Cell parameter correlations in the aluminosilicate-sodalites     

Derek Taylor 《Contributions to Mineralogy and Petrology》1975,51(1):39-47

Cell parameters, ranging from 8.447 to 9.331 Å, are given for 13 synthetic aluminosilicate-sodalites. Correlations between the cell edge of aluminosilicate-sodalites and the sizes of the cavity ions are established and discussed. The principal infrared absorption bands for 6 synthetic and 4 natural aluminosilicate-sodalites are also correlated with the cell edge and discussed in terms of the bonding theory of linked TO₄ tetrahedra (T=Si, Al).  相似文献   

Biomagnification     

Fisk AT  Hoekstra PF  Borgå K  Muir DC 《Marine pollution bulletin》2003,46(4):522-4; author reply 525-6

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The concept of "sustainable ecological succession"; and its value in assessing the recovery of sediment seabed biodiversity from environmental impact     

Ellis DV 《Marine pollution bulletin》2003,46(1):39-41

The problem of determining whether the biodiversity of an impacted muddy seabed is recovering can be resolved by drawing on a concept termed "sustainable ecological succession". At a site impacted by discharge of mine tailings, a suite of approximately 6 primary opportunist species (mostly polychaete worms) had started to sustain itself within 1-2 years after discharge ceased (1995), within the mix of 100+ other species which were not sustaining themselves. The start of a sustaining ecological succession is easily measurable by repeat surveys, and requires only the services of one taxonomic identifier to demonstrate the consistent presence and numbers of a limited range of species. At the assessed site, by 2000, some secondary opportunist species had entered the succession, and the species richness of the impacted area had come to equal that of the reference areas.  相似文献   

For the love of pipes and cables: a response to Deborah Thien   总被引：2，自引：0，他引：2  

Derek McCormack 《Area》2006,38(3):330-332

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Carbon Capture and Storage From Fossil Fuels and Biomass – Costs and Potential Role in Stabilizing the Atmosphere     

Christian Azar  Kristian Lindgren  Eric Larson  Kenneth Möllersten 《Climatic change》2006,74(1-3):47-79

The capture and storage of CO₂ from combustion of fossil fuels is gaining attraction as a means to deal with climate change. CO₂ emissions from biomass conversion processes can also be captured. If that is done, biomass energy with CO₂ capture and storage (BECS) would become a technology that removes CO₂ from the atmosphere and at the same time deliver CO₂-neutral energy carriers (heat, electricity or hydrogen) to society. Here we present estimates of the costs and conversion efficiency of electricity, hydrogen and heat generation from fossil fuels and biomass with CO₂ capture and storage. We then insert these technology characteristics into a global energy and transportation model (GET 5.0), and calculate costs of stabilizing atmospheric CO₂ concentration at 350 and 450 ppm. We find that carbon capture and storage technologies applied to fossil fuels have the potential to reduce the cost of meeting the 350 ppm stabilisation targets by 50% compared to a case where these technologies are not available and by 80% when BECS is allowed. For the 450 ppm scenario, the reduction in costs is 40 and 42%, respectively. Thus, the difference in costs between cases where BECS technologies are allowed and where they are not is marginal for the 450 ppm stabilization target. It is for very low stabilization targets that negative emissions become warranted, and this makes BECS more valuable than in cases with higher stabilization targets. Systematic and stochastic sensitivity analysis is performed. Finally, BECS opens up the possibility to remove CO₂ from the atmosphere. But this option should not be seen as an argument in favour of doing nothing about the climate problem now and then switching on this technology if climate change turns out to be a significant problem. It is not likely that BECS can be initiated sufficiently rapidly at a sufficient scale to follow this path to avoiding abrupt and serious climate changes if that would happen.  相似文献   

Rural diversification in Albania     

Derek R. Hall 《GeoJournal》1998,46(3):283-287

This paper examines the prospects for Albanian rural diversification with particular reference to rural tourism. In the early 1990s, tourism was identified by the Albanian government and Western development consultants as a likely vehicle for an appropriate and sustainable development strategy, given the relative wealth generated by international tourism in neighbouring Greece, Italy and Croatia. Pressure has been exerted by commercial developers for mass coastal tourism and permission for around 40 new tourist development has been granted. But Albania embraces a considerable wealth of natural and cultural heritage, which provides opportunities for the development of small scale rural tourism carefully integrated into the local economy with respect to organic farming, quality wine production and sustainable fishing. But sensitive social integration is vital where it is difficult to identify rural communities where there is a conspicuous absence of local consensus. The resurgence of traditional social systems and the empowerment of local actors in cases where organised crime has taken root pose major problems for rural diversification. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

New Associate Editors     

Derek Sears 《Meteoritics & planetary science》1998,33(3):383-383

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Measuring Rates of Biodegradation in a Contaminated Aquifer Using Field and Laboratory Methods   总被引：5，自引：0，他引：5  

Francis H. Chapelle  Paul M. Bradley  Derek R. Lovley  Don A. Vroblesky 《Ground water》1996,34(4):691-698

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Chemical and physical studies of type 3 chondrites—VI: Siderophile elements in ordinary chondrites     

Derek W. G. Sears  Karen S. Weeks 《Geochimica et cosmochimica acta》1986,50(12):2815-2832

The abundances of Fe, Ni, Co, Au, Ir, Ga, As and Mg have been determined by instrumental neutron activation analysis in 38 type 3 ordinary chondrites (10 of which may be paired) and 15 equilibrated chondrites. Classification of type 3 ordinary chondrites into the H, L and LL classes using oxygen isotopes and parameters which reflect oxidation state (Fa and Fs in the olivine and pyroxene and Co in kamacite) is difficult or impossible. Bulk compositional parameters, based on the equilibrated chondrites, have therefore been used to classify the type 3 chondrites. The distribution of the type 3 ordinary chondrites over the classes is very different from that of the equilibrated chondrites, the LL chondrites being more heavily represented. The type 3 ordinary chondrites contain 5 to 15 percent lower abundances of siderophile elements and a compilation of the present data and literature data indicates a small, systematic decrease in siderophile element concentration with decreasing petrologic type. The type 3 ordinary chondrites have, like the equilibrated ordinary chondrites, suffered a fractionation of their siderophile elements, but the loss of Ni in comparison with Au and Ir is greater for the type 3 chondrites. These siderophile element trends were established at the nebula phase of chondritic history and the co-variation with petrologic type implies onion-shell structures for the ordinary chondrite parent bodies. It is also clear that the relationship between the type 3 and the equilibrated ordinary chondrites involves more than simple, closed-system metamorphism.  相似文献   

Environmental audits     

Derek Ellis 《Marine pollution bulletin》1985,16(5):171-172

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