Focusing educational initiatives

The United States will soon be facing a critical shortage of aerospace scientists and engineers. To address this problem, Space Grant Colleges can assist in focusing interest in existing educational initiatives and in creating new educational opportunities, particularly for women and underrepresented minorities

Exploring the development of reflective practice with trainee teachers, using video annotation software

The initial teacher training programme at Middlesex University provided an opportunity to explore the development of reflective practice in initial teacher training, using video annotation software to capture reflective comments. The participants were studying for their postgraduate certificate in secondary education, at Masters level, on the science subject pathway. An action research approach was used to video microteaching and capture reflective commentary of participants after these recorded sessions. The project constituted two action research cycles each of which was followed by a focus group discussion to reflect more fully, evaluate the approach and assessment focus and inform in-project adaptations between cycles. This paper outlines the key findings relating to development of reflective practice, the use of video to capture this practice and the use of annotation software to capture reflective practice. The findings show positive perceptions of the use of video and the software used, affirming findings from existing literature. Development of reflective practice in this study notably included greater depth over time, a developing use of educational terminology, greater focus on questions within reflective comments, attention to pedagogical subject knowledge and feeding forward to future improvements, completing the reflective cycle. Another key finding was the development of a focus on student activity later in training, from a focus on teacher (participant) activity earlier in the training. A unique aspect of this study was the inclusion of both self-assessment and peer- assessment opportunities, planned to dovetail with the stage of training for the participants of the study and in response to their feedback between cycles. The second cycle of microteaching and reflection provided rich opportunities for reflection through collaborative peer-peer work, in line with recommendations from much of the existing research in this field. The use of annotation software facilitated the capture of participant’s collaborative reflections, giving rich data upon which conclusions are drawn. In addition to the existing body of literature, this study highlighted a focus on the affective aspects of reflective practice, discussion about which is sometimes overlooked in the findings of existing initial teacher training (ITT) literature, despite being an embedded factor in many theoretical models of reflection. The capture of these affective elements of developing reflective practice merits further exploration and is a recommendation of this study

Weak Energy: Form and Function

The equation of motion for a time-independent weak value of a quantum mechanical observable contains a complex valued energy factor - the weak energy of evolution. This quantity is defined by the dynamics of the pre-selected and post-selected states which specify the observable's weak value. It is shown that this energy: (i) is manifested as dynamical and geometric phases that govern the evolution of the weak value during the measurement process; (ii) satisfies the Euler-Lagrange equations when expressed in terms of Pancharatnam (P) phase and Fubini-Study (FS) metric distance; (iii) provides for a PFS stationary action principle for quantum state evolution; (iv) time translates correlation amplitudes; (v) generalizes the temporal persistence of state normalization; and (vi) obeys a time-energy uncertainty relation. A similar complex valued quantity - the pointed weak energy of an evolving state - is also defined and several of its properties in PFS-coordinates are discussed. It is shown that the imaginary part of the pointed weak energy governs the state's survival probability and its real part is - to within a sign - the Mukunda-Simon geometric phase for arbitrary evolutions or the Aharonov-Anandan (AA) phase for cyclic evolutions. Pointed weak energy gauge transformations and the PFS 1-form are discussed and the relationship between the PFS 1-form and the AA connection 1-form is established.Comment: To appear in "Quantum Theory: A Two-Time Success Story"; Yakir Aharonov Festschrif

Welding high-strength aluminum alloys

Handbook has been published which integrates results of 19 research programs involving welding of high-strength aluminum alloys. Book introduces metallurgy and properties of aluminum alloys by discussing commercial alloys and heat treatments. Several current welding processes are reviewed such as gas tungsten-arc welding and gas metal-arc welding

Desensitizing Flame Structure and Exhaust Emissions to Flow Parameters in an Ultra-Compact Combuster

A major thrust of turbine engine research is to improve both efficiency and thrust-to-weight ratio of the engine. A promising solution to this challenge is the Ultra-Compact Combustor (UCC). The UCC shortens the axial length of the combustor by performing combustion circumferentially on the outer diameter of the engine. The reduction in axial length yields significant weight savings and increases the thrust-to-weight ratio. The design also increases combustion efficiency by performing the combustion in a centrifugally loaded environment which allows unreacted particles to remain in the combustor sufficiently long enough to become combustion products. The Air Force Institute of Technology (AFIT) and the Air Force Research Laboratory (AFRL) have been jointly researching the fundamental dynamics of the UCC. To aid in integrating the UCC into a turbine engine, the current objective is to desensitize the exhaust characteristics of the combustor to changes in operating parameters. The following report documents modifications to the AFIT sectional test rig to improve its replication of the AFRL full annulus. High speed video was captured to document flame shape, location, intensity, and stability within the core section. Carbon monoxide, carbon dioxide, oxygen, nitrous oxides, and unburnt hydrocarbon emissions measurements were recorded to quantify the combustors exhaust constituents. A novel vane concept was implemented to desensitize the flame shape, location, intensity, and its exhaust products with changes in operating parameters. The design represents the next step toward creating a UCC vane that can migrate the flow effectively and consistently from the UCC cavity into the core flow. Furthermore, this vane concept represents the first attempt at a design that can be effectively cooled for application in a realistic turbine engin

Sideslip-induced static pressure errors in flight-test measurements

During lateral flight-test maneuvers of a V/STOL research aircraft, large errors in static pressure were observed. An investigation of the data showed a strong correlation of the pressure record with variations in sideslip angle. The sensors for both measurements were located on a standard air-data nose boom. An algorithm based on potential flow over a cylinder that was developed to correct the pressure record for sideslip-induced errors is described. In order to properly apply the correction algorithm, it was necessary to estimate and correct the lag error in the pressure system. The method developed for estimating pressure lag is based on the coupling of sideslip activity into the static ports and can be used as a standard flight-test procedure. The estimation procedure is discussed and the corrected static-pressure record for a typical lateral maneuver is presented. It is shown that application of the correction algorithm effectively attenuates sideslip-induced errors

Transport phenomenology for a holon-spinon fluid

We propose that the normal-state transport in the cuprate superconductors can be understood in terms of a two-fluid model of spinons and holons. In our scenario, the resistivity is determined by the properties of the holons while magnetotransport involves the recombination of holons and spinons to form physical electrons. Our model implies that the Hall transport time is a measure of the electron lifetime, which is shorter than the longitudinal transport time. This agrees with our analysis of the normal-state data. We predict a strong increase in linewidth with increasing temperature in photoemission. Our model also suggests that the AC Hall effect is controlled by the transport time.Comment: 4 pages, 1 postscript figure. Uses RevTeX, epsf, multico

Studies of the auroral substorm. I - Characteristics of modulated energetic electron precipitation occurring during auroral substorms

Characteristics of modulated energetic electron precipitation occurring during auroral substorm