875 research outputs found

    Use of PDV to measure the overdriven products equation of state in PBX 9502 and PBX 9501 and the EOS in shocked foams

    Get PDF
    Author Institution: Los Alamos National LaboratorySlides presented at the 2014 Photonic Doppler Velocimetry (PDV) Workshop Hosted by National Security Technologies, LLC, and the University of Nevada Las Vegas, June 24-26, 2014, Las Vegas, Nevada

    Economic motives to attend university: a cross-country study

    Get PDF
    This paper considers students’ economic motives to attend university. Drawing on selected results from a tri-national survey involving online questionnaires and interviews with students at English, German and Portuguese universities, it examines and compares this particular extrinsic motivational dimension, alongside the influence of the national economic contexts within which the students are located. The findings suggest a strong consensus across all three settings in relation to high levels of motivation driven by the students’ economic goals – careers, qualifications and future income – irrespective of background variables and fee structures. An exploration of the impact of the broader economic climate, however, reveals a more fragmented picture. The differences revealed between national settings offer tentative evidence that the students’ perceptions of their country’s economic situation does have a differential impact on their decision to take up university studies

    Navier-Stokes Simulation of a Heavy Lift Slowed-Rotor Compound Helicopter Configuration

    Get PDF
    Time accurate numerical simulations were performed using the Reynolds-averaged Navier-Stokes (RANS) flow solver OVERFLOW for a heavy lift, slowed-rotor, compound helicopter configuration, tested at the NASA Langley 14- by 22-Foot Subsonic Tunnel. The primary purpose of these simulations is to provide support for the development of a large field of view Particle Imaging Velocimetry (PIV) flow measurement technique supported by the Subsonic Rotary Wing (SRW) project under the NASA Fundamental Aeronautics program. These simulations provide a better understanding of the rotor and body wake flows and helped to define PIV measurement locations as well as requirements for validation of flow solver codes. The large field PIV system can measure the three-dimensional velocity flow field in a 0.914m by 1.83m plane. PIV measurements were performed upstream and downstream of the vertical tail section and are compared to simulation results. The simulations are also used to better understand the tunnel wall and body/rotor support effects by comparing simulations with and without tunnel floor/ceiling walls and supports. Comparisons are also made to the experimental force and moment data for the body and rotor

    Development and Validation of the Behavioral Tendencies Questionnaire

    Get PDF
    At a fundamental level, taxonomy of behavior and behavioral tendencies can be described in terms of approach, avoid, or equivocate (i.e., neither approach nor avoid). While there are numerous theories of personality, temperament, and character, few seem to take advantage of parsimonious taxonomy. The present study sought to implement this taxonomy by creating a questionnaire based on a categorization of behavioral temperaments/tendencies first identified in Buddhist accounts over fifteen hundred years ago. Items were developed using historical and contemporary texts of the behavioral temperaments, described as “Greedy/Faithful”, “Aversive/Discerning”, and “Deluded/Speculative”. To both maintain this categorical typology and benefit from the advantageous properties of forced-choice response format (e.g., reduction of response biases), binary pairwise preferences for items were modeled using Latent Class Analysis (LCA). One sample (n1 = 394) was used to estimate the item parameters, and the second sample (n2 = 504) was used to classify the participants using the established parameters and cross-validate the classification against multiple other measures. The cross-validated measure exhibited good nomothetic span (construct-consistent relationships with related measures) that seemed to corroborate the ideas present in the original Buddhist source documents. The final 13-block questionnaire created from the best performing items (the Behavioral Tendencies Questionnaire or BTQ) is a psychometrically valid questionnaire that is historically consistent, based in behavioral tendencies, and promises practical and clinical utility particularly in settings that teach and study meditation practices such as Mindfulness Based Stress Reduction (MBSR)

    Climate and southern Africa's water-energy-food nexus

    Get PDF
    In southern Africa, the connections between climate and the water-energy-food nexus are strong. Physical and socioeconomic exposure to climate is high in many areas and in crucial economic sectors. Spatial interdependence is also high, driven for example, by the regional extent of many climate anomalies and river basins and aquifers that span national boundaries. There is now strong evidence of the effects of individual climate anomalies, but associations between national rainfall and Gross Domestic Product and crop production remain relatively weak. The majority of climate models project decreases in annual precipitation for southern Africa, typically by as much as 20% by the 2080s. Impact models suggest these changes would propagate into reduced water availability and crop yields. Recognition of spatial and sectoral interdependencies should inform policies, institutions and investments for enhancing water, energy and food security. Three key political and economic instruments could be strengthened for this purpose; the Southern African Development Community, the Southern African Power Pool, and trade of agricultural products amounting to significant transfers of embedded water

    Development and Validation of the Career Competencies Indicators (CCI)

    Get PDF
    This paper describes the development and validation of the Career Competencies Indicator (CCI); a 43-item measure to assess career competencies. Following an extensive literature review, a comprehensive item generation process involving consultation with subject matter experts, a pilot study and a factor analytic study on a large sample yielded a seven factor structure; goal setting and career planning, self-knowledge, job-performance, career-related skills, knowledge of (office) politics, career guidance and networking, and feedback seeking and self-presentation. Coefficient alpha reliabilities of the seven dimensions ranged from .93 to .81. Convergent validity was established by showing below chance similarity between CCI sub-scales, and discrminant validity between the CCI sub-scales and the big five personality scales. The results also suggested criterion-related validity of the CCI, since career competencies were found to jointly predict objective and subjective career success
    corecore