Browsing by Subject "NORM"

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  • Ahmad, Faraaz; Morris, Katherine; Law, Gareth T.W.; Taylor, Kevin G.; Shaw, Samuel (2021)
    Understanding the speciation and fate of radium during operational discharge from the offshore oil and gas industry into the marine environment is important in assessing its long term environmental impact. In the current work, Ra-226 concentrations in marine sediments contaminated by produced water discharge from a site in the UK were analysed using gamma spectroscopy. Radium was present in field samples (0.1-0.3 Bq g(-1)) within International Atomic Energy Agency activity thresholds and was found to be primarily associated with micron sized radiobarite particles (
  • Di Plinio, Francesco; Li, Kangwei; Martikainen, Henri; Vuorinen, Emil (2020)
    We prove L-p bounds for the extensions of standard multilinear Calderon-Zygmund operators to tuples of UMD spaces tied by a natural product structure. The product can, for instance, mean the pointwise product in UMD function lattices, or the composition of operators in the Schatten-von Neumann subclass of the algebra of bounded operators on a Hilbert space. We do not require additional assumptions beyond UMD on each space-in contrast to previous results, we e.g. show that the Rademacher maximal function property is not necessary. The obtained generality allows for novel applications. For instance, we prove new versions of fractional Leibniz rules via our results concerning the boundedness of multilinear singular integrals in non-commutative L-p spaces. Our proof techniques combine a novel scheme of induction on the multilinearity index with dyadic-probabilistic techniques in the UMD space setting.
  • Suominen, Topi (Helsingin yliopisto, 2020)
    Naturally occurring radioactive material (NORM) is defined by the IAEA as “Radioactive material containing no significant amounts of radionuclides other than naturally occurring radionuclides”. In the EC directive 2013/58/Euratom several industry sectors are listed that are known to often deal with NORM, either in residues, wastes, by-products, or products, the mining industry is one of these. The risk posed by NORM is defined by exposure potential and concentration. In the wastes created by the mining industry these are tied to the management of wastes and concentration of radionuclides in the exploited mineral resource. Wastes created by the mining industry are often of environmental concern as they are in many cases piled on the mining site after closure. The tailings of a mine may contain pyrite, which when oxidized creates acid mine drainage. The acidic waters in such sites can enhance the mobility of radionuclides and other harmful elements. In this thesis two mine waste sites were selected for study, which were known to have had issues with natural radioactivity. These two sites were the old Zn, Pb, Cu mine of Vihanti and the Pb, REE mine of Korsnäs. The current state of these two sites was studied. Possible transport of radionuclides or other harmful elements and the dose to a member of the public on the sites was also studied. Soil, waste, sediment, and water samples were collected from both sites and analyzed. Solid samples were analyzed using gamma spectrometry and the radionuclides of interest were: 238U, 226Ra, 210Pb, 232Th, 228Th, 228Ra. Water samples were analyzed with ICP-MS and the elements measured with this method were: Al, Si, P, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Pb and U. In addition, some mine waste samples were studied further using XRF and SR-XRPD methods. The results of this thesis indicate that in Vihanti, the wastes have been adequately covered, reducing the external radiation dose to near background levels. The gamma spectrometry results showed no concerning activity concentrations in soil, sediment or waste samples. Two locations were found where the ICP-MS analyses yielded high concentrations of nearly all measured elements, the pH of these sites was low as well. Signs of acid mine drainage were found in these locations, but the effects seem to be localized and no evidence of large-scale transport of contaminants through waterways was found. In Korsnäs the wastes are split into two piles, one containing tailings, and the other enriched lanthanide that was never sold. The results indicate that the lanthanide pile has been adequately covered and the external radiation dose around the pile is near background levels. While the tailings have not been covered like the lanthanide pile has, the results showed that a member of the public is unlikely to receive a dose exceeding 0.1 mSv/a from spending time on the site. Activity concentrations exceeding 1 Bq/g were detected in samples collected from the lanthanide pile, with some evidence of uranium mobilization also seen. In addition, uranium concentrations in the waters of the old open pit mine were relatively high.
  • Hassan, Karl A.; Liu, Qi; Elbourne, Liam D.H.; Ahmad, Irshad; Sharples, David; Naidu, Varsha; Chan, Chak Lam; Li, Liping; Harborne, Steven P.D.; Pokhrel, Alaska; Postis, Vincent L.G.; Goldman, Adrian; Henderson, Peter J.F.; Paulsen, Ian T. (2018)
    Abstract The proteobacterial antimicrobial compound efflux (PACE) family of transport proteins was only recently described. PACE family transport proteins can confer resistance to a range of biocides used as disinfectants and antiseptics, and are encoded by many important Gram-negative human pathogens. However, we are only just beginning to appreciate the range of functions and the mechanism(s) of transport operating in these proteins. Genes encoding PACE family proteins are typically conserved in the core genomes of bacterial species rather than on recently acquired mobile genetic elements, suggesting that they confer important core functions in addition to biocide resistance. Three-dimensional structural information is not yet available for PACE family proteins. However, PACE proteins have several very highly conserved amino acid sequence motifs that are likely to be important for substrate transport. PACE proteins also display strong amino acid sequence conservation between their N- and C-terminal halves, suggesting that they evolved by duplication of an ancestral protein comprised of two transmembrane helices. In light of their drug resistance functions in Gram-negative pathogens, PACE proteins should be the subject of detailed future investigation.
  • Jokinen, Maarit Anneli; Hujala, Teppo; Paloniemi, Riikka; Vainio, Satu Annukka (2018)
    Species protection legislation has been used as one of the main approaches in conservation - yet in many cases we know only little about the effectiveness and side-effects of such regulation. Noncompliance can limit effectiveness of legislative protection, and deliberate harmful actions by landowners have sometimes been reported as a response to restrictions. We studied attitudes of 186 Finnish forest owners toward the protection of Siberian flying squirrel Pteromys volans - a species which is protected according to the European Union Habitats Directive and is a well-known example for species protection in Finland. We explored the attitudes and claims of harming protected species by comparing the responses of persons with and without direct experience of legal protection by structural equation modelling. We found that experience did not explain forest owners' attitudes toward having the species in their forest. Claims of harming protected species were connected to policy attitudes and should be interpreted as a political phenomenon: they reflect political discourse on conservation policy and are a part of debate between stakeholders. Accidental and reckless noncompliance seem more important phenomena than intentional harming, especially as the chance in Finnish Nature conservation likely Act likely affects information of nest sites on logging areas. Other instruments than legislative protection of known nest sites might be more effective in protecting the flying squirrel population. (C) 2018 The Authors. Published by Elsevier B.V.
  • Hytonen, Tuomas; Petermichl, Stefanie; Volberg, Alexander (2019)
    We prove the matrix A(2) conjecture for the dyadic square function, that is, an estimate of the form vertical bar vertical bar S-w vertical bar vertical bar(L2cd(w)-> Lr2) less than or similar to [W](A2), where the focus is on the sharp linear dependence on the matrix A(2) constant. Moreover, we give a mixed estimate in terms of A(2) and A(infinity) constants. The key to the proof is a sparse domination of a process inspired by the integrated form of the matrix-weighted square function.