Simplified conservative testing method of touch and step voltages by multiple auxiliary electrodes at reduced distance

Grounding systems (GSs) must be tested periodically in order to maintain the touch voltage (TV) and step voltage (SV) below a safe value in all of the zones of the installation. Measurements of the ground resistance and of the TV and SV are typically done by the fall-of-potential (FoP) method, locating the auxiliary current electrode at remote distance to test the effective behavior of the GS. In urban areas, it could be very complicated or impossible to install the auxiliary current electrode as required, not having area around with sufficient accessibility. At this aim, this paper describes a methodology of using multiple current electrodes at short distances, modifying the classic FoP practice, so that the measurements of TV and SV are always conservative. The adequacy of a GS is verified if the values of the TV and SV, tested inside and in the vicinity of the GS, are below the permissible limits, regardless if they are true or conservatively increased. Thus, the measured TV and SV by the suggested method, always conservative, allow verifying the adequacy of GSs, in the cases where it is impossible to locate the remote auxiliary electrode

Grounding System Adequacy of HV/MV Substations in Areas With Reduced Accessibility

The adequacy of grounding systems has to be verified periodically in the operational time. With urban development and buildings growth adjacent to power systems as HV/MV substations, it is very rare to have area around with sufficient accessibility for installing the potential and current electrodes. This paper discusses a safety criterion to verify the effectiveness of a grounding system. This criterion suggests conservative tests for both ground potential rise and touch voltages and step voltages that allow to verify the grounding systems effectiveness in areas with reduced accessibility and to monitor its evolution in the time

Service continuity in complex power systems: safety, operation and maintenance

The research aims to define electrical architectures based on the rationalization of the distribution structure and of power sources with the achievement of the primary objectives of service continuity, power quality, safety and safe maintenance. The thesis consists of two parts: the first part deals with the architecture impact on a complex system analyzing the system configuration and operational safety aspects. New developments and methodologies are presented in the study of critical systems. A theory of complex systems for safety, operation and maintenance aspects is defined that enables to assist the management of the system throughout its whole life cycle and allows an implementation of programming languages. The second part refers to specific issues of mission critical power systems, data centers and hospitals especially. Several measurements were performed in laboratory and on field to analyze sneaky critical cases for the service continuity and the integrity of these strategic power systems.The research aims to define electrical architectures based on the rationalization of the distribution structure and of power sources with the achievement of the primary objectives of service continuity, power quality, safety and safe maintenance. The thesis consists of two parts: the first part deals with the architecture impact on a complex system analyzing the system configuration and operational safety aspects. New developments and methodologies are presented in the study of critical systems. A theory of complex systems for safety, operation and maintenance aspects is defined that enables to assist the management of the system throughout its whole life cycle and allows an implementation of programming languages. The second part refers to specific issues of mission critical power systems, data centers and hospitals especially. Several measurements were performed in laboratory and on field to analyze sneaky critical cases for the service continuity and the integrity of these strategic power systems

Elevator regenerative energy applications with ultracapacitor and battery energy storage systems in complex buildings

Due to the dramatic growth of the global population, building multi-story buildings has become a necessity, which strongly requires the installation of an elevator regardless of the type of building being built. This study focuses on households, which are the second-largest electricity consumers after the transportation sector. In residential buildings, elevators impose huge electricity costs because they are used by many consumers. The novelty of this paper is implementing a Hybrid Energy Storage System (HESS), including an ultracapacitor Energy Storage (UCES) and a Battery Energy Storage (BES) system, in order to reduce the amount of power and energy consumed by elevators in residential buildings. The control strategy of this study includes two main parts. In the first stage, an indirect field-oriented control strategy is implemented to provide new features and flexibility to the system and take benefit of the regenerative energy received from the elevator’s motor. In the second stage, a novel control strategy is proposed to control the HESS efficiently. In this context, the HESS is only fed by regenerated power so the amount of energy stored in the UC can be used to reduce peak consumption. Meanwhile, the BES supplies common electrical loads in the building, e.g., washing machines, heating services (both boiler and heat pump), and lighting, which helps to achieve a nearly zero energy building

Influence of LV Neutral Grounding on Global Earthing Systems

International Standards define a Global Earthing System as an earthing net created interconnecting local Earthing Systems (generally through the shield of MV cables and/or bare buried conductors). In Italy, the regulatory authority for electricity and gas requires distributors to guarantee the electrical continuity of LV neutral conductor. This requirement has led to the standard practice of realizing “reinforcement groundings” along the LV neutral conductor path and at users' delivery cabinet. Moreover, in urban high-load scenarios (prime candidates to be part of a Global Earthing System), it is common that LV distribution scheme creates, through neutral conductors, an effective connection between grounding systems of MV/LV substations, modifying Global Earthing System consistency. The aim of this paper is to evaluate the effect, in terms of electrical safety, of the aforementioned LV neutral distribution scheme when an MV-side fault to ground occurs. For this purpose, simulations are carried out on a realistic urban test case and suitable evaluation indexes are proposed

Prevalence of chronic pain syndrome in patients who have undergone hallux valgus percutaneous surgery: a comparison of sciatic-femoral and ankle regional ultrasound-guided nerve blocks

Background: Chronic pain syndrome (CPS) is a common complication after operative procedures, and only a few studies have focused on the evaluation of CPS in foot-forefoot surgery and specifcally on HV percutaneous correc‑ tion. The objective of this study was to compare postoperative pain levels and incidence of CPS in two groups of patients having undergone femoral-sciatic nerve block or ankle block regional anaesthesia before hallux valgus (HV) percutaneous surgery and the association between postoperative pain levels and risk factors between these patient groups. Methods: A consecutive patient series was enrolled and evaluated prospectively at 7 days, 1, 3 and 6 months after surgery. The participants were divided into two groups according to the regional anaesthesia received, femoral-sciatic nerve block or ankle block, and their outcomes were compared. The parameters assessed were postoperative pain at rest and during movement by the numerical rating scale (NRS), patient satisfaction using the Visual Analogue Scale (VAS), quality of life and return to daily activities. Statistical analysis was performed. Results: One hundred fifty-five patients were assessed, 127 females and 28 males. Pain at rest (p 0.05), quality of life significantly increased and patients returned to daily activities and work (p < 0.0001). No significant impact of type of anaesthesia could be detected. ASA 3 (p = 0.043) was associated to higher pain during movement; BMI (p = 0.005) and lumbago (p = 0.004) to lower satisfaction. No operative-anaesthetic complications were recorded. Postoperative pain at rest and during movement improved over time independently of the regional block used, with low incidence of CPS at last follow-up. Among risk factors, only a higher ASA was associated to higher pain during movement, while higher BMI and lumbago to lower satisfaction. Conclusions: Both ultrasound-guided sciatic-femoral and ankle blocks were safe and effective in reducing postoperative pain with low incidence of CPS at last follow-up

S-Adenosyl-Methionine and Betaine Improve Early Virological Response in Chronic Hepatitis C Patients with Previous Nonresponse

Treatment of chronic hepatitis C (CHC) with pegylated interferon (pegIFN ) and ribavirin results in a sustained response in approximately half of patients. Viral interference with IFN signal transduction through the Jak-STAT pathway might be an important factor underlying treatment failure. S-adenosyl-L-methionine (SAMe) and betaine potentiate IFN signaling in cultured cells that express hepatitis C virus (HCV) proteins, and enhance the inhibitory effect of IFN on HCV replicons. We have performed a clinical study with the aim to evaluate efficacy and safety of the addition of SAMe and betaine to treatment of CHC with pegIFN /ribavirin

Rationale and design of an independent randomised controlled trial evaluating the effectiveness of aripiprazole or haloperidol in combination with clozapine for treatment-resistant schizophrenia

<p>Abstract</p> <p>Background</p> <p>One third to two thirds of people with schizophrenia have persistent psychotic symptoms despite clozapine treatment. Under real-world circumstances, the need to provide effective therapeutic interventions to patients who do not have an optimal response to clozapine has been cited as the most common reason for simultaneously prescribing a second antipsychotic drug in combination treatment strategies. In a clinical area where the pressing need of providing therapeutic answers has progressively increased the occurrence of antipsychotic polypharmacy, despite the lack of robust evidence of its efficacy, we sought to implement a pre-planned protocol where two alternative therapeutic answers are systematically provided and evaluated within the context of a pragmatic, multicentre, independent randomised study.</p> <p>Methods/Design</p> <p>The principal clinical question to be answered by the present project is the relative efficacy and tolerability of combination treatment with clozapine plus aripiprazole compared with combination treatment with clozapine plus haloperidol in patients with an incomplete response to treatment with clozapine over an appropriate period of time. This project is a prospective, multicentre, randomized, parallel-group, superiority trial that follow patients over a period of 12 months. Withdrawal from allocated treatment within 3 months is the primary outcome.</p> <p>Discussion</p> <p>The implementation of the protocol presented here shows that it is possible to create a network of community psychiatric services that accept the idea of using their everyday clinical practice to produce randomised knowledge. The employed pragmatic attitude allowed to randomly allocate more than 100 individuals, which means that this study is the largest antipsychotic combination trial conducted so far in Western countries. We expect that the current project, by generating evidence on whether it is clinically useful to combine clozapine with aripiprazole rather than with haloperidol, provides physicians with a solid evidence base to be directly applied in the routine care of patients with schizophrenia.</p> <p>Trial Registration</p> <p><b>Clincaltrials.gov Identifier</b>: NCT00395915</p

The AGILE Mission

AGILE is an Italian Space Agency mission dedicated to observing the gamma-ray Universe. The AGILE's very innovative instrumentation for the first time combines a gamma-ray imager (sensitive in the energy range 30 MeV-50 GeV), a hard X-ray imager (sensitive in the range 18-60 keV), a calorimeter (sensitive in the range 350 keV-100 MeV), and an anticoincidence system. AGILE was successfully launched on 2007 April 23 from the Indian base of Sriharikota and was inserted in an equatorial orbit with very low particle background. Aims. AGILE provides crucial data for the study of active galactic nuclei, gamma-ray bursts, pulsars, unidentified gamma-ray sources, galactic compact objects, supernova remnants, TeV sources, and fundamental physics by microsecond timing. Methods. An optimal sky angular positioning (reaching 0.1 degrees in gamma- rays and 1-2 arcmin in hard X-rays) and very large fields of view (2.5 sr and 1 sr, respectively) are obtained by the use of Silicon detectors integrated in a very compact instrument. Results. AGILE surveyed the gamma- ray sky and detected many Galactic and extragalactic sources during the first months of observations. Particular emphasis is given to multifrequency observation programs of extragalactic and galactic objects. Conclusions. AGILE is a successful high-energy gamma-ray mission that reached its nominal scientific performance. The AGILE Cycle-1 pointing program started on 2007 December 1, and is open to the international community through a Guest Observer Program