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  • 51.
    Alam, Parvez
    et al.
    Univ Edinburgh, Inst Mat & Proc, Sch Engn, Edinburgh, Midlothian, Scotland.
    Sanka, Immanuel
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre. Univ Gadjah Mada, Fac Biol, KSK Biogama Marine Biol Study Grp, Yogyakarta, Indonesia.
    Alam, Lilja Piuli
    Int Baccalaureate Sch, Turku, Finland.
    Wijaya, Saka
    Univ Gadjah Mada, Fac Biol, Dept Trop Biol, Yogyakarta, Indonesia.
    Sintya, Erly
    Univ Edinburgh, Inst Mat & Proc, Sch Engn, Edinburgh, Midlothian, Scotland; Univ Gadjah Mada, Fac Biol, KSK Biogama Marine Biol Study Grp, Yogyakarta, Indonesia; Kings Coll London, Dept Imaging Sci, London, England; Kings Coll London, Biomed Engn Res Div, London, England.
    Handayani, Niken Satuti Nur
    Univ Gadjah Mada, Fac Biol, Lab Genet & Breeding, Yogyakarta, Indonesia.
    Rivero-Mueller, Adolfo
    Univ Turku, Turku Ctr Biotechnol, Turku, Finland; Åbo Akad Univ, Turku, Finland; Med Univ Lublin, Dept Biochem & Mol Biol, Lublin, Poland.
    The snapping shrimp dactyl plunger: a thermomechanical damage-tolerant sandwich composite2018In: Zoology (Jena), ISSN 0944-2006, E-ISSN 1873-2720, Vol. 126, p. 1-10Article in journal (Refereed)
    Abstract [en]

    The dactyl plunger of Alpheus sp. was found to be a layered composite, with mineral-rich outer and inner layers and a chitin-rich middle layer of high porosity. The chitin-rich middle layer is itself composed of several porous chitin laminae. Modelling heat conduction through the plunger cross-section revealed that the chitin-rich layer is able to insulate heat and retard its progress through the material. Heat accumulates in the plunger after a series of successive snaps and as such, its thermally resistant design can be considered most useful under the conditions of successive snapping. The plunger has a concurrent mechanical damage-tolerant design with biogenic mineral layers, viscous (chitin–mineral) interfaces, energy-dissipating porous chitin, and sidewalls composed of ordered, layered aragonite. The snapping shrimp plunger has a design that may protect it and internal soft tissues from thermomechanical damage during plunger–socket compression prior to cavitation bubble release.

  • 52.
    Alberdi-Muniain, Ane
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Structural and vibroacoustics.
    Gil-Negrete, N.
    Department of Applied Mechanics, CEIT and Tecnun (University of Navarra).
    Kari, Leif
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Structural and vibroacoustics.
    Influence of carbon black and plasticisers on dynamic properties of isotropic magnetosensitive natural rubber2012In: Plastics, rubber and composites, ISSN 1465-8011, E-ISSN 1743-2898, Vol. 41, no 7, p. 310-317Article in journal (Refereed)
    Abstract [en]

    The dynamic shear modulus of magnetosensitive (MS) natural rubber composites is experimentallystudied, where influences of carbon black, plasticiser and iron particle concentrations areinvestigated at various dynamic shear strain amplitudes and external magnetic fields within thelower structure borne frequency range. The iron particles embedded in natural rubber areirregularly shaped and randomly distributed; the plasticisers simplify the iron particle blendingprocess, while carbon black reduces the production costs and improves the mechanicalproperties. The results show that the relative MS effect on the shear modulus magnitude increaseswith increased plasticiser and iron particle concentration and decreases with increased carbonblack concentration. Furthermore, their relative contributions are quantified. Consequently, thestudy provides a basis for optimising the composition of MS natural rubber to meet a variety ofrequirements, including those of vibration isolation, a promising application area for MS materials.

  • 53.
    Albero Caro, Jesus
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena.
    Woldehaimanot, Mussie
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena.
    Rasmuson, Åke Christoffer
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena.
    Semibatch reaction crystallization of salicylic acid2014In: Chemical engineering research & design, ISSN 0263-8762, E-ISSN 1744-3563, Vol. 92, no 3, p. 522-533Article in journal (Refereed)
    Abstract [en]

    Reaction crystallization of salicylic acid has been investigated by experiments and modeling. In the experimental work, dilute hydrochloric acid has been added to an agitated aqueous solution of sodium salicylate in 1 L scale, and product crystals have been characterized by image analysis. The results show that the product crystal number mean size at first increases with increasing agitation rate but then gradually decreases again at further increase in stirring rate. At lower stirring rate, larger crystals are obtained when the feeding point is located close to the agitator instead of being located out in the bulk solution. The mean crystal size increases with decreasing feeding rate and with decreasing reactant concentrations. There is a decrease in mean size with increasing feed pipe diameter. These trends in the experimental results show great similarity with previous results on benzoic acid. The experimental results have been examined by a population balance model accounting for meso and micro mixing, and crystal nucleation and growth rate dispersion. It is found that the crystallization kinetic parameter estimation is quite complex, and the objective function hyper surface contains many different minima. Hence, parameter estimation has to rely on a combination of mathematical optimization strategies and a scientific understanding of the physical meaning of the parameters and their relation to current theories. As opposed to our previous work on benzoic acid, it has not been possible to find a set of kinetic parameters that provides for a good description of all experimental data.

  • 54.
    Albertsson, A-C.
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Andersson, S-O.
    Karlsson, S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    The mechanism of biodegradation of polyethylene1987In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 18, p. 73-87Article in journal (Refereed)
  • 55. Albertsson, A-C.
    et al.
    Barenstedt, C.
    Karlsson, S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Degradation of enhanced environmentally degradable polyethylene in biological aqueous media: mechanisms during the first stages1994In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 51, no 6, p. 1097-1105Article in journal (Refereed)
  • 56. Albertsson, A-C.
    et al.
    Barenstedt, C.
    Karlsson, S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Increased biodegradation of a low-density polyethylene (LDPE) matrix in starch-filled LDPE materials1993In: Journal of environmental polymer degradation, ISSN 1064-7546, E-ISSN 1572-8900, Vol. 1, no 4, p. 241-245Article in journal (Refereed)
  • 57. Albertsson, A-C.
    et al.
    Barenstedt, C.
    Karlsson, S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Solid-phase extraction and gas chromatographic-mass spectrometric identification of degradation products from enhanced environmentally degradable polyethylene1995In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 690, no 2, p. 207-217Article in journal (Refereed)
  • 58. Albertsson, A-C.
    et al.
    Barenstedt, C.
    Karlsson, S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Susceptibility of enhanced environmentally degradable polyethylene to thermal and photo-oxidation1992In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 37, no 2, p. 163-171Article in journal (Refereed)
  • 59. Albertsson, A-C.
    et al.
    Barenstedt, C.
    Karlsson, S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Lindberg, T.
    Degradation product pattern and morphology changes as means to differentiate abiotically and biotically aged degradable polyethylene1995In: Polymer, ISSN 0032-3861, E-ISSN 1873-2291, Vol. 36, no 16, p. 3075-83Article in journal (Refereed)
  • 60. Albertsson, A-C.
    et al.
    Griffin, G. J. L.
    Karlsson, S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Nishimoto, K.
    Watanabe, Y.
    Spectroscopic and mechanical changes in irradiated starch-filled LDPE1994In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 45, no 2, p. 173-178Article in journal (Refereed)
  • 61. Albertsson, A-C.
    et al.
    Karlsson, S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Abiotic degradation products from enhanced environmentally degradable polyethylene1994In: Acta Polymerica, ISSN 0323-7648, E-ISSN 1521-4044, Vol. 45, no 2, p. 97-103Article in journal (Refereed)
  • 62. Albertsson, A-C.
    et al.
    Karlsson, S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Aspects of biodeterioration of inert and degradable polymers1993In: International Biodeterioration & Biodegradation, ISSN 0964-8305, E-ISSN 1879-0208, Vol. 31, no 3, p. 161-170Article in journal (Refereed)
  • 63. Albertsson, A-C.
    et al.
    Karlsson, S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Biodegradable polymers1992In: Comprehensive Polymer Science, Supplement Series, Midland, Michigan: Pergamon Press, 1992, p. 285-Chapter in book (Refereed)
  • 64. Albertsson, A-C.
    et al.
    Karlsson, S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Biodegradation and testmethods for environmental and biomedical applications of polymers1990In: Degradable Materials, Boca Raton: CRC Press, 1990, p. 263-Chapter in book (Refereed)
  • 65. Albertsson, A-C.
    et al.
    Karlsson, S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Chemistry and biochemistry of polymer biodegradation1994In: Chemistry and Technology of Biodegradable Polymers / [ed] G.J.L. Griffin, London, England: Blackie Academic & Professional , 1994, p. 7-17Chapter in book (Refereed)
  • 66. Albertsson, A-C.
    et al.
    Karlsson, S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Chromatographic fingerprinting as a means to predict degradation mechanisms1996In: Journal of environmental polymer degradation, ISSN 1064-7546, E-ISSN 1572-8900, Vol. 4, no 1, p. 51-3Article in journal (Refereed)
  • 67. Albertsson, A-C.
    et al.
    Karlsson, S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Controlled degradation by artificial and biological processes1996In: Macromol. Design of Polymeric Materials, Marcel Dekker, 1996, p. 54-Chapter in book (Refereed)
  • 68. Albertsson, A-C.
    et al.
    Karlsson, S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Degradable polyethylene-starch complex1991In: Makromolekulare Chemie, Macromolecular Symposia, Vol. 48-49, no Eur. Polym. Fed. Symp. Polym. Mater., 3rd, 1990, p. 395-402Article in journal (Refereed)
  • 69. Albertsson, A-C.
    et al.
    Karlsson, S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Degradable Polymers1996In: The Polymeric Materials Encyclopedia: Synthesis, Properties and Applications / [ed] J. C. Salamone, Boca Raton, USA: CRC Press, 1996, p. 150-Chapter in book (Refereed)
  • 70. Albertsson, A-C.
    et al.
    Karlsson, S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Degradable polymers for the future1995In: Acta Polymerica, ISSN 0323-7648, E-ISSN 1521-4044, Vol. 46, no 2, p. 114-123Article in journal (Refereed)
  • 71. Albertsson, A-C.
    et al.
    Karlsson, S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Environment-adaptable polymers1993In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 41, no 3, p. 345-349Article in journal (Refereed)
  • 72. Albertsson, A-C.
    et al.
    Karlsson, S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Increased biodegradation of LDPE-matrix in starch-filled LDPE materials1992In: Materials Science and Engineering, Vol. 67, p. 296-297Article in journal (Refereed)
  • 73. Albertsson, A-C.
    et al.
    Karlsson, S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Macromolecular architecture-nature as model for degradable polymers1996In: Journal of Macromolecular Science, Part A: Pure and Applied Chemistry, Vol. 33, no 10, p. 1565-1570Article in journal (Refereed)
  • 74. Albertsson, A-C.
    et al.
    Karlsson, S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    New tools for analyzing degradation1995In: Macromolecular Symposia, ISSN 1022-1360, E-ISSN 1521-3900, Vol. 98, no 35th IUPAC International Symposium on Macromolecules, 1995, p. 797-801Article in journal (Refereed)
  • 75. Albertsson, A-C.
    et al.
    Karlsson, S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Polyethylene degradation and degradation products1990In: Agricultural and Synthetic Polymers: Biodegradability and Utilization, American Chemical Society (ACS), 1990, Vol. 433, no Agricultural & Synthetic Polymers, p. 60-64Chapter in book (Refereed)
  • 76. Albertsson, A-C.
    et al.
    Karlsson, S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    The Influence of Biotic and Abiotic Environments on the Degradation of Polyethylene.1990In: Progress in polymer science, ISSN 0079-6700, E-ISSN 1873-1619, Vol. 15, no 2, p. 177-192Article in journal (Refereed)
  • 77. Albertsson, A-C.
    et al.
    Sares, C.
    Karlsson, S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Increased biodegradation of low-density polyethylene (LDPE) with nonionic surfactant1993In: Acta Polymerica, ISSN 0323-7648, E-ISSN 1521-4044, Vol. 44, no 5, p. 243-246Article in journal (Refereed)
  • 78.
    Albertsson, Ann-Christine
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Frontiers in Biomacromolecules: Functional Materials from Nature2012In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 13, no 12, p. 3901-3901Article in journal (Other academic)
  • 79.
    Albertsson, Ann-Christine
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Edlund, Ulrica
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Barrier layers for packaging laminates and packaging laminates comprising such barrier layers2009Patent (Other (popular science, discussion, etc.))
  • 80.
    Albertsson, Ann-Christine
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Erlandsson, Bengt
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Hakkarainen, Minna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Karlsson, Sigbritt
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Molecular weight changes and polymeric matrix changes correlated with the formation of degradation products in biodegraded polyethylene1999In: Journal of environmental polymer degradation, ISSN 1064-7546, E-ISSN 1572-8900, Vol. 64, p. 91-99Article in journal (Refereed)
    Abstract [en]

    The molecular weight changes in abiotically and biotically degraded LDPE and LDPE modified with starch and/or prooxidant were compared with the formation of degradation products, The samples were thermooxidized for 6 days at 100 degrees C to initiate degradation and then either inoculated with Arthobacter paraffineus or kept sterile. After 3.5 years homologous series of mono- and dicarboxylic acids and ketoacids were identified by GC-MS in abiotic samples, while complete disappearance of these acids was observed in biotic environments. The molecular weights of the biotically aged samples were slightly higher than the molecular weights of the corresponding abiotically aged samples, which is exemplified by the increase in (M) over bar(n) from 5200 g/mol for a sterile sample with the highest amount of prooxidant to 6000 g/mol for the corresponding biodegraded sample. The higher molecular weight in the biotic environment is explained by the assimilation of carboxylic acids and low molecular weight polyethylene chains by microorganisms. Assimilation of the low molecular weight products is further confirmed by the absence of carboxylic acids in the biotic samples. Fewer carbonyls and more double bonds were seen by FTIR in the biodegraded samples, which is in agreement with the biodegradation mechanism of polyethylene.

  • 81.
    Albertsson, Ann-Christine
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Groning, M.
    Hakkarainen, Minna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Emission of volatiles from polymers - A new approach for understanding polymer degradation2006In: Journal of polymers and the environment, ISSN 1064-7546, E-ISSN 1572-8900, Vol. 14, no 1, p. 8-13Article in journal (Refereed)
    Abstract [en]

    Emission of low molar mass compounds from different polymeric materials was determined and the results from the volatile analysis were applied to predict the degree of degradation and long-term properties, to determine degradation rates and mechanisms, to differentiate between biotic and abiotic degradation and for quality control work. Solid-phase microextraction and solid-phase extraction together with GC-MS were applied to identify and quantify the low molar mass compounds. Volatiles were released and monitored at early stages of degradation before any matrix changes were observed by e.g. SEC, DSC and tensile testing. The analysis of volatiles can thus also be applied to detect small differences between polymeric materials and their susceptibility to degradation. The formation of certain degradation products correlated with the changes taking place in the polymer matrix, these indicator products could, thus, be analysed to rapidly predict the degree of degradation in the polymer matrix and further to predict the long-term properties and remaining lifetime of the product.

  • 82.
    Albertsson, Ann-Christine
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Gröning, Mikael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Hakkarainen, Minna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Chromatographic analysis as a tool for predicting material performance2005In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, p. 247-248Article in journal (Other academic)
  • 83.
    Albertsson, Ann-Christine
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Hakkarainen, Minna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Degradable polymers and their interaction with the environment2007In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 223, p. 566-567Article in journal (Other academic)
  • 84.
    Albertsson, Ann-Christine
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Hakkarainen, Minna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Designed to degrade Suitably designed degradable polymers can play a role in reducing plastic waste2017In: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 358, no 6365, p. 872-873Article in journal (Refereed)
  • 85.
    Albertsson, Ann-Christine
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Karlsson, Sigbritt
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    The three stages in the degradation of polymers- polyethylene as a model substance1988In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 35, p. 1289-1302Article in journal (Refereed)
  • 86. Albertsson, Ann-Christine
    et al.
    Renstad, Rasmus
    Erlandsson, Bengt
    Eldsäter, Carina
    Karlsson, Sigbritt
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Effect of processing additives on (bio)degradability of film-blown poly(ε-caprolactone)1998In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 70, no 1, p. 61-74Article in journal (Refereed)
  • 87.
    Albán Reyes, Diana Carolina
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Skoglund, Nils
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Department of Engineering Sciences and Mathematics, Luleå University of Technology, Luleå, Sweden .
    Svedberg, Anna
    Eliasson, Bertil
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Sundman, Ola
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    The influence of different parameters on the mercerisation of cellulose for viscose production2016In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 23, no 2, p. 1061-1072Article in journal (Refereed)
    Abstract [en]

    A quantitative analysis of degree of transformation from a softwood sulphite dissolving pulp to alkalised material and the yield of this transformation as a function of the simultaneous variation of the NaOH concentration, denoted [NaOH], reaction time and temperature was performed. Samples were analysed with Raman spectroscopy in combination with multivariate data analysis and these results were confirmed by X-ray diffraction. Gravimetry was used to measure the yield. The resulting data were related to the processing conditions in a Partial Least Square regression model, which made it possible to explore the relevance of the three studied variables on the responses. The detailed predictions for the interactive effects of the measured parameters made it possible to determine optimal conditions for both yield and degree of transformation in viscose manufacturing. The yield was positively correlated to the temperature from room temperature up to 45 A degrees C, after which the relation was negative. Temperature was found to be important for the degree of transformation and yield. The time to reach a certain degree of transformation (i.e. mercerisation) depended on both temperature and [NaOH]. At low temperatures and high [NaOH], mercerisation was instantaneous. It was concluded that the size of fibre particles (mesh range 0.25-1 mm) had no influence on degree of transformation in viscose processing conditions, apparently due to the quick reaction with the excess of NaOH.

  • 88.
    Aldaeus, F.
    et al.
    RISE, Innventia.
    Schweinebarth, H.
    RISE, Innventia.
    Törngren, P.
    RISE, Innventia.
    Jacobs, A.
    RISE, Innventia.
    Simplified determination of total lignin content in kraft lignin samples and black liquors2011In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, no 4, p. 601-604Article in journal (Refereed)
  • 89. Aldea, Steliana
    et al.
    Snåre, Mathias
    Eränen, Kari
    Grenman, Henrik
    Rautio, Anne-Riika
    Kordás, Krisztian
    Mikkola, Jyri-Pekka
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Laboratory of Industrial Chemistry and Reaction Engineering, Johan Gadolin Process Chemistry Centre, Åbo Akademi University, Biskopsgatan 8, 20500 Åbo-Turku, Finland.
    Salmi, Tapio
    Murzin, Dmitry Y.
    Crystallization of Nano-Calcium Carbonate: The Influence of Process Parameters2016In: Chemie Ingenieur Technik, ISSN 0009-286X, E-ISSN 1522-2640, Vol. 88, no 11, p. 1609-1616Article in journal (Refereed)
    Abstract [en]

    Precipitated calcium carbonate was synthesized by carbonation of calcium hydroxide in the presence and absence of ultrasound (conventional stirring) at atmospheric as well as at elevated pressures and different initial concentrations of Ca(OH)2. Spherical morphology of the formed calcite was favored at high Ca(OH)2 concentrations and low CO2 pressures. The presence of ultrasound did not show any influence on the reaction rate in case of efficient mixing. A small increase of the reaction rate was observed at lower CO2 pressures. Elevated pressures in combination with ultrasound did not lead to notable changes of reaction rate or particle morphology.

  • 90.
    Aldujaili, Aya
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Berndtson, Emma
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Hedström, Tom
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Piccolo, Sofia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Rahmani, Zakaria
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Åhlén, Michelle
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Hur partikelstorleksfördelning påverkar kritiska parametrar för medicinska enheter2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Projektet har inriktning på Galdermas produkter Deflux och Solesta, de ämnen som produkterna är uppbyggda av (dextran och hyaluronsyra) har studerats laborativt. Ändringar av parametrar såsom koncentration av dextran men även i siktningsmetod (dubbel- respektive enkelsiktningar samt olika filterstorlekar) har genomförts. Resultatet av dessa ändringar har erhållits med hjälp av mikroskop, laserdiffraktometer samt dragprovare. De slutsatser som har kunnat dras från resultaten är att med ökad partikeldiameter erhålls en lägre extruderingskraft, oavsett om använd siktningsmetod var enkel- eller dubbelsiktning. Vidare så erhålls en större extruderingskraft med ökad koncentration av dextran.

  • 91.
    Alemrajabi, Mahmood
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Transport Phenomena.
    Recovery of Rare Earth Elements from an Apatite Concentrate2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Rare earth elements (REE) are a group of 17 elements including lanthanides, yttrium and scandium; which are found in a variety of classes of minerals worldwide. The criticality of the application, lack of high grade and economically feasible REE resources and a monopolistic supply situation has raised significant attention in recovery of these metals from low grade ores and waste materials. In this thesis, the recovery of REE from an apatite concentrate, containing 0.5 mass% of REE, within the nitrophosphate route of fertilizer production has been investigated. Most of the REE (≥ 95%) content can be recovered into a phosphate precipitate with almost 30 mass% REE. Different processes have been developed to convert the REE phosphate precipitate into a more soluble form to obtain a solution suitable for further REE purification and individual separation. It has been shown that after reprecipitation of the REE phosphate concentrate as REE sodium double sulphate and then transformation into a REE hydroxide concentrate, a solution containing 45g/L REE free of Ca, Fe and P can be obtained. The results suggest that the apatite waste after processing of iron ore have the potential to be a very important source for REE in Europe and that the economy is strongly supported by the simultaneous extraction of phosphorous.

    The potential of using hollow fiber supported liquid membrane (HFSLM) extraction in individual and group separation of REE has been investigated. A hollow fiber supported liquid membrane plant in pilot scale has been operated according to the three main configurations: standard hollow fiber supported liquid membrane technology (HFSLM); hollow fiber renewal liquid membrane technology (HFRSLM) and emulsion pertraction technology (EPT). The standard HFSLM operation is more selective than HFRSLM and EPT, while higher metal transport rate is observed in EPT followed by HFRSLM and HFSLM. The HFRLM configuration helps to maintain the performance of the liquid membrane.

  • 92.
    Alemrajabi, Mahmood
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Forsberg, Kerstin
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Korkmaz, Kivanc
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Rasmsuon, Å.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Isolation of Rare Earth Element Phosphate Precipitates in the Nitrophosphate Process for Manufacturing of Fertilizer.2016Conference paper (Refereed)
  • 93.
    Alemrajabi, Mahmood
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Forsberg, Kerstin
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Korkmaz, Kivanc
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Rasmuson, Å.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Dephosphorization and impurity removal from a rare earth phosphate concentrate.2017Conference paper (Refereed)
  • 94.
    Alemrajabi, Mahmood
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Forsberg, Kerstin
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Rasmuson, Å.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Recovery of phosphorous and rare earth elements from an apatite concentrate.2018Conference paper (Refereed)
  • 95.
    Alemrajabi, Mahmood
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Rasmuson, Åke
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Korkmaz, Kivanc
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Forsberg, Kerstin
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Upgrading of a rare earth phosphate concentrate within the nitrophosphate process2018In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 198, p. 551-563Article in journal (Refereed)
    Abstract [en]

    In the nitrophosphate process of fertilizer production, rare earth elements (REE) can be recovered as a REE phosphate concentrate. In this process, after digestion of apatite in concentrated nitric acid, Ca(NO3)2.4H2O is first separated by cooling crystallization and then the REE are precipitated in phosphate form by a partial neutralization step using ammonia. The obtained REE phosphate concentrate is contaminated by mainly calcium and iron, and the main solid phases are CaHPO4.2H2O, FePO4.2H2O and REEPO4.nH2O.

    In this study, a process to obtain a concentrate more enriched with REE with low concentration of calcium and iron and free of phosphorous is developed. In the developed process, enrichment and dephosphorization of the rare earth phosphate concentrate has been achieved by selective dissolution and re-precipitation of the REE as a sodium REE double sulfate salt. It is shown that by selective dissolution of the REE concentrate in nitric acid at a pH of 2.4, most of the calcium and phosphorus are dissolved, and a solid phase more enriched in REE is obtained. Thereafter, the REE phosphate concentrate is first dissolved in a mixture of sulfuric-phosphoric acid and then the REE are reprecipitated as NaREE(SO4)2.H2O by addition of a sodium salt. More than 95% of the Ca, Fe and P are removed and a REE concentrate containing almost 30 mass% total REE is obtained.

  • 96.
    Alemrajabi, Mahmoud
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Forsberg, K.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Rasmuson, Å.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Recovery of REE from an apatite concentrate in the nitrophosphate process of fertilizer production.2015Conference paper (Refereed)
  • 97.
    Alevanau, Aliaksandr
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Process Metallurgy.
    Study of pyrolysis and gasification of biomass from the self-organization perspective2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis focuses on the analysis of kinetics of i) low-temperature pyrolysis of gaseous hydrocarbons, ii) high-temperature steam gasification of char of wood pellets (>700oC), iii) high temperature pyrolysis of straw pellets in an atmosphere of argon and steam, and iv) high temperature pyrolysis of slices of transversally cut wooden sticks. The results of the kinetic measurements in the high-temperature cases are approximated using a least-square based optimization software, which was specially developed to analyse kinetics prone for deviation from the Arrhenius law.In the thesis a general analysis of the researched materials and kinetics of their pyrolysis and gasification is presented from the self-organization perspective. The energy transfer phenomena in both the pyrolysis and gasification processes of biomass are discussed with an emphasis on an analysis of basic phenomena involving the self-organized dynamics on fractal structures in the chosen biomass samples.

  • 98.
    Alexiadis, Alessio
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Cornell, Ann
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Dudukovic, M. P.
    Comparison between CFD calculations of the flow in a rotating disk cell and the Cochran/Levich equations2012In: Journal of Electroanalytical Chemistry, ISSN 1572-6657, Vol. 669, p. 55-66Article in journal (Refereed)
    Abstract [en]

    Three CFD (Computational Fluid Dynamics) models (single-phase. VOF and Euler-Euler) are employed to simulate the flow in a finite, rotating electrode cell under different operative conditions. The main dimensionless groups are derived and their effect on the flow is investigated. Except very close to the rotating electrode (i.e. in the hydrodynamic layer), the results show a flow pattern considerably different from Cochran's approximate analytical solution often used in electrochemistry. Historically, the Cochran equation was used to derive the Levich equation, which permits the calculation of the limiting current density on a rotating electrode. Despite the general inadequacy of Cochran's analytical solution, however, we show that the Levich equation often retains its validity because, in many practical situations, the concentration boundary layer is considerably smaller than the hydrodynamic boundary layer. When bubbles are generated on the electrode and a certain critical void fraction is exceeded, however, the Levich equation also becomes inaccurate. We propose, therefore, an amended version of this equation, which provides results closer to the CFD calculations.

  • 99.
    Alexiadis, Alessio
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Dudukovic, M. P.
    Ramachandran, P.
    Cornell, Ann
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    On the stability of the flow in multi-channel electrochemical systems2012In: Journal of Applied Electrochemistry, ISSN 0021-891X, E-ISSN 1572-8838, Vol. 42, no 9, p. 679-687Article in journal (Refereed)
    Abstract [en]

    The importance of the fluid dynamics in the modelling of electrochemical systems is often underestimated. The knowledge of the flow velocity pattern in an electrochemical cell, in fact, can allow us to associate certain electrochemical reactions with specific fluid patterns to maximize the yield of some reaction and, conversely, to minimize unwanted or side reactions. The correct evaluation of the convective term in the Nernst-Planck equation, however, requires the solution of the so-called Navier-Stokes equations, and computational fluid dynamics (CFD) is today the established method to numerically solve these equations. In this work, a CFD model is employed to show that the gas-liquid flow pattern can be remarkably different in a single channel or in a multi-channel gas-evolving electrochemical system. In the single channel, in fact, under certain conditions, vortices and recirculation regions can appear in the flow, which does not appear in the multi-channel case. The reason of this difference is found in the uneven distribution of the small bubbles in the two cases. Additionally, a second, simplified, model of the flow is discussed to show how a higher concentration of small bubbles in the single channel system can destabilize the flow.

  • 100.
    Alexiadis, Alessio
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Dudukovic, M. P.
    Ramachandran, P.
    Cornell, Ann
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Wanngård, J.
    Bokkers, A.
    The flow pattern in single and multiple submerged channels with gas evolution at the electrodes2012In: International Journal of Chemical Engineering, ISSN 1687-806X, E-ISSN 1687-8078, Vol. 2012, p. 392613-Article in journal (Refereed)
    Abstract [en]

    We show that the gas-liquid flow pattern in a single gas-evolving electrochemical channel can be remarkably different from the flow pattern in multiple submerged gas-evolving electrochemical channels. This is due to the fact that in a single channel there is a higher accumulation of small bubbles and these can considerably affect the liquid velocity pattern which in turn may affect the performance of a cell. Since experimental work is often carried out in single channels, while industrial applications almost always involve multiple channels, this study provides insight into the factors that affect the flow pattern in each situation and establishes the basis for relating the behavior of single-and multiple-channel devices.

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