view Abstract Citations (153) References (10) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Numerical Simulations of a Magnetically Confined Jet Clarke, David A. ; Norman, Michael L. Burns, Jack O. Preliminary results two-dimensional, axisymmetric numerical simulations propagating jet which possesses dominating toroidal magnetic field are presented. Unlike its pure hydrodynamical (HD) counterpart, the magnetohydrodynamical (MHD) presented here no...

view Abstract Citations (117) References (32) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A Consistent Method of Characteristics for Multidimensional Magnetohydrodynamics Clarke, David A. This paper introduces a previously unaddressed problem with performing multidimensional numerical MHD characterized by "explosive" growth (within single time step) weak magnetic fields to possibly dynamic strengths in the vicinity strong velocity shear. has been observed...

We present the extension of previous two-dimensional simulations time-dependent evolution nonrelativistic outflows from surface Keplerian accretion disks to three dimensions. As in work, we investigate outflow that arises a magnetized disk is initially hydrostatic balance with its surrounding cold corona. The itself taken provide set fixed boundary conditions for problem. find mechanism jet acceleration identical what was established simulations. three-dimensional results are consistent...

view Abstract Citations (76) References (30) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS VLA Observations of the Inner Lobes Centaurus A Clarke, David A. ; Burns, Jack O. Norman, Michael L. Scaled-array observations closest active radio galaxy at 1.4, 1.6, and 4.9 GHz with 4.5" x 1.2" resolution have been used to derive spectral polarimetric properties inner lobes source. The extended emission is filamentary, similar other well-resolved galaxies. Two...

1. Formamide and its more potent N-methyl derivative have been described as transient inhibitors of the growth mouse sarcoma 180. This effect is not a property formamides in general since other compounds containing formamide moiety failed to affect tumor. 2. N-methylformamide has shown exert effects when therapy started either 24 or 96 hours after implantation tumor agent given single, large dose. Further, compound found equally effective whether by oral intraperitoneal route. 3. Histologic...

The ROSAT data from the cluster gas of Cygnus A are re-examined in light a three-dimensional hydrodynamic simulation supersonic jet propagating an isothermal King atmosphere designed to follow observed density distribution gas. In addition presence non-uniform atmosphere, this departs previous 3D work that X-ray (bremsstrahlung) brightness has been determined flow variables as function time. This provides compelling evidence for conclusions reached by Carilli et al. who stated major features...

view Abstract Citations (86) References (19) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Numerical Observations of a Simulated Jet with Passive Helical Magnetic Field Clarke, David A. ; Norman, Michael L. Burns, Jack O. The numerical magnetohydrodynamical (MHD) code ZEUS has been used to compute Mach 6 jet (relative the internal sound speed) density ratio η = 0.1 (jet ambient density) which possesses dynamically passive helical magnetic field (i.e., β...

view Abstract Citations (75) References (44) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Origin of the Structures and Polarization in Classical Double 3C 219 Clarke, David A. ; Bridle, Alan H. Burns, Jack O. Perley, Richard Norman, Michael L. Scaled-array VLA observations "classical double" radio galaxy at 1.4, 1.5, 1.7, 4.9 GHz with 1.4" resolution have been used to derive spectral polarimetric properties source. The extended emission lobes is...

Polarization measurements in the Hα, Hβ emission features of southern Be-shell stars and blue supergiants are presented. Using these observations, together with all previous published broad-band data, intrinsic interstellar components separated by an intercomparison three methods. To standardize this approach each method is briefly reviewed discussion possible difficulties misuse. The largest polarizations were found for p Car, ∊ Cap, π Aqr κ Aps (⁠|$p^B_\ast \gtrsim1.0$| per cent),...

We have developed three-dimensional electrospun microfibrous meshes of a novel star branched three-arm poly(ε-caprolactone) (*PCL) as potential scaffolds for tissue engineering applications. The processing conditions required to obtain uniform fibers were optimized by studying their influence on fiber morphology and size. Polymer molecular weight solution feed rate influenced both the mesh microstructure tensile properties mats. Electrospun samples also tested mechanical in wet conditions,...

view Abstract Citations (55) References (22) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Relic Radio Emission in 3C 388 Roettiger, Kurt ; Burns, Jack O. Clarke, David A. Christiansen, Wayne New VLA images of the radio galaxy have revealed an intriguing distribution spectral indices which is quite different from that typical classical double sources. We observe two distinct regions emission separated by a well-defined transition layer delineated dramatic...

view Abstract Citations (63) References (23) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Numerical Simulations of a Restarting Jet Clarke, David A. ; Burns, Jack O. The results from numerical simulation an intermittent jet are presented to address the applicability "restarting jet" model one-sided jets prevalent in Fanaroff & Riley Class II radio sources. Intermittently restarting requires that new be launched into lobes containing thermalized material...

ABSTRACT Recent and not-so-recent critiques of the widely used magnetohydrodynamics (MHD) code, ZEUS-3D , challenge its reliability efficiency suggesting that MHD algorithm is capable “significant errors” in some simple one-dimensional shock-tube problems. I show these concerns are either inapplicable multi-dimensional astrophysical applications, or result from a misuse code rather than “flaws” design. also describe few test problems including one for super-Alfvénic turbulence, highlight...

We have performed three-dimensional MHD equilibrium jet simulations that been designed to excite the Kelvin-Helmholtz (K-H) instability and allow us investigate spatial growth of mixing layer between a magnetized an initially unmagnetized external medium. These differ in magnetic field strength orientation, jet-to-ambient density ratio, amplitude initial (velocity) perturbation. calculate as direct measure mass entrainment or high axial velocity material compare entrained with dynamical...

Eight international riders from Olympic equestrian disciplines, participated in semi-structured interviews investigating developmental factors which they felt had helped them achieve and retain elite status. Key were present across the variable rider journeys to Riders demonstrated a natural aptitude for horse sports, desire learn combined with exposure environments fostered confidence skill development: access horses, observing riders, coaches parental support. consistently questioned...

A new range of heterocyclic ring cis/trans-dihydrodiol derivatives (1B, 3B–8B) obtained from metabolism monocyclic (1A, 3A) and bicyclic heteroarenes (4A–8A) by Pseudomonas putida UV4, has been isolated stereochemically assigned.

view Abstract Citations (58) References (32) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Stability and Collimation of Three-dimensional Jets Hardee, Philip E. ; Clarke, David A. Howell, D. Andrew A three-dimensional hydrodynamical simulation a Mach 5 cylindrical jet established in equilibrium with surrounding uniform atmosphere 10 times the density has been performed is compared previous 3 simulation. grid resolution used significantly higher than was...

A set of three-dimensional magnetohydrodynamical simulations supermagnetosonic magnetized jets has been performed.The contain an equipartition primarily poloidal magnetic Ðeld, and the e †ect jet density on dynamics structure is evaluated.The precessed at origin to break symmetry excite Kelvin-HelmholtzÈunstable helical modes.In linear limit, observed structures are similar in all can be produced by predicted arise as a result instability.The amplitude various unstable modes evaluated.Most...

view Abstract Citations (37) References (19) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Hierarchical Numerical Cosmology with Hydrodynamics: Methods and Code Tests Anninos, Peter ; Norman, Michael L. Clarke, David A. We describe a two-level hierarchical three-dimensional numerical code designed to simulate the formation of galaxies other larger scale structures in an expanding universe Newtonian gravity radiative cooling. The basis is standard...

view Abstract Citations (48) References (34) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS On Jet Response to a Driving Frequency and the Jets in 3C 449 Hardee, Philip E. ; Cooper, Michael A. Clarke, David Hydrodynamical simulations of response an expanding slab jet different driving frequencies have been performed. Amplitude growth resulting sinusoidal oscillation occurs when frequency is lower than resonant at which wave associated with Kelvin-Helmholtz...

Numerical simulations with supercomputers allow analysis of the wide range nonlinear physics inherent in hydrodynamic and magnetohydrodynamic equations. When applied to extragalactic radio sources, these numerical models have begun reproduce many complex structures observed on telescopic images. This combination observations provides powerful probes galaxies. In this review, some recent results from both two-dimensional three-dimensional formation evolution extended morphologies are...

The reactions of the carbonato-complexes [ Pt (CO2) L2] with esters 3-oxopentanedioic acid, RCH2COCH2R, in warm ethanol afford, high yield, formally platinacyclobutan-3-one compounds [Pt(CHRCOCHR)L,] (R = C02Me, L PPh,, AsPh,, PMePh, or PMe2Ph; 2L Ph2PCH2CH2PPh2; - R C02Et, AsPh,; C02Prn, AsPh,). [Pk(CHRCOCHR)- PMePh,, PPh, AsPh,) are also formed upon treatment benzene solutions [PtL,] RCH2COCH2R presence air. Using latter method, triphenylphosphine derivative Pi{CH ( C02Me)COCH C02Me) I(...

view Abstract Citations (15) References (28) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Destabilization of Strongly Magnetized Jets Hardee, Philip E. ; Clarke, David A. Simulations strongly magnetized slab jets in uniform expansion an external atmosphere have been performed and compared to unmagnetized expanding jet. A super-Alfvénic jet with lower magnetosonic Mach number but sonic equal a purely fluid destabilizes much shorter distance than the...