1,657 research outputs found

    Boundary layer integral matrix procedure: Verification of models

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    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

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

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    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

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    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

    ‘They Called Them Communists Then … What D'You Call ‘Em Now? … Insurgents?’. Narratives of British Military Expatriates in the Context of the New Imperialism

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    This paper addresses the question of the extent to which the colonial past provides material for contemporary actors' understanding of difference. The research from which the paper is drawn involved interview and ethnographic work in three largely white working-class estates in an English provincial city. For this paper we focus on ten life-history interviews with older participants who had spent some time abroad in the British military. Our analysis adopts a postcolonial framework because research participants' current constructions of an amorphous 'Other' (labelled variously as black people, immigrants, foreigners, asylum-seekers or Muslims) reveal strong continuities with discourses deployed by the same individuals to narrate their past experiences of living and working as either military expatriates or spouses during British colonial rule. Theoretically, the paper engages with the work of Frantz Fanon and Edward Said. In keeping with a postcolonial approach, we work against essentialised notions of identity based on 'race' or class. Although we establish continuity between white working-class military emigration in the past and contemporary racialised discourses, we argue that the latter are not class-specific, being as much the creations of the middle-class media and political elite

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

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    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

    CFHTLenS: Co-evolution of galaxies and their dark matter haloes

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    Galaxy-galaxy weak lensing is a direct probe of the mean matter distribution around galaxies. The depth and sky coverage of the CFHT Legacy Survey yield statistically significant galaxy halo mass measurements over a much wider range of stellar masses (108.7510^{8.75} to 1011.3M10^{11.3} M_{\odot}) and redshifts (0.2<z<0.80.2 < z < 0.8) than previous weak lensing studies. At redshift z0.5z \sim 0.5, the stellar-to-halo mass ratio (SHMR) reaches a maximum of 4.0±0.24.0\pm0.2 percent as a function of halo mass at 1012.25M\sim 10^{12.25} M_{\odot}. We find, for the first time from weak lensing alone, evidence for significant evolution in the SHMR: the peak ratio falls as a function of cosmic time from 4.5±0.34.5 \pm 0.3 percent at z0.7z \sim 0.7 to 3.4±0.23.4 \pm 0.2 percent at z0.3z \sim 0.3, and shifts to lower stellar mass haloes. These evolutionary trends are dominated by red galaxies, and are consistent with a model in which the stellar mass above which star formation is quenched "downsizes" with cosmic time. In contrast, the SHMR of blue, star-forming galaxies is well-fit by a power law that does not evolve with time. This suggests that blue galaxies form stars at a rate that is balanced with their dark matter accretion in such a way that they evolve along the SHMR locus. The redshift dependence of the SHMR can be used to constrain the evolution of the galaxy population over cosmic time.Comment: 18 pages, MNRAS, in pres

    Modeling the interactions of phthalocyanines in water: From the Cu(II)-tetrasulphonate to the metal-free phthalocyanine

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    A quantum and statistical study on the effects of the ions Cu2+ and SO3− in the solvent structure around the metal-free phthalocyanine (H2Pc) is presented. We developed an ab initio interaction potential for the system CuPc–H2O based on quantum chemical calculations and studied its transferability to the H2Pc–H2O and [CuPc(SO3)4]4−–H2O interactions. The use of the molecular dynamics technique allows the determination of energetic and structural properties of CuPc, H2Pc, and [CuPc(SO3)4]4− in water and the understanding of the keys for the different behaviors of the three phthalocyanine (Pc) derivatives in water. The inclusion of the Cu2+ cation in the Pc structure reinforces the appearance of two axial water molecules and second-shell water molecules in the solvent structure, whereas the presence of SO3− anions implies a well defined hydration shell of about eight water molecules around them making the macrocycle soluble in water. Debye– Waller factors for axial water molecules have been obtained in order to examine the potential sensitivity of the extended x-ray absorption fine structure technique to detect the axial water molecules.Ministerio de Ciencia e Innovación de España-CTQ2008-0527

    Ab initio determination of the ionization potentials of DNA and RNA nucleobases

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    Quantum chemical high level ab initio coupled-cluster and multiconfigurational perturbation methods have been used to compute vertical and adiabatic ionization potentials of the five canonical DNA and RNA nucleobases: uracil, thymine, cytosine, adenine, and guanine. Several states of their cations have been also calculated. The present results represent a systematic compendium of these magnitudes, establishing theoretical reference values at a level not reported before, calibrating computational strategies, and guiding the assignment of the features in the experimental photoelectron [email protected] [email protected] [email protected] [email protected]

    Exploring the Relationship between Ego Development and Mental Health

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    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

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    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
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