Boundary layer integral matrix procedure: Verification of models

The three turbulent models currently available in the JANNAF version of the Aerotherm Boundary Layer Integral Matrix Procedure (BLIMP-J) code were studied. The BLIMP-J program is the standard prediction method for boundary layer effects in liquid rocket engine thrust chambers. Experimental data from flow fields with large edge-to-wall temperature ratios are compared to the predictions of the three turbulence models contained in BLIMP-J. In addition, test conditions necessary to generate additional data on a flat plate or in a nozzle are given. It is concluded that the Cebeci-Smith turbulence model be the recommended model for the prediction of boundary layer effects in liquid rocket engines. In addition, the effects of homogeneous chemical reaction kinetics were examined for a hydrogen/oxygen system. Results show that for most flows, kinetics are probably only significant for stoichiometric mixture ratios

Calculation of three-dimensional compressible laminar and turbulent boundary flows. Three-dimensional compressible boundary layers of reacting gases over realistic configurations

A three-dimensional boundary-layer code was developed for particular application to realistic hypersonic aircraft. It is very general and can be applied to a wide variety of boundary-layer flows. Laminar, transitional, and fully turbulent flows of compressible, reacting gases are efficiently calculated by use of the code. A body-oriented orthogonal coordinate system is used for the calculation and the user has complete freedom in specifying the coordinate system within the restrictions that one coordinate must be normal to the surface and the three coordinates must be mutually orthogonal

In vivo biological activity of the components of haematoporphyrin derivative.

The in vivo biological activity of various fractions and components of haematoporphyrin derivative (HpD) have been determined by measuring the depth of necrosis of implanted tumours in mice exposed to light after the administration of standard doses of porphyrins dissolved in alkali. In this assay, haematoporphyrin, hydroxyethylvinyldeuteroporphyrin and protoporphyrin are inactive, but the mono- and di-acetates of haematoporphyrin (which are major components of HpD) and acetoxyethylvinyldeuteroporphyrin are active. However, the situation appears to be more complex than this. The normal method for preparing HpD for injection involves an alkali treatment which causes hydrolysis and elimination of the acetoxy functions, and the only recognized products (haematoporphyrin, hydroxyethylvinyldeuteroporphyrin and protoporphyrin) are inactive in the in vivo assay. It is concluded that the active component here is a porphyrin, possibly a dimer or oligomer, which is retained on the column during the normal separation by HPLC. This conclusion is supported by the observations that (i) the crude material obtained from the spent column is active without further alkali treatment, and (ii) activity develops over 30 min, when HpD or the mono- or diacetates of haematoporphyrin are treated with sodium bicarbonate in aqueous DMSO. The advantages of working with a pure substance (e.g. haematoporphyrin diacetate) rather than a mixture (HpD) are stressed

Short-term effectiveness of drain-blocking in suppressingenzymic peat decomposition and DOC export

It has become evident that there is a general problem of increasing colour in the water draining from areas of accumulated peat in upland Britain. It was agreed in early 2007 to set up a preliminary investigation into the causes of change in colour using methods based on characterising the breakdown and oxidation of peat. These make use of techniques to measure the activities of extracellular enzymes which catalyse the process of decomposition independently from the microbial population. The overall aim of this investigation was to investigate the effect of grip blocking on the enzymic decomposition of peat and the consequential production of colour. The main study area is located within Langdon Moor, part of the Raby Estate. Peat samples were collected at 5 m intervals along transects perpendicular to a natural gully and a blocked grip. At each 5 m interval peat samples were collected at 5 depths down to 85 cm depth. Peat samples were analysed in the laboratory for carbon-related enzyme activities, microbial activity, colour and phenolic concentration.There were clear differences between enzyme activities in surface peat when compared with peat from greater depth at both study sites. There were no significant differences in magnitude of enzyme activity levels in surface peat from either area. However, there were significant differences between the areas for a number of parameters including enzyme activities in peat collected from depths between 5 and 85cms. These results suggest that increased retention of water within Langdon moor, as a result of grip blocking has caused a significant impact on the amount of colour and phenolic compounds with increasing depth relative to the amounts in a naturally drained area. Furthermore, the relationship between water colour and the concentration of phenolic compounds has been altered in the area of the blocked grip. This indicates some difference, yet to be elucidated, in the processes producing the colour deriving from the two drainage states.There were also significant differences in amounts of colour and phenolic compounds, but not enzyme activities with increasing distance from the blocked grip in contrast to the naturally drained area where amounts were less variable. This again indicates a significant influence of altered drainage patterns on the amount and quality of the coloured compounds produced from the breakdown of peat.Further detailed research will be required to determine whether this phenomenon is site specific or widespread in peatlands, and to the cause and effect of changing enzyme activity, phenolics and colour in peatlands. This preliminary study has only focused on one site per management treatment and therefore, at this stage, the results must be considered to be preliminary and site specific to Langdon moor rather than applicable to peatlands in general.Despite the small size of the study, we have achieved a good indication that there are significant differences between the two sites with contrasting drainage histories that were chosen for study and that it is possible to determine the involvement of a number of soil enzymes in the breakdown processes. It should now be possible to produce a properly convincing dataset with enough replicate study sites included which could quantify spatial variation that will undoubtedly be there at this scale. Now that the methods have been implemented, the funding requirements are relatively modest so that a level similar to that originally provided by Peatscapes (£4k) would enable a design that could cover a substantive area of Langdon Moor in enough detail to clearly demonstrate the impact of impeded drainage on this managed area

How a turn to critical race theory can contribute to our understanding of 'race', racism and anti-racism in sport

As long as racism has been associated with sport there have been consistent, if not coordinated or coherent, struggles to confront its various forms. Critical race theory (CRT) is a framework established to challenge these racialized inequalities and racism in society and has some utility for anti-racism in sport. CRT's focus on social justice and transformation are two areas of convergence between critical race theorists and anti-racists. Of the many nuanced and pernicious forms of racism, one of the most obvious and commonly reported forms of racism in sport, racial abuse, has been described as a kind of dehumanizing process by Gardiner (2003), as those who are its target are simultaneously (re)constructed and objectified according to everyday myth and fantasy. However, this is one of the many forms of everyday racist experiences. Various forms of racism can be experienced in boardrooms, on television, in print, in the stands, on the sidelines and on the pitch. Many times racism is trivialized and put down as part of the game (Long et al., 2000), yet its impact is rarely the source of further exploration. This article will explore the conceptualization of 'race' and racism for a more effective anti-racism. Critical race theory will also be used to explore the ideas that underpin considerations of the severity of racist behaviour and the implications for anti-racism. © The Author(s) 2010

Cross-Presentation of a Spread-Defective MCMV Is Sufficient to Prime the Majority of Virus-Specific CD8+ T Cells

CD8+ T cells can be primed by peptides derived from endogenous proteins (direct presentation), or exogenously acquired protein (cross-presentation). However, the relative ability of these two pathways to prime CD8+ T cells during a viral infection remains controversial. Cytomegaloviruses (CMVs) can infect professional antigen presenting cells (APCs), including dendritic cells, thus providing peptides for direct presentation. However, the viral immune evasion genes profoundly impair recognition of infected cells by CD8+ T cells. Nevertheless, CMV infection elicits a very strong CD8+ T cell response, prompting its recent use as a vaccine vector. We have shown previously that deleting the immune evasion genes from murine cytomegalovirus (MCMV) that target class I MHC presentation, has no impact on the size or breadth of the CD8+ T cell response elicited by infection, suggesting that the majority of MCMV-specific CD8+ T cells in vivo are not directly primed by infected professional APCs. Here we use a novel spread-defective mutant of MCMV, lacking the essential glycoprotein gL, to show that cross-presentation alone can account for the majority of MCMV-specific CD8+ T cell responses to the virus. Our data support the conclusion that cross-presentation is the primary mode of antigen presentation by which CD8+ T cells are primed during MCMV infection