Unbound states in quantum heterostructures

We report in this review on the electronic continuum states of semiconductor Quantum Wells and Quantum Dots and highlight the decisive part played by the virtual bound states in the optical properties of these structures. The two particles continuum states of Quantum Dots control the decoherence of the excited electron – hole states. The part played by Auger scattering in Quantum Dots is also discussed

The Ni-deposited carbon felt as substrate for preparation of Pt-modified electrocatalysts: Application for alkaline water electrolysis

A Ni-modified carbon felt (C) electrode (C/Ni) was used as a substrate for preparation of Pt-modified electrode in view of its possible application as electrocatalytic material for the hydrogen evolution activity. The prepared electrode was characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and cyclic voltammetry (CV) techniques. The hydrogen evolution activity of the electrode was assessed by cathodic current-potential curves and electrochemical impedance spectroscopy (EIS) techniques. It was found that the modification of Ni-deposited C by loading low amount of Pt could enhance the hydrogen evolution activity of the electrode. © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.BAP-52-59-2011 Firat University Scientific Research Projects Management UnitThis study has been financially supported by the Bingöl University Scientific Research Projects (BÜBAP) Coordination Unit (Project Number: BAP-52-59-2011 ). The authors are greatly thankful to BÜBAP. The authors are also greatly thankful to Prof. Mustafa Çulha (Yeditepe University) for SEM analysis

Elimination of copper in tissues and organs of rainbow trout (Oncorhynchus mykiss, Walbaum, 1792) following dietary exposure

Copper (Cu) elimination was investigated in the tissue and organs of rainbow trout (Oncorhynchus mykiss, Walbaum, 1792), after Cu-free diets exposure. In the current study, fish were fed to satiation on diets containing 0.022 (Group 1; Control), 0.043 (Group 2), 0.123 (Group 3), 0.424 (Group 4) g Cu*kg-1 diet for 60 days before elimination experiment. A total of 288 fish (mean weight 84.28±1.05 g) were randomly transferred to 12 fibreglass tanks. The fish were fed the Cu-free diet twice daily, until apparent satiation, during 60 days. Subsequently, the experiment was established for a period of elimination, during which samples were taken at days 15, 30, 45 and 60. Cu concentration in the muscle, gill tissue, digestive system, liver and whole body of fish were determined after 60 days depuration. Cu concentrations in tissues of rainbow trout decreased during depuration period, and the order of Cu elimination in tissue and organs of rainbow trout was: digestive system (73.1 %), then gill (41.1 %), muscle (31.5 %) and liver (17.2 %) for group 2; digestive system (74.1%), then muscle (65.8%), gill (60.0%) and liver (34.6%) for group 3; and digestive system (85.8%), then muscle (80.8%), liver (50.5%) and less/equal in gill (50.2%) for group 4. In statistical analysis, both groups and time were significant factors (P<0.05) on elimination rate. Moreover, significant interaction between groups and time were identified on elimination rate. Digestive system showed the fastest elimination rates of Cu at all groups compared with other tissues. © A. Gündogdu et al

Activity concentration measurements of 137Cs, 90Sr and 40K in a wild food matrix reference material (Wild Berries) CCRI(II)-S8

In 2009, the CCRI approved a supplementary comparison to be organised by the IRMM as pilot laboratory for the activity concentrations of 137Cs, 90Sr and 40K in a matrix material of dried bilberries. The organisation of this comparison and the material and measurement methods used are described. The supplementary comparison reference value (SCRV) for each of the three radionuclides are given together with the degrees of equivalence of each participating laboratory with the SCRV for the specific radionuclide. The results of this supplementary comparison allow the participating NMIs/designated institutes to declare calibration and measurement capabilities (CMCs) for the given radionuclides in a similar type of food matrix, an important aspect seen the relatively few supplementary comparisons for activity in matrix materials organised so far.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard

Technologies of Displacement and Children’s Right to Asylum in Sweden

Through an analysis of 100 asylum decisions and 10 interviews with 20 asylum officers at the Swedish Migration Agency this article reveals two intricate processes through which children’s rights are displaced in the Swedish asylum process; by overlooking children’s individual claims for asylum through a circle of neglect, and negating children’s best interests. The article demonstrates how the balancing act between migration control on one hand and children’s rights on the other hand plays out in the asylum process, which results in a double displacement; the children are not adult enough to be addressed as asylum seekers and not children enough to deserve qualification as bearer of children’s rights. An in-depth analysis of everyday practices at institutions applying children’s rights is essential both to understand the reproduction of discrepancies between rights on paper and rights in practice, and to explore the potential of rights to disrupt oppressive vehicles of power