Search results for "Synchro"
showing 10 items of 886 documents
Translocation time of periodically forced polymer chains.
2010
6 páginas, 11 figuras.-- PACS number(s): 36.20.-r, 05.40.-a, 87.15.A-, 87.10.-e
“Nice to get to know you”
2020
Virtual exchange comprises online collaborative activities in facilitated, educational contexts across borders. This paper offers a multimodal approach to the study of social presence in students’ asynchronous online discourse in the context of virtual exchange. It draws on the Community of Inquiry model of online learning (Garrison 2017) and interprets social presence as the dynamic discursive process of social interaction and self-presentation. The data consists of screenshots collected in a closed Facebook group during the first assignment of a Czech-Finnish virtual exchange project in 2017. The study aims to explore how the method of multimodal discourse analysis can be used to describe…
Role Scripting as a Tool to Foster Transactivity of Asynchronous Student Discussions
2021
Transactivity of student discussions is crucial in computer-supported collaborative learning (CSCL). However, CSCL learners often lack well-developed argumentation and negotiation skills, which makes it challenging for them to engage in and maintain a transactive discussion. Collaboration scripts have been implemented in CSCL contexts and have demonstrated positive effects on students' collaboration and argumentation skills. Yet, the degree of transactivity of student interactions is rarely addressed directly in CSCL research. Employing a qualitative content analysis approach, this study seeks to understand how a role script affects the transactivity of students' argumentative knowledge co-…
Time and the Design of Web-Based Learning Environments
2005
Introduction Design can be seen as a form of creation, which involves complexity and synthesis (Goel & Pirolli, 1992; Schon, 1987). In a broad sense, anyone who designs is a designer. This means that unlike analysts or critics, designers put elements together and bring new creations into being. In so doing they deal with many variables and constraints, some initially known and some discovered through the design process (Etelapelto, 1998). According to Burgoon, Buller, and Woodall (1996), it is typically human to affect and change one's environment. However humans are affected by their physical surroundings as well. Schon (1987) perceives all human constructive and creative activity as desig…
Pressure-Driven Isostructural Phase Transition in InNbO4: In Situ Experimental and Theoretical Investigations
2017
[EN] The high-pressure behavior of technologically important visible-light photocatalytic semiconductor In.NbO4, adopting a monoclinic wolframite-type structure at ambient conditions, was investigated using synchrotron-based X-ray diffraction, Raman spectroscopic measurements, and first-principles calculations. The experimental results indicate the occurrence of a pressure-induced isostructural phase transition in the studied compound beyond 10.8 GPa. The large volume collapse associated with the phase transition and the coexistence of two phases observed over a wide range of pressure shows the nature of transition to be first-order. There is an increase in the oxygen anion coordination num…
Recent Achievement and Perspectives in Synchrotron Radiation X-Ray Absorption Spectroscopy
2003
During the last 20 years, x-ray absorption spectroscopy (XAS) has found extensive application in the materials science [1, 2, 3]. solution chemistry [4], biology [5]. therapeutic chemistry [6] and geochemistry. However. it is relatively recently XAS methods have been utilized for measurements on archaeological materials [7,8].
A new tool for nanoscale X-ray absorption spectroscopy and element-specific SNOM microscopy.
2007
Abstract Investigations of complex nanostructured materials used in modern technologies require special experimental techniques able to provide information on the structure and electronic properties of materials with a spatial resolution down to the nanometer scale. We tried to address these needs through the combination of X-ray absorption spectroscopy (XAS) using synchrotron radiation microbeams with scanning near-field optical microscopy (SNOM) detection of the X-ray excited optical luminescence (XEOL) signal. The first results obtained with the prototype instrumentation installed at the European Synchrotron Radiation Facility (Grenoble, France) are presented. They illustrate the possibi…
X-ray absorption spectroscopy of Cu-doped $WO_{3}$ films for use inelectrochemical metallization cell memory
2014
Abstract We have performed the first synchrotron radiation X-ray absorption spectroscopy (EXAFS/XANES) study of the local atomic and electronic structure around Cu and W ions in WO 3 /Cu/WO 3 /Si and WO 3 /Cu/Si multilayered structures, aimed for the application in the electrochemical metallization cell memory. The influence of low-temperature annealing at 135 °C has been investigated in details, and a structural model of Cu-doped WO 3 films is proposed.
Chemical microimaging and microspectroscopy of surfaces with a photoemission microscope
1997
We applied element sensitive photoemission electron microscopy (PEEM) to investigate surfaces of devices built from complex materials. Conventional PEEM suffers from lack of information about the chemical composition of the imaged surface. Such information can be obtained by PEEM via tuning the photon energy to X-ray absorption edges. To apply spectromicroscopy we acquired and subtracted microscopic images using photon energies just below and at the edges. The resulting difference gives a micro-image of the lateral distribution of a specific element. Microspectroscopy is performed by recording the intensity of secondary electrons in selected spots during a sweep of the photon energy. We app…
Middle Triassic conodont apparatus architecture revealed by synchrotron X-ray microtomography
2018
Abstract The composition of conodont apparatuses is crucial for understanding the feeding mechanisms of these early vertebrates. However, the multielement apparatus reconstructions of most species remain equivocal because they have been inferred from loose element collections, guided by knowledge from rare articulated ‘bedding plane assemblages’ and fused clusters, often from distantly related taxa. Even these natural assemblages can be difficult to interpret because the component elements can be closely juxtaposed or embedded in matrix, making it hard to discern the morphology of each element and their relative positions within the architecture of the feeding apparatus. Here we report five…