A contribution towards the performance and structural understanding of copper and nickel salts as ammonia stores

The ongoing depletion of fossil fuels and the severe consequences of the greenhouse effect make the development of alternative energy systems crucially important. While hydrogen is, in principle, a promising alternative, releasing nothing but energy and pure water. Hydrogen storage is complicated and no completely viable technique has been proposed so far. This work is concerned with the study of one potential alternative to pure hydrogen: ammonia, and more specifically its storage in solids. Ammonia, NH3, can be regarded as a chemical hydrogen carrier with the advantages of strongly reduced flammability and explosiveness as compared to hydrogen. Furthermore, ammine metal salts presented here as promising ammonia stores easily store up to 50 wt.-% ammonia, giving them a volumetric energy density comparable to natural gas. The model system NiX2–NH3 ( X = Cl, Br, I) is studied thoroughly with respect to ammine salt formation, thermal decomposition, air stability and structural effects. The system CuX2–NH3 ( X = Cl, Br) has an adverse thermal decomposition behaviour, making it impractical for use as an ammonia store. This system is, however, most interesting from a structural point of view and some work concerning the study of the structural behaviour of this system is presented. Finally, close chemical relatives to the metal ammine halides, the metal ammine nitrates are studied. They exhibit interesting anion arrangements, which is an impressive showcase for the combination of diffraction and spectroscopic information. The characterisation techniques in this thesis range from powder diffraction over single crystal diffraction, spectroscopy, computational modelling, thermal analyses to gravimetric uptake experiments. Further highlights are the structure solutions and refinements from powder data of (NH4)2[NiCl4(H2O)(NH3)] and Ni(NH3)2(NO3)2, the combination of crystallographic and chemical information for the elucidation of the (NH4)2[NiCl4(H2O)(NH3)] formation reaction and the growth of single crystals under ammonia flow, a technique allowing the first documented successful growth and single crystal diffraction measurement for [Cu(NH3)6]Cl2.

An ecosystem of products and systems for ambient intelligence – the AAL4ALL users perspective

Texto completo em atas de encontros científicos internacionais com arbitragem

A case study of the English language teachers’ attitudes toward use of information and communication technology (ICT) in Finland

This qualitative study was aimed at investigating foreign language teachers’ attitudes toward use of information and communication technology (ICT) in their instruction. The insight was gained through the reported experience of ICT implementation by teachers, in what way and for which purpose they refer to use of technology, what kind of support and training they are provided with, and what beliefs they express about the influence of ICT implementation. This case study took place in one of the training schools in Finland. Five teachers participated in semi-structured interviews through a face-to-face approach. The findings demonstrated positive attitudes of teachers toward integration of ICT. The teachers shared their opinions about positive influence that ICT implementation has on both teaching and learning processes. However, they also pointed out the negative sides of ICT use: distraction of the students from usage of technology and technical problems causing frustration to the teachers. In addition, the responses revealed that the teachers are provided with adequate training aimed at enhancing their qualification which is provided with well-timed technology support and colleagues’ collaboration facilitating an efficient and smooth pace of the teaching process. According to the teachers’ opinions ICT integration in education appeared to have changed the role of the teacher. Due to different alterations in the field of ICT development teachers are required to upgrade their skills. The paper concludes with the limitations of the study and the recommendations for conducting further research.

Seasonal changes of heat and moisture fluxes from the Caspian Sea surface and its effect on synoptic systems with heavy rainfalls in southern shores of the sea during 2005-2010

Caspian Sea with its unique characteristics is a significant source to supply required heat and moisture for passing weather systems over the north of Iran. Investigation of heat and moisture fluxes in the region and their effects on these systems that could lead to floods and major financial and human losses is essential in weather forecasting. Nowadays by improvement of numerical weather and climate prediction models and the increasing need to more accurate forecasting of heavy rainfall, the evaluation and verification of these models has been become much more important. In this study we have used the WRF model as a research-practical one with many valuable characteristics and flexibilities. In this research, the effects of heat and moisture fluxes of Caspian Sea on the synoptic and dynamical structure of 20 selective systems associated with heavy rainfall in the southern shores of Caspian Sea are investigated. These systems are selected based on the rainfall data gathered by three local stations named: Rasht, Babolsar and Gorgan in different seasons during a five-year period (2005-2010) with maximum amount of rainfall through the 24 hours of a day. In addition to synoptic analyses of these systems, the WRF model with and without surface flues was run using the two nested grids with the horizontal resolutions of 12 and 36 km. The results show that there are good consistencies between the predicted distribution of rainfall field, time of beginning and end of rainfall by the model and the observations. But the model underestimates the amounts of rainfall and the maximum difference with the observation is about 69%. Also, no significant changes in the results are seen when the domain and the resolution of computations are changed. The other noticeable point is that the systems are severely weakened by removing heat and moisture fluxes and thereby the amounts of large scale rainfall are decreased up to 77% and the convective rainfalls tend to zero.

A case study of the English language teachers’ attitudes toward use of information and communication technology (ICT) in Finland

This qualitative study was aimed at investigating foreign language teachers’ attitudes toward use of information and communication technology (ICT) in their instruction. The insight was gained through the reported experience of ICT implementation by teachers, in what way and for which purpose they refer to use of technology, what kind of support and training they are provided with, and what beliefs they express about the influence of ICT implementation. This case study took place in one of the training schools in Finland. Five teachers participated in semi-structured interviews through a face-to-face approach. The findings demonstrated positive attitudes of teachers toward integration of ICT. The teachers shared their opinions about positive influence that ICT implementation has on both teaching and learning processes. However, they also pointed out the negative sides of ICT use: distraction of the students from usage of technology and technical problems causing frustration to the teachers. In addition, the responses revealed that the teachers are provided with adequate training aimed at enhancing their qualification which is provided with well-timed technology support and colleagues’ collaboration facilitating an efficient and smooth pace of the teaching process. According to the teachers’ opinions ICT integration in education appeared to have changed the role of the teacher. Due to different alterations in the field of ICT development teachers are required to upgrade their skills. The paper concludes with the limitations of the study and the recommendations for conducting further research.

Infomobility for “Car-Driver” Systems: Reference Model and Case Study

Part 21: Mobility and Logistics

Collaborative Systems of Systems Need Collaborative Design

Part 1: Introduction

Use of alternative wood chips from new botanical species. Their impact on phenolic composition and sensory properties of a white wine from Encruzado grape variety

Mestrado Vinifera Euromaster - Instituto Superior de Agronomia - UL

Origin of and resulting floristic composition from seedbanks in agroforestry systems of Tomé-Açu, Eastern Amazon.

2016

The influence of promoters (Zr, La, Tb, Pr) on the catalytic performance of CuO-CeO2 systems for the preferential oxidation of CO in the presence of CO2 and H2O

CuO supported on CeO2 and Ce0.9X0.1O2, where X is Zr, La, Tb or Pr, were synthesized using nitrate precursors, giving rise ceria based materials with a small particle size which interact with CuO species generating a high amount of interfacial sites. The incorporation of cations to the ceria framework modifies the CeO2 lattice parameter, improving the redox behavior of the catalytic system. The catalysts were characterized by X-ray fluorescence spectrometry (XRFS), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, thermoprogrammed reduction with H2 (H2-TPR) and X-ray photoelectron spectroscopy (XPS). The catalysts were tested in the preferential oxidation of CO under a H2-rich stream (CO-PROX), reaching conversion values higher than 95% between 115 and 140 °C and being the catalyst with 6 wt.% of Cu supported on Ce0.9Zr0.1O2 (sample 6CUZRCE) the most active catalyst. The influence of the presence of CO2 and H2O was also studied simulating a PROX unit, taking place a decrease of the catalytic activity due to the inhibitor effect both CO2 and H2O.

Therapeutic efficacy of alternative primaquine regimens to standard treatment in preventing relapses by Plasmodium vivax : A systematic review and meta-analysis

Objective: To compare efficacy and safety of primaquine regimens currently used to prevent relapses by Plasmodium vivax. Methods: A systematic review was carried out to identify clinical trials evaluating efficacy and safety to prevent malaria recurrences by P. vivax of primaquine regimen 0.5 mg/kg/day for 7 or 14 days compared to standard regimen of 0.25 mg/kg/day for 14 days. Efficacy of primaquine according to cumulative incidence of recurrences after 28 days was determined. The overall relative risk with fixed-effects meta-analysis was estimated. Results: For the regimen 0.5 mg/kg/day/7 days were identified 7 studies, which showed an incidence of recurrence between 0% and 20% with follow-up 60-210 days; only 4 studies comparing with the standard regimen 0.25 mg/kg/day/14 days and no difference in recurrences between both regimens (RR= 0.977, 95% CI= 0.670 to 1.423) were found. 3 clinical trials using regimen 0.5 mg/kg/day/14 days with an incidence of recurrences between 1.8% and 18.0% during 330-365 days were identified; only one study comparing with the standard regimen (RR= 0.846, 95% CI= 0.484 to 1.477). High risk of bias and differences in handling of included studies were found. Conclusion: Available evidence is insufficient to determine whether currently PQ regimens used as alternative rather than standard treatment have better efficacy and safety in preventing relapse of P. vivax. Clinical trials are required to guide changes in treatment regimen of malaria vivax.

Therapeutic efficacy of alternative primaquine regimens to standard treatment in preventing relapses by Plasmodium vivax: A systematic review and meta-analysis

Objective: To compare efficacy and safety of primaquine regimens currently used to prevent relapses by Plasmodium vivax. Methods: A systematic review was carried out to identify clinical trials evaluating efficacy and safety to prevent malaria recurrences by P. vivax of primaquine regimen 0.5 mg/kg/day for 7 or 14 days compared to standard regimen of 0.25 mg/kg/day for 14 days. Efficacy of primaquine according to cumulative incidence of recurrences after 28 days was determined. The overall relative risk with fixed-effects meta-analysis was estimated. Results: For the regimen 0.5 mg/kg/day/7 days were identified 7 studies, which showed an incidence of recurrence between 0% and 20% with follow-up 60-210 days; only 4 studies comparing with the standard regimen 0.25 mg/kg/day/14 days and no difference in recurrences between both regimens (RR= 0.977, 95% CI= 0.670 to 1.423) were found. 3 clinical trials using regimen 0.5 mg/kg/day/14 days with an incidence of recurrences between 1.8% and 18.0% during 330-365 days were identified; only one study comparing with the standard regimen (RR= 0.846, 95% CI= 0.484 to 1.477). High risk of bias and differences in handling of included studies were found. Conclusion: Available evidence is insufficient to determine whether currently PQ regimens used as alternative rather than standard treatment have better efficacy and safety in preventing relapse of P. vivax. Clinical trials are required to guide changes in treatment regimen of malaria vivax.

Modern Computational Chemistry Methods for Prediction of Ground- and Excited-State Properties in Open-Shell Systems

The main goal of the research presented in this work is to provide some important insights about computational modeling of open-shell species. Such projects are: the investigation of the size-extensivity error in Equation-of-Motion Coupled Cluster methods, the analysis of the Long-Range corrected scheme in predicting UV-Vis spectra of Cu(II) complexes with the 4-imidazole acetate and its ethylated derivative, and the exploration of the importance of choosing a proper basis set for the description of systems such as the lithium monoxide anion. The most significant findings of this research are: (i) The contribution of the left operator to the size-extensivity error of the CR-EOMCC(2,3) approach, (ii) The cause of d-d shifts when varying the range-separation parameter and the amount of the exact exchange arising from the imbalanced treatment of localized vs. delocalized orbitals via the "tuned" CAM-B3LYP* functional, (iii) The proper acidity trend of the first-row hydrides and their lithiated analogs that may be reversed if the basis sets are not correctly selected.