Instructional support for enhancing students’ information problem solving ability

This special issue discusses European research on instructional support to foster students’ ability to solve information-based problems. In this introduction, the concept of information problem solving (IPS) and research in this field of interest will be placed in the broader perspective, which is called information behavior. The focus of this special issue is an educational one and the papers all go into a specific kind of instructional support. The main research questions, findings and conclusions of the six contributions will be outlined. It is concluded that the most important directions for future research deal with how instructional support for different aspect of the process, like for instance how to regulated the process, best can be designed in order to make the instruction adaptive and fit to the learners needs.     

Crystal growth of copper-rich ytterbium compounds: The predicted giant unit cell structures YbCu4.4 and YbCu4.25

Two new phases YbCu_4.4 and YbCu_4.25 are found as a result of careful phase diagram investigations. Between the congruent and peritectic formation of YbCu_4.5 and YbCu_3.5, respectively, the phases YbCu_4.4 and YbCu_4.25 are formed peritectically at 934(2) °C and 931(3) °C.Crystal growth was realised using a Bridgman technique and single crystalline grains of about 50–100 μm were analysed by electron diffraction and single crystal X-ray diffraction. Due to the only slight differences in both compositions and formation temperatures the growth of larger single crystals of a defined phase is challenging. The compounds YbCu_4.4 and YbCu_4.25 fit in ?ernýs [J Solid State Chem 2003;174:125] building principle {(RECu₅)_n·(RECu₂)} where RE = Yb with n = 4 and 3. YbCu_4.4 and YbCu_4.25 are based on AuBe₅/MgCu₂-type substructures and contain approximately 4570 and 2780 atoms per unit cell. The new phases close the gap in the series of known copper-rich rare-earth compounds for n = 1, 2 (DyCu_3.5, DyCu_4.0) and n = 5 (YbCu_4.5, DyCu_4.5).     

Students’ experiences with collaborative learning in asynchronous Computer-Supported Collaborative Learning environments

This paper describes an explorative study carried out to gain response from distance students on their experiences with collaborative learning in asynchronous computer supported collaborative learning (CSCL) environments. In addition, this study also attempts to have a good grip of crucial aspects concerning collaborative learning. The study was undertaken among distance learners from the Open University of the Netherlands who were working in groups of 4–11 persons. During and after the course students’ experiences with collaborative learning were measured and after the course also students’ satisfaction with collaborative learning was assessed. The finding revealed that distance learners appreciate the opportunities to work collaboratively. They show positive experiences and are quite satisfied with collaborative learning. This study also sought to explore individuals as well as course characteristics that influenced aspects of collaborative learning, and to search aspects of collaborative learning that influenced students’ satisfaction. The findings suggested that a group product influences group process regulation and group cohesion influences students’ satisfaction with collaborative learning.     

A comparison of methods for mammogram registration

Mammogram registration is an important technique to optimize the display of cases on a digital viewing station, and to find corresponding regions in temporal pairs of mammograms for computer-aided diagnosis algorithms. Four methods for mammogram registration were tested and results were compared. The performance of all registration methods was measured by comparing the distance between annotations of abnormalities in the previous and current view before and after registration. Registration by mutual information outperformed alignment based on nipple location, alignment based on center of mass of breast tissue, and warping.     

Multifunctional thin film sensors based on amorphous diamond-like carbon for use in tribological applications

Amorphous diamond-like carbon films are well known for their excellent tribological properties. In this paper, we will discuss the sensoric properties of multifunctional a-C:H films with respect to force/load/pressure and temperature measurement. It turned out that nanostructured amorphous carbon films showed an impressive piezoresistive effect.Unlike well known strain gages and piezoresistive sensors, which detect a deformation of the base substrate, this novel sensor can be used in a complete stiff arrangement without any elastic joint. For film preparation, rf-plasma CVD processes were used. Besides gas pressure, a variation of the substrate power and bias potential was performed. It turned out that the tribological parameters varied slightly (hardness: 20-30 GPa, friction coefficient: 0.10 to 0.15), whereas the electrical parameters showed remarkable differences with respect to the electrical resistivity and piezoresistivity.This paper will also present different applications of amorphous carbon thin film sensors.     

Characterization of Conventional,Biodynamic, and Organic Purple Grape Juices by Chemical Markers,Antioxidant Capacity,and Instrumental Taste Profile

The objectives of this study were to characterize organic, biodynamic, and conventional purple grape juices (n = 31) produced in Europe based on instrumental taste profile, antioxidant activity, and some chemical markers and to propose a multivariate statistical model to analyze their quality and try to classify the samples from the 3 different crop systems. Results were subjected to ANOVA, correlation, and regression analysis, principal component analysis (PCA), hierarchical cluster analysis (HCA), soft independent modeling of class analogy (SIMCA), and partial least‐squares discriminant analysis (PLSDA). No statistical significant differences (P > 0.05) were observed among juices from the 3 crop systems. Using PCA and HCA, no clear separation among crop systems was observed, corroborating the ANOVA data. However, PCA showed that the producing region highly affects the chemical composition, electronic tongue parameters, and bioactivity of grape juices. In this sense, when organic and biodynamic were grouped as “nonconventional” juices, SIMCA model was able to discriminate 12 out of 13 organic/biodynamic juices and 17 out of 18 conventional juices, presenting an efficiency of 93.5%, while 11 out of 13 non‐conventional and 100% conventional grape juices were correctly classified using PLSDA. The use of electronic tongue and the determination of antioxidant properties and major phenolic compounds have shown to be a quick and accurate analytical approach to assess the quality of grape juices.     

Influence of the texture of gelatin gels and pectin gels on strawberry flavour release and perception

The release of strawberry flavour compounds from pectin gels and gelatin gels was evaluated by instrumental and sensory analysis. Three gel textures were established based on Young’s modulus of elasticity (E) for each gel. The E of the low, medium and high rigidity gelatine and pectin gels was 181, 300 and 493 N m⁻², respectively. Air/gel partition coefficients were determined by static headspace analysis. In-nose/proton transfer reaction-mass spectrometry analysis produced temporal release profiles. Sensory analysis was conducted to assess perceived odour, thickness, strawberry flavour and sweetness using magnitude estimation. The type of hydrocolloid affected static and in-nose compound concentrations significantly. The pectin gels showed lower air/gel partition coefficients than the gelatin gels, but increased flavour release. Increased gel rigidity resulted in lower air/gel partition coefficients; higher maximum concentrations of volatiles and lower release rates during in-nose analysis; decreased perception of odour, strawberry flavour and sweetness; and higher intensity ratings for thickness in sensory analysis. Consequently, both type of hydrocolloid and rigidity of the sample greatly affected flavour release and perception.