Thermal analysis of PMR-polyimides by dielectrometry

A preliminary study was conducted to determine the dielectric properties of glass fabric reinforced composites as influenced by the reactions occurring during the preparation of crosslinked polyimides by the PMR process. The variables studied included: formulated molecular weight, staging temperature and time; rate of temperature increase to cure temperature; and cure temperature and time. The changes of capacitance and, particularly, of dissipation factor were found to be strongly dependent on each of the variables studied

Materials technology for an advanced space power nuclear reactor concept: Program summary

The results of a materials technology program for a long-life (50,000 hr), high-temperature (950 C coolant outlet), lithium-cooled, nuclear space power reactor concept are reviewed and discussed. Fabrication methods and compatibility and property data were developed for candidate materials for fuel pins and, to a lesser extent, for potential control systems, reflectors, reactor vessel and piping, and other reactor structural materials. The effects of selected materials variables on fuel pin irradiation performance were determined. The most promising materials for fuel pins were found to be 85 percent dense uranium mononitride (UN) fuel clad with tungsten-lined T-111 (Ta-8W-2Hf)

Materials technology program for a compact fast reactor for space power

Production engineering and compatibility tests of Ta-8W-2Hf clad UN nuclear fuel element for use in lithium cooled space power unit reactor

What are the key issues regarding the role of geothermal energy in meeting energy needs in the global south?

Globally, the potential of geothermal far exceeds that of all other renewable sources together, although investment in the other sources to date has far exceeded investment in geothermal. World Energy Assessment estimates in 2000 for the global potential of all renewables (EJ/yr) were Geothermal 5000, Solar 1575, Wind 640, Biomass 276, Hydro 50, giving a total of 7541 (UNDP, 2000). When installed, geothermal plants have a far higher capacity factor than other sources (solar depends on the level of direct insolation, wind power on wind, etc.); estimates (REN21, 2009) give wind-power 21%, solar PV 14% but geothermal is at least as high as 75% and often more than 95%, given that once a plant is established it operates continuously except for routine down-time for maintenance and rare break-downs

Defining simple and comprehensive assessment units for CO2 storage in saline formations beneath the UK North Sea and continental shelf

In the UK, by far the largest CO2 storage opportunities lie offshore. The North Sea in particular has a long and complex geological history, with potential reservoirs geographically widespread and occurring at multiple stratigraphic levels. Diverse storage estimates have been made, using a range of working methods, and yielding different values, e.g. SCCS (2009); Bentham (2006). Consequently the UK Storage Appraisal Project (UKSAP), commissioned and funded by the Energy Technologies Institute (ETI), is undertaking the most comprehensive assessment to date, using abundant legacy seismic and borehole data. This study has a remit to use best current practice, consistent between locations, to calculate the CO2 storage capacity of the entire UK Continental Shelf (UKCS) within saline aquifers and hydrocarbon fields. The potential storage formations have been subdivided into units for assessment, and filtered to remove units with only a small estimated storage capacity to concentrate resources on more viable units. The size of potential storage units approximate to a power law distribution, similar to that of hydrocarbon fields, with a large number of small units and a small number of large units

Search for Dark Matter with CRESST

The search for direct interactions of dark matter particles remains one of the most pressing challenges of contemporary experimental physics. A variety of different approaches is required to probe the available parameter space and to meet the technological challenges. Here, we review the experimental efforts towards the detection of direct dark matter interactions using scintillating crystals at cryogenic temperatures. We outline the ideas behind these detectors and describe the principles of their operation. Recent developments are summarized and various results from the search for rare processes are presented. In the search for direct dark matter interactions, the CRESST-II experiment delivers competitive limits, with a sensitivity below 5x10^(-7) pb on the coherent WIMP-nucleon cross section.Comment: Accepted for publication in New Journal of Physics. 25 pages, 18 figure

Pore pressure and reservoir quality evolution in the deep Taranaki Basin, New Zealand

The Palaeocene fluvial to shallow marine sandstones of the Farewell Formation are an important proven hydrocarbon reservoir in the Taranaki Basin, New Zealand. The Kapuni Deep-1 well was drilled to target Farewell Formation sandstones in the deeper overpressured (>5000 m, >3000 psi/21 MPa) sections of the onshore Manaia Graben of the Taranaki Basin. However, the Farewell Formation sandstones display anomalously low measured helium porosities (1–4.5%) and intergranular volumes (6–11%) even for their present-day, close to maximum, burial depth (c.5000 m). One dimensional burial history modelling demonstrates initial rapid burial leading to significant porosity reduction via mechanical compaction, enhanced by poor sorting, angular grain morphology and the presence of ductile grains, which allowed efficient packing and plastic deformation. Low intergranular volume (IGV), anhedral nature of quartz overgrowths, a general lack of fluid inclusions, and poor crystalline clay mineral content indicate that early burial compactional processes significantly influenced reservoir quality. The lack of mudstone to siltstone grade lithologies within the overlying Eocene section inhibited the early or shallow onset of overpressure in the Farewell Formation, which would have led to continued low vertical effective stress (VES), shown to arrest mechanical compaction and preserve anomalously high porosity (>30%). One dimensional basin modelling has shown that rapid Pliocene subsidence related to exceptionally high sedimentation rates generated overpressure through disequilibrium compaction in the overlying Oligocene to early Miocene section during the past 6 Ma. However, the late and deep (>3000 m) onset of overpressure had no effect on arresting porosity loss in the Farewell Formation. Continued compaction of Farewell Formation sandstones after dissolution of early carbonate cements of CO2 rich fluids creates zones of extremely low permeability, which have the potential to act with interbedded shales to form pressure seals as seen in the Kapuni Field