does it refer to, or account for.
Adolescents' cognition of projectile motion: a pilot study.
Zhao, Jun-Yan; Yu, Guoliang
2009-04-01
Previous work on the development of intuitive knowledge about projectile motion has shown a dissociation between action knowledge expressed on an action task and conceptual knowledge expressed on a judgment task for young children. The research investigated the generality of dissociation for adolescents. On the action task, participants were asked to swing Ball A of a bifilar pendulum to some height then release it to collide with Ball B, which was projected to hit a target. On the judgment task, participants indicated orally the desired swing angle at which Ball A should be released so that Ball B would strike a target. Unlike previous findings with adults, the adolescents showed conceptual difficulties on the judgment task and well-developed action knowledge on the action task, which suggests dissociation between the two knowledge systems is also present among adolescents. The result further supports the hypothesis that the two knowledge systems follow different developmental trajectories and at different speeds.
Reaction of Projectiles with Targets during Hypervelocity Impact
Russell, Rod; Bless, Stephan; Persad, Chadee; Manthiram, Karthish
2009-06-01
Hollow tungsten projectiles were filled with bismuth oxide or copper and shot into aluminum blocks at 2200 m/s. The blocks were cut open, and the contents and morphology of the penetration channels were examined. In the case of copper fill, the channel was found to be filled with a black foam containing closed-cell bubbles. X-ray diffraction revealed the presence of CuAl2, indicating reaction with the aluminum target. In the case of bismuth oxide, there was little foam, but the penetration channel walls had many craters, which contained nodules of bismuth metal, again indicating reaction with the target. There were variations in crater diameter apparently corresponding to the onset and termination of the reactions. The exothermic nature of the reactions produced cracks in the target blocks.
Numerical Simulation of Projectile Oblique Impact on Microspacecraft Structure
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Zhiyuan Zhang
2017-01-01
Full Text Available In the present study, the microspacecraft bulkhead was reduced to the double honeycomb panel, and the projectile oblique hypervelocity impact on the double honeycomb panel was simulated. The distribution of the debris cloud and the damage of a honeycomb sandwich panel were investigated when the incident angles were set to be 60°, 45°, and 30°. The results showed that as incident angle decreased, the distribution of debris cloud was increased gradually, while the maximum perforation size of the rear face sheet was firstly increased with the decrease of the incident angle and then decreased. On the other hand, the damage area and the damage degree of the front face sheet of the second honeycomb panel layer were increased with the decrease of the incident angle. Finally, the critical angle of front and rear face sheets of the honeycomb sandwich panel was obtained under oblique hypervelocity impact.
Breakup conditions of projectile spectators from dynamical observables
Begemann-Blaich, M.; Lindenstruth, V.; Pochodzalla, J.; Adloff, J. C.; Bouissou, P.; Hubele, J.; Imme, G.; Iori, I.; Kreutz, P.; Kunde, G. J.; Leray, S.; Liu, Z.; Lynen, U.; Meijer, R. J.; Milkau, U.; Moroni, A.; Müller, W. F.; Ngô, C.; Ogilvie, C. A.; Raciti, G.; Rudolf, G.; Sann, H.; Schnittker, M.; Schüttauf, A.; Seidel, W.; Stuttge, L.; Trautmann, W.; Tucholski, A.
1998-09-01
Momenta and masses of heavy projectile fragments (Z>=8), produced in collisions of 197Au with C, Al, Cu, and Pb targets at E/A=600 MeV, were determined with the ALADIN magnetic spectrometer at SIS. Using this information, an analysis of kinematic correlations between the two and three heaviest projectile fragments in their rest frame was performed. The sensitivity of these correlations to the conditions at breakup was verified within the schematic SOS model. For a quantitative investigation, the data were compared to calculations with statistical multifragmentation models and to classical three-body calculations. With classical trajectory calculations, where the charges and masses of the fragments are taken from a Monte Carlo sampling of the experimental events, the dynamical observables can be reproduced. The deduced breakup parameters, however, differ considerably from those assumed in the statistical multifragmentation models which describe the charge correlations. If, on the other hand, the analysis of kinematic and charge correlations is performed for events with two and three heavy fragments produced by statistical multifragmentation codes, good agreement with the data is found with the exception that the fluctuation widths of the intrinsic fragment energies are significantly underestimated. A new version of the multifragmentation code MCFRAG was therefore used to investigate the potential role of angular momentum at the breakup stage. If a mean angular momentum of 0.75ħ/nucleon is added to the system, the energy fluctuations can be reproduced, but at the same time the charge partitions are modified and deviate from the data.
Breakup conditions of projectile spectators from dynamical observables
Energy Technology Data Exchange (ETDEWEB)
Begemann-Blaich, M.; Lindenstruth, V.; Pochodzalla, J. [and others
1998-03-01
Momenta and masses of heavy projectile fragments (Z {>=} 8), produced in collisions of {sup 197}Au with C, Al, Cu and Pb targets at E/A=600 MeV, were determined with the ALADIN magnetic spectrometer at SIS. Using these informations, an analysis of kinematic correlations between the two and three heaviest projectile fragments in their rest frame was performed. The sensitivity of these correlations to the conditions at breakup was verified within the schematic SOS-model. For a quantitative investigation, the data were compared to calculations with statistical multifragmentation models and to classical three-body calculations. With classical trajectory calculations, where the charges and masses of the fragments are taken from a Monte Carlo sampling of the experimental events, the dynamical observables can be reproduced. The deduced breakup parameters, however, differ considerably from those assumed in the statistical multifragmentation models which describe the charge correlations. If, on the other hand, the analysis of kinematic and charge correlations is performed for events with two and three heavy fragments produced by statistical multifragmentation codes, a good agreement with the data is found with the exception that the fluctuation widths of the intrinsic fragment energies are significantly underestimated. A new version of the multifragmentation code MCFRAG was therefore used to investigate the potential role of angular momentum at the breakup stage. If a mean angular momentum of 0.75 {Dirac_h}/nucleon is added to the system, the energy fluctuations can be reproduced, but at the same time the charge partitions are modified and deviate from the data. (orig.)
Directory of Open Access Journals (Sweden)
Yuanchuan SHEN
2017-06-01
Full Text Available This article presents a complete nonlinear controller design for a class of spin-stabilized canard-controlled projectiles. Uniformly ultimate boundedness and tracking are achieved, exploiting a heavily coupled, bounded uncertain and highly nonlinear model of longitudinal and lateral dynamics. In order to estimate unmeasurable states, an observer is proposed for an augmented multiple-input-multiple-output (MIMO nonlinear system with an adaptive sliding mode term against the disturbances. Under the frame of a backstepping design, an adaptive sliding mode output-feedback dynamic surface control (DSC approach is derived recursively by virtue of the estimated states. The DSC technique is adopted to overcome the problem of “explosion of complexity” and relieve the stress of the guidance loop. It is proven that all signals of the MIMO closed-loop system, including the observer and controller, are uniformly ultimately bounded, and the tracking errors converge to an arbitrarily small neighborhood of the origin. Simulation results for the observer and controller are provided to illustrate the feasibility and effectiveness of the proposed approach.
DEFF Research Database (Denmark)
Jensen, Jens Højgaard
2014-01-01
In a recent paper (Robinson G and Robinson I 2013 Phys. Scr. 88 018101) the authors developed the differential equations which govern the motion of a spherical projectile rotating about an arbitrary axis in the presence of an arbitrary wind, assuming that both the drag force and the lift force...... are independent of the Reynolds number and proportional to the square of the projectile's velocity. In this paper, by dimensional analysis, the latter assumption is shown to be incorrect for forces dependent on the angular velocity of the projectile, e.g. the lift force....
A Preliminary Investigation of the Effect of Bumpers as a Means of Reducing Projectile Penetration
Funkhouser, John O.
1961-01-01
The results of an investigation to determine the effect of bumpers on projectile penetration indicate that for impact velocities up to 12,500 feet per second, the penetration of 0.062-inch-diameter copper projectiles in to aluminum targets can be definitely reduced by using a properly selected bumper spaced a short distance in front of the main target surface. Bumpers and main targets were made of 2024-T4 aluminum alloy, and spherical projectiles made of 0.062-inch-diameter copper were used in all tests.
Projectile motion in real-life situation: Kinematics of basketball shooting
Changjan, A.; Mueanploy, W.
2015-06-01
Basketball shooting is a basic practice for players. The path of the ball from the players to the hoop is projectile motion. For undergraduate introductory physics courses student must be taught about projectile motion. Basketball shooting can be used as a case study for learning projectile motion from real-life situation. In this research, we discuss the relationship between optimal angle, minimum initial velocity and the height of the ball before the player shoots the ball for basketball shooting problem analytically. We found that the value of optimal angle and minimum initial velocity decreases with increasing the height of the ball before the player shoots the ball.
Refining Multivariate Value Set Bounds
Smith, Luke Alexander
Over finite fields, if the image of a polynomial map is not the entire field, then its cardinality can be bounded above by a significantly smaller value. Earlier results bound the cardinality of the value set using the degree of the polynomial, but more recent results make use of the powers of all monomials. In this paper, we explore the geometric properties of the Newton polytope and show how they allow for tighter upper bounds on the cardinality of the multivariate value set. We then explore a method which allows for even stronger upper bounds, regardless of whether one uses the multivariate degree or the Newton polytope to bound the value set. Effectively, this provides an alternate proof of Kosters' degree bound, an improved Newton polytope-based bound, and an improvement of a degree matrix-based result given by Zan and Cao.
Bound anionic states of adenine
Energy Technology Data Exchange (ETDEWEB)
Haranczyk, Maciej; Gutowski, Maciej S; Li, Xiang; Bowen, Kit H
2007-03-20
Anionic states of nucleic acid bases are involved in DNA damage by low-energy electrons and in charge transfer through DNA. Previous gas phase studies of free, unsolvated nucleic acid base parent anions probed only dipole-bound states, which are not present in condensed phase environments, but did not observe valence anionic states, which for purine bases, are thought to be adiabatically unbound. Contrary to this expectation, we have demonstrated that some thus far ignored tautomers of adenine, which result from enamine-imine transformations, support valence anionic states with electron vertical detachment energies as large as 2.2 eV, and at least one of these anionic tautomers is adiabatically bound. Moreover, we predict that the new anionic tautomers should also dominate in solutions and should be characterized by larger values of electron vertical detachment energy than the canonical valence anion. All of the new-found anionic tautomers might be formed in the course of dissociative electron attachment followed by a hydrogen atom attachment to a carbon atom, and they might affect the structure and properties of DNA and RNA exposed to low-energy electrons. The discovery of these valence anionic states of adenine was facilitated by the development of: (i) a new experimental method for preparing parent anions of nucleic acid bases for photoelectron experiments, and (ii) a new combinatorial/ quantum chemical approach for identification of the most stable tautomers of organic molecules. The computational portion of this work was supported by the: (i) Polish State Committee for Scientific Research (KBN) Grants: DS/8000-4-0140-7 (M.G.) and N204 127 31/2963 (M.H.), (ii) European Social Funds (EFS) ZPORR/2.22/II/2.6/ARP/U/2/05 (M.H.), and (iii) US DOE Office of Biological and Environmental Research, Low Dose Radiation Research Program (M.G.). M.H. holds the Foundation for Polish Science (FNP) award for young scientists. The calculations were performed at the Academic
RADIOLOGICAL ANALYSIS OF CANINE DEATH DUE TO PROJECTILE INJURY - A CASE REPORT
Directory of Open Access Journals (Sweden)
Aniruddha Banerjee
2017-12-01
Full Text Available Reason of death of a dog was analysed by radiographic findings of thoracic cavity during post mortem examination and the specific cause of death was diagnosed as due to projectile injury.
High resolution imaging of a subsonic projectile using automated mirrors with large aperture
Tateno, Y.; Ishii, M.; Oku, H.
2017-02-01
Visual tracking of high-speed projectiles is required for studying the aerodynamics around the objects. One solution to this problem is a tracking method based on the so-called 1 ms Auto Pan-Tilt (1ms-APT) system that we proposed in previous work, which consists of rotational mirrors and a high-speed image processing system. However, the images obtained with that system did not have high enough resolution to realize detailed measurement of the projectiles because of the size of the mirrors. In this study, we propose a new system consisting of enlarged mirrors for tracking a high-speed projectiles so as to achieve higher-resolution imaging, and we confirmed the effectiveness of the system via an experiment in which a projectile flying at subsonic speed tracked.
A Web-Based Video Digitizing System for the Study of Projectile Motion.
Chow, John W.; Carlton, Les G.; Ekkekakis, Panteleimon; Hay, James G.
2000-01-01
Discusses advantages of a video-based, digitized image system for the study and analysis of projectile motion in the physics laboratory. Describes the implementation of a web-based digitized video system. (WRM)
Time of flight and range of the motion of a projectile in a constant gravitational field
Directory of Open Access Journals (Sweden)
P. A. Karkantzakos
2009-01-01
Full Text Available In this paper we study the classical problem of the motion of a projectile in a constant gravitational field under the influenceof a retarding force proportional to the velocity. Specifically, we express the time of flight, the time of fall and the range ofthe motion as a function of the constant of resistance per unit mass of the projectile. We also prove that the time of fall isgreater than the time of rise with the exception of the case of zero constant of resistance where we have equality. Finally weprove a formula from which we can compute the constant of resistance per unit mass of the projectile from time of flight andrange of the motion when the acceleration due to gravity and the initial velocity of the projectile are known.
'The Monkey and the Hunter' and Other Projectile Motion Experiments with Logo.
Kolodiy, George Oleh
1988-01-01
Presents the LOGO computer language as a source to experience and investigate scientific laws. Discusses aspects and uses of LOGO. Lists two LOGO programs, one to simulate a gravitational field and the other projectile motion. (MVL)
National Research Council Canada - National Science Library
Marković Miloš D; Milinović Momčilo P; Jeremić Olivera M; Jaramaz Slobodan S
2016-01-01
The Research in this paper considered the temperatures fields as the consequently influenced effects appeared by plastic deformation, in the explosively forming process aimed to design Explosively Formed Projectiles (henceforth EFP...
Computational Simulation of High-Speed Projectiles in Air, Water, and Sand
National Research Council Canada - National Science Library
Edwards, Jack R
2007-01-01
... for efficient time integration at all flow speeds. A solids-stress model based on Mohr-Coulomb critical-state theory is used to account for compaction and deformation of sand during projectile penetration...
Behavior of Reinforced Concrete Panels Subject to Impact by Non-deformable Projectiles
Alkloub, Amer Abdel Karim
2015-01-01
In impact resistance of reinforced concrete (RC) panels against projectiles the contribution of the orthogonal mesh reinforcement has been ignored. In this study the contribution of mesh reinforcement to impact resistance and itseffect on the nature of local damage caused by impact of non-deformable projectiles are investigated. The investigation included a combination of 53 experiments and series of finite-element based numerical simulations. Three levels of local damage modes were investega...
[A sign of the rotational impact of the gunshot projectile on the flat bone].
Leonov, S V
2014-01-01
The objective of the present work was to study the mechanisms of formation of the gunshot fracture of the flat bones with special reference to the translational and rotational motion of the projectile. A total of 120 real and experimental injuries of this type were available for the investigation with the use of simulation by the finite-elemental analysis. A set of morphological features has been identified that make it possible to determine the direction of rotation of the gunshot projectile.
The Effects of High Velocity Variable Mass Projectiles on the Maxillofacial Complex,
1980-06-01
injuring missile, but it may be only one of many contributors to the morphology of the wound. High velocity projectiles, striking bone and/or teeth ...This is especially true of hits shattering the hard enamel of teeth . These findings tend to re-emphasize the work of Mcleod who stated that...through controlled studies to determine the morphology of wounds caused by such projectiles and to establish and disseminate treatment data which
Numeric Computation of the Radar Cross Section of In-flight Projectiles
2016-11-01
ABSTRACT In this report, we evaluate the radar cross section (RCS) of in-flight ballistic projectiles (rockets, artillery rounds, and mortars ) by...examples. We consider 2 types of projectiles: a 155-mm artillery round and a 120-mm mortar , as well as 4 radar frequency bands: L, S, C, and X. Using...10 2.4 Propagation and Antenna Effects and the Radar Received Power 15 3. Simulation of Ballistics Trajectories 18 3.1 The Modified Point Mass
Bounding approaches to system identification
Norton, John; Piet-Lahanier, Hélène; Walter, Éric
1996-01-01
In response to the growing interest in bounding error approaches, the editors of this volume offer the first collection of papers to describe advances in techniques and applications of bounding of the parameters, or state variables, of uncertain dynamical systems. Contributors explore the application of the bounding approach as an alternative to the probabilistic analysis of such systems, relating its importance to robust control-system design.
with Bounded Failure Intensity
Directory of Open Access Journals (Sweden)
Preeti Wanti Srivastava
2011-01-01
Full Text Available This paper deals with the Bayes prediction of the future failures of a deteriorating repairable mechanical system subject to minimal repairs and periodic overhauls. To model the effect of overhauls on the reliability of the system a proportional age reduction model is assumed and the 2-parameter Engelhardt-Bain process (2-EBP is used to model the failure process between two successive overhauls. 2-EBP has an advantage over Power Law Process (PLP models. It is found that the failure intensity of deteriorating repairable systems attains a finite bound when repeated minimal repair actions are combined with some overhauls. If such a data is analyzed through models with unbounded increasing failure intensity, such as the PLP, then pessimistic estimates of the system reliability will arise and incorrect preventive maintenance policy may be defined. On the basis of the observed data and of a number of suitable prior densities reflecting varied degrees of belief on the failure/repair process and effectiveness of overhauls, the prediction of the future failure times and the number of failures in a future time interval is found. Finally, a numerical application is used to illustrate the advantages from overhauls and sensitivity analysis of the improvement parameter carried out.
Marimuthu, N.; Singh, V.; Inbanathan, S. S. R.
2017-04-01
In this article, we present the results of our investigations on the projectile's lightest fragment (proton) multiplicity and probability distributions with 84Kr36 emulsion collision at around 1 A GeV. The multiplicity and normalized multiplicity of projectile's lightest fragment (proton) are correlated with the compound particles, shower particles, black particles, grey particles; alpha (helium nucleus) fragments and heavily ionizing charged particles. It is found that projectile's lightest fragment (proton) is strongly correlated with compound particles and shower particles rather than other particles and the average multiplicity of projectile's lightest fragment (proton) increases with increasing compound, shower and heavily ionizing charge particles. Normalized projectile's lightest fragment (proton) is strongly correlated with compound particles, shower particles and heavily ionizing charge particles. The multiplicity distribution of the projectile's lightest fragment (proton) emitted in the 84Kr36 + emulsion interaction at around 1 A GeV with different target has been well explained by KNO scaling. The mean multiplicity of projectile's lightest fragments (proton) depends on the mass number of the projectile and does not significantly dependent of the projectile energy. The mean multiplicity of projectile's lightest fragment (proton) increases with increasing the target mass number.
Opinion formation with time-varying bounded confidence.
Zhang, YunHong; Liu, QiPeng; Zhang, SiYing
2017-01-01
When individuals in social groups communicate with one another and are under the influence of neighbors' opinions, they typically revise their own opinions to adapt to such peer opinions. The individual threshold of bounded confidence will thus be affected by both a change in individual confidence and by neighbor influence. Individuals thus update their own opinions with new bounded confidence, while their updated opinions also influence their neighbors' opinions. Based on this reasoned factual assumption, we propose an opinion dynamics model with time-varying bounded confidence. A directed network is formed by the rule of the individual bounded confidence threshold. The threshold of individual bounded confidence involves both confidence variation and the in/out degree of the individual node. When the confidence variation is greater, an individual's confidence in persisting in his own opinion in interactions is weaker, and the individual is more likely to adopt neighbors' opinions. In networks, the in/out degree is determined by individual neighbors. Our main research involves the process of opinion evolution and the basic laws of opinion cluster formation. Group opinions converge exponentially to consensus with stable neighbors. An individual opinion evolution is determined by the average neighbor opinion effect strength. We also explore the conditions involved in forming a stable neighbor relationship and the influence of the confidence variation in the convergence of the threshold of bounded confidence. The results show that the influence on opinion evolution is greater with increased confidence variation.
Hartree–Fock variational bounds for ground state energy of ...
Indian Academy of Sciences (India)
The existence of a stable equilibrium high density ferromagnetic state with spheroidal occupation function is possible as long as the ratio of coupling constants Γcm ≡ (U0a3/μ2) is not very small compared to 1. Keywords. Chargeless fermions; magnetic dipole–dipole interaction; Hartree–Fock bounds; ferromagnetic ground ...
Organizational coordination and costly communication with boundedly rational agents
DEFF Research Database (Denmark)
Dietrichson, Jens; Jochem, Torsten
How does costly communication affect organizational coordination? This paper develops a model of costly communication based on the weakest-link game and boundedly rational agents. Solving for the stochastically stable states, we find that communication increases the possibilities for efficient...
Design and Analysis of A Spin-Stabilized Projectile Experimental Apparatus
Siegel, Noah; Rodebaugh, Gregory; Elkins, Christopher; van Poppel, Bret; Benson, Michael; Cremins, Michael; Lachance, Austin; Ortega, Raymond; Vanderyacht, Douglas
2017-11-01
Spinning objects experience an effect termed `The Magnus Moment' due to an uneven pressure distribution based on rotation within a crossflow. Unlike the Magnus force, which is often small for spin-stabilized projectiles, the Magnus moment can have a strong detrimental effect on aerodynamic flight stability. Simulations often fail to accurately predict the Magnus moment in the subsonic flight regime. In an effort to characterize the conditions that cause the Magnus moment, researchers in this work employed Magnetic Resonance Velocimetry (MRV) techniques to measure three dimensional, three component, sub-millimeter resolution fluid velocity fields around a scaled model of a spinning projectile in flight. The team designed, built, and tested using a novel water channel apparatus that was fully MRI-compliant - water-tight and non-ferrous - and capable of spinning a projectile at a constant rotational speed. A supporting numerical simulation effort informed the design process of the scaled projectile to thicken the hydrodynamic boundary layer near the outer surface of the projectile. Preliminary testing produced two-dimensional and three-dimensional velocity data and revealed an asymmetric boundary layer around the projectile, which is indicative of the Magnus effect.
Fairly direct hit. Advances in imaging of shotgun projectiles in MRI
Energy Technology Data Exchange (ETDEWEB)
Eggert, Sebastian [Kantonsspital Baden AG, Department of Radiology, Baden (Switzerland); University of Zurich, Institute of Forensic Medicine, Zurich (Switzerland); Kubik-Huch, Rahel A.; Peters, Alexander [Kantonsspital Baden AG, Department of Radiology, Baden (Switzerland); Klarhoefer, Markus [Siemens Healthcare, Zurich (Switzerland); Bolliger, Stephan A.; Thali, Michael J. [University of Zurich, Institute of Forensic Medicine, Zurich (Switzerland); Anderson, Suzanne [Kantonsspital Baden AG, Department of Radiology, Baden (Switzerland); University of Notre Dame Australia, Radiology, Sydney School of Medicine, Sydney, NSW (Australia); Froehlich, Johannes M. [Federal Institute of Technology, Pharmaceutical Sciences, Zurich (Switzerland)
2015-09-15
To investigate the magnetic properties of different types of projectiles and qualify the metal artefact reduction technique for diagnostic and/or forensic MRI. Ten different projectiles embedded in ordnance gelatine blocks underwent an in vitro 1.5-T MR study with seven sequences including a recently developed metal artefact reduction sequence (Advanced WARP) combining VAT (view-angle-tilting) and SEMAC (slice-encoding metal-artefact-correction). Resulting image quality (five-point scale: 1=best; 5=worst) was scored. Quantifiable magnetic characteristics were correlated with qualitative rating of the MR sequences and torque dislodgment. Metal artefact reduction sequence (median: 2.5) significantly (p < 0.001) improves depiction of projectiles in comparison to all other MR pulse sequences (median: 4.75). Images from diamagnetic composed bullets (median: 2) are much less disturbed compared to magnetic attracted ones (median: 5). Correlation (0.623) between deflection angle measurement (ferromagnetic mean 84.2 ; paramagnetic 62 ; diamagnetic mean 0 ) and median qualitative image quality was highly significant (p = 0.027). Torque dislodgement was distinct for elongated magnetic attracted projectiles. Significant improvement of MR imaging of projectiles using metal artefact reduction techniques has important implications for diagnostic/forensic work-up. The correlations between magnetic attraction force, deflection-angle results and image properties demonstrate that the MR safety of projectiles can be estimated with one of these methods. (orig.)
Pepper spray projectile/disperser for countering hostage and barricade situations
Kelly, Roy
1997-01-01
An improved less-than-lethal projectile for use in hostage, barricade and tactical assault situations has been developed. The projectile is launched from a standoff position and disperse the incapacitating agent oleoresin capsicum in the form of atomized droplets. A literature search followed by an experimental study were conducted of the mechanism of barrier defeat for various shaped projectiles against the targets of interest in this work: window glass, plasterboard and plywood. Some of the trade- offs between velocity, standoff, projectile shape and size, penetration, and residual energy were quantified. Analysis of the ballistic trajectory and recoil, together with calculations of he amount of pepper spray needed to incapacitate the occupants of a typical barricaded structure, indicated the suitability of using a fin stabilized projectile fired from a conventional 37 mm riot control gas gun. Two projectile designs were considered, manufactured and tested. The results of static tests to simulate target impact, together with live firing trials against a variety of targets, showed that rear ejection of the atomized spray was more reproducible and effective than nose ejection. The performance characteristics of the finalized design were investigated in trials using the standard barrier for testing barrier penetrating tear gas agents as defined by the National Institute of Justice.
ExtremeBounds: Extreme Bounds Analysis in R
Directory of Open Access Journals (Sweden)
Marek Hlavac
2016-08-01
Full Text Available This article introduces the R package ExtremeBounds to perform extreme bounds analysis (EBA, a sensitivity test that examines how robustly the dependent variable of a regression model is related to a variety of possible determinants. ExtremeBounds supports Leamer's EBA that focuses on the upper and lower extreme bounds of regression coefficients, as well as Sala-i-Martin's EBA which considers their entire distribution. In contrast to existing alternatives, it can estimate models of a variety of user-defined sizes, use regression models other than ordinary least squares, incorporate non-linearities in the model specification, and apply custom weights and standard errors. To alleviate concerns about the multicollinearity and conceptual overlap of examined variables, ExtremeBounds allows users to specify sets of mutually exclusive variables, and can restrict the analysis to coefficients from regression models that yield a variance inflation factor within a prespecified limit.
Projectile fragmentation studies using F, Ne, and Na isotopes
Mazza, Maria; MoNA Collaboration
2017-09-01
Projectile fragmentation is one of the techniques used at nuclear science facilities around the world for the production and study of rare isotopes. In the inverse kinematics reaction, a heavy high energy primary beam impinges on a reaction target producing an excited pre-fragment that soon decays - in a time range between 10-9 and 10-21 s - by emission of neutrons and gamma rays. The result is a secondary beam of radioactive nuclei suited for each experiment's needs, but the short lifetime of the pre-fragments prevents direct observation. However, an indirect analysis can be conducted from the reaction products. Neutron multiplicities and the excitation energies of the final fragments are in fact related to the pre-fragments produced in the target and this relationship is expected to be enhanced for final fragments with mass number closest to the reacting beam. The experiment was performed at the National Superconducting Cyclotron Laboratory (NSCL), where a 32Mg beam at 86 MeV/u was impinged on a 9Be reaction target. The MoNA Collaboration measured neutron multiplicities and kinetic energy spectra for neutrons in coincidence with sodium, neon, and fluorine final fragments in order to study the reaction mechanisms in the production of specific pre-fragments.
Multiple pulsed hypersonic liquid diesel fuel jetsdriven by projectile impact
Pianthong, K.; Takayama, K.; Milton, B. E.; Behnia, M.
2005-06-01
Further studies on high-speed liquid diesel fuel jets injected into ambient air conditions have been carried out. Projectile impact has been used as the driving mechanism. A vertical two-stage light gas gun was used as a launcher to provide the high-speed impact. This paper describes the experimental technique and visualization methods that provided a rapid series of jet images in the one shot. A high-speed video camera (106 fps) and shadowgraph optical system were used to obtain visualization. Very interesting and unique phenomena have been discovered and confirmed in this study. These are that multiple high frequency jet pulses are generated within the duration of a single shot impact. The associated multiple jet shock waves have been clearly captured. This characteristic consistently occurs with the smaller conical angle, straight cone nozzles but not with those with a very wide cone angle or curved nozzle profile. An instantaneous jet tip velocity of 2680 m/s (Mach number of 7.86) was the maximum obtained with the 40^circ nozzle. However, this jet tip velocity can only be sustained for a few microseconds as attenuation is very rapid.
Bounds for Asian basket options
Deelstra, Griselda; Diallo, Ibrahima; Vanmaele, Michèle
2008-09-01
In this paper we propose pricing bounds for European-style discrete arithmetic Asian basket options in a Black and Scholes framework. We start from methods used for basket options and Asian options. First, we use the general approach for deriving upper and lower bounds for stop-loss premia of sums of non-independent random variables as in Kaas et al. [Upper and lower bounds for sums of random variables, Insurance Math. Econom. 27 (2000) 151-168] or Dhaene et al. [The concept of comonotonicity in actuarial science and finance: theory, Insurance Math. Econom. 31(1) (2002) 3-33]. We generalize the methods in Deelstra et al. [Pricing of arithmetic basket options by conditioning, Insurance Math. Econom. 34 (2004) 55-57] and Vanmaele et al. [Bounds for the price of discrete sampled arithmetic Asian options, J. Comput. Appl. Math. 185(1) (2006) 51-90]. Afterwards we show how to derive an analytical closed-form expression for a lower bound in the non-comonotonic case. Finally, we derive upper bounds for Asian basket options by applying techniques as in Thompson [Fast narrow bounds on the value of Asian options, Working Paper, University of Cambridge, 1999] and Lord [Partially exact and bounded approximations for arithmetic Asian options, J. Comput. Finance 10 (2) (2006) 1-52]. Numerical results are included and on the basis of our numerical tests, we explain which method we recommend depending on moneyness and time-to-maturity.
Yamazaki, T
2000-01-01
A new type of nuclear spectroscopy to study hadron-nucleus bound states is described. The first successful experiment was to search for deeply bound pi sup - states in heavy nuclei using the sup 2 sup 0 sup 8 Pb(d, sup 3 He) reaction at GSI, in which a narrow peak arising from the 2p pi sup - orbital coupled with the neutron-hole states was observed at 135 MeV excitation energy. An improved experiment has just been carried out to separately identify the 1s and 2p pi sup - states. These experiments provide important information on the local potential strength, from which the effective mass of pi sup - is deduced to be 20 MeV. This method will be extended to search for eta and omega bound states as well as for K sup - bound states. The advantage of the bound-state spectroscopy versus invariant mass spectroscopy is emphasized.
Market Access through Bound Tariffs
DEFF Research Database (Denmark)
Sala, Davide; Schröder, Philipp J.H.; Yalcin, Erdal
on the risk that exporters face in destination markets. The present paper formalizes the underlying interaction of risk, fixed export costs and firms' market entry decisions based on techniques known from the real options literature; doing so we highlight the important role of bound tariffs at the extensive......WTO negotiations deal predominantly with bound - besides applied - tariff rates. But, how can reductions in tariffs ceilings, i.e. tariff rates that no exporter may ever actually be confronted with, generate market access? The answer to this question relates to the effects of tariff bindings...... margin of trade. We find that bound tariffs are more effective with higher risk destination markets, that a large binding overhang may still command substantial market access, and that reductions in bound tariffs generate effective market access even when bound rates are above current and long...
Market access through bound tariffs
DEFF Research Database (Denmark)
Sala, Davide; Schröder, Philipp J.H.; Yalcin, Erdal
2010-01-01
on the risk that exporters face in destination markets. The present paper formalizes the underlying interaction of risk, fixed export costs and firms' market entry decisions based on techniques known from the real options literature; doing so we highlight the important role of bound tariffs at the extensive......WTO negotiations deal predominantly with bound - besides applied - tariff rates. But, how can reductions in tariffs ceilings, i.e. tariff rates that no exporter may ever actually be confronted with, generate market access? The answer to this question relates to the effects of tariff bindings...... margin of trade. We find that bound tariffs are more effective with higher risk destination markets, that a large binding overhang may still command substantial market access, and that reductions in bound tariffs generate effective market access even when bound rates are above current and longterm...
National Oceanic and Atmospheric Administration, Department of Commerce — Tissue samples (skin, bone, blood, muscle) are analyzed for stable carbon, stable nitrogen, and stable sulfur analysis. Many samples are used in their entirety for...
2015-09-01
Projectile Using a Coupled Computational Fluid Dynamics (CFD)-based Simulation Technique: Free Motion 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM...38 vi Preface The paper “Flight Behaviors of a Complex Projectile using a Coupled CFD-based Simulation Technique: Free Motion ” was...involves coupling of CFD and rigid body dynamics (RBD) codes for the simulation of projectile free flight motion in a time-accurate manner. This
The influence of aerodynamic coefficients on the elements of classic projectile paths
Directory of Open Access Journals (Sweden)
Damir D. Jerković
2011-04-01
Full Text Available The article deals with the results of the research on the influence of aerodynamic coefficient values on the trajectory elements and the stability parameters of classic axisymmetric projectiles. It presents the characteristic functions of aerodynamic coefficients with regard to aerodynamic parameters and the projectile body shape. The trajectory elements of the model of classic axisymmetric projectiles and the analyses of their changes were presented with respect to the aerodynamic coefficient values. Introduction Classic axisymmetric projectiles fly through atmosphere using muzzle velocity as initial energy resource, so the aerodynamic force and moment have the most significant influence on the motion of projectiles. The aerodynamic force and moment components represented as aerodynamic coefficients depend on motion velocity i. e. flow velocity, the flow features produced by projectile shape and position in the flow, and angular velocity (rate of the body. The functional dependence of aerodynamic coefficients on certain influential parameters, such as angle of attack and angular velocity components is expressed by the derivative of aerodynamic coefficients. The determination of aerodynamic coefficients and derivatives enables complete definition of the aerodynamic force and moment acting on the classic projectile. The projectile motion problem is considered in relation to defining the projectile stability parameters and the conditions under which the stability occurs. The comparative analyses of aerodynamic coefficient values obtained by numerical methods, semi empirical calculations and experimental research give preliminary evaluation of the quality of the determined values. The flight simulation of the motion of a classic axisymetric projectile, which has the shape defined by the aerodynamic coefficient values, enables the comparative analyses of the trajectory elements and stability characteristics. The model of the classic projectile
Xu, Xing; Zhang, Yu-hu; Xu, Hu-shan; Shuai, Peng; Tu, Xiao-lin; Litvinov, Yuri A; Zhou, Xiao-hong; Sun, Bao-hua; Yuan, You-jin; Xia, Jia-wen; Yang, Jian-cheng; Blaum, KLaus; Chen, Rui-jiu; Chen, Xiang-cheng; Fu, Chao-yi; Ge, Zhuang; Hu, Zheng-guo; Huang, Wen-jia; Liu, Da-wei; Lam, Yi-hua; Ma, Xin-wen; Mao, Rui-shi; Uesaka, T; Xiao, Guo-ging; Xing, Yuan-ming; Yamaguchi, T; Yamaguchi, Y; Zeng, Qi; Yan, Xin-liang; Zhao, Hong-wei; Zhao, Tie-cheneg; Zhang, Wei; Zhan, Wen-long
2016-01-01
In this paper, we present direct mass measurements of neutron-rich $^{86}$Kr projectile fragments conducted at the HIRFL-CSR facility in Lanzhou by employing the Isochronous Mass Spectrometry (IMS) method. The new mass excesses of $^{52-54}$Sc nuclides are determined to be -40492(82), -38928(114), -34654(540) keV, which show a significant increase of binding energy compared to the reported ones in the Atomic Mass Evaluation 2012 (AME12). In particular, $^{53}$Sc and $^{54}$Sc are more bound by 0.8 MeV and 1.0 MeV, respectively. The behavior of the two neutron separation energy with neutron numbers indicates a strong sub-shell closure at neutron number $N$ = 32 in Sc isotopes.
Xu, Xing; Wang, Meng; Zhang, Yu-Hu; Xu, Hu-Shan; Shuai, Peng; Tu, Xiao-Lin; Yuri, A. Litvinov; Zhou, Xiao-Hong; Sun, Bao-Hua; Yuan, You-Jin; Xia, Jia-Wen; Yang, Jian-Cheng; Klaus, Blaum; Chen, Rui-Jiu; Chen, Xiang-Cheng; Fu, Chao-Yi; Ge, Zhuang; Hu, Zheng-Guo; Huang, Wen-Jia; Liu, Da-Wei; Lam, Yi-Hua; Ma, Xin-Wen; Mao, Rui-Shi; Uesaka, T.; Xiao, Guo-Qing; Xing, Yuan-Ming; Yamaguchi, T.; Yamaguchi, Y.; Zeng, Qi; Yan, Xin-Liang; Zhao, Hong-Wei; Zhao, Tie-Cheng; Zhang, Wei; Zhan, Wen-Long
2015-10-01
In this paper, we present direct mass measurements of neutron-rich 86Kr projectile fragments conducted at the HIRFL-CSR facility in Lanzhou by employing the Isochronous Mass Spectrometry (IMS) method. The new mass excesses of 52-54Sc nuclides are determined to be -40492(82), -38928(114), -34654(540) keV, which show a significant increase of binding energy compared to the reported ones in the Atomic Mass Evaluation 2012 (AME12). In particular, 53Sc and 54Sc are more bound by 0.8 MeV and 1.0 MeV, respectively. The behavior of the two neutron separation energy with neutron numbers indicates a strong sub-shell closure at neutron number N=32 in Sc isotopes. Supported by 973 Program of China (2013CB834401), the NSFC (U1232208, U1432125, 11205205, 11035007) and the Helmholtz-CAS Joint Research Group (HCJRG-108)
Hybrid Projectile Body Angle Estimation for Selectable Range Increase
Gioia, Christopher J.
A Hybrid Projectile (HP) is a tube launched munition that transforms into a gliding UAV, and is currently being researched at West Virginia University. A simple launch timer was first envisioned to control the transformation point in order to achieve maximum distance. However, this timer would need to be reprogrammed for any distance less than maximum range due to the nominal time to deployment varying with launch angle. A method was sought for automatic wing deployment that would not require reprogramming the round. A body angle estimation system was used to estimate the pitch of the HP relative to the Earth to determine when the HP is properly oriented for the designed glide slope angle. It was also necessary to filter out noise from a simulated inertial measurement unit (IMU), GPS receiver, and magnetometer. An Extended Kalman Filter (EKF) was chosen to estimate the Euler angles, position and velocity of the HP while an algorithm determined when to deploy the wings. A parametric study was done to verify the optimum deployment condition using a Simulink aerodynamic model. Because range is directly related to launch angle, various launch angles were simulated in the model. By fixing the glide slope angle to -10° as a deployment condition for all launch angles, the range differed only by a maximum of 6.1% from the maximum possible range. Based on these findings, the body angle deployment condition provides the most flexible option to maintain maximum distance without the need of reprogramming. Position and velocity estimates were also determined from the EKF using the GPS measurements. Simulations showed that the EKF estimates exhibited low root mean squared error values, corresponding to less than 3% of the total position values. Because the HP was in flight for less than a minute in this experiment, the drift encountered was acceptable.
Combining Alphas via Bounded Regression
Directory of Open Access Journals (Sweden)
Zura Kakushadze
2015-11-01
Full Text Available We give an explicit algorithm and source code for combining alpha streams via bounded regression. In practical applications, typically, there is insufficient history to compute a sample covariance matrix (SCM for a large number of alphas. To compute alpha allocation weights, one then resorts to (weighted regression over SCM principal components. Regression often produces alpha weights with insufficient diversification and/or skewed distribution against, e.g., turnover. This can be rectified by imposing bounds on alpha weights within the regression procedure. Bounded regression can also be applied to stock and other asset portfolio construction. We discuss illustrative examples.
Directory of Open Access Journals (Sweden)
Stuart Leigh Phoenix
2017-03-01
Full Text Available Yarn shooting experiments were conducted to determine the ballistically-relevant, Young’s modulus and tensile strength of ultra-high molecular weight polyethylene (UHMWPE fiber. Target specimens were Dyneema® SK76 yarns (1760 dtex, twisted to 40 turns/m, and initially tensioned to stresses ranging from 29 to 2200 MPa. Yarns were impacted, transversely, by two types of cylindrical steel projectiles at velocities ranging from 150 to 555 m/s: (i a reverse-fired, fragment simulating projectile (FSP where the flat rear face impacted the yarn rather than the beveled nose; and (ii a ‘saddle-nosed projectile’ having a specially contoured nose imparting circular curvature in the region of impact, but opposite curvature transversely to prevent yarn slippage off the nose. Experimental data consisted of sequential photographic images of the progress of the triangular transverse wave, as well as tensile wave speed measured using spaced, piezo-electric sensors. Yarn Young’s modulus, calculated from the tensile wave-speed, varied from 133 GPa at minimal initial tension to 208 GPa at the highest initial tensions. However, varying projectile impact velocity, and thus, the strain jump on impact, had negligible effect on the modulus. Contrary to predictions from the classical Cole-Smith model for 1D yarn impact, the critical velocity for yarn failure differed significantly for the two projectile types, being 18% lower for the flat-faced, reversed FSP projectile compared to the saddle-nosed projectile, which converts to an apparent 25% difference in yarn strength. To explain this difference, a wave-propagation model was developed that incorporates tension wave collision under blunt impact by a flat-faced projectile, in contrast to outward wave propagation in the classical model. Agreement between experiment and model predictions was outstanding across a wide range of initial yarn tensions. However, plots of calculated failure stress versus yarn pre
Accuracy Improvement Capability of Advanced Projectile Based on Course Correction Fuze Concept
Directory of Open Access Journals (Sweden)
Ahmed Elsaadany
2014-01-01
Full Text Available Improvement in terminal accuracy is an important objective for future artillery projectiles. Generally it is often associated with range extension. Various concepts and modifications are proposed to correct the range and drift of artillery projectile like course correction fuze. The course correction fuze concepts could provide an attractive and cost-effective solution for munitions accuracy improvement. In this paper, the trajectory correction has been obtained using two kinds of course correction modules, one is devoted to range correction (drag ring brake and the second is devoted to drift correction (canard based-correction fuze. The course correction modules have been characterized by aerodynamic computations and flight dynamic investigations in order to analyze the effects on deflection of the projectile aerodynamic parameters. The simulation results show that the impact accuracy of a conventional projectile using these course correction modules can be improved. The drag ring brake is found to be highly capable for range correction. The deploying of the drag brake in early stage of trajectory results in large range correction. The correction occasion time can be predefined depending on required correction of range. On the other hand, the canard based-correction fuze is found to have a higher effect on the projectile drift by modifying its roll rate. In addition, the canard extension induces a high-frequency incidence angle as canards reciprocate at the roll motion.
Accuracy improvement capability of advanced projectile based on course correction fuze concept.
Elsaadany, Ahmed; Wen-jun, Yi
2014-01-01
Improvement in terminal accuracy is an important objective for future artillery projectiles. Generally it is often associated with range extension. Various concepts and modifications are proposed to correct the range and drift of artillery projectile like course correction fuze. The course correction fuze concepts could provide an attractive and cost-effective solution for munitions accuracy improvement. In this paper, the trajectory correction has been obtained using two kinds of course correction modules, one is devoted to range correction (drag ring brake) and the second is devoted to drift correction (canard based-correction fuze). The course correction modules have been characterized by aerodynamic computations and flight dynamic investigations in order to analyze the effects on deflection of the projectile aerodynamic parameters. The simulation results show that the impact accuracy of a conventional projectile using these course correction modules can be improved. The drag ring brake is found to be highly capable for range correction. The deploying of the drag brake in early stage of trajectory results in large range correction. The correction occasion time can be predefined depending on required correction of range. On the other hand, the canard based-correction fuze is found to have a higher effect on the projectile drift by modifying its roll rate. In addition, the canard extension induces a high-frequency incidence angle as canards reciprocate at the roll motion.
Fragmentation of armor piercing steel projectiles upon oblique perforation of steel plates
Directory of Open Access Journals (Sweden)
Aizik F.
2012-08-01
Full Text Available In this study, a constitutive strength and failure model for a steel core of a14.5 mm API projectile was developed. Dynamic response of a projectile steel core was described by the Johnson-Cook constitutive model combined with principal tensile stress spall model. In order to obtain the parameters required for numerical description of projectile core material behavior, a series of planar impact experiments was done. The parameters of the Johnson-Cook constitutive model were extracted by matching simulated and experimental velocity profiles of planar impact. A series of oblique ballistic experiments with x-ray monitoring was carried out to study the effect of obliquity angle and armor steel plate thickness on shattering behavior of the 14.5 mm API projectile. According to analysis of x-ray images the fragmentation level increases with both steel plate thickness and angle of inclination. The numerical modeling of the ballistic experiments was done using commercial finite element code, LS-DYNA. Dynamic response of high hardness (HH armor steel was described using a modified Johnson-Cook strength and failure model. A series of simulations with various values of maximal principal tensile stress was run in order to capture the overall fracture behavior of the projectile’s core. Reasonable agreement between simulated and x-ray failure pattern of projectile core has been observed.
Computational Lower Bounds Using Diagonalization
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 7. Computational Lower Bounds Using Diagonalization - Languages, Turing Machines and Complexity Classes. M V Panduranga Rao. General Article Volume 14 Issue 7 July 2009 pp 682-690 ...
Dancing Volvox: Hydrodynamic Bound States of Swimming Algae
Drescher, Knut; Leptos, Kyriacos C.; Tuval, Idan; Ishikawa, Takuji; Pedley, Timothy J.; Goldstein, Raymond E.
2013-01-01
The spherical alga Volvox swims by means of flagella on thousands of surface somatic cells. This geometry and its large size make it a model organism for studying the fluid dynamics of multicellularity. Remarkably, when two nearby Volvox colonies swim close to a solid surface, they attract one another and can form stable bound states in which they “waltz” or “minuet” around each other. A surface-mediated hydrodynamic attraction combined with lubrication forces between spinning, bottom-heavy Volvox explains the formation, stability, and dynamics of the bound states. These phenomena are suggested to underlie observed clustering of Volvox at surfaces. PMID:19518757
Bounded Rationality in Transposition Processes
DEFF Research Database (Denmark)
Vollaard, Hans; Martinsen, Dorte Sindbjerg
2014-01-01
perspective may affect the commonly employed explanatory factors of administrative capacities, misfit and the heterogeneity of preferences among veto players. To prevent retrospective rationalisation of the transposition process, this paper traces this process as it unfolded in Denmark and the Netherlands....... As bounded rationality is apparent in the transposition processes in these relatively well-organised countries, future transposition studies should devote greater consideration to the bounded rationality perspective....
Volume Stability of Bitumen Bound Building Blocks
Directory of Open Access Journals (Sweden)
Thanaya I.N.A.
2010-01-01
Full Text Available This paper covers results of laboratory investigations on the volume stability of masonry units incorporating waste materials bound with bitumen (Bitublocks, due to moisture adsorption, thermal exposure and vacuum saturation. The materials used were steel slag, crushed glass, coal fly ash, and 50 pen bitumen. The samples were produced in hot mix method, compacted, then exposed to moist and temperature. It was found that moisture adsorption from the environment caused the Bitublock to expand. The samples with less intense curing regime experienced lower expansion and became stable faster, and vice versa. Under thermal condition (at 70°C, the samples with less intense curing regime underwent higher expansion, and vice versa. They were also highly reversible. Their volume stability was found unique under water exposure. The expansion on first vacuum saturation cycle was irreversible, then largely reversible on the following cycles.
Special features of high-speed projectile interaction with barriers protected by a water layer
Afanas'eva, S. A.; Belov, N. N.; Burkin, V. V.; D'yachkovskii, A. S.; Evtyushkin, E. V.; Zykov, E. N.; Ishchenko, A. N.; Monakhov, R. Yu.; Rodionov, A. A.; Khabibullin, M. V.; Yugov, N. T.
2013-09-01
The stress-strain state (SSS) of projectiles is investigated when a high-speed projectile enters water and interacts with barriers protected by a water layer. Experimental investigations are carried out using a high-speed ballistic setup. Calculations are performed within the framework of mechanics of continuous media for an elastic plastic model of a solid with allowance for fracture and hydrodynamic water model. Depending on the projectile speed, different SSS regimes are observed: from small deformed at a speed of ≈1 km/s to fractured at a speed of ≈2 km/s. Calculation technique allows distances in water to be determined at which the metal barrier can be punched for the inertial model.
Projectile motion of a once rotating object: physical quantities at the point of return
Arabasi, Sameer
2016-09-01
Vertical circular motion is a widely used example to explain non-uniform circular motion in most undergraduate general physics textbooks. However, most of these textbooks do not elaborate on the case when this motion turns into projectile motion under certain conditions. In this paper, we describe thoroughly when a mass attached to a cord, moving in a vertical circular motion, turns into a projectile and its location and velocity when it rejoins the circular orbit. This paper provides an intuitive understanding, supported by basic kinematic equations, to give an interesting elegant connection between circular motion and projectile motion—something lacking in most physics textbooks—and will be very useful to present to an undergraduate class to deepen their understanding of both models of motion.
Directory of Open Access Journals (Sweden)
Zhang Dongyang
2014-06-01
Full Text Available How to detect the ground motion metal target effectively is an important guarantee for precision strike in the process of Rocket Projectile flight. Accordingly and in view of the millimeter- wave radiation characteristic of the ground motion metal target, a mathematical model was established based on Rocket Projectile about millimeter-wave detection to the ground motion metal target. Through changing various parameters in the process of Rocket Projectile flight, the detection model was studied by simulation. The parameters variation and effective range of millimeter wave radiometer were obtained in the process of rotation and horizontal flight. So a certain theoretical basis was formed for the precision strike to the ground motion metal target.
On the non-equilibrium dynamics of cavitation around the underwater projectile in variable motion
Chen, Y.; Lu, C. J.; Li, J.; Chen, X.; Gong, Z. X.
2015-12-01
In this work, the dynamic behavior of the non-equilibrium cavitation occurring around the underwater projectiles navigating with variable speed was numerically and theoretically investigated. The cavity collapse induced by the decelerating motion of the projectiles can be classified into two types: periodic oscillation and damped oscillation. In each type the evolution of the total mass of vapor in cavity are found to have strict correlation with the pressure oscillation in far field. By defining the equivalent radius of cavity, we introduce the specific kinetic energy of collapse and demonstrate that its change-rate is in good agreement with the pressure disturbance. We numerically investigated the influence of angle of attack on the collapse effect. The result shows that when the projectile decelerates, an asymmetric-focusing effect of the pressure induced by collapse occurs on its pressure side. We analytically explained such asymmetric-focusing effect.
Kirischuk, V I; Khomenkov, V P; Strilchuk, N V; Zheltonozhskij, V A
2004-01-01
/sup 178m2/Hf isomer production in different spallation reactions with protons, alpha particles and neutrons at projectile energies up to 100 MeV has been analyzed using both STAPRE and ALICE code simulations. The STAPRE code was used to calculate the isomeric ratios, while the ALICE code was used to simulate the excitation functions of the respective ground states. A number of spallation reactions have been compared taking into account not only /sup 178m2 /Hf isomer productivity but also, first, the isomeric ratios calculated by the STAPRE code; second, the accumulation of the most undesirable Hf isotopes and isomers, such as /sup 172/Hf, /sup 175 /Hf, and /sup 179m/Hf; and, third, the production of other admixtures and by-products that could degrade the quality of the produced /sup 178m2/Hf isomer sources, including all stable Hf isotopes as well. Possibilities and ways of optimizing /sup 178m2/Hf isomer production in spallation reactions at projectile energies up to 100 MeV are discussed. This can be consi...
Hutem, Artit; Kerdmee, Supoj
2013-01-01
The propose of this study is to study Physics Learning Achievement, projectile motion, using the Mathematica program of Faculty of Science and Technology Phetchabun Rajabhat University students, comparing with Faculty of Science and Technology Phetchabun Rajabhat University students who study the projectile motion experiment set. The samples are…
On The Roman Domination Stable Graphs
Directory of Open Access Journals (Sweden)
Hajian Majid
2017-11-01
Full Text Available A Roman dominating function (or just RDF on a graph G = (V,E is a function f : V → {0, 1, 2} satisfying the condition that every vertex u for which f(u = 0 is adjacent to at least one vertex v for which f(v = 2. The weight of an RDF f is the value f(V (G = Pu2V (G f(u. The Roman domination number of a graph G, denoted by R(G, is the minimum weight of a Roman dominating function on G. A graph G is Roman domination stable if the Roman domination number of G remains unchanged under removal of any vertex. In this paper we present upper bounds for the Roman domination number in the class of Roman domination stable graphs, improving bounds posed in [V. Samodivkin, Roman domination in graphs: the class RUV R, Discrete Math. Algorithms Appl. 8 (2016 1650049].
Distorted wave theories for dressed-ion-atom collisions with GSZ projectile potentials
Energy Technology Data Exchange (ETDEWEB)
Monti, J M; Rivarola, R D [Instituto de Fisica Rosario (CONICET-UNR) and Facultad de Ciencias Exactas, IngenierIa y Agrimensura, Universidad Nacional de Rosario, Avenida Pellegrini 250, 2000 Rosario (Argentina); Fainstein, P D, E-mail: monti@ifir-conicet.gov.ar [Comision Nacional de EnergIa Atomica, Centro Atomico Bariloche, 8400 San Carlos de Bariloche (Argentina)
2011-10-14
The continuum distorted wave and the continuum distorted wave-eikonal initial state approximations for electron emission in ion-atom collisions are generalized to the case of dressed projectiles. The interaction between the dressed projectile and the active electron is represented by the analytic Green-Sellin-Zachor (GSZ) potential. Doubly differential cross sections as a function of the emitted electron energy and angle are computed. The region of the binary encounter peak is analysed in detail. Interference structures appear in agreement with the experimental data and are interpreted as arising from the coherent interference between short- and long-range scattering amplitudes.
Directory of Open Access Journals (Sweden)
Ke Liang
2017-06-01
Full Text Available An optimization method is introduced to design the aerodynamic parameters of a dual-spin two-dimensional guided projectile with the canards for trajectory correction. The nose guidance component contains two pairs of canards which can provide lift and despin with the projectile for stability. The optimal design algorithm is developed to decide the profiles both of the steering and spinning canards, and their deflection angles are also simulated to meet the needs of trajectory correction capabilities. Finally, the aerodynamic efficiency of the specific canards is discussed according to the CFD simulations. Results that obtained here can be further applied to the exterior ballistics design.
Estimating 3D positions and velocities of projectiles from monocular views.
Ribnick, Evan; Atev, Stefan; Papanikolopoulos, Nikolaos P
2009-05-01
In this paper, we consider the problem of localizing a projectile in 3D based on its apparent motion in a stationary monocular view. A thorough theoretical analysis is developed, from which we establish the minimum conditions for the existence of a unique solution. The theoretical results obtained have important implications for applications involving projectile motion. A robust, nonlinear optimization-based formulation is proposed, and the use of a local optimization method is justified by detailed examination of the local convexity structure of the cost function. The potential of this approach is validated by experimental results.
Tissue preservation and projectile context in a Spanish Civil War victim.
Ferllini, Roxana
2010-07-01
Exhumations of mass graves containing the remains of those executed during the Spanish Civil War and the subsequent Franco regime are currently being conducted at the request of surviving relatives. This individual case report illustrates how soft tissue preservation, through copper ion contact in one particular victim aided in preserving the projectile in an anatomical context, thereby permitting the correct interpretation of the projectile's path and angle, which otherwise would not have been possible as no bone tissue was affected. The information obtained has important relevance for human rights investigations and the work of the forensic anthropologist. Copyright 2010 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.
Reliability of double-wall containment against the impact of hard projectiles
Energy Technology Data Exchange (ETDEWEB)
Siddiqui, Nadeem A., E-mail: nadeem@ksu.edu.sa; Khateeb, Baha M.A.; Almusallam, Tarek H.; Abbas, Husain
2014-04-01
Highlights: • The reliability of double-wall containment against impact of projectiles was studied. • Probabilistic procedure based on Monte Carlo simulation technique was used. • Sensitivity studies were carried out to obtain the results of practical interest. • Reliability is correlated with the ballistic limit of the outer RC wall. - Abstract: Effectiveness of single or double-wall containment structures against a possible strike of projectiles, missiles or airplanes is well researched. However, how the uncertainties involved in the various design parameters influence the reliability of the containment is not very well known. In a double-wall containment structure, as name implies, there are two walls – an outer thick reinforced concrete (RC) wall and an inner thin steel shell/wall. In the present study, a simple probabilistic procedure based on Monte Carlo simulation technique is presented to study the reliability of double-wall containment structures against the impact of external hard projectiles on outer RC wall for varying impact velocities. In order to illustrate the proposed methodology, an idealized double-wall containment structure and a hard projectile were chosen. The probability of failure and the reliability indices of the selected double-wall containment structure were obtained for different striking velocities of the projectile and safety of the containment was correlated with the ballistic limit of the outer RC wall. The results of the study show that the double-wall containment is “safe enough” against the impact of the selected projectile if the projectile nominal velocity is less than 65% of the containment outer wall's nominal ballistic limit (V{sub BL}). Results also show that under the given uncertainties, if the nominal impact velocity is less than 65% of the nominal ballistic limit of the outer RC wall (i.e. 0.65V{sub BL}), failure probability of the containment is almost zero. However, when impact velocity is more than
Effectiveness of projectile screening in single and multiple ionization of Ne by B{sup 2+}
Energy Technology Data Exchange (ETDEWEB)
Wolff, W.; Luna, H.; Santos, A. C. F.; Montenegro, E. C. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, Rio de Janeiro, 21945-970 RJ (Brazil); DuBois, R. D. [Department of Physics, Missouri University of Science and Technology, Rolla, Missouri 65409 (United States); Montanari, C. C.; Miraglia, J. E. [Instituto de Astronomia y Fisica del Espacio, Casilla de Correo 67, Sucursal 28, C1428EGA, Buenos Aires (Argentina)
2011-10-15
Pure multiple ionization cross sections of Ne by B{sup 2+} projectiles have been measured in the energy range of 0.75 to 4.0 MeV and calculated using the continuum distorted wave-eikonal initial state approximation. The experiment and calculations show that the ionization cross sections by B{sup 2+}, principally for the production of highly charged recoils, is strongly enhanced when compared to the bare projectile with the same charge state, He{sup 2+}, at the same velocities.
Directory of Open Access Journals (Sweden)
Matthew L. Sisk
2011-01-01
Full Text Available Despite a body of literature focusing on the functionality of modern and stylistically distinct projectile points, comparatively little attention has been paid to quantifying the functionality of the early stages of projectile use. Previous work identified a simple ballistics measure, the Tip Cross-Sectional Area, as a way of determining if a given class of stone points could have served as effective projectile armatures. Here we use this in combination with an alternate measure, the Tip Cross-Sectional Perimeter, a more accurate proxy of the force needed to penetrate a target to a lethal depth. The current study discusses this measure and uses it to analyze a collection of measurements from African Middle Stone Age pointed stone artifacts. Several point types that were rejected in previous studies are statistically indistinguishable from ethnographic projectile points using this new measure. The ramifications of this finding for a Middle Stone Age origin of complex projectile technology is discussed.
Refractive effects in the scattering of loosely bound nuclei
Energy Technology Data Exchange (ETDEWEB)
Carstoiu, F.; Trache, L.; Tribble, R.E.; Gagliardi, C.A. [Texas A and M Univ., College Station, TX (United States). Cyclotron Inst; Carstoiu, F. [Laboratoire de Physique Corpusculaire, IN2P3-CNRS, ISMRA, Universite de Caen, 14 - Caen (France); Carstoiu, F. [National Institute for Physics and Nuclear Engineering, Horia Hulubei, Bucharest-Magurele (Romania)
2004-07-01
A study of the interaction of the loosely bound nuclei {sup 6,7}Li at 9 and 19 MeV/nucleon with light targets has been undertaken. With the determination of unambiguous optical potentials in mind, elastic data for four projectile-target combinations and one neutron transfer reaction {sup 13}C({sup 7}Li,{sup 8}Li){sup 12}C have been measured over a large angular range. The kinematical regime encompasses a region where the mean field (optical potential) has a marked variation with mass and energy, but turns out to be sufficiently surface transparent to allow strong refractive effects to be manifested in elastic scattering data at intermediate angles. The identified exotic feature, a 'plateau' in the angular distributions at intermediate angles, is fully confirmed in four reaction channels and is interpreted as a pre-rainbow oscillation resulting from the interference of the barrier and internal barrier far-side scattering sub-amplitudes. (authors)
Development of odd-Z-projectile reactions for transactinide element synthesis
Energy Technology Data Exchange (ETDEWEB)
Folden, III, Charles Marvin [Univ. of California, Berkeley, CA (United States)
2004-01-01
The development of new odd-Z-projectile reactions leading to the production of transactinide elements is described. The cross section of the even-Z-projectile ^{208}Pb(^{64}Ni, n)^{271}Ds reaction was measured at two new energies using the Berkeley Gas-filled Separator at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron. In total, seven decay chains attributable to ^{271}Ds were observed. These data, combined with previous results, establish an excitation function for the production of ^{271}Ds. The maximum cross section was 20 +15 -11 pb at a center-of-target energy of 311.5 MeV in the laboratory frame.The data from the^{ 27}1Ds experiments were used to estimate the optimum beam energy for the new odd-Z-projectile ^{208}Pb(^{65}Cu, n)272-111 reaction using the Fusion by Diffusion theory proposed by Swiatecki, Siwek-Wilczynska, and Wilczynski. A cross section for this reaction was measured for the first time, at a center-of-target energy of 321.1 MeV in the laboratory frame. The excitation energy f or compound nuclei formed at the target center was 13.2 MeV. One decay chain was observed, resulting in a measured cross section of 1.7 +3.9 -1.4 pb. This decay chain is in good agreement with previously published data on the decay of 272-111.The new odd-Z-projectile ^{208}Pb(^{55}Mn, n)^{26}2Bh reaction was studied at three different projectile energies, and 33 decay chains of ^{262}Bh were observed. The existence of a previously reported alpha-decaying isomeric state in this nuclide was confirmed. Production of the ground state was preferred at all three beam energies. The maximum cross section was 540 +180 -150 pb at a projectile center-of-target energy of 264.0 MeV. This cross section is much larger than that previously reported for the even-Z-projectile ^{209}Bi(^{54}Cr, n)^{262}Bh reaction, which may be because the 54Cr projectile
National Aeronautics and Space Administration — The code in the stableGP package implements Gaussian process calculations using efficient and numerically stable algorithms. Description of the algorithms is in the...
Space-bounded communication complexity
DEFF Research Database (Denmark)
Brody, Joshua Eric; Chen, Shiteng; Papakonstantinou, Periklis A.
2013-01-01
-obliviousness shows up. For this model we also introduce new techniques through which certain limitations of space-bounded computation are revealed. One of the main motivations of this work is in understanding the difference in the use of space when computing the following functions: Equality (EQ), Inner Product (IP......In the past thirty years, Communication Complexity has emerged as a foundational tool to proving lower bounds in many areas of computer science. Its power comes from its generality, but this generality comes at a price---no superlinear communication lower bound is possible, since a player may...... communicate his entire input. However, what if the players are limited in their ability to recall parts of their interaction? We introduce memory models for 2-party communication complexity. Our general model is as follows: two computationally unrestricted players, Alice and Bob, each have s(n) bits of memory...
Iemhoff, R.; Bezhanishvili, N.; Bezhanishvili, Guram
2016-01-01
We introduce stable canonical rules and prove that each normal modal multi-conclusion consequence relation is axiomatizable by stable canonical rules. We apply these results to construct finite refutation patterns for modal formulas, and prove that each normal modal logic is axiomatizable by stable
Bezhanishvili, G.; Bezhanishvili, N.; Iemhoff, R.
We introduce stable canonical rules and prove that each normal modal multi-conclusion consequence relation is axiomatizable by stable canonical rules. We apply these results to construct finite refutation patterns for modal formulas, and prove that each normal modal logic is axiomatizable by stable
Shape Effect Analysis of Aluminum Projectile Impact on Whipple Shields
Carrasquilla, Maria J.; Miller, Joshua E.
2017-01-01
respect to their mass, size, and material composition needs to be summarized in a form that can be used in MMOD analysis. The mechanism that brings these fragment traits into MMOD analysis is through ballistic limit equations (BLE) that have been developed largely for a few types of materials1. As a BLE provides the failure threshold for a shield or spacecraft component based on parameters such as the projectile impact velocity and size, and the target's materials, thickness, and configuration, it is used to design protective shields for spacecraft such as Whipple shields (WS) to an acceptable risk level. The majority of experiments and simulations to test shields and validate BLEs have, heretofore, largely used spheres as the impactor, not properly reflecting the irregular shapes of MMOD. This shortfall has motivated a numerical impact analysis study of HVI involving non-spherical geometries to identify key parameters that environment models should provide.
Living in a physical world II. The bio-ballistics of small projectiles
Indian Academy of Sciences (India)
2005-02-21
Feb 21, 2005 ... Home; Journals; Journal of Biosciences; Volume 30; Issue 2. Living in a physical world II. The bio-ballistics of small projectiles. Steven Vogel. Series Volume 30 Issue 2 March 2005 pp 167-175. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/jbsc/030/02/0167-0175 ...
Hagelberg, Frank
2003-03-01
Computational results on atomic scattering between charged projectiles and transition metal target atoms are presented. This work aims at obtaining detailed information about charge, spin and energy transfer processes that occur between the interacting particles. An in-depth understanding of these phenomena is expected to provide a theoretical basis for the interpretation of various types of ion beam experiments, ranging from gas phase chromatography to spectroscopic observations of fast ions in ferromagnetic media. This contribution focuses on the scattering of light projectiles ranging from He to O, that are prepared in various initial charge states, by 3d transition metal atoms. The presented computations are performed in the framework of Electron Nuclear Dynamics (END)^1 theory which incorporates the coupling between electronic and nuclear degrees of freedom without reliance on the computationally cumbersome and frequently intractable determination of potential energy surfaces. In the present application of END theory to ion - transition metal atom scattering, a supermolecule approach is utilized in conjunction with a spin-unrestricted single determinantal wave function describing the electronic system. Integral scattering, charge and spin exchange cross sections are discussed as functions of the elementary parameters of the problem, such as projectile and target atomic numbers as well as projectile charge and initial kinetic energy. ^1 E.Deumens, A.Diz, R.Longo, Y.Oehrn, Rev.Mod.Phys. 66, 917 (1994)
K-vacancy production by secondaries due to charged projectiles in thick targets
Energy Technology Data Exchange (ETDEWEB)
Onegin, M.S. [St. Petersburg Inst. of Nuclear Physics, Gatchina (Russian Federation); Pashuk, V.V. [St. Petersburg Inst. of Nuclear Physics, Gatchina (Russian Federation); Tverskoy, M.G. [St. Petersburg Inst. of Nuclear Physics, Gatchina (Russian Federation); Vodopyanov, I.B. [St. Petersburg Inst. of Nuclear Physics, Gatchina (Russian Federation)
1997-03-01
K-vacancy production due to ionization of atoms by charged projectiles in thick targets is investigated. Secondary particles contribution is taken into account. The calculations were performed for Pb and U targets irradiated by 1 GeV protons. The results are compared with the experimental data. (orig.).
The scaling and dynamics of a projectile obliquely impacting a granular medium.
Wang, Dengming; Ye, Xiaoyan; Zheng, Xiaojing
2012-01-01
In this paper, the dynamics of a spherical projectile obliquely impacting into a two-dimensional granular bed is numerically investigated using the discrete element method. The influences of projectile's initial velocities and impacting angles are mainly considered. Numerical results show that the relationship between the final penetration depth and the initial impact velocity is very similar to that in the vertical-impact case. However, the dependence of the stopping time on the impact velocity of the projectile exhibits critical characteristics at different impact angles: the stopping time approximately increases linearly with the impact velocity for small impact angles but decreases in an exponential form for larger impact angles, which demonstrates the existence of two different regimes at low and high impact angles. When the impact angle is regarded as a parametric variable, a phenomenological force model at large impact angles is eventually proposed based on the simulation results, which can accurately describe the nature of the resistance force exerted on the projectile by the granular medium at different impact angels during the whole oblique-impact process. The degenerate model agrees well with the existing experimental results in the vertical-impact cases.
Projectile atomic-number effect on ion-induced fragmentation and ionization of fullerenes
Hadjar, O; Hoekstra, R; Morgenstern, R; Schlatholter, T
The delocalized pi electrons of a C-60 cluster can be well described as an electron gas. Electronic friction experienced by a multicharged ion colliding with a fullerene might then be modeled in terms of the electronic stopping power. We investigated such collisions for projectile atomic numbers Z
Energy Technology Data Exchange (ETDEWEB)
Denton, Cristian D. [Departament de Física Aplicada, Universitat d’Alacant, Apartat 99, E-03690 Alacant (Spain); Moreno-Marín, Juan Carlos; Heredia-Avalos, Santiago [Departament de Física, Enginyeria de Sistemes i Teoria de la Senyal, Universitat d’Alacant, Apartat 99, E-03690 Alacant (Spain)
2015-06-01
The idea of using carbon nanotubes (CNTs) as masks against irradiation has recently emerged, because of the region of a given material covered by a CNT can be protected from the effects of irradiation, creating nanowires. In this case, it is interesting to know in detail the number of generated recoils and their energy. In order to obtain these data, we simulate the irradiation of CNTs with carbon ions using a molecular dynamics code. To describe the interaction between carbon ions we use the Brenner potential joined smoothly to the Universal ZBL potential at short distances. We have analyzed the energy distributions of the carbon atoms emerging from the CNT for single projectile irradiation with incident energies from 30 eV to 5 keV. Our results show that the number and the energy of the recoil carbon atoms emerging from the CNT increases with the projectile incident energy. In average, each projectile with incident energy of 1 keV produces ∼3.6 recoils, which have a mean energy of 150 eV, while projectiles with 5 keV produce ∼7 recoils with a mean energy of 400 eV.
Studying the influence of target and projectile properties on low-velocity collisions
Murdoch, N.; Nguyen, G.; Calandry, A.; Cherrier, O.; Gourinat, Y.
2017-09-01
To improve our understanding of landing on small bodies and of asteroid evolution, we have performed new experiments of low-velocity impacts into granular material in both normal and reduced-gravity. We study the influence of the target material, the projectile shape and orientation, and the gravitational acceleration.
Amazing Physics: Learning about Work, Energy and Projectile Motion in a Historical Context
Tural, Guner
2013-01-01
Teaching physics through a historical context provides effective learning and increases students' motivation for and interest in physics. For example, trebuchets and mangonels may be interesting historical contexts for learning about energy, work, and projectile motion. In this study, the implementation of physics lessons related to these subjects…
Projectile Motion with a Drag Force: Were the Medievals Right After All?
La Rocca, Paola; Riggi, Francesco
2009-01-01
An educational and historical study of the projectile motion with drag forces dependent on speed shows, by simple results, that trajectories quite similar to those depicted before the Galilean era may be obtained with a realistic choice of quantities involved. Numerical simulations of the trajectory in space and velocity coordinates help us to…
Directory of Open Access Journals (Sweden)
Mostafa Khalil
2013-01-01
Full Text Available Any trajectory calculation method has three primary sources of errors, which are model error, parameter error, and initial state error. In this paper, based on initial projectile flight trajectory data measured using Doppler radar system; a new iterative method is developed to estimate the projectile attitude and the corresponding impact point to improve the second shot hit probability. In order to estimate the projectile initial state, the launch dynamics model of practical 155 mm self-propelled artillery is defined, and hence, the vibration characteristics of the self-propelled artillery is obtained using the transfer matrix method of linear multibody system MSTMM. A discrete time transfer matrix DTTM-4DOF is developed using the modified point mass equations of motion to compute the projectile trajectory and set a direct algebraic relation between any two successive radar data. During iterations, adjustments to the repose angle are made until an agreement with acceptable tolerance occurs between the Doppler radar measurements and the estimated values. Simulated Doppler radar measurements are generated using the nonlinear six-degree-of-freedom trajectory model using the resulted initial disturbance. Results demonstrate that the data estimated using the proposed algorithm agrees well with the simulated Doppler radar data obtained numerically using the nonlinear six-degree-of-freedom model.
Hynd, Cynthia; And Others
1997-01-01
Investigates changes in preservice teachers' conceptions about projectile motion brought about by a combination of reading and demonstration and appeal to usefulness. Results indicate the effectiveness of a combined Demo-Text condition on immediate posttests and effectiveness of text in producing long-term change. Analysis also indicates an…
Kibirige, Israel; Lehong, Moyahabo Jeridah
2016-01-01
The study explored the effect of cooperative learning on Grade 12 learners' performance in projectile motions. A quasi-experimental research design with non-equivalent control group was used. Two schools were purposively selected from Maleboho Central circuit in South Africa based on their performance in Physical Sciences Grade 12 results of 2011.…
On the Locus Formed by the Maximum Heights of Projectile Motion with Air Resistance
Hernandez-Saldana, H.
2010-01-01
We present an analysis on the locus formed by the set of maxima of the trajectories of a projectile launched in a medium with linear drag. Such a place, the locus of apexes, is written in terms of the Lambert "W" function in polar coordinates, confirming the special role played by this function in the problem. To characterize the locus, a study of…
Approximate Formula for the Vertical Asymptote of Projectile Motion in Midair
Chudinov, Peter Sergey
2010-01-01
The classic problem of the motion of a point mass (projectile) thrown at an angle to the horizon is reviewed. The air drag force is taken into account with the drag factor assumed to be constant. An analytical approach is used for the investigation. An approximate formula is obtained for one of the characteristics of the motion--the vertical…
Directory of Open Access Journals (Sweden)
James O’Daniel
2011-01-01
Full Text Available Simulating fragment penetration into steel involves complicated modeling of severe behavior of the materials through multiple phases of response. Penetration of a fragment-like projectile was simulated using finite element (FE and meshfree particle formulations. Extreme deformation and failure of the material during the penetration event were modeled with several approaches to evaluate each as to how well it represents the actual physics of the material and structural response. A steel Fragment Simulating Projectile (FSP – designed to simulate a fragment of metal from a weapon casing – was simulated for normal impact into a flat square plate. A range of impact velocities was used to examine levels of exit velocity ranging from relatively small to one on the same level as the impact velocity. The numerical code EPIC, used for all the simulations presented herein, contains the element and particle formulations, as well as the explicit methodology and constitutive models needed to perform these simulations. These simulations were compared against experimental data, evaluating the damage caused to the projectile and the target plates, as well as comparing the residual velocity when the projectile perforated the target.
Design and Analysis of Kinetic Energy Projectiles Using Finite Element Optimization
1991-11-01
1991; DeSalvo and Gorman 1987; PRISM/DDM User Manuals 1990; Hallquist 1983). Using 4inite element techniques, simplified models of the projectile can...Handbook: Interior Ballistics of Guns. AMC Pamphlet 706-150, Washington, DC, February 1965. DeSalvo , G. J., and R. W. Gorman. ANSYS Engineering
Tissue simulant response at projectile impact on flexible fabric armour systems
Bree, J.L.M.J. van; Volker, A.; Heiden, N. van der
2006-01-01
Behind Armour Blunt Trauma is a phenomenon which has been studied extensively for rigid personal protective armour systems. These systems used in e.g. bullet proof vests manage to defeat high velocity small arms projectiles. Tissue simulants are used to study behind armour effects. At high velocity
Comment on 'The envelope of projectile trajectories'
Energy Technology Data Exchange (ETDEWEB)
Butikov, Eugene I [St Petersburg State University, St Petersburg (Russian Federation)
2003-07-01
Several simple alternative methods to obtain the equation of the envelope of the family of projectile trajectories corresponding to the same initial speed are suggested, including methods in which the boundary of the region occupied by the parabolic trajectories is found as an envelope of a set of circles. Two possible generalizations of the discussed problem are also suggested. (letters and comments)
Projectile Penetration into Sandy Soil Confined by a Honeycomb-Like Structure
Directory of Open Access Journals (Sweden)
Weiming Luo
2017-01-01
Full Text Available HPS (Honeycomb-like Protective Structure is a newly proposed protective structure filled with sandy soil. In order to investigate the penetration resistance of the structure, numerical simulations based on SPH method had been carried out by using LS-DYNA, which are corresponding to the experiments. The calibrated model leads to reasonable predictions of the dynamic responses and damage modes of the HPS. More situations were carried out taking factors influencing the penetration into consideration, including point of impact, angle of impact, and projectile caliber. Penetration mode was established by analyzing the energy dissipation and investigating the mechanism from the phenomenological viewpoint. Simulation results show that the resisting forces and the torque that act on the long rod projectile would be greater than those acting on the short one when instability occurred. Besides, approximate 45° angle of impact was formed in the case of off-axis, which has a certain influence on the ballistic stability, resulting in more kinetic energy of projectile dissipating in HPS and less depth of penetration. The kinetic energy of projectile dissipated in sandy soil largely and the strip slightly, and the former was greater than the sum of the latter.
Transient Response of a Projectile in Gun Launch Simulation Using Lagrangian and Ale Methods
Directory of Open Access Journals (Sweden)
A Tabiei
2016-09-01
Full Text Available This paper describes the usefulness of Lagrangian and arbitrary Lagrangian/Eulerian (ALE methods in simulating the gun launch dynamics of a generic artillery component subjected to launch simulation in an air gun test. Lagrangian and ALE methods are used to simulate the impact mitigation environment in which the kinetic energy of a projectile is absorbed by the crushing of aluminum honeycomb mitigator. In order to solve the problem due to high impact penetration, a new fluid structure coupling algorithm is developed and implemented in LS-DYNA, a three dimensional FEM code. The fluid structure coupling algorithm used in this paper combined with ALE formulation for the aluminum honeycomb mitigator allows to solve problems for which the contact algorithm in the Lagrangian calculation fails due to high mesh distortion. The numerical method used for the fluid and fluid structure coupling is discussed. A new coupling method is used in order to prevent mesh distortion. Issues related to the effectiveness of these methods in simulating a high degree of distortion of Aluminum honeycomb mitigator with the commonly used material models (metallic honeycomb and crushable foam are discussed. Both computational methods lead to the same prediction for the deceleration of the test projectile and are able to simulate the behavior of the projectile. Good agreement between the test results and the predicted projectile response is achieved via the presented models and the methods employed.
[An unusual embolization of a projectile in the superficial femoral artery].
Roubal, P; Korger, J; Ondrůsková, O; Kratochvíl, D; Holý, M
1997-11-01
The authors present an account on a gunshot wound which penetrated into the lateral side of the distal chest on the right. They describe acute treatment of severe haemorrhagic shock by suture of a lacerated with liver segment and resection of the upper pole of the right kidney. The projectile was not searched for because of the patients general serious condition. After 30 days the patient was discharged in a good condition. Shortly after discharge, i.e. cca one month after the injury, the patient developed signs of chronic ischaemia of the left lower extremity-finally claudications after 150 meters. Based on peripheral arteriography, which revealed the projectile in the area of the beginning of the superficial femoral artery and an ample collateral circulation, surgery was initiated. The bullet was extracted from the lumen of the superficial femoral artery from longitudinal arteriotomy. The artery was then treated by thrombectomy and a venous patch. Peroperative arteriography indicates satisfactory passage into the periphery. The authors try to reconstruct the pathway of the shot and in particular how the projectile penetrated into the artery. They emphasize the necessity to look for the projectice at the site of the shot wound. The objective of the paper is to make readers familiar with a case of uncommon embolization of a projectile into the superficial femoral artery and mistakes which may occur during treatment of a gunshot wound. The result is that the patient is quite free from complaints, as was confirmed by repeated out-patient check-ups.
Cq+-induced excitation and fragmentation of uracil : effects of the projectile electronic structure
de Vries, J.; Hoekstra, R.A.; Morgenstern, R.W.H.; Schlathölter, T.A.
2002-01-01
Ionization and fragmentation of the RNA base uracil (C4H4N2O2) by means of Cq+ ions (q = 1-6) has been studied for ion kinetic energies ranging from ;2 to 120 keV. Whereas for Cq+ (q = 1, 3, 4, 5, 6) very similar fragmentation yields are observed which increase with the projectile velocity v, C2+
Bounded Densities and Their Derivatives
DEFF Research Database (Denmark)
Kozine, Igor; Krymsky, V.
2009-01-01
This paper describes how one can compute interval-valued statistical measures given limited information about the underlying distribution. The particular focus is on a bounded derivative of a probability density function and its combination with other available statistical evidence for computing ...
Physics with loosely bound nuclei
Indian Academy of Sciences (India)
nuclear physics changed drastically as the new generation of accelerators started providing more and more rare isotopes, which are away from the line of stability. These weakly bound nuclei are found to exhibit new forms of nuclear matter and unprecedented exotic behaviour. The low breakup thresholds of these rare ...
Distance bounds on quantum dynamics
Lidar, Daniel A.; Zanardi, Paolo; Khodjasteh, Kaveh
2008-07-01
We derive rigorous upper bounds on the distance between quantum states in an open-system setting in terms of the operator norm between Hamiltonians describing their evolution. We illustrate our results with an example taken from protection against decoherence using dynamical decoupling.
Moderate deviations for bounded subsequences
Directory of Open Access Journals (Sweden)
George Stoica
2006-01-01
Full Text Available We study Davis' series of moderate deviations probabilities for Lp-bounded sequences of random variables (p>2. A certain subseries therein is convergent for the same range of parameters as in the case of martingale difference or i.i.d. sequences.
Scaling and universality in two dimensions: three-body bound states with short-ranged interactions
Energy Technology Data Exchange (ETDEWEB)
Bellotti, F F; Frederico, T [Instituto Tecnologico de Aeronautica, DCTA, 12.228-900 Sao Jose dos Campos, SP (Brazil); Yamashita, M T [Instituto de Fisica Teorica, UNESP-Univ Estadual Paulista, CP 70532-2, CEP 01156-970, Sao Paulo, SP (Brazil); Fedorov, D V; Jensen, A S; Zinner, N T, E-mail: zinner@phys.au.dk [Department of Physics and Astronomy-Aarhus University, Ny Munkegade, bygn. 1520, DK-8000 Arhus C (Denmark)
2011-10-28
The momentum space zero-range model is used to investigate universal properties of three interacting particles confined to two dimensions. The pertinent equations are first formulated for a system of two identical and one distinct particle and the two different two-body subsystems are characterized by two-body energies and masses. The three-body energy in units of one of the two-body energies is a universal function of the other two-body energy and the mass ratio. We derive convenient analytical formulae for calculations of the three-body energy as a function of these two independent parameters and exhibit the results as universal curves. In particular, we show that the three-body system can have any number of stable bound states. When the mass ratio of the distinct to identical particles is greater than 0.22, we find that at most two stable bound states exist, while for two heavy and one light mass an increasing number of bound states is possible. The specific number of stable bound states depends on the ratio of two-body bound state energies and on the mass ratio, and we map out an energy-mass phase diagram of the number of stable bound states. Realizable systems of both fermions and bosons are discussed in this framework.
Collins, Rufus D., Jr.; Kinard, William H.
1960-01-01
The results of this investigation indicate that the penetration of projectiles into quasi-infinite targets can be correlated as a function of the maximum momentum per unit area possessed by the projectiles. The penetration of projectiles into aluminum, copper, and steel targets was found to be a linear function while the penetration into lead targets was a nonlinear function of the momentum per unit area of the impacting projectiles. Penetration varied inversely as the projectile density and the elastic modulus of the target material for a given projectile momentum per unit area. Crater volumes were found to be a linear function of the kinetic energy of the projectile, the greater volumes being obtained in the target materials which had the lowest yield strength and the lowest speed of sound.
Energy Technology Data Exchange (ETDEWEB)
Reiter, Moritz Pascal
2015-07-01
High precision experiments and decay spectroscopy of exotic nuclei are of great interest for nuclear structure and nuclear astro-physics. They allow for studies of the nuclear structure far from stability, test of fundamental interactions and symmetries and give important input for the understanding of the nuclear synthesis in the universe. In the context of this work a second generation stopping cell for the low energy branch of the Super-FRS was commissioned at the FRS at GSI and significant improvements were made to the device. The prototype stopping cell is designed as a cryogenic stopping cell (CSC), featuring enhanced cleanliness and high area density. The CSC was brought into full operation and its performance characteristics were investigated including the maximal area density, extraction times, cleanliness and extraction efficiencies. In three commissioning experiments at the current GSI FRS facility in 2011, 2012 and 2014 up to 22 isotopes from 14 elements produced by in-flight projectile fragmentation and fission of {sup 238}U could be thermalized and extracted with high efficiency. For the first time projectile and fission fragmentation produced at 1000 MeV/u could be thermalized in a stopping cell and provided as a low-energy beam of high brilliance for high precision experiments. The technical improvements of the CSC, such as an improved RF carpet, new cryocooler-based cooling system, a monitoring system of the cleanliness and the high density operation, made it possible to thermalize heavy {sup 238}U projectile fragments with total efficiencies of about 20% in the 2014 experiment. In addition the improvements lead to an increase in the stability and reliability of the CSC and the performance of the CSC during online experiments at the FRS Ion Catcher showed that the utilized techniques are ready for the final CSC for the low-energy branch of the Super-FRS at FAIR. The CSC was operated with an area density of up to 6.3 mg/cm{sup 2} helium during
Meerschaert, Mark M; Straka, Peter
2013-01-01
The inverse stable subordinator provides a probability model for time-fractional differential equations, and leads to explicit solution formulae. This paper reviews properties of the inverse stable subordinator, and applications to a variety of problems in mathematics and physics. Several different governing equations for the inverse stable subordinator have been proposed in the literature. This paper also shows how these equations can be reconciled.
Steeneveld, G.J.
2012-01-01
Understanding and prediction of the stable atmospheric boundary layer is a challenging task. Many physical processes are relevant in the stable boundary layer, i.e. turbulence, radiation, land surface coupling, orographic turbulent and gravity wave drag, and land surface heterogeneity. The development of robust stable boundary layer parameterizations for use in NWP and climate models is hampered by the multiplicity of processes and their unknown interactions. As a result, these models suffer ...
MEERSCHAERT, MARK M.; STRAKA, PETER
2013-01-01
The inverse stable subordinator provides a probability model for time-fractional differential equations, and leads to explicit solution formulae. This paper reviews properties of the inverse stable subordinator, and applications to a variety of problems in mathematics and physics. Several different governing equations for the inverse stable subordinator have been proposed in the literature. This paper also shows how these equations can be reconciled. PMID:25045216
Lower bounds in differential privacy
De, Anindya
2011-01-01
This is a paper about private data analysis, in which a trusted curator holding a confidential database responds to real vector-valued queries. A common approach to ensuring privacy for the database elements is to add appropriately generated random noise to the answers, releasing only these {\\em noisy} responses. In this paper, we investigate various lower bounds on the noise required to maintain different kind of privacy guarantees.
Geometry of Homogeneous Bounded Domains
Vesentini, E
2011-01-01
This title includes: S.G. Gindikin, I.I. Pjateckii-Sapiro, E.B. Vinberg: Homogeneous Kahler manifolds; S.G. Greenfield: Extendibility properties of real submanifolds of Cn; W. Kaup: Holomorphische Abbildungen in Hyperbolische Raume; A. Koranyi: Holomorphic and harmonic functions on bounded symmetric domains; J.L. Koszul: Formes harmoniques vectorielles sur les espaces localement symetriques; S. Murakami: Plongements holomorphes de domaines symetriques; and E.M. Stein: The analogues of Fatous' theorem and estimates for maximal functions.
Wronskian method for bound states
Energy Technology Data Exchange (ETDEWEB)
Fernandez, Francisco M, E-mail: fernande@quimica.unlp.edu.ar [INIFTA (UNLP, CONICET), Division Quimica Teorica, Boulevard 113 S/N, Sucursal 4, Casilla de Correo 16, 1900 La Plata (Argentina)
2011-05-15
We propose a simple and straightforward method based on Wronskians for the calculation of bound-state energies and wavefunctions of one-dimensional quantum-mechanical problems. We explicitly discuss the asymptotic behaviour of the wavefunction and show that the allowed energies make the divergent part vanish. As illustrative examples we consider an exactly solvable model, the Gaussian potential well, and a two-well potential proposed earlier for the interpretation of the infrared spectrum of ammonia.
Cyclotron transitions of bound ions
Bezchastnov, Victor G.; Pavlov, George G.
2017-06-01
A charged particle in a magnetic field possesses discrete energy levels associated with particle rotation around the field lines. The radiative transitions between these levels are the well-known cyclotron transitions. We show that a bound complex of particles with a nonzero net charge displays analogous transitions between the states of confined motion of the entire complex in the field. The latter bound-ion cyclotron transitions are affected by a coupling between the collective and internal motions of the complex and, as a result, differ from the transitions of a "reference" bare ion with the same mass and charge. We analyze the cyclotron transitions for complex ions by including the coupling within a rigorous quantum approach. Particular attention is paid to comparison of the transition energies and oscillator strengths to those of the bare ion. Selection rules based on integrals of collective motion are derived for the bound-ion cyclotron transitions analytically, and the perturbation and coupled-channel approaches are developed to study the transitions quantitatively. Representative examples are considered and discussed for positive and negative atomic and cluster ions.
Energy-dependent expansion of .177 caliber hollow-point air gun projectiles.
Werner, Ronald; Schultz, Benno; Bockholdt, Britta; Ekkernkamp, Axel; Frank, Matthias
2017-05-01
Amongst hundreds of different projectiles for air guns available on the market, hollow-point air gun pellets are of special interest. These pellets are characterized by a tip or a hollowed-out shape in their tip which, when fired, makes the projectiles expand to an increased diameter upon entering the target medium. This results in an increase in release of energy which, in turn, has the potential to cause more serious injuries than non-hollow-point projectiles. To the best of the authors' knowledge, reliable data on the terminal ballistic features of hollow-point air gun projectiles compared to standard diabolo pellets have not yet been published in the forensic literature. The terminal ballistic performance (energy-dependent expansion and penetration) of four different types of .177 caliber hollow-point pellets discharged at kinetic energy levels from approximately 3 J up to 30 J into water, ordnance gelatin, and ordnance gelatin covered with natural chamois as a skin simulant was the subject of this investigation. Energy-dependent expansion of the tested hollow-point pellets was observed after being shot into all investigated target media. While some hollow-point pellets require a minimum kinetic energy of approximately 10 J for sufficient expansion, there are also hollow-point pellets which expand at kinetic energy levels of less than 5 J. The ratio of expansion (RE, calculated by the cross-sectional area (A) after impact divided by the cross-sectional area (A 0) of the undeformed pellet) of hollow-point air gun pellets reached values up of to 2.2. The extent of expansion relates to the kinetic energy of the projectile with a peak for pellet expansion at the 15 to 20 J range. To conclude, this work demonstrates that the hollow-point principle, i.e., the design-related enlargement of the projectiles' frontal area upon impact into a medium, does work in air guns as claimed by the manufacturers.
Indian Academy of Sciences (India)
IAS Admin
After Maynard-Smith and Price [1] mathematically derived why a given behaviour or strategy was adopted by a certain proportion of the population at a given time, it was shown that a strategy which is currently stable in a population need not be stable in evolutionary time (across generations). Additionally it was sug-.
Steeneveld, G.J.
2012-01-01
Understanding and prediction of the stable atmospheric boundary layer is a challenging task. Many physical processes are relevant in the stable boundary layer, i.e. turbulence, radiation, land surface coupling, orographic turbulent and gravity wave drag, and land surface heterogeneity. The
Kalonia, Ramesh C.; Chhachhia, Dharam P.; Bajpai, Phun Phun; Singh, Manjit; Biswas, Ipsita; Yadav, Mohinder S.
2014-03-01
High-speed optical shadowgraphy plays an important role in study of various phenomena including projectile-target interaction for small caliber projectile. Present work reports design, development, and implementation of a multiple laser-based high-speed digital shadowgraphy system to study the behavior of a small caliber projectile in flight as well as the projectile-target interaction. System is based on Cranz-Schardin technique. Low power digitally modulated laser diodes along with low-resolution CMOS cameras in global shuttering mode are used to record good quality digital shadowgraphs. The system can record 11 shadowgraphs at a maximum frame rate of 1 million/s and is able to capture even minute details of fragments in the form of shockwaves. Operation of the system, image recording and analysis are fully computer controlled. The design and system description inclusive ultra-short pulse generator and opto-electronic triggering unit are presented and experimental results are discussed.
National Research Council Canada - National Science Library
Belgacem, Chokri Hadj
Using the Lambert W function, the quadratic resisted projectile motion with an approximation of low-angle trajectory has been studied where the launching point is assumed to be higher than the landing point...
National Research Council Canada - National Science Library
Foriel, Julien; Moynier, Frederic; Schulz, Toni; Koeberl, Christian
2013-01-01
... that an achondritic projectile was involved. We studied the major and trace element composition in samples from the new ICDP drill core obtained near the center of the structure, as well as the chromium isotopic composition of an impact glass...
Bound-state formation in falling liquid films
Nguyen, Phuc-Khanh; Pradas, Marc; Kalliadasis, Serafim; Bontozoglou, Vasilis
2012-11-01
Direct numerical simulation shows that the interaction between solitary pulses may give rise to the formation of bound states consisting of two or more pulses separated by well-defined distances and traveling at the same velocity. Stationary pulse couples are studied first. The resulting equilibrium pulse distances compare favorably to theoretical predictions at large and intermediate pulse separations. When the two pulses are closely spaced, the theory becomes increasingly less accurate. Their time-dependent simulations indicate that all initial conditions of large separations lead to a monotonic attraction or repulsion to the stable bound states. However, intermediate range leads to a self-sustained oscillatory variation of the pulse separation distance, with well-defined amplitude and period, and a mean separation coinciding with the stationary distance. Eventually a very close separation causes an explosive repulsion of two pulses toward much larger stable separation. Bound states consisting of three pulses are computed next. The equilibrium separation distances in a symmetric system are similar to predictions based on simple couples. However, in an asymmetric one, they deviate significantly from simple predictions. Partially supported by FP7-Marie Curie ITN-``MULTIFLOW''-GA-214919-2.
Lower bounds for randomized Exclusive Write PRAMs
Energy Technology Data Exchange (ETDEWEB)
MacKenzie, P.D.
1995-05-02
In this paper we study the question: How useful is randomization in speeding up Exclusive Write PRAM computations? Our results give further evidence that randomization is of limited use in these types of computations. First we examine a compaction problem on both the CREW and EREW PRAM models, and we present randomized lower bounds which match the best deterministic lower bounds known. (For the CREW PRAM model, the lower bound is asymptotically optimal.) These are the first non-trivial randomized lower bounds known for the compaction problem on these models. We show that our lower bounds also apply to the problem of approximate compaction. Next we examine the problem of computing boolean functions on the CREW PRAM model, and we present a randomized lower bound, which improves on the previous best randomized lower bound for many boolean functions, including the OR function. (The previous lower bounds for these functions were asymptotically optimal, but we improve the constant multiplicative factor.) We also give an alternate proof for the randomized lower bound on PARITY, which was already optimal to within a constant additive factor. Lastly, we give a randomized lower bound for integer merging on an EREW PRAM which matches the best deterministic lower bound known. In all our proofs, we use the Random Adversary method, which has previously only been used for proving lower bounds on models with Concurrent Write capabilities. Thus this paper also serves to illustrate the power and generality of this method for proving parallel randomized lower bounds.
Upper and lower bounds for stochastic processes modern methods and classical problems
Talagrand, Michel
2014-01-01
The book develops modern methods and in particular the "generic chaining" to bound stochastic processes. This methods allows in particular to get optimal bounds for Gaussian and Bernoulli processes. Applications are given to stable processes, infinitely divisible processes, matching theorems, the convergence of random Fourier series, of orthogonal series, and to functional analysis. The complete solution of a number of classical problems is given in complete detail, and an ambitious program for future research is laid out.
On the Horizontal Deviation of a Spinning Projectile Penetrating into Granular Systems
Directory of Open Access Journals (Sweden)
Waseem Ghazi Alshanti
2017-01-01
Full Text Available The absence of a general theory that describes the dynamical behavior of the particulate materials makes the numerical simulations the most current powerful tool that can grasp many mechanical problems relevant to the granular materials. In this paper, based on a two-dimensional soft particle discrete element method (DEM, a numerical approach is developed to investigate the consequence of the orthogonal impact into various granular beds of projectile rotating in both clockwise (CW and counterclockwise (CCW directions. Our results reveal that, depending on the rotation direction, there is a significant deviation of the x-coordinate of the final stopping point of a spinning projectile from that of its original impact point. For CW rotations, a deviation to the right occurs while a left deviation has been recorded for CCW rotation case.
Onset of cavity deformation upon subsonic motion of a projectile in a fluid complex plasma.
Zhukhovitskii, D I; Ivlev, A V; Fortov, V E; Morfill, G E
2013-06-01
We study the deformation of a cavity around a large projectile moving with subsonic velocity in the cloud of small dust particles. To solve this problem, we employ the Navier-Stokes equation for a compressible fluid with due regard for friction between dust particles and atoms of neutral gas. The solution shows that due to friction, the pressure of a dust cloud at the surface of a cavity around the projectile can become negative, which entails the emergence of a considerable asymmetry of the cavity, i.e., the cavity deformation. Corresponding threshold velocity is calculated, which is found to decrease with increasing cavity size. Measurement of such velocity makes it possible to estimate the static pressure inside the dust cloud.
Bray, I.; Abdurakhmanov, I. B.; Bailey, J. J.; Bray, A. W.; Fursa, D. V.; Kadyrov, A. S.; Rawlins, C. M.; Savage, J. S.; Stelbovics, A. T.; Zammit, M. C.
2017-10-01
The atomic hydrogen target has played a pivotal role in the development of quantum collision theory. The key complexities of computationally managing the countably infinite discrete states and the uncountably infinite continuum were solved by using atomic hydrogen as the prototype atomic target. In the case of positron or proton scattering the extra complexity of charge exchange was also solved using the atomic hydrogen target. Most recently, molecular hydrogen has been used successfully as a prototype molecule for developing the corresponding scattering theory. We concentrate on the convergent close-coupling computational approach to light projectiles, such as electrons and positrons, and heavy projectiles, such as protons and antiprotons, scattering on atomic and molecular hydrogen.
In medium fragment break-up of projectile in 58Ar+36Ni central collisions
Francalanza, L.
2017-06-01
Latest results concerning the study of central collisions in 36Ar+58Ni reactions, carried out by using the INDRA 4π detector at the GANIL are presented. Reaction mechanisms involved in very central collisions for such asymmetric system and their evolution as function of incident energy are studied, from 32 to 95 AMeV, suggesting an in-medium “break-up” process of the projectile where the presence of nuclear transparency plays an important role. Such a process, leading to forward emission of fragments and lights particles in the laboratory frame, is found to be more and more relevant at high energies, when the contribution from quasi-fusion processes vanishes. Evidences of emissions from an excited quasi-target (QT*), moving along the beam direction with velocity rising with incident energy under the dragging effect of the in-medium “crumbling” of the projectile are highlighted.
Blackmore, D K
1985-01-12
The forces and kinetic energy required to penetrate the isolated heads of calves, adult beef cattle, sheep and red deer with a metal probe the same diameter as the bore of an experimental pistol were determined. Approximately 16 and 127 Joules were required to penetrate the heads of adult sheep and cattle, respectively. Using these data a 10 g projectile, consisting of 49 lead pellets and a lead disc in a polyethylene sleeve, was constructed. This projectile, when fired by a charge sufficient to produce a muzzle velocity of 165 m/second, had sufficient kinetic energy to penetrate the heads and brains of cattle, sheep, horses and deer. The projectile was fired from a new design of humane killer with a spring loaded barrel and fitted with a silencer. After penetration of the frontal bones the projectile fragmented and the kinetic energy of its individual particles were insufficient for them to penetrate the opposite side of the head of any of the animals, including one-week-old calves. Fragmentation also caused more brain damage and inhibition of spinal reflexes than a solid free bullet or captive bolt. It is suggested that the use of such a projectile for the emergency slaughter of animals is less hazardous than a solid free bullet and is easier to use and more effective than either a solid free bullet or captive bolt. The projectile was not suitable for killing adult pigs because of problems associated with the frontal sinus.
A Computer Program to Reduce Digitized Yaw-Card Data from Finned Kinetic-Energy Projectiles
1991-12-01
Witness panels, commonly referred to as yaw cards, are used in ballistic testing to de- termine the pitch (a) and yaw (/3) of a projectile as a function...r(2)).gt..OO1))gotos return 5 xOxO+r(l) yOyO +r (2) goto 6 end 14 *This subroutine solves a system of equations. SUBROUTINE SIMUL(C ,R,N) DOUBLE
2016-04-01
Sciences Meeting; 2003 Jan 6– 9; Reno, NV. AIAA Paper No.: 2003-1352. 2. DeSpirito J. Transient lateral jet interaction effects on a generic fin- stabilized ...Microflaps for Flow Control by Jubaraj Sahu Approved for public release; distribution is unlimited. NOTICES...Computational Fluid Dynamics (CFD) Simulations of a Finned Projectile with Microflaps for Flow Control by Jubaraj Sahu Weapons and Materials Research
Energy Technology Data Exchange (ETDEWEB)
Newsom, M.M.; Alvis, R.L.; Dardick, D.
1976-06-01
This report presents the status of the Terra-Drill development program as of May 31, 1976. The Terra-Drill system uses high velocity projectiles to prefracture the rock in front of a conventional rotary bit. The significant progress is reviewed and a long-range program plan is developed to indicate the level of effort required to bring this system to commercial production.
Range and flight time of quadratic resisted projectile motion using the Lambert W function
Belgacem, Chokri Hadj
2014-09-01
We study projectile motion with air resistance quadratic in speed. An approximation of a low-angle trajectory is considered where the horizontal velocity, v x , is assumed to be much larger than the vertical velocity, v y . The explicit solutions for the range and flight time are expressed in terms of the secondary branch of the Lambert function, {{W}_{-1}}. In addition to their theoretical importance, the results obtained will be of interest to teachers involved in undergraduate physics courses.
2016-12-01
Physics and Industrial Engineering ; 2012; Beijing, China . ICAPIE 1875-3892. 26. Lipowski A, Lipowska D. Roulette-wheel selection via stochastic...Evaluated Genetic Algorithm prepared by Justin L Paul Academy of Applied Science 24 Warren Street Concord, NH 03301 under contract W911SR...Supersonic Bending Body Projectile by a Vector-Evaluated Genetic Algorithm prepared by Justin L Paul Academy of Applied Science 24 Warren Street
Position Estimation for Projectiles Using Low-cost Sensors and Flight Dynamics
2012-04-01
339. 16. Habibi, S.; Cooper, S. J.; Stauffer, J. M. Gun Hard Inertial Measurement Unit Based on MEMS Capacitive Accelerometer and Rate Sensor. In...target. For example, accelerometers and gyroscopes located off the center of gravity of the rigid body can be compensated for in order to obtain...environment using low-cost measurement devices and projectile flight dynamics. An extended Kalman filter (EKF) was developed to blend accelerometer
Primer Output and Initial Projectile Motion for 5.56- and 7.62-mm Ammunition
2015-09-01
10 The impulse from the primer firing was calculated from the integration of the first primer pressure pulse over the time for which it is...ARL-TR-7479 ● SEP 2015 US Army Research Laboratory Primer Output and Initial Projectile Motion for 5.56- and 7.62-mm Ammunition...report when it is no longer needed. Do not return it to the originator. ARL-TR-7479 ● SEP 2015 US Army Research Laboratory Primer
The Influence of Muzzle Gasdynamics upon the Trajectory of Fin- Stabilized Projectiles
1975-06-01
extend behind the sabot. Sufficient extension eliminates aerodynamic interference be- tween the fins and sabot, permitting direct exposure of these... loss of generality that the projectile is launched with an initial angle of attack but zero sideslip. The initial transverse linear and angular...t tt’jC.^/O , (Defined in Figures 16 and 17) (C5) C =.£Si fk - 2 c + C 1 L 2Fr tKa S DJ P P The normal force coefficient, C
Optimization of aerodynamic form of projectile for solving the problem of shooting range increasing
Lipanov, Alexey M.; Korolev, Stanislav A.; Rusyak, Ivan G.
2017-10-01
The article is devoted to the development of methods for solving the problem of external ballistics using a more complete system of motion equation taken into account the rotation and oscillation about the mass center and using aerodynamic coefficients of forces and moments which are calculated on the basis of modeling the hydrodynamics of flow around the projectile. Developed methods allows to study the basic ways of increasing the shooting range or artillery.
Dynamic Analysis of the XM650E4 8-Inch Projectile
1978-04-01
corresponding frequency results from restraining an axial node, the center of gravity , which is necessary in the NONSAP eigenvalue routine. The profile...acceleration forces. Due to these high forces the overall effect is reflected in a shortening of the projectile around the center of gravity as the...Univer- sity Computing Center Library No. G60001, Bethlehem , Pennsylvania, July 1970. 7. Goudreau, G. L., "Evaluation of Discrete Methods for the
Off-shell gluon production in interaction of a projectile with 2 or 3 targets
Energy Technology Data Exchange (ETDEWEB)
Braun, M.A.; Salykin, M.Yu. [Saint-Petersburg State University, Department of High Energy physics, Saint Petersburg (Russian Federation)
2017-07-15
Within the effective QCD action for the Regge kinematics, the amplitudes for virtual gluon emission are studied in collision of a projectile with two and three targets. It is demonstrated that all non-Feynman singularities cancel between induced vertices and rescattering contributions. Formulas simplify considerably in a special gauge, which is a straightforward generalization of the light-cone gauge for emission of real gluons. (orig.)
Demonstration of UXO-PenDepth for the Estimation of Projectile Penetration Depth
2010-08-01
inner filler material shape and distribution, weights of the projectile and fill, case material type, and nose shape. From this information, the...munitions using a physics-based algorithm within the software UXO-PenDepth. The physical dimensions and weight of the munitions, and type of filler ...in Montana. Site # Recovered Depth to CG (cm) Limestone Hills 105mm 1 12 155mm Illumination M118 2 18, 24 Chevallier Ranch 105mm HE 1
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.
Kunz, Sebastian N; Arborelius, Ulf P; Gryth, Dan; Sonden, Anders; Gustavsson, Jenny; Wangyal, Tashi; Svensson, Leif; Rocksén, David
2011-11-01
Cardiac-related injuries caused by blunt chest trauma remain a severe problem. The aim of this study was to investigate pathophysiological changes in the heart that might arise after behind armor blunt trauma or impacts of nonlethal projectiles. Sixteen pigs were shot directly at the sternum with "Sponge Round eXact I Mpact" (nonlethal ammunition; diameter 40 mm and weight 28 g) or hard-plastic ammunition (diameter 65 mm and weight 58 g) to simulate behind armor blunt trauma. To evaluate the influence of the shot location, seven additional pigs where exposed to an oblique heart shot. Physiologic parameters, electrocardiography, echocardiogram, the biochemical marker troponin I (TnI), and myocardial injuries were analyzed. Nonlethal kinetic projectiles (101-108 m/s; 143-163 J) did not cause significant pathophysiological changes. Five of 18 pigs shot with 65-mm plastic projectiles (99-133 m/s; 284-513 J) to the front or side of the thorax died directly after the shot. No major physiologic changes could be observed in surviving animals. Animals shot with an oblique heart shot (99-106 m/s; 284-326 J) demonstrated a small, but significant decrease in saturation. Energy levels over 300 J caused increased TnI and myocardial damages in most of the pigs. This study indicates that nonlethal kinetic projectiles "eXact iMpact" does not cause heart-related damage under the examined conditions. On impact, sudden heart arrest may occur independently from the cardiac's electrical cycle. The cardiac enzyme, TnI, can be used as a reliable diagnostic marker to detect heart tissue damages after blunt chest trauma.
Towards Automatic Resource Bound Analysis for OCaml
Hoffmann, Jan; Das, Ankush; Weng, Shu-Chun
2016-01-01
This article presents a resource analysis system for OCaml programs. This system automatically derives worst-case resource bounds for higher-order polymorphic programs with user-defined inductive types. The technique is parametric in the resource and can derive bounds for time, memory allocations and energy usage. The derived bounds are multivariate resource polynomials which are functions of different size parameters that depend on the standard OCaml types. Bound inference is fully automatic...
Distance hijacking attacks on distance bounding protocols
Cremers, Cas; Rasmussen, Kasper Bonne; Čapkun, Srdjan
2011-01-01
Distance bounding protocols are typically analyzed with respect to three types of attacks: Distance Fraud, Mafia Fraud, and Terrorist Fraud. We define and analyze a fourth main type of attack on distance bounding protocols, called Distance Hijacking. We show that many proposed distance bounding protocols are vulnerable to this type of attack, and we propose solutions to make these protocols resilient to Distance Hijacking. We further show that verifying distance bounding protocols using exist...
Purity- and Gaussianity-bounded uncertainty relations
Mandilara, A.; Karpov, E.; Cerf, N. J.
2014-01-01
Bounded uncertainty relations provide the minimum value of the uncertainty assuming some additional information on the state. We derive analytically an uncertainty relation bounded by a pair of constraints, those of purity and Gaussianity. In a limiting case this uncertainty relation reproduces the purity-bounded derived by Man’ko and Dodonov and the Gaussianity-bounded one (Mandilara and Cerf 2012 Phys. Rev. A 86 030102R).
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.
Fin gaps and body slots of guided projectiles: Effects, data correlation and modeling
Mikhail, Ameer G.
1987-06-01
Prior work concerned with the effect of streamwise fin-body gaps unporting effect and body slots on the fin loads of projectiles and missiles in the transonic speed regime of 0.8 less than or = M less than or = 1.2, was reviewed. Experimental data for the gap effects have been analyzed. A correlation established to predict fin normal force losses due to gaps for any fin shape, size, aspect ratio, fitted very well with the data which span a large variation in Reynolds number, body diameter and boundary layer thickness. Although the Mach range for the present model was intended to be 0.8 less than or = M less than or = 1.2, available data indicated its validity in the wider range of 0.7 less than or = M less than or = 1.6. Fifteen cases were used to validate the present gap model. Application of these two corrections to the Copperhead guided projectile was made and a reduction as large as 38% was predicted for the normal force, which was then validated by the experimental data. The present results can be used for estimating fin load losses for the fin design of guided projectiles and missiles, with 5% accuracy, over the intended Mach number range 0.8 less than or = M less than or = 1.2.
Evaluating simulant materials for understanding cranial backspatter from a ballistic projectile.
Das, Raj; Collins, Alistair; Verma, Anurag; Fernandez, Justin; Taylor, Michael
2015-05-01
In cranial wounds resulting from a gunshot, the study of backspatter patterns can provide information about the actual incidents by linking material to surrounding objects. This study investigates the physics of backspatter from a high-speed projectile impact and evaluates a range of simulant materials using impact tests. Next, we evaluate a mesh-free method called smoothed particle hydrodynamics (SPH) to model the splashing mechanism during backspatter. The study has shown that a projectile impact causes fragmentation at the impact site, while transferring momentum to fragmented particles. The particles travel along the path of least resistance, leading to partial material movement in the reverse direction of the projectile motion causing backspatter. Medium-density fiberboard is a better simulant for a human skull than polycarbonate, and lorica leather is a better simulant for a human skin than natural rubber. SPH is an effective numerical method for modeling the high-speed impact fracture and fragmentations. © 2015 American Academy of Forensic Sciences.
Swerving Orientation of Spin-Stabilized Projectile for Fixed-Cant Canard Control Input
Directory of Open Access Journals (Sweden)
Xu-dong Liu
2015-01-01
Full Text Available Due to the large launch overload and high spin rate of spin-stabilized projectile, no attitude sensor is adopted in square crossing fixed-cant canard concept, which causes the lack of existing projectile linear theory for the close form solution of swerving motion. This work focuses on swerving orientation prediction with the restricted conditions. By importing the mathematical models of canard force and moment into the projectile angular motion equations, trim angle induced by canard control force is extracted as the analytical solution of angle of attack increment (AOAI. On this basis, analytical orientations of trajectory angular rate increment and swerving increment are obtained via the frozen coefficient method. A series of simulations under different conditions were implemented to validate the expressions in this effort. Results state that increment orientation of swerving motion can be predicted with available trajectory parameters. The analytical orientations indicate trim value of numerical orientations. Deviations between analytical and numerical orientations relate to initial launch angles and control start time, both lower initial launch angle, and the start time which is closer to the end of flight decreases the deviation convergence time.
Highly accurate analytic formulae for projectile motion subjected to quadratic drag
Turkyilmazoglu, Mustafa
2016-05-01
The classical phenomenon of motion of a projectile fired (thrown) into the horizon through resistive air charging a quadratic drag onto the object is revisited in this paper. No exact solution is known that describes the full physical event under such an exerted resistance force. Finding elegant analytical approximations for the most interesting engineering features of dynamical behavior of the projectile is the principal target. Within this purpose, some analytical explicit expressions are derived that accurately predict the maximum height, its arrival time as well as the flight range of the projectile at the highest ascent. The most significant property of the proposed formulas is that they are not restricted to the initial speed and firing angle of the object, nor to the drag coefficient of the medium. In combination with the available approximations in the literature, it is possible to gain information about the flight and complete the picture of a trajectory with high precision, without having to numerically simulate the full governing equations of motion.
Energy Technology Data Exchange (ETDEWEB)
Myagkov, N. N., E-mail: nn-myagkov@mail.ru [Russian Academy of Sciences, Institute of Applied Mechanics (Russian Federation)
2017-01-15
The problem of aluminum projectile fragmentation upon high-velocity impact on a thin aluminum shield is considered. A distinctive feature of this description is that the fragmentation has been numerically simulated using the complete system of equations of deformed solid mechanics by a method of smoothed particle hydrodynamics in three-dimensional setting. The transition from damage to fragmentation is analyzed and scaling relations are derived in terms of the impact velocity (V), ratio of shield thickness to projectile diameter (h/D), and ultimate strength (σ{sub p}) in the criterion of projectile and shield fracture. Analysis shows that the critical impact velocity V{sub c} (separating the damage and fragmentation regions) is a power function of σ{sub p} and h/D. In the supercritical region (V > V{sub c}), the weight-average fragment mass asymptotically tends to a power function of the impact velocity with exponent independent of h/D and σ{sub p}. Mean cumulative fragment mass distributions at the critical point are scale-invariant with respect to parameters h/D and σ{sub p}. Average masses of the largest fragments are also scale-invariant at V > V{sub c}, but only with respect to variable parameter σ{sub p}.
Penetration of a Small Caliber Projectile into Single and Multi-layered Targets
Directory of Open Access Journals (Sweden)
Riad A.M.
2010-06-01
Full Text Available The normal penetration of armor-piercing projectiles into single and multi-layered steel plates has been investigated. An experimental program has been conducted to study the effect of spaced and in-contact layered targets on their ballistic resistance. Armor piercing projectiles with caliber of 7.62 mm were fired against a series of single and multi-layered steel targets. The projectile impact velocities were ranged from 300-600 m/s, whereas the total thicknesses of the tested single, spaced and in-contact layered steel targets were 3 mm. The penetration process of different tested target configurations has been simulated using Autodayn-2D hydrocode. The experimental measurements of the present work were used to discuss the effect of impact velocity, target configurations and number of layers of different spaced and in-contact layered steel targets on their ballistic resistance. In addition, the post-firing examination of the tested targets over the used impact velocity range showed that the single and each layer of spaced and in-contact laminated steel targets were failed by petalling. Finally, the obtained experimental measurements were compared with the corresponding numerical results of Autodyn-2D hydrocode, good agreement was generally obtained.
Effect of CFRP strengthening on the response of RC slabs to hard projectile impact
Energy Technology Data Exchange (ETDEWEB)
Almusallam, Tarek; Al-Salloum, Yousef; Alsayed, Saleh; Iqbal, Rizwan; Abbas, Husain, E-mail: abbas_husain@hotmail.com
2015-05-15
Highlights: • Studied response of CFRP-strengthened RC slabs under the impact load. • Slabs were tested under the strike of hemispherical steel projectiles at varying impact. • The slabs were analyzed numerically using LS-DYNA. • Strengthening increased the ballistic limit velocity by 18% and perforation energy by 56.7%. • CFRP sheet reduced the crater damage and contained the flying concrete fragments. - Abstract: In this paper impact response of CFRP-strengthened RC panels under the impact of non-deformable projectiles has been presented. The control and CFRP-strengthened RC slab panels were tested under the strike of hemispherical nosed steel projectiles at varying impact velocities. The response of these panels was investigated experimentally as well as numerically. The damage of the slab panels was measured in terms of the penetration depth, formation of cracks, spalling and scabbing areas and fracture of CFRP sheet. This study presents a practical and efficient numerical method for analyzing the impact response of CFRP-strengthened RC structures using LS-DYNA. The CFRP strengthening was found to increase the ballistic limit velocity by 18%, perforation energy of RC slabs by 56.7%, reduce the front crater damage and contains the flying of concrete fragments from the rear face. The maximum impact force occurs at almost same penetration depth for the control and CFRP-strengthened slabs but the restraint provided by CFRP increased the penetration depth by about 1/19.3 of the thickness of slab.
Electromagnetic dissociation of target nuclei by $^{16}$O and $^{32}$S projectiles
2002-01-01
We have measured the inclusive cross sections for electromagnetic dissociation (ED) of $^{197}$Au targets by 60 and 200 GeV/nucleon $^{16}$O and $^{32}$S projectiles. This is an extension of similar measurements carried out earlier at 2 GeV/nucleon. ED is a purely electromagnetic process occuring when a virtual photon is exchanged between projectile and target. The experiment emphasized precise measurement of total one-neutron-out cross sections. A secondary goal was to test the applicability of the concepts of factorization and limiting fragmentation at ultrarelativistic energies.\\\\ \\\\ Each individual target will be irradiated upstream and parasitic to experiment NA38 on the dimuon spectrometer. Cross sections for reactions of interest will be determined by off-line counting of the appropriate residual $\\gamma$ ray activities in Ames, Iowa, USA. Preliminary results indicate an ED one-neutron removal cross section for 200 GeV/nucleon $^{16}$O projectiles on $^{197}$Au of approximately 0.45~barns. The result i...
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.
Song, Weidong; Lv, Yangtao; Li, Jianqiao; Wang, Cheng; Ning, Jianguo
2016-07-01
For describing hypervelocity impact (relative low-speed as related to space debris and much lower than travelling speed of meteoroids) phenomenon associated with plasma generation, a self-developed 3D code was advanced to numerically simulate projectiles impacting on a rigid wall. The numerical results were combined with a new ionization model which was developed in an early study to calculate the ionized materials during the impact. The calculated results of ionization were compared with the empirical formulas concluded by experiments in references and a good agreement was obtained. Then based on the reliable 3D numerical code, a series of impacts with different projectile configurations were simulated to investigate the influence of impact conditions on hypervelocity impact generated plasma. It was found that the form of empirical formula needed to be modified. A new empirical formula with a critical impact velocity was advanced to describe the velocity dependence of plasma generation and the parameters of the modified formula were ensured by the comparison between the numerical predictions and the empirical formulas. For different projectile configurations, the changes of plasma charges with time are different but the integrals of charges on time almost stayed in the same level.
New measurements of the properties of neutron-rich projectile fragments
Morrissey, D. J.; Meierbachtol, K.; Mosby, M.; Thoennessen, M. R.; MoNa Collaboration
2013-03-01
Two new experiments were carried out at the NSCL to explore the details of the linear moment and excitation energy distributions of projectile fragmentation production. In the first experiment the full linear momentum distributions of fragments from the reaction of a 76 Ge beam with beryllium and gold targets were measured in the S800 spectrometer. The results indicate a strong contribution of "far side" or attractive scattering to the near-projectile products with the gold target. In the second experiment the excitation energy of primary projectile fragments from peripheral nuclear reactions at intermediate energies was carried out at the NSCL. Sodium, neon and fluorine isotopes produced by the fragmentation of a neutron-rich 32Mg beam by a beryllium target were observed in a magnetic spectrometer in coincidence with fast neutrons detected using the Modular Neutron Array (MoNA). A new technique based on an analysis of the observed neutron multiplicity distributions was used to estimate the excitation energy and mass of the precursor intermediate products for the first time. A strong correlation between the neutron multiplicity and the total mass loss was observed indicating that large excitation energies were created in the prefragments by the initial collision. These findings are generally consistent with the internuclear cascade model of the collision dynamics but not with macroscopic abrasion-ablation models.
CFD Simulations of a Finned Projectile with Microflaps for Flow Control
Directory of Open Access Journals (Sweden)
Jubaraj Sahu
2017-01-01
Full Text Available This research describes a computational study undertaken to determine the effect of a flow control mechanism and its associated aerodynamics for a finned projectile. The flow control system consists of small microflaps located between the rear fins of the projectile. These small microflaps alter the flow field in the aft finned region of the projectile, create asymmetric pressure distributions, and thus produce aerodynamic control forces and moments. A number of different geometric parameters, microflap locations, and the number of microflaps were varied in an attempt to maximize the control authority generated by the flaps. Steady-state Navier-Stokes computations were performed to obtain the control aerodynamic forces and moments associated with the microflaps. These results were used to optimize the control authority at a supersonic speed, M=2.5. Computed results showed not only the microflaps to be effective at this speed, but also configurations with 6 and 8 microflaps were found to generate 25%–50% more control force than a baseline 4-flap configuration. These results led to a new optimized 8-flap configuration that was further investigated for a range of Mach numbers from M=0.8 to 5.0 and was found to be a viable configuration effective in providing control at all of these speeds.
Fragmentation of the Pb projectile at 158 GeV/nucleon an Pb-Pb interactions
Energy Technology Data Exchange (ETDEWEB)
Cherry, M.L.; Deines-Jones, P. [Louisiana State University, Baton Rouge (United States); Dabrowska, A. [Institute of Nuclear Physics, Cracow (Poland)] [and others; KLM Collaboration
1998-08-01
We have investigated the process of fragmentation of the Pb nucleus at 158 GeV/nucleon in Pb-Pb interactions recorded in lead-emulsion chambers of the EMU13 CERN experiment. The number of Pb-Pb interactions found was larger than that expected from the nuclear charge changing cross section which indicates an important role of electromagnetic dissociation processes in Pb-Pb interactions at this high energy. The emission angles of multiply charged projectile fragments as well as of spectator protons were measured using the semiautomated device with the CCD camera mounted on a microscope. Taking the advantage of the unconventional design of the emulsion chambers the charges of all multiply charged projectile fragments were measured. On the basis of these measurements, different modes of the Pb projectile break-up are discussed. The rates and properties of the fragmentation processes such as fission, multifragmentation and disintegration only into singly charged fragments are presented. (author) 21 refs, 15 figs, 1 tab
Normal modified stable processes
DEFF Research Database (Denmark)
Barndorff-Nielsen, Ole Eiler; Shephard, N.
2002-01-01
This paper discusses two classes of distributions, and stochastic processes derived from them: modified stable (MS) laws and normal modified stable (NMS) laws. This extends corresponding results for the generalised inverse Gaussian (GIG) and generalised hyperbolic (GH) or normal generalised inverse...... Gaussian (NGIG) laws. The wider framework thus established provides, in particular, for added flexibility in the modelling of the dynamics of financial time series, of importance especially as regards OU based stochastic volatility models for equities. In the special case of the tempered stable OU process...
Baïou, Mourad; Balinski, Michel
2002-01-01
The stable allocation problem is the generalization of the well-known and much studied stable (0,1)-matching problems to the allocation of real numbers (hours or quantities). There are two distinct sets of agents, a set I of "employees" or "buyers" and a set J of "employers" or "sellers", each agent with preferences over the opposite set and each with a given available time or quantity. In common with its specializations, and allocation problem may have exponentially many stable solutions (th...
Bounded rationality and heterogeneous expectations in macroeconomics
Massaro, D.
2012-01-01
This thesis studies the effect of individual bounded rationality on aggregate macroeconomic dynamics. Boundedly rational agents are specified as using simple heuristics in their decision making. An important aspect of the type of bounded rationality described in this thesis is that the population of
Labeling schemes for bounded degree graphs
DEFF Research Database (Denmark)
Adjiashvili, David; Rotbart, Noy Galil
2014-01-01
graphs. Our results complement a similar bound recently obtained for bounded depth trees [Fraigniaud and Korman, SODA 2010], and may provide new insights for closing the long standing gap for adjacency in trees [Alstrup and Rauhe, FOCS 2002]. We also provide improved labeling schemes for bounded degree...
Upper bound on quantum stabilizer codes
Li, Zhuo; Xing, Li-Juan
2009-03-01
By studying sets of operators having constant weight, we present an analytical upper bound on the pure quantum stabilizer codes whose underlying quantum system can be of arbitrary dimension, which outperforms the well-known quantum Hamming bound, the optimal analytical upper bound so far for small code length.
Research of the In-process Artillery Shot in Terms of Projectile Band-engraving
Directory of Open Access Journals (Sweden)
A. K. Efremov
2017-01-01
Full Text Available The paper considers, in the classical treatment of an artillery shot, a pyrostatic (preliminary shot period during which a projectile is assumed to be motionless until the pressure of the powder gases becomes equal to the conditional shot-start pressure. The latter is determined by the maximum force of resistance to the driving band completely engraved by rifling, with resistance related to the projectile cross-section area. In actual practice, the engraving is a gradual process (in this case the shot period is called a forcing one. A level of the axial inertial forces may even be sufficient for fuse arming of inertial safety devices.The fact that there is a need to have a sufficiently large set of the appropriate design and physical parameters, which are, usually, incompletely known, hinders the use of a rigorous calculation technique.To simplify the inter ballistics calculation, an analytical approximation of the engraving curve is proposed. For its description it is necessary to know the maximum force of resistance (or the shot-start pressure, the width of the driving band and the total travel of a projectile when engraving. Thus, it is assumed that after complete engraving of the driving band the resistance super-quickly drops to zero, and an appropriate jump in the acceleration (setback curve of the projectile occurs.For the first time, it is proposed to include the number of inter ballistic parameters into the work of powder gases, thus ensuring an automatic integration of the system of equations regardless of the specific description of the engraving curve (in some cases, analytical integration needed for calculation may be impossible.The example of calculation for the 122-mm D-30 howitzer illustrates a practical application of the proposed technique. Comparison of calculation results using the traditional and proposed techniques is made to show that the integral characteristics of the shot are close. It is found that a progress of the
Capacity Bounds for Parallel Optical Wireless Channels
Chaaban, Anas
2016-01-01
A system consisting of parallel optical wireless channels with a total average intensity constraint is studied. Capacity upper and lower bounds for this system are derived. Under perfect channel-state information at the transmitter (CSIT), the bounds have to be optimized with respect to the power allocation over the parallel channels. The optimization of the lower bound is non-convex, however, the KKT conditions can be used to find a list of possible solutions one of which is optimal. The optimal solution can then be found by an exhaustive search algorithm, which is computationally expensive. To overcome this, we propose low-complexity power allocation algorithms which are nearly optimal. The optimized capacity lower bound nearly coincides with the capacity at high SNR. Without CSIT, our capacity bounds lead to upper and lower bounds on the outage probability. The outage probability bounds meet at high SNR. The system with average and peak intensity constraints is also discussed.
Performance Bounds of Quaternion Estimators.
Xia, Yili; Jahanchahi, Cyrus; Nitta, Tohru; Mandic, Danilo P
2015-12-01
The quaternion widely linear (WL) estimator has been recently introduced for optimal second-order modeling of the generality of quaternion data, both second-order circular (proper) and second-order noncircular (improper). Experimental evidence exists of its performance advantage over the conventional strictly linear (SL) as well as the semi-WL (SWL) estimators for improper data. However, rigorous theoretical and practical performance bounds are still missing in the literature, yet this is crucial for the development of quaternion valued learning systems for 3-D and 4-D data. To this end, based on the orthogonality principle, we introduce a rigorous closed-form solution to quantify the degree of performance benefits, in terms of the mean square error, obtained when using the WL models. The cases when the optimal WL estimation can simplify into the SWL or the SL estimation are also discussed.
Spectral computations for bounded operators
Ahues, Mario; Limaye, Balmohan
2001-01-01
Exact eigenvalues, eigenvectors, and principal vectors of operators with infinite dimensional ranges can rarely be found. Therefore, one must approximate such operators by finite rank operators, then solve the original eigenvalue problem approximately. Serving as both an outstanding text for graduate students and as a source of current results for research scientists, Spectral Computations for Bounded Operators addresses the issue of solving eigenvalue problems for operators on infinite dimensional spaces. From a review of classical spectral theory through concrete approximation techniques to finite dimensional situations that can be implemented on a computer, this volume illustrates the marriage of pure and applied mathematics. It contains a variety of recent developments, including a new type of approximation that encompasses a variety of approximation methods but is simple to verify in practice. It also suggests a new stopping criterion for the QR Method and outlines advances in both the iterative refineme...
On order bounded subsets of locally solid Riesz spaces | Hong ...
African Journals Online (AJOL)
In a topological Riesz space there are two types of bounded subsets: order bounded subsets and topologically bounded subsets. It is natural to ask (1) whether an order bounded subset is topologically bounded and (2) whether a topologically bounded subset is order bounded. A classical result gives a partial answer to (1) ...
Bogdanoff, D. W.; Wilder, M. C.
2006-01-01
The latest developments in a research effort to advance techniques for measuring surface temperatures and heat fluxes and determining transition locations on projectiles in hypersonic free flight in a ballistic range are described. Spherical and hemispherical titanium projectiles were launched at muzzle velocities of 4.6-5.8 km/sec into air and nitrogen at pressures of 95-380 Torr. Hemisphere models with diameters of 2.22 cm had maximum pitch and yaw angles of 5.5-8 degrees and 4.7-7 degrees, depending on whether they were launched using an evacuated launch tube or not. Hemisphere models with diameters of 2.86 cm had maximum pitch and yaw angles of 2.0-2.5 degrees. Three intensified-charge-coupled-device (ICCD) cameras with wavelength sensitivity ranges of 480-870 nm (as well as one infrared camera with a wavelength sensitivity range of 3 to 5 microns), were used to obtain images of the projectiles in flight. Helium plumes were used to remove the radiating gas cap around the projectiles at the locations where ICCD camera images were taken. ICCD and infrared (IR) camera images of titanium hemisphere projectiles at velocities of 4.0-4.4 km/sec are presented as well as preliminary temperature data for these projectiles. Comparisons were made of normalized temperature data for shots at approx.190 Torr in air and nitrogen and with and without the launch tube evacuated. Shots into nitrogen had temperatures 6% lower than those into air. Evacuation of the launch tube was also found to lower the projectile temperatures by approx.6%.
Role of nuclear couplings in the inelastic excitation of weakly-bound neutron-rich nuclei
Energy Technology Data Exchange (ETDEWEB)
Dasso, C.H. [Niels Bohr Institute, Copenhagen (Denmark); Lenzi, S.M.; Vitturi, A. [Universita di Padova (Italy)
1996-12-31
Much effort is presently devoted to the study of nuclear systems far from the stability line. Particular emphasis has been placed in light systems such as {sup 11}Li, {sup 8}B and others, where the very small binding energy of the last particles causes their density distribution to extend considerably outside of the remaining nuclear core. Some of the properties associated with this feature are expected to characterize also heavier systems in the vicinity of the proton or neutron drip lines. It is by now well established that low-lying concentrations of multipole strength arise from pure configurations in which a peculiar matching between the wavelength of the continuum wavefunction of the particles and the range of the weakly-bound hole states occurs. To this end the authors consider the break-up of a weakly-bound system in a heavy-ion collision and focus attention in the inelastic excitation of the low-lying part of the continuum. They make use of the fact that previous investigations have shown that the multipole response in this region is not of a collective nature and describe their excited states as pure particle-hole configurations. Since the relevant parameter determining the strength distributions is the binding energy of the last bound orbital they find it most convenient to use single-particle wavefunctions generated by a sperical square-well potential with characteristic nuclear dimensions and whose depth has been adjusted to give rise to a situation in which the last occupied neutron orbital is loosely-bound. Spin-orbit couplings are, for the present purpose, ignored. The results of this investigation clearly indicate that nuclear couplings have the predominant role in causing projectile dissociation in many circumstances, even at bombarding energies remarkably below the Coulomb barrier.
Using tolerance bounds in scientific investigations
Energy Technology Data Exchange (ETDEWEB)
Wendelberger, J.R.
1996-07-01
Assessment of the variability in population values plays an important role in the analysis of scientific data. Analysis of scientific data often involves developing a bound on a proportion of a population. Sometimes simple probability bounds are obtained using formulas involving known mean and variance parameters and replacing the parameters by sample estimates. The resulting bounds are only approximate and fail to account for the variability in the estimated parameters. Tolerance bounds provide bounds on population proportions which account for the variation resulting from the estimated mean and variance parameters. A beta content, gamma confidence tolerance interval is constructed so that a proportion beta of the population lies within the region bounded by the interval with confidence gamma. An application involving corrosion measurements is used to illustrate the use of tolerance bounds for different situations. Extensions of standard tolerance intervals are applied to generate regression tolerance bounds, tolerance bounds for more general models of measurements collected over time, and tolerance intervals for varying precision data. Tolerance bounds also provide useful information for designing the collection of future data.
Calcium stable isotope geochemistry
Energy Technology Data Exchange (ETDEWEB)
Gausonne, Nikolaus [Muenster Univ. (Germany). Inst. fuer Mineralogie; Schmitt, Anne-Desiree [Strasbourg Univ. (France). LHyGeS/EOST; Heuser, Alexander [Bonn Univ. (Germany). Steinmann-Inst. fuer Geologie, Mineralogie und Palaeontologie; Wombacher, Frank [Koeln Univ. (Germany). Inst. fuer Geologie und Mineralogie; Dietzel, Martin [Technische Univ. Graz (Austria). Inst. fuer Angewandte Geowissenschaften; Tipper, Edward [Cambridge Univ. (United Kingdom). Dept. of Earth Sciences; Schiller, Martin [Copenhagen Univ. (Denmark). Natural History Museum of Denmark
2016-08-01
This book provides an overview of the fundamentals and reference values for Ca stable isotope research, as well as current analytical methodologies including detailed instructions for sample preparation and isotope analysis. As such, it introduces readers to the different fields of application, including low-temperature mineral precipitation and biomineralisation, Earth surface processes and global cycling, high-temperature processes and cosmochemistry, and lastly human studies and biomedical applications. The current state of the art in these major areas is discussed, and open questions and possible future directions are identified. In terms of its depth and coverage, the current work extends and complements the previous reviews of Ca stable isotope geochemistry, addressing the needs of graduate students and advanced researchers who want to familiarize themselves with Ca stable isotope research.
Karlova, Olena; Mykhaylyuk, Volodymyr
2015-01-01
We introduce and study adhesive spaces. Using this concept we obtain a characterization of stable Baire maps $f:X\\to Y$ of the class $\\alpha$ for wide classes of topological spaces. In particular, we prove that for a topological space $X$ and a contractible space $Y$ a map $f:X\\to Y$ belongs to the $n$'th stable Baire class if and only if there exist a sequence $(f_k)_{k=1}^\\infty$ of continuous maps $f_k:X\\to Y$ and a sequence $(F_k)_{k=1}^\\infty$ of functionally ambiguous sets of the $n$'th...
HDL-bound sphingosine 1-phosphate (S1P) predicts the severity of coronary artery atherosclerosis.
Sattler, Katherine; Lehmann, Isa; Gräler, Markus; Bröcker-Preuss, Martina; Erbel, Raimund; Heusch, Gerd; Levkau, Bodo
2014-01-01
We have recently demonstrated a reduction in HDL-bound sphingosine 1-phosphate (S1P) in patients with stable coronary artery disease (CAD). In the current study, we tested whether HDL-associated S1P is predictive for the degree of coronary stenosis, restenosis and overall CAD severity on follow up in patients undergoing elective percutaneous coronary intervention (PCI). Coronary angiography of patients with CAD (n=59) undergoing elective PCI and presenting for a follow up after 6 months (n=48) was graded for disease severity defined clinically as 1- or multi-vessel disease. Target lesion stenosis was quantified by quantitative coronary angiography (QCA). S1P in plasma and isolated HDL were measured by mass spectrometry in the initial samples and in 32 available follow up samples. HDL-bound S1P levels remained stable over time and correlated closely at first visit and follow up. While not associated with the extent of target lesion stenosis or restenosis, HDL-bound S1P correlated negatively with the overall severity of CAD and discriminated 1-vessel-disease from multi-vessel disease. Furthermore, low HDL-bound S1P was predictive for CAD extent. In stable CAD, HDL-bound S1P does not predict the degree of stenosis or restenosis of the target lesion but constitutes a marker of clinically defined disease burden.
HDL-Bound Sphingosine 1-Phosphate (S1P Predicts the Severity of Coronary Artery Atherosclerosis
Directory of Open Access Journals (Sweden)
Katherine Sattler
2014-06-01
Full Text Available Background: We have recently demonstrated a reduction in HDL-bound sphingosine 1-phosphate (S1P in patients with stable coronary artery disease (CAD. In the current study, we tested whether HDL-associated S1P is predictive for the degree of coronary stenosis, restenosis and overall CAD severity on follow up in patients undergoing elective percutaneous coronary intervention (PCI. Methods: Coronary angiography of patients with CAD (n=59 undergoing elective PCI and presenting for a follow up after 6 months (n=48 was graded for disease severity defined clinically as 1- or multi-vessel disease. Target lesion stenosis was quantified by quantitative coronary angiography (QCA. S1P in plasma and isolated HDL were measured by mass spectrometry in the initial samples and in 32 available follow up samples. Results: HDL-bound S1P levels remained stable over time and correlated closely at first visit and follow up. While not associated with the extent of target lesion stenosis or restenosis, HDL-bound S1P correlated negatively with the overall severity of CAD and discriminated 1-vessel-disease from multi-vessel disease. Furthermore, low HDL-bound S1P was predictive for CAD extent. Conclusion: In stable CAD, HDL-bound S1P does not predict the degree of stenosis or restenosis of the target lesion but constitutes a marker of clinically defined disease burden.
Instanton bound states in ABJM theory
Energy Technology Data Exchange (ETDEWEB)
Hatsuda, Yasuyuki [DESY Hamburg (Germany). Theory Group; Tokyo Institute of Technology (Japan). Dept. of Physics; Moriyama, Sanefumi [Nagoya Univ. (Japan). Kobayashi Maskawa Inst. and Graduate School of Mathematics; Okuyama, Kazumi [Shinshu Univ., Matsumoto, Nagano (Japan). Dept. of Physics
2013-06-15
The partition function of the ABJM theory receives non-perturbative corrections due to instanton effects. We study these non-perturbative corrections, including bound states of worldsheet instantons and membrane instantons, in the Fermi-gas approach. We require that the total non-perturbative correction should be always finite for arbitrary Chern-Simons level. This finiteness is realized quite non-trivially because each bound state contribution naively diverges at some levels. The poles of each contribution should be canceled out in total. We use this pole cancellation mechanism to find unknown bound state corrections from known ones. We conjecture a general expression of the bound state contribution. Summing up all the bound state contributions, we find that the effect of bound states is simply incorporated into the worldsheet instanton correction by a redefinition of the chemical potential in the Fermi-gas system. Analytic expressions of the 3- and 4-membrane instanton corrections are also proposed.
Energy Technology Data Exchange (ETDEWEB)
Vidovic, Z
1997-06-15
This work focuses on the study of the emission statistics of secondary electrons from thin carbon foils bombarded with H{sup 0}, H{sub 2}{sup +} and H{sub 3}{sup +} projectiles in the 0.25-2.2 MeV energy range. The phenomenon of secondary electron emission from solids under the impact of swift ions is mainly due to inelastic interactions with target electrons. The phenomenological and theoretical descriptions, as well as a summary of the main theoretical models are the subject of the first chapter. The experimental set-up used to measure event by event the electron emission of the two faces of a thin carbon foil traversed by an energetic projectile is described in the chapter two. In this chapter are also presented the method and algorithms used to process experimental spectra in order to obtain the statistical distribution of the emitted electrons. Chapter three presents the measurements of secondary electron emission induced by H atoms passing through thin carbon foils. The secondary electron yields are studied in correlation with the emergent projectile charge state. We show the peculiar role of the projectile electron, whether it remains or not bound to the incident proton. The fourth chapter is dedicated to the secondary electron emission induced by H{sub 2}{sup +} and H{sub 3}{sup +} polyatomic ions. The results are interpreted in terms of collective effects in the interactions of these ions with solids. The role of the proximity of the protons, molecular ion fragments, upon the amplitude of these collective effects is evidenced from the study of the statistics of forward emission. These experiences allowed us to shed light on various aspects of atom and polyatomic ion inter-actions with solid surfaces. (author)
Schmidt, G.; Kratz, K.
2009-12-01
Ancient surfaces of solid planets show that impact cratering is a major process in planet formation. Understanding origin and influence of impactors on the chemical composition of planets (core, mantle and crust) it is important to know the relative abundances of highly siderophile elements (Os, Ir, Ru, Pt, Rh, Pd) in the silicate mantle and crust of planets and meteorites. Refractory highly siderophile elements, such as Os and Ir, are abundant in most meteorites but depleted in crustal rocks (low target/meteorite ratios) and thus the most reliable elements for projectile identification. However, target/meteorite ratios are high if target rocks consist of mantle rocks. In such cases elements are enriched in impactites due to relatively high abundances (ng/g level) in target rocks to make the identification of projectile types difficult (e.g., Gardnos impact structure in Norway). The Ru/Ir ratio is the most reliable key ratio that rules out Earth primitive upper mantle (PUM) derived refractory highly siderophile element components in impactites. The well established Ru/Ir ratio of the Earth mantle of 2.0 ± 0.1 (e.g. Schmidt and Kratz 2004) is significantly above the chondritic ratios varying from 1.4 to 1.6. On Earth Rh/Ir, Ru/Ir, Pd/Ir, and Pt/Os derived from PUM match the ratios of group IV irons with fractionated trace element patterns. The question raise if HSE in mantle rocks are added to the accreting Earth by a late bombardment of pre-differentiated objects or the cores of these objects (magmatic iron meteorites as remnants of the first planetesimals, e.g. Kleine et al. 2009) or some unsampled inner solar system materials from the Mercury-Venus formation region, not sampled through meteorite collections (Schmidt 2009). The PGE and Ni systematics of the upper continental crust (UCC) closely resembles group IIIAB iron meteorites with highly fractionated refractory trace element patterns, pallasites, and the evolved suite of Martian meteorites (representing
Distance hijacking attacks on distance bounding protocols
Cremers, Cas; Rasmussen, Kasper Bonne; Čapkun, Srdjan
2011-01-01
Distance bounding protocols are typically analyzed with respect to three types of attacks: Distance Fraud, Mafia Fraud, and Terrorist Fraud. We define a fourth main type of attacks on distance bounding protocols, called Distance Hijacking attacks. We show that many proposed distance bounding protocols are vulnerable to these attacks, and we propose solutions to make these protocols resilient to Distance Hijacking. Additionally, we generalize Distance Hijacking to Location Hijacking, to which ...
Boundedly UC spaces: characterisations and preservation | Jain ...
African Journals Online (AJOL)
A metric space (X, d) is called a boundedly UC space if every closed and bounded subset of X is a UC space. A metric space (X, d) is called a UC space if each real-valued continuous function on (X, d) is uniformly continuous. In this paper, we study twenty-two equivalent conditions for a metric space to be a boundedly UC ...
Bounded cohomology of discrete groups
Frigerio, Roberto
2017-01-01
The author manages a near perfect equilibrium between necessary technicalities (always well motivated) and geometric intuition, leading the readers from the first simple definition to the most striking applications of the theory in 13 very pleasant chapters. This book can serve as an ideal textbook for a graduate topics course on the subject and become the much-needed standard reference on Gromov's beautiful theory. -Michelle Bucher The theory of bounded cohomology, introduced by Gromov in the late 1980s, has had powerful applications in geometric group theory and the geometry and topology of manifolds, and has been the topic of active research continuing to this day. This monograph provides a unified, self-contained introduction to the theory and its applications, making it accessible to a student who has completed a first course in algebraic topology and manifold theory. The book can be used as a source for research projects for master's students, as a thorough introduction to the field for graduate student...
Heaton, Tim B.; Albrecht, Stan L.
1991-01-01
Examined prevalence and determinants of stable unhappy marriage using data from national survey. Results indicated age, lack of prior marital experience, commitment to marriage as an institution, low social activity, lack of control over one's life, and belief that divorce would detract from happiness were all predictive of stability in unhappy…
Directory of Open Access Journals (Sweden)
Behnaz Tolue
2018-07-01
Full Text Available In this paper we introduce stable subgroup graph associated to the group $G$. It is a graph with vertex set all subgroups of $G$ and two distinct subgroups $H_1$ and $H_2$ are adjacent if $St_{G}(H_1\\cap H_2\
Bezhanishvili, G.; Bezhanishvili, N.; Ilin, J.
2016-01-01
We generalize the (∧,∨)-canonical formulas to (∧,∨)-canonical rules, and prove that each intuitionistic multi-conclusion consequence relation is axiomatizable by (∧,∨)-canonical rules. This yields a convenient characterization of stable superintuitionistic logics. The (∧,∨)-canonical formulas are
Performance of primary repair on colon injuries sustained from low-versus high-energy projectiles
Lazovic, Ranko; Radojevic, Nemanja; Curovic, Ivana
2017-01-01
Among various reasons, colon injuries may be caused by low- or high-energy firearm bullets, with the latter producing a temporary cavitation phenomenon. The available treatment options include primary repair and two-stage management, but recent studies have shown that primary repair can be widely used with a high success rate. This paper investigates the differences in performance of primary repair on these two types of colon injuries. Two groups of patients who sustained colon injuries due to single gunshot wounds, were retrospectively categorized based on the type of bullet. Primary colon repair was performed in all patients selected based on the inclusion and exclusion criteria (Stone and Fabian's criteria). An almost absolute homogeneity was attained among the groups in terms of age, latent time before surgery, and four trauma indexes. Only one patient from the low-energy firearm projectile group (4%) developed a postsurgical complication versus nine patients (25.8%) from the high-energy group, showing statistically significant difference (p = 0.03). These nine patients experienced the following postsurgical complications: pneumonia, abscess, fistula, suture leakage, and one multiorgan failure with sepsis. Previous studies concluded that one-stage primary repair is the best treatment option for colon injuries. However, terminal ballistics testing determined the projectile's path through the body and revealed that low-energy projectiles caused considerably lesser damage than their high-energy counterparts. Primary colon repair must be performed definitely for low-energy short firearm injuries but very carefully for high-energy injuries. Given these findings, we suggest that the treatment option should be determined based not only on the bullet type alone but also on other clinical findings. PMID:26874437
Haar, Rohini J; Iacopino, Vincent; Ranadive, Nikhil; Dandu, Madhavi; Weiser, Sheri D
2017-01-01
Objective We conducted a systematic review of the available literature on deaths, injuries and permanent disability from rubber and plastic bullets, as well as from bean bag rounds, shot pellets and other projectiles used in arrests, protests and other contexts from 1 January 1990 until 1 June 2017. Data sources PubMed, Scopus, JSTOR and grey literature. Data synthesis We report on descriptive statistics as well as data on injury severity, permanent disability and death. We analysed potential risk factors for injury severity, including the site of impact, firing distance and access to medical care. Results Of 3228 identified articles, 26 articles met inclusion criteria. These articles included injury data on 1984 people, 53 of whom died as a result of their injuries. 300 people suffered permanent disability. Deaths and permanent disability often resulted from strikes to the head and neck (49.1% of deaths and 82.6% of permanent disabilities). Of the 2135 injuries in those who survived their injuries, 71% were severe, injuries to the skin and to the extremities were most frequent. Anatomical site of impact, firing distance and timely access to medical care were correlated with injury severity and risk of disability. Conclusions Kinetic impact projectiles (KIPs), often called rubber or plastic bullets, are used commonly in crowd-control settings. We find that these projectiles have caused significant morbidity and mortality during the past 27 years, much of it from penetrative injuries and head, neck and torso trauma. Given their inherent inaccuracy, potential for misuse and associated health consequences of severe injury, disability and death, KIPs do not appear to be appropriate weapons for use in crowd-control settings. There is an urgent need to establish international guidelines on the use of crowd-control weapons to prevent unnecessary injuries and deaths. PMID:29255079
Haar, Rohini J; Iacopino, Vincent; Ranadive, Nikhil; Dandu, Madhavi; Weiser, Sheri D
2017-12-05
We conducted a systematic review of the available literature on deaths, injuries and permanent disability from rubber and plastic bullets, as well as from bean bag rounds, shot pellets and other projectiles used in arrests, protests and other contexts from 1 January 1990 until 1 June 2017. PubMed, Scopus, JSTOR and grey literature. We report on descriptive statistics as well as data on injury severity, permanent disability and death. We analysed potential risk factors for injury severity, including the site of impact, firing distance and access to medical care. Of 3228 identified articles, 26 articles met inclusion criteria. These articles included injury data on 1984 people, 53 of whom died as a result of their injuries. 300 people suffered permanent disability. Deaths and permanent disability often resulted from strikes to the head and neck (49.1% of deaths and 82.6% of permanent disabilities). Of the 2135 injuries in those who survived their injuries, 71% were severe, injuries to the skin and to the extremities were most frequent. Anatomical site of impact, firing distance and timely access to medical care were correlated with injury severity and risk of disability. Kinetic impact projectiles (KIPs), often called rubber or plastic bullets, are used commonly in crowd-control settings. We find that these projectiles have caused significant morbidity and mortality during the past 27 years, much of it from penetrative injuries and head, neck and torso trauma. Given their inherent inaccuracy, potential for misuse and associated health consequences of severe injury, disability and death, KIPs do not appear to be appropriate weapons for use in crowd-control settings. There is an urgent need to establish international guidelines on the use of crowd-control weapons to prevent unnecessary injuries and deaths. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless
Equilibrium mercury isotope fractionation between dissolved Hg(II) species and thiol-bound Hg
Wiederhold, Jan G.; Cramer, Christopher J.; Daniel, Kelly; Infante, Ivan; Bourdon, Bernard; Kretzschmar, Ruben
2010-01-01
Stable Hg isotope ratios provide a new tool to trace environmental Hg cycling. Thiols (-SH) are the dominant Hg-binding groups in natural organic matter. Here, we report experimental and computational results on equilibrium Hg isotope fractionation between dissolved Hg(II) species and thiol-bound
Bounded sets in fast complete inductive limits
Directory of Open Access Journals (Sweden)
Jan Kucera
1984-01-01
Full Text Available Let E1⊂E2⊂… be a sequence of locally convex spaces with all identity maps: En→En+1 continuous and E=indlim En fast complete. Then each set bounded in E is also bounded in some En iff for any Banach disk B bounded in E and n∈N, the closure of B⋂En in B is bounded in some Em. This holds, in particular, if all spaces En are webbed.
Valuation models and Simon's bounded rationality
National Research Council Canada - National Science Library
Alexandra Strommer de Farias Godoi
2009-01-01
This paper aims at reconciling the evidence that sophisticated valuation models are increasingly used by companies in their investment appraisal with the literature of bounded rationality, according...
Some Improved Nonperturbative Bounds for Fermionic Expansions
Energy Technology Data Exchange (ETDEWEB)
Lohmann, Martin, E-mail: marlohmann@gmail.com [Universita di Roma Tre, Dipartimento di Matematica (Italy)
2016-06-15
We reconsider the Gram-Hadamard bound as it is used in constructive quantum field theory and many body physics to prove convergence of Fermionic perturbative expansions. Our approach uses a recursion for the amplitudes of the expansion, discovered in a model problem by Djokic (2013). It explains the standard way to bound the expansion from a new point of view, and for some of the amplitudes provides new bounds, which avoid the use of Fourier transform, and are therefore superior to the standard bounds for models like the cold interacting Fermi gas.
A strongly quasiconvex PAC-Bayesian bound
DEFF Research Database (Denmark)
Thiemann, Niklas; Igel, Christian; Wintenberger, Olivier
We propose a new PAC-Bayesian bound and a way of constructing a hypothesis space, so that the bound is convex in the posterior distribution and also convex in a trade-off parameter between empirical performance of the posterior distribution and its complexity. The complexity is measured by the Ku......We propose a new PAC-Bayesian bound and a way of constructing a hypothesis space, so that the bound is convex in the posterior distribution and also convex in a trade-off parameter between empirical performance of the posterior distribution and its complexity. The complexity is measured...
Bhattacharjee, B.; Talukdar, R.
2011-09-01
The effect of the system size on a number of traditionally accepted signatures of cluster approximation technique of critical behavior have been examined for projectile multifragmenting systems like Mg at 4.5 AGeV and Kr at 0.95 AGeV. The results obtained from analyzing our experimental data on the fluctuation of size of the largest fragments, reduced variance and the mean value of the second moments of charge distribution provide clear evidences of size effect in terms of the height and position of the peaks of the studied parameters.
Influence of projectile neutron number on cross section in cold fusion reactions
Energy Technology Data Exchange (ETDEWEB)
Dragojevic, Irena; Dragojevic, I.; Gregorich, K.E.; Dullmann, Ch.E.; Folden III, C.M.; Garcia, M.A.; Gates, J.M.; Nelson, S.L.; Sudowe, R.; Nitsche, H.
2007-09-01
Elements 107-112 [1,2] have been discovered in reactions between {sup 208}Pb or {sup 209}Bi targets and projectiles ranging from {sup 54}Cr through {sup 70}Zn. In such reactions, the compound nucleus can be formed at excitation energies as low as {approx}12 MeV, thus this type of reaction has been referred to as 'cold fusion'. The study of cold fusion reactions is an indispensable approach to gaining a better understanding of heavy element formation and decay. A theoretical model that successfully predicts not only the magnitudes of cold fusion cross sections, but also the shapes of excitation functions and the cross section ratios between various reaction pairs was recently developed by Swiatecki, Siwek-Wilczynska, and Wilczynski [3,4]. This theoretical model, also referred to as Fusion by Diffusion, has been the guide in all of our cold fusion studies. One particularly interesting aspect of this model is the large predicted difference in cross sections between projectiles differing by two neutrons. The projectile pair where this difference is predicted to be largest is {sup 48}Ti and {sup 50}Ti. To test and extend this model, {sup 208}Pb({sup 48}Ti,n){sup 255}Rf and {sup 208}Pb({sup 50}Ti,n){sup 257}Rf excitation functions were recently measured at the Lawrence Berkeley National Laboratory's (LBNL) 88-Inch Cyclotron utilizing the Berkeley Gas-filled Separator (BGS). The {sup 50}Ti reaction was carried out with thin lead targets ({approx}100 {micro}g/cm{sup 2}), and the {sup 48}Ti reaction with both thin and thick targets ({approx}470 {micro}g/cm{sup 2}). In addition to this reaction pair, reactions with projectile pairs {sup 52}Cr and {sup 54}Cr [5], {sup 56}Fe and {sup 58}Fe [6], and {sup 62}Ni [7] and {sup 64}Ni [8] will be discussed and compared to the Fusion by Diffusion predictions. The model predictions show a very good agreement with the data.
Anomalies in the Flow over Projectile with Wrap-around Fins
Ravi Krishna; Rhishabh Surit; Abhijit Kushari; Ghosh, A K
2009-01-01
This paper presents the results of a numerical study to understand the flow field over a projectile with wraparoundfins. This investigation is performed in order to determine aerodynamic coefficients for the missile model for varying Mach number from 1.2 to 2.5. The roll moment coefficients were computed from the flow field solution and compared with other computational models and experimental works. The results show a reversal of the rolling moment in a Mach number from 1.2 to 1.4. While gen...
Projectile motion on an inclined misty surface: II. Scoring a goal
Foong, S. K.; Lim, C. C.; Kuppan, L.
2009-05-01
Feedback on part I of this series (Ho et al 2009 Phys. Educ. 44 253) motivated us to make hitting the target more interesting with a simple innovation: changing the target to a ring shaped hoop or goalpost and shooting for it in the 'air', as if playing basketball on the inclined plane. We discuss in detail the demarcation of the boundary (safety parabola) between the accessible region and the inaccessible region for a projectile on the surface of the inclined plane, and derive the angle of projection for scoring a goal. We also consider the orientation of the rings for maximizing the chance of scoring.
Multiple-projectile penetrating neck injury from a modified nail-containing gas pistol.
Pazardzhikliev, Dimitar Dimitrov
2014-09-01
Penetrating neck injuries result from missiles and stab wounds. A gas pistol is a non-lethal weapon for self-defence. We present a case where the use of a modified gun led to multiple injuries in a single shot. Four projectiles were embedded in the neck, one in the larynx and three in the cervical spine. The first was removed via a combined external and endoscopic approach, while the rest were put on follow-up. The reported case shows that damage from modified gas pistols, although rarely life threatening, may cause long term discomfort and diminished quality of life.
Clovis age Western stemmed projectile points and human coprolites at the Paisley Caves
DEFF Research Database (Denmark)
Jenkins, Dennis L.; Davis, Loren G.; Stafford jr., Thomas
2012-01-01
The Paisley Caves in Oregon record the oldest directly dated human remains (DNA) in the Western Hemisphere. More than 100 high-precision radiocarbon dates show that deposits containing artifacts and coprolites ranging in age from 12,450 to 2295 C years ago are well stratified. Western Stemmed...... projectile points were recovered in deposits dated to 11,070 to 11,340 C years ago, a time contemporaneous with or preceding the Clovis technology. There is no evidence of diagnostic Clovis technology at the site. These two distinct technologies were parallel developments, not the product of a unilinear...
Fragmentation of Millimeter-Size Hypervelocity Projectiles on Combined Mesh-Plate Bumpers
Cherniaev, Aleksandr; Telichev, Igor
2017-01-01
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 alu...
Methyl Centralite Coated M10 Propellant for the 25-mm Bushmaster Gun Projectiles
1984-09-01
USrO FOR GOVERNMENT PURPOSES ONLY L’ would bo marginal with the lower, projectile weights for SP KC coated propellant (RAD-PE-485-Bl) or NP KC coated...EXPLOSIVE (SOLID) CLASS B 25umm GUN HE LOT RAD-PE-559- 6 0.024" WEB SP GRAIN 150 LBS NET 101 LBS GROSS 4.2 CU FT PACKD * *Insert as applicable. TO...IA,14n Avne_ . 5 MANUFATURE O PROPELLANTSC 35 5 62-IP _Weter n 1 11 7& 76 Coating Cycle -58 1 67 Post Coating
Hockey, iPads, and Projectile Motion in a Physics Classroom
Hechter, Richard P.
2013-09-01
With the increased availability of modern technology and handheld probeware for classrooms, the iPad1 and the Video Physics2 application developed by Vernier are used to capture and analyze the motion of an ice hockey puck within secondary-level physics education. Students collect, analyze, and generate digital modes of representation of physics phenomena using modern technologies to complement theoretical plots. This activity acknowledges hockey players' implicit understanding of the launch angle and initial velocity of a saucer pass as basic projectile motion while engaging students in authentic physics-based problem solving.
Multifragmentation of the Pb projectile at 158 GeV/nucleon in Pb-Pb interactions
Energy Technology Data Exchange (ETDEWEB)
Holynski, R.; Dabrowska, A.; Olszewski, A.; Szarska, M.; Trzupek, A.; Wilczynska, B.; Wilczynski, H.; Wolter, W.; Wosiek, B.; Wozniak, K. [Institute of Nuclear Physics, Cracow (Poland); Cherry, M.L.; Deines-Jones, P.; Nilsen, B.S.; Waddington, C.J.; Wefel, J.P.
1999-06-01
We have investigated the process of fragmentation of the Pb nucleus at 158 GeV/nucleon in Pb-Pb interactions recorded in the lead-emulsion chambers of the EMU13 CERN experiment. The number of Pb-Pb interactions found was larger than expected from the nuclear charge changing cross section, which indicates an important role of electromagnetic dissociation processes in Pb-Pb interactions at this energy. Different modes of the Pb projectile break-up, including the multifragmentation process, are discussed. The rates and properties of fragmentation processes such as fission, multifragmentation and disintegration into singly charged fragments are presented. (orig.) 7 refs.
Effect of a Bore Evacuator on Projectile In-Bore Dynamics
2004-11-01
VEL QCýITY 534 m/s •0 200 5500 2ൈ,• i • / / 50 20 __ ACCE RATION 240 40 220 40"O 4 i000 40 41000 3:00 100 ( ISO < 00o.t °300 140.... 120 2000 2 0 0...Figure 6 Projectile velocity, travel, and acceleration versus time - TRN 82 5 Acceleration (G’s) Travel 28500 t(in.) 2550 TRAVEL 6 255 i C EL R TIi500 260
New lower bound for the Capacitated Arc Routing Problem
DEFF Research Database (Denmark)
Wøhlk, Sanne
2006-01-01
We present a new lower bound, the Multiple Cuts Node Duplication Lower Bound, for the undirected Capacitated Arc Routing Problem.We prove that this new bound dominates the existing bounds for the problem. Computational results are also provided.......We present a new lower bound, the Multiple Cuts Node Duplication Lower Bound, for the undirected Capacitated Arc Routing Problem.We prove that this new bound dominates the existing bounds for the problem. Computational results are also provided....
Bounded rationality and learning in complex markets
Hommes, C.H.; Barkely Rosser Jr, J.
2009-01-01
This chapter reviews some work on bounded rationality, expectation formation and learning in complex markets, using the familiar demand-supply cobweb model. We emphasize two stories of bounded rationality, one story of adaptive learning and another story of evolutionary selection. According to the
Bounded rationality and learning in complex markets
Hommes, C.H.
2007-01-01
This chapter reviews some work on bounded rationality, expectation formation and learning in complex markets, using the familiar demand-supply cobweb model. We emphasize two stories of bounded rationality, one story of adaptive learning and another story of evolutionary selection. According to the
Spatial coagulation with bounded coagulation rate
Bailleul, Ismael
2010-01-01
We prove that the spatial coagulation equation with bounded coagulation rate is well-posed for all times in a given class of kernels if the convection term of the underlying particle dynamics has divergence bounded below by a positive constant. Multiple coagulations, fragmentation and scattering are also considered.
Schroedinger upper bounds to semirelativistic eigenvalues
Energy Technology Data Exchange (ETDEWEB)
Hall, Richard L [Department of Mathematics and Statistics, Concordia University, 1455 de Maisonneuve Boulevard West, Montreal, Quebec, H3G 1M8 (Canada); Lucha, Wolfgang [Institut fuer Hochenergiephysik, Oesterreichische Akademie der Wissenschaften, Nikolsdorfergasse 18, A-1050 Vienna (Austria)
2005-09-16
Problems posed by semirelativistic Hamiltonians of the form H = {radical}(m{sup 2} + p{sup 2}) + V(r) are studied. It is shown that energy upper bounds can be constructed in terms of certain related Schroedinger operators; these bounds include free parameters which can be chosen optimally.
No-arbitrage bounds for financial scenarios
DEFF Research Database (Denmark)
Geyer, Alois; Hanke, Michael; Weissensteiner, Alex
2014-01-01
We derive no-arbitrage bounds for expected excess returns to generate scenarios used in financial applications. The bounds allow to distinguish three regions: one where arbitrage opportunities will never exist, a second where arbitrage may be present, and a third, where arbitrage opportunities...
Nonatomic dual bakery algorithm with bounded tokens
Aravind, Alex A.; Hesselink, Wim H.
A simple mutual exclusion algorithm is presented that only uses nonatomic shared variables of bounded size, and that satisfies bounded overtaking. When the shared variables behave atomically, it has the first-come-first-served property (FCFS). Nonatomic access makes information vulnerable. The
Polynomially Bounded Sequences and Polynomial Sequences
Directory of Open Access Journals (Sweden)
Okazaki Hiroyuki
2015-09-01
Full Text Available In this article, we formalize polynomially bounded sequences that plays an important role in computational complexity theory. Class P is a fundamental computational complexity class that contains all polynomial-time decision problems [11], [12]. It takes polynomially bounded amount of computation time to solve polynomial-time decision problems by the deterministic Turing machine. Moreover we formalize polynomial sequences [5].
Upper Bounds on Numerical Approximation Errors
DEFF Research Database (Denmark)
Raahauge, Peter
2004-01-01
This paper suggests a method for determining rigorous upper bounds on approximationerrors of numerical solutions to infinite horizon dynamic programming models.Bounds are provided for approximations of the value function and the policyfunction as well as the derivatives of the value function...
On the range of completely bounded maps
Directory of Open Access Journals (Sweden)
Richard I. Loebl
1978-01-01
Full Text Available It is shown that if every bounded linear map from a C*-algebra α to a von Neumann algebra β is completely bounded, then either α is finite-dimensional or β⫅⊗Mn, where is a commutative von Neumann algebra and Mn is the algebra of n×n complex matrices.
A polynomial lower bound for testing monotonicity
A. Belovs (Aleksandr); Blais, E. (Eric)
2016-01-01
textabstractWe show that every algorithm for testing n-variate Boolean functions for monotonicity has query complexity Ω(n1/4). All previous lower bounds for this problem were designed for nonadaptive algorithms and, as a result, the best previous lower bound for general (possibly adaptive)
Stable Hybrid Adaptive Control,
1982-07-01
STABLE HYBRID ADAPTIVE CONTROL(U) YALE UNIV NEW HAVEN i/i CT CENTER FOR SYSTEMS SCIENCE K S NARENDRA ET AL. JUL 82 8286 Ne@04-76-C-8e7 UNCLASSIFIED...teasrallepsaaw1tflbe~ll b ydd Il"t 5 As is the comtanuous Case cistral to the stability analysis of the hybrid ~IVt* COnRol PO* IMare the sur Models
Energy Technology Data Exchange (ETDEWEB)
Lopez-Jimenez, M.J.; Saint-Laurent, M.G.; Achouri, L.; Daugas, J.M. [Grand Accelerateur National d`Ions Lourds, 14 - Caen (France); Belleguic, M.; Azaiez, F.; Bourgeois, C. [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire; Stanoiu, M.; Borcea, C. [Institute of Atomic Physics, Bucharest (Romania); Angelique, J.C. [Caen Univ., 14 (France). Lab. de Physique Corpusculaire] [and others
1999-11-01
The structure of nuclei far from stability around {sup 32}Mg have been recently investigated by means of a novel method. In-beam {gamma}-decay spectroscopy of a large number of exotic neutron-rich nuclei produced by projectile fragmentation of a {sup 36}S projectile has been performed, using coincidences between the recoil fragments collected at the focal plane of SPEG spectrometer and {gamma}-rays emitted at the target location. Preliminary results on both the population mechanism and the decay of excited states in nuclei around {sup 32}Mg are presented. (author) 24 refs.
Energy Technology Data Exchange (ETDEWEB)
Beck, C. [Institut Pluridisciplinaire Hubert Curien, UMR 7178, IN2P3-CNRS et Universite Louis Pasteur (Strasbourg I), 23 rue du Loess - BP28, F-67037 Strasbourg Cedex 2 (France); Keeley, N. [DSM/DAPNIA/SPhN CEA Saclay, Orme des Merisiers, F-91191 Gif-sur-Yvette Cedex (France); Diaz-Torres, A. [Department of Nuclear Physics, Research School of Physical Sciences and Engineering, The Australian National University, Canberra ACT 0200 (Australia)
2007-03-15
The influence on fusion of coupling to the breakup process is investigated for reactions where at least one of the colliding nuclei has a sufficiently low binding energy for breakup to become an important process. Elastic scattering, excitation functions for sub-and near-barrier fusion cross sections, and breakup yields are analyzed for {sup 6,7}Li+{sup 59}Co. Continuum-Discretized Coupled-Channels (CDCC) calculations describe well the data at and above the barrier. Elastic scattering with {sup 6}Li (as compared to {sup 7}Li) indicates the significant role of breakup for weakly bound projectiles. A study of {sup 4,6}He induced fusion reactions with a three-body CDCC method for the {sup 6}He halo nucleus is presented. The relative importance of breakup and bound-state structure effects on total fusion is discussed. (authors)
Computational design of graphene sheets for withstanding the impact of ultrafast projectiles.
Sadeghzadeh, Sadegh
2016-11-01
A multi-scale method is employed in this paper to conduct a virtual study of the high-strain behavior of single- and multi-layer graphene sheets and to investigate the design of related graphene-based devices. By bridging the length and time scales by combining the Molecular Dynamics and Finite Element methods together, a comprehensive multiscale model is developed to study the fascinating capabilities of single- and multi-layer graphene sheets in withstanding the impact of ultrafast projectiles. In order to contribute to future developments and innovations in this field, several quantitative and qualitative comparisons are also performed. By employing the validated model, the effects of several parameters on the impact resistance efficiency of the examined sheets are evaluated. The specific penetration energy of multilayer graphene sheets is several times greater than that of metal sheets. It is demonstrated that the number of layers, aspect ratio, sheet size, interlayer distance, delamination, and projectile shape significantly influence the impact resistance of graphene sheets. The specific critical rupture velocity decreases asymptotically with the increase in the number of layers. A large-scale array of fewer graphene layers can withstand bullets of much higher velocities than a multilayer graphene sheet with equivalent weight. Finally, the coefficient of restitution for the oblique collision of gold and steel nanoparticles with multilayer graphene sheets is calculated at different impact velocities. Copyright Â© 2016 Elsevier Inc. All rights reserved.
Effect of projectile structure on evaporation residue yields in incomplete fusion reactions
Babu, K S; Sudarshan, K; Shrivastava, B D; Goswami, A; Tomar, B S
2003-01-01
The excitation functions of heavy residues, representing complete and incomplete fusion products, produced in the reaction of sup 1 sup 2 C and sup 1 sup 3 C on sup 1 sup 8 sup 1 Ta have been measured over the projectile energy range of 5 to 6.5 MeV/nucleon by the recoil catcher method and off-line gamma-ray spectrometry. Comparison of the measured excitation functions with those calculated using the PACE2 code based on the statistical model revealed the occurrence of incomplete fusion reactions in the formation of alpha emission products. The fraction of incomplete fusion cross sections in the sup 1 sup 2 C + sup 1 sup 8 sup 1 Ta reaction was found to be higher, by a factor of approx 2, than that in the sup 1 sup 3 C + sup 1 sup 8 sup 1 Ta reaction. The results have been discussed in terms of the effect of alpha cluster structure of the projectile on incomplete fusion reactions.
Assessment of two fast codes used for preliminary aerodynamic design of guided projectiles
Mikhail, Ameer G.
1986-07-01
Two missile aerodynamic prediction fast codes, namely NSWCAP and Missile-DATCOM, have been applied to the geometry of the guided, gun-launched Copperhead projectile. Assessment of the two codes was made in comparison with wind tunnel and free-flight range test data. Two configurations were considered for computation: the launch configuration (body-tail) in the Mach range of 0.5 to 1.8 and the maneuvering configuration (body-wing-tail) in the Mach range of 0.3 to 0.95. Results show reasonable agreement for the drag coefficient, C sub D, and show very large disagreements for both C sub N sub alpha and C sub M sub alpha. The incapability of both codes to include body slots and fin gap effects seems to have contributed largely to these differences. The dynamic derivatives C sub l sub p and (C sub M sub q + C sub M sub alpha) are not adequately estimated by the NSWCAP code, and are not calculated in the DATCOM code. For the coefficients actually computed, the DATCOM code results were slightly more accurate than those of the NSWCAP code. Both codes lack the determination of the explicit effects of control surface deflection angles on the aerodynamic coefficients. Development is needed for the determination if both codes are to be used for predictions for guided projectiles. Several areas of improvements in both codes are identified.
Directory of Open Access Journals (Sweden)
Marković Miloš D.
2016-01-01
Full Text Available The Research in this paper considered the temperatures fields as the consequently influenced effects appeared by plastic deformation, in the explosively forming process aimed to design Explosively Formed Projectiles (henceforth EFP. As the special payloads of the missiles, used projectiles are packaged as the metal liners, joined with explosive charges, to design explosive propulsion effect. Their final form and velocity during shaping depend on distributed temperatures in explosively driven plastic deformation process. Developed simulation model consider forming process without metal cover of explosive charge, in aim to discover liner’s dynamical correlations of effective plastic strains and temperatures in the unconstrained detonation environment made by payload construction. The temperature fields of the liner’s copper material are considered in time, as the consequence of strain/stress displacements driven by explosion environmental thermodynamically fields of pressures and temperatures. Achieved final velocities and mass loses as the expected EFP performances are estimated regarding their dynamical shaping and thermal gradients behavior vs. effective plastic strains. Performances and parameters are presented vs. process time, numerically simulated by the Autodyne software package. [Projekat Ministarstva nauke Republike Srbije, br. III-47029
Handayani, Langlang; Prasetya Aji, Mahardika; Susilo; Marwoto, Putut
2016-08-01
An alternative approach of an arts-based instruction for Basic Physics class has been developed through the implementation of video analysis of a Javanesse traditional dance: Bambangan Cakil. A particular movement of the dance -weapon throwing- was analyzed by employing the LoggerPro software package to exemplify projectile motion. The results of analysis indicated that the movement of the thrown weapon in Bambangan Cakil dance provides some helping explanations of several physics concepts of projectile motion: object's path, velocity, and acceleration, in a form of picture, graph and also table. Such kind of weapon path and velocity can be shown via a picture or graph, while such concepts of decreasing velocity in y direction (weapon moving downward and upward) due to acceleration g can be represented through the use of a table. It was concluded that in a Javanesse traditional dance there are many physics concepts which can be explored. The study recommends to bring the traditional dance into a science class which will enable students to get more understanding of both physics concepts and Indonesia cultural heritage.
Effects of the projectile electronic structure on Bethe-Bloch stopping parameters for Ag
Energy Technology Data Exchange (ETDEWEB)
Moussa, D., E-mail: djamelmoussa@gmail.co [USTHB, Faculte de Physique, B.P. 32, 16111 Bab-Ezzouar, Algiers (Algeria); Damache, S. [Division de Physique, CRNA, 02 Bd. Frantz Fanon, B.P. 399 Alger-gare, Algiers (Algeria); Ouichaoui, S., E-mail: souichaoui@gmail.co [USTHB, Faculte de Physique, B.P. 32, 16111 Bab-Ezzouar, Algiers (Algeria)
2010-06-15
Energy losses of protons and alpha particles in silver have been accurately measured under the same experimental conditions over the velocity range E{sub lab}=(0.192-2.595) MeV/amu using the transmission method. Deduced S(E) stopping powers are compared to most accurate ones from the literature, to values generated by the SRIM-2008 computer code and to ICRU-49 compilation. They were analyzed in the framework of modified Bethe-Bloch theory for extracting Ag target mean excitation and ionization potential, I, and Barkas effect parameter, b. Values of (466{+-}5) eV and 1.20{+-}0.01 for these two parameters were inferred from the proton S(E) data while the alpha particle data yielded values of (438{+-}4) eV and 1.38{+-}0.01, respectively. The (I, b) stopping parameters thus exhibit opposite variations as the projectile charge increases, similarly as we have found previously for nickel . This can be ascribed only to an effect of the projectile electronic structure at low velocities. The obtained results are discussed in comparison to previous ones reported in the literature.
Evaluation of the performance of three elastomers for non-lethal projectile applications
Directory of Open Access Journals (Sweden)
Thota N.
2015-01-01
Full Text Available Less lethal kinetic ammunitions with soft noses such as eXact iMpact 1006, National Sports Spartan and B&T have been commonly used by military and law enforcement officers in the situations where lethal force is not warranted. In order to explore new materials to be used as nose in such ammunitions, a scholastic study using finite element simulations has been carried out to evaluate the effectiveness of two rubber like elastomers and a polyolefinic foam (low density, highly compressible, stiff and closed cell type of thermos plastic elastomer. State-of-the art thorax surrogate MTHOTA has been employed for the evaluation of blunt thoracic trauma. Force-rigid wall method was employed for the evaluation of head damage curves for each material. XM 1006 has been used as the benchmark projectile for the purpose of comparison. Both blunt thoracic trauma and head damage criterion point of view, both rubbers (R1 and R2 have yielded high values of VCmax and peak impact force. Polyolefinic foam (F1 considered in the study has yielded very promising VCmax values and very less peak impact force when compared with those of bench mark projectile XM 1006.
A New Mechanism of Sediment Attachment to Oil in Turbulent Flows: Projectile Particles.
Zhao, Lin; Boufadel, Michel C; Katz, Joseph; Haspel, Gal; Lee, Kenneth; King, Thomas; Robinson, Brian
2017-10-03
The interaction of oil and sediment in the environment determines, to a large extent, the trajectory and fate of oil. Using confocal microscope imaging techniques to obtain detailed 3D structures of oil-particle aggregates (OPAs) formed in turbulent flows, we elucidated a new mechanism of particle attachment, whereby the particles behave as projectiles penetrating the oil droplets to depths varying from ∼2 to 10 μm due to the hydrodynamic forces in the water. This mechanism results in a higher attachment of particles on oil in comparison with adsorption, as commonly assumed. The projectile hypothesis also explains the fragmentation of oil droplets with time, which occurred after long hours of mixing, leading to the formation of massive OPA clusters. Various lines of inquiry strongly suggested that protruding particles get torn from oil droplets and carry oil with them, causing the torn particles to be amphiphillic so that they contribute to the formation of massive OPAs of smaller oil droplets (<∼5-10 μm). Low particle concentration resulted in large, irregularly shaped oil blobs over time, the deformation of which without fragmentation could be due to partial coverage of the oil droplet surface by particles. The findings herein revealed a new pathway for the fate of oil in environments containing non-negligible sediment concentrations.
Prospects for the discovery of the next new element: Influence of projectiles with Z > 20
Folden, Charles M; Werke, Tyler A; Alfonso, Marisa C; Bennett, Megan E; DeVanzo, Michael J
2012-01-01
The possibility of forming new superheavy elements with projectiles having Z > 20 is discussed. Current research has focused on the fusion of 48Ca with actinides targets, but these reactions cannot be used for new element discoveries in the future due to a lack of available target material. The influence on reaction cross sections of projectiles with Z > 20 have been studied in so-called analog reactions, which utilize lanthanide targets carefully chosen to create compound nuclei with energetics similar to those found in superheavy element production. The reactions 48Ca, 45Sc, 50Ti, 54Cr + 159Tb, 162Dy have been studied at the Cyclotron Institute at Texas A&M University using the Momentum Achromat Recoil Spectrometer. The results of these experimental studies are discussed in terms of the influence of collective enhancements to level density for compound nuclei near closed shells, and the implications for the production of superheavy elements. We have observed no evidence to contradict theoretical predict...
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.
Evaluation of the performance of three elastomers for non-lethal projectile applications
Thota, N.; Epaarachchi, J.; Lau, K. T.
2015-09-01
Less lethal kinetic ammunitions with soft noses such as eXact iMpact 1006, National Sports Spartan and B&T have been commonly used by military and law enforcement officers in the situations where lethal force is not warranted. In order to explore new materials to be used as nose in such ammunitions, a scholastic study using finite element simulations has been carried out to evaluate the effectiveness of two rubber like elastomers and a polyolefinic foam (low density, highly compressible, stiff and closed cell type of thermos plastic elastomer). State-of-the art thorax surrogate MTHOTA has been employed for the evaluation of blunt thoracic trauma. Force-rigid wall method was employed for the evaluation of head damage curves for each material. XM 1006 has been used as the benchmark projectile for the purpose of comparison. Both blunt thoracic trauma and head damage criterion point of view, both rubbers (R1 and R2) have yielded high values of VCmax and peak impact force. Polyolefinic foam (F1) considered in the study has yielded very promising VCmax values and very less peak impact force when compared with those of bench mark projectile XM 1006.
EFFECT OF BODY SHAPE ON THE AERODYNAMICS OF PROJECTILES AT SUPERSONIC SPEEDS
Directory of Open Access Journals (Sweden)
ABDULKAREEM SH. MAHDI
2008-12-01
Full Text Available An investigation has been made to predict the effects of forebody and afterbody shapes on the aerodynamic characteristics of several projectile bodies at supersonic speeds using analytical methods combined with semi-empirical design curves. The considered projectile bodies had a length-to-diameter ratio of 6.67 and included three variations of forebody shape and three variations of afterbody shape. The results, which are verified by comparison with available experimental data, indicated that the lowest drag was achieved with a cone-cylinder at the considered Mach number range. It is also shown that the drag can be reduced by boattailing the afterbody. The centre-of-pressure assumed a slightly rearward location for the ogive-cylinder configuration when compared to the configuration with boattailed afterbody where it was the most forward. With the exception of the boattailed afterbody, all the bodies indicated inherent static stability above Mach number 2 for a centre-of-gravity location at about 40% from the body nose.
Rubber mixing process and its relationship with bound rubber and crosslink density
Hasan, A.; Rochmadi; Sulistyo, H.; Honggokusumo, S.
2017-06-01
This research studied the relationship between bound rubber and crosslink density based on rubber mixing process. Bound rubber was obtained after natural rubber was masticated and mixed with rubber chemicals and filler while crosslink density was collected after rubber compound was vulcanized. Four methods are used and each method refers to four ways of incorporating carbon black during mixing. The first method, after rubber was masticated for 5 minutes, the addition of rubber chemicals and filler was done simultaneously. Rubber was masticated for 1 minute and continued mixing of rubber chemicals and filler where mixing was different from first method. This was the second method. The third method was the same as the second method but the filler used N 660 while in the second method N 330. The last method is not the same as the first and second, the rubber is only masticated for 3 minutes and then mixed with filler and followed by rubber chemicals sequentially. The results showed that bound rubber and crosslink density were influenced by mixing and mastication process. Bound rubber dropped and crosslink density was relatively stable in the first three mixing methods for increasing carbon black at the beginning of the mixing process. Bound rubber and crosslink density stated opposite results in the fourth mixing method. The higher the bound rubber the lower the crosslink density. Without regard to mixing methods, there is a non-linear relationship between bound rubber formation and crosslink density determination
Match-bounded String Rewriting Systems
Geser, Alfons; Hofbauer, Dieter; Waldmann, Johannes
2003-01-01
We introduce a new class of automated proof methods for the termination of rewriting systems on strings. The basis of all these methods is to show that rewriting preserves regular languages. To this end, letters are annotated with natural numbers, called match heights. If the minimal height of all positions in a redex is h+1 then every position in the reduct will get height h+1. In a match-bounded system, match heights are globally bounded. Using recent results on deleting systems, we prove that rewriting by a match-bounded system preserves regular languages. Hence it is decidable whether a given rewriting system has a given match bound. We also provide a sufficient criterion for the abence of a match-bound. The problem of existence of a match-bound is still open. Match-boundedness for all strings can be used as an automated criterion for termination, for match-bounded systems are terminating. This criterion can be strengthened by requiring match-boundedness only for a restricted set of strings, for instance the set of right hand sides of forward closures.
Energy Technology Data Exchange (ETDEWEB)
McAninch, J.E.; Hainsworth, L.J.; Marchetti, A.A. [and others
1996-05-01
The long-lived isotopes of nickel ({sup 59}Ni, {sup 63}Ni) have current and potential use in a number of applications including cosmic radiation studies, biomedical tracing, characterization of low-level radioactive wastes, and neutron dosimetry. Methods are being developed at LLNL for the routine detection of these isotopes by AMS. One intended application is in Hiroshima dosimetry. The reaction {sup 63}Cu(n,p){sup 63}Ni has been identified as one of a small number of reactions which might be used for the direct determination of the fast neutron fluence emitted by the Hiroshima bomb. AMS measurement of {sup 63}Ni(t{sub 1/2} = 100 y) requires the chemical removal of {sup 63}Cu, which is a stable isobar of {sup 63}Ni. Following the electrochemical separation of Ni from gram-sized copper samples, the Cu concentration is further lowered to < 2 x 10{sup -8} (Cu/Ni) using the reaction of Ni with carbon monoxide to form the gas Ni(CO){sub 4}. The Ni(CO){sub 4} is thermally decomposed directly in sample holders for measurement by AMS. After analysis in the AMS spectrometer, the ions are identified using characteristic projectile x-rays, allowing further rejection of remaining {sup 63}Cu. In a demonstration experiment, {sup 63}Ni was measured in Cu wires (2-20 g) which had been exposed to neutrons from a {sup 252}Cf source. We successfully measured {sup 63}Ni at levels necessary for the measurement of Cu samples exposed near the Hiroshima hypocenter. For the demonstration samples, the Cu content was chemically reduced by a factor of 10{sup 12} with quantitative retention of {sup 63}Ni. Detection sensitivity (3{sigma}) was {approximately}20 fg {sup 63}Ni in 1 mg Ni carrier ({sup 63}Ni/Ni {approx} 2 x 10{sup -11}). Significant improvements in sensitivity are expected with planned incremental changes in the methods. Preliminary results indicate that a similar sensitivity is achievable for {sup 59}Ni (t{sub 1/2} = 10{sup 5} y).
DEFF Research Database (Denmark)
Hallett, Andrew Hughes; Hougaard Jensen, Svend E.
2011-01-01
-term stabilisation. We argue for public sector debt targets as a practical way to achieve such a set up, and an excess debt protocol is constructed to give enforceable form to those targets. The ideas of “fiscal space” and optimal debt levels are used to provide a mechanism for identifying a stable region within...... which the debt targeting regime should operate. Making these factors explicit would both improve the credibility of planned fiscal policies and reduce risk premia on borrowing costs. We finally show how Europe’s competitiveness pact, and debt restructuring operations, can be used to maximise...
Sound velocity bound and neutron stars.
Bedaque, Paulo; Steiner, Andrew W
2015-01-23
It has been conjectured that the velocity of sound in any medium is smaller than the velocity of light in vacuum divided by sqrt[3]. Simple arguments support this bound in nonrelativistic and/or weakly coupled theories. The bound has been demonstrated in several classes of strongly coupled theories with gravity duals and is saturated only in conformal theories. We point out that the existence of neutron stars with masses around two solar masses combined with the knowledge of the equation of state of hadronic matter at "low" densities is in strong tension with this bound.
Lability of copper bound to humic acid
Mao, Lingchen; Young, Scott D.; Bailey, Liz
2015-01-01
Geochemical speciation models generally include the assumption that all metal bound to humic acid and fulvic acid (HA, FA) is labile. However, in the current study, we determined the presence of a soluble ‘non-labile’ Cu fraction bound to HA extracted from grassland and peat soils. This was quantified by determining isotopically-exchangeable Cu (E-value) and EDTA-extraction of HA-bound Cu, separated by size-exclusion chromatography (SEC) and assayed by coupled ICP-MS. Evidence of time-depend...
Lower bound for the nuclear kinetic energy
Energy Technology Data Exchange (ETDEWEB)
Dehesa, J.S. (Granada Univ. (Spain). Dept. de Fisica Nuclear); Galvez, F.J. (Granada Univ. (Spain). Dept. de Fisica Teorica)
1985-06-27
We argue that the kinetic energy of a many-fermion system is bounded from below by Kqsup(-2/3)A sup(5/3) /
Continuous bounded cohomology of locally compact groups
2001-01-01
Recent research has repeatedly led to connections between important rigidity questions and bounded cohomology. However, the latter has remained by and large intractable. This monograph introduces the functorial study of the continuous bounded cohomology for topological groups, with coefficients in Banach modules. The powerful techniques of this more general theory have successfully solved a number of the original problems in bounded cohomology. As applications, one obtains, in particular, rigidity results for actions on the circle, for representations on complex hyperbolic spaces and on Teichmüller spaces. A special effort has been made to provide detailed proofs or references in quite some generality.
Leung, Lai Yee; Larimore, Zachary; Holmes, Larry; Cartagena, Casandra; Mountney, Andrea; Deng-Bryant, Ying; Schmid, Kara; Shear, Deborah; Tortella, Frank
2014-08-01
The WRAIR projectile concussive impact (PCI) model was developed for preclinical study of concussion. It represents a truly non-invasive closed-head injury caused by a blunt impact. The original design, however, has several drawbacks that limit the manipulation of injury parameters. The present study describes engineering advancements made to the PCI injury model including helmet material testing, projectile impact energy/head kinematics and impact location. Material testing indicated that among the tested materials, 'fiber-glass/carbon' had the lowest elastic modulus and yield stress for providing an relative high percentage of load transfer from the projectile impact, resulting in significant hippocampal astrocyte activation. Impact energy testing of small projectiles, ranging in shape and size, showed the steel sphere produced the highest impact energy and the most consistent impact characteristics. Additional tests confirmed the steel sphere produced linear and rotational motions on the rat's head while remaining within a range that meets the criteria for mTBI. Finally, impact location testing results showed that PCI targeted at the temporoparietal surface of the rat head produced the most prominent gait abnormalities. Using the parameters defined above, pilot studies were conducted to provide initial validation of the PCI model demonstrating quantifiable and significant increases in righting reflex recovery time, axonal damage and astrocyte activation following single and multiple concussions.
Ormö, J.; Wünnemann, K.; Collins, G.; Melero Asensio, I.
2012-09-01
The Experimental Projectile Impact Chamber (EPIC) consists of a 20.5mm caliber, compressed gas gun and a 7m wide test bed. It is possible to vary the projectile size and density, the velocity up to about 5001n/"s, the impact angle. and the target composition. The EPIC is especially designed for the analysis of impacts into unconsolidated and liquid targets. i.e. allowing the use of gravity scaling. The general objective with the EPIC is to analyze the cratering and modification processes at wet-target (e.g. marinle) impacts. We have carried out 14 shots into dry sand targets with two projectile compositions (light and weak; heavy and strong), at two impact angles. at three impact velocities, and in both quarter-space and half- space geometries. We recorded the impacts with a high-speed camera and compared the results with numerical simulations using iSALE. The evaluation demonstrated that there are noticeable differences between the results from the two projectile types, but that the crater dimensions are consistent with scaling laws based on other impact experiments [1]. This proves the usefulness of the EPIC in the analysis of natural impacts.
Directory of Open Access Journals (Sweden)
Chang-hai Chen
2017-10-01
Full Text Available Ballistic experiments were conducted on thin steel plates that are normally impacted by hemispherical-nosed projectiles at velocities higher than their ballistic limits. The deformation and failure modes of the thin steel plates were analyzed. A new method was proposed according to the experimental results and the perforation phenomenon of the thin steel plates to determine the radius of the bulging region. In establishing this new method, a dynamic method combined with the plastic wave propagation concept based on the rigid plastic assumption was adopted. The whole perforation process was divided into four consecutive stages, namely, bulging deformation, dishing deformation, ductile hole enlargement, and projectile exit. On the basis of the energy conservation principle, a new model was developed to predict the residual velocities of hemispherical-nosed projectiles that perforate thin steel plates at low velocities. The results obtained from the theoretical calculations by the present model were compared with the experimental results. Theoretical predictions were in good agreement with the experimental results in terms of both the radius of the bulging region and the residual velocity of the projectile when the strain rate effects of the target material during each stage were considered.
Plass, W. R.; Dickel, T.; Purushothaman, S.; Dendooven, P.; Geissel, H.; Ebert, J.; Haettner, E.; Jesch, C.; Ranjan, M.; Reiter, M. P.; Weick, H.; Amjad, F.; Ayet, S.; Diwisch, M.; Estrade, A.; Farinon, F.; Greiner, F.; Kalantar-Nayestanaki, N.; Knoebel, R.; Kurcewicz, J.; Lang, J.; Moore, I.; Mukha, I.; Nociforo, C.; Petrick, M.; Pfuetzner, M.; Pietri, S.; Prochazka, A.; Rink, A. -K.; Rinta-Antila, S.; Schaefer, D.; Scheidenberger, C.; Takechi, M.; Tanaka, Y. K.; Winfield, J. S.; Yavor, M. I.
2013-01-01
At the FRS Ion Catcher at GSI, projectile and fission fragments are produced at relativistic energies, separated in-flight, range-focused, slowed down and thermalized in a cryogenic stopping cell. A multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) is used to perform direct mass
Boschmans, Bart; Van Royen, Pieter; Van Vaeck, Luc
2005-01-01
The application of polyatomic primary ions is a strongly developing branch of static secondary ion mass spectrometry (S-SIMS), since these projectiles allow a significant increase in the secondary ion yields to be achieved. However, the different limitations and possibilities of certain polyatomic primary ions for use on specific functional classes of samples are still not completely known. This paper compares the use of monoatomic and polyatomic primary ions in S-SIMS for thin layers of polylactic acid (PLA), obtained by spin-coating solutions on silicon wafers. Bombardment with Ga+, Xe+ and SF5+ primary ions allowed the contribution of the projectile mass and number of atoms in the gain in ion yield and molecular specificity (relative importance of high m/z and low m/z signals) to be assessed. Samples obtained by spin-coating solutions with increasing concentration showed that optimal layer thickness depended on the primary ion used. In comparison with the use of Ga+ projectiles, the yield of structural ions increased by a factor of about 1.5 to 2 and by about 7 to 12 when Xe+ and SF5+ primary ion bombardment were applied, respectively. A detailed fragmentation pattern was elaborated to interpret ion signal intensity changes for different projectiles in terms of energy deposition and collective processes in the subsurface, and the internal energy of radical and even-electron precursor ions. Copyright (c) 2005 John Wiley & Sons, Ltd.
Mahoney, Joyce; And Others
1988-01-01
Evaluates 10 courseware packages covering topics for introductory physics. Discusses the price; sub-topics; program type; interaction; possible hardware; time; calculus required; graphics; and comments on each program. Recommends two packages in projectile and circular motion, and three packages in statics and rotational dynamics. (YP)
Moreau, Luc; Odar, Boštjan; Higham, Tom; Horvat, Aleksander; Pirkmajer, Darja; Turk, Peter
2015-01-01
The Palaeolithic of southern Central Europe has a long history of archaeological research. Particularly, the presence of numerous osseous projectile points in many early Upper Palaeolithic (EUP) assemblages in this region has attracted the attention of the international research community. However, the scarcity of properly identified and well-dated Aurignacian contexts represents an obstacle for investigation of the nature and timing of the Middle to Upper Palaeolithic transition. In this context, the question of whether Neandertals made Aurignacian osseous projectile points, either on their own or as a consequence of cultural interaction with anatomically modern humans (AMH), still remains an open issue. Here we reassess the EUP record of Slovenia by evaluating the Aurignacian character of the assemblages from Potočka zijalka, Mokriška jama and Divje babe I in the light of their suggested roots in the local Mousterian. We provide a comprehensive description of the lithic industry from Potočka zijalka, which represents one of the rare EUP assemblages of southern Central Europe with a representative number of lithic artefacts to be analysed from the perspective of lithic technology and raw material economy. Our re-analysis of the Slovenian assemblages is backed by a series of 11 new ultrafiltered collagen 14C dates obtained directly on associated osseous projectile points from the studied assemblages. The Aurignacian of Potočka zijalka underlines the remarkable consistency of the Early Aurignacian with low typo-technological variability across Europe, resulting from a marked dependence on transported toolkits and raw material conservation. The new radiocarbon determinations for the Aurignacian of Slovenia appear to post-date the 34-32 ka BP (thousands of years before present) threshold for the last Neandertals in the region. Although not falsified, the hypothesis of Aurignacian bone tools in southern Central Europe as a product of late Neandertals is not
Redshift-space limits of bound structures
Duenner, Rolando; Reisenegger, Andreas; Meza, Andres; Araya, Pablo A.; Quintana, Hernan
2007-01-01
An exponentially expanding Universe, possibly governed by a cosmological constant, forces gravitationally bound structures to become more and more isolated, eventually becoming causally disconnected from each other and forming so-called 'island universes'. This new scenario reformulates the question
Directory of Open Access Journals (Sweden)
Yuhua Xu
2017-01-01
Full Text Available The objective of this paper is to discuss finite-time bounded synchronization for a class of the growing complex network with nondelayed and delayed coupling. In order to realize finite-time synchronization of complex networks, a new finite-time stable theory is proposed; effective criteria are developed to realize synchronization of the growing complex dynamical network in finite time. Moreover, the error of two growing networks is bounded simultaneously in the process of finite-time synchronization. Finally, some numerical examples are provided to verify the theoretical results established in this paper.
New Spectral Features from Bound Dark Matter
DEFF Research Database (Denmark)
Catena, Riccardo; Kouvaris, Chris
2016-01-01
We demonstrate that dark matter particles gravitationally bound to the Earth can induce a characteristic nuclear recoil signal at low energies in direct detection experiments. The new spectral feature we predict can provide the ultimate smoking gun for dark matter discovery for experiments...... with positive signal but unclear background. The new feature is universal, in that the ratio of bound over halo dark matter event rates at detectors is independent of the dark matter-nucleon cross section....
On bounds for symmetric divergence measures
Furuichi, S.; Yanagi, K.; Kuriyama, K.
2017-06-01
In the paper [1], tight bounds for symmetric divergence measures applying the results established by G.L.Gilardoni. In this article, we report on two kinds of extensions for the Sason's results, namely a classical q-extension and a non-commutative(quantum) extension. Especially, we improve Sason's bound of the summation of the absolute value for the difference between two probability distributions, applying the parameter q of Tsallis entropy, under a certain assumption.
Malabsorption of protein bound vitamin B12.
Dawson, D W; Sawers, A H; Sharma, R K
1984-01-01
Patients with subnormal serum vitamin B12 concentrations were tested for absorption of protein bound vitamin B12 and compared with controls. Absorption of the protein bound vitamin appeared to decrease with increasing age in healthy subjects. Differences between the result of this test and the result of the Schilling test in patients who had undergone gastric surgery were confirmed; such differences were also seen in some patients who had iron deficiency anaemia, an excessive alcohol intake, ...
Dynamic optimization problems with bounded terminal conditions
Lee, A. Y.
1987-01-01
Bounded terminal conditions of nonlinear optimization problems are converted to equality terminal conditions via Valentine's device. In so doing, additional unknown parameters are introduced into the problem. The transformed problems can still be easily solved using the sequential gradient-restoration algorithm (SGRA) via a simple augmentation of the unknown parameter vector pi. Three example problems with bounded terminal conditions are solved to verify this technique.
Directory of Open Access Journals (Sweden)
Danilo V. Ćuk
2010-01-01
Full Text Available U radu su prikazane metode korekcije putanje žiroskopski stabilisanih projektila primenom proporcionalne navigacije. Sekcija upravljanja tipa 'patka' ugrađena je na klasični projektil radi generisanja aerodinamičke sile. Efikasnost projektila sa korekcijom putanje prikazana je pomoću rezultata numeričke simulacije leta, primenom proporcionalne navigacije sa i bez kompenzacije poremećaja zbog gravitacionog i tangentnog ubrzanja. Analizirani su, takođe, uticaji početnog ugla elevacije i odstupanja ravni upravljanja od ravni praćenja cilja na promašaj projektila. Pokazano je da se precesioni oblik oscilovanja ugaonog kretanja projektila prenosi na ugaonu brzinu linije viziranja cilja koju treba filtrirati kako bi se otklonila pojava rezonantne nestabilnosti leta projektila. / This paper presents the methods of the trajectory correction of gyroscopic stabilized projectiles using different modifications of proportional navigation. The canard section is built into the conventional projectile to generate aerodynamic force. The effectiveness of the trajectory correctable projectile is shown by the results of a flight numerical simulation using proportional navigation with and without the compensation of the disturbance due to gravitational and tangent acceleration. The paper also analyzes the effects of the initial elevation angle and the deflection of the control plane from the target tracking one on the miss distance. It is shown that the precessional mode of the projectile angular motion is transferred to the line of sight rate which should be filtered to prevent the phenomenon of resonance instability of the projectile flight.
LX-04 Violence Measurements-Steven Tests Impacted by Projectiles Shot from a Howitzer Gun
Chidester, Steven K.; Vandersall, Kevin S.; Switzer, Lori L.; Tarver, Craig M.
2006-07-01
Characterization of the reaction violence of LX-04 explosive (85% HMX and 15% Viton A by weight) was obtained from Steven Impact Tests performed above the reaction initiation threshold. A 155 mm Howitzer propellant driven gas gun was used to accelerate the Steven Test projectiles in the range of approximately 170-300 m/s to react (ignite) the LX-04 explosive. Blast overpressure gauges, acoustic microphones, and high-speed photography characterized the level of high explosive reaction violence. A detonation in this velocity range was not observed and when comparing these results (and the Susan test results) with that of other HMX based explosives, LX-04 has a more gradual reaction violence slope as the impact velocity increases. The high binder content (15%) of the LX-04 explosive is believed to be the key factor to the lower level of violence.
A Monolithic High-G SOI-MEMS Accelerometer for Measuring Projectile Launch and Flight Accelerations
Directory of Open Access Journals (Sweden)
Bradford S. Davis
2006-01-01
Full Text Available Analog Devices (ADI has designed and fabricated a monolithic high-g acceleration sensor (ADXSTC3-HG fabricated with the ADI silicon-on-insulator micro-electro-mechanical system (SOI-MEMS process. The SOI-MEMS sensor structure has a thickness of 10 um, allowing for the design of inertial sensors with excellent cross-axis rejection. The high-g accelerometer discussed in this paper was designed to measure in-plane acceleration to 10,000 g while subjected to 100,000 g in the orthogonal axes. These requirements were intended to meet Army munition applications. The monolithic sensor was packaged in an 8-pin leadless chip carrier (LCC-8 and was successfully demonstrated by the US Army Research Laboratory (ARL as part of an inertial measurement unit during an instrumented flight experiment of artillery projectiles launched at 15,000 g.
Projectile X-ray emission in relativistic ion-atom collisions
Energy Technology Data Exchange (ETDEWEB)
Salem, Shadi Mohammad Ibrahim
2010-03-16
This work reports on the study of the projectile X-ray emission in relativistic ion-atom collisions. Excitation of K-shell in He-like uranium ions, electron capture into H-like uranium ions and Simultaneous ionization and excitation of initially He-like uranium ions have been studied using the experimental storage ring at GSI. For the K{sub {alpha}}{sub 1} and K{sub {alpha}}{sub 2} transitions originating from the excitation of the He-like uranium ions, no alignment was observed. In contrast, the Ly{sub {alpha}}{sub 1} radiation from the simultaneous ionization-excitation process of the He-like uranium ions shows a clear alignment. The experimental value leads to the inclusion of a magnetic term in the interaction potential. The capture process of target electrons into the highly-charged heavy ions was studied using H-like uranium ions at an incident energy of 220 MeV/u, impinging on N{sub 2} gas-target. It was shown that, the strongly aligned electrons captured in 2p{sub 3/2} level couple with the available 1s{sub 1/2} electron which shows no initial directional preference. The magnetic sub-state population of the 2p{sub 3/2} electron is redistributed according to the coupling rules to the magnetic sub-states of the relevant two-electron states. This leads to the large anisotropy in the corresponding individual ground state transitions contributing to the K{sub {alpha}}{sub 1} emission. From the K{sub {alpha}}{sub 1}/K{sub {alpha}}{sub 2} ratio, the current results show that the incoherent addition of the E1 and M2 transition components yield to an almost isotropic emission of the total K{sub {alpha}}{sub 1}. In contrast to the radiative electron capture, the experimental results for the K-shell single excitation of He-like uranium ions indicate that only the {sup 1}P{sub 1} level contributes to the K{sub {alpha}}{sub 1} transition. For this case, the anisotropy parameter {beta}{sub 20} was found to be -0.20{+-}0.03. This work also reports on the study of a two
2002-01-01
% EMU19 \\\\ \\\\ The collisions of heavy ions at relativistic energies have been studied to explore a number of questions related with hot and dense nuclear matter in order to extend our knowledge of nuclear equation-of-state. There are other aspects of these interactions which are studied to expound the process of projectile and/or target disintegrations. The disintegrations in question could be simply binary fissions or more complex processes leading to spallation or complete fragmentation. These important aspects of nuclear reactions are prone to investigations with nuclear track detectors. \\\\ \\\\One of the comparatively new track detector materials, CR-39, is sensitive enough to record particles of Z~$\\geq$~6 with almost 100\\% efficiency up to highly relativistic energies. The wide angle acceptance and exclusive measurements possible with plastic track detectors offer an opportunity to use them in a variety of situations in which high energy charged fragments are produced. The off-line nature of measuring tra...
Comparative Analysis of the $^{178m2}$Hf Yield at Reactions with Different Projectiles
Karamian, S A
2004-01-01
The long-lived high-spin $^{178m2}$Hf $K$-isomer can be produced in nuclear reactions with different projectiles. The reaction yields and cross-sections have been measured in the series of experiments and the results are now overviewed. The systematics of isomer-to-ground state ratios are drawn and real production capabilities are estimated for the best reactions. Such a summary is relevant to the significance of the isomer studies both for the nuclear-science knowledge and for possible applications. Potential isomer applications have been earlier stressed in popular publications with probably overestimated expectations. The real possibilities are restricted in part by the production yield and by other shortcomings as well.
LX-04 VIOLENCE MEASUREMENTS- STEVEN TESTS IMPACTED BY PROJECTILES SHOT FROM A HOWITZER GUN
Energy Technology Data Exchange (ETDEWEB)
Chidester, S K; Vandersall, K S; Switzer, L L; Tarver, C M
2005-07-18
Characterization of the reaction violence of LX-04 explosive (85% HMX and 15% Viton A by weight) was obtained from Steven Impact Tests performed above the reaction initiation threshold. A 155 mm Howitzer propellant driven gas gun was used to accelerate the Steven Test projectiles in the range of approximately 170-300 m/s to react (ignite) the LX-04 explosive. Blast overpressure gauges, acoustic microphones, and high-speed photography characterized the level of high explosive reaction violence. A detonation in this velocity range was not observed and when comparing these results (and the Susan test results) with that of other HMX based explosives, LX-04 has a more gradual reaction violence slope as the impact velocity increases. The high binder content (15%) of the LX-04 explosive is believed to be the key factor to the lower level of violence.
Pion production in dp-->dNπ reactions with deuteron projectiles
Greiff, J.; Koch I.; Scobel, W.; Rohdjeß, H.; Dyring, J.; Fransson, K.; Gustafsson, L.; Häggström, S.; Höistad, B.; Johanson, J.; Johansson, A.; Johansson, T.; Khoukaz, A.; Kullander, S.; Ruber, R. J.; Złomańczuk, J.; Dunin, V.; Morosov, B.; Sukhanov, A.; Zernov, A.; Kupść, A.; Marciniewski, P.; Stepaniak, J.; Bilger, R.; Brodowski, W.; Clement, H.; Wagner, G. J.; Calén, H.; Ekström, C.; Zabierowski, J.; Shwartz, B.; Sukhanov, A.; Oelert, W.; Sefzick, T.; Turowiecki, A.
2000-12-01
Kinematically complete events have been studied for the reactions dp-->dpπ0 and dp-->dnπ+ at projectile energies between 437 and 559 MeV. The measurement covers a range of pion momenta η=pmaxπ,c.m./mπc from near the production threshold (η=0.32) to η=0.86 close to the NN-->NNπ threshold. The measurements were performed at the CELSIUS storage ring with the PROMICE/WASA setup. Angular and spectral distributions of the charged ejectiles as well as total cross sections are decomposed into the fractions that can be attributed to a quasifree NN-->dπ process with a spectator nucleon, and to a process involving all three nucleons. The quasifree contribution increases with energy and dominates from the NN-->NNπ threshold on. The results are compared to calculations with a spectator model with and without dp final state interactions.
Projectile compositions and modal frequencies on the chemistry of micrometeoroids LDEF experiment
Bernhard, Ronald P.; See, Thomas H.; Hoerz, Friedrich
1993-01-01
The Chemistry of Micrometeoroids Experiment (LDEF instrument A0187-1) exposed witness plates of high-purity gold (greater than 99.99 percent Au) and commercial aluminum (greater than 99 percent Al) with the objective of analyzing the residues of cosmic-dust and orbital-debris particles associated with hypervelocity impact craters. The gold substrates were located approximately 8 deg off LDEF's trailing edge (Bay A03), while the aluminum surfaces resided in Bay A11, approximately 52 deg from LDEF's leading edge. SEM-EDX techniques were employed to analyze the residues associated with 199 impacts on the gold and 415 impacts on the aluminum surfaces. The residues that could be analyzed represent natural or man-made materials. The natural particles dominate at all particle sizes less than 5 micron. It is possible to subdivide both particle populations into subclasses. Chondritic compositions dominate the natural impactors (71 percent), followed by monomineralic, mafic-silicate compositions (26 percent), and by Fe-Ni rich sulfides (approximately 3 percent). Approximately 30 percent of all craters on the gold collectors were caused by man-made debris such as aluminum, paint flakes, and other disintegrated, structural and electronic components. Equations-of-state and associated calculations of shock stresses for typical LDEF impacts into the gold and aluminum substrates suggest that substantial vaporization may have occurred during many of the impacts and is the reason why approximately 50 percent of all craters did not contain sufficient residue to permit analysis by the SEM-EDX technique. After converting the crater diameters into projectile sizes using encounter speeds typical for the trailing-edge and forward-facing (Row 11) directions, and accounting for normalized exposure conditions of the CME collectors, we derived the absolute and relative fluxes of specific projectile classes. The natural impactors encounter all LDEF pointing directions with comparable, modal
Damage visualization and deformation measurement in glass laminates during projectile penetration
Directory of Open Access Journals (Sweden)
Elmar Strassburger
2014-06-01
Full Text Available Transparent armor consists of glass-polymer laminates in most cases. The formation and propagation of damage in the different glass layers has a strong influence on the ballistic resistance of such laminates. In order to clarify the course of events during projectile penetration, an experimental technique was developed, which allows visualizing the onset and propagation of damage in each single layer of the laminate. A telecentric objective lens was used together with a microsecond video camera that allows recording 100 frames at a maximum rate of 1 MHz in a backlit photography set-up. With this technique, the damage evolution could be visualized in glass laminates consisting of four glass layers with lateral dimensions 500 mm × 500 mm. Damage evolution was recorded during penetration of 7.62 mm AP projectiles with tungsten carbide core and a total mass of 11.1 g in the impact velocity range from 800 to 880 m/s. In order to measure the deformation of single glass plates within the laminates, a piece of reflecting tape was attached to the corresponding glass plate, and photonic Doppler velocimetry (PDV was applied. With the photonic Doppler velocimeter, an infrared laser is used to illuminate an object to be measured and the Doppler-shifted light is superimposed to a reference light beam at the detector. The simultaneous visualization and PDV measurement of the glass deformation allow determining the deformation at the time of the onset of fracture. The analysis of the experimental data was supported by numerical simulations, using the AUTODYN commercial hydro-code.
Breeze, John; Lewis, E A; Fryer, R; Hepper, A E; Mahoney, Peter F; Clasper, Jon C
2016-08-01
Body armour is a type of equipment worn by military personnel that aims to prevent or reduce the damage caused by ballistic projectiles to structures within the thorax and abdomen. Such injuries remain the leading cause of potentially survivable deaths on the modern battlefield. Recent developments in computer modelling in conjunction with a programme to procure the next generation of UK military body armour has provided the impetus to re-evaluate the optimal anatomical coverage provided by military body armour against high energy projectiles. A systematic review of the literature was undertaken to identify those anatomical structures within the thorax and abdomen that if damaged were highly likely to result in death or significant long-term morbidity. These structures were superimposed upon two designs of ceramic plate used within representative body armour systems using a computerised representation of human anatomy. Those structures requiring essential medical coverage by a plate were demonstrated to be the heart, great vessels, liver and spleen. For the 50th centile male anthropometric model used in this study, the front and rear plates from the Enhanced Combat Body Armour system only provide limited coverage, but do fulfil their original requirement. The plates from the current Mark 4a OSPREY system cover all of the structures identified in this study as requiring coverage except for the abdominal sections of the aorta and inferior vena cava. Further work on sizing of plates is recommended due to its potential to optimise essential medical coverage. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Pilling, Sergio; Duarte, Eduardo Seperuelo; Domaracka, Alicja; Rothard, Hermann; Boduch, Philippe; da Silveira, Enio F
2011-09-21
An experimental study of the interaction of highly charged, energetic ions (52 MeV (58)Ni(13+) and 15.7 MeV (16)O(5+)) with mixed H(2)O : C(18)O(2) astrophysical ice analogs at two different temperatures is presented. This analysis aims to simulate the chemical and the physicochemical interactions induced by cosmic rays inside dense, cold astrophysical environments, such as molecular clouds or protostellar clouds as well at the surface of outer solar system bodies. The measurements were performed at the heavy ion accelerator GANIL (Grand Accelerateur National d'Ions Lourds) in Caen, France. The gas samples were deposited onto a CsI substrate at 13 K and 80 K. In situ analysis was performed by a Fourier transform infrared (FTIR) spectrometer at different fluences. Radiolysis yields of the produced species were quantified. The dissociation cross section at 13 K of both H(2)O and CO(2) is about 3-4 times smaller when O ions are employed. The ice temperature seems to affect differently each species when the same projectile was employed. The formation cross section at 13 K of molecules such as C(18)O, CO (with oxygen from water), and H(2)O(2) increases when Ni ions are employed. The formation of organic compounds seems to be enhanced by the oxygen projectiles and at lower temperatures. In addition, because the organic production at 13 K is at least 4 times higher than the value at 80 K, we also expect that interstellar ices are more organic-rich than the surfaces of outer solar system bodies.
Tight bounds on computing error-correcting codes by bounded-depth circuits with arbitrary gates
DEFF Research Database (Denmark)
Gal, A.; Hansen, Kristoffer Arnsfelt; Koucky, Michal
2013-01-01
We bound the minimum number w of wires needed to compute any (asymptotically good) error-correcting code C:{0,1}Ω(n)→{0,1}n with minimum distance Ω(n), using unbounded fan-in circuits of depth d with arbitrary gates. Our main results are: 1) if d=2, then w=Θ(n (lgn/lglgn)2); 2) if d=3, then w...... bound gives the largest known lower bound for computing any linear map. The upper bounds imply that a (necessarily dense) generator matrix for our code can be written as the product of two sparse matrices. Using known techniques, we also obtain similar (but not tight) bounds for computing pairwise......-independent hash functions. Our lower bounds are based on a superconcentrator-like condition that the graphs of circuits computing good codes must satisfy. This condition is provably intermediate between superconcentrators and their weakenings considered before...
Schüller, A; Winter, H
2008-03-07
Fast atoms with keV energies are scattered under a grazing angle of incidence from a clean and flat LiF(001) surface. For scattering along low index azimuthal directions within the surface plane ("axial surface channeling") we observe pronounced peak structures in the angular distributions for scattered projectiles that are attributed to "supernumerary rainbows." This phenomenon can be understood in the framework of quantum scattering only and is observed here up to projectile energies of 20 keV. We demonstrate that the interaction potential and, in particular, its corrugation for fast atomic projectiles at surfaces can be derived with a high accuracy.
Stability of bound species during alkene reactions on solid acids
Sarazen, Michele L.; Iglesia, Enrique
2017-05-01
This study reports the thermodynamics of bound species derived from ethene, propene, n-butene, and isobutene on solid acids with diverse strength and confining voids. Density functional theory (DFT) and kinetic data indicate that covalently bound alkoxides form C-C bonds in the kinetically relevant step for dimerization turnovers on protons within TON (0.57 nm) and MOR (0.67 nm) zeolitic channels and on stronger acids HPW (polyoxometalate clusters on silica). Turnover rates for mixed alkenes give relative alkoxide stabilities; the respective adsorption constants are obtained from in situ infrared spectra. Tertiary alkoxides (from isobutene) within larger voids (MOR, HPW) are more stable than less substituted isomers but are destabilized within smaller concave environments (TON) because framework distortions are required to avoid steric repulsion. Adsorption constants are similar on MOR and HPW for each alkoxide, indicating that binding is insensitive to acid strength for covalently bound species. DFT-derived formation free energies for alkoxides with different framework attachments and backbone length/structure agree with measurements when dispersion forces, which mediate stabilization by confinement in host-guest systems, are considered. Theory reveals previously unrecognized framework distortions that balance the C-O bond lengths required for covalency with host-guest distances that maximize van der Waals contacts. These distortions, reported here as changes in O-atom locations and dihedral angles, become stronger for larger, more substituted alkoxides. The thermodynamic properties reported here for alkoxides and acid hosts differing in size and conjugate-anion stability are benchmarked against DFT-derived free energies; their details are essential to design host-guest pairs that direct alkoxide species toward specific products.
Dynamics of quadratic polynomials: Complex bounds for real maps
Lyubich, Mikhail; Yampolsky, Michael
1995-01-01
We extend Sullivan's complex a priori bounds to real quadratic polynomials with essentially bounded combinatorics. Combined with the previous results of the first author, this yields complex bounds for all real quadratics. Local connectivity of the corresponding Julia sets follows.
Bounds Estimation Via Regression with Asymmetric Cost Functions
DeCoste, D.
1997-01-01
This paper addresses a significant but mostly-neglected class of problems that we call bounds estimation. This includes learning empirical best-case and worst-case algorithmic complexity bounds and red-line bounds on sensor data.
Pulliam, G. R.; Ross, W. E.; MacNeal, B.; Bailey, R. F.
1982-03-01
Large, thin-film single domain areas have been observed, in the absence of a bias field, in garnets with magnetization perpendicular to the film plane.1,2 The domain stability in the work by Krumme1 was attributed to a combination of low saturation magnetization and a low Curie temperature. Uchishiba2 relates the stability in his double layer system to appropriate anisotropy fields in one layer compared to the magnetization in the other layer. A more complete model for large domain stability in a bias field free environment is given in this work. Three distinct stability regimes are predicted by the model and all have been observed experimentally. Areas 3.5-cm in diameter have been made into stable single domains. This was achieved in a material showing a zero bias strip width of 4.5 μm. The single domain diameter was, therefore, 7500 times the equilibrium energy domain width. The technique developed and the model have led to a new means for observing magnetic defects. More importantly, it also offers a means for measuring the strength of the defects. Possible applications of the model are also discussed.
Universal bounds in even-spin CFTs
Energy Technology Data Exchange (ETDEWEB)
Qualls, Joshua D. [Department of Physics, National Taiwan University,Taipei, Taiwan (China)
2015-12-01
We prove using invariance under the modular S− and ST−transformations that every unitary two-dimensional conformal field theory (CFT) having only even-spin primary operators (with no extended chiral algebra and with right- and left-central charges c,c̃>1) contains a primary operator with dimension Δ{sub 1} satisfying 0<Δ{sub 1}<((c+c̃)/24)+0.09280…. After deriving both analytical and numerical bounds, we discuss how to extend our methods to bound higher conformal dimensions before deriving lower and upper bounds on the number of primary operators in a given energy range. Using the AdS{sub 3}/CFT{sub 2} dictionary, the bound on Δ{sub 1} proves the lightest massive excitation in appropriate theories of 3D matter and gravity with cosmological constant Λ<0 can be no heavier than 1/8G{sub N}+O(√(−Λ)); the bounds on the number of operators are related via AdS/CFT to the entropy of states in the dual gravitational theory. In the flat-space approximation, the limiting mass is exactly that of the lightest BTZ black hole.
Higgs boson mass bounds in the presence of a heavy fourth quark family
Bulava, John; Nagy, Attila; Kallarackal, Jim; Jansen, Karl
2012-01-01
We present Higgs boson mass bounds in a lattice regularization allowing thus for non-perturbative investigations. In particular, we employ a lattice modified chiral invariant Higgs-Yukawa model using the overlap operator. We show results for the upper and lower Higgs boson mass bounds in the presence of a heavy mass-degenerate quark doublet with masses ranging up to 700 GeV. We perform infinite volume extrapolations in most cases, and examine several values of the lattice cutoff. Furthermore, we argue that the lower Higgs boson mass bound is stable with respect to the addition of higher dimensional operators to the scalar field potential. Our results have severe consequences for the phenomenology of a fourth generation of quarks if a light Higgs boson is discovered at the LHC.
Strongest model-independent bound on the lifetime of Dark Matter
Audren, Benjamin; Mangano, Gianpiero; Serpico, Pasquale Dario; Tram, Thomas
2014-01-01
Dark Matter is essential for structure formation in the late Universe so it must be stable on cosmological time scales. But how stable exactly? Only assuming decays into relativistic particles, we report an otherwise model independent bound on the lifetime of Dark Matter using current cosmological data. Since these decays affect only the low-$\\ell$ multipoles of the CMB, the Dark Matter lifetime is expected to correlate with the tensor-to-scalar ratio $r$ as well as curvature $\\Omega_k$. We consider two models, including $r$ and $r+\\Omega_k$ respectively, versus data from Planck, WMAP, WiggleZ and Baryon Acoustic Oscillations, with or without the BICEP2 data (if interpreted in terms of primordial gravitational waves). This results in a lower bound on the lifetime of CDM given by 160Gyr (without BICEP2) or 200Gyr (with BICEP2) at 95% confidence level.
Strongly bound noncovalent (SO3)n:H2CO complexes (n = 1, 2).
Azofra, Luis Miguel; Alkorta, Ibon; Scheiner, Steve
2014-09-21
The potential energy surfaces (PES) for the SO3:H2CO and (SO3)2:H2CO complexes were thoroughly examined at the MP2/aug-cc-pVDZ computational level. Heterodimers and trimers are held together primarily by SO chalcogen bonds, supplemented by weaker CHO and/or OC bonds. The nature of the interactions is probed by a variety of means, including electrostatic potentials, AIM, NBO, energy decomposition, and electron density redistribution maps. The most stable dimer is strongly bound, with an interaction energy exceeding 10 kcal mol(-1). Trimers adopt the geometry of the most stable dimer, with an added SO3 molecule situated so as to interact with both of the original molecules. The trimers are strongly bound, with total interaction energies of more than 20 kcal mol(-1). Most such trimers show positive cooperativity, with shorter SO distances, and three-body interaction energies of nearly 3 kcal mol(-1).
Resistivity bound for hydrodynamic bad metals
Lucas, Andrew; Hartnoll, Sean A.
2017-10-01
We obtain a rigorous upper bound on the resistivity ρ of an electron fluid whose electronic mean free path is short compared with the scale of spatial inhomogeneities. When such a hydrodynamic electron fluid supports a nonthermal diffusion process—such as an imbalance mode between different bands—we show that the resistivity bound becomes ρ≲AΓ. The coefficient A is independent of temperature and inhomogeneity lengthscale, and Γ is a microscopic momentum-preserving scattering rate. In this way, we obtain a unified mechanism—without umklapp—for ρ˜T2 in a Fermi liquid and the crossover to ρ˜T in quantum critical regimes. This behavior is widely observed in transition metal oxides, organic metals, pnictides, and heavy fermion compounds and has presented a long-standing challenge to transport theory. Our hydrodynamic bound allows phonon contributions to diffusion constants, including thermal diffusion, to directly affect the electrical resistivity.
Properties of Water Bound in Hydrogels
Directory of Open Access Journals (Sweden)
Vladimir M. Gun’ko
2017-10-01
Full Text Available In this review, the importance of water in hydrogel (HG properties and structure is analyzed. A variety of methods such as 1H NMR (nuclear magnetic resonance, DSC (differential scanning calorimetry, XRD (X-ray powder diffraction, dielectric relaxation spectroscopy, thermally stimulated depolarization current, quasi-elastic neutron scattering, rheometry, diffusion, adsorption, infrared spectroscopy are used to study water in HG. The state of HG water is rather non-uniform. According to thermodynamic features of water in HG, some of it is non-freezing and strongly bound, another fraction is freezing and weakly bound, and the third fraction is non-bound, free water freezing at 0 °C. According to structural features of water in HG, it can be divided into two fractions with strongly associated and weakly associated waters. The properties of the water in HG depend also on the amounts and types of solutes, pH, salinity, structural features of HG functionalities.
Correlation Distance and Bounds for Mutual Information
Directory of Open Access Journals (Sweden)
Michael J. W. Hall
2013-09-01
Full Text Available The correlation distance quantifies the statistical independence of two classical or quantum systems, via the distance from their joint state to the product of the marginal states. Tight lower bounds are given for the mutual information between pairs of two-valued classical variables and quantum qubits, in terms of the corresponding classical and quantum correlation distances. These bounds are stronger than the Pinsker inequality (and refinements thereof for relative entropy. The classical lower bound may be used to quantify properties of statistical models that violate Bell inequalities. Partially entangled qubits can have lower mutual information than can any two-valued classical variables having the same correlation distance. The qubit correlation distance also provides a direct entanglement criterion, related to the spin covariance matrix. Connections of results with classically-correlated quantum states are briefly discussed.
Equivalence principle and bound kinetic energy.
Hohensee, Michael A; Müller, Holger; Wiringa, R B
2013-10-11
We consider the role of the internal kinetic energy of bound systems of matter in tests of the Einstein equivalence principle. Using the gravitational sector of the standard model extension, we show that stringent limits on equivalence principle violations in antimatter can be indirectly obtained from tests using bound systems of normal matter. We estimate the bound kinetic energy of nucleons in a range of light atomic species using Green's function Monte Carlo calculations, and for heavier species using a Woods-Saxon model. We survey the sensitivities of existing and planned experimental tests of the equivalence principle, and report new constraints at the level of between a few parts in 10(6) and parts in 10(8) on violations of the equivalence principle for matter and antimatter.
Yukawa Bound States and Their LHC Phenomenology
Directory of Open Access Journals (Sweden)
Enkhbat Tsedenbaljir
2013-01-01
Full Text Available We present the current status on the possible bound states of extra generation quarks. These include phenomenology and search strategy at the LHC. If chiral fourth-generation quarks do exist their strong Yukawa couplings, implied by current experimental lower bound on their masses, may lead to formation of bound states. Due to nearly degenerate 4G masses suggested by Precision Electroweak Test one can employ “heavy isospin” symmetry to classify possible spectrum. Among these states, the color-octet isosinglet vector ω 8 is the easiest to be produced at the LHC. The discovery potential and corresponding decay channels are covered in this paper. With possible light Higgs at ~125 GeV two-Higgs doublet version is briefly discussed.
Braneworld black holes and entropy bounds
Directory of Open Access Journals (Sweden)
Y. Heydarzade
2018-01-01
Full Text Available The Bousso's D-bound entropy for the various possible black hole solutions on a 4-dimensional brane is checked. It is found that the D-bound entropy here is apparently different from that of obtained for the 4-dimensional black hole solutions. This difference is interpreted as the extra loss of information, associated to the extra dimension, when an extra-dimensional black hole is moved outward the observer's cosmological horizon. Also, it is discussed that N-bound entropy is hold for the possible solutions here. Finally, by adopting the recent Bohr-like approach to black hole quantum physics for the excited black holes, the obtained results are written also in terms of the black hole excited states.
Braneworld black holes and entropy bounds
Heydarzade, Y.; Hadi, H.; Corda, C.; Darabi, F.
2018-01-01
The Bousso's D-bound entropy for the various possible black hole solutions on a 4-dimensional brane is checked. It is found that the D-bound entropy here is apparently different from that of obtained for the 4-dimensional black hole solutions. This difference is interpreted as the extra loss of information, associated to the extra dimension, when an extra-dimensional black hole is moved outward the observer's cosmological horizon. Also, it is discussed that N-bound entropy is hold for the possible solutions here. Finally, by adopting the recent Bohr-like approach to black hole quantum physics for the excited black holes, the obtained results are written also in terms of the black hole excited states.
Entropy Bounds, Holographic Principle and Uncertainty Relation
Directory of Open Access Journals (Sweden)
I. V. Volovich
2001-06-01
Full Text Available Abstract: A simple derivation of the bound on entropy is given and the holographic principle is discussed. We estimate the number of quantum states inside space region on the base of uncertainty relation. The result is compared with the Bekenstein formula for entropy bound, which was initially derived from the generalized second law of thermodynamics for black holes. The holographic principle states that the entropy inside a region is bounded by the area of the boundary of that region. This principle can be called the kinematical holographic principle. We argue that it can be derived from the dynamical holographic principle which states that the dynamics of a system in a region should be described by a system which lives on the boundary of the region. This last principle can be valid in general relativity because the ADM hamiltonian reduces to the surface term.
Stable electroosmotically driven actuators
Sritharan, Deepa; Motsebo, Mylene; Tumbic, Julia; Smela, Elisabeth
2013-04-01
We have previously presented "nastic" actuators based on electroosmotic (EO) pumping of fluid in microchannels using high electric fields for potential application in soft robotics. In this work we address two challenges facing this technology: applying EO to meso-scale devices and the stability of the pumping fluid. The hydraulic pressure achieved by EO increases with as 1/d2, where d is the depth of the microchannel, but the flow rate (which determines the stroke and the speed) is proportional to nd, where n is the number of channels. Therefore to get high force and high stroke the device requires a large number of narrow channels, which is not readily achievable using standard microfabrication techniques. Furthermore, for soft robotics the structure must be soft. In this work we present a method of fabricating a three-dimensional porous elastomer to serve as the array of channels based on a sacrificial sugar scaffold. We demonstrate the concept by fabricating small pumps. The flexible devices were made from polydimethylsiloxane (PDMS) and comprise the 3D porous elastomer flanked on either side by reservoirs containing electrodes. The second issue addressed here involves the pumping fluid. Typically, water is used for EO, but water undergoes electrolysis even at low voltages. Since EO takes place at kV, these systems must be open to release the gases. We have recently reported that propylene carbonate (PC) is pumped at a comparable rate as water and is also stable for over 30 min at 8 kV. Here we show that PC is, however, degraded by moisture, so future EO systems must prevent water from reaching the PC.
National Research Council Canada - National Science Library
Tagle, Roald; Berlin, Jana
2008-01-01
.... To obtain a better knowledge of compositional differences between potential chondritic projectile types, meteorite analyses of the elements Ru, Rh, Pd, Os, Ir, Pt, Cr, Co, Ni, and Au were gathered into a database...
Improved metastability bounds on the standard model Higgs mass
Espinosa, J R; Espinosa, J R; Quiros, M
1995-01-01
Depending on the Higgs-boson and top-quark masses, M_H and M_t, the effective potential of the Standard Model at finite (and zero) temperature can have a deep and unphysical stable minimum \\langle \\phi(T)\\rangle at values of the field much larger than G_F^{-1/2}. We have computed absolute lower bounds on M_H, as a function of M_t, imposing the condition of no decay by thermal fluctuations, or quantum tunnelling, to the stable minimum. Our effective potential at zero temperature includes all next-to-leading logarithmic corrections (making it extremely scale-independent), and we have used pole masses for the Higgs-boson and top-quark. Thermal corrections to the effective potential include plasma effects by one-loop ring resummation of Debye masses. All calculations, including the effective potential and the bubble nucleation rate, are performed numerically and so the results do not rely on any kind of analytical approximation. Easy-to-use fits are provided for the benefit of the reader. Conclusions on the possi...
Creed, Peter A.; Patton, Wendy; Hood, Michelle
2010-01-01
We surveyed 506 Australian high school students on career development (exploration, planning, job-knowledge, decision-making, indecision), personal functioning (well-being, self-esteem, life satisfaction, school satisfaction) and control variables (parent education, school achievement), and tested differences among work-bound, college-bound and…
2013-03-26
... Agency Information Collection Activities; Comment Request; Upward Bound and Upward Bound Math Science... hand delivery. Please note that comments submitted by fax or email and those submitted after the... 1995 (PRA) (44 U.S.C. 3506(c)(2)(A)), provides the general public and Federal agencies with an...
Tight bounds on computing error-correcting codes by bounded-depth circuits with arbitrary gates
DEFF Research Database (Denmark)
Gál, Anna; Hansen, Kristoffer Arnsfelt; Koucký, Michal
2011-01-01
We bound the minimum number w of wires needed to compute any (asymptotically good) error-correcting code C:01(n)01n with minimum distance (n), using unbounded fan-in circuits of depth d with arbitrary gates. Our main results are: (1) If d=2 then w=(n(lognloglogn)2) . (2) If d=3 then w=(nlglgn). (3......, our (n(lognloglogn)2) lower bound gives the largest known lower bound for computing any linear map, improving on the (nlg32n) bound of Pudlak and Rodl (Discrete Mathematics '94). We find the upper bounds surprising. They imply that a (necessarily dense) generator matrix for the code can be written...... as the product of two sparse matrices. The upper bounds are non-explicit: we show the existence of circuits (consisting of only XOR gates) computing good codes within the stated bounds. Using a result by Ishai, Kushilevitz, Ostrovsky, and Sahai (STOC '08), we also obtain similar bounds for computing pairwise...
Guerrini, Luca; Sodini, Mauro
2014-01-01
We introduce a time-to-build technology in a Solow model with bounded technological progress. Our analysis shows that the system may be asymptotically stable, or it can produce stability switches and Hopf bifurcations when time delay varies. The direction and the stability criteria of the bifurcating periodic solutions are obtained by the normal form theory and the center manifold theorem. Numerical simulations confirms the theoretical results.
Semirelativistic stability of N-boson systems bound by 1/r{sub ij} pair potentials
Energy Technology Data Exchange (ETDEWEB)
Hall, Richard L [Department of Mathematics and Statistics, Concordia University, 1455 de Maisonneuve Boulevard West, Montreal, Quebec H3G 1M8 (Canada); Lucha, Wolfgang [Institute for High Energy Physics, Austrian Academy of Sciences, Nikolsdorfergasse 18, A-1050 Vienna (Austria)], E-mail: rhall@mathstat.concordia.ca, E-mail: wolfgang.lucha@oeaw.ac.at
2008-09-05
We analyse a system of self-gravitating identical bosons by means of a semirelativistic Hamiltonian comprising the relativistic kinetic energies of the involved particles and added (instantaneous) Newtonian gravitational pair potentials. With the help of an improved lower bound to the bottom of the spectrum of this Hamiltonian, we are able to enlarge the known region for relativistic stability for such boson systems against gravitational collapse and to sharpen the predictions for their maximum stable mass.
Gyroscope precession along bound equatorial plane orbits around a Kerr black hole
Bini, Donato; Jantzen, Robert T
2016-01-01
The precession of a test gyroscope along stable bound equatorial plane orbits around a Kerr black hole is analyzed and the precession angular velocity of the gyro's parallel transported spin vector and the increment in precession angle after one orbital period is evaluated. The parallel transported Marck frame which enters this discussion is shown to have an elegant geometrical explanation in terms of the electric and magnetic parts of the Killing-Yano 2-form and a Wigner rotation effect.
Violation of Energy Bounds in Designer Gravity
Hertog, T
2007-01-01
We continue our study of the stability of designer gravity theories, where one considers anti-de Sitter gravity coupled to certain tachyonic scalars with boundary conditions defined by a smooth function W. It has recently been argued there is a lower bound on the conserved energy in terms of the global minimum of W, if the scalar potential arises from a superpotential P and the scalar reaches an extremum of P at infinity. We show, however, there are superpotentials for which these bounds do not hold.
G-frames with bounded linear operators
Xiao, Xiang-chun; Zhu, Yu-can; Shu, Zhi-biao; Ding, Ming-ling
2015-01-01
In this paper, we introduce the more general g-frame which is called a $K$-g-frame by combining a g-frame with a bounded linear operator $K$ in a Hilbert space. We give several equivalent characterizations for $K$-g-frames and discuss the stability of perturbation for $K$-g-frames. We also investigate the relationship between a $K$-g-frame and the range of the bounded linear operator $K$. In the end, we give two sufficient conditions for the remainder of a $K$-g-frame after an erasure to stil...
Bounds on fake weighted projective space
Kasprzyk, Alexander M.
2009-01-01
A fake weighted projective space X is a Q-factorial toric variety with Picard number one. As with weighted projective space, X comes equipped with a set of weights (λ0, ..., λn). We see how the singularities of P (λ0, ..., λn) influence the singularities of X, and how the weights bound the number of possible fake weighted projective spaces for a fixed dimension. Finally, we present an upper bound on the ratios λj/Σλi if we wish X to have only terminal (or canonical) singularities.
Fibered Transverse Knots and the Bennequin Bound
Etnyre, John B.; Van Horn-Morris, Jeremy
2008-01-01
We prove that a nicely fibered link (by which we mean the binding of an open book) in a tight contact manifold $(M,\\xi)$ with zero Giroux torsion has a transverse representative realizing the Bennequin bound if and only if the contact structure it supports (since it is also the binding of an open book) is $\\xi.$ This gives a geometric reason for the non-sharpness of the Bennequin bound for fibered links. We also note that this allows the classification, up to contactomorphism, of maximal self...
Verifying bound entanglement of dephased Werner states
Thomas, P.; Bohmann, M.; Vogel, W.
2017-10-01
The verification of quantum entanglement under the influence of realistic noise and decoherence is crucial for the development of quantum technologies. Unfortunately, a full entanglement characterization is generally not possible with most entanglement criteria such as entanglement witnesses or the partial transposition criterion. In particular, so-called bound entanglement cannot be certified via the partial transposition criterion. Here we present the full entanglement verification of dephased qubit and qutrit Werner states via entanglement quasiprobabilities. Remarkably, we are able to reveal bound entanglement for noisy mixed states in the qutrit case. This example demonstrates the strength of the entanglement quasiprobabilities for verifying the full entanglement of quantum states suffering from noise.
A note on BPS vortex bound states
Directory of Open Access Journals (Sweden)
A. Alonso-Izquierdo
2016-02-01
Full Text Available In this note we investigate bound states, where scalar and vector bosons are trapped by BPS vortices in the Abelian Higgs model with a critical ratio of the couplings. A class of internal modes of fluctuation around cylindrically symmetric BPS vortices is characterized mathematically, analyzing the spectrum of the second-order fluctuation operator when the Higgs and vector boson masses are equal. A few of these bound states with low values of quantized magnetic flux are described fully, and their main properties are discussed.
A note on BPS vortex bound states
Energy Technology Data Exchange (ETDEWEB)
Alonso-Izquierdo, A., E-mail: alonsoiz@usal.es [Departamento de Matematica Aplicada, Universidad de Salamanca (Spain); Garcia Fuertes, W., E-mail: wifredo@uniovi.es [Departamento de Fisica, Universidad de Oviedo (Spain); Mateos Guilarte, J., E-mail: guilarte@usal.es [Departamento de Fisica Fundamental, Universidad de Salamanca (Spain)
2016-02-10
In this note we investigate bound states, where scalar and vector bosons are trapped by BPS vortices in the Abelian Higgs model with a critical ratio of the couplings. A class of internal modes of fluctuation around cylindrically symmetric BPS vortices is characterized mathematically, analyzing the spectrum of the second-order fluctuation operator when the Higgs and vector boson masses are equal. A few of these bound states with low values of quantized magnetic flux are described fully, and their main properties are discussed.
Directory of Open Access Journals (Sweden)
Luay Hashem Abbud
2016-12-01
Full Text Available In this study, a response of hybrid composite laminate woven fiber Kevlar29 – Al2O3 Powder/ Epoxy subjected to high velocity impact loading is presented. The energy absorbed due to impact of small rigid projectile on composite materials targets is determined experimentally. The energy absorbed due to impact of hemispherical projectiles on the developed composite laminates is investigated. The results revealed the maximum ballistic limit at impact velocity is found to be 390.87 ± 6 m/s for an the 18 mm target thickness. The ballistic limit velocity predictions are based on the theoretical method presented from another article. The initial velocity and residual velocity results showed good is agreement compared with the predicted results of Ipson and Recht equations. With 5.4 % of accuracy based on the experimental value for the theoretical model for ballistic limit velocity.
Binary projectile fragmentation of 12C at an incident energy of 33.3 MeV/nucleon
Förtsch, S V; Gadioli, E; Bassini, R; Buthelezi, E Z; Cerutti, F; Connell, S H; Cowley, A A; Fujita, H; Mabiala, J; Mairani, A; Mira, J; Papka, P; Neveling, R; Smit, F D
2010-01-01
Direct binary projectile fragmentation is being investigated for the case where a 400 MeV 12C projectile breaks up into an particle and a 8Be fragment in the interaction with a thin 93Nb and 197Au target. While the 8Be fragments were measured at 9 , the correlated particles were detected in an angular range between 16 and 30 on the opposite side of the beam. From the preliminary results presented here one may obtain information on the amount of quasi-elastic fragmentation (both fragments do not suffer any further interactions after they are produced). These experimental results indicate that the quasi-elastic break-up process is the dominant contribution to the measured correlation spectra. As was also observed in earlier work, the most forward quasi-elastically emitted particles have energies exceeding the beam velocity.
Energy Technology Data Exchange (ETDEWEB)
Perez-Loureiro, D., E-mail: david.loureiro@usc.es [Universidade de Santiago de Compostela, E-15782 (Spain); Benlliure, J.; Alvarez-Pol, H. [Universidade de Santiago de Compostela, E-15782 (Spain); Blank, B. [Centre d' Etudes Nucleaires, F-33175 Bordeaux-Gradignan Cedex (France); Casarejos, E. [Universidade de Santiago de Compostela, E-15782 (Spain); Dragosavac, D. [Universidade de Santiago de Compostela, E-15782 (Spain); Institute of Nuclear Sciences Vinca, University of Belgrade, 11001 Belgrade (Serbia); Foehr, V. [GSI Helmholtzzentrum fuer Schwerionenforschung, D-64291 Darmstadt (Germany); Gascon, M. [Universidade de Santiago de Compostela, E-15782 (Spain); Gawlikowicz, W. [Heavy Ion Laboratory, University of Warsaw, PL-02-093 Warsaw (Poland); Cardinal Stefan Wyszynski University, PL-01-938 Warsaw (Poland); Heinz, A. [A.W. Wright Nuclear Structure Laboratory, Yale University, New Haven, CT 06520 (United States); Helariutta, K. [University of Helsinki, FI-00014 Helsinki (Finland); Kelic-Heil, A.; Lukic, S.; Montes, F. [GSI Helmholtzzentrum fuer Schwerionenforschung, D-64291 Darmstadt (Germany); Pienkowski, L. [Heavy Ion Laboratory, University of Warsaw, PL-02-093 Warsaw (Poland); Schmidt, K.-H.; Staniou, M. [GSI Helmholtzzentrum fuer Schwerionenforschung, D-64291 Darmstadt (Germany); Subotic, K. [Institute of Nuclear Sciences Vinca, University of Belgrade, 11001 Belgrade (Serbia); Suemmerer, K. [GSI Helmholtzzentrum fuer Schwerionenforschung, D-64291 Darmstadt (Germany); Taieb, J. [CEA/DAM Ile-de-France, F-91297 Arpajon Cedex (France)
2011-09-26
The fragmentation of neutron-rich {sup 132}Sn nuclei produced in the fission of {sup 238}U projectiles at 950 A MeV has been investigated at the FRagment Separator (FRS) at GSI. This work represents the first investigation of fragmentation of medium-mass radioactive projectiles with a large neutron excess. The measured production cross sections of the residual nuclei are relevant for the possible use of a two-stage reaction scheme (fission + fragmentation) for the production of extremely neutron-rich medium-mass nuclei in future rare-ion-beam facilities. Moreover, the new data will provide a better understanding of the 'memory' effect in fragmentation reactions.
Blanco, Philip R.; Mungan, Carl E.
2016-07-01
Starting with conservation of energy and angular momentum, we derive a convenient method for determining the periapsis distance of an orbiting object, by expressing its velocity components in terms of the local circular speed. This relation is used to extend the results of our previous paper, examining the effects of an adhesive inelastic collision between a projectile launched from the surface of a planet (of radius R) and an equal-mass satellite in a circular orbit of radius r s. We show that there is a maximum orbital radius r s ≈ 18.9R beyond which such a collision cannot cause the satellite to impact the planet. The difficulty of bringing down a satellite in a high orbit with a surface-launched projectile provides a useful topic for a discussion of orbital angular momentum and energy. The material is suitable for an undergraduate intermediate mechanics course.
Behavior of steel fiber high strength concrete under impact of projectiles
Directory of Open Access Journals (Sweden)
Cánovas, M. F.
2012-09-01
Full Text Available This paper presents the results of the investigation carried out by the authors about the behavior of 80 MPa characteristic compression strength concrete reinforced with different amount of high carbon content steel fiber, submit to impact of different caliber projectiles, determining the thickness of this type of concrete walls needs to prevent no perforation, as well as the maximum penetration to reach into them, so that in the event of no perforation and only penetration, "scabbing" phenomena does not take place on the rear surface of the wall. Prior to ballistic testing was necessary to design the high-strength concrete with specific mechanical properties, especially those related to ductility, since these special concrete must absorb the high energy of projectiles and also the shock waves that accompany them.Este trabajo presenta los resultados de la investigación llevada a cabo por los autores sobre el comportamiento de hormigón de 80 MPa de resistencia característica a compresión reforzado con diferentes cuantías de fibras de acero de alto contenido en carbono sometido al impacto de proyectiles de distintos calibres, determinando el espesor de muros de este tipo de hormigón que sería preciso disponer para impedir su perforación por dichos proyectiles, así como los valores máximos de penetración, para que en el caso de no producirse perforación y sólo penetración, no se genera cráter, “scabbing”, en el trasdós de los mismos. Previamente a los ensayos balísticos fue preciso diseñar los hormigones para que, presentaran determinadas características mecánicas, especialmente las relacionadas con la ductilidad, dado que estos hormigones especiales deben absorber la elevada energía que le transmiten los proyectiles y las ondas de choque que los acompañan.
Observation of wounding characteristics in dogs wounded by super velocity projectile.
Li, B; Wu, G; Chen, J; Wang, J; Zhang, L; Chen, Z; Chen, X
2001-05-01
To understand wounding characteristics in dogs wounded by super velocity projectile with a purpose of providing a basis for prevention and treatment of such wounds. A specially-made explosive gun was used to shoot aluminium bullet weighing 3.0 g and 1.4 g to injure both legs of dogs at velocities of 2330 m/s, 3200 m/s and 4250 m/s, respectively, and the soap specially made was also shot. At the same time, steel ball of 1.03 g was shot with a Type 53 smooth chamber gun at a speed of 1280 m/s. Within 30 min after wounding, debridement and pathological anatomy were performed and specimens were taken for light microscope observation. When the dogs were wounded by the 3 g bullet at speed of 2330 m/s, the entrance of the left leg was penetrated explosively with a defect area of 225 cm(2), and the femur trunk was also injured and the residual femur had comminution fracture. The exit of the right leg was blindly wounded with a defect area of 63 cm(2), but only the skin was not penetrated. Both testes and part pelvis were injured too. Under light microscope, degenerative myofibers and bleeding of the spatium between the myofibers could be found at the place 4 cm away from the wounding track. Furthermore, serious bleeding of the bladder and blood vessels of the brain could be observed. The lungs showed changes of blast injury. Vacuolar change was presented in the cytoplasm of hepatocytes. Injuries of the animals in other two experimental groups were similar to those described above, but the defect area of the wounded track was 124 cm(2) in the group of 4250 m/s. Injuries caused by the steel ball were milder than caused by the explosive gun. The volume of the residual cavity in the soap was 5000 ml. The super-velocity projectile causes destructive damage to the local tissues and multi-organ injuries. Therefore, the practical medical care needs not only amputation but also management of multi-organ injuries.
Plaß, W. R.; Dickel, T.; Purushothaman, S.; Dendooven, P.; Geissel, H.; Ebert, J.; Haettner, E.; Jesch, C.; Ranjan, M.; Reiter, M. P.; Weick, H.; Amjad, F.; Ayet, S.; Diwisch, M.; Estrade, A.; Farinon, F.; Greiner, F.; Kalantar-Nayestanaki, N.; Knöbel, R.; Kurcewicz, J.; Lang, J.; Moore, I.; Mukha, I.; Nociforo, C.; Petrick, M.; Pfützner, M.; Pietri, S.; Prochazka, A.; Rink, A.-K.; Rinta-Antila, S.; Schäfer, D.; Scheidenberger, C.; Takechi, M.; Tanaka, Y. K.; Winfield, J. S.; Yavor, M. I.
2013-12-01
At the FRS Ion Catcher at GSI, projectile and fission fragments are produced at relativistic energies, separated in-flight, range-focused, slowed down and thermalized in a cryogenic stopping cell. A multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) is used to perform direct mass measurements and to provide an isobarically clean beam for further experiments, such as mass-selected decay spectroscopy. A versatile RF quadrupole transport and diagnostics unit guides the ions from the stopping cell to the MR-TOF-MS, provides differential pumping, ion identification and includes reference ion sources. The FRS Ion Catcher serves as a test facility for the Low-Energy Branch of the Super-FRS at the Facility for Antiproton and Ion Research (FAIR), where the cryogenic stopping cell and the MR-TOF-MS will be key devices for the research with stopped projectile and fission fragments that will be performed with the experiments MATS and LaSpec. Off-line tests of the stopping cell yield a combined ion survival and extraction efficiency for 219Rn ions of about 30% and an extraction time of about 25 ms. The stopping cell and the MR-TOF-MS were commissioned on-line as part of the FRS Ion Catcher. For the first time, a stopping cell for exotic nuclei was operated on-line at cryogenic temperatures. Using a gas density almost two times higher than ever reached before for a stopping cell with RF ion repelling structures, various 238U projectile fragments were thermalized and extracted with very high efficiency. Direct mass measurements of projectile fragments were performed with the MR-TOF-MS, among them the nuclide 213Rn with a half-life of 19.5 ms only.
2016-06-01
large electrical currents to generate strong magnetic fields which accelerate projectiles (armature) to speeds of over seven times the speed of sound ...an electric circuit and a magnetic field creating a magnetic force, the voltage V needed to hold the current constant must increase as the...the muzzle. This energy, which is due to the loss of the low-voltage electrical contact that is ordinarily between the armature and the rail, is
Characterization of plasma membrane bound inorganic ...
African Journals Online (AJOL)
Background: Currently, a major problem in the management of visceral leishmaniasis or kala-azar, especially in the Indian subcontinent, is the growing unresponsiveness to conventional antimonial therapy. Membrane bound pyrophophatase (PPases) do not exist in plasma membrane from mammals. Thus, H+-PPases ...
Stacked spheres and lower bound theorem
Indian Academy of Sciences (India)
BASUDEB DATTA
2011-11-20
Nov 20, 2011 ... Using Kalai's result, Tay (1995) proved LBT for a bigger class of simplicial complexes (namely, normal pseudomanifolds). In 2008, we (Bagchi & Datta) have presented a self-contained combinatorial proof of LBT for normal pseudomanifolds. Stacked spheres and lower bound theorem. Basudeb Datta.
Computational Lower Bounds Using Diagonalization-II
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 4. Computational Lower Bounds Using Diagonalization - II. M V Panduranga Rao. General Article Volume 15 Issue 4 April 2010 pp 337-346 ... Keywords. Diagonalization; time–hierarchy theorem; relativization; Baker–Gill–Solovay theorem.
Vulnerable Derivatives and Good Deal Bounds
DEFF Research Database (Denmark)
Murgoci, Agatha
2013-01-01
We price vulnerable derivatives – i.e. derivatives where the counterparty may default. These are basically the derivatives traded on the over-the-counter (OTC) markets. Default is modelled in a structural framework. The technique employed for pricing is good deal bounds (GDBs). The method imposes...
ASSESSMENT OF REAP-UPWARD BOUND.
LANG, MELVIN; HOPP, LAURENCE
THE IMPACT OF AN UPWARD BOUND (UB) PROGRAM ON THE ATTITUDES, MOTIVATION, AND ACADEMIC ACHIEVEMENT OF DISADVANTAGED STUDENTS WITH COLLEGE POTENTIAL IS EVALUATED. THE PROGRAM IS ONE OF THE 21 UB PROGRAMS RANDOMLY SELECTED FOR INTENSIVE STUDY. AT RUTGERS UB STUDENTS' ATTITUDES AND MOTIVATION TOWARD COLLEGE GOALS, SELF-EVALUATION AND SELF-ESTEEM,…
Lower Bounds for External Memory Dictionaries
DEFF Research Database (Denmark)
Brodal, Gerth Stølting; Fagerberg, Rolf
2003-01-01
We study trade-offs between the update time and the query time for comparison based external memory dictionaries. The main contributions of this paper are two lower bound trade offs between the I/O complexity of member queries and insertions: If N
Book Selection, Collection Development, and Bounded Rationality.
Schwartz, Charles A.
1989-01-01
Reviews previously proposed schemes of classical rationality in book selection, describes new approaches to rational choice behavior, and presents a model of book selection based on bounded rationality in a garbage can decision process. The role of tacit knowledge and symbolic content in the selection process are also discussed. (102 references)…
The metamorphosis of 'culture-bound' syndromes.
Jilek, W G; Jilek-Aall, L
1985-01-01
Starting from a critical review of the concept of 'culture-bound' disorders and its development in comparative psychiatry, the authors present the changing aspects of two so-called culture-bound syndromes as paradigms of transcultural metamorphosis (koro) and intra-cultural metamorphosis (Salish Indian spirit sickness), respectively. The authors present recent data on epidemics of koro, which is supposedly bound to Chinese culture, in Thailand and India among non-Chinese populations. Neither the model of Oedipal castration anxiety nor the model of culture-specific pathogenicity, commonly adduced in psychiatric and ethnological literature, explain these phenomena. The authors' data on Salish Indian spirit sickness describes the contemporary condition as anomic depression, which is significantly different from its traditional namesake. The traditional concept was redefined by Salish ritual specialists in response to current needs imposed by social changes. The stresses involved in creating the contemporary phenomena of koro and spirit sickness are neither culture-specific nor culture-inherent, as postulated for 'culture-bound' syndromes, rather they are generated by a feeling of powerlessness caused by perceived threats to ethnic survival.
Bounded relative motion under zonal harmonics perturbations
Baresi, Nicola; Scheeres, Daniel J.
2017-04-01
The problem of finding natural bounded relative trajectories between the different units of a distributed space system is of great interest to the astrodynamics community. This is because most popular initialization methods still fail to establish long-term bounded relative motion when gravitational perturbations are involved. Recent numerical searches based on dynamical systems theory and ergodic maps have demonstrated that bounded relative trajectories not only exist but may extend up to hundreds of kilometers, i.e., well beyond the reach of currently available techniques. To remedy this, we introduce a novel approach that relies on neither linearized equations nor mean-to-osculating orbit element mappings. The proposed algorithm applies to rotationally symmetric bodies and is based on a numerical method for computing quasi-periodic invariant tori via stroboscopic maps, including extra constraints to fix the average of the nodal period and RAAN drift between two consecutive equatorial plane crossings of the quasi-periodic solutions. In this way, bounded relative trajectories of arbitrary size can be found with great accuracy as long as these are allowed by the natural dynamics and the physical constraints of the system (e.g., the surface of the gravitational attractor). This holds under any number of zonal harmonics perturbations and for arbitrary time intervals as demonstrated by numerical simulations about an Earth-like planet and the highly oblate primary of the binary asteroid (66391) 1999 KW4.
Upper Bounds for Mutations of Potentials
Directory of Open Access Journals (Sweden)
John Alexander Cruz Morales
2013-01-01
Full Text Available In this note we provide a new, algebraic proof of the excessive Laurent phenomenon for mutations of potentials (in the sense of [Galkin S., Usnich A., Preprint IPMU 10-0100, 2010] by introducing to this theory the analogue of the upper bounds from [Berenstein A., Fomin S., Zelevinsky A., Duke Math. J. 126 (2005, 1-52].
Verhaeghe, Wim; Schepers, Serge; Sun, Yi; Orye, Johan; Vrielinck, Luc; Lakiere, Eva; De Temmerman, Griet; Politis, Constantinus
2012-03-01
A patient surviving after a metal projectile penetrates the sphenoid sinus is unusual. Removing a foreign object from this region is challenging because of the difficult access and proximity to delicate structures. The use of navigation-guided endoscopy makes the manipulation of the surgical instruments near delicate structures safer, and the procedure is minimally invasive. A computed tomographic scan of brain showed the projectile located at the base of the left sphenoid sinus. To prevent infection and irritation and avoid secondary surgical damage, navigation-guided endoscopy was used to remove the bullet. Using the BRAINLAB navigation system, the movement of the endoscope could be followed on the screen, and the tip could be navigated into close contact with the projectile. The bullet could be located, without being visible through the endoscope, making the incision and removal of the bony wall of the sinus minimal; it was removed without complications. Intraoperative navigation of endoscopes is very useful because it enables the surgeon to correlate the visual information through the endoscope with the localization of the instruments seen on the navigation screen. Patient safety and reinforced self-confidence of surgeons are advantages of this procedure. Reduced operative time may not always occur because of a lack of experience with the navigation system. When there are no vascular or neurologic complications, a minimally invasive treatment using nasal navigation-guided endoscopic removal can limit the potential surgical damage.
Insoluble-Bound Phenolics in Food.
Shahidi, Fereidoon; Yeo, Ju-Dong
2016-09-11
This contribution provides a review of the topic of insoluble-bound phenolics, especially their localization, synthesis, transfer and formation in plant cells, as well as their metabolism in the human digestive system and corresponding bioactivities. In addition, their release from the food matrix during food processing and extraction methods are discussed. The synthesis of phenolics takes place mainly at the endoplasmic reticulum and they are then transferred to each organ through transport proteins such as the ATP-binding cassette (ABC) and multidrug and toxic compound extrusion (MATE) transporter at the organ's compartment membrane or via transport vesicles such as cytoplasmic and Golgi vesicles, leading to the formation of soluble and insoluble-bound phenolics at the vacuole and cell wall matrix, respectively. This part has not been adequately discussed in the food science literature, especially regarding the synthesis site and their transfer at the cellular level, thus this contribution provides valuable information to the involved scientists. The bound phenolics cannot be absorbed at the small intestine as the soluble phenolics do (5%-10%), thus passing into the large intestine and undergoing fermentation by a number of microorganisms, partially released from cell wall matrix of foods. Bound phenolics such as phenolic acids and flavonoids display strong bioactivities such as anticancer, anti-inflammation and cardiovascular disease ameliorating effects. They can be extracted by several methods such as acid, alkali and enzymatic hydrolysis to quantify their contents in foods. In addition, they can also be released from the cell wall matrix during food processing procedures such as fermentation, germination, roasting, extrusion cooking and boiling. This review provides critical information for better understanding the insoluble-bound phenolics in food and fills an existing gap in the literature.
Essentially asymptotically stable homoclinic networks
Driesse, R.; Homburg, A.J.
2009-01-01
Melbourne [An example of a nonasymptotically stable attractor, Nonlinearity 4(3) (1991), pp. 835-844] discusses an example of a robust heteroclinic network that is not asymptotically stable but which has the strong attracting property called essential asymptotic stability. We establish that this
Isotopic fractionation of hydrate-bound hydrocarbons in the sub-bottom sediments of Lake Baikal
Hachikubo, A.; Khlystov, O.; Sakagami, H.; Minami, H.; Yamashita, S.; Takahashi, N.; Shoji, H.; Kalmychkov, G.; Poort, J.
2010-12-01
We investigated the molecular and stable isotope composition of hydrate-bound and dissolved hydrocarbons in pore water in subsurface sediments of Lake Baikal. Hydrate-bearing sediment cores were retrieved at southern and central Baikal basins in 2002-2009. Gas hydrates exist at the mud volcanoes at Malenky, Bolshoy, Malyutka and Peschanka in the southern Baikal basin and Kukuy in the central Baikal basin. The Goloustnoye seepage site in the southern Baikal basin seems active and gas plumes are ascending from the lake bottom. Delta 13C of hydrate-bound methane is several permil lower than that of dissolved methane in pore water at most places, however, delta 13C values of hydrate-bound and dissolved methane are almost the same each other and delta D values of hydrate-bound methane was about 5 permil lower than that of dissolved methane at Goloustnoye. Hachikubo et al. [2007] revealed in their laboratory experiments that delta D of hydrate-bound methane and ethane becomes several permil lower than that of the original gases at a formation of gas hydrate, whereas delta 13C of hydrate-bound and original gases remains almost constant. Based on their results, the current gas dissolved in pore water is not the source of the gas hydrates at most hydrate-bearing sites in Lake Baikal. On the contrary, the gas hydrate at Goloustnoye seems to be rather new crystal. Although isotopic fractionation of ethane also occurs at the formation of gas hydrate in the laboratory experiments, isotopic differences between hydrate-bound and dissolved ethane differ from each other according to the sediment cores. Hachikubo, A., T. Kosaka, M. Kida, A. Krylov, H. Sakagami, H. Minami, N. Takahashi, and H. Shoji (2007), Isotopic fractionation of methane and ethane hydrates between gas and hydrate phases, Geophys. Res. Lett., 34, L21502, doi:10.1029/2007GL030557.
Sputtering of octatetraene by 15 keV C60 projectiles: Comparison of reactive interatomic potentials
Kanski, Michal; Maciazek, Dawid; Golunski, Mikolaj; Postawa, Zbigniew
2017-02-01
Molecular dynamics computer simulations have been used to probe the effect of the AIREBO, ReaxFF and COMB3 interatomic potentials on sputtering of an organic sample composed of octatetraene molecules. The system is bombarded by a 15 keV C60 projectile at normal incidence. The effect of the applied force fields on the total time of simulation, the calculated sputtering yield and the angular distribution of sputtered particles is investigated and discussed. It has been found that caution should be taken when simulating particles ejection from nonhomogeneous systems that undergo significant fragmentation described by the ReaxFF. In this case, the charge state of many particles is improper due to an inadequacy of a procedure used for calculating partial charges on atoms in molecules for conditions present during sputtering. A two-step simulation procedure is proposed to minimize the effect of this deficiency. There is also a possible problem with the COMB3 potential, at least at conditions present during cluster impact, as its results are very different from AIREBO or ReaxFF.
LX-04 Violence Measurments: Steven Tests Impacted By Projectiles Shot From A Howitzer Gun
Chidester, Steven K.
2005-07-01
Characterization of the reaction violence of LX-04 explosive (85% HMX and 15% Viton by weight) was obtained from Steven Impact Tests performed above the reaction initiation threshold. A 155 mm Howitzer propellant driven gas gun was used to accelerate the Steven Test projectiles in the range of approximately 150-300 m/s to react (ignite) the LX-04 explosive. Blast overpressure gauges, acoustic microphones, and high-speed photography characterized the level of high explosive reaction violence. A detonation in this velocity range was not observed and when comparing these results (and the Susan test results) with that of other HMX based explosives, LX-04 has a more gradual reaction violence slope as the impact velocity increases. The high binder content (15%) of the LX-04 explosive is believed to be the key factor to the lower level of violence. This work was performed under the auspices of the U. S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under Contract No. W-7405-Eng-48.
Andrade, Sérgio Araújo; Varotti, Fernando de Pilla; Bagnato, Vanderlei Salvador; Pratavieira, Sebastião
2017-10-10
Demonstrate the use of wide-field optical fluorescence as an adjunctive examination in a clinical routine to oral diagnosis. Use of wide-field optical fluorescence in the oral cavity has been restricted to topics related to the detection and diagnosis of oral cancer. In a regular medical appointment, a 58-year-old female patient, without any complaint or oral symptom, underwent the complementary examination by wide-field optical fluorescence. A device with high-power light-emitting diode emitting light centered at a wavelength of (400 ± 10) nm and maximum irradiance of (0.040 ± 0.008) W/cm(2) was used for fluorescence visualization. We report the location of a firearm projectile, intraosseous, in the maxillary tuberosity using wide-field optical fluorescence. It is evidenced that wide-field optical fluorescence, within a clinical routine, can provide relevant images and data, with an immediate result, without the use of ionizing radiation, enabling an efficient oral diagnosis.
Detailed Modeling of Projectile Impact on Dyneema Composite Using Dynamic Properties
Utomo, B. D. Heru; Ernst, L. J.
Dyneema composite panels, which contain high Ultra High Molecular Weight Polyethylene fibers, are used in armor applications. They give good protection against fragments, bullets or other projectiles. In order to be able to study the internal processes in such a composite panel, a new modeling approach is developed and is described in this paper. This approach uses a detailed modeling approach that discretises the fibrous phase in Dyneema composite. In the past, continuum approaches and layer discretisation have been used by other researchers to study the processes in Dyneema composite panels and to predict the ballistic strength of these panels. The aforementioned approaches were however not very successful in predicting the ballistic strength, because fiber sliding, fiber failure and delamination of layers were not taken into account and static properties of the material were used. In addition to this, these models were often too coarse to study the processes in the panel. This often resulted in a calculated ballistic strength that was often too low. In this research, fiber sliding, fiber failure and delamination of layers are taken into account in the proposed model together with dynamically determined material properties. It is expected that studying the physical processes in a Dyneema composite panel and a better ballistic strength prediction should be possible using the aforementioned fiber bundle discretisation approach. The modeling of Dyneema composite is done in ABAQUS/Standard for the quasi-static simulations and in ABAQUS/Explicit for the dynamic simulations.
Half-life measurements of isomeric states populated in projectile fragmentation
Bowry, M.; Podolyák, Zs.; Kurcewicz, J.; Pietri, S.; Bunce, M.; Regan, P. H.; Farinon, F.; Geissel, H.; Nociforo, C.; Prochazka, A.; Weick, H.; Allegro, P.; Benlliure, J.; Benzoni, G.; Boutachkov, P.; Gerl, J.; Gorska, M.; Gottardo, A.; Gregor, N.; Janik, R.; Knöbel, R.; Kojouharov, I.; Kubo, T.; Litvinov, Y. A.; Merchan, E.; Mukha, I.; Naqvi, F.; Pfeiffer, B.; Pfützner, M.; Plaß, W.; Pomorski, M.; Riese, B.; Ricciardi, M. V.; Schmidt, K.-H.; Schaffner, H.; Kurz, N.; Denis Bacelar, A. M.; Bruce, A. M.; Farrelly, G. F.; Alkhomashi, N.; Al-Dahan, N.; Scheidenberger, C.; Sitar, B.; Spiller, P.; Stadlmann, J.; Strmen, P.; Sun, B.; Takeda, H.; Tanihata, I.; Terashima, S.; Valiente Dobon, J. J.; Winfield, J. S.; Wollersheim, H.-J.; Woods, P. J.
2012-10-01
The half-lives of excited isomeric states observed in 195Au, 201Tl and 215Rn are reported for the first time. Delayed γ-rays were correlated with nuclei produced in the projectile fragmentation of relativistic 238U ions, unambiguously identified in terms of their atomic number (Z) and mass-to-charge ratio (A/Q) after traversing an in-flight separator. The observation of a long-lived isomeric state in 195Au with t1/2 = 16-4+8 μs is presented. Two shorter-lived isomeric states were detected in 201Tl and 215Rn with t1/2 = 95-21+39 and 57-12+21 ns respectively. In total 24 isomeric states were identified in different nuclei from Pt to Rn (A ˜ 200) during the current study, the majority of which were previously reported. The wealth of spectroscopic data provides the opportunity to determine the isomeric ratios over a wide range of Z, A and angular momentum (I ħ) of the reaction products. In particular, high-spin states with I ≳ 18 ħ provide a robust test of theoretical models of fragmentation.
Study of Relativistic Nucleus-nucleus Coll.Induced by 16O Projectiles
2002-01-01
A double experiment in which two detector systems (Streamer Chamber, Plastic Ball Calorimeter), running concurrently via a beam split (West Area H3, X5), search for quark matter formation in violent collisions of |1|6O or |2|0Ne with target nuclei between |4|0Ca and |2|0|6Pb. The acceleration of |1|6O will be facilitated by a high charge state injector, consisting of an ECR source and an RFQ pre-accelerator, installed by GSI and LBL at the PS Linac 1. Experimental equipment will be a streamer chamber installed in the Vertex Magnet of experiment WA75 together with beam hodoscopes and a downstream trigger calorimeter selecting violent events by the absence of energy flow to the projectile fragmentation region. Observed particles will be p, @p, K|0, @L and @L. In addition there will be the Plastic Ball, 800-fold @DE-E particle identifier system, covering the target fragmentation and backward fireball regions. Together with a multisegmented large solid angle (@+~9|0 of beam) energy calorimeter and a trigger calor...
Influence of the embedded structure on the EFP formation of compact terminal sensitive projectile
Directory of Open Access Journals (Sweden)
Bo-yang Xing
2017-08-01
Full Text Available To improve the damage efficiency of compact terminal sensitive projectile with EFP warhead, it is vital to understand how the embedded structure (ES affects the EFP forming performance. In this paper, the corresponding numerical investigation is focused on, in which the fluid-structure interaction (FSI method and the experimental verification are used. Based on the obtained quantitative relations between the forming performance and α (the ratio of height to maximum radius of ES, an optimal design is further provided. The results indicate that: when the embedded structural length and width range 0.1–0.3D and 0.1–0.2D (D: diameter of EFP warhead at a fixed volume, respectively, EFP forming velocity nearly keeps as a constant, 1760 m/s; the height of ES has a dramatical effect on the propagating range of detonation wave, resulting in significant influence on the aerodynamic shape and length-to-diameter ratio of EFP; under the given constraints, the EFP length-diameter ratio can reach the optimal value 2.76, when the height of ES is 0.22D.
Energy Technology Data Exchange (ETDEWEB)
Plaß, W.R., E-mail: Wolfgang.R.Plass@exp2.physik.uni-giessen.de [II. Physikalisches Institut, Justus-Liebig-Universität Gießen, 35392 Gießen (Germany); GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Dickel, T. [II. Physikalisches Institut, Justus-Liebig-Universität Gießen, 35392 Gießen (Germany); GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Purushothaman, S. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Dendooven, P. [KVI, University of Groningen, 9747 AA Groningen (Netherlands); Geissel, H. [II. Physikalisches Institut, Justus-Liebig-Universität Gießen, 35392 Gießen (Germany); GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Ebert, J. [II. Physikalisches Institut, Justus-Liebig-Universität Gießen, 35392 Gießen (Germany); Haettner, E. [II. Physikalisches Institut, Justus-Liebig-Universität Gießen, 35392 Gießen (Germany); GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Jesch, C. [II. Physikalisches Institut, Justus-Liebig-Universität Gießen, 35392 Gießen (Germany); Ranjan, M. [KVI, University of Groningen, 9747 AA Groningen (Netherlands); and others
2013-12-15
Highlights: • An overview of the FRS Ion Catcher experiment at GSI is given. • The FRS Ion Catcher consists of the FRS, a cryogenic stopping cell, an RF quadrupole-based beam transport and diagnostics unit and a multiple-reflection time-of-flight mass spectrometer. • Off-line tests of the stopping cell with {sup 219}Rn ions. • First on-line operation of a stopping cell for exotic nuclei at cryogenic temperatures. • First mass measurements of heavy projectile fragments using a multiple-reflection time-of-flight mass spectrometer. -- Abstract: At the FRS Ion Catcher at GSI, projectile and fission fragments are produced at relativistic energies, separated in-flight, range-focused, slowed down and thermalized in a cryogenic stopping cell. A multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) is used to perform direct mass measurements and to provide an isobarically clean beam for further experiments, such as mass-selected decay spectroscopy. A versatile RF quadrupole transport and diagnostics unit guides the ions from the stopping cell to the MR-TOF-MS, provides differential pumping, ion identification and includes reference ion sources. The FRS Ion Catcher serves as a test facility for the Low-Energy Branch of the Super-FRS at the Facility for Antiproton and Ion Research (FAIR), where the cryogenic stopping cell and the MR-TOF-MS will be key devices for the research with stopped projectile and fission fragments that will be performed with the experiments MATS and LaSpec. Off-line tests of the stopping cell yield a combined ion survival and extraction efficiency for {sup 219}Rn ions of about 30% and an extraction time of about 25 ms. The stopping cell and the MR-TOF-MS were commissioned on-line as part of the FRS Ion Catcher. For the first time, a stopping cell for exotic nuclei was operated on-line at cryogenic temperatures. Using a gas density almost two times higher than ever reached before for a stopping cell with RF ion repelling structures
Moravanský, Norbert; Rekeň, Viktor; Juříček, Ludvík; Zummerová, Anežka; Kováč, Peter
2013-01-01
The question of handgun use in a city or densely populated aglomerations requires a highly practical level of solution to this issue, though with the knowledge of theoretical presumptions of wound ballistics of ricochet projectiles. The application of wound ballistics into the practice of a forensic pathologist, as well as a surgeon or a traumatologist, enables a good understanding of the dynamics of projectile penetration through anatomic structures of the human body. In forensic assessment, gunshot wounds of limbs are relatively frequent cases. By the integration of wound ballistics principles into the research of gunshot wounds, it is also possible to establish, whether the projectile entered into the anatomic structures under direct trajectory steadily or whether through the course of its trajectory, before reaching the human body, it firstly contacted a particular object in the space, i. e. whether the injury could have been caused by a ricochet projectile. In connection with unclear gunshot wounds and their morphological image, it is necessary to consider the possibility of the effects of a ricochet projectile, especially when persons are injured accidentally. The daily practice of the officers of the Police Corps of the Slovak Republic essentially enhances the necessity of being informed about the behaviour of parametrically designated ricochet projectiles in a ballistic experiment with the use of a model of a built-up area in a town, with typical materials and surfaces of objects in between and a model of a human limb part as a potential target of an uncontrolled ricochet projectile. The proposed design of the situation is undoubtedly of an enormous significance, even when forensically evaluating the morphological consequences of ricochet projectiles. By the application of results of such experiments and their final comparison, when different types of projectiles are used, it is also possible to contribute to the experts groundwork in the process of
Aerodynamics of intermittent bounds in flying birds
Tobalske, Bret W.; Hearn, Jason W. D.; Warrick, Douglas R.
Flap-bounding is a common flight style in small birds in which flapping phases alternate with flexed-wing bounds. Body lift is predicted to be essential to making this flight style an aerodynamically attractive flight strategy. To elucidate the contributions of the body and tail to lift and drag during the flexed-wing bound phase, we used particle image velocimetry (PIV) and measured properties of the wake of zebra finch (Taeniopygia guttata, N = 5), flying at 6-10 m s- 1 in a variable speed wind tunnel as well as flow around taxidermically prepared specimens (N = 4) mounted on a sting instrumented with force transducers. For the specimens, we varied air velocity from 2 to 12 m s- 1 and body angle from -15∘ to 50∘. The wake of bounding birds and mounted specimens consisted of a pair of counterrotating vortices shed into the wake from the tail, with induced downwash in the sagittal plane and upwash in parasagittal planes lateral to the bird. This wake structure was present even when the tail was entirely removed. We observed good agreement between force measures derived from PIV and force transducers over the range of body angles typically used by zebra finch during forward flight. Body lift:drag (L:D) ratios averaged 1.4 in live birds and varied between 1 and 1.5 in specimens at body angles from 10∘ to 30∘. Peak (L:D) ratio was the same in live birds and specimens (1.5) and was exhibited in specimens at body angles of 15∘ or 20∘, consistent with the lower end of body angles utilized during bounds. Increasing flight velocity in live birds caused a decrease in CL and CD from maximum values of 1.19 and 0.95 during flight at 6 m s- 1 to minimum values of 0.70 and 0.54 during flight at 10 m s- 1. Consistent with delta-wing theory as applied to birds with a graduated-tail shape, trimming the tail to 0 and 50% of normal length reduced L:D ratios and extending tail length to 150% of normal increased L:D ratio. As downward induced velocity is present in the
Spin Labeling ESR Investigation of Covalently Bound Residues in Soil
Aleksandrova, Olga; Steinhoff, Heinz-Juergen; Klasmeier, Joerg; Schulz, Marcus; Matthies, Michael
2013-04-01
Organic xenobiotic chemicals, such as pesticides, biocides and veterinary pharmaceuticals, interact with soil, which results in the simultaneous formations of metabolites, mineralization products, and bound or non-extractable residues (NER). Substances or metabolites with reactive functional groups, such as aniline or phenol, have a tendency to give a larger proportion of NER. Despite numerous studies on NER, the majority of their chemical structures is still unknown. Reversible sequestration and irreversible formation of NER were also observed for veterinary antibiotic pharmaceuticals, after their application to soil with and without manure. For this purpose, we hypothesized a key role of specific functional groups of soil contaminants, via which contaminants are covalently bound to soil constituents, and advance a method of spin labeling ESR investigation of reaction products using a membrane method. Spin labels (SL) represent chemically stable paramagnetic molecules used as molecular labels and molecular probes for testing the covalent binding, structural properties, and molecular mobility of different physical, chemical, and biological systems. In the case of covalent binding of SL, their ESR spectra become broadened. We used stable nitroxide radicals (NR) as SL. These radicals modeled organic chemical contaminants and differed only in one functional group. The paramagnetic SL 4-Amino Tempo (4-amino-2,2,6,6-tetramethyl-1-piperidinylox) differed from Tempo (2,2,6,6-Tetramethylpiperidinooxy) in a substituent at the para-position of the piperidine ring, whereas Aniline Tempo (1-Piperidinyloxy, 2,2,6,-tetramethyl, 6-Aniline) differed from Tempo in an Aniline substituting one CH3 functional group. Before experimental analysis, we tested temporal changes in the concentration of both NR incubated with soil and found that the life-times of them in soil exceeded 3 days. We contaminated and labeled soil samples with NR, adding to soil the aqueous solution, which already
Optimal Bounds in Parametric LTL Games
Directory of Open Access Journals (Sweden)
Martin Zimmermann
2011-06-01
Full Text Available We consider graph games of infinite duration with winning conditions in parameterized linear temporal logic, where the temporal operators are equipped with variables for time bounds. In model checking such specifications were introduced as "PLTL" by Alur et al. and (in a different version called "PROMPT-LTL" by Kupferman et al.. We present an algorithm to determine optimal variable valuations that allow a player to win a game. Furthermore, we show how to determine whether a player wins a game with respect to some, infinitely many, or all valuations. All our algorithms run in doubly-exponential time; so, adding bounded temporal operators does not increase the complexity compared to solving plain LTL games.
Bounded rational choice behaviour: applications in transport
DEFF Research Database (Denmark)
Jensen, Anders Fjendbo
2016-01-01
Even though the theory of rational behaviour has been challenged for almost 100 years, the dominant approach within the field of transport has been based upon the assumptions of neoclassical economics that we live in a world of rational decision makers who always have perfect knowledge and aim to...... and limited processing may occur due to time constraints, low involvement in the decision at hand, relying on habits or the task requiring too high a mental effort....... to maximise some subjective measure. Where other fields, for example within the social sciences and psychology, have made serious efforts to explore alternative models derived from principles of bounded rationality, this direction has begun to take speed within transport applications only recently. Bounded...
Tight Bounds for Distributed Functional Monitoring
DEFF Research Database (Denmark)
Woodruff, David P.; Zhang, Qin
2011-01-01
output to a function $f$ computed over the union of the inputs. The goal is to minimize the communication. We show the randomized communication complexity of estimating the number of distinct elements up to a $1+\\eps$ factor is $\\Omega(k/\\eps^2)$, improving the previous $\\Omega(k + 1/\\eps^2)$ bound......} t))$ to $\\tilde{\\Omega}(n^{1-2/p}/(\\eps^{4/p} t))$, giving the first bound for estimating $F_0$ in $t$ passes of $\\Omega(1/(\\eps^2 t))$ bits of space that does not use the gap-hamming problem, and showing a distribution for the gap-hamming problem with high external information cost or super...
A holographic bound for D3-brane
Energy Technology Data Exchange (ETDEWEB)
Momeni, Davood; Myrzakul, Aizhan; Myrzakulov, Ratbay [Eurasian National University, Eurasian International Center for Theoretical Physics, Astana (Kazakhstan); Eurasian National University, Department of General Theoretical Physics, Astana (Kazakhstan); Faizal, Mir [University of British Columbia-Okanagan, Irving K. Barber School of Arts and Sciences, Kelowna, BC (Canada); University of Lethbridge, Department of Physics and Astronomy, Lethbridge, AB (Canada); Bahamonde, Sebastian [University College London, Department of Mathematics, London (United Kingdom)
2017-06-15
In this paper, we will regularize the holographic entanglement entropy, holographic complexity and fidelity susceptibility for a configuration of D3-branes. We will also study the regularization of the holographic complexity from the action for a configuration of D3-branes. It will be demonstrated that for a spherical shell of D3-branes the regularized holographic complexity is always greater than or equal to the regularized fidelity susceptibility. Furthermore, we will also demonstrate that the regularized holographic complexity is related to the regularized holographic entanglement entropy for this system. Thus, we will obtain a holographic bound involving regularized holographic complexity, regularized holographic entanglement entropy and regularized fidelity susceptibility of a configuration of D3-brane. We will also discuss a bound for regularized holographic complexity from action, for a D3-brane configuration. (orig.)
Novel black hole bound states and entropy
Govindarajan, T R
2011-01-01
We solve for the spectrum of the Laplacian as Hamiltonian on $\\mathbb{R}^{2}-\\mathbb{D}$ and in $\\mathbb{R}^{3}-\\mathbb{B}$. A self-adjointness analysis with $\\partial\\mathbb{D}$ and $\\partial\\mathbb{B}$ as the boundary for the two cases shows that a general class of boundary conditions for which the Hamiltonian operator is essentially self-adjoint are of the mixed (Robin) type. With this class of boundary conditions we obtain 'bound state' solutions for the Schroedinger equation. Interestingly, these solutions are all localized near the boundary. We further show that the number of bound states is finite and is infact proportional to the perimeter or area of the removed \\emph{disc} or \\emph{ball}. We then argue that similar considerations should hold for static black hole backgrounds with the horizon treated as the boundary.