| 1. |
- Renman, Viktor, et al.
(författare)
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Structural-electrochemical relations in the aqueous copper hexacyanoferrate-zinc system examined by synchrotron X-ray diffraction
- 2017
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Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753 .- 1873-2755. ; 369, s. 146-153
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Tidskriftsartikel (refereegranskat)abstract
- The storage process of Zn2+ in the Prussian blue analogue (PBA) copper hexacyanoferrate (Cu[Fe(CN)(6)](2/3)-nH(2) O-CuHCF) framework structure in a context of rechargeable aqueous batteries is examined by means of in operando synchrotron X-ray diffraction. Via sequential unit-cell parameter refinements of time-resolved diffraction data, it is revealed that the step-profile of the cell output voltage curves during repeated electrochemical insertion and removal of Zn2+ in the CuHCF host structure is associated with a non-linear contraction and expansion of the unit-cell in the range 0.36 < x < 1.32 for Znx/3Cu[Fe(CN)(6)](2/3)-nH(2)O. For a high insertion cation content there is no apparent change in the unit-cell contraction. Furthermore, a structural analysis with respect to the occupancies of possible Zn2+ sites suggests that the Fe(CN)(6) vacancies within the CuHCF framework play an important role in the structural-electrochemical behavior of this particular system. More specifically, it is observed that Zn2+ swaps position during electrochemical cycling, hopping between cavity sites to vacant ferricyanide sites.
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| 2. |
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| 3. |
- Axelsson, O., et al.
(författare)
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A coarse-fine-mesh stabilization for an alternating Schwarz domain decomposition method
- 2019
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Ingår i: Numerical Linear Algebra with Applications. - : Wiley. - 1070-5325 .- 1099-1506. ; 26:3
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Tidskriftsartikel (refereegranskat)abstract
- Domain decomposition methods can be solved in various ways. In this paper, domain decomposition in strips is used. It is demonstrated that a special version of the Schwarz alternating iteration method coupled with coarse-fine-mesh stabilization leads to a very efficient solver, which is easy to implement and has a behavior nearly independent of mesh and problem parameters. The novelty of the method is the use of alternating iterations between odd- and even-numbered subdomains and the replacement of the commonly used coarse-mesh stabilization method with coarse-fine-mesh stabilization.
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| 4. |
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| 5. |
- Gustafsson, N O, et al.
(författare)
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Measurement of diffusion coefficients in gels using holographic laser interferometry
- 1993
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Ingår i: Biotechnology Progress. - : Wiley. - 1520-6033 .- 8756-7938. ; 9:4, s. 436-441
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Tidskriftsartikel (refereegranskat)abstract
- The accuracy and precision of holographic interferometry as a method to measure diffusion coefficients in gels are investigated both experimentally and theoretically. The standard deviations in the experimentally determined diffusion coefficient for ethanol in 4% (w/v) agarose gel were 3.3% for diffusion into the gel and 6.1% for diffusion out of the gel. These are in good agreement with the standard deviations obtained using Monte Carlo simulations. Systematic errors derived from an assumption of constant diffusion coefficients were also investigated.
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| 6. |
- Johansson-Pajala, Rose-Marie, et al.
(författare)
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Improved Knowledge Changes the Mindset : Older Adults’ Perceptions of Care Robots
- 2019
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Ingår i: Lecture Notes in Computer Science, vol. 11592. - Cham : Springer Verlag. - 9783030220112 ; , s. 212-227
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Konferensbidrag (refereegranskat)abstract
- This paper explores Finnish, German and Swedish older adults’ perceptions of a future welfare service with increased use of welfare technologies, specifically care robots. The issues are the rapid digitalization and development of health and welfare technology, which presently is mainly technology driven (not need or user driven), and the demographic challenge. The aim of the study was to explore older adults’ perception of the future use of welfare technology or care robots. A qualitative approach with focus group discussions was employed, followed by thematic analysis. The results are presented in four overall themes: the impact on daily life for older adults and professional caregivers, codes of practice and terms of use, dissemination of information and knowledge, and conditions for successful implementation. There were significant differences in the informants’ attitudes toward and knowledge about care robots. However, the informants’ attitudes appeared to change during the focus groups and in general, became more positive. Authentic needs, which care robots could support, refer to independence, safety and security, and the ability to manage or ease daily life or working life. The results suggest that older adults, after receiving relevant information, were open to the idea of being supported by care robots in their daily lives.
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| 7. |
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| 8. |
- Ludwig, Frank, et al.
(författare)
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Magnetic, Structural, and Particle Size Analysis of Single- and Multi-Core Magnetic Nanoparticles
- 2014
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Ingår i: IEEE Transactions on Magnetics. - 0018-9464 .- 1941-0069. ; 50:11
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Tidskriftsartikel (refereegranskat)abstract
- We have measured and analyzed three different commercial magnetic nanoparticle systems, both multi-core and single-core in nature, with the particle (core) size ranging from 20 to 100 nm. Complementary analysis methods and same characterization techniques were carried out in different labs and the results are compared with each other. The presented results primarily focus on determining the particle size-both the hydrodynamic size and the individual magnetic core size-as well as magnetic and structural properties. The used analysis methods include transmission electron microscopy, static and dynamic magnetization measurements, and Mossbauer spectroscopy. We show that particle (hydrodynamic and core) size parameters can be determined from different analysis techniques and the individual analysis results agree reasonably well. However, in order to compare size parameters precisely determined from different methods and models, it is crucial to establish standardized analysis methods and models to extract reliable parameters from the data.
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| 9. |
- Mitraka, Evangelia, et al.
(författare)
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Solution processed liquid metal-conducting polymer hybrid thin films as electrochemical pH-threshold indicators
- 2015
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Ingår i: Journal of Materials Chemistry C. - : Royal Society of Chemistry. - 2050-7526 .- 2050-7534. ; 3:29, s. 7604-7611
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Tidskriftsartikel (refereegranskat)abstract
- A global and accurate mapping of the environment could be achieved if sensors and indicators are mass-produced at low cost. Printed electronics using polymeric (semi) conductors offer a platform for such sensor/indicator based circuits. Herein, we present the material concept for an electrochemical pH-threshold indicator based on a printable hybrid electrode which comprises a liquid metal alloy (GaInSn) embedded in a conducting polymer matrix (PEDOT). This hybrid electrode displays a large variation in open circuit potential versus pH in an electrochemical cell, which when connected to the gate of an electrochemical transistor leads to a dramatic change in the drain current in a narrow range of pH.
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| 10. |
- Sracek, O., et al.
(författare)
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Behavior of arsenic and geochemical modeling of arsenic enrichment in aqueous environments
- 2004
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Ingår i: Applied Geochemistry. - : Elsevier BV. - 0883-2927 .- 1872-9134. ; 19:2, s. 169-180
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Tidskriftsartikel (refereegranskat)abstract
- Arsenic is present in aqueous environments in +III and +V oxidation states. In oxidizing environments, the principle attenuation mechanism of As migration is its adsorption on Fe(III) oxide and hydroxides. The adsorption affinity is higher for As(V) under lower pH conditions and for As(III) under higher pH conditions. Ferric oxide and hydroxides can dissolve under low Eh and pH conditions releasing adsorbed As. Oxidation-reduction processes often involve high organic matter content in sediments and also contamination by organics such as BTEX. Arsenic may desorb under high pH conditions. Changes of pH can be related to some redox reactions, cation exchange reactions driving dissolution of carbonates, and dissolution of silicates. In very reducing environments, where SO4 reduction takes place, secondary sulfide minerals like As-bearing pyrite and orpiment, As2S3, can incorporate As. Geochemical modeling can be divided into two principal categories: (a) forward modeling and (b) inverse modeling. Forward modeling is used to predict water chemistry after completion of predetermined reactions. Inverse modeling is used to suggest which processes take place along a flowpath. Complex coupled transport and geochemistry programs, which allow for simulation of As adsorption, are becoming available. A common modeling approach is based on forward modeling with surface complexation modeling (SCM) of As adsorption, which can incorporate the effect of different adsorbent/As ratios, adsorption sites density, area available for adsorption, pH changes and competition of As for adsorption sites with other dissolved species such as phosphate. The adsorption modeling can be performed in both batch and transport modes in codes such as PHREEQC. Inverse modeling is generally used to verify hypotheses on the origin of As. Basic prerequisites of inverse modeling are the knowledge of flow pattern (sampling points used in model have to be hydraulically connected) and information about mineralogy including As mineral phases. Case studies of geochemical modeling including modeling of As adsorption are presented.
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