Sunyaev-Zel'dovich-measured Pressure Profiles from the Bolocam X-Ray/SZ Galaxy Cluster Sample

We describe Sunyaev-Zel'dovich (SZ) effect measurements and analysis of the intracluster medium (ICM) pressure profiles of a set of 45 massive galaxy clusters imaged using Bolocam at the Caltech Submillimeter Observatory. We deproject the average pressure profile of our sample into 13 logarithmically spaced radial bins between 0.07R_(500) and 3.5R_(500), and we find that a generalized Navarro, Frenk, and White (gNFW) profile describes our data with sufficient goodness-of-fit and best-fit parameters (C_(500), α, β, γ, P_0 = 1.18, 0.86, 3.67, 0.67, 4.29). We use X-ray data to define cool-core and disturbed subsamples of clusters, and we constrain the average pressure profiles of each of these subsamples. We find that, given the precision of our data, the average pressure profiles of disturbed and cool-core clusters are consistent with one another at R≳ 0.15R_(500), with cool-core systems showing indications of higher pressure at R≾ 0.15R_(500). In addition, for the first time, we place simultaneous constraints on the mass scaling of cluster pressure profiles, their ensemble mean profile, and their radius-dependent intrinsic scatter between 0.1R_(500) and 2.0R_(500). The scatter among profiles is minimized at radii between ≃ 0.2R_(500) and ≃ 0.5R_(500), with a value of ≃ 20%. These results for the intrinsic scatter are largely consistent with previous analyses, most of which have relied heavily on X-ray derived pressures of clusters at significantly lower masses and redshifts compared to our sample. Therefore, our data provide further evidence that cluster pressure profiles are largely universal with scatter of ≃ 20%-40% about the universal profile over a wide range of masses and redshifts

Damage signature of fatigued fabric reinforced plastics in the pulsed ultrasonic polar scan

This study investigates the use of both the amplitude and time-of-flight based pulsed ultrasonic polar scan (P-UPS) for the nondestructive detection and evaluation of fatigue damage in fiber reinforced composites. Several thermoplastic carbon fabric reinforced PPS specimens (CETEX), loaded under various fatigue conditions, have been scanned at multiple material spots according to the P-UPS technique in order to extract material degradation in a quantitative way. The P-UPS results indicate that shear dominated fatigued carbon/PPS goes with a reduction of shear properties combined with large fiber distortions. The P-UPS results of the tension-tension fatigued carbon/PPS samples on the other hand reveal a directional degradation of the stiffness properties, reaching a maximum reduction of -12.8% along the loading direction. The P-UPS extracted damage characteristics are fully supported by simulations, conventional destructive tests as well as visual inspection. The results demonstrate the excellent capability of the P-UPS method for nondestructively assessing and quantifying both shear-dominated and tension-tension fatigue damage in fabric reinforced plastics

Validation of a source-receiver model for road traffic-induced vibrations in buildings. II: Receiver model.

The objective of part II of this paper is to couple the validated source model for free-field traffic-induced vibrations, which has been presented in part I of the paper, to a receiver model that incorporates the structure and accounts for dynamic soil-structure interaction. The incident wave field is applied to the structure and the response is calculated using a subdomain formulation for dynamic soil-structure interaction. A finite element method is applied to the structure, while the unbounded soil domain is calculated with a boundary element method using the Green's functions of a homogeneous or a layered half-space. The results of elaborate in situ experiments in and around a single family dwelling during the passage of a truck on joints in a concrete pavement and on a plywood unevenness, are used for the validation of the numerical prediction model. The predicted structural response during the passage of a truck at a speed v = 50km/h is compared with the experimental results. The agreement between the numerical and the experimental results is very good for the passage on the plywood unevenness and satisfactory for the passage on the joints between the concrete plates