3,550 research outputs found
The Microstratigraphy of Two Peat Sequences from Northeastern Newfounland
Commonly, the ombrotrophic peats of Newfoundland have a well-defined banded appearance. Each band consists of a light-coloured lower section and a dark upper component. The bands are separated by abrupt recurrence surfaces. The regularity of the bands implies cyclicity. The physical, elemental, micro- and macro-stratigraphies of two banded profiles from the Wesleyville area were examined in an attempt to document the differences and to provide insight into cause. Ash content, fibre content, bulk density, water content and water retention were measured. The latter three showed consistent changes through each profile. There were no obvious patterns in the values for the biologically active elements that were measured (Mg, Cl, Ca, Na, Al, Mn and I), but the curves for Br, V, and U, biologically inert elements, showed systematic variations that appear to reflect variations in peat accumulation rate. The pollen, spore and macrofossil stratigraphies were generally complacent, although the representation of Sphagnum macrofossils and spores varied regularly as did pollen and spore concentrations. Each light-dark sequence appears to reflect a cycle of self-sustaining hydrologie changes involving changes in community composition, and in oxidation and accumulation rate, rather than climate. The cycles appear to be ca. 700 years in length, and are system-wide, but with variable lag times.Les tourbes ombrothrophes de Terre-Neuve présentent d'ordinaire des couches nettement définies. Chaque couche comporte une partie inférieure claire et une partie supérieure foncée. Les couches sont séparées par des surfaces de récurrence abruptes. La régularité des couches suppose l'existence d'un phénomène cyclique. Les micro et macrostratigraphies physique et celles des éléments de deux coupes de deux profils rubanés de la région de Wesleyville ont été étudiés en vue d'en observer les différences et de déterminer les causes de ces différences. Les teneurs en cendres et en fibres, le poids volumétrique, la teneur en eau et la rétention d'eau ont été mesurés. Les trois dernières propriétés ont montré des changements uniformes dans chacune des coupes. Aucune configuration évidente n'est ressortie des valeurs des éléments biologiquement actifs qui ont été mesurés (Mg, Cl, Ca, Na, Mn et I), mais les courbes de Br, V et U, biologiquement inertes, ont montré des variations systématiques qui semblaient refléter les variations du taux d'accumulation de la tourbe. Les stratigraphies du pollen, des spores et des macrofossiles étaient dans l'ensemble insensibles, bien que la représentation des macrofossiles et des spores de Sphagnum variait de façon régulière, tout comme les concentrations de pollen et de spores. Chacune des séquences claire-foncée semble correspondre à un cycle de changements hydrologiques autogénérateurs impliquant des modifications dans la composition de l'association végétale et dans les taux d'oxydation et d'accumulation, plutôt que dans le climat. Les cycles, qui s'étendent à l'ensemble du système, semblent durer environ 700 ans, mais avec des décalages variables.Im allgemeinen treten die ombrotrophen Torfe Neufundlands in gut erkennbaren Streifen auf. Jeder Streifen besteht aus einer leichtgefà rbten unteren Schicht und einem dunklen oberen Teil. Die Streifen werden durch plôtzlich zu Tage tretende Grenzhorizonte getrennt. Die RegelmâBigkeit der Streifen setzt Periodizità t voraus. Die Milkro- und Makrostratigraphie des physikalischen und elementaren Aufbaus zweier Streifenprofile aus der Gegend von Wesleyville wurden untersucht, um die Unterschiede aufzuzeichnen und um die Ursachen zu ergrùnden. Gehalt an Asche und Fasern, spezifische Dichte, Wassergehalt und Wasserzurùckhaltungsvermôgen wurden gemessen. Die drei letzteren wiesen konstante Wechsel in jedem Profil auf. Keine deutlichen Muster in den Werten der biologisch aktiven Elemente konnten gemessen werden (Mg, Cl, Ca, Na, Al, Mn und I), aber die kurven von Br, V und U, den biologisch inaktiven Elementen, zeigten systematische Variationen, welche die Variationen von Torfansammlungsraten wiederzuspiegeln schienen. Die Pollen-, Sporen- und makrofossilen Stratigraphien waren im allgemeinen unverà ndert, wenn auch das Vorkommen von Sphagnum-Makrofossilen und Sporen genauso wie Pollen- und Sporen- konzentrationen regelmâBige Verà nderungen aufwies. Jede helldunkel Sequenz scheint einen Zyklus sich selbsttragender hydrologischer Verâderungen wiederzuspiegeln, die viel mehr Verà nderungen in der pflanzlichen Zusammensetzung, der Oxydierung und der Akkumulationsrate zur Folge hatten als klimatische Verà nderungen. Die Perioden scheinen etwa 700 Jahre gedauert zu haben, betreffen das ganze System aber mit variablen Verzôgerungen
Between college and work in the Further Education and Training College sector
Students studying Civil Engineering (CE) at the Further Education and Training (FET) colleges spend periods of time in the classroom and workshop as well as in the workplace during experiential learning. The overall purpose of education and training in the college sector is generally understood as preparing students for employability, and difficulties in colleges performing this role are well known. In this article, these difficulties are examined in a novel way. The everyday perspectives of lecturers and supervisors about student learning in their college programmes and their work experience are translated into more theoretical language, using activity theory. A theoretical argument is made, which suggests that different sites of learning create different purposes, and that these different purposes derive from a distinction between knowledge and practice, which in turn has historical roots. The study concludes by suggesting that a new, common object of integrating theory and practice at all the sites would better link the college and workplace education and training systems, and tentatively suggests how this new object could be put into practice.Key words: activity theory; civil engineering; further education and training; theory and practic
The Effect of the LISA Response Function on Observations of Monochromatic Sources
The Laser Interferometer Space Antenna (LISA) is expected to provide the
largest observational sample of binary systems of faint sub-solar mass compact
objects, in particular white-dwarfs, whose radiation is monochromatic over most
of the LISA observational window. Current astrophysical estimates suggest that
the instrument will be able to resolve about 10000 such systems, with a large
fraction of them at frequencies above 3 mHz, where the wavelength of
gravitational waves becomes comparable to or shorter than the LISA arm-length.
This affects the structure of the so-called LISA transfer function which cannot
be treated as constant in this frequency range: it introduces characteristic
phase and amplitude modulations that depend on the source location in the sky
and the emission frequency. Here we investigate the effect of the LISA transfer
function on detection and parameter estimation for monochromatic sources. For
signal detection we show that filters constructed by approximating the transfer
function as a constant (long wavelength approximation) introduce a negligible
loss of signal-to-noise ratio -- the fitting factor always exceeds 0.97 -- for
f below 10mHz, therefore in a frequency range where one would actually expect
the approximation to fail. For parameter estimation, we conclude that in the
range 3mHz to 30mHz the errors associated with parameter measurements differ
from about 5% up to a factor of 10 (depending on the actual source parameters
and emission frequency) with respect to those computed using the long
wavelength approximation.Comment: replacement version with typos correcte
Social Identity and Psychosis: Associations and Psychological Mechanisms
Humans possess a basic need to belong and will join groups even when they provide no practical benefit. Paranoid symptoms imply a disruption of the processes involved in belonging and social trust. Past research suggests that joining social groups and incorporating those groups into one’s identity (social identification) promotes positive self-views and better physical and mental health. However, no research has investigated whether social identity is associated with paranoia, nor the mechanisms by which this effect may emerge. Here, we examined the relationship between social identity and mental health (paranoia, auditory verbal hallucinations [AVHs], and depression), and tested the mediating role of self-esteem. In study 1, we analyzed data collected from 4319 UK residents as part of the NIHR CLAHRC NWC Household Health Survey. Study 2 comprised data collected from 1167 students attending a large UK university. The studies provided convergent evidence that social identification reduces symptoms of paranoia and depression by furnishing people with self-esteem. There was no consistent effect of social identification on AVHs. People developing mental health assessments, treatments, and policies are encouraged to consider the notion that joining and identifying with social groups may reduce people’s risk of paranoia and depression
The way of the world
At the age of just 53, in 1856, the 5th Noyon Khutughtu, Danzanravjaa, lay dying at the monastery of Boyiniyin SĂĽme in southern Mongolia. His poetry, which had made him so popular among the ordinary people and so disliked by some of the clergy whom he blatantly mocked, now turned to a savage critique of the world
Anaerobic digestion of soft drink beverage waste and sewage sludge
© 2018 Soft drink beverage waste (BW) was evaluated as a potential substrate for anaerobic co-digestion with sewage sludge to increase biogas production. Results from this study show that the increase in biogas production is proportional to the increase in organic loading rate (OLR) rate due to BW addition. The OLR increase of 86 and 171% corresponding to 10 and 20% BW by volume in the feed resulted in 89 and 191% increase in biogas production, respectively. Under a stable condition, anaerobic co-digestion with BW did not lead to any significant impact on digestate quality (in terms of COD removal and biosolids odour) and biogas composition. The results suggest that existing nutrients in sewage sludge can support an increase in OLR by about 2 kg COD/m3/d from a carbon rich substrate such as soft drink BW without inhibition or excessive impact on subsequent handling of the digestate
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