Abstract
A sensing configuration for the real-time monitoring, detection, and quantification of dissolved carbon dioxide (dCO(2)) was developed for aquaculture and other applications in freshwater and saline water. A chemical sensing membrane, based on a colorimetric indicator, is combined with multimode optical fiber and a dual wavelength light-emitting diode (LED) to measure the dCO(2)-induced absorbance changes in a self-referenced ratiometric scheme. The detection and processing were achieved with an embeded solution having a mini spectrometer and microcontroller. For optrode calibration, chemical standard solutions using sodium carbonate in acid media were used. Preliminary results in a laboratory environment showed sensitivity for small added amounts of CO2 (0.25 mg.L-1). Accuracy and response time were not affected by the type of solution, while precision was affected by salinity. Calibration in freshwater showed a limit of detection (LOD) and a limit of quantification (LOQ) of 1.23 and 1.87 mg.L-1, respectively. Results in saline water (2.5%) showed a LOD and LOQ of 1.05 and 1.16 mg.L-1, respectively. Generally, performance was improved when moving from fresh to saline water. Studies on the dynamics of dissolved CO2 in a recirculating shallow raceway system (SRS+RAS) prototype showed higher precision than the tested commercial sensor. The new sensor is a compact and robust device, and unlike other sensors used in aquaculture, stirring is not required for correct and fast detection. Tests performed showed that this new sensor has a fast accurate detection as well as a strong potential for assessing dCO(2) dynamics in aquaculture applications.

Abstract
Testing large-scale distributed system software is still far from practical as the sheer scale needed and the inherent non-determinism make it very expensive to deploy and use realistically large environments, even with cloud computing and state-of-the-art automation. Moreover, observing global states without disturbing the system under test is itself difficult. This is particularly troubling as the gap between distributed algorithms and their implementations can easily introduce subtle bugs that are disclosed only with suitably large scale tests. We address this challenge with Minha, a framework that virtualizes multiple JVM instances in a single JVM, thus simulating a distributed environment where each host runs on a separate machine, accessing dedicated network and CPU resources. The key contributions are the ability to run off-the-shelf concurrent and distributed JVM bytecode programs while at the same time scaling up to thousands of virtual nodes; and enabling global observation within standard software testing frameworks. Our experiments with two distributed systems show the usefulness of Minha in disclosing errors, evaluating global properties, and in scaling tests orders of magnitude with the same hardware resources.

Abstract
This article describes the development cycle of an educational robot designed to act as an interdisciplinary teaching tool integrated into the curriculum of STEM areas (Science, Technology, Engineering and Mathematics). We focused on the creation of the alpha version of the prototype and its heuristic evaluation by three experts, with the objective of appraising both usability and potential design problems. After all the issues and suggestions from the experts have been resolved and implemented, a beta version was developed and evaluated in its usability by five representatives of end-users with different age ranges and robotics knowledge. The System Usability Scale score of 92.5 points - Best Imaginable - show a very stable and satisfactory robot, with almost no usability problems detected.

Abstract

Abstract
The European Union aims to achieve a nearly zero energy balance in buildings by 2020. The present study takes into consideration the passive systems of the building, energy demand, and energy generated by the on-site photovoltaic and storage system, and how they interact in different scenarios. The study also considers the energy demand from the grid and the surplus of renewable energy. The software EnergyPlus was used and the parametric sensitivity simulation method was applied, taking into account blinds operation, ventilation strategies, HVAC operation schemes and battery storage capacity, in 96 scenarios. The results highlight that there is great variability between the considered scenarios, highlighting the importance of sizing methodologies for the passive systems and the use of optimized home management algorithms. It was found that the use of batteries with higher storage capacity increases the demand-supply from the on-site PV energy but decreases the amount of energy injected into the grid. The design of the PV and battery system based on yearly integrated simulations allows for an optimized solution. This study also emphasizes the importance of knowing the expected occupancy during the design phase, as a significant input to the sizing methodologies of the storage capacity and on-site generation.

Abstract
The valuation of whether network operators meet users' expectations in ensuring a continuous supply to their premises is important in determining their willingness-to-pay (WTP) for electricity. Distributed resources such as photovoltaic (PV) systems will dominate future networks, and thus customers' WTP will vary dynamically, both spatially and temporally. Whereas system-wide indices are typically used to assess network performance, there is a requirement to complement these with customer-based indices to accurately quantify the risk of outages to affected and worst-served customers. This paper presents an enhanced Monte Carlo simulation technique, which performs reliability assessment of a typical MV/LV urban distribution network. Two smart grid scenarios considering controllability of PV and energy storage (ES) are designed to improve network performance. Customerbased reliability indices, measuring the frequency and duration of interruptions, and energy not supplied are thoroughly assessed. Results demonstrate the potential of hybrid PV-ES in reducing power supply risk for worst-served customers.