| 1. |
- Bontidean, Ibolya, et al.
(författare)
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Biosensors for detection of mercury in contaminated soils
- 2004
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Ingår i: Environmental Pollution. - : Elsevier BV. - 0269-7491. ; 131:2, s. 255-262
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Tidskriftsartikel (refereegranskat)abstract
- Biosensors based on whole bacterial cells and on bacterial heavy metal binding protein were used to determine the mercury concentration in soil. The soil samples were collected in a vegetable garden accidentally contaminated with elemental mercury 25 years earlier. Bioavailable mercury was measured using different sensors: a protein-based biosensor, a whole bacterial cell based biosensor, and a plant sensor, i.e. morphological and biochemical responses in primary leaves and roots of bean seedlings grown in the mercury-contaminated soil. For comparison the total mercury concentration of the soil samples was determined by AAS. Whole bacterial cell and protein-based biosensors gave accurate responses proportional to the total amount of mercury in the soil samples. On the contrary, plant sensors were found to be less useful indicators of soil mercury contamination, as determined by plant biomass, mercury content of primary leaves and enzyme activities. (C) 2004 Elsevier Ltd. All rights reserved.
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| 2. |
- Kuznetsov, A. Y., et al.
(författare)
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Self-interstitial migration during ion irradiation of boron delta-doped silicon
- 2000
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Ingår i: Materials Science in Semiconductor Processing. - 1369-8001 .- 1873-4081. ; 3:4, s. 279-283
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Tidskriftsartikel (refereegranskat)abstract
- Boron delta layers in silicon, grown by molecular beam epitaxy and characterized by the secondary ion mass spectrometry, have been employed to investigate the migration of silicon self-interstitials during irradiation with MeV protons in the 500-850 degreesC temperature range. After growth, the samples were thinned from the backside to a thickness that made them transparent for the proton energies used. As a result, the generation rate of point defects can be considered as essentially uniform throughout the samples. However: the evolution of the boron profiles is almost identical to that observed after injection of self-interstitials caused by thermal oxidation of the samples at elevated temperature. This strongly indicates that the surface acts as a reflective boundary for the migrating self-interstitials or/ and an efficient sink for mobile vacancies. Furthermore, higher value of interstitial supersaturation in the near-surface region in proton-irradiated samples is consistent with experimentally detected depth dependence for immobile fraction in boron clusters. Then, activation energy of boron mobilization, (0.9 +/- 0.4) eV, was attributed to the dissociation of boron clusters.
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