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| 2. |
- Liedberg, Bo, et al.
(författare)
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Self-assembly of alpha-functionalized terthiophenes on gold
- 1997
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Ingår i: JOURNAL OF PHYSICAL CHEMISTRY B. - : AMER CHEMICAL SOC. - 1089-5647 .- 1520-6106 .- 1520-5207. ; 101:31, s. 5951-5962
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Tidskriftsartikel (refereegranskat)abstract
- alpha-Functionalized terthiophenes containing disulfide (-S-T-3-H)(2) and alkanethiol (HS-(CH2)(11)-T-3-H) anchoring groups have been synthesized for direct immobilization onto gold. Monolayer structures of these compounds are prepared by spontaneous assembly from ethanol solutions on evaporated gold substrates and thoroughly characterized by ellipsometry, contact angle goniometry, infrared and X-ray photoelectron spectroscopy, and cyclic voltammetry. The two molecules coordinate to the gold substrate exclusively via the anchoring groups upon formation of gold-thiolate bonds. The kinetics of monolayer formation vary dramatically for the two compounds. The alkanethiol analogue assembles rapidly, within a few minutes, and forms a densely packed and highly organized monolayer, with the alkyl chains in an almost perfect all-trans conformation and the C-alpha-C-alpha axis of the alpha-T-3 units tilted about 14 degrees away from the surface normal. The assembly process is much slower for the disulfide, but an organized monolayer with an average alpha-T-3 chain tilt of about 33 degrees will eventually form when the assembly is allowed to equilibrate with a solution containing the disulfide for at least 1 day. Moreover, the two monolayer assemblies also display a remarkably different electrochemical, behavior. The heterogeneous electron-transfer rate at the disulfide-covered gold substrate is almost indistinguishable from that at bare gold, suggesting that the assembly contains a large number of easily accessible defects. An alternative mechanism for explaining the large electron-transfer rate involving electronic coupling via the conjugated pi-system of the alpha-T-3 units is also proposed. The electrochemical response is significantly reduced for the HS-(CH2)(11)-T-3-H assembly, but another type of defects, the so-called shallow defects originating from sparsely populated areas on the electrode surface, can be identified.
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| 5. |
- Yang, Liyun, 1992-, et al.
(författare)
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Distance Ergonomics Laboratory Using Flipped Classroom and Smartphone Application as Learning Tools – A Case Study
- 2021
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Ingår i: 21st Congress of the International Ergonomics Association, IEA 2021. - Cham : Springer Nature. ; , s. 130-134
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Konferensbidrag (refereegranskat)abstract
- Distance laboratory training in ergonomics with a flipped-classroom approach and smartphone applications as a tool was designed, implemented, and evaluated at two Swedish universities. Most students (10/13) were satisfied with the laboratory training. In this small-scale study, sufficient preparation time, tailored instructions and timely support during the pre-lab work were identified as factors that may improve students’ learning. This case study points to that distance laboratory training can be a feasible method in future ergonomics education. The findings also contribute to better understanding on the design of distance laboratory training in the future.
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| 6. |
- Yang, Zhongping, et al.
(författare)
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Preparation and characterization of mixed monolayer assemblies composed of thiol analogues of cholesterol and fatty acid
- 1997
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Ingår i: Langmuir. - : American Chemical Society. - 0743-7463 .- 1520-5827. ; 13:12, s. 3210-3218
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Tidskriftsartikel (refereegranskat)abstract
- Mixed self-assembled monolayers provide an attractive model system for investigating the role of different molecules in biological membranes. This paper describes the preparation and characterization of a novel type of mixed monolayer assemblies composed of thiol analogues of cholesterol and fatty acid. The mixed: monolayers are prepared by coadsorbing 11-mercaptoundecanoic acid (MUA) and thiocholesterol(cholest-5-ene-3 beta-thiol, TC) from solution directly onto evaporated gold surfaces. The influence of TC on the molecular composition and conformation in the mixed monolayer is analyzed by using a combination of infrared reflection-absorption spectroscopy (IRAS), X-ray photoelectron spectroscopy (XPS), ellipsometry, contact angle measurement, and cyclic voltammetry. The results indicate that the TC molecules maintain their conformation in the mixed monolayers, whereas the MUA molecules display a significantly more disordered conformation as compared to the MUA molecules in the pure monolayer. Cyclic voltammetry shows that the mixed monolayers are more densely packed and less permeable than the pure TC and MUA monolayers. The kinetics of the coadsorption of TC and MUA from ethanol indicates that adsorption of TC initially is strongly preferred over MUA but that MUA dominates over TC at long coadsorption times. This is because there is a larger energy gain per unit area in forming monolayers with MUA, Further, it is also seen that the number of molecules per unit area changes with the molecular composition, as a consequence of the different sizes of TC and MUA. We present herein a method for calculating the mole fraction of TC on the gold surface, (chi TC), which accounts for this variation. As a consequence of the dissimilar size and shape of the two molecules, the wetting properties of the mixed monolayer are found to be mainly governed by the fractional area of TC, rather than by the molecular composition of TC, (chi TC).
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| 7. |
- Ariel, Gil, et al.
(författare)
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Gaussian Beam Decomposition of High Frequency Wave Fields Using Expectation-Maximization
- 2011
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Ingår i: Journal of Computational Physics. - : Elsevier. - 0021-9991 .- 1090-2716. ; 230:6, s. 2303-2321
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Tidskriftsartikel (refereegranskat)abstract
- A new numerical method for approximating highly oscillatory wave fields as a superposition of Gaussian beams is presented. The method estimates the number of beams and their parameters automatically. This is achieved by an expectation–maximization algorithm that fits real, positive Gaussians to the energy of the highly oscillatory wave fields and its Fourier transform. Beam parameters are further refined by an optimization procedure that minimizes the difference between the Gaussian beam superposition and the highly oscillatory wave field in the energy norm.
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| 8. |
- Bäckman, Karin, et al.
(författare)
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Deep venous thrombosis : A new task for primary health care - A randomised economic study of outpatient and inpatient treatment
- 2004
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Ingår i: Scandinavian Journal of Primary Health Care. - : Informa UK Limited. - 0281-3432 .- 1502-7724. ; 22:1, s. 44-49
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Tidskriftsartikel (refereegranskat)abstract
- Objective - A health economic evaluation of two alternative treatment settings, inpatient care and outpatient care, for acute deep venous thrombosis. Design - A randomised multicentre trial in a defined population in regular clinical practice. Setting - Hospitals and related health care centres in the Jönköping county council in Sweden. Interventions - Patients were randomised to either an inpatient strategy (n = 66) or an outpatient strategy (n = 65) using low-molecular-weight heparin, dalteparin, administered subcutaneously once daily and adjusted for body weight. Subjects - Of 224 eligible patients, 131 entered the trial and 124 completed the economic part of the study. Main outcome measures - Direct medical and direct non-medical costs during a 3-month period. Results - Total direct costs were higher for those in the inpatient strategy group, i.e. Swedish Crowns (SEK) 16 400 per patient (Euro 1899) compared to SEK 12 100 per patient (Euro 1405) in the outpatient strategy group (p < 0.001). More patients in the outpatient group received assistance when they returned home. Few patients in either group reported sick leave. There was no difference in total number of days between the two groups. Conclusions - Total direct costs were significantly lower for the outpatient treatment strategy for deep venous thrombosis compared to the inpatient treatment strategy. No significant difference in health impact could be detected. Deep venous thrombosis can to a greater extent than previously be treated in primary care, safely, at a lower cost, and in accordance with patient preferences.
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| 9. |
- Dorobantu, M, et al.
(författare)
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Wavelet-based numerical homogenization
- 1998
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Ingår i: SIAM Journal on Numerical Analysis. - 0036-1429 .- 1095-7170. ; 35:2, s. 540-559
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Tidskriftsartikel (refereegranskat)abstract
- A numerical homogenization procedure for elliptic differential equations is presented. It is based on wavelet decompositions of discrete operators in find and coarse scale components followed by the elemination of the fine scale contributions. If the operator is in divergence form, this is preserved by the homogenization procedure. For periodic problems, results similar to classical effective coefficient theory is proved. The procedure can be applied to problems that are not cell-periodic.
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| 10. |
- Engquist, Björn, et al.
(författare)
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Proceedings PDC Seventh Annual Conference : Simulation and Visualization on the Grid
- 2000. - 13
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Bok (refereegranskat)abstract
- The Grid is an emerging computational infrastructure, similar to the pervasive energy infrastructure provided by national power grids. Simulation and Visualization on the Grid focuses on applications and technologies on this emerging computational Grid. Readers will find interesting discussions of such Grid technologies as distributed file I/O, clustering, CORBA software infrastructure, tele-immersion, interaction environments, visualization steering and virtual reality as well as applications in biology, chemistry and physics. A lively panel discussion addresses current successes and pitfalls of the Grid. This book provides an understanding of the Grid that offers a persistent, wide-scale infrastructure for solving problems.
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