| 1. |
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| 2. |
- Kehoe, Laura, et al.
(författare)
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Make EU trade with Brazil sustainable
- 2019
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 364:6438, s. 341-
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 3. |
- Tao, Qiang, 1987, et al.
(författare)
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D-A(1)-D-A(2) Copolymers with Extended Donor Segments for Efficient Polymer Solar Cells
- 2015
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Ingår i: Macromolecules. - : American Chemical Society (ACS). - 1520-5835 .- 0024-9297. ; 48:4, s. 1009-1016
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Tidskriftsartikel (refereegranskat)abstract
- Typically a donor-acceptor (D-A) design strategy is used for engineering the bandgap of polymers for solar cells. However, in this work, a series of alternating D-A(1-)D-A(2) copolymers PnTQTI(F) were synthesized and characterized with oligothiophenes (nT, n = 1, 2, 3) as the donor and two electron-deficient moieties, quinoxaline and isoindigo, as the acceptors in the repeating unit. We have studied the influence of the donor segments with different numbers of thiophene units and the effect of the addition of fluorine to the quinoxaline unit of the D-A(1)-D-A(2) polymers. The photophysical, electrochemical, and photovoltaic properties of the polymers were examined via a range of techniques and related to theoretical simulations. On increasing the length of the donor thiophene units, broader absorption spectra were observed in addition to a sequential increase in HOMO levels, while the LUMO levels displayed very small variations. The addition of fluorine to the quinoxaline unit not only decreased the HOMO levels of the resulting polymers but also enhanced the absorption coefficients. A superior photovoltaic performance was observed for the P3TQTI-F-based device with a power conversion efficiency (PCE) of 7.0%, which is the highest efficiency for alternating D-A(1)-D-A(2) polymers reported to date. The structureproperty correlations of the PnTQTI(F) polymers demonstrate that varying of the length of the donor segments is a valuable method for designing high-performance D-A(1)-D-A(2) copolymers and highlight the promising nature of D-A(1)-D-A(2) copolymers for efficient bulk-heterojunction solar cells.
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| 4. |
- Fornara, Andrea, et al.
(författare)
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Tailored Magnetic Nanoparticles for Direct and Sensitive Detection of Biomolecules in Biological Samples
- 2008
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Ingår i: Nano letters (Print). - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 8:10, s. 3423-3428
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Tidskriftsartikel (refereegranskat)abstract
- We developed nanoparticles with tailored magnetic properties for sensitive detection of biomolecules directly in biological samples in a single step. Thermally blocked nanoparticles obtained by thermal hydrolysis are mixed with sample solutions and the variation of the magnetic relaxation due to surface binding is used to detect the presence of biomolecules. The binding events significantly increase the hydrodynamic volume of nanoparticles, thus changing their Brownian relaxation frequency which is measured by a specifically developed AC-susceptometer.The system was tested for the presence of Brucella antibodies in serum samples from infected cows and the surface of the nanoparticles was functionalized with lipopolysaccarides (LPS) from Brucella abortus. The hydrodynamic volume of functionalized particles increased by 25-35% as a result of the binding of the antibodies, as measured by changes in the susceptibility in an alternating magnetic field. The method has shown high sensitivity, with detection limit of 7 nmol·L-1 in serum without any pre-treatment of the biological samples.The detection method is very sensitive, cost-efficient and versatile, giving a direct indication if the animal is infected or not, making it suitable for point-of care applications. The functionalization of tailored magnetic nanoparticles can be modified to suit numerous homogenous assays for a wide range of applications.
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| 5. |
- Lind, Petter N., et al.
(författare)
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Augmented Single Loop Single Vector Algorithm Using Nonlinear Approximations of Constraints in Reliability-Based Design Optimization
- 2019
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Ingår i: Journal of mechanical design (1990). - : ASME. - 1050-0472 .- 1528-9001. ; 141:10
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Tidskriftsartikel (refereegranskat)abstract
- Reliability-based design optimization (RBDO) aims at minimizing a function of probabilistic design variables, given a maximum allowed probability of failure. The most efficient methods available for solving moderately nonlinear problems are single loop single vector (SLSV) algorithms that use a first-order approximation of the probability of failure in order to rewrite the inherently nested structure of the loop into a more efficient single loop algorithm. The research presented in this paper takes off from the fundamental idea of this algorithm. An augmented SLSV algorithm is proposed that increases the rate of convergence by making nonlinear approximations of the constraints. The nonlinear approximations are constructed in the following way: first, the SLSV experiments are performed. The gradient of the performance function is known, as well as an estimate of the most probable failure point (MPP). Then, one extra experiment, a probe point, per performance function is conducted at the first estimate of the MPP. The gradient of each performance function is not updated but the probe point facilitates the use of a natural cubic spline as an approximation of an augmented MPP estimate. The SLSV algorithm using probing (SLSVP) also incorporates a simple and effective move limit (ML) strategy that also minimizes the heuristics needed for initiating the optimization algorithm. The size of the forward finite difference design of experiment (DOE) is scaled proportionally with the change of the ML and so is the relative position of the MPP estimate at the current iteration. Benchmark comparisons against results taken from the literature show that the SLSVP algorithm is more efficient than other established RBDO algorithms and converge in situations where the SLSV algorithm fails.
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| 6. |
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| 7. |
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| 8. |
- Sjödin, Martin, 1974-, et al.
(författare)
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Sustainable Batteries
- 2014
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Ingår i: NFM conference, Prague 16-18th June 2014..
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 9. |
- Sterky, Fredrik, et al.
(författare)
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Gene discovery in the wood-forming tissues of poplar : Analysis of 5,692 expressed sequence tags
- 1998
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 95:22, s. 13330-13335
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Tidskriftsartikel (refereegranskat)abstract
- A rapidly growing area of genome research is the generation of expressed sequence tags (ESTs) in which large numbers of randomly selected cDNA clones are partially sequenced. The collection of ESTs reflects the level and complexity of gene expression in the sampled tissue, To date, the majority of plant ESTs are from nonwoody plants such as Arabidopsis, Brassica, maize, and rice. Here, we present a large-scale production of ESTs from the wood-forming tissues of two poplars, Populus tremula L, x tremuloides Michx, and Populus trichocarpa 'Trichobel.' The 5,692 ESTs analyzed represented a total of 3,719 unique transcripts for the two cDNA libraries, Putative functions could be assigned to 2,245 of these transcripts that corresponded to 820 protein functions. Of specific interest to forest biotechnology are the 4% of ESTs involved in various processes of cell wall formation, such as lignin and cellulose synthesis, 5% similar to developmental regulators and members of known signal transduction pathways, and 2% involved in hormone biosynthesis. An additional 12% of the ESTs show ed no significant similarity to any other DNA or protein sequences in existing databases. The absence of these sequences from public databases may indicate a specific role for these proteins in wood formation. The cDNA libraries and the accompanying database are valuable resources for forest research directed toward understanding the genetic control of wood formation and future endeavors to modify wood and fiber properties for industrial use.
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| 10. |
- Tammela, Petter, 1986-, et al.
(författare)
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Influence of Separator and Electrode Thickness on Cell Resistance in Energy Storage Devices based on Polypyrrole-Cellulose Composites
- 2014
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Ingår i: GradSAM21 workshop 2014.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The next-generation electronic industry requires access to inexpensive, flexible, light-weight and environmentally friendly energy storage devices [1]. Consequently, a lot of research has been directed toward producing versatile and flexible materials as a complement to the materials used in contemporary batteries and supercapacitors. Electroactive polymers represent an attractive alternative and electronically conducting polymers have hence received considerable interest as it is well-known that these materials can be used to manufacture all-polymer-based batteries and supercapacitors [2]. The performance of such energy storage devices is, however, ultimately limited by the resistance of the cell [3]. One important aspect is therefore to consider the cell resistance when optimizing the performance and cell design.Our recent activities have shown that a flexible and highly porous cellulose and polypyrrole composite, obtained by polymerizing pyrrole on cellulose from the Cladophora sp. algae, can be used as paper-based electrode materials and together with an aqueous salt solution form an environmentally friendly charge storage device [4, 5]. The cellulose-polypyrrole-based device proved to cycle for thousands of cycles without significant loss of capacity even at high charge and discharge rates.In the present work, the cell resistances of cellulose-polypyrrole-based charge storage devices are investigated, and the influence of electrode material and separator thickness are examined. The effect of absorption of electrolyte in the separator compared to bulk solutions of electrolyte, and the contact resistances between current collectors and the composite are discussed, as well as the possibilities of designing inexpensive all-organic energy storage devices with promising performance regarding cycling stability, rate capability and cell resistance.
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