1,435 research outputs found

    Boundary layer integral matrix procedure: Verification of models

    Get PDF
    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

    Exploring the Relationship between Ego Development and Mental Health

    Get PDF
    The goal of this study was to examine the relationship between ego identity in adults (ego development), symptoms of psychological distress, and self-esteem. Ego identity was operationalized using Loevinger’s (1976) stage theory of ego development, further modified by Cook-Greuter (1994; 2010). The test used to measure ego development was the Sentence Completion Test Integral (SCTi). Symptoms of mental disorders or psychological distress were measured using Derogatis’ (1994) Symptom Checklist 90 Revised (SCL-90-Revised). Self-esteem was measured using the Rosenberg Self Esteem Scale (RSES). It has been thought there would be noticeable differences in the relationship between ego development and the types of psychological symptoms or between ego development and self-esteem but no studies have been done to explore this (Cook-Greuter, personal communication, 2016). In summary, my hypotheses were that graduate students would have later ego development than the norms for the general population, that participants at conventional stages of ego development would report different psychological symptoms than participants at later stages of ego development, that participants in this sample who score at post-conventional levels of ego development would report more depression while those at conventional levels of ego development would endorse more anxiety, and that participants at post-conventional stage of ego development would report higher self-esteem than those at conventional levels of ego development.In this study, ego development functioned as a non-metric (ordinal) variable studied in comparison to two ratio variables (psychological symptoms endorsed and self-esteem). The SCTi tests were scored by professional raters certified by Cook-Greuter and Associates. The SCL-90-R and Rosenberg self-esteem scale were scored by the researcher and the dissertation director. Analysis of variance of all study variables was run by ego development level. Also, a process called data imputation was conducted to see if the trend-level results of the analysis would have been stronger with a larger sample. Though it was not one of my hypotheses, subjects at so-called “transitional” ego stages reported a broader array of psychological symptoms than subjects at so-called “stable” stages of ego development

    Use of Colossus to Measure the General Damages of a Personal Injury Claim Demonstrates Good Faith Claims Handling

    Get PDF
    Because the law of bad faith is the most volatile of the causes of action, this Note will discuss how using Colossus demonstrates good faith claims handling by insurance companies. Initially, this Note will discuss how Colossus works so readers have an understanding of the product. Following the Colossus section, the Note will discuss the history of bad faith. Finally, this Note will analyze how Colossus assists insurers in meeting the different good faith standards across the nation

    NASA-Ames three-dimensional potential flow analysis system (POTFAN) equation solver code (SOLN) version 1

    Get PDF
    A computer program known as SOLN was developed as an independent segment of the NASA-Ames three-dimensional potential flow analysis systems of linear algebraic equations. Methods used include: LU decomposition, Householder's method, a partitioning scheme, and a block successive relaxation method. Due to the independent modular nature of the program, it may be used by itself and not necessarily in conjunction with other segments of the POTFAN system

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

    Get PDF
    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

    Biased sampling activity: an investigation to promote discussion.

    Get PDF
    The statistical concept of sampling is often given little direct attention, typically reduced to the mantra "take a random sample". This low resource and adaptable activity demonstrates sampling and explores issues that arise due to biased sampling

    In vivo biological activity of the components of haematoporphyrin derivative.

    Get PDF
    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

    Guidelines for monitoring the success of peatland restoration

    Get PDF
    The aim of this guidance is to provide information to enable peatland restoration projects to develop appropriate monitoring programmes. Degraded peatlands are restored for a wide range of reasons. Restoration objectives can include protecting and enhancing biodiversity, improving water quality, reducing flood risk and protecting cultural heritage or carbon stores. Restoration projects need monitoring programmes to show whether these objectives are being met and to help them to adapt practices to respond to environmental changes

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

    Get PDF
    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
    corecore