Use of Pt/CexZr1-xAl2O3 as Advanced Catalyst for Hydrogen Peroxide Thrusters

The capability of different Pt/Ce0.6Zr0.4/Al2O3 catalytic systems of effectively decomposing H2O2 has been studied in view of their application to monopropellant thrusters. BET surface area measurements, X-Ray Diffractometry (XRD) and Scanning Electron Microscopy (SEM) have been used together with catalytic tests in order to evaluate the advantages of using CeO2-ZrO2 mixed oxide solid solution as an alternative to current three ways catalysts (TWCs). From the assessment of alternative solutions, a Pt/Ce0.6Zr0.4/Al2O3 catalyst suitable to effectively decompose H2O2 has been identified. SEM-EDX analyses ruled out the occurrence of phase segregation and selective deposition of Pt on Zr during the catalyst preparation. No changes in the crystalline arrangement of the catalyst samples after H2O2 decomposition have been detected by XRD measurements, except for a slight crystallization or grain size growth as a consequence of the high temperatures experienced during the reaction...

Public Preferences for Investments in Renewable Energy Production and Energy Efficiency

In this paper we investigate the choices citizens make when asked to express willingness to support a proposed energy policy and are then compelled to allocate the program funds to either renewable energy or energy efficiency. In a survey study based on a random sample of residents of the state of Maine, USA, we find that citizens have preferences for specific types of renewable energy but these preferences do not yield significantly different allocation of investment funds between renewable energy and energy efficiency. We find that preferences are generally consistent regardless of presentation of options (i.e. limited ordering effects). Our results also indicate that personal characteristics that are understudied in the energy literature, including promotion/prevention focus and social/fiscal leanings, influence both willingness to support energy policies and also their allocation of fund choices, but in different ways. This suggests the importance of including multiple options in energy policy proposals, and that targeted messages regarding the components of such policies is key for optimal communication

An adaptive multi-step balancing modulation technique for multi-point clamped converters

In this paper, a new pulse-width modulation technique is proposed for the output voltage control and the DC-bus capacitors voltage balancing of a Multi-Point Clamped multilevel converter. The voltage equalization is achieved by allowing each converter’s leg voltage to switch though multiple levels in a single modulation period (multi-step operation). The approach is generalized with respect to the number of levels and phases and can be applied regardless of the converter operating conditions. Nevertheless, the multi-step behaviour generally leads to an increase of the average switching transitions rate. In the proposed method, this drawback is mitigated with an online adaptive selection of the number of switching levels. The algorithm is validated through an extensive hardware-in-the-loop testing and compared to other approaches

Symmetric equilibria in double auctions with markdown buyers and markup sellers

Zhan and Friedman (2007) study double auctions where buyers and sellers are constrained to using simple markdown and markup rules. In spite of the alleged symmetry in roles and assumptions, buyers are shown to have the upper hand both in the call market and in the continuous double auction. We replicate the study and show that their formulation of the sellers’ markup strategies, while seemingly natural, exhibits a hidden asymmetry.We introduce a symmetric set of markup strategies for the sellers and show how it explains away the paradox of buyers’ advantage in three different double-sided market protocols

How communication technology fosters individual and social wellbeing during the Covid-19 pandemic: preliminary support for a digital interaction model

The aim of the present study was to test an explanatory model for individual and social wellbeing which incorporates the advantages of using digital technologies during the COVID-19 pandemic. The study was carried out in Italy, one of the countries that has been most severely affected by the pandemic worldwide. The study was designed to include variables that might be specifically pertinent to the uniqueness of the restrictions imposed by the pandemic. Adults living in Italy (n = 1412) completed an online survey during the lockdown period in March 2020. Results showed two distinct digital interaction processes highlighted by the facilitating use of online emotions (“e-motions”) and online social support (“e-support”). In short, e-motions were positively related to posttraumatic growth, which in turn was positively associated with positive mental health and higher engagement in prosocial behaviors. Moreover, individuals who perceived themselves as having greater e-support were characterized by higher levels of positive mental health, which it turn was positively associated with prosocial behaviors. Collectively, these two digital interaction processes suggest that digital technologies appear to be critical resources in helping individuals cope with difficulties raised by the COVID-19 pandemic