Geometric properties of a prestressed segmented spherical shell

Design and construction of plastic model of prestressed segmented spherical shel

Modeling and parameter uncertainties for aircraft flight control system design

Values of plant dynamic uncertainties for some recent aircraft design and development programs are given. Histories of pertinent aerodynamic, inertial, and structural parameter variations are given for a period of time from program initiation to aircraft certification. These data can be used as typical of future vehicles so that control system design concepts are evaluated with due consideration to their sensitivity to uncertainties in plant dynamics

Timing and Magnitude of Drought Impacts on Carbon Uptake Across a Grassland Biome

Although drought is known to negatively impact grassland functioning, the timing and magnitude of these impacts within a growing season remains unresolved. Previous small-scale assessments indicate grasslands may only respond to drought during narrow periods within a year; however, large-scale assessments are now needed to uncover the general patterns and determinants of this timing. We combined remote sensing datasets of gross primary productivity and weather to assess the timing and magnitude of grassland responses to drought at 5 km2 temporal resolution across two expansive ecoregions of the western US Great Plains biome: the C4-dominated shortgrass steppe and the C3-dominated northern mixed prairies. Across over 700,000 pixel-year combinations covering more than 600,000 km2, we studied how the driest years between 2003-2020 altered the daily and bi-weekly dynamics of grassland carbon (C) uptake. Reductions to C uptake intensified into the early summer during drought and peaked in mid- and late June in both ecoregions. Stimulation of spring C uptake during drought was small and insufficient to compensate for losses during summer. Thus, total grassland C uptake was consistently reduced by drought across both ecoregions; however, reductions were twice as large across the more southern and warmer shortgrass steppe. Across the biome, increased summer vapor pressure deficit was strongly linked to peak reductions in vegetation greenness during drought. Rising vapor pressure deficit will likely exacerbate reductions in C uptake during drought across the western US Great Plains, with these reductions greatest during the warmest months and in the warmest locations. High spatiotemporal resolution analyses of grassland response to drought over large areas provide both generalizable insights and new opportunities for basic and applied ecosystem science in these water-limited ecoregions amid climate change

Energy conservation: a case study for a large manufacturing plant

The methods of formulating, implementing, and evaluating a conservation program in a commercial building or light industrial plant are examined in this paper. The results of one case study are also presented. In commercial and light industrial applications, most energy is consumed to maintain proper environmental conditions; light levels, heat levels, and fresh air levels. Most buildings today expend too much energy on these services. A co-ordinated program to maintain environmental conditions at levels pointed out in this report could save as mu h as 20% each year in energy consumption. This report presents a method that can be used by many commercial and light industrial concerns to establish a conservation program. Guidelines are presented that can be used to examine environmental conditions and determine how they must be changed. A system of program analysis is also presented. Results of this study show that saving 20% is possible, but motivation of the company and workforce will be a problem. The report also concludes that new buildings can be made more energy efficient if energy conservation is kept in mind during building design

Developement of real time diagnostics and feedback algorithms for JET in view of the next step

Real time control of many plasma parameters will be an essential aspect in the development of reliable high performance operation of Next Step Tokamaks. The main prerequisites for any feedback scheme are the precise real-time determination of the quantities to be controlled, requiring top quality and highly reliable diagnostics, and the availability of robust control algorithms. A new set of real time diagnostics was recently implemented on JET to prove the feasibility of determining, with high accuracy and time resolution, the most important plasma quantities. With regard to feedback algorithms, new model–based controllers were developed to allow a more robust control of several plasma parameters. Both diagnostics and algorithms were successfully used in several experiments, ranging from H-mode plasmas to configuration with ITBs. Since elaboration of computationally heavy measurements is often required, significant attention was devoted to non-algorithmic methods like Digital or Cellular Neural/Nonlinear Networks. The real time hardware and software adopted architectures are also described with particular attention to their relevance to ITER.Comment: 12th International Congress on Plasma Physics, 25-29 October 2004, Nice (France

Successfully Teaching Ethics For Effective Learning

This paper is concerned with identifying keys to successfully teach ethics. The keys are: addressing the relevance challenge; striving to achieve a balance between the active engagement of students with issues and a critical analysis of choices in to be made in real-life situations; attending to or managing the learning process to include learning styles and experiential learning; debriefing experientially-oriented learning activities; and institutionalizing outcomes of ethics education objectives. The paper discusses results of a study that attempted to answer the question “What is required to successfully deliver experientially-oriented ethics educatio

Detailed investigation of a vaporising fuel spray. Part 1: Experimental investigation of time averaged spray

A laser tomographic light scattering technique provides rapid and accurate high resolution measurements of droplet sizes, concentrations, and vaporization. Measurements using a computer interfaced thermocouple are presented and it is found that the potential exists for separating gas and liquid temperature measurements and diagnosing local spray density by in situ analysis of the response characteristics of the thermocouple. The thermocouple technique provides a convenient means for measuring mean gas velocity in both hot and cold two phase flows. The experimental spray is axisymmetric and has carefully controlled initial and boundary conditions. The flow is designed to give relatively insignificant transfer of momentum and mass from spray to air flow. The effects of (1) size-dependent droplet dispersion by the turbulence, (2) the initial spatial segregation of droplet sizes during atomization, and (3) the interaction between droplets and coherent large eddies are diagnosed

Utilization of Virtual Server Technology in Mission Operations

Virtualization provides the opportunity to continue to do "more with less"---more computing power with fewer physical boxes, thus reducing the overall hardware footprint, power and cooling requirements, software licenses, and their associated costs. This paper explores the tremendous advantages and any disadvantages of virtualization in all of the environments associated with software and systems development to operations flow. It includes the use and benefits of the Intelligent Platform Management Interface (IPMI) specification, and identifies lessons learned concerning hardware and network configurations. Using the Huntsville Operations Support Center (HOSC) at NASA Marshall Space Flight Center as an example, we demonstrate that deploying virtualized servers as a means of managing computing resources is applicable and beneficial to many areas of application, up to and including flight operations

A Qualitative Exploration of Sport and Social Pressures on Elite Athletes in Relation to Disordered Eating

Introduction: Athletes are at increased risk of disordered eating compared to non-athletes. Inspired by previous investigation into quantitative work on an etiological model of disordered eating in athletes, the current study aimed to explore a problematic aspect of the model: athletes' lived experiences of social and sport pressures in relation to the onset of disordered eating and differing eating behaviors. / Methods: Nine (N = 9) male and female athletes representing a range of endurance sports took part in semi-structured interviews. Thematic analysis was utilized. / Analysis: Analysis revealed two main themes each with two corresponding subthemes (1) Conflating physical appearance and sporting ability with the subthemes of (1a) social comparison in a sporting world and (1b) societal notions of “the athlete body” and (2) Living as an athlete with the corresponding subthemes of (2a) discipline and sacrifice and (2b) the balancing act. / Discussion: It is the complex interaction between societal expectations as lived out in social messages and comparisons, and sport pressures that contributes to the development of disordered eating behaviors. These findings suggest that prevention and treatment of disordered eating in athletes can be applied from those already established in non-sporting realm