| 1. |
- Ylmén, Rikard E, 1982, et al.
(author)
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DR-FTIR method for the study of early hydration of cement
- 2008
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In: Conference Proceedings for “SCC 2008: Challenges and Barriers to Application.
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Conference paper (peer-reviewed)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.
(author)
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Crystal structure and proton conductivity of BaZr0.9Sc0
- 2008
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In: Journal of the American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 91:9, s. 3039-3044
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Journal article (peer-reviewed)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. |
- Aksouh, F., et al.
(author)
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STUDY OF THE O-15(2p,gamma)Ne-17 CROSS SECTION BY COULOMB DISSOCIATION OF Ne-17 FOR THE rp PROCESS OF NUCLEOSYNTHESIS
- 2014
-
In: Acta Physica Polonica, Series B.. - 1509-5770 .- 0587-4254. ; 45:2, s. 229-234
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Journal article (peer-reviewed)abstract
- The O-15(2p, gamma)Ne-17 cross section has been studied by the inverse reaction, the Coulomb dissociation of Ne-17. The experiment has been performed at the GSI. The Ne-17 excitation energy prior to decay has been reconstructed by using the invariant-mass method. The preliminary differential and integral Coulomb dissociation cross sections (sigma(Coul)) have been extracted, which provide a photoabsorption (sigma(photo)) and a radiative capture cross section (sigma(cap)). Additionally, important information about the Ne-17 nuclear structure will be obtained. The analysis is in progress.
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| 4. |
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| 5. |
- Berland, Kristian, 1983, et al.
(author)
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Temperature stability of intersubband transitions in AlN/GaN quantum wells
- 2010
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In: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 97:4, s. 043507-
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Journal article (peer-reviewed)abstract
- Temperature dependence of intersubband transitions in AlN/GaN multiple quantum wells grown with molecular beam epitaxy is investigated both by absorption studies at different temperatures and modeling of conduction-band electrons. For the absorption study, the sample is heated in increments up to 400 degrees C. The self-consistent Schroumldinger-Poisson modeling includes temperature effects of the band gap and the influence of thermal expansion on the piezoelectric field. We find that the intersubband absorption energy decreases only by similar to 6 meV at 400 degrees C relative to its room temperature value.
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| 6. |
- Ekberg, Christian, 1967, et al.
(author)
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The structure of plutonium(IV) oxide as hydrolysed clusters in aqueous suspensions
- 2013
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In: Dalton Transactions. - : Royal Society of Chemistry (RSC). - 1477-9226 .- 1477-9234. ; 42:6, s. 2035-2040
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Journal article (peer-reviewed)abstract
- The behavior of plutonium still puzzles scientists 70 years after its discovery. There are several factors making the chemistry of plutonium interesting including its ability to keep several oxidation states. Another unique property is that the oxidation states +III, +IV, +V and +VI may exist simultaneously in solution. Another property plutonium shares with some other tetravalent metal ions is the ability to form stable polynuclear complexes or colloids. The structures of freshly prepared and five-year old plutonium(IV) colloids are compared with crystalline plutonium(IV) oxide using Pu L-3-edge EXAFS. It was shown that as the plutonium colloids age they do in fact shrink in size, contrary to previous expectations. The aged colloidal particles are indeed very small with only 3-4 plutonium atoms, and with a structure very similar to solid plutonium(IV) oxide, but with somewhat shorter mean Pu-O bond and Pu. Pu distances indicating a partial oxidation. The very small size of the colloidal particles is further supported by the fact that they do not sediment on heavy ultra-centrifugation.
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| 7. |
- Langer, C., et al.
(author)
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Thermonuclear reaction S-30(p,gamma)Cl-31 studied via Coulomb breakup of Cl-31
- 2014
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In: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 89:3
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Journal article (peer-reviewed)abstract
- Coulomb breakup at high energy in inverse kinematics of proton-rich Cl-31 was used to constrain the thermonuclear S-30(p,gamma)Cl-31 capture reaction rate under typical Type I x-ray burst conditions. This reaction is a bottleneck during rapid proton-capture nucleosynthesis (rp process), where its rate depends predominantly on the nuclear structure of Cl-31. Two low-lying states just above the proton-separation threshold of S-p = 296( 50) keV in Cl-31 have been identified experimentally using the (RB)-B-3-LAND setup at the GSI Helmholtzzentrum fur Schwerionenforschung GmbH. Both states are considered to play a key role in the thermonuclear S-30( p,gamma)Cl-31 capture reaction. Excitation energies of the first J(pi) = 1/2(+), 5/2(+) states have been extracted and the reaction rate for proton capture on S-30 under typical rp-process temperatures has been investigated.
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| 8. |
- Larsson, Kristian, 1982
(author)
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Characterization and Dissolution of HEV NiMH Batteries
- 2010
-
Licentiate thesis (other academic/artistic)abstract
- The recycling of batteries is an important issue in a sustainable society where materials recycling of complex products is a necessity. Without an efficient recycling there will be an unnecessary loss of both materials and energy due to inefficient or non-existent recycling. This project concerns the recycling of nickel metal hydride (NiMH) hybrid electric vehicle (HEV) batteries and aims to outline the potentials and possibilities inherent in this waste stream. The main valuable metals in the batteries are nickel, cobalt and lanthanoids. The active cathode material is a triprecipitate of mainly nickel with zinc and cobalt in hydroxide form with yttrium and magnesium added,pasted onto a nickel metal foam-mesh support. The active anode material is a hydrogen absorbing alloy containing approximately 54% nickel and 31% lanthanoids and smaller amounts of manganese, cobalt, aluminium and yttrium. The recovery of these metals should be performed using a method which minimizes the use of energy and chemicals. The work presented in this thesis is a characterization of the batteries and a dissolution study of individual electrode materials as a first step in a hydrometallurgical recycling process. A nickel removal and purification process has also been investigated, the so called Mond process, by which nickel reacts with carbon monoxide and forms nickel tetracarbonyl. The nickel tetracarbonyl both forms and is highly volatile at a low temperature, unlike other relevant carbonyl compounds. This means that the volatilized nickel can easily be separated from the rest of the material and thereby purified. This gives both pure nickel and an interesting residue to work with.The positive electrode active material, nickel hydroxide, can be dissolved without dissolving the electrode backing material (nickel metal). A rapid dissolution of the active material on the positive electrode can be achieved at low temperature and relatively low acid concentration (pH 0.5-1.5), while leaving the major part of the nickel metal undissolved. This is possible with all the acids tested, nitric, sulphuric and hydrochloric acid. Therefore the most suitable acid depends on the choice of process following the dissolution.
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| 9. |
- Larsson, Kristian, 1982, et al.
(author)
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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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In: Proceedings of ISEC 2008, Tucson, Arizona, US, Sept. 15-19, 2008, Vol 1 189-194. - 1894475801
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Conference paper (peer-reviewed)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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| 10. |
- Larsson, Kristian, 1982, et al.
(author)
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Dissolution and characterization of HEV NiMH batteries
- 2013
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In: Waste Management. - : Elsevier BV. - 0956-053X .- 1879-2456. ; 33:3, s. 689-698
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Journal article (peer-reviewed)abstract
- Metal recovery is an essential part of the recycling of hybrid electric vehicle battery waste and the first step in a hydrometallurgical treatment is dissolution of the solid material. The properties of separated battery electrode materials were investigated. Focus was put on both the solid waste and then the dissolution behaviour. The cathode contains metallic nickel that remains undissolved when utilizing non-oxidizing conditions such as hydrochloric or sulphuric acid in combination with a low oxygen atmosphere. In these conditions the cathode active electrode material is fully dissolved. Not dissolving the nickel metal saves up to 37% of the acid consumption for the cathode electrode material. In the commonly used case of oxidizing conditions the nickel metal dissolves and a cobalt-rich phase remains undissolved from the cathode active material. For the anode material a complete and rapid dissolution can be achieved at mild conditions with hydrochloric, nitric or sulphuric acid. Optimal parameters for all cases of dissolution was pH 1 with a reaction time of approximately >= 20,000 s.
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| 11. |
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| 12. |
- Larsson, Kristian, 1982, et al.
(author)
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Selective Dissolution of Electrode Materials from NiMH Batteries
- 2010
-
In: Proceedings of Hydroprocess 2010 the 3rd International Workshop on Process Hydrometallurgy.
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Conference paper (peer-reviewed)abstract
- Nickel-metal hydride (NiMH) batteries are one of the mostcommon battery types used in hybrid electric vehicles (hev).The electrodes of these batteries contain large amounts ofnickel, cobalt and rare earth metals. Recovery of these metals is economically and environmentally beneficial as it mines an easily accessible source of raw material. Recovery should be performed using a method which minimizes the use of energy and chemicals.One way to perform the recovery is to selectively dissolveelectrode materials during hydrochemical processing. In the case of NiMH batteries, the positive electrode active material, nickel hydroxide, can be dissolved without dissolving the electrode backing material (usually nickel metal). To rapidly dissolve all of the nickel hydroxide, and as little as possible of the nickel metal,becomes an optimization problem: where is the suitable point at which to stop dissolving material in combination with the choice of chemical surrounding Experiments were performed with a temperature controlled by pH-stat, which maintains a constant pH during dissolution. This work shows that rapid dissolution of the active material on the positive electrode can be achieved at a low temperature and a relatively low acid concentration (pH 0.5 –1.5) whilst leaving the major part of the nickel metal undissolved. This is possible with all three tested minerals: acidsnitric, sulphuric and hydrochloric. The speed of dissolution is mostly affected by the pH and only slightly affected by the type of acid. Therefore the most suitable acid depends on the choice of process following the dissolution.
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| 13. |
- Larsson, Kristian, 1982, et al.
(author)
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Using Cyanex 923 for selective extraction in a high concentration chloride medium on nickel metal hydride battery waste
- 2012
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In: Hydrometallurgy. - : Elsevier BV. - 0304-386X. ; 129, s. 35-42
-
Journal article (peer-reviewed)abstract
- The extraction properties of the solvating extractant trialkylphosphine oxide mixture Cyanex 923 have been investigated using liquid-liquid extraction methods on leach liquors from nickel metal hydride batteries dissolved in 8 M hydrochloric acid. Separation routes for leach liquors from individual electrode materials and a mixed material were developed. The batteries used in this study contained thirteen metals and the developed separation schemes separate them in up to four fractions. The main fraction in each case contains nickel, also potassium and magnesium if present in the feed. Part of the nickel raffinate is refluxed to the dissolution step in order to reduce the amount of metals to be extracted into the organic phase. A nitrate strip step separates the cobalt and manganese from the lanthanoid content, since lanthanoid nitrate complexes are extracted.
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| 14. |
- Larsson, Kristian, 1982, et al.
(author)
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Using Cyanex 923 for selective extraction in a high concentration chloride medium on nickel metal hydride battery waste Part II: mixer-settler experiments
- 2013
-
In: Hydrometallurgy. - : Elsevier BV. - 0304-386X. ; 133, s. 168-175
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Journal article (peer-reviewed)abstract
- Nickel metal hydride batteries are extensively used throughout society and represent a large and complex metallic mixture requiring recycling. This paper deals with the recovery and separation of metals from nickel metal hydride battery waste dissolved in 8 M hydrochloric acid. Three processes based on leachates from individual electrode materials and a mixed material have been evaluated using mixer-settlers. The solvating extractant used is the trialkylphosphine oxide mixture Cyanex 923. The batteries used in this study contained thirteen metals and the processes separate them in up to four fractions. The main fraction in each process successfully creates a high-concentration nickel stream with low levels of potassium and magnesium (if present in the feed) by extracting the other metals. The purity of the nickel stream after the main process step (4-5 stages) is >99.9%, excluding magnesium and potassium. The extracted metals are separated using a nitrate strip, which allows the rare earth metals and aluminium to be separated from cobalt and manganese.
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| 15. |
- Maierbeck, P., et al.
(author)
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Probing the single particle structure around Ca-54 with one-neutron knock-out
- 2008
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In: AIP Conference Proceedings. - 1551-7616 .- 0094-243X. ; 1012, s. 89-93
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Conference paper (peer-reviewed)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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| 16. |
- Maierbeck, P., et al.
(author)
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Structure of 55Ti from relativistic one-neutron knockout
- 2009
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In: Physics Letters B. - : Elsevier BV. - 0370-2693. ; 675:1, s. 22-27
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Journal article (peer-reviewed)abstract
- Results are presented from a one-neutron knockout reaction at relativistic energies on 56Ti using the GSI FRS as a two-stage magnetic spectrometer and the Miniball array for gamma-ray detection. Inclusive and exclusive longitudinal momentum distributions and cross-sections were measured enabling the determination of the orbital angular momentum of the populated states. First-time observation of the 955(6) keV -hole state in 55Ti is reported. The measured data for the first time proves that the ground state of 55Ti is a 1/2- state, in agreement with shell-model calculations using the GXPF1A interaction that predict a sizable N=34 gap in 54Ca.
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| 17. |
- Marganiec, J., et al.
(author)
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Coulomb Dissociation experiment of 27P
- 2015
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In: Acta Physica Polonica, Series B.. - 1509-5770 .- 0587-4254. ; 46:3, s. 473-476
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Journal article (peer-reviewed)abstract
- The 26Si(p; γ)27P reaction, which might play an important role in the rp process, was studied by the Coulomb Dissociation method. The experiment was performed at GSI, Darmstadt. A secondary 27P ion beam of 500 MeV/nucleon was directed onto a Pb target. From this experiment, the Coulomb Dissociation cross section, σCoulex, will be deduced and then converted to the photoabsorption cross section, σphoto, and the radiativecapture cross section, σcap. Also information on the structure of 27P will be obtained. The analysis is in progress.
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| 18. |
- Marganiec, J., et al.
(author)
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Experimental study of the O-15(2p, gamma) Ne-17 cross section by Coulomb Dissociation for the rp process
- 2016
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In: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 665:1
-
Conference paper (peer-reviewed)abstract
- The time-reversed reaction O-15(2p, gamma) Ne-17 has been studied by the Coulomb dissociation technique. Secondary 17Ne ion beams at 500 AMeV have been produced by fragmentation reactions of Ne-20 in a beryllium production target and dissociated on a secondary Pb target. The incoming beam and the reaction products have been identified with the kinematically complete LAND-(RB)-B-3 experimental setup at GSI. The excitation energy prior to decay has been reconstructed by using the invariant-mass method. The preliminary differential and integral Coulomb Dissociation cross sections (sigma(Coul)) have been calculated, which provide a photoabsorption (sigma(photo)) and a radiative capture cross section (sigma(cap)). Additionally, important information about the nuclear structure of the Ne-17 nucleus will be obtained. The analysis is in progress.
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| 19. |
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| 20. |
- Rodriguez-Tajes, C., et al.
(author)
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One-neutron knockout from light neutron-rich nuclei at relativistic energies
- 2010
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In: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 82:2
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Journal article (peer-reviewed)abstract
- One-neutron knockout reactions from neutron-rich nuclei, with Z=6-13 and N=8-22, were studied at the Fragment Separator (GSI) at high beam energies, around 700 MeV/nucleon. Structural phenomena such as the formation of one-neutron halos in odd-mass carbon isotopes (15,17,19C) will be discussed. In addition, one-neutron knockout measurements from 22N were carried out for the first time and demonstrate clearly the change from a 0d5/2 to a 1s1/2 orbital for the valence neutron, an effect that is expected above N=14 and that was also observed in 23O and 24F. The possibility of an anomalous structure of 26F, due to a significant 1s1/2 neutron admixture, will also be discussed in the light of the experimental data obtained in this work. Finally, the ground-state configuration of neutron-rich neon isotopes (24-28Ne) was studied, providing new information in a region that is relatively close to the island of inversion.
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| 21. |
- Rodriguez-Tajes, C., et al.
(author)
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One-neutron knockout from Ne24-28 isotopes
- 2010
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In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 687:1, s. 26-30
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Journal article (peer-reviewed)abstract
- One-neutron knockout reactions of Ne24-28 in a beryllium target have been studied in the Fragment Separator (FRS), at GSI. The results include inclusive one-neutron knockout cross-sections as well as longitudinal-momentum distributions of the knockout fragments. The ground-state structure of the neutron-rich neon isotopes was obtained from an analysis of the measured momentum distributions. The results indicate that the two heaviest isotopes, Ne-27 and Ne-28, are dominated by a configuration in which a s(1/2) neutron is coupled to an excited state of the Ne-26 and Ne-27 core, respectively. (C) 2010 Elsevier B.V. All rights reserved.
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| 22. |
- Schwertel, S., et al.
(author)
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One-neutron knockout from Sc51-55
- 2012
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In: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-601X .- 1434-6001. ; 48:Dec., s. 191-10
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Journal article (peer-reviewed)abstract
- Results are presented from a one-neutron knockout experiment at relativistic energies of approximate to 420 A MeV on Sc51-55 using the GSI Fragment Separator as a two-stage magnetic spectrometer and the Miniball array for gamma-ray detection. Inclusive longitudinal momentum distributions and cross-sections were measured enabling the determination of the contributions corresponding to knockout from the nu p(1/2), nu p(3/2), (L = 1) and nu f(7/2), nu f(5/2) (L = 3) neutron orbitals. The observed L = 1 and L = 3 contributions are compared with theoretical cross-sections using eikonal knockout theory and spectroscopic factors from shell model calculations using the GXPF1A interaction. The measured inclusive knockout cross-sections generally follow the trends expected theoretically and given by the spectroscopic strength predicted from the shell model calculations. However, the deduced L = 1 cross-sections are generally 30-40% higher while the L = 3 contributions are about a factor of two smaller than predicted. This points to a promotion of neutrons from the nu f(7/2) to the nu p(3/2) orbital indicating a weakening of the N = 28 shell gap in these nuclei. While this is not predicted for the phenomenological GXPF1A interaction such a weakening is predicted by recent calculations using realistic low-momentum interactions V-lowk obtained by evolving a chiral N3LO nucleon-nucleon potential.
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| 23. |
- Wamers, F., et al.
(author)
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Exclusive measurements of nuclear breakup reactions of 17Ne
- 2014
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In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 66
-
Conference paper (peer-reviewed)abstract
- We have studied one-proton-removal reactions of about 500MeV/u 17Ne beams on a carbon target at the R3B/LAND setup at GSI by detecting beam-like 15O-p and determining their relative-energy distribution. We exclusively selected the removal of a 17Ne halo proton, and the Glauber-model analysis of the 16F momentum distribution resulted in an s2 contribution in the 17Ne ground state of about 40%. © Owned by the authors, published by EDP Sciences, 2014.
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