Numerical Investigation of Second Mode Attenuation over Carbon/Carbon Surfaces on a Sharp Slender Cone

We have carried out axisymmetric numerical simulations of a spatially developing hypersonic boundary layer over a sharp 7$^{\circ{}}$-half-angle cone at $M_\infty=7.5$ inspired by the experimental investigations by Wagner (2015). Simulations are first performed with impermeable (or solid) walls with a one-time broadband pulse excitation applied upstream to determine the most convectively-amplified frequencies resulting in the range 260kHz -- 400kHz, consistent with experimental observations of second-mode instability waves. Subsequently, we introduce harmonic disturbances via continuous periodic suction and blowing at 270kHz and 350kHz. For each of these forcing frequencies complex impedance boundary conditions (IBC), modeling the acoustic response of two different carbon/carbon (C/C) ultrasonically absorptive porous surfaces, are applied at the wall. The IBCs are derived as an output of a pore-scale aeroacoustic analysis -- the inverse Helmholtz Solver (iHS) -- which is able to return the broadband real and imaginary components of the surface-averaged impedance. The introduction of the IBCs in all cases leads to a significant attenuation of the harmonically-forced second-mode wave. In particular, we observe a higher attenuation rate of the introduced waves with frequency of 350kHz in comparison with 270kHz, and, along with the iHS impedance results, we establish that the C/C surfaces absorb acoustic energy more effectively at higher frequencies.Comment: AIAA-SciTech 201

Communication interventions in adult and pediatric oncology: A scoping review and analysis of behavioral targets

BackgroundImproving communication requires that clinicians and patients change their behaviors. Interventions might be more successful if they incorporate principles from behavioral change theories. We aimed to determine which behavioral domains are targeted by communication interventions in oncology.MethodsSystematic search of literature indexed in Ovid Medline, Embase, Scopus, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Clinicaltrials.gov (2000-October 2018) for intervention studies targeting communication behaviors of clinicians and/or patients in oncology. Two authors extracted the following information: population, number of participants, country, number of sites, intervention target, type and context, study design. All included studies were coded based on which behavioral domains were targeted, as defined by Theoretical Domains Framework.FindingsEighty-eight studies met inclusion criteria. Interventions varied widely in which behavioral domains were engaged. Knowledge and skills were engaged most frequently (85%, 75/88 and 73%, 64/88, respectively). Fewer than 5% of studies engaged social influences (3%, 3/88) or environmental context/resources (5%, 4/88). No studies engaged reinforcement. Overall, 7/12 behavioral domains were engaged by fewer than 30% of included studies. We identified methodological concerns in many studies. These 88 studies reported 188 different outcome measures, of which 156 measures were reported by individual studies.ConclusionsMost communication interventions target few behavioral domains. Increased engagement of behavioral domains in future studies could support communication needs in feasible, specific, and sustainable ways. This study is limited by only including interventions that directly facilitated communication interactions, which excluded stand-alone educational interventions and decision-aids. Also, we applied stringent coding criteria to allow for reproducible, consistent coding, potentially leading to underrepresentation of behavioral domains

SDSSJ143244.91+301435.3 at VLBI: a compact radio galaxy in a narrow-line Seyfert 1

We present VLBI observations, carried out with the European Very Long Baseline Interferometry Network (EVN), of SDSSJ143244.91+301435.3, a radio-loud narrow-line Seyfert 1 (RLNLS1) characterized by a steep radio spectrum. The source, compact at Very Large Array (VLA) resolution, is resolved on the milliarcsec scale, showing a central region plus two extended structures. The relatively high brightness temperature of all components (5x10^6-1.3x10^8 K) supports the hypothesis that the radio emission is non-thermal and likely produced by a relativistic jet and/or small radio lobes. The observed radio morphology, the lack of a significant core and the presence of a low frequency (230 MHz) spectral turnover are reminiscent of the Compact Steep Spectrum sources (CSS). However, the linear size of the source (~0.5kpc) measured from the EVN map is lower than the value predicted using the turnover/size relation valid for CSS sources (~6kpc). This discrepancy can be explained by an additional component not detected in our observations, accounting for about a quarter of the total source flux density, combined to projection effects. The low core-dominance of the source (CD<0.29) confirms that SDSSJ143244.91+301435.3 is not a blazar, i.e. the relativistic jet is not pointing towards the observer. This supports the idea that SDSSJ143244.91+301435.3 may belong to the "parent population" of flat-spectrum RLNLS1 and favours the hypothesis of a direct link between RLNLS1 and compact, possibly young, radio galaxies.Comment: 8 pages, 3 figures, accepted for publication in MNRA

Effective Field Theories

Effective field theories encode the predictions of a quantum field theory at low energy. The effective theory has a fairly low ultraviolet cutoff. As a result, loop corrections are small, at least if the effective action contains a term which is quadratic in the fields, and physical predictions can be read straight from the effective Lagrangean. Methods will be discussed how to compute an effective low energy action from a given fundamental action, either analytically or numerically, or by a combination of both methods. Basically,the idea is to integrate out the high frequency components of fields. This requires the choice of a "blockspin",i.e. the specification of a low frequency field as a function of the fundamental fields. These blockspins will be the fields of the effective field theory. The blockspin need not be a field of the same type as one of the fundamental fields, and it may be composite. Special features of blockspins in nonabelian gauge theories will be discussed in some detail. In analytical work and in multigrid updating schemes one needs interpolation kernels \A from coarse to fine grid in addition to the averaging kernels $C$ which determines the blockspin. A neural net strategy for finding optimal kernels is presented. Numerical methods are applicable to obtain actions of effective theories on lattices of finite volume. The constraint effective potential) is of particular interest. In a Higgs model it yields the free energy, considered as a function of a gauge covariant magnetization. Its shape determines the phase structure of the theory. Its loop expansion with and without gauge fields can be used to determine finite size corrections to numerical data.Comment: 45 pages, 9 figs., preprint DESY 92-070 (figs. 3-9 added in ps format

Signatures in a Giant Radio Galaxy of a Cosmological Shock Wave at Intersecting Filaments of Galaxies

Sensitive images of low-level, Mpc-sized radio cocoons offer new opportunities to probe large scale intergalactic gas flows outside clusters of galaxies. New radio images of high surface brightness sensitivity at strategically chosen wavelengths of the giant radio galaxy NGC 315 (Mack et al. 1997,1998) reveal significant asymmetries and particularities in the morphology, radio spectrum and polarization of the ejected radio plasma. We argue that the combination of these signatures provides a sensitive probe of an environmental shock wave. Analysis of optical redshifts in NGC 315 vicinity confirms its location to be near, or at a site of large-scale flow collisions in the 100 Mpc sized Pisces-Perseus Supercluster region. NGC 315 resides at the intersection of several galaxy filaments, and its radio plasma serves there as a `weather station' (Burns 1998) probing the flow of the elusive and previously invisible IGM gas. If our interpretation is correct, this is the first indication for a shock wave in flows caused by the cosmological large scale structure formation, which is located in a filament of galaxies. The possibility that the putative shock wave is a source of gamma-rays and ultra high energy cosmic rays is briefly discussed.Comment: accepted by Astrophysical Journal Letters, 4 pages, 3 figures (incl. 2 color), uses emulateapj5.sty (included), aastex.sty (included) and psfig.st

Continued investigation of LDEF's structural frame and thermal blankets by the Meteoroid and Debris Special Investigation Group

This report focuses on the data acquired by detailed examination of LDEF intercostals, 68 of which are now in possession of the Meteoroid and Debris Special Investigation Group (M&D SIG) at JSC. In addition, limited data will be presented for several small sections from the A0178 thermal control blankets that were examined/counted prior to being shipped to Principal Investigators (PI's) for scientific study. The data presented here are limited to measurements of crater and penetration-hole diameters and their frequency of occurrence which permits, yet also constrains, more model-dependent, interpretative efforts. Such efforts will focus on the conversion of crater and penetration-hole sizes to projectile diameters (and masses), on absolute particle fluxes, and on the distribution of particle-encounter velocities. These are all complex issues that presently cannot be pursued without making various assumptions which relate, in part, to crater-scaling relationships, and to assumed trajectories of natural and man-made particle populations in LEO that control the initial impact conditions

Bioassessment of Four Karst Springs at Hobbs State Park – Conservation Area with a Focus on Diving Beetle (Dytiscidae: Hydroporinae) Species of Concern

Four springs were surveyed at Hobbs State Park-Conservation Area to provide an initial bioassessment and to determine occurrences of two endemic predaceous diving beetles of concern, Heterosternuta sulphuria and Sanfilippodytes sp. Habitat in the four spring runs were dominated by bedrock and gravel substrate with heavy accumulations of leaf litter. Thirty-three taxa representing 11 orders were collected from the four springs. Non-insect taxa included Oligochaeta, Physidae, and Isopoda, and predominant insect orders included Ephemeroptera, Coleoptera, Diptera, and Trichoptera. The total number of taxa across springs ranged from seven to 19, with total abundances ranging from 39 to 86 individuals. No individual taxon occurred across all four springs. Percent tolerant organisms and the Hilsenhoff Biotic Index showed that spring communities were dominated by taxa tolerant to organic pollution, likely because of low flows and heavy accumulations of leaves. Predators were the dominant functional group followed by shredders. The endemic, predaceous diving beetle Heterosternuta sulphuria was collected from two springs and Sanfilippodytes sp. was collected from three springs. One spring contained the largest number of Sanfilippodytes sp. individuals recorded among all other aquatic habitats surveyed to date. Findings highlight the importance of spring systems at Hobbs State Park Conservation Area for endemic-species conservation, while information on the invertebrate community provides a baseline for future monitoring and comparison

Dual variables for the SU(2) lattice gauge theory at finite temperature

We study the three-dimensional SU(2) lattice gauge theory at finite temperature using an observable which is dual to the Wilson line. This observable displays a behaviour which is the reverse of that seen for the Wilson line. It is non-zero in the confined phase and becomes zero in the deconfined phase. At large distances, it's correlation function falls off exponentially in the deconfined phase and remains non-zero in the confined phase. The dual variable is non-local and has a string attached to it which creates a Z(2) interface in the system. It's correlation function measures the string tension between oppositely oriented Z(2) domains. The construction of this variable can also be made in the four-dimensional theory where it measures the surface tension between oppositely oriented Z(2) domains.Comment: 13 pages, LaTeX, 4 figures are included in the latex fil