Dichromatic polynomials and Potts models summed over rooted maps

We consider the sum of dichromatic polynomials over non-separable rooted planar maps, an interesting special case of which is the enumeration of such maps. We present some known results and derive new ones. The general problem is equivalent to the $q$-state Potts model randomized over such maps. Like the regular ferromagnetic lattice models, it has a first-order transition when $q$ is greater than a critical value $q_c$, but $q_c$ is much larger - about 72 instead of 4.Comment: 29 pages, three figures changes in App D, introduction and acknowledgement

Connecting Numerical Relativity and Data Analysis of Gravitational Wave Detectors

Gravitational waves deliver information in exquisite detail about astrophysical phenomena, among them the collision of two black holes, a system completely invisible to the eyes of electromagnetic telescopes. Models that predict gravitational wave signals from likely sources are crucial for the success of this endeavor. Modeling binary black hole sources of gravitational radiation requires solving the Eintein equations of General Relativity using powerful computer hardware and sophisticated numerical algorithms. This proceeding presents where we are in understanding ground-based gravitational waves resulting from the merger of black holes and the implications of these sources for the advent of gravitational-wave astronomy.Comment: Appeared in the Proceedings of 2014 Sant Cugat Forum on Astrophysics. Astrophysics and Space Science Proceedings, ed. C.Sopuerta (Berlin: Springer-Verlag

Membrane System for Recovery of Volatile Organic Compounds from Remediation Off-Gases.: Phase 1.

In situ vacuum extraction, air or steam sparging, and vitrification are widely used methods of remediating soil contaminated with volatile organic compounds (VOCs). All of these processes produce a VOC-laden air stream from which the VOC must be removed before the air can be discharged or recycled to the generating process. Treatment of these off-gases is often a major portion of the cost of the remediation project. Carbon adsorption and catalytic incineration, the most common methods of treating these gas streams, suffer from significant drawbacks. This report covers the first phase of a two-phase project. The first phase involved the laboratory demonstration of the water separation section of the unit, the production and demonstration of new membrane modules to improve the separation, the design studies required for the demonstration system, and initial contacts with potential field sites. In the second phase, the demonstration system will be built and, after a short laboratory evaluation, will be tested at two field sites

Area Invariance of Apparent Horizons under Arbitrary Boosts

It is a well known analytic result in general relativity that the 2-dimensional area of the apparent horizon of a black hole remains invariant regardless of the motion of the observer, and in fact is independent of the $t=constant$ slice, which can be quite arbitrary in general relativity. Nonetheless the explicit computation of horizon area is often substantially more difficult in some frames (complicated by the coordinate form of the metric), than in other frames. Here we give an explicit demonstration for very restricted metric forms of (Schwarzschild and Kerr) vacuum black holes. In the Kerr-Schild coordinate expression for these spacetimes they have an explicit Lorentz-invariant form. We consider {\it boosted} versions with the black hole moving through the coordinate system. Since these are stationary black hole spacetimes, the apparent horizons are two dimensional cross sections of their event horizons, so we compute the areas of apparent horizons in the boosted space with (boosted) $t = constant$, and obtain the same result as in the unboosted case. Note that while the invariance of area is generic, we deal only with black holes in the Kerr-Schild form, and consider only one particularly simple change of slicing which amounts to a boost. Even with these restrictions we find that the results illuminate the physics of the horizon as a null surface and provide a useful pedagogical tool. As far as we can determine, this is the first explicit calculation of this type demonstrating the area invariance of horizons. Further, these calculations are directly relevant to transformations that arise in computational representation of moving black holes. We present an application of this result to initial data for boosted black holes.Comment: 19 pages, 3 figures. Added a new section and 2 plots along with a coautho

LABORATORY INVESTIGATIONS IN SUPPORT OF FLUID BED FLUORIDE VOLATILITY PROCESSES. PART IV. THE FLUID BED FLUORINATION OF Usub3sub 3Osub8sub 8

In one of the processes under development, the uranium and plutonium content of a spent reactor fuel of the Dresden type would be fluorinated in a fluid-bed reactor to produce the volatile uranium and plutonium hexafluorides. The study of the fluorination of U/sub 3/O/sub 8/ was undertaken because it is the major product obtained in an oxidative decladding step that is being proposed for the removal of uranium and plutonium from stainless steel-clad and Zircaloy- clad fuel elements. The study Will also provide data needed for the development of apparatus and procedures for future work with mixtures of uranosic oxide and plutoniam dioxide. Experiments were performed to determine the optimum reaction conditions for the conversion of U/sub 3/O/sub 8/ to uranium hexafluoride and for minimizing the elutriation of unreacted U/sub 3/O/sub 8/ from the fluid bed. Elutriation of U/sub 3/O/sub 8/ from the fluid bed was minimized when a fluid bed height of 8 in. of 120 mesh alumina, a fluorinating gas phase containing 20 vol% fluorine, and a reaction temperature of 500 deg C were employed. Conversion of greater than 99% of the U/sub 3/O/sub 8/ to uranium hexafluoride was obtained when the feeding-fluorination period, in w,hich the U/sub 3/O/sub 8/ powder was fed into the fluid bed and the major part of the fluorination was accomplished by reacting the oxide with 20 vol % fluorine, was followed by a recycle-fluorination period of 5 hr at 500 deg C with 100% fluorine. Kinetic data for the fluorination of U/sub 3/O/sub 8/, obtained by means of a thermobalance, are reported for the temperature range from 300 to 400 deg C. The data were treated by the diminishing-sphere model. Experimental results are also presented for the oxidative decladding of stainless steelclad and Zircaloy-clad uranium dioxide pellets. (auth

Pediatric patients with multi-organ dysfunction syndrome receiving continuous renal replacement therapy

Pediatric patients with multi-organ dysfunction syndrome receiving continuous renal replacement therapy.BackgroundCritical illness leading to multi-organ dysfunction syndrome (MODS) and associated acute renal failure (ARF) is less common in children compared to adult patients. As a result, many issues plague the pediatric ARF outcome literature, including a relative lack of prospective study, a lack of modality stratification in subject populations and inconsistent controls for patient illness severity in outcome analysis.MethodsWe now report data from the first multicenter study to assess the outcome of pediatric patients with MODS receiving continuous renal replacement therapy (CRRT). One hundred twenty of 157 Registry patients (63 male/57 female) experienced MODS during their course.ResultsOne hundred sixteen patients had complete data available for analysis. The most common causes leading to CRRT were sepsis (N = 47; 39.2%) and cardiogenic shock (N = 24; 20%). Overall survival was 51.7%. Pediatric Risk of Mortality (PRISM 2) score, central venous pressure (CVP), and% fluid overload (%FO) at CRRT initiation were significantly lower for survivors versus nonsurvivors. Multivariate analysis controlling for severity of illness using PRISM 2 at CRRT initiation revealed that%FO was still significantly lower for survivors versus nonsurvivors (P < 0.05) even for patients receiving both mechanical ventilation and vasoactive pressors. We speculate that increased fluid administration from PICU admission to CRRT initiation is an independent risk factor for mortality in pediatric patients with MODS receiving CRRT.ConclusionWe suggest that after initial resuscitative efforts, an increased emphasis should be placed on early initiation of CRRT and inotropic agent use over fluid administration to maintain acceptable blood pressure

Population overlap and habitat segregation in wintering Black-tailed Godwits Limosa limosa

Distinct breeding populations of migratory species may overlap both spatially and temporally, but differ in patterns of habitat use. This has important implications for population monitoring and conservation. To quantify the extent to which two distinct breeding populations of a migratory shorebird, the Black-tailed Godwit Limosa limosa, overlap spatially, temporally and in their use of different habitats during winter. We use mid-winter counts between 1990 and 2001 to identify the most important sites in Iberia for Black-tailed Godwits. Monthly surveys of estuarine mudflats and rice-fields at one major site, the Tejo estuary in Portugal in 2005-2007, together with detailed tracking of colour-ringed individuals, are used to explore patterns of habitat use and segregation of the Icelandic subspecies L. l. islandica and the nominate continental subspecies L. l. limosa. In the period 1990-2001, over 66 000 Black-tailed Godwits were counted on average in Iberia during mid-winter (January), of which 80% occurred at just four sites: Tejo and Sado lower basins in Portugal, and Coto Dontildeana and Ebro Delta in Spain. Icelandic Black-tailed Godwits are present throughout the winter and forage primarily in estuarine habitats. Continental Black-tailed Godwits are present from December to March and primarily use rice-fields. Iberia supports about 30% of the Icelandic population in winter and most of the continental population during spring passage. While the Icelandic population is currently increasing, the continental population is declining rapidly. Although the estuarine habitats used by Icelandic godwits are largely protected as Natura 2000 sites, the habitat segregation means that conservation actions for the decreasing numbers of continental godwits should focus on protection of rice-fields and re-establishment of freshwater wetlands

Data Analysis Challenges for the Einstein Telescope

The Einstein Telescope is a proposed third generation gravitational wave detector that will operate in the region of 1 Hz to a few kHz. As well as the inspiral of compact binaries composed of neutron stars or black holes, the lower frequency cut-off of the detector will open the window to a number of new sources. These will include the end stage of inspirals, plus merger and ringdown of intermediate mass black holes, where the masses of the component bodies are on the order of a few hundred solar masses. There is also the possibility of observing intermediate mass ratio inspirals, where a stellar mass compact object inspirals into a black hole which is a few hundred to a few thousand times more massive. In this article, we investigate some of the data analysis challenges for the Einstein Telescope such as the effects of increased source number, the need for more accurate waveform models and the some of the computational issues that a data analysis strategy might face.Comment: 18 pages, Invited review for Einstein Telescope special edition of GR