Study and production of polybenzimidazole billets, laminates, and cylinders

Mechanical properties and physical, chemical, and thermal tests of polybenzimidazole and carbon fabric laminates for spacecraft thermal insulatio

An observational test of common-envelope evolution

By analysing and modelling the change in the abundance ratio of $^{12}$C/$^{13}$C and $^{16}$O/$^{17}$O on the surface of the lower mass star of a binary during the common-envelope (CE) phase of evolution, we propose a simple observational test of the CE scenario. The test is based on the infrared measurement of either the $^{12}$C/$^{13}$C or $^{16}$O/$^{17}$O ratio of red dwarfs in post-common envelope binaries (PCEB's). In certain cases (main-sequence red dwarf secondaries in PCEB's without planetary nebulae), as well as determining whether or not accretion has occurred during the CE phase, we can determine the amount of mass accreted during the CE phase and hence the initial mass of the red dwarf component prior to the CE phase. In the other cases considered (low-mass red dwarfs in PCEB's and red dwarf's in PCEB's with planetary nebulae) we can only say whether or not accretion has occurred during the CE phase.Comment: uuencoded compressed postscript. The preprint are also available at URL http://www.ast.cam.ac.uk/preprint/PrePrint.htm

Collaborative soft object manipulation for game engine-based virtual reality surgery simulators

In this paper we analyse and evaluate the capabilities of popular game engines to simulate and interact with soft objects. We discuss how these engines can be used for simulated surgical training applications, determine their shortcomings and make suggestions how game engines can be extended to make them more suitable for such applications

Knot undulator to generate linearly polarized photons with low on-axis power density

Heat load on beamline optics is a serious problem to generate pure linearly polarized photons in the third generation synchrotron radiation facilities. For permanent magnet undulators, this problem can be overcome by a figure-8 operating mode. But there is still no good method to tackle this problem for electromagnetic elliptical undulators. Here, a novel operating mode is suggested, which can generate pure linearly polarized photons with very low on-axis heat load. Also the available minimum photon energy of linearly polarized photons can be extended much by this method

Enhancing virtual environment-based surgical teamwork training with non-verbal communication

Virtual reality simulations for training surgical skills are increasingly used in medical education and have been shown to improve patient outcome. While advances in hardware and simulation techniques have resulted in many commercial applications for training technical skills, most of these simulators are extremely expensive and do not consider non-technical skills like teamwork and communication. This is a major drawback since recent research suggests that a large percentage of mistakes in clinical settings are due to communication problems. In addition, training teamwork can also improve the efficiency of a surgical team and as such reduce costs and workload. We present an inexpensive camera-based system for capturing aspects of non-verbal communication of users participating in virtual environment-based teamwork simulations. This data can be used for the enhancement of virtual-environment-based simulations to increase the realism and effectiveness of team communication

Seeing with sound? Exploring different characteristics of a visual-to-auditory sensory substitution device

Sensory substitution devices convert live visual images into auditory signals, for example with a web camera (to record the images), a computer (to perform the conversion) and headphones (to listen to the sounds). In a series of three experiments, the performance of one such device (‘The vOICe’) was assessed under various conditions on blindfolded sighted participants. The main task that we used involved identifying and locating objects placed on a table by holding a webcam (like a flashlight) or wearing it on the head (like a miner’s light). Identifying objects on a table was easier with a hand-held device, but locating the objects was easier with a head-mounted device. Brightness converted into loudness was less effective than the reverse contrast (dark being loud), suggesting that performance under these conditions (natural indoor lighting, novice users) is related more to the properties of the auditory signal (ie the amount of noise in it) than the cross-modal association between loudness and brightness. Individual differences in musical memory (detecting pitch changes in two sequences of notes) was related to the time taken to identify or recognise objects, but individual differences in self-reported vividness of visual imagery did not reliably predict performance across the experiments. In general, the results suggest that the auditory characteristics of the device may be more important for initial learning than visual associations

An intuitive tangible game controller

This paper outlines the development of a sensory feedback device providing a low cost, versatile and intuitive interface for controlling digital environments, in this example a flight simulator. Gesture based input allows for a more immersive experience, so rather than making the user feel like they are controlling an aircraft the intuitive interface allows the user to become the aircraft that is controlled by the movements of the user's hand. The movements are designed to feel intuitive and allow for a sense of immersion that would be difficult to achieve with an alternative interface. In this example the user's hand can become the aircraft much the same way that a child would imagine it