Stellar Orbits and the Interstellar Gas Temperature in Elliptical Galaxies

We draw attention to the close relationship between the anisotropy parameter beta(r) for stellar orbits in elliptical galaxies and the temperature profile T(r) of the hot interstellar gas. For nearly spherical galaxies the gas density can be accurately determined from X-ray observations and the stellar luminosity density can be accurately found from the optical surface brightness. The Jeans equation and hydrostatic equilibrium establish a connection between beta(r) and T(r) that must be consistent with the observed stellar velocity dispersion. Purely optical observations of the bright elliptical galaxy NGC 4472 indicate beta(r) < 0.35 within the effective radius. However, the X-ray gas temperature profile T(r) for NGC 4472 requires significantly larger anisotropy, beta = 0.6 - 0.7, about twice the optical value. This strong preference for radial stellar orbits must be understood in terms of the formation history of massive elliptical galaxies. Conversely, if the smaller, optically determined anisotropy is indeed correct, we are led to the important conclusion that the temperature profile T(r) of the hot interstellar gas in NGC 4472 must differ from that indicated by X-ray observations, or that the hot gas is not in hydrostatic equilibrium.Comment: 6 pages (emulateapj5) with 4 figures; accepted by The Astrophysical Journa

Educational Operations Four Days a Week

Four day work weeks have been employed by industry, state agencies, and recently by higher education. The generally perceived benefit of the four day work week is reduced energy costs. These costs savings include more efficient building operations and less energy consumption driving to a facility. The generally perceived negative impact of four day operations, particularly of state agencies, is a decreased level of service. How much energy would be saved and could the level of service be maintained in a higher educational environment by switching from five to four day weeks? This study occurs at a regional university within an Industrial and Engineering Technology department that has exclusive use of a building. The department contains seven degree programs ranging from TAC-ABET programs to non-accredited technical degree programs. During the study period all classes and laboratories were scheduled Monday through Thursday. Staff only worked Monday through Thursday. Faculty but not students could gain access to the building on Fridays. The objective of this paper is to study the costs, benefits, and educational impacts of changing the five day academic and building availability week to four days a week. The paper will present the costs savings and the results of a survey of stakeholders collected during one academic quarter. The results of the energy costs are presented in tabular form and the results of the survey are presented in graphical form. The data and conclusions are expected to help decision makers make informed decisions when contemplating an alternative work schedule for higher education

Life and efficiency of incandescent lamps

Citation: Bender, Louis Blaine and Davis, William DeOzro. Life and efficiency of incandescent lamps. Senior thesis, Kansas State Agricultural College, 1904.Morse Department of Special CollectionsIntroduction: The intelligent selection and proper use of incandescent lamps largely determine the volume and growth of the electric lighting industry. Nothing produces such radical improvement in the lighting service as, first, the exclusive use of the best lamps and, second, the frequent and regular renewal of dim lamps. These principles are the precepts and practice of the leading central stations of the country, and should be law for every electric lighting company. Central stations are in the business of making and selling light. They may sell by the Watt hour or by contract, but, regardless of the way it is measured, the customer is in reality buying and using light. Since the lamp transforms the electrical energy of the generators into light, the best lamp is an absolute necessity to obtain the best light. It is, then, almost a self-evident truth that the exclusive use of the best lamps is the only means of obtaining the best results

Advanced Estimation of Coastal Storm Surge: Application of Swan+Adcirc in Northeast Florida/Georgia Storm Surge

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

Automated Mesh Development Tools for Central Florida Storm Surge Study

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

Interpreting the seasonal cycles of atmospheric oxygen and carbon dioxide concentrations at American Samoa Observatory

We present seven years of atmospheric O2/N2 ratio and CO2 concentration data measured from flask samples collected at American Samoa. These data are unusual, exhibiting higher short-term variability, and seasonal cycles not in phase with other sampling stations. The unique nature of atmospheric data from Samoa has been noted previously from measurements of CO2, methyl chloroform, and ozone. With our O2 data, we observe greater magnitude in the short-term variability, but, in contrast, no clear seasonal pattern to this variability. This we attribute to significant regional sources and sinks existing for O2 in both hemispheres, and a dependence on both the latitudinal and altitudinal origins of air masses. We also hypothesize that some samples exhibit a component of "older" air, demonstrating recirculation of air within the tropics. Our findings could be used to help constrain atmospheric transport models which are not well characterized in tropical regions

Lawrence Head Volcanics and Dunnage Mélange, Newfoundland Appalachians: Origin by Ordovician Ridge Subduction or in Back-Arc Rift?

This paper reviews the geological setting and reports new geochemical trace element data from the Ordovician Lawrence Head Volcanics (LHV) and the underlying gabbro sills in the Exploits Group. In combination with existing published analyses and ages of these rocks, the volcanic rocks and sills are indistinguishable in composition and age, and the data are consistent with the hypothesis that they represent the same (mostly E-MORB composition) magmatic event in the early–mid Darriwilian (~465 ± 2 Ma). The LHV and their enclosing strata show regional evidence for: 1) upward decline of volume and grain size of arc-derived volcaniclastic materials over the uppermost interval of turbidite sedimentary strata below the LHV; 2) change to shallow marine conditions locally by the end of the LHV event, followed immediately by significant subsidence, and 3) no evidence of coarse-grained clastic input, nor of normal faulting, during or immediately after LHV magmatism. Ridge–trench interaction (ridge subduction) at a subduction system is consistent with all of these features and spatial distribution of related elements, but a rift (back-arc) origin over a subduction zone can only accommodate the compositions, and is inconsistent with the geological evidence. The Dunnage Mélange (DM) has been interpreted either as olistostromal in a developing back-arc rift basin, or as a subduction accretionary prism. Peraluminous intrusions in the mélange (Coaker Porphyry ― CP) are more readily explained by ridge subduction, and a previously reported zircon age (469 ± 4 Ma) is consistent with the age of the LHV and gabbro sills, also interpreted as products of ridge subduction. Localization of the CP in the eastern area of DM, and of most of the large LHV-derived volcanic blocks in the western DM, suggests a slightly younger age, and perhaps a different mechanism, for the origin of the western DM.SOMMAIRECet article passe en revue le contexte géologique et présente de nouvelles données géochimiques d’éléments traces des roches volcaniques ordoviciennes de Lawrence Head (LHV) et des filons-couches de gabbro sous-jacents du Groupe Exploits.  Considérant la combinaison des données d’analyse publiées et des datations de ces roches, les roches volcaniques et les filons-couches sont indiscernables tant en composition qu’en âge, et les données sont compatibles avec l’hypothèse selon laquelle ils représentent le même événement magmatique (principalement E-MORB) du Darriwilien précoce à moyen (~465 ± 2 Ma).  Les LHV ainsi que les strates de l’encaissant renferment des indices régionaux qui montrent : 1) que le volume et la granulométrie des matériaux volcanoclastiques d’arc diminuent vers le haut dans l’intervalle supérieur des strates de turbidites sédimentaires sous les LHV; 2) que le changement vers des milieux marins peu profonds localement vers la fin de l’événement des LHV a été suivi immédiatement par une subsidence importante, et 3) qu’il n’existe pas d’indices d’apports clastiques à gros grains, non plus que de formation de failles normales, durant ou immédiatement après le magmatisme des LHV.  L’interaction crête-fosse (subduction de la crête) au lieu d’un système de subduction concorde avec toutes ces caractéristiques et la répartition spatiale des éléments reliés, alors qu’une origine de crête (arrière-arc) au-dessus d’une zone de subduction ne peut expliquer que les compositions et qu’elle est incompatible avec l’évidence géologique.  Le Dunnage Mélange (DM) a été interprété soit comme un olistostome dans un bassin d’arrière-arc en développement, ou comme un prisme d’accrétion de subduction.  Les intrusions hyperalumineuses dans le mélange (Porphyre Coaker — CP), s’explique plus facilement par une subduction de crête, et un âge de datation sur zircon de (469 ± 4 Ma) correspond à l’âge des LHV et des filons-couche de gabbro, aussi interprétés comme produits d’une subduction de crête.  La localisation du CP dans la portion orientale du DM, et de la majeure partie des grands blocs volcaniques dérivés des LHV de la portion ouest du DM, suggère un âge légèrement plus jeune, et peut-être un mécanisme différent, pour l’origine de la portion ouest du DM

Incremental Edge Orientation in Forests

For any forest G = (V, E) it is possible to orient the edges E so that no vertex in V has out-degree greater than 1. This paper considers the incremental edge-orientation problem, in which the edges E arrive over time and the algorithm must maintain a low-out-degree edge orientation at all times. We give an algorithm that maintains a maximum out-degree of 3 while flipping at most O(log log n) edge orientations per edge insertion, with high probability in n. The algorithm requires worst-case time O(log n log log n) per insertion, and takes amortized time O(1). The previous state of the art required up to O(log n / log log n) edge flips per insertion. We then apply our edge-orientation results to the problem of dynamic Cuckoo hashing. The problem of designing simple families ? of hash functions that are compatible with Cuckoo hashing has received extensive attention. These families ? are known to satisfy static guarantees, but do not come typically with dynamic guarantees for the running time of inserts and deletes. We show how to transform static guarantees (for 1-associativity) into near-state-of-the-art dynamic guarantees (for O(1)-associativity) in a black-box fashion. Rather than relying on the family ? to supply randomness, as in past work, we instead rely on randomness within our table-maintenance algorithm