Multiconductor Cell Analysis of AC High Speed Railway Lines

The aim of this article is the application of Multiconductor Cell Analysis (MCA) to a very special case of a multiconductor system, i.e., the AC high-speed railway system, with 14 parallel conductors. The present matrix approach allows representing both the single elements and the entire railway system also including the high-voltage (HV) three-phase supply network. The algorithm allows computing all the steady-state regime electrical quantities (voltages, currents, and power) of each section: in particular, the ground return current, responsible for electromagnetic interferences (EMIs), can be derived by the knowledge of all the circulating currents. It is also possible to evaluate the electric unbalance impact on the supply three-phase power system given by the railway system. Eventually, two different scenarios are presented, i.e., a maximum allowable high-speed line power request and a contact-wire-to-rail short circuit

A Three-Phase Power-Flow Algorithm for Transmission Networks: a Hybrid Phase/Sequence Approach

In this paper, the three-phase generalization of a single-phase power flow (named PFPD) developed by the first author is presented. This three-phase formulation is chiefly conceived for HV/EHV transmission network applications, but it preserves a general validity for any power system. An iterative method for the solution achievement is throughout expounded. The algorithm quantitatively aims at investigating the impact of the asymmetrical transmission structures on power systems. This impact is evaluated in terms of voltage and current sequence components. Moreover, discussions on possible improvement actions to enhance the power quality are developed. The algorithm is implemented in Matlab environment and tested by several fictitious networks. Eventually, extensive comparisons in terms of execution time, number of iterations and solution accuracy with the software DIgSILENT PowerFactory are presented

First-time success with needle procedures was higher with a warm lidocaine and tetracaine patch than an eutectic mixture of lidocaine and prilocaine cream

AIM: More than 50% of children report apian during venepuncture or intravenous cannulation and using local anaesthetics before needle procedures can lead to different success rates. This study examined how many needle procedures were successful at the first attempt when children received either a warm lidocaine and tetracaine patch or an eutectic mixture of lidocaine and prilocaine (EMLA) cream. METHODS: We conducted this multicentre randomised controlled trial at three tertiary-level children's hospitals in Italy in 2015. Children aged three to 10 years were enrolled in an emergency department, paediatric day hospital and paediatric ward and randomly allocated to receive a warm lidocaine and tetracaine patch or EMLA cream. The primary outcome was the success rate at the first attempt. RESULTS: The analysis included 172 children who received a warm lidocaine and tetracaine patch and 167 who received an EMLA cream. The needle procedure was successful at the first attempt in 158 children (92.4%) who received the warm patch and in 142 children (85.0%) who received the cream (p = 0.03). The pain scores were similar in both groups. CONCLUSION: This study showed that the first-time needle procedure success was 7.4% higher in children receiving a warm lidocaine and tetracaine patch than EMLA cream