An evaluation of the NASA Tech House, including live-in test results, volume 1

The NASA Tech House was designed and constructed at the NASA Langley Research Center, Hampton, Virginia, to demonstrate and evaluate new technology potentially applicable for conservation of energy and resources and for improvements in safety and security in a single-family residence. All technology items, including solar-energy systems and a waste-water-reuse system, were evaluated under actual living conditions for a 1 year period with a family of four living in the house in their normal lifestyle. Results are presented which show overall savings in energy and resources compared with requirements for a defined similar conventional house under the same conditions. General operational experience and performance data are also included for all the various items and systems of technology incorporated into the house design

Vegetation above a feral pig barrier fence in rain forests of Kilauea's East Rift, Hawaii Volcanoes National Park

Reports were scanned in black and white at a resolution of 600 dots per inch and were converted to text using Adobe Paper Capture Plug-in.Immediately after the 1993 construction of a barrier fence to block the movements of feral pigs in forests of Kilauea's East Rift within Hawaii Volcanoes National Park (HAVO), a systematic framework of transects and plots was established for collection of baseline vegetation data upslope of the fence. Distribution and estimated abundance of the most invasive alien plant species were determined. The most widespread alien grass species was Hilo grass (Paspalum conjugatum); although it typically had low estimated cover values, this grass was almost ubiquitous. The most common invasive alien tree species was strawberry guava (Psidium cattleianum); it was found along transects in the western half of the study area, where its cover was estimated as 5-25% or 25-50%. Firetree (Myrica faya) occurred less frequently and had lower cover values than strawberry guava. Two other invasive woody species were found at low frequency or in limited areas; yellow Himalayan raspberry (Rubus ellipticus) was restricted to the slopes of Kane Nui o Hamo, and cane tibouchina (Tibouchina herbacea) occurred infrequently at widely scattered localities. Alien plant frequencies from the current survey were compared with those from a previous plant survey in 1988. A third of the alien plant species along transects, including firetree, yellow raspberry, and strawberry guava, had very similar frequencies on both surveys. Frequency of Hilo grass and scaly swordfern (Nephrolepis multiflora) increased greatly in the study area between the two surveys. Some of the observed changes in vegetation may have been influenced by recent disturbance to the forests by cinder deposits from Pu'u '0'o, in an earlier phase of the current eruption. The locations of rare native plants were mapped along transects, and numbers were compared with those from the previous survey of 1988. The endangered pendent kihi fern (Adenophorus periens) was not relocated on Park transects; this species may have disappeared from the slopes of Kane Nui o Hamo in the last five years. Koli'i (Trematolobelia grandifolia), a "species of concern" has persisted on Kane Nui o Hamo, and its current size class structure indicates a stable population. The 12 rare plant species that were observed on East Rift transects were concentrated in several sites, including Kane Nui o Hamo, forests south and west of Napau crater, relatively open forest southeast of the 1840 flow, and the southwest corner of the study area near the Naulu Trail. Frequencies of 'oha (Clermontia spp.), indicator species for pig damage in Hawai'i, were relatively high overall in the study area, although the impact of pig predation was indicated by the paucity of terrestrial plants and a low freqeuncy of large Clermontia. Remonitoring a subset of transects after 1.5 years revealed that terrestrial Clermontia declined in frequency, while epiphytic plants increased over the same period. Tree fern density in the study area was 38/100m2, and the trunk height class of 1-2 m was well represented in East Rift forests. A higher density of tree ferns was observed in the western half of the study area, primarily due to the greater number of tree ferns >1m. There were fewer tree ferns on the lower halves of three main transects than were found on the upper reaches, farthest away from the barrier fence and upslope from uluhe-dominated forest. 'Olapa (Cheirodendron trigynum) appeared to be an inconsistent indicator species for pig activity. This important rain forest tree was maintaining a stable population in East Rift forests, despite the long-term presence of feral pigs there. Differences in 'olapa density were noted in the western versus the eastern, unprotected part of the study area, where lower numbers of terrestrial 'olapa saplings were seen. When compared with the upper transect reaches, fewer 'olapa saplings were found along the lower portions of the three main transects, in the area near the open end of the barrier fence. Vegetation cover and woody plant density of recently pig-disturbed sites were examined in 1994 using 39 vegetation plots, and a subset of 26 plots was remonitored 1.5-2 years later. The vegetation of disturbed East Rift forests was found to be poor in native woody plant species, and ground cover was very sparse. In the interval between monitoring, the cover of two alien species (Hilo grass and scaly swordfern) increased dramatically. Early succession indicates that these two plants will become dominant components of ground cover in pig-disturbed areas. Little change was noted in native woody plant density overall, but several native species, including tree ferns, displayed increases over the 1.5 year monitoring period. Feral pig density, estimated from frequency of pig activity, was low in the East Rift study area (averaging 1.9 pig/km2), even before systematic control efforts began. Quarterly pig activity monitoring revealed an increase in activity along Park transects until the end of 1993, followed by a steady decline to 2.4 pig/km2 by the end of the study in January 1996. Data from this study suggest that the park's snaring efforts reduced the feral pig population in the most protected, interior part of the forest upslope of the barrier fence within two years of the project initiation. Success in lowering pig density was not observed on transects at or beyond the open terminus of the barrier fence, indicating that pig ingress continued throughout the study. The current survey may only be considered a baseline study of vegetation and pig activity in managed East Rift forests. Future remonitoring may be needed to evaulate the success of this management effort in promoting long-term recovery of native vegetation.National Park Service Cooperative Agreement 8010 2 900

QED in external fields, a functional point of view

A functional partial differential equation is set for the proper graphs generating functional of QED in external electromagnetic fields. This equation leads to the evolution of the proper graphs with the external field amplitude and the external field gauge dependence of the complete fermion propagator and vertex is derived non-perturbativally.Comment: 8 pages, published versio

Population coding by globally coupled phase oscillators

A system of globally coupled phase oscillators subject to an external input is considered as a simple model of neural circuits coding external stimulus. The information coding efficiency of the system in its asynchronous state is quantified using Fisher information. The effect of coupling and noise on the information coding efficiency in the stationary state is analyzed. The relaxation process of the system after the presentation of an external input is also studied. It is found that the information coding efficiency exhibits a large transient increase before the system relaxes to the final stationary state.Comment: 7 pages, 9 figures, revised version, new figures added, to appear in JPSJ Vol 75, No.

Vacuum Bubble in an Inhomogeneous Cosmology

We study the propagation of bubbles of new vacuum in a radially inhomogeneous Lemaitre-Tolman-Bondi background that includes a cosmological constant. This exemplifies the classical evolution of a tunneling bubble through a metastable state with curvature inhomogeneities, and will be relevant in the context of the Landscape. We demand that the matter profile in the LTB background satisfy the weak energy condition. For sample profiles that satisfy this restriction, we find that the evolution of the bubble (in terms of the physically relevant coordinates intrinsic to the shell) is largely unaffected by the prsence of local inhomogeneities. Our setup should also be a useful toy model for capturing the effects of ambient inhomogeneities on an inflating region.Comment: 31 pages, 21(!) figures, v2: minor changes, figures re-sized (might require zoom on some systems), references adde

Historic Archeological Investigations at Roberts Cemetery Near Troy, Bell County, Texas

A preliminary archeological investigation was conducted in 2008 at Roberts Cemetery near Troy, Texas, as part of the Texas Department of Transportation’s planned expansion of Interstate Highway 35. Mechanical trenching discovered one unmarked grave near the highway right of way, and this led to an extensive mechanical search of the eastern edge of the cemetery in 2012. Following the removal of the southbound access road and thick layer of artificial fill, five additional unmarked graves were discovered. Of the six unmarked graves, two are located in the cemetery property and were left in place, but the four burials inside the highway right of way were exhumed. They were reinterred in a nearby plot in Roberts Cemetery. Analyses of the mortuary items and skeletal remains indicate that the three adult males and one child were interred between 1895 and the late 1930s. DNA analyses were used to try and match the four interred individuals with possible living relatives, but the results were negative or inconclusive. Archival research provided historical context for Roberts Cemetery and defined the sequence of road expansions that impacted the east side of the cemetery in the twentieth century

Lightcone reference for total gravitational energy

We give an explicit expression for gravitational energy, written solely in terms of physical spacetime geometry, which in suitable limits agrees with the total Arnowitt-Deser-Misner and Trautman-Bondi-Sachs energies for asymptotically flat spacetimes and with the Abbot-Deser energy for asymptotically anti-de Sitter spacetimes. Our expression is a boundary value of the standard gravitational Hamiltonian. Moreover, although it stands alone as such, we derive the expression by picking the zero-point of energy via a ``lightcone reference.''Comment: latex, 7 pages, no figures. Uses an amstex symbo

Two Boosted Black Holes in Asymptotically de Sitter Space-Time - Relation between Mass and Apparent Horizon Formation -

We study the apparent horizon for two boosted black holes in the asymptotically de Sitter space-time by solving the initial data on a space with punctures. We show that the apparent horizon enclosing both black holes is not formed if the conserved mass of the system (Abbott-Deser mass) is larger than a critical mass. The black hole with too large AD mass therefore cannot be formed in the asymptotically de Sitter space-time even though each black hole has any inward momentum. We also discuss the dynamical meaning of AD mass by examining the electric part of the Weyl tensor (the tidal force) for various initial data.Comment: 15 pages, accepted for publication in PR

Primordial Gravitational Waves From Open Inflation

We calculate the spectrum of gravitational waves generated during inflation in open $(\Omega _0<1)$ inflationary models. In such models an initial epoch of old inflation solves the horizon and flatness problems, and during this first epoch of inflation the quantum state of the graviton field rapidly approaches the Bunch-Davies vacuum. Then old inflation ends by the nucleation of a single bubble, inside of which there is a shortened epoch of slow-roll inflation giving $\Omega _0<1$ today. In this paper we re-express the Bunch-Davies vacuum for the graviton field in terms of the hyperbolic modes inside the bubble and propagate these modes forward in time into the present era. We derive the expression for the contribution from these gravity waves to the cosmic microwave background anisotropy including the effect of a finite energy difference across the bubble wall.Comment: 40 pages, TEX with phyzzx macro, 5 figure