· · · Institutional Repository

The fuel composition of the Generation IV 600 MWth 'efficient' Gas Cooled Fast Reactor (GCFR) that realizes zero breeding gain without using fertile blankets is determined. The analysis includes all the stages of the nuclear fuel cycle, including irradiation, reprocessing and fuel fabrication. The time-dependent multiplication factor, reactor safety parameters, and decay heat production for different fuel compositions are simulated using the deterministic SCALE 4.4 code. The depletion equation and the 1-D transport equation are solved for multiple timesteps during reactor irradiation. It is seen that adding a small percentage of minor actinides (MA) to a mixture of uranium- and plutonium carbide favors the creation of a closed fuel cycle with zero breeding gain. Furthermore, addition of MA increases the burnup potential of the fuel, extending its feasible irradiation time from 40 to 90 MWd / kg, due to the transmutation of Np-237 to fissionable Pu-238 and Am-241 to fissionable Am-242. Mixing MA negatively affects safety parameters by decreasing the delayed neutron fraction, decreasing the negative Doppler feedback and increasing the positive reactivity introduced when the reactor is depressurized. However, the magnitude of the delayed neutron fraction is comparable to existing fast reactors. Worths of individual isotopes are introduced as a value of their contribution to the core reactivity. Throughout the fuel cycle, the time-dependence of the isotopic and total worth of the fuel is determined. Zero breeding gain is achieved when the initial total worth of the fuel stays constant for multiple cycle burnup. The effect of different reprocessing strategies on the closed fuel cycle is shown. Research confirms that when there are no reprocessing losses, depleted uranium can be used during the recycling step to replace fission products and obtain a new critical fuel composition.

Nowadays, refineries face a double challenge: increasing hydrogen consumption for deeper hydrotreating, together with stricter environmental legislation on the sulfur content of fuels, which further increases refinery hydrogen demand. Therefore,hydrogen system is bottlenecked and hence hydrogen management has become a priority issue in current refinery operations. Pinch Analysis is a powerful tool for targeting minimum hydrogen utility in refinery hydrogen network and establishing improvement directions. The concept of hydrogen surplus is not only used to identify the bottlenecks in the hydrogen distribution system, but also provides valuable theoretical insights into the impact of hydrogen purification on the performance of a hydrogen distribution network. In this thesis, hydrogen pinch methodology has been successfully applied to a refinery hydrogen distribution network. Both low cost and capital investment solutions have been developed to improve the hydrogen network efficiency. Moreover, the low cost solutions delivered significant potential benefit to site and will be implemented in September 2004. In addition to the pinch analysis for deciding improvement solutions, hydrogen management requires further tools for system representation. A shortcut method has been successfully applied and a deterministic steady-state lumped model has been developed for simulating the behaviors of hydrogen distribution system and predicting the impact of network modifications on the individual network elements, as well as the network constraints. Besides delivering improvements to the site, the hydrogen system requires support for sustaining performance. Sensitivity analysis and pinch based solutions (operating strategies) have been developed for sustaining performance of hydrogen distribution network. Finally, A systematic approach has been developed for hydrogen management studies,based on experiences with a case study.

The goal of this project was to embed the Shock Wave Reactor (SWR) into an ethylene plant in order to assess the performance of this unique reactor. The performances are based on the energy consumption and ethylene yield. There are some researches done. Unfortunately no information is found in articles about how to embed the SWR in an ethylene plant. So, to embed the SWR, the behavior of the whole plant must be monitored. The embedding of the SWR in an ethylene plant is done by integration this reactor in an ethylene plant based on conventional cracking. Conventional cracking is done by a furnace. The only different is the cracking reactor.The separation configuration is taken the same. Strong GDP (gross domestic product) growth in major regions results in strong petrochemical demand growth. The reason of this growth is due to the growing market of China and India. So the importance of ethylene increases. Ethylene is and in the future still be an important bulk chemistry in the petrochemical and industry The process chemistry with its thermodynamics and kinetics are based in earlier research done by R.Bosma. Normally more than 1 million reactions occur during ethane cracking but here 7 major reactions are used. The residence time plays a big role in this cracking. Thermodynamically high temperature is favorable but kinetically not. High temperatures increase the secondary reactions with more by-products as result.The SWR was already modeled in Matlab by R.Bosma [21]. To investigate the SWR energy consumption, the SWR is modeled in Aspen. A user model in Aspen has been made, which reflects the behavior of the SWR at some given conditions. This Aspen model is validated in order to determine the reliability of this model. The model is successfully made but some parameters where slightly different. With Aspen Pinch, the determination of the energy consumption is made. This is very important because the energy consumption will conclude if this SWR economical favorable compared with a conventional furnace. Also the environmental impact of the SWR has been studied. It is known in the aviation industry, shock waves produce a lot of sound power. It can have a certain risk to the human health and environment. This is a complex problem because of the difficulties to monitor the sound behavior of this reactor. It is concluded that the SWR is an energy slurping process compared with a conventional furnace. The ethylene yield is also lower than the ethylene yield produced with a conventional furnace.

In this bachelor thesis, blood flow in simplified stenosed and unstenosed arteries under influence of a steady localized non-uniform magnetic field is investigated by performing 3D numerical simulations. The mathematical model is a combination of the principles of ferrohydrodynamics (FHD), magnetohydrodynamics (MHD) and a simplified set of Amperes law and Maxwell's equations. The numerical solving is performed with a non-commercial FORTRAN77 code, based on the finite volume method with a second order central differencing scheme (CDS). The blood is modelled as an incompressible homogeneous Newtonian fluid. As a result, it is found that the magnetic field can create and influence the size of recirculations in the mainstream and also creates significantly large secondary motions. Furthermore, the wall shear stress (WSS) on the artery walls is investigated. The WSS profile shows a significantly different profile when a magnetic field is applied.

This thesis focuses on the metabolic aspects of cellular adaptation processes to oxidative and iron limiting stresses. These stress conditions are generally encountered by pathogenic species upon the invasion of host organisms. It has attracted the attention of researchers and resulted in the initiation of a European project on Bacillus subtilis systems biology. This project aims at elucidating the regulatory pathways of B. subtilis under oxidative and iron stress for the subsequent application to pathogens. The present study attempts to identify and quantify the adaptations in central carbon metabolism in response to imposed stresses. Therefore a recently developed system of mini-chemostats is used as a culturing system. This setup allows a quick and economic way of culturing under many different conditions. The main finding in oxidative stress adaptations is the re-routing of carbon through the pentose phosphate pathway in order to generate NADPH. NADPH is used by processes that relief the cells of oxidative stress. Next to the production of reduction equivalents, there was an increased amount of extracellular TCA cycle intermediates as fumarate and succinate. The fluxes through this pathway did not change. The iron limitation experiments yielded less clear results on the impact on metabolism. This might be due to the chosen method to deferrate the medium. Deferoxamine caused only minor iron stress and was not life threatening for the cells. That the cells were only slightly affected was shown by the increased production of siderophores, bacterial iron harvesting compounds. The cells were able to survive the situation by the production of siderophores. The results of this study aid the BaSysBio project in obtaining a better understanding of B subtilis adaptation to a shift in environmental conditions. The generated data gives further insight into the adaptation processes and help model development by providing quantitative information on the stress responses. The results can be processed by BaSysBio and can eventually result in new strategies to combat pathogenic bacteria.

The Front End Tools (FET) Project's goal is to create a software application which should aid the process engineer in creative design of process plants. Since this application will be written using object-oriented techniques, an object model has been designed by Akzo-Nobel Engineering. This document describes the verification procedure of this object model, which should be able to contain chemical engineering process design data and methods. During this verification (which included examining separation processes and reactors as well as writing two C++ applications) several elements of the original model have been modified. The conclusions made at the end of the project state that the currently developed object model can be used for its intended purpose. Apart from this conclusion, several concepts were proposed for further development in conjunction with the FET project.

Steam pyrolysis of ethane and naphtha is an important chemical bulk process. It produces ethylene and propylene, which are important base chemicals. In order to be competitive, crackers have to be operated at near optimal conditions. Hence, a simulation program of the process, particularly of the pyrolysis is very helpful. KTI uses and licenses such a program called SPYRO*. Development of this program has started over 20 years ago. Consequently, it uses a closed model. It has been the objective of this study to investigate the feasibility of the development of an open version of SPYRO. Here open means that the equations are written in residual form .This enhances the flexibility of the program very much. For our studies we have used the model of Froment for ethane cracking because the documentation to make an open SPYRO model was insufficient. This Froment model has been modified as to improve the modeling of the bends. It has been checked, whether the solution of this model would pose any problems. It was found that the index might become more than 1 during integration. As yet no sound physical explanation has been found for this phenomena. It also follows from investigation of the index that a start-up problem of the numerical integration exists for the original set of differential equations. We have found a more elegant method to circumvent this problem than Froment. Moreover, we were able to solve the set of equations for bad initial conditions (equal to the boundary conditions). The ordinary differential equations of the model are turned into algebraic equations using orthogonal collocation on finite elements. This allows the model to be solved with an equation solver. The results were compared with various commercial numerical integrators. Excellent agreement was found for limited numbers of sections and collocation points. The speed of solution of the linearized set of modal equations depends on the size, the sparsity and structure of the Jacobian. The latter has an enormous effect on the fill-in of the L and U decomposition matrices. We found a very satisfying structure by modification of the equations and proper arrangement in the Jacobian. On the basis of the above results we may draw the following conclusions regarding the feasibility of the development of an Open SPYRO model. Unfortunately we had to use a simple model of Froment rather than the SPYRO equations themselves. Nevertheless, we have concluded that such a development is feasible. Within a reasonable time an accurate solution will be found even with bad starting values. The computation time can be further reduced with a smart initialization procedure.

Geometrical optics analysis is carried out in order to establish a relationship between the intensity distribution at the base plane of a column of scintillation material and the depth of interaction. Slabs of scintillation material are treated as a two dimensional model case, and the results are extended to approximations for circular and rectangular columns. The application of the detectable optical signal at the base plane of the columns for the reconstruction of the depth of interaction is also discussed.

In dit onderzoek wordt bekeken wat de (voor)kennis bij leerlingen uit HAVO 4 en VWO 4 is, met betrekking tot modelleerbegrip en modelleervaardigheden. Wij concluderen dat leerlingen geen goed begrip van een model hebben. Leerlingen neigen een vergelijking uit de tekst te willen destileren, en op te willen lossen zonder dat ze zich voldoende realiseren waar ze eigenlijk mee bezig zijn, of wat hun antwoorden betekenen. Leerlingen hebben geen goed idee dat modelleren een iteratief proces is; dus dat een door een wetenschapper gebruikt model bij nieuwe inzichten aangepast kan worden. Ook heerst er een idee bij de leerlingen dat modelleren datafitten is. Ze realiseren zich onvoldoende dat modelleren bestaat uit het maken van vereenvoudigingen, en dus een benadering is die niet (noodzakelijk) gelijk is aan de absolute werkelijkheid. Nevendoelen die we aangetoond hebben zijn de volgende. Leerlingen op het HAVO minder goed scoren op onze vragen lijst dan leerlingen van het VWO. Leerlingen die wiskunde B doen, scoren beter dan leerlingen die wiskunde A doen. Leerlingen die goede cijfers halen scoren beter dan leerlingen die minder goede cijfers halen. Leerlingen die wiskunde leuk vinden scoren beter dan leerlingen die wiskunde minder leuk vinden. Ons onderzoek is bruikbaar voor docenten die modelleeronderwijs geven en ontwikkelaars die modelleeropgaven samenstellen.

This is a research and design graduation project for the Master-education tracks Integrated Product Design and Science Communication TU Delft, with a Sustainability-annotation (TiSD). The client of this project is Euro RSCG Bikker, a consultancy with the proposition ‘committed to trust’. The Bikker-consultants develop products and services in the form of advice for corporate communication professionals of large organizations. Since current investigations and publications related to ‘trust’ are hardly comparable or applicable for strategic corporate communication professionals, Euro RSCG Bikker was looking for generic, supportive tools, methods and techniques to make trust and thereby the agency’s proposition more tangible in their advice development process. Eventually, Bikker wants to develop a ‘trust measurement instrument’. To anticipate to the desire of Euro RSCG Bikker for tools, methods and techniques, a research and design process was initiated. The process aimed to develop a Toolbox and ‘trust determinants’ for advice development of Bikker consultants. The underlying research question was: “What theoretically defined trust determinants are potentially useful for corporate communication consultancy practice according to Bikker consultants?” To answer this question the author conducted a design based research to develop a toolbox with trust determinants for the analysis phase of advice development of Bikker consultants, in which consultants analyze the client's organization, identify problems, and set objectives for the advice that needs to be developed. Various research and design techniques were used to investigate trust, corporate communication and consultancy practice at Euro RSCG Bikker, and to develop the toolbox and its trust determinants. The preliminary design proposals were tested by practitioners and optimized by the author, but Euro RSCG Bikker will take responsibility for the further development of the toolbox. The final set of trust determinants is Common values, Consistent, Transparent, Innovative, Freedom, Shared success, Stakeholder involvement, Stakeholder relationships, Pride, and Respectful. These determinants could be identified in theory ánd practice as indicators of whether and why there is high trust, ánd as strategies to build, restore, or retain trust íf that appears to be low. The toolbox contains an underlayment, coasters for each trust determinant, pawns, and paper money. A client can also introduce a new determinant (‘Jester’) in order to encounter client specific desires and whishes in the advice that a Bikker consultant is about to develop based on the analysis of the organization. In a playful interaction, both the consultants ánd clients can do a ‘trust-diagnosis’ of the client’s organizations, and ‘set starting points for the advice’, which forms a fruitful base for a mutually rewarding consultant-client relationship. The research conclusion is the list of 10 theoretically defined trust determinants, and a list of conditions for theoretically defined trust determinants with potential usefulness for advice development practice at Euro RSCG Bikker in general, based on the toolbox design process and results. The trust determinants require further elaboration in the future, but for the current consultancy practice at Euro RSCG Bikker they form a start. Also, the toolbox requires maintenance and an update in the near future, especially if Euro RSCG Bikker wants to develop a trust-measurement instrument eventually. The report ends with various recommendations for future research into trust, design-based researchers, and future exploration opportunities for Euro RSCG Bikker to extend the proposition ‘committed to trust’.

The thesis research was conducted at the section E&I (energy and industry) of the faculty of Technology, Policy and Management. The world around us is complex and this complexity is only expected to increase as technological development spurs on. This complexity arises from social and technical parts that interact with each other and co‐evolve over time, resulting in emergent system behaviour and structure. Today’s industrial systems are interesting examples of socio‐technical systems that contain large aggregates of technical components and actors that make economic and strategic decisions, which shape the physical world. It is impossible to predict or steer future developments of these systems because of the non‐linear interaction and feedback loops between the different social and technical components. However, insight about the fundamental behavioural modes and possible evolutionary pathways can be gained by building a computer model. In this thesis agent‐based modelling (ABM) was used; in ABM, an agent represents an independent socio‐technical component in the system. It has a state that represents the physical and economic assets and a behavioural component in which reasoning and decision‐making takes place which in turn influence the state of the agent and interactions with the outside world. Maasvlakte II, the new extension of the Rotterdam harbour area that is currently under construction is an ideal case study to expand experience with ABM; the ambition of the Port of Rotterdam is to realise sustainable chemical facilities, like a synthesis gas cluster that uses different types of feedstock to produce a variety of clean end products, like fuels and value‐added chemicals. The problem with previously built ABMs is that the technical detail represented is too limited to apply it to syngas networks; the technical part of the agents is currently modelled as a black box and generic facilities are taken as a starting point. The question is whether this lack of detail makes a significant difference for the structure of the syngas cluster that evolves and the agent decision‐making. The main question of the research was therefore: “What is the added value of Agent based modelling of large scale syngas networks at Maasvlakte II with ‘grey‐box’ models representing syngas technologies instead of black‐box models?” The research method consisted of a literature study of the different syngas technologies and building the agent‐based model. Developing the ABM entails conceptualisation and formalisation of the syngas technologies in an ontology (the system decomposition method), making a storyboard of the agent’s behaviour and transcribing this to (pseudo‐)code. There was unfortunately not enough time left for full implementation and running of the model. The main added detail that was proposed is a description of the composition of the gasifier feedstock and syngas, and a more detailed description of technologies that may influence this composition; i.e. treatment units and reactors are described separately, and descriptions of reactors are diversified to several reactors that produce low or high quality syngas. The general conclusion from the research is that the expected added value of adding technical detail to the black box descriptions of syngas technologies is related to the increased realism of network connections, while unfeasible connections are ruled out by the constraints that are imposed by adding technical detail in describing different reactor types and including the syngas composition. The description of treatment units and impurities in the composition of streams also make it better possible to evaluate the sustainability of the system and economic viability of routes from feedstock to end product. The amount of work that should is involved in adding technical detail to the agentbased model is however considerable, and the added value is partly offset by the problems that were found during the research. The three main problems are: There is a myriad of different syngas technologies, and it is very easy to get lost in the details, while it is hard to conceptualise them and formalise them. This is because all detail levels are somehow connected. The major problem of this class was to decide how the mass balances should be dealt with; the optimal solutions lies in between using a few standard input and output compositions without calculating anything, or detailed calculation of the composition as is done with flowsheeting programs like ASPEN. The second main problem was that the technical detail added does also imply that agents will have to reason about the design criteria that are added, which means that the more technical detail is added, the more (pseuco‐)code has to be written to capture agent reasoning and decision‐making. The final main problem was that in some cases this reasoning and decision‐making is so complex that it can hardly be captured in (pseudo‐)code, for example strategic behaviour and contract negotiation. The largest danger is falling in the trap of (having the intention of) adding too much detail. The main recommendation is thus to define the level of detail per case study, and at a level relevant for the context of that case study; it is better to have a partial model than no model at all. For the research of syngas network evolution over time one should focus on the interface between syngas producing and syngas consuming technologies, which means including the composition of syngas and factors that influence this composition, like different reactor types and gas treatment technology. When evaluating the sustainability of a syngas network, one should also include pre‐treatment of gasifier feedstock. A second recommendation is to conduct a parameter sweep for certain variables of which it is unsure how they influence the decision‐making of the agents or when the behaviour of the agents is too complex to capture with simple (pseudo‐)code. The final recommendation to be made when conducting agent‐based modelling is to be aware of the fragile balance between too much and too few detail; the system should be defined in such an extent that the behaviour of the agents is restricted in a realistic way while leaving enough degrees of freedom for the system to exhibit complex and emergent phenomena. Future research should focus on solving the problems with mass balance calculations by taking a chemical engineering point of view and learning from how flowsheeting programs have tackled these problems previously, and figure out what the breath and depth of the interplay is between technological details, social decision‐making, and economic aspects of the model.

Determining the scintillation pulse shapes of PET scintillation crystals, especially the rise time of the pulse, will yield valuable information for making choices in the design of time of flight-PET scanners, with respect to e.g. scintillator crystal material and the detector trigger schemes. This can eventually improve the image quality of PET scans by noise reduction and/or reduce the image acquisition time and the dose to the patient. Knowledge of the rise time of the scintillation pulse is also of great importance in the modelling of the physical processes involved in scintillations. Several setups are presented and assessed with the intention to develop a procedure that is relatively easy to implement and is suitable for determining scintillation pulse shapes of PET scintillation crystals, excited by 511 keV photons, with sub-nanosecond timing resolution. The emphasis is on characterizing the rising edge of the scintillation pulse. The time correlated single photon counting method was employed in all of the setup variations. A proof-of-principle of the applicability of a suitable measurement procedure is given, which achieves a timing resolution of 120 ps FWHM and was used to determine the exponential rise time of a lutetium-yttrium oxyorthosilicate (LYSO) scintillator to be 81 ps with an estimated uncertainty interval of [50,120] ps. Also recommendations for further work on the basis of this procedure are made.

In this thesis a binaural CASA localization algorithm is developed for the implementation in a binaural hearing aid with downstream speech enhancement. Two binaural CASA localization algorithms, based on the Albani model, are proposed to enhance the localization performance in noisy and reverberant acoustic environments. The Albani model is extended with a zero-lag interaural coherence (IC) time window pre-selection, detection of multiple sources per time-window, coincidence detection between interaural level and time differences (ILD and ITD) and a lagged time window comparison, in the proposed extended Albani algorithm. A further addition to the proposed extended Albani algorithm with a binaural cue selector based on an inhibition process, is proposed in the extended Albani algorithm with cue selection by inhibition. Performed simulations show that the extended Albani algorithm performs the best in noisy situations up to a SNR level of -12 dB and the extended Albani algorithm with cue selection by inhibition performs the best in reverberant situations up to a reverberation time of 2.0 s. These proposed localization algorithms show a better performance than the present known CASA methods in both noise and reverberation.

Nowadays, industries are become more open to conduct part of their research outside of their own companies. The industries can work together with an independent research institute like NELF Contract Research Organization (NELFCRO), the problem owner of the case that is used in this thesis research. The management of NELFCRO is aware of the emergence of many potential partnerships between contract research organizations and the industries. Moreover, the management considers improving NELFCRO’s acquisition process in order to successfully enter the market. According to NELFCRO’s experience, the acquisition phase of NELFCRO usually takes a lot of time before the customer makes a decision to cooperate. NELFCRO’s management mentions that a significant percentage of company’s time is used for reducing perceived barriers and negative thought of the customer towards NELFCRO. In order to assist NELFCRO to improve their acquisition process, this research was initiated. The main research question of this thesis is: “How can the acquisition process of NELFCRO be improved by integrating theory from academic literature and practice from NELFCRO employees’ perspective?” To answer this question, this research was conducted in different phases, namely analysis and synthesis phases. As part of the analysis phase, context analysis and concept analysis were carried out. In the context analysis phase, interviews of NELFCRO’s employees and NELFCRO’s flyer analysis were conducted. The main results of this phase are the company context which emphasized the perceived positive aspects and perceived negative aspects of NELFCRO based on its employees’ perspective. Next to the context analysis, a concept analysis was conducted by a literature study on acquisition process in order to develop the ground of this research. The results of this literature study are theoretical framework of acquisition process and list of aspects that are theoretically involved in acquisition process. As part of synthesis phase, the integration of the context analysis result and the concept analysis result were carried out. Validation of the research results on context analysis and concept analysis were conducted. The validation was part of the focus group activity with NELFCRO’s employees as participants. The focus group was also aimed to enrich the concept of the integrated frameworks and NELFCRO’s context with new ideas. The main result of the synthesis research phase is an integrated matrix of theoretical framework and NELFCRO’s context. This matrix was used to analyze the NELFCRO’s perceived aspects, which are closely related to acquisition process. Furthermore, it was used to generate possible unique selling propositions (USPs) of NELFCRO. Then, possible solutions to generate company’s proposed-USPs were discussed and some recommendations were generated. In this research phase, the validation of the research results was carried out. Also, in the focus group, NELFCRO’s employees were involved to think together about their company’s acquisition case based on the research result. To conclude, as the answers to the main question, the acquisition process can be improved by making NELFCRO’ employees aware of their perceived positive aspects and making them focus on those perceived positive aspects of the company. These perceived positive aspects of the company are possible to become NELFCRO’s unique selling propositions (USPs). These USPs are important to be emphasized to the potential customer, especially in the acquisition process. Beside the perceived positive aspects, emphasis could be given to the improvement of the company’s perceived negative aspects into more positive aspects, eventually making them potential company’s USPs. Besides the recommendations that are generated from the discussion on possible solution for NELFCRO, further recommendations are also presented in the end of the research. The results of this research can be used as the start for further study of NELFCRO in its acquisition process.

The HPLWR (High Performance Light Water Reactor) is the European version of the SCWR (Supercritical Water Reactor) and is one of the Generation IV concepts that have enhanced safety, improved efficiency and less nuclear waste compared to current nuclear reactors. A possible way to enhance the safety is by using natural convection as the driving mechanism for the coolant flow. Natural convection is especially interesting because of the large differences in density occurring under supercritical conditions. This is safer because of its independence of mechanical systems (i.e. pumps, which are used in forced convection loops). The goal of this project was to investigate the linear stability of a one-dimensional, simplified version of the HPLWR (without the power-density feedback, but with constant power) around the steady-state solution for a range of operational conditions. A code was written based on one-dimensional equations for mass, energy and momentum transport. The code successfully predicted the steady-state behaviour of a system. The results were benchmarked with data from literature. The code works for natural convection loops as well as forced convection systems. The stability plots do not agree with literature and are therefore considered to be incorrect.

Geothermal energy is increasingly being explored as an attractive renewable energy source. In recent years several geothermal energy projects have been developed in the Netherlands reflecting growing governmental, industrial and scientific interests. Increasing the use of renewable energy is high on the policy agenda world wide. The degree varies to which governmental policies have been successful, but overall social acceptance has been recognized as crucial to the achievement of renewable energy targets. The Dutch geothermal community has also become aware of the need to take social awareness of its activities seriously, and the extent to which these activities are regarded as acceptable by lay publics. The Geothermal Energy Platform in its capacity of advocating geothermal energy and assisting geothermal project development has recognized the need to be prepared for the expected substantial rise in geothermal projects with the associated increase in the visibility of geothermal facilities, the public awareness of their presence and any disadvantages perceived to be involved. It has commissioned a communication strategy which is aimed at achieving social acceptance of geothermal energy and which takes into account the specific characteristics of this renewable energy source. Social acceptance is an often used term in the practical policy literature on renewable energy and has become a value-laden politicized concept with many dimensions. Despite a range of studies being carried out on public attitudes towards renewable energy technologies, genuine understanding of the dynamics of public acceptance remains elusive. From a citizen or consumer point of view, acceptance might signify positive approval, consent and active endorsement, but it might otherwise signify acquiescence, resignation and passive compliance because rejection or resistance is infeasible. From the standpoint of the advocate or promoter of a new technology, acceptance of any description might be sought, although it can be assumed that a more active form might be preferred by stakeholders because it appears to confer legitimacy. The first part of this report is devoted to uncovering the findings of psycho-social research into various aspects of social acceptance. By comparing the implementation processes of different but related renewable energy technologies clues have been found on societal developments which are considered relevant for geothermal energy. The various issues related to a geothermal project, i.e. topics that may be debated by stakeholders and may require settling, are grouped into three discourses: the siting discourse (where geothermal technology is experienced in terms of a proposed construction of a geothermal facility in a given locality); the energy-innovation discourse (where geothermal technology is experienced as an innovation that may or may not fit in with preferred ways of life); and the investment discourse (where geothermal technology is experienced as an investment opportunity that may be acceptable, or not, in the light of the possible gains it will produce). To establish what acceptance of renewable energy is in terms of a psycho-social phenomenon various models for the public acceptance of technology have been explored. From these models a communication framework has been developed that shows how social acceptance of geothermal energy may be created among stakeholders and how this process can be managed using a series of steps which are to be incorporated into the development process of a geothermal project. Effective communication is crucial to facilitating and maintaining the acceptance creation and management process. In the advisory second part of this report considerations and recommendations have been drafted on the elements of a communication strategy for geothermal projects. It is stressed that any communication process requires a thorough preparation in which communication objectives are established, a stakeholder analysis is performed, an approach to communication is determined, and messages are formulated. When considering communication objectives it is important to distinguish between acceptance and active support. Acceptance may signify positive approval, consent and active support, but also acquiescence, resignation and passive compliance; active support may be expressed by actual positive behavior toward the project: co-operation with project officials, agreement to publicly voice support, or some form of co-financing. A well executed stakeholder analysis provides information about interests, knowledge, attitudes, points of resistance with respect to the geothermal project, and relationships and co-operations between stakeholders. The leading approach for a communication strategy for a geothermal project is to take its societal surroundings seriously. Whether this is sufficiently accomplished depends on all parties involved and significantly determines the difference between resistance and acceptance. To take the project surroundings seriously has its consequences for not only the communication process but also the project development process itself. Key words for successful messages about geothermal energy are: concrete thinking, local significance and repetition. It is essential to present specific, preferably visible effects of geothermal energy which are of interest to the societal surroundings of the project. Demonstrable environmental effects appeal more than abstract issues, like global climate change. In addition it is important to connect effects to the local project area. This includes naming locations with issues or problems caused by the project. Such openness is not only important during the early developmental stages of a geothermal project, but also during its exploitation phase. Measuring a level of acceptability or evaluating a communication process aimed at its advancement is expected to be a precarious enterprise. Finally, various evaluation criteria are proposed concerning the transfer of information, the expression of support for contested issues, and the communication process itself.