Social acceptance of renewable energy innovation: An introduction to the concept

This paper introduces the special issue on Social Acceptance of Renewable Energy Innovation. It is a collection of best papers presented at an international research conference held in Tramelan (Switzerland) in February 2006. While there are ambitious government targets to increase the share of renewable energy in many countries, it is increasingly recognized that social acceptance may be a constraining factor in achieving this target. This is particularly apparent in the case of wind energy, which has become a subject of contested debates in several countries largely due to its visual impact on landscapes. This paper introduces three dimensions of social acceptance, namely socio-political, community and market acceptance. Factors influencing socio-political and community acceptance are increasingly recognized as being important for understanding the apparent contradictions between general public support for renewable energy innovation and the difficult realization of specific projects. The third dimension, market acceptance, has received less attention so far and provides opportunities for further research, particularly from management scholars.     

Stochastic Prediction of Sediment Transport in Sand-Gravel Bed Rivers

Classical deterministic bedload transport predictors are applied to sand-gravel bed rivers. The turbulent bed shear stress is modeled according to a probability distribution to obtain realistic bedload transport rates at incipient motion. In extending the predictors to stochastic predictors for nonuniform sediment, many parameters that represent near-bed turbulence and the particle size distribution must be chosen. The parameters that give realistic results are chosen by analyzing the results of a new experimental flume dataset with relatively large water depths. Choosing other combinations of parameters may give equal total bedload transport rates, but at the cost of large errors in fractional transport rates. Attention is given to the hiding-exposure phenomenon and a hindrance effect related to nonuniform sediment. Validation based on two independent field datasets shows that successful predictions of particle sizes near the threshold for motion are feasible using the stochastic approach, while the deterministic approach gives successful predictions well above incipient motion.     

Simplifying interactive design of solid models: A hypertext approach

Conceptual design and editing parameterized models of 3D solids often requires user interactions with many types of entities and relations. In this paper, we present a concept for simplifying the design process. The simplification is based on three paradigms; integration of data structures and control structures, multiple view interface, and use of hypertext techniques for fast traversal and selective display of data. Data structures and control structures are integrated into uniform building blocks called cells. Cells define assemblies of CSG solids and can be grouped bottom-up into more complex cells or, alternatively, can be refined top-down during the design process. Efficient specification of complex cells and patterns is made possible through the use of automatic default values, multiple instantiation, built-in repetition, and recursion. A multiple-view interface enables the designer to view and edit both the cell parameters and the hierarchical structure of the model. The interface provides integrated textual, 2D graphical, and 3D direct-manipulation techniques for specifying primitive dimensions and relative transformations.     

Increasing thermal stability of subtilisin from mutations suggested by strongly interacting side-chain clusters

In this paper we present for seven subtilisin structures a systematiccomparison of densely packed side-group clusters (defined asan ensemble of side chains with extensive internal atomic contactsas compared with those made with the surrounding protein environmentand measured relative to the maximum possible for each residuetype). Spatially consistent clusters are observed at structurallyequivalent positions in the proteins, as revealed by carefulmultiple superpositioning of the respective backbone atoms.The clusters are positioned at strategic loop-connecting sitesnear the protein surfaces. The residues within consistent clustersdisplaying extensive association show varying conservation atstructurally equivalent alignment sites. Suggestions for residuesubstitutions, as observed over the seven tertiary structures,were taken from the cluster positions and were shown to be consistentwith a number of point mutations in one of the seven structures(savinase) that result in increased thermal stability.     

MIMO feed-forward design in wafer scanners using a gradient approximation-based algorithm

An experimental demonstration is given of a data-based multi-input multi-output (MIMO) feed-forward control design applied to the motion systems of a wafer scanner. Atop a nominal single-input single-output (SISO) feed-forward controller, a MIMO controller is designed having a finite impulse response (FIR) filter structure. The coefficients in this structure are obtained from a gradient approximation-based algorithm. The aid of the FIR filter structure is mostly through its efficient (and limited) set of perturbed-parameter experiments needed to obtain the FIR coefficients. The effectiveness of the optimized feed-forward design in achieving improved servo tracking performances is demonstrated on a high-speed and nano-accurate MIMO wafer stage of an industrial wafer scanner.     

Internal-model-based design of repetitive and iterative learning controllers for linear multivariable systems

Repetitive and iterative learning control are two modern control strategies for tracking systems in which the signals are periodic in nature. This paper discusses repetitive and iterative learning control from an internal model principle point of view. This allows the formulation of existence conditions for multivariable implementations of repetitive and learning control. It is shown that repetitive control can be realized by an implementation of a robust servomechanism controller that uses the appropriate internal model for periodic distrubances. The design of such controllers is discussed. Next it is shown that iterative learning control can be implemented in the format of a disturbance observer/compensator. It is shown that the resulting control structure is dual to the repetitive controller, and that both constitute an implementation of the internal model principle. Consequently, the analysis and design of repetitive and iterative learning control can be generalized to the powerful analysis and design procedure of the internal model framework, allowing to trade-off the convergence speed for periodic-disturbance cancellation versus other control objectives, such as stochastic disturbance suppression.     

FI3D: direct-touch interaction for the exploration of 3D scientific visualization spaces

We present the design and evaluation of FI3D, a direct-touch data exploration technique for 3D visualization spaces. The exploration of three-dimensional data is core to many tasks and domains involving scientific visualizations. Thus, effective data navigation techniques are essential to enable comprehension, understanding, and analysis of the information space. While evidence exists that touch can provide higher-bandwidth input, somesthetic information that is valuable when interacting with virtual worlds, and awareness when working in collaboration, scientific data exploration in 3D poses unique challenges to the development of effective data manipulations. We present a technique that provides touch interaction with 3D scientific data spaces in 7 DOF. This interaction does not require the presence of dedicated objects to constrain the mapping, a design decision important for many scientific datasets such as particle simulations in astronomy or physics. We report on an evaluation that compares the technique to conventional mouse-based interaction. Our results show that touch interaction is competitive in interaction speed for translation and integrated interaction, is easy to learn and use, and is preferred for exploration and wayfinding tasks. To further explore the applicability of our basic technique for other types of scientific visualizations we present a second case study, adjusting the interaction to the illustrative visualization of fiber tracts of the brain and the manipulation of cutting planes in this context.     

Tuning the Structural and Optoelectronic Properties of Cs2AgBiBr6 Double-Perovskite Single Crystals through Alkali-Metal Substitution

Lead-free double perovskites have great potential as stable and nontoxic optoelectronic materials. Recently, Cs₂AgBiBr₆ has emerged as a promising material, with suboptimal photon-to-charge carrier conversion efficiency, yet well suited for high-energy photon-detection applications. Here, the optoelectronic and structural properties of pure Cs₂AgBiBr₆ and alkali-metal-substituted (Cs_1−xY_x)₂AgBiBr₆ (Y: Rb⁺, K⁺, Na⁺; x = 0.02) single crystals are investigated. Strikingly, alkali-substitution entails a tunability to the material system in its response to X-rays and structural properties that is most strongly revealed in Rb-substituted compounds whose X-ray sensitivity outperforms other double-perovskite-based devices reported. While the fundamental nature and magnitude of the bandgap remains unchanged, the alkali-substituted materials exhibit a threefold boost in their fundamental carrier recombination lifetime at room temperature. Moreover, an enhanced electron–acoustic phonon scattering is found compared to Cs₂AgBiBr₆. The study thus paves the way for employing cation substitution to tune the properties of double perovskites toward a new material platform for optoelectronics.     

The changing role of the Dutch social rented sector

The article traces the evolution of the research interests of Dieleman, an academic who combined the development of analytical models with explorations of the policy implications of the changing structure of housing markets. During his long career as a professor of geography, he championed international cooperation in research and played a major role in disseminating the results of Dutch academic studies to an international audience. His own work was concentrated on the analysis of residential mobility. But much of that work also revealed his interest in applying scholarly insights to policy issues. Throughout his career he showed a deep commitment to improving the functioning of the social rented sector in the Dutch housing market. After reviewing some of Dieleman’s major contributions to the understanding of the housing market, the article follows in his footsteps by analyzing the current use of social rented housing. In this way, this article provides an update on his field of interest based on recent survey data that underlines the validity of his insights.