| 1. |
- Shu, Rui, 1990-, et al.
(författare)
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Influence of Metal Substitution and Ion Energy on Microstructure Evolution of High-Entropy Nitride (TiZrTaMe)N1-x (Me = Hf, Nb, Mo, or Cr) Films
- 2021
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Ingår i: ACS APPLIED ELECTRONIC MATERIALS. - : American Chemical Society (ACS). - 2637-6113. ; 3:6, s. 2748-2756
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Tidskriftsartikel (refereegranskat)abstract
- Multicomponent or high-entropy ceramics show unique combinations of mechanical, electrical, and chemical properties of importance in coating applications. However, generalizing controllable thin-film processes for these complex materials remains a challenge. Here, understoichiometric (TiZrTaMe)N1-x (Me = Hf, Nb, Mo, or Cr, 0.12 <= x <= 0.30) films were deposited on Si(100) substrates at 400 degrees C by reactive magnetron sputtering using single elemental targets. The influence of ion energy during film growth was investigated by varying the negative substrate bias voltage from similar to 10 V (floating potential) to 130 V. The nitrogen content for the samples determined by elastic recoil detection analysis varied from 34.9 to 43.8 at. % (0.12 <= x <= 0.30), and the metal components were near-equimolar and not affected by the bias voltage. On increasing the substrate bias, the phase structures of (TiZrTaMe)N1-x (Me = Hf, Nb, or Mo) films evolved from a polycrystalline fcc phase to a (002) preferred orientation along with a change in surface morphology from faceted triangular features to a dense and smooth structure with nodular mounds. All the four series of (TiZrTaMe)N1-x (Me = Hf, Nb, Mo, or Cr) films exhibited increasing intrinsic stress with increasing negative bias. The maximum compressive stress reached similar to 3.1 GPa in Hf- and Cr-containing films deposited at -130 V. The hardness reached a maximum value of 28.0 +/- 1.0 GPa at a negative bias >= 100 V for all the four series of films. The effect of bias on the mechanical properties of (TiNbZrMe)N1-x films can thus guide the design of protective high-entropy nitride films.
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| 2. |
- Nzulu, Gabriel Kofi, 1974-, et al.
(författare)
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Growth and thermal stability of Sc-doped BaZrO 3 thin films deposited on single crystal substrates
- 2023
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Ingår i: Thin Solid Films. - : Elsevier BV. - 0040-6090 .- 1879-2731. ; 772
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Tidskriftsartikel (refereegranskat)abstract
- Thin films of BaZr1-xScxO3-x/2, (0 ≤ x ≤ 0.64), well known as proton conducting solid electrolytes for intermediate temperature solid oxide fuel cell, were deposited by magnetron sputtering. X-ray diffraction analysis of the as deposited films reveals the presence of single-phase perovskite structure. The films were deposited on four different substrates (c-Al2O3, LaAlO3〈100〉, LaAlO3〈110〉, LaAlO3〈111〉) yielding random, (110)- or (100)-oriented films. The stability of the as-deposited films was assessed by annealing in air at 600 °C for 2 h. The annealing treatment revealed instabilities of the perovskite structure for the (110) and randomly oriented films, but not for (100) oriented film. The instability of the coating under heat treatment was attributed to the low oxygen content in the film (understoichiometry) prior annealing combined with the surface energy and atomic layers stacking along the growth direction. An understoichiometric (100) oriented perovskite films showed higher stability of the structure under an annealing in air at 600 °C.
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| 3. |
- Martin, Michael, 1982-
(författare)
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Industrial Symbiosis in the Biofuel Industry : Quantification of the Environmental Performance and Identification of Synergies
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The production of biofuels has increased in recent years, to reduce the dependence on fossil fuels and mitigate climate change. However, current production practices are heavily criticized on their environmental sustainability. Life cycle assessments have therefore been used in policies and academic studies to assess the systems; with divergent results. In the coming years however, biofuel production practices must improve to meet strict environmental sustainability policies.The aims of the research presented in this thesis, are to explore and analyze concepts from industrial symbiosis (IS) to improve the efficiency and environmental performance of biofuel production and identify possible material and energy exchanges between biofuel producers and external industries.An exploration of potential material and energy exchanges resulted in a diverse set of possible exchanges. Many exchanges were identified between biofuel producers to make use of each other’s by-products. There is also large potential for exchanges with external industries, e.g. with the food, energy and chemical producing industries. As such, the biofuel industry and external industries have possibilities for potential collaboration and environmental performance improvements, though implementation of the exchanges may be influenced by many conditions.In order to analyze if concepts from IS can provide benefits to firms of an IS network, an approach was created which outlines how quantifications of IS networks can be produced using life cycle assessment literature for guidelines and methodological considerations. The approach offers methods for quantifying the environmental performance for firms of the IS network and an approach to distribute impacts and credits for the exchanges between firm, to test the assumed benefits for the firms of the IS network.Life cycle assessment, and the approach from this thesis, have been used to quantify the environmental performance of IS networks by building scenarios based on an example from an IS network of biofuel producers in Sweden. From the analyses, it has been found that exchanges of material and energy may offer environmental performance improvements for the IS network and for firms of the network. However, the results are dependent upon the methodological considerations of the assessments, including the reference system, functional unit and allocation methods, in addition to important processes such as the agricultural inputs for the system and energy systems employed.By using industrial symbiosis concepts, biofuel producers have possibilities to improve the environmental performance. This is done by making use of by-products and waste and diversifying their products, promoting a transition toward biorefinery systems and a bio-based economy for regional environmental sustainability.
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| 4. |
- Martin, Michael, 1982-, et al.
(författare)
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Who gets the benefits? An approach for assessing the environmental performance of industrial symbiosis
- 2015
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Ingår i: Journal of Cleaner Production. - : Elsevier. - 0959-6526 .- 1879-1786. ; 98, s. 263-271
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Tidskriftsartikel (refereegranskat)abstract
- Industrial symbiosis networks are generally assumed to provide economic and environmental benefits for all firms involved, though few quantifications have been produced in the literature, and the methods for these quantifications have varied. This paper provides an approach to quantify the environmental performance of industrial symbiosis networks using guidance from the literature of life cycle assessment. Additionally, an approach to distribute credits due to exchanges for firms in the industrial symbiosis network is outlined. From the approach, influential methodological considerations used for the quantifications are discussed, including e.g. the production of reference systems, allocation methods, system boundaries and functional unit. The implications of such an approach may be beneficial for the industrial symbiosis community and provide information crucial for taxes, subsidies, business relations, expansion possibilities for the network, marketing and other issues related to the environmental performance of firms in the industrial symbiosis network.
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| 5. |
- Berntsson, Lars-Olof, et al.
(författare)
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EAST-ADL 2.0 Specification
- 2008
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Rapport (refereegranskat)abstract
- This specification of the EAST ADL 2.0 is based on the EAST-ADL developed in the EAST EEA projectand has been further refined and harmonized with on-going modelling appraches in the automotiveindustry. It presents the modeling infrastructure, i.e. how the modeling elements should be represented inthe language and the UML representation. For each package a usage example is provided.The EAST-ADL 2.0 is harmonized with AUTOSAR.The metamodel and UML profile of EAST ADL 2.0 is defined in two steps: A domain (automotive)metamodel is defined, capturing only the domain specific needs of the language, without adding the UML2details. The basic concepts of UML are used for this purpose, such as classes, compositions andassociations. Based on the domain metamodel, a UML2 profile for the domain metamodel is defined,specifying stereotypes with properties and constraints.Comments on the content of this document are welcomed, and should be directed to .Please download the latest available specification and the XMI file ready for use in UML2 tools from the website.
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| 6. |
- Martin, Michael, et al.
(författare)
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Quantifying the environmental performance of integrated bioethanol and biogas production
- 2014
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Ingår i: Renewable energy. - : Elsevier. - 0960-1481 .- 1879-0682. ; 6, s. 109-116
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Tidskriftsartikel (refereegranskat)abstract
- As the production of biofuels continues to expand worldwide, criticism about, e.g. the energy output versus input and the competition with food has been questioned. However, biofuels have the possibility to be optimized in order to improve the environmental performance. This could be accomplished through the use of concepts from industrial symbiosis. This paper provides a quantification of the environmental performance of industrial symbiosis in the biofuel industry through integration of biogas and ethanol processes using a life cycle approach. Results show that although increasing integration is assumed to produce environmental benefits, not all impact categories have achieved this and the results depend upon the allocation methods, energy system and assumptions chosen.
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| 7. |
- Martin, Michael, et al.
(författare)
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Who gets the benefits? : An approach for assessing the environmentalperformance of industrial symbiosis
- 2012
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Ingår i: Greening of Industry Network.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- It is generally assumed that industrial symbiosis creates economic and environmental benefits for all firmsinvolved, though only a few quantifications have been produced in the literature. An approach to quantifyenvironmental performance of industrial symbiosis using life cycle assessment has been provided,outlining the choice of functional unit, system boundaries, impact assessment and allocation as well as thedistribution of benefits among firms in the symbiotic activity. The implications of such an approach maybe beneficial for the industrial symbiosis and life cycle assessment communities and provide informationcrucial for taxes, subsidies, business relations, marketing and other issues related to the environmentalperformance of firms in the industrial symbiosis network.
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| 8. |
- Andersson, Martin, et al.
(författare)
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Verification of a blind mismatch error equalization method for randomly interleaved ADCs using a 2.5V/12b/30MSs PSAADC
- 2003
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Ingår i: Proceedings of the 29th European Solid-State Circuits Conference (IEEE Cat. No.03EX705). - 0780379950 ; , s. 473-476
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Konferensbidrag (refereegranskat)abstract
- A 2.5V/12b/30MS/s randomly time interleaved ADC system has been implemented. Using this circuit an earlier presented [6] blind gain error equalization method has been verified. It is verified that the gain in each ADC unit can be found and equalized by using the blind estimation method, since the randomization assures that there is no correlation between the ADC unit used and the input data. It has been found that the blind gain error equalization attenuates the energy of the gain distortion tones by up to 72 dB. The SNDR of the random time interleaved ADC system was improved by 10.1 [dB] after the amplitude offset and gain equalization was performed. The measured system SNDR is only 2.1 [dB] worse than the measured SNDR of a single ADC unit
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| 9. |
- Buchholt, Kristina, et al.
(författare)
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Growth and characterization of epitaxial Ti3GeC2 thin films on 4H-SiC(0001)
- 2012
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Ingår i: Journal of Crystal Growth. - : Elsevier. - 0022-0248 .- 1873-5002. ; 343:1, s. 133-137
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Tidskriftsartikel (refereegranskat)abstract
- Epitaxial Ti3GeC2 thin films were deposited on 4 degrees off-cut 4H-SiC(0001) using magnetron sputtering from high purity Ti, C, and Ge targets. Scanning electron microscopy and helium ion microscopy show that the Ti3GeC2 films grow by lateral step-flow with {11 (2) over bar0} faceting on the SiC surface. Using elastic recoil detection analysis, atomic force microscopy, and X-Ray diffraction the films were found to be substoichiometric in Ge with the presence of small Ge particles at the surface of the film.
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| 10. |
- Buchholt, Kristina, et al.
(författare)
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Ohmic contact properties of magnetron sputtered Ti3SiC2 on n- and p-type 4H-silicon carbide
- 2011
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 98:4, s. 042108-
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Tidskriftsartikel (refereegranskat)abstract
- Epitaxial Ti3SiC2 (0001) thin film contacts were grown on doped 4H-SiC (0001) using magnetron sputtering in an ultra high vacuum system. The specific contact resistance was investigated using linear transmission line measurements. Rapid thermal annealing at 950 degrees C for 1 min of as-deposited films yielded ohmic contacts to n-type SiC with contact resistances in the order of 10(-4) Omega cm(2). Transmission electron microscopy shows that the interface between Ti3SiC2 and n-type SiC is atomically sharp with evidence of interfacial ordering after annealing. (c) 2011 American Institute of Physics.
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