| 1. |
- Bjorkbacka, Asa, et al.
(författare)
-
Role of the Oxide Layer in Radiation-Induced Corrosion of Copper in Anoxic Water
- 2016
-
Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 120:21, s. 11450-11455
-
Tidskriftsartikel (refereegranskat)abstract
- The influence of a pregrown copper oxide layer on radiation-induced corrosion of polished copper in pure anoxic water has been explored. The resulting amount of copper oxide formed during corrosion was measured with cathodic reduction, and the concentration of dissolved copper in solution was measured with inductively coupled plasma atomic emission spectroscopy. The identity of corrosion products and their topography was determined with Raman spectroscopy and scanning electron microscopy, respectively. Nonirradiated reference samples were analyzed for comparison. The results show that radiation-induced corrosion of copper in anoxic water is significantly more effective on preoxidized copper compared to polished copper. The total amount of oxidized copper exceeds the amount expected solely from radiation chemistry of water by more than 3 orders of magnitude. To explain this discrepancy a mechanism is suggested where the hydroxyl radical (HO center dot) is the main radiolytic oxidative species driving the corrosion process. If the thermodynamic driving force would be large enough (such as for the hydroxyl radical or its precursor, H2O+), the oxide layer could conduct electrons from the metal to the hydroxyl radicals formed at oxide surfaces. The formation of an oxide layer will then result in an increased reactive surface area partly accounting for the observed discrepancy.
|
|
| 2. |
- Jonsson, Asa C, et al.
(författare)
-
Tinted contact lenses in Bothnia dystrophy.
- 2007
-
Ingår i: Acta Ophthalmologica Scandinavica. - : Wiley. - 1395-3907 .- 1600-0420. ; 85:5, s. 534-539
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To determine whether tinted contact lenses can improve visual function in patients with Bothnia dystrophy (BD), a genetically defined retinal dystrophy with prolonged dark adaptation. METHODS: Twelve patients with BD were fitted with the same type of soft contact lenses tinted dark brown. Visual acuity (VA), contrast vision, near vision and visual fields were tested before and 1 month after contact lens fitting. The patients completed a visual function questionnaire. The physical properties of the contact lenses were tested using spectrophotometry. RESULTS: The patients with the lowest VA described the most obvious improvement in visual function. This group of patients preferred darker contact lenses and continued wearing their contact lenses after the study ended. The patients with the best VA preferred lighter contact lenses and a few patients in this group discontinued contact lens wear upon completion of the study. CONCLUSIONS: Visual function in BD patients was improved by dark tinted contact lenses. The optimal colour for lenses varies, depending on the season and the individual. Other patient groups with retinal dystrophies associated with prolonged dark adaptation or dysfunction of the cone system, such as cone dystrophies or achromatopsia, may also benefit from this type of contact lens.
|
|
