Time filter

Source Type

Rome, Italy

Lauri R.,INAIL Ricerca
Chemical Engineering Transactions | Year: 2015

Industrial fires and explosions are neither infrequent nor inconsequential. In consequence of the complexity of the phenomena, which are involved in an unconfined vapor cloud explosion (UVCE), a variety of prediction methods and calculation procedures is available to estimate the consequences (overpressure) of the flammable cloud explosion. These methodologies range from simplified methods, which relatively require few calculations, to complicated numerical models, that can involve millions of calculations. In the present paper an ammonia vapor cloud explosion is studied. The cloud is generated by an accidental release of aqueous ammonia (evaporation from pool) in a DeNOX plant, which is installed in a steam power plant. The analysis is carried out by a prediction method, that requires a specification of the chemical reactivity, congestion (obstacles density) and confinement in order to establish the maximum flame speed. The study has been focused on effects of area congestion on overpressure profile. In general for realistic plants geometries a high level of congestion results in higher turbulence and therefore higher flame speeds and overpressures. This parameter often is the most difficult element to assess in consequence of the plants complexities and has important effects on overpressure peak. In fact the definition of the congestion level requires meticulous and painstaking inspections of the plant areas. The results of the study are presented and compared. The goal of the paper is the illustration of a methodology, which can provide useful elements (an estimate of the plant congestion) to enrich the preliminary knowledge of the explosion consequences in order to improve the process safety during the operation of the DeNOX plants. Copyright © 2015, AIDIC Servizi S.r.l. Source

Di Leone G.,SPESAL ASL Bari | Campo G.,INAIL Ricerca | Martini B.,INAIL Ricerca
Giornale Italiano di Medicina del Lavoro ed Ergonomia | Year: 2014

The Inail data show that in the last years the complaints and acknowledgments of occupational diseases has been increasing, in contrast what happened previously. This growth is the expected and desired emergence of workrelated diseases and it's also an alarm bell that the institutions can not ignore. In addition to the data provided by INAIL, the MalProf system gives an important contribution to the understanding of occupational diseases. MalProf is a system for recording and analysis of reported occupational diseases using the source information provided by Service Prevention of ASL. The model used by the Surveillance System MALPROF, by combines the information in a consistent and standardized, assesses the relevance of a causal link between the disease and reports the activity carried out by the worker during his professional history. The two systems (INAIL database and MALPROF), although with some differences have largely confirmed the same data. The past decade has marked the final decline of the working traditional occupational diseases (respiratory toxic substance related diseases and by the accumulation of poisoning, skin, etc....); the hearing loss is still frequent but less important than it was in the past relevance. Tumors and, in particular, musculoskeletal disorders, have been emerging as one of the hidden problems before tumors but, above all, appeared on the scene and the group of musculoskeletal disorders. As indicated by the National Plan for the preventive actions should be directed in several directions: active surveillance, training of the subjects of prevention and other figures, the promotion of the quality of the risk assessment documents. Source

Tranfo G.,INAIL Ricerca | Paci E.,INAIL Ricerca | Fustinoni S.,University of Milan | Barbieri A.,University of Bologna | Carrieri M.,University of Padua
Giornale Italiano di Medicina del Lavoro ed Ergonomia | Year: 2013

This paper aims to examine some methods to measure human exposure to benzene, both in life and occupational environments, through environmental and biological monitoring, examining the critical issues and optimal conditions of use. The overall performance of environmental monitoring, from the analytical point of view, strongly depend on the choice of an appropriate method of sampling and analysis. Urinary SPMA and t, t-MA are the biomarkers listed by ACGIH to evaluate occupational exposure: most of the recent studies use HPLC with tandem mass spectrometry, but since t, t-MA is present in the urine in larger quantities it is also determinable with UV detectors. The urinary benzene is an index not officially Included in the list of the ACGIH BEIs, but it is useful to assess exposure and benzene at low concentrations, that most frequently are found today in the occupational and life environments. Source

Pochi D.,Italian Agricultural Research Council | Fanigliulo R.,Italian Agricultural Research Council | Del Duca L.,ACTIVE di Lindoro Del Duca | Nataletti P.,INAIL Ricerca | And 5 more authors.
Journal of Agricultural Engineering | Year: 2013

In last years, several research teams pointed their attention on the application of active noise control systems (ANC) inside the cabs of agricultural tractor, with the purpose of reducing the driver exposition to noise, that is only partially controlled by the frame of the cab. This paper reports the results of a first experience that aimed at verifying the applicability of an ANC on a medium-high power, tracked tractor without cab. The tested tractor was a Fiat Allis 150 A, equipped with rear power take off, used in the execution of deep primary tillage in compact soils. It is a tracked tractor without cab, with maximum power of 108.8 kW at 1840 min–1 of the engine. The ANC consists of a control unit box based on a digital signal processor (DPS), two microphones, two speakers and a power amplifier. The instrumentation used in noise data collecting and processing consisted of a multichannel signal analyzer (Sinus - Soundbook), a ½” microphone capsule and an acoustic calibrator, both Bruel & Kjaer. The study aimed at evaluating the behaviour of the ANC by means of tests carried out under repeatable conditions, characterized by pre-defined engine speed values. Three replications have been made for each engine speed. The sampling time was 30 s. Two series of tests were performed in order to compare the results observed with the ANC on and off. The engine speed adopted in the study ranged from 600 min– 1, up to 2000 min–1 (maximum speed) with steps of 100 min–1. The ANC proved to be effective in the interval of speed between 1400 and 1700 min–1, where the samplings have been intensified, adopting steps of 50 min–1. In such an interval, the attenuation observed with the ANC system on appeared evident both as weighed A sound pressure level (from 1.29 up to 2.46 dB(A)) and linear (from 4.54 up to 8.53 dB). The best performance has been observed at the engine speed of 1550 min–1, with attenuations, respectively of 2.46 dB(A) and 7.67 dB. Outside of the engine speed interval 1400 - 1700 min–1, the attenuations always resulted lower than 1 dB(A) for the weighed A sound pressure level and between 0.66 and 7.72 dB. © 2013, Copyright D. Pochi et al. Source

Deitinger P.,INAIL Ricerca | Nardella C.,INAIL Ricerca | Ronchetti M.,INAIL Ricerca | Bonafede M.,INAIL Ricerca | Grandi C.,INAIL Ricerca
Giornale Italiano di Medicina del Lavoro ed Ergonomia | Year: 2011

Introduction: This study analyzed the effect of expertise, by comparing the opinions of groups of "experts" and "non-experts" on the so-called "classic" risks and on the risks from exposure to electromagnetic fields. Methods. A protocol comprising personal history questionnaires, including lifestyle details, STAI-Y, and two rating scales based on the "psychometric paradigm" was administered to 48 people, 22 experts on these risks and 26 non-experts. The findings were analyzed by one-way analysis of variance, exploratory factor, correlational and birariate regression analysis. Results. Significant differences emerged between the perceptions of the two groups, though the underlying qualitative dimensions were similar. Bivariate regression analysis showed that both state and trait anxiety exert a statistically significant effect on some risks, both classic and related to electromagnetic fields exposure. Conclusions. This study displayed the role of expertise in risk perception processes, giving indications on the relationships between anxiety and risk perception. On the basis of the available data it is concluded that people prone to anxiety and individual emotional states filter the perception of risk arising from activities, technologies, substances etc. included in the present study. © PI-ME, Pavia 2011. Source

Discover hidden collaborations