Search results for "Volt"

Prussian blue films deposited on graphite+epoxy composite electrodes: electrochemical detection of the second percolation threshold

2000

Abstract The electrochemical behavior of Prussian blue films galvanostatically electrodeposited on graphite+epoxy-resin composite electrodes was studied. The composite electrodes were prepared with different graphite proportions and their effect on electrochemical reduction of the Prussian blue was analyzed by means of the uncompensated resistance approximation and the electrical percolation theory. The results suggest that the electrode with 60% graphite reaches the second percolation threshold and its internal structure changes from a compact to a porous one. Mechanical tensile tests were performed in order to confirm the critical behavior of this material at the percolation thresholds. T…

Improving the onset potential and Tafel slope determination of earth-abundant water oxidation electrocatalysts

2021

To date, a plethora of electrocatalysts for the Oxygen Evolution Reaction (OER) have been proposed. For evaluating their electrocatalytic behavior the determination of the onset potential in each studied electrolyte is a key parameter. Nevertheless, this evaluation becomes particularly problematic for first- transition metal catalysts as well as by the use of electroactive collectors ( e.g. Ni foams) whose redox peaks overlap the onset potential. A usual solution to detect the onset potential requires the availabil- ity of in-situ mass spectrometric determination of the generated oxygen. In this work, we present fast and easier available cyclic voltammetry and coulovoltammetric responses to…

Platinum and rhodium in wine samples by using voltammetric techniques

2017

For the first time, the concentrations of Pt and Rh in 42 different alcoholic beverages (white and red wines, vodka and brandy) produced in Italy, Malta and Gozo were investigated. Only the voltammetric techniques, in particular, differential Pulse Voltammetry (DPV/a) and Adsorptive Stripping Voltammetry (AdSV) were used for the determination of Pt and Rh respectively. Accuracy was tested with standard addition method and recoveries ranged from 90% to 98%. In analyzed wine samples, Pt and Rh concentrations are in the ranges from 3 to 470 μg L− 1and from 0.0006 to 0.36 μg L− 1respectively. We found a Pt/Rh ratios ranged from 37 to 180,000, in quite disagreement with the ratio in …

Applying Dynamic Performance Management to the Photovoltaic Sector: the Municipality of Palermo case study

Today, the even more compelling need to limit carbon dioxide emissions from energy generation – to address the ongoing global warming – implies the recourse to renewable energy sources (RESs). Indeed, these latter are able to meet energy demand into a more sustainable way. Considering the EU targets for the year 2020 in the matter of climate and energy, public organizations are expected to take an active role e.g. by adopting and promoting RESs. In Italy, over the last decade, among the various technologies based on RESs, solar PV technology witnessed a remarkable growth thanks to the support of a government incentive scheme, which ceased to be applied in 2013. Since then, the PV power inst…

Critical assessment of support for the evolution of photovoltaics and feed-in tariff(s) in Italy

2015

Abstract The feed-in tariff(s) mechanism involves an obligation on the part of an electricity provider to purchase electricity generated by renewable energy sources in its relevant area, paying a tariff determined by public authorities and guaranteed for a specific time period. Feed-in tariff(s) have been the primary mechanism used for supporting the development of renewable energy sources in the EU and, up to date, they are being applied in 20 EU Member Countries. On 6 July 2013, the Italian experience with feed-in tariff(s) for photovoltaic systems finished. During its lifetime of eight years, this incentive mechanism, named “Conto Energia”, was characterized by periods of great success f…

A powerful thyristor modulator for a microtron

1980

Abstract The circuit of a powerful modulator is illustrated and a detailed description is given of the modulator construction and in particular of the components employed. The main parameters are: length of shaped pulse 2 μs; amplitude of the output voltage 30 kV; pulse repetition frequency 50–200 Hz. The compactness of this device, its comparatively low cost and its good performance, as illustrated in the attached photographs, make it suitable for use in accelerator engineering (microtron).

An optimal operating strategy for combined RES–based Generators and Electric Storage Systems for load shifting applications

2013

This paper focuses on an optimal operating strategy of combined RES-based generators and electric storage systems for small/medium-scale public facilities. The operating strategy can be used in load shifting applications in response to a time-of-use (TOU) rate design with differential pricing for on- and off-peak usage. Load shifting applications can be exploited by customers using battery energy storage systems (BESS) in order to reduce their electricity bill, charging the storage when off-peak time periods are applied and discharging it during on-peak periods, when electricity energy prices are high. The operating strategy is implemented within a bidirectional converter that provides an i…

Study and simulation of photovoltaic installation connected to the grid with storage system

2016

In the present paper, a new approach to the management of energy resources in a research laboratory is proposed and evaluated by a simulation for the PV installation realized for the Tunisian-Italian cooperation project DE.DU.ENER.T, using renewable energy and economic criteria. The aim of this project is to improve energy efficiency order to minimize the electricity cost consumed at the laboratory, because according to the bills of electricity received we noticed that there is a high consumption of electrical current, from the STEG grid, and especially by the energy intensive equipment such as drying ovens and all the workstations. So we targeted to install a photovoltaic field of 12KWc to…

Performance of zero energy homes in smart village skarpnes

2016

In Smart Village Skarpnes in southern Norway, five detached houses are designed as zero energy homes. This work reports on the photovoltaic (PV) power production and energy consumption behavior of these homes and discusses whether an annual zero energy budget may be achieved. Results so far indicate that the extremely low annual energy consumption assumed for these types of homes may be difficult to achieve, and also point at a need for better matching between production and consumption power profiles. Performance results are based on monitoring data combined with estimated performances from PVsyst simulations. The work is part of a larger research project that investigates how the introduc…

Some new fixed point theorems in Menger PM-spaces with application to Volterra type integral equation

2014

Abstract We establish some fixed point theorems by introducing two new classes of contractive mappings in Menger PM-spaces. First, we prove our results for an α - ψ -type contractive mapping and then for a generalized β -type contractive mapping. Some examples and an application to Volterra type integral equation are given to support the obtained results.