Coupling for linear shaped charge Patent

Coupling device for linear shaped charge for space vehicle abort syste

A nanoindentation investigation of local strain rate sensitivity in dual-phase Ti alloys

Using nanoindentation we have investigated the local strain rate sensitivity in dual-phase Ti alloys, Ti-6Al-2Sn-4Zr-xMo (x=2 and 6), as strain rate sensitivity could be a potential factor causing cold dwell fatigue. Electron backscatter diffraction (EBSD) was used to select hard and soft grain orientations within each of the alloys. Nanoindentation based tests using the continuous stiffness measurement (CSM) method were performed with variable strain rates, on the order of 10−1 to 10−3s−1. Local strain rate sensitivity is determined using a power law linking equivalent flow stress and equivalent plastic strain rate. Analysis of residual impressions using both a scanning electron microscope (SEM) and a focused ion beam (FIB) reveals local deformation around the indents and shows that nanoindentation tested structures containing both α and β phases within individual colonies. This indicates that the indentation results are derived from averaged α/β properties. The results show that a trend of local rate sensitivity in Ti6242 and Ti6246 is strikingly different; as similar rate sensitivities are found in Ti6246 regardless of grain orientation, whilst a grain orientation dependence is observed in Ti6242. These findings are important for understanding dwell fatigue deformation modes, and the methodology demonstrated can be used for screening new alloy designs and microstructures

Deep gamma ray penetration in thick shields

Appropriate importance function and sampling scheme facilitates the application of the Monte Carlo method to problems involving the deep penetration of radiation

Numerical study of weakly unstable electron plasma oscillations

Vlasov equation for solving initial value problem for unstable electron plasm

Adaptive Frequency Neural Networks for Dynamic Pulse and Metre Perception.

Beat induction, the means by which humans listen to music and perceive a steady pulse, is achieved via a perceptualand cognitive process. Computationally modelling this phenomenon is an open problem, especially when processing expressive shaping of the music such as tempo change.To meet this challenge we propose Adaptive Frequency Neural Networks (AFNNs), an extension of Gradient Frequency Neural Networks (GFNNs).GFNNs are based on neurodynamic models and have been applied successfully to a range of difficult music perception problems including those with syncopated and polyrhythmic stimuli. AFNNs extend GFNNs by applying a Hebbian learning rule to the oscillator frequencies. Thus the frequencies in an AFNN adapt to the stimulus through an attraction to local areas of resonance, and allow for a great dimensionality reduction in the network.Where previous work with GFNNs has focused on frequency and amplitude responses, we also consider phase information as critical for pulse perception. Evaluating the time-based output, we find significantly improved re-sponses of AFNNs compared to GFNNs to stimuli with both steady and varying pulse frequencies. This leads us to believe that AFNNs could replace the linear filtering methods commonly used in beat tracking and tempo estimationsystems, and lead to more accurate methods

Characteristics, of TIROS, GOES, DMSP and LANDSAT Systems

The characteristics of the TIROS, GOES, DMSP and LANDSAT systems of satellites are described. The data listed for each system are altitude of orbit, inclination/position, orbit type, orbits per day, expected operational lifetime and the sensor systems. The sensor systems are described as to wavelength of each channel, resolution, field of view and other pertinent information. Data information such as availability rate, collection method, primary use/application and how to obtain additional information is also given

'Looking away': private writing techniques as a form of transformational text shaping in art & design and the natural sciences

Despite their long history and wide-spread use, the private writing techniques of journaling and freewriting remain largely underexploited in the field of academic writing instruction. They are seen only as forms of pre-writing, and are criticised by some for being under-theorised, vague and asocial. Contextualizing them within a writing-as-social-practice approach, and drawing on a conceptual framework including a notion of looking-away developed by Derrida, Vygotsky’s conception of learning development, and Ivanic’s notion of writer identity, this paper aims to throw new light on these private writing techniques and argues they can be transformational in developing students’ learning and identity, as well as written and non-written outputs. In this paper we theorise these practices through reflection on two instances of teaching in which they played an important part. The teaching interventions were in different disciplinary contexts (architectural design and Natural Sciences), with writers of different levels of expertise/competence (undergraduate and PhD), in both L1 and multilingual settings. In both interventions, we found that these private writing techniques were transformational due to the space they allowed writers to self-reflect, and to look away from their public-facing outputs. The techniques provided significant developmental benefits and moved the students along a continuum towards a more expert-like identity

LDEF geometry/mass model for radiation analyses

A three-dimensional geometry/mass model of LDEF is under development for ionizing radiation analyses. This model, together with ray tracing algorithms, is being programmed for use both as a stand alone code in determining three-dimensional shielding distributions at dosimetry locations and as a geometry module that can be interfaced with radiation transport codes