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- Aaboen, Lise, 1978
(författare)
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Incubators and incubation -Resources and activities in relation to different actors
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- ABSTRACTIncubators prepare new technology-based firms (NTBFs) for the obstacles ahead, they complement and develop the entrepreneurial ability of the firm founder, advise regarding financing, as well as providing structure and credibility to the firm. Incubators accelerate the development of the firms towards growth, create an entrepreneurial and innovative climate in the region, and contribute to the commercialization of research results from the university. There are many descriptions but still there remains the difficulty of understanding what an incubator is, and what it does. There is a great difference between incubators due to them having been formed in relation to different actors who have varying histories. Based on the appended papers the principal actors in relation to incubators are: the incubator, the NTBFs, the university, the policy actors and the financial actors. Moreover, the part played by the incubator differs depending on the roles in relation to the different actors, and they often have more than one role in relation to the same actor. Hence, the purpose of this thesis is to explore incubation in relation to different actors. The exploration includes five appended papers. Three of the papers focus on the role of the incubators when helping the NTBFs find and utilize resources. The three types of resources are knowledge, financing and relationships. The two remaining papers focus on the incubator as an organization with particular interest in value creation and efficiency. All five appended papers are written using the resource-based view. In the cover paper the findings in the appended papers are reflected upon using the industrial network approach in order to provide another perspective, focusing on relationships as opportunities leading to an understanding of incubators and incubation. In the cover paper principal actors, activities and resources are explored. The NTBFs are developed through the incubation with the help of resources contributed by the other actors. Additional to the development, the cover paper discussed other activities included in the incubation, i.e. mediation, innovation and acceleration. These activities enable actors to access and combine resources, within and across firm boundaries, that they would otherwise have difficulties combining at that point in time, as quickly or in that way. The relationships of the incubator enable mediation of contacts between actors who are otherwise reluctant to collaborate. Through these collaborations new resource combinations may be found. Resource combinations in already existing relationship can be found using experience from other relationships. In other words, the relationships of the incubator contribute to innovation among the actors. Furthermore, the relationships of the incubator contribute to the acceleration of the NTBFs’ development by being a trusted third party actor, and by contributing to the coordination of actors aiming at improving the innovative climate. Hence, relationships are a special kind of resource for the incubators. The importance of the relationships for the incubators implies that the critical issues might not be to pick NTBFs based on criteria for growth potential, but rather on the ability to form and develop relationships for themselves, as well as the NTBF, in order to develop the firm. Furthermore, arguments regarding the increasing homogeneity among Swedish incubators are based on the rather formalized relationships with the policy actors where incubators tend to play rather similar roles. The heterogeneity is likely to be perceived as larger from the perspective of relationships that are more context specific. Moreover, the relationships, activities and combination of resources cross-fertilize each other without a natural or manageable direction that cannot be controlled by one or a few of the actors involved. After the concluding discussion there is a retrospection of the development of the thesis and the empirical material, which is based on qualitative and quantitative data that has been gathered within the Swedish incubator program mainly during 1999, 2005 and 2006.
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| 3. |
- Aalto, Susanne, 1964
(författare)
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Molecular Clouds in Starburst Galaxies
- 1994
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Starbursts in the centres of galaxies are believed to be caused by funneling of gas towards the inner regions. Gravitational interactions between galaxies are known to cause vast rearrangements of their structure as well as induce bursts of star formation in their nuclear regions. However, radial gas-transport may also be the result of a bar- instability intrinsic to the system. This report deals with the effect of a starburst on the molecular medium of galaxies. The mm-wave, rotational transitions of interstellar molecules serve as probes of the physical conditions, kinematics and total mass of the molecular gas. Observations of the J=1-0, J=2-1 and J=3-2 transitions of 12Co, the J=1-0 and J=2-1 transitions of 13Co, the J=1-0 transitions of C180 and HCN and the J=2-1 transition of CS are used to determine the properties of the molecular gas in starbursting and normal galaxies. The mean escape probability approximation is used to solve the radiative transfer equations. The inferred properties of the molecular clouds in the centres of starburst galaxies differ from those of Galactic disk clouds. Such a deviation is likely to be induced by a central gas concentration and/or the nuclear starburst disrupting the clouds. Large 12CO/13CO J=1-0 intensity ratios (R>20) are measured towards luminous mergers implying unusual, high-pressure, molecular cloud ensembles. Model cloud ensembles for the merging system, NGC 3256, and the starburst spiral NGC 1808 suggest that the 12CO-emission is dominated by warm (Tk = 100 - 300 K), small (0.5-1 pc) and moderately dense (n = 2 - 7 x 103 cm-3) molecular clouds. Such temperatures and densities are typical of Galactic photon dominated regions (PDRs). Statistical studies of molecular line ratios towards galaxy centres indicate that the optical depth of the 12CO 1-0 emission is moderate, .tau.Ã? 1. Many starburst galaxies have large-scale excitation gradients indicating warm, dense gas in the centre, and normal cool molecular gas in their extended disks. NGC 3256, in particular, has a large R = 35 in the centre, while it is found to be only R = 10 - 15 at positions 43" off centre. The model cloud ensemble of NGC 1808 indicate that the 12CO-emitting gas may be diffuse rather than self-gravitating, this could be a common phenomenon in starburst galaxies.
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| 4. |
- Aasa, Annika, 1963
(författare)
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User Defined Syntax
- 1992
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis describes two examples of user defined syntax. The first, and most thoroughly investigated, is a new datatype construction, the conctype, the elements of which have a very flexible syntax. An embedded language can easily be introduced into a programming language using conctypes and computations are easily expressed using the concrete syntax and a special pattern matching form. The second example is user defined distfix operators which give a user possibility to extend the syntax for expressions in a programming language. We describe both a user's view and the implementation of these two examples. In both cases, context-free grammars serve as a basis for the definition of the new syntax. A problem that is investigated is how to disambiguate grammars with precedences. To see how this should be done we investigate which language a grammar together with precedence rules defines. For a sub-class of context-free grammars we give a predicate that defines the precedence correct syntax trees according to some precedence rules. We also give an algorithm that transforms such a grammar to an ordinary unambiguous context-free grammar and prove the correctness of the algorithm. We use the algorithm in our implementation of distfix operators. For more general grammars, we isolate one kind of ambiguity which is suitable to resolve with precedence rules. We define the generated language for such a grammar by an attribute grammar. This approach of resolving ambiguity is used in the implementation of conctypes.
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| 6. |
- Abadei, Saeed, 1961
(författare)
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Ferroelectric Thin Films on Si-substrate for Tunable Microwave Applications
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The thesis presents the development of microwave tunable devices based onferroelectric thin films. The main tasks in this work are the fabrication, optimization, andintegration of ferroelectric thin film into Si-MMIC. This work has been motivated byincreased interest on advanced tunable microwave components which meet therequirements of low microwave losses, high tunability, easy to integrate to largersystems, and low cost.Dielectric permittivity, tunability, and loss tangent are the most important parameters,characterizing ferroelectrics for application in tunable microwave devices. Most of theefforts in this work have been devoted to the optimization of film fabrication processes interms of microwave loss reduction. Experimental investigations of these parameters forNa0.5K0.5NbO3 (NKN), (SrTiO3) STO, Ba0.25Sr0.75TiO3 (BSTO) and (Pb, Zr) TiO3 (PZT)films are carried out in a wide frequency, DC bias, and temperature ranges. Thesemeasurements give important information about dispersion, temperature, and dc-fielddependencies of dielectric permittivity and losses. The latter are useful for understandingthe basic physical processes in ferroelectric films and help to optimize film depositionand device fabrication processes in terms of low losses, high tunability, and temperaturestability.Coplanar-plate structure is used to integrate the ferroelectric films into the siliconcircuits. Planar varactors are fabricated by depositing tunable ferroelectric films onSi/SiO2 substrates using laser ablation, RF magnetron sputtering, and sol-gel technique,followed by metal electrode deposition. Different varactor designs based on as straightgap, interdigital gap, and circular gap have been investigated and further used in thecomponents. Experiments show the capability and potential of tunable devices based onferroelectric thin films and confirm that they are competitive with other technologies likesemiconductors at frequency above 20 GHz. It is shown that NKN films in polar phaseare also useful for tunable microwave applications demonstrating low loss and goodtunability in a frequency above 20 GHz. BSTO films, which are in paraelectric phase atroom temperature, are used to fabricate microwave varactors. These varactors are used intwo different phase shifters designs. These tunable devices show more than 60°/dB figureof merit, which is one the best value reported so far.
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| 7. |
- Abadikhah, Hossein, 1987
(författare)
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Dynamic higher order equations
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The subject of this thesis is to derive and evaluate governing equations and correspondingboundary conditions for solid cylinders and rectangular plates, where the materialconstituting the cylinder or plate are governed by classical elasticity, micropolar elasticityor a functionally graded case of the previously mentioned models. This is achieved by asystematic power series expansion approach, by either adopting a generalized Hamilton'sprinciple or a direct approach.For the solid cylinders a power series expansion in the radial coordinate for the sought fields are adopted. Equations of motion together with consistent sets of end boundaryconditions are derived in a systematic fashion up to arbitrary order using a generalizedHamilton's principle. Governing equations are obtained for longitudinal, torsional, andexural modes. In the case of the rectangular plate, a power series expansion of thesought fields are adopted in the thickness coordinate. Governing equations of motion, forextensional and exural case, together with consistent sets of edge boundary conditionsare derived in a systematic fashion up to arbitrary order with use of the direct approach.Both the governing equations for the solid cylinder and the rectangular plate areasymptotically correct to all studied orders. Numerical examples are presented fordifferent sorts of problems, using exact theory, the present series expansion theories ofdifferent order, various classical theories and other newly developed approximate theories.These results cover dispersion curves, eigenfrequencies, various curves of cross sectionalquantities such as displacements, stresses and micro-rotations, as well as fixed frequencymotion due to prescribed end displacement or lateral distributed forces. The resultsillustrate that the present approach may render benchmark solutions provided higher ordertruncations are used, and act as engineering equations when using low order truncations.
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| 8. |
- Abadikhah, Marie, 1992
(författare)
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Microbial communities in biological electrochemical systems
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Biological electrochemical systems (BES) can be used as biosensors and for recovery of resources from waste streams. BES utilizes microbial communities that grow on the surface of electrodes in the form of biofilms. Electrogenic bacteria residing in the anode biofilm initiate oxidation reactions, resulting in the release of electrons and subsequent electrical current generation. The electrons flow to the cathode where reduction reactions take place. Microbial biofilms may also be involved in the catalysis of cathode reactions. Many factors are involved in shaping the composition and performance of the microbial communities in BES, most of which remain poorly understood. In this thesis, the impact of electrode material and biotic interactions on performance and microbial community assembly was investigated in microbial electrolysis cells (MECs) oxidizing volatile fatty acids at the anode. MECs are a type of BES that require an applied electric potential to generate products such as H2, CH4, and acetate at the cathode. MECs with mixed-culture biofilms on both the anode and the cathode were studied. Two experiments were conducted. The first was a comparison of MECs with three different cathode materials: carbon nanoparticles, titanium, and steel. The second was a comparison of MECs with three different anode materials: carbon cloth, graphene, and nickel. Furthermore, the effect of dispersal limitation as well as the presence of viruses and their associations with microorganisms was investigated. MECs with carbon cloth anodes had the highest current density and shortest lag time during startup. In contrast, no significant impact of cathode material on MEC performance was seen. The anode communities were dominated by electrogens from the Desulfobacterota phylum, while the cathodes were dominated by methanogens from the Methanobacteriaceae family. Stochastic initial attachment by competing electrogens on the anode explained variations in the startup time between replicate MECs. In each experiment at least two different Desulfobacterota species competed for dominance on the anode. MECs that enabled dispersal between the system tended to have the same dominating taxa. Biotic interactions also affected the microbial communities in the system. Network analysis showed that the anode communities had a greater number of negative interactions between taxa compared to the cathode. Due to the need for direct contact by electrogens to transfer electrons to the anode, there is a higher competitive element to the colonization of the anode biofilm. Viral infection is another type of biotic interaction. Analysis of the prokaryotic and viral communities resulted in the identification of CRISPR-based and prophage virus-host associations, indicating previous infections and prophage inductions of electrochemically active microorganisms. These findings suggest that while there is selective pressure for electrogenic bacteria on the anode, stochastic factors, and biotic interactions play a larger role compared to electrode material in shaping the anode community.
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| 9. |
- Abarkan, Abdellah, 1960
(författare)
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Bebyggelsemönster i medelhavsområdet: en studie av medinan i Fes ställd i relief mot Siena|
- 1995
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis is an analysis and comparative study of medieval Mediterranean urban patterns. With urban patterns is meant the arrangement of houses and public spaces with special regard to the relations between them. The thesis contains four parts. Previous research on Muslim cities is described and commented in the first part. A difference between research before and after 1960 is noted. The Medina of Fes is discussed in the second part. In an historical background sketch the foundation of the Medina and its development are presented. The spatial analysis shows that the physical structure of the Medina is based on a primary pattern unit of a square courtyard house with a closed, inward-turned physical structure. A number of these primary units are grouped around a cul de sac to form a second-level community unit; a number of these latter form a quarter. The quarters are adjacent and close to each other which means that the Medina as a whole can be regarded as a complex physical and social unit surrounded with the city walls. In a comparable approach the physical and social structure of Siena is studied. The primary units here are the casa corte, which is similar to the courtyard of the Medina, and the casa a schiera which is a filehouse without any comparative physical form in the medina. These two different primary units engendered two types of building patterns, one in the city centre where courtyard units are grouped around a central square, and the other one in the periphery of the city formed by the alignment of the filehouses along the street. An attempt to compare the physical and social units in the Medina and Siena is made in the fourth part of this thesis. The primary units, the community units, the quarters and the cities are compared. This comparative study shows that the similarities between the Medina and Siena are much more apparent on the social level and on the level of the smaller physical units, i.e. the habitat, than between the larger social and physical composition of the quarters.
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