| 1. |
- Dwibedi, Chinmay Kumar, et al.
(författare)
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Biological amplification of low frequency mutations unravels laboratory culture history of the bio-threat agent Francisella tularensis
- 2020
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Ingår i: Forensic Science International. - : Elsevier. - 1872-4973 .- 1878-0326. ; 45
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Tidskriftsartikel (refereegranskat)abstract
- Challenges of investigating a suspected bio attack include establishing if microorganisms have been cultured to produce attack material and to identify their source. Addressing both issues, we have investigated genetic variations that emerge during laboratory culturing of the bacterial pathogen Francisella tularensis. Key aims were to identify genetic variations that are characteristic of laboratory culturing and explore the possibility of using biological amplification to identify genetic variation present at exceedingly low frequencies in a source sample. We used parallel serial passage experiments and high-throughput sequencing of F. tularensis to explore the genetic variation. We found that during early laboratory culture passages of F. tularensis, gene duplications emerged in the pathogen genome followed by single-nucleotide polymorphisms in genes for bacterial capsule synthesis. Based on a biological enrichment scheme and the use of high-throughput sequencing, we identified genetic variation that likely pre-existed in a source sample. The results support that capsule synthesis gene mutations are common during laboratory culture, and that a biological amplification strategy is useful for linking a F. tularensis sample to a specific laboratory variant among many highly similar variants.
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| 2. |
- Pettersson, Karl, 1983-, et al.
(författare)
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Simulation Aided Design and Testing of Hydromechanical Transmissions
- 2014
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Ingår i: The 9th JFPS International Symposium on Fluid Power, Matsue, 2014. - 4931070108
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Konferensbidrag (refereegranskat)abstract
- This paper demonstrates the use of high-speed simulation in transmission conceptual design and presents a transmission test bed for hardware-in-the-loop simulations of hydromechanical transmission concepts. Complex transmissions, such as multiple-mode hydromechanical transmissions and hydraulic hybrid transmissions, present new difficulties and costs in the development process. There is today a greater demand for more efficient product development and more work has shifted towards simulation. The Hopsan simulation package allows robust, high-speed simulations suitable for both offline and hardware-in-the-loop simulation. New simulation models for hydromechanical transmissions are developed and used to simulate a known two-mode transmission concept. The same concept is also tested in hardware-in-the-loop simulations in the proposed transmission test bed. Results show good agreement with the hardware tests and highlight the proficiency of the simulation tools.
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| 3. |
- Szczerba, Krzysztof, 1985, et al.
(författare)
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Impact of Forward Error Correction on Energy Consumption of VCSEL-based Transmitters
- 2015
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Ingår i: 41st European Conference on Optical Communication, ECOC 2015, Valencia, Spain, 27 September - 1 October 2015. - 9788460817413
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Konferensbidrag (refereegranskat)abstract
- We present an analysis of the effect of FEC on energy consumption of VCSEL based transmitters for short-range optical links. We show that a low-complexity FEC can reduce the overall energy consumption of the transmitter.
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| 4. |
- Ahlinder, Jon, et al.
(författare)
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Increased knowledge of Francisella genus diversity highlights the benefits of optimised DNA-based assays
- 2012
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Ingår i: BMC Microbiology. - : Springer Science and Business Media LLC. - 1471-2180. ; 12, s. 220-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Recent advances in sequencing technologies offer promising tools for generating large numbers of genomes, larger typing databases and improved mapping of environmental bacterial diversity. However, DNA-based methods for the detection of Francisella were developed with limited knowledge about genetic diversity. This, together with the high sequence identity between several Francisella species, means there is a high risk of false identification and detection of the highly virulent pathogen Francisella tularensis. Moreover, phylogenetic reconstructions using single or limited numbers of marker sequences often result in incorrect tree topologies and inferred evolutionary distances. The recent growth in publicly accessible whole-genome sequences now allows evaluation of published genetic markers to determine optimal combinations of markers that minimise both time and laboratory costs. Results: In the present study, we evaluated 38 previously published DNA markers and the corresponding PCR primers against 42 genomes representing the currently known diversity of the genus Francisella. The results highlight that PCR assays for Francisella tularensis are often complicated by low specificity, resulting in a high probability of false positives. A method to select a set of one to seven markers for obtaining optimal phylogenetic resolution or diagnostic accuracy is presented. Conclusions: Current multiple-locus sequence-typing systems and detection assays of Francisella, could be improved by redesigning some of the primers and reselecting typing markers. The use of only a few optimally selected sequence-typing markers allows construction of phylogenetic topologies with almost the same accuracy as topologies based on whole-genome sequences.
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| 5. |
- Aiempanakit, Montri, et al.
(författare)
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Effect of peak power in reactive high power impulse magnetron sputtering of titanium dioxide
- 2011
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Ingår i: Surface & Coatings Technology. - : Elsevier BV. - 0257-8972 .- 1879-3347. ; 205:20, s. 4828-4831
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Tidskriftsartikel (refereegranskat)abstract
- The effect of peak power in a high power impulse magnetron sputtering (HiPIMS) reactive deposition of TiO(2) films has been studied with respect to the deposition rate and coating properties. With increasing peak power not only the ionization of the sputtered material increases but also their energy. In order to correlate the variation in the ion energy distributions with the film properties, the phase composition, density and optical properties of the films grown with different HiPIMS-parameters have been investigated and compared to a film grown using direct current magnetron sputtering (DCMS). All experiments were performed for constant average power and pulse on time (100W and 35 mu s, respectively), different peak powers were achieved by varying the frequency of pulsing. Ion energy distributions for Ti and O and its dependence on the process conditions have been studied. It was found that films with the highest density and highest refractive index were grown under moderate HiPIMS conditions (moderate peak powers) resulting in only a small loss in mass-deposition rate compared to DCMS. It was further found that TiO2 films with anatase and rutile phases can be grown at room temperature without substrate heating and without post-deposition annealing.
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| 6. |
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| 7. |
- Aiempanakit, Montri, et al.
(författare)
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Hysteresis and process stability in reactive high power impulse magnetron sputtering of metal oxides
- 2011
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Ingår i: Thin Solid Films. - : Elsevier BV. - 0040-6090 .- 1879-2731. ; 519:22, s. 7779-7784
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Tidskriftsartikel (refereegranskat)abstract
- In the further development of reactive sputter deposition, strategies which allow for stabilization of the transition zone between the metallic and compound modes, elimination of the process hysteresis, and increase of the deposition rate, are of particular interest. In this study, the hysteresis behavior and the characteristics of the transition zone during reactive high power impulse magnetron sputtering (HiPIMS) of Al and Ce targets in an Ar-O(2) atmosphere as a function of the pulsing frequency and the pumping speed are investigated. Comparison with reactive direct current magnetron sputtering (DCMS) reveals that HiPIMS allows for elimination/suppression of the hysteresis and a smoother transition from the metallic to the compound sputtering mode. For the experimental conditions employed in the present study, optimum behavior with respect to the hysteresis width is obtained at frequency values between 2 and 4 kHz, while HiPIMS processes with values below or above this range resemble the DCMS behavior. Al-O films are deposited using both HiPIMS and DCMS. Analysis of the film properties shows that elimination/suppression of the hysteresis in HiPIMS facilitates the growth of stoichiometric and transparent Al(2)O(3) at relatively high deposition rates over a wider range of experimental conditions as compared to DCMS.
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| 8. |
- Aijaz, Asim, et al.
(författare)
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Dual-magnetron open field sputtering system for sideways deposition of thin films
- 2010
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Ingår i: SURFACE and COATINGS TECHNOLOGY. - : Elsevier BV. - 0257-8972. ; 204:14, s. 2165-2169
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Tidskriftsartikel (refereegranskat)abstract
- A dual-magnetron system for deposition inside tubular substrates has been developed. The two magnetrons are facing each other and have opposing magnetic fields forcing electrons and thereby also ionized material to be transported radially towards the substrate. The depositions were made employing direct current magnetron sputtering (DCMS) and high power impulse magnetron sputtering (HiPIMS). To optimize the deposition rate, the system was characterized at different separation distances between the magnetrons under the same sputtering conditions. The deposition rate is found to increase with increasing separation distance independent of discharge technique. The emission spectrum from the HiPIMS plasma shows a highly ionized fraction of the sputtered material. The electron densities of the order of 10(16) m(-3) and 10(18) m(-3) have been determined in the DCMS and the HiPIMS plasma discharges respectively. The results demonstrate a successful implementation of the concept of sideways deposition of thin films providing a solution for coating complex shaped surfaces.
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| 9. |
- Andersson, Petter, et al.
(författare)
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A case study of how knowledge based engineering tools support experience re-use
- 2011
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Ingår i: Research into Design. - Bangalore, India : Research Publishing Services. - 9789810877217
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Konferensbidrag (refereegranskat)abstract
- A manufacturing company’s unique intellectual capital is to a large extent built on experience from its own product development and manufacturing processes. Thus, methods and tools to utilize and benefit from this experience in an efficient way have an impact on a company’s ability to stay competitive and advance on the global market. Knowledge Based Engineering (KBE) is an engineering methodology to capture engineering knowledge systematically into the design system. Hence, KBE tools are considered to support experience re-use and improve engineering activities. This paper presents the results from a study where the objective was to investigate the support for experience re-use in KBE applications in an aerospace company. A proposed framework is presented to analyze the capturing and use of experience in a company’s processes identifying gaps and propose improvements. The study revealed weaknesses in the process steps for experience feedback which can be used to improve KBE applications further.
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| 10. |
- Andersson, Petter, et al.
(författare)
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Project: Robust Machining
- 2010
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Annan publikation (populärvet., debatt m.m.)abstract
- New generations of environmentally friendly and safe vehicles require manufacturing of light weight materials with higher strength and, as a consequence, tougher machining conditions and increased machining robustness. There is a lack of practical and reliable methods and tools to meet these challenges in the automotive industry. The very complex system of machine tool, fixture, cutting tools and the machined part is almost impossible to model without complementary measurements of the real system at the factory floor in full production. Using Virtual Engineering together with studies of machining processes the project team will assess these challenges.
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