11,995 research outputs found
Geometric variations of the Boltzmann entropy
We perform a calculation of the first and second order infinitesimal
variations, with respect to energy, of the Boltzmann entropy of constant energy
hypersurfaces of a system with a finite number of degrees of freedom. We
comment on the stability interpretation of the second variation in this
framework.Comment: 9 pages, no figure
Removal of steroid estrogens from municipal wastewater in a pilot scale expanded granular sludge blanket reactor and anaerobic membrane bioreactor
Anaerobic treatment of municipal wastewater offers the prospect of a new paradigm by reducing aeration costs and minimizing sludge production. It has been successfully applied in warm climates, but does not always achieve the desired outcomes in temperate climates at the biochemical oxygen demand (BOD) values of municipal crude wastewater. Recently the concept of fortification' has been proposed to increase organic strength and has been demonstrated at the laboratory and pilot scale treating municipal wastewater at temperatures of 10-17°C. The process treats a proportion of the flow anaerobically by combining it with primary sludge from the residual flow and then polishing it to a high effluent standard aerobically. Energy consumption is reduced as is sludge production. However, no new treatment process is viable if it only addresses the problems of traditional pollutants (suspended solids - SS, BOD, nitrogen - N and phosphorus - P); it must also treat hazardous substances. This study compared three potential municipal anaerobic treatment regimes, crude wastewater in an expanded granular sludge blanket (EGSB) reactor, fortified crude wastewater in an EGSB and crude wastewater in an anaerobic membrane bioreactor. The benefits of fortification were demonstrated for the removal of SS, BOD, N and P. These three systems were further challenged with the removal of steroid estrogens at environmental concentrations from natural indigenous sources. All three systems removed these compounds to a significant degree, confirming that estrogen removal is not restricted to highly aerobic autotrophs, or aerobic heterotrophs, but is also a faculty of anaerobic bacteria
Shell tile thermal protection system
A reusable, externally applied thermal protection system for use on aerospace vehicles subject to high thermal and mechanical stresses utilizes a shell tile structure which effectively separates its primary functions as an insulator and load absorber. The tile consists of structurally strong upper and lower metallic shells manufactured from materials meeting the thermal and structural requirements incident to tile placement on the spacecraft. A lightweight, high temperature package of insulation is utilized in the upper shell while a lightweight, low temperature insulation is utilized in the lower shell. Assembly of the tile which is facilitated by a self-locking mechanism, may occur subsequent to installation of the lower shell on the spacecraft structural skin
Crustal accretion near ridge-transform intersections : Kane fracture zone, mid-Atlantic ridge.
Once upon a Time: The \u3ci\u3eMorte D’Arthur\u3c/i\u3e’s Relationship to the Fairy Tale Canon
The tales of the legendary King Arthur have become a part of British literary history. They are stories of romance, chivalry, magic, and adventure; the development of the stories took place over centuries, beginning primarily with Geoffrey of Monmouth in 1136 and continuing on in the work of many other writers, including Sir Thomas Malory in 1469. Despite its classification as a chivalric romance, many elements of the Arthurian romance cycle that developed over its lifespan reflect common folklore or storytelling motifs that are still recogniz- able today in the form of literary fairy tales. These include the evil stepmother (The Fyrste and the Secunde Boke of Syr Trystrams de Lyones), the rags-to-riches story (The Tale of Sir Gareth of Orkeney), and the poison apple (The Tale of Sir Launcelot and Quene Gwenyvere). The following paper will explore the roots of each of these motifs in an attempt to uncover the relationship between Thomas Malory’s Morte D’Arthur and familiar literary fairy tales.
There is some dispute about whether or not the Ar- thurian romances have any foundation in the folk- lore genre in the same way that literary fairy tales do. However, the persistence of folkloric motifs is undeniable. It bears resemblance to the literary fairy tales that emerged across Europe later, and it is possible that the Morte D’Arthur has a part to play in the development of literary fairy tales. But is it an early literary fairy tale, predating even the work of the Neapolitan Giambattista Basile, a distant cousin to the folklore genre or a work unto itself, related only marginally to the folkloric tradition? The motifs examined in an effort to answer this question will be compared to their use in popular literary fairy tales of Perrault’s Cendrillon and the Grimms’ Sneewittchen, with some attention paid to these motifs in other familiar literary fairy tales
Comparison of Mycobacterium tuberculosis drug susceptibility using solid and liquid culture in Nigeria.
BACKGROUND: This study compares Mycobacterium tuberculosis culture isolation and drug sensitivity testing (DST) using solid (LJ) and liquid (BACTEC-MGIT-960) media in Nigeria. METHODS: This was a cross sectional survey of adults attending reference centres in Abuja, Ibadan and Nnewi with a new diagnosis of pulmonary tuberculosis (TB) or having failed the first-line TB treatment. Patients were requested to provide three sputum specimens for smear-microscopy and culture on LJ and BACTEC-MGIT-960. Positive cultures underwent DST for streptomycin, isoniazid, rifampicin and ethambutol. RESULTS: 527 specimens were cultured. 428 (81%) were positive with BACTEC-MGIT-960, 59 (11%) negative, 36 (7%) contaminated and 4 (1%) had non-tuberculosis mycobacteria (NTM). 411 (78%) LJ cultures were positive, 89 (17%) negative, 22 (4%) contaminated and 5 (1%) had NTM. The mean (SD) detection time was 11 (6) and 30 (11) days for BACTEC-MGIT-960 and LJ. DST patterns were compared in the 389 concordant positive BACTEC-MGIT-960 and LJ cultures. Rifampicin and isoniazid DST patterns were similar. Streptomycin resistance was detected more frequently with LJ than BACTEC-MGIT-960 and ethambutol resistance was detected more frequently with BACTEC-MGIT-960 than LJ, but differences were not statistically significant. MDR-TB was detected in 27 cases by LJ and 25 by BACTEC-MGIT-960 and using both methods detected 29 cases. CONCLUSIONS: There was a substantial degree of agreement between the two methods. However using the two in tandem increased the number of culture-positive patients and those with MDR-TB. The choice of culture method should depend on local availability, cost and test performance characteristics
Scholarly success of orthopaedic surgeons participating in the Clinician Scholar Career Development Program
High-resolution spectroscopy of V854 Cen in decline - Absorption and emission lines of C_2 molecules
High-resolution optical spectra of the R Coronae Borealis (RBC) star V854
Centauri in the early stages of a decline show, in addition to the features
reported for other RCBs in decline, narrow absorption lines from the C_2
Phillips system. The low rotational temperature, T_rot = 1150K, of the C_2
ground electronic state suggests the cold gas is associated with the developing
shroud of carbon dust. These absorption lines were not seen at a fainter
magnitude on the rise from minimum light nor at maximum light. This is the
first detection of cold gas around a RCB star.Comment: 5 pages, 5 figures, accepted for publication by Monthly Notices of
the Royal Society of Astronom
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