Laser metal deposition on-line monitoring via plasma emission spectroscopy and spectral correlation techniques

Plasma spectroscopic techniques focused on the analysis of the plasma background radiation have been studied to enable an efficient on-line monitoring of a laser metal deposition process. The influence of different process parameters and elements, such as laser power, process speed, powder feeding rate and different powder and substrate compositions has been analyzed by means of several experimental trials. The resulting cladding patch analyzes via visual inspection and macrographs have been correlated with their associated spectroscopic monitoring signals. These studies have indicated that on-line quality monitoring of the laser metal deposition process is feasible by means of the proposed solutions, avoiding the identification and use of plasma emission lines. The latter improves the computational performance and avoids, not only the identification of each emission line, but also their specific sensitivity to certain defects. Spectral correlation techniques have also been proposed for monitoring purposes, thus enabling a more quantitative analysisThis work was supported in part by the Project “Noves tecnologies de laser cladding per a processos de conformat” (RD15-1-0098) funded by ACCIO (Generalitat de Catalunya) via FEDER funds. This work was also supported by projects PID2019-107270RB-C21/ AEI / 10.13039/501100011033

Sequential uncaging with green light can be achieved by fine-tuning the structure of a dicyanocoumarin chromophore

We report the synthesis and photochemical properties of a series of dicyanocoumarinylmethyl (DEAdcCM)- and dicyanocoumarinylethyl (DEAdcCE)-based photocages of carboxylic acids and amines with absorption maximum around 500 nm. Photolysis studies with green light have demonstrated that the structure of the coumarin chromophore as well as the nature of the leaving group and the type of bond to be photocleaved (ester or carbamate) have a strong influence on the rate and efficiency of the uncaging process. These experimental observations were also supported by DFT calculations. Such differences in deprotection kinetics have been exploited to sequentially photolyze two dicyanocoumarin-caged model compounds (e.g. benzoic acid and ethylamine), and open the way to increasing the number of functional levels that can be addressed with light in a single system, particularly when combining dicyanocoumarin caging groups with other photocleavable protecting groups that remain intact under green light irradiation

3Cat-1 project: a multi-payload CubeSat for scientific experiments and technology demonstrators

This article introduces 3Cat-1, the first project of the Technical University of Catalonia to build and launch a nano-satellite. Its main scope is to develop, construct, assemble, test and launch into a low Earth orbit a CubeSat with seven different payloads (mono-atomic oxygen detector, graphene field-effect transistor, self-powered beacon, Geiger radiation counter, wireless power transfer (WPT), new topology solar cells and WPT experiment), all fitted in a single-unit CubeSat. On one hand, this is mainly an educational project in which the development of some of the subsystems is carried out by undergraduate and postgraduate students. The satellite demonstrates its capabilities as a cost-effective platform to perform small scientific experiments and to demonstrate some of the new technologies that it incorporates

3Cat-1 project: a multi-payload CubeSat for scientific experiments and technology demonstrators

This article introduces 3 Cat-1, the first project of the Technical University of Catalonia to build and launch a nano-satellite. Its main scope is to develop, construct, assemble, test and launch into a low Earth orbit a CubeSat with seven different payloads (mono-atomic oxygen detector, graphene field-effect transistor, self-powered beacon, Geiger radiation counter, wireless power transfer (WPT), new topology solar cells and WPT experiment), all fitted in a single-unit CubeSat. On one hand, this is mainly an educational project in which the development of some of the subsystems is carried out by undergraduate and postgraduate students. The satellite demonstrates its capabilities as a cost-effective platform to perform small scientific experiments and to demonstrate some of the new technologies that it incorporates

3Cat-1 project: a multi-payload CubeSat for scientific experiments and technology demonstrators

This article introduces 3 Cat-1, the first project of the Technical University of Catalonia to build and launch a nano-satellite. Its main scope is to develop, construct, assemble, test and launch into a low Earth orbit a CubeSat with seven different payloads (mono-atomic oxygen detector, graphene field-effect transistor, self-powered beacon, Geiger radiation counter, wireless power transfer (WPT), new topology solar cells and WPT experiment), all fitted in a single-unit CubeSat. On one hand, this is mainly an educational project in which the development of some of the subsystems is carried out by undergraduate and postgraduate students. The satellite demonstrates its capabilities as a cost-effective platform to perform small scientific experiments and to demonstrate some of the new technologies that it incorporates