Application of biological filters in water treatment systems

Silver chloride placed on or close to barrier kills bacteria as they arrive. Dead bacteria accumulate linearly, whereas previously, live bacteria accumulated exponentially. During continuous 30-day tests, no bacteriological contamination was found downstream of filters with silver chloride added

Potable water bactericide agent development

The results are summarized of the work performed for the development and evaluation of a bactericide agent/system concept capable of being used in the space shuttle potable water system. The concept selected for evaluation doses fuel cell water with silver ions before the water is stored and used, by passing this water through columns packed with silver chloride and silver bromide particles, respectively. Four simulated space shuttle potable water system tests, each of seven days duration, were performed to demonstrate that this concept is capable of delivering sterile water even though 3 + or - 1 x 10 to the 9th power Type IIIa or Pseudomonas aeruginosa bacteria, two types which have been found in the Apollo potable water system, are purposely injected into the system each day. This result, coupled with the fact that silver ions do not have to be periodically added to the stored water, indicates that this concept is superior to the chlorine and iodine techniques used on Apollo

The Interplanetary Network Supplement to the BeppoSAX Gamma-Ray Burst Catalogs

Between 1996 July and 2002 April, one or more spacecraft of the interplanetary network detected 787 cosmic gamma-ray bursts that were also detected by the Gamma-Ray Burst Monitor and/or Wide-Field X-Ray Camera experiments aboard the BeppoSAX spacecraft. During this period, the network consisted of up to six spacecraft, and using triangulation, the localizations of 475 bursts were obtained. We present the localization data for these events.Comment: 89 pages, 3 figures. Submitted to the Astrophysical Journal Supplement Serie

BIOTECHNOLOGY AND PEST RESISTANCE: AN ECONOMIC ASSESSMENT OF REFUGES

Transgenic crops offer farmers a new and effective pest control option. However, the wide spread adoption of these crops could lead to a resistant pest population. This paper demonstrates how a pest refuge can be used to maximise the value of farm income in a dynamic model with genetic foundations.Crop Production/Industries, Research and Development/Tech Change/Emerging Technologies,

Study for evaluation of incineration and microwave treatment of human fecal matter for spacecraft operation

Incineration and microwave treatment of human fecal matter to determine concentration ranges and identities of liquid, gaseous, and solid product

BT CORN AND INSECT RESISTANCE: AN ECONOMIC ASSESSMENT OF REFUGES

Genetically engineered crops offer farmers a new option for controlling pests. The high efficacy of these pesticidal crops, combined with the potential for widespread adoption, has raised concerns that pest resistance may prematurely diminish their value. In response to these concerns, the Environmental Protection Agency requires resistance management plans. Current resistance management plans rely on a high-dose refuge strategy. This analysis extends the current framework for evaluating high-dose refuge strategies to include a measure of agricultural productivity and conventional pesticide use. The economic tradeoff relative to agricultural productivity, conventional pesticide use, and pest resistance is assessed when Bt corn is planted to control the European corn borer.Crop Production/Industries,

BATSE Observations of Gamma-Ray Burst Tails

I discuss in this paper the phenomenon of post-burst emission in BATSE gamma-ray bursts at energies traditionally associated with prompt emission. By summing the background-subtracted signals from hundreds of bursts, I find that tails out to hundreds of seconds after the trigger may be a common feature of long events (duration greater than 2s), and perhaps of the shorter bursts at a lower and shorter-lived level. The tail component appears independent of both the duration (within the long GRB sample) and brightness of the prompt burst emission, and may be softer. Some individual bursts have visible tails at gamma-ray energies and the spectrum in at least a few cases is different from that of the prompt emission.Comment: 33 Pages from LaTex including 7 figures, with aastex. To appear in Astrophysical Journa

Variation in Resistance of Experienced and Naïve Seedlings of Jewelweed (Impatiens capensis) to Invasive Garlic Mustard (Alliaria petiolata)

Author Institution: Wilmington CollegeThe invasive species garlic mustard, Alliaria petiolata, has negative impacts on understory forest species in the Midwest. Plants that coexist with A. petiolata in the field may show resistance to its negative effects as a result of natural selection. In a growth room experiment, we investigated if naïve and experienced seedlings of impatiens capensis vary in their response to the presence of A. petiolata. Impatiens capensis individuals from areas without A. petiolata (i.e., naïve plants) and from nearby areas with A. petiolata (i.e., experienced plants) were collected from the field and were then grown with A. petiolata in pots for 16 weeks. We measured height, stem diameter, reproduction and biomass of I. capensis and biomass of A. petiolata. There was a significant (P < 0.05) negative correlation between biomass and height of naïve I. capensis and biomass of A. petiolata, while there was no significant correlation between these variables for experienced I. capensis. Our results indicate the potential for the evolution of resistance to the presence of A. petiolata in I. capensis and point toward the need for further studies

X-Ray Light Curves of Gamma-ray Bursts Detected with the All-Sky Monitor on RXTE

We present X-ray light curves (1.5-12 keV) for fifteen gamma-ray bursts (GRBs) detected by the All-Sky Monitor on the Rossi X-ray Timing Explorer. We compare these soft X-ray light curves with count rate histories obtained by the high-energy (>12 keV) experiments BATSE, Konus-Wind, the BeppoSAX Gamma-Ray Burst Monitor, and the burst monitor on Ulysses. We discuss these light curves within the context of a simple relativistic fireball and synchrotron shock paradigm, and we address the possibility of having observed the transition between a GRB and its afterglow. The light curves show diverse morphologies, with striking differences between energy bands. In several bursts, intervals of significant emission are evident in the ASM energy range with little or no corresponding emission apparent in the high-energy light curves. For example, the final peak of GRB 970815 as recorded by the ASM is only detected in the softest BATSE energy bands. We also study the duration of bursts as a function of energy. Simple, singly-peaked bursts seem consistent with the E^{-0.5} power law expected from an origin in synchrotron radiation, but durations of bursts that exhibit complex temporal structure are not consistent with this prediction. Bursts such as GRB 970828 that show many short spikes of emission at high energies last significantly longer at low energies than the synchrotron cooling law would predict.Comment: 15 pages with 20 figures and 2 tables. In emulateapj format. Accepted by ApJ

The distances of short-hard GRBs and the SGR connection

We present a search for nearby (D<100 Mpc) galaxies in the error boxes of six well-localized short-hard gamma-ray bursts (GRBs). None of the six error boxes reveals the presence of a plausible nearby host galaxy. This allows us to set lower limits on the distances and, hence, the isotropic-equivalent energy of these GRBs. Our lower limits are around $1 \times 10^{49}$ erg (at $2\sigma$ confidence level); as a consequence, some of the short-hard GRBs we examine would have been detected by BATSE out to distances greater than 1 Gpc and therefore constitute a bona fide cosmological population. Our search is partially motivated by the December 27, 2004 hypergiant flare from SGR 1806-20, and the intriguing possibility that short-hard GRBs are extragalactic events of a similar nature. Such events would be detectable with BATSE to a distance of \~50 Mpc, and their detection rate should be comparable to the actual BATSE detection rate of short-hard GRBs. The failure of our search, by contrast, suggests that such flares constitute less than 15% of the short-hard GRBs (<40% at 95% confidence). We discuss possible resolutions of this discrepancy.Comment: Enlarged sample of bursts; ApJ in pres