| 1. |
- Fallqvist, Mikael, et al.
(författare)
-
Nucleation And Growth Of Cvd α-Al2O3 On TiXOY Template
- 2012
-
Ingår i: Surface & Coatings Technology. - : Elsevier. - 0257-8972 .- 1879-3347. ; 207, s. 254-261
-
Tidskriftsartikel (refereegranskat)abstract
- The microstructure, phase and chemical composition of TixOy templates used to nucleate α-Al2O3 on Ti(C,N) coated cemented carbide have been elucidated using scanning electron microscopy, X-ray diffraction, Auger electron spectroscopy and Time-of-Flight Secondary Ion Mass Spectrometry. Further, the adhesive strength of the α-Al2O3–TixOy–Ti(C,N) interfaces was investigated using scratch adhesion testing.The present study confirmed that the as-deposited template consisted of a Ti4O7 phase which during subsequent deposition of the Al2O3 layer transformed to a Ti3O5 phase and that the grown Al2O3 layer consisted of 100% α-Al2O3. Furthermore, the results showed that the lowest interfacial strength within the multilayer structure was exhibited by the Ti(C,N)–TixOy interface and that the transformation of Ti4O7 to Ti3O5 in the template resulted in formation of pores in the Ti(C,N)-template interface lowering the interfacial strength even more. The use of surface analysis techniques such as Auger electron spectroscopy and especially Time-of-Flight Secondary Ion Mass Spectrometry enabled trace element analyses using depth profiling to characterise the thin interfacial layers in detail.
|
|
| 2. |
- Backlund, Sandra, 1986-, et al.
(författare)
-
Energy efficiency potentials and energy management practices in Swedish firms
- 2012
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In order to improve energy efficiency and reach the EU:s 20-20-20 primary energy saving target, focus has mainly been on diffusion of technology. Previous studies have illustrated large untapped energy saving potentials from implementing energy management practices in firms. Energy management practices have large effects on energy utilization and also a short pay-back time. According to these studies, energy management practices also effect investment decisions and the outcome of investments in energy efficient technologies. This paper investigates to what extent energy management practices influence firms estimation of energy efficiency potentials. Further it investigates two Swedish policy programs that promote industrial energy management practices: The Programme For improving Energy efficiency in energy-intensive industry (PFE) and the energy audit program and whether these have increased energy management practices in Swedish firms. A multiple case study has been conducted in order to investigate energy practices in firms in different industrial sectors. Employment of energy management varies between firms. The firms estimate equal energy efficiency potentials from implementation of energy efficient technology as for energy management practices. In total the firms estimate energy efficiency potentials of 12 %. The study shows that firms that have participated in the programs work more actively with energy management. This can be illustrated by the fact that 75 % of the firms that have not participated in any of the programs lack a person responsible for energy management and 50 % also lack a long term energy strategy. For firms that have participated in the programs the corresponding figures are 30 % and 33 %. The results indicate an untapped potential of energy efficiency measures that could be reached through increased energy management in Swedish industries.
|
|
| 3. |
- Backlund, Sandra, 1986-, et al.
(författare)
-
Extending the Energy efficiency gap
- 2012
-
Ingår i: Energy Policy. - : Elsevier. - 0301-4215 .- 1873-6777. ; 51, s. 392-396
-
Tidskriftsartikel (refereegranskat)abstract
- In order to reach the EU: s 20–20–20 primary energy savings target, energy efficiency needs to increase. Previous research on energy use and energy efficiency has focused mainly on the diffusion of energy efficient technologies. The discrepancy between optimal and actual implementation of energy efficient technologies has been illustrated in numerous articles and is often referred to as the energy efficiency gap. However, efficient technologies are not the only ways to increase energy efficiency. Empirical studies have found that a cost-effective way to improve energy efficiency is to combine investments in energy-efficient technologies with continuous energy management practices. By including energy management into an estimated energy efficiency potential this paper introduces an extended energy efficiency gap, mainly in manufacturing industries and the commercial sector. The inclusion of energy management components in future energy policy will play an important role if the energy savings targets for 2020, and later 2050, are to be met in the EU.
|
|
| 4. |
- Fallberg, Anna, 1980-
(författare)
-
Chemical Vapour Deposition of Undoped and Oxygen Doped Copper (I) Nitride
- 2010
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In science and technology there is a steadily increased demand of new materials and new materials production processes since they create new application areas as well as improved production technology and economy. This thesis includes development and studies of a chemical vapour deposition (CVD) process for growth of thin films of the metastable material copper nitride, Cu3N, which is a semiconductor and decomposes at around 300 oC. The combination of these properties opens for a variety of applications ranging from solar cells to sensor and information technology. The CVD process developed is based on a metal-organic compound copper hexafluoroacetylacetonate, Cu(hfac)2 , ammonia and water and was working at about 300 oC and 5 Torr. It was found that a small amount of water in the vapour increased the growth rate considerably and that the phase content, film texture, chemical composition and morphology were strongly dependent on the deposition conditions. In-situ oxygen doping during the CVD of Cu3N to an amount of 9 atomic % could also be accomplished by increasing the water concentration in the vapour. Oxygen doping increases the band gap of the material as well as the electrical resistivity and changes the stability. The crystal structure of Cu3N is very open and contains several sites which can be used for doping. Different spectroscopic techniques like X-ray photoelectron spectroscopy, Raman spectroscopy and near edge X-ray absorption fine structure spectroscopy were used to identify the oxygen doping site(s) in Cu3N. Besides the properties, the oxygen doping also affected the morphology and texture of the films. By combining thin layers of different materials several properties can be optimized at the same time. It has been demonstrated in this thesis that multilayers, composed of alternating Cu3N and Cu2O layers, i.e. a metastable and a stable material, could be grown by CVD technique. However, the stacking sequence affected the texture, morphology and chemical composition. The interfaces between the different layers were sharp and no signs of decomposition of the initially deposited metastable Cu3N layer could be detected.
|
|
| 5. |
- Fallberg, Anna, et al.
(författare)
-
Phase stability and oxygen doping in the Cu-N-O system
- 2010
-
Ingår i: Journal of Crystal Growth. - North Holland : Elsevier. - 0022-0248 .- 1873-5002. ; 312:10, s. 1779-1784
-
Tidskriftsartikel (refereegranskat)abstract
- A growth stability diagram for the system Cu-N-O has been determined in the temperature range 250-500°C for a thermally activated CVD process, based on copper (II) hexafluoroacetylacetonate (Cu(hfac)2), NH3 and H2O. Without any addition of water only Cu3N was obtained. Addition of water introduces oxygen into the Cu3N structure to a maximum amount of 9 atomic % at a water/nitrogen molar ratio of 0.36 at 325 °C. Above this molar ratio Cu2O starts to deposit in addition to an oxygen doped Cu3N phase. Only Cu2O is deposited at a large excess of water. XPS and Raman spectroscopy indicated that the additional oxygen in the doped Cu3N structure occupies an interstitial position with a chemical environment similar to oxygen in Cu2O. The oxygen doping of the Cu3N phase did not influence the lattice parameter which was close to the bulk parameter of 3.814 Å. The film morphology varied markedly with both deposition temperature and water concentration in the vapour during deposition. Increasing the water concentration results in less faceted and textured films with smoother and more sphere like grains. The resistivity of the Cu3N films increased with increased oxygen content of the film and varied between 10-100 Ωcm (0 to 9 atomic% O). The optical band gap increased from 1.25 to 1.45 eV as the oxygen content increased (0 to 9 atomic %).
|
|
| 6. |
|
|
| 7. |
- Lindahl, Erik, et al.
(författare)
-
Gas-Pulsed CVD for Film Growth in the Cu-Ni-N System
- 2012
-
Ingår i: Chemical Vapor Deposition. - : Wiley. - 0948-1907 .- 1521-3862. ; 18:1-3, s. 10-16
-
Tidskriftsartikel (refereegranskat)abstract
- A new ternary solid solution, Cu3-xNix+yN, is prepared by gas-pulsed CVD at 260 degrees C. Gas pulses of the precursor mixtures Cu(hfac)2+NH3 and Ni(thd)2+NH3, separated by intermittent ammonia pulses, are employed for the deposition of Cu3N and Ni3N, respectively. A few monolayers of the nitrides are grown in each CVD pulse and then mixed by diffusion to produce the solid solution. The metal content of the solid solution can be varied continuously from 100% to about 20% Cu, which means that the electrical properties can be varied from 1.6eV (band gap of Cu3N) to metallic (Ni3N). This is of interest for various applications, e.g., solar energy, catalysis, and microelectronics.
|
|
| 8. |
|
|
| 9. |
- Lindahl, Erik, et al.
(författare)
-
In situ study of nickel formation during decomposition of chemical vapor deposition Ni3N films
- 2010
-
Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. - : American Vacuum Society. - 0734-2101 .- 1520-8559. ; 28:5, s. 1203-1209
-
Tidskriftsartikel (refereegranskat)abstract
- The thermal decomposition of Ni3N thin films, deposited by chemical vapor deposition on SrTiO3 (001) and Si (100) substrates, has been studied by in situ x-ray diffraction, as well as temperature-programed controlled gas emission in both inert and hydrogen atmospheres. The decomposition at inert atmosphere conditions starts at the film/substrate interface, which results in a high degree of ordering in the formed nickel film. In the H-2 atmosphere, the initial film ordering is less pronounced and the decomposition occurs from the film surface and downward. This means that by choosing the annealing atmosphere, inert or hydrogen, the formation of the Ni film can be localized to either the original nitride/substrate interface or to the surface of the nitride. The annealed films show a cube-on-cube growth with respect to the SrTiO3 (001) substrate. The film morphology after the annealing experiments resembles the one of the as-deposited films. The lowest resistivity value is measured for the films annealed in the H-2 atmosphere. (C) 2010 American Vacuum Society. [DOI: 10.1116/1.3478298]
|
|
| 10. |
- Ottosson, Lars-Göran, et al.
(författare)
-
Sulfate assimilation mediates tellurite reduction and toxicity in Saccharomyces cerevisiae
- 2010
-
Ingår i: Eukaryotic Cell. - 1535-9778 .- 1535-9786. ; 9:10, s. 1635-1647
-
Tidskriftsartikel (refereegranskat)abstract
- Despite a century of research and increasing environmental and human health concerns, the mechanistic basis of the toxicity of derivatives of the metalloid tellurium, Te, in particular the oxyanion tellurite, Te(IV), remains unsolved. Here, we provide an unbiased view of the mechanisms of tellurium metabolism in the yeast Saccharomyces cerevisiae by measuring deviations in Te-related traits of a complete collection of gene knockout mutants. Reduction of Te(IV) and intracellular accumulation as metallic tellurium strongly correlated with loss of cellular fitness, suggesting that Te(IV) reduction and toxicity are causally linked. The sulfate assimilation pathway upstream of Met17, in particular, the sulfite reductase and its cofactor siroheme, was shown to be central to tellurite toxicity and its reduction to elemental tellurium. Gene knockout mutants with altered Te(IV) tolerance also showed a similar deviation in tolerance to both selenite and, interestingly, selenomethionine, suggesting that the toxicity of these agents stems from a common mechanism. We also show that Te(IV) reduction and toxicity in yeast is partially mediated via a mitochondrial respiratory mechanism that does not encompass the generation of substantial oxidative stress. The results reported here represent a robust base from which to attack the mechanistic details of Te(IV) toxicity and reduction in a eukaryotic organism.
|
|
