Assessing the time-sensitive impacts of energy efficiency and flexibility in the US building sector

The building sector consumes 75% of US electricity, offering substantial energy, cost, and CO2 emissions savings potential. New technologies enable buildings to flexibly manage electric loads across different times of day and season in support of a low-cost, low-carbon electric grid. Assessing the value of such technologies requires an understanding of building electric load variability at a higher temporal resolution than is demonstrated in previous studies of US building efficiency potential. We adapt Scout, an open-access model of US building energy use, to characterize sub-annual variations in baseline building electricity use, costs, and emissions at the national scale. We apply this baseline in time-sensitive analyses of the energy, cost, and CO2 emissions savings potential of various degrees of energy efficiency and flexibility, finding that efficiency continues to have strong value in a time-sensitive assessment framework while the value of flexibility depends on assumed electricity rates, measure magnitude and duration, and the amount of savings already captured by efficiency

Assessing the threat of lone-actor terrorism: the reliability and validity of the TRAP-18

Terrorism, especially lone-actor terrorism, is considered a major national security threat in both North America and Europe. The threat of terrorism has many faces and violence can arise from all ideological extremes. The authors present the theoretical model and current empirical validation of the Terrorist Radicalization Assessment Protocol (TRAP-18), a structured professional judgment instrument for those engaged in risk assessment of persons of concern for acts of terrorist violence. It can be used independently of a particular ideology. The TRAP-18 consists of 8 proximal warning behaviors and 10 distal characteristics, and has been designed to help prioritize the imminency of risk in specific cases, and therefore determine the intensity of monitoring and active management a case requires. Research has demonstrated excellent interrater reliability, and promising content, criterion, discriminant, and predictive validity. More research is in progress. The TRAP-18 is currently used by counterterrorism experts in North America and Europe. It offers a useful approach for professionals who may be assessing and treating individuals of national security concern

The Interstellar Lines of the Feige Stars

New measurements of the equivalent widths and radial velocities of the interstellar lines of Ca ii and Na i in the spectra of Feige stars are presented. The upper limits to the Na i interstellar line imply that the gas in the halo has a much larger value of the ratio of the column density of Ca ii to that of Na i than does the plane, and that this ratio is larger than the intermediate value obtained previously from a group of brighter halo stars. From this we deduce that there is gas up to at least 1 kpc above the plane, and that this gas has much more Ca ii relative to Na i than does the plane. The interstellar equivalent width corresponding to looking out of the Galaxy from the plane at b^(II) = 90° is about 300 mÅ for the stronger of the Ca n lines. The velocity measurements imply that this gas is moving slowly toward the plane in a time scale such that replenishment of the halo gas is necessary

Nuclear Black Hole Formation in Clumpy Galaxies at High Redshift

Massive stellar clumps in high redshift galaxies interact and migrate to the center to form a bulge and exponential disk in <1 Gyr. Here we consider the fate of intermediate mass black holes (BHs) that might form by massive-star coalescence in the dense young clusters of these disk clumps. We find that the BHs move inward with the clumps and reach the inner few hundred parsecs in only a few orbit times. There they could merge into a supermassive BH by dynamical friction. The ratio of BH mass to stellar mass in the disk clumps is approximately preserved in the final ratio of BH to bulge mass. Because this ratio for individual clusters has been estimated to be ~10^{-3}, the observed BH-to-bulge mass ratio results. We also obtain a relation between BH mass and bulge velocity dispersion that is compatible with observations of present-day galaxies.Comment: 10 pages, 3 figures, accepted by Ap

A Turbulent Origin for Flocculent Spiral Structure in Galaxies: II. Observations and Models of M33

Fourier transform power spectra of azimuthal scans of the optical structure of M33 are evaluated for B, V, and R passbands and fit to fractal models of continuum emission with superposed star formation. Power spectra are also determined for Halpha. The best models have intrinsic power spectra with 1D slopes of around -0.7pm0.7, significantly shallower than the Kolmogorov spectrum (slope =-1.7) but steeper than pure noise (slope=0). A fit to the power spectrum of the flocculent galaxy NGC 5055 gives a steeper slope of around -1.5pm0.2, which could be from turbulence. Both cases model the optical light as a superposition of continuous and point-like stellar sources that follow an underlying fractal pattern. Foreground bright stars are clipped in the images, but they are so prominent in M33 that even their residual affects the power spectrum, making it shallower than what is intrinsic to the galaxy. A model consisting of random foreground stars added to the best model of NGC 5055 fits the observed power spectrum of M33 as well as the shallower intrinsic power spectrum that was made without foreground stars. Thus the optical structure in M33 could result from turbulence too.Comment: accepted by ApJ, 13 pages, 10 figure