Cost/benefit analysis of advanced materials technologies for future aircraft turbine engines

The materials technologies studied included thermal barrier coatings for turbine airfoils, turbine disks, cases, turbine vanes and engine and nacelle composite materials. The cost/benefit of each technology was determined in terms of Relative Value defined as change in return on investment times probability of success divided by development cost. A recommended final ranking of technologies was based primarily on consideration of Relative Values with secondary consideration given to changes in other economic parameters. Technologies showing the most promising cost/benefits were thermal barrier coated temperature nacelle/engine system composites

A Short Ion Path High Voltage Tube

A vacuum tube for the acceleration of charged particles is described. The total acceleration of the ions takes place in a distance of 18 inches although the total height of the tube is about 14 feet. It has been used at one million volts peak a.c. with target currents of 5 ma of electrons and 0.2 ma of positive ions

Quartz crystal microbalances to measure wind velocity and air humidity

Instrument includes four temperature-sensing, Y-cut quartz crystals to determine wind direction, velocity, and temperature. Two additional AT-cut crystals are used to determine air humidity. Entire signal processing is provided by built-in electronics circuits

Wind sensor

An apparatus is described for sensing the temperature, velocity, and direction of the wind, including four temperature-dependent crystal oscillators spaced about an axis, a heater centered on the axis, and a screen through which the wind blows to pass over the crystals. In one method of operation, the frequency of the oscillators is taken when the heater is not energized, to obtain the temperature of the wind, and the frequencies of the oscillators are taken after the heater is energized to determine the direction and velocity of the wind. When the heater is energized, the wind causes the downwind crystals to achieve a higher temperature than the upwind crystals, and with the magnitude of the difference indicating the velocity of the wind

Linear and nonlinear aspects of the tropical 30-60 day oscillation: A modeling study

The scientific problem focused on study of the tropical 30-60 day oscillation and explanation for this phenomenon is discussed. The following subject areas are covered: the scientific problem (the importance of low frequency oscillations; suggested mechanisms for developing the tropical 30-60 day oscillation); proposed research and its objective; basic approach to research; and results (satellite data analysis and retrieval development; thermodynamic model of the oscillation; the 5-level GCM)

Linking academic emotions and student engagement: mature-aged distance students’ transition to university

This is an Accepted Manuscript of an article published by Taylor & Francis in Journal of Further and Higher Education on 2013, available online: https://www.tandfonline.com/doi/full/10.1080/0309877X.2014.895305Research into both student engagement and student emotions is increasing, with widespread agreement that both are critical determinants of student success in higher education. Less researched are the complex, reciprocal relationships between these important influences. Two theoretical frameworks inform this paper: Pekrun’s taxonomy of academic emotions and Kahu’s conceptual framework of student engagement. The prospective qualitative design aims to allow a rich understanding of the fluctuating and diverse emotions that students experience during the transition to university and to explore the relationships between academic emotions and student engagement. The study follows 19 mature-aged (aged 24 and over) distance students throughout their first semester at university, using video diaries to collect data on their emotional experiences and their engagement with their study. Pre and post-semester interviews were also conducted. Findings highlight that different emotions have different links to engagement: as important elements in emotional engagement, as inhibitors of engagement and as outcomes that reciprocally influence engagement. There are two key conclusions. First, student emotions are the point of intersection between the university factors such as course design and student variables such as motivation and background. Second, the flow of influence between emotions, engagement, and learning is reciprocal and complex and can spiral upwards towards ideal engagement or downwards towards disengagement and withdrawal.Publishe

Estimating Refractive Index Spectra in Regions of Clear Air Turbulence

Estimation of refractive index spectra in regions of clear air turbulenc

Comprehensive rotorcraft analysis methods

The development and application of comprehensive rotorcraft analysis methods in the field of rotorcraft technology are described. These large scale analyses and the resulting computer programs are intended to treat the complex aeromechanical phenomena that describe the behavior of rotorcraft. They may be used to predict rotor aerodynamics, acoustic, performance, stability and control, handling qualities, loads and vibrations, structures, dynamics, and aeroelastic stability characteristics for a variety of applications including research, preliminary and detail design, and evaluation and treatment of field problems. The principal comprehensive methods developed or under development in recent years and generally available to the rotorcraft community because of US Army Aviation Research and Technology Activity (ARTA) sponsorship of all or part of the software systems are the Rotorcraft Flight Simulation (C81), Dynamic System Coupler (DYSCO), Coupled Rotor/Airframe Vibration Analysis Program (SIMVIB), Comprehensive Analytical Model of Rotorcraft Aerodynamics and Dynamics (CAMRAD), General Rotorcraft Aeromechanical Stability Program (GRASP), and Second Generation Comprehensive Helicopter Analysis System (2GCHAS)