2,785 research outputs found
Marriage record of Benbow, Alfred and Edwards, Mary
No full textMarriage license for Alfred Benbow and Mary Edwards. R.D. Lewis was the officiant
Solution of the problem of composite charge using R.D.38
No full textIn this paper the author has solved the problem of internal ballistics of composite charge using 'R.D.38' method which is based upon the usual isothermal approximation. A linear law of burning has been assumed
Author index
No full textThe articles have been scanned in colour with a HP Scanjet 5590; 300dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.This is a continuation of the "Author and Subject Index to the Onderstepoort Journal
of Veterinary Science and Animal Industry (1933- l950)" and the "Onderstepoort Journal
of Veterinary Research (1951 - 1968)" which appeared in June 1969 and covers the period
1969 to 1973, i.e. Volumes 36 to 40.
As from 1974 (Volume 41) it is intended to furnish an Author and Subject Index
in Number 4 of each volume covering all four numbers for that particular year
Noise due to unsteady flow past trailing edges
No full textThis paper presents two-dimensional direct numerical simulations (DNS) of noise generated at trailing edges (TE) with zero thickness. The simulations are conducted specifying either no-slip or slip walls in order to investigate viscous effects. In both cases, small amplitude disturbances are introduced close to the inflow boundary that serve as pressure disturbances at the TE. DNS data reveals that the unsteady Kutta condition is not satisfied, irrespective of the wall boundary condition. However, it appears that the validity of the unsteady Kutta condition is not essential for making an accurate prediction of the far field noise. The far field pressure is predicted as a function of the surface pressure difference using a 2-D modification of Amiet's classical theory, and compared with the far field pressure computed directly. Directivity plots provide evidence that the presence of boundary layers and noise generated by an unsteady wake in the no-slip cases lead to smearing of individual lobes, and that the downstream pointing lobes in no-slip wall cases are probably due to nonlinear noise generation in the wake. The simulations are conducted using a high-order accurate numerical method which is free of upwinding, artificial dissipation or any form of explicit filtering, and employs a novel boundary treatment
Characteristic distribution and scale interaction of turbulence in a boundary layer
No full textThis work revisits the concept of turbulent boundary layers from a novel perspective on scale transfer. Turbulence production and dissipation together with the energy budgets are analyzed in the velocity gradient invariant phase space. In combination with filtering, the mechanism of scale coupling is investigated and illustrated for different characteristic flow topologies. The understanding of the scale coupling is important to model turbulence. Turbulence models describe the complex interaction of the scales of motion in a simplified form. The essential task of turbulence modeling is to capture the coupling of the modeled and unmodeled scales as well as the evolution of the modeled scales within the unmodeled flow. This work characterizes the scale coupling by focusing on the interfaces between modeled and unmodeled flow such as production and dissipation. The mechanisms that govern the evolution of the modeled quantities are investigated for their core properties and universal features. Direct numerical simulation (DNS) is carried out to obtain data of a compressible zero pressure-gradient flat plate turbulent boundary layer flow. This flow topology allows to unveil the effect of a wall on the coupling of scales and evolution of turbulence
Spatial variability of diploptene δ<sup>13</sup>C values in thermokarst lakes: the potential to analyse the complexity of lacustrine methane cycling
No full textCryospheric changes in northern high latitudes are linked to significant greenhouse gas flux to the atmosphere, including methane release that originates from organic matter decomposition in thermokarst lakes. The connections between methane production in sediments, transport pathways and oxidation are not well understood and this has implications for any attempts to reconstruct methane production from sedimentary archives. We assessed methane oxidation as represented by methane oxidising bacteria across the surface sediments of two interior Alaska thermokarst lakes in relation to methane emissions via ebullition (bubbling). The bacterial biomarker diploptene was present and had low ?13C values (lower than ?38 ‰) in all sediments analysed, suggesting methane oxidation was widespread. The most ?13C-depleted diploptene was found in the area of highest methane ebullition emissions in Ace Lake (?13C diplotene values between ?68.2 and ?50.1 ‰), suggesting a positive link between methane production, oxidation, and emission in this area. In contrast, significantly less depleted diploptene ?13C values (between ?42.9 and ?38.8 ‰) were found in the area of highest methane ebullition emissions in Smith Lake. Lower ?13C values of diploptene were found in the central area of Smith Lake (between ?56.8 and ?46.9 ‰), where methane ebullition rates are low but methane diffusion appears high. Using ?13C-diplotene as a proxy for methane oxidation activity, we suggest the observed differences in methane oxidation levels among sites within the two lakes could be linked to differences in source area of methane production (e.g. age and type of organic carbon) and bathymetry as it relates to varying oxycline depths and changing pressure gradients. As a result, methane oxidation is highly lake-dependent. The diploptene ?13C values also highlight strong within-lake variability, implying that single-value, down-core records of hopanoid isotopic signatures are not secure indicators of changing methane flux at the whole-lake scale
Learning from One's Mistakes
No full textCreated by R.D. Lee for the Royal Statistics Society, this article describes an exercise, which highlights the effect of sampling without replacement in small populations, and leads to consideration of the relative importance of sample and population size when examining standard error. The author provides a number of exercises, an explanation of statistical errors and the importance of sample size. This is a brief, yet fine resource for those in the field of statistics
Mad to be Normal: Thoughts on Psychiatrist R.D Laing and Connections to Liberation Psychology
No full textThis article uses the film Mad to be Normal, about R.D. Laing, as an opening into the liberation psychology approaches of Martin-Baro. Examples from the author\u27s own clinical practice as well as personal experiences from life in a Catholic Worker community are included
R.D. Laing's language of experience
No full textThe radical psychiatrist R.D. Laing (1927-1989) was an accomplished author with an extensive philosophical knowledge that informed his ideas on reading, writing, and interpretation. Laing argues that psychiatry should be modeled on skilful textual exegesis rather than scientific explanation. The exegesis of a psychotic’s words and actions is difficult, he infers, because the impoverishment of our experience cuts us off from the sense that lies within seeming madness. Like philosophers such as Edmund Husserl, Laing therefore criticizes the way in which the natural sciences have invalidated subjective experience. He consequently employs a rhetoric designed to disclose with renewed vigor its complexity, variety and reality. Laing fails, however, to find an alternative to scientific reason: "experience", in his weakest work, is an irrational realm of mystical and self-validating certainty that closely parallels Heidegger’s later accounts of "Being"
A probabilistic calibration of climate sensitivity and terrestrial carbon change in GENIE-1
No full textIn order to investigate Last Glacial Maximum and future climate, we “precalibrate” the intermediate complexity model GENIE-1 by applying a rejection sampling approach to deterministic emulations of the model. We develop ~1,000 parameter sets which reproduce the main features of modern climate, but not precise observations. This allows a wide range of large-scale feedback response strengths which generally encompass the range of GCM behaviour. We build a deterministic emulator of climate sensitivity and quantify the contributions of atmospheric (±0.93°C, 1?) vegetation (±0.32°C), ocean (±0.24°C) and sea–ice (±0.14°C) parameterisations to the total uncertainty. We then perform an LGM-constrained Bayesian calibration, incorporating data-driven priors and formally accounting for structural error. We estimate climate sensitivity as likely (66% confidence) to lie in the range 2.6–4.4°C, with a peak probability at 3.6°C. We estimate LGM cooling likely to lie in the range 5.3–7.5°C, with a peak probability at 6.2°C. In addition to estimates of global temperature change, we apply our ensembles to derive LGM and 2xCO2 probability distributions for land carbon storage, Atlantic overturning and sea–ice coverage. Notably, under 2xCO2 we calculate a probability of 37% that equilibrium terrestrial carbon storage is reduced from modern values, so the land sink has become a net source of atmospheric CO2
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