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| 2. |
- Carling, Tobias, et al.
(författare)
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Hyperparathyroidism of multiple endocrine neoplasia type 1 : candidate gene and parathyroid calcium sensing protein expression
- 1995
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Ingår i: Surgery. - 0039-6060 .- 1532-7361. ; 118:6, s. 924-931
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:Hyperparathyroidism affects most patients with multiple endocrine neoplasia type 1 (MEN 1). This study investigates expression of the candidate MEN1 gene phospholipase C beta 3 (PLC beta 3) and expression and function of a putative calcium sensing protein (CAS) in hyperparathyroidism of MEN 1.METHODS:In 31 parathyroid glands from 17 patients with MEN 1, CAS distribution was studied immunohistochemically and parallel sections were explored for PLC beta 3 mRNA expression by in situ hybridization. Enzymatically dispersed parathyroid cells were analyzed for cytoplasmic calcium concentrations [Ca2+]i and parathyroid hormone (PTH) release.RESULTS:All glands exhibited a heterogeneously reduced CAS immunoreactivity, especially meager in nodularly assembled parathyroid cells. Calcium regulated [Ca2+]i and PTH release tended to be more deranged in the glands possessing the lowest immunostaining. Parathyroid PLC beta 3 invariably was homogeneously expressed, and this included even MEN 1 patients with reduced PLC beta 3 expression in endocrine pancreatic tumors.CONCLUSIONS:The findings support variable calcium insensitivity of [Ca2+]i and PTH release in hyperparathyroidism of MEN 1, apparently coupled to heterogeneously reduced CAS expression. For clarification of the role of PLC beta 3 in MEN 1 parathyroid tumorigenesis further study of this protein is required.
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| 3. |
- Drugge, Lars, et al.
(författare)
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Modelling and simulation of catenary-pantograph interaction
- 1999
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Ingår i: Vehicle System Dynamics. - : Informa UK Limited. - 0042-3114 .- 1744-5159. ; 33:suppl 1, s. 490-501
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Tidskriftsartikel (refereegranskat)abstract
- Modelling and simulation of the dynamic behaviour of catenary-pantograph interaction is an important part when assessing the capability of a current collection system for railway traffic. The large variation in infrastructure characteristics in different countries and railway companies, different types of traffic, designs of pantographs etc. makes it almost impossible to develop a final simulation model of such a system. Instead, it would be favourable to have a tool that has the ability to set up models of such systems, choose relevant detail of the models, run simulations and finally visualize the results. To make the tool useful for engineers, design experts as well as simulation experts, the functionality of the tool must be worked out. Aspects on computer simulation such as developed models, simulation methods and computer tools are presented. The aim is to develop a scenario that considers different designs, models, solution methods and user levels. The scenario focuses on how to structure the use of simulation of dynamics in catenary-pantograph development. A scenario is sketched built on different user levels, a modular structure and a structure for information management
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| 4. |
- Drugge, Lars, et al.
(författare)
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The nonlinear behaviour of a pantograph current collector suspension
- 1999
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Ingår i: Proceedings of the 1999 ASME Design Engineering Technical Conferences.
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Konferensbidrag (refereegranskat)abstract
- The pantograph-catenary system is a critical component for trains required to run at higher speeds. The pantograph often includes nonlinear characteristics and the scope of this work is to investigate if nonlinear dynamic phenomena can occur in an existing design. A model of a pantograph suspension subsystem has been developed according to physical parameter values of the head suspension of the Schunk WBL88/X2 pantograph, providing electric power to the Swedish high-speed train X2. Studies of the system response for different force excitation show both harmonic, subharmonic and chaotic behaviour for the investigated parameter regions.
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| 5. |
- Johansson, Henrik, et al.
(författare)
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Information flow and simulation support in the product development process : a case study
- 1998
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Ingår i: Proceedings / Produktmodeller -98, 10-11 november [1998]. - Linköping : Linköpings universitet. - 9172193646 ; , s. 271-280
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Konferensbidrag (refereegranskat)abstract
- This paper consists of a case study of the product development process at Indexator AB, manufacturer of rotators for heavy equipment. The process has been studied concerning the information flow and computer support in the engineering design department and its interacting departments. It is shown that the company has a clear view of how information flows and which computer tools they use in the different parts of the processes. The advantage of using computer tools for analysis and planning is seen. Ways of communication and information flows concerning the design processes can sometimes happen in unplanned ways. Lack of integration between the different computer tools leads to unnecessary regeneration of the product information in the different parts of the development process.
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| 6. |
- Larsson, Tobias, 1972-, et al.
(författare)
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Dynamic behaviour of pantographs due to different wear situations
- 1998
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Ingår i: Computers in railways, VI : [Sixth International Conference on Computer Aided Design, Manufacture and Operation on the Railway and Other Advanced Mass Transit Systems, Lisbon, Portugal, 2 - 4 September 1998.
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Konferensbidrag (refereegranskat)abstract
- The overhead power system supplying electricity to a train consists of the pantograph current collector and the overhead line equipment. Many of the parameters describing the dynamic characteristics of the pantograph vary during the lifetime due to wear, mounting conditions, weather etc. When evaluating the dynamic performance of the pantograph it is important to consider a realistic range of variation in key parameters. To study this problem a three-dimensional pantograph model has been developed. It is based on the Schunk WBL88/X2 pantograph used for the Swedish high-speed train X2. The performance of the model of the overhead power system is analysed using a multibody dynamics program. In this work, the influence on the dynamic behaviour of the pantograph, due to changes of key parameters in the head suspension, is investigated using numerical simulations and the methodology of factorial design. The ranges of variation in parameter values are determined from measurements on pantographs subjected to different wear situations.
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| 7. |
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| 8. |
- Larsson, Tobias
(författare)
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Effective development of dynamic systems : a structured approach
- 1999
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This licentiate thesis deals with effective simulation of multibody dynamic systems in the product development process. Previous work to make simulation more effective has concentrated on developing faster calculation methods. Instead, this approach is to make the process of multibody dynamics simulation more effective by structuring of products, simulation models and their usage. Efforts have been made to clarify how computer tools are used in product development in industry today. Insight into the two domains of product development and multibody dynamics is given. These domains have traditionally been separated but the introduction of concurrent engineering and faster computers puts new demands on the integration of computer support and analysis in the development process. A proposal for performing the multibody dynamics methodology in a modular way in the product development process is given based on the performed work.
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| 9. |
- Stensson, Annika, et al.
(författare)
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Industry demands on vehicle development - methods and tools
- 1999
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Ingår i: Vehicle System Dynamics. - : Informa UK Limited. - 0042-3114 .- 1744-5159. ; 33:Suppl 1, s. 202-213
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Tidskriftsartikel (refereegranskat)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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