Pitfalls and Opportunities in Knowledge Sharing - Experiences from a research capacity building project in Central America

A number of attempts have been made in the North to assist in the formation of independent research capacities in the South by establishing knowledge sharing through North-South research collaboration. One such attempt was initiated by Danida through its programme for Enhancement of Research Capacity (ENRECA). Aalborg University was approached by the National University of Costa Rica to make a joint research venture within the field of sustainable development. The project got a Central American (CA) regional perspective by including participants from Nicaragua and El Salvador. The project was titled Sustainable Development Strategies for Central America (SUDESCA) and aimed at support of relevant CA research activities, including the formation of adequate organizational setups that would eventually sustain forthwith. The project focused on two theoretical themes, i.e. the National Systems of Innovation and the Social Construction of Technology approaches. In this paper the CA universities are viewed as important sub-systems of the respective national systems of innovation. Thus, the following is an analysis of the institutional sustainability of the research capacity of universities perceived as parts of the national systems of innovation. To what extent did the knowledge transfer and exchange as well as the organizational capacity building efforts succeed? What were the main pitfalls and opportunities experienced? What did the Aalborg team learn about its own research capacity set-up? Our overall conclusion is that it is a mistake to assume that research capacity may be more or less directly transferred from the North to the South. Research capacity existing in the North has to be carefully adapted to the specific conditions where it may be expected to be useful.Innovation system, knowledge adaption, Central America

The Fluidity of the Self-Concept as a Framework to Explain the Motivation to Play Video Games

A better understanding of the motivation to play video games and potential antecedents have a long history in Human Computer Interaction research. Besides different motivational dimensions specific to video games, researchers already used the personality of players to explain the motivation to play and the subsequent video game use. At this juncture, they postulated a rather static self-concept underlying the personality of players. The study at hand tries to resolve this shortcoming and proposes a more holistic perspective on personality following the assumptions of the Social Identity Approach from psychology, which postulates a much more fluid and context-specific salient parts of the self-concept. Specifically, we use findings from consumer research arguing that the dimensional fit between the perception of the self-concept of a player and the corresponding video game holds the potential to explain the motivation to play as well as the subsequent usage of the video game

Adsorption studies of DNA origami on silicon dioxide

Self-assembled DNA nanostructures promise low-cost ways to create nanoscale shapes. DNA nanostructures can also be used to position particles with nanometer precision. Yet, reliable and low-cost ways of integrating the structures with MEMS technology still have to be developed and innovations are of great interest to the field. We have examined in detail the adherence of DNA origami tiles on silicon oxide surfaces of wafers in dependence on pH-value and magnesium ion concentration. The results of this work will help to pursue new strategies of positioning DNA nanostruc-tures on SiO2. Precise control over the strength of structure-surface adhesion is a prerequisite of relia-ble processes

Methods for higher order numerical simulations of complex inviscid fluids with immersed boundaries

Within this thesis, we study inviscid compressible flows of fluids modelled by several equations of state. Namely, these are the ideal gas law, the stiffened gas law, Tait's law and the covolume gas law. In their entirety, these equations of state can be used as models for the behaviour of many gases and liquids. After deriving new exact solutions for the corresponding variants of the Euler equations, we use the results as a tool for the verification of a higher-order accurate numerical scheme that has been implemented during the course of this thesis. The scheme is based on a Runge-Kutta Discontinuous Galerkin Method and the presented verification results show that we are able to obtain the expected rates of convergence in both, space and time. In the main part of this thesis, we consider an important building block for the extension of this conventional discretization by means of a treatment for generic immersed boundaries, namely the numerical integration of general functions over domains that are at least partly defined by the zero iso-contour of a level set function defining the domain boundary. Here, we study two new, generally applicable approaches in terms of their robustness and convergence behaviour. The first approach is based on a classical adaptive strategy, while the second approach is based on a hierarchical moment-fitting strategy with variable Ansatz order P. Both methods have been designed such that they are applicable on general element types. Most notably, the results of our numerical experiments suggest that the moment-fitting procedure leads to integration errors that decrease with a rate of O(h^(P+1)), thus allowing for a severe increase of integration accuracy at constant computational effort

Quantitative passive imaging by iterative holography: The example of helioseismic holography

In passive imaging, one attempts to reconstruct some coefficients in a wave equation from correlations of observed randomly excited solutions to this wave equation. Many methods proposed for this class of inverse problem so far are only qualitative, e.g., trying to identify the support of a perturbation. Major challenges are the increase in dimensionality when computing correlations from primary data in a preprocessing step, and often very poor pointwise signal-to-noise ratios. In this paper, we propose an approach that addresses both of these challenges: It works only on the primary data while implicitly using the full information contained in the correlation data, and it provides quantitative estimates and convergence by iteration. Our work is motivated by helioseismic holography, a powerful imaging method to map heterogenities and flows in the solar interior. We show that the back-propagation used in classical helioseismic holography can be interpreted as the adjoint of the Fr\'echet derivative of the operator which maps the properties of the solar interior to the correlation data on the solar surface. The theoretical and numerical framework for passive imaging problems developed in this paper extends helioseismic holography to nonlinear problems and allows for quantitative reconstructions. We present a proof of concept in uniform media

Thermal analysis of the ceramic material and evaluation of the bonding behavior of silicon-ceramic composite substrates

Abstract Thermal bonding of silicon and low-temperature cofired ceramics (LTCC) at sintering temperatures of 900 ° C represents currently the standard process in silicon-ceramic composite (SiCer) substrate fabrication. We analyse the thermal behavior of the LTCC using thermogravimetric analysis, differential scanning calorimetry and laser flash analysis. The thermal decomposition could be identified with a mass loss of 24% in the temperature range up to 1000 ° C what influences the thermal diffusivity with values from about 0.19 mm 2 s −1 before thermal treatment to below 0.10 mm 2 s −1 after thermal treatment. A specific heat capacity of 1 – 2 J (g · K) −1 is calculated. Further, an influence of low-temperature lamination of the LTCC seems to have an influence on the thermal behaviour. The sintering process was investigated with temperatures of 550 ° C, 730 ° C and 900 ° C, applied pressures of 12.2 kPa and 6.1 kPa and intermediate wetting layers of TiO 2 (normal deposition and oblique angle deposition). Optical observations, ultrasonic and scanning electron microscopy, and pull-tests are used to compare the properties of the sintered SiCer substrates. Whereas the sintering temperature has an obvious impact on the sintering behaviour of the LTCC, a direct conclusion of parameter variation on the bonding result was not observed