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| 2. |
- Eivazihollagh, Alireza, et al.
(författare)
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On chelating surfactants : Molecular perspectives and application prospects
- 2019
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Ingår i: Journal of Molecular Liquids. - : Elsevier BV. - 0167-7322 .- 1873-3166. ; 278, s. 688-705
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Tidskriftsartikel (refereegranskat)abstract
- Chelating agents, molecules that very strongly coordinates certain metal ions, are used industrially as well as in consumer products to minimize disturbances and increase performance of reactions and applications. The widely used sequestering agents, nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA) belong to this branch of readily water-soluble compounds. When these chemical structures also have hydrophobic parts, they are prone to adsorb at air-water interfaces and to self-assemble. Such bifunctional molecules can be called chelating surfactants and will have more extended utilization prospects than common chelating agents or ordinary ionic surfactants. The present review attempts to highlight the fundamental behavior of chelating surfactants in solution and at interfaces, and their very specific interactions with metal ions. Methods to recover chelating surfactants from metal chelates are also described. Moreover, utilization of chelating surfactants in applications for metal removal in environmental engineering and mineral processing, as well as for metal control in the fields of biology, chemistry and physics, is exemplified and discussed.
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| 3. |
- Trigo, João Pedro, 1995, et al.
(författare)
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Mild blanching prior to pH-shift processing of Saccharina latissima retains protein extraction yields and amino acid levels of extracts while minimizing iodine content
- 2023
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Ingår i: Food Chemistry. - : Elsevier BV. - 0308-8146 .- 1873-7072. ; 404
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Tidskriftsartikel (refereegranskat)abstract
- The seaweed Saccharina latissima is often blanched to lower iodine levels, however, it is not known how blanching affects protein extraction. We assessed the effect of blanching or soaking (80/45/12 °C, 2 min) on protein yield and protein extract characteristics after pH-shift processing of S. latissima. Average protein yields and extract amino acid levels ranked treatments as follows: blanching-45 °C ∼ control > soaking ∼ blanching-80 °C. Although blanching-45 °C decreased protein solubilization yield at pH 12, it increased isoelectric protein precipitation yield at pH 2 (p < 0.05). The former could be explained by a higher ratio of large peptides/proteins in the blanched biomass as shown by HP-SEC, whereas the latter by blanching-induced lowering of ionic strength, as verified by a dialysis model. Moreover, blanching-45 °C yielded a protein extract with 49 % less iodine compared with the control extract. We recommend blanching-45 °C since it is effective at removing iodine and does not compromise total protein extraction yield.
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| 4. |
- Grishenkov, Dmitry, 1983-, et al.
(författare)
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Characterization of Acoustic Properties of PVA-Shelled Ultrasound Contrast Agents
- 2010
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Ingår i: Ultrasound Contrast Agents. - Italia : Springer-Verlag. - 9788847014930 ; , s. 99-108
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This work examines the acoustic behavior of ultrasound contrast agents made of poly (vinyl alcohol) (PVA) shelled microbubbles manufactured at three different pH and temperature conditions. Backscattering amplitude, attenuation coefficient and phase velocity of ultrasonic waves propagating through suspensions of PVA contrast agents were measured at temperature values ranging between 24 oC and 37 oC in a frequency range from 3 MHz to 13 MHz. A significant enhancement of the backscattering amplitude and displaying a weak dependence on temperature were observed. Attenuation and phase velocity, on the other hand, showed higher sensitivity to temperature variations. The dependence on system parameters such as the number of cycles, frequency, and exposure of the peak negative pressure, Pthr, at which ultrasound contrast agents fracture was also investigated. The effects of temperature, blood, and, wherever data are available, of the dimension of the microbubbles on Pthr are also considered. The large shell thickness notwithstanding, the results of this investigation show that at room temperature PVA contrast agents fracture at negative peak pressure values within the recommended safety limit. Furthermore, Pthr decreases with increasing temperature, radius of the microbubbles, and number of cycles of the incident wave. In conclusion, these results suggest that PVA-shelled microbubbles may offer a potentially viable system to be employed for both imaging and therapeutic purposes.
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| 5. |
- Hoveskog, Maya
(författare)
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Innovation-related Activities in a Low-tech Industry : A Study of the Electroplating and Surface Treatment Industry in Sweden
- 2011
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Ingår i: Research on Technology, Innovation and Marketing Management 2009‐2011. - Halmstad : Högskolan i Halmstad. - 9789197507516 ; , s. 55-81
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Given the complex and interdependent nature of innovation, it is a diverse phenomenon which takes place both in high‐ and low‐tech industries. The purpose of this paper is to increase our understanding about low‐tech industries’ innovation‐related activities and the specific capabilities of the companies that influence those. To achieve this purpose this study has performed an empirical analysis of the Swedish context of the Swedish Electroplating and Surface Treatment Industry (ESTI) and the characteristics of the companies operating in it. It investigated how the companies perceived their expertise and innovative activities in comparison with their main competitors. The main types of innovation the ESTI companieshad undertaken in a three‐year period (2004–2006) were studied. The research and development (R&D) and personnel qualification improvement expenditures were explored. The study looked into collaboration and the factors which companies perceived as important in order to collaborate. Our empirical evidence shows that innovation in the ESTI is shaped notby R&D but by other determinants, such as specific and rare capabilities in, for example, processing technologies, logistics, ability to spot, evaluate and exploit external knowledge as well as their ability to establish and sustain intercompany relationships. Strong relationships and integration with customers and suppliers emerge as pivotal for the innovation‐related activities in the ESTI. Additionally, close collaboration, facilitated by a strong intermediate institution, such as the Swedish Association of Surface Treatment Companies (Svensk YtbehandlingsFörening – SYF, also shape the innovation‐related activities in the ESTI.
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| 6. |
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| 7. |
- Almgren, Karin, et al.
(författare)
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Role of fibre-fibre and fibre-matrix adhesion in stress transfer in composites made from resin-impregnated paper sheets.
- 2009
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Ingår i: International Journal of Adhesion and Adhesives. - : Elsevier BV. - 0143-7496 .- 1879-0127. ; 29:5, s. 551-557
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Tidskriftsartikel (refereegranskat)abstract
- Paper-reinforced plastics are gaining increased interest as packaging materials, where mechanical properties are of great importance. Strength and stress transfer in paper sheets are controlled by fibre-fibre bonds. In paper-reinforced plastics, where the sheet is impregnated with a polymer resin, other stress-transfer mechanisms may be more important. The influence of fibre-fibre bonds on the strength of paper-reinforced plastics was therefore investigated. Paper sheets with different degrees of fibre-fibre bonding were manufactured and used as reinforcement in a polymeric matrix. Image analysis tools were used to verify that the difference in the degree of fibre-fibre bonding had been preserved in the composite materials. Strength and stiffness of the composites were experimentally determined and showed no correlation to the degree of fibre-fibre bonding, in contrast to the behaviour of unimpregnated paper sheets. The degree of fibre-fibre bonding is therefore believed to have little importance in this type of material, where stress is mainly transferred through the fibre-matrix interface.
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| 8. |
- Bessman, Alexander, et al.
(författare)
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Aging effects of AC harmonics on lithium-ion cells
- 2019
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Ingår i: Journal of Energy Storage. - : Elsevier. - 2352-152X .- 2352-1538. ; 21, s. 741-749
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Tidskriftsartikel (refereegranskat)abstract
- With the vehicle industry poised to take the step into the era of electric vehicles, concerns have been raised that AC harmonics arising from switching of power electronics and harmonics in electric machinery may damage the battery. In light of this, we have studied the effect of several different frequencies on the aging of 28 Ah commercial NMC/graphite prismatic lithium-ion battery cells. The tested frequencies are 1 Hz, 100 Hz, and 1 kHz, all with a peak amplitude of 21 A. Both the effect on cycled cells and calendar aged cells is tested. The cycled cells are cycled at a rate of 1C:1C, i.e., 28 A during both charging and discharging, with the exception of a period of constant voltage at the end of every charge. After running for one year, the cycled cells have completed approximately 2000 cycles. The cells are characterized periodically to follow how their capacities and power capabilities evolve. After completion of the test about 80% of the initial capacity remained and no increase in resistance was observed. No negative effect on either capacity fade or power fade is observed in this study, and no difference in aging mechanism is detected when using non-invasive electrochemical methods of post mortem investigation.
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| 9. |
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| 10. |
- Lindström, Stefan B, 1974-, et al.
(författare)
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A numerical investigation of the rheology of sheared fiber suspensions
- 2009
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Ingår i: Physics of fluids. - : AIP Publishing. - 1070-6631 .- 1089-7666. ; 21:8, s. 083301-
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Tidskriftsartikel (refereegranskat)abstract
- Particle-level simulations are performed to study the rheology of monodispersed non-Brownian fibers suspended in a Newtonian fluid in shear flow. The effects of fiber aspect ratio, concentration, and interparticle friction on the stress tensor of the suspension in the steady state and on the tendency of fiber agglomeration are investigated. Semiempirical expressions for the steady state apparent shear viscosity and the steady state first and second normal stress difference were obtained for the case of well dispersed suspensions in the nonconcentrated regimes. The simulation predictions of the specific viscosity were in fair agreement with previous experimental investigations.
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