7 research outputs found
The pen-based technology towards the lecture improvement
Abstract Nowadays perhaps the most widespread way of giving lectures at the universities is the slides presentation using computer and data projector. The common problems concerning this type of lecture presentation include one-way static transfer of information from teacher towards students, uncomfortable ways of active entries into the presentation, low students' engagement with no feedback, and static or no access to presentation materials. This contribution presents four years of experience in the effort to improve lectures using different presentation applications and several penbased technologies. Currently, the Tablet PC accompanied with Enhanced Classroom Presenter tends to be one of the most suitable solutions
Visualization of Verilog Digital Systems Models
Abstract-Nowadays the digital systems design is almost exclusively realized using hardware description languages (HDL). Verilog belongs to the HDLs that are the most widespread especially in the United States. However, the textual HDL representation of structural model is less understandable compared the schematic one. Therefore a transformation of the structural HDL description into its graphical schematic representation is a useful function for hardware designers. In this paper the HDL Visualizator is described that was designed and implemented to support this function for Verilog structural models. The paper addresses several problems of visualization process and their possible solutions. The design and implementation of visualization tool that is able to display the schematic view as well as the simulation results of structural Verilog model is also presented. I. INTRODUCTION In the process of complex digital systems design hardware description languages (HDLs) have an irrecoverable role. They provide designers the possibility to describe the hardware behavior and structure on the various abstraction levels. However, the structural description in HDL form is often unreadable for the persons not familiar with this kind of design. In these situations the tools for graphical visualization of HDL structural description are very useful. There are several applications, design tools or development environments that are capable of graphical visualization of a design structure. This possibility is usually only one of many other functions available in the expensive and often too complex solutions for certain group of users, e.g. students or beginners in HDL design. There are very few, if any at all, easy-to-use and affordable applications offering HDL models visualization especially when they are written in Verilog. Our aim was to overcome this gap. The problem of digital system Verilog structural description visualization is the main subject of this paper. The paper covers application design, its implementation and testing results
Diastereomeric dinickel(ii) complexes with non-innocent bis(octaazamacrocyclic) ligands: isomerization, spectroelectrochemistry, DFT calculations and use in catalytic oxidation of cyclohexane
Diastereomeric dinickel(ii) complexes with bis-octaazamacrocyclic 15-membered ligands [Ni(L1-3-L1-3)Ni] (4-6) have been prepared by oxidative dehydrogenation of nickel(ii) complexes NiL1-3 (1-3) derived from 1,2- and 1,3-diketones and S-methylisothiocarbohydrazide. The compounds were characterized by elemental analysis, ESI mass spectrometry, and IR, UV-vis, 1H NMR, and 13C NMR spectroscopy. Single crystal X-ray diffraction (SC-XRD) confirmed the isolation of the anti and syn isomers of bis-octaazamacrocyclic dinickel(ii) complexes 4a and 4s, the syn-configuration of 5s and the anti-configuration of the dinickel(ii) complex 6a. Dimerization of prochiral nickel(ii) complexes 1-3 generates two chiral centers at the bridging carbon atoms. The anti-complexes were isolated as meso-isomers (4a and 6a) and the syn-compounds as racemic mixtures of R,R/S,S-enantiomers (4s and 5s). The syn-anti isomerization (epimerization) of the isolated complexes in chloroform was disclosed. The isomerization kinetics of 5a was monitored at five different temperatures ranging from 20 °C to 50 °C by 1H NMR spectroscopy indicating the clean conversion of 5a into 5s. The activation barrier determined from the temperature dependence of the rate constants via the Eyring equation was found to be ΔH‡ = 114 ± 1 kJ mol−1 with activation entropy ΔS‡ = 13 ± 3 J K−1 mol−1. The complexes contain two low-spin nickel(ii) ions in a square-planar coordination environment. The electrochemical behavior of 4a, 4s, 5s and 6a and the electronic structure of the oxidized species were studied by UV-vis-NIR-spectroelectrochemistry (SEC) and DFT calculations indicating the redox non-innocent behavior of the complexes. The dinickel(ii) complexes 4a, 4s, 5s and 6a/6s were investigated as catalysts for microwave-assisted solvent-free oxidation of cyclohexane by tert-butyl hydroperoxide to produce a mixture of cyclohexanone and cyclohexanol (KA oil). The best value for KA oil yield (16%) was obtained with a mixture of 6a/6s after 2 h of microwave irradiation at 100 °C. © 2022 The Royal Society of Chemistry