Aerothermal modeling, phase 1. Volume 2: Experimental data

The experimental test effort is discussed. The test data are presented. The compilation is divided into sets representing each of the 18 experimental configurations tested. A detailed description of each configuration, and plots of the temperature difference ratio parameter or pattern factor parameter calculated from the test data are also provided

Neutrons from 9Be/alpha,n/ reaction for E alpha between 6 and 10 MeV

Neutron energy spectra measured as function of neutron emission angle and ion bombardment energ

High-concentration Er:YAG single-crystal fibers grown by laser-heated pedestal growth technique

High-concentration Er:YAG single-crystal fibers have been grown using the laser-heated pedestal growth technique. Instability in the melt and concomitant opacity of fibers were observed at source concentrations higher than 15 mol.%. Spectroscopic examination shows that broadening of the linewidth of the I<sub>13/2</sub>4→I<sub>15/2</sub>4 transition is strongly dependent on Er<sup>3+</sup> concentration

Energy Efficient Engine combustor test hardware detailed design report

The Energy Efficient Engine (E3) Combustor Development effort was conducted as part of the overall NASA/GE E3 Program. This effort included the selection of an advanced double-annular combustion system design. The primary intent was to evolve a design which meets the stringent emissions and life goals of the E3 as well as all of the usual performance requirements of combustion systems for modern turbofan engines. Numerous detailed design studies were conducted to define the features of the combustion system design. Development test hardware was fabricated, and an extensive testing effort was undertaken to evaluate the combustion system subcomponents in order to verify and refine the design. Technology derived from this development effort will be incorporated into the engine combustion system hardware design. This advanced engine combustion system will then be evaluated in component testing to verify the design intent. What is evolving from this development effort is an advanced combustion system capable of satisfying all of the combustion system design objectives and requirements of the E3. Fuel nozzle, diffuser, starting, and emissions design studies are discussed

Energy Efficient Engine (E3) combustion system component technology performance report

The Energy Efficient Engine (E3) combustor effort was conducted as part of the overall NASA/GE E3 Program. This effort included the selection of an advanced double-annular combustion system design. The primary intent of this effort was to evolve a design that meets the stringent emissions and life goals of the E3, as well as all of the usual performance requirements of combustion systems for modern turbofan engines. Numerous detailed design studies were conducted to define the features of the combustion system design. Development test hardware was fabricated, and an extensive testing effort was undertaken to evaluate the combustion system subcomponents in order to verify and refine the design. Technology derived from this effort was incorporated into the engine combustion hardware design. The advanced engine combustion system was then evaluated in component testing to verify the design intent. What evolved from this effort was an advanced combustion system capable of satisfying all of the combustion system design objectives and requirements of the E3

1987 Update of Agronomic Performance of Tall Fescue Varieties

Tall fescue (Festuca arundinacea, Schreb.) is a well adapted, widely used pasture species occupying approximately 5.5 million acres in Kentucky and 35 million acres in the south central United States. Commercial tall fescue varieties have been developed from plant materials of either northern European or Mediterranean origin. Varieties developed at the University of Kentucky -- Kentucky 31, Kenmont, Kenwell, Kenhy, and Johnstone -- trace to plant materials of northern European origin. The Kentucky varieties have later maturity dates and have greater resistance to certain foliar diseases during summer than varieties that are of Mediterranean origin (i.e., Alta, Fawn, Goar, and AU-Triumph) when grown under environmental conditions and management regimes prevailing in Kentucky. Varieties of Mediterranean origin have excellent ear1y spring and late fall growth when foliar diseases are not a problem. Foliar diseases, however, may cause them to be of inferior quality and to make poor growth during the summer. Generally, in Kentucky, tall fescue is used for hay and for pasture in spring, summer and fall. Agronomic research data indicate that varieties of northern European origin are superior to varieties of Mediterranean origin for forage purposes in Kentucky

Aerothermal modeling, phase 1. Volume 1: Model assessment

Phase 1 was conducted as part of the overall NASA Hot Section Technology (HOST) Program. The purpose of this effort was to determine the predictive accuracy of and the deficiencies within the various analytical modules comprising the overall combustor aerothermal model used at General Electric, as well as to formulate recommendations for improvement where needed. This effort involved the assembly of a benchmark quality data base from selected available literature, and from General Electric engine and combustor component test data. This data base was supplemented with additional definitive data obtained from an experimental test program conducted as part of the Phase 1 effort. Using selections from this data base, assessment studies were conducted to evaluate the various modules. Assessment of the internal flow module was conducted using 2-D parabolic and ellipitic, as well as 3-D elliptic internal flow calculations of definitive test data selected from the assembled data base. The 2-D assessment provided methodical examination of the mathematical techniques and the physical submodules, while the 3-D assessment focused on usefulness as a design tool. Calculations of combustor linear metal temperatures, pressure loss performance, and airflow distribution were performed using aerothermal modules which were in general use for many years at General Electric. The results of these assessment provided for the identification of deficiencies within the modules. The deficiencies were addressed in some detail providing a foundation on which to formulate a prioritized list of recommendations for improvement

Detecting periodicity in experimental data using linear modeling techniques

Fourier spectral estimates and, to a lesser extent, the autocorrelation function are the primary tools to detect periodicities in experimental data in the physical and biological sciences. We propose a new method which is more reliable than traditional techniques, and is able to make clear identification of periodic behavior when traditional techniques do not. This technique is based on an information theoretic reduction of linear (autoregressive) models so that only the essential features of an autoregressive model are retained. These models we call reduced autoregressive models (RARM). The essential features of reduced autoregressive models include any periodicity present in the data. We provide theoretical and numerical evidence from both experimental and artificial data, to demonstrate that this technique will reliably detect periodicities if and only if they are present in the data. There are strong information theoretic arguments to support the statement that RARM detects periodicities if they are present. Surrogate data techniques are used to ensure the converse. Furthermore, our calculations demonstrate that RARM is more robust, more accurate, and more sensitive, than traditional spectral techniques.Comment: 10 pages (revtex) and 6 figures. To appear in Phys Rev E. Modified styl

Evaluation of therapists’ individual characteristics’ influence on recommendations to CLBP patients

IntroductionThis study measured different therapists’ biopsychosocial parameters and their influence on treatment recommendations for chronic low back pain (CLBP) patients. Based on previous studies and with a biopsychosocial approach, this work aimed to understand the variations in recommendations depending on personal dispositions.MethodsEighty-two therapists (aged 37±11 years, 34 men/48 women) were recruited within our rehabilitation clinic (CRR). Their physical activity was objectively assessed by tri-axial accelerometry and questionnaires have been used to evaluate the following variables: subjective physical activity (BAECKE), pain attitudes and beliefs (TSK and POAM-P), anxiety and depression (HADS), uncertainty intolerance (EII) and social desirability (MC-SDS). Objective stress level was measured by salivary cortisol.In order to measure the variability in recommendations, 3 validated vignettes for CLBP patients management were distributed.ResultsBehavioural patterns coping with pain (Avoidance, Overdoing and Pacing) do occur in therapists (10% Avoidance, 47% Pacing and 43% Overdoing) and do affect recommendations’ application. These 3 different patterns are also related to age, sex, BMI, depression and physical activity. Others relations are currently being analysed.ConclusionThis study suggests that we could categorise therapists depending onidiosyncratics variablespersonal dispositions. This classification would determine recommendations orientation for physical and professional activity. For future research studies, it would be interesting to deal in depth with these relations in order to individualize recommendations to get a better rehabilitation procedure