| 1. |
- Ylmén, Rikard E, 1982, et al.
(författare)
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DR-FTIR method for the study of early hydration of cement
- 2008
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Ingår i: Conference Proceedings for “SCC 2008: Challenges and Barriers to Application.
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Konferensbidrag (refereegranskat)abstract
- A method has been developed to study early hydration reactions of ordinary Portland cement using freeze drying and Diffuse Reflectance Fourier Transform Infrared Spectroscopy (DR-FTIR). The hydration process was studied after 3 minutes up to 2 hours. The cement samples were mixed and after different hydration times the samples were placed in frozen liquid hydrogen to stop the hydration process. The samples were freeze dried under vacuum and analyzed with DR-FTIR. Measurements were also made on cement that was only dried in vacuum. The results showed that the freezing of the cement instantly stopped without any further hydration. This makes it possible to monitor chemical changes during very early hydration stages of cement by using the freeze drying combined with DR-FTIR. It was also possible to dry the samples with only vacuum, but then it was not possible to study the hydration process on a short timescale. Comparison between frozen and non-frozen samples showed that the freezing do not cause any detectable differences. This clearly indicates that the freezing do not change the chemical or physical structure of the samples to any larger extent. The freezing of the samples gave a much better time resolution and made it easier to handle the samples technically as they could be stored in the liquid nitrogen and put in the freeze drier together. The vacuum dried samples on the other hand had to be put in the drier at specified times. After a sample is put in the drier, vacuum has to be established and the sample must be sufficiently dry for the hydration to stop. This limits the time resolution of the vacuum technique in this study at best to a few minutes. The limiting time step of the freezing technique is the time for freezing the samples, which in this study was a few seconds.
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| 2. |
- Ahmed, Istaq, 1972, et al.
(författare)
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Crystal structure and proton conductivity of BaZr0.9Sc0
- 2008
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Ingår i: Journal of the American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 91:9, s. 3039-3044
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Tidskriftsartikel (refereegranskat)abstract
- Solid-state sintering has been used to prepare the perovskite BaZr0.9Sc0.1O3-delta. Analysis of X-ray powder diffraction data shows that an increase of the unit cell parameter, a, was observed after deuteration. Rietveld analysis of room-temperature neutron powder diffraction data confirmed cubic symmetry (space group Pm-3m). Dynamic thermogravimetric analysis indicates that the hydration process occurs below 335 degrees C and approximately 58% of the theoretical number of protonic defects can be filled. The presence of protons/deutrons is seen from the strong O-H/O-D stretch band in the infrared spectrum of the hydrated/deuterated samples. The proton conductivity of a prehydrated sample was investigated under dry and wet Ar atmospheres
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| 3. |
- Larsson, Kristian, 1982, et al.
(författare)
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Characterization and dissolution of hybrid electric vehicle (HEV) NIMH batteries for the development of a hydrometallurgical recycling method
- 2008
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Ingår i: Proceedings of ISEC 2008, Tucson, Arizona, US, Sept. 15-19, 2008, Vol 1 189-194. - 1894475801
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Konferensbidrag (refereegranskat)abstract
- This paper deals with a study of the chemistry behind and the development of a hydrometallurgical method specifically targeted to recycle Hybrid Electric Vehicle (HEV) type NiMH batteries. The batteries are characterized through ICP-OES, SEM and XRD to determine phases and metal content. Different dissolution techniques are utilized and their respective effect on the subsequent solvent extraction process is discussed. Thus the selection of dissolution method is closely linked to the extraction and the selective stripping of the metals.
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| 4. |
- Maierbeck, P., et al.
(författare)
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Probing the single particle structure around Ca-54 with one-neutron knock-out
- 2008
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Ingår i: AIP Conference Proceedings. - 1551-7616 .- 0094-243X. ; 1012, s. 89-93
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Konferensbidrag (refereegranskat)abstract
- The nuclei Ca-47 and Ti-55 were populated in one-neutron knock-out reactions at relativistic energies. Momentum distributions of the residual nuclei as well as gamma-ray spectra were measured at the GSI fragment separator (FRS). Preliminary results of the ongoing analysis including cross sections and spin/parity assignments are presented.
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