| 1. |
- Reifarth, R., et al.
(författare)
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Nuclear astrophysics with radioactive ions at FAIR
- 2016
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Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 665:1
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Konferensbidrag (refereegranskat)abstract
- The nucleosynthesis of elements beyond iron is dominated by neutron captures in the s and r processes. However, 32 stable, proton-rich isotopes cannot be formed during those processes, because they are shielded from the s-process flow and r-process beta-decay chains. These nuclei are attributed to the p and rp process. For all those processes, current research in nuclear astrophysics addresses the need for more precise reaction data involving radioactive isotopes. Depending on the particular reaction, direct or inverse kinematics, forward or time-reversed direction are investigated to determine or at least to constrain the desired reaction cross sections. The Facility for Antiproton and Ion Research (FAIR) will offer unique, unprecedented opportunities to investigate many of the important reactions. The high yield of radioactive isotopes, even far away from the valley of stability, allows the investigation of isotopes involved in processes as exotic as the r or rp processes.
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| 2. |
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| 3. |
- Christensen, M. J., et al.
(författare)
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Software-based data acquisition and processing for neutron detectors at European Spallation Source-early experience from four detector designs
- 2018
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 13:11
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Tidskriftsartikel (refereegranskat)abstract
- European Spallation Source (ESS) will deliver neutrons at high flux for use in diverse neutron scattering techniques. The neutron source facility and the scientific instruments will be located in Lund, and the Data Management and Software Centre (DMSC), in Copenhagen. A number of detector prototypes are being developed at ESS together with its European in-kind partners, for example: SoNDe, Multi-Grid, Multi-Blade and Gd-GEM. These are all position sensitive detectors but use different techniques for the detection of neutrons. Except for digitization of electronics readout, all neutron data is anticipated to be processed in software. This provides maximum flexibility and adaptability and allows deep inspection of the raw data for commissioning which will reduce the risk of starting up new detector technologies. But it also requires development of high performance software processing pipelines and optimized and scalable processing algorithms. This report provides a description of the ESS system architecture for the neutron data path. Special focus is on the interface between the detectors and DMSC which is based on UDP over Ethernet links. The report also describes the software architecture for detector data processing and the tools we have developed, which have proven very useful for efficient early experimentation, and can be run on a single laptop. Processing requirements for the SoNDe, Multi-Grid, Multi-Blade and Ge-GEM detectors are presented and compared to event processing rates archived so far.
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| 4. |
- Cozzolino, C. A., et al.
(författare)
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Exploiting the nano-sized features of microfibrillated cellulose (MFC) for the development of controlled-release packaging
- 2013
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Ingår i: Colloids and Surfaces B. - : Elsevier BV. - 0927-7765 .- 1873-4367. ; 110, s. 208-216
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Tidskriftsartikel (refereegranskat)abstract
- Microfibrillated cellulose (MFC) was used in this study to prepare films containing an active molecule, lysozyme, which is a natural antimicrobial agent. The main goal of this research was to assess the potential for exploiting the nano-sized dimension of cellulose fibrils to slow the release of the antimicrobial molecule, thus avoiding a too-quick release into the surrounding medium, which is a major disadvantage of most release systems. For this purpose, the release kinetics of lysozyme over a 10-day period in two different media (pure water and water/ethanol 10. wt.%) were obtained, and the experimental data was fitted with a solution of Fick's second law to quantify the apparent diffusion coefficient (D). The results indicate that the MFC retained lysozyme, presumably due to electrostatic, hydrogen, and ion-dipole interactions, with the largest release of lysozyme-approximately 14%-occurring from the initial amount loaded on the films. As expected, ethanol as a co-solvent slightly decreased the diffusion of lysozyme from the MFC polymer network. The addition of two potential modulating release agents-glycerol and sodium chloride-was also evaluated. Findings from this work suggest that MFC-based films can be considered a suitable candidate for use in controlled-release packaging systems.
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| 5. |
- Elf, Patric, et al.
(författare)
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Molecular Dynamics Simulations of Cellulose and Dialcohol Cellulose under Dry and Moist Conditions
- 2023
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Ingår i: Biomacromolecules. - : American Chemical Society (ACS). - 1525-7797 .- 1526-4602. ; 24:6, s. 2706-2720
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Tidskriftsartikel (refereegranskat)abstract
- The development of wood-based thermoplastic polymers that can replace synthetic plastics is of high environmental importance, and previous studies have indicated that cellulose-rich fiber containing dialcohol cellulose (ring-opened cellulose) is a very promising candidate material. In this study, molecular dynamics simulations, complemented with experiments, were used to investigate how and why the degree of ring opening influences the properties of dialcohol cellulose, and how temperature and presence of water affect the material properties. Mechanical tensile properties, diffusion/mobility-related properties, densities, glass-transition temperatures, potential energies, hydrogen bonds, and free volumes were simulated for amorphous cellulosic materials with 0-100% ring opening, at ambient and high (150 °C) temperatures, with and without water. The simulations showed that the impact of ring openings, with respect to providing molecular mobility, was higher at high temperatures. This was also observed experimentally. Hence, the ring opening had the strongest beneficial effect on “processability” (reduced stiffness and strength) above the glass-transition temperature and in wet conditions. It also had the effect of lowering the glass-transition temperature. The results here showed that molecular dynamics is a valuable tool in the development of wood-based materials with optimal thermoplastic properties.
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| 6. |
- Nyberg, A., et al.
(författare)
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Abdominal aortic aneurysm and the impact of infectious burden
- 2008
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Ingår i: European Journal of Vascular and Endovascular Surgery. - : Elsevier BV. - 1532-2165 .- 1078-5884. ; 36:3, s. 292-296
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Little is known about the biological processes causing aortic aneurysm rupture. Chronic Chlomydophila pneumoniae infection has been suggested as a possible contributing factor to the development and expansion of abdominal aortic aneurysm (AAA). The importance of infection in AAA may be related to the previous pathogen burden, that is, the number of significant titres of antibodies against infectious pathogens rather than to single infectious agents. The aim of this study was to examine the relationship between infectious burden and AAA rupture. Methods: In a case-control study, 119 patients with abdominal aortic aneurysm and 36 matched controls without aneurysm were prospectively investigated for specific. IgG class antibodies against C. pneumoniae, Helicobacter pylori, Cytomegalovirus, and Herpes simplex virus. Results: Patients with ruptured AAA have similar levels of pathogen burden as patients with nonruptured electively operated AAA, small AAA, and controls without aneurysm. Conclusion: The present study fails to demonstrate a connection between infectious burden and abdominal aortic aneurysm rupture. (C) 2008 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.
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| 7. |
- Andersson, Henrik, et al.
(författare)
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Processing and characterization of a position sensitive lateral-effect metal oxide semiconductor detector
- 2004
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : ELSEVIER SCIENCE BV. - 0168-9002 .- 1872-9576. ; 531:1-2, s. 140-146
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Tidskriftsartikel (refereegranskat)abstract
- Position sensingdetectors (PSDs) are useful in many applications, such as vibration, displacement, and triangulation measurements. In this paper we present a lateral-effect metal oxide semiconductor PSD with switchingcapability fabricated by our group. The detector can be switched off by the application of 0V on the substrate and 0.2V on the gate. A linear current-position behaviour is exhibited by the detector at a substrate bias of both 5 and 10V with the gate at 0V. There is no effect on the linearity when the substrate voltage is changed from 5 to 10V. The non-linearity is within 0.2% at a distance of 71.5mm from origin for 5, 10 and 15mm device length.
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| 8. |
- Andersson, Henrik, et al.
(författare)
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System of nano-silver inkjet printed memory cards and PC card reader and programmer
- 2011
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Ingår i: Microelectronics Journal. - : Elsevier BV. - 0959-8324 .- 0026-2692. ; 42:1, s. 21-27
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Tidskriftsartikel (refereegranskat)abstract
- This work describes the development of inkjet printed, low-cost memory cards, and complementary pair of memory card reader and card reader/programmer for PCs. This constitutes a complete system that can be used for various applications. The memory cards are manufactured by inkjet printing nano-silver ink on photo paper substrate. The printed memory structures have an initial high resistance that can later be programmed to specific values representing data on the cards, the so called Write Once Read Many (WORM) memories. The memory card reader measures the resistance values of the memory cells and reads it back to the computer by USB connection. Using multiple resistance levels that represent different states it is possible to have a larger number of selectable combinations with fewer physical bits compared to binary coding. This somewhat counters one of the limitations of resistive memory technology that basically each cell needs one physical contact. The number of possible states is related to the resolution of the reader and the stability of the WORM memory.
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| 9. |
- Bogdanov, A. L., et al.
(författare)
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Fabrication of arrays of nanometer size test structures for scanning probe microscope tips characterization
- 1994
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Ingår i: Journal of Vacuum Science & Technology B: Microelectronics Processing and Phenomena. - : American Vacuum Society. - 0734-211X. ; 12:6, s. 3681-3684
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Konferensbidrag (refereegranskat)abstract
- A problem in scanning probe microscopy (SPM) is the unknown shape of the probing tip. Generally, the image is a convolution between the shape of the tip and the surface. Information of the shape of the probe may be gained by imaging very sharp tips. Here we present a method for making two-dimensional arrays of very sharp tips. The tip arrays were made of silicon using electron beam lithography with subsequent ion-beam etching. To achieve the best possible resolution, ultrasonic excitation was used during development of the bilayered PMMA resist. Thus, openings in the resist with size nearly equal to the spot size of the writing e-beam have been obtained. A further decrease of the radius of the tips was obtained by the choice of appropriate thickness for the masking NiCr layer. The tips were conical with a height up to 100 nm with a radius of the tip down to 10 nm. The tips were suitable for study of the shape of AFM probe tips, under condition that the tip array samples were rinsed in water prior to the measurement. Without the rinsing procedure, strong sticking forces between the probe and the sample would have eroded both of them. The regularity of the array provided an easy way to calibrate the lateral motion of the scanner
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| 10. |
- Ciamulski, T, et al.
(författare)
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Parallel FDTD Processing on Shared Memory Computers
- 2007
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Ingår i: The 23rd annual review of Progress in Applied computational electromagnetics.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- An ongoing European project on customization of electromagnetic simulation tool is ready to present significantly improved performance of parallel version of a professional FDTD simulator. The first stage of the work is concentrated on solution for computers with the shared memory architecture. The relevance and feasibility study of the solution for contemporary computers is shown. Possible ways to reach further performance improvements as well as solutions for distributed memory machines are discussed.
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