4,216 research outputs found
Electro-optic architecture for servicing sensors and actuators in advanced aircraft propulsion systems
A detailed design of a fiber optic propulsion control system, integrating favored sensors and electro-optics architecture is presented. Layouts, schematics, and sensor lists describe an advanced fighter engine system model. Components and attributes of candidate fiber optic sensors are identified, and evaluation criteria are used in a trade study resulting in favored sensors for each measurand. System architectural ground rules were applied to accomplish an electro-optics architecture for the favored sensors. A key result was a considerable reduction in signal conductors. Drawings, schematics, specifications, and printed circuit board layouts describe the detailed system design, including application of a planar optical waveguide interface
All Creative Being: Interview with Anna Bella Geiger
In the following interview with Anna Bella Geiger, the Brazilian artist talks about her trajectory and various influences, which have always been deeply marked by the lived situation in Brazil, especially during the dictatorship (1964-1985). Starting with the beginnings of her artistic practice in the early 1950s, she details her affiliation with abstract art, her view of the Brazilian art scene during the 1950s and 1960s and reveals the roots of her topographic works and the importance of her pedagogical experiences
An Examination of Enterprise Social Media and its Impact on Employees in a Global Corporate Organization
The purpose of this qualitative case study was to explore perceptions on the impact enterprise social media has on employees in a global corporate organization with a geographically diverse workforce. The 15 study participants were part of three select groups of a global corporate organization, each with differing levels of geographic distribution. There were three instruments used in this study to maximize the acquisition of information from the study participants: a written survey, one-on-one interviews with each study participant, and a focus group where multiple study participants were permitted to share their perceptions on the use and effectiveness of enterprise social media in the workplace. The findings from the research show that as the workplace becomes more geographically distributed and the number of employees working from home increases, enterprise social media is a tool that can help support the challenges of employee communication, collaboration, and connection. A geographically diverse workplace can leave employees with a sense of disconnectedness impacting their overall performance. When employees feel engaged by the organization they work for, they are more motivated to connect with others, share new ideas and innovations, collaborate with other employees, and participate more actively in the employee socialization process. The findings from this study could provide direction for corporate leadership to take advantage of enterprise social media’s impacts on collaboration, communication, and connectedness
Explaining new trends in the gender gap of mortality: Insights from a regional trend- analysis of the Netherlands
The recent decrease of the male-female mortality gap in Western Europe has been accompanied by changes in the life style, educational level, family roles and employment of women. In this paper we try to find out whether a relationship indeed exists between the increase in gender equality and the decrease in the male/female mortality difference. We used regional-level data for the Netherlands for the periods 1980-83 and 1996-99 on gender differences in life expectancy, by age group and cause of death, and various measures of gender inequality on the same regional level. In doing this we followed as far as possible a framework recently developed by Ingrid Waldron to analyse changes in gender differences in mortality in the US. The cross-sectional analyses showed that in 1980-83 it was rather socioeconomic than gender role variables that were important in explaining gender difference in mortality, while in the period 1996-99, it was the other way around.
A new survey for high velocity HI detections in the southern hemisphere
A new high-sensitivity HI survey of the southern sky was made south of Declination , at the Instituto Argentino de RadioastronomĂa (IAR), on a half-degree grid in galactic coordinates. A total of 50980 positions were observed. One of the goals of this survey was to search for high velocity clouds (HVCs). The HI profiles have been smoothed to a velocity resolution of 8 km s-1. The resulting rms noise falls in the range 0.015 to 0.020 K. We have detected 6848 high velocity (HV) components.Fil: Morras, Ricardo. Provincia de Buenos Aires. GobernaciĂłn. ComisiĂłn de Investigaciones CientĂficas. Instituto Argentino de RadioastronomĂa. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto Argentino de RadioastronomĂa; ArgentinaFil: Bajaja, Esteban. Provincia de Buenos Aires. GobernaciĂłn. ComisiĂłn de Investigaciones CientĂficas. Instituto Argentino de RadioastronomĂa. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto Argentino de RadioastronomĂa; ArgentinaFil: Arnal, Edmundo Marcelo. Provincia de Buenos Aires. GobernaciĂłn. ComisiĂłn de Investigaciones CientĂficas. Instituto Argentino de RadioastronomĂa. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto Argentino de RadioastronomĂa; ArgentinaFil: Poppel, W. G. L.. Provincia de Buenos Aires. GobernaciĂłn. ComisiĂłn de Investigaciones CientĂficas. Instituto Argentino de RadioastronomĂa. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto Argentino de RadioastronomĂa; Argentin
Pragma-Dialectics and Health Communication: Arguing for behavioural change in advisory health brochures
In this paper, it is argued that a pragma-dialectical perspective on advisory health brochures can complement current research in the medical domain and vice versa. Advisory health brochures are characterized as a particular communicative activity type to show how this context influences the argumentative process. It is argued that the quality of argumentation in health communication needs more attention. Insights from behavioural theory and persuasion research may help to detect possibly fallacious manoeuvres
Fiber optic control system integration
A total fiber optic, integrated propulsion/flight control system concept for advanced fighter aircraft is presented. Fiber optic technology pertaining to this system is identified and evaluated for application readiness. A fiber optic sensor vendor survey was completed, and the results are reported. The advantages of centralized/direct architecture are reviewed, and the concept of the protocol branch is explained. Preliminary protocol branch selections are made based on the F-18/F404 application. Concepts for new optical tools are described. Development plans for the optical technology and the described system are included
Numerical Methods for Simulating Multiphase Electrohydrodynamic Flows with Application to Liquid Fuel Injection
One approach to small-scale fuel injection is to capitalize upon the benefits of electrohydrodynamics (EHD) and enhance fuel atomization. There are many potential advantages to EHD aided atomization for combustion, such as smaller droplets, wider spray cone, and the ability to control and tune the spray for improved performance. Electrohydrodynamic flows and sprays have drawn increasing interest in recent years, yet key questions regarding the complex interactions among electrostatic charge, electric fields, and the dynamics of atomizing liquids remain unanswered. The complex, multi-physics and multi-scale nature of EHD atomization processes limits both experimental and computational explorations.
In this work, novel, numerically sharp methods are developed and subsequently employed in high-fidelity direct numerical simulations of electrically charged liquid hydrocarbon jets. The level set approach is combined with the ghost fluid method (GFM) to accurately simulate primary atomization phenomena for this class of flows. Surface effects at the phase interface as well as bulk dynamics are modeled in an accurate and robust manner. The new methods are implemented within a conservative finite difference scheme of high-order accuracy that employs state-of-the-art interface transport techniques. This approach, validated using several cases with exact analytic solutions, demonstrates significant improvements in accuracy and efficiency compared to previous methods used for EHD simulations. As a final validation, the computational scheme is applied in direct numerical simulation of a charged and uncharged liquid kerosene jet. Then, a detailed numerical study of EHD atomization is conducted for a range of relevant dimensionless parameters to predict the onset of liquid break-up, identify characteristic modes of liquid disintegration, and report elucidating statistics such as drop size and spray dispersion. Because the methodologies developed and validated in this work open new, simulations-based avenues of exploration within a broader category of electrohydrodynamics, some perspectives on extensions or continuations of this work are offered in conclusion
Choosing variants of pragmatic argumentation in anticipation of countermoves in health brochures
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