| 11. |
- Larsson, Annika
(author)
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Capability in machining systems
- 2002
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Licentiate thesis (other academic/artistic)abstract
- The vehicle industry has derived a vision of simulatingmachining systems and their cutting processes with accuracy andcapability indices as a result. The accuracy of machined partsis the result of properties and characteristics of the totalmachining system and its environment. Natural deviation resultsin deviations between each machined part which in turn effectthe functionality of an assembled product.A machining system is defined as consisting of the fivemodules: machine tool, tool, cutting process, workpiece andfixture.The thoughts and discussions about the vision of simulatinga machining systems and its environment have resulted in aresearch question:“What is required to give a reliablesimulated value of capability and accuracy?"Being able to predict the accuracy of machined parts in aspecific machining system and its environment gives thepossibility of optimising the cutting process and detect errorsin the machining systems. It also gives the possibility todesign more robust machining systems and avoid mistakes duringthe designing of the machining systems.This study has shown that to be able to predict capabilityindices for both existing and future machining system it isnecessary to have thorough knowledge in four areas; capabilityas a statistical tool, accuracy in machining system,measurement tools and methods, and modelling andsimulation.To achieve a reliable capability index, the capability studyhas to be properly planned, performed and evaluated. Thestatistical method of capability indices needs to be well-knownwhen choosing index, comparing different indices and whenmaking comparisons between indices from several machiningsystems.The machining accuracy of a machining system is dependent onfour groups of characteristics: temperature influence, geometryand kinematics, static stiffness and, finally, dynamicstiffness.There are a great number of models available for cuttingprocesses, process state variables and different modules of amachining system. Usually, these models can only be useddiscretely since there is almost no relationship between thestructures, required data and assumptions of the models. It istherefore not yet possible to model and simulate a machiningsystem to achieve a reliable accuracy value.
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| 12. |
- Larsson-Mauleon, Annika
(author)
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Newly graduated nurse anesthetists' experiences and views on anesthesia nursing -- a phenomenographic study
- 2002
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In: AANA Journal. - Park Ridge, IL, USA : AANA Publishing, Inc.. - 0094-6354. ; 70:4, s. 281-287
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Journal article (peer-reviewed)abstract
- This qualitative study identifies and describes different ways in which newly graduated nurse anesthetist (NAs) experience and perceive nurse anesthesia. It explains different approaches to nurse anesthesia care and, thus, to clinical nursing care ( in an anesthesia and surgical context), provided by new NAs. One month after graduation, all NAs who had completed an anesthesia program responded to 4 open-ended questions. A phenomnographic method was used to analyze their responses. The results were divided into 3 categories, which describe nurse anesthesia from the perspectives of (1) maintaining physical well-being; (2) being protectors and advocates; and (3) ability to perform good nurse anesthesia given all the demands placed on the NAs. The results indicate that, for new NAs, the nurse anesthesia care situation was largely influenced by context and generated feelings of inadequacy because the NAs could not provide the emotional support that they believed their patients required.
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| 13. |
- Nilsson, Annika, et al.
(author)
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The catabolic capacity of Saccharomyces cerevisiae is preserved to a higher extent during carbon compared to nitrogen starvation
- 2001
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In: Yeast. - Chichester : Wiley. - 0749-503X .- 1097-0061. ; 18:15, s. 1371-1381
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Journal article (peer-reviewed)abstract
- A comparison of catabolic capacity was made between S. cerevisiae cells subjected to 24 h carbon or nitrogen starvation. The cells were shifted to starvation conditions at the onset of respiratory growth on ethanol in aerobic batch cultures, using glucose as the carbon and energy source. The results showed that the catabolic capacity was preserved to a much larger extent during carbon compared to nitrogen starvation. Nitrogen starvation experiments were made in the presence of ethanol (not glucose) to exclude the effect of glucose transport inactivation (Busturia and Lagunas, 1986). Hence, the difference in catabolic capacity could not be attributed to differences in glucose transport capacity during these conditions. In order to understand the reason for this difference in starvation response, measurement of protein composition, adenine nucleotides, inorganic phosphate, poly phosphate and storage carbohydrates were performed. No clear correlation between any of these variables and catabolic capacity after starvation could be obtained. However, there was a positive correlation between total catabolic activity and intracellular ATP concentration when glucose was added to starved cells. The possible mechanism for this correlation, as well as what determines the ATP level, is discussed.
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| 14. |
- Para, Alessia, 1972-
(author)
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Meristem Maintenance in Arabidopsis thaliana
- 2004
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Doctoral thesis (other academic/artistic)abstract
- The shoot apical meristem (SAM) is the structure that shapes the aerial architecture of the plant, by producing lateral organs throughout development. In the model plant Arabidopsis thaliana, the SAM is always identifiable as a characteristic dome, whether it is found in the centre of a rosette of leaves or at the tip of an inflorescence. When senescence occurs and organogenesis ceases, the now inactive SAM still retains its characteristic appearance and it is never consumed into a terminal structure, such as a flower. Mutant plants that undergo termination represent a valuable tool to understand how the SAM structure and function are maintained during plant life. The aim of this work was to investigate the dynamics of meristem development through morphological and genetic studies of three Arabidopsis mutants that exhibit distinct modes of SAM termination: distorted architecture 1 (dar1), adenosine kinase 1 (adk1) and terminal flower 2 (tfl2). The dar1 mutation is characterised by a severely distorted cellular architecture within the SAM. We propose that dar1 affects the pattern of cell differentiation and/or cell proliferation within the SAM apical dome, resulting in termination by meristem consumption. Instead, the adk1 mutation affects the organogenic potential of the SAM, without altering its structure. The adk1 mutant has increased levels of cytokinins and, as a consequence of this, cell division is enhanced and cell differentiation is prevented in the apex, causing termination by meristem arrest. Finally, tfl2 is mutated in the conserved chromatin remodelling factor HP1, a transcriptional repressor with multiple roles during plant development. The tfl2 SAM terminates by conversion into a floral structure, due to de-repression of floral identity genes. Interestingly, tfl2 mutants also show an altered response to light, an indication that TFL2 might act as a repressor also in the context of light signalling.
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| 15. |
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| 16. |
- Stensson, Annika, et al.
(author)
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Industry demands on vehicle development - methods and tools
- 2000
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In: Vehicle System Dynamics. - : Taylor & Francis Ltd.. - 0042-3114 .- 1744-5159. ; 33:Suppl, s. 202-213
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Journal article (peer-reviewed)abstract
- A very important goal of mechatronics in system development is the integration of mechanical, electronic and software subsystems in order to increase functionality, minimize weight, and reduce production costs. In this work, industry demands on methods and tools for mechatronic vehicle development are addressed from the current product development in industry. The development of a mechatronic car door concept and dynamic stability control are used as examples to identify strong and weak parts of the current processes. Railway vehicle development aspects are also discussed. It is shown that a very important aspect for a successful mechatronic design is co-operation in an interdisciplinary design team. In terms of design methodology, the systematic identification of mechatronic potential based on function analysis is a main issue. Computer tools and technology for concept simulation, co-simulation, managing of models with different complexity as well as model exchange are identified as important demands for future effective development of mechatronic vehicles.
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| 17. |
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