Introducing Adaptivity and Collaborative Support into a Web-Based LMS

In this paper the design and implementation of AHyCo (Adaptive Hypermedia Courseware), a web-based learning management system based on adaptive hypermedia, is described. AHyCo consists of a domain model, a student model, an adaptive model and a collaborative model. AHyCo supports interaction between students and content by using adaptive hypermedia and online tests. Particular attention is given to the design of the collaborative functionality which enables automatic grouping of students based on various criteria. Furthermore, student to student and student to teacher interaction is supported through asynchronous communication (forum). File sharing and inter-group grading and evaluation modules were introduced into the collaborative module as well enticing interaction between students across groups

Synthesis, structure, and reactivity of borabenzene and boratabenzene complexes

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 1998.Vita.Includes bibliographical references.Although complexes derived from anionic borabenzenes (boratabenzenes) had been used for a long time, little was known about their neutral counterparts, mostly because an easy synthetic entry to them was not available. A facile three-step synthesis that allows the preparation of large quantities of neutral borabenzenes in three days, from commercially available starting materials is described in Chapter 2. In Chapter 3 it is shown that neutral borabenzenes can be converted into anionic boratabenzenes, thereby providing a versatile new synthesis of this family of compounds. The solid state structures of these complexes are described. The developments in Chapters 2 and 3 allowed us to continue on to studies of both borabenzene and boratabenzene complexes. Chapter 4 deals with the complexation of borabenzenes and boratabenzenes to some common transition metal fragments, mostly Cr(CO)3 and [Rh(olefin) 2 ]+ , as well as structural studies thereof. We also discuss the interconversion between borabenzene- and boratabenzene-metal complexes. Chapter 5 deals with the chemistry of the parent 1-H-boratabenzene. We discuss its synthesis, structure (in the solid state and in solution), and reactivity. In this chapter it is shown that the B-H is hydridic, and that the ring can form R-complexes with transition metals. The electron-donating ability of 1-H-boratabenzene is shown to lie somewhere between that of benzene and of Cp. Chapter 6 is concerned with the chemistry of diphenylphosphidoboratabenzene. This molecule is unique among boratabenzenes in that it prefers to bind main group electrophiles and transition metals through its boron substituent. Solid state structural studies establish that it has the same steric bulk as triphenylphosphine. Comparative studies of its transition metal complexes show that it is considerably more electron-donating than triphenylphosphine.by Diego Andrés Hoic.Ph.D

A bimetallic 1,1’-bis(boratabenzene) complex: unprecedented intramolecular metal-metal communication through a B-B bond

We report the synthesis of the first 1,1’-bis (boratabenzene) species by tetrabromodiborane(4) induced ring-expansion reactions of cobaltocene. Six equivalents of cobaltocene are required as the species plays the dual role of reagent as well as reductant to yield [{(η5-C5H5)Co}2{μ:η6,η6-(BC5H5)2}]. X-ray crystallographic analysis shows that the compound consists of coplanar BC5H5 rings which are coordinated on opposite faces to two cyclopentadienyl cobalt moieties, resulting in a trans-configured bimetallic complex. The formally dianionic bis(boratabenzene) moiety with a boron-boron single bond can be viewed as a symmetric dimer of the parent boratabenzene anion as well as the first example of a diboron analogue of biphenyl. The solution electrochemistry of the bimetallic complex shows four stepwise redox events, indicating significant intramolecular interaction between the cobalt ions across the 1,1’-bis(boratabenzene) unit. The magnetic properties, as investigated by variable-temperature SQUID magnetometry, reveal weak intramolecular antiferromagnetic interactions (J = −6.0 cm−1). Density Functional Theory calculations support the experimental results and add insights into the various electronic states of the complex

Research on the use of Digital Tools by STEM Students at the University of Rijeka

The use of digital tools for learning has the potential to positively affect student motivation. While exploring the extent of use of digital tools for learning by STEM students at the University of Rijeka, it was observed that the current level of use is not at the expected level. Obtained research results have shown that surveyed STEM students are currently not encouraged nor intrinsically motivated enough to explore the possibilities of using freely available digital tools for learning. With the aim of influencing student motivation, we propose building an evaluation system in STEM education based on the principles of Educational Recommender System

A System Architecture for a Context-aware Blended Mobile Learning Environment

Mobility offers new possibilities for interaction and communication in education. Pervasive nature of mobile devices makes learning on the move and across time a reality. Their characteristics fit into the blended use of technology in education since they posses socializing powers, re-conceptualize learning by making it more informal, ambient, collaborative and personal. Nevertheless, the problem of creation and coordination of a learning environment based on mobile devices still exists. This article presents a system called MILE and its extensible context-aware architecture to support the use of mobile devices in blended learning environments. In the end, some experience and lessons learned during the development of the system are described

Synthesis, structures and coordination chemistry of singly bridged phosphane-boranes with coordinately unsaturated platinum group metals

A range of singly bridged phosphane-boranes (PBs) have been investigated as potential ligands for basic transition metals. The PBs Ph2PC(Ph)=C(R)BR2 (R = Bu 1, Ph 2, Et 3), based on a rigid cis-ethylene bridges, have been prepared, improving upon limited literature precedent. All three compounds have been comprehensively characterised for the first time, including by X-ray diffraction studies. Significant intramolecular P→B association is apparent in each case, which serves to preclude their engagement as ligands. In contrast, the more flexible PBs R2P(CH2)2BBN (R = Fu 5, Ph 6) readily coordinate to the platinum group metals Pt, Pd and Rh. These complexes have been fully characterised, including an X-ray diffraction study of [Rh(CO){Fu2P(CH2)2-BBN}2Cl] (13)