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

La gestione del rischio elettrico nelle attività di cantiere

Analizzando il fenomeno infortunistico nella complessità dei fattori che lo generano, emerge che le caratteristiche di elementi critici ricorrenti, spesso indotti da errori e/o omissioni procedurali, condizionano la pericolosità delle attività lavorative, soprattutto con riferimento al rischio elettrico e nell’ambito delle attività di cantiere. E’ altresì evidente che in generale la realizzazione di un processo lavorativo “sicuro” è una prestazione attesa, che richiede competenze, investimenti e dedizione più frequentemente attuati nelle imprese grandi che non in quelle piccole e medie, nelle competenze lavorative mature che non in quelle più giovani o anziane, dalle maestranze nazionali meglio che da quelle straniere. Queste risultanze statistiche contribuiscono a fornire il primo set di indicazioni utili a caratterizzare il rischio rispetto al caso concreto della specifica attività lavorativa e a gestirne gli effetti, progettando opportuni sistemi di prevenzione, soprattutto laddove l’aspetto del coordinamento può risultare particolarmente rilevante, essendo i rapporti più frequentemente orientati a stabilire confini di responsabilità piuttosto che delineare politiche comuni di prevenzione. Frequentemente gli infortuni sul lavoro sono interpretati, a tali fini predittivi, attraverso caratterizzazioni tendenzialmente informali. Obiettivo preliminare dell’analisi presentata è di formalizzare la descrizione degli eventi di infortunio, disponibili nelle banche dati di settore in forma di schede descrittive di dettaglio, in casi algebrici rappresentabili nello spazio Rn dei determinanti (cause di infortunio) al fine di poter operare trattamenti statistici descrittivi finalizzati all’acquisizione di informazioni omogenee e predittive. L’introduzione di questa potenzialità esplicativa consente, infatti, l’applicazione di tecniche di analisi statistica multivariata a campioni stratificati per modalità di infortunio, con l’obiettivo di ricercare modalità ricorrenti di infortunio a supporto delle attività di prevenzione del rischio totale (valore atteso del danno) e gestione del rischio residuo. Sulla base della collezione di infortuni mortali - riconducibili, rispetto all’ambito generatore, al rischio elettrico - disponibile nel database Infor.MO - che costituisce a tutti gli effetti una serie storica del fenomeno osservato, si è proceduto, quindi, ad aggregare i casi di infortunio mediante tecniche di cluster analysis e di analisi multifattoriale (ACM) che, con riferimento alle cause prodromiche del flusso del pericolo, possano evidenziare modalità peculiari e ricorrenti di infortunio, ossia genesi preferenziali, esplicative del fenomeno infortunistico registrato e predittive delle future realizzazioni dello stesso. In particolare, applicando questi modelli ai casi di infortunio mortale relativi al settore AtEco F3, con riferimento al "rischio elettrico", è possibile indirizzare in modo razionale gli interventi di prevenzione e/o protezione, in una prospettiva di massima efficienza gestionale

IMPIANTI DI ILLUMINAZIONE DELLE GALLERIE STRADALI CON POTENZA ELETTRICA CONDIZIONATA

Gli assorbimenti di energia elettrica e la pianificazione e gestione dell’illuminazione delle gallerie suggeriscono configurazioni flessibili e modulabili per gli impianti e criteri di gestione che consentano un esercizio con potenza elettrica programmabil

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

Spatiotemporal patterns of distribution of large predatory sharks in Calabria (central Mediterranean, southern Italy)

During the 2000-2009, a survey study on the spatiotemporal patterns of distribution of large predatory sharks was carried out in the Calabria region. A total of 12 species were recorded and among them the blue shark Prionace glauca and the bluntnose sixgill shark Hexanchus griseus were the most common ones. Also of interest was the frequency of species such as Carcharodon carcharias, Sphyrna zygaena and Cetorhinus maximus. 57% of all reported records derived from the Tyrrhenian side of the region and 43% on the Ionian side. A significant relationship between season of the year versus number of records was found, but this could be related to the small number of observers that were active during the winter months. The presence of Sphyrna lewini is reported for the study area; this species was previously recorded only in the western part of the Mediterranean Sea. This paper also provides evidence of the second and first documented accounts of white shark predation upon Tursiops truncatus and Stenella coeruleoalba, respectively, in the Mediterranean Sea. The recover ing of Ionian Sphyrna zygaena populations and the declining of Lamna nasus populations were also noted

Landslides, floods and sinkholes in a karst environment: the 1–6 September 2014 Gargano event, southern Italy

Abstract. In karst environments, heavy rainfall is known to cause multiple geohydrological hazards, including inundations, flash floods, landslides and sinkholes. We studied a period of intense rainfall from 1 to 6 September 2014 in the Gargano Promontory, a karst area in Puglia, southern Italy. In the period, a sequence of torrential rainfall events caused severe damage and claimed two fatalities. The amount and accuracy of the geographical and temporal information varied for the different hazards. The temporal information was most accurate for the inundation caused by a major river, less accurate for flash floods caused by minor torrents and even less accurate for landslides. For sinkholes, only generic information on the period of occurrence of the failures was available. Our analysis revealed that in the promontory, rainfall-driven hazards occurred in response to extreme meteorological conditions and that the karst landscape responded to the torrential rainfall with a threshold behaviour. We exploited the rainfall and the landslide information to design the new ensemble–non-exceedance probability (E-NEP) algorithm for the quantitative evaluation of the possible occurrence of rainfall-induced landslides and of related geohydrological hazards. The ensemble of the metrics produced by the E-NEP algorithm provided better diagnostics than the single metrics often used for landslide forecasting, including rainfall duration, cumulated rainfall and rainfall intensity. We expect that the E-NEP algorithm will be useful for landslide early warning in karst areas and in other similar environments. We acknowledge that further tests are needed to evaluate the algorithm in different meteorological, geological and physiographical settings

Off-label long acting injectable antipsychotics in real-world clinical practice: a cross-sectional analysis of prescriptive patterns from the STAR Network DEPOT study

Introduction Information on the off-label use of Long-Acting Injectable (LAI) antipsychotics in the real world is lacking. In this study, we aimed to identify the sociodemographic and clinical features of patients treated with on- vs off-label LAIs and predictors of off-label First- or Second-Generation Antipsychotic (FGA vs. SGA) LAI choice in everyday clinical practice. Method In a naturalistic national cohort of 449 patients who initiated LAI treatment in the STAR Network Depot Study, two groups were identified based on off- or on-label prescriptions. A multivariate logistic regression analysis was used to test several clinically relevant variables and identify those associated with the choice of FGA vs SGA prescription in the off-label group. Results SGA LAIs were more commonly prescribed in everyday practice, without significant differences in their on- and off-label use. Approximately 1 in 4 patients received an off-label prescription. In the off-label group, the most frequent diagnoses were bipolar disorder (67.5%) or any personality disorder (23.7%). FGA vs SGA LAI choice was significantly associated with BPRS thought disorder (OR = 1.22, CI95% 1.04 to 1.43, p = 0.015) and hostility/suspiciousness (OR = 0.83, CI95% 0.71 to 0.97, p = 0.017) dimensions. The likelihood of receiving an SGA LAI grew steadily with the increase of the BPRS thought disturbance score. Conversely, a preference towards prescribing an FGA was observed with higher scores at the BPRS hostility/suspiciousness subscale. Conclusion Our study is the first to identify predictors of FGA vs SGA choice in patients treated with off-label LAI antipsychotics. Demographic characteristics, i.e. age, sex, and substance/alcohol use co-morbidities did not appear to influence the choice towards FGAs or SGAs. Despite a lack of evidence, clinicians tend to favour FGA over SGA LAIs in bipolar or personality disorder patients with relevant hostility. Further research is needed to evaluate treatment adherence and clinical effectiveness of these prescriptive patterns