Downward migration of Chernobyl-derived radionuclides in soils in Poland and Sweden   总被引：1，自引：0，他引：1  

Gerald Matisoff  Michael E. KettererKlas Rosén  Jerzy W. MietelskiLauren F. Vitko  Henning PerssonEdyta Lokas 《Applied Geochemistry》2011,26(1):105-115

Vertical profiles of ¹³⁷Cs and ^239,240Pu were measured in soils collected from two sites in southern Sweden and three sites in southern Poland and were modeled using both a solute transport model and a bioturbation model to better understand their downward migration. A time series of measured ¹³⁷Cs profiles indicates that ¹³⁷Cs from Chernobyl was found at the soil surface in 1986 but it has migrated progressively downward into the soil 4.5-25.5 cm since. However, because of dispersion during the migration and mixing following Chernobyl deposition and the much higher activities of ¹³⁷Cs from Chernobyl, stratospheric fallout of ¹³⁷Cs from the 1960s cannot be identified as a second ¹³⁷Cs activity maximum lower in the soil column at any of the sites. Conversely, the ²⁴⁰Pu/²³⁹Pu ratio indicates that no Chernobyl-derived Pu is present in any of the cores with the exception of one sample in Sweden. This difference may be attributed to the nature of the release from Chernobyl. Cesium volatilized at the reactor temperature during the accident, and was released as a vapor whereas Pu was not volatile and was only released in the form of minute fuel particles that traveled regionally. Both the solute diffusion and the bioturbation models accurately simulate the downward migration of the radionuclides at some sites but poorly describe the distributions at other sites. The distribution coefficients required by the solute transport model are about 100 times lower than reported values from the literature indicating that even though the solute transport model can simulate the profile shapes, transport as a solute is not the primary mechanism governing the downward migration of either Cs or Pu. The bioturbation model uses reported values from the literature of the distribution coefficients and can simulate the downward migration because that model buries the fallout by placing soil from depth on top and mixing it slightly throughout the mixing zone (0.6-2% per year of mixing). However, mixing in that model predicts concentrations in the top parts of the soil profiles which are too high in many cases. Future progress at understanding the downward migration of radionuclides and other tracers will require a more comprehensive approach, combining solute transport with bioturbation and including other important soil processes.  相似文献   

Ecosystem-based marine spatial management: Review of concepts, policies, tools, and critical issues   总被引：1，自引：0，他引：1  

Stelios Katsanevakis  Vanessa Stelzenmüller  Andy South  Thomas Kirk Sørensen  Peter J.S. Jones  Sandy Kerr  Fabio Badalamenti  Christos Anagnostou  Patricia Breen  Guillem Chust  Giovanni D’Anna  Mike Duijn  Tatiana Filatova  Fabio Fiorentino  Helena Hulsman  Kate Johnson  Aristomenis P. Karageorgis  Ingrid Kröncke  Simone Mirto  Carlo Pipitone  Susan Portelli  Wanfei Qiu  Henning Reiss  Dimitris Sakellariou  Maria Salomidi  Luc van Hoof  Vassiliki Vassilopoulou  Tomás Vega Fernández  Sandra Vöge  Anke Weber  Argyro Zenetos  Remment ter Hofstede 《Ocean & Coastal Management》2011,54(11):807-820

Conventional sectoral management and piecemeal governance are considered less and less appropriate in pursuit of sustainable development. Ecosystem based marine spatial management (EB-MSM) is an approach that recognizes the full array of interactions within an ecosystem, including human uses, rather than considering single issues, species, or ecosystem services in isolation. Marine spatial planning and ocean zoning are emerging concepts that can support EB-MSM. EB-MSM is driven by high-level goals that managers aim to achieve through the implementation of measures. High-level goals and objectives need to be translated into more operational objectives before specific targets, limits and measures can be elaborated.Monitoring, evaluation and adaptation are necessary to ensure that marine management measures are both effective and efficient. Solid monitoring frameworks are the foundation of adaptive management, as they provide the necessary information to evaluate performance and the effectiveness of management actions. Marine protected areas (MPAs) - possibly set up in networks - constitute a key component in EB-MSM policies and practises and have been applied as a cornerstone in conservation of marine biodiversity, management of fish populations, development of coastal tourism, etc. Moreover, MPA experiences have provided methods and concepts (such as zoning) to a wider EB-MSM context. The assignment of values to biophysical features of the marine environment allows the direct assessment of related management choices and may assist EB-MSM.A range of monetary valuation techniques have been proposed to reduce attributes of goods and services to a single metric. However, in the marine environment such an approach is often over simplistic, and thus less reductive techniques may be necessary. Rather than producing a single metric, the results of non-monetary assessments guide policy allowing weight to be given as necessary to potential areas of conflict and consensus.Strategies to take into account climate change effects and geohazard risks in EB-MSM have been applied or proposed worldwide. EB-MSM regimes must be alert to such risks and flexible to account for changes.  相似文献   

The importance of health co-benefits in macroeconomic assessments of UK Greenhouse Gas emission reduction strategies     

Henning Tarp Jensen  Marcus R. Keogh-Brown  Richard D. Smith  Zaid Chalabi  Alan D. Dangour  Mike Davies  Phil Edwards  Tara Garnett  Moshe Givoni  Ulla Griffiths  Ian Hamilton  James Jarrett  Ian Roberts  Paul Wilkinson  James Woodcock  Andy Haines 《Climatic change》2013,119(2):223-237

We employ a single-country dynamically-recursive Computable General Equilibrium model to make health-focussed macroeconomic assessments of three contingent UK Greenhouse Gas (GHG) mitigation strategies, designed to achieve 2030 emission targets as suggested by the UK Committee on Climate Change. In contrast to previous assessment studies, our main focus is on health co-benefits additional to those from reduced local air pollution. We employ a conservative cost-effectiveness methodology with a zero net cost threshold. Our urban transport strategy (with cleaner vehicles and increased active travel) brings important health co-benefits and is likely to be strongly cost-effective; our food and agriculture strategy (based on abatement technologies and reduction in livestock production) brings worthwhile health co-benefits, but is unlikely to eliminate net costs unless new technological measures are included; our household energy efficiency strategy is likely to breakeven only over the long term after the investment programme has ceased (beyond our 20 year time horizon). We conclude that UK policy makers will, most likely, have to adopt elements which involve initial net societal costs in order to achieve future emission targets and longer-term benefits from GHG reduction. Cost-effectiveness of GHG strategies is likely to require technological mitigation interventions and/or demand-constraining interventions with important health co-benefits and other efficiency-enhancing policies that promote internalization of externalities. Health co-benefits can play a crucial role in bringing down net costs, but our results also suggest the need for adopting holistic assessment methodologies which give proper consideration to welfare-improving health co-benefits with potentially negative economic repercussions (such as increased longevity).  相似文献   

A comment on an analytical stellar model     

Henning Knutsen 《Astrophysics and Space Science》1988,150(1):201-201

Recently, an analytical stellar model was presented. We show that the results are incorrect as they stand.  相似文献   

The large-scale distribution of neutral hydrogen in the Fornax region     

Meryl Waugh  M. J. Drinkwater  R. L. Webster  L. Staveley-Smith  V. A. Kilborn  D. G. Barnes  R. Bhathal  W. J. G. de Blok  P. J. Boyce  M. J. Disney  R. D. Ekers  K. C. Freeman  B. K. Gibson  P. A. Henning  H. Jerjen  P. M. Knezek  B. Koribalski  M. Marquarding  R. F. Minchin  R. M. Price  M. E. Putman  †  S. D. Ryder  E. M. Sadler  F. Stootman  M. A. Zwaan 《Monthly notices of the Royal Astronomical Society》2002,337(2):641-656

  相似文献   

Bert Bolin and His Scientific Career     

Henning Rodhe  . 《地球，A辑:动力气象学与海洋学》1991,43(4):3-7

  相似文献   

Metallographic cooling rates of group IIF iron meteorites     

Kaare L. RASMUSSEN  Henning HAACK  Finn ULFF‐M LLER 《Meteoritics & planetary science》2001,36(7):883-896

Abstract— Metallographic cooling rates have been calculated for all five members of the iron meteorites group IIF using two different techniques. We have determined cooling rates of ～5 °C/Ma based on Ni profiles through the taenite rim enclosing kamacite spindles. Ni profiles through the kamacite phase are less precise cooling rate indicators, but suggest a cooling rate of ～1 °C/Ma within an order of magnitude at lower temperatures (360–400 °C). Based on the kamacite bandwidth and the Ni profiles through the taenite, we estimate that the kamacite nucleated 130–200 °C below the temperature predicted from the phase diagram. The size of and the distance between the large kamacite spindles is found to be consistent with the thermal history that we have determined on the basis of Ni profiles in kamacite and taenite. We find that previously published kamacite bandwidth cooling rates for the five group IIF members are most likely in error because of the presence of large schreibersite spindles in some kamacite spindles and because undercooling of kamacite was ignored. Contrary to previous workers we find that the metallographic cooling rates are consistent with cooling in a common core.  相似文献   

The search for extrasolar giant planets using integral field spectroscopy: Simulations     

Alessandro Berton  Markus Feldt  Raffaele Gratton  Stefan Hippler  Thomas Henning 《New Astronomy Reviews》2006,49(10-12):661

We present here simulations of extrasolar planets detections obtained using a combination of extreme adaptive optics and integral field spectroscopy. The simulation code, written for IDL, provides images and, in particular, spectra, taking into account realistic Speckle Noise, AO correction effects and specific instrumental features. A detailed study has been done for ESO VLT telescopes (8.2 m), within the Phase A of the CHEOPS project, but the code is particularly flexible and can be updated for larger telescope diameters (ELTs) in order to give a realistic estimate of the detection limits, for giant telescopes, in standard conditions of seeing.  相似文献   

The Arecibo Galaxy Environment Survey: precursor observations of the NGC 628 group     

R. Auld  R. F. Minchin  J. I. Davies  B. Catinella  W. van Driel  P. A. Henning  S. Linder  E. Momjian  E. Muller  K. O'Neil  S. Sabatini  S. Schneider  G. Bothun  L. Cortese  M. Disney  G. L. Hoffman  M. Putman  J. L. Rosenberg  M. Baes  W. J. G. de Blok  A. Boselli  E. Brinks  N. Brosch  J. Irwin  I. D. Karachentsev  V. A. Kilborn  B. Koribalski  K. Spekkens † 《Monthly notices of the Royal Astronomical Society》2006,371(4):1617-1640

  相似文献   

EDITORIAL     

Harald LejenäsEditor-in-Chief Tellus A  Henning RodheEditor-in-Chief Tellus B 《地球，A辑:动力气象学与海洋学》2004,56(1):1-1

  相似文献