Coal feed component testing for CDIF

Investigations conducted during the conceptual design of the Montana MHD Component Development and Integration Facility (CDIF) identified commercially available processing and feeding equipment potentially suitable for use in a reference design. Tests on sub-scale units of this equipment indicated that they would perform as intended

The Physio-Chemical Properties for the Interior of Enceladus

We have reviewed the current physical and chemical conditions of the Enceladus sub-surface environment, including the composition, temperature, pH and pressure. Here we have defined some of these parameters and, through the aid of modelling, will define and refine the remaining parameters needed for our experimental work. Simulations of the chemical reactions occurring within Enceladus can then be carried out to advance our understanding of the internal environment of Enceladus and help evaluate its potential habitability. Once a better understanding of the chemical reactions occurring at the rock-water interface has been carried out, then potential analogues on Earth can be evaluated and known microbial life can be tested to see if it could survive the conditions of Enceladus

Differentiation and Replication of Spots in a Reaction Diffusion System with Many Chemicals

The replication and differentiation of spots in reaction diffusion equations are studied by extending the Gray-Scott model with self-replicating spots to include many degrees of freedom needed to model systems with many chemicals. By examining many possible reaction networks, the behavior of this model is categorized into three types: replication of homogeneous fixed spots, replication of oscillatory spots, and differentiation from `m ultipotent spots'. These multipotent spots either replicate or differentiate into other types of spots with different fixed-point dynamics, and as a result, an inhomogeneous pattern of spots is formed. This differentiation process of spots is analyzed in terms of the loss of chemical diversity and decrease of the local Kolmogorov-Sinai entropy. The relevance of the results to developmental cell biology and stem cells is also discussed.Comment: 8 pages, 12 figures, Submitted to EP

Comprehensive Organic Analysis of Antartic Micrometeorites

Introduction: Micrometeorites (MMs) are thought to be significant contributors of organic material to the early Earth [1], and a variety of techniques have been employed to identify their organic composition [2-6]. These include the identification of key organic groups using combinations of infrared, energy dispersive Xray, electron energy loss and Raman spectroscopy and scanning transmission X-ray microscopy [2-4], highlighting similarities between that of MMs and carbonaceous chondrites. Few studies, however, have focused on the characterisation of individual micrometeoritic organic components. Microscopic L2MS has been used to identify up to C5 polycyclic aromatic hydrocarbons and their alkyl derivatives [5]. A combination of ionexchange chromatography and fluorimetric detection has also been successful in identifying a number of protein amino acids including glycine and alanine [6]. We have previously reported a method to analyse ?g-sized quantities of extraterrestrial materials, with prior application to assessing organic volatile release from MM atmospheric entry heating simulations [7]. In this study we utilise this technique to characterise the organic composition of Antarctic terrestrial particles and MMs collected in 1994 from Cap-Prudhomme [8]

Learning Incoherent Subspaces: Classification via Incoherent Dictionary Learning

In this article we present the supervised iterative projections and rotations (s-ipr) algorithm, a method for learning discriminative incoherent subspaces from data. We derive s-ipr as a supervised extension of our previously proposed iterative projections and rotations (ipr) algorithm for incoherent dictionary learning, and we employ it to learn incoherent sub-spaces that model signals belonging to different classes. We test our method as a feature transform for supervised classification, first by visualising transformed features from a synthetic dataset and from the ‘iris’ dataset, then by using the resulting features in a classification experiment

On the accuracy of retrieved wind information from Doppler lidar observations

A single pulsed Doppler lidar was successfully deployed to measure air flow and turbulence over the Malvern hills, Worcester, UK. The DERA Malvern lidar used was a CO2 µm pulsed Doppler lidar. The lidar pulse repetition rate was 120 Hz and had a pulse duration of 0.6 µs The system was set up to have 41 range gates with range resolution of 112 m. This gave a theoretical maximum range of approximately 4.6 km. The lidar site was 2 km east of the Malvern hill ridge which runs in a north-south direction and is approximately 6 km long. The maximum height of the ridge is 430 m. Two elevation scans (Range-Height Indicators) were carried out parallel and perpendicular to the mean surface flow. Since the surface wind was primarily westerly the scans were carried out perpendicular and parallel to the ridge of the Malvern hills. The data were analysed and horizontal winds, vertical winds and turbulent fluxes were calculated for profiles throughout the boundary layer. As an aid to evaluating the errors associated with the derivation of velocity and turbulence profiles, data from a simple idealized profile was also analysed using the same method. The error analysis shows that wind velocity profiles can be derived to an accuracy of 0.24 m s-1 in the horizontal and 0.3 m s-1 in the vertical up to a height of 2500 m. The potential for lidars to make turbulence measurements, over a wide area, through the whole depth of the planetary boundary layer and over durations from seconds to hours is discussed

Mask-Less Crystalline Silicon Solar Cell (May 2009)

A mask-less crystalline silicon solar cell was made by using a surface texturing technique coupled with an oblique aluminum evaporation. To achieve this, trenches with a steep sidewall are mechanically grooved into the bulk silicon using the KS 775 Wafer Saw. More importantly, metal evaporation with the CVC evaporator at angles near parallel to the wafer surface allows deposition to occur along the side of the trenches creating the self-aligning front metal contacts. Of the four solar cells that made it through the processing, only one solar cell showed diode like 1-V characteristics. The dark conditions shows a diode 1-V where current doesn’t flow with a negative applied voltage and in the forward applied voltage, there is a turn on voltage around 0.6V, typical of a silicon diode. This is followed by an exponential gain in current. The n value of the diode is under dark conditions is 1.7. Under illuminated conditions, the I-V curve shows a dramatic negative current for voltages below 0.25V. This isn’t the I-V curve of a solar cell but it does show that this device is light sensitive. The other three solar cells made are resistors with resistances of 4 Ω, 2 Ω and 19.2 Ω for wafers 3, 4 and 5 respectively. The shorts on the solar cells are due to a nonuniformly coated N-250 spin on glass (SOG) for the n+ layer on the p type wafer. Air pockets remained in the trenches and kept certain spots on the wafer surface to remain p. When the Al front contacts and bus paste are applied to the solar cells, it creates the p-n junction shorts. This was confirmed by breaking wafer 3 into smaller pieces where one of the pieces had a uniform n+ layer that showed I-V curves of a diode

Patient reactions to a web-based cardiovascular risk calculator in type 2 diabetes: a qualitative study in primary care.

Use of risk calculators for specific diseases is increasing, with an underlying assumption that they promote risk reduction as users become better informed and motivated to take preventive action. Empirical data to support this are, however, sparse and contradictory