λ5-Phosphorus-Containing α-Diazo Compounds (PCDCs): a valuable tool for accessing phosphorus-functionalized molecules

The compounds characterized by the presence of a λ5-phosphorus functionality at the α-position with respect to the diazo moiety, here referred to as λ5-phosphorus-containing α-diazo compounds (PCDCs), represent a vast class of extremely versatile reagents in organic chemistry and are particularly useful in the preparation of phosphonate- and phosphinoxide-functionalized molecules. Indeed, thanks to the high reactivity of the diazo moiety, PCDCs can be induced to undergo a wide variety of chemical transformations. Among them are carbon–hydrogen, as well as heteroatom–hydrogen insertion reactions, cyclopropanation, ylide formation, Wolff rearrangement, and cycloaddition reactions. PCDCs can be easily prepared from readily accessible precursors by a variety of different methods, such as diazotization, Bamford–Stevens-type elimination, and diazo transfer reactions. This evidence along with their relative stability and manageability make them appealing tools in organic synthesis. This Review aims to demonstrate the ongoing utility of PCDCs in the modern preparation of different classes of phosphorus-containing compounds, phosphonates, in particular. Furthermore, to address the lack of precedent collective papers, this Review also summarizes the methods for PCDCs preparatio

Nucleosided derived antibiotics to fight microbial drug resistance: New utilities for an established class of drugs?

Novel antibiotics are urgently needed to combat the rise of infections due to drug-resistant microorganisms. Numerous natural nucleosides and their synthetically modified analogues have been reported to have moderate to good antibiotic activity against different bacterial and fungal strains. Nucleoside-based compounds target several crucial processes of bacterial and fungal cells such as nucleoside metabolism and cell wall, nucleic acid, and protein biosynthesis. Nucleoside analogues have also been shown to target many other bacterial and fungal cellular processes although these are not well characterized and may therefore represent opportunities to discover new drugs with unique mechanisms of action. In this Perspective, we demonstrate that nucleoside analogues, cornerstones of anticancer and antiviral treatments, also have great potential to be repurposed as antibiotics so that an old drug can learn new tricks

A Novel Highly Integrated Hybrid Energy Storage System for Electric Propulsion and Smart Grid Applications

This chapter addresses potentialities and advantages of a highly integrated hybrid energy storage system (HESS) for electric propulsion and smart grids. This configuration consists of a highly integrated battery-ultracapacitor system (HIBUC) and aims to benefit from the advantages of both passive and active HESS configurations. Particularly, the integration of the ultracapacitor module (UM) within the DC-link of the DC/AC multilevel converter enables the decoupling between DC-link voltage and energy content without the need for any additional DC/DC converter. As a result, HIBUC benefits from simplicity and energy flow management capabilities very similar to those achieved by passive and active HESS configurations, respectively. This is highlighted properly by a theoretical analysis, which also accounts for a comparison between HIBUC and both passive and active HESS configurations. Some HIBUC application examples are also reported, which highlight the flexibility and potentialities of HIBUC for both electric propulsion systems and smart grids

Symmetrical diamidate prodrugs of nucleotide analogues for drug delivery

The use of pronucleotides to circumvent the well-known drawbacks of nucleotide analogs has played a significant role in the area of antiviral and anticancer drug delivery. Several motifs have been designed to mask the negative charges on the phosphorus moiety of either nucleoside monophosphates or nucleoside phosphonates, in order to increase their hydrophobicity and allow entry of the compound into the cell. Among them the bis-amidate analogs, having two identical amino acids as masking groups through a P–N bond, represent a more recent approach for the delivery of nucleotide analogs, endowed with antiviral or anticancer activity. Different synthetic strategies are commonly used for preparing phosphorodiamidates of nucleosides. In this protocol, we would like to focus on the description of the synthetic methodology that in our hand gave the best results using 2′-3′-didehydro-2′-3′-dideoxythymidine (d4T, Stavudine) as model nucleoside. A second strategy for preparing diamidates of nucleoside phosphonates will be reported using {[2-(6-amino-9 H-purin-9-yl)ethoxy]methyl}phosphonic acid (PMEA, adefovir) as model substrate

Predictive control of electrical drives

In this work, the application of the Predictive Control Technique to the electrical drives has been considered and discussed, especially in comparison with the employment of the traditional control techniques. First of all, a predictive control algorithm for the Brushless DC drive is developed with the aim of improving the traditional current commutation as best as possible. Then, a novel predictive control algorithm is proposed by imposing both the reference torque value and the minimum Joule losses condition. Then, several predictive control algorithms are proposed for the Synchronous Reluctance Machine, taking into account the magnetic saturation effects too. They are based either on the traditional control strategy or on optimization criteria, such as the minimum steady state Joule losses condition and the fastest achievement of the reference torque value. Finally, a novel predictive Direct Torque Control algorithm is synthesized for the Asynchronous Machine, by taking into account both voltage saturation and current limitation constraints. The synthesizing procedure adopted is also shown by an interesting graphical representation. The effectiveness of all the proposed algorithms has been properly tested by appropriate simulation studies, performed in the Matlab Simulink environment. The corresponding results have highlighted how the employment of the Predictive Control Technique allows better performances compared to those achievable by the traditional control ones

Design of flux-weakening space vector control algorithms for permanent magnet brushless DC machines on suitable synchronous reference frames

The design of Space Vector Control (SVC) systems suitable for flux-weakening operation of Permanent Magnet Brushless DC Machines (PMBDCMs) is presented in this paper. The proposed design approach enables overcoming the critical issues arising from the non-linearities of PMBDCM voltage and torque equations; these issues derive from the trapezoidal shapes of back-emfs and affect PMBDCM constraint management significantly. The SVCs presented in this paper have been developed within two different synchronous reference frames, both of which enable distinguishing torque and demagnetizing current components clearly. Therefore, reference torque current component is determined in accordance with PMBDCM torque demand, while reference demagnetizing current component is computed through a voltage follower PI regulator, which processes the voltage deficit detected on the DC-link. In this regard, a novel synchronous reference frame is proposed in this paper, which improves PMBDCM constraint management and results into a wider constant-power speed range, but at the cost of some torque ripple. The enhanced performances achievable by SVC approaches are highlighted by numerical simulations, which regard the comparison among the SVCs and an SVC with no flux-weakening capability, at different operating conditions

A Genetic Algorithm for the Definition of Nodal Load Time Evolutions in Micro Grids Assessment

One of the on-going research topic in smart grid planning and assessment is the definition of suitable time evolution of load profiles in micro grids by using the information about the network topology and the available electrical measurements. This paper presents an approach for a heuristic definition of nodal load profiles in micro grids when the available measurements are not exhaustive for its state evaluation. In particular, in order to develop the preliminary micro grids assessment, a Genetic Algorithm (GA) has been employed to determine possible evolution of nodal load profiles that satisfy the power system constraints and input measurements. In order to verify the effectiveness of proposed methodology a real micro grid has been considered as case of study. The micro grid has been simulated in Digsilent and the used GA has been implemented in Matlab environment. Finally, Digsilent Programming Language (DPL) has been employed for interfacing the GA with Digsilent

A multistage design procedure for planning and implementing public charging infrastructures for electric vehicles

Presented in this paper is a Multistage Design Procedure (MSDP) for planning and implementing Public Charging Infrastructures (PCIs) to satisfy intracity charging demand of Electric Vehicles (EVs). The proposed MSDP splits planning and design processes into multiple stages, from macroscale to fine-scale levels. Consequently, the preliminary results achieved at each stage can be refined at the subsequent stages, leading to determine the accurate number and precise geographical location of each charging point. The main advantage of the proposed approach is that it splits a very complicated procedure into multiple and simpler stages, at each of which appropriate goals, targets and constraints can be included. As a result, the iterative interactions among all the stakeholders involved in the PCI design process are significantly simplified. The proposed MSDP has been employed in the planning and design of the PCI of the Italian island of Sardinia, accordingly to all the public bodies

Value Co-Destruction: a Text-Mining-Based Mixed Method Study on Social Media Interactions

To better understand how big data interconnects firms and customers, we analyse the role of customers’ emotions in the process of value co-destruction in a social media context. We perform a text mining based algorithm capable of identifying anger, expectation, disgust, fear, and sadness in peaks of problematic social interactions. The developed algorithm associated with an in-depth qualitative analysis shows how to employ unstructured big data to understand the role of negative emotions in the process of value co-destruction

Energy Management and Control System Design of an Integrated Flywheel Energy Storage System for Residential Users

This paper presents the energy management and control system design of an integrated flywheel energy storage system (FESS) for residential users. The proposed FESS is able to draw/deliver 8 kWh at 8 kW, and relies on a large-airgap surface-mounted permanent magnet synchronous machine, the inner rotor of which integrates a carbon-fiber flywheel, leading to a compact and efficient FESS. The proposed energy management system is based on four different operating modes, which are defined and can be selected in accordance with FESS speed and/or user’s preference, while FESS control system is devoted to power/current tracking at both machine- and grid-side converters. The effectiveness of the proposed solutions, as well as the overall energy performance of the proposed FESS, are verified by real-time simulations, which regard different operating conditions and/or realistic scenarios