A comparison of two baseline screening approaches to regional energy facility siting

This study evaluates the impact of Pakistan's development policies on regional development, using multi-variate statistical techniques of analysis. Regional economic development policies were inspired by the growth pole theory, but the centralized sectoral planning processes, relying on the market mechanism on the one hand and controlled fiscal and monetary policies on the other, have increased interregional development inequalities. The growth pole planning strategies have stimulated very little development in the lagging areas, especially agricultural development. Future planning strategies need to be divised that will assure development advances in Pakistan's backward regions.     

Weather compilations as a source of data for the reconstruction of european climate during the medieval period

Research into the climate of the Middle Ages has relied heavily upon data provided by compilations of references to weather and related phenomena extracted from a variety of historical texts and source documents. These compilations, produced from 1858 onwards, have generally neglected the essential need for source validation. While a considerable amount of reliable and useful information about medieval climate is to be found in documentary sources, it occurs together with material which is spurious, inaccurate, or whose reliability cannot be properly authenticated. Because they were, for the most part, scientists, unfamiliar with historical methodology and techniques of source analysis, the authors of the compilations were either unaware of the problematic character of their sources, or ignorant of the techniques developed by historians for dealing with them. The material included in the compilations must be regarded as suspect until its authenticity has been checked by validating individual sources. Unless this is done, a misleading picture of the climate of the Middle Ages may emerge from uncritical use of the compilations. In particular, the climate may appear to have been more extreme than authentic sources alone would suggest.     

Salt and subsidence in Cheshire,England

Rock salt occurs in the Keuper Marl Series of Cheshire. There are two saliferous beds, the lower being 190 m and the upper 404 m thick. However, most of the Triassic rocks in Cheshire are covered by thick superficial deposits. Nevertheless natural brine springs occur at the surface and salt has been evaporated from these springs since pre-Roman times.Subsidence occurs as a result of wild brine pumping. Gradual collapse takes place above the subterranean brine runs giving rise to cambered depressions at the surface, the flanks of which are often interrupted by tension scars. Flashes occupy many of these depressions. The most disastrous subsidences occurred towards the end of the nineteenth century due to bastard brine pumping, that is, pumping, with reckless abandon, from old mine workings. The associated subsidences were rapid and caused the destruction of many buildings. One of the awkward characteristics of subsidence in salt due to wild brine pumping is that it is unpredictable, indeed subsidence may occur several kilometres from the point of extraction. This means that an individual brine pumper could not and still cannot be proved responsible for subsidence. Accordingly, the Cheshire Brine Subsidence Compensation Board was established by act of Parliament at the end of the nineteenth century which obliged each brine pumper to contribute towards the compensation fund. Because controlled solution mining has not given rise to subsidence in its 40 years of operation this form of extraction is eventually to be extended throughout the whole of the salt field, another field is now being developed. It is hoped to phase out wild brine pumping by the 1980's.     

A crystal fractionation model for the basaltic rocks of the New Georgia Group,British Solomon Islands

Study of the data provided by Stanton and Bell (1969) for certain basaltic rocks from the New Georgia Group reveals an apparent discrepancy between compositional variation and the sequence of phenocryst phases available for fractionation. The discrepancy none-the-less appears explicable in terms of two low-pressure crystal fractionation mechanisms. The first of these we term compensated crystal settling, a process which, it is postulated, allows a substantial amount of magma undergoing crystal settling to maintain its overall composition since crystals settling from it are continually replaced by compositionally similar crystals which settle into it from higher levels. The second process involves selective fractionation of phases sinking at different rates. Slow sinking of plagioclase relative to ferromagnesian minerals is believed to produce cumulus enrichment in plagioclase in the upper part of the chamber, the resultant magmas being erupted as highly porphyritic, high-alumina, basaltic andesites.     

The geotechnical properties and behaviour of a pro-glacial lake clay, and its cementitious stabilization

The Tees Laminated Clay forms a continuous deposit around the Tees estuary in north east England and was deposited in a proglacial lake which occupied the Teesside area during late Devensian times, disappearing about 13 000 years ago. It overlies till, with which it has a sharp contact and reaches a maximum thickness in parts of central Middlesbrough of just over 9 m. The laminations consist of alternating thin layers of clay and silt, and represent seasonal increments of sediment. Kaolinite and illite, with lesser amounts of chlorite, dominate the mineral composition. Quartz tends to account for less than 35%. The notable carbonate content may be diagenetic in origin. The birefringence ratio of the clay minerals indicates a medium degree of particle orientation which suggests a partially flocculated fabric.This laminated clay has a high plasticity. However, the liquid and plastic limits of the silty layers differ significantly from those of the clay layers or the bulk samples. The clay fraction has a greater influence on these limits than the silty fraction. In addition, the linear shrinkage, liquidity indices and consistency indices of the silty layers differ appreciably from those of the clay layers and the bulk samples. The laminated clay is inactive. The orientation of the laminations in relation to the direction of maximum principal stress influences the shear strength, the lowest strengths being developed when these orientations are between 30° and 60°. The stress paths, anisotropic ratios and values of Af indicate that the Tees Laminated Clay is normally consolidated or lightly overconsolidated. The McLamore–Gray concept possibly can be applied to the anisotropic strength behaviour.Tees Laminated Clay can give rise to problems during construction operations since it can lose strength significantly on remoulding. Accordingly, these soils were treated with cementitious materials to determine the extent to which their engineering behaviour was enhanced by the addition of such materials. © Rapid Science Ltd. 1998     

New seismic data support Cenozoic rifting in George VI Sound, Antarctic Peninsula

New multifold seismic-reflection and wide-angle reflection/refraction data across George VI Sound, Antarctic Peninsula, show the presence of graben and horst structures indicating an extensional origin. The data suggest that rocks of an accretionary complex and fore-arc basin underlie the Sound and are in faulted contact along its eastern boundary with volcanic and plutonic rocks of the associated Mesozoic arc of western Palmer Land. A cover of possible syn- and postglacial Cenozoic deposits drapes the structures. The combination of new seismic, synthetic-aperture radar and previously acquired data suggests subduction-related rifting in the Sound was segmented, with opening in the south predominately by normal extension whilst in the north, dextral transtension predominated.     

Water uptake by two river red gum (Eucalyptus camaldulensis) clones in a discharge site plantation in the Western Australian wheatbelt

The heat-pulse technique was used to estimate year-long water uptake in a discharge zone plantation of 9-year-old clonal Eucalyptus camaldulensis Dehnh. near Wubin, Western Australia. Water uptake matched rainfall closely during weter months but exceeded rainfall as the dry season progressed. Average annual water uptake (1148 mm) exceeded rainfall (432 mm) by about 2.7 fold and approached 56% of pan evaporation for the area. The data suggest that at least 37% (i.e. (1/2.7) × 100) of the lower catchment discharge zone should be planted to prevent the rise of groundwater.

Water uptake varied with soil environment, season and genotype. Upslope trees used more water than did downslope trees. Water uptake was higher in E. camaldulensis clone M80 than in clone M66 until late spring. The difference reversed as summer progressed. Both clones, however, have the potential to dry out the landscape when potential evapotranspiration exceeds rainfall. This variation in water uptake within the species indicates the potential for manipulating plantation uptake by matching tree characteristics to site characteristics.

Controlled experiments on the heat-pulse technique indicated accuracy errors of approximately 10%. This, combined with the ability to obtain long-term, continuous data and the superior logistics of use of the heat-pulse technique, suggests that results obtained by it would be much more reliable than those achieved by the ventilated chamber technique.