| 1. |
- Abadei, S., et al.
(författare)
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Microwave properties of tunable capacitors basee on magnetron sputtered ferroelectric Na0.5K0.5NbO3 film on low and high resistivity silicon substrates
- 2001
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Ingår i: Integrated Ferroelectrics. - : Informa UK Limited. - 1058-4587 .- 1607-8489. ; 39:1-4, s. 359-366
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In this work, small signal DC voltage dependent dielectric permittivity, loss tangent, and tuneability of magnetron sputtered epitaxial Na0.5K0.5NO3 films are studied experimentally. (100)-oriented Na0.5K0.5NbO3 films are deposited onto SiO2-buffered CMOS grade low resistivity (p = 10-20 cm) and high resistivity (p = 15-45 kcm) silicon substrates. Planar capacitors with 2 or 4 m gaps between electrodes have been fabricated on top of ferroelectric films. These devices have been characterized in the frequency range 1.0 MHz to 50 GHz at temperatures 30 - 300K. Na0.5K0.5NbO3/SiO2/Si structures on high resistivity silicon substrate exhibit C-V performances typical for Metal-Insulator- Semiconductor (MIS) capacitors. At low frequencies, f 1.0 GHz, the large tuneability and large losses are associated with the MIS structure, while at higher microwave frequencies the tuneability is mainly associated with the ferroelectric, film. At 1.0 MHz and room temperature, the tuneability of Na0.5K0.5NbO3/SiO2/Si structures more than 90%, reducing to 10-15 % at 50 GHz. The losses decrease with increasing the DC bias and frequency. A Q-factor more than 15 at 50 GHz is observed. The dielectric permittivity of the Na0.5K0.5NbO3 film is in the range 50-150 at frequencies 0.045-50 GHz. On low resistivity substrate the performance of Na0.5K0.5NbO3 films is completely screened by the high losses in silicon, and the tuneability is negligible. © 2001 Taylor and Francis.
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| 2. |
- Abdullah, M Ailieen, et al.
(författare)
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Building Networks for Delivering Integrated Product-Service Offerings (IPSOs)
- 2010
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Ingår i: Industrial product-service systems -IPS². - Linköping : CIRP. - 9789173933810 - 9173933813
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Konferensbidrag (refereegranskat)abstract
- The paper describes the effect of forming business networks and collaborations for the purpose of developing an Integrated Product-Service Offering (IPSO) using the Product/Service Systems (PSS). The research method is an in-depth case study of a joint venture formed by four companies developing a new technology for chemical extraction from water sludge waste within the pulp and paper industry.Combining literature from PSS, network theories and collaborative product development, this paper puts forward the benefits for SMEs to collaborate in business networks and produce IPSOs when introducing a new technology in an emerging market. The case study shows that working towards the new market would not have been possible if each party acted individually or maintained their traditional buyer-supplieroperator roles, and that IPSOs can reduce the business risk.
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| 3. |
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| 4. |
- Aftab, Umair, et al.
(författare)
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Two step synthesis of TiO2–Co3O4 composite for efficient oxygen evolution reaction
- 2021
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Ingår i: International journal of hydrogen energy. - : Elsevier. - 0360-3199 .- 1879-3487. ; 46:13, s. 9110-9122
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Tidskriftsartikel (refereegranskat)abstract
- For an active hydrogen gas generation through water dissociation, the sluggish oxygen evolution reaction (OER) kinetics due to large overpotential is a main hindrance. Herein, a simple approach is used to produce composite material based on TiO2/Co3O4 for efficient OER and overpotential is linearly reduced with increasing amount of TiO2. The scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) investigations reveal the wire like morphology of composite materials, formed by the self-assembly of nanoparticles. The titania nanoparticles were homogenously distributed on the larger Co3O4 nanoparticles. The powder x-ray diffraction revealed a tetragonal phase of TiO2 and the cubic phase of Co3O4 in the composite materials. Composite samples with increasing TiO2 content were obtained (18%, 33%, 41% and 65% wt.). Among the composites, cobalt oxide-titanium oxide with the highest TiO2 content (CT-20) possesses the lowest overpotential for OER with a Tafel slope of 60 mV dec−1 and an exchange current density of 2.98 × 10−3A/cm2. The CT-20 is highly durable for 45 h at different current densities of 10, 20 and 30 mA/cm2. Electrochemical impedance spectroscopy (EIS) confirmed the fast charge transport for the CT-20 sample, which potentially accelerated the OER kinetics. These results based on a two-step methodology for the synthesis of TiO2/Co3O4 material can be useful and interesting for various energy storage and energy conversion systems.
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| 5. |
- Alexandrou, Christina, et al.
(författare)
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User experiences of an app-based mHealth intervention (MINISTOP 2.0) integrated in Swedish primary child healthcare among Swedish-, Somali- and Arabic-speaking parents and child healthcare nurses: A qualitative study
- 2023
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Ingår i: Digital Health. - : Sage Publications. - 2055-2076. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Background: Preventive and scalable interventions, accessible to all, to counteract childhood obesity are urgently needed. We have recently developed a novel, digital parental intervention (MINISTOP 2.0 app) available in Swedish, Somali, Arabic and English. We have previously reported its positive effects on children's health behaviors and on parental self-efficacy. However, before introducing the app at scale in primary child healthcare, implementation aspects also need to be explored.Aim: This study aims to explore and describe user experiences as well as acceptability and feasibility of the MINISTOP 2.0 app-based intervention in a diverse group of parents (end-users) and Swedish child healthcare nurses (implementers).Methods: Individual interviews were conducted with Swedish- (n = 9), Somali- (n = 9), Arabic- (n = 5) and English-speaking (n = 1) parents as well as Swedish primary child healthcare nurses (n = 15). Data was analyzed using content analysis with an inductive latent approach.Results: Parents described how the app facilitated behavior change through increased awareness regarding current diet and physical activity behaviors. Furthermore, the evidence-based app content further facilitated trust and behavior change. Both parents and nurses acknowledged the app's preventive potential and the potential for reaching parents with diverse backgrounds or in need of extra support.Conclusion: The MINISTOP 2.0 app was perceived as a useful tool for health promotion both by parents and healthcare professionals, especially since it was adapted to several languages. These findings coupled with the previously shown beneficial effects on health behaviors support the large-scale implementation of the app in primary child healthcare.
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| 6. |
- Alm, Håkan, et al.
(författare)
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The use of car phones and changes in driver behaviour
- 2001
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Ingår i: International Journal of Vehicle Design. - 0143-3369 .- 1741-5314. ; 26:1, s. 4-11
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Tidskriftsartikel (refereegranskat)abstract
- The effects of mobile telephone use on traffic safety is discussed in the article. A number of empirical studies are reviewed and it is concluded that the use of a mobile telephone concurrently with car driving may have a negative impact upon traffic safety. The sub-tasks of entering a telephone number and having a demanding conversation are especially likely to increase the risk of an accident. To minimize the negative impact from telephoning on traffic safety a number of recommendations are suggested.
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| 7. |
- Almer, J, et al.
(författare)
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Microstructure and thermal stability of arc-evaporated Cr-C-N coatings
- 2004
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Ingår i: Philosophical Magazine. - : Informa UK Limited. - 1478-6435 .- 1478-6443. ; 84:7, s. 611-630
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Tidskriftsartikel (refereegranskat)abstract
- The role of C incorporation in the microstructure and thermal stability of arc-evaporated Cr-C-N coatings is explored via reactive growth in a mixed C2H4-N2 environment. C is found to react more readily than N at both the Cr cathode and the coating surfaces, so that a C2H4-to-N2 flow ratio of only 1% yields a C-to-N ratio of approximately 10% within the coatings. The as-deposited microstructures consist primarily of the δ-Cr(C, N) phase and possess high compressive residual stresses, which decrease with increasing C content. Post-deposition annealing up to 700°C results in depletion of lattice defects, and concomitant reductions in stress and coating hardness, together with phase transformations which suggest metastable phase formation during growth. Apparent activation energies for this lattice defect are found to be in the range expected for bulk diffusion of N and C (2.4-2.8 eV). The results suggest that inclusion of small amounts of C in this system offers the ability to reduce internal stresses while maintaining defect-related hardness increases, permitting growth of thicker and thus more wear-resistant coatings.
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| 8. |
- Almer, J., et al.
(författare)
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Strain and texture analysis of coatings using high-energy x-rays
- 2003
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 94:1, s. 697-702
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the internal strain and crystallographic orientation (texture) in physical-vapor deposited metal nitride coatings of TiN and CrN. A high-energy diffraction technique is presented that uses synchrotron x rays and an area detector, and which allows the strain and intensity distributions of multiple crystallographic planes to be measured by a single x-ray exposure. Unique texture states and nonlinear sin2 strain distributions are observed for all coatings investigated. Quantitative analysis indicates that existing micromechanical models can reasonably predict strain and corresponding stress for mixed-hkl reflections but are inadequate for fully describing measured data. Alternative mechanisms involving deposition-induced defects are proposed
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| 9. |
- Andersson, Erik, et al.
(författare)
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Ambio fit for the 2020s
- 2022
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Ingår i: Ambio. - : Springer Nature. - 0044-7447 .- 1654-7209. ; 51:5, s. 1091-1093
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Tidskriftsartikel (refereegranskat)
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| 10. |
- Antti, Marta-Lena, et al.
(författare)
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Synthesis and phase development in the Ct-Al-N system
- 2009
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Ingår i: Mechanical properties and processing of ceramic binary, ternary and composite systems. - Hoboken, NJ : John Wiley & Sons. - 9780470344927 ; , s. 3-12
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Konferensbidrag (refereegranskat)abstract
- The ternary nitride system Cr-Al-N has been investigated by sintering different powder compositions. The powder compositions belong to four groups, AIN- + Cr-powder (5 compositions between 20-90 molar% AlN), Al- + Cr 2N-powder (5 compositions between 15-80 molar% Cr2N), AlN-+ Cr2N-powder (50- and 90 molar% Cr2N) and Al- + Cr-powder. The powders were dry mixed and pressed into pellets by uniaxial pressing followed by cold isostatic pressing (ClP). Sintering took place in a graphite lined reaction bonding furnace under nitrogen atmosphere at three different temperatures, 1350°C, 1500°C and 1800°C and in an alumina tube furnace in order to avoid access to carbon. Holding times were varied, from 2 hours up to 72 hours. The phase development was evaluated by thermal analysis and XRD. CrAlN was formed at 1350°C but decomposed at higher temperatures. Both pure Al and Cr-powder were prone to react with carbon in the graphite furnace. Thermal analysis showed a sublimation of Cr2N at temperatures around 1050°C and nitridation of pure Al-powder between 680-750°C and of pure Cr-powder between 610-1080°C. Samples with pure Al-powder showed a very large expansion due to melting of aluminium in combination with nitridation. AIN was found to be more stable than Cr 2N at higher temperatures and longer holding times. The mixtures of Al-+Cr-powder produced an intermediate Al-Cr-phase.
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