Energy, Shading and Daylighting Analysis for the Austin Bergstrom International Airport Terminal

Our firm was under contract with the City of Austin, Texas to perform energy analysis and analysis of the daylighting potential within the New Austin Bergstrom International Airport Terminal. Design of the Passenger Terminal Facility for the New Austin Airport included large glass areas for viewing arriving and departing planes, the sky, and the surrounding terrain. The glass was envisioned to provide quality natural lighting for the terminal during daylight hours in order to improve the quality of the space and save energy throughout the usable life of the terminal. For the glass to achieve the design goals, adverse qualities were minimized and beneficial qualities must be enhanced. Using computer simulation, we studied the shading devices on the south clearstories to maximize the daylight and minimize problems of direct gain in a large commercial space. The study also included analysis of skylights above the baggage claim, indirect lighting of major spaces within the airport, and the controls of the artificial lights for integrating the efficient use of the available daylight. The energy, shading, and daylighting analysis includes analysis of a mix of low and high volume spaces. The daylight sources include glass walls, clearstories, and skylights

Energy, Shading and Daylighting Analysis for the Austin Bergstrom International Airport Terminal

Our firm was under contract with the City of Austin, Texas to perform energy analysis and analysis of the daylighting potential within the New Austin Bergstrom International Airport Terminal. Design of the Passenger Terminal Facility for the New Austin Airport included large glass areas for viewing arriving and departing planes, the sky, and the surrounding terrain. The glass was envisioned to provide quality natural lighting for the terminal during daylight hours in order to improve the quality of the space and save energy throughout the usable life of the terminal. For the glass to achieve the design goals, adverse qualities were minimized and beneficial qualities must be enhanced. Using computer simulation, we studied the shading devices on the south clearstories to maximize the daylight and minimize problems of direct gain in a large commercial space. The study also included analysis of skylights above the baggage claim, indirect lighting of major spaces within the airport, and the controls of the artificial lights for integrating the efficient use of the available daylight. The energy, shading, and daylighting analysis includes analysis of a mix of low and high volume spaces. The daylight sources include glass walls, clearstories, and skylights

Planck 2013 results. XX. Cosmology from Sunyaev-Zeldovich cluster counts

We present constraints on cosmological parameters using number counts as a function of redshift for a sub-sample of 189 galaxy clusters from the Planck SZ (PSZ) catalogue. The PSZ is selected through the signature of the Sunyaev--Zeldovich (SZ) effect, and the sub-sample used here has a signal-to-noise threshold of seven, with each object confirmed as a cluster and all but one with a redshift estimate. We discuss the completeness of the sample and our construction of a likelihood analysis. Using a relation between mass $M$ and SZ signal $Y$ calibrated to X-ray measurements, we derive constraints on the power spectrum amplitude $\sigma_8$ and matter density parameter $\Omega_{\mathrm{m}}$ in a flat $\Lambda$CDM model. We test the robustness of our estimates and find that possible biases in the $Y$--$M$ relation and the halo mass function are larger than the statistical uncertainties from the cluster sample. Assuming the X-ray determined mass to be biased low relative to the true mass by between zero and 30%, motivated by comparison of the observed mass scaling relations to those from a set of numerical simulations, we find that $\sigma_8=0.75\pm 0.03$, $\Omega_{\mathrm{m}}=0.29\pm 0.02$, and $\sigma_8(\Omega_{\mathrm{m}}/0.27)^{0.3} = 0.764 \pm 0.025$. The value of $\sigma_8$ is degenerate with the mass bias; if the latter is fixed to a value of 20% we find $\sigma_8(\Omega_{\mathrm{m}}/0.27)^{0.3}=0.78\pm 0.01$ and a tighter one-dimensional range $\sigma_8=0.77\pm 0.02$. We find that the larger values of $\sigma_8$ and $\Omega_{\mathrm{m}}$ preferred by Planck's measurements of the primary CMB anisotropies can be accommodated by a mass bias of about 40%. Alternatively, consistency with the primary CMB constraints can be achieved by inclusion of processes that suppress power on small scales relative to the $\Lambda$CDM model, such as a component of massive neutrinos (abridged).Comment: 20 pages, accepted for publication by A&

Insights into the high-energy γ-ray emission of Markarian 501 from extensive multifrequency observations in the Fermi era

We report on the γ-ray activity of the blazar Mrk 501 during the first 480 days of Fermi operation. We find that the average Large Area Telescope (LAT) γ-ray spectrum of Mrk 501 can be well described by a single power-law function with a photon index of 1.78 ± 0.03. While we observe relatively mild flux variations with the Fermi-LAT (within less than a factor of two), we detect remarkable spectral variability where the hardest observed spectral index within the LAT energy range is 1.52 ± 0.14, and the softest one is 2.51 ± 0.20. These unexpected spectral changes do not correlate with the measured flux variations above 0.3 GeV. In this paper, we also present the first results from the 4.5 month long multifrequency campaign (2009 March 15-August 1) on Mrk 501, which included the Very Long Baseline Array (VLBA), Swift, RXTE, MAGIC, and VERITAS, the F-GAMMA, GASP-WEBT, and other collaborations and instruments which provided excellent temporal and energy coverage of the source throughout the entire campaign. The extensive radio to TeV data set from this campaign provides us with the most detailed spectral energy distribution yet collected for this source during its relatively low activity. The average spectral energy distribution of Mrk 501 is well described by the standard one-zone synchrotron self-Compton (SSC) model. In the framework of this model, we find that the dominant emission region is characterized by a size ≲0.1 pc (comparable within a factor of few to the size of the partially resolved VLBA core at 15-43 GHz), and that the total jet power (≃1044 erg s-1) constitutes only a small fraction (∼10-3) of the Eddington luminosity. The energy distribution of the freshly accelerated radiating electrons required to fit the time-averaged data has a broken power-law form in the energy range 0.3 GeV-10 TeV, with spectral indices 2.2 and 2.7 below and above the break energy of 20 GeV. We argue that such a form is consistent with a scenario in which the bulk of the energy dissipation within the dominant emission zone of Mrk 501 is due to relativistic, proton-mediated shocks. We find that the ultrarelativistic electrons and mildly relativistic protons within the blazar zone, if comparable in number, are in approximate energy equipartition, with their energy dominating the jet magnetic field energy by about two orders of magnitude. © 2011. The American Astronomical Society

Design Tools for Evaluating Alternative Strategies' Impact on Human Comfort

Many designers recognize that energy savings can be achieved with alternative or innovative strategies; however, few design tools have been available to assist designers with evaluating alternatives. This paper demonstrates the use of a standard psychrometric chart enhanced with an expanded comfort zone plot based on multiple energy conservation strategies. Average local weather conditions can be plotted by month on the psychrometric chart to indicate which design alternatives have the greatest potential benefits. By utilizing a familiar engineering design tool to communicate integrated design techniques, better coordination can be achieved between architects and engineers. Victor Olgyay pioneered similar work at Notre Dame in the 1950's; however, his unusual graphical presentation has hindered widespread understanding and use of the fundamentals of expanded comfort zones. This paper outlines the basic concept of the expanded comfort zone with applications for use of mean radiant temperatures, direct radiation. air movement and evaporative cooling with examples shown for Dallas and Houston climates

TEST OF MODELS OF THE COSMIC INFRARED BACKGROUND WITH MULTIWAVELENGTH OBSERVATIONS OF THE BLAZAR 1ES 1218+30.4 IN 2009

We present the results of a multi-wavelength campaign targeting the blazar 1ES 1218+30.4 with observations with the 1.3 m McGraw-Hill optical telescope, the Rossi X-ray Timing Explorer (RXTE), the Fermi Gamma-Ray Space Telescope, and the Very Energetic Radiation Imaging Telescope Array System (VERITAS). The RXTE and VERITAS observations were spread over a 13 day period and revealed clear evidence for flux variability, and a strong X-ray and gamma-ray flare on 2009 February 26 (MJD 54888). The campaign delivered a well-sampled broadband energy spectrum with simultaneous RXTE and VERITAS very high energy (VHE, > 100 GeV) observations, as well as contemporaneous optical and Fermi observations. The 1ES 1218+30.4 broadband energy spectrum-the first with simultaneous X-ray and VHE gamma-ray energy spectra-is of particular interest as the source is located at a high cosmological redshift for a VHE source (z = 0.182), leading to strong absorption of VHE gamma rays by photons from the optical/infrared extragalactic background light (EBL) via gamma VHE +gamma EBL -> e(+) e(-)pair-creation processes. We model the data with a one-zone synchrotron self-Compton (SSC) emission model and with the extragalactic absorption predicted by several recent EBL models. We find that the observations are consistent with the SSC scenario and all the EBL models considered in this work. We discuss observational and theoretical avenues to improve on the EBL constraints