| 1. |
- Fuhrer, Andreas, et al.
(författare)
-
Few electron double quantum dots in InAs/InP nanowire heterostructures
- 2007
-
Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 7:2, s. 243-246
-
Tidskriftsartikel (refereegranskat)abstract
- We report on fabrication of double quantum dots in catalytically grown InAs/InP nanowire heterostructures. In the few-electron regime, starting with both dots empty, our low-temperature transport measurements reveal a clear shell structure for sequential charging of the larger of the two dots with up to 12 electrons. The resonant current through the double dot is found to depend on the orbital coupling between states of different radial symmetry. The charging energies are well described by a capacitance model if next-neighbor capacitances are taken into account.
|
|
| 2. |
- Uddh Söderberg, Terese, 1976-, et al.
(författare)
-
Metal solubility and transport at a contaminated landfill site – From the source zone into the groundwater
- 2019
-
Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 668, s. 1064-1076
-
Tidskriftsartikel (refereegranskat)abstract
- Risks associated with metal contaminated sites are tightly linked to material leachability and contaminant mobility. In this study, metal solubility and transport were characterized within a glass waste landfill through i) lysimeter-collection of pore water and standardized batch leaching tests, ii) soil profiles extending from the landfill surface, through unsaturated soil underneath, and into the groundwater zone, and iii) groundwater samples upstream, at, and downstream of the landfill. The soil analyzes targeted both pseudo-total and geochemically active concentrations of contaminant metals (As, Cd, Pb, Sb) and basic soil geochemistry (pH, org. C, Fe,Mn). Water samples were analyzed for dissolved, colloid-bound and particulate metals, and speciation modelling of the aqueous phase was conducted. The results revealed a highly contaminated system, with mean metal concentrationsin the waste zone between 90 and 250 times the regional background levels. Despite severe contamination of the waste zone and high geochemically active fractions (80–100%) of all contaminant metals as well as elevated concentrations in landfill pore water, the concentrations of Cd and Pb decrease abruptly at the transition between landfill and underlying natural soil and no indication of groundwater contamination was found. The efficient cation retention is likely due to the high pH. However, the sorption of As and Sb is weaker at such high pH,which explains their higher mobility from the pore water zone into groundwater. The field soil:solution for Pb, ranging from 140 to 2,900,000 l kg−1), despite little variability in basic geochemical variables, which we suggest is due to waste material heterogeneity.
|
|
| 3. |
- Wallenberg, Nils, 1986, et al.
(författare)
-
The effects of warm weather on children’s outdoor heat stress and physical activity in a preschool yard in Gothenburg, Sweden
- 2023
-
Ingår i: International Journal of Biometeorology. - 0020-7128 .- 1432-1254. ; 67:12, s. 1927-40
-
Tidskriftsartikel (refereegranskat)abstract
- Hot weather conditions can have negative impacts on the thermal comfort and physical activity of vulnerable groups such as children. The aim of this study is to analyze the effects of warm weather on 5-year-old children’s thermal comfort and physical activity in a preschool yard in Gothenburg, Sweden. In situ measurements were conducted for 1–1.5 h in the early afternoon on 8 days in May, June, and August of 2022. The thermal comfort and physical activity was estimated with GPS-tracks, heart rate monitors, and step counts and compared to observed weather conditions. Results show that physical activity decreases under warmer weather conditions, depicted by a decrease in distance moved, step counts, and highest registered pulse. Moreover, on warm days, the children avoid sunlit areas. For 50% or more of the time spent in sunlit areas, the children are exposed to cautious levels of heat. In shaded areas, on the other hand, the children are less exposed, with five out of 8 days having 50% or more of the time at neutral levels. The study demonstrates the importance of access to shaded areas in preschool yards where children can continue their active play while simultaneously maintaining a safe thermal status.
|
|
| 4. |
- Augustsson, Anna, et al.
(författare)
-
Failure of generic risk assessment model framework to predict groundwater pollution risk at hundreds of metal contaminated sites : Implications for research needs
- 2020
-
Ingår i: Environmental Research. - : Elsevier. - 0013-9351 .- 1096-0953. ; 185, s. 1-9
-
Tidskriftsartikel (refereegranskat)abstract
- Soil pollution constitutes one of the major threats to public health, where spreading to groundwater is one of several critical aspects. In most internationally adopted frameworks for routine risk assessments of contaminated land, generic models and soil guideline values are cornerstones. In order to protect the groundwater at contaminated sites, a common practice worldwide today is to depart from health risk-based limit concentrations for groundwater, and use generic soil-to-groundwater spreading models to back-calculate corresponding equilibrium levels (concentration limits) in soil, which must not be exceeded at the site. This study presents an extensive survey of how actual soil and groundwater concentrations, compiled for all high-priority contaminated sites in Sweden, relate to the national model for risk management of contaminated sites, with focus on As, Cu, Pb and Zn. Results show that soil metal concentrations, as well as total amounts, constitute a poor basis for assessing groundwater contamination status. The evaluated model was essentially incapable of predicting groundwater contamination (i.e. concentrations above limit values) based on soil data, and erred on the "unsafe side" in a significant number of cases, with modelled correlations not being conservative enough. Further, the risk of groundwater contamination was almost entirely independent of industry type. In essence, since neither soil contaminant loads nor industry type is conclusive, there is a need for a supportive framework for assessing metal spreading to groundwater accounting for site-specific, geochemical conditions.
|
|
| 5. |
|
|
| 6. |
- Dolby, Viveka, et al.
(författare)
-
Effects of pH, salt and time on ligand binding properties of overexpressed melanocortin 4 receptor.
- 2004
-
Ingår i: Journal of Biochemical and Biophysical Methods. - : Elsevier BV. - 0165-022X. ; 58:3, s. 195-205
-
Tidskriftsartikel (refereegranskat)abstract
- The G-protein coupled melanocortin 4 receptor (MC4r) plays an important role in the energy metabolism. We overexpressed the MC4r in CHO cells and performed characterisation studies on the cell membranes to determine functional stability and ligand binding properties of the receptor. The affinity for the ligands [Nle4, Image-Phe7]-αMSH and MTII was lost below pH 6 but could be restored by returning to physiological pH. Increasing NaCl concentration up to 1 M had little influence on the binding of either ligand. At neutral pH, physiological salt concentration and 4 °C the ligand affinity of the receptor was stable for up to 6 days. These findings will facilitate design of purification methods for the receptor.
|
|
| 7. |
- Björk, Mikael, et al.
(författare)
-
Tunable effective g factor in InAs nanowire quantum dots
- 2005
-
Ingår i: Physical Review B (Condensed Matter and Materials Physics). - 1098-0121. ; 72:20
-
Tidskriftsartikel (refereegranskat)abstract
- We report tunneling spectroscopy measurements of the Zeeman spin splitting in InAs few-electron quantum dots. The dots are formed between two InP barriers in InAs nanowires with a wurtzite crystal structure grown using chemical beam epitaxy. The values of the electron g factors of the first few electrons entering the dot are found to strongly depend on dot size. They range from close to the InAs bulk value in large dots vertical bar g(*)vertical bar=13 down to vertical bar g(*)vertical bar=2.3 for the smallest dots.
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
|
|
