12,204 research outputs found
Recommended from our members
The normalisation of Food Aid: What happened to feeding people well?
In the UK, food poverty has increased in the last 15 years and the food aid supply chain that has emerged to tackle it is now roughly 10 years old. In this time, we have seen the food aid supply chain grow at a rate that has astounded many. Recently that growth has been aided by a grant of £20m from a large supermarket chain. It appears institutionalisation is just around the corner, if not already here. It also appears that there is far greater emphasis on dealing with the symptoms as opposed to solving the root causes of the problem. As an opinion piece, this paper reflects on some of the prevalent issues, and suggests some ways forward
Cold water aquifer storage
A working prototype system is described in which water is pumped from an aquifer at 70 F in the winter time, chilled to a temperature of less than 50 F, injected into a ground-water aquifer, stored for a period of several months, pumped back to the surface in the summer time. A total of 8.1 million gallons of chilled water at an average temperature of 48 F were injected. This was followed by a storage period of 100 days. The recovery cycle was completed a year later with a total of 8.1 million gallons recovered. Approximately 20 percent of the chill energy was recovered
Geodesic flow on three dimensional ellipsoids with equal semi-axes
Following on from our previous study of the geodesic flow on three
dimensional ellipsoid with equal middle semi-axes, here we study the remaining
cases: Ellipsoids with two sets of equal semi-axes with
symmetry, ellipsoids with equal larger or smaller semi-axes with SO(2)
symmetry, and ellipsoids with three semi-axes coinciding with SO(3) symmetry.
All of these cases are Liouville-integrable, and reduction of the symmetry
leads to singular reduced systems on lower-dimensional ellipsoids. The critical
values of the energy-momentum maps and their singular fibers are completely
classified. In the cases with SO(2) symmetry there are corank 1 degenerate
critical points; all other critical points are non-degenreate. We show that in
the case with symmetry three global action variables exist
and the image of the energy surface under the energy-momentum map is a convex
polyhedron. The case with SO(3) symmetry is non-commutatively integrable, and
we show that the fibers over regular points of the energy-casimir map are
bundles over .Comment: 34 pages, 10 figure
Phase equilibrium modeling for high temperature metallization on GaAs solar cells
Recent trends in performance specifications and functional requirements have brought about the need for high temperature metallization technology to be developed for survivable DOD space systems and to enhance solar cell reliability. The temperature constitution phase diagrams of selected binary and ternary systems were reviewed to determine the temperature and type of phase transformation present in the alloy systems. Of paramount interest are the liquid-solid and solid-solid transformations. Data are being utilized to aid in the selection of electrical contact materials to gallium arsenide solar cells. Published data on the phase diagrams for binary systems is readily available. However, information for ternary systems is limited. A computer model is being developed which will enable the phase equilibrium predictions for ternary systems where experimental data is lacking
Changes in movement symmetry over the stages of the shoeing process in military working horses
DeepFactors: Real-time probabilistic dense monocular SLAM
The ability to estimate rich geometry and camera motion from monocular imagery is fundamental to future interactive robotics and augmented reality applications. Different approaches have been proposed that vary in scene geometry representation (sparse landmarks, dense maps), the consistency metric used for optimising the multi-view problem, and the use of learned priors. We present a SLAM system that unifies these methods in a probabilistic framework while still maintaining real-time performance. This is achieved through the use of a learned compact depth map representation and reformulating three different types of errors: photometric, reprojection and geometric, which we make use of within standard factor graph software. We evaluate our system on trajectory estimation and depth reconstruction on real-world sequences and present various examples of estimated dense geometry
- …
