| 1. |
- Barth, Henrik, 1971-
(författare)
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Barriers to growth and development in small firms
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The purpose of the extended summary is to develop the understanding of the existence and reasons behind barriers to growth and development in small firms. More specifically, four questions are addressed: (1) What do we know about the term barrier, how can it be defined? (2) What types of barriers to growth and development have been identified? (3) How can barriers to growth and development be addressed in a framework? and (4) How do the results of the appended papers (Papers I-V) contribute to the research field of barriers to growth and development?A literature review was undertaken to answer the first two questions. The literature review was conducted in two phases. The conceptual and operational definition of barriers was addressed in the first phase. The results reveal diverse ways of focusing on barriers, which made it necessary to address similar terms, such as problem and causes of business failure in the second phase of the literature review. The different terms used in the papers of the literature review are discussed in order to determine whether or not the understanding of their content is coherent and conceptual. Based on the conceptual understanding and definition of barriers, the different aspects focused on in the literature were discussed, which led to the second question, What are the various aspects of barriers to growth and development?The knowledge gained from the literature review and the development of the understanding of the barrier concept led to the third question, Can barriers to growth and development be addressed in a framework? The discussion takes its starting point in the studies identified in the literature review and is related to some of the appended papers (Papers I and II). Similarities and differences between frameworks used in the papers identified in the literature review are discussed and, based on this knowledge, a framework for barriers to growth and development in small firms is presented. The framework distinguishes two types of barriers, namely internal/external barriers and tangible/intangible barriers.The knowledge available in the reviewed papers within the field of barriers to growth and development in small firms in combination with the results from the appended papers (Papers I-V) resulted in the fourth question. Part of the contribution of the appended papers concerns the operational definition, for example that barriers to innovation should be categorised as either occurring or preventing firms from innovating (Paper II), while other contributions concern specific types of barriers, for example the importance of managerial skills (Paper V). Overall, the contribution focuses on conditional factors, such as strategy and planning, organisation and management, and institution and policy factors, in relation to growth and development.
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| 2. |
- Grönlund, Erik
(författare)
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Microalgae at wastewater pond treatment in cold climate : an ecological engineering approach
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Three types of wastewater ponds in subarctic climates were investigated, each of them highly dependent on microalgae. They were fellingsdams, i.e. wastewater stabilization ponds complemented with chemical precipitation, high-rate algal ponds (HRAPs), and a type of aquaculture interface ponds between a wastewater treatment plant and the natural surrounding. From a microalgae taxa perspective green algae and cryptophytes were dominant in the wastewater ponds. Green algae and cryptophytes were also, together with chryso- and haptophytes, dominating the hypereutrophic and eutrophic stages of the natural lakes. Biomasses in the different types of ponds were of very different order of magnitude. From 100-1000 mg/l in the stabilization ponds during summer and 10-100 mg/l in spring and autumn, 70- 90 mg/l in a HRAP in autumn, to 5-30 mg/l in the most hypereutrophic stage in the natural ponds, 1-10 mg/l in the eutrophic stage, and below 1 mg/l in the oligotrophic stage. The connection between wastewater pond treatment and the field of ecological engineering was recognized. Future development of pond technology may benefit from a stronger connection to the theoretical framework of systems ecology developed in collaboration with the field of ecological engineering and ecotechnology.
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| 3. |
- Fredriksson, Maria
(författare)
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From Customer Satisfaction to Citizen Interaction : a cooperation model for community development based on Total Quality Management
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Current problems with unemployment and the consequences of cut-down in the public sector need appropriate solutions, where private citizens perhaps take on more active roles than today, individually or in groups. The aim with this doctoral thesis is to contribute to one such solution, which is a cooperation model for societal development in local communities, based on Total Quality Management (TQM) and on the participation of many residents. The model is gradually developed with the help of collected experiences and opinions from three stakeholder groups in two different Swedish communities, as well as from general theories and literature. These groups are the quality-project initiators, the community residents and the local politicians. The disposition of the thesis is accordingly. The thesis contains two case studies. The first one concerns the use of TQM as a support of societal development in a local community. The improvement work is conducted within a non-profit organisation built on voluntary engagement. These experiences have then been compared, in the second case study, to the ones in another community where TQM is not used, but where the ambitions are the same. Here the framework for the improvement work is both a non-profit organisation and a for-profit one. The analyses indicate that TQM can be used with success within societal development, even if some of its tools or methodologies are interpreted in new ways, or not used at all. As TQM should be applied with regard to the type of organisation and its purpose, a certain flexibility is both expected and helpful. As far as management is concerned, the leadership needs to be “softer” and more diplomatic when managing unpaid volunteers, as compared to the situation in a commercial enterprise. Another observation is that the societal work is best conducted within groups, defined by situations or activities in life or in the society. An active resident can join a group according to interest. This is a modified version of the “quality circles” inherent to TQM. In a separate, and more theoretical study, the issue of adopting TQM to new sectors in society is discussed. In both the studied societies, there are difficulties to get residents involved or active, which puts into question the mandate with a large community project that aims at improving the quality of life for all residents. There are also difficulties with finding and renewing the leadership, and with communication with, above all, local politicians. Nevertheless, these politicians are in general positive to private initiatives like the ones in the two communities, and consider such projects very important for the future development of rural areas. They think that the experienced weaknesses can be reduced if the improvement work is distinctly defined and organised, if information and communication improve, and if the active residents become more educated about the procedures and limitations of the political governing of the communities. These and other observations of the two communities lead to a model where a cooperation between societal stakeholders develop in three phases; the start-up, the establishment and the continuation of the work. Each phase is discussed separately, and advice is given how to avoid, or meet, various problems that are likely to appear along the way.
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| 4. |
- Almqvist, Torbjörn
(författare)
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Computational fluid dynamics in theoretical simulations of elastohydrodynamic lubrication
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The work presented in this thesis concerns computer simulations of lubrication processes, and the main part deals with simulations in the elastohydrodynamic lubrication (EHL) regime. The thesis summarises the work performed in the five papers referred to as Paper A, B, C, D and E. The aim is to give the reader a more explanatory description of the investigations performed in the papers and of the physical processes present in EHL. Lubrication is a sub-area of tribology, which is the science of interacting bodies in relative motion, two other sub-areas being wear and friction. Lubrication is commonly referred to as a way of reducing friction and protecting the surfaces from wear. Typical devices where EHL is present are machine components. Examples of these are bearings, cams and gears. The lubricant can in such an application have many different tasks. The ultimate goal is that the surfaces in motion should be separated by a fluid film, thus reducing the friction and wear. That leads to low frictional losses and long operating life for the machine components. This goal is, however, not always fulfilled, and to protect the surfaces from wear when the lubricating film collapses, there are additives added to the lubricant. Commonly, lubricants contain of a number of additives, but these are not in focus in this thesis. Common to many EHL-applications, especially machine components, are thin lubricating films and high fluid pressures. The high pressures result in elastic deformation of the contacting bodies. The lubricating films in such applications are very thin, often in the range 0.1-1 10^-6m with pressures ranging from 0.5-3 GPa. The contact diameter is approximately 1 mm and the time a fluid element needs to pass through the contact is approximately 0.1 ms. The altering geometrical scales and rapid changes in the physical variables, such as pressure, viscosity and temperature etc., make numerical simulations to a challenging task. The variables of primary interest in the numerical simulations are: film thickness, pressure, temperature and friction. The film thickness is an important variable that gives information as to whether the surfaces are separated by the lubricating film. It is the lifting force generated by the hydrodynamic pressure that governs the separation of the surfaces in motion. However, even if a lubricating film is present, EHL machine components deteriorate when they have been in service for a long time. It is then that the cycling in pressure and temperature leads to fatigue of the surfaces, so that the level of these variables is also of importance. The friction that has developed in the EHL-contacts leads to a loss of energy, which increases the temperature in the conjunctions. Friction is therefore important not only for the efficiency, but also when thermal aspects have to be considered. The physical processes present in EHL are inter-disciplinary, closely related to other fields of science such as fluid mechanics, solid mechanics, and rheology. In almost all numerical simulations of lubrication performed today, the hydrodynamics are modelled by an equation referred to as the Reynolds equation. This equation is derived from a simplified form of the momentum equations, which are combined with the continuity equation; and the result is a Poisson equation for the fluid pressure. The assumptions made when deriving this equation limit the size of the computational or spatial domain, and the equation cannot predict pressure variations across the lubricating fluid film. In the work presented in this thesis, an extended approach, where the technique is based on CFD (computational fluid dynamics), is used to simulate the lubricant flow. The extended approach is here based on more complete forms of the equations of momentum, continuity and energy and the above degeneracy will be removed. That implies, if such an approach works, that it should now be possible to simulate the lubricant flow under conditions where the Reynolds equation is not valid. So far, only few attempts have been made to use the CFD-technique. From the preceding discussion of rapid changes in accordance with elastic deformation of the contacting surfaces, a great deal of work has been carried out to modify the numerical algorithm in the CFD-software to fit EHL-problems. The CFD- software used throughout the work in this thesis is CFX4 (2003).
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| 5. |
- Azadian, Saied
(författare)
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Aspects of precipitation in alloy Inconel 718
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A study was made of the microstructure of the Ni-base alloy Inconel 718 with emphasis on the precipitation and stability of intermetallic phases as affected by heat treatments. In addition the effect of the precipitation on selected mechanical properties namely hardness, creep notch sensitivity and hot ductlity were investigated. The materials studied were a spray-formed version and three wrought versions of the alloy. The spray-formed version of the alloy was of interest since it exhibited a superior compositional homogeneity to more conventional forms of the alloy. To characterise the precipitation kinetics and to determine the associated hardening, a series of isothermal ageing treatments were carried out on both spray-formed and ring rolled material at selected temperatures between 600°C and 1025°C for up to 100h. The results were presented in the form of TTH diagrams for the two alloys. The heat treated specimens were then studied using optical microscopy, scanning electron microscopy and transmission electron microscopy. Where possible these were supplemented with quantitative metallographic measurements of volume fraction and precipitates size.The three main intermetallic precipitation phases in IN 718 are (i) gamma’ having a composition Ni3(Al,Ti), a cubic crystal structure and cubic or spherical particle shape (ii) gamma” having a composition Ni3Nb, a bct crystal structure and a lens-like disc shape (iii)delta having composition Ni3Nb, an orthorhombic crystal structure and forming as grain boundary particles and films as well as thin plates extending long distances into the grains. In thermomechanically processed material the delta-phase can also occur as shorter platelets and particles resulting from fragmentation of the original plates. In this work the rates of precipitation and the temperature ranges of their existence were determined qualitatively. Moreover the coarsening of the ganmma" precipitates was determined quantitatively. The kinetics of precipitation and dimensional coarsening of the delta-phase were also established quantitatively. Similarly, the dissolution kinetics of the delta-phase were measured in the spray-formed and three wrought versions of the alloy leading to a determination of the effect of Nb-content on the delta solvus temperature. After a standard heat treatment, the spray-formed IN 718 was found to be creep notch sensitive according to an SAE-AMS standard rupture test. It was found that notch ductility could be restored to the alloy by inserting a delta-phase precipitation treatment at 875°C-900°C prior to the standard heat treatment. This could be attributed to the formation of a more favourable delta-phase morphology than that formed during the solution treatment at 954°C in the standard heat treatment cycle. A study was made of high temperature tensile properties of a wrought version of IN 718 in particular in relation to the problem of hot cracking in repair welding. Measurements were made of the strength loss temperature on heating and the strength and ductility return temperatures on cooling. These properties provide an indication of the sensitivity of the alloy to hot cracking due to liquation. The tests were made on the alloy after various heat treatments designed to produce microstructures with two different grain sizes with and without delta-phase precipitation. Hot tensile tests were also performed on the in-situ solidified alloy in order to describe the weld metal ductility and properties. The grain size and the presence of large fractions of delta-phase precipitated at 900°C had only small effects on the strength loss temperature and brittle-ductile transition of the alloy. On the other hand, a small fraction of delta-phase precipitated in the grain boundaries at 960°C reduced the brittle-ductile transition temperature significantly. It is proposed that the reduction was associated with interaction between the grain boundary delta-phase and grain boundary boron segregation that was observed in all the heat treated materials.
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| 6. |
- Bergström, Max
(författare)
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Industrialised timber frame housing : managing customisation, change, and information
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The overall aim of this thesis is to develop an increased understanding of industrialised timber frame housing (timber frame housing construction fully or partially conducted in a controlled environment utilising industrial processes and machinery). Of specific interest is how industrialised timber frame housing companies manage customisation, change, and information. Three single case studies (at a medium-sized industrialised timber frame housing company), one multiple-case study, and one survey were conducted. The first single case study investigates how production can benefit from integrating a customer-oriented design and production. The second single case study illustrates the shift towards an enterprise resource planning (ERP) approach through a change process. The third single case study describes the ERP system implementation. The multiple-case study investigates the prospects and pitfalls among four small and medium-sized industrialised timber frame housing companies that manufacture complex products utilising advanced prefabrication. The survey, conducted among the vast majority of industrialised timber frame housing companies in Sweden, presents the industry structure and investigates the benefits and disadvantages of ERP. The results demonstrate that matching customer requirements and an industrialised building system is facilitated through product and process development. Other findings suggest that ERP can meet the needs of industrialised timber frame housing, promote an organisation to be re- engineered through comprehensive change, and act as a driver for a more efficient internal and external supply chain. However, a lack of history regarding information technology (IT) systems for production processes and the timing of the system selection in the overall ERP adoption are both critical for the ERP system implementation outcome. With no previous history of IT systems for production processes, an ERP system implementation is a big step even if it is carefully conducted. Industrialised timber frame housing has increased in popularity on the market over the last years. An important reason for this is the increased customer focus. However, blind customer focus leads to poor utilisation of resources. By balancing customer orientation with internal efficiency, achieving an effective construction process seems possible. Communication between different actors in the construction process, finding a reasonable level of customer focus, and capacity limitations are current problem areas with the potential for improvement. Possible ways of improving the construction process are an increased integration between actors, a gradual increase in IT support, and finding the balance between project and process orientation. The survey demonstrates low ERP usage in industrialised timber frame housing with a low degree of strategic importance, while there are operational and managerial benefits. The results also show the potential of the ERP approach for industrialised timber frame housing, while its use is favoured by an increased maturity in IT. The overall results show that customer orientation, change, and information management are important ingredients in industrialised timber frame housing. Customer orientation can act as a driver for change and for improved information management. Changes in business processes are needed to facilitate customisation and information management. Information management has a key role in the entire construction process to facilitate customisation, while the need of efficient information management can act as a driver for change.
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| 7. |
- Berrebi, Jonathan
(författare)
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Self-diagnosis techniques and their applications to error reduction for ultrasonic flow measurement
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Flow metering plays a major role in modern life. In the process industry, flow metering is critical in industries ranging from food processing to cosmetics. It is also essential in custody transfer or billing, as flow meters are present in gas pumps and district heating substations. In the district heating industry, the ultrasonic flow meter has become the desired meter in many of its applications because it has a low cost while being accurate. This accuracy is however sensitive to installation effects and other sources of errors. This thesis stems from research that addresses the recognition of these installation effects, informs when they are unacceptable and considers reducing the measurement errors. To present these concepts, the thesis details the estimation of the mean flow velocity, the calibration of the meter and the measurement noise properties. Once installed, any kind of meter provides larger errors than in the facility where it has been calibrated and compensated. It is particularly true for ultrasonic flow meters as they are very sensitive to installation effects. Installation effects can either be static or dynamic. Special attention is paid to errors generated by temperature and velocity profile variations. Velocity profile variations can be due to pipe bends or flow pulsations. Such disturbances often induce a bias error and change the properties of the measurement noise. It is therefore with help of the change in noise that velocity profile disturbances can be detected. The detection of such abnormal behaviour of the measurement process constitutes a diagnosis. A diagnosis of the sensitivity of the meter to installations effects would allow for compensations for the errors. Signal analysis allows detection of specific noise properties, characteristic of installation effects. An example of self-diagnosis showing the detection of real pulsations in a flow is described in details. The detection of the flow pulsations and the estimation of their frequency allow to reduce the error of estimation on the flow rate. This technique is confirmed by the simulations of a pulsating flow. To empower one with the decision whether a flowmeter performance is normal or abnormal, a study of the relative error as a function of flow rate and temperature has been conducted.
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| 8. |
- Bérube, Andrew Patrick
(författare)
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Investigating the streaming potential phenomenon using electric measurements and numerical modelling with special reference to seepage monitoring in embankment dams
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A three-dimensional finite element computer program has been developed to numerically model the streaming potential phenomenon. The program can in fact calculate and display the primary and secondary potential distributions for any two coupled flows in a three dimensional domain. For streaming potentials, the primary flow is hydraulic and the secondary flow is electrical. The program operates in three separate stages. The program first determines the hydraulic potential distribution in the ground based on hydraulic conductivity values and the hydraulic driving forces, such as the pressure drop through an embankment dam. The program then calculates the geometry and magnitude of the electric current sources based on the fluid flow and cross-coupling conductivity values. Finally the electric potential distribution is solved for using these current sources and the electric conductivity distribution. Additionally, the program can incorporate external current sources, which can be used to simulate resistivity measurements in a model. The model domain can take any three-dimensional shape and can be divided into elements as desired. The individual elements can be assigned separate hydraulic, electric and cross-coupling conductivity values, creating an inhomogeneous anisotropic domain with three separate conductivity distributions. Four different types of finite element are available to choose from; two- and three-dimensional versions of isoparametric elements with either linear or quadratic interpolating polynomials. The program has been made fully graphical, allowing the user quick and easy access to information at any particular point of the domain. In order to provide a better picture of the streaming potentials in earth dams and the potential of the SP method for dam safety monitoring, SP investigations were performed on a number of embankment dams. Electric resistivity measurements were also performed on some of the dams to compliment the SP data. The resistivity data was found to be of considerable assistance for interpreting the SP measurements as well as for simulating real dam conditions with the modelling program. Three hydro-electric dams of different size on the Luleå River in northern Sweden were studied together with several dams built by mining companies for containing mine tailing reservoirs. A number of potential seepage areas were identified in several of the investigated dams.
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| 9. |
- Brännström, Oskar
(författare)
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Market offer development : industrial experiences in a business-to-business context
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A company’s competitive advantage is best understood in its ability to fill its relationships with a unique and meaningful value. Especially in business-to-business relationships value is complex and abstract, so complex that the product alone is not a meaningful representation of that value. Rather, the complete set of values represented by the company’s market offer needs to be considered. A market offer could be seen as the carrier of all values in a relationship. It contains both products and services but its essence is far more complex and multi dimensional than simply the combination thereof. While marketing scholars especially within the fields of service and relationship marketing have discussed the need for new or alternative product constructs, or conceptualisations, to embody this set of values, they have not addressed the issue from the point of view of actually develop a market offer. And while scholars within the field of product development research have been concerned with understanding how to practically manage product development – also presenting a number of best practice models – they have been limited by the context of the product as a physical artefact. There is an apparent gap between these two fields of research. Drawing on the knowledge on both these fields this work contributes to the filling of this gap by means of answering two main research questions: 1. How can a market offer be conceptualised to support its development? 2. What constitutes a market offer development process? In addition this work has also addressed how the product as such is affected by being part of larger solution and examined the possibility of expanding the product platform concept to include the complete market offer. To answer these questions four studies have been carried out during a period of three and a half years between April 2000 and June 2003. The first was an explorative survey covering 8 companies with the purpose of sharpening the problem formulation and to get a broad industrial view of the problem area. The second was a case study where the phenomenon was studied more in-depth based on the models of the first study. On this followed two participative studies at two different companies, each for a period of six months. In both these studies I was a fully participating member of a project team. On the second occasion, I also initiated the project and had a coordinating function. Both research questions have been answered by means of different models. Each model is a graphical framework with a description. These models are also verified in practice by means of implementation in the final participating research project. On research question one an important finding is that the current conceptualisation, made from a marketing perspective, is not detailed enough to support the management of developing market offers. Instead a model with three layers has been developed. These three layers are: the product & service layer; the business solutions layer; and the customer interaction layer. Between these layers different types of relationships have been identified. On research question two this project presents the first description of a market offer development process and clarify its relationship to currently published product as well as service development processes. Verifying findings of current marketing research it is found to be a continuous process rather than a process with a clearly defined start or end. It is found to be the continuous management of: the customer portfolio; products and services; commercial logic and business solutions; customer interaction; the resource structure; internal marketing efforts to facilitate internal change and overcome political and cultural boundaries; business analysis and follow-up to ensure profitability.
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| 10. |
- Bylund, Nicklas
(författare)
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Simulation driven product development applied to car body design
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis deals with the development of complex mechanical structures, from concept to detail design, as applied to car bodies. Efforts have been made to clarify how computer tools and analysis methods are used in product development in industry today. It has been found that the design and the analysis activities are separated, leading to product development that is simulation-verified rather than simulation-driven. This calls for better integration of computer support and analysis in the development process. Based on the above findings, a framework for car bodies is proposed, extending from concept to detail design. A property based model (PBM)/concept model, consisting of the following three sub- systems: beams, joints and panels, has been made to break down the requirements to sub-system level according to the design areas of the design engineers. Analysis tools have been developed and implemented, tailor-made according to the requirements at sub-system level. It has been shown that by providing design engineers with requirements according to their design area, and with corresponding analysis tools, it is possible for the design engineer to do preliminary analysis on their design in parallel with their normal design activity, leaving complete-vehicle a posteori simulation to the analysis experts. This increases the use of simulation in product development so that more solution alternatives are evaluated, leading to better design. The findings are corroborated by industrial studies, both at pilot level and full-scale. The implementation of simulation-driven design by designers is ongoing and increasing in projects at VCC. The implementation of the framework and tools has resulted in depended knowledge regarding interaction with industry and a contribution regarding how improvement of product development can be made.
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